/*-
* Copyright (c) 2016-2020 Netflix, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
#include "opt_ratelimit.h"
#include <sys/param.h>
#include <sys/arb.h>
#include <sys/module.h>
#include <sys/kernel.h>
#ifdef TCP_HHOOK
#include <sys/hhook.h>
#endif
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/mbuf.h>
#include <sys/proc.h> /* for proc0 declaration */
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#ifdef STATS
#include <sys/qmath.h>
#include <sys/tree.h>
#include <sys/stats.h> /* Must come after qmath.h and tree.h */
#else
#include <sys/tree.h>
#endif
#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/tim_filter.h>
#include <sys/smp.h>
#include <sys/kthread.h>
#include <sys/kern_prefetch.h>
#include <sys/protosw.h>
#include <vm/uma.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/vnet.h>
#define TCPSTATES /* for logging */
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_pcb.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h> /* required for icmp_var.h */
#include <netinet/icmp_var.h> /* for ICMP_BANDLIM */
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet/tcp.h>
#define TCPOUTFLAGS
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_log_buf.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_hpts.h>
#include <netinet/tcp_ratelimit.h>
#include <netinet/tcpip.h>
#include <netinet/cc/cc.h>
#include <netinet/tcp_fastopen.h>
#include <netinet/tcp_lro.h>
#ifdef NETFLIX_SHARED_CWND
#include <netinet/tcp_shared_cwnd.h>
#endif
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif /* TCPDEBUG */
#ifdef TCP_OFFLOAD
#include <netinet/tcp_offload.h>
#endif
#ifdef INET6
#include <netinet6/tcp6_var.h>
#endif
#include <netipsec/ipsec_support.h>
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#endif /* IPSEC */
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <machine/in_cksum.h>
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
#include "sack_filter.h"
#include "tcp_rack.h"
#include "rack_bbr_common.h"
uma_zone_t rack_zone;
uma_zone_t rack_pcb_zone;
#ifndef TICKS2SBT
#define TICKS2SBT(__t) (tick_sbt * ((sbintime_t)(__t)))
#endif
struct sysctl_ctx_list rack_sysctl_ctx;
struct sysctl_oid *rack_sysctl_root;
#define CUM_ACKED 1
#define SACKED 2
#ifdef FSTACK
#define MODNAME tcp_rack
#define STACKNAME rack
#endif
/*
* The RACK module incorporates a number of
* TCP ideas that have been put out into the IETF
* over the last few years:
* - Matt Mathis's Rate Halving which slowly drops
* the congestion window so that the ack clock can
* be maintained during a recovery.
* - Yuchung Cheng's RACK TCP (for which its named) that
* will stop us using the number of dup acks and instead
* use time as the gage of when we retransmit.
* - Reorder Detection of RFC4737 and the Tail-Loss probe draft
* of Dukkipati et.al.
* RACK depends on SACK, so if an endpoint arrives that
* cannot do SACK the state machine below will shuttle the
* connection back to using the "default" TCP stack that is
* in FreeBSD.
*
* To implement RACK the original TCP stack was first decomposed
* into a functional state machine with individual states
* for each of the possible TCP connection states. The do_segement
* functions role in life is to mandate the connection supports SACK
* initially and then assure that the RACK state matches the conenction
* state before calling the states do_segment function. Each
* state is simplified due to the fact that the original do_segment
* has been decomposed and we *know* what state we are in (no
* switches on the state) and all tests for SACK are gone. This
* greatly simplifies what each state does.
*
* TCP output is also over-written with a new version since it
* must maintain the new rack scoreboard.
*
*/
static int32_t rack_tlp_thresh = 1;
static int32_t rack_tlp_limit = 2; /* No more than 2 TLPs w-out new data */
static int32_t rack_tlp_use_greater = 1;
static int32_t rack_reorder_thresh = 2;
static int32_t rack_reorder_fade = 60000; /* 0 - never fade, def 60,000
* - 60 seconds */
/* Attack threshold detections */
static uint32_t rack_highest_sack_thresh_seen = 0;
static uint32_t rack_highest_move_thresh_seen = 0;
static int32_t rack_pkt_delay = 1;
static int32_t rack_early_recovery = 1;
static int32_t rack_send_a_lot_in_prr = 1;
static int32_t rack_min_to = 1; /* Number of ms minimum timeout */
static int32_t rack_verbose_logging = 0;
static int32_t rack_ignore_data_after_close = 1;
static int32_t rack_enable_shared_cwnd = 0;
static int32_t rack_limits_scwnd = 1;
static int32_t rack_enable_mqueue_for_nonpaced = 0;
static int32_t rack_disable_prr = 0;
static int32_t use_rack_rr = 1;
static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
static int32_t rack_persist_min = 250; /* 250ms */
static int32_t rack_persist_max = 2000; /* 2 Second */
static int32_t rack_sack_not_required = 0; /* set to one to allow non-sack to use rack */
static int32_t rack_default_init_window = 0; /* Use system default */
static int32_t rack_limit_time_with_srtt = 0;
static int32_t rack_hw_pace_adjust = 0;
/*
* Currently regular tcp has a rto_min of 30ms
* the backoff goes 12 times so that ends up
* being a total of 122.850 seconds before a
* connection is killed.
*/
static uint32_t rack_def_data_window = 20;
static uint32_t rack_goal_bdp = 2;
static uint32_t rack_min_srtts = 1;
static uint32_t rack_min_measure_usec = 0;
static int32_t rack_tlp_min = 10;
static int32_t rack_rto_min = 30; /* 30ms same as main freebsd */
static int32_t rack_rto_max = 4000; /* 4 seconds */
static const int32_t rack_free_cache = 2;
static int32_t rack_hptsi_segments = 40;
static int32_t rack_rate_sample_method = USE_RTT_LOW;
static int32_t rack_pace_every_seg = 0;
static int32_t rack_delayed_ack_time = 200; /* 200ms */
static int32_t rack_slot_reduction = 4;
static int32_t rack_wma_divisor = 8; /* For WMA calculation */
static int32_t rack_cwnd_block_ends_measure = 0;
static int32_t rack_rwnd_block_ends_measure = 0;
static int32_t rack_lower_cwnd_at_tlp = 0;
static int32_t rack_use_proportional_reduce = 0;
static int32_t rack_proportional_rate = 10;
static int32_t rack_tlp_max_resend = 2;
static int32_t rack_limited_retran = 0;
static int32_t rack_always_send_oldest = 0;
static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
static uint16_t rack_per_of_gp_ss = 250; /* 250 % slow-start */
static uint16_t rack_per_of_gp_ca = 200; /* 200 % congestion-avoidance */
static uint16_t rack_per_of_gp_rec = 200; /* 200 % of bw */
/* Probertt */
static uint16_t rack_per_of_gp_probertt = 60; /* 60% of bw */
static uint16_t rack_per_of_gp_lowthresh = 40; /* 40% is bottom */
static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
static uint16_t rack_atexit_prtt_hbp = 130; /* Clamp to 130% on exit prtt if highly buffered path */
static uint16_t rack_atexit_prtt = 130; /* Clamp to 100% on exit prtt if non highly buffered path */
static uint32_t rack_max_drain_wait = 2; /* How man gp srtt's before we give up draining */
static uint32_t rack_must_drain = 1; /* How many GP srtt's we *must* wait */
static uint32_t rack_probertt_use_min_rtt_entry = 1; /* Use the min to calculate the goal else gp_srtt */
static uint32_t rack_probertt_use_min_rtt_exit = 0;
static uint32_t rack_probe_rtt_sets_cwnd = 0;
static uint32_t rack_probe_rtt_safety_val = 2000000; /* No more than 2 sec in probe-rtt */
static uint32_t rack_time_between_probertt = 9600000; /* 9.6 sec in us */
static uint32_t rack_probertt_gpsrtt_cnt_mul = 0; /* How many srtt periods does probe-rtt last top fraction */
static uint32_t rack_probertt_gpsrtt_cnt_div = 0; /* How many srtt periods does probe-rtt last bottom fraction */
static uint32_t rack_min_probertt_hold = 200000; /* Equal to delayed ack time */
static uint32_t rack_probertt_filter_life = 10000000;
static uint32_t rack_probertt_lower_within = 10;
static uint32_t rack_min_rtt_movement = 250; /* Must move at least 250 useconds to count as a lowering */
static int32_t rack_pace_one_seg = 0; /* Shall we pace for less than 1.4Meg 1MSS at a time */
static int32_t rack_probertt_clear_is = 1;
static int32_t rack_max_drain_hbp = 1; /* Extra drain times gpsrtt for highly buffered paths */
static int32_t rack_hbp_thresh = 3; /* what is the divisor max_rtt/min_rtt to decided a hbp */
/* Part of pacing */
static int32_t rack_max_per_above = 30; /* When we go to increment stop if above 100+this% */
/* Timely information */
/* Combine these two gives the range of 'no change' to bw */
/* ie the up/down provide the upper and lower bound */
static int32_t rack_gp_per_bw_mul_up = 2; /* 2% */
static int32_t rack_gp_per_bw_mul_down = 4; /* 4% */
static int32_t rack_gp_rtt_maxmul = 3; /* 3 x maxmin */
static int32_t rack_gp_rtt_minmul = 1; /* minrtt + (minrtt/mindiv) is lower rtt */
static int32_t rack_gp_rtt_mindiv = 4; /* minrtt + (minrtt * minmul/mindiv) is lower rtt */
static int32_t rack_gp_decrease_per = 20; /* 20% decrease in multipler */
static int32_t rack_gp_increase_per = 2; /* 2% increase in multipler */
static int32_t rack_per_lower_bound = 50; /* Don't allow to drop below this multiplier */
static int32_t rack_per_upper_bound_ss = 0; /* Don't allow SS to grow above this */
static int32_t rack_per_upper_bound_ca = 0; /* Don't allow CA to grow above this */
static int32_t rack_do_dyn_mul = 0; /* Are the rack gp multipliers dynamic */
static int32_t rack_gp_no_rec_chg = 1; /* Prohibit recovery from reducing it's multiplier */
static int32_t rack_timely_dec_clear = 6; /* Do we clear decrement count at a value (6)? */
static int32_t rack_timely_max_push_rise = 3; /* One round of pushing */
static int32_t rack_timely_max_push_drop = 3; /* Three round of pushing */
static int32_t rack_timely_min_segs = 4; /* 4 segment minimum */
static int32_t rack_use_max_for_nobackoff = 0;
static int32_t rack_timely_int_timely_only = 0; /* do interim timely's only use the timely algo (no b/w changes)? */
static int32_t rack_timely_no_stopping = 0;
static int32_t rack_down_raise_thresh = 100;
static int32_t rack_req_segs = 1;
/* Weird delayed ack mode */
static int32_t rack_use_imac_dack = 0;
/* Rack specific counters */
counter_u64_t rack_badfr;
counter_u64_t rack_badfr_bytes;
counter_u64_t rack_rtm_prr_retran;
counter_u64_t rack_rtm_prr_newdata;
counter_u64_t rack_timestamp_mismatch;
counter_u64_t rack_reorder_seen;
counter_u64_t rack_paced_segments;
counter_u64_t rack_unpaced_segments;
counter_u64_t rack_calc_zero;
counter_u64_t rack_calc_nonzero;
counter_u64_t rack_saw_enobuf;
counter_u64_t rack_saw_enetunreach;
counter_u64_t rack_per_timer_hole;
/* Tail loss probe counters */
counter_u64_t rack_tlp_tot;
counter_u64_t rack_tlp_newdata;
counter_u64_t rack_tlp_retran;
counter_u64_t rack_tlp_retran_bytes;
counter_u64_t rack_tlp_retran_fail;
counter_u64_t rack_to_tot;
counter_u64_t rack_to_arm_rack;
counter_u64_t rack_to_arm_tlp;
counter_u64_t rack_to_alloc;
counter_u64_t rack_to_alloc_hard;
counter_u64_t rack_to_alloc_emerg;
counter_u64_t rack_to_alloc_limited;
counter_u64_t rack_alloc_limited_conns;
counter_u64_t rack_split_limited;
counter_u64_t rack_sack_proc_all;
counter_u64_t rack_sack_proc_short;
counter_u64_t rack_sack_proc_restart;
counter_u64_t rack_sack_attacks_detected;
counter_u64_t rack_sack_attacks_reversed;
counter_u64_t rack_sack_used_next_merge;
counter_u64_t rack_sack_splits;
counter_u64_t rack_sack_used_prev_merge;
counter_u64_t rack_sack_skipped_acked;
counter_u64_t rack_ack_total;
counter_u64_t rack_express_sack;
counter_u64_t rack_sack_total;
counter_u64_t rack_move_none;
counter_u64_t rack_move_some;
counter_u64_t rack_used_tlpmethod;
counter_u64_t rack_used_tlpmethod2;
counter_u64_t rack_enter_tlp_calc;
counter_u64_t rack_input_idle_reduces;
counter_u64_t rack_collapsed_win;
counter_u64_t rack_tlp_does_nada;
counter_u64_t rack_try_scwnd;
/* Temp CPU counters */
counter_u64_t rack_find_high;
counter_u64_t rack_progress_drops;
counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
static void
rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line);
static int
rack_process_ack(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to,
uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
static int
rack_process_data(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
static void
rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
struct tcphdr *th, uint16_t nsegs, uint16_t type, int32_t recovery);
static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
uint8_t limit_type);
static struct rack_sendmap *
rack_check_recovery_mode(struct tcpcb *tp,
uint32_t tsused);
static void
rack_cong_signal(struct tcpcb *tp, struct tcphdr *th,
uint32_t type);
static void rack_counter_destroy(void);
static int
rack_ctloutput(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp);
static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
static void
rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line);
static void
rack_do_segment(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint8_t iptos);
static void rack_dtor(void *mem, int32_t size, void *arg);
static void
rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
uint32_t t, uint32_t cts);
static void
rack_log_alt_to_to_cancel(struct tcp_rack *rack,
uint32_t flex1, uint32_t flex2,
uint32_t flex3, uint32_t flex4,
uint32_t flex5, uint32_t flex6,
uint16_t flex7, uint8_t mod);
static void
rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line, struct rack_sendmap *rsm);
static struct rack_sendmap *
rack_find_high_nonack(struct tcp_rack *rack,
struct rack_sendmap *rsm);
static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
static int
rack_get_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
static void
rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq th_ack, int line);
static uint32_t
rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
static int32_t rack_handoff_ok(struct tcpcb *tp);
static int32_t rack_init(struct tcpcb *tp);
static void rack_init_sysctls(void);
static void
rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
struct tcphdr *th);
static void
rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
uint8_t pass, struct rack_sendmap *hintrsm, uint32_t us_cts);
static void
rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm);
static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
static int32_t rack_output(struct tcpcb *tp);
static uint32_t
rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
uint32_t cts, int *moved_two);
static void rack_post_recovery(struct tcpcb *tp, struct tcphdr *th);
static void rack_remxt_tmr(struct tcpcb *tp);
static int
rack_set_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
static int32_t rack_stopall(struct tcpcb *tp);
static void
rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
uint32_t delta);
static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
static uint32_t
rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts, int32_t * lenp);
static void
rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts);
static int
rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
static int
rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_closing(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_established(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_lastack(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
static int
rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
struct rack_sendmap *
tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
uint32_t tsused);
static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
static void
tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th);
int32_t rack_clear_counter=0;
static int
sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
{
uint32_t stat;
int32_t error;
error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
if (error || req->newptr == NULL)
return error;
error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
if (error)
return (error);
if (stat == 1) {
#ifdef INVARIANTS
printf("Clearing RACK counters\n");
#endif
counter_u64_zero(rack_badfr);
counter_u64_zero(rack_badfr_bytes);
counter_u64_zero(rack_rtm_prr_retran);
counter_u64_zero(rack_rtm_prr_newdata);
counter_u64_zero(rack_timestamp_mismatch);
counter_u64_zero(rack_reorder_seen);
counter_u64_zero(rack_tlp_tot);
counter_u64_zero(rack_tlp_newdata);
counter_u64_zero(rack_tlp_retran);
counter_u64_zero(rack_tlp_retran_bytes);
counter_u64_zero(rack_tlp_retran_fail);
counter_u64_zero(rack_to_tot);
counter_u64_zero(rack_to_arm_rack);
counter_u64_zero(rack_to_arm_tlp);
counter_u64_zero(rack_paced_segments);
counter_u64_zero(rack_calc_zero);
counter_u64_zero(rack_calc_nonzero);
counter_u64_zero(rack_unpaced_segments);
counter_u64_zero(rack_saw_enobuf);
counter_u64_zero(rack_saw_enetunreach);
counter_u64_zero(rack_per_timer_hole);
counter_u64_zero(rack_to_alloc_hard);
counter_u64_zero(rack_to_alloc_emerg);
counter_u64_zero(rack_sack_proc_all);
counter_u64_zero(rack_sack_proc_short);
counter_u64_zero(rack_sack_proc_restart);
counter_u64_zero(rack_to_alloc);
counter_u64_zero(rack_to_alloc_limited);
counter_u64_zero(rack_alloc_limited_conns);
counter_u64_zero(rack_split_limited);
counter_u64_zero(rack_find_high);
counter_u64_zero(rack_sack_attacks_detected);
counter_u64_zero(rack_sack_attacks_reversed);
counter_u64_zero(rack_sack_used_next_merge);
counter_u64_zero(rack_sack_used_prev_merge);
counter_u64_zero(rack_sack_splits);
counter_u64_zero(rack_sack_skipped_acked);
counter_u64_zero(rack_ack_total);
counter_u64_zero(rack_express_sack);
counter_u64_zero(rack_sack_total);
counter_u64_zero(rack_move_none);
counter_u64_zero(rack_move_some);
counter_u64_zero(rack_used_tlpmethod);
counter_u64_zero(rack_used_tlpmethod2);
counter_u64_zero(rack_enter_tlp_calc);
counter_u64_zero(rack_progress_drops);
counter_u64_zero(rack_tlp_does_nada);
counter_u64_zero(rack_try_scwnd);
counter_u64_zero(rack_collapsed_win);
}
rack_clear_counter = 0;
return (0);
}
static void
rack_init_sysctls(void)
{
struct sysctl_oid *rack_counters;
struct sysctl_oid *rack_attack;
struct sysctl_oid *rack_pacing;
struct sysctl_oid *rack_timely;
struct sysctl_oid *rack_timers;
struct sysctl_oid *rack_tlp;
struct sysctl_oid *rack_misc;
struct sysctl_oid *rack_measure;
struct sysctl_oid *rack_probertt;
rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"sack_attack",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Sack Attack Counters and Controls");
rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"stats",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Counters");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "rate_sample_method", CTLFLAG_RW,
&rack_rate_sample_method , USE_RTT_LOW,
"What method should we use for rate sampling 0=high, 1=low ");
/* Probe rtt related controls */
rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"probertt",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"ProbeRTT related Controls");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
&rack_atexit_prtt_hbp, 130,
"What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
&rack_atexit_prtt, 130,
"What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_mul", CTLFLAG_RW,
&rack_per_of_gp_probertt, 60,
"What percentage of goodput do we pace at in probertt");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
&rack_per_of_gp_probertt_reduce, 10,
"What percentage of goodput do we reduce every gp_srtt");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "gp_per_low", CTLFLAG_RW,
&rack_per_of_gp_lowthresh, 40,
"What percentage of goodput do we allow the multiplier to fall to");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "time_between", CTLFLAG_RW,
& rack_time_between_probertt, 96000000,
"How many useconds between the lowest rtt falling must past before we enter probertt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "safety", CTLFLAG_RW,
&rack_probe_rtt_safety_val, 2000000,
"If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "sets_cwnd", CTLFLAG_RW,
&rack_probe_rtt_sets_cwnd, 0,
"Do we set the cwnd too (if always_lower is on)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
&rack_max_drain_wait, 2,
"Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
&rack_must_drain, 1,
"We must drain this many gp_srtt's waiting for flight to reach goal");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
&rack_probertt_use_min_rtt_entry, 1,
"Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
&rack_probertt_use_min_rtt_exit, 0,
"How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "length_div", CTLFLAG_RW,
&rack_probertt_gpsrtt_cnt_div, 0,
"How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "length_mul", CTLFLAG_RW,
&rack_probertt_gpsrtt_cnt_mul, 0,
"How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
&rack_min_probertt_hold, 200000,
"What is the minimum time we hold probertt at target");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "filter_life", CTLFLAG_RW,
&rack_probertt_filter_life, 10000000,
"What is the time for the filters life in useconds");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "lower_within", CTLFLAG_RW,
&rack_probertt_lower_within, 10,
"If the rtt goes lower within this percentage of the time, go into probe-rtt");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "must_move", CTLFLAG_RW,
&rack_min_rtt_movement, 250,
"How much is the minimum movement in rtt to count as a drop for probertt purposes");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
&rack_probertt_clear_is, 1,
"Do we clear I/S counts on exiting probe-rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
&rack_max_drain_hbp, 1,
"How many extra drain gpsrtt's do we get in highly buffered paths");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_probertt),
OID_AUTO, "hbp_threshold", CTLFLAG_RW,
&rack_hbp_thresh, 3,
"We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
/* Pacing related sysctls */
rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"pacing",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Pacing related Controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "max_pace_over", CTLFLAG_RW,
&rack_max_per_above, 30,
"What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "pace_to_one", CTLFLAG_RW,
&rack_pace_one_seg, 0,
"Do we allow low b/w pacing of 1MSS instead of two");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
&rack_limit_time_with_srtt, 0,
"Do we limit pacing time based on srtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "init_win", CTLFLAG_RW,
&rack_default_init_window, 0,
"Do we have a rack initial window 0 = system default");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "hw_pacing_adjust", CTLFLAG_RW,
&rack_hw_pace_adjust, 0,
"What percentage do we raise the MSS by (11 = 1.1%)");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_ss", CTLFLAG_RW,
&rack_per_of_gp_ss, 250,
"If non zero, what percentage of goodput to pace at in slow start");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_ca", CTLFLAG_RW,
&rack_per_of_gp_ca, 150,
"If non zero, what percentage of goodput to pace at in congestion avoidance");
SYSCTL_ADD_U16(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "gp_per_rec", CTLFLAG_RW,
&rack_per_of_gp_rec, 200,
"If non zero, what percentage of goodput to pace at in recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "pace_max_seg", CTLFLAG_RW,
&rack_hptsi_segments, 40,
"What size is the max for TSO segments in pacing and burst mitigation");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_pacing),
OID_AUTO, "burst_reduces", CTLFLAG_RW,
&rack_slot_reduction, 4,
"When doing only burst mitigation what is the reduce divisor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "use_pacing", CTLFLAG_RW,
&rack_pace_every_seg, 0,
"If set we use pacing, if clear we use only the original burst mitigation");
rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"timely",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Rack Timely RTT Controls");
/* Timely based GP dynmics */
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upper", CTLFLAG_RW,
&rack_gp_per_bw_mul_up, 2,
"Rack timely upper range for equal b/w (in percentage)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "lower", CTLFLAG_RW,
&rack_gp_per_bw_mul_down, 4,
"Rack timely lower range for equal b/w (in percentage)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
&rack_gp_rtt_maxmul, 3,
"Rack timely multipler of lowest rtt for rtt_max");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_min_div", CTLFLAG_RW,
&rack_gp_rtt_mindiv, 4,
"Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
&rack_gp_rtt_minmul, 1,
"Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "decrease", CTLFLAG_RW,
&rack_gp_decrease_per, 20,
"Rack timely decrease percentage of our GP multiplication factor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "increase", CTLFLAG_RW,
&rack_gp_increase_per, 2,
"Rack timely increase perentage of our GP multiplication factor");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "lowerbound", CTLFLAG_RW,
&rack_per_lower_bound, 50,
"Rack timely lowest percentage we allow GP multiplier to fall to");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upperboundss", CTLFLAG_RW,
&rack_per_upper_bound_ss, 0,
"Rack timely higest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "upperboundca", CTLFLAG_RW,
&rack_per_upper_bound_ca, 0,
"Rack timely higest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "dynamicgp", CTLFLAG_RW,
&rack_do_dyn_mul, 0,
"Rack timely do we enable dynmaic timely goodput by default");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "no_rec_red", CTLFLAG_RW,
&rack_gp_no_rec_chg, 1,
"Rack timely do we prohibit the recovery multiplier from being lowered");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
&rack_timely_dec_clear, 6,
"Rack timely what threshold do we count to before another boost during b/w decent");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "max_push_rise", CTLFLAG_RW,
&rack_timely_max_push_rise, 3,
"Rack timely how many times do we push up with b/w increase");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "max_push_drop", CTLFLAG_RW,
&rack_timely_max_push_drop, 3,
"Rack timely how many times do we push back on b/w decent");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "min_segs", CTLFLAG_RW,
&rack_timely_min_segs, 4,
"Rack timely when setting the cwnd what is the min num segments");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "noback_max", CTLFLAG_RW,
&rack_use_max_for_nobackoff, 0,
"Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "interim_timely_only", CTLFLAG_RW,
&rack_timely_int_timely_only, 0,
"Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "nonstop", CTLFLAG_RW,
&rack_timely_no_stopping, 0,
"Rack timely don't stop increase");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
&rack_down_raise_thresh, 100,
"If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timely),
OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
&rack_req_segs, 1,
"Bottom dragging if not these many segments outstanding and room");
/* TLP and Rack related parameters */
rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"tlp",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TLP and Rack related Controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "use_rrr", CTLFLAG_RW,
&use_rack_rr, 1,
"Do we use Rack Rapid Recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
&rack_non_rxt_use_cr, 0,
"Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlpmethod", CTLFLAG_RW,
&rack_tlp_threshold_use, TLP_USE_TWO_ONE,
"What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "limit", CTLFLAG_RW,
&rack_tlp_limit, 2,
"How many TLP's can be sent without sending new data");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "use_greater", CTLFLAG_RW,
&rack_tlp_use_greater, 1,
"Should we use the rack_rtt time if its greater than srtt");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlpminto", CTLFLAG_RW,
&rack_tlp_min, 10,
"TLP minimum timeout per the specification (10ms)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "send_oldest", CTLFLAG_RW,
&rack_always_send_oldest, 0,
"Should we always send the oldest TLP and RACK-TLP");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "rack_tlimit", CTLFLAG_RW,
&rack_limited_retran, 0,
"How many times can a rack timeout drive out sends");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlp_retry", CTLFLAG_RW,
&rack_tlp_max_resend, 2,
"How many times does TLP retry a single segment or multiple with no ACK");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
&rack_lower_cwnd_at_tlp, 0,
"When a TLP completes a retran should we enter recovery");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "reorder_thresh", CTLFLAG_RW,
&rack_reorder_thresh, 2,
"What factor for rack will be added when seeing reordering (shift right)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
&rack_tlp_thresh, 1,
"What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "reorder_fade", CTLFLAG_RW,
&rack_reorder_fade, 0,
"Does reorder detection fade, if so how many ms (0 means never)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_tlp),
OID_AUTO, "pktdelay", CTLFLAG_RW,
&rack_pkt_delay, 1,
"Extra RACK time (in ms) besides reordering thresh");
/* Timer related controls */
rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"timers",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Timer related controls");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "persmin", CTLFLAG_RW,
&rack_persist_min, 250,
"What is the minimum time in milliseconds between persists");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "persmax", CTLFLAG_RW,
&rack_persist_max, 2000,
"What is the largest delay in milliseconds between persists");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "delayed_ack", CTLFLAG_RW,
&rack_delayed_ack_time, 200,
"Delayed ack time (200ms)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "minrto", CTLFLAG_RW,
&rack_rto_min, 0,
"Minimum RTO in ms -- set with caution below 1000 due to TLP");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "maxrto", CTLFLAG_RW,
&rack_rto_max, 0,
"Maxiumum RTO in ms -- should be at least as large as min_rto");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_timers),
OID_AUTO, "minto", CTLFLAG_RW,
&rack_min_to, 1,
"Minimum rack timeout in milliseconds");
/* Measure controls */
rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"measure",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Measure related controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "wma_divisor", CTLFLAG_RW,
&rack_wma_divisor, 8,
"When doing b/w calculation what is the divisor for the WMA");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "end_cwnd", CTLFLAG_RW,
&rack_cwnd_block_ends_measure, 0,
"Does a cwnd just-return end the measurement window (app limited)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "end_rwnd", CTLFLAG_RW,
&rack_rwnd_block_ends_measure, 0,
"Does an rwnd just-return end the measurement window (app limited -- not persists)");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_target", CTLFLAG_RW,
&rack_def_data_window, 20,
"What is the minimum target window (in mss) for a GP measurements");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "goal_bdp", CTLFLAG_RW,
&rack_goal_bdp, 2,
"What is the goal BDP to measure");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_srtts", CTLFLAG_RW,
&rack_min_srtts, 1,
"What is the goal BDP to measure");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_measure),
OID_AUTO, "min_measure_tim", CTLFLAG_RW,
&rack_min_measure_usec, 0,
"What is the Minimum time time for a measurement if 0, this is off");
/* Misc rack controls */
rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO,
"misc",
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"Misc related controls");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "shared_cwnd", CTLFLAG_RW,
&rack_enable_shared_cwnd, 0,
"Should RACK try to use the shared cwnd on connections where allowed");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
&rack_limits_scwnd, 1,
"Should RACK place low end time limits on the shared cwnd feature");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
&rack_enable_mqueue_for_nonpaced, 0,
"Should RACK use mbuf queuing for non-paced connections");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "iMac_dack", CTLFLAG_RW,
&rack_use_imac_dack, 0,
"Should RACK try to emulate iMac delayed ack");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "no_prr", CTLFLAG_RW,
&rack_disable_prr, 0,
"Should RACK not use prr and only pace (must have pacing on)");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "bb_verbose", CTLFLAG_RW,
&rack_verbose_logging, 0,
"Should RACK black box logging be verbose");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "data_after_close", CTLFLAG_RW,
&rack_ignore_data_after_close, 1,
"Do we hold off sending a RST until all pending data is ack'd");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "no_sack_needed", CTLFLAG_RW,
&rack_sack_not_required, 0,
"Do we allow rack to run on connections not supporting SACK");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "recovery_loss_prop", CTLFLAG_RW,
&rack_use_proportional_reduce, 0,
"Should we proportionaly reduce cwnd based on the number of losses ");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "recovery_prop", CTLFLAG_RW,
&rack_proportional_rate, 10,
"What percent reduction per loss");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "prr_sendalot", CTLFLAG_RW,
&rack_send_a_lot_in_prr, 1,
"Send a lot in prr");
SYSCTL_ADD_S32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_misc),
OID_AUTO, "earlyrecovery", CTLFLAG_RW,
&rack_early_recovery, 1,
"Do we do early recovery with rack");
/* Sack Attacker detection stuff */
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
&rack_highest_sack_thresh_seen, 0,
"Highest sack to ack ratio seen");
SYSCTL_ADD_U32(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
&rack_highest_move_thresh_seen, 0,
"Highest move to non-move ratio seen");
rack_ack_total = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "acktotal", CTLFLAG_RD,
&rack_ack_total,
"Total number of Ack's");
rack_express_sack = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
&rack_express_sack,
"Total expresss number of Sack's");
rack_sack_total = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "sacktotal", CTLFLAG_RD,
&rack_sack_total,
"Total number of SACKs");
rack_move_none = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "move_none", CTLFLAG_RD,
&rack_move_none,
"Total number of SACK index reuse of postions under threshold");
rack_move_some = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "move_some", CTLFLAG_RD,
&rack_move_some,
"Total number of SACK index reuse of postions over threshold");
rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "attacks", CTLFLAG_RD,
&rack_sack_attacks_detected,
"Total number of SACK attackers that had sack disabled");
rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "reversed", CTLFLAG_RD,
&rack_sack_attacks_reversed,
"Total number of SACK attackers that were later determined false positive");
rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "nextmerge", CTLFLAG_RD,
&rack_sack_used_next_merge,
"Total number of times we used the next merge");
rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "prevmerge", CTLFLAG_RD,
&rack_sack_used_prev_merge,
"Total number of times we used the prev merge");
/* Counters */
rack_badfr = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "badfr", CTLFLAG_RD,
&rack_badfr, "Total number of bad FRs");
rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "badfr_bytes", CTLFLAG_RD,
&rack_badfr_bytes, "Total number of bad FRs");
rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prrsndret", CTLFLAG_RD,
&rack_rtm_prr_retran,
"Total number of prr based retransmits");
rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prrsndnew", CTLFLAG_RD,
&rack_rtm_prr_newdata,
"Total number of prr based new transmits");
rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tsnf", CTLFLAG_RD,
&rack_timestamp_mismatch,
"Total number of timestamps that we could not find the reported ts");
rack_find_high = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "findhigh", CTLFLAG_RD,
&rack_find_high,
"Total number of FIN causing find-high");
rack_reorder_seen = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "reordering", CTLFLAG_RD,
&rack_reorder_seen,
"Total number of times we added delay due to reordering");
rack_tlp_tot = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_to_total", CTLFLAG_RD,
&rack_tlp_tot,
"Total number of tail loss probe expirations");
rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_new", CTLFLAG_RD,
&rack_tlp_newdata,
"Total number of tail loss probe sending new data");
rack_tlp_retran = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran", CTLFLAG_RD,
&rack_tlp_retran,
"Total number of tail loss probe sending retransmitted data");
rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
&rack_tlp_retran_bytes,
"Total bytes of tail loss probe sending retransmitted data");
rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
&rack_tlp_retran_fail,
"Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
rack_to_tot = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "rack_to_tot", CTLFLAG_RD,
&rack_to_tot,
"Total number of times the rack to expired");
rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "arm_rack", CTLFLAG_RD,
&rack_to_arm_rack,
"Total number of times the rack timer armed");
rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "arm_tlp", CTLFLAG_RD,
&rack_to_arm_tlp,
"Total number of times the tlp timer armed");
rack_calc_zero = counter_u64_alloc(M_WAITOK);
rack_calc_nonzero = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "calc_zero", CTLFLAG_RD,
&rack_calc_zero,
"Total number of times pacing time worked out to zero");
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "calc_nonzero", CTLFLAG_RD,
&rack_calc_nonzero,
"Total number of times pacing time worked out to non-zero");
rack_paced_segments = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "paced", CTLFLAG_RD,
&rack_paced_segments,
"Total number of times a segment send caused hptsi");
rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "unpaced", CTLFLAG_RD,
&rack_unpaced_segments,
"Total number of times a segment did not cause hptsi");
rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "saw_enobufs", CTLFLAG_RD,
&rack_saw_enobuf,
"Total number of times a segment did not cause hptsi");
rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
&rack_saw_enetunreach,
"Total number of times a segment did not cause hptsi");
rack_to_alloc = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allocs", CTLFLAG_RD,
&rack_to_alloc,
"Total allocations of tracking structures");
rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allochard", CTLFLAG_RD,
&rack_to_alloc_hard,
"Total allocations done with sleeping the hard way");
rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "allocemerg", CTLFLAG_RD,
&rack_to_alloc_emerg,
"Total allocations done from emergency cache");
rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "alloc_limited", CTLFLAG_RD,
&rack_to_alloc_limited,
"Total allocations dropped due to limit");
rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
&rack_alloc_limited_conns,
"Connections with allocations dropped due to limit");
rack_split_limited = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "split_limited", CTLFLAG_RD,
&rack_split_limited,
"Split allocations dropped due to limit");
rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_long", CTLFLAG_RD,
&rack_sack_proc_all,
"Total times we had to walk whole list for sack processing");
rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_restart", CTLFLAG_RD,
&rack_sack_proc_restart,
"Total times we had to walk whole list due to a restart");
rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "sack_short", CTLFLAG_RD,
&rack_sack_proc_short,
"Total times we took shortcut for sack processing");
rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
&rack_enter_tlp_calc,
"Total times we called calc-tlp");
rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
&rack_used_tlpmethod,
"Total number of runt sacks");
rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
&rack_used_tlpmethod2,
"Total number of times we hit TLP method 2");
rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "skipacked", CTLFLAG_RD,
&rack_sack_skipped_acked,
"Total number of times we skipped previously sacked");
rack_sack_splits = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_attack),
OID_AUTO, "ofsplit", CTLFLAG_RD,
&rack_sack_splits,
"Total number of times we did the old fashion tree split");
rack_progress_drops = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "prog_drops", CTLFLAG_RD,
&rack_progress_drops,
"Total number of progress drops");
rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
&rack_input_idle_reduces,
"Total number of idle reductions on input");
rack_collapsed_win = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "collapsed_win", CTLFLAG_RD,
&rack_collapsed_win,
"Total number of collapsed windows");
rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tlp_nada", CTLFLAG_RD,
&rack_tlp_does_nada,
"Total number of nada tlp calls");
rack_try_scwnd = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "tried_scwnd", CTLFLAG_RD,
&rack_try_scwnd,
"Total number of scwnd attempts");
rack_per_timer_hole = counter_u64_alloc(M_WAITOK);
SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_counters),
OID_AUTO, "timer_hole", CTLFLAG_RD,
&rack_per_timer_hole,
"Total persists start in timer hole");
COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "outsize", CTLFLAG_RD,
rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "opts", CTLFLAG_RD,
rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
SYSCTL_ADD_PROC(&rack_sysctl_ctx,
SYSCTL_CHILDREN(rack_sysctl_root),
OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
&rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
}
static __inline int
rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
{
if (SEQ_GEQ(b->r_start, a->r_start) &&
SEQ_LT(b->r_start, a->r_end)) {
/*
* The entry b is within the
* block a. i.e.:
* a -- |-------------|
* b -- |----|
* <or>
* b -- |------|
* <or>
* b -- |-----------|
*/
return (0);
} else if (SEQ_GEQ(b->r_start, a->r_end)) {
/*
* b falls as either the next
* sequence block after a so a
* is said to be smaller than b.
* i.e:
* a -- |------|
* b -- |--------|
* or
* b -- |-----|
*/
return (1);
}
/*
* Whats left is where a is
* larger than b. i.e:
* a -- |-------|
* b -- |---|
* or even possibly
* b -- |--------------|
*/
return (-1);
}
RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
static uint32_t
rc_init_window(struct tcp_rack *rack)
{
uint32_t win;
if (rack->rc_init_win == 0) {
/*
* Nothing set by the user, use the system stack
* default.
*/
return(tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
}
win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
return(win);
}
static uint64_t
rack_get_fixed_pacing_bw(struct tcp_rack *rack)
{
if (IN_RECOVERY(rack->rc_tp->t_flags))
return (rack->r_ctl.rc_fixed_pacing_rate_rec);
else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
return (rack->r_ctl.rc_fixed_pacing_rate_ss);
else
return (rack->r_ctl.rc_fixed_pacing_rate_ca);
}
static uint64_t
rack_get_bw(struct tcp_rack *rack)
{
if (rack->use_fixed_rate) {
/* Return the fixed pacing rate */
return (rack_get_fixed_pacing_bw(rack));
}
if (rack->r_ctl.gp_bw == 0) {
/*
* We have yet no b/w measurement,
* if we have a user set initial bw
* return it. If we don't have that and
* we have an srtt, use the tcp IW (10) to
* calculate a fictional b/w over the SRTT
* which is more or less a guess. Note
* we don't use our IW from rack on purpose
* so if we have like IW=30, we are not
* calculating a "huge" b/w.
*/
uint64_t bw, srtt;
if (rack->r_ctl.init_rate)
return (rack->r_ctl.init_rate);
/* Has the user set a max peak rate? */
#ifdef NETFLIX_PEAKRATE
if (rack->rc_tp->t_maxpeakrate)
return (rack->rc_tp->t_maxpeakrate);
#endif
/* Ok lets come up with the IW guess, if we have a srtt */
if (rack->rc_tp->t_srtt == 0) {
/*
* Go with old pacing method
* i.e. burst mitigation only.
*/
return (0);
}
/* Ok lets get the initial TCP win (not racks) */
bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
srtt = ((uint64_t)TICKS_2_USEC(rack->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
bw *= (uint64_t)USECS_IN_SECOND;
bw /= srtt;
return (bw);
} else {
uint64_t bw;
if(rack->r_ctl.num_avg >= RACK_REQ_AVG) {
/* Averaging is done, we can return the value */
bw = rack->r_ctl.gp_bw;
} else {
/* Still doing initial average must calculate */
bw = rack->r_ctl.gp_bw / rack->r_ctl.num_avg;
}
#ifdef NETFLIX_PEAKRATE
if ((rack->rc_tp->t_maxpeakrate) &&
(bw > rack->rc_tp->t_maxpeakrate)) {
/* The user has set a peak rate to pace at
* don't allow us to pace faster than that.
*/
return (rack->rc_tp->t_maxpeakrate);
}
#endif
return (bw);
}
}
static uint16_t
rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
if (rack->use_fixed_rate) {
return (100);
} else if (rack->in_probe_rtt && (rsm == NULL))
return(rack->r_ctl.rack_per_of_gp_probertt);
else if ((IN_RECOVERY(rack->rc_tp->t_flags) &&
rack->r_ctl.rack_per_of_gp_rec)) {
if (rsm) {
/* a retransmission always use the recovery rate */
return(rack->r_ctl.rack_per_of_gp_rec);
} else if (rack->rack_rec_nonrxt_use_cr) {
/* Directed to use the configured rate */
goto configured_rate;
} else if (rack->rack_no_prr &&
(rack->r_ctl.rack_per_of_gp_rec > 100)) {
/* No PRR, lets just use the b/w estimate only */
return(100);
} else {
/*
* Here we may have a non-retransmit but we
* have no overrides, so just use the recovery
* rate (prr is in effect).
*/
return(rack->r_ctl.rack_per_of_gp_rec);
}
}
configured_rate:
/* For the configured rate we look at our cwnd vs the ssthresh */
if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
return (rack->r_ctl.rack_per_of_gp_ss);
else
return(rack->r_ctl.rack_per_of_gp_ca);
}
static uint64_t
rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm)
{
/*
* We allow rack_per_of_gp_xx to dictate our bw rate we want.
*/
uint64_t bw_est;
uint64_t gain;
gain = (uint64_t)rack_get_output_gain(rack, rsm);
bw_est = bw * gain;
bw_est /= (uint64_t)100;
/* Never fall below the minimum (def 64kbps) */
if (bw_est < RACK_MIN_BW)
bw_est = RACK_MIN_BW;
return (bw_est);
}
static void
rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
if ((mod != 1) && (rack_verbose_logging == 0)) {
/*
* We get 3 values currently for mod
* 1 - We are retransmitting and this tells the reason.
* 2 - We are clearing a dup-ack count.
* 3 - We are incrementing a dup-ack count.
*
* The clear/increment are only logged
* if you have BBverbose on.
*/
return;
}
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = tsused;
log.u_bbr.flex2 = thresh;
log.u_bbr.flex3 = rsm->r_flags;
log.u_bbr.flex4 = rsm->r_dupack;
log.u_bbr.flex5 = rsm->r_start;
log.u_bbr.flex6 = rsm->r_end;
log.u_bbr.flex8 = mod;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_SETTINGS_CHG, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = TICKS_2_MSEC(rack->rc_tp->t_srtt >> TCP_RTT_SHIFT);
log.u_bbr.flex2 = to * 1000;
log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = slot;
log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
log.u_bbr.flex7 = rack->rc_in_persist;
log.u_bbr.flex8 = which;
if (rack->rack_no_prr)
log.u_bbr.pkts_out = 0;
else
log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERSTAR, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex8 = to_num;
log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
log.u_bbr.flex2 = rack->rc_rack_rtt;
if (rsm == NULL)
log.u_bbr.flex3 = 0;
else
log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_RTO, 0,
0, &log, false, &tv);
}
}
static void
rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
struct rack_sendmap *rsm, int conf)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = t;
log.u_bbr.flex2 = len;
log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt * HPTS_USEC_IN_MSEC;
log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest * HPTS_USEC_IN_MSEC;
log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest * HPTS_USEC_IN_MSEC;
log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_rtt_cnt;
log.u_bbr.flex7 = conf;
log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot * (uint64_t)HPTS_USEC_IN_MSEC;
log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
if (rack->rack_no_prr)
log.u_bbr.pkts_out = 0;
else
log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtt;
log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
if (rsm) {
log.u_bbr.pkt_epoch = rsm->r_start;
log.u_bbr.lost = rsm->r_end;
log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
} else {
/* Its a SYN */
log.u_bbr.pkt_epoch = rack->rc_tp->iss;
log.u_bbr.lost = 0;
log.u_bbr.cwnd_gain = 0;
}
/* Write out general bits of interest rrs here */
log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->forced_ack;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
TCP_LOG_EVENTP(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRRTT, 0,
0, &log, false, &tv);
}
}
static void
rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
{
/*
* Log the rtt sample we are
* applying to the srtt algorithm in
* useconds.
*/
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
/* Convert our ms to a microsecond */
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = rtt * 1000;
log.u_bbr.flex2 = rack->r_ctl.ack_count;
log.u_bbr.flex3 = rack->r_ctl.sack_count;
log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
log.u_bbr.flex8 = rack->sack_attack_disable;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_LOG_RTT, 0,
0, &log, false, &tv);
}
}
static inline void
rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick, int event, int line)
{
if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = tick;
log.u_bbr.flex3 = tp->t_maxunacktime;
log.u_bbr.flex4 = tp->t_acktime;
log.u_bbr.flex8 = event;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_PROGRESS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = slot;
if (rack->rack_no_prr)
log.u_bbr.flex2 = 0;
else
log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.timeStamp = cts;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRSND, 0,
0, &log, false, tv);
}
}
static void
rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = did_out;
log.u_bbr.flex2 = nxt_pkt;
log.u_bbr.flex3 = way_out;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex7 = rack->r_wanted_output;
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_DOSEG_DONE, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_hrdwtso(struct tcpcb *tp, struct tcp_rack *rack, int len, int mod, int32_t orig_len, int frm)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
uint32_t cts;
memset(&log, 0, sizeof(log));
cts = tcp_get_usecs(&tv);
log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex4 = len;
log.u_bbr.flex5 = orig_len;
log.u_bbr.flex6 = rack->r_ctl.rc_sacked;
log.u_bbr.flex7 = mod;
log.u_bbr.flex8 = frm;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(tp, NULL,
&tp->t_inpcb->inp_socket->so_rcv,
&tp->t_inpcb->inp_socket->so_snd,
TCP_HDWR_TLS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = slot;
log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex4 = reason;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex7 = hpts_calling;
log.u_bbr.flex8 = rack->rc_in_persist;
log.u_bbr.lt_epoch = cwnd_to_use;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_JUSTRET, 0,
tlen, &log, false, &tv);
}
}
static void
rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
struct timeval *tv, uint32_t flags_on_entry)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
log.u_bbr.flex3 = flags_on_entry;
log.u_bbr.flex4 = us_cts;
if (rack->rack_no_prr)
log.u_bbr.flex5 = 0;
else
log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
log.u_bbr.flex7 = hpts_removed;
log.u_bbr.flex8 = 1;
log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
log.u_bbr.timeStamp = us_cts;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERCANC, 0,
0, &log, false, tv);
}
}
static void
rack_log_alt_to_to_cancel(struct tcp_rack *rack,
uint32_t flex1, uint32_t flex2,
uint32_t flex3, uint32_t flex4,
uint32_t flex5, uint32_t flex6,
uint16_t flex7, uint8_t mod)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
if (mod == 1) {
/* No you can't use 1, its for the real to cancel */
return;
}
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.flex1 = flex1;
log.u_bbr.flex2 = flex2;
log.u_bbr.flex3 = flex3;
log.u_bbr.flex4 = flex4;
log.u_bbr.flex5 = flex5;
log.u_bbr.flex6 = flex6;
log.u_bbr.flex7 = flex7;
log.u_bbr.flex8 = mod;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TIMERCANC, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = timers;
log.u_bbr.flex2 = ret;
log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
log.u_bbr.flex5 = cts;
if (rack->rack_no_prr)
log.u_bbr.flex6 = 0;
else
log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_TO_PROCESS, 0,
0, &log, false, &tv);
}
}
static void
rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
if (rack->rack_no_prr)
log.u_bbr.flex3 = 0;
else
log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
log.u_bbr.flex8 = frm;
log.u_bbr.pkts_out = orig_cwnd;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_BBRUPD, 0,
0, &log, false, &tv);
}
}
#ifdef NETFLIX_EXP_DETECTION
static void
rack_log_sad(struct tcp_rack *rack, int event)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = rack->r_ctl.sack_count;
log.u_bbr.flex2 = rack->r_ctl.ack_count;
log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
log.u_bbr.lt_epoch = (tcp_force_detection << 8);
log.u_bbr.lt_epoch |= rack->do_detection;
log.u_bbr.applimited = tcp_map_minimum;
log.u_bbr.flex7 = rack->sack_attack_disable;
log.u_bbr.flex8 = event;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.delivered = tcp_sad_decay_val;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_SAD_DETECTION, 0,
0, &log, false, &tv);
}
}
#endif
static void
rack_counter_destroy(void)
{
counter_u64_free(rack_ack_total);
counter_u64_free(rack_express_sack);
counter_u64_free(rack_sack_total);
counter_u64_free(rack_move_none);
counter_u64_free(rack_move_some);
counter_u64_free(rack_sack_attacks_detected);
counter_u64_free(rack_sack_attacks_reversed);
counter_u64_free(rack_sack_used_next_merge);
counter_u64_free(rack_sack_used_prev_merge);
counter_u64_free(rack_badfr);
counter_u64_free(rack_badfr_bytes);
counter_u64_free(rack_rtm_prr_retran);
counter_u64_free(rack_rtm_prr_newdata);
counter_u64_free(rack_timestamp_mismatch);
counter_u64_free(rack_find_high);
counter_u64_free(rack_reorder_seen);
counter_u64_free(rack_tlp_tot);
counter_u64_free(rack_tlp_newdata);
counter_u64_free(rack_tlp_retran);
counter_u64_free(rack_tlp_retran_bytes);
counter_u64_free(rack_tlp_retran_fail);
counter_u64_free(rack_to_tot);
counter_u64_free(rack_to_arm_rack);
counter_u64_free(rack_to_arm_tlp);
counter_u64_free(rack_calc_zero);
counter_u64_free(rack_calc_nonzero);
counter_u64_free(rack_paced_segments);
counter_u64_free(rack_unpaced_segments);
counter_u64_free(rack_saw_enobuf);
counter_u64_free(rack_saw_enetunreach);
counter_u64_free(rack_to_alloc);
counter_u64_free(rack_to_alloc_hard);
counter_u64_free(rack_to_alloc_emerg);
counter_u64_free(rack_to_alloc_limited);
counter_u64_free(rack_alloc_limited_conns);
counter_u64_free(rack_split_limited);
counter_u64_free(rack_sack_proc_all);
counter_u64_free(rack_sack_proc_restart);
counter_u64_free(rack_sack_proc_short);
counter_u64_free(rack_enter_tlp_calc);
counter_u64_free(rack_used_tlpmethod);
counter_u64_free(rack_used_tlpmethod2);
counter_u64_free(rack_sack_skipped_acked);
counter_u64_free(rack_sack_splits);
counter_u64_free(rack_progress_drops);
counter_u64_free(rack_input_idle_reduces);
counter_u64_free(rack_collapsed_win);
counter_u64_free(rack_tlp_does_nada);
counter_u64_free(rack_try_scwnd);
counter_u64_free(rack_per_timer_hole);
COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
}
static struct rack_sendmap *
rack_alloc(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
rsm = uma_zalloc(rack_zone, M_NOWAIT);
if (rsm) {
rack->r_ctl.rc_num_maps_alloced++;
counter_u64_add(rack_to_alloc, 1);
return (rsm);
}
if (rack->rc_free_cnt) {
counter_u64_add(rack_to_alloc_emerg, 1);
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
rack->rc_free_cnt--;
return (rsm);
}
return (NULL);
}
static struct rack_sendmap *
rack_alloc_full_limit(struct tcp_rack *rack)
{
if ((V_tcp_map_entries_limit > 0) &&
(rack->do_detection == 0) &&
(rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
counter_u64_add(rack_to_alloc_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
return (NULL);
}
return (rack_alloc(rack));
}
/* wrapper to allocate a sendmap entry, subject to a specific limit */
static struct rack_sendmap *
rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
{
struct rack_sendmap *rsm;
if (limit_type) {
/* currently there is only one limit type */
if (V_tcp_map_split_limit > 0 &&
(rack->do_detection == 0) &&
rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
counter_u64_add(rack_split_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
return (NULL);
}
}
/* allocate and mark in the limit type, if set */
rsm = rack_alloc(rack);
if (rsm != NULL && limit_type) {
rsm->r_limit_type = limit_type;
rack->r_ctl.rc_num_split_allocs++;
}
return (rsm);
}
static void
rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
if (rsm->r_flags & RACK_APP_LIMITED) {
if (rack->r_ctl.rc_app_limited_cnt > 0) {
rack->r_ctl.rc_app_limited_cnt--;
}
}
if (rsm->r_limit_type) {
/* currently there is only one limit type */
rack->r_ctl.rc_num_split_allocs--;
}
if (rsm == rack->r_ctl.rc_first_appl) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_first_appl = NULL;
else {
/* Follow the next one out */
struct rack_sendmap fe;
fe.r_start = rsm->r_nseq_appl;
rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
}
}
if (rsm == rack->r_ctl.rc_resend)
rack->r_ctl.rc_resend = NULL;
if (rsm == rack->r_ctl.rc_rsm_at_retran)
rack->r_ctl.rc_rsm_at_retran = NULL;
if (rsm == rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl = NULL;
if (rack->r_ctl.rc_tlpsend == rsm)
rack->r_ctl.rc_tlpsend = NULL;
if (rack->r_ctl.rc_sacklast == rsm)
rack->r_ctl.rc_sacklast = NULL;
if (rack->rc_free_cnt < rack_free_cache) {
memset(rsm, 0, sizeof(struct rack_sendmap));
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
rsm->r_limit_type = 0;
rack->rc_free_cnt++;
return;
}
rack->r_ctl.rc_num_maps_alloced--;
uma_zfree(rack_zone, rsm);
}
static uint32_t
rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
{
uint64_t srtt, bw, len, tim;
uint32_t segsiz, def_len, minl;
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
def_len = rack_def_data_window * segsiz;
if (rack->rc_gp_filled == 0) {
/*
* We have no measurement (IW is in flight?) so
* we can only guess using our data_window sysctl
* value (usually 100MSS).
*/
return (def_len);
}
/*
* Now we have a number of factors to consider.
*
* 1) We have a desired BDP which is usually
* at least 2.
* 2) We have a minimum number of rtt's usually 1 SRTT
* but we allow it too to be more.
* 3) We want to make sure a measurement last N useconds (if
* we have set rack_min_measure_usec.
*
* We handle the first concern here by trying to create a data
* window of max(rack_def_data_window, DesiredBDP). The
* second concern we handle in not letting the measurement
* window end normally until at least the required SRTT's
* have gone by which is done further below in
* rack_enough_for_measurement(). Finally the third concern
* we also handle here by calculating how long that time
* would take at the current BW and then return the
* max of our first calculation and that length. Note
* that if rack_min_measure_usec is 0, we don't deal
* with concern 3. Also for both Concern 1 and 3 an
* application limited period could end the measurement
* earlier.
*
* So lets calculate the BDP with the "known" b/w using
* the SRTT has our rtt and then multiply it by the
* goal.
*/
bw = rack_get_bw(rack);
srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
len = bw * srtt;
len /= (uint64_t)HPTS_USEC_IN_SEC;
len *= max(1, rack_goal_bdp);
/* Now we need to round up to the nearest MSS */
len = roundup(len, segsiz);
if (rack_min_measure_usec) {
/* Now calculate our min length for this b/w */
tim = rack_min_measure_usec;
minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
if (minl == 0)
minl = 1;
minl = roundup(minl, segsiz);
if (len < minl)
len = minl;
}
/*
* Now if we have a very small window we want
* to attempt to get the window that is
* as small as possible. This happens on
* low b/w connections and we don't want to
* span huge numbers of rtt's between measurements.
*
* We basically include 2 over our "MIN window" so
* that the measurement can be shortened (possibly) by
* an ack'ed packet.
*/
if (len < def_len)
return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
else
return (max((uint32_t)len, def_len));
}
static int
rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack)
{
uint32_t tim, srtts, segsiz;
/*
* Has enough time passed for the GP measurement to be valid?
*/
if ((tp->snd_max == tp->snd_una) ||
(th_ack == tp->snd_max)){
/* All is acked */
return (1);
}
if (SEQ_LT(th_ack, tp->gput_seq)) {
/* Not enough bytes yet */
return (0);
}
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
if (SEQ_LT(th_ack, tp->gput_ack) &&
((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
/* Not enough bytes yet */
return (0);
}
if (rack->r_ctl.rc_first_appl &&
(rack->r_ctl.rc_first_appl->r_start == th_ack)) {
/*
* We are up to the app limited point
* we have to measure irrespective of the time..
*/
return (1);
}
/* Now what about time? */
srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
if (tim >= srtts) {
return (1);
}
/* Nope not even a full SRTT has passed */
return (0);
}
static void
rack_log_timely(struct tcp_rack *rack,
uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
uint64_t up_bnd, int line, uint8_t method)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = logged;
log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_incr;
log.u_bbr.flex2 <<= 4;
log.u_bbr.flex2 |= rack->rc_gp_bwred;
log.u_bbr.flex3 = rack->rc_gp_incr;
log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.flex7 = rack->rc_gp_bwred;
log.u_bbr.flex8 = method;
log.u_bbr.cur_del_rate = cur_bw;
log.u_bbr.delRate = low_bnd;
log.u_bbr.bw_inuse = up_bnd;
log.u_bbr.rttProp = rack_get_bw(rack);
log.u_bbr.pkt_epoch = line;
log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
log.u_bbr.lost = rack->r_ctl.rc_loss_count;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
TCP_TIMELY_WORK, 0,
0, &log, false, &tv);
}
}
static int
rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
{
/*
* Before we increase we need to know if
* the estimate just made was less than
* our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
*
* If we already are pacing at a fast enough
* rate to push us faster there is no sense of
* increasing.
*
* We first caculate our actual pacing rate (ss or ca multipler
* times our cur_bw).
*
* Then we take the last measured rate and multipy by our
* maximum pacing overage to give us a max allowable rate.
*
* If our act_rate is smaller than our max_allowable rate
* then we should increase. Else we should hold steady.
*
*/
uint64_t act_rate, max_allow_rate;
if (rack_timely_no_stopping)
return (1);
if ((cur_bw == 0) || (last_bw_est == 0)) {
/*
* Initial startup case or
* everything is acked case.
*/
rack_log_timely(rack, mult, cur_bw, 0, 0,
__LINE__, 9);
return (1);
}
if (mult <= 100) {
/*
* We can always pace at or slightly above our rate.
*/
rack_log_timely(rack, mult, cur_bw, 0, 0,
__LINE__, 9);
return (1);
}
act_rate = cur_bw * (uint64_t)mult;
act_rate /= 100;
max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
max_allow_rate /= 100;
if (act_rate < max_allow_rate) {
/*
* Here the rate we are actually pacing at
* is smaller than 10% above our last measurement.
* This means we are pacing below what we would
* like to try to achieve (plus some wiggle room).
*/
rack_log_timely(rack, mult, cur_bw, act_rate, max_allow_rate,
__LINE__, 9);
return (1);
} else {
/*
* Here we are already pacing at least rack_max_per_above(10%)
* what we are getting back. This indicates most likely
* that we are being limited (cwnd/rwnd/app) and can't
* get any more b/w. There is no sense of trying to
* raise up the pacing rate its not speeding us up
* and we already are pacing faster than we are getting.
*/
rack_log_timely(rack, mult, cur_bw, act_rate, max_allow_rate,
__LINE__, 8);
return (0);
}
}
static void
rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
{
/*
* When we drag bottom, we want to assure
* that no multiplier is below 1.0, if so
* we want to restore it to at least that.
*/
if (rack->r_ctl.rack_per_of_gp_rec < 100) {
/* This is unlikely we usually do not touch recovery */
rack->r_ctl.rack_per_of_gp_rec = 100;
}
if (rack->r_ctl.rack_per_of_gp_ca < 100) {
rack->r_ctl.rack_per_of_gp_ca = 100;
}
if (rack->r_ctl.rack_per_of_gp_ss < 100) {
rack->r_ctl.rack_per_of_gp_ss = 100;
}
}
static void
rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
{
if (rack->r_ctl.rack_per_of_gp_ca > 100) {
rack->r_ctl.rack_per_of_gp_ca = 100;
}
if (rack->r_ctl.rack_per_of_gp_ss > 100) {
rack->r_ctl.rack_per_of_gp_ss = 100;
}
}
static void
rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
{
int32_t calc, logged, plus;
logged = 0;
if (override) {
/*
* override is passed when we are
* loosing b/w and making one last
* gasp at trying to not loose out
* to a new-reno flow.
*/
goto extra_boost;
}
/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
if (rack->rc_gp_incr &&
((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
/*
* Reset and get 5 strokes more before the boost. Note
* that the count is 0 based so we have to add one.
*/
extra_boost:
plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
rack->rc_gp_timely_inc_cnt = 0;
} else
plus = (uint32_t)rack_gp_increase_per;
/* Must be at least 1% increase for true timely increases */
if ((plus < 1) &&
((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
plus = 1;
if (rack->rc_gp_saw_rec &&
(rack->rc_gp_no_rec_chg == 0) &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_rec)) {
/* We have been in recovery ding it too */
calc = rack->r_ctl.rack_per_of_gp_rec + plus;
if (calc > 0xffff)
calc = 0xffff;
logged |= 1;
rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
if (rack_per_upper_bound_ss &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
}
if (rack->rc_gp_saw_ca &&
(rack->rc_gp_saw_ss == 0) &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_ca)) {
/* In CA */
calc = rack->r_ctl.rack_per_of_gp_ca + plus;
if (calc > 0xffff)
calc = 0xffff;
logged |= 2;
rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
if (rack_per_upper_bound_ca &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
}
if (rack->rc_gp_saw_ss &&
rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
rack->r_ctl.rack_per_of_gp_ss)) {
/* In SS */
calc = rack->r_ctl.rack_per_of_gp_ss + plus;
if (calc > 0xffff)
calc = 0xffff;
rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
if (rack_per_upper_bound_ss &&
(rack->rc_dragged_bottom == 0) &&
(rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
logged |= 4;
}
if (logged &&
(rack->rc_gp_incr == 0)){
/* Go into increment mode */
rack->rc_gp_incr = 1;
rack->rc_gp_timely_inc_cnt = 0;
}
if (rack->rc_gp_incr &&
logged &&
(rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
rack->rc_gp_timely_inc_cnt++;
}
rack_log_timely(rack, logged, plus, 0, 0,
__LINE__, 1);
}
static uint32_t
rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
{
/*
* norm_grad = rtt_diff / minrtt;
* new_per = curper * (1 - B * norm_grad)
*
* B = rack_gp_decrease_per (default 10%)
* rtt_dif = input var current rtt-diff
* curper = input var current percentage
* minrtt = from rack filter
*
*/
uint64_t perf;
perf = (((uint64_t)curper * ((uint64_t)1000000 -
((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
(((uint64_t)rtt_diff * (uint64_t)1000000)/
(uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
(uint64_t)1000000)) /
(uint64_t)1000000);
if (perf > curper) {
/* TSNH */
perf = curper - 1;
}
return ((uint32_t)perf);
}
static uint32_t
rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
{
/*
* highrttthresh
* result = curper * (1 - (B * ( 1 - ------ ))
* gp_srtt
*
* B = rack_gp_decrease_per (default 10%)
* highrttthresh = filter_min * rack_gp_rtt_maxmul
*/
uint64_t perf;
uint32_t highrttthresh;
highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
perf = (((uint64_t)curper * ((uint64_t)1000000 -
((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
((uint64_t)highrttthresh * (uint64_t)1000000) /
(uint64_t)rtt)) / 100)) /(uint64_t)1000000);
return (perf);
}
static void
rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
{
uint64_t logvar, logvar2, logvar3;
uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
if (rack->rc_gp_incr) {
/* Turn off increment counting */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
}
ss_red = ca_red = rec_red = 0;
logged = 0;
/* Calculate the reduction value */
if (rtt_diff < 0) {
rtt_diff *= -1;
}
/* Must be at least 1% reduction */
if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
/* We have been in recovery ding it too */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_rec > val) {
rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
} else {
rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
rec_red = 0;
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
logged |= 1;
}
if (rack->rc_gp_saw_ss) {
/* Sent in SS */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
} else {
ss_red = new_per;
rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
logvar = new_per;
logvar <<= 32;
logvar |= alt;
logvar2 = (uint32_t)rtt;
logvar2 <<= 32;
logvar2 |= (uint32_t)rtt_diff;
logvar3 = rack_gp_rtt_maxmul;
logvar3 <<= 32;
logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
rack_log_timely(rack, timely_says,
logvar2, logvar3,
logvar, __LINE__, 10);
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
logged |= 4;
} else if (rack->rc_gp_saw_ca) {
/* Sent in CA */
if (timely_says == 2) {
new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
if (alt < new_per)
val = alt;
else
val = new_per;
} else
val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
if (rack->r_ctl.rack_per_of_gp_ca > val) {
ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
} else {
rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
ca_red = 0;
logvar = new_per;
logvar <<= 32;
logvar |= alt;
logvar2 = (uint32_t)rtt;
logvar2 <<= 32;
logvar2 |= (uint32_t)rtt_diff;
logvar3 = rack_gp_rtt_maxmul;
logvar3 <<= 32;
logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
rack_log_timely(rack, timely_says,
logvar2, logvar3,
logvar, __LINE__, 10);
}
if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
logged |= 2;
}
if (rack->rc_gp_timely_dec_cnt < 0x7) {
rack->rc_gp_timely_dec_cnt++;
if (rack_timely_dec_clear &&
(rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
rack->rc_gp_timely_dec_cnt = 0;
}
logvar = ss_red;
logvar <<= 32;
logvar |= ca_red;
rack_log_timely(rack, logged, rec_red, rack_per_lower_bound, logvar,
__LINE__, 2);
}
static void
rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
uint32_t rtt, uint32_t line, uint8_t reas)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = line;
log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex5 = rtt;
log.u_bbr.flex6 = rack->rc_highly_buffered;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->forced_ack;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->in_probe_rtt;
log.u_bbr.flex6 <<= 1;
log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.flex8 = reas;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.delRate = rack_get_bw(rack);
log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
log.u_bbr.cur_del_rate <<= 32;
log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
log.u_bbr.rttProp = us_cts;
log.u_bbr.rttProp <<= 32;
log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_RTT_SHRINKS, 0,
0, &log, false, &rack->r_ctl.act_rcv_time);
}
}
static void
rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
{
uint64_t bwdp;
bwdp = rack_get_bw(rack);
bwdp *= (uint64_t)rtt;
bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
/*
* A window protocol must be able to have 4 packets
* outstanding as the floor in order to function
* (especially considering delayed ack :D).
*/
rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
}
}
static void
rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
{
/**
* ProbeRTT is a bit different in rack_pacing than in
* BBR. It is like BBR in that it uses the lowering of
* the RTT as a signal that we saw something new and
* counts from there for how long between. But it is
* different in that its quite simple. It does not
* play with the cwnd and wait until we get down
* to N segments outstanding and hold that for
* 200ms. Instead it just sets the pacing reduction
* rate to a set percentage (70 by default) and hold
* that for a number of recent GP Srtt's.
*/
uint32_t segsiz;
if (rack->rc_gp_dyn_mul == 0)
return;
if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
/* We are idle */
return;
}
if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
/*
* Stop the goodput now, the idea here is
* that future measurements with in_probe_rtt
* won't register if they are not greater so
* we want to get what info (if any) is available
* now.
*/
rack_do_goodput_measurement(rack->rc_tp, rack,
rack->rc_tp->snd_una, __LINE__);
}
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
rack->r_ctl.rc_time_probertt_entered = us_cts;
segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
rack->r_ctl.rc_pace_min_segs);
rack->in_probe_rtt = 1;
rack->measure_saw_probe_rtt = 1;
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_starts = 0;
rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
if (rack_probertt_use_min_rtt_entry)
rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
else
rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
rack_log_rtt_shrinks(rack, us_cts, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_ENTERPROBE);
}
static void
rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
{
struct rack_sendmap *rsm;
uint32_t segsiz;
segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
rack->r_ctl.rc_pace_min_segs);
rack->in_probe_rtt = 0;
if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
/*
* Stop the goodput now, the idea here is
* that future measurements with in_probe_rtt
* won't register if they are not greater so
* we want to get what info (if any) is available
* now.
*/
rack_do_goodput_measurement(rack->rc_tp, rack,
rack->rc_tp->snd_una, __LINE__);
} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
/*
* We don't have enough data to make a measurement.
* So lets just stop and start here after exiting
* probe-rtt. We probably are not interested in
* the results anyway.
*/
rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
}
/*
* Measurements through the current snd_max are going
* to be limited by the slower pacing rate.
*
* We need to mark these as app-limited so we
* don't collapse the b/w.
*/
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
else {
/*
* Go out to the end app limited and mark
* this new one as next and move the end_appl up
* to this guy.
*/
if (rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
rack->r_ctl.rc_end_appl = rsm;
}
rsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
/*
* Now, we need to examine our pacing rate multipliers.
* If its under 100%, we need to kick it back up to
* 100%. We also don't let it be over our "max" above
* the actual rate i.e. 100% + rack_clamp_atexit_prtt.
* Note setting clamp_atexit_prtt to 0 has the effect
* of setting CA/SS to 100% always at exit (which is
* the default behavior).
*/
if (rack_probertt_clear_is) {
rack->rc_gp_incr = 0;
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_inc_cnt = 0;
rack->rc_gp_timely_dec_cnt = 0;
}
/* Do we do any clamping at exit? */
if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
}
if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
}
/*
* Lets set rtt_diff to 0, so that we will get a "boost"
* after exiting.
*/
rack->r_ctl.rc_rtt_diff = 0;
/* Clear all flags so we start fresh */
rack->rc_tp->t_bytes_acked = 0;
rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
/*
* If configured to, set the cwnd and ssthresh to
* our targets.
*/
if (rack_probe_rtt_sets_cwnd) {
uint64_t ebdp;
uint32_t setto;
/* Set ssthresh so we get into CA once we hit our target */
if (rack_probertt_use_min_rtt_exit == 1) {
/* Set to min rtt */
rack_set_prtt_target(rack, segsiz,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
} else if (rack_probertt_use_min_rtt_exit == 2) {
/* Set to current gp rtt */
rack_set_prtt_target(rack, segsiz,
rack->r_ctl.rc_gp_srtt);
} else if (rack_probertt_use_min_rtt_exit == 3) {
/* Set to entry gp rtt */
rack_set_prtt_target(rack, segsiz,
rack->r_ctl.rc_entry_gp_rtt);
} else {
uint64_t sum;
uint32_t setval;
sum = rack->r_ctl.rc_entry_gp_rtt;
sum *= 10;
sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
if (sum >= 20) {
/*
* A highly buffered path needs
* cwnd space for timely to work.
* Lets set things up as if
* we are heading back here again.
*/
setval = rack->r_ctl.rc_entry_gp_rtt;
} else if (sum >= 15) {
/*
* Lets take the smaller of the
* two since we are just somewhat
* buffered.
*/
setval = rack->r_ctl.rc_gp_srtt;
if (setval > rack->r_ctl.rc_entry_gp_rtt)
setval = rack->r_ctl.rc_entry_gp_rtt;
} else {
/*
* Here we are not highly buffered
* and should pick the min we can to
* keep from causing loss.
*/
setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
}
rack_set_prtt_target(rack, segsiz,
setval);
}
if (rack_probe_rtt_sets_cwnd > 1) {
/* There is a percentage here to boost */
ebdp = rack->r_ctl.rc_target_probertt_flight;
ebdp *= rack_probe_rtt_sets_cwnd;
ebdp /= 100;
setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
} else
setto = rack->r_ctl.rc_target_probertt_flight;
rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
/* Enforce a min */
rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
}
/* If we set in the cwnd also set the ssthresh point so we are in CA */
rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
}
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_EXITPROBE);
/* Clear times last so log has all the info */
rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
rack->r_ctl.rc_time_probertt_entered = us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_of_last_probertt = us_cts;
}
static void
rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
{
/* Check in on probe-rtt */
if (rack->rc_gp_filled == 0) {
/* We do not do p-rtt unless we have gp measurements */
return;
}
if (rack->in_probe_rtt) {
uint64_t no_overflow;
uint32_t endtime, must_stay;
if (rack->r_ctl.rc_went_idle_time &&
((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
/*
* We went idle during prtt, just exit now.
*/
rack_exit_probertt(rack, us_cts);
} else if (rack_probe_rtt_safety_val &&
TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
/*
* Probe RTT safety value triggered!
*/
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_SAFETY);
rack_exit_probertt(rack, us_cts);
}
/* Calculate the max we will wait */
endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
if (rack->rc_highly_buffered)
endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
/* Calculate the min we must wait */
must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
TSTMP_LT(us_cts, endtime)) {
uint32_t calc;
/* Do we lower more? */
no_exit:
if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
else
calc = 0;
calc /= max(rack->r_ctl.rc_gp_srtt, 1);
if (calc) {
/* Maybe */
calc *= rack_per_of_gp_probertt_reduce;
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
/* Limit it too */
if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
}
/* We must reach target or the time set */
return;
}
if (rack->r_ctl.rc_time_probertt_starts == 0) {
if ((TSTMP_LT(us_cts, must_stay) &&
rack->rc_highly_buffered) ||
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
rack->r_ctl.rc_target_probertt_flight)) {
/* We are not past the must_stay time */
goto no_exit;
}
rack_log_rtt_shrinks(rack, us_cts,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
__LINE__, RACK_RTTS_REACHTARGET);
rack->r_ctl.rc_time_probertt_starts = us_cts;
if (rack->r_ctl.rc_time_probertt_starts == 0)
rack->r_ctl.rc_time_probertt_starts = 1;
/* Restore back to our rate we want to pace at in prtt */
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
}
/*
* Setup our end time, some number of gp_srtts plus 200ms.
*/
no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
(uint64_t)rack_probertt_gpsrtt_cnt_mul);
if (rack_probertt_gpsrtt_cnt_div)
endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
else
endtime = 0;
endtime += rack_min_probertt_hold;
endtime += rack->r_ctl.rc_time_probertt_starts;
if (TSTMP_GEQ(us_cts, endtime)) {
/* yes, exit probertt */
rack_exit_probertt(rack, us_cts);
}
} else if((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
/* Go into probertt, its been too long since we went lower */
rack_enter_probertt(rack, us_cts);
}
}
static void
rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
uint32_t rtt, int32_t rtt_diff)
{
uint64_t cur_bw, up_bnd, low_bnd, subfr;
uint32_t losses;
if ((rack->rc_gp_dyn_mul == 0) ||
(rack->use_fixed_rate) ||
(rack->in_probe_rtt) ||
(rack->rc_always_pace == 0)) {
/* No dynamic GP multipler in play */
return;
}
losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
cur_bw = rack_get_bw(rack);
/* Calculate our up and down range */
up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
up_bnd /= 100;
up_bnd += rack->r_ctl.last_gp_comp_bw;
subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
subfr /= 100;
low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
/*
* This is the case where our RTT is above
* the max target and we have been configured
* to just do timely no bonus up stuff in that case.
*
* There are two configurations, set to 1, and we
* just do timely if we are over our max. If its
* set above 1 then we slam the multipliers down
* to 100 and then decrement per timely.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
if (rack->r_ctl.rc_no_push_at_mrtt > 1)
rack_validate_multipliers_at_or_below_100(rack);
rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
} else if ((last_bw_est < low_bnd) && !losses) {
/*
* We are decreasing this is a bit complicated this
* means we are loosing ground. This could be
* because another flow entered and we are competing
* for b/w with it. This will push the RTT up which
* makes timely unusable unless we want to get shoved
* into a corner and just be backed off (the age
* old problem with delay based CC).
*
* On the other hand if it was a route change we
* would like to stay somewhat contained and not
* blow out the buffers.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
rack->r_ctl.last_gp_comp_bw = cur_bw;
if (rack->rc_gp_bwred == 0) {
/* Go into reduction counting */
rack->rc_gp_bwred = 1;
rack->rc_gp_timely_dec_cnt = 0;
}
if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
(timely_says == 0)) {
/*
* Push another time with a faster pacing
* to try to gain back (we include override to
* get a full raise factor).
*/
if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
(rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
(timely_says == 0) ||
(rack_down_raise_thresh == 0)) {
/*
* Do an override up in b/w if we were
* below the threshold or if the threshold
* is zero we always do the raise.
*/
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
} else {
/* Log it stays the same */
rack_log_timely(rack, 0, last_bw_est, low_bnd, 0,
__LINE__, 11);
}
rack->rc_gp_timely_dec_cnt++;
/* We are not incrementing really no-count */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
} else {
/*
* Lets just use the RTT
* information and give up
* pushing.
*/
goto use_timely;
}
} else if ((timely_says != 2) &&
!losses &&
(last_bw_est > up_bnd)) {
/*
* We are increasing b/w lets keep going, updating
* our b/w and ignoring any timely input, unless
* of course we are at our max raise (if there is one).
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
rack->r_ctl.last_gp_comp_bw = cur_bw;
if (rack->rc_gp_saw_ss &&
rack_per_upper_bound_ss &&
(rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
/*
* In cases where we can't go higher
* we should just use timely.
*/
goto use_timely;
}
if (rack->rc_gp_saw_ca &&
rack_per_upper_bound_ca &&
(rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
/*
* In cases where we can't go higher
* we should just use timely.
*/
goto use_timely;
}
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_dec_cnt = 0;
/* You get a set number of pushes if timely is trying to reduce */
if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
} else {
/* Log it stays the same */
rack_log_timely(rack, 0, last_bw_est, up_bnd, 0,
__LINE__, 12);
}
return;
} else {
/*
* We are staying between the lower and upper range bounds
* so use timely to decide.
*/
rack_log_timely(rack, timely_says, cur_bw, low_bnd, up_bnd,
__LINE__, 3);
use_timely:
if (timely_says) {
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
!losses &&
(last_bw_est < low_bnd)) {
/* We are loosing ground */
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
rack->rc_gp_timely_dec_cnt++;
/* We are not incrementing really no-count */
rack->rc_gp_incr = 0;
rack->rc_gp_timely_inc_cnt = 0;
} else
rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
} else {
rack->rc_gp_bwred = 0;
rack->rc_gp_timely_dec_cnt = 0;
rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
}
}
}
static int32_t
rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
{
int32_t timely_says;
uint64_t log_mult, log_rtt_a_diff;
log_rtt_a_diff = rtt;
log_rtt_a_diff <<= 32;
log_rtt_a_diff |= (uint32_t)rtt_diff;
if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
rack_gp_rtt_maxmul)) {
/* Reduce the b/w multipler */
timely_says = 2;
log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
log_mult <<= 32;
log_mult |= prev_rtt;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
log_rtt_a_diff, __LINE__, 4);
} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
max(rack_gp_rtt_mindiv , 1)))) {
/* Increase the b/w multipler */
log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
max(rack_gp_rtt_mindiv , 1));
log_mult <<= 32;
log_mult |= prev_rtt;
timely_says = 0;
rack_log_timely(rack, timely_says, log_mult ,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
log_rtt_a_diff, __LINE__, 5);
} else {
/*
* Use a gradient to find it the timely gradient
* is:
* grad = rc_rtt_diff / min_rtt;
*
* anything below or equal to 0 will be
* a increase indication. Anything above
* zero is a decrease. Note we take care
* of the actual gradient calculation
* in the reduction (its not needed for
* increase).
*/
log_mult = prev_rtt;
if (rtt_diff <= 0) {
/*
* Rttdiff is less than zero, increase the
* b/w multipler (its 0 or negative)
*/
timely_says = 0;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
} else {
/* Reduce the b/w multipler */
timely_says = 1;
rack_log_timely(rack, timely_says, log_mult,
get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
}
}
return (timely_says);
}
static void
rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq th_ack, int line)
{
uint64_t tim, bytes_ps, ltim, stim, utim;
uint32_t segsiz, bytes, reqbytes, us_cts;
int32_t gput, new_rtt_diff, timely_says;
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
if (TSTMP_GEQ(us_cts, tp->gput_ts))
tim = us_cts - tp->gput_ts;
else
tim = 0;
if (TSTMP_GT(rack->r_ctl.rc_gp_cumack_ts, rack->r_ctl.rc_gp_output_ts))
stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
else
stim = 0;
/*
* Use the larger of the send time or ack time. This prevents us
* from being influenced by ack artifacts to come up with too
* high of measurement. Note that since we are spanning over many more
* bytes in most of our measurements hopefully that is less likely to
* occur.
*/
if (tim > stim)
utim = max(tim, 1);
else
utim = max(stim, 1);
/* Lets validate utim */
ltim = max(1, (utim/HPTS_USEC_IN_MSEC));
gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
if ((tim == 0) && (stim == 0)) {
/*
* Invalid measurement time, maybe
* all on one ack/one send?
*/
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
/* We never made a us_rtt measurement? */
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
/*
* Calculate the maximum possible b/w this connection
* could have. We base our calculation on the lowest
* rtt we have seen during the measurement and the
* largest rwnd the client has given us in that time. This
* forms a BDP that is the maximum that we could ever
* get to the client. Anything larger is not valid.
*
* I originally had code here that rejected measurements
* where the time was less than 1/2 the latest us_rtt.
* But after thinking on that I realized its wrong since
* say you had a 150Mbps or even 1Gbps link, and you
* were a long way away.. example I am in Europe (100ms rtt)
* talking to my 1Gbps link in S.C. Now measuring say 150,000
* bytes my time would be 1.2ms, and yet my rtt would say
* the measurement was invalid the time was < 50ms. The
* same thing is true for 150Mb (8ms of time).
*
* A better way I realized is to look at what the maximum
* the connection could possibly do. This is gated on
* the lowest RTT we have seen and the highest rwnd.
* We should in theory never exceed that, if we are
* then something on the path is storing up packets
* and then feeding them all at once to our endpoint
* messing up our measurement.
*/
rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
if (SEQ_LT(th_ack, tp->gput_seq)) {
/* No measurement can be made */
bytes = 0;
bytes_ps = 0;
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
0, 0, 0, 10, __LINE__, NULL);
goto skip_measurement;
} else
bytes = (th_ack - tp->gput_seq);
bytes_ps = (uint64_t)bytes;
/*
* Don't measure a b/w for pacing unless we have gotten at least
* an initial windows worth of data in this measurement interval.
*
* Small numbers of bytes get badly influenced by delayed ack and
* other artifacts. Note we take the initial window or our
* defined minimum GP (defaulting to 10 which hopefully is the
* IW).
*/
if (rack->rc_gp_filled == 0) {
/*
* The initial estimate is special. We
* have blasted out an IW worth of packets
* without a real valid ack ts results. We
* then setup the app_limited_needs_set flag,
* this should get the first ack in (probably 2
* MSS worth) to be recorded as the timestamp.
* We thus allow a smaller number of bytes i.e.
* IW - 2MSS.
*/
reqbytes -= (2 * segsiz);
/* Also lets fill previous for our first measurement to be neutral */
rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
}
if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
rack->r_ctl.rc_app_limited_cnt,
0, 0, 10, __LINE__, NULL);
goto skip_measurement;
}
/*
* We now need to calculate the Timely like status so
* we can update (possibly) the b/w multipliers.
*/
new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
if (rack->rc_gp_filled == 0) {
/* No previous reading */
rack->r_ctl.rc_rtt_diff = new_rtt_diff;
} else {
if (rack->measure_saw_probe_rtt == 0) {
/*
* We don't want a probertt to be counted
* since it will be negative incorrectly. We
* expect to be reducing the RTT when we
* pace at a slower rate.
*/
rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
}
}
timely_says = rack_make_timely_judgement(rack,
rack->r_ctl.rc_gp_srtt,
rack->r_ctl.rc_rtt_diff,
rack->r_ctl.rc_prev_gp_srtt
);
bytes_ps *= HPTS_USEC_IN_SEC;
bytes_ps /= utim;
if (bytes_ps > rack->r_ctl.last_max_bw) {
/*
* Something is on path playing
* since this b/w is not possible based
* on our BDP (highest rwnd and lowest rtt
* we saw in the measurement window).
*
* Another option here would be to
* instead skip the measurement.
*/
rack_log_pacing_delay_calc(rack, bytes, reqbytes,
bytes_ps, rack->r_ctl.last_max_bw, 0,
11, __LINE__, NULL);
bytes_ps = rack->r_ctl.last_max_bw;
}
/* We store gp for b/w in bytes per second */
if (rack->rc_gp_filled == 0) {
/* Initial measurment */
if (bytes_ps) {
rack->r_ctl.gp_bw = bytes_ps;
rack->rc_gp_filled = 1;
rack->r_ctl.num_avg = 1;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else {
rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
rack->r_ctl.rc_app_limited_cnt,
0, 0, 10, __LINE__, NULL);
}
if (rack->rc_inp->inp_in_hpts &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/*
* Ok we can't trust the pacer in this case
* where we transition from un-paced to paced.
* Or for that matter when the burst mitigation
* was making a wild guess and got it wrong.
* Stop the pacer and clear up all the aggregate
* delays etc.
*/
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack->r_ctl.rc_hpts_flags = 0;
rack->r_ctl.rc_last_output_to = 0;
}
} else if (rack->r_ctl.num_avg < RACK_REQ_AVG) {
/* Still a small number run an average */
rack->r_ctl.gp_bw += bytes_ps;
rack->r_ctl.num_avg++;
if (rack->r_ctl.num_avg >= RACK_REQ_AVG) {
/* We have collected enought to move forward */
rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_avg;
}
} else {
/*
* We want to take 1/wma of the goodput and add in to 7/8th
* of the old value weighted by the srtt. So if your measurement
* period is say 2 SRTT's long you would get 1/4 as the
* value, if it was like 1/2 SRTT then you would get 1/16th.
*
* But we must be careful not to take too much i.e. if the
* srtt is say 20ms and the measurement is taken over
* 400ms our weight would be 400/20 i.e. 20. On the
* other hand if we get a measurement over 1ms with a
* 10ms rtt we only want to take a much smaller portion.
*/
uint64_t resid_bw, subpart, addpart, srtt;
srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
if (srtt == 0) {
/*
* Strange why did t_srtt go back to zero?
*/
if (rack->r_ctl.rc_rack_min_rtt)
srtt = (rack->r_ctl.rc_rack_min_rtt * HPTS_USEC_IN_MSEC);
else
srtt = HPTS_USEC_IN_MSEC;
}
/*
* XXXrrs: Note for reviewers, in playing with
* dynamic pacing I discovered this GP calculation
* as done originally leads to some undesired results.
* Basically you can get longer measurements contributing
* too much to the WMA. Thus I changed it if you are doing
* dynamic adjustments to only do the aportioned adjustment
* if we have a very small (time wise) measurement. Longer
* measurements just get there weight (defaulting to 1/8)
* add to the WMA. We may want to think about changing
* this to always do that for both sides i.e. dynamic
* and non-dynamic... but considering lots of folks
* were playing with this I did not want to change the
* calculation per.se. without your thoughts.. Lawerence?
* Peter??
*/
if (rack->rc_gp_dyn_mul == 0) {
subpart = rack->r_ctl.gp_bw * utim;
subpart /= (srtt * 8);
if (subpart < (rack->r_ctl.gp_bw / 2)) {
/*
* The b/w update takes no more
* away then 1/2 our running total
* so factor it in.
*/
addpart = bytes_ps * utim;
addpart /= (srtt * 8);
} else {
/*
* Don't allow a single measurement
* to account for more than 1/2 of the
* WMA. This could happen on a retransmission
* where utim becomes huge compared to
* srtt (multiple retransmissions when using
* the sending rate which factors in all the
* transmissions from the first one).
*/
subpart = rack->r_ctl.gp_bw / 2;
addpart = bytes_ps / 2;
}
resid_bw = rack->r_ctl.gp_bw - subpart;
rack->r_ctl.gp_bw = resid_bw + addpart;
} else {
if ((utim / srtt) <= 1) {
/*
* The b/w update was over a small period
* of time. The idea here is to prevent a small
* measurement time period from counting
* too much. So we scale it based on the
* time so it attributes less than 1/rack_wma_divisor
* of its measurement.
*/
subpart = rack->r_ctl.gp_bw * utim;
subpart /= (srtt * rack_wma_divisor);
addpart = bytes_ps * utim;
addpart /= (srtt * rack_wma_divisor);
} else {
/*
* The scaled measurement was long
* enough so lets just add in the
* portion of the measurment i.e. 1/rack_wma_divisor
*/
subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
addpart = bytes_ps / rack_wma_divisor;
}
if ((rack->measure_saw_probe_rtt == 0) ||
(bytes_ps > rack->r_ctl.gp_bw)) {
/*
* For probe-rtt we only add it in
* if its larger, all others we just
* add in.
*/
resid_bw = rack->r_ctl.gp_bw - subpart;
rack->r_ctl.gp_bw = resid_bw + addpart;
}
}
}
/* We do not update any multipliers if we are in or have seen a probe-rtt */
if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
rack_update_multiplier(rack, timely_says, bytes_ps,
rack->r_ctl.rc_gp_srtt,
rack->r_ctl.rc_rtt_diff);
rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
rack_get_bw(rack), 3, line, NULL);
/* reset the gp srtt and setup the new prev */
rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
/* Record the lost count for the next measurement */
rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
/*
* We restart our diffs based on the gpsrtt in the
* measurement window.
*/
rack->rc_gp_rtt_set = 0;
rack->rc_gp_saw_rec = 0;
rack->rc_gp_saw_ca = 0;
rack->rc_gp_saw_ss = 0;
rack->rc_dragged_bottom = 0;
skip_measurement:
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
gput);
/*
* XXXLAS: This is a temporary hack, and should be
* chained off VOI_TCP_GPUT when stats(9) grows an
* API to deal with chained VOIs.
*/
if (tp->t_stats_gput_prev > 0)
stats_voi_update_abs_s32(tp->t_stats,
VOI_TCP_GPUT_ND,
((gput - tp->t_stats_gput_prev) * 100) /
tp->t_stats_gput_prev);
#endif
tp->t_flags &= ~TF_GPUTINPROG;
tp->t_stats_gput_prev = gput;
/*
* Now are we app limited now and there is space from where we
* were to where we want to go?
*
* We don't do the other case i.e. non-applimited here since
* the next send will trigger us picking up the missing data.
*/
if (rack->r_ctl.rc_first_appl &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
rack->r_ctl.rc_app_limited_cnt &&
(SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
((rack->r_ctl.rc_first_appl->r_start - th_ack) >
max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
/*
* Yep there is enough outstanding to make a measurement here.
*/
struct rack_sendmap *rsm, fe;
tp->t_flags |= TF_GPUTINPROG;
rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rack->app_limited_needs_set = 0;
tp->gput_seq = th_ack;
if (rack->in_probe_rtt)
rack->measure_saw_probe_rtt = 1;
else if ((rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
if ((rack->r_ctl.rc_first_appl->r_start - th_ack) >= rack_get_measure_window(tp, rack)) {
/* There is a full window to gain info from */
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
} else {
/* We can only measure up to the applimited point */
tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_start - th_ack);
}
/*
* Now we need to find the timestamp of the send at tp->gput_seq
* for the send based measurement.
*/
fe.r_start = tp->gput_seq;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm) {
/* Ok send-based limit is set */
if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
/*
* Move back to include the earlier part
* so our ack time lines up right (this may
* make an overlapping measurement but thats
* ok).
*/
tp->gput_seq = rsm->r_start;
}
if (rsm->r_flags & RACK_ACKED)
tp->gput_ts = rsm->r_ack_arrival;
else
rack->app_limited_needs_set = 1;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
} else {
/*
* If we don't find the rsm due to some
* send-limit set the current time, which
* basically disables the send-limit.
*/
rack->r_ctl.rc_gp_output_ts = tcp_get_usecs(NULL);
}
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
}
}
/*
* CC wrapper hook functions
*/
static void
rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, struct tcphdr *th, uint16_t nsegs,
uint16_t type, int32_t recovery)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
tp->ccv->nsegs = nsegs;
tp->ccv->bytes_this_ack = BYTES_THIS_ACK(tp, th);
if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
uint32_t max;
max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
if (tp->ccv->bytes_this_ack > max) {
tp->ccv->bytes_this_ack = max;
}
}
if (rack->r_ctl.cwnd_to_use <= tp->snd_wnd)
tp->ccv->flags |= CCF_CWND_LIMITED;
else
tp->ccv->flags &= ~CCF_CWND_LIMITED;
#ifdef STATS
stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
#endif
if ((tp->t_flags & TF_GPUTINPROG) &&
rack_enough_for_measurement(tp, rack, th->th_ack)) {
/* Measure the Goodput */
rack_do_goodput_measurement(tp, rack, th->th_ack, __LINE__);
#ifdef NETFLIX_PEAKRATE
if ((type == CC_ACK) &&
(tp->t_maxpeakrate)) {
/*
* We update t_peakrate_thr. This gives us roughly
* one update per round trip time. Note
* it will only be used if pace_always is off i.e
* we don't do this for paced flows.
*/
tcp_update_peakrate_thr(tp);
}
#endif
}
if (rack->r_ctl.cwnd_to_use > tp->snd_ssthresh) {
tp->t_bytes_acked += tp->ccv->bytes_this_ack;
if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
tp->ccv->flags |= CCF_ABC_SENTAWND;
}
} else {
tp->ccv->flags &= ~CCF_ABC_SENTAWND;
tp->t_bytes_acked = 0;
}
if (CC_ALGO(tp)->ack_received != NULL) {
/* XXXLAS: Find a way to live without this */
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->ack_received(tp->ccv, type);
}
#ifdef STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
#endif
if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
}
#ifdef NETFLIX_PEAKRATE
/* we enforce max peak rate if it is set and we are not pacing */
if ((rack->rc_always_pace == 0) &&
tp->t_peakrate_thr &&
(tp->snd_cwnd > tp->t_peakrate_thr)) {
tp->snd_cwnd = tp->t_peakrate_thr;
}
#endif
}
static void
tcp_rack_partialack(struct tcpcb *tp, struct tcphdr *th)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* If we are doing PRR and have enough
* room to send <or> we are pacing and prr
* is disabled we will want to see if we
* can send data (by setting r_wanted_output to
* true).
*/
if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
rack->rack_no_prr)
rack->r_wanted_output = 1;
}
static void
rack_post_recovery(struct tcpcb *tp, struct tcphdr *th)
{
struct tcp_rack *rack;
uint32_t orig_cwnd;
orig_cwnd = tp->snd_cwnd;
INP_WLOCK_ASSERT(tp->t_inpcb);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_not_backing_off == 0) {
/* only alert CC if we alerted when we entered */
if (CC_ALGO(tp)->post_recovery != NULL) {
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->post_recovery(tp->ccv);
}
if (tp->snd_cwnd > tp->snd_ssthresh) {
/* Drop us down to the ssthresh (1/2 cwnd at loss) */
tp->snd_cwnd = tp->snd_ssthresh;
}
}
if ((rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt > 0)) {
/* Suck the next prr cnt back into cwnd */
tp->snd_cwnd += rack->r_ctl.rc_prr_sndcnt;
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 1, 0);
}
rack_log_to_prr(rack, 14, orig_cwnd);
tp->snd_recover = tp->snd_una;
EXIT_RECOVERY(tp->t_flags);
}
static void
rack_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type)
{
struct tcp_rack *rack;
INP_WLOCK_ASSERT(tp->t_inpcb);
rack = (struct tcp_rack *)tp->t_fb_ptr;
switch (type) {
case CC_NDUPACK:
tp->t_flags &= ~TF_WASFRECOVERY;
tp->t_flags &= ~TF_WASCRECOVERY;
if (!IN_FASTRECOVERY(tp->t_flags)) {
rack->r_ctl.rc_prr_delivered = 0;
rack->r_ctl.rc_prr_out = 0;
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 2, 0);
}
rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
tp->snd_recover = tp->snd_max;
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
}
break;
case CC_ECN:
if (!IN_CONGRECOVERY(tp->t_flags) ||
/*
* Allow ECN reaction on ACK to CWR, if
* that data segment was also CE marked.
*/
SEQ_GEQ(th->th_ack, tp->snd_recover)) {
EXIT_CONGRECOVERY(tp->t_flags);
KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
tp->snd_recover = tp->snd_max + 1;
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
}
break;
case CC_RTO:
tp->t_dupacks = 0;
tp->t_bytes_acked = 0;
EXIT_RECOVERY(tp->t_flags);
tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
tp->snd_cwnd = ctf_fixed_maxseg(tp);
if (tp->t_flags2 & TF2_ECN_PERMIT)
tp->t_flags2 |= TF2_ECN_SND_CWR;
break;
case CC_RTO_ERR:
KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
/* RTO was unnecessary, so reset everything. */
tp->snd_cwnd = tp->snd_cwnd_prev;
tp->snd_ssthresh = tp->snd_ssthresh_prev;
tp->snd_recover = tp->snd_recover_prev;
if (tp->t_flags & TF_WASFRECOVERY) {
ENTER_FASTRECOVERY(tp->t_flags);
tp->t_flags &= ~TF_WASFRECOVERY;
}
if (tp->t_flags & TF_WASCRECOVERY) {
ENTER_CONGRECOVERY(tp->t_flags);
tp->t_flags &= ~TF_WASCRECOVERY;
}
tp->snd_nxt = tp->snd_max;
tp->t_badrxtwin = 0;
break;
}
/*
* If we are below our max rtt, don't
* signal the CC control to change things.
* instead set it up so that we are in
* recovery but not going to back off.
*/
if (rack->rc_highly_buffered) {
/*
* Do we use the higher rtt for
* our threshold to not backoff (like CDG)?
*/
uint32_t rtt_mul, rtt_div;
if (rack_use_max_for_nobackoff) {
rtt_mul = (rack_gp_rtt_maxmul - 1);
rtt_div = 1;
} else {
rtt_mul = rack_gp_rtt_minmul;
rtt_div = max(rack_gp_rtt_mindiv , 1);
}
if (rack->r_ctl.rc_gp_srtt <= (rack->r_ctl.rc_lowest_us_rtt +
((rack->r_ctl.rc_lowest_us_rtt * rtt_mul) /
rtt_div))) {
/* below our min threshold */
rack->rc_not_backing_off = 1;
ENTER_RECOVERY(rack->rc_tp->t_flags);
rack_log_rtt_shrinks(rack, 0,
rtt_mul,
rtt_div,
RACK_RTTS_NOBACKOFF);
return;
}
}
rack->rc_not_backing_off = 0;
if (CC_ALGO(tp)->cong_signal != NULL) {
if (th != NULL)
tp->ccv->curack = th->th_ack;
CC_ALGO(tp)->cong_signal(tp->ccv, type);
}
}
static inline void
rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
{
uint32_t i_cwnd;
INP_WLOCK_ASSERT(tp->t_inpcb);
#ifdef NETFLIX_STATS
KMOD_TCPSTAT_INC(tcps_idle_restarts);
if (tp->t_state == TCPS_ESTABLISHED)
KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
#endif
if (CC_ALGO(tp)->after_idle != NULL)
CC_ALGO(tp)->after_idle(tp->ccv);
if (tp->snd_cwnd == 1)
i_cwnd = tp->t_maxseg; /* SYN(-ACK) lost */
else
i_cwnd = rc_init_window(rack);
/*
* Being idle is no differnt than the initial window. If the cc
* clamps it down below the initial window raise it to the initial
* window.
*/
if (tp->snd_cwnd < i_cwnd) {
tp->snd_cwnd = i_cwnd;
}
}
/*
* Indicate whether this ack should be delayed. We can delay the ack if
* following conditions are met:
* - There is no delayed ack timer in progress.
* - Our last ack wasn't a 0-sized window. We never want to delay
* the ack that opens up a 0-sized window.
* - LRO wasn't used for this segment. We make sure by checking that the
* segment size is not larger than the MSS.
* - Delayed acks are enabled or this is a half-synchronized T/TCP
* connection.
*/
#define DELAY_ACK(tp, tlen) \
(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
((tp->t_flags & TF_DELACK) == 0) && \
(tlen <= tp->t_maxseg) && \
(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
static struct rack_sendmap *
rack_find_lowest_rsm(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
/*
* Walk the time-order transmitted list looking for an rsm that is
* not acked. This will be the one that was sent the longest time
* ago that is still outstanding.
*/
TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
if (rsm->r_flags & RACK_ACKED) {
continue;
}
goto finish;
}
finish:
return (rsm);
}
static struct rack_sendmap *
rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
{
struct rack_sendmap *prsm;
/*
* Walk the sequence order list backward until we hit and arrive at
* the highest seq not acked. In theory when this is called it
* should be the last segment (which it was not).
*/
counter_u64_add(rack_find_high, 1);
prsm = rsm;
RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
continue;
}
return (prsm);
}
return (NULL);
}
static uint32_t
rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
{
int32_t lro;
uint32_t thresh;
/*
* lro is the flag we use to determine if we have seen reordering.
* If it gets set we have seen reordering. The reorder logic either
* works in one of two ways:
*
* If reorder-fade is configured, then we track the last time we saw
* re-ordering occur. If we reach the point where enough time as
* passed we no longer consider reordering has occuring.
*
* Or if reorder-face is 0, then once we see reordering we consider
* the connection to alway be subject to reordering and just set lro
* to 1.
*
* In the end if lro is non-zero we add the extra time for
* reordering in.
*/
if (srtt == 0)
srtt = 1;
if (rack->r_ctl.rc_reorder_ts) {
if (rack->r_ctl.rc_reorder_fade) {
if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
lro = cts - rack->r_ctl.rc_reorder_ts;
if (lro == 0) {
/*
* No time as passed since the last
* reorder, mark it as reordering.
*/
lro = 1;
}
} else {
/* Negative time? */
lro = 0;
}
if (lro > rack->r_ctl.rc_reorder_fade) {
/* Turn off reordering seen too */
rack->r_ctl.rc_reorder_ts = 0;
lro = 0;
}
} else {
/* Reodering does not fade */
lro = 1;
}
} else {
lro = 0;
}
thresh = srtt + rack->r_ctl.rc_pkt_delay;
if (lro) {
/* It must be set, if not you get 1/4 rtt */
if (rack->r_ctl.rc_reorder_shift)
thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
else
thresh += (srtt >> 2);
} else {
thresh += 1;
}
/* We don't let the rack timeout be above a RTO */
if (thresh > TICKS_2_MSEC(rack->rc_tp->t_rxtcur)) {
thresh = TICKS_2_MSEC(rack->rc_tp->t_rxtcur);
}
/* And we don't want it above the RTO max either */
if (thresh > rack_rto_max) {
thresh = rack_rto_max;
}
return (thresh);
}
static uint32_t
rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t srtt)
{
struct rack_sendmap *prsm;
uint32_t thresh, len;
int segsiz;
if (srtt == 0)
srtt = 1;
if (rack->r_ctl.rc_tlp_threshold)
thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
else
thresh = (srtt * 2);
/* Get the previous sent packet, if any */
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
counter_u64_add(rack_enter_tlp_calc, 1);
len = rsm->r_end - rsm->r_start;
if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
/* Exactly like the ID */
if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
uint32_t alt_thresh;
/*
* Compensate for delayed-ack with the d-ack time.
*/
counter_u64_add(rack_used_tlpmethod, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
/* 2.1 behavior */
prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
if (prsm && (len <= segsiz)) {
/*
* Two packets outstanding, thresh should be (2*srtt) +
* possible inter-packet delay (if any).
*/
uint32_t inter_gap = 0;
int idx, nidx;
counter_u64_add(rack_used_tlpmethod, 1);
idx = rsm->r_rtr_cnt - 1;
nidx = prsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
/* Yes it was sent later (or at the same time) */
inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
}
thresh += inter_gap;
} else if (len <= segsiz) {
/*
* Possibly compensate for delayed-ack.
*/
uint32_t alt_thresh;
counter_u64_add(rack_used_tlpmethod2, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
/* 2.2 behavior */
if (len <= segsiz) {
uint32_t alt_thresh;
/*
* Compensate for delayed-ack with the d-ack time.
*/
counter_u64_add(rack_used_tlpmethod, 1);
alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
if (alt_thresh > thresh)
thresh = alt_thresh;
}
}
/* Not above an RTO */
if (thresh > TICKS_2_MSEC(tp->t_rxtcur)) {
thresh = TICKS_2_MSEC(tp->t_rxtcur);
}
/* Not above a RTO max */
if (thresh > rack_rto_max) {
thresh = rack_rto_max;
}
/* Apply user supplied min TLP */
if (thresh < rack_tlp_min) {
thresh = rack_tlp_min;
}
return (thresh);
}
static uint32_t
rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
{
/*
* We want the rack_rtt which is the
* last rtt we measured. However if that
* does not exist we fallback to the srtt (which
* we probably will never do) and then as a last
* resort we use RACK_INITIAL_RTO if no srtt is
* yet set.
*/
if (rack->rc_rack_rtt)
return(rack->rc_rack_rtt);
else if (tp->t_srtt == 0)
return(RACK_INITIAL_RTO);
return (TICKS_2_MSEC(tp->t_srtt >> TCP_RTT_SHIFT));
}
static struct rack_sendmap *
rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
{
/*
* Check to see that we don't need to fall into recovery. We will
* need to do so if our oldest transmit is past the time we should
* have had an ack.
*/
struct tcp_rack *rack;
struct rack_sendmap *rsm;
int32_t idx;
uint32_t srtt, thresh;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
return (NULL);
}
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm == NULL)
return (NULL);
if (rsm->r_flags & RACK_ACKED) {
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL)
return (NULL);
}
idx = rsm->r_rtr_cnt - 1;
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_rack(rack, srtt, tsused);
if (TSTMP_LT(tsused, rsm->r_tim_lastsent[idx])) {
return (NULL);
}
if ((tsused - rsm->r_tim_lastsent[idx]) < thresh) {
return (NULL);
}
/* Ok if we reach here we are over-due and this guy can be sent */
if (IN_RECOVERY(tp->t_flags) == 0) {
/*
* For the one that enters us into recovery record undo
* info.
*/
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
}
rack_cong_signal(tp, NULL, CC_NDUPACK);
return (rsm);
}
static uint32_t
rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
{
int32_t t;
int32_t tt;
uint32_t ret_val;
t = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT) + ((tp->t_rttvar * 4) >> TCP_RTT_SHIFT));
TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
rack_persist_min, rack_persist_max);
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
ret_val = (uint32_t)tt;
return (ret_val);
}
static uint32_t
rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
{
/*
* Start the FR timer, we do this based on getting the first one in
* the rc_tmap. Note that if its NULL we must stop the timer. in all
* events we need to stop the running timer (if its running) before
* starting the new one.
*/
uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
uint32_t srtt_cur;
int32_t idx;
int32_t is_tlp_timer = 0;
struct rack_sendmap *rsm;
if (rack->t_timers_stopped) {
/* All timers have been stopped none are to run */
return (0);
}
if (rack->rc_in_persist) {
/* We can't start any timer in persists */
return (rack_get_persists_timer_val(tp, rack));
}
rack->rc_on_min_to = 0;
if ((tp->t_state < TCPS_ESTABLISHED) ||
((tp->t_flags & TF_SACK_PERMIT) == 0))
goto activate_rxt;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if ((rsm == NULL) || sup_rack) {
/* Nothing on the send map */
activate_rxt:
time_since_sent = 0;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm) {
idx = rsm->r_rtr_cnt - 1;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(cts, tstmp_touse))
time_since_sent = cts - tstmp_touse;
}
if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
to = TICKS_2_MSEC(tp->t_rxtcur);
if (to > time_since_sent)
to -= time_since_sent;
else
to = rack->r_ctl.rc_min_to;
if (to == 0)
to = 1;
return (to);
}
return (0);
}
if (rsm->r_flags & RACK_ACKED) {
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL) {
/* No lowest? */
goto activate_rxt;
}
}
if (rack->sack_attack_disable) {
/*
* We don't want to do
* any TLP's if you are an attacker.
* Though if you are doing what
* is expected you may still have
* SACK-PASSED marks.
*/
goto activate_rxt;
}
/* Convert from ms to usecs */
if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
if ((tp->t_flags & TF_SENTFIN) &&
((tp->snd_max - tp->snd_una) == 1) &&
(rsm->r_flags & RACK_HAS_FIN)) {
/*
* We don't start a rack timer if all we have is a
* FIN outstanding.
*/
goto activate_rxt;
}
if ((rack->use_rack_rr == 0) &&
(IN_RECOVERY(tp->t_flags)) &&
(rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) {
/*
* We are not cheating, in recovery and
* not enough ack's to yet get our next
* retransmission out.
*
* Note that classified attackers do not
* get to use the rack-cheat.
*/
goto activate_tlp;
}
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_rack(rack, srtt, cts);
idx = rsm->r_rtr_cnt - 1;
exp = rsm->r_tim_lastsent[idx] + thresh;
if (SEQ_GEQ(exp, cts)) {
to = exp - cts;
if (to < rack->r_ctl.rc_min_to) {
to = rack->r_ctl.rc_min_to;
if (rack->r_rr_config == 3)
rack->rc_on_min_to = 1;
}
} else {
to = rack->r_ctl.rc_min_to;
if (rack->r_rr_config == 3)
rack->rc_on_min_to = 1;
}
} else {
/* Ok we need to do a TLP not RACK */
activate_tlp:
if ((rack->rc_tlp_in_progress != 0) &&
(rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
/*
* The previous send was a TLP and we have sent
* N TLP's without sending new data.
*/
goto activate_rxt;
}
rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
if (rsm == NULL) {
/* We found no rsm to TLP with. */
goto activate_rxt;
}
if (rsm->r_flags & RACK_HAS_FIN) {
/* If its a FIN we dont do TLP */
rsm = NULL;
goto activate_rxt;
}
idx = rsm->r_rtr_cnt - 1;
time_since_sent = 0;
if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], rack->r_ctl.rc_tlp_rxt_last_time))
tstmp_touse = rsm->r_tim_lastsent[idx];
else
tstmp_touse = rack->r_ctl.rc_tlp_rxt_last_time;
if (TSTMP_GT(cts, tstmp_touse))
time_since_sent = cts - tstmp_touse;
is_tlp_timer = 1;
if (tp->t_srtt) {
srtt_cur = (tp->t_srtt >> TCP_RTT_SHIFT);
srtt = TICKS_2_MSEC(srtt_cur);
} else
srtt = RACK_INITIAL_RTO;
/*
* If the SRTT is not keeping up and the
* rack RTT has spiked we want to use
* the last RTT not the smoothed one.
*/
if (rack_tlp_use_greater && (srtt < rack_grab_rtt(tp, rack)))
srtt = rack_grab_rtt(tp, rack);
thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
if (thresh > time_since_sent)
to = thresh - time_since_sent;
else {
to = rack->r_ctl.rc_min_to;
rack_log_alt_to_to_cancel(rack,
thresh, /* flex1 */
time_since_sent, /* flex2 */
tstmp_touse, /* flex3 */
rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
rsm->r_tim_lastsent[idx],
srtt,
idx, 99);
}
if (to > TCPTV_REXMTMAX) {
/*
* If the TLP time works out to larger than the max
* RTO lets not do TLP.. just RTO.
*/
goto activate_rxt;
}
}
if (is_tlp_timer == 0) {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
} else {
rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
}
if (to == 0)
to = 1;
return (to);
}
static void
rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (rack->rc_in_persist == 0) {
if (tp->t_flags & TF_GPUTINPROG) {
/*
* Stop the goodput now, the calling of the
* measurement function clears the flag.
*/
rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__);
}
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 1;
}
#endif
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_timer_cancel(tp, rack, cts, __LINE__);
tp->t_rxtshift = 0;
rack->rc_in_persist = 1;
}
}
static void
rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (rack->rc_inp->inp_in_hpts) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
rack->r_ctl.rc_hpts_flags = 0;
}
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 0;
}
#endif
if (rack->rc_gp_dyn_mul &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/*
* Do we count this as if a probe-rtt just
* finished?
*/
uint32_t time_idle, idle_min;
time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
idle_min = rack_min_probertt_hold;
if (rack_probertt_gpsrtt_cnt_div) {
uint64_t extra;
extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
(uint64_t)rack_probertt_gpsrtt_cnt_mul;
extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
idle_min += (uint32_t)extra;
}
if (time_idle >= idle_min) {
/* Yes, we count it as a probe-rtt. */
uint32_t us_cts;
us_cts = tcp_get_usecs(NULL);
if (rack->in_probe_rtt == 0) {
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
} else {
rack_exit_probertt(rack, us_cts);
}
}
}
rack->rc_in_persist = 0;
rack->r_ctl.rc_went_idle_time = 0;
tp->t_rxtshift = 0;
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
}
static void
rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
struct hpts_diag *diag, struct timeval *tv)
{
if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.flex1 = diag->p_nxt_slot;
log.u_bbr.flex2 = diag->p_cur_slot;
log.u_bbr.flex3 = diag->slot_req;
log.u_bbr.flex4 = diag->inp_hptsslot;
log.u_bbr.flex5 = diag->slot_remaining;
log.u_bbr.flex6 = diag->need_new_to;
log.u_bbr.flex7 = diag->p_hpts_active;
log.u_bbr.flex8 = diag->p_on_min_sleep;
/* Hijack other fields as needed */
log.u_bbr.epoch = diag->have_slept;
log.u_bbr.lt_epoch = diag->yet_to_sleep;
log.u_bbr.pkts_out = diag->co_ret;
log.u_bbr.applimited = diag->hpts_sleep_time;
log.u_bbr.delivered = diag->p_prev_slot;
log.u_bbr.inflight = diag->p_runningtick;
log.u_bbr.bw_inuse = diag->wheel_tick;
log.u_bbr.rttProp = diag->wheel_cts;
log.u_bbr.timeStamp = cts;
log.u_bbr.delRate = diag->maxticks;
log.u_bbr.cur_del_rate = diag->p_curtick;
log.u_bbr.cur_del_rate <<= 32;
log.u_bbr.cur_del_rate |= diag->p_lasttick;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSDIAG, 0,
0, &log, false, tv);
}
}
static void
rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
int32_t slot, uint32_t tot_len_this_send, int sup_rack)
{
struct hpts_diag diag;
struct inpcb *inp;
struct timeval tv;
uint32_t delayed_ack = 0;
uint32_t hpts_timeout;
uint8_t stopped;
uint32_t left = 0;
uint32_t us_cts;
inp = tp->t_inpcb;
if ((tp->t_state == TCPS_CLOSED) ||
(tp->t_state == TCPS_LISTEN)) {
return;
}
if (inp->inp_in_hpts) {
/* Already on the pacer */
return;
}
stopped = rack->rc_tmr_stopped;
if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
left = rack->r_ctl.rc_timer_exp - cts;
}
rack->r_ctl.rc_timer_exp = 0;
rack->r_ctl.rc_hpts_flags = 0;
us_cts = tcp_get_usecs(&tv);
/* Now early/late accounting */
if (rack->r_early) {
/*
* We have a early carry over set,
* we can always add more time so we
* can always make this compensation.
*/
slot += rack->r_ctl.rc_agg_early;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
}
if (rack->r_late) {
/*
* This is harder, we can
* compensate some but it
* really depends on what
* the current pacing time is.
*/
if (rack->r_ctl.rc_agg_delayed >= slot) {
/*
* We can't compensate for it all.
* And we have to have some time
* on the clock. We always have a min
* 10 slots (10 x 10 i.e. 100 usecs).
*/
if (slot <= HPTS_TICKS_PER_USEC) {
/* We gain delay */
rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_USEC - slot);
slot = HPTS_TICKS_PER_USEC;
} else {
/* We take off some */
rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_USEC);
slot = HPTS_TICKS_PER_USEC;
}
} else {
slot -= rack->r_ctl.rc_agg_delayed;
rack->r_ctl.rc_agg_delayed = 0;
/* Make sure we have 100 useconds at minimum */
if (slot < HPTS_TICKS_PER_USEC) {
rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_USEC - slot;
slot = HPTS_TICKS_PER_USEC;
}
if (rack->r_ctl.rc_agg_delayed == 0)
rack->r_late = 0;
}
}
if (slot) {
/* We are pacing too */
rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
}
hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
#ifdef NETFLIX_EXP_DETECTION
if (rack->sack_attack_disable &&
(slot < tcp_sad_pacing_interval)) {
/*
* We have a potential attacker on
* the line. We have possibly some
* (or now) pacing time set. We want to
* slow down the processing of sacks by some
* amount (if it is an attacker). Set the default
* slot for attackers in place (unless the orginal
* interval is longer). Its stored in
* micro-seconds, so lets convert to msecs.
*/
slot = tcp_sad_pacing_interval;
}
#endif
if (tp->t_flags & TF_DELACK) {
delayed_ack = TICKS_2_MSEC(tcp_delacktime);
rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
}
if (delayed_ack && ((hpts_timeout == 0) ||
(delayed_ack < hpts_timeout)))
hpts_timeout = delayed_ack;
else
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
/*
* If no timers are going to run and we will fall off the hptsi
* wheel, we resort to a keep-alive timer if its configured.
*/
if ((hpts_timeout == 0) &&
(slot == 0)) {
if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)) {
/*
* Ok we have no timer (persists, rack, tlp, rxt or
* del-ack), we don't have segments being paced. So
* all that is left is the keepalive timer.
*/
if (TCPS_HAVEESTABLISHED(tp->t_state)) {
/* Get the established keep-alive time */
hpts_timeout = TP_KEEPIDLE(tp);
} else {
/* Get the initial setup keep-alive time */
hpts_timeout = TP_KEEPINIT(tp);
}
rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
if (rack->in_probe_rtt) {
/*
* We want to instead not wake up a long time from
* now but to wake up about the time we would
* exit probe-rtt and initiate a keep-alive ack.
* This will get us out of probe-rtt and update
* our min-rtt.
*/
hpts_timeout = (rack_min_probertt_hold / HPTS_USEC_IN_MSEC);
}
}
}
if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
(rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
/*
* RACK, TLP, persists and RXT timers all are restartable
* based on actions input .. i.e we received a packet (ack
* or sack) and that changes things (rw, or snd_una etc).
* Thus we can restart them with a new value. For
* keep-alive, delayed_ack we keep track of what was left
* and restart the timer with a smaller value.
*/
if (left < hpts_timeout)
hpts_timeout = left;
}
if (hpts_timeout) {
/*
* Hack alert for now we can't time-out over 2,147,483
* seconds (a bit more than 596 hours), which is probably ok
* :).
*/
if (hpts_timeout > 0x7ffffffe)
hpts_timeout = 0x7ffffffe;
rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
}
if ((rack->rc_gp_filled == 0) &&
(hpts_timeout < slot) &&
(rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
/*
* We have no good estimate yet for the
* old clunky burst mitigation or the
* real pacing. And the tlp or rxt is smaller
* than the pacing calculation. Lets not
* pace that long since we know the calculation
* so far is not accurate.
*/
slot = hpts_timeout;
}
rack->r_ctl.last_pacing_time = slot;
if (slot) {
rack->r_ctl.rc_last_output_to = us_cts + slot;
if (rack->rc_always_pace || rack->r_mbuf_queue) {
if ((rack->rc_gp_filled == 0) ||
rack->pacing_longer_than_rtt) {
inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
} else {
inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
(rack->r_rr_config != 3))
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
else
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
}
if ((rack->use_rack_rr) &&
(rack->r_rr_config < 2) &&
((hpts_timeout) && ((hpts_timeout * HPTS_USEC_IN_MSEC) < slot))) {
/*
* Arrange for the hpts to kick back in after the
* t-o if the t-o does not cause a send.
*/
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
} else {
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
}
} else if (hpts_timeout) {
if (rack->rc_always_pace || rack->r_mbuf_queue) {
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) {
/* For a rack timer, don't wake us */
inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
if (rack->r_rr_config != 3)
inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
else
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
} else {
/* All other timers wake us up */
inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
}
(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_MS_TO_SLOTS(hpts_timeout),
__LINE__, &diag);
rack_log_hpts_diag(rack, us_cts, &diag, &tv);
rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
} else {
/* No timer starting */
#ifdef INVARIANTS
if (SEQ_GT(tp->snd_max, tp->snd_una)) {
panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
}
#endif
}
rack->rc_tmr_stopped = 0;
if (slot)
rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
}
/*
* RACK Timer, here we simply do logging and house keeping.
* the normal rack_output() function will call the
* appropriate thing to check if we need to do a RACK retransmit.
* We return 1, saying don't proceed with rack_output only
* when all timers have been stopped (destroyed PCB?).
*/
static int
rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
/*
* This timer simply provides an internal trigger to send out data.
* The check_recovery_mode call will see if there are needed
* retransmissions, if so we will enter fast-recovery. The output
* call may or may not do the same thing depending on sysctl
* settings.
*/
struct rack_sendmap *rsm;
int32_t recovery;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
recovery = IN_RECOVERY(tp->t_flags);
counter_u64_add(rack_to_tot, 1);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
rack->rc_on_min_to = 0;
rsm = rack_check_recovery_mode(tp, cts);
rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
if (rsm) {
uint32_t rtt;
rack->r_ctl.rc_resend = rsm;
if (rack->use_rack_rr) {
/*
* Don't accumulate extra pacing delay
* we are allowing the rack timer to
* over-ride pacing i.e. rrr takes precedence
* if the pacing interval is longer than the rrr
* time (in other words we get the min pacing
* time versus rrr pacing time).
*/
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
rtt = rack->rc_rack_rtt;
if (rtt == 0)
rtt = 1;
if (rack->rack_no_prr == 0) {
if ((recovery == 0) &&
(rack->r_ctl.rc_prr_sndcnt < ctf_fixed_maxseg(tp))) {
/*
* The rack-timeout that enter's us into recovery
* will force out one MSS and set us up so that we
* can do one more send in 2*rtt (transitioning the
* rack timeout into a rack-tlp).
*/
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack->r_timer_override = 1;
rack_log_to_prr(rack, 3, 0);
} else if ((rack->r_ctl.rc_prr_sndcnt < (rsm->r_end - rsm->r_start)) &&
rack->use_rack_rr) {
/*
* When a rack timer goes, if the rack rr is
* on, arrange it so we can send a full segment
* overriding prr (though we pay a price for this
* for future new sends).
*/
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 4, 0);
}
}
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
if (rsm == NULL) {
/* restart a timer and return 1 */
rack_start_hpts_timer(rack, tp, cts,
0, 0, 0);
return (1);
}
return (0);
}
static __inline void
rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
struct rack_sendmap *rsm, uint32_t start)
{
int idx;
nrsm->r_start = start;
nrsm->r_end = rsm->r_end;
nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
nrsm->r_flags = rsm->r_flags;
nrsm->r_dupack = rsm->r_dupack;
nrsm->usec_orig_send = rsm->usec_orig_send;
nrsm->r_rtr_bytes = 0;
rsm->r_end = nrsm->r_start;
nrsm->r_just_ret = rsm->r_just_ret;
for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
}
}
static struct rack_sendmap *
rack_merge_rsm(struct tcp_rack *rack,
struct rack_sendmap *l_rsm,
struct rack_sendmap *r_rsm)
{
/*
* We are merging two ack'd RSM's,
* the l_rsm is on the left (lower seq
* values) and the r_rsm is on the right
* (higher seq value). The simplest way
* to merge these is to move the right
* one into the left. I don't think there
* is any reason we need to try to find
* the oldest (or last oldest retransmitted).
*/
struct rack_sendmap *rm;
l_rsm->r_end = r_rsm->r_end;
if (l_rsm->r_dupack < r_rsm->r_dupack)
l_rsm->r_dupack = r_rsm->r_dupack;
if (r_rsm->r_rtr_bytes)
l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
if (r_rsm->r_in_tmap) {
/* This really should not happen */
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
r_rsm->r_in_tmap = 0;
}
/* Now the flags */
if (r_rsm->r_flags & RACK_HAS_FIN)
l_rsm->r_flags |= RACK_HAS_FIN;
if (r_rsm->r_flags & RACK_TLP)
l_rsm->r_flags |= RACK_TLP;
if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
l_rsm->r_flags |= RACK_RWND_COLLAPSED;
if ((r_rsm->r_flags & RACK_APP_LIMITED) &&
((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
/*
* If both are app-limited then let the
* free lower the count. If right is app
* limited and left is not, transfer.
*/
l_rsm->r_flags |= RACK_APP_LIMITED;
r_rsm->r_flags &= ~RACK_APP_LIMITED;
if (r_rsm == rack->r_ctl.rc_first_appl)
rack->r_ctl.rc_first_appl = l_rsm;
}
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
#ifdef INVARIANTS
if (rm != r_rsm) {
panic("removing head in rack:%p rsm:%p rm:%p",
rack, r_rsm, rm);
}
#endif
if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
/* Transfer the split limit to the map we free */
r_rsm->r_limit_type = l_rsm->r_limit_type;
l_rsm->r_limit_type = 0;
}
rack_free(rack, r_rsm);
return(l_rsm);
}
/*
* TLP Timer, here we simply setup what segment we want to
* have the TLP expire on, the normal rack_output() will then
* send it out.
*
* We return 1, saying don't proceed with rack_output only
* when all timers have been stopped (destroyed PCB?).
*/
static int
rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
/*
* Tail Loss Probe.
*/
struct rack_sendmap *rsm = NULL;
struct rack_sendmap *insret;
struct socket *so;
uint32_t amm, old_prr_snd = 0;
uint32_t out, avail;
int collapsed_win = 0;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
/* Its not time yet */
return (0);
}
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
return (1);
}
/*
* A TLP timer has expired. We have been idle for 2 rtts. So we now
* need to figure out how to force a full MSS segment out.
*/
rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
counter_u64_add(rack_tlp_tot, 1);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
so = tp->t_inpcb->inp_socket;
avail = sbavail(&so->so_snd);
out = tp->snd_max - tp->snd_una;
if (out > tp->snd_wnd) {
/* special case, we need a retransmission */
collapsed_win = 1;
goto need_retran;
}
/*
* Check our send oldest always settings, and if
* there is an oldest to send jump to the need_retran.
*/
if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
goto need_retran;
if (avail > out) {
/* New data is available */
amm = avail - out;
if (amm > ctf_fixed_maxseg(tp)) {
amm = ctf_fixed_maxseg(tp);
if ((amm + out) > tp->snd_wnd) {
/* We are rwnd limited */
goto need_retran;
}
} else if (amm < ctf_fixed_maxseg(tp)) {
/* not enough to fill a MTU */
goto need_retran;
}
if (IN_RECOVERY(tp->t_flags)) {
/* Unlikely */
if (rack->rack_no_prr == 0) {
old_prr_snd = rack->r_ctl.rc_prr_sndcnt;
if (out + amm <= tp->snd_wnd) {
rack->r_ctl.rc_prr_sndcnt = amm;
rack_log_to_prr(rack, 4, 0);
}
} else
goto need_retran;
} else {
/* Set the send-new override */
if (out + amm <= tp->snd_wnd)
rack->r_ctl.rc_tlp_new_data = amm;
else
goto need_retran;
}
rack->r_ctl.rc_tlpsend = NULL;
counter_u64_add(rack_tlp_newdata, 1);
goto send;
}
need_retran:
/*
* Ok we need to arrange the last un-acked segment to be re-sent, or
* optionally the first un-acked segment.
*/
if (collapsed_win == 0) {
if (rack_always_send_oldest)
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
else {
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
rsm = rack_find_high_nonack(rack, rsm);
}
}
if (rsm == NULL) {
counter_u64_add(rack_tlp_does_nada, 1);
#ifdef TCP_BLACKBOX
tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
#endif
goto out;
}
} else {
/*
* We must find the last segment
* that was acceptable by the client.
*/
RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
/* Found one */
break;
}
}
if (rsm == NULL) {
/* None? if so send the first */
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm == NULL) {
counter_u64_add(rack_tlp_does_nada, 1);
#ifdef TCP_BLACKBOX
tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
#endif
goto out;
}
}
}
if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
/*
* We need to split this the last segment in two.
*/
struct rack_sendmap *nrsm;
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
/*
* No memory to split, we will just exit and punt
* off to the RXT timer.
*/
counter_u64_add(rack_tlp_does_nada, 1);
goto out;
}
rack_clone_rsm(rack, nrsm, rsm,
(rsm->r_end - ctf_fixed_maxseg(tp)));
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
rsm = nrsm;
}
rack->r_ctl.rc_tlpsend = rsm;
send:
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
return (0);
out:
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
return (0);
}
/*
* Delayed ack Timer, here we simply need to setup the
* ACK_NOW flag and remove the DELACK flag. From there
* the output routine will send the ack out.
*
* We only return 1, saying don't proceed, if all timers
* are stopped (destroyed PCB?).
*/
static int
rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
KMOD_TCPSTAT_INC(tcps_delack);
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
return (0);
}
/*
* Persists timer, here we simply send the
* same thing as a keepalive will.
* the one byte send.
*
* We only return 1, saying don't proceed, if all timers
* are stopped (destroyed PCB?).
*/
static int
rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
struct tcptemp *t_template;
struct inpcb *inp;
int32_t retval = 1;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (rack->rc_in_persist == 0)
return (0);
if (ctf_progress_timeout_check(tp, false)) {
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(inp, ETIMEDOUT);
return (1);
}
KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
/*
* Persistence timer into zero window. Force a byte to be output, if
* possible.
*/
KMOD_TCPSTAT_INC(tcps_persisttimeo);
/*
* Hack: if the peer is dead/unreachable, we do not time out if the
* window is closed. After a full backoff, drop the connection if
* the idle time (no responses to probes) reaches the maximum
* backoff that we would use if retransmitting.
*/
if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
(ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
KMOD_TCPSTAT_INC(tcps_persistdrop);
retval = 1;
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
goto out;
}
if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
tp->snd_una == tp->snd_max)
rack_exit_persist(tp, rack, cts);
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
/*
* If the user has closed the socket then drop a persisting
* connection after a much reduced timeout.
*/
if (tp->t_state > TCPS_CLOSE_WAIT &&
(ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
retval = 1;
KMOD_TCPSTAT_INC(tcps_persistdrop);
tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
goto out;
}
t_template = tcpip_maketemplate(rack->rc_inp);
if (t_template) {
/* only set it if we were answered */
if (rack->forced_ack == 0) {
rack->forced_ack = 1;
rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
}
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
tp->rcv_nxt, tp->snd_una - 1, 0);
/* This sends an ack */
if (tp->t_flags & TF_DELACK)
tp->t_flags &= ~TF_DELACK;
free(t_template, M_TEMP);
}
if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
tp->t_rxtshift++;
out:
rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
rack_start_hpts_timer(rack, tp, cts,
0, 0, 0);
return (retval);
}
/*
* If a keepalive goes off, we had no other timers
* happening. We always return 1 here since this
* routine either drops the connection or sends
* out a segment with respond.
*/
static int
rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
struct tcptemp *t_template;
struct inpcb *inp;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
inp = tp->t_inpcb;
rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
/*
* Keep-alive timer went off; send something or drop connection if
* idle for too long.
*/
KMOD_TCPSTAT_INC(tcps_keeptimeo);
if (tp->t_state < TCPS_ESTABLISHED)
goto dropit;
if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
tp->t_state <= TCPS_CLOSING) {
if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
goto dropit;
/*
* Send a packet designed to force a response if the peer is
* up and reachable: either an ACK if the connection is
* still alive, or an RST if the peer has closed the
* connection due to timeout or reboot. Using sequence
* number tp->snd_una-1 causes the transmitted zero-length
* segment to lie outside the receive window; by the
* protocol spec, this requires the correspondent TCP to
* respond.
*/
KMOD_TCPSTAT_INC(tcps_keepprobe);
t_template = tcpip_maketemplate(inp);
if (t_template) {
if (rack->forced_ack == 0) {
rack->forced_ack = 1;
rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
}
tcp_respond(tp, t_template->tt_ipgen,
&t_template->tt_t, (struct mbuf *)NULL,
tp->rcv_nxt, tp->snd_una - 1, 0);
free(t_template, M_TEMP);
}
}
rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
return (1);
dropit:
KMOD_TCPSTAT_INC(tcps_keepdrops);
tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
return (1);
}
/*
* Retransmit helper function, clear up all the ack
* flags and take care of important book keeping.
*/
static void
rack_remxt_tmr(struct tcpcb *tp)
{
/*
* The retransmit timer went off, all sack'd blocks must be
* un-acked.
*/
struct rack_sendmap *rsm, *trsm = NULL;
struct tcp_rack *rack;
int32_t cnt = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack_timer_cancel(tp, rack, tcp_ts_getticks(), __LINE__);
rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
if (rack->r_state && (rack->r_state != tp->t_state))
rack_set_state(tp, rack);
/*
* Ideally we would like to be able to
* mark SACK-PASS on anything not acked here.
* However, if we do that we would burst out
* all that data 1ms apart. This would be unwise,
* so for now we will just let the normal rxt timer
* and tlp timer take care of it.
*/
RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if (rsm->r_flags & RACK_ACKED) {
cnt++;
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
if (rsm->r_in_tmap == 0) {
/* We must re-add it back to the tlist */
if (trsm == NULL) {
TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
} else {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
}
rsm->r_in_tmap = 1;
}
}
trsm = rsm;
if (rsm->r_flags & RACK_ACKED)
rsm->r_flags |= RACK_WAS_ACKED;
rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
}
/* Clear the count (we just un-acked them) */
rack->r_ctl.rc_sacked = 0;
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
rack->r_late = 0;
/* Clear the tlp rtx mark */
rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 6, 0);
rack->r_timer_override = 1;
}
static void
rack_cc_conn_init(struct tcpcb *tp)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
cc_conn_init(tp);
/*
* We want a chance to stay in slowstart as
* we create a connection. TCP spec says that
* initially ssthresh is infinite. For our
* purposes that is the snd_wnd.
*/
if (tp->snd_ssthresh < tp->snd_wnd) {
tp->snd_ssthresh = tp->snd_wnd;
}
/*
* We also want to assure a IW worth of
* data can get inflight.
*/
if (rc_init_window(rack) < tp->snd_cwnd)
tp->snd_cwnd = rc_init_window(rack);
}
/*
* Re-transmit timeout! If we drop the PCB we will return 1, otherwise
* we will setup to retransmit the lowest seq number outstanding.
*/
static int
rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
{
int32_t rexmt;
struct inpcb *inp;
int32_t retval = 0;
bool isipv6;
inp = tp->t_inpcb;
if (tp->t_timers->tt_flags & TT_STOPPED) {
return (1);
}
if (ctf_progress_timeout_check(tp, false)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(inp, ETIMEDOUT);
return (1);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_una == tp->snd_max)) {
/* Nothing outstanding .. nothing to do */
return (0);
}
/*
* Retransmission timer went off. Message has not been acked within
* retransmit interval. Back off to a longer retransmit interval
* and retransmit one segment.
*/
rack_remxt_tmr(tp);
if ((rack->r_ctl.rc_resend == NULL) ||
((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
/*
* If the rwnd collapsed on
* the one we are retransmitting
* it does not count against the
* rxt count.
*/
tp->t_rxtshift++;
}
if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
tp->t_rxtshift = TCP_MAXRXTSHIFT;
KMOD_TCPSTAT_INC(tcps_timeoutdrop);
retval = 1;
tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
tcp_set_inp_to_drop(rack->rc_inp,
(tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
goto out;
}
if (tp->t_state == TCPS_SYN_SENT) {
/*
* If the SYN was retransmitted, indicate CWND to be limited
* to 1 segment in cc_conn_init().
*/
tp->snd_cwnd = 1;
} else if (tp->t_rxtshift == 1) {
/*
* first retransmit; record ssthresh and cwnd so they can be
* recovered if this turns out to be a "bad" retransmit. A
* retransmit is considered "bad" if an ACK for this segment
* is received within RTT/2 interval; the assumption here is
* that the ACK was already in flight. See "On Estimating
* End-to-End Network Path Properties" by Allman and Paxson
* for more details.
*/
tp->snd_cwnd_prev = tp->snd_cwnd;
tp->snd_ssthresh_prev = tp->snd_ssthresh;
tp->snd_recover_prev = tp->snd_recover;
if (IN_FASTRECOVERY(tp->t_flags))
tp->t_flags |= TF_WASFRECOVERY;
else
tp->t_flags &= ~TF_WASFRECOVERY;
if (IN_CONGRECOVERY(tp->t_flags))
tp->t_flags |= TF_WASCRECOVERY;
else
tp->t_flags &= ~TF_WASCRECOVERY;
tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
tp->t_flags |= TF_PREVVALID;
} else
tp->t_flags &= ~TF_PREVVALID;
KMOD_TCPSTAT_INC(tcps_rexmttimeo);
if ((tp->t_state == TCPS_SYN_SENT) ||
(tp->t_state == TCPS_SYN_RECEIVED))
rexmt = MSEC_2_TICKS(RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift]);
else
rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
TCPT_RANGESET(tp->t_rxtcur, rexmt,
max(MSEC_2_TICKS(rack_rto_min), rexmt),
MSEC_2_TICKS(rack_rto_max));
/*
* We enter the path for PLMTUD if connection is established or, if
* connection is FIN_WAIT_1 status, reason for the last is that if
* amount of data we send is very small, we could send it in couple
* of packets and process straight to FIN. In that case we won't
* catch ESTABLISHED state.
*/
#ifdef INET6
isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
#else
isipv6 = false;
#endif
if (((V_tcp_pmtud_blackhole_detect == 1) ||
(V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
(V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
((tp->t_state == TCPS_ESTABLISHED) ||
(tp->t_state == TCPS_FIN_WAIT_1))) {
/*
* Idea here is that at each stage of mtu probe (usually,
* 1448 -> 1188 -> 524) should be given 2 chances to recover
* before further clamping down. 'tp->t_rxtshift % 2 == 0'
* should take care of that.
*/
if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
(TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
(tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
tp->t_rxtshift % 2 == 0)) {
/*
* Enter Path MTU Black-hole Detection mechanism: -
* Disable Path MTU Discovery (IP "DF" bit). -
* Reduce MTU to lower value than what we negotiated
* with peer.
*/
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
/* Record that we may have found a black hole. */
tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
/* Keep track of previous MSS. */
tp->t_pmtud_saved_maxseg = tp->t_maxseg;
}
/*
* Reduce the MSS to blackhole value or to the
* default in an attempt to retransmit.
*/
#ifdef INET6
if (isipv6 &&
tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
/* Use the sysctl tuneable blackhole MSS. */
tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
} else if (isipv6) {
/* Use the default MSS. */
tp->t_maxseg = V_tcp_v6mssdflt;
/*
* Disable Path MTU Discovery when we switch
* to minmss.
*/
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
/* Use the sysctl tuneable blackhole MSS. */
tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
} else {
/* Use the default MSS. */
tp->t_maxseg = V_tcp_mssdflt;
/*
* Disable Path MTU Discovery when we switch
* to minmss.
*/
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
}
#endif
} else {
/*
* If further retransmissions are still unsuccessful
* with a lowered MTU, maybe this isn't a blackhole
* and we restore the previous MSS and blackhole
* detection flags. The limit '6' is determined by
* giving each probe stage (1448, 1188, 524) 2
* chances to recover.
*/
if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
(tp->t_rxtshift >= 6)) {
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
tp->t_maxseg = tp->t_pmtud_saved_maxseg;
KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
}
}
}
/*
* If we backed off this far, our srtt estimate is probably bogus.
* Clobber it so we'll take the next rtt measurement as our srtt;
* move the current srtt into rttvar to keep the current retransmit
* times until then.
*/
if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
#ifdef INET6
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
in6_losing(tp->t_inpcb);
else
#endif
in_losing(tp->t_inpcb);
tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
tp->t_srtt = 0;
}
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
tp->snd_recover = tp->snd_max;
tp->t_flags |= TF_ACKNOW;
tp->t_rtttime = 0;
rack_cong_signal(tp, NULL, CC_RTO);
out:
return (retval);
}
static int
rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling)
{
int32_t ret = 0;
int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
if (timers == 0) {
return (0);
}
if (tp->t_state == TCPS_LISTEN) {
/* no timers on listen sockets */
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
return (0);
return (1);
}
if ((timers & PACE_TMR_RACK) &&
rack->rc_on_min_to) {
/*
* For the rack timer when we
* are on a min-timeout (which means rrr_conf = 3)
* we don't want to check the timer. It may
* be going off for a pace and thats ok we
* want to send the retransmit (if its ready).
*
* If its on a normal rack timer (non-min) then
* we will check if its expired.
*/
goto skip_time_check;
}
if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
uint32_t left;
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
ret = -1;
rack_log_to_processing(rack, cts, ret, 0);
return (0);
}
if (hpts_calling == 0) {
/*
* A user send or queued mbuf (sack) has called us? We
* return 0 and let the pacing guards
* deal with it if they should or
* should not cause a send.
*/
ret = -2;
rack_log_to_processing(rack, cts, ret, 0);
return (0);
}
/*
* Ok our timer went off early and we are not paced false
* alarm, go back to sleep.
*/
ret = -3;
left = rack->r_ctl.rc_timer_exp - cts;
tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
rack_log_to_processing(rack, cts, ret, left);
return (1);
}
skip_time_check:
rack->rc_tmr_stopped = 0;
rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
if (timers & PACE_TMR_DELACK) {
ret = rack_timeout_delack(tp, rack, cts);
} else if (timers & PACE_TMR_RACK) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_rack(tp, rack, cts);
} else if (timers & PACE_TMR_TLP) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_tlp(tp, rack, cts);
} else if (timers & PACE_TMR_RXT) {
rack->r_ctl.rc_tlp_rxt_last_time = cts;
ret = rack_timeout_rxt(tp, rack, cts);
} else if (timers & PACE_TMR_PERSIT) {
ret = rack_timeout_persist(tp, rack, cts);
} else if (timers & PACE_TMR_KEEP) {
ret = rack_timeout_keepalive(tp, rack, cts);
}
rack_log_to_processing(rack, cts, ret, timers);
return (ret);
}
static void
rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
{
struct timeval tv;
uint32_t us_cts, flags_on_entry;
uint8_t hpts_removed = 0;
flags_on_entry = rack->r_ctl.rc_hpts_flags;
us_cts = tcp_get_usecs(&tv);
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
((tp->snd_max - tp->snd_una) == 0))) {
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
hpts_removed = 1;
/* If we were not delayed cancel out the flag. */
if ((tp->snd_max - tp->snd_una) == 0)
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
}
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
if (rack->rc_inp->inp_in_hpts &&
((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
/*
* Canceling timer's when we have no output being
* paced. We also must remove ourselves from the
* hpts.
*/
tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
hpts_removed = 1;
}
rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
}
if (hpts_removed == 0)
rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
}
static void
rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
{
return;
}
static int
rack_stopall(struct tcpcb *tp)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack->t_timers_stopped = 1;
return (0);
}
static void
rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
{
return;
}
static int
rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
{
return (0);
}
static void
rack_stop_all_timers(struct tcpcb *tp)
{
struct tcp_rack *rack;
/*
* Assure no timers are running.
*/
if (tcp_timer_active(tp, TT_PERSIST)) {
/* We enter in persists, set the flag appropriately */
rack = (struct tcp_rack *)tp->t_fb_ptr;
rack->rc_in_persist = 1;
}
tcp_timer_suspend(tp, TT_PERSIST);
tcp_timer_suspend(tp, TT_REXMT);
tcp_timer_suspend(tp, TT_KEEP);
tcp_timer_suspend(tp, TT_DELACK);
}
static void
rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts)
{
int32_t idx;
rsm->r_rtr_cnt++;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
rsm->r_dupack = 0;
if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
rsm->r_flags |= RACK_OVERMAX;
}
if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
}
idx = rsm->r_rtr_cnt - 1;
rsm->r_tim_lastsent[idx] = ts;
if (rsm->r_flags & RACK_ACKED) {
/* Problably MTU discovery messing with us */
rsm->r_flags &= ~RACK_ACKED;
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
}
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
if (rsm->r_flags & RACK_SACK_PASSED) {
/* We have retransmitted due to the SACK pass */
rsm->r_flags &= ~RACK_SACK_PASSED;
rsm->r_flags |= RACK_WAS_SACKPASS;
}
}
static uint32_t
rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, uint32_t ts, int32_t *lenp)
{
/*
* We (re-)transmitted starting at rsm->r_start for some length
* (possibly less than r_end.
*/
struct rack_sendmap *nrsm, *insret;
uint32_t c_end;
int32_t len;
len = *lenp;
c_end = rsm->r_start + len;
if (SEQ_GEQ(c_end, rsm->r_end)) {
/*
* We retransmitted the whole piece or more than the whole
* slopping into the next rsm.
*/
rack_update_rsm(tp, rack, rsm, ts);
if (c_end == rsm->r_end) {
*lenp = 0;
return (0);
} else {
int32_t act_len;
/* Hangs over the end return whats left */
act_len = rsm->r_end - rsm->r_start;
*lenp = (len - act_len);
return (rsm->r_end);
}
/* We don't get out of this block. */
}
/*
* Here we retransmitted less than the whole thing which means we
* have to split this into what was transmitted and what was not.
*/
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
/*
* We can't get memory, so lets not proceed.
*/
*lenp = 0;
return (0);
}
/*
* So here we are going to take the original rsm and make it what we
* retransmitted. nrsm will be the tail portion we did not
* retransmit. For example say the chunk was 1, 11 (10 bytes). And
* we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
* 1, 6 and the new piece will be 6, 11.
*/
rack_clone_rsm(rack, nrsm, rsm, c_end);
nrsm->r_dupack = 0;
rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
rack_update_rsm(tp, rack, rsm, ts);
*lenp = 0;
return (0);
}
static void
rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
uint32_t seq_out, uint8_t th_flags, int32_t err, uint32_t ts,
uint8_t pass, struct rack_sendmap *hintrsm, uint32_t us_cts)
{
struct tcp_rack *rack;
struct rack_sendmap *rsm, *nrsm, *insret, fe;
register uint32_t snd_max, snd_una;
/*
* Add to the RACK log of packets in flight or retransmitted. If
* there is a TS option we will use the TS echoed, if not we will
* grab a TS.
*
* Retransmissions will increment the count and move the ts to its
* proper place. Note that if options do not include TS's then we
* won't be able to effectively use the ACK for an RTT on a retran.
*
* Notes about r_start and r_end. Lets consider a send starting at
* sequence 1 for 10 bytes. In such an example the r_start would be
* 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
* This means that r_end is actually the first sequence for the next
* slot (11).
*
*/
/*
* If err is set what do we do XXXrrs? should we not add the thing?
* -- i.e. return if err != 0 or should we pretend we sent it? --
* i.e. proceed with add ** do this for now.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
if (err)
/*
* We don't log errors -- we could but snd_max does not
* advance in this case either.
*/
return;
if (th_flags & TH_RST) {
/*
* We don't log resets and we return immediately from
* sending
*/
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
snd_una = tp->snd_una;
if (SEQ_LEQ((seq_out + len), snd_una)) {
/* Are sending an old segment to induce an ack (keep-alive)? */
return;
}
if (SEQ_LT(seq_out, snd_una)) {
/* huh? should we panic? */
uint32_t end;
end = seq_out + len;
seq_out = snd_una;
if (SEQ_GEQ(end, seq_out))
len = end - seq_out;
else
len = 0;
}
snd_max = tp->snd_max;
if (th_flags & (TH_SYN | TH_FIN)) {
/*
* The call to rack_log_output is made before bumping
* snd_max. This means we can record one extra byte on a SYN
* or FIN if seq_out is adding more on and a FIN is present
* (and we are not resending).
*/
if ((th_flags & TH_SYN) && (seq_out == tp->iss))
len++;
if (th_flags & TH_FIN)
len++;
if (SEQ_LT(snd_max, tp->snd_nxt)) {
/*
* The add/update as not been done for the FIN/SYN
* yet.
*/
snd_max = tp->snd_nxt;
}
}
if (len == 0) {
/* We don't log zero window probes */
return;
}
rack->r_ctl.rc_time_last_sent = ts;
if (IN_RECOVERY(tp->t_flags)) {
rack->r_ctl.rc_prr_out += len;
}
/* First question is it a retransmission or new? */
if (seq_out == snd_max) {
/* Its new */
again:
rsm = rack_alloc(rack);
if (rsm == NULL) {
/*
* Hmm out of memory and the tcb got destroyed while
* we tried to wait.
*/
return;
}
if (th_flags & TH_FIN) {
rsm->r_flags = RACK_HAS_FIN;
} else {
rsm->r_flags = 0;
}
rsm->r_tim_lastsent[0] = ts;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->usec_orig_send = us_cts;
if (th_flags & TH_SYN) {
/* The data space is one beyond snd_una */
rsm->r_flags |= RACK_HAS_SIN;
rsm->r_start = seq_out + 1;
rsm->r_end = rsm->r_start + (len - 1);
} else {
/* Normal case */
rsm->r_start = seq_out;
rsm->r_end = rsm->r_start + len;
}
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
/*
* Special case detection, is there just a single
* packet outstanding when we are not in recovery?
*
* If this is true mark it so.
*/
if ((IN_RECOVERY(tp->t_flags) == 0) &&
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
struct rack_sendmap *prsm;
prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (prsm)
prsm->r_one_out_nr = 1;
}
return;
}
/*
* If we reach here its a retransmission and we need to find it.
*/
memset(&fe, 0, sizeof(fe));
more:
if (hintrsm && (hintrsm->r_start == seq_out)) {
rsm = hintrsm;
hintrsm = NULL;
} else {
/* No hints sorry */
rsm = NULL;
}
if ((rsm) && (rsm->r_start == seq_out)) {
seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
if (len == 0) {
return;
} else {
goto more;
}
}
/* Ok it was not the last pointer go through it the hard way. */
refind:
fe.r_start = seq_out;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm) {
if (rsm->r_start == seq_out) {
seq_out = rack_update_entry(tp, rack, rsm, ts, &len);
if (len == 0) {
return;
} else {
goto refind;
}
}
if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
/* Transmitted within this piece */
/*
* Ok we must split off the front and then let the
* update do the rest
*/
nrsm = rack_alloc_full_limit(rack);
if (nrsm == NULL) {
rack_update_rsm(tp, rack, rsm, ts);
return;
}
/*
* copy rsm to nrsm and then trim the front of rsm
* to not include this part.
*/
rack_clone_rsm(rack, nrsm, rsm, seq_out);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
seq_out = rack_update_entry(tp, rack, nrsm, ts, &len);
if (len == 0) {
return;
} else if (len > 0)
goto refind;
}
}
/*
* Hmm not found in map did they retransmit both old and on into the
* new?
*/
if (seq_out == tp->snd_max) {
goto again;
} else if (SEQ_LT(seq_out, tp->snd_max)) {
#ifdef INVARIANTS
printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
seq_out, len, tp->snd_una, tp->snd_max);
printf("Starting Dump of all rack entries\n");
RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
printf("rsm:%p start:%u end:%u\n",
rsm, rsm->r_start, rsm->r_end);
}
printf("Dump complete\n");
panic("seq_out not found rack:%p tp:%p",
rack, tp);
#endif
} else {
#ifdef INVARIANTS
/*
* Hmm beyond sndmax? (only if we are using the new rtt-pack
* flag)
*/
panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
seq_out, len, tp->snd_max, tp);
#endif
}
}
/*
* Record one of the RTT updates from an ack into
* our sample structure.
*/
static void
tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
{
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
}
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
}
if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
rack->r_ctl.rc_gp_lowrtt = us_rtt;
if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
}
if ((confidence == 1) &&
((rsm == NULL) ||
(rsm->r_just_ret) ||
(rsm->r_one_out_nr &&
len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
/*
* If the rsm had a just return
* hit it then we can't trust the
* rtt measurement for buffer deterimination
* Note that a confidence of 2, indicates
* SACK'd which overrides the r_just_ret or
* the r_one_out_nr. If it was a CUM-ACK and
* we had only two outstanding, but get an
* ack for only 1. Then that also lowers our
* confidence.
*/
confidence = 0;
}
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
(rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
if (rack->r_ctl.rack_rs.confidence == 0) {
/*
* We take anything with no current confidence
* saved.
*/
rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
rack->r_ctl.rack_rs.confidence = confidence;
rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
} else if (confidence || rack->r_ctl.rack_rs.confidence) {
/*
* Once we have a confident number,
* we can update it with a smaller
* value since this confident number
* may include the DSACK time until
* the next segment (the second one) arrived.
*/
rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
rack->r_ctl.rack_rs.confidence = confidence;
rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
}
}
rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
rack->r_ctl.rack_rs.rs_rtt_cnt++;
}
/*
* Collect new round-trip time estimate
* and update averages and current timeout.
*/
static void
tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
{
int32_t delta;
uint32_t o_srtt, o_var;
int32_t hrtt_up = 0;
int32_t rtt;
if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
/* No valid sample */
return;
if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
/* We are to use the lowest RTT seen in a single ack */
rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
/* We are to use the highest RTT seen in a single ack */
rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
/* We are to use the average RTT seen in a single ack */
rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
} else {
#ifdef INVARIANTS
panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
#endif
return;
}
if (rtt == 0)
rtt = 1;
if (rack->rc_gp_rtt_set == 0) {
/*
* With no RTT we have to accept
* even one we are not confident of.
*/
rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
rack->rc_gp_rtt_set = 1;
} else if (rack->r_ctl.rack_rs.confidence) {
/* update the running gp srtt */
rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
}
if (rack->r_ctl.rack_rs.confidence) {
/*
* record the low and high for highly buffered path computation,
* we only do this if we are confident (not a retransmission).
*/
if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
hrtt_up = 1;
}
if (rack->rc_highly_buffered == 0) {
/*
* Currently once we declare a path has
* highly buffered there is no going
* back, which may be a problem...
*/
if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
rack->r_ctl.rc_highest_us_rtt,
rack->r_ctl.rc_lowest_us_rtt,
RACK_RTTS_SEEHBP);
rack->rc_highly_buffered = 1;
}
}
}
if ((rack->r_ctl.rack_rs.confidence) ||
(rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
/*
* If we are highly confident of it <or> it was
* never retransmitted we accept it as the last us_rtt.
*/
rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
/* The lowest rtt can be set if its was not retransmited */
if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
if (rack->r_ctl.rc_lowest_us_rtt == 0)
rack->r_ctl.rc_lowest_us_rtt = 1;
}
}
rack_log_rtt_sample(rack, rtt);
o_srtt = tp->t_srtt;
o_var = tp->t_rttvar;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (tp->t_srtt != 0) {
/*
* srtt is stored as fixed point with 5 bits after the
* binary point (i.e., scaled by 8). The following magic is
* equivalent to the smoothing algorithm in rfc793 with an
* alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
* Adjust rtt to origin 0.
*/
delta = ((rtt - 1) << TCP_DELTA_SHIFT)
- (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
tp->t_srtt += delta;
if (tp->t_srtt <= 0)
tp->t_srtt = 1;
/*
* We accumulate a smoothed rtt variance (actually, a
* smoothed mean difference), then set the retransmit timer
* to smoothed rtt + 4 times the smoothed variance. rttvar
* is stored as fixed point with 4 bits after the binary
* point (scaled by 16). The following is equivalent to
* rfc793 smoothing with an alpha of .75 (rttvar =
* rttvar*3/4 + |delta| / 4). This replaces rfc793's
* wired-in beta.
*/
if (delta < 0)
delta = -delta;
delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
tp->t_rttvar += delta;
if (tp->t_rttvar <= 0)
tp->t_rttvar = 1;
if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
} else {
/*
* No rtt measurement yet - use the unsmoothed rtt. Set the
* variance to half the rtt (so our first retransmit happens
* at 3*rtt).
*/
tp->t_srtt = rtt << TCP_RTT_SHIFT;
tp->t_rttvar = rtt << (TCP_RTTVAR_SHIFT - 1);
tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
}
KMOD_TCPSTAT_INC(tcps_rttupdated);
tp->t_rttupdated++;
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
#endif
tp->t_rxtshift = 0;
/*
* the retransmit should happen at rtt + 4 * rttvar. Because of the
* way we do the smoothing, srtt and rttvar will each average +1/2
* tick of bias. When we compute the retransmit timer, we want 1/2
* tick of rounding and 1 extra tick because of +-1/2 tick
* uncertainty in the firing of the timer. The bias will give us
* exactly the 1.5 tick we need. But, because the bias is
* statistical, we have to test that we don't drop below the minimum
* feasible timer (which is 2 ticks).
*/
TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
max(MSEC_2_TICKS(rack_rto_min), rtt + 2), MSEC_2_TICKS(rack_rto_max));
tp->t_softerror = 0;
}
static void
rack_earlier_retran(struct tcpcb *tp, struct rack_sendmap *rsm,
uint32_t t, uint32_t cts)
{
/*
* For this RSM, we acknowledged the data from a previous
* transmission, not the last one we made. This means we did a false
* retransmit.
*/
struct tcp_rack *rack;
if (rsm->r_flags & RACK_HAS_FIN) {
/*
* The sending of the FIN often is multiple sent when we
* have everything outstanding ack'd. We ignore this case
* since its over now.
*/
return;
}
if (rsm->r_flags & RACK_TLP) {
/*
* We expect TLP's to have this occur.
*/
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
/* should we undo cc changes and exit recovery? */
if (IN_RECOVERY(tp->t_flags)) {
if (rack->r_ctl.rc_rsm_start == rsm->r_start) {
/*
* Undo what we ratched down and exit recovery if
* possible
*/
EXIT_RECOVERY(tp->t_flags);
tp->snd_recover = tp->snd_una;
if (rack->r_ctl.rc_cwnd_at > tp->snd_cwnd)
tp->snd_cwnd = rack->r_ctl.rc_cwnd_at;
if (rack->r_ctl.rc_ssthresh_at > tp->snd_ssthresh)
tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at;
}
}
if (rsm->r_flags & RACK_WAS_SACKPASS) {
/*
* We retransmitted based on a sack and the earlier
* retransmission ack'd it - re-ordering is occuring.
*/
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
counter_u64_add(rack_badfr, 1);
counter_u64_add(rack_badfr_bytes, (rsm->r_end - rsm->r_start));
}
static void
rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
{
/*
* Apply to filter the inbound us-rtt at us_cts.
*/
uint32_t old_rtt;
old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
us_rtt, us_cts);
if (rack->r_ctl.last_pacing_time &&
rack->rc_gp_dyn_mul &&
(rack->r_ctl.last_pacing_time > us_rtt))
rack->pacing_longer_than_rtt = 1;
else
rack->pacing_longer_than_rtt = 0;
if (old_rtt > us_rtt) {
/* We just hit a new lower rtt time */
rack_log_rtt_shrinks(rack, us_cts, old_rtt,
__LINE__, RACK_RTTS_NEWRTT);
/*
* Only count it if its lower than what we saw within our
* calculated range.
*/
if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
if (rack_probertt_lower_within &&
rack->rc_gp_dyn_mul &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/*
* We are seeing a new lower rtt very close
* to the time that we would have entered probe-rtt.
* This is probably due to the fact that a peer flow
* has entered probe-rtt. Lets go in now too.
*/
uint32_t val;
val = rack_probertt_lower_within * rack_time_between_probertt;
val /= 100;
if ((rack->in_probe_rtt == 0) &&
((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val))) {
rack_enter_probertt(rack, us_cts);
}
}
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
}
}
}
static int
rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
{
int32_t i;
uint32_t t, len_acked;
if ((rsm->r_flags & RACK_ACKED) ||
(rsm->r_flags & RACK_WAS_ACKED))
/* Already done */
return (0);
if (ack_type == CUM_ACKED) {
if (SEQ_GT(th_ack, rsm->r_end))
len_acked = rsm->r_end - rsm->r_start;
else
len_acked = th_ack - rsm->r_start;
} else
len_acked = rsm->r_end - rsm->r_start;
if (rsm->r_rtr_cnt == 1) {
uint32_t us_rtt;
t = cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
if ((int)t <= 0)
t = 1;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
if (!rack->r_ctl.rc_rack_min_rtt ||
SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - rsm->usec_orig_send;
if (us_rtt == 0)
us_rtt = 1;
rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
if (ack_type == SACKED)
tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
else {
/*
* For cum-ack we are only confident if what
* is being acked is included in a measurement.
* Otherwise it could be an idle period that
* includes Delayed-ack time.
*/
tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
(rack->app_limited_needs_set ? 0 : 1), rsm, rsm->r_rtr_cnt);
}
if ((rsm->r_flags & RACK_TLP) &&
(!IN_RECOVERY(tp->t_flags))) {
/* Segment was a TLP and our retrans matched */
if (rack->r_ctl.rc_tlp_cwnd_reduce) {
rack->r_ctl.rc_rsm_start = tp->snd_max;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure
* we send one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 7, 0);
}
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
rack->rc_rack_rtt = t;
}
return (1);
}
/*
* We clear the soft/rxtshift since we got an ack.
* There is no assurance we will call the commit() function
* so we need to clear these to avoid incorrect handling.
*/
tp->t_rxtshift = 0;
tp->t_softerror = 0;
if ((to->to_flags & TOF_TS) &&
(ack_type == CUM_ACKED) &&
(to->to_tsecr) &&
((rsm->r_flags & RACK_OVERMAX) == 0)) {
/*
* Now which timestamp does it match? In this block the ACK
* must be coming from a previous transmission.
*/
for (i = 0; i < rsm->r_rtr_cnt; i++) {
if (rsm->r_tim_lastsent[i] == to->to_tsecr) {
t = cts - rsm->r_tim_lastsent[i];
if ((int)t <= 0)
t = 1;
if ((i + 1) < rsm->r_rtr_cnt) {
/* Likely */
rack_earlier_retran(tp, rsm, t, cts);
}
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
rack->rc_rack_rtt = t;
}
tcp_rack_xmit_timer(rack, t + 1, len_acked, (t * HPTS_USEC_IN_MSEC), 0, rsm,
rsm->r_rtr_cnt);
return (1);
}
}
goto ts_not_found;
} else {
/*
* Ok its a SACK block that we retransmitted. or a windows
* machine without timestamps. We can tell nothing from the
* time-stamp since its not there or the time the peer last
* recieved a segment that moved forward its cum-ack point.
*/
ts_not_found:
i = rsm->r_rtr_cnt - 1;
t = cts - rsm->r_tim_lastsent[i];
if ((int)t <= 0)
t = 1;
if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
/*
* We retransmitted and the ack came back in less
* than the smallest rtt we have observed. We most
* likey did an improper retransmit as outlined in
* 4.2 Step 3 point 2 in the rack-draft.
*/
i = rsm->r_rtr_cnt - 2;
t = cts - rsm->r_tim_lastsent[i];
rack_earlier_retran(tp, rsm, t, cts);
} else if (rack->r_ctl.rc_rack_min_rtt) {
/*
* We retransmitted it and the retransmit did the
* job.
*/
if (!rack->r_ctl.rc_rack_min_rtt ||
SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
rack->r_ctl.rc_rack_min_rtt = t;
if (rack->r_ctl.rc_rack_min_rtt == 0) {
rack->r_ctl.rc_rack_min_rtt = 1;
}
}
if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, rsm->r_tim_lastsent[i])) {
/* New more recent rack_tmit_time */
rack->r_ctl.rc_rack_tmit_time = rsm->r_tim_lastsent[i];
rack->rc_rack_rtt = t;
}
return (1);
}
}
return (0);
}
/*
* Mark the SACK_PASSED flag on all entries prior to rsm send wise.
*/
static void
rack_log_sack_passed(struct tcpcb *tp,
struct tcp_rack *rack, struct rack_sendmap *rsm)
{
struct rack_sendmap *nrsm;
nrsm = rsm;
TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
rack_head, r_tnext) {
if (nrsm == rsm) {
/* Skip orginal segment he is acked */
continue;
}
if (nrsm->r_flags & RACK_ACKED) {
/*
* Skip ack'd segments, though we
* should not see these, since tmap
* should not have ack'd segments.
*/
continue;
}
if (nrsm->r_flags & RACK_SACK_PASSED) {
/*
* We found one that is already marked
* passed, we have been here before and
* so all others below this are marked.
*/
break;
}
nrsm->r_flags |= RACK_SACK_PASSED;
nrsm->r_flags &= ~RACK_WAS_SACKPASS;
}
}
static void
rack_need_set_test(struct tcpcb *tp,
struct tcp_rack *rack,
struct rack_sendmap *rsm,
tcp_seq th_ack,
int line,
int use_which)
{
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
/*
* We were app limited, and this ack
* butts up or goes beyond the point where we want
* to start our next measurement. We need
* to record the new gput_ts as here and
* possibly update the start sequence.
*/
uint32_t seq, ts;
if (rsm->r_rtr_cnt > 1) {
/*
* This is a retransmit, can we
* really make any assessment at this
* point? We are not really sure of
* the timestamp, is it this or the
* previous transmission?
*
* Lets wait for something better that
* is not retransmitted.
*/
return;
}
seq = tp->gput_seq;
ts = tp->gput_ts;
rack->app_limited_needs_set = 0;
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
/* Do we start at a new end? */
if ((use_which == RACK_USE_BEG) &&
SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
/*
* When we get an ACK that just eats
* up some of the rsm, we set RACK_USE_BEG
* since whats at r_start (i.e. th_ack)
* is left unacked and thats where the
* measurement not starts.
*/
tp->gput_seq = rsm->r_start;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if ((use_which == RACK_USE_END) &&
SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
/*
* We use the end when the cumack
* is moving forward and completely
* deleting the rsm passed so basically
* r_end holds th_ack.
*
* For SACK's we also want to use the end
* since this piece just got sacked and
* we want to target anything after that
* in our measurement.
*/
tp->gput_seq = rsm->r_end;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if (use_which == RACK_USE_END_OR_THACK) {
/*
* special case for ack moving forward,
* not a sack, we need to move all the
* way up to where this ack cum-ack moves
* to.
*/
if (SEQ_GT(th_ack, rsm->r_end))
tp->gput_seq = th_ack;
else
tp->gput_seq = rsm->r_end;
rack->r_ctl.rc_gp_output_ts = rsm->usec_orig_send;
}
if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
/*
* We moved beyond this guy's range, re-calculate
* the new end point.
*/
if (rack->rc_gp_filled == 0) {
tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
} else {
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
}
}
/*
* We are moving the goal post, we may be able to clear the
* measure_saw_probe_rtt flag.
*/
if ((rack->in_probe_rtt == 0) &&
(rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
seq, tp->gput_seq, 0, 5, line, NULL);
if (rack->rc_gp_filled &&
((tp->gput_ack - tp->gput_seq) <
max(rc_init_window(rack), (MIN_GP_WIN *
ctf_fixed_maxseg(tp))))) {
/*
* There is no sense of continuing this measurement
* because its too small to gain us anything we
* trust. Skip it and that way we can start a new
* measurement quicker.
*/
rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
0, 0, 0, 6, __LINE__, NULL);
tp->t_flags &= ~TF_GPUTINPROG;
}
}
}
static uint32_t
rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
{
uint32_t start, end, changed = 0;
struct rack_sendmap stack_map;
struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next;
int32_t used_ref = 1;
int moved = 0;
start = sack->start;
end = sack->end;
rsm = *prsm;
memset(&fe, 0, sizeof(fe));
do_rest_ofb:
if ((rsm == NULL) ||
(SEQ_LT(end, rsm->r_start)) ||
(SEQ_GEQ(start, rsm->r_end)) ||
(SEQ_LT(start, rsm->r_start))) {
/*
* We are not in the right spot,
* find the correct spot in the tree.
*/
used_ref = 0;
fe.r_start = start;
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
moved++;
}
if (rsm == NULL) {
/* TSNH */
goto out;
}
/* Ok we have an ACK for some piece of this rsm */
if (rsm->r_start != start) {
if ((rsm->r_flags & RACK_ACKED) == 0) {
/**
* Need to split this in two pieces the before and after,
* the before remains in the map, the after must be
* added. In other words we have:
* rsm |--------------|
* sackblk |------->
* rsm will become
* rsm |---|
* and nrsm will be the sacked piece
* nrsm |----------|
*
* But before we start down that path lets
* see if the sack spans over on top of
* the next guy and it is already sacked.
*/
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (next && (next->r_flags & RACK_ACKED) &&
SEQ_GEQ(end, next->r_start)) {
/**
* So the next one is already acked, and
* we can thus by hookery use our stack_map
* to reflect the piece being sacked and
* then adjust the two tree entries moving
* the start and ends around. So we start like:
* rsm |------------| (not-acked)
* next |-----------| (acked)
* sackblk |-------->
* We want to end like so:
* rsm |------| (not-acked)
* next |-----------------| (acked)
* nrsm |-----|
* Where nrsm is a temporary stack piece we
* use to update all the gizmos.
*/
/* Copy up our fudge block */
nrsm = &stack_map;
memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
/* Now adjust our tree blocks */
rsm->r_end = start;
next->r_start = start;
/* Clear out the dup ack count of the remainder */
rsm->r_dupack = 0;
rsm->r_just_ret = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
/* Now lets make sure our fudge block is right */
nrsm->r_start = start;
/* Now lets update all the stats and such */
rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
changed += (nrsm->r_end - nrsm->r_start);
rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
if (nrsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
/*
* Now we want to go up from rsm (the
* one left un-acked) to the next one
* in the tmap. We do this so when
* we walk backwards we include marking
* sack-passed on rsm (The one passed in
* is skipped since it is generally called
* on something sacked before removing it
* from the tmap).
*/
if (rsm->r_in_tmap) {
nrsm = TAILQ_NEXT(rsm, r_tnext);
/*
* Now that we have the next
* one walk backwards from there.
*/
if (nrsm && nrsm->r_in_tmap)
rack_log_sack_passed(tp, rack, nrsm);
}
/* Now are we done? */
if (SEQ_LT(end, next->r_end) ||
(end == next->r_end)) {
/* Done with block */
goto out;
}
counter_u64_add(rack_sack_used_next_merge, 1);
/* Postion for the next block */
start = next->r_end;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
if (rsm == NULL)
goto out;
} else {
/**
* We can't use any hookery here, so we
* need to split the map. We enter like
* so:
* rsm |--------|
* sackblk |----->
* We will add the new block nrsm and
* that will be the new portion, and then
* fall through after reseting rsm. So we
* split and look like this:
* rsm |----|
* sackblk |----->
* nrsm |---|
* We then fall through reseting
* rsm to nrsm, so the next block
* picks it up.
*/
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/*
* failed XXXrrs what can we do but loose the sack
* info?
*/
goto out;
}
counter_u64_add(rack_sack_splits, 1);
rack_clone_rsm(rack, nrsm, rsm, start);
rsm->r_just_ret = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
rsm->r_flags &= (~RACK_HAS_FIN);
/* Position us to point to the new nrsm that starts the sack blk */
rsm = nrsm;
}
} else {
/* Already sacked this piece */
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
if (end == rsm->r_end) {
/* Done with block */
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
goto out;
} else if (SEQ_LT(end, rsm->r_end)) {
/* A partial sack to a already sacked block */
moved++;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
goto out;
} else {
/*
* The end goes beyond this guy
* repostion the start to the
* next block.
*/
start = rsm->r_end;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (rsm == NULL)
goto out;
}
}
}
if (SEQ_GEQ(end, rsm->r_end)) {
/**
* The end of this block is either beyond this guy or right
* at this guy. I.e.:
* rsm --- |-----|
* end |-----|
* <or>
* end |---------|
*/
if ((rsm->r_flags & RACK_ACKED) == 0) {
rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
if (rsm->r_in_tmap) /* should be true */
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rsm->r_flags &= ~RACK_TLP;
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
} else {
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
}
if (end == rsm->r_end) {
/* This block only - done, setup for next */
goto out;
}
/*
* There is more not coverend by this rsm move on
* to the next block in the RB tree.
*/
nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
start = rsm->r_end;
rsm = nrsm;
if (rsm == NULL)
goto out;
goto do_rest_ofb;
}
/**
* The end of this sack block is smaller than
* our rsm i.e.:
* rsm --- |-----|
* end |--|
*/
if ((rsm->r_flags & RACK_ACKED) == 0) {
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
if (prev && (prev->r_flags & RACK_ACKED)) {
/**
* Goal, we want the right remainder of rsm to shrink
* in place and span from (rsm->r_start = end) to rsm->r_end.
* We want to expand prev to go all the way
* to prev->r_end <- end.
* so in the tree we have before:
* prev |--------| (acked)
* rsm |-------| (non-acked)
* sackblk |-|
* We churn it so we end up with
* prev |----------| (acked)
* rsm |-----| (non-acked)
* nrsm |-| (temporary)
*/
nrsm = &stack_map;
memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
prev->r_end = end;
rsm->r_start = end;
/* Now adjust nrsm (stack copy) to be
* the one that is the small
* piece that was "sacked".
*/
nrsm->r_end = end;
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
/*
* Now nrsm is our new little piece
* that is acked (which was merged
* to prev). Update the rtt and changed
* based on that. Also check for reordering.
*/
rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
changed += (nrsm->r_end - nrsm->r_start);
rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
if (nrsm->r_flags & RACK_SACK_PASSED) {
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
rsm = prev;
counter_u64_add(rack_sack_used_prev_merge, 1);
} else {
/**
* This is the case where our previous
* block is not acked either, so we must
* split the block in two.
*/
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* failed rrs what can we do but loose the sack info? */
goto out;
}
/**
* In this case nrsm becomes
* nrsm->r_start = end;
* nrsm->r_end = rsm->r_end;
* which is un-acked.
* <and>
* rsm->r_end = nrsm->r_start;
* i.e. the remaining un-acked
* piece is left on the left
* hand side.
*
* So we start like this
* rsm |----------| (not acked)
* sackblk |---|
* build it so we have
* rsm |---| (acked)
* nrsm |------| (not acked)
*/
counter_u64_add(rack_sack_splits, 1);
rack_clone_rsm(rack, nrsm, rsm, end);
rsm->r_flags &= (~RACK_HAS_FIN);
rsm->r_just_ret = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
nrsm->r_dupack = 0;
rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
changed += (rsm->r_end - rsm->r_start);
rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
if (rsm->r_in_tmap) /* should be true */
rack_log_sack_passed(tp, rack, rsm);
/* Is Reordering occuring? */
if (rsm->r_flags & RACK_SACK_PASSED) {
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rack->r_ctl.rc_reorder_ts = cts;
}
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rsm->r_flags &= ~RACK_TLP;
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
}
} else if (start != end){
/*
* The block was already acked.
*/
counter_u64_add(rack_sack_skipped_acked, 1);
moved++;
}
out:
if (rsm && (rsm->r_flags & RACK_ACKED)) {
/*
* Now can we merge where we worked
* with either the previous or
* next block?
*/
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
while (next) {
if (next->r_flags & RACK_ACKED) {
/* yep this and next can be merged */
rsm = rack_merge_rsm(rack, rsm, next);
next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
} else
break;
}
/* Now what about the previous? */
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
while (prev) {
if (prev->r_flags & RACK_ACKED) {
/* yep the previous and this can be merged */
rsm = rack_merge_rsm(rack, prev, rsm);
prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
} else
break;
}
}
if (used_ref == 0) {
counter_u64_add(rack_sack_proc_all, 1);
} else {
counter_u64_add(rack_sack_proc_short, 1);
}
/* Save off the next one for quick reference. */
if (rsm)
nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
else
nrsm = NULL;
*prsm = rack->r_ctl.rc_sacklast = nrsm;
/* Pass back the moved. */
*moved_two = moved;
return (changed);
}
static void inline
rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
{
struct rack_sendmap *tmap;
tmap = NULL;
while (rsm && (rsm->r_flags & RACK_ACKED)) {
/* Its no longer sacked, mark it so */
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
#ifdef INVARIANTS
if (rsm->r_in_tmap) {
panic("rack:%p rsm:%p flags:0x%x in tmap?",
rack, rsm, rsm->r_flags);
}
#endif
rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
/* Rebuild it into our tmap */
if (tmap == NULL) {
TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
tmap = rsm;
} else {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
tmap = rsm;
}
tmap->r_in_tmap = 1;
rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
}
/*
* Now lets possibly clear the sack filter so we start
* recognizing sacks that cover this area.
*/
sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
}
static void
rack_do_decay(struct tcp_rack *rack)
{
struct timeval res;
#define timersub(tvp, uvp, vvp) \
do { \
(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec; \
(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec; \
if ((vvp)->tv_usec < 0) { \
(vvp)->tv_sec--; \
(vvp)->tv_usec += 1000000; \
} \
} while (0)
timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
#undef timersub
rack->r_ctl.input_pkt++;
if ((rack->rc_in_persist) ||
(res.tv_sec >= 1) ||
(rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
/*
* Check for decay of non-SAD,
* we want all SAD detection metrics to
* decay 1/4 per second (or more) passed.
*/
uint32_t pkt_delta;
pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
/* Update our saved tracking values */
rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
/* Now do we escape without decay? */
#ifdef NETFLIX_EXP_DETECTION
if (rack->rc_in_persist ||
(rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
(pkt_delta < tcp_sad_low_pps)){
/*
* We don't decay idle connections
* or ones that have a low input pps.
*/
return;
}
/* Decay the counters */
rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
tcp_sad_decay_val);
rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
tcp_sad_decay_val);
rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
tcp_sad_decay_val);
rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
tcp_sad_decay_val);
#endif
}
}
static void
rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th)
{
uint32_t changed, entered_recovery = 0;
struct tcp_rack *rack;
struct rack_sendmap *rsm, *rm;
struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
register uint32_t th_ack;
int32_t i, j, k, num_sack_blks = 0;
uint32_t cts, acked, ack_point, sack_changed = 0;
int loop_start = 0, moved_two = 0;
uint32_t tsused;
INP_WLOCK_ASSERT(tp->t_inpcb);
if (th->th_flags & TH_RST) {
/* We don't log resets */
return;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
cts = tcp_ts_getticks();
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
changed = 0;
th_ack = th->th_ack;
if (rack->sack_attack_disable == 0)
rack_do_decay(rack);
if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
/*
* You only get credit for
* MSS and greater (and you get extra
* credit for larger cum-ack moves).
*/
int ac;
ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
rack->r_ctl.ack_count += ac;
counter_u64_add(rack_ack_total, ac);
}
if (rack->r_ctl.ack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
if (SEQ_GT(th_ack, tp->snd_una)) {
rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
tp->t_acktime = ticks;
}
if (rsm && SEQ_GT(th_ack, rsm->r_start))
changed = th_ack - rsm->r_start;
if (changed) {
/*
* The ACK point is advancing to th_ack, we must drop off
* the packets in the rack log and calculate any eligble
* RTT's.
*/
rack->r_wanted_output = 1;
more:
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm == NULL) {
if ((th_ack - 1) == tp->iss) {
/*
* For the SYN incoming case we will not
* have called tcp_output for the sending of
* the SYN, so there will be no map. All
* other cases should probably be a panic.
*/
goto proc_sack;
}
if (tp->t_flags & TF_SENTFIN) {
/* if we send a FIN we will not hav a map */
goto proc_sack;
}
#ifdef INVARIANTS
panic("No rack map tp:%p for th:%p state:%d rack:%p snd_una:%u snd_max:%u snd_nxt:%u chg:%d\n",
tp,
th, tp->t_state, rack,
tp->snd_una, tp->snd_max, tp->snd_nxt, changed);
#endif
goto proc_sack;
}
if (SEQ_LT(th_ack, rsm->r_start)) {
/* Huh map is missing this */
#ifdef INVARIANTS
printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
rsm->r_start,
th_ack, tp->t_state, rack->r_state);
#endif
goto proc_sack;
}
rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
/* Now do we consume the whole thing? */
if (SEQ_GEQ(th_ack, rsm->r_end)) {
/* Its all consumed. */
uint32_t left;
uint8_t newly_acked;
rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
rsm->r_rtr_bytes = 0;
/* Record the time of highest cumack sent */
rack->r_ctl.rc_gp_cumack_ts = rsm->usec_orig_send;
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (rm != rsm) {
panic("removing head in rack:%p rsm:%p rm:%p",
rack, rsm, rm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 0;
}
newly_acked = 1;
if (rsm->r_flags & RACK_ACKED) {
/*
* It was acked on the scoreboard -- remove
* it from total
*/
rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
newly_acked = 0;
} else if (rsm->r_flags & RACK_SACK_PASSED) {
/*
* There are segments ACKED on the
* scoreboard further up. We are seeing
* reordering.
*/
rsm->r_flags &= ~RACK_SACK_PASSED;
counter_u64_add(rack_reorder_seen, 1);
rsm->r_ack_arrival = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rsm->r_flags |= RACK_ACKED;
rack->r_ctl.rc_reorder_ts = cts;
}
left = th_ack - rsm->r_end;
if (rack->app_limited_needs_set && newly_acked)
rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
/* Free back to zone */
rack_free(rack, rsm);
if (left) {
goto more;
}
goto proc_sack;
}
if (rsm->r_flags & RACK_ACKED) {
/*
* It was acked on the scoreboard -- remove it from
* total for the part being cum-acked.
*/
rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
}
/*
* Clear the dup ack count for
* the piece that remains.
*/
rsm->r_dupack = 0;
rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
if (rsm->r_rtr_bytes) {
/*
* It was retransmitted adjust the
* sack holes for what was acked.
*/
int ack_am;
ack_am = (th_ack - rsm->r_start);
if (ack_am >= rsm->r_rtr_bytes) {
rack->r_ctl.rc_holes_rxt -= ack_am;
rsm->r_rtr_bytes -= ack_am;
}
}
/*
* Update where the piece starts and record
* the time of send of highest cumack sent.
*/
rack->r_ctl.rc_gp_cumack_ts = rsm->usec_orig_send;
rsm->r_start = th_ack;
if (rack->app_limited_needs_set)
rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
}
proc_sack:
/* Check for reneging */
rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
/*
* The peer has moved snd_una up to
* the edge of this send, i.e. one
* that it had previously acked. The only
* way that can be true if the peer threw
* away data (space issues) that it had
* previously sacked (else it would have
* given us snd_una up to (rsm->r_end).
* We need to undo the acked markings here.
*
* Note we have to look to make sure th_ack is
* our rsm->r_start in case we get an old ack
* where th_ack is behind snd_una.
*/
rack_peer_reneges(rack, rsm, th->th_ack);
}
if ((to->to_flags & TOF_SACK) == 0) {
/* We are done nothing left */
goto out;
}
/* Sack block processing */
if (SEQ_GT(th_ack, tp->snd_una))
ack_point = th_ack;
else
ack_point = tp->snd_una;
for (i = 0; i < to->to_nsacks; i++) {
bcopy((to->to_sacks + i * TCPOLEN_SACK),
&sack, sizeof(sack));
sack.start = ntohl(sack.start);
sack.end = ntohl(sack.end);
if (SEQ_GT(sack.end, sack.start) &&
SEQ_GT(sack.start, ack_point) &&
SEQ_LT(sack.start, tp->snd_max) &&
SEQ_GT(sack.end, ack_point) &&
SEQ_LEQ(sack.end, tp->snd_max)) {
sack_blocks[num_sack_blks] = sack;
num_sack_blks++;
#ifdef NETFLIX_STATS
} else if (SEQ_LEQ(sack.start, th_ack) &&
SEQ_LEQ(sack.end, th_ack)) {
/*
* Its a D-SACK block.
*/
tcp_record_dsack(sack.start, sack.end);
#endif
}
}
/*
* Sort the SACK blocks so we can update the rack scoreboard with
* just one pass.
*/
num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
num_sack_blks, th->th_ack);
ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
if (num_sack_blks == 0) {
/* Nothing to sack (DSACKs?) */
goto out_with_totals;
}
if (num_sack_blks < 2) {
/* Only one, we don't need to sort */
goto do_sack_work;
}
/* Sort the sacks */
for (i = 0; i < num_sack_blks; i++) {
for (j = i + 1; j < num_sack_blks; j++) {
if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
sack = sack_blocks[i];
sack_blocks[i] = sack_blocks[j];
sack_blocks[j] = sack;
}
}
}
/*
* Now are any of the sack block ends the same (yes some
* implementations send these)?
*/
again:
if (num_sack_blks == 0)
goto out_with_totals;
if (num_sack_blks > 1) {
for (i = 0; i < num_sack_blks; i++) {
for (j = i + 1; j < num_sack_blks; j++) {
if (sack_blocks[i].end == sack_blocks[j].end) {
/*
* Ok these two have the same end we
* want the smallest end and then
* throw away the larger and start
* again.
*/
if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
/*
* The second block covers
* more area use that
*/
sack_blocks[i].start = sack_blocks[j].start;
}
/*
* Now collapse out the dup-sack and
* lower the count
*/
for (k = (j + 1); k < num_sack_blks; k++) {
sack_blocks[j].start = sack_blocks[k].start;
sack_blocks[j].end = sack_blocks[k].end;
j++;
}
num_sack_blks--;
goto again;
}
}
}
}
do_sack_work:
/*
* First lets look to see if
* we have retransmitted and
* can use the transmit next?
*/
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm &&
SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
/*
* We probably did the FR and the next
* SACK in continues as we would expect.
*/
acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
if (acked) {
rack->r_wanted_output = 1;
changed += acked;
sack_changed += acked;
}
if (num_sack_blks == 1) {
/*
* This is what we would expect from
* a normal implementation to happen
* after we have retransmitted the FR,
* i.e the sack-filter pushes down
* to 1 block and the next to be retransmitted
* is the sequence in the sack block (has more
* are acked). Count this as ACK'd data to boost
* up the chances of recovering any false positives.
*/
rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
counter_u64_add(rack_express_sack, 1);
if (rack->r_ctl.ack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
goto out_with_totals;
} else {
/*
* Start the loop through the
* rest of blocks, past the first block.
*/
moved_two = 0;
loop_start = 1;
}
}
/* Its a sack of some sort */
rack->r_ctl.sack_count++;
if (rack->r_ctl.sack_count > 0xfff00000) {
/*
* reduce the number to keep us under
* a uint32_t.
*/
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
counter_u64_add(rack_sack_total, 1);
if (rack->sack_attack_disable) {
/* An attacker disablement is in place */
if (num_sack_blks > 1) {
rack->r_ctl.sack_count += (num_sack_blks - 1);
rack->r_ctl.sack_moved_extra++;
counter_u64_add(rack_move_some, 1);
if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
rack->r_ctl.sack_moved_extra /= 2;
rack->r_ctl.sack_noextra_move /= 2;
}
}
goto out;
}
rsm = rack->r_ctl.rc_sacklast;
for (i = loop_start; i < num_sack_blks; i++) {
acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
if (acked) {
rack->r_wanted_output = 1;
changed += acked;
sack_changed += acked;
}
if (moved_two) {
/*
* If we did not get a SACK for at least a MSS and
* had to move at all, or if we moved more than our
* threshold, it counts against the "extra" move.
*/
rack->r_ctl.sack_moved_extra += moved_two;
counter_u64_add(rack_move_some, 1);
} else {
/*
* else we did not have to move
* any more than we would expect.
*/
rack->r_ctl.sack_noextra_move++;
counter_u64_add(rack_move_none, 1);
}
if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
/*
* If the SACK was not a full MSS then
* we add to sack_count the number of
* MSS's (or possibly more than
* a MSS if its a TSO send) we had to skip by.
*/
rack->r_ctl.sack_count += moved_two;
counter_u64_add(rack_sack_total, moved_two);
}
/*
* Now we need to setup for the next
* round. First we make sure we won't
* exceed the size of our uint32_t on
* the various counts, and then clear out
* moved_two.
*/
if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
(rack->r_ctl.sack_noextra_move > 0xfff00000)) {
rack->r_ctl.sack_moved_extra /= 2;
rack->r_ctl.sack_noextra_move /= 2;
}
if (rack->r_ctl.sack_count > 0xfff00000) {
rack->r_ctl.ack_count /= 2;
rack->r_ctl.sack_count /= 2;
}
moved_two = 0;
}
out_with_totals:
if (num_sack_blks > 1) {
/*
* You get an extra stroke if
* you have more than one sack-blk, this
* could be where we are skipping forward
* and the sack-filter is still working, or
* it could be an attacker constantly
* moving us.
*/
rack->r_ctl.sack_moved_extra++;
counter_u64_add(rack_move_some, 1);
}
out:
#ifdef NETFLIX_EXP_DETECTION
if ((rack->do_detection || tcp_force_detection) &&
tcp_sack_to_ack_thresh &&
tcp_sack_to_move_thresh &&
((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
/*
* We have thresholds set to find
* possible attackers and disable sack.
* Check them.
*/
uint64_t ackratio, moveratio, movetotal;
/* Log detecting */
rack_log_sad(rack, 1);
ackratio = (uint64_t)(rack->r_ctl.sack_count);
ackratio *= (uint64_t)(1000);
if (rack->r_ctl.ack_count)
ackratio /= (uint64_t)(rack->r_ctl.ack_count);
else {
/* We really should not hit here */
ackratio = 1000;
}
if ((rack->sack_attack_disable == 0) &&
(ackratio > rack_highest_sack_thresh_seen))
rack_highest_sack_thresh_seen = (uint32_t)ackratio;
movetotal = rack->r_ctl.sack_moved_extra;
movetotal += rack->r_ctl.sack_noextra_move;
moveratio = rack->r_ctl.sack_moved_extra;
moveratio *= (uint64_t)1000;
if (movetotal)
moveratio /= movetotal;
else {
/* No moves, thats pretty good */
moveratio = 0;
}
if ((rack->sack_attack_disable == 0) &&
(moveratio > rack_highest_move_thresh_seen))
rack_highest_move_thresh_seen = (uint32_t)moveratio;
if (rack->sack_attack_disable == 0) {
if ((ackratio > tcp_sack_to_ack_thresh) &&
(moveratio > tcp_sack_to_move_thresh)) {
/* Disable sack processing */
rack->sack_attack_disable = 1;
if (rack->r_rep_attack == 0) {
rack->r_rep_attack = 1;
counter_u64_add(rack_sack_attacks_detected, 1);
}
if (tcp_attack_on_turns_on_logging) {
/*
* Turn on logging, used for debugging
* false positives.
*/
rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
}
/* Clamp the cwnd at flight size */
rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
rack_log_sad(rack, 2);
}
} else {
/* We are sack-disabled check for false positives */
if ((ackratio <= tcp_restoral_thresh) ||
(rack->r_ctl.rc_num_maps_alloced < tcp_map_minimum)) {
rack->sack_attack_disable = 0;
rack_log_sad(rack, 3);
/* Restart counting */
rack->r_ctl.sack_count = 0;
rack->r_ctl.sack_moved_extra = 0;
rack->r_ctl.sack_noextra_move = 1;
rack->r_ctl.ack_count = max(1,
(BYTES_THIS_ACK(tp, th)/ctf_fixed_maxseg(rack->rc_tp)));
if (rack->r_rep_reverse == 0) {
rack->r_rep_reverse = 1;
counter_u64_add(rack_sack_attacks_reversed, 1);
}
/* Restore the cwnd */
if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
}
}
}
#endif
if (changed) {
/* Something changed cancel the rack timer */
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
}
tsused = tcp_ts_getticks();
rsm = tcp_rack_output(tp, rack, tsused);
if ((!IN_RECOVERY(tp->t_flags)) &&
rsm) {
/* Enter recovery */
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
entered_recovery = 1;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure we send
* one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
rack_log_to_prr(rack, 8, 0);
}
rack->r_timer_override = 1;
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
} else if (IN_RECOVERY(tp->t_flags) &&
rsm &&
(rack->r_rr_config == 3)) {
/*
* Assure we can output and we get no
* remembered pace time except the retransmit.
*/
rack->r_timer_override = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack->r_ctl.rc_resend = rsm;
}
if (IN_RECOVERY(tp->t_flags) &&
(rack->rack_no_prr == 0) &&
(entered_recovery == 0)) {
/* Deal with PRR here (in recovery only) */
uint32_t pipe, snd_una;
rack->r_ctl.rc_prr_delivered += changed;
/* Compute prr_sndcnt */
if (SEQ_GT(tp->snd_una, th_ack)) {
snd_una = tp->snd_una;
} else {
snd_una = th_ack;
}
pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
if (pipe > tp->snd_ssthresh) {
long sndcnt;
sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
if (rack->r_ctl.rc_prr_recovery_fs > 0)
sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
else {
rack->r_ctl.rc_prr_sndcnt = 0;
rack_log_to_prr(rack, 9, 0);
sndcnt = 0;
}
sndcnt++;
if (sndcnt > (long)rack->r_ctl.rc_prr_out)
sndcnt -= rack->r_ctl.rc_prr_out;
else
sndcnt = 0;
rack->r_ctl.rc_prr_sndcnt = sndcnt;
rack_log_to_prr(rack, 10, 0);
} else {
uint32_t limit;
if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
else
limit = 0;
if (changed > limit)
limit = changed;
limit += ctf_fixed_maxseg(tp);
if (tp->snd_ssthresh > pipe) {
rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
rack_log_to_prr(rack, 11, 0);
} else {
rack->r_ctl.rc_prr_sndcnt = min(0, limit);
rack_log_to_prr(rack, 12, 0);
}
}
if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
((rack->rc_inp->inp_in_hpts == 0) &&
((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
/*
* If you are pacing output you don't want
* to override.
*/
rack->r_early = 0;
rack->r_ctl.rc_agg_early = 0;
rack->r_timer_override = 1;
}
}
}
static void
rack_strike_dupack(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm && (rsm->r_dupack < 0xff)) {
rsm->r_dupack++;
if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
rack->r_wanted_output = 1;
rack->r_timer_override = 1;
rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
} else {
rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
}
}
}
static void
rack_check_bottom_drag(struct tcpcb *tp,
struct tcp_rack *rack,
struct socket *so, int32_t acked)
{
uint32_t segsiz, minseg;
segsiz = ctf_fixed_maxseg(tp);
minseg = segsiz;
if (tp->snd_max == tp->snd_una) {
/*
* We are doing dynamic pacing and we are way
* under. Basically everything got acked while
* we were still waiting on the pacer to expire.
*
* This means we need to boost the b/w in
* addition to any earlier boosting of
* the multipler.
*/
rack->rc_dragged_bottom = 1;
rack_validate_multipliers_at_or_above100(rack);
/*
* Lets use the segment bytes acked plus
* the lowest RTT seen as the basis to
* form a b/w estimate. This will be off
* due to the fact that the true estimate
* should be around 1/2 the time of the RTT
* but we can settle for that.
*/
if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
acked) {
uint64_t bw, calc_bw, rtt;
rtt = rack->r_ctl.rack_rs.rs_us_rtt;
bw = acked;
calc_bw = bw * 1000000;
calc_bw /= rtt;
if (rack->r_ctl.last_max_bw &&
(rack->r_ctl.last_max_bw < calc_bw)) {
/*
* If we have a last calculated max bw
* enforce it.
*/
calc_bw = rack->r_ctl.last_max_bw;
}
/* now plop it in */
if (rack->rc_gp_filled == 0) {
if (calc_bw > ONE_POINT_TWO_MEG) {
/*
* If we have no measurement
* don't let us set in more than
* 1.2Mbps. If we are still too
* low after pacing with this we
* will hopefully have a max b/w
* available to sanity check things.
*/
calc_bw = ONE_POINT_TWO_MEG;
}
rack->r_ctl.rc_rtt_diff = 0;
rack->r_ctl.gp_bw = calc_bw;
rack->rc_gp_filled = 1;
rack->r_ctl.num_avg = RACK_REQ_AVG;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else if (calc_bw > rack->r_ctl.gp_bw) {
rack->r_ctl.rc_rtt_diff = 0;
rack->r_ctl.num_avg = RACK_REQ_AVG;
rack->r_ctl.gp_bw = calc_bw;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else
rack_increase_bw_mul(rack, -1, 0, 0, 1);
/*
* For acks over 1mss we do a extra boost to simulate
* where we would get 2 acks (we want 110 for the mul).
*/
if (acked > segsiz)
rack_increase_bw_mul(rack, -1, 0, 0, 1);
} else {
/*
* Huh, this should not be, settle
* for just an old increase.
*/
rack_increase_bw_mul(rack, -1, 0, 0, 1);
}
} else if ((IN_RECOVERY(tp->t_flags) == 0) &&
(sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
minseg)) &&
(rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
(tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
(ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
(segsiz * rack_req_segs))) {
/*
* We are doing dynamic GP pacing and
* we have everything except 1MSS or less
* bytes left out. We are still pacing away.
* And there is data that could be sent, This
* means we are inserting delayed ack time in
* our measurements because we are pacing too slow.
*/
rack_validate_multipliers_at_or_above100(rack);
rack->rc_dragged_bottom = 1;
rack_increase_bw_mul(rack, -1, 0, 0, 1);
}
}
/*
* Return value of 1, we do not need to call rack_process_data().
* return value of 0, rack_process_data can be called.
* For ret_val if its 0 the TCP is locked, if its non-zero
* its unlocked and probably unsafe to touch the TCB.
*/
static int
rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to,
uint32_t tiwin, int32_t tlen,
int32_t * ofia, int32_t thflags, int32_t * ret_val)
{
int32_t ourfinisacked = 0;
int32_t nsegs, acked_amount;
int32_t acked;
struct mbuf *mfree;
struct tcp_rack *rack;
int32_t under_pacing = 0;
int32_t recovery = 0;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (SEQ_GT(th->th_ack, tp->snd_max)) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
rack->r_wanted_output = 1;
return (1);
}
if (rack->rc_gp_filled &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
under_pacing = 1;
}
if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
if (rack->rc_in_persist)
tp->t_rxtshift = 0;
if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
rack_strike_dupack(rack);
rack_log_ack(tp, to, th);
}
if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
/*
* Old ack, behind (or duplicate to) the last one rcv'd
* Note: Should mark reordering is occuring! We should also
* look for sack blocks arriving e.g. ack 1, 4-4 then ack 1,
* 3-3, 4-4 would be reording. As well as ack 1, 3-3 <no
* retran and> ack 3
*/
return (0);
}
/*
* If we reach this point, ACK is not a duplicate, i.e., it ACKs
* something we sent.
*/
if (tp->t_flags & TF_NEEDSYN) {
/*
* T/TCP: Connection was half-synchronized, and our SYN has
* been ACK'd (so connection is now fully synchronized). Go
* to non-starred state, increment snd_una for ACK of SYN,
* and check if we can do window scaling.
*/
tp->t_flags &= ~TF_NEEDSYN;
tp->snd_una++;
/* Do window scaling? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
/* Send window already scaled. */
}
}
nsegs = max(1, m->m_pkthdr.lro_nsegs);
INP_WLOCK_ASSERT(tp->t_inpcb);
acked = BYTES_THIS_ACK(tp, th);
KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
/*
* If we just performed our first retransmit, and the ACK arrives
* within our recovery window, then it was a mistake to do the
* retransmit in the first place. Recover our original cwnd and
* ssthresh, and proceed to transmit where we left off.
*/
if (tp->t_flags & TF_PREVVALID) {
tp->t_flags &= ~TF_PREVVALID;
if (tp->t_rxtshift == 1 &&
(int)(ticks - tp->t_badrxtwin) < 0)
rack_cong_signal(tp, th, CC_RTO_ERR);
}
if (acked) {
/* assure we are not backed off */
tp->t_rxtshift = 0;
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
/*
* If it is the RXT timer we want to
* stop it, so we can restart a TLP.
*/
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
#ifdef NETFLIX_HTTP_LOGGING
tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
#endif
}
/*
* If we have a timestamp reply, update smoothed round trip time. If
* no timestamp is present but transmit timer is running and timed
* sequence number was acked, update smoothed round trip time. Since
* we now have an rtt measurement, cancel the timer backoff (cf.,
* Phil Karn's retransmit alg.). Recompute the initial retransmit
* timer.
*
* Some boxes send broken timestamp replies during the SYN+ACK
* phase, ignore timestamps of 0 or we could calculate a huge RTT
* and blow up the retransmit timer.
*/
/*
* If all outstanding data is acked, stop retransmit timer and
* remember to restart (more output or persist). If there is more
* data to be acked, restart retransmit timer, using current
* (possibly backed-off) value.
*/
if (acked == 0) {
if (ofia)
*ofia = ourfinisacked;
return (0);
}
if (rack->r_ctl.rc_early_recovery) {
if (IN_RECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover) &&
(SEQ_LT(th->th_ack, tp->snd_max))) {
tcp_rack_partialack(tp, th);
} else {
rack_post_recovery(tp, th);
recovery = 1;
}
}
}
/*
* Let the congestion control algorithm update congestion control
* related information. This typically means increasing the
* congestion window.
*/
rack_ack_received(tp, rack, th, nsegs, CC_ACK, recovery);
SOCKBUF_LOCK(&so->so_snd);
acked_amount = min(acked, (int)sbavail(&so->so_snd));
tp->snd_wnd -= acked_amount;
mfree = sbcut_locked(&so->so_snd, acked_amount);
if ((sbused(&so->so_snd) == 0) &&
(acked > acked_amount) &&
(tp->t_state >= TCPS_FIN_WAIT_1) &&
(tp->t_flags & TF_SENTFIN)) {
/*
* We must be sure our fin
* was sent and acked (we can be
* in FIN_WAIT_1 without having
* sent the fin).
*/
ourfinisacked = 1;
}
SOCKBUF_UNLOCK(&so->so_snd);
tp->t_flags |= TF_WAKESOW;
m_freem(mfree);
if (rack->r_ctl.rc_early_recovery == 0) {
if (IN_RECOVERY(tp->t_flags)) {
if (SEQ_LT(th->th_ack, tp->snd_recover) &&
(SEQ_LT(th->th_ack, tp->snd_max))) {
tcp_rack_partialack(tp, th);
} else {
rack_post_recovery(tp, th);
}
}
}
tp->snd_una = th->th_ack;
if (SEQ_GT(tp->snd_una, tp->snd_recover))
tp->snd_recover = tp->snd_una;
if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
tp->snd_nxt = tp->snd_una;
}
if (under_pacing &&
(rack->use_fixed_rate == 0) &&
(rack->in_probe_rtt == 0) &&
rack->rc_gp_dyn_mul &&
rack->rc_always_pace) {
/* Check if we are dragging bottom */
rack_check_bottom_drag(tp, rack, so, acked);
}
if (tp->snd_una == tp->snd_max) {
/* Nothing left outstanding */
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
tp->t_acktime = 0;
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
/* Set need output so persist might get set */
rack->r_wanted_output = 1;
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
(sbavail(&so->so_snd) == 0) &&
(tp->t_flags2 & TF2_DROP_AF_DATA)) {
/*
* The socket was gone and the
* peer sent data, time to
* reset him.
*/
*ret_val = 1;
/* tcp_close will kill the inp pre-log the Reset */
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
tp = tcp_close(tp);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
return (1);
}
}
if (ofia)
*ofia = ourfinisacked;
return (0);
}
static void
rack_collapsed_window(struct tcp_rack *rack)
{
/*
* Now we must walk the
* send map and divide the
* ones left stranded. These
* guys can't cause us to abort
* the connection and are really
* "unsent". However if a buggy
* client actually did keep some
* of the data i.e. collapsed the win
* and refused to ack and then opened
* the win and acked that data. We would
* get into an ack war, the simplier
* method then of just pretending we
* did not send those segments something
* won't work.
*/
struct rack_sendmap *rsm, *nrsm, fe, *insret;
tcp_seq max_seq;
max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
memset(&fe, 0, sizeof(fe));
fe.r_start = max_seq;
/* Find the first seq past or at maxseq */
rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (rsm == NULL) {
/* Nothing to do strange */
rack->rc_has_collapsed = 0;
return;
}
/*
* Now do we need to split at
* the collapse point?
*/
if (SEQ_GT(max_seq, rsm->r_start)) {
nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
if (nrsm == NULL) {
/* We can't get a rsm, mark all? */
nrsm = rsm;
goto no_split;
}
/* Clone it */
rack_clone_rsm(rack, nrsm, rsm, max_seq);
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
nrsm, insret, rack, rsm);
}
#endif
if (rsm->r_in_tmap) {
TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
nrsm->r_in_tmap = 1;
}
/*
* Set in the new RSM as the
* collapsed starting point
*/
rsm = nrsm;
}
no_split:
counter_u64_add(rack_collapsed_win, 1);
RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
nrsm->r_flags |= RACK_RWND_COLLAPSED;
rack->rc_has_collapsed = 1;
}
}
static void
rack_un_collapse_window(struct tcp_rack *rack)
{
struct rack_sendmap *rsm;
RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
if (rsm->r_flags & RACK_RWND_COLLAPSED)
rsm->r_flags &= ~RACK_RWND_COLLAPSED;
else
break;
}
rack->rc_has_collapsed = 0;
}
static void
rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
int32_t tlen, int32_t tfo_syn)
{
if (DELAY_ACK(tp, tlen) || tfo_syn) {
if (rack->rc_dack_mode &&
(tlen > 500) &&
(rack->rc_dack_toggle == 1)) {
goto no_delayed_ack;
}
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
no_delayed_ack:
rack->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
if (rack->rc_dack_mode) {
if (tp->t_flags & TF_DELACK)
rack->rc_dack_toggle = 1;
else
rack->rc_dack_toggle = 0;
}
}
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
{
/*
* Update window information. Don't look at window if no ACK: TAC's
* send garbage on first SYN.
*/
int32_t nsegs;
int32_t tfo_syn;
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
INP_WLOCK_ASSERT(tp->t_inpcb);
nsegs = max(1, m->m_pkthdr.lro_nsegs);
if ((thflags & TH_ACK) &&
(SEQ_LT(tp->snd_wl1, th->th_seq) ||
(tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
(tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
/* keep track of pure window updates */
if (tlen == 0 &&
tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
KMOD_TCPSTAT_INC(tcps_rcvwinupd);
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
tp->snd_wl2 = th->th_ack;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
rack->r_wanted_output = 1;
} else if (thflags & TH_ACK) {
if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
tp->snd_wl2 = th->th_ack;
}
}
if (tp->snd_wnd < ctf_outstanding(tp))
/* The peer collapsed the window */
rack_collapsed_window(rack);
else if (rack->rc_has_collapsed)
rack_un_collapse_window(rack);
/* Was persist timer active and now we have window space? */
if ((rack->rc_in_persist != 0) &&
(tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
rack->r_ctl.rc_pace_min_segs))) {
rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
tp->snd_nxt = tp->snd_max;
/* Make sure we output to start the timer */
rack->r_wanted_output = 1;
}
/* Do we enter persists? */
if ((rack->rc_in_persist == 0) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/*
* Here the rwnd is less than
* the pacing size, we are established,
* nothing is outstanding, and there is
* data to send. Enter persists.
*/
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
if (tp->t_flags2 & TF2_DROP_AF_DATA) {
m_freem(m);
return (0);
}
/*
* don't process the URG bit, ignore them drag
* along the up.
*/
tp->rcv_up = tp->rcv_nxt;
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* Process the segment text, merging it into the TCP sequencing
* queue, and arranging for acknowledgment of receipt if necessary.
* This process logically involves adjusting tp->rcv_wnd as data is
* presented to the user (this happens in tcp_usrreq.c, case
* PRU_RCVD). If a FIN has already been received on this connection
* then we just ignore the text.
*/
tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
IS_FASTOPEN(tp->t_flags));
if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
TCPS_HAVERCVDFIN(tp->t_state) == 0) {
tcp_seq save_start = th->th_seq;
tcp_seq save_rnxt = tp->rcv_nxt;
int save_tlen = tlen;
m_adj(m, drop_hdrlen); /* delayed header drop */
/*
* Insert segment which includes th into TCP reassembly
* queue with control block tp. Set thflags to whether
* reassembly now includes a segment with FIN. This handles
* the common case inline (segment is the next to be
* received on an established connection, and the queue is
* empty), avoiding linkage into and removal from the queue
* and repetition of various conversions. Set DELACK for
* segments received in order, but ack immediately when
* segments are out of order (so fast retransmit can work).
*/
if (th->th_seq == tp->rcv_nxt &&
SEGQ_EMPTY(tp) &&
(TCPS_HAVEESTABLISHED(tp->t_state) ||
tfo_syn)) {
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (0);
}
}
#endif
rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
tp->rcv_nxt += tlen;
if (tlen &&
((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
(tp->t_fbyte_in == 0)) {
tp->t_fbyte_in = ticks;
if (tp->t_fbyte_in == 0)
tp->t_fbyte_in = 1;
if (tp->t_fbyte_out && tp->t_fbyte_in)
tp->t_flags2 |= TF2_FBYTES_COMPLETE;
}
thflags = th->th_flags & TH_FIN;
KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
SOCKBUF_UNLOCK(&so->so_rcv);
tp->t_flags |= TF_WAKESOR;
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && appended != mcnt)
counter_fo_release(so->so_rcv.sb_shlim,
mcnt - appended);
#endif
} else {
/*
* XXX: Due to the header drop above "th" is
* theoretically invalid by now. Fortunately
* m_adj() doesn't actually frees any mbufs when
* trimming from the head.
*/
tcp_seq temp = save_start;
thflags = tcp_reass(tp, th, &temp, &tlen, m);
tp->t_flags |= TF_ACKNOW;
}
if ((tp->t_flags & TF_SACK_PERMIT) && (save_tlen > 0)) {
if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
/*
* DSACK actually handled in the fastpath
* above.
*/
RACK_OPTS_INC(tcp_sack_path_1);
tcp_update_sack_list(tp, save_start,
save_start + save_tlen);
} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
if ((tp->rcv_numsacks >= 1) &&
(tp->sackblks[0].end == save_start)) {
/*
* Partial overlap, recorded at todrop
* above.
*/
RACK_OPTS_INC(tcp_sack_path_2a);
tcp_update_sack_list(tp,
tp->sackblks[0].start,
tp->sackblks[0].end);
} else {
RACK_OPTS_INC(tcp_sack_path_2b);
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
}
} else if (tlen >= save_tlen) {
/* Update of sackblks. */
RACK_OPTS_INC(tcp_sack_path_3);
tcp_update_dsack_list(tp, save_start,
save_start + save_tlen);
} else if (tlen > 0) {
RACK_OPTS_INC(tcp_sack_path_4);
tcp_update_dsack_list(tp, save_start,
save_start + tlen);
}
}
} else {
m_freem(m);
thflags &= ~TH_FIN;
}
/*
* If FIN is received ACK the FIN and let the user know that the
* connection is closing.
*/
if (thflags & TH_FIN) {
if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
socantrcvmore(so);
/* The socket upcall is handled by socantrcvmore. */
tp->t_flags &= ~TF_WAKESOR;
/*
* If connection is half-synchronized (ie NEEDSYN
* flag on) then delay ACK, so it may be piggybacked
* when SYN is sent. Otherwise, since we received a
* FIN then no more input can be expected, send ACK
* now.
*/
if (tp->t_flags & TF_NEEDSYN) {
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
tp->t_flags |= TF_ACKNOW;
}
tp->rcv_nxt++;
}
switch (tp->t_state) {
/*
* In SYN_RECEIVED and ESTABLISHED STATES enter the
* CLOSE_WAIT state.
*/
case TCPS_SYN_RECEIVED:
tp->t_starttime = ticks;
/* FALLTHROUGH */
case TCPS_ESTABLISHED:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_state_change(tp, TCPS_CLOSE_WAIT);
break;
/*
* If still in FIN_WAIT_1 STATE FIN has not been
* acked so enter the CLOSING state.
*/
case TCPS_FIN_WAIT_1:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_state_change(tp, TCPS_CLOSING);
break;
/*
* In FIN_WAIT_2 state enter the TIME_WAIT state,
* starting the time-wait timer, turning off the
* other standard timers.
*/
case TCPS_FIN_WAIT_2:
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tcp_twstart(tp);
return (1);
}
}
/*
* Return any desired output.
*/
if ((tp->t_flags & TF_ACKNOW) ||
(sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
rack->r_wanted_output = 1;
}
INP_WLOCK_ASSERT(tp->t_inpcb);
return (0);
}
/*
* Here nothing is really faster, its just that we
* have broken out the fast-data path also just like
* the fast-ack.
*/
static int
rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
{
int32_t nsegs;
int32_t newsize = 0; /* automatic sockbuf scaling */
struct tcp_rack *rack;
#ifdef NETFLIX_SB_LIMITS
u_int mcnt, appended;
#endif
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.
*/
u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;
short ostate = 0;
#endif
/*
* If last ACK falls within this segment's sequence numbers, record
* the timestamp. NOTE that the test is modified according to the
* latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
*/
if (__predict_false(th->th_seq != tp->rcv_nxt)) {
return (0);
}
if (__predict_false(tp->snd_nxt != tp->snd_max)) {
return (0);
}
if (tiwin && tiwin != tp->snd_wnd) {
return (0);
}
if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
return (0);
}
if (__predict_false((to->to_flags & TOF_TS) &&
(TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
return (0);
}
if (__predict_false((th->th_ack != tp->snd_una))) {
return (0);
}
if (__predict_false(tlen > sbspace(&so->so_rcv))) {
return (0);
}
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
/*
* This is a pure, in-sequence data packet with nothing on the
* reassembly queue and we have enough buffer space to take it.
*/
nsegs = max(1, m->m_pkthdr.lro_nsegs);
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim) {
mcnt = m_memcnt(m);
appended = 0;
if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
CFO_NOSLEEP, NULL) == false) {
counter_u64_add(tcp_sb_shlim_fails, 1);
m_freem(m);
return (1);
}
}
#endif
/* Clean receiver SACK report if present */
if (tp->rcv_numsacks)
tcp_clean_sackreport(tp);
KMOD_TCPSTAT_INC(tcps_preddat);
tp->rcv_nxt += tlen;
if (tlen &&
((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
(tp->t_fbyte_in == 0)) {
tp->t_fbyte_in = ticks;
if (tp->t_fbyte_in == 0)
tp->t_fbyte_in = 1;
if (tp->t_fbyte_out && tp->t_fbyte_in)
tp->t_flags2 |= TF2_FBYTES_COMPLETE;
}
/*
* Pull snd_wl1 up to prevent seq wrap relative to th_seq.
*/
tp->snd_wl1 = th->th_seq;
/*
* Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
*/
tp->rcv_up = tp->rcv_nxt;
KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp,
(void *)tcp_saveipgen, &tcp_savetcp, 0);
#endif
newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
/* Add data to socket buffer. */
SOCKBUF_LOCK(&so->so_rcv);
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
m_freem(m);
} else {
/*
* Set new socket buffer size. Give up when limit is
* reached.
*/
if (newsize)
if (!sbreserve_locked(&so->so_rcv,
newsize, so, NULL))
so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
m_adj(m, drop_hdrlen); /* delayed header drop */
#ifdef NETFLIX_SB_LIMITS
appended =
#endif
sbappendstream_locked(&so->so_rcv, m, 0);
ctf_calc_rwin(so, tp);
}
SOCKBUF_UNLOCK(&so->so_rcv);
tp->t_flags |= TF_WAKESOR;
#ifdef NETFLIX_SB_LIMITS
if (so->so_rcv.sb_shlim && mcnt != appended)
counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
#endif
rack_handle_delayed_ack(tp, rack, tlen, 0);
if (tp->snd_una == tp->snd_max)
sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
return (1);
}
/*
* This subfunction is used to try to highly optimize the
* fast path. We again allow window updates that are
* in sequence to remain in the fast-path. We also add
* in the __predict's to attempt to help the compiler.
* Note that if we return a 0, then we can *not* process
* it and the caller should push the packet into the
* slow-path.
*/
static int
rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
{
int32_t acked;
int32_t nsegs;
#ifdef TCPDEBUG
/*
* The size of tcp_saveipgen must be the size of the max ip header,
* now IPv6.
*/
u_char tcp_saveipgen[IP6_HDR_LEN];
struct tcphdr tcp_savetcp;
short ostate = 0;
#endif
int32_t under_pacing = 0;
struct tcp_rack *rack;
if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
/* Old ack, behind (or duplicate to) the last one rcv'd */
return (0);
}
if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
/* Above what we have sent? */
return (0);
}
if (__predict_false(tp->snd_nxt != tp->snd_max)) {
/* We are retransmitting */
return (0);
}
if (__predict_false(tiwin == 0)) {
/* zero window */
return (0);
}
if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
/* We need a SYN or a FIN, unlikely.. */
return (0);
}
if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
/* Timestamp is behind .. old ack with seq wrap? */
return (0);
}
if (__predict_false(IN_RECOVERY(tp->t_flags))) {
/* Still recovering */
return (0);
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->r_ctl.rc_sacked) {
/* We have sack holes on our scoreboard */
return (0);
}
/* Ok if we reach here, we can process a fast-ack */
if (rack->rc_gp_filled &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
under_pacing = 1;
}
nsegs = max(1, m->m_pkthdr.lro_nsegs);
rack_log_ack(tp, to, th);
/* Did the window get updated? */
if (tiwin != tp->snd_wnd) {
tp->snd_wnd = tiwin;
tp->snd_wl1 = th->th_seq;
if (tp->snd_wnd > tp->max_sndwnd)
tp->max_sndwnd = tp->snd_wnd;
}
/* Do we exit persists? */
if ((rack->rc_in_persist != 0) &&
(tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
rack->r_ctl.rc_pace_min_segs))) {
rack_exit_persist(tp, rack, cts);
}
/* Do we enter persists? */
if ((rack->rc_in_persist == 0) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->snd_max == tp->snd_una) &&
sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
(sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
/*
* Here the rwnd is less than
* the pacing size, we are established,
* nothing is outstanding, and there is
* data to send. Enter persists.
*/
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* the timestamp. NOTE that the test is modified according to the
* latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* This is a pure ack for outstanding data.
*/
KMOD_TCPSTAT_INC(tcps_predack);
/*
* "bad retransmit" recovery.
*/
if (tp->t_flags & TF_PREVVALID) {
tp->t_flags &= ~TF_PREVVALID;
if (tp->t_rxtshift == 1 &&
(int)(ticks - tp->t_badrxtwin) < 0)
rack_cong_signal(tp, th, CC_RTO_ERR);
}
/*
* Recalculate the transmit timer / rtt.
*
* Some boxes send broken timestamp replies during the SYN+ACK
* phase, ignore timestamps of 0 or we could calculate a huge RTT
* and blow up the retransmit timer.
*/
acked = BYTES_THIS_ACK(tp, th);
#ifdef TCP_HHOOK
/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
hhook_run_tcp_est_in(tp, th, to);
#endif
KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
sbdrop(&so->so_snd, acked);
if (acked) {
/* assure we are not backed off */
tp->t_rxtshift = 0;
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
/*
* If it is the RXT timer we want to
* stop it, so we can restart a TLP.
*/
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
#ifdef NETFLIX_HTTP_LOGGING
tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
#endif
}
/*
* Let the congestion control algorithm update congestion control
* related information. This typically means increasing the
* congestion window.
*/
rack_ack_received(tp, rack, th, nsegs, CC_ACK, 0);
tp->snd_una = th->th_ack;
if (tp->snd_wnd < ctf_outstanding(tp)) {
/* The peer collapsed the window */
rack_collapsed_window(rack);
} else if (rack->rc_has_collapsed)
rack_un_collapse_window(rack);
/*
* Pull snd_wl2 up to prevent seq wrap relative to th_ack.
*/
tp->snd_wl2 = th->th_ack;
tp->t_dupacks = 0;
m_freem(m);
/* ND6_HINT(tp); *//* Some progress has been made. */
/*
* If all outstanding data are acked, stop retransmit timer,
* otherwise restart timer using current (possibly backed-off)
* value. If process is waiting for space, wakeup/selwakeup/signal.
* If data are ready to send, let tcp_output decide between more
* output or persist.
*/
#ifdef TCPDEBUG
if (so->so_options & SO_DEBUG)
tcp_trace(TA_INPUT, ostate, tp,
(void *)tcp_saveipgen,
&tcp_savetcp, 0);
#endif
if (under_pacing &&
(rack->use_fixed_rate == 0) &&
(rack->in_probe_rtt == 0) &&
rack->rc_gp_dyn_mul &&
rack->rc_always_pace) {
/* Check if we are dragging bottom */
rack_check_bottom_drag(tp, rack, so, acked);
}
if (tp->snd_una == tp->snd_max) {
rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
if (rack->r_ctl.rc_went_idle_time == 0)
rack->r_ctl.rc_went_idle_time = 1;
rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
tp->t_acktime = 0;
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
}
/* Wake up the socket if we have room to write more */
tp->t_flags |= TF_WAKESOW;
if (sbavail(&so->so_snd)) {
rack->r_wanted_output = 1;
}
return (1);
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t todrop;
int32_t ourfinisacked = 0;
struct tcp_rack *rack;
ctf_calc_rwin(so, tp);
/*
* If the state is SYN_SENT: if seg contains an ACK, but not for our
* SYN, drop the input. if seg contains a RST, then drop the
* connection. if seg does not contain SYN, then drop it. Otherwise
* this is an acceptable SYN segment initialize tp->rcv_nxt and
* tp->irs if seg contains ack then advance tp->snd_una if seg
* contains an ECE and ECN support is enabled, the stream is ECN
* capable. if SYN has been acked change to ESTABLISHED else
* SYN_RCVD state arrange for segment to be acked (eventually)
* continue processing rest of data/controls.
*/
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
TCP_PROBE5(connect__refused, NULL, tp,
mtod(m, const char *), tp, th);
tp = tcp_drop(tp, ECONNREFUSED);
ctf_do_drop(m, tp);
return (1);
}
if (thflags & TH_RST) {
ctf_do_drop(m, tp);
return (1);
}
if (!(thflags & TH_SYN)) {
ctf_do_drop(m, tp);
return (1);
}
tp->irs = th->th_seq;
tcp_rcvseqinit(tp);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (thflags & TH_ACK) {
int tfo_partial = 0;
KMOD_TCPSTAT_INC(tcps_connects);
soisconnected(so);
#ifdef MAC
mac_socketpeer_set_from_mbuf(m, so);
#endif
/* Do window scaling on this connection? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
}
tp->rcv_adv += min(tp->rcv_wnd,
TCP_MAXWIN << tp->rcv_scale);
/*
* If not all the data that was sent in the TFO SYN
* has been acked, resend the remainder right away.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->snd_una != tp->snd_max)) {
tp->snd_nxt = th->th_ack;
tfo_partial = 1;
}
/*
* If there's data, delay ACK; if there's also a FIN ACKNOW
* will be turned on later.
*/
if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
rack_timer_cancel(tp, rack,
rack->r_ctl.rc_rcvtime, __LINE__);
tp->t_flags |= TF_DELACK;
} else {
rack->r_wanted_output = 1;
tp->t_flags |= TF_ACKNOW;
rack->rc_dack_toggle = 0;
}
if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
(V_tcp_do_ecn == 1)) {
tp->t_flags2 |= TF2_ECN_PERMIT;
KMOD_TCPSTAT_INC(tcps_ecn_shs);
}
if (SEQ_GT(th->th_ack, tp->snd_una)) {
/*
* We advance snd_una for the
* fast open case. If th_ack is
* acknowledging data beyond
* snd_una we can't just call
* ack-processing since the
* data stream in our send-map
* will start at snd_una + 1 (one
* beyond the SYN). If its just
* equal we don't need to do that
* and there is no send_map.
*/
tp->snd_una++;
}
/*
* Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
* SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
*/
tp->t_starttime = ticks;
if (tp->t_flags & TF_NEEDFIN) {
tcp_state_change(tp, TCPS_FIN_WAIT_1);
tp->t_flags &= ~TF_NEEDFIN;
thflags &= ~TH_SYN;
} else {
tcp_state_change(tp, TCPS_ESTABLISHED);
TCP_PROBE5(connect__established, NULL, tp,
mtod(m, const char *), tp, th);
rack_cc_conn_init(tp);
}
} else {
/*
* Received initial SYN in SYN-SENT[*] state => simultaneous
* open. If segment contains CC option and there is a
* cached CC, apply TAO test. If it succeeds, connection is *
* half-synchronized. Otherwise, do 3-way handshake:
* SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
* there was no CC option, clear cached CC value.
*/
tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
tcp_state_change(tp, TCPS_SYN_RECEIVED);
}
INP_WLOCK_ASSERT(tp->t_inpcb);
/*
* Advance th->th_seq to correspond to first data byte. If data,
* trim to stay within window, dropping FIN if necessary.
*/
th->th_seq++;
if (tlen > tp->rcv_wnd) {
todrop = tlen - tp->rcv_wnd;
m_adj(m, -todrop);
tlen = tp->rcv_wnd;
thflags &= ~TH_FIN;
KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
}
tp->snd_wl1 = th->th_seq - 1;
tp->rcv_up = th->th_seq;
/*
* Client side of transaction: already sent SYN and data. If the
* remote host used T/TCP to validate the SYN, our data will be
* ACK'd; if so, enter normal data segment processing in the middle
* of step 5, ack processing. Otherwise, goto step 6.
*/
if (thflags & TH_ACK) {
/* For syn-sent we need to possibly update the rtt */
if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
uint32_t t;
t = tcp_ts_getticks() - to->to_tsecr;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
tcp_rack_xmit_timer(rack, t + 1, 1, (t * HPTS_USEC_IN_MSEC), 0, NULL, 2);
tcp_rack_xmit_timer_commit(rack, tp);
}
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
return (ret_val);
/* We may have changed to FIN_WAIT_1 above */
if (tp->t_state == TCPS_FIN_WAIT_1) {
/*
* In FIN_WAIT_1 STATE in addition to the processing
* for the ESTABLISHED state if our FIN is now
* acknowledged then enter FIN_WAIT_2.
*/
if (ourfinisacked) {
/*
* If we can't receive any more data, then
* closing user can proceed. Starting the
* timer is contrary to the specification,
* but if we don't get a FIN we'll hang
* forever.
*
* XXXjl: we should release the tp also, and
* use a compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
struct tcp_rack *rack;
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->snd_una) ||
SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (IS_FASTOPEN(tp->t_flags)) {
/*
* When a TFO connection is in SYN_RECEIVED, the
* only valid packets are the initial SYN, a
* retransmit/copy of the initial SYN (possibly with
* a subset of the original data), a valid ACK, a
* FIN, or a RST.
*/
if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
} else if (thflags & TH_SYN) {
/* non-initial SYN is ignored */
if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
(rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
(rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
ctf_do_drop(m, NULL);
return (0);
}
} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
ctf_do_drop(m, NULL);
return (0);
}
}
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
/*
* In the SYN-RECEIVED state, validate that the packet belongs to
* this connection before trimming the data to fit the receive
* window. Check the sequence number versus IRS since we know the
* sequence numbers haven't wrapped. This is a partial fix for the
* "LAND" DoS attack.
*/
if (SEQ_LT(th->th_seq, tp->irs)) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
tp->snd_wnd = tiwin;
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (IS_FASTOPEN(tp->t_flags)) {
rack_cc_conn_init(tp);
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
KMOD_TCPSTAT_INC(tcps_connects);
soisconnected(so);
/* Do window scaling? */
if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
(TF_RCVD_SCALE | TF_REQ_SCALE)) {
tp->rcv_scale = tp->request_r_scale;
}
/*
* Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* ->
* FIN-WAIT-1
*/
tp->t_starttime = ticks;
if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
tcp_fastopen_decrement_counter(tp->t_tfo_pending);
tp->t_tfo_pending = NULL;
}
if (tp->t_flags & TF_NEEDFIN) {
tcp_state_change(tp, TCPS_FIN_WAIT_1);
tp->t_flags &= ~TF_NEEDFIN;
} else {
tcp_state_change(tp, TCPS_ESTABLISHED);
TCP_PROBE5(accept__established, NULL, tp,
mtod(m, const char *), tp, th);
/*
* TFO connections call cc_conn_init() during SYN
* processing. Calling it again here for such connections
* is not harmless as it would undo the snd_cwnd reduction
* that occurs when a TFO SYN|ACK is retransmitted.
*/
if (!IS_FASTOPEN(tp->t_flags))
rack_cc_conn_init(tp);
}
/*
* Account for the ACK of our SYN prior to
* regular ACK processing below, except for
* simultaneous SYN, which is handled later.
*/
if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
tp->snd_una++;
/*
* If segment contains data or ACK, will call tcp_reass() later; if
* not, do so now to pass queued data to user.
*/
if (tlen == 0 && (thflags & TH_FIN) == 0)
(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
(struct mbuf *)0);
tp->snd_wl1 = th->th_seq - 1;
/* For syn-recv we need to possibly update the rtt */
if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
uint32_t t;
t = tcp_ts_getticks() - to->to_tsecr;
if (!tp->t_rttlow || tp->t_rttlow > t)
tp->t_rttlow = t;
tcp_rack_xmit_timer(rack, t + 1, 1, (t * HPTS_USEC_IN_MSEC), 0, NULL, 2);
tcp_rack_xmit_timer_commit(rack, tp);
}
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (tp->t_state == TCPS_FIN_WAIT_1) {
/* We could have went to FIN_WAIT_1 (or EST) above */
/*
* In FIN_WAIT_1 STATE in addition to the processing for the
* ESTABLISHED state if our FIN is now acknowledged then
* enter FIN_WAIT_2.
*/
if (ourfinisacked) {
/*
* If we can't receive any more data, then closing
* user can proceed. Starting the timer is contrary
* to the specification, but if we don't get a FIN
* we'll hang forever.
*
* XXXjl: we should release the tp also, and use a
* compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
struct tcp_rack *rack;
/*
* Header prediction: check for the two common cases of a
* uni-directional data xfer. If the packet has no control flags,
* is in-sequence, the window didn't change and we're not
* retransmitting, it's a candidate. If the length is zero and the
* ack moved forward, we're the sender side of the xfer. Just free
* the data acked & wake any higher level process that was blocked
* waiting for space. If the length is non-zero and the ack didn't
* move, we're the receiver side. If we're getting packets in-order
* (the reassembly queue is empty), add the data toc The socket
* buffer and note that we need a delayed ack. Make sure that the
* hidden state-flags are also off. Since we check for
* TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
*/
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
__predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
__predict_true(SEGQ_EMPTY(tp)) &&
__predict_true(th->th_seq == tp->rcv_nxt)) {
if (tlen == 0) {
if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
return (0);
}
} else {
if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
tiwin, nxt_pkt, iptos)) {
return (0);
}
}
}
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output= 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
/* State changes only happen in rack_process_data() */
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static int
rack_check_data_after_close(struct mbuf *m,
struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
{
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack->rc_allow_data_af_clo == 0) {
close_now:
tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
/* tcp_close will kill the inp pre-log the Reset */
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
tp = tcp_close(tp);
KMOD_TCPSTAT_INC(tcps_rcvafterclose);
ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
return (1);
}
if (sbavail(&so->so_snd) == 0)
goto close_now;
/* Ok we allow data that is ignored and a followup reset */
tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
tp->rcv_nxt = th->th_seq + *tlen;
tp->t_flags2 |= TF2_DROP_AF_DATA;
rack->r_wanted_output = 1;
*tlen = 0;
return (0);
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
/*
* If we can't receive any more data, then closing user can
* proceed. Starting the timer is contrary to the
* specification, but if we don't get a FIN we'll hang
* forever.
*
* XXXjl: we should release the tp also, and use a
* compressed state.
*/
if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
soisdisconnected(so);
tcp_timer_activate(tp, TT_2MSL,
(tcp_fast_finwait2_recycle ?
tcp_finwait2_timeout :
TP_MAXIDLE(tp)));
}
tcp_state_change(tp, TCPS_FIN_WAIT_2);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output= 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
tcp_twstart(tp);
m_freem(m);
return (1);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) && tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* case TCPS_LAST_ACK: Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (ourfinisacked) {
tp = tcp_close(tp);
ctf_do_drop(m, tp);
return (1);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
/*
* Return value of 1, the TCB is unlocked and most
* likely gone, return value of 0, the TCP is still
* locked.
*/
static int
rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
{
int32_t ret_val = 0;
int32_t ourfinisacked = 0;
ctf_calc_rwin(so, tp);
/* Reset receive buffer auto scaling when not in bulk receive mode. */
if ((thflags & TH_RST) ||
(tp->t_fin_is_rst && (thflags & TH_FIN)))
return (ctf_process_rst(m, th, so, tp));
/*
* RFC5961 Section 4.2 Send challenge ACK for any SYN in
* synchronized state.
*/
if (thflags & TH_SYN) {
ctf_challenge_ack(m, th, tp, &ret_val);
return (ret_val);
}
/*
* RFC 1323 PAWS: If we have a timestamp reply on this segment and
* it's less than ts_recent, drop it.
*/
if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
TSTMP_LT(to->to_tsval, tp->ts_recent)) {
if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
return (ret_val);
}
if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
return (ret_val);
}
/*
* If new data are received on a connection after the user processes
* are gone, then RST the other end.
*/
if ((so->so_state & SS_NOFDREF) &&
tlen) {
if (rack_check_data_after_close(m, tp, &tlen, th, so))
return (1);
}
/*
* If last ACK falls within this segment's sequence numbers, record
* its timestamp. NOTE: 1) That the test incorporates suggestions
* from the latest proposal of the tcplw@cray.com list (Braden
* 1993/04/26). 2) That updating only on newer timestamps interferes
* with our earlier PAWS tests, so this check should be solely
* predicated on the sequence space of this segment. 3) That we
* modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
* + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
* SEG.Len, This modified check allows us to overcome RFC1323's
* limitations as described in Stevens TCP/IP Illustrated Vol. 2
* p.869. In such cases, we can still calculate the RTT correctly
* when RCV.NXT == Last.ACK.Sent.
*/
if ((to->to_flags & TOF_TS) != 0 &&
SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
((thflags & (TH_SYN | TH_FIN)) != 0))) {
tp->ts_recent_age = tcp_ts_getticks();
tp->ts_recent = to->to_tsval;
}
/*
* If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
* is on (half-synchronized state), then queue data for later
* processing; else drop segment and return.
*/
if ((thflags & TH_ACK) == 0) {
if (tp->t_flags & TF_NEEDSYN) {
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
} else if (tp->t_flags & TF_ACKNOW) {
ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
return (ret_val);
} else {
ctf_do_drop(m, NULL);
return (0);
}
}
/*
* Ack processing.
*/
if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
return (ret_val);
}
if (sbavail(&so->so_snd)) {
if (ctf_progress_timeout_check(tp, true)) {
rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
tp, tick, PROGRESS_DROP, __LINE__);
tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return (1);
}
}
return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
tiwin, thflags, nxt_pkt));
}
static void inline
rack_clear_rate_sample(struct tcp_rack *rack)
{
rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
rack->r_ctl.rack_rs.rs_rtt_tot = 0;
}
static void
rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line)
{
uint64_t bw_est, rate_wanted;
int chged = 0;
uint32_t user_max;
user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
chged = 1;
rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
if (rack->use_fixed_rate || rack->rc_force_max_seg) {
if (user_max != rack->r_ctl.rc_pace_max_segs)
chged = 1;
}
if (rack->rc_force_max_seg) {
rack->r_ctl.rc_pace_max_segs = user_max;
} else if (rack->use_fixed_rate) {
bw_est = rack_get_bw(rack);
if ((rack->r_ctl.crte == NULL) ||
(bw_est != rack->r_ctl.crte->rate)) {
rack->r_ctl.rc_pace_max_segs = user_max;
} else {
/* We are pacing right at the hardware rate */
uint32_t segsiz;
segsiz = min(ctf_fixed_maxseg(tp),
rack->r_ctl.rc_pace_min_segs);
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
bw_est, segsiz, 0,
rack->r_ctl.crte, NULL);
}
} else if (rack->rc_always_pace) {
if (rack->r_ctl.gp_bw ||
#ifdef NETFLIX_PEAKRATE
rack->rc_tp->t_maxpeakrate ||
#endif
rack->r_ctl.init_rate) {
/* We have a rate of some sort set */
uint32_t orig;
bw_est = rack_get_bw(rack);
orig = rack->r_ctl.rc_pace_max_segs;
rate_wanted = rack_get_output_bw(rack, bw_est, NULL);
if (rate_wanted) {
/* We have something */
rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
rate_wanted,
ctf_fixed_maxseg(rack->rc_tp));
} else
rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
if (orig != rack->r_ctl.rc_pace_max_segs)
chged = 1;
} else if ((rack->r_ctl.gp_bw == 0) &&
(rack->r_ctl.rc_pace_max_segs == 0)) {
/*
* If we have nothing limit us to bursting
* out IW sized pieces.
*/
chged = 1;
rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
}
}
if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
chged = 1;
rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
}
if (chged)
rack_log_type_hrdwtso(tp, rack, 0, rack->rc_inp->inp_socket->so_snd.sb_flags, line, 2);
}
static int
rack_init(struct tcpcb *tp)
{
struct tcp_rack *rack = NULL;
struct rack_sendmap *insret;
uint32_t iwin, snt, us_cts;
tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
if (tp->t_fb_ptr == NULL) {
/*
* We need to allocate memory but cant. The INP and INP_INFO
* locks and they are recusive (happens during setup. So a
* scheme to drop the locks fails :(
*
*/
return (ENOMEM);
}
memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
rack = (struct tcp_rack *)tp->t_fb_ptr;
RB_INIT(&rack->r_ctl.rc_mtree);
TAILQ_INIT(&rack->r_ctl.rc_free);
TAILQ_INIT(&rack->r_ctl.rc_tmap);
rack->rc_tp = tp;
if (tp->t_inpcb) {
rack->rc_inp = tp->t_inpcb;
}
/* Probably not needed but lets be sure */
rack_clear_rate_sample(rack);
rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
if (use_rack_rr)
rack->use_rack_rr = 1;
if (V_tcp_delack_enabled)
tp->t_delayed_ack = 1;
else
tp->t_delayed_ack = 0;
if (rack_enable_shared_cwnd)
rack->rack_enable_scwnd = 1;
rack->rc_user_set_max_segs = rack_hptsi_segments;
rack->rc_force_max_seg = 0;
if (rack_use_imac_dack)
rack->rc_dack_mode = 1;
rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
rack->r_ctl.rc_prop_reduce = rack_use_proportional_reduce;
rack->r_ctl.rc_prop_rate = rack_proportional_rate;
rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
rack->r_ctl.rc_early_recovery = rack_early_recovery;
rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
rack->r_ctl.rc_highest_us_rtt = 0;
if (rack_disable_prr)
rack->rack_no_prr = 1;
if (rack_gp_no_rec_chg)
rack->rc_gp_no_rec_chg = 1;
rack->rc_always_pace = rack_pace_every_seg;
if (rack_enable_mqueue_for_nonpaced)
rack->r_mbuf_queue = 1;
else
rack->r_mbuf_queue = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
rack_set_pace_segments(tp, rack, __LINE__);
if (rack_limits_scwnd)
rack->r_limit_scw = 1;
else
rack->r_limit_scw = 0;
rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
rack->r_ctl.rc_min_to = rack_min_to;
microuptime(&rack->r_ctl.act_rcv_time);
rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
rack->r_running_late = 0;
rack->r_running_early = 0;
rack->rc_init_win = rack_default_init_window;
rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
if (rack_do_dyn_mul) {
/* When dynamic adjustment is on CA needs to start at 100% */
rack->rc_gp_dyn_mul = 1;
if (rack_do_dyn_mul >= 100)
rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
} else
rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
rack_probertt_filter_life);
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_of_last_probertt = us_cts;
rack->r_ctl.rc_time_probertt_starts = 0;
/* Do we force on detection? */
#ifdef NETFLIX_EXP_DETECTION
if (tcp_force_detection)
rack->do_detection = 1;
else
#endif
rack->do_detection = 0;
if (rack_non_rxt_use_cr)
rack->rack_rec_nonrxt_use_cr = 1;
if (tp->snd_una != tp->snd_max) {
/* Create a send map for the current outstanding data */
struct rack_sendmap *rsm;
rsm = rack_alloc(rack);
if (rsm == NULL) {
uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
return (ENOMEM);
}
rsm->r_flags = RACK_OVERMAX;
rsm->r_tim_lastsent[0] = rack->r_ctl.rc_tlp_rxt_last_time;
rsm->r_rtr_cnt = 1;
rsm->r_rtr_bytes = 0;
rsm->r_start = tp->snd_una;
if (tp->t_flags & TF_SENTFIN) {
rsm->r_end = tp->snd_max - 1;
rsm->r_flags |= RACK_HAS_FIN;
} else {
rsm->r_end = tp->snd_max;
}
rsm->usec_orig_send = us_cts;
rsm->r_dupack = 0;
insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (insret != NULL) {
panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
insret, rack, rsm);
}
#endif
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
rsm->r_in_tmap = 1;
}
/* Cancel the GP measurement in progress */
tp->t_flags &= ~TF_GPUTINPROG;
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
iwin = rc_init_window(rack);
if (snt < iwin) {
/* We are not past the initial window
* so we need to make sure cwnd is
* correct.
*/
if (tp->snd_cwnd < iwin)
tp->snd_cwnd = iwin;
/*
* If we are within the initial window
* we want ssthresh to be unlimited. Setting
* it to the rwnd (which the default stack does
* and older racks) is not really a good idea
* since we want to be in SS and grow both the
* cwnd and the rwnd (via dynamic rwnd growth). If
* we set it to the rwnd then as the peer grows its
* rwnd we will be stuck in CA and never hit SS.
*
* Its far better to raise it up high (this takes the
* risk that there as been a loss already, probably
* we should have an indicator in all stacks of loss
* but we don't), but considering the normal use this
* is a risk worth taking. The consequences of not
* hitting SS are far worse than going one more time
* into it early on (before we have sent even a IW).
* It is highly unlikely that we will have had a loss
* before getting the IW out.
*/
tp->snd_ssthresh = 0xffffffff;
}
rack_stop_all_timers(tp);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
rack_log_rtt_shrinks(rack, us_cts, 0,
__LINE__, RACK_RTTS_INIT);
return (0);
}
static int
rack_handoff_ok(struct tcpcb *tp)
{
if ((tp->t_state == TCPS_CLOSED) ||
(tp->t_state == TCPS_LISTEN)) {
/* Sure no problem though it may not stick */
return (0);
}
if ((tp->t_state == TCPS_SYN_SENT) ||
(tp->t_state == TCPS_SYN_RECEIVED)) {
/*
* We really don't know if you support sack,
* you have to get to ESTAB or beyond to tell.
*/
return (EAGAIN);
}
if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
/*
* Rack will only send a FIN after all data is acknowledged.
* So in this case we have more data outstanding. We can't
* switch stacks until either all data and only the FIN
* is left (in which case rack_init() now knows how
* to deal with that) <or> all is acknowledged and we
* are only left with incoming data, though why you
* would want to switch to rack after all data is acknowledged
* I have no idea (rrs)!
*/
return (EAGAIN);
}
if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
return (0);
}
/*
* If we reach here we don't do SACK on this connection so we can
* never do rack.
*/
return (EINVAL);
}
static void
rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
{
if (tp->t_fb_ptr) {
struct tcp_rack *rack;
struct rack_sendmap *rsm, *nrsm, *rm;
rack = (struct tcp_rack *)tp->t_fb_ptr;
#ifdef NETFLIX_SHARED_CWND
if (rack->r_ctl.rc_scw) {
uint32_t limit;
if (rack->r_limit_scw)
limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
else
limit = 0;
tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
rack->r_ctl.rc_scw_index,
limit);
rack->r_ctl.rc_scw = NULL;
}
#endif
/* rack does not use force data but other stacks may clear it */
tp->t_flags &= ~TF_FORCEDATA;
if (tp->t_inpcb) {
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
}
#ifdef TCP_BLACKBOX
tcp_log_flowend(tp);
#endif
RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
#ifdef INVARIANTS
if (rm != rsm) {
panic("At fini, rack:%p rsm:%p rm:%p",
rack, rsm, rm);
}
#endif
uma_zfree(rack_zone, rsm);
}
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
while (rsm) {
TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
uma_zfree(rack_zone, rsm);
rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
}
rack->rc_free_cnt = 0;
uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
tp->t_fb_ptr = NULL;
}
/* Cancel the GP measurement in progress */
tp->t_flags &= ~TF_GPUTINPROG;
/* Make sure snd_nxt is correctly set */
tp->snd_nxt = tp->snd_max;
}
static void
rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
{
switch (tp->t_state) {
case TCPS_SYN_SENT:
rack->r_state = TCPS_SYN_SENT;
rack->r_substate = rack_do_syn_sent;
break;
case TCPS_SYN_RECEIVED:
rack->r_state = TCPS_SYN_RECEIVED;
rack->r_substate = rack_do_syn_recv;
break;
case TCPS_ESTABLISHED:
rack_set_pace_segments(tp, rack, __LINE__);
rack->r_state = TCPS_ESTABLISHED;
rack->r_substate = rack_do_established;
break;
case TCPS_CLOSE_WAIT:
rack->r_state = TCPS_CLOSE_WAIT;
rack->r_substate = rack_do_close_wait;
break;
case TCPS_FIN_WAIT_1:
rack->r_state = TCPS_FIN_WAIT_1;
rack->r_substate = rack_do_fin_wait_1;
break;
case TCPS_CLOSING:
rack->r_state = TCPS_CLOSING;
rack->r_substate = rack_do_closing;
break;
case TCPS_LAST_ACK:
rack->r_state = TCPS_LAST_ACK;
rack->r_substate = rack_do_lastack;
break;
case TCPS_FIN_WAIT_2:
rack->r_state = TCPS_FIN_WAIT_2;
rack->r_substate = rack_do_fin_wait_2;
break;
case TCPS_LISTEN:
case TCPS_CLOSED:
case TCPS_TIME_WAIT:
default:
break;
};
}
static void
rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
{
/*
* We received an ack, and then did not
* call send or were bounced out due to the
* hpts was running. Now a timer is up as well, is
* it the right timer?
*/
struct rack_sendmap *rsm;
int tmr_up;
tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
return;
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
(tmr_up == PACE_TMR_RXT)) {
/* Should be an RXT */
return;
}
if (rsm == NULL) {
/* Nothing outstanding? */
if (tp->t_flags & TF_DELACK) {
if (tmr_up == PACE_TMR_DELACK)
/* We are supposed to have delayed ack up and we do */
return;
} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
/*
* if we hit enobufs then we would expect the possiblity
* of nothing outstanding and the RXT up (and the hptsi timer).
*/
return;
} else if (((V_tcp_always_keepalive ||
rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)) &&
(tmr_up == PACE_TMR_KEEP) &&
(tp->snd_max == tp->snd_una)) {
/* We should have keep alive up and we do */
return;
}
}
if (SEQ_GT(tp->snd_max, tp->snd_una) &&
((tmr_up == PACE_TMR_TLP) ||
(tmr_up == PACE_TMR_RACK) ||
(tmr_up == PACE_TMR_RXT))) {
/*
* Either a Rack, TLP or RXT is fine if we
* have outstanding data.
*/
return;
} else if (tmr_up == PACE_TMR_DELACK) {
/*
* If the delayed ack was going to go off
* before the rtx/tlp/rack timer were going to
* expire, then that would be the timer in control.
* Note we don't check the time here trusting the
* code is correct.
*/
return;
}
/*
* Ok the timer originally started is not what we want now.
* We will force the hpts to be stopped if any, and restart
* with the slot set to what was in the saved slot.
*/
if (rack->rc_inp->inp_in_hpts) {
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
uint32_t us_cts;
us_cts = tcp_get_usecs(NULL);
if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
rack->r_early = 1;
rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
}
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
}
rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
}
static int
rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
int32_t nxt_pkt, struct timeval *tv)
{
int32_t thflags, retval, did_out = 0;
int32_t way_out = 0;
uint32_t cts;
uint32_t tiwin;
struct timespec ts;
struct tcpopt to;
struct tcp_rack *rack;
struct rack_sendmap *rsm;
int32_t prev_state = 0;
uint32_t us_cts;
/*
* tv passed from common code is from either M_TSTMP_LRO or
* tcp_get_usecs() if no LRO m_pkthdr timestamp is present. The
* rack_pacing stack assumes tv always refers to 'now', so we overwrite
* tv here to guarantee that.
*/
if (m->m_flags & M_TSTMP_LRO)
tcp_get_usecs(tv);
cts = tcp_tv_to_mssectick(tv);
rack = (struct tcp_rack *)tp->t_fb_ptr;
if ((m->m_flags & M_TSTMP) ||
(m->m_flags & M_TSTMP_LRO)) {
mbuf_tstmp2timespec(m, &ts);
rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
} else
rack->r_ctl.act_rcv_time = *tv;
kern_prefetch(rack, &prev_state);
prev_state = 0;
thflags = th->th_flags;
NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(tp->t_inpcb);
KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
__func__));
KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
__func__));
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval ltv;
#ifdef NETFLIX_HTTP_LOGGING
struct http_sendfile_track *http_req;
if (SEQ_GT(th->th_ack, tp->snd_una)) {
http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
} else {
http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
}
#endif
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
if (rack->rack_no_prr == 0)
log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
else
log.u_bbr.flex1 = 0;
log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
log.u_bbr.flex3 = m->m_flags;
log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
if (m->m_flags & M_TSTMP) {
/* Record the hardware timestamp if present */
mbuf_tstmp2timespec(m, &ts);
ltv.tv_sec = ts.tv_sec;
ltv.tv_usec = ts.tv_nsec / 1000;
log.u_bbr.lt_epoch = tcp_tv_to_usectick(<v);
} else if (m->m_flags & M_TSTMP_LRO) {
/* Record the LRO the arrival timestamp */
mbuf_tstmp2timespec(m, &ts);
ltv.tv_sec = ts.tv_sec;
ltv.tv_usec = ts.tv_nsec / 1000;
log.u_bbr.flex5 = tcp_tv_to_usectick(<v);
}
log.u_bbr.timeStamp = tcp_get_usecs(<v);
/* Log the rcv time */
log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
#ifdef NETFLIX_HTTP_LOGGING
log.u_bbr.applimited = tp->t_http_closed;
log.u_bbr.applimited <<= 8;
log.u_bbr.applimited |= tp->t_http_open;
log.u_bbr.applimited <<= 8;
log.u_bbr.applimited |= tp->t_http_req;
if (http_req) {
/* Copy out any client req info */
/* seconds */
log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
/* useconds */
log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
log.u_bbr.rttProp = http_req->timestamp;
log.u_bbr.cur_del_rate = http_req->start;
if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
log.u_bbr.flex8 |= 1;
} else {
log.u_bbr.flex8 |= 2;
log.u_bbr.bw_inuse = http_req->end;
}
log.u_bbr.flex6 = http_req->start_seq;
if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
log.u_bbr.flex8 |= 4;
log.u_bbr.epoch = http_req->end_seq;
}
}
#endif
TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
tlen, &log, true, <v);
}
if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
way_out = 4;
retval = 0;
m_freem(m);
goto done_with_input;
}
/*
* If a segment with the ACK-bit set arrives in the SYN-SENT state
* check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
*/
if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
(SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
return(1);
}
/*
* Parse options on any incoming segment.
*/
tcp_dooptions(&to, (u_char *)(th + 1),
(th->th_off << 2) - sizeof(struct tcphdr),
(thflags & TH_SYN) ? TO_SYN : 0);
/*
* If timestamps were negotiated during SYN/ACK and a
* segment without a timestamp is received, silently drop
* the segment, unless it is a RST segment or missing timestamps are
* tolerated.
* See section 3.2 of RFC 7323.
*/
if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
way_out = 5;
retval = 0;
m_freem(m);
goto done_with_input;
}
/*
* Segment received on connection. Reset idle time and keep-alive
* timer. XXX: This should be done after segment validation to
* ignore broken/spoofed segs.
*/
if (tp->t_idle_reduce &&
(tp->snd_max == tp->snd_una) &&
((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
counter_u64_add(rack_input_idle_reduces, 1);
rack_cc_after_idle(rack, tp);
}
tp->t_rcvtime = ticks;
/*
* Unscale the window into a 32-bit value. For the SYN_SENT state
* the scale is zero.
*/
tiwin = th->th_win << tp->snd_scale;
#ifdef STATS
stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
#endif
if (tiwin > rack->r_ctl.rc_high_rwnd)
rack->r_ctl.rc_high_rwnd = tiwin;
/*
* TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
* this to occur after we've validated the segment.
*/
if (tp->t_flags2 & TF2_ECN_PERMIT) {
if (thflags & TH_CWR) {
tp->t_flags2 &= ~TF2_ECN_SND_ECE;
tp->t_flags |= TF_ACKNOW;
}
switch (iptos & IPTOS_ECN_MASK) {
case IPTOS_ECN_CE:
tp->t_flags2 |= TF2_ECN_SND_ECE;
KMOD_TCPSTAT_INC(tcps_ecn_ce);
break;
case IPTOS_ECN_ECT0:
KMOD_TCPSTAT_INC(tcps_ecn_ect0);
break;
case IPTOS_ECN_ECT1:
KMOD_TCPSTAT_INC(tcps_ecn_ect1);
break;
}
/* Process a packet differently from RFC3168. */
cc_ecnpkt_handler(tp, th, iptos);
/* Congestion experienced. */
if (thflags & TH_ECE) {
rack_cong_signal(tp, th, CC_ECN);
}
}
/*
* If echoed timestamp is later than the current time, fall back to
* non RFC1323 RTT calculation. Normalize timestamp if syncookies
* were used when this connection was established.
*/
if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
to.to_tsecr -= tp->ts_offset;
if (TSTMP_GT(to.to_tsecr, cts))
to.to_tsecr = 0;
}
/*
* If its the first time in we need to take care of options and
* verify we can do SACK for rack!
*/
if (rack->r_state == 0) {
/* Should be init'd by rack_init() */
KASSERT(rack->rc_inp != NULL,
("%s: rack->rc_inp unexpectedly NULL", __func__));
if (rack->rc_inp == NULL) {
rack->rc_inp = tp->t_inpcb;
}
/*
* Process options only when we get SYN/ACK back. The SYN
* case for incoming connections is handled in tcp_syncache.
* According to RFC1323 the window field in a SYN (i.e., a
* <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
* this is traditional behavior, may need to be cleaned up.
*/
if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
/* Handle parallel SYN for ECN */
if (!(thflags & TH_ACK) &&
((thflags & (TH_CWR | TH_ECE)) == (TH_CWR | TH_ECE)) &&
((V_tcp_do_ecn == 1) || (V_tcp_do_ecn == 2))) {
tp->t_flags2 |= TF2_ECN_PERMIT;
tp->t_flags2 |= TF2_ECN_SND_ECE;
TCPSTAT_INC(tcps_ecn_shs);
}
if ((to.to_flags & TOF_SCALE) &&
(tp->t_flags & TF_REQ_SCALE)) {
tp->t_flags |= TF_RCVD_SCALE;
tp->snd_scale = to.to_wscale;
} else
tp->t_flags &= ~TF_REQ_SCALE;
/*
* Initial send window. It will be updated with the
* next incoming segment to the scaled value.
*/
tp->snd_wnd = th->th_win;
if ((to.to_flags & TOF_TS) &&
(tp->t_flags & TF_REQ_TSTMP)) {
tp->t_flags |= TF_RCVD_TSTMP;
tp->ts_recent = to.to_tsval;
tp->ts_recent_age = cts;
} else
tp->t_flags &= ~TF_REQ_TSTMP;
if (to.to_flags & TOF_MSS)
tcp_mss(tp, to.to_mss);
if ((tp->t_flags & TF_SACK_PERMIT) &&
(to.to_flags & TOF_SACKPERM) == 0)
tp->t_flags &= ~TF_SACK_PERMIT;
if (IS_FASTOPEN(tp->t_flags)) {
if (to.to_flags & TOF_FASTOPEN) {
uint16_t mss;
if (to.to_flags & TOF_MSS)
mss = to.to_mss;
else
if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
mss = TCP6_MSS;
else
mss = TCP_MSS;
tcp_fastopen_update_cache(tp, mss,
to.to_tfo_len, to.to_tfo_cookie);
} else
tcp_fastopen_disable_path(tp);
}
}
/*
* At this point we are at the initial call. Here we decide
* if we are doing RACK or not. We do this by seeing if
* TF_SACK_PERMIT is set and the sack-not-required is clear.
* The code now does do dup-ack counting so if you don't
* switch back you won't get rack & TLP, but you will still
* get this stack.
*/
if ((rack_sack_not_required == 0) &&
((tp->t_flags & TF_SACK_PERMIT) == 0)) {
tcp_switch_back_to_default(tp);
(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
tlen, iptos);
return (1);
}
/* Set the flag */
rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
tcp_set_hpts(tp->t_inpcb);
sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
}
if (thflags & TH_FIN)
tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
if ((rack->rc_gp_dyn_mul) &&
(rack->use_fixed_rate == 0) &&
(rack->rc_always_pace)) {
/* Check in on probertt */
rack_check_probe_rtt(rack, us_cts);
}
if (rack->forced_ack) {
uint32_t us_rtt;
/*
* A persist or keep-alive was forced out, update our
* min rtt time. Note we do not worry about lost
* retransmissions since KEEP-ALIVES and persists
* are usually way long on times of sending (though
* if we were really paranoid or worried we could
* at least use timestamps if available to validate).
*/
rack->forced_ack = 0;
us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
if (us_rtt == 0)
us_rtt = 1;
rack_log_rtt_upd(tp, rack, us_rtt, 0, NULL, 3);
rack_apply_updated_usrtt(rack, us_rtt, us_cts);
}
/*
* This is the one exception case where we set the rack state
* always. All other times (timers etc) we must have a rack-state
* set (so we assure we have done the checks above for SACK).
*/
rack->r_ctl.rc_rcvtime = cts;
if (rack->r_state != tp->t_state)
rack_set_state(tp, rack);
if (SEQ_GT(th->th_ack, tp->snd_una) &&
(rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
kern_prefetch(rsm, &prev_state);
prev_state = rack->r_state;
rack_clear_rate_sample(rack);
retval = (*rack->r_substate) (m, th, so,
tp, &to, drop_hdrlen,
tlen, tiwin, thflags, nxt_pkt, iptos);
#ifdef INVARIANTS
if ((retval == 0) &&
(tp->t_inpcb == NULL)) {
panic("retval:%d tp:%p t_inpcb:NULL state:%d",
retval, tp, prev_state);
}
#endif
if (retval == 0) {
/*
* If retval is 1 the tcb is unlocked and most likely the tp
* is gone.
*/
INP_WLOCK_ASSERT(tp->t_inpcb);
if ((rack->rc_gp_dyn_mul) &&
(rack->rc_always_pace) &&
(rack->use_fixed_rate == 0) &&
rack->in_probe_rtt &&
(rack->r_ctl.rc_time_probertt_starts == 0)) {
/*
* If we are going for target, lets recheck before
* we output.
*/
rack_check_probe_rtt(rack, us_cts);
}
if (rack->set_pacing_done_a_iw == 0) {
/* How much has been acked? */
if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
/* We have enough to set in the pacing segment size */
rack->set_pacing_done_a_iw = 1;
rack_set_pace_segments(tp, rack, __LINE__);
}
}
tcp_rack_xmit_timer_commit(rack, tp);
if (nxt_pkt == 0) {
if (rack->r_wanted_output != 0) {
do_output_now:
did_out = 1;
(void)tp->t_fb->tfb_tcp_output(tp);
}
rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
}
if ((nxt_pkt == 0) &&
((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
(SEQ_GT(tp->snd_max, tp->snd_una) ||
(tp->t_flags & TF_DELACK) ||
((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
(tp->t_state <= TCPS_CLOSING)))) {
/* We could not send (probably in the hpts but stopped the timer earlier)? */
if ((tp->snd_max == tp->snd_una) &&
((tp->t_flags & TF_DELACK) == 0) &&
(rack->rc_inp->inp_in_hpts) &&
(rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
/* keep alive not needed if we are hptsi output yet */
;
} else {
int late = 0;
if (rack->rc_inp->inp_in_hpts) {
if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
us_cts = tcp_get_usecs(NULL);
if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
rack->r_early = 1;
rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
} else
late = 1;
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
}
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
}
if (late && (did_out == 0)) {
/*
* We are late in the sending
* and we did not call the output
* (this probably should not happen).
*/
goto do_output_now;
}
rack_start_hpts_timer(rack, tp, tcp_ts_getticks(), 0, 0, 0);
}
way_out = 1;
} else if (nxt_pkt == 0) {
/* Do we have the correct timer running? */
rack_timer_audit(tp, rack, &so->so_snd);
way_out = 2;
}
done_with_input:
rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out);
if (did_out)
rack->r_wanted_output = 0;
#ifdef INVARIANTS
if (tp->t_inpcb == NULL) {
panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
did_out,
retval, tp, prev_state);
}
#endif
}
return (retval);
}
void
rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
{
struct timeval tv;
/* First lets see if we have old packets */
if (tp->t_in_pkt) {
if (ctf_do_queued_segments(so, tp, 1)) {
m_freem(m);
return;
}
}
if (m->m_flags & M_TSTMP_LRO) {
tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
} else {
/* Should not be should we kassert instead? */
tcp_get_usecs(&tv);
}
if(rack_do_segment_nounlock(m, th, so, tp,
drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
tcp_handle_wakeup(tp, so);
INP_WUNLOCK(tp->t_inpcb);
}
}
struct rack_sendmap *
tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
{
struct rack_sendmap *rsm = NULL;
int32_t idx;
uint32_t srtt = 0, thresh = 0, ts_low = 0;
/* Return the next guy to be re-transmitted */
if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
return (NULL);
}
if (tp->t_flags & TF_SENTFIN) {
/* retran the end FIN? */
return (NULL);
}
/* ok lets look at this one */
rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
goto check_it;
}
rsm = rack_find_lowest_rsm(rack);
if (rsm == NULL) {
return (NULL);
}
check_it:
if (rsm->r_flags & RACK_ACKED) {
return (NULL);
}
if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
(rsm->r_dupack < DUP_ACK_THRESHOLD)) {
/* Its not yet ready */
return (NULL);
}
srtt = rack_grab_rtt(tp, rack);
idx = rsm->r_rtr_cnt - 1;
ts_low = rsm->r_tim_lastsent[idx];
thresh = rack_calc_thresh_rack(rack, srtt, tsused);
if ((tsused == ts_low) ||
(TSTMP_LT(tsused, ts_low))) {
/* No time since sending */
return (NULL);
}
if ((tsused - ts_low) < thresh) {
/* It has not been long enough yet */
return (NULL);
}
if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
((rsm->r_flags & RACK_SACK_PASSED) &&
(rack->sack_attack_disable == 0))) {
/*
* We have passed the dup-ack threshold <or>
* a SACK has indicated this is missing.
* Note that if you are a declared attacker
* it is only the dup-ack threshold that
* will cause retransmits.
*/
/* log retransmit reason */
rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
return (rsm);
}
return (NULL);
}
static void
rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
int line, struct rack_sendmap *rsm)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = slot;
log.u_bbr.flex2 = len;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
log.u_bbr.use_lt_bw = rack->app_limited_needs_set;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw = rack->rc_gp_filled;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
log.u_bbr.use_lt_bw <<= 1;
log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
log.u_bbr.pkt_epoch = line;
log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
log.u_bbr.bw_inuse = bw_est;
log.u_bbr.delRate = bw;
if (rack->r_ctl.gp_bw == 0)
log.u_bbr.cur_del_rate = 0;
else
log.u_bbr.cur_del_rate = rack_get_bw(rack);
log.u_bbr.rttProp = len_time;
log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
/* We are in slow start */
log.u_bbr.flex7 = 1;
} else {
/* we are on congestion avoidance */
log.u_bbr.flex7 = 0;
}
log.u_bbr.flex8 = method;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
log.u_bbr.cwnd_gain <<= 1;
log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HPTSI_CALC, 0,
0, &log, false, &tv);
}
}
static uint32_t
rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
{
uint32_t new_tso, user_max;
user_max = rack->rc_user_set_max_segs * mss;
if (rack->rc_force_max_seg) {
return (user_max);
}
if (rack->use_fixed_rate &&
((rack->r_ctl.crte == NULL) ||
(bw != rack->r_ctl.crte->rate))) {
/* Use the user mss since we are not exactly matched */
return (user_max);
}
new_tso = tcp_get_pacing_burst_size(bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
if (new_tso > user_max)
new_tso = user_max;
return(new_tso);
}
static void
rack_log_hdwr_pacing(struct tcp_rack *rack, const struct ifnet *ifp,
uint64_t rate, uint64_t hw_rate, int line,
int error)
{
if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log, 0, sizeof(log));
log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
log.u_bbr.flex3 = (((uint64_t)ifp >> 32) & 0x00000000ffffffff);
log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.bw_inuse = rate;
log.u_bbr.flex5 = line;
log.u_bbr.flex6 = error;
log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex8 = rack->use_fixed_rate;
log.u_bbr.flex8 <<= 1;
log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
TCP_LOG_EVENTP(rack->rc_tp, NULL,
&rack->rc_inp->inp_socket->so_rcv,
&rack->rc_inp->inp_socket->so_snd,
BBR_LOG_HDWR_PACE, 0,
0, &log, false, &tv);
}
}
static int32_t
pace_to_fill_cwnd(struct tcp_rack *rack, int32_t slot, uint32_t len, uint32_t segsiz)
{
uint64_t lentim, fill_bw;
/* Lets first see if we are full, if so continue with normal rate */
if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
return (slot);
if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
return (slot);
if (rack->r_ctl.rc_last_us_rtt == 0)
return (slot);
if (rack->rc_pace_fill_if_rttin_range &&
(rack->r_ctl.rc_last_us_rtt >=
(get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
/* The rtt is huge, N * smallest, lets not fill */
return (slot);
}
/*
* first lets calculate the b/w based on the last us-rtt
* and the sndwnd.
*/
fill_bw = rack->r_ctl.cwnd_to_use;
/* Take the rwnd if its smaller */
if (fill_bw > rack->rc_tp->snd_wnd)
fill_bw = rack->rc_tp->snd_wnd;
fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
/* We are below the min b/w */
if (fill_bw < RACK_MIN_BW)
return (slot);
/*
* Ok fill_bw holds our mythical b/w to fill the cwnd
* in a rtt, what does that time wise equate too?
*/
lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
lentim /= fill_bw;
if (lentim < slot) {
rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
0, lentim, 12, __LINE__, NULL);
return ((int32_t)lentim);
} else
return (slot);
}
static int32_t
rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
{
struct rack_sendmap *lrsm;
int32_t slot = 0;
int err;
if (rack->rc_always_pace == 0) {
/*
* We use the most optimistic possible cwnd/srtt for
* sending calculations. This will make our
* calculation anticipate getting more through
* quicker then possible. But thats ok we don't want
* the peer to have a gap in data sending.
*/
uint32_t srtt, cwnd, tr_perms = 0;
int32_t reduce = 0;
old_method:
/*
* We keep no precise pacing with the old method
* instead we use the pacer to mitigate bursts.
*/
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
if (rack->r_ctl.rc_rack_min_rtt)
srtt = rack->r_ctl.rc_rack_min_rtt;
else
srtt = TICKS_2_MSEC((tp->t_srtt >> TCP_RTT_SHIFT));
if (rack->r_ctl.rc_rack_largest_cwnd)
cwnd = rack->r_ctl.rc_rack_largest_cwnd;
else
cwnd = rack->r_ctl.cwnd_to_use;
tr_perms = cwnd / srtt;
if (tr_perms == 0) {
tr_perms = ctf_fixed_maxseg(tp);
}
/*
* Calculate how long this will take to drain, if
* the calculation comes out to zero, thats ok we
* will use send_a_lot to possibly spin around for
* more increasing tot_len_this_send to the point
* that its going to require a pace, or we hit the
* cwnd. Which in that case we are just waiting for
* a ACK.
*/
slot = len / tr_perms;
/* Now do we reduce the time so we don't run dry? */
if (slot && rack_slot_reduction) {
reduce = (slot / rack_slot_reduction);
if (reduce < slot) {
slot -= reduce;
} else
slot = 0;
}
slot *= HPTS_USEC_IN_MSEC;
if (rsm == NULL) {
/*
* We always consider ourselves app limited with old style
* that are not retransmits. This could be the initial
* measurement, but thats ok its all setup and specially
* handled. If another send leaks out, then that too will
* be mark app-limited.
*/
lrsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (lrsm && ((lrsm->r_flags & RACK_APP_LIMITED) == 0)) {
rack->r_ctl.rc_first_appl = lrsm;
lrsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
}
rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL);
} else {
uint64_t bw_est, res, lentim, rate_wanted;
uint32_t orig_val, srtt, segs, oh;
if ((rack->r_rr_config == 1) && rsm) {
return (rack->r_ctl.rc_min_to * HPTS_USEC_IN_MSEC);
}
if (rack->use_fixed_rate) {
rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
} else if ((rack->r_ctl.init_rate == 0) &&
#ifdef NETFLIX_PEAKRATE
(rack->rc_tp->t_maxpeakrate == 0) &&
#endif
(rack->r_ctl.gp_bw == 0)) {
/* no way to yet do an estimate */
bw_est = rate_wanted = 0;
} else {
bw_est = rack_get_bw(rack);
rate_wanted = rack_get_output_bw(rack, bw_est, rsm);
}
if ((bw_est == 0) || (rate_wanted == 0)) {
/*
* No way yet to make a b/w estimate or
* our raise is set incorrectly.
*/
goto old_method;
}
/* We need to account for all the overheads */
segs = (len + segsiz - 1) / segsiz;
/*
* We need the diff between 1514 bytes (e-mtu with e-hdr)
* and how much data we put in each packet. Yes this
* means we may be off if we are larger than 1500 bytes
* or smaller. But this just makes us more conservative.
*/
if (ETHERNET_SEGMENT_SIZE > segsiz)
oh = ETHERNET_SEGMENT_SIZE - segsiz;
else
oh = 0;
segs *= oh;
lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
res = lentim / rate_wanted;
slot = (uint32_t)res;
orig_val = rack->r_ctl.rc_pace_max_segs;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
/* Did we change the TSO size, if so log it */
if (rack->r_ctl.rc_pace_max_segs != orig_val)
rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL);
if ((rack->rc_pace_to_cwnd) &&
(rack->in_probe_rtt == 0) &&
(IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
/*
* We want to pace at our rate *or* faster to
* fill the cwnd to the max if its not full.
*/
slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz);
}
if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
(rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
if ((rack->rack_hdw_pace_ena) &&
(rack->rack_hdrw_pacing == 0) &&
(rack->rack_attempt_hdwr_pace == 0)) {
/*
* Lets attempt to turn on hardware pacing
* if we can.
*/
rack->rack_attempt_hdwr_pace = 1;
rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted,
RS_PACING_GEQ,
&err);
if (rack->r_ctl.crte) {
rack->rack_hdrw_pacing = 1;
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(rate_wanted, segsiz,
0, rack->r_ctl.crte,
NULL);
rack_log_hdwr_pacing(rack, rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted, rack->r_ctl.crte->rate, __LINE__,
err);
}
} else if (rack->rack_hdrw_pacing &&
(rack->r_ctl.crte->rate != rate_wanted)) {
/* Do we need to adjust our rate? */
const struct tcp_hwrate_limit_table *nrte;
nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
rack->rc_tp,
rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted,
RS_PACING_GEQ,
&err);
if (nrte == NULL) {
/* Lost the rate */
rack->rack_hdrw_pacing = 0;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
} else if (nrte != rack->r_ctl.crte) {
rack->r_ctl.crte = nrte;
rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(rate_wanted,
segsiz, 0,
rack->r_ctl.crte,
NULL);
rack_log_hdwr_pacing(rack, rack->rc_inp->inp_route.ro_nh->nh_ifp,
rate_wanted, rack->r_ctl.crte->rate, __LINE__,
err);
}
}
}
if (rack_limit_time_with_srtt &&
(rack->use_fixed_rate == 0) &&
#ifdef NETFLIX_PEAKRATE
(rack->rc_tp->t_maxpeakrate == 0) &&
#endif
(rack->rack_hdrw_pacing == 0)) {
/*
* Sanity check, we do not allow the pacing delay
* to be longer than the SRTT of the path. If it is
* a slow path, then adding a packet should increase
* the RTT and compensate for this i.e. the srtt will
* be greater so the allowed pacing time will be greater.
*
* Note this restriction is not for where a peak rate
* is set, we are doing fixed pacing or hardware pacing.
*/
if (rack->rc_tp->t_srtt)
srtt = (TICKS_2_USEC(rack->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
else
srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC; /* its in ms convert */
if (srtt < slot) {
rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL);
slot = srtt;
}
}
rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm);
}
if (slot)
counter_u64_add(rack_calc_nonzero, 1);
else
counter_u64_add(rack_calc_zero, 1);
return (slot);
}
static void
rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
tcp_seq startseq, uint32_t sb_offset)
{
struct rack_sendmap *my_rsm = NULL;
struct rack_sendmap fe;
if (tp->t_state < TCPS_ESTABLISHED) {
/*
* We don't start any measurements if we are
* not at least established.
*/
return;
}
tp->t_flags |= TF_GPUTINPROG;
rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
tp->gput_seq = startseq;
rack->app_limited_needs_set = 0;
if (rack->in_probe_rtt)
rack->measure_saw_probe_rtt = 1;
else if ((rack->measure_saw_probe_rtt) &&
(SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
rack->measure_saw_probe_rtt = 0;
if (rack->rc_gp_filled)
tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
else {
/* Special case initial measurement */
rack->r_ctl.rc_gp_output_ts = tp->gput_ts = tcp_get_usecs(NULL);
}
/*
* We take a guess out into the future,
* if we have no measurement and no
* initial rate, we measure the first
* initial-windows worth of data to
* speed up getting some GP measurement and
* thus start pacing.
*/
if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
rack->app_limited_needs_set = 1;
tp->gput_ack = startseq + max(rc_init_window(rack),
(MIN_GP_WIN * ctf_fixed_maxseg(tp)));
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
0,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
return;
}
if (sb_offset) {
/*
* We are out somewhere in the sb
* can we use the already outstanding data?
*/
if (rack->r_ctl.rc_app_limited_cnt == 0) {
/*
* Yes first one is good and in this case
* the tp->gput_ts is correctly set based on
* the last ack that arrived (no need to
* set things up when an ack comes in).
*/
my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if ((my_rsm == NULL) ||
(my_rsm->r_rtr_cnt != 1)) {
/* retransmission? */
goto use_latest;
}
} else {
if (rack->r_ctl.rc_first_appl == NULL) {
/*
* If rc_first_appl is NULL
* then the cnt should be 0.
* This is probably an error, maybe
* a KASSERT would be approprate.
*/
goto use_latest;
}
/*
* If we have a marker pointer to the last one that is
* app limited we can use that, but we need to set
* things up so that when it gets ack'ed we record
* the ack time (if its not already acked).
*/
rack->app_limited_needs_set = 1;
/*
* We want to get to the rsm that is either
* next with space i.e. over 1 MSS or the one
* after that (after the app-limited).
*/
my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
rack->r_ctl.rc_first_appl);
if (my_rsm) {
if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
/* Have to use the next one */
my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
my_rsm);
else {
/* Use after the first MSS of it is acked */
tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
goto start_set;
}
}
if ((my_rsm == NULL) ||
(my_rsm->r_rtr_cnt != 1)) {
/*
* Either its a retransmit or
* the last is the app-limited one.
*/
goto use_latest;
}
}
tp->gput_seq = my_rsm->r_start;
start_set:
if (my_rsm->r_flags & RACK_ACKED) {
/*
* This one has been acked use the arrival ack time
*/
tp->gput_ts = my_rsm->r_ack_arrival;
rack->app_limited_needs_set = 0;
}
rack->r_ctl.rc_gp_output_ts = my_rsm->usec_orig_send;
tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)my_rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9,
__LINE__, NULL);
return;
}
use_latest:
/*
* We don't know how long we may have been
* idle or if this is the first-send. Lets
* setup the flag so we will trim off
* the first ack'd data so we get a true
* measurement.
*/
rack->app_limited_needs_set = 1;
tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
/* Find this guy so we can pull the send time */
fe.r_start = startseq;
my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
if (my_rsm) {
rack->r_ctl.rc_gp_output_ts = my_rsm->usec_orig_send;
if (my_rsm->r_flags & RACK_ACKED) {
/*
* Unlikely since its probably what was
* just transmitted (but I am paranoid).
*/
tp->gput_ts = my_rsm->r_ack_arrival;
rack->app_limited_needs_set = 0;
}
if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
/* This also is unlikely */
tp->gput_seq = my_rsm->r_start;
}
} else {
/*
* TSNH unless we have some send-map limit,
* and even at that it should not be hitting
* that limit (we should have stopped sending).
*/
rack->r_ctl.rc_gp_output_ts = tcp_get_usecs(NULL);
}
rack_log_pacing_delay_calc(rack,
tp->gput_seq,
tp->gput_ack,
(uint64_t)my_rsm,
tp->gput_ts,
rack->r_ctl.rc_app_limited_cnt,
9, __LINE__, NULL);
}
static inline uint32_t
rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cwnd_to_use,
uint32_t avail, int32_t sb_offset)
{
uint32_t len;
uint32_t sendwin;
if (tp->snd_wnd > cwnd_to_use)
sendwin = cwnd_to_use;
else
sendwin = tp->snd_wnd;
if (ctf_outstanding(tp) >= tp->snd_wnd) {
/* We never want to go over our peers rcv-window */
len = 0;
} else {
uint32_t flight;
flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
if (flight >= sendwin) {
/*
* We have in flight what we are allowed by cwnd (if
* it was rwnd blocking it would have hit above out
* >= tp->snd_wnd).
*/
return (0);
}
len = sendwin - flight;
if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
/* We would send too much (beyond the rwnd) */
len = tp->snd_wnd - ctf_outstanding(tp);
}
if ((len + sb_offset) > avail) {
/*
* We don't have that much in the SB, how much is
* there?
*/
len = avail - sb_offset;
}
}
return (len);
}
static int
rack_output(struct tcpcb *tp)
{
struct socket *so;
uint32_t recwin = 0;
uint32_t sb_offset;
int32_t len, flags, error = 0;
struct mbuf *m;
struct mbuf *mb;
uint32_t if_hw_tsomaxsegcount = 0;
uint32_t if_hw_tsomaxsegsize = 0;
int32_t segsiz, minseg;
long tot_len_this_send = 0;
struct ip *ip = NULL;
#ifdef TCPDEBUG
struct ipovly *ipov = NULL;
#endif
struct udphdr *udp = NULL;
struct tcp_rack *rack;
struct tcphdr *th;
uint8_t pass = 0;
uint8_t mark = 0;
uint8_t wanted_cookie = 0;
u_char opt[TCP_MAXOLEN];
unsigned ipoptlen, optlen, hdrlen, ulen=0;
uint32_t rack_seq;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
unsigned ipsec_optlen = 0;
#endif
int32_t idle, sendalot;
int32_t sub_from_prr = 0;
volatile int32_t sack_rxmit;
struct rack_sendmap *rsm = NULL;
int32_t tso, mtu;
struct tcpopt to;
int32_t slot = 0;
int32_t sup_rack = 0;
uint32_t cts, us_cts, delayed, early;
uint8_t hpts_calling, new_data_tlp = 0, doing_tlp = 0;
uint32_t cwnd_to_use;
int32_t do_a_prefetch;
int32_t prefetch_rsm = 0;
int32_t orig_len;
struct timeval tv;
int32_t prefetch_so_done = 0;
struct tcp_log_buffer *lgb = NULL;
struct inpcb *inp;
struct sockbuf *sb;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
int32_t isipv6;
#endif
uint8_t filled_all = 0;
bool hw_tls = false;
/* setup and take the cache hits here */
rack = (struct tcp_rack *)tp->t_fb_ptr;
inp = rack->rc_inp;
so = inp->inp_socket;
sb = &so->so_snd;
kern_prefetch(sb, &do_a_prefetch);
do_a_prefetch = 1;
hpts_calling = inp->inp_hpts_calls;
hw_tls = (so->so_snd.sb_flags & SB_TLS_IFNET) != 0;
NET_EPOCH_ASSERT();
INP_WLOCK_ASSERT(inp);
#ifdef TCP_OFFLOAD
if (tp->t_flags & TF_TOE)
return (tcp_offload_output(tp));
#endif
/*
* For TFO connections in SYN_RECEIVED, only allow the initial
* SYN|ACK and those sent by the retransmit timer.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN|ACK sent */
(rack->r_ctl.rc_resend == NULL)) /* not a retransmit */
return (0);
#ifdef INET6
if (rack->r_state) {
/* Use the cache line loaded if possible */
isipv6 = rack->r_is_v6;
} else {
isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
}
#endif
early = 0;
us_cts = tcp_get_usecs(&tv);
cts = tcp_tv_to_mssectick(&tv);
if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
inp->inp_in_hpts) {
/*
* We are on the hpts for some timer but not hptsi output.
* Remove from the hpts unconditionally.
*/
rack_timer_cancel(tp, rack, cts, __LINE__);
}
/* Are we pacing and late? */
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) {
/* We are delayed */
delayed = us_cts - rack->r_ctl.rc_last_output_to;
} else {
delayed = 0;
}
/* Do the timers, which may override the pacer */
if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
if (rack_process_timers(tp, rack, cts, hpts_calling)) {
counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
return (0);
}
}
if ((rack->r_timer_override) ||
(delayed) ||
(tp->t_state < TCPS_ESTABLISHED)) {
if (tp->t_inpcb->inp_in_hpts)
tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
} else if (tp->t_inpcb->inp_in_hpts) {
/*
* On the hpts you can't pass even if ACKNOW is on, we will
* when the hpts fires.
*/
counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
return (0);
}
inp->inp_hpts_calls = 0;
/* Finish out both pacing early and late accounting */
if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
early = rack->r_ctl.rc_last_output_to - us_cts;
} else
early = 0;
if (delayed) {
rack->r_ctl.rc_agg_delayed += delayed;
rack->r_late = 1;
} else if (early) {
rack->r_ctl.rc_agg_early += early;
rack->r_early = 1;
}
/* Now that early/late accounting is done turn off the flag */
rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
rack->r_wanted_output = 0;
rack->r_timer_override = 0;
/*
* For TFO connections in SYN_SENT or SYN_RECEIVED,
* only allow the initial SYN or SYN|ACK and those sent
* by the retransmit timer.
*/
if (IS_FASTOPEN(tp->t_flags) &&
((tp->t_state == TCPS_SYN_RECEIVED) ||
(tp->t_state == TCPS_SYN_SENT)) &&
SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
(tp->t_rxtshift == 0)) { /* not a retransmit */
cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
goto just_return_nolock;
}
/*
* Determine length of data that should be transmitted, and flags
* that will be used. If there is some data or critical controls
* (SYN, RST) to send, then transmit; otherwise, investigate
* further.
*/
idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
if (tp->t_idle_reduce) {
if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
rack_cc_after_idle(rack, tp);
}
tp->t_flags &= ~TF_LASTIDLE;
if (idle) {
if (tp->t_flags & TF_MORETOCOME) {
tp->t_flags |= TF_LASTIDLE;
idle = 0;
}
}
if ((tp->snd_una == tp->snd_max) &&
rack->r_ctl.rc_went_idle_time &&
TSTMP_GT(us_cts, rack->r_ctl.rc_went_idle_time)) {
idle = us_cts - rack->r_ctl.rc_went_idle_time;
if (idle > rack_min_probertt_hold) {
/* Count as a probe rtt */
if (rack->in_probe_rtt == 0) {
rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
} else {
rack_exit_probertt(rack, us_cts);
}
}
idle = 0;
}
again:
/*
* If we've recently taken a timeout, snd_max will be greater than
* snd_nxt. There may be SACK information that allows us to avoid
* resending already delivered data. Adjust snd_nxt accordingly.
*/
sendalot = 0;
us_cts = tcp_get_usecs(&tv);
cts = tcp_tv_to_mssectick(&tv);
tso = 0;
mtu = 0;
segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
minseg = segsiz;
sb_offset = tp->snd_max - tp->snd_una;
cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
#ifdef NETFLIX_SHARED_CWND
if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
rack->rack_enable_scwnd) {
/* We are doing cwnd sharing */
if (rack->rc_gp_filled &&
(rack->rack_attempted_scwnd == 0) &&
(rack->r_ctl.rc_scw == NULL) &&
tp->t_lib) {
/* The pcbid is in, lets make an attempt */
counter_u64_add(rack_try_scwnd, 1);
rack->rack_attempted_scwnd = 1;
rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
&rack->r_ctl.rc_scw_index,
segsiz);
}
if (rack->r_ctl.rc_scw &&
(rack->rack_scwnd_is_idle == 1) &&
(rack->rc_in_persist == 0) &&
sbavail(sb)) {
/* we are no longer out of data */
tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 0;
}
if (rack->r_ctl.rc_scw) {
/* First lets update and get the cwnd */
rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
rack->r_ctl.rc_scw_index,
tp->snd_cwnd, tp->snd_wnd, segsiz);
}
}
#endif
flags = tcp_outflags[tp->t_state];
while (rack->rc_free_cnt < rack_free_cache) {
rsm = rack_alloc(rack);
if (rsm == NULL) {
if (inp->inp_hpts_calls)
/* Retry in a ms */
slot = (1 * HPTS_USEC_IN_MSEC);
goto just_return_nolock;
}
TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
rack->rc_free_cnt++;
rsm = NULL;
}
if (inp->inp_hpts_calls)
inp->inp_hpts_calls = 0;
sack_rxmit = 0;
len = 0;
rsm = NULL;
if (flags & TH_RST) {
SOCKBUF_LOCK(sb);
goto send;
}
if (rack->r_ctl.rc_resend) {
/* Retransmit timer */
rsm = rack->r_ctl.rc_resend;
rack->r_ctl.rc_resend = NULL;
rsm->r_flags &= ~RACK_TLP;
len = rsm->r_end - rsm->r_start;
sack_rxmit = 1;
sendalot = 0;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
if (len >= segsiz)
len = segsiz;
} else if ((rack->rc_in_persist == 0) &&
((rsm = tcp_rack_output(tp, rack, cts)) != NULL)) {
/* We have a retransmit that takes precedence */
rsm->r_flags &= ~RACK_TLP;
if ((!IN_RECOVERY(tp->t_flags)) &&
((tp->t_flags & (TF_WASFRECOVERY | TF_WASCRECOVERY)) == 0)) {
/* Enter recovery if not induced by a time-out */
rack->r_ctl.rc_rsm_start = rsm->r_start;
rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
rack_cong_signal(tp, NULL, CC_NDUPACK);
/*
* When we enter recovery we need to assure we send
* one packet.
*/
if (rack->rack_no_prr == 0) {
rack->r_ctl.rc_prr_sndcnt = segsiz;
rack_log_to_prr(rack, 13, 0);
}
}
#ifdef INVARIANTS
if (SEQ_LT(rsm->r_start, tp->snd_una)) {
panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
tp, rack, rsm, rsm->r_start, tp->snd_una);
}
#endif
len = rsm->r_end - rsm->r_start;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
/* Can we send it within the PRR boundary? */
if (rack->rack_no_prr == 0) {
if ((rack->use_rack_rr == 0) && (len > rack->r_ctl.rc_prr_sndcnt)) {
/* It does not fit */
if ((ctf_flight_size(tp, rack->r_ctl.rc_sacked) > len) &&
(rack->r_ctl.rc_prr_sndcnt < segsiz)) {
/*
* prr is less than a segment, we
* have more acks due in besides
* what we need to resend. Lets not send
* to avoid sending small pieces of
* what we need to retransmit.
*/
len = 0;
goto just_return_nolock;
}
len = rack->r_ctl.rc_prr_sndcnt;
}
}
sendalot = 0;
if (len >= segsiz)
len = segsiz;
if (len > 0) {
sub_from_prr = 1;
sack_rxmit = 1;
KMOD_TCPSTAT_INC(tcps_sack_rexmits);
KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
min(len, segsiz));
counter_u64_add(rack_rtm_prr_retran, 1);
}
} else if (rack->r_ctl.rc_tlpsend) {
/* Tail loss probe */
long cwin;
long tlen;
doing_tlp = 1;
/*
* Check if we can do a TLP with a RACK'd packet
* this can happen if we are not doing the rack
* cheat and we skipped to a TLP and it
* went off.
*/
rsm = rack->r_ctl.rc_tlpsend;
rsm->r_flags |= RACK_TLP;
rack->r_ctl.rc_tlpsend = NULL;
sack_rxmit = 1;
tlen = rsm->r_end - rsm->r_start;
if (tlen > segsiz)
tlen = segsiz;
KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
__func__, __LINE__,
rsm->r_start, tp->snd_una, tp, rack, rsm));
sb_offset = rsm->r_start - tp->snd_una;
cwin = min(tp->snd_wnd, tlen);
len = cwin;
}
/*
* Enforce a connection sendmap count limit if set
* as long as we are not retransmiting.
*/
if ((rsm == NULL) &&
(rack->do_detection == 0) &&
(V_tcp_map_entries_limit > 0) &&
(rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
counter_u64_add(rack_to_alloc_limited, 1);
if (!rack->alloc_limit_reported) {
rack->alloc_limit_reported = 1;
counter_u64_add(rack_alloc_limited_conns, 1);
}
goto just_return_nolock;
}
if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
/* we are retransmitting the fin */
len--;
if (len) {
/*
* When retransmitting data do *not* include the
* FIN. This could happen from a TLP probe.
*/
flags &= ~TH_FIN;
}
}
#ifdef INVARIANTS
/* For debugging */
rack->r_ctl.rc_rsm_at_retran = rsm;
#endif
/*
* Get standard flags, and add SYN or FIN if requested by 'hidden'
* state flags.
*/
if (tp->t_flags & TF_NEEDFIN)
flags |= TH_FIN;
if (tp->t_flags & TF_NEEDSYN)
flags |= TH_SYN;
if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
void *end_rsm;
end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
if (end_rsm)
kern_prefetch(end_rsm, &prefetch_rsm);
prefetch_rsm = 1;
}
SOCKBUF_LOCK(sb);
/*
* If snd_nxt == snd_max and we have transmitted a FIN, the
* sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
* negative length. This can also occur when TCP opens up its
* congestion window while receiving additional duplicate acks after
* fast-retransmit because TCP will reset snd_nxt to snd_max after
* the fast-retransmit.
*
* In the normal retransmit-FIN-only case, however, snd_nxt will be
* set to snd_una, the sb_offset will be 0, and the length may wind
* up 0.
*
* If sack_rxmit is true we are retransmitting from the scoreboard
* in which case len is already set.
*/
if ((sack_rxmit == 0) &&
(TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
uint32_t avail;
avail = sbavail(sb);
if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
sb_offset = tp->snd_nxt - tp->snd_una;
else
sb_offset = 0;
if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
if (rack->r_ctl.rc_tlp_new_data) {
/* TLP is forcing out new data */
if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
}
if (rack->r_ctl.rc_tlp_new_data > tp->snd_wnd)
len = tp->snd_wnd;
else
len = rack->r_ctl.rc_tlp_new_data;
rack->r_ctl.rc_tlp_new_data = 0;
new_data_tlp = doing_tlp = 1;
} else
len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
if (IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
/*
* For prr=off, we need to send only 1 MSS
* at a time. We do this because another sack could
* be arriving that causes us to send retransmits and
* we don't want to be on a long pace due to a larger send
* that keeps us from sending out the retransmit.
*/
len = segsiz;
}
} else {
uint32_t outstanding;
/*
* We are inside of a SACK recovery episode and are
* sending new data, having retransmitted all the
* data possible so far in the scoreboard.
*/
outstanding = tp->snd_max - tp->snd_una;
if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
if (tp->snd_wnd > outstanding) {
len = tp->snd_wnd - outstanding;
/* Check to see if we have the data */
if ((sb_offset + len) > avail) {
/* It does not all fit */
if (avail > sb_offset)
len = avail - sb_offset;
else
len = 0;
}
} else
len = 0;
} else if (avail > sb_offset)
len = avail - sb_offset;
else
len = 0;
if (len > 0) {
if (len > rack->r_ctl.rc_prr_sndcnt)
len = rack->r_ctl.rc_prr_sndcnt;
if (len > 0) {
sub_from_prr = 1;
counter_u64_add(rack_rtm_prr_newdata, 1);
}
}
if (len > segsiz) {
/*
* We should never send more than a MSS when
* retransmitting or sending new data in prr
* mode unless the override flag is on. Most
* likely the PRR algorithm is not going to
* let us send a lot as well :-)
*/
if (rack->r_ctl.rc_prr_sendalot == 0)
len = segsiz;
} else if (len < segsiz) {
/*
* Do we send any? The idea here is if the
* send empty's the socket buffer we want to
* do it. However if not then lets just wait
* for our prr_sndcnt to get bigger.
*/
long leftinsb;
leftinsb = sbavail(sb) - sb_offset;
if (leftinsb > len) {
/* This send does not empty the sb */
len = 0;
}
}
}
} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
/*
* If you have not established
* and are not doing FAST OPEN
* no data please.
*/
if ((sack_rxmit == 0) &&
(!IS_FASTOPEN(tp->t_flags))){
len = 0;
sb_offset = 0;
}
}
if (prefetch_so_done == 0) {
kern_prefetch(so, &prefetch_so_done);
prefetch_so_done = 1;
}
/*
* Lop off SYN bit if it has already been sent. However, if this is
* SYN-SENT state and if segment contains data and if we don't know
* that foreign host supports TAO, suppress sending segment.
*/
if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
/*
* When sending additional segments following a TFO SYN|ACK,
* do not include the SYN bit.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_state == TCPS_SYN_RECEIVED))
flags &= ~TH_SYN;
}
/*
* Be careful not to send data and/or FIN on SYN segments. This
* measure is needed to prevent interoperability problems with not
* fully conformant TCP implementations.
*/
if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
len = 0;
flags &= ~TH_FIN;
}
/*
* On TFO sockets, ensure no data is sent in the following cases:
*
* - When retransmitting SYN|ACK on a passively-created socket
*
* - When retransmitting SYN on an actively created socket
*
* - When sending a zero-length cookie (cookie request) on an
* actively created socket
*
* - When the socket is in the CLOSED state (RST is being sent)
*/
if (IS_FASTOPEN(tp->t_flags) &&
(((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
((tp->t_state == TCPS_SYN_SENT) &&
(tp->t_tfo_client_cookie_len == 0)) ||
(flags & TH_RST))) {
sack_rxmit = 0;
len = 0;
}
/* Without fast-open there should never be data sent on a SYN */
if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
tp->snd_nxt = tp->iss;
len = 0;
}
orig_len = len;
if (len <= 0) {
/*
* If FIN has been sent but not acked, but we haven't been
* called to retransmit, len will be < 0. Otherwise, window
* shrank after we sent into it. If window shrank to 0,
* cancel pending retransmit, pull snd_nxt back to (closed)
* window, and set the persist timer if it isn't already
* going. If the window didn't close completely, just wait
* for an ACK.
*
* We also do a general check here to ensure that we will
* set the persist timer when we have data to send, but a
* 0-byte window. This makes sure the persist timer is set
* even if the packet hits one of the "goto send" lines
* below.
*/
len = 0;
if ((tp->snd_wnd == 0) &&
(TCPS_HAVEESTABLISHED(tp->t_state)) &&
(tp->snd_una == tp->snd_max) &&
(sb_offset < (int)sbavail(sb))) {
tp->snd_nxt = tp->snd_una;
rack_enter_persist(tp, rack, cts);
}
} else if ((rsm == NULL) &&
((doing_tlp == 0) || (new_data_tlp == 1)) &&
(len < rack->r_ctl.rc_pace_max_segs)) {
/*
* We are not sending a maximum sized segment for
* some reason. Should we not send anything (think
* sws or persists)?
*/
if ((tp->snd_wnd < min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)), minseg)) &&
(TCPS_HAVEESTABLISHED(tp->t_state)) &&
(len < minseg) &&
(len < (int)(sbavail(sb) - sb_offset))) {
/*
* Here the rwnd is less than
* the minimum pacing size, this is not a retransmit,
* we are established and
* the send is not the last in the socket buffer
* we send nothing, and we may enter persists
* if nothing is outstanding.
*/
len = 0;
if (tp->snd_max == tp->snd_una) {
/*
* Nothing out we can
* go into persists.
*/
rack_enter_persist(tp, rack, cts);
tp->snd_nxt = tp->snd_una;
}
} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
(ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(len < minseg)) {
/*
* Here we are not retransmitting, and
* the cwnd is not so small that we could
* not send at least a min size (rxt timer
* not having gone off), We have 2 segments or
* more already in flight, its not the tail end
* of the socket buffer and the cwnd is blocking
* us from sending out a minimum pacing segment size.
* Lets not send anything.
*/
len = 0;
} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
(ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
(len < (int)(sbavail(sb) - sb_offset)) &&
(TCPS_HAVEESTABLISHED(tp->t_state))) {
/*
* Here we have a send window but we have
* filled it up and we can't send another pacing segment.
* We also have in flight more than 2 segments
* and we are not completing the sb i.e. we allow
* the last bytes of the sb to go out even if
* its not a full pacing segment.
*/
len = 0;
}
}
/* len will be >= 0 after this point. */
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
tcp_sndbuf_autoscale(tp, so, min(tp->snd_wnd, cwnd_to_use));
/*
* Decide if we can use TCP Segmentation Offloading (if supported by
* hardware).
*
* TSO may only be used if we are in a pure bulk sending state. The
* presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
* options prevent using TSO. With TSO the TCP header is the same
* (except for the sequence number) for all generated packets. This
* makes it impossible to transmit any options which vary per
* generated segment or packet.
*
* IPv4 handling has a clear separation of ip options and ip header
* flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
* the right thing below to provide length of just ip options and thus
* checking for ipoptlen is enough to decide if ip options are present.
*/
#ifdef INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
if (tp->t_inpcb->inp_options)
ipoptlen = tp->t_inpcb->inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
else
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
/*
* Pre-calculate here as we save another lookup into the darknesses
* of IPsec that way and can actually decide if TSO is ok.
*/
#ifdef INET6
if (isipv6 && IPSEC_ENABLED(ipv6))
ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
#ifdef INET
else
#endif
#endif /* INET6 */
#ifdef INET
if (IPSEC_ENABLED(ipv4))
ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
#endif /* INET */
#endif
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
(tp->t_port == 0) &&
((tp->t_flags & TF_SIGNATURE) == 0) &&
tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
ipoptlen == 0)
tso = 1;
{
uint32_t outstanding;
outstanding = tp->snd_max - tp->snd_una;
if (tp->t_flags & TF_SENTFIN) {
/*
* If we sent a fin, snd_max is 1 higher than
* snd_una
*/
outstanding--;
}
if (sack_rxmit) {
if ((rsm->r_flags & RACK_HAS_FIN) == 0)
flags &= ~TH_FIN;
} else {
if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
sbused(sb)))
flags &= ~TH_FIN;
}
}
recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
(long)TCP_MAXWIN << tp->rcv_scale);
/*
* Sender silly window avoidance. We transmit under the following
* conditions when len is non-zero:
*
* - We have a full segment (or more with TSO) - This is the last
* buffer in a write()/send() and we are either idle or running
* NODELAY - we've timed out (e.g. persist timer) - we have more
* then 1/2 the maximum send window's worth of data (receiver may be
* limited the window size) - we need to retransmit
*/
if (len) {
if (len >= segsiz) {
goto send;
}
/*
* NOTE! on localhost connections an 'ack' from the remote
* end may occur synchronously with the output and cause us
* to flush a buffer queued with moretocome. XXX
*
*/
if (!(tp->t_flags & TF_MORETOCOME) && /* normal case */
(idle || (tp->t_flags & TF_NODELAY)) &&
((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
(tp->t_flags & TF_NOPUSH) == 0) {
pass = 2;
goto send;
}
if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
pass = 22;
goto send;
}
if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
pass = 4;
goto send;
}
if (SEQ_LT(tp->snd_nxt, tp->snd_max)) { /* retransmit case */
pass = 5;
goto send;
}
if (sack_rxmit) {
pass = 6;
goto send;
}
if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
(ctf_outstanding(tp) < (segsiz * 2))) {
/*
* We have less than two MSS outstanding (delayed ack)
* and our rwnd will not let us send a full sized
* MSS. Lets go ahead and let this small segment
* out because we want to try to have at least two
* packets inflight to not be caught by delayed ack.
*/
pass = 12;
goto send;
}
}
/*
* Sending of standalone window updates.
*
* Window updates are important when we close our window due to a
* full socket buffer and are opening it again after the application
* reads data from it. Once the window has opened again and the
* remote end starts to send again the ACK clock takes over and
* provides the most current window information.
*
* We must avoid the silly window syndrome whereas every read from
* the receive buffer, no matter how small, causes a window update
* to be sent. We also should avoid sending a flurry of window
* updates when the socket buffer had queued a lot of data and the
* application is doing small reads.
*
* Prevent a flurry of pointless window updates by only sending an
* update when we can increase the advertized window by more than
* 1/4th of the socket buffer capacity. When the buffer is getting
* full or is very small be more aggressive and send an update
* whenever we can increase by two mss sized segments. In all other
* situations the ACK's to new incoming data will carry further
* window increases.
*
* Don't send an independent window update if a delayed ACK is
* pending (it will get piggy-backed on it) or the remote side
* already has done a half-close and won't send more data. Skip
* this if the connection is in T/TCP half-open state.
*/
if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
!(tp->t_flags & TF_DELACK) &&
!TCPS_HAVERCVDFIN(tp->t_state)) {
/*
* "adv" is the amount we could increase the window, taking
* into account that we are limited by TCP_MAXWIN <<
* tp->rcv_scale.
*/
int32_t adv;
int oldwin;
adv = recwin;
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
oldwin = (tp->rcv_adv - tp->rcv_nxt);
if (adv > oldwin)
adv -= oldwin;
else {
/* We can't increase the window */
adv = 0;
}
} else
oldwin = 0;
/*
* If the new window size ends up being the same as or less
* than the old size when it is scaled, then don't force
* a window update.
*/
if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
goto dontupdate;
if (adv >= (int32_t)(2 * segsiz) &&
(adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
so->so_rcv.sb_hiwat <= 8 * segsiz)) {
pass = 7;
goto send;
}
if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
pass = 23;
goto send;
}
}
dontupdate:
/*
* Send if we owe the peer an ACK, RST, SYN, or urgent data. ACKNOW
* is also a catch-all for the retransmit timer timeout case.
*/
if (tp->t_flags & TF_ACKNOW) {
pass = 8;
goto send;
}
if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
pass = 9;
goto send;
}
/*
* If our state indicates that FIN should be sent and we have not
* yet done so, then we need to send.
*/
if ((flags & TH_FIN) &&
(tp->snd_nxt == tp->snd_una)) {
pass = 11;
goto send;
}
/*
* No reason to send a segment, just return.
*/
just_return:
SOCKBUF_UNLOCK(sb);
just_return_nolock:
{
int app_limited = CTF_JR_SENT_DATA;
if (tot_len_this_send > 0) {
/* Make sure snd_nxt is up to max */
if (SEQ_GT(tp->snd_max, tp->snd_nxt))
tp->snd_nxt = tp->snd_max;
slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
} else {
int end_window = 0;
uint32_t seq = tp->gput_ack;
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm) {
/*
* Mark the last sent that we just-returned (hinting
* that delayed ack may play a role in any rtt measurement).
*/
rsm->r_just_ret = 1;
}
counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
if ((ctf_outstanding(tp) +
min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
minseg)) >= tp->snd_wnd) {
/* We are limited by the rwnd */
app_limited = CTF_JR_RWND_LIMITED;
} else if (ctf_outstanding(tp) >= sbavail(sb)) {
/* We are limited by whats available -- app limited */
app_limited = CTF_JR_APP_LIMITED;
} else if ((idle == 0) &&
((tp->t_flags & TF_NODELAY) == 0) &&
((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
(len < segsiz)) {
/*
* No delay is not on and the
* user is sending less than 1MSS. This
* brings out SWS avoidance so we
* don't send. Another app-limited case.
*/
app_limited = CTF_JR_APP_LIMITED;
} else if (tp->t_flags & TF_NOPUSH) {
/*
* The user has requested no push of
* the last segment and we are
* at the last segment. Another app
* limited case.
*/
app_limited = CTF_JR_APP_LIMITED;
} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
/* Its the cwnd */
app_limited = CTF_JR_CWND_LIMITED;
} else if (rack->rc_in_persist == 1) {
/* We are in persists */
app_limited = CTF_JR_PERSISTS;
} else if (IN_RECOVERY(tp->t_flags) &&
(rack->rack_no_prr == 0) &&
(rack->r_ctl.rc_prr_sndcnt < segsiz)) {
app_limited = CTF_JR_PRR;
} else {
/* Now why here are we not sending? */
#ifdef NOW
#ifdef INVARIANTS
panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
#endif
#endif
app_limited = CTF_JR_ASSESSING;
}
/*
* App limited in some fashion, for our pacing GP
* measurements we don't want any gap (even cwnd).
* Close down the measurement window.
*/
if (rack_cwnd_block_ends_measure &&
((app_limited == CTF_JR_CWND_LIMITED) ||
(app_limited == CTF_JR_PRR))) {
/*
* The reason we are not sending is
* the cwnd (or prr). We have been configured
* to end the measurement window in
* this case.
*/
end_window = 1;
} else if (app_limited == CTF_JR_PERSISTS) {
/*
* We never end the measurement window
* in persists, though in theory we
* should be only entering after everything
* is acknowledged (so we will probably
* never come here).
*/
end_window = 0;
} else if (rack_rwnd_block_ends_measure &&
(app_limited == CTF_JR_RWND_LIMITED)) {
/*
* We are rwnd limited and have been
* configured to end the measurement
* window in this case.
*/
end_window = 1;
} else if (app_limited == CTF_JR_APP_LIMITED) {
/*
* A true application limited period, we have
* ran out of data.
*/
end_window = 1;
} else if (app_limited == CTF_JR_ASSESSING) {
/*
* In the assessing case we hit the end of
* the if/else and had no known reason
* This will panic us under invariants..
*
* If we get this out in logs we need to
* investagate which reason we missed.
*/
end_window = 1;
}
if (end_window) {
uint8_t log = 0;
if ((tp->t_flags & TF_GPUTINPROG) &&
SEQ_GT(tp->gput_ack, tp->snd_max)) {
/* Mark the last packet has app limited */
tp->gput_ack = tp->snd_max;
log = 1;
}
rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
if (rack->r_ctl.rc_app_limited_cnt == 0)
rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
else {
/*
* Go out to the end app limited and mark
* this new one as next and move the end_appl up
* to this guy.
*/
if (rack->r_ctl.rc_end_appl)
rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
rack->r_ctl.rc_end_appl = rsm;
}
rsm->r_flags |= RACK_APP_LIMITED;
rack->r_ctl.rc_app_limited_cnt++;
}
if (log)
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_app_limited_cnt, seq,
tp->gput_ack, 0, 0, 4, __LINE__, NULL);
}
}
if (slot) {
/* set the rack tcb into the slot N */
counter_u64_add(rack_paced_segments, 1);
} else if (tot_len_this_send) {
counter_u64_add(rack_unpaced_segments, 1);
}
/* Check if we need to go into persists or not */
if ((rack->rc_in_persist == 0) &&
(tp->snd_max == tp->snd_una) &&
TCPS_HAVEESTABLISHED(tp->t_state) &&
sbavail(sb) &&
(sbavail(sb) > tp->snd_wnd) &&
(tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
/* Yes lets make sure to move to persist before timer-start */
rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
}
rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
}
#ifdef NETFLIX_SHARED_CWND
if ((sbavail(sb) == 0) &&
rack->r_ctl.rc_scw) {
tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
rack->rack_scwnd_is_idle = 1;
}
#endif
return (0);
send:
if ((flags & TH_FIN) &&
sbavail(sb)) {
/*
* We do not transmit a FIN
* with data outstanding. We
* need to make it so all data
* is acked first.
*/
flags &= ~TH_FIN;
}
/* Enforce stack imposed max seg size if we have one */
if (rack->r_ctl.rc_pace_max_segs &&
(len > rack->r_ctl.rc_pace_max_segs)) {
mark = 1;
len = rack->r_ctl.rc_pace_max_segs;
}
SOCKBUF_LOCK_ASSERT(sb);
if (len > 0) {
if (len >= segsiz)
tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
else
tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
}
/*
* Before ESTABLISHED, force sending of initial options unless TCP
* set not to do any options. NOTE: we assume that the IP/TCP header
* plus TCP options always fit in a single mbuf, leaving room for a
* maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
* + optlen <= MCLBYTES
*/
optlen = 0;
#ifdef INET6
if (isipv6)
hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
else
#endif
hdrlen = sizeof(struct tcpiphdr);
/*
* Compute options for segment. We only have to care about SYN and
* established connection segments. Options for SYN-ACK segments
* are handled in TCP syncache.
*/
to.to_flags = 0;
if ((tp->t_flags & TF_NOOPT) == 0) {
/* Maximum segment size. */
if (flags & TH_SYN) {
tp->snd_nxt = tp->iss;
to.to_mss = tcp_mssopt(&inp->inp_inc);
#ifdef NETFLIX_TCPOUDP
if (tp->t_port)
to.to_mss -= V_tcp_udp_tunneling_overhead;
#endif
to.to_flags |= TOF_MSS;
/*
* On SYN or SYN|ACK transmits on TFO connections,
* only include the TFO option if it is not a
* retransmit, as the presence of the TFO option may
* have caused the original SYN or SYN|ACK to have
* been dropped by a middlebox.
*/
if (IS_FASTOPEN(tp->t_flags) &&
(tp->t_rxtshift == 0)) {
if (tp->t_state == TCPS_SYN_RECEIVED) {
to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
to.to_tfo_cookie =
(u_int8_t *)&tp->t_tfo_cookie.server;
to.to_flags |= TOF_FASTOPEN;
wanted_cookie = 1;
} else if (tp->t_state == TCPS_SYN_SENT) {
to.to_tfo_len =
tp->t_tfo_client_cookie_len;
to.to_tfo_cookie =
tp->t_tfo_cookie.client;
to.to_flags |= TOF_FASTOPEN;
wanted_cookie = 1;
/*
* If we wind up having more data to
* send with the SYN than can fit in
* one segment, don't send any more
* until the SYN|ACK comes back from
* the other end.
*/
sendalot = 0;
}
}
}
/* Window scaling. */
if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
to.to_wscale = tp->request_r_scale;
to.to_flags |= TOF_SCALE;
}
/* Timestamps. */
if ((tp->t_flags & TF_RCVD_TSTMP) ||
((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
to.to_tsval = cts + tp->ts_offset;
to.to_tsecr = tp->ts_recent;
to.to_flags |= TOF_TS;
}
/* Set receive buffer autosizing timestamp. */
if (tp->rfbuf_ts == 0 &&
(so->so_rcv.sb_flags & SB_AUTOSIZE))
tp->rfbuf_ts = tcp_ts_getticks();
/* Selective ACK's. */
if (flags & TH_SYN)
to.to_flags |= TOF_SACKPERM;
else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
tp->rcv_numsacks > 0) {
to.to_flags |= TOF_SACK;
to.to_nsacks = tp->rcv_numsacks;
to.to_sacks = (u_char *)tp->sackblks;
}
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
/* TCP-MD5 (RFC2385). */
if (tp->t_flags & TF_SIGNATURE)
to.to_flags |= TOF_SIGNATURE;
#endif /* TCP_SIGNATURE */
/* Processing the options. */
hdrlen += optlen = tcp_addoptions(&to, opt);
/*
* If we wanted a TFO option to be added, but it was unable
* to fit, ensure no data is sent.
*/
if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
!(to.to_flags & TOF_FASTOPEN))
len = 0;
}
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
if (V_tcp_udp_tunneling_port == 0) {
/* The port was removed?? */
SOCKBUF_UNLOCK(&so->so_snd);
return (EHOSTUNREACH);
}
hdrlen += sizeof(struct udphdr);
}
#endif
#ifdef INET6
if (isipv6)
ipoptlen = ip6_optlen(tp->t_inpcb);
else
#endif
if (tp->t_inpcb->inp_options)
ipoptlen = tp->t_inpcb->inp_options->m_len -
offsetof(struct ipoption, ipopt_list);
else
ipoptlen = 0;
#if defined(IPSEC) || defined(IPSEC_SUPPORT)
ipoptlen += ipsec_optlen;
#endif
/*
* Adjust data length if insertion of options will bump the packet
* length beyond the t_maxseg length. Clear the FIN bit because we
* cut off the tail of the segment.
*/
if (len + optlen + ipoptlen > tp->t_maxseg) {
if (tso) {
uint32_t if_hw_tsomax;
uint32_t moff;
int32_t max_len;
/* extract TSO information */
if_hw_tsomax = tp->t_tsomax;
if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
KASSERT(ipoptlen == 0,
("%s: TSO can't do IP options", __func__));
/*
* Check if we should limit by maximum payload
* length:
*/
if (if_hw_tsomax != 0) {
/* compute maximum TSO length */
max_len = (if_hw_tsomax - hdrlen -
max_linkhdr);
if (max_len <= 0) {
len = 0;
} else if (len > max_len) {
sendalot = 1;
len = max_len;
mark = 2;
}
}
/*
* Prevent the last segment from being fractional
* unless the send sockbuf can be emptied:
*/
max_len = (tp->t_maxseg - optlen);
if ((sb_offset + len) < sbavail(sb)) {
moff = len % (u_int)max_len;
if (moff != 0) {
mark = 3;
len -= moff;
}
}
/*
* In case there are too many small fragments don't
* use TSO:
*/
if (len <= segsiz) {
mark = 4;
tso = 0;
}
/*
* Send the FIN in a separate segment after the bulk
* sending is done. We don't trust the TSO
* implementations to clear the FIN flag on all but
* the last segment.
*/
if (tp->t_flags & TF_NEEDFIN) {
sendalot = 4;
}
} else {
mark = 5;
if (optlen + ipoptlen >= tp->t_maxseg) {
/*
* Since we don't have enough space to put
* the IP header chain and the TCP header in
* one packet as required by RFC 7112, don't
* send it. Also ensure that at least one
* byte of the payload can be put into the
* TCP segment.
*/
SOCKBUF_UNLOCK(&so->so_snd);
error = EMSGSIZE;
sack_rxmit = 0;
goto out;
}
len = tp->t_maxseg - optlen - ipoptlen;
sendalot = 5;
}
} else {
tso = 0;
mark = 6;
}
KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
("%s: len > IP_MAXPACKET", __func__));
#ifdef DIAGNOSTIC
#ifdef INET6
if (max_linkhdr + hdrlen > MCLBYTES)
#else
if (max_linkhdr + hdrlen > MHLEN)
#endif
panic("tcphdr too big");
#endif
/*
* This KASSERT is here to catch edge cases at a well defined place.
* Before, those had triggered (random) panic conditions further
* down.
*/
KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
if ((len == 0) &&
(flags & TH_FIN) &&
(sbused(sb))) {
/*
* We have outstanding data, don't send a fin by itself!.
*/
goto just_return;
}
/*
* Grab a header mbuf, attaching a copy of data to be transmitted,
* and initialize the header from the template for sends on this
* connection.
*/
if (len) {
uint32_t max_val;
uint32_t moff;
if (rack->r_ctl.rc_pace_max_segs)
max_val = rack->r_ctl.rc_pace_max_segs;
else if (rack->rc_user_set_max_segs)
max_val = rack->rc_user_set_max_segs * segsiz;
else
max_val = len;
/*
* We allow a limit on sending with hptsi.
*/
if (len > max_val) {
mark = 7;
len = max_val;
}
#ifdef INET6
if (MHLEN < hdrlen + max_linkhdr)
m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
else
#endif
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
SOCKBUF_UNLOCK(sb);
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
m->m_data += max_linkhdr;
m->m_len = hdrlen;
/*
* Start the m_copy functions from the closest mbuf to the
* sb_offset in the socket buffer chain.
*/
mb = sbsndptr_noadv(sb, sb_offset, &moff);
if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
m_copydata(mb, moff, (int)len,
mtod(m, caddr_t)+hdrlen);
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
sbsndptr_adv(sb, mb, len);
m->m_len += len;
} else {
struct sockbuf *msb;
if (SEQ_LT(tp->snd_nxt, tp->snd_max))
msb = NULL;
else
msb = sb;
m->m_next = tcp_m_copym(
mb, moff, &len,
if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
((rsm == NULL) ? hw_tls : 0)
#ifdef NETFLIX_COPY_ARGS
, &filled_all
#endif
);
if (len <= (tp->t_maxseg - optlen)) {
/*
* Must have ran out of mbufs for the copy
* shorten it to no longer need tso. Lets
* not put on sendalot since we are low on
* mbufs.
*/
tso = 0;
}
if (m->m_next == NULL) {
SOCKBUF_UNLOCK(sb);
(void)m_free(m);
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
}
if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
if (rsm && (rsm->r_flags & RACK_TLP)) {
/*
* TLP should not count in retran count, but
* in its own bin
*/
counter_u64_add(rack_tlp_retran, 1);
counter_u64_add(rack_tlp_retran_bytes, len);
} else {
tp->t_sndrexmitpack++;
KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
}
#ifdef STATS
stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
len);
#endif
} else {
KMOD_TCPSTAT_INC(tcps_sndpack);
KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
#ifdef STATS
stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
len);
#endif
}
/*
* If we're sending everything we've got, set PUSH. (This
* will keep happy those implementations which only give
* data to the user when a buffer fills or a PUSH comes in.)
*/
if (sb_offset + len == sbused(sb) &&
sbused(sb) &&
!(flags & TH_SYN))
flags |= TH_PUSH;
SOCKBUF_UNLOCK(sb);
} else {
SOCKBUF_UNLOCK(sb);
if (tp->t_flags & TF_ACKNOW)
KMOD_TCPSTAT_INC(tcps_sndacks);
else if (flags & (TH_SYN | TH_FIN | TH_RST))
KMOD_TCPSTAT_INC(tcps_sndctrl);
else
KMOD_TCPSTAT_INC(tcps_sndwinup);
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
sack_rxmit = 0;
goto out;
}
#ifdef INET6
if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
MHLEN >= hdrlen) {
M_ALIGN(m, hdrlen);
} else
#endif
m->m_data += max_linkhdr;
m->m_len = hdrlen;
}
SOCKBUF_UNLOCK_ASSERT(sb);
m->m_pkthdr.rcvif = (struct ifnet *)0;
#ifdef MAC
mac_inpcb_create_mbuf(inp, m);
#endif
#ifdef INET6
if (isipv6) {
ip6 = mtod(m, struct ip6_hdr *);
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = tp->t_port;
ulen = hdrlen + len - sizeof(struct ip6_hdr);
udp->uh_ulen = htons(ulen);
th = (struct tcphdr *)(udp + 1);
} else
#endif
th = (struct tcphdr *)(ip6 + 1);
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip6, th);
} else
#endif /* INET6 */
{
ip = mtod(m, struct ip *);
#ifdef TCPDEBUG
ipov = (struct ipovly *)ip;
#endif
#ifdef NETFLIX_TCPOUDP
if (tp->t_port) {
udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
udp->uh_sport = htons(V_tcp_udp_tunneling_port);
udp->uh_dport = tp->t_port;
ulen = hdrlen + len - sizeof(struct ip);
udp->uh_ulen = htons(ulen);
th = (struct tcphdr *)(udp + 1);
} else
#endif
th = (struct tcphdr *)(ip + 1);
tcpip_fillheaders(inp,
#ifdef NETFLIX_TCPOUDP
tp->t_port,
#endif
ip, th);
}
/*
* Fill in fields, remembering maximum advertised window for use in
* delaying messages about window sizes. If resending a FIN, be sure
* not to use a new sequence number.
*/
if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
tp->snd_nxt == tp->snd_max)
tp->snd_nxt--;
/*
* If we are starting a connection, send ECN setup SYN packet. If we
* are on a retransmit, we may resend those bits a number of times
* as per RFC 3168.
*/
if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
if (tp->t_rxtshift >= 1) {
if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
flags |= TH_ECE | TH_CWR;
} else
flags |= TH_ECE | TH_CWR;
}
/* Handle parallel SYN for ECN */
if ((tp->t_state == TCPS_SYN_RECEIVED) &&
(tp->t_flags2 & TF2_ECN_SND_ECE)) {
flags |= TH_ECE;
tp->t_flags2 &= ~TF2_ECN_SND_ECE;
}
if (tp->t_state == TCPS_ESTABLISHED &&
(tp->t_flags2 & TF2_ECN_PERMIT)) {
/*
* If the peer has ECN, mark data packets with ECN capable
* transmission (ECT). Ignore pure ack packets,
* retransmissions.
*/
if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
(sack_rxmit == 0)) {
#ifdef INET6
if (isipv6)
ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
else
#endif
ip->ip_tos |= IPTOS_ECN_ECT0;
KMOD_TCPSTAT_INC(tcps_ecn_ect0);
/*
* Reply with proper ECN notifications.
* Only set CWR on new data segments.
*/
if (tp->t_flags2 & TF2_ECN_SND_CWR) {
flags |= TH_CWR;
tp->t_flags2 &= ~TF2_ECN_SND_CWR;
}
}
if (tp->t_flags2 & TF2_ECN_SND_ECE)
flags |= TH_ECE;
}
/*
* If we are doing retransmissions, then snd_nxt will not reflect
* the first unsent octet. For ACK only packets, we do not want the
* sequence number of the retransmitted packet, we want the sequence
* number of the next unsent octet. So, if there is no data (and no
* SYN or FIN), use snd_max instead of snd_nxt when filling in
* ti_seq. But if we are in persist state, snd_max might reflect
* one byte beyond the right edge of the window, so use snd_nxt in
* that case, since we know we aren't doing a retransmission.
* (retransmit and persist are mutually exclusive...)
*/
if (sack_rxmit == 0) {
if (len || (flags & (TH_SYN | TH_FIN)) ||
rack->rc_in_persist) {
th->th_seq = htonl(tp->snd_nxt);
rack_seq = tp->snd_nxt;
} else {
th->th_seq = htonl(tp->snd_max);
rack_seq = tp->snd_max;
}
} else {
th->th_seq = htonl(rsm->r_start);
rack_seq = rsm->r_start;
}
th->th_ack = htonl(tp->rcv_nxt);
if (optlen) {
bcopy(opt, th + 1, optlen);
th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
}
th->th_flags = flags;
/*
* Calculate receive window. Don't shrink window, but avoid silly
* window syndrome.
* If a RST segment is sent, advertise a window of zero.
*/
if (flags & TH_RST) {
recwin = 0;
} else {
if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
recwin < (long)segsiz)
recwin = 0;
if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
}
/*
* According to RFC1323 the window field in a SYN (i.e., a <SYN> or
* <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is
* handled in syncache.
*/
if (flags & TH_SYN)
th->th_win = htons((u_short)
(min(sbspace(&so->so_rcv), TCP_MAXWIN)));
else {
/* Avoid shrinking window with window scaling. */
recwin = roundup2(recwin, 1 << tp->rcv_scale);
th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
}
/*
* Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
* window. This may cause the remote transmitter to stall. This
* flag tells soreceive() to disable delayed acknowledgements when
* draining the buffer. This can occur if the receiver is
* attempting to read more data than can be buffered prior to
* transmitting on the connection.
*/
if (th->th_win == 0) {
tp->t_sndzerowin++;
tp->t_flags |= TF_RXWIN0SENT;
} else
tp->t_flags &= ~TF_RXWIN0SENT;
tp->snd_up = tp->snd_una; /* drag it along, its deprecated */
#if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
if (to.to_flags & TOF_SIGNATURE) {
/*
* Calculate MD5 signature and put it into the place
* determined before.
* NOTE: since TCP options buffer doesn't point into
* mbuf's data, calculate offset and use it.
*/
if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
(u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
/*
* Do not send segment if the calculation of MD5
* digest has failed.
*/
goto out;
}
}
#endif
/*
* Put TCP length in extended header, and then checksum extended
* header and data.
*/
m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
#ifdef INET6
if (isipv6) {
/*
* ip6_plen is not need to be filled now, and will be filled
* in ip6_output.
*/
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in6_cksum_pseudo(ip6,
sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
0);
}
}
#endif
#if defined(INET6) && defined(INET)
else
#endif
#ifdef INET
{
if (tp->t_port) {
m->m_pkthdr.csum_flags = CSUM_UDP;
m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
th->th_sum = htons(0);
UDPSTAT_INC(udps_opackets);
} else {
m->m_pkthdr.csum_flags = CSUM_TCP;
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
th->th_sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
IPPROTO_TCP + len + optlen));
}
/* IP version must be set here for ipv4/ipv6 checking later */
KASSERT(ip->ip_v == IPVERSION,
("%s: IP version incorrect: %d", __func__, ip->ip_v));
}
#endif
/*
* Enable TSO and specify the size of the segments. The TCP pseudo
* header checksum is always provided. XXX: Fixme: This is currently
* not the case for IPv6.
*/
if (tso) {
KASSERT(len > tp->t_maxseg - optlen,
("%s: len <= tso_segsz", __func__));
m->m_pkthdr.csum_flags |= CSUM_TSO;
m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
}
KASSERT(len + hdrlen == m_length(m, NULL),
("%s: mbuf chain different than expected: %d + %u != %u",
__func__, len, hdrlen, m_length(m, NULL)));
#ifdef TCP_HHOOK
/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
hhook_run_tcp_est_out(tp, th, &to, len, tso);
#endif
#ifdef TCPDEBUG
/*
* Trace.
*/
if (so->so_options & SO_DEBUG) {
u_short save = 0;
#ifdef INET6
if (!isipv6)
#endif
{
save = ipov->ih_len;
ipov->ih_len = htons(m->m_pkthdr.len /* - hdrlen +
* (th->th_off << 2) */ );
}
tcp_trace(TA_OUTPUT, tp->t_state, tp, mtod(m, void *), th, 0);
#ifdef INET6
if (!isipv6)
#endif
ipov->ih_len = save;
}
#endif /* TCPDEBUG */
/* We're getting ready to send; log now. */
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
union tcp_log_stackspecific log;
struct timeval tv;
memset(&log.u_bbr, 0, sizeof(log.u_bbr));
log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
log.u_bbr.ininput = rack->rc_inp->inp_in_input;
if (rack->rack_no_prr)
log.u_bbr.flex1 = 0;
else
log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
log.u_bbr.flex4 = orig_len;
if (filled_all)
log.u_bbr.flex5 = 0x80000000;
else
log.u_bbr.flex5 = 0;
/* Save off the early/late values */
log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
log.u_bbr.bw_inuse = rack_get_bw(rack);
if (rsm || sack_rxmit) {
if (doing_tlp)
log.u_bbr.flex8 = 2;
else
log.u_bbr.flex8 = 1;
} else {
log.u_bbr.flex8 = 0;
}
log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
log.u_bbr.flex7 = mark;
log.u_bbr.pkts_out = tp->t_maxseg;
log.u_bbr.timeStamp = tcp_get_usecs(&tv);
log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
log.u_bbr.lt_epoch = cwnd_to_use;
log.u_bbr.delivered = sendalot;
lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
len, &log, false, NULL, NULL, 0, &tv);
} else
lgb = NULL;
/*
* Fill in IP length and desired time to live and send to IP level.
* There should be a better way to handle ttl and tos; we could keep
* them in the template, but need a way to checksum without them.
*/
/*
* m->m_pkthdr.len should have been set before cksum calcuration,
* because in6_cksum() need it.
*/
#ifdef INET6
if (isipv6) {
/*
* we separately set hoplimit for every segment, since the
* user might want to change the value via setsockopt. Also,
* desired default hop limit might be changed via Neighbor
* Discovery.
*/
ip6->ip6_hlim = in6_selecthlim(inp, NULL);
/*
* Set the packet size here for the benefit of DTrace
* probes. ip6_output() will set it properly; it's supposed
* to include the option header lengths as well.
*/
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
else
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
TCP_PROBE5(send, NULL, tp, ip6, tp, th);
/* TODO: IPv6 IP6TOS_ECT bit on */
error = ip6_output(m, inp->in6p_outputopts,
&inp->inp_route6,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
NULL, NULL, inp);
if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
mtu = inp->inp_route6.ro_nh->nh_mtu;
}
#endif /* INET6 */
#if defined(INET) && defined(INET6)
else
#endif
#ifdef INET
{
ip->ip_len = htons(m->m_pkthdr.len);
#ifdef INET6
if (inp->inp_vflag & INP_IPV6PROTO)
ip->ip_ttl = in6_selecthlim(inp, NULL);
#endif /* INET6 */
/*
* If we do path MTU discovery, then we set DF on every
* packet. This might not be the best thing to do according
* to RFC3390 Section 2. However the tcp hostcache migitates
* the problem so it affects only the first tcp connection
* with a host.
*
* NB: Don't set DF on small MTU/MSS to have a safe
* fallback.
*/
if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
tp->t_flags2 |= TF2_PLPMTU_PMTUD;
if (tp->t_port == 0 || len < V_tcp_minmss) {
ip->ip_off |= htons(IP_DF);
}
} else {
tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
}
if (tp->t_state == TCPS_SYN_SENT)
TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
TCP_PROBE5(send, NULL, tp, ip, tp, th);
error = ip_output(m, inp->inp_options, &inp->inp_route,
((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
inp);
if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
mtu = inp->inp_route.ro_nh->nh_mtu;
}
#endif /* INET */
out:
if (lgb) {
lgb->tlb_errno = error;
lgb = NULL;
}
/*
* In transmit state, time the transmission and arrange for the
* retransmit. In persist state, just set snd_max.
*/
if (error == 0) {
rack->forced_ack = 0; /* If we send something zap the FA flag */
if (rsm && (doing_tlp == 0)) {
/* Set we retransmitted */
rack->rc_gp_saw_rec = 1;
} else {
if (cwnd_to_use > tp->snd_ssthresh) {
/* Set we sent in CA */
rack->rc_gp_saw_ca = 1;
} else {
/* Set we sent in SS */
rack->rc_gp_saw_ss = 1;
}
}
if (TCPS_HAVEESTABLISHED(tp->t_state) &&
(tp->t_flags & TF_SACK_PERMIT) &&
tp->rcv_numsacks > 0)
tcp_clean_dsack_blocks(tp);
tot_len_this_send += len;
if (len == 0)
counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
else if (len == 1) {
counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
} else if (len > 1) {
int idx;
idx = (len / segsiz) + 3;
if (idx >= TCP_MSS_ACCT_ATIMER)
counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
else
counter_u64_add(rack_out_size[idx], 1);
}
}
if (rack->rack_no_prr == 0) {
if (sub_from_prr && (error == 0)) {
if (rack->r_ctl.rc_prr_sndcnt >= len)
rack->r_ctl.rc_prr_sndcnt -= len;
else
rack->r_ctl.rc_prr_sndcnt = 0;
}
}
sub_from_prr = 0;
rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error, cts,
pass, rsm, us_cts);
if ((error == 0) &&
(len > 0) &&
(tp->snd_una == tp->snd_max))
rack->r_ctl.rc_tlp_rxt_last_time = cts;
/* Now are we in persists? */
if (rack->rc_in_persist == 0) {
tcp_seq startseq = tp->snd_nxt;
/* Track our lost count */
if (rsm && (doing_tlp == 0))
rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
/*
* Advance snd_nxt over sequence space of this segment.
*/
if (error)
/* We don't log or do anything with errors */
goto nomore;
if (doing_tlp == 0) {
if (rsm == NULL) {
/*
* Not a retransmission of some
* sort, new data is going out so
* clear our TLP count and flag.
*/
rack->rc_tlp_in_progress = 0;
rack->r_ctl.rc_tlp_cnt_out = 0;
}
} else {
/*
* We have just sent a TLP, mark that it is true
* and make sure our in progress is set so we
* continue to check the count.
*/
rack->rc_tlp_in_progress = 1;
rack->r_ctl.rc_tlp_cnt_out++;
}
if (flags & (TH_SYN | TH_FIN)) {
if (flags & TH_SYN)
tp->snd_nxt++;
if (flags & TH_FIN) {
tp->snd_nxt++;
tp->t_flags |= TF_SENTFIN;
}
}
/* In the ENOBUFS case we do *not* update snd_max */
if (sack_rxmit)
goto nomore;
tp->snd_nxt += len;
if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
if (tp->snd_una == tp->snd_max) {
/*
* Update the time we just added data since
* none was outstanding.
*/
rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
tp->t_acktime = ticks;
}
tp->snd_max = tp->snd_nxt;
/*
* Time this transmission if not a retransmission and
* not currently timing anything.
* This is only relevant in case of switching back to
* the base stack.
*/
if (tp->t_rtttime == 0) {
tp->t_rtttime = ticks;
tp->t_rtseq = startseq;
KMOD_TCPSTAT_INC(tcps_segstimed);
}
if (len &&
((tp->t_flags & TF_GPUTINPROG) == 0))
rack_start_gp_measurement(tp, rack, startseq, sb_offset);
}
} else {
/*
* Persist case, update snd_max but since we are in persist
* mode (no window) we do not update snd_nxt.
*/
int32_t xlen = len;
if (error)
goto nomore;
if (flags & TH_SYN)
++xlen;
if (flags & TH_FIN) {
++xlen;
tp->t_flags |= TF_SENTFIN;
}
/* In the ENOBUFS case we do *not* update snd_max */
if (SEQ_GT(tp->snd_nxt + xlen, tp->snd_max)) {
if (tp->snd_una == tp->snd_max) {
/*
* Update the time we just added data since
* none was outstanding.
*/
rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
tp->t_acktime = ticks;
}
tp->snd_max = tp->snd_nxt + len;
}
}
nomore:
if (error) {
rack->r_ctl.rc_agg_delayed = 0;
rack->r_early = 0;
rack->r_late = 0;
rack->r_ctl.rc_agg_early = 0;
SOCKBUF_UNLOCK_ASSERT(sb); /* Check gotos. */
/*
* Failures do not advance the seq counter above. For the
* case of ENOBUFS we will fall out and retry in 1ms with
* the hpts. Everything else will just have to retransmit
* with the timer.
*
* In any case, we do not want to loop around for another
* send without a good reason.
*/
sendalot = 0;
switch (error) {
case EPERM:
tp->t_softerror = error;
return (error);
case ENOBUFS:
if (slot == 0) {
/*
* Pace us right away to retry in a some
* time
*/
slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
if (rack->rc_enobuf < 126)
rack->rc_enobuf++;
if (slot > ((rack->rc_rack_rtt / 2) * HPTS_USEC_IN_MSEC)) {
slot = (rack->rc_rack_rtt / 2) * HPTS_USEC_IN_MSEC;
}
if (slot < (10 * HPTS_USEC_IN_MSEC))
slot = 10 * HPTS_USEC_IN_MSEC;
}
counter_u64_add(rack_saw_enobuf, 1);
error = 0;
goto enobufs;
case EMSGSIZE:
/*
* For some reason the interface we used initially
* to send segments changed to another or lowered
* its MTU. If TSO was active we either got an
* interface without TSO capabilits or TSO was
* turned off. If we obtained mtu from ip_output()
* then update it and try again.
*/
if (tso)
tp->t_flags &= ~TF_TSO;
if (mtu != 0) {
tcp_mss_update(tp, -1, mtu, NULL, NULL);
goto again;
}
slot = 10 * HPTS_USEC_IN_MSEC;
rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
return (error);
case ENETUNREACH:
counter_u64_add(rack_saw_enetunreach, 1);
case EHOSTDOWN:
case EHOSTUNREACH:
case ENETDOWN:
if (TCPS_HAVERCVDSYN(tp->t_state)) {
tp->t_softerror = error;
}
/* FALLTHROUGH */
default:
slot = 10 * HPTS_USEC_IN_MSEC;
rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
return (error);
}
} else {
rack->rc_enobuf = 0;
}
KMOD_TCPSTAT_INC(tcps_sndtotal);
/*
* Data sent (as far as we can tell). If this advertises a larger
* window than any other segment, then remember the size of the
* advertised window. Any pending ACK has now been sent.
*/
if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
tp->rcv_adv = tp->rcv_nxt + recwin;
tp->last_ack_sent = tp->rcv_nxt;
tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
enobufs:
/* Assure when we leave that snd_nxt will point to top */
if (SEQ_GT(tp->snd_max, tp->snd_nxt))
tp->snd_nxt = tp->snd_max;
if (sendalot) {
/* Do we need to turn off sendalot? */
if (rack->r_ctl.rc_pace_max_segs &&
(tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
/* We hit our max. */
sendalot = 0;
} else if ((rack->rc_user_set_max_segs) &&
(tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
/* We hit the user defined max */
sendalot = 0;
}
}
if ((error == 0) && (flags & TH_FIN))
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
if (flags & TH_RST) {
/*
* We don't send again after sending a RST.
*/
slot = 0;
sendalot = 0;
if (error == 0)
tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
/*
* Get our pacing rate, if an error
* occured in sending (ENOBUF) we would
* hit the else if with slot preset. Other
* errors return.
*/
slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
}
if (rsm &&
rack->use_rack_rr) {
/* Its a retransmit and we use the rack cheat? */
if ((slot == 0) ||
(rack->rc_always_pace == 0) ||
(rack->r_rr_config == 1)) {
/*
* We have no pacing set or we
* are using old-style rack or
* we are overriden to use the old 1ms pacing.
*/
slot = rack->r_ctl.rc_min_to * HPTS_USEC_IN_MSEC;
}
}
if (slot) {
/* set the rack tcb into the slot N */
counter_u64_add(rack_paced_segments, 1);
} else if (sendalot) {
if (len)
counter_u64_add(rack_unpaced_segments, 1);
sack_rxmit = 0;
goto again;
} else if (len) {
counter_u64_add(rack_unpaced_segments, 1);
}
rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
return (error);
}
static void
rack_update_seg(struct tcp_rack *rack)
{
uint32_t orig_val;
orig_val = rack->r_ctl.rc_pace_max_segs;
rack_set_pace_segments(rack->rc_tp, rack, __LINE__);
if (orig_val != rack->r_ctl.rc_pace_max_segs)
rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL);
}
/*
* rack_ctloutput() must drop the inpcb lock before performing copyin on
* socket option arguments. When it re-acquires the lock after the copy, it
* has to revalidate that the connection is still valid for the socket
* option.
*/
static int
rack_set_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
{
struct epoch_tracker et;
uint64_t val;
int32_t error = 0, optval;
uint16_t ca, ss;
switch (sopt->sopt_name) {
case TCP_RACK_PROP_RATE: /* URL:prop_rate */
case TCP_RACK_PROP : /* URL:prop */
case TCP_RACK_TLP_REDUCE: /* URL:tlp_reduce */
case TCP_RACK_EARLY_RECOV: /* URL:early_recov */
case TCP_RACK_PACE_REDUCE: /* Not used */
/* Pacing related ones */
case TCP_RACK_PACE_ALWAYS: /* URL:pace_always */
case TCP_BBR_RACK_INIT_RATE: /* URL:irate */
case TCP_BBR_IWINTSO: /* URL:tso_iwin */
case TCP_RACK_PACE_MAX_SEG: /* URL:pace_max_seg */
case TCP_RACK_FORCE_MSEG: /* URL:force_max_seg */
case TCP_RACK_PACE_RATE_CA: /* URL:pr_ca */
case TCP_RACK_PACE_RATE_SS: /* URL:pr_ss*/
case TCP_RACK_PACE_RATE_REC: /* URL:pr_rec */
case TCP_RACK_GP_INCREASE_CA: /* URL:gp_inc_ca */
case TCP_RACK_GP_INCREASE_SS: /* URL:gp_inc_ss */
case TCP_RACK_GP_INCREASE_REC: /* URL:gp_inc_rec */
case TCP_RACK_RR_CONF: /* URL:rrr_conf */
case TCP_BBR_HDWR_PACE: /* URL:hdwrpace */
/* End pacing related */
case TCP_DELACK:
case TCP_RACK_PRR_SENDALOT: /* URL:prr_sendalot */
case TCP_RACK_MIN_TO: /* URL:min_to */
case TCP_RACK_EARLY_SEG: /* URL:early_seg */
case TCP_RACK_REORD_THRESH: /* URL:reord_thresh */
case TCP_RACK_REORD_FADE: /* URL:reord_fade */
case TCP_RACK_TLP_THRESH: /* URL:tlp_thresh */
case TCP_RACK_PKT_DELAY: /* URL:pkt_delay */
case TCP_RACK_TLP_USE: /* URL:tlp_use */
case TCP_RACK_TLP_INC_VAR: /* URL:tlp_inc_var */
case TCP_RACK_IDLE_REDUCE_HIGH: /* URL:idle_reduce_high */
case TCP_BBR_RACK_RTT_USE: /* URL:rttuse */
case TCP_BBR_USE_RACK_RR: /* URL:rackrr */
case TCP_RACK_DO_DETECTION: /* URL:detect */
case TCP_NO_PRR: /* URL:noprr */
case TCP_TIMELY_DYN_ADJ: /* URL:dynamic */
case TCP_DATA_AFTER_CLOSE:
case TCP_RACK_NONRXT_CFG_RATE: /* URL:nonrxtcr */
case TCP_SHARED_CWND_ENABLE: /* URL:scwnd */
case TCP_RACK_MBUF_QUEUE: /* URL:mqueue */
case TCP_RACK_NO_PUSH_AT_MAX: /* URL:npush */
case TCP_RACK_PACE_TO_FILL: /* URL:fillcw */
case TCP_SHARED_CWND_TIME_LIMIT: /* URL:lscwnd */
case TCP_RACK_PROFILE: /* URL:profile */
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
if (error)
return (error);
INP_WLOCK(inp);
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
INP_WUNLOCK(inp);
return (ECONNRESET);
}
tp = intotcpcb(inp);
rack = (struct tcp_rack *)tp->t_fb_ptr;
switch (sopt->sopt_name) {
case TCP_RACK_PROFILE:
RACK_OPTS_INC(tcp_profile);
if (optval == 1) {
/* pace_always=1 */
rack->rc_always_pace = 1;
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
/* scwnd=1 */
rack->rack_enable_scwnd = 1;
/* dynamic=100 */
rack->rc_gp_dyn_mul = 1;
rack->r_ctl.rack_per_of_gp_ca = 100;
/* rrr_conf=3 */
rack->r_rr_config = 3;
/* npush=2 */
rack->r_ctl.rc_no_push_at_mrtt = 2;
/* fillcw=1 */
rack->rc_pace_to_cwnd = 1;
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
/* noprr=1 */
rack->rack_no_prr = 1;
/* lscwnd=1 */
rack->r_limit_scw = 1;
} else if (optval == 2) {
/* pace_always=1 */
rack->rc_always_pace = 1;
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
/* scwnd=1 */
rack->rack_enable_scwnd = 1;
/* dynamic=100 */
rack->rc_gp_dyn_mul = 1;
rack->r_ctl.rack_per_of_gp_ca = 100;
/* rrr_conf=3 */
rack->r_rr_config = 3;
/* npush=2 */
rack->r_ctl.rc_no_push_at_mrtt = 2;
/* fillcw=1 */
rack->rc_pace_to_cwnd = 1;
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
/* noprr=1 */
rack->rack_no_prr = 1;
/* lscwnd=0 */
rack->r_limit_scw = 0;
}
break;
case TCP_SHARED_CWND_TIME_LIMIT:
RACK_OPTS_INC(tcp_lscwnd);
if (optval)
rack->r_limit_scw = 1;
else
rack->r_limit_scw = 0;
break;
case TCP_RACK_PACE_TO_FILL:
RACK_OPTS_INC(tcp_fillcw);
if (optval == 0)
rack->rc_pace_to_cwnd = 0;
else
rack->rc_pace_to_cwnd = 1;
if ((optval >= rack_gp_rtt_maxmul) &&
rack_gp_rtt_maxmul &&
(optval < 0xf)) {
rack->rc_pace_fill_if_rttin_range = 1;
rack->rtt_limit_mul = optval;
} else {
rack->rc_pace_fill_if_rttin_range = 0;
rack->rtt_limit_mul = 0;
}
break;
case TCP_RACK_NO_PUSH_AT_MAX:
RACK_OPTS_INC(tcp_npush);
if (optval == 0)
rack->r_ctl.rc_no_push_at_mrtt = 0;
else if (optval < 0xff)
rack->r_ctl.rc_no_push_at_mrtt = optval;
else
error = EINVAL;
break;
case TCP_SHARED_CWND_ENABLE:
RACK_OPTS_INC(tcp_rack_scwnd);
if (optval == 0)
rack->rack_enable_scwnd = 0;
else
rack->rack_enable_scwnd = 1;
break;
case TCP_RACK_MBUF_QUEUE:
/* Now do we use the LRO mbuf-queue feature */
RACK_OPTS_INC(tcp_rack_mbufq);
if (optval)
rack->r_mbuf_queue = 1;
else
rack->r_mbuf_queue = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
break;
case TCP_RACK_NONRXT_CFG_RATE:
RACK_OPTS_INC(tcp_rack_cfg_rate);
if (optval == 0)
rack->rack_rec_nonrxt_use_cr = 0;
else
rack->rack_rec_nonrxt_use_cr = 1;
break;
case TCP_NO_PRR:
RACK_OPTS_INC(tcp_rack_noprr);
if (optval == 0)
rack->rack_no_prr = 0;
else
rack->rack_no_prr = 1;
break;
case TCP_TIMELY_DYN_ADJ:
RACK_OPTS_INC(tcp_timely_dyn);
if (optval == 0)
rack->rc_gp_dyn_mul = 0;
else {
rack->rc_gp_dyn_mul = 1;
if (optval >= 100) {
/*
* If the user sets something 100 or more
* its the gp_ca value.
*/
rack->r_ctl.rack_per_of_gp_ca = optval;
}
}
break;
case TCP_RACK_DO_DETECTION:
RACK_OPTS_INC(tcp_rack_do_detection);
if (optval == 0)
rack->do_detection = 0;
else
rack->do_detection = 1;
break;
case TCP_RACK_PROP_RATE:
if ((optval <= 0) || (optval >= 100)) {
error = EINVAL;
break;
}
RACK_OPTS_INC(tcp_rack_prop_rate);
rack->r_ctl.rc_prop_rate = optval;
break;
case TCP_RACK_TLP_USE:
if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
error = EINVAL;
break;
}
RACK_OPTS_INC(tcp_tlp_use);
rack->rack_tlp_threshold_use = optval;
break;
case TCP_RACK_PROP:
/* RACK proportional rate reduction (bool) */
RACK_OPTS_INC(tcp_rack_prop);
rack->r_ctl.rc_prop_reduce = optval;
break;
case TCP_RACK_TLP_REDUCE:
/* RACK TLP cwnd reduction (bool) */
RACK_OPTS_INC(tcp_rack_tlp_reduce);
rack->r_ctl.rc_tlp_cwnd_reduce = optval;
break;
case TCP_RACK_EARLY_RECOV:
/* Should recovery happen early (bool) */
RACK_OPTS_INC(tcp_rack_early_recov);
rack->r_ctl.rc_early_recovery = optval;
break;
/* Pacing related ones */
case TCP_RACK_PACE_ALWAYS:
/*
* zero is old rack method, 1 is new
* method using a pacing rate.
*/
RACK_OPTS_INC(tcp_rack_pace_always);
if (optval > 0)
rack->rc_always_pace = 1;
else
rack->rc_always_pace = 0;
if (rack->r_mbuf_queue || rack->rc_always_pace)
tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
else
tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
/* A rate may be set irate or other, if so set seg size */
rack_update_seg(rack);
break;
case TCP_BBR_RACK_INIT_RATE:
RACK_OPTS_INC(tcp_initial_rate);
val = optval;
/* Change from kbits per second to bytes per second */
val *= 1000;
val /= 8;
rack->r_ctl.init_rate = val;
if (rack->rc_init_win != rack_default_init_window) {
uint32_t win, snt;
/*
* Options don't always get applied
* in the order you think. So in order
* to assure we update a cwnd we need
* to check and see if we are still
* where we should raise the cwnd.
*/
win = rc_init_window(rack);
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
if ((snt < win) &&
(tp->snd_cwnd < win))
tp->snd_cwnd = win;
}
if (rack->rc_always_pace)
rack_update_seg(rack);
break;
case TCP_BBR_IWINTSO:
RACK_OPTS_INC(tcp_initial_win);
if (optval && (optval <= 0xff)) {
uint32_t win, snt;
rack->rc_init_win = optval;
win = rc_init_window(rack);
if (SEQ_GT(tp->snd_max, tp->iss))
snt = tp->snd_max - tp->iss;
else
snt = 0;
if ((snt < win) &&
(tp->t_srtt |
#ifdef NETFLIX_PEAKRATE
tp->t_maxpeakrate |
#endif
rack->r_ctl.init_rate)) {
/*
* We are not past the initial window
* and we have some bases for pacing,
* so we need to possibly adjust up
* the cwnd. Note even if we don't set
* the cwnd, its still ok to raise the rc_init_win
* which can be used coming out of idle when we
* would have a rate.
*/
if (tp->snd_cwnd < win)
tp->snd_cwnd = win;
}
if (rack->rc_always_pace)
rack_update_seg(rack);
} else
error = EINVAL;
break;
case TCP_RACK_FORCE_MSEG:
RACK_OPTS_INC(tcp_rack_force_max_seg);
if (optval)
rack->rc_force_max_seg = 1;
else
rack->rc_force_max_seg = 0;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments size in a pace in bytes */
RACK_OPTS_INC(tcp_rack_max_seg);
rack->rc_user_set_max_segs = optval;
rack_set_pace_segments(tp, rack, __LINE__);
break;
case TCP_RACK_PACE_RATE_REC:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_rec);
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_PACE_RATE_SS:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_ss);
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_PACE_RATE_CA:
/* Set the fixed pacing rate in Bytes per second ca */
RACK_OPTS_INC(tcp_rack_pace_rate_ca);
rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
rack->use_fixed_rate = 1;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rc_fixed_pacing_rate_ss,
rack->r_ctl.rc_fixed_pacing_rate_ca,
rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_REC:
RACK_OPTS_INC(tcp_gp_inc_rec);
rack->r_ctl.rack_per_of_gp_rec = optval;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_CA:
RACK_OPTS_INC(tcp_gp_inc_ca);
ca = optval;
if (ca < 100) {
/*
* We don't allow any reduction
* over the GP b/w.
*/
error = EINVAL;
break;
}
rack->r_ctl.rack_per_of_gp_ca = ca;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_GP_INCREASE_SS:
RACK_OPTS_INC(tcp_gp_inc_ss);
ss = optval;
if (ss < 100) {
/*
* We don't allow any reduction
* over the GP b/w.
*/
error = EINVAL;
break;
}
rack->r_ctl.rack_per_of_gp_ss = ss;
rack_log_pacing_delay_calc(rack,
rack->r_ctl.rack_per_of_gp_ss,
rack->r_ctl.rack_per_of_gp_ca,
rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
__LINE__, NULL);
break;
case TCP_RACK_RR_CONF:
RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
if (optval && optval <= 3)
rack->r_rr_config = optval;
else
rack->r_rr_config = 0;
break;
case TCP_BBR_HDWR_PACE:
RACK_OPTS_INC(tcp_hdwr_pacing);
if (optval){
if (rack->rack_hdrw_pacing == 0) {
rack->rack_hdw_pace_ena = 1;
rack->rack_attempt_hdwr_pace = 0;
} else
error = EALREADY;
} else {
rack->rack_hdw_pace_ena = 0;
#ifdef RATELIMIT
if (rack->rack_hdrw_pacing) {
rack->rack_hdrw_pacing = 0;
in_pcbdetach_txrtlmt(rack->rc_inp);
}
#endif
}
break;
/* End Pacing related ones */
case TCP_RACK_PRR_SENDALOT:
/* Allow PRR to send more than one seg */
RACK_OPTS_INC(tcp_rack_prr_sendalot);
rack->r_ctl.rc_prr_sendalot = optval;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
RACK_OPTS_INC(tcp_rack_min_to);
rack->r_ctl.rc_min_to = optval;
break;
case TCP_RACK_EARLY_SEG:
/* If early recovery max segments */
RACK_OPTS_INC(tcp_rack_early_seg);
rack->r_ctl.rc_early_recovery_segs = optval;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
RACK_OPTS_INC(tcp_rack_reord_thresh);
if ((optval > 0) && (optval < 31))
rack->r_ctl.rc_reorder_shift = optval;
else
error = EINVAL;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
RACK_OPTS_INC(tcp_rack_reord_fade);
rack->r_ctl.rc_reorder_fade = optval;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
RACK_OPTS_INC(tcp_rack_tlp_thresh);
if (optval)
rack->r_ctl.rc_tlp_threshold = optval;
else
error = EINVAL;
break;
case TCP_BBR_USE_RACK_RR:
RACK_OPTS_INC(tcp_rack_rr);
if (optval)
rack->use_rack_rr = 1;
else
rack->use_rack_rr = 0;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
RACK_OPTS_INC(tcp_rack_pkt_delay);
rack->r_ctl.rc_pkt_delay = optval;
break;
case TCP_RACK_TLP_INC_VAR:
/* Does TLP include rtt variance in t-o */
error = EINVAL;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
error = EINVAL;
break;
case TCP_DELACK:
if (optval == 0)
tp->t_delayed_ack = 0;
else
tp->t_delayed_ack = 1;
if (tp->t_flags & TF_DELACK) {
tp->t_flags &= ~TF_DELACK;
tp->t_flags |= TF_ACKNOW;
NET_EPOCH_ENTER(et);
rack_output(tp);
NET_EPOCH_EXIT(et);
}
break;
case TCP_BBR_RACK_RTT_USE:
if ((optval != USE_RTT_HIGH) &&
(optval != USE_RTT_LOW) &&
(optval != USE_RTT_AVG))
error = EINVAL;
else
rack->r_ctl.rc_rate_sample_method = optval;
break;
case TCP_DATA_AFTER_CLOSE:
if (optval)
rack->rc_allow_data_af_clo = 1;
else
rack->rc_allow_data_af_clo = 0;
break;
case TCP_RACK_PACE_REDUCE:
/* sysctl only now */
error = EINVAL;
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
#ifdef NETFLIX_STATS
tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
#endif
INP_WUNLOCK(inp);
return (error);
}
static int
rack_get_sockopt(struct socket *so, struct sockopt *sopt,
struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
{
int32_t error, optval;
uint64_t val;
/*
* Because all our options are either boolean or an int, we can just
* pull everything into optval and then unlock and copy. If we ever
* add a option that is not a int, then this will have quite an
* impact to this routine.
*/
error = 0;
switch (sopt->sopt_name) {
case TCP_RACK_PROFILE:
/* You cannot retrieve a profile, its write only */
error = EINVAL;
break;
case TCP_RACK_PACE_TO_FILL:
optval = rack->rc_pace_to_cwnd;
break;
case TCP_RACK_NO_PUSH_AT_MAX:
optval = rack->r_ctl.rc_no_push_at_mrtt;
break;
case TCP_SHARED_CWND_ENABLE:
optval = rack->rack_enable_scwnd;
break;
case TCP_RACK_NONRXT_CFG_RATE:
optval = rack->rack_rec_nonrxt_use_cr;
break;
case TCP_NO_PRR:
optval = rack->rack_no_prr;
break;
case TCP_RACK_DO_DETECTION:
optval = rack->do_detection;
break;
case TCP_RACK_MBUF_QUEUE:
/* Now do we use the LRO mbuf-queue feature */
optval = rack->r_mbuf_queue;
break;
case TCP_TIMELY_DYN_ADJ:
optval = rack->rc_gp_dyn_mul;
break;
case TCP_BBR_IWINTSO:
optval = rack->rc_init_win;
break;
case TCP_RACK_PROP_RATE:
optval = rack->r_ctl.rc_prop_rate;
break;
case TCP_RACK_PROP:
/* RACK proportional rate reduction (bool) */
optval = rack->r_ctl.rc_prop_reduce;
break;
case TCP_RACK_TLP_REDUCE:
/* RACK TLP cwnd reduction (bool) */
optval = rack->r_ctl.rc_tlp_cwnd_reduce;
break;
case TCP_RACK_EARLY_RECOV:
/* Should recovery happen early (bool) */
optval = rack->r_ctl.rc_early_recovery;
break;
case TCP_RACK_PACE_REDUCE:
/* RACK Hptsi reduction factor (divisor) */
error = EINVAL;
break;
case TCP_BBR_RACK_INIT_RATE:
val = rack->r_ctl.init_rate;
/* convert to kbits per sec */
val *= 8;
val /= 1000;
optval = (uint32_t)val;
break;
case TCP_RACK_FORCE_MSEG:
optval = rack->rc_force_max_seg;
break;
case TCP_RACK_PACE_MAX_SEG:
/* Max segments in a pace */
optval = rack->rc_user_set_max_segs;
break;
case TCP_RACK_PACE_ALWAYS:
/* Use the always pace method */
optval = rack->rc_always_pace;
break;
case TCP_RACK_PRR_SENDALOT:
/* Allow PRR to send more than one seg */
optval = rack->r_ctl.rc_prr_sendalot;
break;
case TCP_RACK_MIN_TO:
/* Minimum time between rack t-o's in ms */
optval = rack->r_ctl.rc_min_to;
break;
case TCP_RACK_EARLY_SEG:
/* If early recovery max segments */
optval = rack->r_ctl.rc_early_recovery_segs;
break;
case TCP_RACK_REORD_THRESH:
/* RACK reorder threshold (shift amount) */
optval = rack->r_ctl.rc_reorder_shift;
break;
case TCP_RACK_REORD_FADE:
/* Does reordering fade after ms time */
optval = rack->r_ctl.rc_reorder_fade;
break;
case TCP_BBR_USE_RACK_RR:
/* Do we use the rack cheat for rxt */
optval = rack->use_rack_rr;
break;
case TCP_RACK_RR_CONF:
optval = rack->r_rr_config;
break;
case TCP_BBR_HDWR_PACE:
optval = rack->rack_hdw_pace_ena;
break;
case TCP_RACK_TLP_THRESH:
/* RACK TLP theshold i.e. srtt+(srtt/N) */
optval = rack->r_ctl.rc_tlp_threshold;
break;
case TCP_RACK_PKT_DELAY:
/* RACK added ms i.e. rack-rtt + reord + N */
optval = rack->r_ctl.rc_pkt_delay;
break;
case TCP_RACK_TLP_USE:
optval = rack->rack_tlp_threshold_use;
break;
case TCP_RACK_TLP_INC_VAR:
/* Does TLP include rtt variance in t-o */
error = EINVAL;
break;
case TCP_RACK_IDLE_REDUCE_HIGH:
error = EINVAL;
break;
case TCP_RACK_PACE_RATE_CA:
optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
break;
case TCP_RACK_PACE_RATE_SS:
optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
break;
case TCP_RACK_PACE_RATE_REC:
optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
break;
case TCP_RACK_GP_INCREASE_SS:
optval = rack->r_ctl.rack_per_of_gp_ca;
break;
case TCP_RACK_GP_INCREASE_CA:
optval = rack->r_ctl.rack_per_of_gp_ss;
break;
case TCP_BBR_RACK_RTT_USE:
optval = rack->r_ctl.rc_rate_sample_method;
break;
case TCP_DELACK:
optval = tp->t_delayed_ack;
break;
case TCP_DATA_AFTER_CLOSE:
optval = rack->rc_allow_data_af_clo;
break;
case TCP_SHARED_CWND_TIME_LIMIT:
optval = rack->r_limit_scw;
break;
default:
return (tcp_default_ctloutput(so, sopt, inp, tp));
break;
}
INP_WUNLOCK(inp);
if (error == 0) {
error = sooptcopyout(sopt, &optval, sizeof optval);
}
return (error);
}
static int
rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
{
int32_t error = EINVAL;
struct tcp_rack *rack;
rack = (struct tcp_rack *)tp->t_fb_ptr;
if (rack == NULL) {
/* Huh? */
goto out;
}
if (sopt->sopt_dir == SOPT_SET) {
return (rack_set_sockopt(so, sopt, inp, tp, rack));
} else if (sopt->sopt_dir == SOPT_GET) {
return (rack_get_sockopt(so, sopt, inp, tp, rack));
}
out:
INP_WUNLOCK(inp);
return (error);
}
static int
rack_pru_options(struct tcpcb *tp, int flags)
{
if (flags & PRUS_OOB)
return (EOPNOTSUPP);
return (0);
}
static struct tcp_function_block __tcp_rack = {
.tfb_tcp_block_name = __XSTRING(STACKNAME),
.tfb_tcp_output = rack_output,
.tfb_do_queued_segments = ctf_do_queued_segments,
.tfb_do_segment_nounlock = rack_do_segment_nounlock,
.tfb_tcp_do_segment = rack_do_segment,
.tfb_tcp_ctloutput = rack_ctloutput,
.tfb_tcp_fb_init = rack_init,
.tfb_tcp_fb_fini = rack_fini,
.tfb_tcp_timer_stop_all = rack_stopall,
.tfb_tcp_timer_activate = rack_timer_activate,
.tfb_tcp_timer_active = rack_timer_active,
.tfb_tcp_timer_stop = rack_timer_stop,
.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
.tfb_tcp_handoff_ok = rack_handoff_ok,
.tfb_pru_options = rack_pru_options,
};
static const char *rack_stack_names[] = {
__XSTRING(STACKNAME),
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#endif
};
static int
rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
{
memset(mem, 0, size);
return (0);
}
static void
rack_dtor(void *mem, int32_t size, void *arg)
{
}
static bool rack_mod_inited = false;
static int
tcp_addrack(module_t mod, int32_t type, void *data)
{
int32_t err = 0;
int num_stacks;
switch (type) {
case MOD_LOAD:
rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
sizeof(struct rack_sendmap),
rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
sizeof(struct tcp_rack),
rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
sysctl_ctx_init(&rack_sysctl_ctx);
rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
OID_AUTO,
#ifdef STACKALIAS
__XSTRING(STACKALIAS),
#else
__XSTRING(STACKNAME),
#endif
CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"");
if (rack_sysctl_root == NULL) {
printf("Failed to add sysctl node\n");
err = EFAULT;
goto free_uma;
}
rack_init_sysctls();
num_stacks = nitems(rack_stack_names);
err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
rack_stack_names, &num_stacks);
if (err) {
printf("Failed to register %s stack name for "
"%s module\n", rack_stack_names[num_stacks],
__XSTRING(MODNAME));
sysctl_ctx_free(&rack_sysctl_ctx);
free_uma:
uma_zdestroy(rack_zone);
uma_zdestroy(rack_pcb_zone);
rack_counter_destroy();
printf("Failed to register rack module -- err:%d\n", err);
return (err);
}
tcp_lro_reg_mbufq();
rack_mod_inited = true;
break;
case MOD_QUIESCE:
err = deregister_tcp_functions(&__tcp_rack, true, false);
break;
case MOD_UNLOAD:
err = deregister_tcp_functions(&__tcp_rack, false, true);
if (err == EBUSY)
break;
if (rack_mod_inited) {
uma_zdestroy(rack_zone);
uma_zdestroy(rack_pcb_zone);
sysctl_ctx_free(&rack_sysctl_ctx);
rack_counter_destroy();
rack_mod_inited = false;
}
tcp_lro_dereg_mbufq();
err = 0;
break;
default:
return (EOPNOTSUPP);
}
return (err);
}
static moduledata_t tcp_rack = {
.name = __XSTRING(MODNAME),
.evhand = tcp_addrack,
.priv = 0
};
MODULE_VERSION(MODNAME, 1);
DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);