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vcpe/l2tp/pppd/solaris/ppp_ahdlc.c

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/*
* ppp_ahdlc.c - STREAMS module for doing PPP asynchronous HDLC.
*
* Re-written by Adi Masputra <adi.masputra@sun.com>, based on
* the original ppp_ahdlc.c
*
* Copyright (c) 2000 by Sun Microsystems, Inc.
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, provided that the above copyright
* notice appears in all copies.
*
* SUN MAKES NO REPRESENTATION OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES
*
* Copyright (c) 1994 Paul Mackerras. All rights reserved.
*
* 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.
*
* 3. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <paulus@samba.org>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* $Id: ppp_ahdlc.c,v 1.5 2005/06/27 00:59:57 carlsonj Exp $
*/
/*
* This file is used under Solaris 2, SVR4, SunOS 4, and Digital UNIX.
*/
#include <sys/types.h>
#include <sys/param.h>
#include <sys/stream.h>
#include <sys/stropts.h>
#include <sys/errno.h>
#ifdef SVR4
#include <sys/conf.h>
#include <sys/kmem.h>
#include <sys/cmn_err.h>
#include <sys/ddi.h>
#else
#include <sys/user.h>
#ifdef __osf__
#include <sys/cmn_err.h>
#endif
#endif /* SVR4 */
#include <net/ppp_defs.h>
#include <net/pppio.h>
#include "ppp_mod.h"
/*
* Right now, mutex is only enabled for Solaris 2.x
*/
#if defined(SOL2)
#define USE_MUTEX
#endif /* SOL2 */
#ifdef USE_MUTEX
#define MUTEX_ENTER(x) mutex_enter(x)
#define MUTEX_EXIT(x) mutex_exit(x)
#else
#define MUTEX_ENTER(x)
#define MUTEX_EXIT(x)
#endif
/*
* intpointer_t and uintpointer_t are signed and unsigned integer types
* large enough to hold any data pointer; that is, data pointers can be
* assigned into or from these integer types without losing precision.
* On recent Solaris releases, these types are defined in sys/int_types.h,
* but not on SunOS 4.x or the earlier Solaris versions.
*/
#if defined(_LP64) || defined(_I32LPx)
typedef long intpointer_t;
typedef unsigned long uintpointer_t;
#else
typedef int intpointer_t;
typedef unsigned int uintpointer_t;
#endif
MOD_OPEN_DECL(ahdlc_open);
MOD_CLOSE_DECL(ahdlc_close);
static int ahdlc_wput __P((queue_t *, mblk_t *));
static int ahdlc_rput __P((queue_t *, mblk_t *));
static void ahdlc_encode __P((queue_t *, mblk_t *));
static void ahdlc_decode __P((queue_t *, mblk_t *));
static int msg_byte __P((mblk_t *, unsigned int));
#if defined(SOL2)
/*
* Don't send HDLC start flag is last transmit is within 1.5 seconds -
* FLAG_TIME is defined is microseconds
*/
#define FLAG_TIME 1500
#define ABS(x) (x >= 0 ? x : (-x))
#endif /* SOL2 */
/*
* Extract byte i of message mp
*/
#define MSG_BYTE(mp, i) ((i) < (mp)->b_wptr - (mp)->b_rptr? (mp)->b_rptr[i]: \
msg_byte((mp), (i)))
/*
* Is this LCP packet one we have to transmit using LCP defaults?
*/
#define LCP_USE_DFLT(mp) (1 <= (code = MSG_BYTE((mp), 4)) && code <= 7)
/*
* Standard STREAMS declarations
*/
static struct module_info minfo = {
0x7d23, "ppp_ahdl", 0, INFPSZ, 32768, 512
};
static struct qinit rinit = {
ahdlc_rput, NULL, ahdlc_open, ahdlc_close, NULL, &minfo, NULL
};
static struct qinit winit = {
ahdlc_wput, NULL, NULL, NULL, NULL, &minfo, NULL
};
#if defined(SVR4) && !defined(SOL2)
int phdldevflag = 0;
#define ppp_ahdlcinfo phdlinfo
#endif /* defined(SVR4) && !defined(SOL2) */
struct streamtab ppp_ahdlcinfo = {
&rinit, /* ptr to st_rdinit */
&winit, /* ptr to st_wrinit */
NULL, /* ptr to st_muxrinit */
NULL, /* ptr to st_muxwinit */
#if defined(SUNOS4)
NULL /* ptr to ptr to st_modlist */
#endif /* SUNOS4 */
};
#if defined(SUNOS4)
int ppp_ahdlc_count = 0; /* open counter */
#endif /* SUNOS4 */
/*
* Per-stream state structure
*/
typedef struct ahdlc_state {
#if defined(USE_MUTEX)
kmutex_t lock; /* lock for this structure */
#endif /* USE_MUTEX */
int flags; /* link flags */
mblk_t *rx_buf; /* ptr to receive buffer */
int rx_buf_size; /* receive buffer size */
ushort_t infcs; /* calculated rx HDLC FCS */
u_int32_t xaccm[8]; /* 256-bit xmit ACCM */
u_int32_t raccm; /* 32-bit rcv ACCM */
int mtu; /* interface MTU */
int mru; /* link MRU */
int unit; /* current PPP unit number */
struct pppstat stats; /* statistic structure */
#if defined(SOL2)
clock_t flag_time; /* time in usec between flags */
clock_t lbolt; /* last updated lbolt */
#endif /* SOL2 */
} ahdlc_state_t;
/*
* Values for flags
*/
#define ESCAPED 0x100 /* last saw escape char on input */
#define IFLUSH 0x200 /* flushing input due to error */
/*
* RCV_B7_1, etc., defined in net/pppio.h, are stored in flags also.
*/
#define RCV_FLAGS (RCV_B7_1|RCV_B7_0|RCV_ODDP|RCV_EVNP)
/*
* FCS lookup table as calculated by genfcstab.
*/
static u_short fcstab[256] = {
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};
static u_int32_t paritytab[8] =
{
0x96696996, 0x69969669, 0x69969669, 0x96696996,
0x69969669, 0x96696996, 0x96696996, 0x69969669
};
/*
* STREAMS module open (entry) point
*/
MOD_OPEN(ahdlc_open)
{
ahdlc_state_t *state;
mblk_t *mp;
/*
* Return if it's already opened
*/
if (q->q_ptr) {
return 0;
}
/*
* This can only be opened as a module
*/
if (sflag != MODOPEN) {
OPEN_ERROR(EINVAL);
}
state = (ahdlc_state_t *) ALLOC_NOSLEEP(sizeof(ahdlc_state_t));
if (state == 0)
OPEN_ERROR(ENOSR);
bzero((caddr_t) state, sizeof(ahdlc_state_t));
q->q_ptr = (caddr_t) state;
WR(q)->q_ptr = (caddr_t) state;
#if defined(USE_MUTEX)
mutex_init(&state->lock, NULL, MUTEX_DEFAULT, NULL);
#endif /* USE_MUTEX */
state->xaccm[0] = ~0; /* escape 0x00 through 0x1f */
state->xaccm[3] = 0x60000000; /* escape 0x7d and 0x7e */
state->mru = PPP_MRU; /* default of 1500 bytes */
#if defined(SOL2)
state->flag_time = drv_usectohz(FLAG_TIME);
#endif /* SOL2 */
#if defined(SUNOS4)
ppp_ahdlc_count++;
#endif /* SUNOS4 */
qprocson(q);
if ((mp = allocb(1, BPRI_HI)) != NULL) {
mp->b_datap->db_type = M_FLUSH;
*mp->b_wptr++ = FLUSHR;
putnext(q, mp);
}
return 0;
}
/*
* STREAMS module close (exit) point
*/
MOD_CLOSE(ahdlc_close)
{
ahdlc_state_t *state;
qprocsoff(q);
state = (ahdlc_state_t *) q->q_ptr;
if (state == 0) {
DPRINT("state == 0 in ahdlc_close\n");
return 0;
}
if (state->rx_buf != 0) {
freemsg(state->rx_buf);
state->rx_buf = 0;
}
#if defined(USE_MUTEX)
mutex_destroy(&state->lock);
#endif /* USE_MUTEX */
FREE(q->q_ptr, sizeof(ahdlc_state_t));
q->q_ptr = NULL;
OTHERQ(q)->q_ptr = NULL;
#if defined(SUNOS4)
if (ppp_ahdlc_count)
ppp_ahdlc_count--;
#endif /* SUNOS4 */
return 0;
}
/*
* Write side put routine
*/
static int
ahdlc_wput(q, mp)
queue_t *q;
mblk_t *mp;
{
ahdlc_state_t *state;
struct iocblk *iop;
int error;
mblk_t *np;
struct ppp_stats *psp;
state = (ahdlc_state_t *) q->q_ptr;
if (state == 0) {
DPRINT("state == 0 in ahdlc_wput\n");
freemsg(mp);
return 0;
}
switch (mp->b_datap->db_type) {
case M_DATA:
/*
* A data packet - do character-stuffing and FCS, and
* send it onwards.
*/
ahdlc_encode(q, mp);
freemsg(mp);
break;
case M_IOCTL:
iop = (struct iocblk *) mp->b_rptr;
error = EINVAL;
switch (iop->ioc_cmd) {
case PPPIO_XACCM:
if ((iop->ioc_count < sizeof(u_int32_t)) ||
(iop->ioc_count > sizeof(ext_accm))) {
break;
}
if (mp->b_cont == 0) {
DPRINT1("ahdlc_wput/%d: PPPIO_XACCM b_cont = 0!\n", state->unit);
break;
}
MUTEX_ENTER(&state->lock);
bcopy((caddr_t)mp->b_cont->b_rptr, (caddr_t)state->xaccm,
iop->ioc_count);
state->xaccm[2] &= ~0x40000000; /* don't escape 0x5e */
state->xaccm[3] |= 0x60000000; /* do escape 0x7d, 0x7e */
MUTEX_EXIT(&state->lock);
iop->ioc_count = 0;
error = 0;
break;
case PPPIO_RACCM:
if (iop->ioc_count != sizeof(u_int32_t))
break;
if (mp->b_cont == 0) {
DPRINT1("ahdlc_wput/%d: PPPIO_RACCM b_cont = 0!\n", state->unit);
break;
}
MUTEX_ENTER(&state->lock);
bcopy((caddr_t)mp->b_cont->b_rptr, (caddr_t)&state->raccm,
sizeof(u_int32_t));
MUTEX_EXIT(&state->lock);
iop->ioc_count = 0;
error = 0;
break;
case PPPIO_GCLEAN:
np = allocb(sizeof(int), BPRI_HI);
if (np == 0) {
error = ENOSR;
break;
}
if (mp->b_cont != 0)
freemsg(mp->b_cont);
mp->b_cont = np;
MUTEX_ENTER(&state->lock);
*(int *)np->b_wptr = state->flags & RCV_FLAGS;
MUTEX_EXIT(&state->lock);
np->b_wptr += sizeof(int);
iop->ioc_count = sizeof(int);
error = 0;
break;
case PPPIO_GETSTAT:
np = allocb(sizeof(struct ppp_stats), BPRI_HI);
if (np == 0) {
error = ENOSR;
break;
}
if (mp->b_cont != 0)
freemsg(mp->b_cont);
mp->b_cont = np;
psp = (struct ppp_stats *) np->b_wptr;
np->b_wptr += sizeof(struct ppp_stats);
bzero((caddr_t)psp, sizeof(struct ppp_stats));
psp->p = state->stats;
iop->ioc_count = sizeof(struct ppp_stats);
error = 0;
break;
case PPPIO_LASTMOD:
/* we knew this anyway */
error = 0;
break;
default:
error = -1;
break;
}
if (error < 0)
putnext(q, mp);
else if (error == 0) {
mp->b_datap->db_type = M_IOCACK;
qreply(q, mp);
} else {
mp->b_datap->db_type = M_IOCNAK;
iop->ioc_count = 0;
iop->ioc_error = error;
qreply(q, mp);
}
break;
case M_CTL:
switch (*mp->b_rptr) {
case PPPCTL_MTU:
MUTEX_ENTER(&state->lock);
state->mtu = ((unsigned short *)mp->b_rptr)[1];
MUTEX_EXIT(&state->lock);
break;
case PPPCTL_MRU:
MUTEX_ENTER(&state->lock);
state->mru = ((unsigned short *)mp->b_rptr)[1];
MUTEX_EXIT(&state->lock);
break;
case PPPCTL_UNIT:
MUTEX_ENTER(&state->lock);
state->unit = mp->b_rptr[1];
MUTEX_EXIT(&state->lock);
break;
default:
putnext(q, mp);
return 0;
}
freemsg(mp);
break;
default:
putnext(q, mp);
}
return 0;
}
/*
* Read side put routine
*/
static int
ahdlc_rput(q, mp)
queue_t *q;
mblk_t *mp;
{
ahdlc_state_t *state;
state = (ahdlc_state_t *) q->q_ptr;
if (state == 0) {
DPRINT("state == 0 in ahdlc_rput\n");
freemsg(mp);
return 0;
}
switch (mp->b_datap->db_type) {
case M_DATA:
ahdlc_decode(q, mp);
break;
case M_HANGUP:
MUTEX_ENTER(&state->lock);
if (state->rx_buf != 0) {
/* XXX would like to send this up for debugging */
freemsg(state->rx_buf);
state->rx_buf = 0;
}
state->flags = IFLUSH;
MUTEX_EXIT(&state->lock);
putnext(q, mp);
break;
default:
putnext(q, mp);
}
return 0;
}
/*
* Extract bit c from map m, to determine if c needs to be escaped
*/
#define IN_TX_MAP(c, m) ((m)[(c) >> 5] & (1 << ((c) & 0x1f)))
static void
ahdlc_encode(q, mp)
queue_t *q;
mblk_t *mp;
{
ahdlc_state_t *state;
u_int32_t *xaccm, loc_xaccm[8];
ushort_t fcs;
size_t outmp_len;
mblk_t *outmp, *tmp;
uchar_t *dp, fcs_val;
int is_lcp, code;
#if defined(SOL2)
clock_t lbolt;
#endif /* SOL2 */
if (msgdsize(mp) < 4) {
return;
}
state = (ahdlc_state_t *)q->q_ptr;
MUTEX_ENTER(&state->lock);
/*
* Allocate an output buffer large enough to handle a case where all
* characters need to be escaped
*/
outmp_len = (msgdsize(mp) << 1) + /* input block x 2 */
(sizeof(fcs) << 2) + /* HDLC FCS x 4 */
(sizeof(uchar_t) << 1); /* HDLC flags x 2 */
outmp = allocb(outmp_len, BPRI_MED);
if (outmp == NULL) {
state->stats.ppp_oerrors++;
MUTEX_EXIT(&state->lock);
putctl1(RD(q)->q_next, M_CTL, PPPCTL_OERROR);
return;
}
#if defined(SOL2)
/*
* Check if our last transmit happenned within flag_time, using
* the system's LBOLT value in clock ticks
*/
if (drv_getparm(LBOLT, &lbolt) != -1) {
if (ABS((clock_t)lbolt - state->lbolt) > state->flag_time) {
*outmp->b_wptr++ = PPP_FLAG;
}
state->lbolt = lbolt;
} else {
*outmp->b_wptr++ = PPP_FLAG;
}
#else
/*
* If the driver below still has a message to process, skip the
* HDLC flag, otherwise, put one in the beginning
*/
if (qsize(q->q_next) == 0) {
*outmp->b_wptr++ = PPP_FLAG;
}
#endif
/*
* All control characters must be escaped for LCP packets with code
* values between 1 (Conf-Req) and 7 (Code-Rej).
*/
is_lcp = ((MSG_BYTE(mp, 0) == PPP_ALLSTATIONS) &&
(MSG_BYTE(mp, 1) == PPP_UI) &&
(MSG_BYTE(mp, 2) == (PPP_LCP >> 8)) &&
(MSG_BYTE(mp, 3) == (PPP_LCP & 0xff)) &&
LCP_USE_DFLT(mp));
xaccm = state->xaccm;
if (is_lcp) {
bcopy((caddr_t)state->xaccm, (caddr_t)loc_xaccm, sizeof(loc_xaccm));
loc_xaccm[0] = ~0; /* force escape on 0x00 through 0x1f */
xaccm = loc_xaccm;
}
fcs = PPP_INITFCS; /* Initial FCS is 0xffff */
/*
* Process this block and the rest (if any) attached to the this one
*/
for (tmp = mp; tmp; tmp = tmp->b_cont) {
if (tmp->b_datap->db_type == M_DATA) {
for (dp = tmp->b_rptr; dp < tmp->b_wptr; dp++) {
fcs = PPP_FCS(fcs, *dp);
if (IN_TX_MAP(*dp, xaccm)) {
*outmp->b_wptr++ = PPP_ESCAPE;
*outmp->b_wptr++ = *dp ^ PPP_TRANS;
} else {
*outmp->b_wptr++ = *dp;
}
}
} else {
continue; /* skip if db_type is something other than M_DATA */
}
}
/*
* Append the HDLC FCS, making sure that escaping is done on any
* necessary bytes
*/
fcs_val = (fcs ^ 0xffff) & 0xff;
if (IN_TX_MAP(fcs_val, xaccm)) {
*outmp->b_wptr++ = PPP_ESCAPE;
*outmp->b_wptr++ = fcs_val ^ PPP_TRANS;
} else {
*outmp->b_wptr++ = fcs_val;
}
fcs_val = ((fcs ^ 0xffff) >> 8) & 0xff;
if (IN_TX_MAP(fcs_val, xaccm)) {
*outmp->b_wptr++ = PPP_ESCAPE;
*outmp->b_wptr++ = fcs_val ^ PPP_TRANS;
} else {
*outmp->b_wptr++ = fcs_val;
}
/*
* And finally, append the HDLC flag, and send it away
*/
*outmp->b_wptr++ = PPP_FLAG;
state->stats.ppp_obytes += msgdsize(outmp);
state->stats.ppp_opackets++;
MUTEX_EXIT(&state->lock);
putnext(q, outmp);
}
/*
* Checks the 32-bit receive ACCM to see if the byte needs un-escaping
*/
#define IN_RX_MAP(c, m) ((((unsigned int) (uchar_t) (c)) < 0x20) && \
(m) & (1 << (c)))
/*
* Process received characters.
*/
static void
ahdlc_decode(q, mp)
queue_t *q;
mblk_t *mp;
{
ahdlc_state_t *state;
mblk_t *om;
uchar_t *dp;
state = (ahdlc_state_t *) q->q_ptr;
MUTEX_ENTER(&state->lock);
state->stats.ppp_ibytes += msgdsize(mp);
for (; mp != 0; om = mp->b_cont, freeb(mp), mp = om)
for (dp = mp->b_rptr; dp < mp->b_wptr; dp++) {
/*
* This should detect the lack of 8-bit communication channel
* which is necessary for PPP to work. In addition, it also
* checks on the parity.
*/
if (*dp & 0x80)
state->flags |= RCV_B7_1;
else
state->flags |= RCV_B7_0;
if (paritytab[*dp >> 5] & (1 << (*dp & 0x1f)))
state->flags |= RCV_ODDP;
else
state->flags |= RCV_EVNP;
/*
* So we have a HDLC flag ...
*/
if (*dp == PPP_FLAG) {
/*
* If we think that it marks the beginning of the frame,
* then continue to process the next octects
*/
if ((state->flags & IFLUSH) ||
(state->rx_buf == 0) ||
(msgdsize(state->rx_buf) == 0)) {
state->flags &= ~IFLUSH;
continue;
}
/*
* We get here because the above condition isn't true,
* in which case the HDLC flag was there to mark the end
* of the frame (or so we think)
*/
om = state->rx_buf;
if (state->infcs == PPP_GOODFCS) {
state->stats.ppp_ipackets++;
adjmsg(om, -PPP_FCSLEN);
putnext(q, om);
} else {
DPRINT2("ppp%d: bad fcs (len=%d)\n",
state->unit, msgdsize(state->rx_buf));
freemsg(state->rx_buf);
state->flags &= ~(IFLUSH | ESCAPED);
state->stats.ppp_ierrors++;
putctl1(q->q_next, M_CTL, PPPCTL_IERROR);
}
state->rx_buf = 0;
continue;
}
if (state->flags & IFLUSH) {
continue;
}
/*
* Allocate a receive buffer, large enough to store a frame (after
* un-escaping) of at least 1500 octets. If MRU is negotiated to
* be more than the default, then allocate that much. In addition,
* we add an extra 32-bytes for a fudge factor
*/
if (state->rx_buf == 0) {
state->rx_buf_size = (state->mru < PPP_MRU ? PPP_MRU : state->mru);
state->rx_buf_size += (sizeof(u_int32_t) << 3);
state->rx_buf = allocb(state->rx_buf_size, BPRI_MED);
/*
* If allocation fails, try again on the next frame
*/
if (state->rx_buf == 0) {
state->flags |= IFLUSH;
continue;
}
state->flags &= ~(IFLUSH | ESCAPED);
state->infcs = PPP_INITFCS;
}
if (*dp == PPP_ESCAPE) {
state->flags |= ESCAPED;
continue;
}
/*
* Make sure we un-escape the necessary characters, as well as the
* ones in our receive async control character map
*/
if (state->flags & ESCAPED) {
*dp ^= PPP_TRANS;
state->flags &= ~ESCAPED;
} else if (IN_RX_MAP(*dp, state->raccm))
continue;
/*
* Unless the peer lied to us about the negotiated MRU, we should
* never get a frame which is too long. If it happens, toss it away
* and grab the next incoming one
*/
if (msgdsize(state->rx_buf) < state->rx_buf_size) {
state->infcs = PPP_FCS(state->infcs, *dp);
*state->rx_buf->b_wptr++ = *dp;
} else {
DPRINT2("ppp%d: frame too long (%d)\n",
state->unit, msgdsize(state->rx_buf));
freemsg(state->rx_buf);
state->rx_buf = 0;
state->flags |= IFLUSH;
}
}
MUTEX_EXIT(&state->lock);
}
static int
msg_byte(mp, i)
mblk_t *mp;
unsigned int i;
{
while (mp != 0 && i >= mp->b_wptr - mp->b_rptr)
mp = mp->b_cont;
if (mp == 0)
return -1;
return mp->b_rptr[i];
}
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