f-stack/freebsd/sys/unpcb.h

190 lines
6.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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.
*
* @(#)unpcb.h 8.1 (Berkeley) 6/2/93
* $FreeBSD$
*/
#ifndef _SYS_UNPCB_H_
#define _SYS_UNPCB_H_
typedef uint64_t unp_gen_t;
#if defined(_KERNEL) || defined(_WANT_UNPCB)
#include <sys/queue.h>
#include <sys/ucred.h>
/*
* Protocol control block for an active
* instance of a UNIX internal protocol.
*
* A socket may be associated with a vnode in the
* filesystem. If so, the unp_vnode pointer holds
* a reference count to this vnode, which should be irele'd
* when the socket goes away.
*
* A socket may be connected to another socket, in which
* case the control block of the socket to which it is connected
* is given by unp_conn.
*
* A socket may be referenced by a number of sockets (e.g. several
* sockets may be connected to a datagram socket.) These sockets
* are in a linked list starting with unp_refs, linked through
* unp_nextref and null-terminated. Note that a socket may be referenced
* by a number of other sockets and may also reference a socket (not
* necessarily one which is referencing it). This generates
* the need for unp_refs and unp_nextref to be separate fields.
*
* Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
* so that changes in the sockbuf may be computed to modify
* back pressure on the sender accordingly.
*
* Locking key:
* (a) Atomic
* (c) Constant
* (g) Locked using linkage lock
* (l) Locked using list lock
* (p) Locked using pcb lock
*/
LIST_HEAD(unp_head, unpcb);
struct unpcb {
/* Cache line 1 */
struct mtx unp_mtx; /* PCB mutex */
struct unpcb *unp_conn; /* (p) connected socket */
volatile u_int unp_refcount; /* (a, p) atomic refcount */
short unp_flags; /* (p) PCB flags */
short unp_gcflag; /* (g) Garbage collector flags */
struct sockaddr_un *unp_addr; /* (p) bound address of socket */
struct socket *unp_socket; /* (c) pointer back to socket */
/* Cache line 2 */
u_int unp_pairbusy; /* (p) threads acquiring peer locks */
struct vnode *unp_vnode; /* (p) associated file if applicable */
struct xucred unp_peercred; /* (p) peer credentials if applicable */
LIST_ENTRY(unpcb) unp_reflink; /* (l) link in unp_refs list */
LIST_ENTRY(unpcb) unp_link; /* (g) glue on list of all PCBs */
struct unp_head unp_refs; /* (l) referencing socket linked list */
unp_gen_t unp_gencnt; /* (g) generation count of this item */
struct file *unp_file; /* (g) back-pointer to file for gc */
u_int unp_msgcount; /* (g) references from message queue */
u_int unp_gcrefs; /* (g) garbage collector refcount */
ino_t unp_ino; /* (g) fake inode number */
LIST_ENTRY(unpcb) unp_dead; /* (g) link in dead list */
} __aligned(CACHE_LINE_SIZE);
/*
* Flags in unp_flags.
*
* UNP_HAVEPC - indicates that the unp_peercred member is filled in
* and is really the credentials of the connected peer. This is used
* to determine whether the contents should be sent to the user or
* not.
*/
#define UNP_HAVEPC 0x001
#define UNP_WANTCRED_ALWAYS 0x002 /* credentials wanted always */
#define UNP_WANTCRED_ONESHOT 0x004 /* credentials wanted once */
#define UNP_CONNWAIT 0x008 /* connect blocks until accepted */
#define UNP_WANTCRED_MASK (UNP_WANTCRED_ONESHOT | UNP_WANTCRED_ALWAYS)
/*
* These flags are used to handle non-atomicity in connect() and bind()
* operations on a socket: in particular, to avoid races between multiple
* threads or processes operating simultaneously on the same socket.
*/
#define UNP_CONNECTING 0x010 /* Currently connecting. */
#define UNP_BINDING 0x020 /* Currently binding. */
#define UNP_WAITING 0x040 /* Peer state is changing. */
/*
* Flags in unp_gcflag.
*/
#define UNPGC_DEAD 0x1 /* unpcb might be dead. */
#define UNPGC_IGNORE_RIGHTS 0x2 /* Attached rights are freed */
#define sotounpcb(so) ((struct unpcb *)((so)->so_pcb))
#endif /* _KERNEL || _WANT_UNPCB */
/*
* UNPCB structure exported to user-land via sysctl(3).
*
* Fields prefixed with "xu_" are unique to the export structure, and fields
* with "unp_" or other prefixes match corresponding fields of 'struct unpcb'.
*
* Legend:
* (s) - used by userland utilities in src
* (p) - used by utilities in ports
* (3) - is known to be used by third party software not in ports
* (n) - no known usage
*
* Evil hack: declare only if sys/socketvar.h have been included.
*/
#ifdef _SYS_SOCKETVAR_H_
struct xunpcb {
ksize_t xu_len; /* length of this structure */
kvaddr_t xu_unpp; /* to help netstat, fstat */
kvaddr_t unp_vnode; /* (s) */
kvaddr_t unp_conn; /* (s) */
kvaddr_t xu_firstref; /* (s) */
kvaddr_t xu_nextref; /* (s) */
unp_gen_t unp_gencnt; /* (s) */
int64_t xu_spare64[8];
int32_t xu_spare32[8];
union {
struct sockaddr_un xu_addr; /* our bound address */
char xu_dummy1[256];
};
union {
struct sockaddr_un xu_caddr; /* their bound address */
char xu_dummy2[256];
};
struct xsocket xu_socket;
} __aligned(MAX(8, sizeof(void *)));
struct xunpgen {
ksize_t xug_len;
u_int xug_count;
unp_gen_t xug_gen;
so_gen_t xug_sogen;
} __aligned(8);;
#endif /* _SYS_SOCKETVAR_H_ */
#if defined(_KERNEL)
struct thread;
/* In uipc_userreq.c */
void
unp_copy_peercred(struct thread *td, struct unpcb *client_unp,
struct unpcb *server_unp, struct unpcb *listen_unp);
#endif
#endif /* _SYS_UNPCB_H_ */