1/*	$NetBSD: unpcb.h,v 1.18 2016/04/06 19:45:46 roy Exp $	*/
2
3/*
4 * Copyright (c) 1982, 1986, 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 *	@(#)unpcb.h	8.1 (Berkeley) 6/2/93
32 */
33
34#ifndef _SYS_UNPCB_H_
35#define _SYS_UNPCB_H_
36
37#include <sys/un.h>
38#include <sys/mutex.h>
39
40/*
41 * Protocol control block for an active
42 * instance of a UNIX internal protocol.
43 *
44 * A socket may be associated with an vnode in the
45 * file system.  If so, the unp_vnode pointer holds
46 * a reference count to this vnode, which should be irele'd
47 * when the socket goes away.
48 *
49 * A socket may be connected to another socket, in which
50 * case the control block of the socket to which it is connected
51 * is given by unp_conn.
52 *
53 * A socket may be referenced by a number of sockets (e.g. several
54 * sockets may be connected to a datagram socket.)  These sockets
55 * are in a linked list starting with unp_refs, linked through
56 * unp_nextref and null-terminated.  Note that a socket may be referenced
57 * by a number of other sockets and may also reference a socket (not
58 * necessarily one which is referencing it).  This generates
59 * the need for unp_refs and unp_nextref to be separate fields.
60 *
61 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
62 * so that changes in the sockbuf may be computed to modify
63 * back pressure on the sender accordingly.
64 *
65 * The unp_ctime holds the creation time of the socket: it might be part of
66 * a socketpair created by pipe(2), and POSIX requires pipe(2) to initialize
67 * a stat structure's st_[acm]time members with the pipe's creation time.
68 * N.B.: updating st_[am]time when reading/writing the pipe is not required,
69 *       so we just use a single timespec and do not implement that.
70 */
71struct	unpcb {
72	struct	socket *unp_socket;	/* pointer back to socket */
73	struct	vnode *unp_vnode;	/* if associated with file */
74	ino_t	unp_ino;		/* fake inode number */
75	struct	unpcb *unp_conn;	/* control block of connected socket */
76	struct	unpcb *unp_refs;	/* referencing socket linked list */
77	struct 	unpcb *unp_nextref;	/* link in unp_refs list */
78	struct	sockaddr_un *unp_addr;	/* bound address of socket */
79	kmutex_t *unp_streamlock;	/* lock for est. stream connections */
80	size_t	unp_addrlen;		/* size of socket address */
81	int	unp_cc;			/* copy of rcv.sb_cc */
82	int	unp_mbcnt;		/* copy of rcv.sb_mbcnt */
83	struct	timespec unp_ctime;	/* holds creation time */
84	int	unp_flags;		/* misc flags; see below*/
85	struct	unpcbid unp_connid; 	/* pid and eids of peer */
86};
87
88/*
89 * Flags in unp_flags.
90 *
91 * UNP_EIDSVALID - indicates that the unp_connid member is filled in
92 * and is really the effective ids of the connected peer.  This is used
93 * to determine whether the contents should be sent to the user or
94 * not.
95 *
96 * UNP_EIDSBIND - indicates that the unp_connid member is filled
97 * in with data for the listening process.  This is set up in unp_bind() when
98 * it fills in unp_connid for later consumption by unp_connect().
99 */
100#define	UNP_OWANTCRED	0x0001		/* credentials wanted */
101#define	UNP_CONNWAIT	0x0002		/* connect blocks until accepted */
102#define	UNP_EIDSVALID	0x0004		/* unp_connid contains valid data */
103#define	UNP_EIDSBIND	0x0008		/* unp_connid was set by bind() */
104#define	UNP_BUSY	0x0010		/* busy connecting or binding */
105#define	UNP_WANTCRED	0x0020		/* credentials wanted */
106
107#define	sotounpcb(so)	((struct unpcb *)((so)->so_pcb))
108
109#endif /* !_SYS_UNPCB_H_ */
110