unpcb.h revision 2165 
1/*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)unpcb.h	8.1 (Berkeley) 6/2/93
34 * $Id: unpcb.h,v 1.2 1994/08/02 07:54:05 davidg Exp $
35 */
36
37#ifndef _SYS_UNPCB_H_
38#define _SYS_UNPCB_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 */
65struct	unpcb {
66	struct	socket *unp_socket;	/* pointer back to socket */
67	struct	vnode *unp_vnode;	/* if associated with file */
68	ino_t	unp_ino;		/* fake inode number */
69	struct	unpcb *unp_conn;	/* control block of connected socket */
70	struct	unpcb *unp_refs;	/* referencing socket linked list */
71	struct 	unpcb *unp_nextref;	/* link in unp_refs list */
72	struct	mbuf *unp_addr;		/* bound address of socket */
73	int	unp_cc;			/* copy of rcv.sb_cc */
74	int	unp_mbcnt;		/* copy of rcv.sb_mbcnt */
75};
76
77#define	sotounpcb(so)	((struct unpcb *)((so)->so_pcb))
78
79#endif
80