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_ */