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      1 /*	$NetBSD: unpcb.h,v 1.19 2024/09/08 09:36:52 rillig 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 a 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  */
     71 struct	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