1 /* 2 * Copyright (c) 1982, 1986, 1989 Regents of the University of California. 3 * 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 * $Id$ 34 * 35 * Protocol control block for an active 36 * instance of a UNIX internal protocol. 37 * 38 * A socket may be associated with an vnode in the 39 * file system. If so, the unp_vnode pointer holds 40 * a reference count to this vnode, which should be irele'd 41 * when the socket goes away. 42 * 43 * A socket may be connected to another socket, in which 44 * case the control block of the socket to which it is connected 45 * is given by unp_conn. 46 * 47 * A socket may be referenced by a number of sockets (e.g. several 48 * sockets may be connected to a datagram socket.) These sockets 49 * are in a linked list starting with unp_refs, linked through 50 * unp_nextref and null-terminated. Note that a socket may be referenced 51 * by a number of other sockets and may also reference a socket (not 52 * necessarily one which is referencing it). This generates 53 * the need for unp_refs and unp_nextref to be separate fields. 54 * 55 * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt 56 * so that changes in the sockbuf may be computed to modify 57 * back pressure on the sender accordingly. 58 */ 59 struct unpcb { 60 struct socket *unp_socket; /* pointer back to socket */ 61 struct vnode *unp_vnode; /* if associated with file */ 62 ino_t unp_ino; /* fake inode number */ 63 struct unpcb *unp_conn; /* control block of connected socket */ 64 struct unpcb *unp_refs; /* referencing socket linked list */ 65 struct unpcb *unp_nextref; /* link in unp_refs list */ 66 struct mbuf *unp_addr; /* bound address of socket */ 67 int unp_cc; /* copy of rcv.sb_cc */ 68 int unp_mbcnt; /* copy of rcv.sb_mbcnt */ 69 }; 70 71 #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) 72