123453Smckusick /* 229055Smckusick * Copyright (c) 1982, 1986 Regents of the University of California. 333290Sbostic * All rights reserved. 423453Smckusick * 533290Sbostic * Redistribution and use in source and binary forms are permitted 6*34837Sbostic * provided that the above copyright notice and this paragraph are 7*34837Sbostic * duplicated in all such forms and that any documentation, 8*34837Sbostic * advertising materials, and other materials related to such 9*34837Sbostic * distribution and use acknowledge that the software was developed 10*34837Sbostic * by the University of California, Berkeley. The name of the 11*34837Sbostic * University may not be used to endorse or promote products derived 12*34837Sbostic * from this software without specific prior written permission. 13*34837Sbostic * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14*34837Sbostic * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15*34837Sbostic * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 1633290Sbostic * 17*34837Sbostic * @(#)unpcb.h 7.3 (Berkeley) 06/27/88 1823453Smckusick */ 197622Sroot 207622Sroot /* 217622Sroot * Protocol control block for an active 227622Sroot * instance of a UNIX internal protocol. 237622Sroot * 247622Sroot * A socket may be associated with an inode in the 257622Sroot * file system. If so, the unp_inode pointer holds 267622Sroot * a reference count to this inode, which should be irele'd 277622Sroot * when the socket goes away. 287622Sroot * 297622Sroot * A socket may be connected to another socket, in which 307622Sroot * case the control block of the socket to which it is connected 317622Sroot * is given by unp_conn. 327622Sroot * 337622Sroot * A socket may be referenced by a number of sockets (e.g. several 347622Sroot * sockets may be connected to a datagram socket.) These sockets 357622Sroot * are in a linked list starting with unp_refs, linked through 367622Sroot * unp_nextref and null-terminated. Note that a socket may be referenced 377622Sroot * by a number of other sockets and may also reference a socket (not 387622Sroot * necessarily one which is referencing it). This generates 397622Sroot * the need for unp_refs and unp_nextref to be separate fields. 4025594Skarels * 4125594Skarels * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt 4225594Skarels * so that changes in the sockbuf may be computed to modify 4325594Skarels * back pressure on the sender accordingly. 447622Sroot */ 457622Sroot struct unpcb { 467622Sroot struct socket *unp_socket; /* pointer back to socket */ 477622Sroot struct inode *unp_inode; /* if associated with file */ 4825594Skarels ino_t unp_ino; /* fake inode number */ 497622Sroot struct unpcb *unp_conn; /* control block of connected socket */ 507622Sroot struct unpcb *unp_refs; /* referencing socket linked list */ 517622Sroot struct unpcb *unp_nextref; /* link in unp_refs list */ 5225594Skarels struct mbuf *unp_addr; /* bound address of socket */ 5325594Skarels int unp_cc; /* copy of rcv.sb_cc */ 5425594Skarels int unp_mbcnt; /* copy of rcv.sb_mbcnt */ 557622Sroot }; 567643Sroot 577643Sroot #define sotounpcb(so) ((struct unpcb *)((so)->so_pcb)) 58