2.11BSD#431 - /usr/src/sys/h/unpcb.h

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms are permitted
   6:  * provided that this notice is preserved and that due credit is given
   7:  * to the University of California at Berkeley. The name of the University
   8:  * may not be used to endorse or promote products derived from this
   9:  * software without specific prior written permission. This software
  10:  * is provided ``as is'' without express or implied warranty.
  11:  *
  12:  *	@(#)unpcb.h	7.2 (Berkeley) 1/7/88
  13:  */
  14: 
  15: /*
  16:  * Protocol control block for an active
  17:  * instance of a UNIX internal protocol.
  18:  *
  19:  * A socket may be associated with an inode in the
  20:  * file system.  If so, the unp_inode pointer holds
  21:  * a reference count to this inode, which should be irele'd
  22:  * when the socket goes away.
  23:  *
  24:  * A socket may be connected to another socket, in which
  25:  * case the control block of the socket to which it is connected
  26:  * is given by unp_conn.
  27:  *
  28:  * A socket may be referenced by a number of sockets (e.g. several
  29:  * sockets may be connected to a datagram socket.)  These sockets
  30:  * are in a linked list starting with unp_refs, linked through
  31:  * unp_nextref and null-terminated.  Note that a socket may be referenced
  32:  * by a number of other sockets and may also reference a socket (not
  33:  * necessarily one which is referencing it).  This generates
  34:  * the need for unp_refs and unp_nextref to be separate fields.
  35:  *
  36:  * Stream sockets keep copies of receive sockbuf sb_cc and sb_mbcnt
  37:  * so that changes in the sockbuf may be computed to modify
  38:  * back pressure on the sender accordingly.
  39:  */
  40: struct  unpcb {
  41:     struct  socket *unp_socket; /* pointer back to socket */
  42:     struct  inode *unp_inode;   /* if associated with file */
  43:     ino_t   unp_ino;        /* fake inode number */
  44:     struct  unpcb *unp_conn;    /* control block of connected socket */
  45:     struct  unpcb *unp_refs;    /* referencing socket linked list */
  46:     struct  unpcb *unp_nextref; /* link in unp_refs list */
  47:     struct  mbuf *unp_addr;     /* bound address of socket */
  48:     int unp_cc;         /* copy of rcv.sb_cc */
  49:     int unp_mbcnt;      /* copy of rcv.sb_mbcnt */
  50: };
  51: 
  52: #define sotounpcb(so)   ((struct unpcb *)((so)->so_pcb))

Defined struct's

Defined macros

Usage of this include