4.3BSD-Reno/src/sys/sys/msgbuf.h

/*
 * Copyright (c) 1981, 1984 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution is only permitted until one year after the first shipment
 * of 4.4BSD by the Regents.  Otherwise, redistribution and use in source and
 * binary forms are permitted provided that: (1) source distributions retain
 * this entire copyright notice and comment, and (2) distributions including
 * binaries display the following acknowledgement:  This product includes
 * software developed by the University of California, Berkeley and its
 * contributors'' in the documentation or other materials provided with the
 * distribution and in all advertising materials mentioning features or use
 * of this software.  Neither the name of the University nor the names of
 * its contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * THIS SOFTWARE IS PROVIDED AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 *	@(#)msgbuf.h	7.3 (Berkeley) 6/28/90
 */

#define	MSG_MAGIC	0x063061
#define	MSG_BSIZE	(4096 - 3 * sizeof(long))
struct	msgbuf {
	long	msg_magic;
	long	msg_bufx;
	long	msg_bufr;
	char	msg_bufc[MSG_BSIZE];
};
#ifdef KERNEL
struct	msgbuf msgbuf;
#endif