1 /* 2 * Copyright (c) 1981, 1984, 1993 3 * The Regents of the University of California. 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 * @(#)msgbuf.h 8.1 (Berkeley) 6/2/93 34 * $FreeBSD$ 35 */ 36 37 #ifndef _SYS_MSGBUF_H_ 38 #define _SYS_MSGBUF_H_ 39 40 struct msgbuf { 41 char *msg_ptr; /* pointer to buffer */ 42 #define MSG_MAGIC 0x063062 43 u_int msg_magic; 44 u_int msg_size; /* size of buffer area */ 45 u_int msg_wseq; /* write sequence number */ 46 u_int msg_rseq; /* read sequence number */ 47 u_int msg_cksum; /* checksum of contents */ 48 u_int msg_seqmod; /* range for sequence numbers */ 49 }; 50 51 /* Normalise a sequence number or a difference between sequence numbers */ 52 #define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \ 53 (mbp)->msg_seqmod) 54 #define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size) 55 /* Subtract sequence numbers, but note that only positive values result. */ 56 #define MSGBUF_SEQSUB(mbp, seq1, seq2) (MSGBUF_SEQNORM((mbp), (seq1) - (seq2))) 57 58 #ifdef _KERNEL 59 extern int msgbuftrigger; 60 extern struct msgbuf *msgbufp; 61 void msgbufinit(void *ptr, int size); 62 void msgbuf_addchar(struct msgbuf *mbp, int c); 63 void msgbuf_clear(struct msgbuf *mbp); 64 void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst); 65 int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen); 66 int msgbuf_getchar(struct msgbuf *mbp); 67 int msgbuf_getcount(struct msgbuf *mbp); 68 void msgbuf_init(struct msgbuf *mbp, void *ptr, int size); 69 void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size); 70 int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen, 71 u_int *seqp); 72 73 #if !defined(MSGBUF_SIZE) 74 #define MSGBUF_SIZE 32768 75 #endif 76 77 #endif 78 79 #endif 80