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 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#)msgbuf.h 8.1 (Berkeley) 6/2/93 30 * $FreeBSD$ 31 */ 32 33 #ifndef _SYS_MSGBUF_H_ 34 #define _SYS_MSGBUF_H_ 35 36 struct msgbuf { 37 char *msg_ptr; /* pointer to buffer */ 38 #define MSG_MAGIC 0x063062 39 u_int msg_magic; 40 u_int msg_size; /* size of buffer area */ 41 u_int msg_wseq; /* write sequence number */ 42 u_int msg_rseq; /* read sequence number */ 43 u_int msg_cksum; /* checksum of contents */ 44 u_int msg_seqmod; /* range for sequence numbers */ 45 }; 46 47 /* Normalise a sequence number or a difference between sequence numbers. */ 48 #define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \ 49 (mbp)->msg_seqmod) 50 #define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size) 51 /* Subtract sequence numbers. Note that only positive values result. */ 52 #define MSGBUF_SEQSUB(mbp, seq1, seq2) (MSGBUF_SEQNORM((mbp), (seq1) - (seq2))) 53 54 #ifdef _KERNEL 55 extern int msgbuftrigger; 56 extern struct msgbuf *msgbufp; 57 extern struct mtx msgbuf_lock; 58 59 void msgbufinit(void *ptr, int size); 60 void msgbuf_addchar(struct msgbuf *mbp, int c); 61 void msgbuf_clear(struct msgbuf *mbp); 62 void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst); 63 int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen); 64 int msgbuf_getchar(struct msgbuf *mbp); 65 int msgbuf_getcount(struct msgbuf *mbp); 66 void msgbuf_init(struct msgbuf *mbp, void *ptr, int size); 67 int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen, 68 u_int *seqp); 69 void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size); 70 71 #ifndef MSGBUF_SIZE 72 #define MSGBUF_SIZE (32768 * 2) 73 #endif 74 #endif /* KERNEL */ 75 76 #endif /* !_SYS_MSGBUF_H_ */ 77