1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1981, 1984, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * @(#)msgbuf.h 8.1 (Berkeley) 6/2/93 32 * $FreeBSD$ 33 */ 34 35 #ifndef _SYS_MSGBUF_H_ 36 #define _SYS_MSGBUF_H_ 37 38 #include <sys/lock.h> 39 #include <sys/mutex.h> 40 41 struct msgbuf { 42 char *msg_ptr; /* pointer to buffer */ 43 #define MSG_MAGIC 0x063062 44 u_int msg_magic; 45 u_int msg_size; /* size of buffer area */ 46 u_int msg_wseq; /* write sequence number */ 47 u_int msg_rseq; /* read sequence number */ 48 u_int msg_cksum; /* checksum of contents */ 49 u_int msg_seqmod; /* range for sequence numbers */ 50 int msg_lastpri; /* saved priority value */ 51 u_int msg_flags; 52 #define MSGBUF_NEEDNL 0x01 /* set when newline needed */ 53 struct mtx msg_lock; /* mutex to protect the buffer */ 54 }; 55 56 /* Normalise a sequence number or a difference between sequence numbers. */ 57 #define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \ 58 (mbp)->msg_seqmod) 59 #define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size) 60 /* Subtract sequence numbers. Note that only positive values result. */ 61 #define MSGBUF_SEQSUB(mbp, seq1, seq2) (MSGBUF_SEQNORM((mbp), (seq1) - (seq2))) 62 63 #ifdef _KERNEL 64 extern int msgbufsize; 65 extern int msgbuftrigger; 66 extern struct msgbuf *msgbufp; 67 extern struct mtx msgbuf_lock; 68 69 void msgbufinit(void *ptr, int size); 70 void msgbuf_addchar(struct msgbuf *mbp, int c); 71 void msgbuf_addstr(struct msgbuf *mbp, int pri, const char *str, int filter_cr); 72 void msgbuf_clear(struct msgbuf *mbp); 73 void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst); 74 int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen); 75 int msgbuf_getchar(struct msgbuf *mbp); 76 int msgbuf_getcount(struct msgbuf *mbp); 77 void msgbuf_init(struct msgbuf *mbp, void *ptr, int size); 78 int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen, 79 u_int *seqp); 80 void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size); 81 82 #ifndef MSGBUF_SIZE 83 #define MSGBUF_SIZE (32768 * 3) 84 #endif 85 #endif /* KERNEL */ 86 87 #endif /* !_SYS_MSGBUF_H_ */ 88