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
32#ifndef _SYS_MSGBUF_H_
33#define _SYS_MSGBUF_H_
34
35#include <sys/lock.h>
36#include <sys/mutex.h>
37
38struct msgbuf {
39 char *msg_ptr; /* pointer to buffer */
40#define MSG_MAGIC 0x063062
41 u_int msg_magic;
42 u_int msg_size; /* size of buffer area */
43 u_int msg_wseq; /* write sequence number */
44 u_int msg_rseq; /* read sequence number */
45 u_int msg_cksum; /* checksum of contents */
46 u_int msg_seqmod; /* range for sequence numbers */
47 int msg_lastpri; /* saved priority value */
48 u_int msg_flags;
49#define MSGBUF_NEEDNL 0x01 /* set when newline needed */
50#define MSGBUF_WRAP 0x02 /* buffer has wrapped around */
51 struct mtx msg_lock; /* mutex to protect the buffer */
52};
53
54/* Normalise a sequence number or a difference between sequence numbers. */
55#define MSGBUF_SEQNORM(mbp, seq) (((seq) + (mbp)->msg_seqmod) % \
56 (mbp)->msg_seqmod)
57#define MSGBUF_SEQ_TO_POS(mbp, seq) ((seq) % (mbp)->msg_size)
58/* Add/subtract normalized sequence numbers. Normalized values result. */
59#define MSGBUF_SEQADD(mbp, seq1, seq2) (((seq1) + (seq2)) % (mbp)->msg_seqmod)
60#define MSGBUF_SEQSUB(mbp, seq1, seq2) ((seq1) >= (seq2) ? (seq1) - (seq2) : \
61 (seq1) + (mbp)->msg_seqmod - (seq2))
62
63#ifdef _KERNEL
64extern int msgbufsize;
65extern int msgbuftrigger;
66extern struct msgbuf *msgbufp;
67extern struct mtx msgbuf_lock;
68
69void msgbufinit(void *ptr, int size);
70void msgbuf_addchar(struct msgbuf *mbp, int c);
71void msgbuf_addstr(struct msgbuf *mbp, int pri, const char *str, int filter_cr);
72void msgbuf_clear(struct msgbuf *mbp);
73void msgbuf_copy(struct msgbuf *src, struct msgbuf *dst);
74int msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen);
75int msgbuf_getchar(struct msgbuf *mbp);
76int msgbuf_getcount(struct msgbuf *mbp);
77void msgbuf_init(struct msgbuf *mbp, void *ptr, int size);
78int msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen,
79 u_int *seqp);
80void msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size);
81void msgbuf_duplicate(struct msgbuf *src, struct msgbuf *dst, char *msgptr);
82
83#ifndef MSGBUF_SIZE
84#define MSGBUF_SIZE (32768 * 3)
85#endif
86#endif /* KERNEL */
87
88#endif /* !_SYS_MSGBUF_H_ */