FreeBSD/Linux Kernel Cross Reference
sys/sys/msgbuf.h
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: releng/12.0/sys/sys/msgbuf.h 337545 2018-08-09 17:47:47Z kevans $
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_ */
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