1/*	$OpenBSD: msg.h,v 1.21 2024/04/30 17:03:05 op Exp $	*/
2/*	$NetBSD: msg.h,v 1.9 1996/02/09 18:25:18 christos Exp $	*/
3
4/*
5 * SVID compatible msg.h file
6 *
7 * Author:  Daniel Boulet
8 *
9 * Copyright 1993 Daniel Boulet and RTMX Inc.
10 *
11 * This system call was implemented by Daniel Boulet under contract from RTMX.
12 *
13 * Redistribution and use in source forms, with and without modification,
14 * are permitted provided that this entire comment appears intact.
15 *
16 * Redistribution in binary form may occur without any restrictions.
17 * Obviously, it would be nice if you gave credit where credit is due
18 * but requiring it would be too onerous.
19 *
20 * This software is provided ``AS IS'' without any warranties of any kind.
21 */
22
23#ifndef _SYS_MSG_H_
24#define _SYS_MSG_H_
25
26#include <sys/ipc.h>
27
28/*
29 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
30 * are as defined by the SV API Intel 386 Processor Supplement.
31 */
32
33#define MSG_NOERROR	010000		/* don't complain about too long msgs */
34
35typedef unsigned long	 msgqnum_t;
36typedef unsigned long	 msglen_t;
37
38struct msqid_ds {
39	struct ipc_perm	msg_perm;	/* msg queue permission bits */
40	struct msg	*msg_first;	/* first message in the queue */
41	struct msg	*msg_last;	/* last message in the queue */
42	msglen_t	msg_cbytes;	/* number of bytes in use on the queue */
43	msgqnum_t	msg_qnum;	/* number of msgs in the queue */
44	msglen_t	msg_qbytes;	/* max # of bytes on the queue */
45	pid_t		msg_lspid;	/* pid of last msgsnd() */
46	pid_t		msg_lrpid;	/* pid of last msgrcv() */
47	time_t		msg_stime;	/* time of last msgsnd() */
48	long		msg_pad1;
49	time_t		msg_rtime;	/* time of last msgrcv() */
50	long		msg_pad2;
51	time_t		msg_ctime;	/* time of last msgctl() */
52	long		msg_pad3;
53	long		msg_pad4[4];
54};
55
56#ifdef _KERNEL
57#include <sys/queue.h>
58
59struct msg {
60	long		 msg_type;
61	size_t		 msg_len;
62	struct mbuf	*msg_data;
63
64	TAILQ_ENTRY(msg)	msg_next;
65};
66
67struct que {
68	struct msqid_ds	msqid_ds;
69	int		que_ix;		/* pseudo-index */
70	int		que_flags;
71	int		que_references;
72
73	TAILQ_ENTRY(que)	que_next;
74	TAILQ_HEAD(, msg) que_msgs;
75};
76
77/* for que_flags */
78#define	MSGQ_READERS	0x01
79#define	MSGQ_WRITERS	0x02
80#define	MSGQ_DYING	0x04
81
82#define	QREF(q)	(q)->que_references++
83
84#define QRELE(q) do {							\
85	if (--(q)->que_references == 0 && (q)->que_flags & MSGQ_DYING)	\
86		wakeup_one(&(q)->que_references);			\
87} while (0)
88#endif
89
90/*
91 * Structure describing a message.  The SVID doesn't suggest any
92 * particular name for this structure.  There is a reference in the
93 * msgop man page that reads "The structure mymsg is an example of what
94 * this user defined buffer might look like, and includes the following
95 * members:".  This sentence is followed by two lines equivalent
96 * to the mtype and mtext field declarations below.  It isn't clear
97 * if "mymsg" refers to the name of the structure type or the name of an
98 * instance of the structure...
99 */
100struct mymsg {
101	long	mtype;		/* message type (+ve integer) */
102	char	mtext[1];	/* message body */
103};
104
105
106#ifdef _KERNEL
107/*
108 * Based on the configuration parameters described in an SVR2 (yes, two)
109 * config(1m) man page.
110 *
111 * Each message is broken up and stored in segments that are msgssz bytes
112 * long.  For efficiency reasons, this should be a power of two.  Also,
113 * it doesn't make sense if it is less than 8 or greater than about 256.
114 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
115 * two between 8 and 1024 inclusive (and panic's if it isn't).
116 */
117struct msginfo {
118	int	msgmax,		/* max chars in a message */
119		msgmni,		/* max message queue identifiers */
120		msgmnb,		/* max chars in a queue */
121		msgtql,		/* max messages in system */
122		msgssz,		/* size of a message segment (see notes above) */
123		msgseg;		/* number of message segments */
124};
125#ifdef SYSVMSG
126extern struct msginfo	msginfo;
127#endif
128
129int sysctl_sysvmsg(int *, u_int, void *, size_t *);
130
131struct msg_sysctl_info {
132	struct msginfo msginfo;
133	struct msqid_ds msgids[1];
134};
135
136#ifndef MSGSSZ
137#define MSGSSZ	8		/* Each segment must be 2^N long */
138#endif
139#ifndef MSGSEG
140#define MSGSEG	2048		/* must be less than 32767 */
141#endif
142#undef MSGMAX			/* ALWAYS compute MSGMAX! */
143#define MSGMAX	(MSGSSZ*MSGSEG)
144#ifndef MSGMNB
145#define MSGMNB	2048		/* max # of bytes in a queue */
146#endif
147#ifndef MSGMNI
148#define MSGMNI	40
149#endif
150#ifndef MSGTQL
151#define MSGTQL	40
152#endif
153
154/*
155 * macros to convert between msqid_ds's and msqid's.
156 * XXX unused, going away
157 */
158#define MSQID(ix,ds)	((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
159#define MSQID_IX(id)	((id) & 0xffff)
160#define MSQID_SEQ(id)	(((id) >> 16) & 0xffff)
161#endif
162
163
164#ifndef _KERNEL
165__BEGIN_DECLS
166int msgctl(int, int, struct msqid_ds *);
167int msgget(key_t, int);
168int msgsnd(int, const void *, size_t, int);
169int msgrcv(int, void *, size_t, long, int);
170__END_DECLS
171#else
172struct proc;
173
174void	msginit(void);
175#endif /* !_KERNEL */
176
177#endif /* !_SYS_MSG_H_ */
178