msg.h revision 137613 
1/* $FreeBSD: head/sys/sys/msg.h 137613 2004-11-12 13:23:47Z rwatson $ */
2/*	$NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd 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/cdefs.h>
27#include <sys/_types.h>
28#include <sys/ipc.h>
29
30/*
31 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
32 * are as defined by the SV API Intel 386 Processor Supplement.
33 */
34
35#define MSG_NOERROR	010000		/* don't complain about too long msgs */
36
37typedef	unsigned long	msglen_t;
38typedef	unsigned long	msgqnum_t;
39
40#ifndef _PID_T_DECLARED
41typedef	__pid_t		pid_t;
42#define	_PID_T_DECLARED
43#endif
44
45#ifndef _SIZE_T_DECLARED
46typedef	__size_t	size_t;
47#define	_SIZE_T_DECLARED
48#endif
49
50#ifndef _SSIZE_T_DECLARED
51typedef	__ssize_t	ssize_t;
52#define	_SSIZE_T_DECLARED
53#endif
54
55#ifndef _TIME_T_DECLARED
56typedef	__time_t	time_t;
57#define	_TIME_T_DECLARED
58#endif
59
60/*
61 * XXX there seems to be no prefix reserved for this header, so the name
62 * "msg" in "struct msg" and the names of all of the nonstandard members
63 * (mainly "msg_pad*) are namespace pollution.
64 */
65
66struct msqid_ds {
67	struct	ipc_perm msg_perm;	/* msg queue permission bits */
68	struct	msg *msg_first;	/* first message in the queue */
69	struct	msg *msg_last;	/* last message in the queue */
70	msglen_t msg_cbytes;	/* number of bytes in use on the queue */
71	msgqnum_t msg_qnum;	/* number of msgs in the queue */
72	msglen_t msg_qbytes;	/* max # of bytes on the queue */
73	pid_t	msg_lspid;	/* pid of last msgsnd() */
74	pid_t	msg_lrpid;	/* pid of last msgrcv() */
75	time_t	msg_stime;	/* time of last msgsnd() */
76	long	msg_pad1;
77	time_t	msg_rtime;	/* time of last msgrcv() */
78	long	msg_pad2;
79	time_t	msg_ctime;	/* time of last msgctl() */
80	long	msg_pad3;
81	long	msg_pad4[4];
82};
83
84#if __BSD_VISIBLE
85/*
86 * Structure describing a message.  The SVID doesn't suggest any
87 * particular name for this structure.  There is a reference in the
88 * msgop man page that reads "The structure mymsg is an example of what
89 * this user defined buffer might look like, and includes the following
90 * members:".  This sentence is followed by two lines equivalent
91 * to the mtype and mtext field declarations below.  It isn't clear
92 * if "mymsg" refers to the name of the structure type or the name of an
93 * instance of the structure...
94 */
95struct mymsg {
96	long	mtype;		/* message type (+ve integer) */
97	char	mtext[1];	/* message body */
98};
99#endif
100
101#ifdef _KERNEL
102
103struct msg {
104	struct	msg *msg_next;  /* next msg in the chain */
105	long	msg_type; 	/* type of this message */
106				/* >0 -> type of this message */
107				/* 0 -> free header */
108	u_short	msg_ts;		/* size of this message */
109	short	msg_spot;	/* location of start of msg in buffer */
110};
111
112/*
113 * Based on the configuration parameters described in an SVR2 (yes, two)
114 * config(1m) man page.
115 *
116 * Each message is broken up and stored in segments that are msgssz bytes
117 * long.  For efficiency reasons, this should be a power of two.  Also,
118 * it doesn't make sense if it is less than 8 or greater than about 256.
119 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
120 * two between 8 and 1024 inclusive (and panic's if it isn't).
121 */
122struct msginfo {
123	int	msgmax,		/* max chars in a message */
124		msgmni,		/* max message queue identifiers */
125		msgmnb,		/* max chars in a queue */
126		msgtql,		/* max messages in system */
127		msgssz,		/* size of a message segment (see notes above) */
128		msgseg;		/* number of message segments */
129};
130extern struct msginfo	msginfo;
131
132/*
133 * Kernel wrapper for the user-level structure.
134 */
135struct msqid_kernel {
136	/*
137	 * Data structure exposed to user space.
138	 */
139	struct	msqid_ds u;
140
141	/*
142	 * Kernel-private components of the message queue.
143	 */
144};
145
146#else /* !_KERNEL */
147
148__BEGIN_DECLS
149int msgctl(int, int, struct msqid_ds *);
150int msgget(key_t, int);
151/* XXX return value should be ssize_t. */
152int msgrcv(int, void *, size_t, long, int);
153int msgsnd(int, const void *, size_t, int);
154#if __BSD_VISIBLE
155int msgsys(int, ...);
156#endif
157__END_DECLS
158
159#endif /* _KERNEL */
160
161#endif /* !_SYS_MSG_H_ */
162