msg.h revision 330897 
1/* $FreeBSD: stable/11/sys/sys/msg.h 330897 2018-03-14 03:19:51Z eadler $ */
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 * SPDX-License-Identifier: MIT
8 *
9 * Author:  Daniel Boulet
10 *
11 * Copyright 1993 Daniel Boulet and RTMX Inc.
12 *
13 * This system call was implemented by Daniel Boulet under contract from RTMX.
14 *
15 * Redistribution and use in source forms, with and without modification,
16 * are permitted provided that this entire comment appears intact.
17 *
18 * Redistribution in binary form may occur without any restrictions.
19 * Obviously, it would be nice if you gave credit where credit is due
20 * but requiring it would be too onerous.
21 *
22 * This software is provided ``AS IS'' without any warranties of any kind.
23 */
24
25#ifndef _SYS_MSG_H_
26#define _SYS_MSG_H_
27
28#include <sys/cdefs.h>
29#include <sys/_types.h>
30#include <sys/ipc.h>
31
32/*
33 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct
34 * are as defined by the SV API Intel 386 Processor Supplement.
35 */
36
37#define MSG_NOERROR	010000		/* don't complain about too long msgs */
38
39typedef	unsigned long	msglen_t;
40typedef	unsigned long	msgqnum_t;
41
42#ifndef _PID_T_DECLARED
43typedef	__pid_t		pid_t;
44#define	_PID_T_DECLARED
45#endif
46
47#ifndef _SIZE_T_DECLARED
48typedef	__size_t	size_t;
49#define	_SIZE_T_DECLARED
50#endif
51
52#ifndef _SSIZE_T_DECLARED
53typedef	__ssize_t	ssize_t;
54#define	_SSIZE_T_DECLARED
55#endif
56
57#ifndef _TIME_T_DECLARED
58typedef	__time_t	time_t;
59#define	_TIME_T_DECLARED
60#endif
61
62#if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \
63    defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7)
64struct msqid_ds_old {
65	struct	ipc_perm_old msg_perm;	/* msg queue permission bits */
66	struct	msg *msg_first;	/* first message in the queue */
67	struct	msg *msg_last;	/* last message in the queue */
68	msglen_t msg_cbytes;	/* number of bytes in use on the queue */
69	msgqnum_t msg_qnum;	/* number of msgs in the queue */
70	msglen_t msg_qbytes;	/* max # of bytes on the queue */
71	pid_t	msg_lspid;	/* pid of last msgsnd() */
72	pid_t	msg_lrpid;	/* pid of last msgrcv() */
73	time_t	msg_stime;	/* time of last msgsnd() */
74	long	msg_pad1;
75	time_t	msg_rtime;	/* time of last msgrcv() */
76	long	msg_pad2;
77	time_t	msg_ctime;	/* time of last msgctl() */
78	long	msg_pad3;
79	long	msg_pad4[4];
80};
81#endif
82
83/*
84 * XXX there seems to be no prefix reserved for this header, so the name
85 * "msg" in "struct msg" and the names of all of the nonstandard members
86 * (mainly "msg_pad*) are namespace pollution.
87 */
88
89struct msqid_ds {
90	struct	ipc_perm msg_perm;	/* msg queue permission bits */
91	struct	msg *msg_first;	/* first message in the queue */
92	struct	msg *msg_last;	/* last message in the queue */
93	msglen_t msg_cbytes;	/* number of bytes in use on the queue */
94	msgqnum_t msg_qnum;	/* number of msgs in the queue */
95	msglen_t msg_qbytes;	/* max # of bytes on the queue */
96	pid_t	msg_lspid;	/* pid of last msgsnd() */
97	pid_t	msg_lrpid;	/* pid of last msgrcv() */
98	time_t	msg_stime;	/* time of last msgsnd() */
99	time_t	msg_rtime;	/* time of last msgrcv() */
100	time_t	msg_ctime;	/* time of last msgctl() */
101};
102
103#if __BSD_VISIBLE
104/*
105 * Structure describing a message.  The SVID doesn't suggest any
106 * particular name for this structure.  There is a reference in the
107 * msgop man page that reads "The structure mymsg is an example of what
108 * this user defined buffer might look like, and includes the following
109 * members:".  This sentence is followed by two lines equivalent
110 * to the mtype and mtext field declarations below.  It isn't clear
111 * if "mymsg" refers to the name of the structure type or the name of an
112 * instance of the structure...
113 */
114struct mymsg {
115	long	mtype;		/* message type (+ve integer) */
116	char	mtext[1];	/* message body */
117};
118#endif
119
120#ifdef _KERNEL
121
122struct msg {
123	struct	msg *msg_next;  /* next msg in the chain */
124	long	msg_type; 	/* type of this message */
125				/* >0 -> type of this message */
126				/* 0 -> free header */
127	u_short	msg_ts;		/* size of this message */
128	short	msg_spot;	/* location of start of msg in buffer */
129	struct	label *label;	/* MAC Framework label */
130};
131
132/*
133 * Based on the configuration parameters described in an SVR2 (yes, two)
134 * config(1m) man page.
135 *
136 * Each message is broken up and stored in segments that are msgssz bytes
137 * long.  For efficiency reasons, this should be a power of two.  Also,
138 * it doesn't make sense if it is less than 8 or greater than about 256.
139 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
140 * two between 8 and 1024 inclusive (and panic's if it isn't).
141 */
142struct msginfo {
143	int	msgmax,		/* max chars in a message */
144		msgmni,		/* max message queue identifiers */
145		msgmnb,		/* max chars in a queue */
146		msgtql,		/* max messages in system */
147		msgssz,		/* size of a message segment (see notes above) */
148		msgseg;		/* number of message segments */
149};
150extern struct msginfo	msginfo;
151
152/*
153 * Kernel wrapper for the user-level structure.
154 */
155struct msqid_kernel {
156	/*
157	 * Data structure exposed to user space.
158	 */
159	struct	msqid_ds u;
160
161	/*
162	 * Kernel-private components of the message queue.
163	 */
164	struct	label *label;	/* MAC label */
165	struct	ucred *cred;	/* creator's credentials */
166};
167
168#endif /* _KERNEL */
169
170#if !defined(_KERNEL) || defined(_WANT_MSG_PROTOTYPES)
171__BEGIN_DECLS
172int msgctl(int, int, struct msqid_ds *);
173int msgget(key_t, int);
174/* XXX return value should be ssize_t. */
175int msgrcv(int, void *, size_t, long, int);
176int msgsnd(int, const void *, size_t, int);
177#if __BSD_VISIBLE
178int msgsys(int, ...);
179#endif
180__END_DECLS
181
182#endif /* !_KERNEL || _WANT_MSG_PROTOTYPES  */
183
184#endif /* !_SYS_MSG_H_ */
185