xref: /netbsd/sys/sys/msg.h (revision 47df294c)
1 /*	$NetBSD: msg.h,v 1.29 2023/02/12 16:28:32 andvar Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999, 2007 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center, and by Andrew Doran.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34  * SVID compatible msg.h file
35  *
36  * Author:  Daniel Boulet
37  *
38  * Copyright 1993 Daniel Boulet and RTMX Inc.
39  *
40  * This system call was implemented by Daniel Boulet under contract from RTMX.
41  *
42  * Redistribution and use in source forms, with and without modification,
43  * are permitted provided that this entire comment appears intact.
44  *
45  * Redistribution in binary form may occur without any restrictions.
46  * Obviously, it would be nice if you gave credit where credit is due
47  * but requiring it would be too onerous.
48  *
49  * This software is provided ``AS IS'' without any warranties of any kind.
50  */
51 
52 #ifndef _SYS_MSG_H_
53 #define _SYS_MSG_H_
54 
55 #include <sys/featuretest.h>
56 #include <sys/ipc.h>
57 #ifdef _KERNEL
58 #include <sys/condvar.h>
59 #include <sys/mutex.h>
60 #endif
61 
62 #ifdef _KERNEL
63 struct __msg {
64 	struct	__msg *msg_next; /* next msg in the chain */
65 	long	msg_type;	/* type of this message */
66     				/* >0 -> type of this message */
67     				/* 0 -> free header */
68 	u_short	msg_ts;		/* size of this message */
69 	short	msg_spot;	/* location of start of msg in buffer */
70 };
71 #endif /* _KERNEL */
72 
73 #define MSG_NOERROR	010000		/* don't complain about too long msgs */
74 
75 typedef unsigned long	msgqnum_t;
76 typedef size_t		msglen_t;
77 
78 struct msqid_ds {
79 	struct ipc_perm	msg_perm;	/* operation permission structure */
80 	msgqnum_t	msg_qnum;	/* number of messages in the queue */
81 	msglen_t	msg_qbytes;	/* max # of bytes in the queue */
82 	pid_t		msg_lspid;	/* process ID of last msgsend() */
83 	pid_t		msg_lrpid;	/* process ID of last msgrcv() */
84 	time_t		msg_stime;	/* time of last msgsend() */
85 	time_t		msg_rtime;	/* time of last msgrcv() */
86 	time_t		msg_ctime;	/* time of last change */
87 
88 	/*
89 	 * These members are private and used only in the internal
90 	 * implementation of this interface.
91 	 */
92 	struct __msg	*_msg_first;	/* first message in the queue */
93 	struct __msg	*_msg_last;	/* last message in the queue */
94 	msglen_t	_msg_cbytes;	/* # of bytes currently in queue */
95 };
96 
97 #if defined(_NETBSD_SOURCE)
98 /*
99  * Based on the configuration parameters described in an SVR2 (yes, two)
100  * config(1m) man page.
101  *
102  * Each message is broken up and stored in segments that are msgssz bytes
103  * long.  For efficiency reasons, this should be a power of two.  Also,
104  * it doesn't make sense if it is less than 8 or greater than about 256.
105  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
106  * two between 8 and 1024 inclusive (and panic's if it isn't).
107  */
108 struct msginfo {
109 	int32_t	msgmax;		/* max chars in a message */
110 	int32_t	msgmni;		/* max message queue identifiers */
111 	int32_t	msgmnb;		/* max chars in a queue */
112 	int32_t	msgtql;		/* max messages in system */
113 	int32_t	msgssz;		/* size of a message segment
114 				   (see notes above) */
115 	int32_t	msgseg;		/* number of message segments */
116 };
117 
118 /* Warning: 64-bit structure padding is needed here */
119 struct msgid_ds_sysctl {
120 	struct		ipc_perm_sysctl msg_perm;
121 	uint64_t	msg_qnum;
122 	uint64_t	msg_qbytes;
123 	uint64_t	_msg_cbytes;
124 	pid_t		msg_lspid;
125 	pid_t		msg_lrpid;
126 	time_t		msg_stime;
127 	time_t		msg_rtime;
128 	time_t		msg_ctime;
129 	int32_t		pad;
130 };
131 struct msg_sysctl_info {
132 	struct	msginfo msginfo;
133 	struct	msgid_ds_sysctl msgids[1];
134 };
135 #endif /* !_POSIX_C_SOURCE && !_XOPEN_SOURCE */
136 
137 #ifdef _KERNEL
138 
139 #ifndef MSGSSZ
140 #define MSGSSZ	8		/* Each segment must be 2^N long */
141 #endif
142 #ifndef MSGSEG
143 #define MSGSEG	2048		/* must be less than 32767 */
144 #endif
145 #undef MSGMAX			/* ALWAYS compute MGSMAX! */
146 #define MSGMAX	(MSGSSZ*MSGSEG)
147 #ifndef MSGMNB
148 #define MSGMNB	2048		/* max # of bytes in a queue */
149 #endif
150 #ifndef MSGMNI
151 #define MSGMNI	40
152 #endif
153 #ifndef MSGTQL
154 #define MSGTQL	40
155 #endif
156 
157 /*
158  * macros to convert between msqid_ds's and msqid's.
159  */
160 #define MSQID(ix,ds)	((ix) & 0xffff | (((ds).msg_perm._seq << 16) & 0xffff0000))
161 #define MSQID_IX(id)	((id) & 0xffff)
162 #define MSQID_SEQ(id)	(((id) >> 16) & 0xffff)
163 
164 /*
165  * Stuff allocated in machdep.h
166  */
167 struct msgmap {
168 	short	next;		/* next segment in buffer */
169     				/* -1 -> available */
170     				/* 0..(MSGSEG-1) -> index of next segment */
171 };
172 
173 typedef struct kmsq {
174 	struct msqid_ds msq_u;
175 	kcondvar_t	msq_cv;
176 } kmsq_t;
177 
178 extern struct msginfo msginfo;
179 extern kmsq_t	*msqs;		/* MSGMNI queues */
180 extern kmutex_t	msgmutex;
181 
182 #define MSG_LOCKED	01000	/* Is this msqid_ds locked? */
183 
184 #define SYSCTL_FILL_MSG(src, dst) do { \
185 	SYSCTL_FILL_PERM((src).msg_perm, (dst).msg_perm); \
186 	(dst).msg_qnum = (src).msg_qnum; \
187 	(dst).msg_qbytes = (src).msg_qbytes; \
188 	(dst)._msg_cbytes = (src)._msg_cbytes; \
189 	(dst).msg_lspid = (src).msg_lspid; \
190 	(dst).msg_lrpid = (src).msg_lrpid; \
191 	(dst).msg_stime = (src).msg_stime; \
192 	(dst).msg_rtime = (src).msg_rtime; \
193 	(dst).msg_ctime = (src).msg_ctime; \
194 } while (/*CONSTCOND*/ 0)
195 
196 #endif /* _KERNEL */
197 
198 #ifndef _KERNEL
199 #include <sys/cdefs.h>
200 
201 __BEGIN_DECLS
202 int	msgctl(int, int, struct msqid_ds *) __RENAME(__msgctl50);
203 int	msgget(key_t, int);
204 int	msgsnd(int, const void *, size_t, int);
205 ssize_t	msgrcv(int, void *, size_t, long, int);
206 __END_DECLS
207 #else
208 #include <sys/systm.h>
209 
210 struct proc;
211 
212 int	msginit(void);
213 int	msgfini(void);
214 int	msgctl1(struct lwp *, int, int, struct msqid_ds *);
215 int	msgsnd1(struct lwp *, int, const char *, size_t, int, size_t,
216     copyin_t);
217 int	msgrcv1(struct lwp *, int, char *, size_t, long, int, size_t,
218     copyout_t, register_t *);
219 #endif /* !_KERNEL */
220 
221 #endif /* !_SYS_MSG_H_ */
222