xref: /openbsd/sys/sys/msg.h (revision 298e3ffd)
1 /*	$OpenBSD: msg.h,v 1.24 2024/10/27 22:08:25 jsg 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 
35 typedef unsigned long	 msgqnum_t;
36 typedef unsigned long	 msglen_t;
37 
38 struct 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 
59 struct msg {
60 	long		 msg_type;
61 	size_t		 msg_len;
62 	struct mbuf	*msg_data;
63 
64 	TAILQ_ENTRY(msg)	msg_next;
65 };
66 
67 struct 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 
89 /*
90  * Based on the configuration parameters described in an SVR2 (yes, two)
91  * config(1m) man page.
92  *
93  * Each message is broken up and stored in segments that are msgssz bytes
94  * long.  For efficiency reasons, this should be a power of two.  Also,
95  * it doesn't make sense if it is less than 8 or greater than about 256.
96  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
97  * two between 8 and 1024 inclusive (and panic's if it isn't).
98  */
99 struct msginfo {
100 	int	msgmax,		/* max chars in a message */
101 		msgmni,		/* max message queue identifiers */
102 		msgmnb,		/* max chars in a queue */
103 		msgtql,		/* max messages in system */
104 		msgssz,		/* size of a message segment (see notes above) */
105 		msgseg;		/* number of message segments */
106 };
107 #ifdef SYSVMSG
108 extern struct msginfo	msginfo;
109 #endif
110 
111 int sysctl_sysvmsg(int *, u_int, void *, size_t *);
112 
113 struct msg_sysctl_info {
114 	struct msginfo msginfo;
115 	struct msqid_ds msgids[1];
116 };
117 
118 #ifndef MSGSSZ
119 #define MSGSSZ	8		/* Each segment must be 2^N long */
120 #endif
121 #ifndef MSGSEG
122 #define MSGSEG	2048		/* must be less than 32767 */
123 #endif
124 #undef MSGMAX			/* ALWAYS compute MSGMAX! */
125 #define MSGMAX	(MSGSSZ*MSGSEG)
126 #ifndef MSGMNB
127 #define MSGMNB	2048		/* max # of bytes in a queue */
128 #endif
129 #ifndef MSGMNI
130 #define MSGMNI	40
131 #endif
132 #ifndef MSGTQL
133 #define MSGTQL	40
134 #endif
135 
136 void msginit(void);
137 #else /* !_KERNEL */
138 __BEGIN_DECLS
139 int msgctl(int, int, struct msqid_ds *);
140 int msgget(key_t, int);
141 int msgsnd(int, const void *, size_t, int);
142 int msgrcv(int, void *, size_t, long, int);
143 __END_DECLS
144 #endif
145 
146 #endif /* !_SYS_MSG_H_ */
147