msg.h revision 139825
1/* $FreeBSD: head/sys/sys/msg.h 139825 2005-01-07 02:29:27Z imp $ */ 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 struct label *label; /* MAC Framework label */ 111}; 112 113/* 114 * Based on the configuration parameters described in an SVR2 (yes, two) 115 * config(1m) man page. 116 * 117 * Each message is broken up and stored in segments that are msgssz bytes 118 * long. For efficiency reasons, this should be a power of two. Also, 119 * it doesn't make sense if it is less than 8 or greater than about 256. 120 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 121 * two between 8 and 1024 inclusive (and panic's if it isn't). 122 */ 123struct msginfo { 124 int msgmax, /* max chars in a message */ 125 msgmni, /* max message queue identifiers */ 126 msgmnb, /* max chars in a queue */ 127 msgtql, /* max messages in system */ 128 msgssz, /* size of a message segment (see notes above) */ 129 msgseg; /* number of message segments */ 130}; 131extern struct msginfo msginfo; 132 133/* 134 * Kernel wrapper for the user-level structure. 135 */ 136struct msqid_kernel { 137 /* 138 * Data structure exposed to user space. 139 */ 140 struct msqid_ds u; 141 142 /* 143 * Kernel-private components of the message queue. 144 */ 145 struct label *label; /* MAC label */ 146}; 147 148#else /* !_KERNEL */ 149 150__BEGIN_DECLS 151int msgctl(int, int, struct msqid_ds *); 152int msgget(key_t, int); 153/* XXX return value should be ssize_t. */ 154int msgrcv(int, void *, size_t, long, int); 155int msgsnd(int, const void *, size_t, int); 156#if __BSD_VISIBLE 157int msgsys(int, ...); 158#endif 159__END_DECLS 160 161#endif /* _KERNEL */ 162 163#endif /* !_SYS_MSG_H_ */ 164