00001 /* $FreeBSD: src/sys/sys/msg.h,v 1.20 2005/01/07 02:29:23 imp Exp $ */ 00002 /* $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $ */ 00003 00004 /*- 00005 * SVID compatible msg.h file 00006 * 00007 * Author: Daniel Boulet 00008 * 00009 *© Portions copyright (c) 2006 Nokia Corporation. All rights reserved. 00010 * Copyright 1993 Daniel Boulet and RTMX Inc. 00011 * 00012 * This system call was implemented by Daniel Boulet under contract from RTMX. 00013 * 00014 * Redistribution and use in source forms, with and without modification, 00015 * are permitted provided that this entire comment appears intact. 00016 * 00017 * Redistribution in binary form may occur without any restrictions. 00018 * Obviously, it would be nice if you gave credit where credit is due 00019 * but requiring it would be too onerous. 00020 * 00021 * This software is provided ``AS IS'' without any warranties of any kind. 00022 */ 00023 00024 #ifndef _SYS_MSG_H_ 00025 #define _SYS_MSG_H_ 00026 00027 #include <sys/cdefs.h> 00028 #include <sys/_types.h> 00029 #include <sys/ipc.h> 00030 00031 /* 00032 * The MSG_NOERROR identifier value, the msqid_ds struct and the msg struct 00033 * are as defined by the SV API Intel 386 Processor Supplement. 00034 */ 00035 00036 #define MSG_NOERROR 010000 /* don't complain about too long msgs */ 00037 00038 typedef unsigned long msglen_t; 00039 typedef unsigned long msgqnum_t; 00040 00041 #ifndef _PID_T_DECLARED 00042 typedef __pid_t pid_t; 00043 #define _PID_T_DECLARED 00044 #endif 00045 00046 #ifndef _SIZE_T_DECLARED 00047 typedef __size_t size_t; 00048 #define _SIZE_T_DECLARED 00049 #endif 00050 00051 #ifndef _SSIZE_T_DECLARED 00052 typedef __ssize_t ssize_t; 00053 #define _SSIZE_T_DECLARED 00054 #endif 00055 00056 #ifndef _TIME_T_DECLARED 00057 typedef __time_t time_t; 00058 #define _TIME_T_DECLARED 00059 #endif 00060 00061 /* 00062 * XXX there seems to be no prefix reserved for this header, so the name 00063 * "msg" in "struct msg" and the names of all of the nonstandard members 00064 * (mainly "msg_pad*) are namespace pollution. 00065 */ 00066 00067 struct msqid_ds { 00068 struct ipc_perm msg_perm; /* msg queue permission bits */ 00069 struct msg *msg_first; /* first message in the queue */ 00070 struct msg *msg_last; /* last message in the queue */ 00071 msglen_t msg_cbytes; /* number of bytes in use on the queue */ 00072 msgqnum_t msg_qnum; /* number of msgs in the queue */ 00073 msglen_t msg_qbytes; /* max # of bytes on the queue */ 00074 pid_t msg_lspid; /* pid of last msgsnd() */ 00075 pid_t msg_lrpid; /* pid of last msgrcv() */ 00076 time_t msg_stime; /* time of last msgsnd() */ 00077 long msg_pad1; 00078 time_t msg_rtime; /* time of last msgrcv() */ 00079 long msg_pad2; 00080 time_t msg_ctime; /* time of last msgctl() */ 00081 long msg_pad3; 00082 long msg_pad4[4]; 00083 }; 00084 00085 #if __BSD_VISIBLE 00086 /* 00087 * Structure describing a message. The SVID doesn't suggest any 00088 * particular name for this structure. There is a reference in the 00089 * msgop man page that reads "The structure mymsg is an example of what 00090 * this user defined buffer might look like, and includes the following 00091 * members:". This sentence is followed by two lines equivalent 00092 * to the mtype and mtext field declarations below. It isn't clear 00093 * if "mymsg" refers to the name of the structure type or the name of an 00094 * instance of the structure... 00095 */ 00096 struct mymsg { 00097 long mtype; /* message type (+ve integer) */ 00098 char mtext[1]; /* message body */ 00099 }; 00100 #endif 00101 00102 #ifdef _KERNEL 00103 00104 struct msg { 00105 struct msg *msg_next; /* next msg in the chain */ 00106 long msg_type; /* type of this message */ 00107 /* >0 -> type of this message */ 00108 /* 0 -> free header */ 00109 u_short msg_ts; /* size of this message */ 00110 short msg_spot; /* location of start of msg in buffer */ 00111 struct label *label; /* MAC Framework label */ 00112 }; 00113 00114 /* 00115 * Based on the configuration parameters described in an SVR2 (yes, two) 00116 * config(1m) man page. 00117 * 00118 * Each message is broken up and stored in segments that are msgssz bytes 00119 * long. For efficiency reasons, this should be a power of two. Also, 00120 * it doesn't make sense if it is less than 8 or greater than about 256. 00121 * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of 00122 * two between 8 and 1024 inclusive (and panic's if it isn't). 00123 */ 00124 struct msginfo { 00125 int msgmax, /* max chars in a message */ 00126 msgmni, /* max message queue identifiers */ 00127 msgmnb, /* max chars in a queue */ 00128 msgtql, /* max messages in system */ 00129 msgssz, /* size of a message segment (see notes above) */ 00130 msgseg; /* number of message segments */ 00131 }; 00132 extern struct msginfo msginfo; 00133 00134 /* 00135 * Kernel wrapper for the user-level structure. 00136 */ 00137 struct msqid_kernel { 00138 /* 00139 * Data structure exposed to user space. 00140 */ 00141 struct msqid_ds u; 00142 00143 /* 00144 * Kernel-private components of the message queue. 00145 */ 00146 struct label *label; /* MAC label */ 00147 }; 00148 00149 #else /* !_KERNEL */ 00150 00151 /* Template for struct to be used as argument for `msgsnd' and `msgrcv'. */ 00152 struct msgbuf 00153 { 00154 long int mtype; /* type of received/sent message */ 00155 char mtext[1]; /* text of the message */ 00156 }; 00157 00158 // FUNCTION PROTOTYPES 00159 00160 00161 // FORWARD DECLARATIONS 00162 00163 00164 // CLASS/STRUCT/FUNCTION DECLARATION 00165 __BEGIN_DECLS 00166 00167 /* 00168 * Get the message queue identifier using the IPC key generated by ftok. 00169 */ 00170 00171 IMPORT_C int msgget(key_t key, int msgflg); 00172 00173 /* 00174 * Used to send a message to the queue associated with the message identifier specified by msqid. 00175 */ 00176 00177 IMPORT_C int msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg); 00178 00179 /* 00180 * Reads a message from the queue associated with the message queue identifier. 00181 */ 00182 00183 IMPORT_C ssize_t msgrcv(int msqid, void* msgp, size_t msgsz, long msgtyp, int msgflg); 00184 00185 /* 00186 * Provides an interface to control message queue and control operations as specified by cmd. 00187 */ 00188 00189 IMPORT_C int msgctl(int msqid, int cmd, struct msqid_ds* buf); 00190 00191 00192 __END_DECLS 00193 00194 #endif /* !_KERNEL */ 00195 00196 // _SYS_MSG_H_ 00197 #endif 00198 00199 // End of File