bsd/sys/msg.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*      $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $      */
  29
  30 /*
  31  * SVID compatible msg.h file
  32  *
  33  * Author:  Daniel Boulet
  34  *
  35  * Copyright 1993 Daniel Boulet and RTMX Inc.
  36  *
  37  * This system call was implemented by Daniel Boulet under contract from RTMX.
  38  *
  39  * Redistribution and use in source forms, with and without modification,
  40  * are permitted provided that this entire comment appears intact.
  41  *
  42  * Redistribution in binary form may occur without any restrictions.
  43  * Obviously, it would be nice if you gave credit where credit is due
  44  * but requiring it would be too onerous.
  45  *
  46  * This software is provided ``AS IS'' without any warranties of any kind.
  47  */
  48
  49 #ifndef _SYS_MSG_H_
  50 #define _SYS_MSG_H_
  51
  52 #include <sys/appleapiopts.h>
  53
  54 #include <sys/_types.h>
  55 #include <sys/cdefs.h>
  56
  57 /*
  58  * [XSI] All of the symbols from <sys/ipc.h> SHALL be defined when this
  59  * header is included
  60  */
  61 #include <sys/ipc.h>
  62
  63
  64 /*
  65  * [XSI] The pid_t, time_t, key_t, size_t, and ssize_t types shall be
  66  * defined as described in <sys/types.h>.
  67  *
  68  * NOTE:        The definition of the key_t type is implicit from the
  69  *              inclusion of <sys/ipc.h>
  70  */
  71 #ifndef _PID_T
  72 typedef __darwin_pid_t          pid_t;
  73 #define _PID_T
  74 #endif
  75
  76 #ifndef _TIME_T
  77 #define _TIME_T
  78 typedef __darwin_time_t         time_t;
  79 #endif
  80
  81 #ifndef _SIZE_T
  82 #define _SIZE_T
  83 typedef __darwin_size_t         size_t;
  84 #endif
  85
  86 #ifndef _SSIZE_T
  87 #define _SSIZE_T
  88 typedef __darwin_ssize_t        ssize_t;
  89 #endif
  90
  91 /* [XSI] Used for the number of messages in the message queue */
  92 typedef unsigned long           msgqnum_t;
  93
  94 /* [XSI] Used for the number of bytes allowed in a message queue */
  95 typedef unsigned long           msglen_t;
  96
  97
  98 /*
  99  * Possible values for the fifth parameter to msgrcv(), in addition to the
 100  * IPC_NOWAIT flag, which is permitted.
 101  */
 102 #define MSG_NOERROR     010000          /* [XSI] No error if big message */
 103
 104
 105 /*
 106  * Technically, we should force all code references to the new structure
 107  * definition, not in just the standards conformance case, and leave the
 108  * legacy interface there for binary compatibility only.  Currently, we
 109  * are only forcing this for programs requesting standards conformance.
 110  */
 111 #if defined(__POSIX_C_SOURCE) || defined(kernel) || defined(__LP64__)
 112 /*
 113  * Structure used internally.
 114  *
 115  * Structure whose address is passed as the third parameter to msgctl()
 116  * when the second parameter is IPC_SET or IPC_STAT.  In the case of the
 117  * IPC_SET command, only the msg_perm.{uid|gid|perm} and msg_qbytes are
 118  * honored.  In the case of IPC_STAT, only the fields indicated as [XSI]
 119  * mandated fields are guaranteed to meaningful: DO NOT depend on the
 120  * contents of the other fields.
 121  *
 122  * NOTES:       Reserved fields are not preserved across IPC_SET/IPC_STAT.
 123  */
 124 struct __msqid_ds_new {
 125         struct __ipc_perm_new   msg_perm; /* [XSI] msg queue permissions */
 126         __int32_t       msg_first;      /* RESERVED: kernel use only */
 127         __int32_t       msg_last;       /* RESERVED: kernel use only */
 128         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 129         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 130         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 131         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 132         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 133         time_t          msg_stime;      /* [XSI] time of last msgsnd() */
 134         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 135         time_t          msg_rtime;      /* [XSI] time of last msgrcv() */
 136         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 137         time_t          msg_ctime;      /* [XSI] time of last msgctl() */
 138         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 139         __int32_t       msg_pad4[4];    /* RESERVED: DO NOT USE */
 140 };
 141 #define msqid_ds        __msqid_ds_new
 142 #else   /* !_POSIX_C_SOURCE */
 143 #define msqid_ds        __msqid_ds_old
 144 #endif  /* !_POSIX_C_SOURCE */
 145
 146 #if !defined(__POSIX_C_SOURCE) && !defined(__LP64__)
 147 struct __msqid_ds_old {
 148         struct __ipc_perm_old   msg_perm; /* [XSI] msg queue permissions */
 149         __int32_t       msg_first;      /* RESERVED: kernel use only */
 150         __int32_t       msg_last;       /* RESERVED: kernel use only */
 151         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 152         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 153         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 154         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 155         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 156         time_t          msg_stime;      /* [XSI] time of last msgsnd() */
 157         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 158         time_t          msg_rtime;      /* [XSI] time of last msgrcv() */
 159         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 160         time_t          msg_ctime;      /* [XSI] time of last msgctl() */
 161         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 162         __int32_t       msg_pad4[4];    /* RESERVED: DO NOT USE */
 163 };
 164 #endif  /* !_POSIX_C_SOURCE */
 165
 166 #ifdef KERNEL
 167 #ifdef __APPLE_API_PRIVATE
 168 #include <machine/types.h>
 169
 170 // LP64todo - should this move?
 171
 172 #if __DARWIN_ALIGN_NATURAL
 173 #pragma options align=natural
 174 #endif
 175
 176 struct user_msqid_ds {
 177         struct ipc_perm msg_perm;       /* [XSI] msg queue permissions */
 178         struct msg      *msg_first;     /* first message in the queue */
 179         struct msg      *msg_last;      /* last message in the queue */
 180         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 181         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 182         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 183         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 184         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 185         user_time_t     msg_stime;      /* [XSI] time of last msgsnd() */
 186         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 187         user_time_t     msg_rtime;      /* [XSI] time of last msgrcv() */
 188         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 189         user_time_t     msg_ctime;      /* [XSI] time of last msgctl() */
 190         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 191         __int32_t       msg_pad4[4];
 192 };
 193
 194 #if __DARWIN_ALIGN_NATURAL
 195 #pragma options align=reset
 196 #endif
 197
 198 #endif  /* __APPLE_API_PRIVATE */
 199 #endif  /* KERNEL */
 200
 201
 202 #ifndef _POSIX_C_SOURCE
 203 #ifdef __APPLE_API_UNSTABLE
 204 /* XXX kernel only; protect with macro later */
 205
 206 struct msg {
 207         struct msg      *msg_next;      /* next msg in the chain */
 208         long            msg_type;       /* type of this message */
 209                                         /* >0 -> type of this message */
 210                                         /* 0 -> free header */
 211         unsigned short  msg_ts;         /* size of this message */
 212         short           msg_spot;       /* location of msg start in buffer */
 213 };
 214
 215 /*
 216  * Example structure describing a message whose address is to be passed as
 217  * the second argument to the functions msgrcv() and msgsnd().  The only
 218  * actual hard requirement is that the first field be of type long, and
 219  * contain the message type.  The user is encouraged to define their own
 220  * application specific structure; this definition is included solely for
 221  * backward compatability with existing source code.
 222  */
 223 struct mymsg {
 224         long    mtype;          /* message type (+ve integer) */
 225         char    mtext[1];       /* message body */
 226 };
 227
 228 /*
 229  * Based on the configuration parameters described in an SVR2 (yes, two)
 230  * config(1m) man page.
 231  *
 232  * Each message is broken up and stored in segments that are msgssz bytes
 233  * long.  For efficiency reasons, this should be a power of two.  Also,
 234  * it doesn't make sense if it is less than 8 or greater than about 256.
 235  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
 236  * two between 8 and 1024 inclusive (and panic's if it isn't).
 237  */
 238 struct msginfo {
 239         int     msgmax,         /* max chars in a message */
 240                 msgmni,         /* max message queue identifiers */
 241                 msgmnb,         /* max chars in a queue */
 242                 msgtql,         /* max messages in system */
 243                 msgssz,         /* size of a message segment (see notes above) */
 244                 msgseg;         /* number of message segments */
 245 };
 246 #ifdef KERNEL
 247 extern struct msginfo   msginfo;
 248
 249 #ifndef MSGSSZ
 250 #define MSGSSZ  8               /* Each segment must be 2^N long */
 251 #endif
 252 #ifndef MSGSEG
 253 #define MSGSEG  2048            /* must be less than 32767 */
 254 #endif
 255 #define MSGMAX  (MSGSSZ*MSGSEG)
 256 #ifndef MSGMNB
 257 #define MSGMNB  2048            /* max # of bytes in a queue */
 258 #endif
 259 #ifndef MSGMNI
 260 #define MSGMNI  40
 261 #endif
 262 #ifndef MSGTQL
 263 #define MSGTQL  40
 264 #endif
 265
 266 /*
 267  * macros to convert between msqid_ds's and msqid's.
 268  * (specific to this implementation)
 269  */
 270 #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
 271 #define MSQID_IX(id)    ((id) & 0xffff)
 272 #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
 273
 274 /*
 275  * The rest of this file is specific to this particular implementation.
 276  */
 277
 278
 279 /*
 280  * Stuff allocated in machdep.h
 281  */
 282 struct msgmap {
 283         short   next;           /* next segment in buffer */
 284                                 /* -1 -> available */
 285                                 /* 0..(MSGSEG-1) -> index of next segment */
 286 };
 287
 288 /* The following four externs really, really need to die; should be static */
 289 extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
 290 extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
 291 extern struct msg *msghdrs;     /* MSGTQL msg headers */
 292 extern struct user_msqid_ds     *msqids; /* MSGMNI user_msqid_ds struct's */
 293
 294 #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
 295
 296 #endif  /* KERNEL */
 297 #endif  /* __APPLE_API_UNSTABLE */
 298 #endif  /* !_POSIX_C_SOURCE */
 299
 300 #ifndef KERNEL
 301
 302 __BEGIN_DECLS
 303 #ifndef _POSIX_C_SOURCE
 304 int msgsys(int, ...);
 305 #endif  /* !_POSIX_C_SOURCE */
 306 int msgctl(int, int, struct msqid_ds *) __DARWIN_ALIAS(msgctl);
 307 int msgget(key_t, int);
 308 ssize_t msgrcv(int, void *, size_t, long, int);
 309 int msgsnd(int, const void *, size_t, int);
 310 __END_DECLS
 311
 312 #endif /* !KERNEL */
 313
 314 #endif /* !_SYS_MSG_H_ */