bsd/sys/msg.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*      $NetBSD: msg.h,v 1.4 1994/06/29 06:44:43 cgd Exp $      */
  31
  32 /*
  33  * SVID compatible msg.h file
  34  *
  35  * Author:  Daniel Boulet
  36  *
  37  * Copyright 1993 Daniel Boulet and RTMX Inc.
  38  *
  39  * This system call was implemented by Daniel Boulet under contract from RTMX.
  40  *
  41  * Redistribution and use in source forms, with and without modification,
  42  * are permitted provided that this entire comment appears intact.
  43  *
  44  * Redistribution in binary form may occur without any restrictions.
  45  * Obviously, it would be nice if you gave credit where credit is due
  46  * but requiring it would be too onerous.
  47  *
  48  * This software is provided ``AS IS'' without any warranties of any kind.
  49  */
  50
  51 #ifndef _SYS_MSG_H_
  52 #define _SYS_MSG_H_
  53
  54 #include <sys/appleapiopts.h>
  55
  56 #include <sys/_types.h>
  57 #include <sys/cdefs.h>
  58
  59 /*
  60  * [XSI] All of the symbols from <sys/ipc.h> SHALL be defined when this
  61  * header is included
  62  */
  63 #include <sys/ipc.h>
  64
  65
  66 /*
  67  * [XSI] The pid_t, time_t, key_t, size_t, and ssize_t types shall be
  68  * defined as described in <sys/types.h>.
  69  *
  70  * NOTE:        The definition of the key_t type is implicit from the
  71  *              inclusion of <sys/ipc.h>
  72  */
  73 #ifndef _PID_T
  74 typedef __darwin_pid_t          pid_t;
  75 #define _PID_T
  76 #endif
  77
  78 #ifndef _TIME_T
  79 #define _TIME_T
  80 typedef __darwin_time_t         time_t;
  81 #endif
  82
  83 #ifndef _SIZE_T
  84 #define _SIZE_T
  85 typedef __darwin_size_t         size_t;
  86 #endif
  87
  88 #ifndef _SSIZE_T
  89 #define _SSIZE_T
  90 typedef __darwin_ssize_t        ssize_t;
  91 #endif
  92
  93 /* [XSI] Used for the number of messages in the message queue */
  94 typedef unsigned long           msgqnum_t;
  95
  96 /* [XSI] Used for the number of bytes allowed in a message queue */
  97 typedef unsigned long           msglen_t;
  98
  99
 100 /*
 101  * Possible values for the fifth parameter to msgrcv(), in addition to the
 102  * IPC_NOWAIT flag, which is permitted.
 103  */
 104 #define MSG_NOERROR     010000          /* [XSI] No error if big message */
 105
 106
 107 /*
 108  * Technically, we should force all code references to the new structure
 109  * definition, not in just the standards conformance case, and leave the
 110  * legacy interface there for binary compatibility only.  Currently, we
 111  * are only forcing this for programs requesting standards conformance.
 112  */
 113 #if defined(__POSIX_C_SOURCE) || defined(kernel) || defined(__LP64__)
 114 /*
 115  * Structure used internally.
 116  *
 117  * Structure whose address is passed as the third parameter to msgctl()
 118  * when the second parameter is IPC_SET or IPC_STAT.  In the case of the
 119  * IPC_SET command, only the msg_perm.{uid|gid|perm} and msg_qbytes are
 120  * honored.  In the case of IPC_STAT, only the fields indicated as [XSI]
 121  * mandated fields are guaranteed to meaningful: DO NOT depend on the
 122  * contents of the other fields.
 123  *
 124  * NOTES:       Reserved fields are not preserved across IPC_SET/IPC_STAT.
 125  */
 126 struct __msqid_ds_new {
 127         struct __ipc_perm_new   msg_perm; /* [XSI] msg queue permissions */
 128         __int32_t       msg_first;      /* RESERVED: kernel use only */
 129         __int32_t       msg_last;       /* RESERVED: kernel use only */
 130         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 131         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 132         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 133         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 134         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 135         time_t          msg_stime;      /* [XSI] time of last msgsnd() */
 136         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 137         time_t          msg_rtime;      /* [XSI] time of last msgrcv() */
 138         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 139         time_t          msg_ctime;      /* [XSI] time of last msgctl() */
 140         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 141         __int32_t       msg_pad4[4];    /* RESERVED: DO NOT USE */
 142 };
 143 #define msqid_ds        __msqid_ds_new
 144 #else   /* !_POSIX_C_SOURCE */
 145 #define msqid_ds        __msqid_ds_old
 146 #endif  /* !_POSIX_C_SOURCE */
 147
 148 #if !defined(__POSIX_C_SOURCE) && !defined(__LP64__)
 149 struct __msqid_ds_old {
 150         struct __ipc_perm_old   msg_perm; /* [XSI] msg queue permissions */
 151         __int32_t       msg_first;      /* RESERVED: kernel use only */
 152         __int32_t       msg_last;       /* RESERVED: kernel use only */
 153         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 154         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 155         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 156         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 157         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 158         time_t          msg_stime;      /* [XSI] time of last msgsnd() */
 159         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 160         time_t          msg_rtime;      /* [XSI] time of last msgrcv() */
 161         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 162         time_t          msg_ctime;      /* [XSI] time of last msgctl() */
 163         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 164         __int32_t       msg_pad4[4];    /* RESERVED: DO NOT USE */
 165 };
 166 #endif  /* !_POSIX_C_SOURCE */
 167
 168 #ifdef KERNEL
 169 #ifdef __APPLE_API_PRIVATE
 170 #include <machine/types.h>
 171
 172 // LP64todo - should this move?
 173
 174 #if __DARWIN_ALIGN_NATURAL
 175 #pragma options align=natural
 176 #endif
 177
 178 struct user_msqid_ds {
 179         struct ipc_perm msg_perm;       /* [XSI] msg queue permissions */
 180         struct msg      *msg_first;     /* first message in the queue */
 181         struct msg      *msg_last;      /* last message in the queue */
 182         msglen_t        msg_cbytes;     /* # of bytes on the queue */
 183         msgqnum_t       msg_qnum;       /* [XSI] number of msgs on the queue */
 184         msglen_t        msg_qbytes;     /* [XSI] max bytes on the queue */
 185         pid_t           msg_lspid;      /* [XSI] pid of last msgsnd() */
 186         pid_t           msg_lrpid;      /* [XSI] pid of last msgrcv() */
 187         user_time_t     msg_stime;      /* [XSI] time of last msgsnd() */
 188         __int32_t       msg_pad1;       /* RESERVED: DO NOT USE */
 189         user_time_t     msg_rtime;      /* [XSI] time of last msgrcv() */
 190         __int32_t       msg_pad2;       /* RESERVED: DO NOT USE */
 191         user_time_t     msg_ctime;      /* [XSI] time of last msgctl() */
 192         __int32_t       msg_pad3;       /* RESERVED: DO NOT USE */
 193         __int32_t       msg_pad4[4];
 194 };
 195
 196 #if __DARWIN_ALIGN_NATURAL
 197 #pragma options align=reset
 198 #endif
 199
 200 #endif  /* __APPLE_API_PRIVATE */
 201 #endif  /* KERNEL */
 202
 203
 204 #ifndef _POSIX_C_SOURCE
 205 #ifdef __APPLE_API_UNSTABLE
 206 /* XXX kernel only; protect with macro later */
 207
 208 struct msg {
 209         struct msg      *msg_next;      /* next msg in the chain */
 210         long            msg_type;       /* type of this message */
 211                                         /* >0 -> type of this message */
 212                                         /* 0 -> free header */
 213         unsigned short  msg_ts;         /* size of this message */
 214         short           msg_spot;       /* location of msg start in buffer */
 215 };
 216
 217 /*
 218  * Example structure describing a message whose address is to be passed as
 219  * the second argument to the functions msgrcv() and msgsnd().  The only
 220  * actual hard requirement is that the first field be of type long, and
 221  * contain the message type.  The user is encouraged to define their own
 222  * application specific structure; this definition is included solely for
 223  * backward compatability with existing source code.
 224  */
 225 struct mymsg {
 226         long    mtype;          /* message type (+ve integer) */
 227         char    mtext[1];       /* message body */
 228 };
 229
 230 /*
 231  * Based on the configuration parameters described in an SVR2 (yes, two)
 232  * config(1m) man page.
 233  *
 234  * Each message is broken up and stored in segments that are msgssz bytes
 235  * long.  For efficiency reasons, this should be a power of two.  Also,
 236  * it doesn't make sense if it is less than 8 or greater than about 256.
 237  * Consequently, msginit in kern/sysv_msg.c checks that msgssz is a power of
 238  * two between 8 and 1024 inclusive (and panic's if it isn't).
 239  */
 240 struct msginfo {
 241         int     msgmax,         /* max chars in a message */
 242                 msgmni,         /* max message queue identifiers */
 243                 msgmnb,         /* max chars in a queue */
 244                 msgtql,         /* max messages in system */
 245                 msgssz,         /* size of a message segment (see notes above) */
 246                 msgseg;         /* number of message segments */
 247 };
 248 #ifdef KERNEL
 249 extern struct msginfo   msginfo;
 250
 251 #ifndef MSGSSZ
 252 #define MSGSSZ  8               /* Each segment must be 2^N long */
 253 #endif
 254 #ifndef MSGSEG
 255 #define MSGSEG  2048            /* must be less than 32767 */
 256 #endif
 257 #define MSGMAX  (MSGSSZ*MSGSEG)
 258 #ifndef MSGMNB
 259 #define MSGMNB  2048            /* max # of bytes in a queue */
 260 #endif
 261 #ifndef MSGMNI
 262 #define MSGMNI  40
 263 #endif
 264 #ifndef MSGTQL
 265 #define MSGTQL  40
 266 #endif
 267
 268 /*
 269  * macros to convert between msqid_ds's and msqid's.
 270  * (specific to this implementation)
 271  */
 272 #define MSQID(ix,ds)    ((ix) & 0xffff | (((ds).msg_perm.seq << 16) & 0xffff0000))
 273 #define MSQID_IX(id)    ((id) & 0xffff)
 274 #define MSQID_SEQ(id)   (((id) >> 16) & 0xffff)
 275
 276 /*
 277  * The rest of this file is specific to this particular implementation.
 278  */
 279
 280
 281 /*
 282  * Stuff allocated in machdep.h
 283  */
 284 struct msgmap {
 285         short   next;           /* next segment in buffer */
 286                                 /* -1 -> available */
 287                                 /* 0..(MSGSEG-1) -> index of next segment */
 288 };
 289
 290 /* The following four externs really, really need to die; should be static */
 291 extern char *msgpool;           /* MSGMAX byte long msg buffer pool */
 292 extern struct msgmap *msgmaps;  /* MSGSEG msgmap structures */
 293 extern struct msg *msghdrs;     /* MSGTQL msg headers */
 294 extern struct user_msqid_ds     *msqids; /* MSGMNI user_msqid_ds struct's */
 295
 296 #define MSG_LOCKED      01000   /* Is this msqid_ds locked? */
 297
 298 #endif  /* KERNEL */
 299 #endif  /* __APPLE_API_UNSTABLE */
 300 #endif  /* !_POSIX_C_SOURCE */
 301
 302 #ifndef KERNEL
 303
 304 __BEGIN_DECLS
 305 #ifndef _POSIX_C_SOURCE
 306 int msgsys(int, ...);
 307 #endif  /* !_POSIX_C_SOURCE */
 308 int msgctl(int, int, struct msqid_ds *) __DARWIN_ALIAS(msgctl);
 309 int msgget(key_t, int);
 310 ssize_t msgrcv(int, void *, size_t, long, int);
 311 int msgsnd(int, const void *, size_t, int);
 312 __END_DECLS
 313
 314 #endif /* !KERNEL */
 315
 316 #endif /* !_SYS_MSG_H_ */