osfmk/ipc/mach_msg.c

   1 /*
   2  * Copyright (c) 2000-2007 Apple 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 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  * NOTICE: This file was modified by McAfee Research in 2004 to introduce
  58  * support for mandatory and extensible security protections.  This notice
  59  * is included in support of clause 2.2 (b) of the Apple Public License,
  60  * Version 2.0.
  61  * Copyright (c) 2005 SPARTA, Inc.
  62  */
  63 /*
  64  */
  65 /*
  66  *      File:   ipc/mach_msg.c
  67  *      Author: Rich Draves
  68  *      Date:   1989
  69  *
  70  *      Exported message traps.  See mach/message.h.
  71  */
  72
  73 #include <mach/mach_types.h>
  74 #include <mach/kern_return.h>
  75 #include <mach/port.h>
  76 #include <mach/message.h>
  77 #include <mach/mig_errors.h>
  78 #include <mach/mach_traps.h>
  79
  80 #include <kern/kern_types.h>
  81 #include <kern/assert.h>
  82 #include <kern/counters.h>
  83 #include <kern/cpu_number.h>
  84 #include <kern/ipc_kobject.h>
  85 #include <kern/ipc_mig.h>
  86 #include <kern/task.h>
  87 #include <kern/thread.h>
  88 #include <kern/lock.h>
  89 #include <kern/sched_prim.h>
  90 #include <kern/exception.h>
  91 #include <kern/misc_protos.h>
  92 #include <kern/kalloc.h>
  93 #include <kern/processor.h>
  94 #include <kern/syscall_subr.h>
  95
  96 #include <vm/vm_map.h>
  97
  98 #include <ipc/ipc_types.h>
  99 #include <ipc/ipc_kmsg.h>
 100 #include <ipc/ipc_mqueue.h>
 101 #include <ipc/ipc_object.h>
 102 #include <ipc/ipc_notify.h>
 103 #include <ipc/ipc_port.h>
 104 #include <ipc/ipc_pset.h>
 105 #include <ipc/ipc_space.h>
 106 #include <ipc/ipc_entry.h>
 107
 108 #include <machine/machine_routines.h>
 109 #include <security/mac_mach_internal.h>
 110
 111 #include <sys/kdebug.h>
 112
 113
 114 #ifndef offsetof
 115 #define offsetof(type, member)  ((size_t)(&((type *)0)->member))
 116 #endif /* offsetof */
 117
 118 /*
 119  * Forward declarations - kernel internal routines
 120  */
 121
 122 mach_msg_return_t mach_msg_send(
 123         mach_msg_header_t       *msg,
 124         mach_msg_option_t       option,
 125         mach_msg_size_t         send_size,
 126         mach_msg_timeout_t      send_timeout,
 127         mach_port_name_t        notify);
 128
 129 mach_msg_return_t mach_msg_receive(
 130         mach_msg_header_t       *msg,
 131         mach_msg_option_t       option,
 132         mach_msg_size_t         rcv_size,
 133         mach_port_name_t        rcv_name,
 134         mach_msg_timeout_t      rcv_timeout,
 135         void                    (*continuation)(mach_msg_return_t),
 136         mach_msg_size_t         slist_size);
 137
 138
 139 mach_msg_return_t msg_receive_error(
 140         ipc_kmsg_t              kmsg,
 141         mach_vm_address_t       msg_addr,
 142         mach_msg_option_t       option,
 143         mach_port_seqno_t       seqno,
 144         ipc_space_t             space);
 145
 146 security_token_t KERNEL_SECURITY_TOKEN = KERNEL_SECURITY_TOKEN_VALUE;
 147 audit_token_t KERNEL_AUDIT_TOKEN = KERNEL_AUDIT_TOKEN_VALUE;
 148
 149 mach_msg_format_0_trailer_t trailer_template = {
 150         /* mach_msg_trailer_type_t */ MACH_MSG_TRAILER_FORMAT_0,
 151         /* mach_msg_trailer_size_t */ MACH_MSG_TRAILER_MINIMUM_SIZE,
 152         /* mach_port_seqno_t */       0,
 153         /* security_token_t */        KERNEL_SECURITY_TOKEN_VALUE
 154 };
 155
 156 /*
 157  *      Routine:        mach_msg_send
 158  *      Purpose:
 159  *              Send a message.
 160  *      Conditions:
 161  *              Nothing locked.
 162  *      Returns:
 163  *              MACH_MSG_SUCCESS        Sent the message.
 164  *              MACH_SEND_MSG_TOO_SMALL Message smaller than a header.
 165  *              MACH_SEND_NO_BUFFER     Couldn't allocate buffer.
 166  *              MACH_SEND_INVALID_DATA  Couldn't copy message data.
 167  *              MACH_SEND_INVALID_HEADER
 168  *                      Illegal value in the message header bits.
 169  *              MACH_SEND_INVALID_DEST  The space is dead.
 170  *              MACH_SEND_INVALID_NOTIFY        Bad notify port.
 171  *              MACH_SEND_INVALID_DEST  Can't copyin destination port.
 172  *              MACH_SEND_INVALID_REPLY Can't copyin reply port.
 173  *              MACH_SEND_TIMED_OUT     Timeout expired without delivery.
 174  *              MACH_SEND_INTERRUPTED   Delivery interrupted.
 175  */
 176
 177 mach_msg_return_t
 178 mach_msg_send(
 179         mach_msg_header_t       *msg,
 180         mach_msg_option_t       option,
 181         mach_msg_size_t         send_size,
 182         mach_msg_timeout_t      send_timeout,
 183         __unused mach_port_name_t       notify)
 184 {
 185         ipc_space_t space = current_space();
 186         vm_map_t map = current_map();
 187         ipc_kmsg_t kmsg;
 188         mach_msg_return_t mr;
 189         mach_msg_size_t msg_and_trailer_size;
 190         mach_msg_max_trailer_t  *trailer;
 191
 192         if ((send_size < sizeof(mach_msg_header_t)) || (send_size & 3))
 193                 return MACH_SEND_MSG_TOO_SMALL;
 194
 195         if (send_size > MACH_MSG_SIZE_MAX - MAX_TRAILER_SIZE)
 196                 return MACH_SEND_TOO_LARGE;
 197
 198         msg_and_trailer_size = send_size + MAX_TRAILER_SIZE;
 199
 200         kmsg = ipc_kmsg_alloc(msg_and_trailer_size);
 201
 202         if (kmsg == IKM_NULL)
 203                 return MACH_SEND_NO_BUFFER;
 204
 205         (void) memcpy((void *) kmsg->ikm_header, (const void *) msg, send_size);
 206
 207         kmsg->ikm_header->msgh_size = send_size;
 208
 209         /*
 210          * reserve for the trailer the largest space (MAX_TRAILER_SIZE)
 211          * However, the internal size field of the trailer (msgh_trailer_size)
 212          * is initialized to the minimum (sizeof(mach_msg_trailer_t)), to optimize
 213          * the cases where no implicit data is requested.
 214          */
 215         trailer = (mach_msg_max_trailer_t *) ((vm_offset_t)kmsg->ikm_header + send_size);
 216         trailer->msgh_sender = current_thread()->task->sec_token;
 217         trailer->msgh_audit = current_thread()->task->audit_token;
 218         trailer->msgh_trailer_type = MACH_MSG_TRAILER_FORMAT_0;
 219         trailer->msgh_trailer_size = MACH_MSG_TRAILER_MINIMUM_SIZE;
 220
 221         mr = ipc_kmsg_copyin(kmsg, space, map, option & MACH_SEND_NOTIFY);
 222         if (mr != MACH_MSG_SUCCESS) {
 223                 ipc_kmsg_free(kmsg);
 224                 return mr;
 225         }
 226
 227         mr = ipc_kmsg_send(kmsg, option & MACH_SEND_TIMEOUT, send_timeout);
 228         if (mr != MACH_MSG_SUCCESS) {
 229             mr |= ipc_kmsg_copyout_pseudo(kmsg, space, map, MACH_MSG_BODY_NULL);
 230             (void) memcpy((void *) msg, (const void *) kmsg->ikm_header,
 231                           kmsg->ikm_header->msgh_size);
 232             ipc_kmsg_free(kmsg);
 233         }
 234
 235         return mr;
 236 }
 237
 238 /*
 239  *      Routine:        mach_msg_receive_results
 240  *      Purpose:
 241  *              Receive a message.
 242  *      Conditions:
 243  *              Nothing locked.
 244  *      Returns:
 245  *              MACH_MSG_SUCCESS        Received a message.
 246  *              MACH_RCV_INVALID_NAME   The name doesn't denote a right,
 247  *                      or the denoted right is not receive or port set.
 248  *              MACH_RCV_IN_SET         Receive right is a member of a set.
 249  *              MACH_RCV_TOO_LARGE      Message wouldn't fit into buffer.
 250  *              MACH_RCV_TIMED_OUT      Timeout expired without a message.
 251  *              MACH_RCV_INTERRUPTED    Reception interrupted.
 252  *              MACH_RCV_PORT_DIED      Port/set died while receiving.
 253  *              MACH_RCV_PORT_CHANGED   Port moved into set while receiving.
 254  *              MACH_RCV_INVALID_DATA   Couldn't copy to user buffer.
 255  *              MACH_RCV_INVALID_NOTIFY Bad notify port.
 256  *              MACH_RCV_HEADER_ERROR
 257  */
 258
 259 mach_msg_return_t
 260 mach_msg_receive_results(void)
 261 {
 262         thread_t          self = current_thread();
 263         ipc_space_t       space = current_space();
 264         vm_map_t          map = current_map();
 265
 266         ipc_object_t      object = self->ith_object;
 267         mach_msg_return_t mr = self->ith_state;
 268         mach_vm_address_t msg_addr = self->ith_msg_addr;
 269         mach_msg_option_t option = self->ith_option;
 270         ipc_kmsg_t        kmsg = self->ith_kmsg;
 271         mach_port_seqno_t seqno = self->ith_seqno;
 272         mach_msg_trailer_size_t trailer_size;
 273
 274         io_release(object);
 275
 276         if (mr != MACH_MSG_SUCCESS) {
 277
 278           if (mr == MACH_RCV_TOO_LARGE ) {
 279             if (option & MACH_RCV_LARGE) {
 280               /*
 281                * We need to inform the user-level code that it needs more
 282                * space.  The value for how much space was returned in the
 283                * msize save area instead of the message (which was left on
 284                * the queue).
 285                */
 286               if (copyout((char *) &self->ith_msize,
 287                           msg_addr + offsetof(mach_msg_header_t, msgh_size),
 288                           sizeof(mach_msg_size_t)))
 289                 mr = MACH_RCV_INVALID_DATA;
 290               goto out;
 291             }
 292
 293             if (msg_receive_error(kmsg, msg_addr, option, seqno, space)
 294                 == MACH_RCV_INVALID_DATA)
 295               mr = MACH_RCV_INVALID_DATA;
 296           }
 297           goto out;
 298         }
 299
 300         trailer_size = ipc_kmsg_add_trailer(kmsg, space, option, self, seqno, FALSE,
 301                         kmsg->ikm_header->msgh_remote_port->ip_context);
 302         /*
 303          * If MACH_RCV_OVERWRITE was specified, try to get the scatter
 304          * list and verify it against the contents of the message.  If
 305          * there is any problem with it, we will continue without it as
 306          * normal.
 307          */
 308         if (option & MACH_RCV_OVERWRITE) {
 309                 mach_msg_size_t slist_size = self->ith_scatter_list_size;
 310                 mach_msg_body_t *slist;
 311
 312                 slist = ipc_kmsg_get_scatter(msg_addr, slist_size, kmsg);
 313                 mr = ipc_kmsg_copyout(kmsg, space, map, slist);
 314                 ipc_kmsg_free_scatter(slist, slist_size);
 315         } else {
 316                 mr = ipc_kmsg_copyout(kmsg, space, map, MACH_MSG_BODY_NULL);
 317         }
 318
 319         if (mr != MACH_MSG_SUCCESS) {
 320                 if ((mr &~ MACH_MSG_MASK) == MACH_RCV_BODY_ERROR) {
 321                         if (ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size +
 322                            trailer_size) == MACH_RCV_INVALID_DATA)
 323                                 mr = MACH_RCV_INVALID_DATA;
 324                 }
 325                 else {
 326                         if (msg_receive_error(kmsg, msg_addr, option, seqno, space)
 327                                                 == MACH_RCV_INVALID_DATA)
 328                                 mr = MACH_RCV_INVALID_DATA;
 329                 }
 330                 goto out;
 331         }
 332         mr = ipc_kmsg_put(msg_addr,
 333                           kmsg,
 334                           kmsg->ikm_header->msgh_size +
 335                           trailer_size);
 336  out:
 337         return mr;
 338 }
 339
 340 mach_msg_return_t
 341 mach_msg_receive(
 342         mach_msg_header_t       *msg,
 343         mach_msg_option_t       option,
 344         mach_msg_size_t         rcv_size,
 345         mach_port_name_t        rcv_name,
 346         mach_msg_timeout_t      rcv_timeout,
 347         void                    (*continuation)(mach_msg_return_t),
 348         mach_msg_size_t         slist_size)
 349 {
 350         thread_t self = current_thread();
 351         ipc_space_t space = current_space();
 352         ipc_object_t object;
 353         ipc_mqueue_t mqueue;
 354         mach_msg_return_t mr;
 355
 356         mr = ipc_mqueue_copyin(space, rcv_name, &mqueue, &object);
 357         if (mr != MACH_MSG_SUCCESS) {
 358                 return mr;
 359         }
 360         /* hold ref for object */
 361
 362         self->ith_msg_addr = CAST_DOWN(mach_vm_address_t, msg);
 363         self->ith_object = object;
 364         self->ith_msize = rcv_size;
 365         self->ith_option = option;
 366         self->ith_scatter_list_size = slist_size;
 367         self->ith_continuation = continuation;
 368
 369         ipc_mqueue_receive(mqueue, option, rcv_size, rcv_timeout, THREAD_ABORTSAFE);
 370         if ((option & MACH_RCV_TIMEOUT) && rcv_timeout == 0)
 371                 thread_poll_yield(self);
 372         return mach_msg_receive_results();
 373 }
 374
 375 void
 376 mach_msg_receive_continue(void)
 377 {
 378         thread_t self = current_thread();
 379
 380         (*self->ith_continuation)(mach_msg_receive_results());
 381 }
 382
 383
 384 /*
 385  *      Routine:        mach_msg_overwrite_trap [mach trap]
 386  *      Purpose:
 387  *              Possibly send a message; possibly receive a message.
 388  *      Conditions:
 389  *              Nothing locked.
 390  *      Returns:
 391  *              All of mach_msg_send and mach_msg_receive error codes.
 392  */
 393
 394 mach_msg_return_t
 395 mach_msg_overwrite_trap(
 396         struct mach_msg_overwrite_trap_args *args)
 397 {
 398         mach_vm_address_t       msg_addr = args->msg;
 399         mach_msg_option_t       option = args->option;
 400         mach_msg_size_t         send_size = args->send_size;
 401         mach_msg_size_t         rcv_size = args->rcv_size;
 402         mach_port_name_t        rcv_name = args->rcv_name;
 403         mach_msg_timeout_t      msg_timeout = args->timeout;
 404         __unused mach_port_name_t notify = args->notify;
 405         mach_vm_address_t       rcv_msg_addr = args->rcv_msg;
 406         mach_msg_size_t         scatter_list_size = 0; /* NOT INITIALIZED - but not used in pactice */
 407         __unused mach_port_seqno_t temp_seqno = 0;
 408
 409         mach_msg_return_t  mr = MACH_MSG_SUCCESS;
 410         vm_map_t map = current_map();
 411
 412         if (option & MACH_SEND_MSG) {
 413                 ipc_space_t space = current_space();
 414                 ipc_kmsg_t kmsg;
 415
 416                 mr = ipc_kmsg_get(msg_addr, send_size, &kmsg);
 417
 418                 if (mr != MACH_MSG_SUCCESS)
 419                         return mr;
 420
 421                 mr = ipc_kmsg_copyin(kmsg, space, map, option & MACH_SEND_NOTIFY);
 422                 if (mr != MACH_MSG_SUCCESS) {
 423                         ipc_kmsg_free(kmsg);
 424                         return mr;
 425                 }
 426
 427                 mr = ipc_kmsg_send(kmsg, option & MACH_SEND_TIMEOUT, msg_timeout);
 428
 429                 if (mr != MACH_MSG_SUCCESS) {
 430                         mr |= ipc_kmsg_copyout_pseudo(kmsg, space, map, MACH_MSG_BODY_NULL);
 431                         (void) ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size);
 432                         return mr;
 433                 }
 434
 435         }
 436
 437         if (option & MACH_RCV_MSG) {
 438                 thread_t self = current_thread();
 439                 ipc_space_t space = current_space();
 440                 ipc_object_t object;
 441                 ipc_mqueue_t mqueue;
 442
 443                 mr = ipc_mqueue_copyin(space, rcv_name, &mqueue, &object);
 444                 if (mr != MACH_MSG_SUCCESS) {
 445                         return mr;
 446                 }
 447                 /* hold ref for object */
 448
 449                 /*
 450                  * 1. MACH_RCV_OVERWRITE is on, and rcv_msg is our scatter list
 451                  *    and receive buffer
 452                  * 2. MACH_RCV_OVERWRITE is off, and rcv_msg might be the
 453                  *    alternate receive buffer (separate send and receive buffers).
 454                  */
 455                 if (option & MACH_RCV_OVERWRITE)
 456                         self->ith_msg_addr = rcv_msg_addr;
 457                 else if (rcv_msg_addr != (mach_vm_address_t)0)
 458                         self->ith_msg_addr = rcv_msg_addr;
 459                 else
 460                         self->ith_msg_addr = msg_addr;
 461                 self->ith_object = object;
 462                 self->ith_msize = rcv_size;
 463                 self->ith_option = option;
 464                 self->ith_scatter_list_size = scatter_list_size;
 465                 self->ith_receiver_name = MACH_PORT_NULL;
 466                 self->ith_continuation = thread_syscall_return;
 467
 468                 ipc_mqueue_receive(mqueue, option, rcv_size, msg_timeout, THREAD_ABORTSAFE);
 469                 if ((option & MACH_RCV_TIMEOUT) && msg_timeout == 0)
 470                         thread_poll_yield(self);
 471                 return mach_msg_receive_results();
 472         }
 473
 474         return MACH_MSG_SUCCESS;
 475 }
 476
 477 /*
 478  *      Routine:        mach_msg_trap [mach trap]
 479  *      Purpose:
 480  *              Possibly send a message; possibly receive a message.
 481  *      Conditions:
 482  *              Nothing locked.
 483  *      Returns:
 484  *              All of mach_msg_send and mach_msg_receive error codes.
 485  */
 486
 487 mach_msg_return_t
 488 mach_msg_trap(
 489         struct mach_msg_overwrite_trap_args *args)
 490 {
 491         kern_return_t kr;
 492         args->rcv_msg = (mach_vm_address_t)0;
 493
 494         kr = mach_msg_overwrite_trap(args);
 495         return kr;
 496 }
 497
 498
 499 /*
 500  *      Routine:        msg_receive_error       [internal]
 501  *      Purpose:
 502  *              Builds a minimal header/trailer and copies it to
 503  *              the user message buffer.  Invoked when in the case of a
 504  *              MACH_RCV_TOO_LARGE or MACH_RCV_BODY_ERROR error.
 505  *      Conditions:
 506  *              Nothing locked.
 507  *      Returns:
 508  *              MACH_MSG_SUCCESS        minimal header/trailer copied
 509  *              MACH_RCV_INVALID_DATA   copyout to user buffer failed
 510  */
 511
 512 mach_msg_return_t
 513 msg_receive_error(
 514         ipc_kmsg_t              kmsg,
 515         mach_vm_address_t       msg_addr,
 516         mach_msg_option_t       option,
 517         mach_port_seqno_t       seqno,
 518         ipc_space_t             space)
 519 {
 520         mach_vm_address_t       context;
 521         mach_msg_trailer_size_t trailer_size;
 522         mach_msg_max_trailer_t  *trailer;
 523
 524         context = kmsg->ikm_header->msgh_remote_port->ip_context;
 525
 526         /*
 527          * Copy out the destination port in the message.
 528          * Destroy all other rights and memory in the message.
 529          */
 530         ipc_kmsg_copyout_dest(kmsg, space);
 531
 532         /*
 533          * Build a minimal message with the requested trailer.
 534          */
 535         trailer = (mach_msg_max_trailer_t *)
 536                         ((vm_offset_t)kmsg->ikm_header +
 537                         round_msg(sizeof(mach_msg_header_t)));
 538         kmsg->ikm_header->msgh_size = sizeof(mach_msg_header_t);
 539         bcopy(  (char *)&trailer_template,
 540                 (char *)trailer,
 541                 sizeof(trailer_template));
 542
 543         trailer_size = ipc_kmsg_add_trailer(kmsg, space,
 544                         option, current_thread(), seqno,
 545                         TRUE, context);
 546
 547         /*
 548          * Copy the message to user space
 549          */
 550         if (ipc_kmsg_put(msg_addr, kmsg, kmsg->ikm_header->msgh_size +
 551                         trailer_size) == MACH_RCV_INVALID_DATA)
 552                 return(MACH_RCV_INVALID_DATA);
 553         else
 554                 return(MACH_MSG_SUCCESS);
 555 }