bus/connection.c

   1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
   2 /* connection.c  Client connections
   3  *
   4  * Copyright (C) 2003  Red Hat, Inc.
   5  *
   6  * Licensed under the Academic Free License version 2.1
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  21  *
  22  */
  23
  24 #include <config.h>
  25 #include "connection.h"
  26 #include "dispatch.h"
  27 #include "policy.h"
  28 #include "services.h"
  29 #include "utils.h"
  30 #include "signals.h"
  31 #include "expirelist.h"
  32 #include "selinux.h"
  33 #include <dbus/dbus-list.h>
  34 #include <dbus/dbus-hash.h>
  35 #include <dbus/dbus-timeout.h>
  36
  37 /* Trim executed commands to this length; we want to keep logs readable */
  38 #define MAX_LOG_COMMAND_LEN 50
  39
  40 static void bus_connection_remove_transactions (DBusConnection *connection);
  41
  42 typedef struct
  43 {
  44   BusExpireItem expire_item;
  45
  46   DBusConnection *will_get_reply;
  47   DBusConnection *will_send_reply;
  48
  49   dbus_uint32_t reply_serial;
  50
  51 } BusPendingReply;
  52
  53 struct BusConnections
  54 {
  55   int refcount;
  56   DBusList *completed;  /**< List of all completed connections */
  57   int n_completed;      /**< Length of completed list */
  58   DBusList *incomplete; /**< List of all not-yet-active connections */
  59   int n_incomplete;     /**< Length of incomplete list */
  60   BusContext *context;
  61   DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */
  62   DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */
  63   int stamp;                   /**< Incrementing number */
  64   BusExpireList *pending_replies; /**< List of pending replies */
  65 };
  66
  67 static dbus_int32_t connection_data_slot = -1;
  68
  69 typedef struct
  70 {
  71   BusConnections *connections;
  72   DBusList *link_in_connection_list;
  73   DBusConnection *connection;
  74   DBusList *services_owned;
  75   int n_services_owned;
  76   DBusList *match_rules;
  77   int n_match_rules;
  78   char *name;
  79   DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
  80   DBusMessage *oom_message;
  81   DBusPreallocatedSend *oom_preallocated;
  82   BusClientPolicy *policy;
  83
  84   char *cached_loginfo_string;
  85   BusSELinuxID *selinux_id;
  86
  87   long connection_tv_sec;  /**< Time when we connected (seconds component) */
  88   long connection_tv_usec; /**< Time when we connected (microsec component) */
  89   int stamp;               /**< connections->stamp last time we were traversed */
  90 } BusConnectionData;
  91
  92 static dbus_bool_t bus_pending_reply_expired (BusExpireList *list,
  93                                               DBusList      *link,
  94                                               void          *data);
  95
  96 static void bus_connection_drop_pending_replies (BusConnections  *connections,
  97                                                  DBusConnection  *connection);
  98
  99 static dbus_bool_t expire_incomplete_timeout (void *data);
 100
 101 #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
 102
 103 static DBusLoop*
 104 connection_get_loop (DBusConnection *connection)
 105 {
 106   BusConnectionData *d;
 107
 108   d = BUS_CONNECTION_DATA (connection);
 109
 110   return bus_context_get_loop (d->connections->context);
 111 }
 112
 113
 114 static int
 115 get_connections_for_uid (BusConnections *connections,
 116                          dbus_uid_t      uid)
 117 {
 118   void *val;
 119   int current_count;
 120
 121   /* val is NULL is 0 when it isn't in the hash yet */
 122
 123   val = _dbus_hash_table_lookup_ulong (connections->completed_by_user,
 124                                        uid);
 125
 126   current_count = _DBUS_POINTER_TO_INT (val);
 127
 128   return current_count;
 129 }
 130
 131 static dbus_bool_t
 132 adjust_connections_for_uid (BusConnections *connections,
 133                             dbus_uid_t      uid,
 134                             int             adjustment)
 135 {
 136   int current_count;
 137
 138   current_count = get_connections_for_uid (connections, uid);
 139
 140   _dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT
 141                  ": was %d adjustment %d making %d\n",
 142                  uid, current_count, adjustment, current_count + adjustment);
 143
 144   _dbus_assert (current_count >= 0);
 145
 146   current_count += adjustment;
 147
 148   _dbus_assert (current_count >= 0);
 149
 150   if (current_count == 0)
 151     {
 152       _dbus_hash_table_remove_ulong (connections->completed_by_user, uid);
 153       return TRUE;
 154     }
 155   else
 156     {
 157       dbus_bool_t retval;
 158
 159       retval = _dbus_hash_table_insert_ulong (connections->completed_by_user,
 160                                               uid, _DBUS_INT_TO_POINTER (current_count));
 161
 162       /* only positive adjustment can fail as otherwise
 163        * a hash entry should already exist
 164        */
 165       _dbus_assert (adjustment > 0 ||
 166                     (adjustment <= 0 && retval));
 167
 168       return retval;
 169     }
 170 }
 171
 172 void
 173 bus_connection_disconnected (DBusConnection *connection)
 174 {
 175   BusConnectionData *d;
 176   BusService *service;
 177   BusMatchmaker *matchmaker;
 178
 179   d = BUS_CONNECTION_DATA (connection);
 180   _dbus_assert (d != NULL);
 181
 182   _dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n",
 183                  d->name ? d->name : "(inactive)");
 184
 185   /* Delete our match rules */
 186   if (d->n_match_rules > 0)
 187     {
 188       matchmaker = bus_context_get_matchmaker (d->connections->context);
 189       bus_matchmaker_disconnected (matchmaker, connection);
 190     }
 191
 192   /* Drop any service ownership. Unfortunately, this requires
 193    * memory allocation and there doesn't seem to be a good way to
 194    * handle it other than sleeping; we can't "fail" the operation of
 195    * disconnecting a client, and preallocating a broadcast "service is
 196    * now gone" message for every client-service pair seems kind of
 197    * involved.
 198    */
 199   while ((service = _dbus_list_get_last (&d->services_owned)))
 200     {
 201       BusTransaction *transaction;
 202       DBusError error;
 203
 204     retry:
 205
 206       dbus_error_init (&error);
 207
 208       while ((transaction = bus_transaction_new (d->connections->context)) == NULL)
 209         _dbus_wait_for_memory ();
 210
 211       if (!bus_service_remove_owner (service, connection,
 212                                      transaction, &error))
 213         {
 214           _DBUS_ASSERT_ERROR_IS_SET (&error);
 215
 216           if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
 217             {
 218               dbus_error_free (&error);
 219               bus_transaction_cancel_and_free (transaction);
 220               _dbus_wait_for_memory ();
 221               goto retry;
 222             }
 223           else
 224             {
 225               _dbus_verbose ("Failed to remove service owner: %s %s\n",
 226                              error.name, error.message);
 227               _dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason");
 228             }
 229         }
 230
 231       bus_transaction_execute_and_free (transaction);
 232     }
 233
 234   bus_dispatch_remove_connection (connection);
 235
 236   /* no more watching */
 237   if (!dbus_connection_set_watch_functions (connection,
 238                                             NULL, NULL, NULL,
 239                                             connection,
 240                                             NULL))
 241     _dbus_assert_not_reached ("setting watch functions to NULL failed");
 242
 243   if (!dbus_connection_set_timeout_functions (connection,
 244                                               NULL, NULL, NULL,
 245                                               connection,
 246                                               NULL))
 247     _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 248
 249   dbus_connection_set_unix_user_function (connection,
 250                                           NULL, NULL, NULL);
 251   dbus_connection_set_windows_user_function (connection,
 252                                              NULL, NULL, NULL);
 253
 254   dbus_connection_set_dispatch_status_function (connection,
 255                                                 NULL, NULL, NULL);
 256
 257   bus_connection_remove_transactions (connection);
 258
 259   if (d->link_in_connection_list != NULL)
 260     {
 261       if (d->name != NULL)
 262         {
 263           unsigned long uid;
 264
 265           _dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list);
 266           d->link_in_connection_list = NULL;
 267           d->connections->n_completed -= 1;
 268
 269           if (dbus_connection_get_unix_user (connection, &uid))
 270             {
 271               if (!adjust_connections_for_uid (d->connections,
 272                                                uid, -1))
 273                 _dbus_assert_not_reached ("adjusting downward should never fail");
 274             }
 275         }
 276       else
 277         {
 278           _dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list);
 279           d->link_in_connection_list = NULL;
 280           d->connections->n_incomplete -= 1;
 281         }
 282
 283       _dbus_assert (d->connections->n_incomplete >= 0);
 284       _dbus_assert (d->connections->n_completed >= 0);
 285     }
 286
 287   bus_connection_drop_pending_replies (d->connections, connection);
 288
 289   /* frees "d" as side effect */
 290   dbus_connection_set_data (connection,
 291                             connection_data_slot,
 292                             NULL, NULL);
 293
 294   dbus_connection_unref (connection);
 295 }
 296
 297 static dbus_bool_t
 298 connection_watch_callback (DBusWatch     *watch,
 299                            unsigned int   condition,
 300                            void          *data)
 301 {
 302  /* FIXME this can be done in dbus-mainloop.c
 303   * if the code in activation.c for the babysitter
 304   * watch handler is fixed.
 305   */
 306
 307 #if 0
 308   _dbus_verbose ("Calling handle_watch\n");
 309 #endif
 310   return dbus_watch_handle (watch, condition);
 311 }
 312
 313 static dbus_bool_t
 314 add_connection_watch (DBusWatch      *watch,
 315                       void           *data)
 316 {
 317   DBusConnection *connection = data;
 318
 319   return _dbus_loop_add_watch (connection_get_loop (connection),
 320                                watch, connection_watch_callback, connection,
 321                                NULL);
 322 }
 323
 324 static void
 325 remove_connection_watch (DBusWatch      *watch,
 326                          void           *data)
 327 {
 328   DBusConnection *connection = data;
 329
 330   _dbus_loop_remove_watch (connection_get_loop (connection),
 331                            watch, connection_watch_callback, connection);
 332 }
 333
 334 static void
 335 connection_timeout_callback (DBusTimeout   *timeout,
 336                              void          *data)
 337 {
 338   /* DBusConnection *connection = data; */
 339
 340   /* can return FALSE on OOM but we just let it fire again later */
 341   dbus_timeout_handle (timeout);
 342 }
 343
 344 static dbus_bool_t
 345 add_connection_timeout (DBusTimeout    *timeout,
 346                         void           *data)
 347 {
 348   DBusConnection *connection = data;
 349
 350   return _dbus_loop_add_timeout (connection_get_loop (connection),
 351                                  timeout, connection_timeout_callback, connection, NULL);
 352 }
 353
 354 static void
 355 remove_connection_timeout (DBusTimeout    *timeout,
 356                            void           *data)
 357 {
 358   DBusConnection *connection = data;
 359
 360   _dbus_loop_remove_timeout (connection_get_loop (connection),
 361                              timeout, connection_timeout_callback, connection);
 362 }
 363
 364 static void
 365 dispatch_status_function (DBusConnection    *connection,
 366                           DBusDispatchStatus new_status,
 367                           void              *data)
 368 {
 369   DBusLoop *loop = data;
 370
 371   if (new_status != DBUS_DISPATCH_COMPLETE)
 372     {
 373       while (!_dbus_loop_queue_dispatch (loop, connection))
 374         _dbus_wait_for_memory ();
 375     }
 376 }
 377
 378 static dbus_bool_t
 379 allow_unix_user_function (DBusConnection *connection,
 380                           unsigned long   uid,
 381                           void           *data)
 382 {
 383   BusConnectionData *d;
 384
 385   d = BUS_CONNECTION_DATA (connection);
 386
 387   _dbus_assert (d != NULL);
 388
 389   return bus_context_allow_unix_user (d->connections->context, uid);
 390 }
 391
 392 static void
 393 free_connection_data (void *data)
 394 {
 395   BusConnectionData *d = data;
 396
 397   /* services_owned should be NULL since we should be disconnected */
 398   _dbus_assert (d->services_owned == NULL);
 399   _dbus_assert (d->n_services_owned == 0);
 400   /* similarly */
 401   _dbus_assert (d->transaction_messages == NULL);
 402
 403   if (d->oom_preallocated)
 404     dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated);
 405
 406   if (d->oom_message)
 407     dbus_message_unref (d->oom_message);
 408
 409   if (d->policy)
 410     bus_client_policy_unref (d->policy);
 411
 412   if (d->selinux_id)
 413     bus_selinux_id_unref (d->selinux_id);
 414
 415   dbus_free (d->cached_loginfo_string);
 416
 417   dbus_free (d->name);
 418
 419   dbus_free (d);
 420 }
 421
 422 static void
 423 call_timeout_callback (DBusTimeout   *timeout,
 424                        void          *data)
 425 {
 426   /* can return FALSE on OOM but we just let it fire again later */
 427   dbus_timeout_handle (timeout);
 428 }
 429
 430 BusConnections*
 431 bus_connections_new (BusContext *context)
 432 {
 433   BusConnections *connections;
 434
 435   if (!dbus_connection_allocate_data_slot (&connection_data_slot))
 436     goto failed_0;
 437
 438   connections = dbus_new0 (BusConnections, 1);
 439   if (connections == NULL)
 440     goto failed_1;
 441
 442   connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_ULONG,
 443                                                          NULL, NULL);
 444   if (connections->completed_by_user == NULL)
 445     goto failed_2;
 446
 447   connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */
 448                                                    expire_incomplete_timeout,
 449                                                    connections, NULL);
 450   if (connections->expire_timeout == NULL)
 451     goto failed_3;
 452
 453   _dbus_timeout_set_enabled (connections->expire_timeout, FALSE);
 454
 455   connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context),
 456                                                       bus_context_get_reply_timeout (context),
 457                                                       bus_pending_reply_expired,
 458                                                       connections);
 459   if (connections->pending_replies == NULL)
 460     goto failed_4;
 461
 462   if (!_dbus_loop_add_timeout (bus_context_get_loop (context),
 463                                connections->expire_timeout,
 464                                call_timeout_callback, NULL, NULL))
 465     goto failed_5;
 466
 467   connections->refcount = 1;
 468   connections->context = context;
 469
 470   return connections;
 471
 472  failed_5:
 473   bus_expire_list_free (connections->pending_replies);
 474  failed_4:
 475   _dbus_timeout_unref (connections->expire_timeout);
 476  failed_3:
 477   _dbus_hash_table_unref (connections->completed_by_user);
 478  failed_2:
 479   dbus_free (connections);
 480  failed_1:
 481   dbus_connection_free_data_slot (&connection_data_slot);
 482  failed_0:
 483   return NULL;
 484 }
 485
 486 BusConnections *
 487 bus_connections_ref (BusConnections *connections)
 488 {
 489   _dbus_assert (connections->refcount > 0);
 490   connections->refcount += 1;
 491
 492   return connections;
 493 }
 494
 495 void
 496 bus_connections_unref (BusConnections *connections)
 497 {
 498   _dbus_assert (connections->refcount > 0);
 499   connections->refcount -= 1;
 500   if (connections->refcount == 0)
 501     {
 502       /* drop all incomplete */
 503       while (connections->incomplete != NULL)
 504         {
 505           DBusConnection *connection;
 506
 507           connection = connections->incomplete->data;
 508
 509           dbus_connection_ref (connection);
 510           dbus_connection_close (connection);
 511           bus_connection_disconnected (connection);
 512           dbus_connection_unref (connection);
 513         }
 514
 515       _dbus_assert (connections->n_incomplete == 0);
 516
 517       /* drop all real connections */
 518       while (connections->completed != NULL)
 519         {
 520           DBusConnection *connection;
 521
 522           connection = connections->completed->data;
 523
 524           dbus_connection_ref (connection);
 525           dbus_connection_close (connection);
 526           bus_connection_disconnected (connection);
 527           dbus_connection_unref (connection);
 528         }
 529
 530       _dbus_assert (connections->n_completed == 0);
 531
 532       bus_expire_list_free (connections->pending_replies);
 533
 534       _dbus_loop_remove_timeout (bus_context_get_loop (connections->context),
 535                                  connections->expire_timeout,
 536                                  call_timeout_callback, NULL);
 537
 538       _dbus_timeout_unref (connections->expire_timeout);
 539
 540       _dbus_hash_table_unref (connections->completed_by_user);
 541
 542       dbus_free (connections);
 543
 544       dbus_connection_free_data_slot (&connection_data_slot);
 545     }
 546 }
 547
 548 /* Used for logging */
 549 static dbus_bool_t
 550 cache_peer_loginfo_string (BusConnectionData *d,
 551                            DBusConnection    *connection)
 552 {
 553   DBusString loginfo_buf;
 554   unsigned long uid;
 555   unsigned long pid;
 556   char *windows_sid;
 557   dbus_bool_t prev_added;
 558
 559   if (!_dbus_string_init (&loginfo_buf))
 560     return FALSE;
 561
 562   prev_added = FALSE;
 563   if (dbus_connection_get_unix_user (connection, &uid))
 564     {
 565       if (!_dbus_string_append_printf (&loginfo_buf, "uid=%ld", uid))
 566         goto oom;
 567       else
 568         prev_added = TRUE;
 569     }
 570
 571   if (dbus_connection_get_unix_process_id (connection, &pid))
 572     {
 573       if (prev_added)
 574         {
 575           if (!_dbus_string_append_byte (&loginfo_buf, ' '))
 576             goto oom;
 577         }
 578       if (!_dbus_string_append_printf (&loginfo_buf, "pid=%ld comm=\"", pid))
 579         goto oom;
 580       /* Ignore errors here; we may not have permissions to read the
 581        * proc file. */
 582       _dbus_command_for_pid (pid, &loginfo_buf, MAX_LOG_COMMAND_LEN, NULL);
 583       if (!_dbus_string_append_byte (&loginfo_buf, '"'))
 584         goto oom;
 585     }
 586
 587   if (dbus_connection_get_windows_user (connection, &windows_sid))
 588     {
 589       if (!_dbus_string_append_printf (&loginfo_buf, "sid=\"%s\" ", windows_sid))
 590         goto oom;
 591       dbus_free (windows_sid);
 592     }
 593
 594   if (!_dbus_string_steal_data (&loginfo_buf, &(d->cached_loginfo_string)))
 595     goto oom;
 596
 597   _dbus_string_free (&loginfo_buf);
 598
 599   return TRUE;
 600 oom:
 601    _dbus_string_free (&loginfo_buf);
 602    return FALSE;
 603 }
 604
 605 dbus_bool_t
 606 bus_connections_setup_connection (BusConnections *connections,
 607                                   DBusConnection *connection)
 608 {
 609
 610   BusConnectionData *d;
 611   dbus_bool_t retval;
 612   DBusError error;
 613
 614
 615   d = dbus_new0 (BusConnectionData, 1);
 616
 617   if (d == NULL)
 618     return FALSE;
 619
 620   d->connections = connections;
 621   d->connection = connection;
 622
 623   _dbus_get_current_time (&d->connection_tv_sec,
 624                           &d->connection_tv_usec);
 625
 626   _dbus_assert (connection_data_slot >= 0);
 627
 628   if (!dbus_connection_set_data (connection,
 629                                  connection_data_slot,
 630                                  d, free_connection_data))
 631     {
 632       dbus_free (d);
 633       return FALSE;
 634     }
 635
 636   dbus_connection_set_route_peer_messages (connection, TRUE);
 637
 638   retval = FALSE;
 639
 640   dbus_error_init (&error);
 641   d->selinux_id = bus_selinux_init_connection_id (connection,
 642                                                   &error);
 643   if (dbus_error_is_set (&error))
 644     {
 645       /* This is a bit bogus because we pretend all errors
 646        * are OOM; this is done because we know that in bus.c
 647        * an OOM error disconnects the connection, which is
 648        * the same thing we want on any other error.
 649        */
 650       dbus_error_free (&error);
 651       goto out;
 652     }
 653
 654   if (!dbus_connection_set_watch_functions (connection,
 655                                             add_connection_watch,
 656                                             remove_connection_watch,
 657                                             NULL,
 658                                             connection,
 659                                             NULL))
 660     goto out;
 661
 662   if (!dbus_connection_set_timeout_functions (connection,
 663                                               add_connection_timeout,
 664                                               remove_connection_timeout,
 665                                               NULL,
 666                                               connection, NULL))
 667     goto out;
 668
 669   /* For now we don't need to set a Windows user function because
 670    * there are no policies in the config file controlling what
 671    * Windows users can connect. The default 'same user that owns the
 672    * bus can connect' behavior of DBusConnection is fine on Windows.
 673    */
 674   dbus_connection_set_unix_user_function (connection,
 675                                           allow_unix_user_function,
 676                                           NULL, NULL);
 677
 678   dbus_connection_set_dispatch_status_function (connection,
 679                                                 dispatch_status_function,
 680                                                 bus_context_get_loop (connections->context),
 681                                                 NULL);
 682
 683   d->link_in_connection_list = _dbus_list_alloc_link (connection);
 684   if (d->link_in_connection_list == NULL)
 685     goto out;
 686
 687   /* Setup the connection with the dispatcher */
 688   if (!bus_dispatch_add_connection (connection))
 689     goto out;
 690
 691   if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE)
 692     {
 693       if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection))
 694         {
 695           bus_dispatch_remove_connection (connection);
 696           goto out;
 697         }
 698     }
 699
 700   _dbus_list_append_link (&connections->incomplete, d->link_in_connection_list);
 701   connections->n_incomplete += 1;
 702
 703   dbus_connection_ref (connection);
 704
 705   /* Note that we might disconnect ourselves here, but it only takes
 706    * effect on return to the main loop. We call this to free up
 707    * expired connections if possible, and to queue the timeout for our
 708    * own expiration.
 709    */
 710   bus_connections_expire_incomplete (connections);
 711
 712   /* And we might also disconnect ourselves here, but again it
 713    * only takes effect on return to main loop.
 714    */
 715   if (connections->n_incomplete >
 716       bus_context_get_max_incomplete_connections (connections->context))
 717     {
 718       _dbus_verbose ("Number of incomplete connections exceeds max, dropping oldest one\n");
 719
 720       _dbus_assert (connections->incomplete != NULL);
 721       /* Disconnect the oldest unauthenticated connection.  FIXME
 722        * would it be more secure to drop a *random* connection?  This
 723        * algorithm seems to mean that if someone can create new
 724        * connections quickly enough, they can keep anyone else from
 725        * completing authentication. But random may or may not really
 726        * help with that, a more elaborate solution might be required.
 727        */
 728       dbus_connection_close (connections->incomplete->data);
 729     }
 730
 731   retval = TRUE;
 732
 733  out:
 734   if (!retval)
 735     {
 736       if (d->selinux_id)
 737         bus_selinux_id_unref (d->selinux_id);
 738       d->selinux_id = NULL;
 739
 740       if (!dbus_connection_set_watch_functions (connection,
 741                                                 NULL, NULL, NULL,
 742                                                 connection,
 743                                                 NULL))
 744         _dbus_assert_not_reached ("setting watch functions to NULL failed");
 745
 746       if (!dbus_connection_set_timeout_functions (connection,
 747                                                   NULL, NULL, NULL,
 748                                                   connection,
 749                                                   NULL))
 750         _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 751
 752       dbus_connection_set_unix_user_function (connection,
 753                                               NULL, NULL, NULL);
 754
 755       dbus_connection_set_windows_user_function (connection,
 756                                                  NULL, NULL, NULL);
 757
 758       dbus_connection_set_dispatch_status_function (connection,
 759                                                     NULL, NULL, NULL);
 760
 761       if (d->link_in_connection_list != NULL)
 762         {
 763           _dbus_assert (d->link_in_connection_list->next == NULL);
 764           _dbus_assert (d->link_in_connection_list->prev == NULL);
 765           _dbus_list_free_link (d->link_in_connection_list);
 766           d->link_in_connection_list = NULL;
 767         }
 768
 769       if (!dbus_connection_set_data (connection,
 770                                      connection_data_slot,
 771                                      NULL, NULL))
 772         _dbus_assert_not_reached ("failed to set connection data to null");
 773
 774       /* "d" has now been freed */
 775     }
 776
 777   return retval;
 778 }
 779
 780 void
 781 bus_connections_expire_incomplete (BusConnections *connections)
 782 {
 783   int next_interval;
 784
 785   next_interval = -1;
 786
 787   if (connections->incomplete != NULL)
 788     {
 789       long tv_sec, tv_usec;
 790       DBusList *link;
 791       int auth_timeout;
 792
 793       _dbus_get_current_time (&tv_sec, &tv_usec);
 794       auth_timeout = bus_context_get_auth_timeout (connections->context);
 795
 796       link = _dbus_list_get_first_link (&connections->incomplete);
 797       while (link != NULL)
 798         {
 799           DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 800           DBusConnection *connection;
 801           BusConnectionData *d;
 802           double elapsed;
 803
 804           connection = link->data;
 805
 806           d = BUS_CONNECTION_DATA (connection);
 807
 808           _dbus_assert (d != NULL);
 809
 810           elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec,
 811                                                 d->connection_tv_usec,
 812                                                 tv_sec, tv_usec);
 813
 814           if (elapsed >= (double) auth_timeout)
 815             {
 816               _dbus_verbose ("Timing out authentication for connection %p\n", connection);
 817               dbus_connection_close (connection);
 818             }
 819           else
 820             {
 821               /* We can end the loop, since the connections are in oldest-first order */
 822               next_interval = ((double)auth_timeout) - elapsed;
 823               _dbus_verbose ("Connection %p authentication expires in %d milliseconds\n",
 824                              connection, next_interval);
 825
 826               break;
 827             }
 828
 829           link = next;
 830         }
 831     }
 832
 833   bus_expire_timeout_set_interval (connections->expire_timeout,
 834                                    next_interval);
 835 }
 836
 837 static dbus_bool_t
 838 expire_incomplete_timeout (void *data)
 839 {
 840   BusConnections *connections = data;
 841
 842   _dbus_verbose ("Running %s\n", _DBUS_FUNCTION_NAME);
 843
 844   /* note that this may remove the timeout */
 845   bus_connections_expire_incomplete (connections);
 846
 847   return TRUE;
 848 }
 849
 850 dbus_bool_t
 851 bus_connection_get_unix_groups  (DBusConnection   *connection,
 852                                  unsigned long   **groups,
 853                                  int              *n_groups,
 854                                  DBusError        *error)
 855 {
 856   BusConnectionData *d;
 857   unsigned long uid;
 858
 859   d = BUS_CONNECTION_DATA (connection);
 860
 861   _dbus_assert (d != NULL);
 862
 863   *groups = NULL;
 864   *n_groups = 0;
 865
 866   if (dbus_connection_get_unix_user (connection, &uid))
 867     {
 868       if (!_dbus_unix_groups_from_uid (uid, groups, n_groups))
 869         {
 870           _dbus_verbose ("Did not get any groups for UID %lu\n",
 871                          uid);
 872           return FALSE;
 873         }
 874       else
 875         {
 876           _dbus_verbose ("Got %d groups for UID %lu\n",
 877                          *n_groups, uid);
 878           return TRUE;
 879         }
 880     }
 881   else
 882     return TRUE; /* successfully got 0 groups */
 883 }
 884
 885 dbus_bool_t
 886 bus_connection_is_in_unix_group (DBusConnection *connection,
 887                                  unsigned long   gid)
 888 {
 889   int i;
 890   unsigned long *group_ids;
 891   int n_group_ids;
 892
 893   if (!bus_connection_get_unix_groups (connection, &group_ids, &n_group_ids,
 894                                        NULL))
 895     return FALSE;
 896
 897   i = 0;
 898   while (i < n_group_ids)
 899     {
 900       if (group_ids[i] == gid)
 901         {
 902           dbus_free (group_ids);
 903           return TRUE;
 904         }
 905       ++i;
 906     }
 907
 908   dbus_free (group_ids);
 909   return FALSE;
 910 }
 911
 912 const char *
 913 bus_connection_get_loginfo (DBusConnection        *connection)
 914 {
 915   BusConnectionData *d;
 916
 917   d = BUS_CONNECTION_DATA (connection);
 918
 919   if (!bus_connection_is_active (connection))
 920     return "inactive";
 921   return d->cached_loginfo_string;
 922 }
 923
 924 BusClientPolicy*
 925 bus_connection_get_policy (DBusConnection *connection)
 926 {
 927   BusConnectionData *d;
 928
 929   d = BUS_CONNECTION_DATA (connection);
 930
 931   _dbus_assert (d != NULL);
 932   _dbus_assert (d->policy != NULL);
 933
 934   return d->policy;
 935 }
 936
 937 static dbus_bool_t
 938 foreach_active (BusConnections               *connections,
 939                 BusConnectionForeachFunction  function,
 940                 void                         *data)
 941 {
 942   DBusList *link;
 943
 944   link = _dbus_list_get_first_link (&connections->completed);
 945   while (link != NULL)
 946     {
 947       DBusConnection *connection = link->data;
 948       DBusList *next = _dbus_list_get_next_link (&connections->completed, link);
 949
 950       if (!(* function) (connection, data))
 951         return FALSE;
 952
 953       link = next;
 954     }
 955
 956   return TRUE;
 957 }
 958
 959 static dbus_bool_t
 960 foreach_inactive (BusConnections               *connections,
 961                   BusConnectionForeachFunction  function,
 962                   void                         *data)
 963 {
 964   DBusList *link;
 965
 966   link = _dbus_list_get_first_link (&connections->incomplete);
 967   while (link != NULL)
 968     {
 969       DBusConnection *connection = link->data;
 970       DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 971
 972       if (!(* function) (connection, data))
 973         return FALSE;
 974
 975       link = next;
 976     }
 977
 978   return TRUE;
 979 }
 980
 981 /**
 982  * Calls function on each active connection; if the function returns
 983  * #FALSE, stops iterating. Active connections are authenticated
 984  * and have sent a Hello message.
 985  *
 986  * @param connections the connections object
 987  * @param function the function
 988  * @param data data to pass to it as a second arg
 989  */
 990 void
 991 bus_connections_foreach_active (BusConnections               *connections,
 992                                 BusConnectionForeachFunction  function,
 993                                 void                         *data)
 994 {
 995   foreach_active (connections, function, data);
 996 }
 997
 998 /**
 999  * Calls function on each connection; if the function returns
1000  * #FALSE, stops iterating.
1001  *
1002  * @param connections the connections object
1003  * @param function the function
1004  * @param data data to pass to it as a second arg
1005  */
1006 void
1007 bus_connections_foreach (BusConnections               *connections,
1008                          BusConnectionForeachFunction  function,
1009                          void                         *data)
1010 {
1011   if (!foreach_active (connections, function, data))
1012     return;
1013
1014   foreach_inactive (connections, function, data);
1015 }
1016
1017 BusContext*
1018 bus_connections_get_context (BusConnections *connections)
1019 {
1020   return connections->context;
1021 }
1022
1023 /*
1024  * This is used to avoid covering the same connection twice when
1025  * traversing connections. Note that it assumes we will
1026  * bus_connection_mark_stamp() each connection at least once per
1027  * INT_MAX increments of the global stamp, or wraparound would break
1028  * things.
1029  */
1030 void
1031 bus_connections_increment_stamp (BusConnections *connections)
1032 {
1033   connections->stamp += 1;
1034 }
1035
1036 /* Mark connection with current stamp, return TRUE if it
1037  * didn't already have that stamp
1038  */
1039 dbus_bool_t
1040 bus_connection_mark_stamp (DBusConnection *connection)
1041 {
1042   BusConnectionData *d;
1043
1044   d = BUS_CONNECTION_DATA (connection);
1045
1046   _dbus_assert (d != NULL);
1047
1048   if (d->stamp == d->connections->stamp)
1049     return FALSE;
1050   else
1051     {
1052       d->stamp = d->connections->stamp;
1053       return TRUE;
1054     }
1055 }
1056
1057 BusContext*
1058 bus_connection_get_context (DBusConnection *connection)
1059 {
1060   BusConnectionData *d;
1061
1062   d = BUS_CONNECTION_DATA (connection);
1063
1064   _dbus_assert (d != NULL);
1065
1066   return d->connections->context;
1067 }
1068
1069 BusConnections*
1070 bus_connection_get_connections (DBusConnection *connection)
1071 {
1072   BusConnectionData *d;
1073
1074   d = BUS_CONNECTION_DATA (connection);
1075
1076   _dbus_assert (d != NULL);
1077
1078   return d->connections;
1079 }
1080
1081 BusRegistry*
1082 bus_connection_get_registry (DBusConnection *connection)
1083 {
1084   BusConnectionData *d;
1085
1086   d = BUS_CONNECTION_DATA (connection);
1087
1088   _dbus_assert (d != NULL);
1089
1090   return bus_context_get_registry (d->connections->context);
1091 }
1092
1093 BusActivation*
1094 bus_connection_get_activation (DBusConnection *connection)
1095 {
1096   BusConnectionData *d;
1097
1098   d = BUS_CONNECTION_DATA (connection);
1099
1100   _dbus_assert (d != NULL);
1101
1102   return bus_context_get_activation (d->connections->context);
1103 }
1104
1105 BusMatchmaker*
1106 bus_connection_get_matchmaker (DBusConnection *connection)
1107 {
1108   BusConnectionData *d;
1109
1110   d = BUS_CONNECTION_DATA (connection);
1111
1112   _dbus_assert (d != NULL);
1113
1114   return bus_context_get_matchmaker (d->connections->context);
1115 }
1116
1117 BusSELinuxID*
1118 bus_connection_get_selinux_id (DBusConnection *connection)
1119 {
1120   BusConnectionData *d;
1121
1122   d = BUS_CONNECTION_DATA (connection);
1123
1124   _dbus_assert (d != NULL);
1125
1126   return d->selinux_id;
1127 }
1128
1129 /**
1130  * Checks whether the connection is registered with the message bus.
1131  *
1132  * @param connection the connection
1133  * @returns #TRUE if we're an active message bus participant
1134  */
1135 dbus_bool_t
1136 bus_connection_is_active (DBusConnection *connection)
1137 {
1138   BusConnectionData *d;
1139
1140   d = BUS_CONNECTION_DATA (connection);
1141
1142   return d != NULL && d->name != NULL;
1143 }
1144
1145 dbus_bool_t
1146 bus_connection_preallocate_oom_error (DBusConnection *connection)
1147 {
1148   DBusMessage *message;
1149   DBusPreallocatedSend *preallocated;
1150   BusConnectionData *d;
1151
1152   d = BUS_CONNECTION_DATA (connection);
1153
1154   _dbus_assert (d != NULL);
1155
1156   if (d->oom_preallocated != NULL)
1157     return TRUE;
1158
1159   preallocated = dbus_connection_preallocate_send (connection);
1160   if (preallocated == NULL)
1161     return FALSE;
1162
1163   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1164
1165   if (message == NULL)
1166     {
1167       dbus_connection_free_preallocated_send (connection, preallocated);
1168       return FALSE;
1169     }
1170
1171   /* d->name may be NULL, but that is OK */
1172   if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) ||
1173       !dbus_message_set_destination (message, d->name) ||
1174       !dbus_message_set_sender (message,
1175                                 DBUS_SERVICE_DBUS))
1176     {
1177       dbus_connection_free_preallocated_send (connection, preallocated);
1178       dbus_message_unref (message);
1179       return FALSE;
1180     }
1181
1182   /* set reply serial to placeholder value just so space is already allocated
1183    * for it.
1184    */
1185   if (!dbus_message_set_reply_serial (message, 14))
1186     {
1187       dbus_connection_free_preallocated_send (connection, preallocated);
1188       dbus_message_unref (message);
1189       return FALSE;
1190     }
1191
1192   d->oom_message = message;
1193   d->oom_preallocated = preallocated;
1194
1195   return TRUE;
1196 }
1197
1198 void
1199 bus_connection_send_oom_error (DBusConnection *connection,
1200                                DBusMessage    *in_reply_to)
1201 {
1202   BusConnectionData *d;
1203
1204   d = BUS_CONNECTION_DATA (connection);
1205
1206   _dbus_assert (d != NULL);
1207   _dbus_assert (d->oom_message != NULL);
1208
1209   /* should always succeed since we set it to a placeholder earlier */
1210   if (!dbus_message_set_reply_serial (d->oom_message,
1211                                       dbus_message_get_serial (in_reply_to)))
1212     _dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message");
1213
1214   _dbus_assert (dbus_message_get_sender (d->oom_message) != NULL);
1215
1216   dbus_connection_send_preallocated (connection, d->oom_preallocated,
1217                                      d->oom_message, NULL);
1218
1219   dbus_message_unref (d->oom_message);
1220   d->oom_message = NULL;
1221   d->oom_preallocated = NULL;
1222 }
1223
1224 void
1225 bus_connection_add_match_rule_link (DBusConnection *connection,
1226                                     DBusList       *link)
1227 {
1228   BusConnectionData *d;
1229
1230   d = BUS_CONNECTION_DATA (connection);
1231   _dbus_assert (d != NULL);
1232
1233   _dbus_list_append_link (&d->match_rules, link);
1234
1235   d->n_match_rules += 1;
1236 }
1237
1238 dbus_bool_t
1239 bus_connection_add_match_rule (DBusConnection *connection,
1240                                BusMatchRule   *rule)
1241 {
1242     DBusList *link;
1243
1244   link = _dbus_list_alloc_link (rule);
1245
1246   if (link == NULL)
1247     return FALSE;
1248
1249   bus_connection_add_match_rule_link (connection, link);
1250
1251   return TRUE;
1252 }
1253
1254 void
1255 bus_connection_remove_match_rule (DBusConnection *connection,
1256                                   BusMatchRule   *rule)
1257 {
1258   BusConnectionData *d;
1259
1260   d = BUS_CONNECTION_DATA (connection);
1261   _dbus_assert (d != NULL);
1262
1263   _dbus_list_remove_last (&d->match_rules, rule);
1264
1265   d->n_match_rules -= 1;
1266   _dbus_assert (d->n_match_rules >= 0);
1267 }
1268
1269 int
1270 bus_connection_get_n_match_rules (DBusConnection *connection)
1271 {
1272   BusConnectionData *d;
1273
1274   d = BUS_CONNECTION_DATA (connection);
1275   _dbus_assert (d != NULL);
1276
1277   return d->n_match_rules;
1278 }
1279
1280 void
1281 bus_connection_add_owned_service_link (DBusConnection *connection,
1282                                        DBusList       *link)
1283 {
1284   BusConnectionData *d;
1285
1286   d = BUS_CONNECTION_DATA (connection);
1287   _dbus_assert (d != NULL);
1288
1289   _dbus_list_append_link (&d->services_owned, link);
1290
1291   d->n_services_owned += 1;
1292 }
1293
1294 dbus_bool_t
1295 bus_connection_add_owned_service (DBusConnection *connection,
1296                                   BusService     *service)
1297 {
1298   DBusList *link;
1299
1300   link = _dbus_list_alloc_link (service);
1301
1302   if (link == NULL)
1303     return FALSE;
1304
1305   bus_connection_add_owned_service_link (connection, link);
1306
1307   return TRUE;
1308 }
1309
1310 void
1311 bus_connection_remove_owned_service (DBusConnection *connection,
1312                                      BusService     *service)
1313 {
1314   BusConnectionData *d;
1315
1316   d = BUS_CONNECTION_DATA (connection);
1317   _dbus_assert (d != NULL);
1318
1319   _dbus_list_remove_last (&d->services_owned, service);
1320
1321   d->n_services_owned -= 1;
1322   _dbus_assert (d->n_services_owned >= 0);
1323 }
1324
1325 int
1326 bus_connection_get_n_services_owned (DBusConnection *connection)
1327 {
1328   BusConnectionData *d;
1329
1330   d = BUS_CONNECTION_DATA (connection);
1331   _dbus_assert (d != NULL);
1332
1333   return d->n_services_owned;
1334 }
1335
1336 dbus_bool_t
1337 bus_connection_complete (DBusConnection   *connection,
1338                          const DBusString *name,
1339                          DBusError        *error)
1340 {
1341   BusConnectionData *d;
1342   unsigned long uid;
1343
1344   d = BUS_CONNECTION_DATA (connection);
1345   _dbus_assert (d != NULL);
1346   _dbus_assert (d->name == NULL);
1347   _dbus_assert (d->policy == NULL);
1348
1349   _dbus_assert (!bus_connection_is_active (connection));
1350
1351   if (!_dbus_string_copy_data (name, &d->name))
1352     {
1353       BUS_SET_OOM (error);
1354       return FALSE;
1355     }
1356
1357   _dbus_assert (d->name != NULL);
1358
1359   _dbus_verbose ("Name %s assigned to %p\n", d->name, connection);
1360
1361   d->policy = bus_context_create_client_policy (d->connections->context,
1362                                                 connection,
1363                                                 error);
1364
1365   /* we may have a NULL policy on OOM or error getting list of
1366    * groups for a user. In the latter case we don't handle it so
1367    * well currently, as it will just keep failing over and over.
1368    */
1369
1370   if (d->policy == NULL)
1371     {
1372       _dbus_verbose ("Failed to create security policy for connection %p\n",
1373                      connection);
1374       _DBUS_ASSERT_ERROR_IS_SET (error);
1375       dbus_free (d->name);
1376       d->name = NULL;
1377       return FALSE;
1378     }
1379
1380   if (dbus_connection_get_unix_user (connection, &uid))
1381     {
1382       if (!adjust_connections_for_uid (d->connections,
1383                                        uid, 1))
1384         goto fail;
1385     }
1386
1387   /* Create and cache a string which holds information about the
1388    * peer process; used for logging purposes.
1389    */
1390   if (!cache_peer_loginfo_string (d, connection))
1391     goto fail;
1392
1393   /* Now the connection is active, move it between lists */
1394   _dbus_list_unlink (&d->connections->incomplete,
1395                      d->link_in_connection_list);
1396   d->connections->n_incomplete -= 1;
1397   _dbus_list_append_link (&d->connections->completed,
1398                           d->link_in_connection_list);
1399   d->connections->n_completed += 1;
1400
1401   _dbus_assert (d->connections->n_incomplete >= 0);
1402   _dbus_assert (d->connections->n_completed > 0);
1403
1404   /* See if we can remove the timeout */
1405   bus_connections_expire_incomplete (d->connections);
1406
1407   _dbus_assert (bus_connection_is_active (connection));
1408
1409   return TRUE;
1410 fail:
1411   BUS_SET_OOM (error);
1412   dbus_free (d->name);
1413   d->name = NULL;
1414   if (d->policy)
1415     bus_client_policy_unref (d->policy);
1416   d->policy = NULL;
1417   return FALSE;
1418 }
1419
1420 const char *
1421 bus_connection_get_name (DBusConnection *connection)
1422 {
1423   BusConnectionData *d;
1424
1425   d = BUS_CONNECTION_DATA (connection);
1426   _dbus_assert (d != NULL);
1427
1428   return d->name;
1429 }
1430
1431 /**
1432  * Check whether completing the passed-in connection would
1433  * exceed limits, and if so set error and return #FALSE
1434  */
1435 dbus_bool_t
1436 bus_connections_check_limits (BusConnections  *connections,
1437                               DBusConnection  *requesting_completion,
1438                               DBusError       *error)
1439 {
1440   BusConnectionData *d;
1441   unsigned long uid;
1442
1443   d = BUS_CONNECTION_DATA (requesting_completion);
1444   _dbus_assert (d != NULL);
1445
1446   _dbus_assert (d->name == NULL);
1447
1448   if (connections->n_completed >=
1449       bus_context_get_max_completed_connections (connections->context))
1450     {
1451       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1452                       "The maximum number of active connections has been reached");
1453       return FALSE;
1454     }
1455
1456   if (dbus_connection_get_unix_user (requesting_completion, &uid))
1457     {
1458       if (get_connections_for_uid (connections, uid) >=
1459           bus_context_get_max_connections_per_user (connections->context))
1460         {
1461           dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1462                           "The maximum number of active connections for UID %lu has been reached",
1463                           uid);
1464           return FALSE;
1465         }
1466     }
1467
1468   return TRUE;
1469 }
1470
1471 static void
1472 bus_pending_reply_free (BusPendingReply *pending)
1473 {
1474   _dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n",
1475                  pending,
1476                  pending->will_send_reply,
1477                  pending->will_get_reply,
1478                  pending->reply_serial);
1479
1480   dbus_free (pending);
1481 }
1482
1483 static dbus_bool_t
1484 bus_pending_reply_send_no_reply (BusConnections  *connections,
1485                                  BusTransaction  *transaction,
1486                                  BusPendingReply *pending)
1487 {
1488   DBusMessage *message;
1489   DBusMessageIter iter;
1490   dbus_bool_t retval;
1491   const char *errmsg;
1492
1493   retval = FALSE;
1494
1495   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1496   if (message == NULL)
1497     return FALSE;
1498
1499   dbus_message_set_no_reply (message, TRUE);
1500
1501   if (!dbus_message_set_reply_serial (message,
1502                                       pending->reply_serial))
1503     goto out;
1504
1505   if (!dbus_message_set_error_name (message,
1506                                     DBUS_ERROR_NO_REPLY))
1507     goto out;
1508
1509   errmsg = "Message did not receive a reply (timeout by message bus)";
1510   dbus_message_iter_init_append (message, &iter);
1511   if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg))
1512     goto out;
1513
1514   if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply,
1515                                          message))
1516     goto out;
1517
1518   retval = TRUE;
1519
1520  out:
1521   dbus_message_unref (message);
1522   return retval;
1523 }
1524
1525 static dbus_bool_t
1526 bus_pending_reply_expired (BusExpireList *list,
1527                            DBusList      *link,
1528                            void          *data)
1529 {
1530   BusPendingReply *pending = link->data;
1531   BusConnections *connections = data;
1532   BusTransaction *transaction;
1533
1534   /* No reply is forthcoming. So nuke it if we can. If not,
1535    * leave it in the list to try expiring again later when we
1536    * get more memory.
1537    */
1538
1539   _dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n",
1540                  pending,
1541                  pending->will_send_reply,
1542                  pending->will_get_reply,
1543                  pending->reply_serial);
1544
1545   transaction = bus_transaction_new (connections->context);
1546   if (transaction == NULL)
1547     return FALSE;
1548
1549   if (!bus_pending_reply_send_no_reply (connections,
1550                                         transaction,
1551                                         pending))
1552     {
1553       bus_transaction_cancel_and_free (transaction);
1554       return FALSE;
1555     }
1556
1557   bus_expire_list_remove_link (connections->pending_replies, link);
1558
1559   bus_pending_reply_free (pending);
1560   bus_transaction_execute_and_free (transaction);
1561
1562   return TRUE;
1563 }
1564
1565 static void
1566 bus_connection_drop_pending_replies (BusConnections  *connections,
1567                                      DBusConnection  *connection)
1568 {
1569   /* The DBusConnection is almost 100% finalized here, so you can't
1570    * do anything with it except check for pointer equality
1571    */
1572   DBusList *link;
1573
1574   _dbus_verbose ("Dropping pending replies that involve connection %p\n",
1575                  connection);
1576
1577   link = bus_expire_list_get_first_link (connections->pending_replies);
1578   while (link != NULL)
1579     {
1580       DBusList *next;
1581       BusPendingReply *pending;
1582
1583       next = bus_expire_list_get_next_link (connections->pending_replies,
1584                                             link);
1585       pending = link->data;
1586
1587       if (pending->will_get_reply == connection)
1588         {
1589           /* We don't need to track this pending reply anymore */
1590
1591           _dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n",
1592                          pending,
1593                          pending->will_send_reply,
1594                          pending->will_get_reply,
1595                          pending->reply_serial);
1596
1597           bus_expire_list_remove_link (connections->pending_replies,
1598                                        link);
1599           bus_pending_reply_free (pending);
1600         }
1601       else if (pending->will_send_reply == connection)
1602         {
1603           /* The reply isn't going to be sent, so set things
1604            * up so it will be expired right away
1605            */
1606           _dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n",
1607                          pending,
1608                          pending->will_send_reply,
1609                          pending->will_get_reply,
1610                          pending->reply_serial);
1611
1612           pending->will_send_reply = NULL;
1613           pending->expire_item.added_tv_sec = 0;
1614           pending->expire_item.added_tv_usec = 0;
1615
1616           bus_expire_list_recheck_immediately (connections->pending_replies);
1617         }
1618
1619       link = next;
1620     }
1621 }
1622
1623
1624 typedef struct
1625 {
1626   BusPendingReply *pending;
1627   BusConnections  *connections;
1628 } CancelPendingReplyData;
1629
1630 static void
1631 cancel_pending_reply (void *data)
1632 {
1633   CancelPendingReplyData *d = data;
1634
1635   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1636
1637   if (!bus_expire_list_remove (d->connections->pending_replies,
1638                                &d->pending->expire_item))
1639     _dbus_assert_not_reached ("pending reply did not exist to be cancelled");
1640
1641   bus_pending_reply_free (d->pending); /* since it's been cancelled */
1642 }
1643
1644 static void
1645 cancel_pending_reply_data_free (void *data)
1646 {
1647   CancelPendingReplyData *d = data;
1648
1649   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1650
1651   /* d->pending should be either freed or still
1652    * in the list of pending replies (owned by someone
1653    * else)
1654    */
1655
1656   dbus_free (d);
1657 }
1658
1659 /*
1660  * Record that a reply is allowed; return TRUE on success.
1661  */
1662 dbus_bool_t
1663 bus_connections_expect_reply (BusConnections  *connections,
1664                               BusTransaction  *transaction,
1665                               DBusConnection  *will_get_reply,
1666                               DBusConnection  *will_send_reply,
1667                               DBusMessage     *reply_to_this,
1668                               DBusError       *error)
1669 {
1670   BusPendingReply *pending;
1671   dbus_uint32_t reply_serial;
1672   DBusList *link;
1673   CancelPendingReplyData *cprd;
1674   int count;
1675
1676   _dbus_assert (will_get_reply != NULL);
1677   _dbus_assert (will_send_reply != NULL);
1678   _dbus_assert (reply_to_this != NULL);
1679
1680   if (dbus_message_get_no_reply (reply_to_this))
1681     return TRUE; /* we won't allow a reply, since client doesn't care for one. */
1682
1683   reply_serial = dbus_message_get_serial (reply_to_this);
1684
1685   link = bus_expire_list_get_first_link (connections->pending_replies);
1686   count = 0;
1687   while (link != NULL)
1688     {
1689       pending = link->data;
1690
1691       if (pending->reply_serial == reply_serial &&
1692           pending->will_get_reply == will_get_reply &&
1693           pending->will_send_reply == will_send_reply)
1694         {
1695           dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1696                           "Message has the same reply serial as a currently-outstanding existing method call");
1697           return FALSE;
1698         }
1699
1700       link = bus_expire_list_get_next_link (connections->pending_replies,
1701                                             link);
1702       if (pending->will_get_reply == will_get_reply)
1703         ++count;
1704     }
1705
1706   if (count >=
1707       bus_context_get_max_replies_per_connection (connections->context))
1708     {
1709       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1710                       "The maximum number of pending replies per connection has been reached");
1711       return FALSE;
1712     }
1713
1714   pending = dbus_new0 (BusPendingReply, 1);
1715   if (pending == NULL)
1716     {
1717       BUS_SET_OOM (error);
1718       return FALSE;
1719     }
1720
1721 #ifdef DBUS_ENABLE_VERBOSE_MODE
1722   /* so we can see a not-yet-added pending reply */
1723   pending->expire_item.added_tv_sec = 1;
1724   pending->expire_item.added_tv_usec = 1;
1725 #endif
1726
1727   pending->will_get_reply = will_get_reply;
1728   pending->will_send_reply = will_send_reply;
1729   pending->reply_serial = reply_serial;
1730
1731   cprd = dbus_new0 (CancelPendingReplyData, 1);
1732   if (cprd == NULL)
1733     {
1734       BUS_SET_OOM (error);
1735       bus_pending_reply_free (pending);
1736       return FALSE;
1737     }
1738
1739   if (!bus_expire_list_add (connections->pending_replies,
1740                             &pending->expire_item))
1741     {
1742       BUS_SET_OOM (error);
1743       dbus_free (cprd);
1744       bus_pending_reply_free (pending);
1745       return FALSE;
1746     }
1747
1748   if (!bus_transaction_add_cancel_hook (transaction,
1749                                         cancel_pending_reply,
1750                                         cprd,
1751                                         cancel_pending_reply_data_free))
1752     {
1753       BUS_SET_OOM (error);
1754       bus_expire_list_remove (connections->pending_replies, &pending->expire_item);
1755       dbus_free (cprd);
1756       bus_pending_reply_free (pending);
1757       return FALSE;
1758     }
1759
1760   cprd->pending = pending;
1761   cprd->connections = connections;
1762
1763   _dbus_get_current_time (&pending->expire_item.added_tv_sec,
1764                           &pending->expire_item.added_tv_usec);
1765
1766   _dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n",
1767                  pending,
1768                  pending->will_send_reply,
1769                  pending->will_get_reply,
1770                  pending->reply_serial);
1771
1772   return TRUE;
1773 }
1774
1775 typedef struct
1776 {
1777   DBusList        *link;
1778   BusConnections  *connections;
1779 } CheckPendingReplyData;
1780
1781 static void
1782 cancel_check_pending_reply (void *data)
1783 {
1784   CheckPendingReplyData *d = data;
1785
1786   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1787
1788   bus_expire_list_add_link (d->connections->pending_replies,
1789                             d->link);
1790   d->link = NULL;
1791 }
1792
1793 static void
1794 check_pending_reply_data_free (void *data)
1795 {
1796   CheckPendingReplyData *d = data;
1797
1798   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1799
1800   if (d->link != NULL)
1801     {
1802       BusPendingReply *pending = d->link->data;
1803
1804       _dbus_assert (!bus_expire_list_contains_item (d->connections->pending_replies,
1805                                                     &pending->expire_item));
1806
1807       bus_pending_reply_free (pending);
1808       _dbus_list_free_link (d->link);
1809     }
1810
1811   dbus_free (d);
1812 }
1813
1814 /*
1815  * Check whether a reply is allowed, remove BusPendingReply
1816  * if so, return TRUE if so.
1817  */
1818 dbus_bool_t
1819 bus_connections_check_reply (BusConnections *connections,
1820                              BusTransaction *transaction,
1821                              DBusConnection *sending_reply,
1822                              DBusConnection *receiving_reply,
1823                              DBusMessage    *reply,
1824                              DBusError      *error)
1825 {
1826   CheckPendingReplyData *cprd;
1827   DBusList *link;
1828   dbus_uint32_t reply_serial;
1829
1830   _dbus_assert (sending_reply != NULL);
1831   _dbus_assert (receiving_reply != NULL);
1832
1833   reply_serial = dbus_message_get_reply_serial (reply);
1834
1835   link = bus_expire_list_get_first_link (connections->pending_replies);
1836   while (link != NULL)
1837     {
1838       BusPendingReply *pending = link->data;
1839
1840       if (pending->reply_serial == reply_serial &&
1841           pending->will_get_reply == receiving_reply &&
1842           pending->will_send_reply == sending_reply)
1843         {
1844           _dbus_verbose ("Found pending reply with serial %u\n", reply_serial);
1845           break;
1846         }
1847
1848       link = bus_expire_list_get_next_link (connections->pending_replies,
1849                                             link);
1850     }
1851
1852   if (link == NULL)
1853     {
1854       _dbus_verbose ("No pending reply expected\n");
1855
1856       return FALSE;
1857     }
1858
1859   cprd = dbus_new0 (CheckPendingReplyData, 1);
1860   if (cprd == NULL)
1861     {
1862       BUS_SET_OOM (error);
1863       return FALSE;
1864     }
1865
1866   if (!bus_transaction_add_cancel_hook (transaction,
1867                                         cancel_check_pending_reply,
1868                                         cprd,
1869                                         check_pending_reply_data_free))
1870     {
1871       BUS_SET_OOM (error);
1872       dbus_free (cprd);
1873       return FALSE;
1874     }
1875
1876   cprd->link = link;
1877   cprd->connections = connections;
1878
1879   bus_expire_list_unlink (connections->pending_replies,
1880                           link);
1881
1882   _dbus_assert (!bus_expire_list_contains_item (connections->pending_replies, link->data));
1883
1884   return TRUE;
1885 }
1886
1887 /*
1888  * Transactions
1889  *
1890  * Note that this is fairly fragile; in particular, don't try to use
1891  * one transaction across any main loop iterations.
1892  */
1893
1894 typedef struct
1895 {
1896   BusTransaction *transaction;
1897   DBusMessage    *message;
1898   DBusPreallocatedSend *preallocated;
1899 } MessageToSend;
1900
1901 typedef struct
1902 {
1903   BusTransactionCancelFunction cancel_function;
1904   DBusFreeFunction free_data_function;
1905   void *data;
1906 } CancelHook;
1907
1908 struct BusTransaction
1909 {
1910   DBusList *connections;
1911   BusContext *context;
1912   DBusList *cancel_hooks;
1913 };
1914
1915 static void
1916 message_to_send_free (DBusConnection *connection,
1917                       MessageToSend  *to_send)
1918 {
1919   if (to_send->message)
1920     dbus_message_unref (to_send->message);
1921
1922   if (to_send->preallocated)
1923     dbus_connection_free_preallocated_send (connection, to_send->preallocated);
1924
1925   dbus_free (to_send);
1926 }
1927
1928 static void
1929 cancel_hook_cancel (void *element,
1930                     void *data)
1931 {
1932   CancelHook *ch = element;
1933
1934   _dbus_verbose ("Running transaction cancel hook\n");
1935
1936   if (ch->cancel_function)
1937     (* ch->cancel_function) (ch->data);
1938 }
1939
1940 static void
1941 cancel_hook_free (void *element,
1942                   void *data)
1943 {
1944   CancelHook *ch = element;
1945
1946   if (ch->free_data_function)
1947     (* ch->free_data_function) (ch->data);
1948
1949   dbus_free (ch);
1950 }
1951
1952 static void
1953 free_cancel_hooks (BusTransaction *transaction)
1954 {
1955   _dbus_list_foreach (&transaction->cancel_hooks,
1956                       cancel_hook_free, NULL);
1957
1958   _dbus_list_clear (&transaction->cancel_hooks);
1959 }
1960
1961 BusTransaction*
1962 bus_transaction_new (BusContext *context)
1963 {
1964   BusTransaction *transaction;
1965
1966   transaction = dbus_new0 (BusTransaction, 1);
1967   if (transaction == NULL)
1968     return NULL;
1969
1970   transaction->context = context;
1971
1972   return transaction;
1973 }
1974
1975 BusContext*
1976 bus_transaction_get_context (BusTransaction  *transaction)
1977 {
1978   return transaction->context;
1979 }
1980
1981 BusConnections*
1982 bus_transaction_get_connections (BusTransaction  *transaction)
1983 {
1984   return bus_context_get_connections (transaction->context);
1985 }
1986
1987 dbus_bool_t
1988 bus_transaction_send_from_driver (BusTransaction *transaction,
1989                                   DBusConnection *connection,
1990                                   DBusMessage    *message)
1991 {
1992   /* We have to set the sender to the driver, and have
1993    * to check security policy since it was not done in
1994    * dispatch.c
1995    */
1996   _dbus_verbose ("Sending %s %s %s from driver\n",
1997                  dbus_message_get_interface (message) ?
1998                  dbus_message_get_interface (message) : "(no interface)",
1999                  dbus_message_get_member (message) ?
2000                  dbus_message_get_member (message) : "(no member)",
2001                  dbus_message_get_error_name (message) ?
2002                  dbus_message_get_error_name (message) : "(no error name)");
2003
2004   if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
2005     return FALSE;
2006
2007   if (bus_connection_is_active (connection))
2008     {
2009       if (!dbus_message_set_destination (message,
2010                                          bus_connection_get_name (connection)))
2011         return FALSE;
2012     }
2013
2014   /* bus driver never wants a reply */
2015   dbus_message_set_no_reply (message, TRUE);
2016
2017   /* If security policy doesn't allow the message, we silently
2018    * eat it; the driver doesn't care about getting a reply.
2019    */
2020   if (!bus_context_check_security_policy (bus_transaction_get_context (transaction),
2021                                           transaction,
2022                                           NULL, connection, connection, message, NULL))
2023     return TRUE;
2024
2025   return bus_transaction_send (transaction, connection, message);
2026 }
2027
2028 dbus_bool_t
2029 bus_transaction_send (BusTransaction *transaction,
2030                       DBusConnection *connection,
2031                       DBusMessage    *message)
2032 {
2033   MessageToSend *to_send;
2034   BusConnectionData *d;
2035   DBusList *link;
2036
2037   _dbus_verbose ("  trying to add %s interface=%s member=%s error=%s to transaction%s\n",
2038                  dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" :
2039                  dbus_message_get_reply_serial (message) != 0 ? "reply" :
2040                  "message",
2041                  dbus_message_get_interface (message) ?
2042                  dbus_message_get_interface (message) : "(unset)",
2043                  dbus_message_get_member (message) ?
2044                  dbus_message_get_member (message) : "(unset)",
2045                  dbus_message_get_error_name (message) ?
2046                  dbus_message_get_error_name (message) : "(unset)",
2047                  dbus_connection_get_is_connected (connection) ?
2048                  "" : " (disconnected)");
2049
2050   _dbus_assert (dbus_message_get_sender (message) != NULL);
2051
2052   if (!dbus_connection_get_is_connected (connection))
2053     return TRUE; /* silently ignore disconnected connections */
2054
2055   d = BUS_CONNECTION_DATA (connection);
2056   _dbus_assert (d != NULL);
2057
2058   to_send = dbus_new (MessageToSend, 1);
2059   if (to_send == NULL)
2060     {
2061       return FALSE;
2062     }
2063
2064   to_send->preallocated = dbus_connection_preallocate_send (connection);
2065   if (to_send->preallocated == NULL)
2066     {
2067       dbus_free (to_send);
2068       return FALSE;
2069     }
2070
2071   dbus_message_ref (message);
2072   to_send->message = message;
2073   to_send->transaction = transaction;
2074
2075   _dbus_verbose ("about to prepend message\n");
2076
2077   if (!_dbus_list_prepend (&d->transaction_messages, to_send))
2078     {
2079       message_to_send_free (connection, to_send);
2080       return FALSE;
2081     }
2082
2083   _dbus_verbose ("prepended message\n");
2084
2085   /* See if we already had this connection in the list
2086    * for this transaction. If we have a pending message,
2087    * then we should already be in transaction->connections
2088    */
2089   link = _dbus_list_get_first_link (&d->transaction_messages);
2090   _dbus_assert (link->data == to_send);
2091   link = _dbus_list_get_next_link (&d->transaction_messages, link);
2092   while (link != NULL)
2093     {
2094       MessageToSend *m = link->data;
2095       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2096
2097       if (m->transaction == transaction)
2098         break;
2099
2100       link = next;
2101     }
2102
2103   if (link == NULL)
2104     {
2105       if (!_dbus_list_prepend (&transaction->connections, connection))
2106         {
2107           _dbus_list_remove (&d->transaction_messages, to_send);
2108           message_to_send_free (connection, to_send);
2109           return FALSE;
2110         }
2111     }
2112
2113   return TRUE;
2114 }
2115
2116 static void
2117 connection_cancel_transaction (DBusConnection *connection,
2118                                BusTransaction *transaction)
2119 {
2120   DBusList *link;
2121   BusConnectionData *d;
2122
2123   d = BUS_CONNECTION_DATA (connection);
2124   _dbus_assert (d != NULL);
2125
2126   link = _dbus_list_get_first_link (&d->transaction_messages);
2127   while (link != NULL)
2128     {
2129       MessageToSend *m = link->data;
2130       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2131
2132       if (m->transaction == transaction)
2133         {
2134           _dbus_list_remove_link (&d->transaction_messages,
2135                                   link);
2136
2137           message_to_send_free (connection, m);
2138         }
2139
2140       link = next;
2141     }
2142 }
2143
2144 void
2145 bus_transaction_cancel_and_free (BusTransaction *transaction)
2146 {
2147   DBusConnection *connection;
2148
2149   _dbus_verbose ("TRANSACTION: cancelled\n");
2150
2151   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2152     connection_cancel_transaction (connection, transaction);
2153
2154   _dbus_assert (transaction->connections == NULL);
2155
2156   _dbus_list_foreach (&transaction->cancel_hooks,
2157                       cancel_hook_cancel, NULL);
2158
2159   free_cancel_hooks (transaction);
2160
2161   dbus_free (transaction);
2162 }
2163
2164 static void
2165 connection_execute_transaction (DBusConnection *connection,
2166                                 BusTransaction *transaction)
2167 {
2168   DBusList *link;
2169   BusConnectionData *d;
2170
2171   d = BUS_CONNECTION_DATA (connection);
2172   _dbus_assert (d != NULL);
2173
2174   /* Send the queue in order (FIFO) */
2175   link = _dbus_list_get_last_link (&d->transaction_messages);
2176   while (link != NULL)
2177     {
2178       MessageToSend *m = link->data;
2179       DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link);
2180
2181       if (m->transaction == transaction)
2182         {
2183           _dbus_list_remove_link (&d->transaction_messages,
2184                                   link);
2185
2186           _dbus_assert (dbus_message_get_sender (m->message) != NULL);
2187
2188           dbus_connection_send_preallocated (connection,
2189                                              m->preallocated,
2190                                              m->message,
2191                                              NULL);
2192
2193           m->preallocated = NULL; /* so we don't double-free it */
2194
2195           message_to_send_free (connection, m);
2196         }
2197
2198       link = prev;
2199     }
2200 }
2201
2202 void
2203 bus_transaction_execute_and_free (BusTransaction *transaction)
2204 {
2205   /* For each connection in transaction->connections
2206    * send the messages
2207    */
2208   DBusConnection *connection;
2209
2210   _dbus_verbose ("TRANSACTION: executing\n");
2211
2212   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2213     connection_execute_transaction (connection, transaction);
2214
2215   _dbus_assert (transaction->connections == NULL);
2216
2217   free_cancel_hooks (transaction);
2218
2219   dbus_free (transaction);
2220 }
2221
2222 static void
2223 bus_connection_remove_transactions (DBusConnection *connection)
2224 {
2225   MessageToSend *to_send;
2226   BusConnectionData *d;
2227
2228   d = BUS_CONNECTION_DATA (connection);
2229   _dbus_assert (d != NULL);
2230
2231   while ((to_send = _dbus_list_get_first (&d->transaction_messages)))
2232     {
2233       /* only has an effect for the first MessageToSend listing this transaction */
2234       _dbus_list_remove (&to_send->transaction->connections,
2235                          connection);
2236
2237       _dbus_list_remove (&d->transaction_messages, to_send);
2238       message_to_send_free (connection, to_send);
2239     }
2240 }
2241
2242 /**
2243  * Converts the DBusError to a message reply
2244  */
2245 dbus_bool_t
2246 bus_transaction_send_error_reply (BusTransaction  *transaction,
2247                                   DBusConnection  *connection,
2248                                   const DBusError *error,
2249                                   DBusMessage     *in_reply_to)
2250 {
2251   DBusMessage *reply;
2252
2253   _dbus_assert (error != NULL);
2254   _DBUS_ASSERT_ERROR_IS_SET (error);
2255
2256   _dbus_verbose ("Sending error reply %s \"%s\"\n",
2257                  error->name, error->message);
2258
2259   reply = dbus_message_new_error (in_reply_to,
2260                                   error->name,
2261                                   error->message);
2262   if (reply == NULL)
2263     return FALSE;
2264
2265   if (!bus_transaction_send_from_driver (transaction, connection, reply))
2266     {
2267       dbus_message_unref (reply);
2268       return FALSE;
2269     }
2270
2271   dbus_message_unref (reply);
2272
2273   return TRUE;
2274 }
2275
2276 dbus_bool_t
2277 bus_transaction_add_cancel_hook (BusTransaction               *transaction,
2278                                  BusTransactionCancelFunction  cancel_function,
2279                                  void                         *data,
2280                                  DBusFreeFunction              free_data_function)
2281 {
2282   CancelHook *ch;
2283
2284   ch = dbus_new (CancelHook, 1);
2285   if (ch == NULL)
2286     return FALSE;
2287
2288   _dbus_verbose ("     adding cancel hook function = %p data = %p\n",
2289                  cancel_function, data);
2290
2291   ch->cancel_function = cancel_function;
2292   ch->data = data;
2293   ch->free_data_function = free_data_function;
2294
2295   /* It's important that the hooks get run in reverse order that they
2296    * were added
2297    */
2298   if (!_dbus_list_prepend (&transaction->cancel_hooks, ch))
2299     {
2300       dbus_free (ch);
2301       return FALSE;
2302     }
2303
2304   return TRUE;
2305 }