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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  *
  22  */
  23 #include "connection.h"
  24 #include "dispatch.h"
  25 #include "policy.h"
  26 #include "services.h"
  27 #include "utils.h"
  28 #include "signals.h"
  29 #include "expirelist.h"
  30 #include "selinux.h"
  31 #include <dbus/dbus-list.h>
  32 #include <dbus/dbus-hash.h>
  33 #include <dbus/dbus-timeout.h>
  34
  35 /* Trim executed commands to this length; we want to keep logs readable */
  36 #define MAX_LOG_COMMAND_LEN 50
  37
  38 static void bus_connection_remove_transactions (DBusConnection *connection);
  39
  40 typedef struct
  41 {
  42   BusExpireItem expire_item;
  43
  44   DBusConnection *will_get_reply;
  45   DBusConnection *will_send_reply;
  46
  47   dbus_uint32_t reply_serial;
  48
  49 } BusPendingReply;
  50
  51 struct BusConnections
  52 {
  53   int refcount;
  54   DBusList *completed;  /**< List of all completed connections */
  55   int n_completed;      /**< Length of completed list */
  56   DBusList *incomplete; /**< List of all not-yet-active connections */
  57   int n_incomplete;     /**< Length of incomplete list */
  58   BusContext *context;
  59   DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */
  60   DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */
  61   int stamp;                   /**< Incrementing number */
  62   BusExpireList *pending_replies; /**< List of pending replies */
  63 };
  64
  65 static dbus_int32_t connection_data_slot = -1;
  66
  67 typedef struct
  68 {
  69   BusConnections *connections;
  70   DBusList *link_in_connection_list;
  71   DBusConnection *connection;
  72   DBusList *services_owned;
  73   int n_services_owned;
  74   DBusList *match_rules;
  75   int n_match_rules;
  76   char *name;
  77   DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
  78   DBusMessage *oom_message;
  79   DBusPreallocatedSend *oom_preallocated;
  80   BusClientPolicy *policy;
  81
  82   char *cached_loginfo_string;
  83   BusSELinuxID *selinux_id;
  84
  85   long connection_tv_sec;  /**< Time when we connected (seconds component) */
  86   long connection_tv_usec; /**< Time when we connected (microsec component) */
  87   int stamp;               /**< connections->stamp last time we were traversed */
  88 } BusConnectionData;
  89
  90 static dbus_bool_t bus_pending_reply_expired (BusExpireList *list,
  91                                               DBusList      *link,
  92                                               void          *data);
  93
  94 static void bus_connection_drop_pending_replies (BusConnections  *connections,
  95                                                  DBusConnection  *connection);
  96
  97 static dbus_bool_t expire_incomplete_timeout (void *data);
  98
  99 #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
 100
 101 static DBusLoop*
 102 connection_get_loop (DBusConnection *connection)
 103 {
 104   BusConnectionData *d;
 105
 106   d = BUS_CONNECTION_DATA (connection);
 107
 108   return bus_context_get_loop (d->connections->context);
 109 }
 110
 111
 112 static int
 113 get_connections_for_uid (BusConnections *connections,
 114                          dbus_uid_t      uid)
 115 {
 116   void *val;
 117   int current_count;
 118
 119   /* val is NULL is 0 when it isn't in the hash yet */
 120
 121   val = _dbus_hash_table_lookup_ulong (connections->completed_by_user,
 122                                        uid);
 123
 124   current_count = _DBUS_POINTER_TO_INT (val);
 125
 126   return current_count;
 127 }
 128
 129 static dbus_bool_t
 130 adjust_connections_for_uid (BusConnections *connections,
 131                             dbus_uid_t      uid,
 132                             int             adjustment)
 133 {
 134   int current_count;
 135
 136   current_count = get_connections_for_uid (connections, uid);
 137
 138   _dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT
 139                  ": was %d adjustment %d making %d\n",
 140                  uid, current_count, adjustment, current_count + adjustment);
 141
 142   _dbus_assert (current_count >= 0);
 143
 144   current_count += adjustment;
 145
 146   _dbus_assert (current_count >= 0);
 147
 148   if (current_count == 0)
 149     {
 150       _dbus_hash_table_remove_ulong (connections->completed_by_user, uid);
 151       return TRUE;
 152     }
 153   else
 154     {
 155       dbus_bool_t retval;
 156
 157       retval = _dbus_hash_table_insert_ulong (connections->completed_by_user,
 158                                               uid, _DBUS_INT_TO_POINTER (current_count));
 159
 160       /* only positive adjustment can fail as otherwise
 161        * a hash entry should already exist
 162        */
 163       _dbus_assert (adjustment > 0 ||
 164                     (adjustment <= 0 && retval));
 165
 166       return retval;
 167     }
 168 }
 169
 170 void
 171 bus_connection_disconnected (DBusConnection *connection)
 172 {
 173   BusConnectionData *d;
 174   BusService *service;
 175   BusMatchmaker *matchmaker;
 176
 177   d = BUS_CONNECTION_DATA (connection);
 178   _dbus_assert (d != NULL);
 179
 180   _dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n",
 181                  d->name ? d->name : "(inactive)");
 182
 183   /* Delete our match rules */
 184   if (d->n_match_rules > 0)
 185     {
 186       matchmaker = bus_context_get_matchmaker (d->connections->context);
 187       bus_matchmaker_disconnected (matchmaker, connection);
 188     }
 189
 190   /* Drop any service ownership. Unfortunately, this requires
 191    * memory allocation and there doesn't seem to be a good way to
 192    * handle it other than sleeping; we can't "fail" the operation of
 193    * disconnecting a client, and preallocating a broadcast "service is
 194    * now gone" message for every client-service pair seems kind of
 195    * involved.
 196    */
 197   while ((service = _dbus_list_get_last (&d->services_owned)))
 198     {
 199       BusTransaction *transaction;
 200       DBusError error;
 201
 202     retry:
 203
 204       dbus_error_init (&error);
 205
 206       while ((transaction = bus_transaction_new (d->connections->context)) == NULL)
 207         _dbus_wait_for_memory ();
 208
 209       if (!bus_service_remove_owner (service, connection,
 210                                      transaction, &error))
 211         {
 212           _DBUS_ASSERT_ERROR_IS_SET (&error);
 213
 214           if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
 215             {
 216               dbus_error_free (&error);
 217               bus_transaction_cancel_and_free (transaction);
 218               _dbus_wait_for_memory ();
 219               goto retry;
 220             }
 221           else
 222             {
 223               _dbus_verbose ("Failed to remove service owner: %s %s\n",
 224                              error.name, error.message);
 225               _dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason");
 226             }
 227         }
 228
 229       bus_transaction_execute_and_free (transaction);
 230     }
 231
 232   bus_dispatch_remove_connection (connection);
 233
 234   /* no more watching */
 235   if (!dbus_connection_set_watch_functions (connection,
 236                                             NULL, NULL, NULL,
 237                                             connection,
 238                                             NULL))
 239     _dbus_assert_not_reached ("setting watch functions to NULL failed");
 240
 241   if (!dbus_connection_set_timeout_functions (connection,
 242                                               NULL, NULL, NULL,
 243                                               connection,
 244                                               NULL))
 245     _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 246
 247   dbus_connection_set_unix_user_function (connection,
 248                                           NULL, NULL, NULL);
 249   dbus_connection_set_windows_user_function (connection,
 250                                              NULL, NULL, NULL);
 251
 252   dbus_connection_set_dispatch_status_function (connection,
 253                                                 NULL, NULL, NULL);
 254
 255   bus_connection_remove_transactions (connection);
 256
 257   if (d->link_in_connection_list != NULL)
 258     {
 259       if (d->name != NULL)
 260         {
 261           unsigned long uid;
 262
 263           _dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list);
 264           d->link_in_connection_list = NULL;
 265           d->connections->n_completed -= 1;
 266
 267           if (dbus_connection_get_unix_user (connection, &uid))
 268             {
 269               if (!adjust_connections_for_uid (d->connections,
 270                                                uid, -1))
 271                 _dbus_assert_not_reached ("adjusting downward should never fail");
 272             }
 273         }
 274       else
 275         {
 276           _dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list);
 277           d->link_in_connection_list = NULL;
 278           d->connections->n_incomplete -= 1;
 279         }
 280
 281       _dbus_assert (d->connections->n_incomplete >= 0);
 282       _dbus_assert (d->connections->n_completed >= 0);
 283     }
 284
 285   bus_connection_drop_pending_replies (d->connections, connection);
 286
 287   /* frees "d" as side effect */
 288   dbus_connection_set_data (connection,
 289                             connection_data_slot,
 290                             NULL, NULL);
 291
 292   dbus_connection_unref (connection);
 293 }
 294
 295 static dbus_bool_t
 296 connection_watch_callback (DBusWatch     *watch,
 297                            unsigned int   condition,
 298                            void          *data)
 299 {
 300  /* FIXME this can be done in dbus-mainloop.c
 301   * if the code in activation.c for the babysitter
 302   * watch handler is fixed.
 303   */
 304
 305 #if 0
 306   _dbus_verbose ("Calling handle_watch\n");
 307 #endif
 308   return dbus_watch_handle (watch, condition);
 309 }
 310
 311 static dbus_bool_t
 312 add_connection_watch (DBusWatch      *watch,
 313                       void           *data)
 314 {
 315   DBusConnection *connection = data;
 316
 317   return _dbus_loop_add_watch (connection_get_loop (connection),
 318                                watch, connection_watch_callback, connection,
 319                                NULL);
 320 }
 321
 322 static void
 323 remove_connection_watch (DBusWatch      *watch,
 324                          void           *data)
 325 {
 326   DBusConnection *connection = data;
 327
 328   _dbus_loop_remove_watch (connection_get_loop (connection),
 329                            watch, connection_watch_callback, connection);
 330 }
 331
 332 static void
 333 connection_timeout_callback (DBusTimeout   *timeout,
 334                              void          *data)
 335 {
 336   /* DBusConnection *connection = data; */
 337
 338   /* can return FALSE on OOM but we just let it fire again later */
 339   dbus_timeout_handle (timeout);
 340 }
 341
 342 static dbus_bool_t
 343 add_connection_timeout (DBusTimeout    *timeout,
 344                         void           *data)
 345 {
 346   DBusConnection *connection = data;
 347
 348   return _dbus_loop_add_timeout (connection_get_loop (connection),
 349                                  timeout, connection_timeout_callback, connection, NULL);
 350 }
 351
 352 static void
 353 remove_connection_timeout (DBusTimeout    *timeout,
 354                            void           *data)
 355 {
 356   DBusConnection *connection = data;
 357
 358   _dbus_loop_remove_timeout (connection_get_loop (connection),
 359                              timeout, connection_timeout_callback, connection);
 360 }
 361
 362 static void
 363 dispatch_status_function (DBusConnection    *connection,
 364                           DBusDispatchStatus new_status,
 365                           void              *data)
 366 {
 367   DBusLoop *loop = data;
 368
 369   if (new_status != DBUS_DISPATCH_COMPLETE)
 370     {
 371       while (!_dbus_loop_queue_dispatch (loop, connection))
 372         _dbus_wait_for_memory ();
 373     }
 374 }
 375
 376 static dbus_bool_t
 377 allow_unix_user_function (DBusConnection *connection,
 378                           unsigned long   uid,
 379                           void           *data)
 380 {
 381   BusConnectionData *d;
 382
 383   d = BUS_CONNECTION_DATA (connection);
 384
 385   _dbus_assert (d != NULL);
 386
 387   return bus_context_allow_unix_user (d->connections->context, uid);
 388 }
 389
 390 static void
 391 free_connection_data (void *data)
 392 {
 393   BusConnectionData *d = data;
 394
 395   /* services_owned should be NULL since we should be disconnected */
 396   _dbus_assert (d->services_owned == NULL);
 397   _dbus_assert (d->n_services_owned == 0);
 398   /* similarly */
 399   _dbus_assert (d->transaction_messages == NULL);
 400
 401   if (d->oom_preallocated)
 402     dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated);
 403
 404   if (d->oom_message)
 405     dbus_message_unref (d->oom_message);
 406
 407   if (d->policy)
 408     bus_client_policy_unref (d->policy);
 409
 410   if (d->selinux_id)
 411     bus_selinux_id_unref (d->selinux_id);
 412
 413   dbus_free (d->cached_loginfo_string);
 414
 415   dbus_free (d->name);
 416
 417   dbus_free (d);
 418 }
 419
 420 static void
 421 call_timeout_callback (DBusTimeout   *timeout,
 422                        void          *data)
 423 {
 424   /* can return FALSE on OOM but we just let it fire again later */
 425   dbus_timeout_handle (timeout);
 426 }
 427
 428 BusConnections*
 429 bus_connections_new (BusContext *context)
 430 {
 431   BusConnections *connections;
 432
 433   if (!dbus_connection_allocate_data_slot (&connection_data_slot))
 434     goto failed_0;
 435
 436   connections = dbus_new0 (BusConnections, 1);
 437   if (connections == NULL)
 438     goto failed_1;
 439
 440   connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_ULONG,
 441                                                          NULL, NULL);
 442   if (connections->completed_by_user == NULL)
 443     goto failed_2;
 444
 445   connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */
 446                                                    expire_incomplete_timeout,
 447                                                    connections, NULL);
 448   if (connections->expire_timeout == NULL)
 449     goto failed_3;
 450
 451   _dbus_timeout_set_enabled (connections->expire_timeout, FALSE);
 452
 453   connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context),
 454                                                       bus_context_get_reply_timeout (context),
 455                                                       bus_pending_reply_expired,
 456                                                       connections);
 457   if (connections->pending_replies == NULL)
 458     goto failed_4;
 459
 460   if (!_dbus_loop_add_timeout (bus_context_get_loop (context),
 461                                connections->expire_timeout,
 462                                call_timeout_callback, NULL, NULL))
 463     goto failed_5;
 464
 465   connections->refcount = 1;
 466   connections->context = context;
 467
 468   return connections;
 469
 470  failed_5:
 471   bus_expire_list_free (connections->pending_replies);
 472  failed_4:
 473   _dbus_timeout_unref (connections->expire_timeout);
 474  failed_3:
 475   _dbus_hash_table_unref (connections->completed_by_user);
 476  failed_2:
 477   dbus_free (connections);
 478  failed_1:
 479   dbus_connection_free_data_slot (&connection_data_slot);
 480  failed_0:
 481   return NULL;
 482 }
 483
 484 BusConnections *
 485 bus_connections_ref (BusConnections *connections)
 486 {
 487   _dbus_assert (connections->refcount > 0);
 488   connections->refcount += 1;
 489
 490   return connections;
 491 }
 492
 493 void
 494 bus_connections_unref (BusConnections *connections)
 495 {
 496   _dbus_assert (connections->refcount > 0);
 497   connections->refcount -= 1;
 498   if (connections->refcount == 0)
 499     {
 500       /* drop all incomplete */
 501       while (connections->incomplete != NULL)
 502         {
 503           DBusConnection *connection;
 504
 505           connection = connections->incomplete->data;
 506
 507           dbus_connection_ref (connection);
 508           dbus_connection_close (connection);
 509           bus_connection_disconnected (connection);
 510           dbus_connection_unref (connection);
 511         }
 512
 513       _dbus_assert (connections->n_incomplete == 0);
 514
 515       /* drop all real connections */
 516       while (connections->completed != NULL)
 517         {
 518           DBusConnection *connection;
 519
 520           connection = connections->completed->data;
 521
 522           dbus_connection_ref (connection);
 523           dbus_connection_close (connection);
 524           bus_connection_disconnected (connection);
 525           dbus_connection_unref (connection);
 526         }
 527
 528       _dbus_assert (connections->n_completed == 0);
 529
 530       bus_expire_list_free (connections->pending_replies);
 531
 532       _dbus_loop_remove_timeout (bus_context_get_loop (connections->context),
 533                                  connections->expire_timeout,
 534                                  call_timeout_callback, NULL);
 535
 536       _dbus_timeout_unref (connections->expire_timeout);
 537
 538       _dbus_hash_table_unref (connections->completed_by_user);
 539
 540       dbus_free (connections);
 541
 542       dbus_connection_free_data_slot (&connection_data_slot);
 543     }
 544 }
 545
 546 /* Used for logging */
 547 static dbus_bool_t
 548 cache_peer_loginfo_string (BusConnectionData *d,
 549                            DBusConnection    *connection)
 550 {
 551   DBusString loginfo_buf;
 552   unsigned long uid;
 553   unsigned long pid;
 554   char *windows_sid;
 555   dbus_bool_t prev_added;
 556
 557   if (!_dbus_string_init (&loginfo_buf))
 558     return FALSE;
 559
 560   prev_added = FALSE;
 561   if (dbus_connection_get_unix_user (connection, &uid))
 562     {
 563       if (!_dbus_string_append_printf (&loginfo_buf, "uid=%ld", uid))
 564         goto oom;
 565       else
 566         prev_added = TRUE;
 567     }
 568
 569   if (dbus_connection_get_unix_process_id (connection, &pid))
 570     {
 571       if (prev_added)
 572         {
 573           if (!_dbus_string_append_byte (&loginfo_buf, ' '))
 574             goto oom;
 575         }
 576       if (!_dbus_string_append_printf (&loginfo_buf, "pid=%ld comm=\"", pid))
 577         goto oom;
 578       /* Ignore errors here; we may not have permissions to read the
 579        * proc file. */
 580       _dbus_command_for_pid (pid, &loginfo_buf, MAX_LOG_COMMAND_LEN, NULL);
 581       if (!_dbus_string_append_byte (&loginfo_buf, '"'))
 582         goto oom;
 583     }
 584
 585   if (dbus_connection_get_windows_user (connection, &windows_sid))
 586     {
 587       if (!_dbus_string_append_printf (&loginfo_buf, "sid=\"%s\" ", windows_sid))
 588         goto oom;
 589       dbus_free (windows_sid);
 590     }
 591
 592   if (!_dbus_string_steal_data (&loginfo_buf, &(d->cached_loginfo_string)))
 593     goto oom;
 594
 595   _dbus_string_free (&loginfo_buf);
 596
 597   return TRUE;
 598 oom:
 599    _dbus_string_free (&loginfo_buf);
 600    return FALSE;
 601 }
 602
 603 dbus_bool_t
 604 bus_connections_setup_connection (BusConnections *connections,
 605                                   DBusConnection *connection)
 606 {
 607
 608   BusConnectionData *d;
 609   dbus_bool_t retval;
 610   DBusError error;
 611
 612
 613   d = dbus_new0 (BusConnectionData, 1);
 614
 615   if (d == NULL)
 616     return FALSE;
 617
 618   d->connections = connections;
 619   d->connection = connection;
 620
 621   _dbus_get_current_time (&d->connection_tv_sec,
 622                           &d->connection_tv_usec);
 623
 624   _dbus_assert (connection_data_slot >= 0);
 625
 626   if (!dbus_connection_set_data (connection,
 627                                  connection_data_slot,
 628                                  d, free_connection_data))
 629     {
 630       dbus_free (d);
 631       return FALSE;
 632     }
 633
 634   dbus_connection_set_route_peer_messages (connection, TRUE);
 635
 636   retval = FALSE;
 637
 638   dbus_error_init (&error);
 639   d->selinux_id = bus_selinux_init_connection_id (connection,
 640                                                   &error);
 641   if (dbus_error_is_set (&error))
 642     {
 643       /* This is a bit bogus because we pretend all errors
 644        * are OOM; this is done because we know that in bus.c
 645        * an OOM error disconnects the connection, which is
 646        * the same thing we want on any other error.
 647        */
 648       dbus_error_free (&error);
 649       goto out;
 650     }
 651
 652   if (!dbus_connection_set_watch_functions (connection,
 653                                             add_connection_watch,
 654                                             remove_connection_watch,
 655                                             NULL,
 656                                             connection,
 657                                             NULL))
 658     goto out;
 659
 660   if (!dbus_connection_set_timeout_functions (connection,
 661                                               add_connection_timeout,
 662                                               remove_connection_timeout,
 663                                               NULL,
 664                                               connection, NULL))
 665     goto out;
 666
 667   /* For now we don't need to set a Windows user function because
 668    * there are no policies in the config file controlling what
 669    * Windows users can connect. The default 'same user that owns the
 670    * bus can connect' behavior of DBusConnection is fine on Windows.
 671    */
 672   dbus_connection_set_unix_user_function (connection,
 673                                           allow_unix_user_function,
 674                                           NULL, NULL);
 675
 676   dbus_connection_set_dispatch_status_function (connection,
 677                                                 dispatch_status_function,
 678                                                 bus_context_get_loop (connections->context),
 679                                                 NULL);
 680
 681   d->link_in_connection_list = _dbus_list_alloc_link (connection);
 682   if (d->link_in_connection_list == NULL)
 683     goto out;
 684
 685   /* Setup the connection with the dispatcher */
 686   if (!bus_dispatch_add_connection (connection))
 687     goto out;
 688
 689   if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE)
 690     {
 691       if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection))
 692         {
 693           bus_dispatch_remove_connection (connection);
 694           goto out;
 695         }
 696     }
 697
 698   _dbus_list_append_link (&connections->incomplete, d->link_in_connection_list);
 699   connections->n_incomplete += 1;
 700
 701   dbus_connection_ref (connection);
 702
 703   /* Note that we might disconnect ourselves here, but it only takes
 704    * effect on return to the main loop. We call this to free up
 705    * expired connections if possible, and to queue the timeout for our
 706    * own expiration.
 707    */
 708   bus_connections_expire_incomplete (connections);
 709
 710   /* And we might also disconnect ourselves here, but again it
 711    * only takes effect on return to main loop.
 712    */
 713   if (connections->n_incomplete >
 714       bus_context_get_max_incomplete_connections (connections->context))
 715     {
 716       _dbus_verbose ("Number of incomplete connections exceeds max, dropping oldest one\n");
 717
 718       _dbus_assert (connections->incomplete != NULL);
 719       /* Disconnect the oldest unauthenticated connection.  FIXME
 720        * would it be more secure to drop a *random* connection?  This
 721        * algorithm seems to mean that if someone can create new
 722        * connections quickly enough, they can keep anyone else from
 723        * completing authentication. But random may or may not really
 724        * help with that, a more elaborate solution might be required.
 725        */
 726       dbus_connection_close (connections->incomplete->data);
 727     }
 728
 729   retval = TRUE;
 730
 731  out:
 732   if (!retval)
 733     {
 734       if (d->selinux_id)
 735         bus_selinux_id_unref (d->selinux_id);
 736       d->selinux_id = NULL;
 737
 738       if (!dbus_connection_set_watch_functions (connection,
 739                                                 NULL, NULL, NULL,
 740                                                 connection,
 741                                                 NULL))
 742         _dbus_assert_not_reached ("setting watch functions to NULL failed");
 743
 744       if (!dbus_connection_set_timeout_functions (connection,
 745                                                   NULL, NULL, NULL,
 746                                                   connection,
 747                                                   NULL))
 748         _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 749
 750       dbus_connection_set_unix_user_function (connection,
 751                                               NULL, NULL, NULL);
 752
 753       dbus_connection_set_windows_user_function (connection,
 754                                                  NULL, NULL, NULL);
 755
 756       dbus_connection_set_dispatch_status_function (connection,
 757                                                     NULL, NULL, NULL);
 758
 759       if (d->link_in_connection_list != NULL)
 760         {
 761           _dbus_assert (d->link_in_connection_list->next == NULL);
 762           _dbus_assert (d->link_in_connection_list->prev == NULL);
 763           _dbus_list_free_link (d->link_in_connection_list);
 764           d->link_in_connection_list = NULL;
 765         }
 766
 767       if (!dbus_connection_set_data (connection,
 768                                      connection_data_slot,
 769                                      NULL, NULL))
 770         _dbus_assert_not_reached ("failed to set connection data to null");
 771
 772       /* "d" has now been freed */
 773     }
 774
 775   return retval;
 776 }
 777
 778 void
 779 bus_connections_expire_incomplete (BusConnections *connections)
 780 {
 781   int next_interval;
 782
 783   next_interval = -1;
 784
 785   if (connections->incomplete != NULL)
 786     {
 787       long tv_sec, tv_usec;
 788       DBusList *link;
 789       int auth_timeout;
 790
 791       _dbus_get_current_time (&tv_sec, &tv_usec);
 792       auth_timeout = bus_context_get_auth_timeout (connections->context);
 793
 794       link = _dbus_list_get_first_link (&connections->incomplete);
 795       while (link != NULL)
 796         {
 797           DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 798           DBusConnection *connection;
 799           BusConnectionData *d;
 800           double elapsed;
 801
 802           connection = link->data;
 803
 804           d = BUS_CONNECTION_DATA (connection);
 805
 806           _dbus_assert (d != NULL);
 807
 808           elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec,
 809                                                 d->connection_tv_usec,
 810                                                 tv_sec, tv_usec);
 811
 812           if (elapsed >= (double) auth_timeout)
 813             {
 814               _dbus_verbose ("Timing out authentication for connection %p\n", connection);
 815               dbus_connection_close (connection);
 816             }
 817           else
 818             {
 819               /* We can end the loop, since the connections are in oldest-first order */
 820               next_interval = ((double)auth_timeout) - elapsed;
 821               _dbus_verbose ("Connection %p authentication expires in %d milliseconds\n",
 822                              connection, next_interval);
 823
 824               break;
 825             }
 826
 827           link = next;
 828         }
 829     }
 830
 831   bus_expire_timeout_set_interval (connections->expire_timeout,
 832                                    next_interval);
 833 }
 834
 835 static dbus_bool_t
 836 expire_incomplete_timeout (void *data)
 837 {
 838   BusConnections *connections = data;
 839
 840   _dbus_verbose ("Running %s\n", _DBUS_FUNCTION_NAME);
 841
 842   /* note that this may remove the timeout */
 843   bus_connections_expire_incomplete (connections);
 844
 845   return TRUE;
 846 }
 847
 848 dbus_bool_t
 849 bus_connection_get_unix_groups  (DBusConnection   *connection,
 850                                  unsigned long   **groups,
 851                                  int              *n_groups,
 852                                  DBusError        *error)
 853 {
 854   BusConnectionData *d;
 855   unsigned long uid;
 856
 857   d = BUS_CONNECTION_DATA (connection);
 858
 859   _dbus_assert (d != NULL);
 860
 861   *groups = NULL;
 862   *n_groups = 0;
 863
 864   if (dbus_connection_get_unix_user (connection, &uid))
 865     {
 866       if (!_dbus_unix_groups_from_uid (uid, groups, n_groups))
 867         {
 868           _dbus_verbose ("Did not get any groups for UID %lu\n",
 869                          uid);
 870           return FALSE;
 871         }
 872       else
 873         {
 874           _dbus_verbose ("Got %d groups for UID %lu\n",
 875                          *n_groups, uid);
 876           return TRUE;
 877         }
 878     }
 879   else
 880     return TRUE; /* successfully got 0 groups */
 881 }
 882
 883 dbus_bool_t
 884 bus_connection_is_in_unix_group (DBusConnection *connection,
 885                                  unsigned long   gid)
 886 {
 887   int i;
 888   unsigned long *group_ids;
 889   int n_group_ids;
 890
 891   if (!bus_connection_get_unix_groups (connection, &group_ids, &n_group_ids,
 892                                        NULL))
 893     return FALSE;
 894
 895   i = 0;
 896   while (i < n_group_ids)
 897     {
 898       if (group_ids[i] == gid)
 899         {
 900           dbus_free (group_ids);
 901           return TRUE;
 902         }
 903       ++i;
 904     }
 905
 906   dbus_free (group_ids);
 907   return FALSE;
 908 }
 909
 910 const char *
 911 bus_connection_get_loginfo (DBusConnection        *connection)
 912 {
 913   BusConnectionData *d;
 914
 915   d = BUS_CONNECTION_DATA (connection);
 916
 917   if (!bus_connection_is_active (connection))
 918     return "inactive";
 919   return d->cached_loginfo_string;
 920 }
 921
 922 BusClientPolicy*
 923 bus_connection_get_policy (DBusConnection *connection)
 924 {
 925   BusConnectionData *d;
 926
 927   d = BUS_CONNECTION_DATA (connection);
 928
 929   _dbus_assert (d != NULL);
 930   _dbus_assert (d->policy != NULL);
 931
 932   return d->policy;
 933 }
 934
 935 static dbus_bool_t
 936 foreach_active (BusConnections               *connections,
 937                 BusConnectionForeachFunction  function,
 938                 void                         *data)
 939 {
 940   DBusList *link;
 941
 942   link = _dbus_list_get_first_link (&connections->completed);
 943   while (link != NULL)
 944     {
 945       DBusConnection *connection = link->data;
 946       DBusList *next = _dbus_list_get_next_link (&connections->completed, link);
 947
 948       if (!(* function) (connection, data))
 949         return FALSE;
 950
 951       link = next;
 952     }
 953
 954   return TRUE;
 955 }
 956
 957 static dbus_bool_t
 958 foreach_inactive (BusConnections               *connections,
 959                   BusConnectionForeachFunction  function,
 960                   void                         *data)
 961 {
 962   DBusList *link;
 963
 964   link = _dbus_list_get_first_link (&connections->incomplete);
 965   while (link != NULL)
 966     {
 967       DBusConnection *connection = link->data;
 968       DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 969
 970       if (!(* function) (connection, data))
 971         return FALSE;
 972
 973       link = next;
 974     }
 975
 976   return TRUE;
 977 }
 978
 979 /**
 980  * Calls function on each active connection; if the function returns
 981  * #FALSE, stops iterating. Active connections are authenticated
 982  * and have sent a Hello message.
 983  *
 984  * @param connections the connections object
 985  * @param function the function
 986  * @param data data to pass to it as a second arg
 987  */
 988 void
 989 bus_connections_foreach_active (BusConnections               *connections,
 990                                 BusConnectionForeachFunction  function,
 991                                 void                         *data)
 992 {
 993   foreach_active (connections, function, data);
 994 }
 995
 996 /**
 997  * Calls function on each connection; if the function returns
 998  * #FALSE, stops iterating.
 999  *
1000  * @param connections the connections object
1001  * @param function the function
1002  * @param data data to pass to it as a second arg
1003  */
1004 void
1005 bus_connections_foreach (BusConnections               *connections,
1006                          BusConnectionForeachFunction  function,
1007                          void                         *data)
1008 {
1009   if (!foreach_active (connections, function, data))
1010     return;
1011
1012   foreach_inactive (connections, function, data);
1013 }
1014
1015 BusContext*
1016 bus_connections_get_context (BusConnections *connections)
1017 {
1018   return connections->context;
1019 }
1020
1021 /*
1022  * This is used to avoid covering the same connection twice when
1023  * traversing connections. Note that it assumes we will
1024  * bus_connection_mark_stamp() each connection at least once per
1025  * INT_MAX increments of the global stamp, or wraparound would break
1026  * things.
1027  */
1028 void
1029 bus_connections_increment_stamp (BusConnections *connections)
1030 {
1031   connections->stamp += 1;
1032 }
1033
1034 /* Mark connection with current stamp, return TRUE if it
1035  * didn't already have that stamp
1036  */
1037 dbus_bool_t
1038 bus_connection_mark_stamp (DBusConnection *connection)
1039 {
1040   BusConnectionData *d;
1041
1042   d = BUS_CONNECTION_DATA (connection);
1043
1044   _dbus_assert (d != NULL);
1045
1046   if (d->stamp == d->connections->stamp)
1047     return FALSE;
1048   else
1049     {
1050       d->stamp = d->connections->stamp;
1051       return TRUE;
1052     }
1053 }
1054
1055 BusContext*
1056 bus_connection_get_context (DBusConnection *connection)
1057 {
1058   BusConnectionData *d;
1059
1060   d = BUS_CONNECTION_DATA (connection);
1061
1062   _dbus_assert (d != NULL);
1063
1064   return d->connections->context;
1065 }
1066
1067 BusConnections*
1068 bus_connection_get_connections (DBusConnection *connection)
1069 {
1070   BusConnectionData *d;
1071
1072   d = BUS_CONNECTION_DATA (connection);
1073
1074   _dbus_assert (d != NULL);
1075
1076   return d->connections;
1077 }
1078
1079 BusRegistry*
1080 bus_connection_get_registry (DBusConnection *connection)
1081 {
1082   BusConnectionData *d;
1083
1084   d = BUS_CONNECTION_DATA (connection);
1085
1086   _dbus_assert (d != NULL);
1087
1088   return bus_context_get_registry (d->connections->context);
1089 }
1090
1091 BusActivation*
1092 bus_connection_get_activation (DBusConnection *connection)
1093 {
1094   BusConnectionData *d;
1095
1096   d = BUS_CONNECTION_DATA (connection);
1097
1098   _dbus_assert (d != NULL);
1099
1100   return bus_context_get_activation (d->connections->context);
1101 }
1102
1103 BusMatchmaker*
1104 bus_connection_get_matchmaker (DBusConnection *connection)
1105 {
1106   BusConnectionData *d;
1107
1108   d = BUS_CONNECTION_DATA (connection);
1109
1110   _dbus_assert (d != NULL);
1111
1112   return bus_context_get_matchmaker (d->connections->context);
1113 }
1114
1115 BusSELinuxID*
1116 bus_connection_get_selinux_id (DBusConnection *connection)
1117 {
1118   BusConnectionData *d;
1119
1120   d = BUS_CONNECTION_DATA (connection);
1121
1122   _dbus_assert (d != NULL);
1123
1124   return d->selinux_id;
1125 }
1126
1127 /**
1128  * Checks whether the connection is registered with the message bus.
1129  *
1130  * @param connection the connection
1131  * @returns #TRUE if we're an active message bus participant
1132  */
1133 dbus_bool_t
1134 bus_connection_is_active (DBusConnection *connection)
1135 {
1136   BusConnectionData *d;
1137
1138   d = BUS_CONNECTION_DATA (connection);
1139
1140   return d != NULL && d->name != NULL;
1141 }
1142
1143 dbus_bool_t
1144 bus_connection_preallocate_oom_error (DBusConnection *connection)
1145 {
1146   DBusMessage *message;
1147   DBusPreallocatedSend *preallocated;
1148   BusConnectionData *d;
1149
1150   d = BUS_CONNECTION_DATA (connection);
1151
1152   _dbus_assert (d != NULL);
1153
1154   if (d->oom_preallocated != NULL)
1155     return TRUE;
1156
1157   preallocated = dbus_connection_preallocate_send (connection);
1158   if (preallocated == NULL)
1159     return FALSE;
1160
1161   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1162
1163   if (message == NULL)
1164     {
1165       dbus_connection_free_preallocated_send (connection, preallocated);
1166       return FALSE;
1167     }
1168
1169   /* d->name may be NULL, but that is OK */
1170   if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) ||
1171       !dbus_message_set_destination (message, d->name) ||
1172       !dbus_message_set_sender (message,
1173                                 DBUS_SERVICE_DBUS))
1174     {
1175       dbus_connection_free_preallocated_send (connection, preallocated);
1176       dbus_message_unref (message);
1177       return FALSE;
1178     }
1179
1180   /* set reply serial to placeholder value just so space is already allocated
1181    * for it.
1182    */
1183   if (!dbus_message_set_reply_serial (message, 14))
1184     {
1185       dbus_connection_free_preallocated_send (connection, preallocated);
1186       dbus_message_unref (message);
1187       return FALSE;
1188     }
1189
1190   d->oom_message = message;
1191   d->oom_preallocated = preallocated;
1192
1193   return TRUE;
1194 }
1195
1196 void
1197 bus_connection_send_oom_error (DBusConnection *connection,
1198                                DBusMessage    *in_reply_to)
1199 {
1200   BusConnectionData *d;
1201
1202   d = BUS_CONNECTION_DATA (connection);
1203
1204   _dbus_assert (d != NULL);
1205   _dbus_assert (d->oom_message != NULL);
1206
1207   /* should always succeed since we set it to a placeholder earlier */
1208   if (!dbus_message_set_reply_serial (d->oom_message,
1209                                       dbus_message_get_serial (in_reply_to)))
1210     _dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message");
1211
1212   _dbus_assert (dbus_message_get_sender (d->oom_message) != NULL);
1213
1214   dbus_connection_send_preallocated (connection, d->oom_preallocated,
1215                                      d->oom_message, NULL);
1216
1217   dbus_message_unref (d->oom_message);
1218   d->oom_message = NULL;
1219   d->oom_preallocated = NULL;
1220 }
1221
1222 void
1223 bus_connection_add_match_rule_link (DBusConnection *connection,
1224                                     DBusList       *link)
1225 {
1226   BusConnectionData *d;
1227
1228   d = BUS_CONNECTION_DATA (connection);
1229   _dbus_assert (d != NULL);
1230
1231   _dbus_list_append_link (&d->match_rules, link);
1232
1233   d->n_match_rules += 1;
1234 }
1235
1236 dbus_bool_t
1237 bus_connection_add_match_rule (DBusConnection *connection,
1238                                BusMatchRule   *rule)
1239 {
1240     DBusList *link;
1241
1242   link = _dbus_list_alloc_link (rule);
1243
1244   if (link == NULL)
1245     return FALSE;
1246
1247   bus_connection_add_match_rule_link (connection, link);
1248
1249   return TRUE;
1250 }
1251
1252 void
1253 bus_connection_remove_match_rule (DBusConnection *connection,
1254                                   BusMatchRule   *rule)
1255 {
1256   BusConnectionData *d;
1257
1258   d = BUS_CONNECTION_DATA (connection);
1259   _dbus_assert (d != NULL);
1260
1261   _dbus_list_remove_last (&d->match_rules, rule);
1262
1263   d->n_match_rules -= 1;
1264   _dbus_assert (d->n_match_rules >= 0);
1265 }
1266
1267 int
1268 bus_connection_get_n_match_rules (DBusConnection *connection)
1269 {
1270   BusConnectionData *d;
1271
1272   d = BUS_CONNECTION_DATA (connection);
1273   _dbus_assert (d != NULL);
1274
1275   return d->n_match_rules;
1276 }
1277
1278 void
1279 bus_connection_add_owned_service_link (DBusConnection *connection,
1280                                        DBusList       *link)
1281 {
1282   BusConnectionData *d;
1283
1284   d = BUS_CONNECTION_DATA (connection);
1285   _dbus_assert (d != NULL);
1286
1287   _dbus_list_append_link (&d->services_owned, link);
1288
1289   d->n_services_owned += 1;
1290 }
1291
1292 dbus_bool_t
1293 bus_connection_add_owned_service (DBusConnection *connection,
1294                                   BusService     *service)
1295 {
1296   DBusList *link;
1297
1298   link = _dbus_list_alloc_link (service);
1299
1300   if (link == NULL)
1301     return FALSE;
1302
1303   bus_connection_add_owned_service_link (connection, link);
1304
1305   return TRUE;
1306 }
1307
1308 void
1309 bus_connection_remove_owned_service (DBusConnection *connection,
1310                                      BusService     *service)
1311 {
1312   BusConnectionData *d;
1313
1314   d = BUS_CONNECTION_DATA (connection);
1315   _dbus_assert (d != NULL);
1316
1317   _dbus_list_remove_last (&d->services_owned, service);
1318
1319   d->n_services_owned -= 1;
1320   _dbus_assert (d->n_services_owned >= 0);
1321 }
1322
1323 int
1324 bus_connection_get_n_services_owned (DBusConnection *connection)
1325 {
1326   BusConnectionData *d;
1327
1328   d = BUS_CONNECTION_DATA (connection);
1329   _dbus_assert (d != NULL);
1330
1331   return d->n_services_owned;
1332 }
1333
1334 dbus_bool_t
1335 bus_connection_complete (DBusConnection   *connection,
1336                          const DBusString *name,
1337                          DBusError        *error)
1338 {
1339   BusConnectionData *d;
1340   unsigned long uid;
1341
1342   d = BUS_CONNECTION_DATA (connection);
1343   _dbus_assert (d != NULL);
1344   _dbus_assert (d->name == NULL);
1345   _dbus_assert (d->policy == NULL);
1346
1347   _dbus_assert (!bus_connection_is_active (connection));
1348
1349   if (!_dbus_string_copy_data (name, &d->name))
1350     {
1351       BUS_SET_OOM (error);
1352       return FALSE;
1353     }
1354
1355   _dbus_assert (d->name != NULL);
1356
1357   _dbus_verbose ("Name %s assigned to %p\n", d->name, connection);
1358
1359   d->policy = bus_context_create_client_policy (d->connections->context,
1360                                                 connection,
1361                                                 error);
1362
1363   /* we may have a NULL policy on OOM or error getting list of
1364    * groups for a user. In the latter case we don't handle it so
1365    * well currently, as it will just keep failing over and over.
1366    */
1367
1368   if (d->policy == NULL)
1369     {
1370       _dbus_verbose ("Failed to create security policy for connection %p\n",
1371                      connection);
1372       _DBUS_ASSERT_ERROR_IS_SET (error);
1373       dbus_free (d->name);
1374       d->name = NULL;
1375       return FALSE;
1376     }
1377
1378   if (dbus_connection_get_unix_user (connection, &uid))
1379     {
1380       if (!adjust_connections_for_uid (d->connections,
1381                                        uid, 1))
1382         goto fail;
1383     }
1384
1385   /* Create and cache a string which holds information about the
1386    * peer process; used for logging purposes.
1387    */
1388   if (!cache_peer_loginfo_string (d, connection))
1389     goto fail;
1390
1391   /* Now the connection is active, move it between lists */
1392   _dbus_list_unlink (&d->connections->incomplete,
1393                      d->link_in_connection_list);
1394   d->connections->n_incomplete -= 1;
1395   _dbus_list_append_link (&d->connections->completed,
1396                           d->link_in_connection_list);
1397   d->connections->n_completed += 1;
1398
1399   _dbus_assert (d->connections->n_incomplete >= 0);
1400   _dbus_assert (d->connections->n_completed > 0);
1401
1402   /* See if we can remove the timeout */
1403   bus_connections_expire_incomplete (d->connections);
1404
1405   _dbus_assert (bus_connection_is_active (connection));
1406
1407   return TRUE;
1408 fail:
1409   BUS_SET_OOM (error);
1410   dbus_free (d->name);
1411   d->name = NULL;
1412   if (d->policy)
1413     bus_client_policy_unref (d->policy);
1414   d->policy = NULL;
1415   return FALSE;
1416 }
1417
1418 const char *
1419 bus_connection_get_name (DBusConnection *connection)
1420 {
1421   BusConnectionData *d;
1422
1423   d = BUS_CONNECTION_DATA (connection);
1424   _dbus_assert (d != NULL);
1425
1426   return d->name;
1427 }
1428
1429 /**
1430  * Check whether completing the passed-in connection would
1431  * exceed limits, and if so set error and return #FALSE
1432  */
1433 dbus_bool_t
1434 bus_connections_check_limits (BusConnections  *connections,
1435                               DBusConnection  *requesting_completion,
1436                               DBusError       *error)
1437 {
1438   BusConnectionData *d;
1439   unsigned long uid;
1440
1441   d = BUS_CONNECTION_DATA (requesting_completion);
1442   _dbus_assert (d != NULL);
1443
1444   _dbus_assert (d->name == NULL);
1445
1446   if (connections->n_completed >=
1447       bus_context_get_max_completed_connections (connections->context))
1448     {
1449       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1450                       "The maximum number of active connections has been reached");
1451       return FALSE;
1452     }
1453
1454   if (dbus_connection_get_unix_user (requesting_completion, &uid))
1455     {
1456       if (get_connections_for_uid (connections, uid) >=
1457           bus_context_get_max_connections_per_user (connections->context))
1458         {
1459           dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1460                           "The maximum number of active connections for UID %lu has been reached",
1461                           uid);
1462           return FALSE;
1463         }
1464     }
1465
1466   return TRUE;
1467 }
1468
1469 static void
1470 bus_pending_reply_free (BusPendingReply *pending)
1471 {
1472   _dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n",
1473                  pending,
1474                  pending->will_send_reply,
1475                  pending->will_get_reply,
1476                  pending->reply_serial);
1477
1478   dbus_free (pending);
1479 }
1480
1481 static dbus_bool_t
1482 bus_pending_reply_send_no_reply (BusConnections  *connections,
1483                                  BusTransaction  *transaction,
1484                                  BusPendingReply *pending)
1485 {
1486   DBusMessage *message;
1487   DBusMessageIter iter;
1488   dbus_bool_t retval;
1489   const char *errmsg;
1490
1491   retval = FALSE;
1492
1493   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1494   if (message == NULL)
1495     return FALSE;
1496
1497   dbus_message_set_no_reply (message, TRUE);
1498
1499   if (!dbus_message_set_reply_serial (message,
1500                                       pending->reply_serial))
1501     goto out;
1502
1503   if (!dbus_message_set_error_name (message,
1504                                     DBUS_ERROR_NO_REPLY))
1505     goto out;
1506
1507   errmsg = "Message did not receive a reply (timeout by message bus)";
1508   dbus_message_iter_init_append (message, &iter);
1509   if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg))
1510     goto out;
1511
1512   if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply,
1513                                          message))
1514     goto out;
1515
1516   retval = TRUE;
1517
1518  out:
1519   dbus_message_unref (message);
1520   return retval;
1521 }
1522
1523 static dbus_bool_t
1524 bus_pending_reply_expired (BusExpireList *list,
1525                            DBusList      *link,
1526                            void          *data)
1527 {
1528   BusPendingReply *pending = link->data;
1529   BusConnections *connections = data;
1530   BusTransaction *transaction;
1531
1532   /* No reply is forthcoming. So nuke it if we can. If not,
1533    * leave it in the list to try expiring again later when we
1534    * get more memory.
1535    */
1536
1537   _dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n",
1538                  pending,
1539                  pending->will_send_reply,
1540                  pending->will_get_reply,
1541                  pending->reply_serial);
1542
1543   transaction = bus_transaction_new (connections->context);
1544   if (transaction == NULL)
1545     return FALSE;
1546
1547   if (!bus_pending_reply_send_no_reply (connections,
1548                                         transaction,
1549                                         pending))
1550     {
1551       bus_transaction_cancel_and_free (transaction);
1552       return FALSE;
1553     }
1554
1555   bus_expire_list_remove_link (connections->pending_replies, link);
1556
1557   bus_pending_reply_free (pending);
1558   bus_transaction_execute_and_free (transaction);
1559
1560   return TRUE;
1561 }
1562
1563 static void
1564 bus_connection_drop_pending_replies (BusConnections  *connections,
1565                                      DBusConnection  *connection)
1566 {
1567   /* The DBusConnection is almost 100% finalized here, so you can't
1568    * do anything with it except check for pointer equality
1569    */
1570   DBusList *link;
1571
1572   _dbus_verbose ("Dropping pending replies that involve connection %p\n",
1573                  connection);
1574
1575   link = bus_expire_list_get_first_link (connections->pending_replies);
1576   while (link != NULL)
1577     {
1578       DBusList *next;
1579       BusPendingReply *pending;
1580
1581       next = bus_expire_list_get_next_link (connections->pending_replies,
1582                                             link);
1583       pending = link->data;
1584
1585       if (pending->will_get_reply == connection)
1586         {
1587           /* We don't need to track this pending reply anymore */
1588
1589           _dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n",
1590                          pending,
1591                          pending->will_send_reply,
1592                          pending->will_get_reply,
1593                          pending->reply_serial);
1594
1595           bus_expire_list_remove_link (connections->pending_replies,
1596                                        link);
1597           bus_pending_reply_free (pending);
1598         }
1599       else if (pending->will_send_reply == connection)
1600         {
1601           /* The reply isn't going to be sent, so set things
1602            * up so it will be expired right away
1603            */
1604           _dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n",
1605                          pending,
1606                          pending->will_send_reply,
1607                          pending->will_get_reply,
1608                          pending->reply_serial);
1609
1610           pending->will_send_reply = NULL;
1611           pending->expire_item.added_tv_sec = 0;
1612           pending->expire_item.added_tv_usec = 0;
1613
1614           bus_expire_list_recheck_immediately (connections->pending_replies);
1615         }
1616
1617       link = next;
1618     }
1619 }
1620
1621
1622 typedef struct
1623 {
1624   BusPendingReply *pending;
1625   BusConnections  *connections;
1626 } CancelPendingReplyData;
1627
1628 static void
1629 cancel_pending_reply (void *data)
1630 {
1631   CancelPendingReplyData *d = data;
1632
1633   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1634
1635   if (!bus_expire_list_remove (d->connections->pending_replies,
1636                                &d->pending->expire_item))
1637     _dbus_assert_not_reached ("pending reply did not exist to be cancelled");
1638
1639   bus_pending_reply_free (d->pending); /* since it's been cancelled */
1640 }
1641
1642 static void
1643 cancel_pending_reply_data_free (void *data)
1644 {
1645   CancelPendingReplyData *d = data;
1646
1647   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1648
1649   /* d->pending should be either freed or still
1650    * in the list of pending replies (owned by someone
1651    * else)
1652    */
1653
1654   dbus_free (d);
1655 }
1656
1657 /*
1658  * Record that a reply is allowed; return TRUE on success.
1659  */
1660 dbus_bool_t
1661 bus_connections_expect_reply (BusConnections  *connections,
1662                               BusTransaction  *transaction,
1663                               DBusConnection  *will_get_reply,
1664                               DBusConnection  *will_send_reply,
1665                               DBusMessage     *reply_to_this,
1666                               DBusError       *error)
1667 {
1668   BusPendingReply *pending;
1669   dbus_uint32_t reply_serial;
1670   DBusList *link;
1671   CancelPendingReplyData *cprd;
1672   int count;
1673
1674   _dbus_assert (will_get_reply != NULL);
1675   _dbus_assert (will_send_reply != NULL);
1676   _dbus_assert (reply_to_this != NULL);
1677
1678   if (dbus_message_get_no_reply (reply_to_this))
1679     return TRUE; /* we won't allow a reply, since client doesn't care for one. */
1680
1681   reply_serial = dbus_message_get_serial (reply_to_this);
1682
1683   link = bus_expire_list_get_first_link (connections->pending_replies);
1684   count = 0;
1685   while (link != NULL)
1686     {
1687       pending = link->data;
1688
1689       if (pending->reply_serial == reply_serial &&
1690           pending->will_get_reply == will_get_reply &&
1691           pending->will_send_reply == will_send_reply)
1692         {
1693           dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1694                           "Message has the same reply serial as a currently-outstanding existing method call");
1695           return FALSE;
1696         }
1697
1698       link = bus_expire_list_get_next_link (connections->pending_replies,
1699                                             link);
1700       if (pending->will_get_reply == will_get_reply)
1701         ++count;
1702     }
1703
1704   if (count >=
1705       bus_context_get_max_replies_per_connection (connections->context))
1706     {
1707       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1708                       "The maximum number of pending replies per connection has been reached");
1709       return FALSE;
1710     }
1711
1712   pending = dbus_new0 (BusPendingReply, 1);
1713   if (pending == NULL)
1714     {
1715       BUS_SET_OOM (error);
1716       return FALSE;
1717     }
1718
1719 #ifdef DBUS_ENABLE_VERBOSE_MODE
1720   /* so we can see a not-yet-added pending reply */
1721   pending->expire_item.added_tv_sec = 1;
1722   pending->expire_item.added_tv_usec = 1;
1723 #endif
1724
1725   pending->will_get_reply = will_get_reply;
1726   pending->will_send_reply = will_send_reply;
1727   pending->reply_serial = reply_serial;
1728
1729   cprd = dbus_new0 (CancelPendingReplyData, 1);
1730   if (cprd == NULL)
1731     {
1732       BUS_SET_OOM (error);
1733       bus_pending_reply_free (pending);
1734       return FALSE;
1735     }
1736
1737   if (!bus_expire_list_add (connections->pending_replies,
1738                             &pending->expire_item))
1739     {
1740       BUS_SET_OOM (error);
1741       dbus_free (cprd);
1742       bus_pending_reply_free (pending);
1743       return FALSE;
1744     }
1745
1746   if (!bus_transaction_add_cancel_hook (transaction,
1747                                         cancel_pending_reply,
1748                                         cprd,
1749                                         cancel_pending_reply_data_free))
1750     {
1751       BUS_SET_OOM (error);
1752       bus_expire_list_remove (connections->pending_replies, &pending->expire_item);
1753       dbus_free (cprd);
1754       bus_pending_reply_free (pending);
1755       return FALSE;
1756     }
1757
1758   cprd->pending = pending;
1759   cprd->connections = connections;
1760
1761   _dbus_get_current_time (&pending->expire_item.added_tv_sec,
1762                           &pending->expire_item.added_tv_usec);
1763
1764   _dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n",
1765                  pending,
1766                  pending->will_send_reply,
1767                  pending->will_get_reply,
1768                  pending->reply_serial);
1769
1770   return TRUE;
1771 }
1772
1773 typedef struct
1774 {
1775   DBusList        *link;
1776   BusConnections  *connections;
1777 } CheckPendingReplyData;
1778
1779 static void
1780 cancel_check_pending_reply (void *data)
1781 {
1782   CheckPendingReplyData *d = data;
1783
1784   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1785
1786   bus_expire_list_add_link (d->connections->pending_replies,
1787                             d->link);
1788   d->link = NULL;
1789 }
1790
1791 static void
1792 check_pending_reply_data_free (void *data)
1793 {
1794   CheckPendingReplyData *d = data;
1795
1796   _dbus_verbose ("%s: d = %p\n", _DBUS_FUNCTION_NAME, d);
1797
1798   if (d->link != NULL)
1799     {
1800       BusPendingReply *pending = d->link->data;
1801
1802       _dbus_assert (!bus_expire_list_contains_item (d->connections->pending_replies,
1803                                                     &pending->expire_item));
1804
1805       bus_pending_reply_free (pending);
1806       _dbus_list_free_link (d->link);
1807     }
1808
1809   dbus_free (d);
1810 }
1811
1812 /*
1813  * Check whether a reply is allowed, remove BusPendingReply
1814  * if so, return TRUE if so.
1815  */
1816 dbus_bool_t
1817 bus_connections_check_reply (BusConnections *connections,
1818                              BusTransaction *transaction,
1819                              DBusConnection *sending_reply,
1820                              DBusConnection *receiving_reply,
1821                              DBusMessage    *reply,
1822                              DBusError      *error)
1823 {
1824   CheckPendingReplyData *cprd;
1825   DBusList *link;
1826   dbus_uint32_t reply_serial;
1827
1828   _dbus_assert (sending_reply != NULL);
1829   _dbus_assert (receiving_reply != NULL);
1830
1831   reply_serial = dbus_message_get_reply_serial (reply);
1832
1833   link = bus_expire_list_get_first_link (connections->pending_replies);
1834   while (link != NULL)
1835     {
1836       BusPendingReply *pending = link->data;
1837
1838       if (pending->reply_serial == reply_serial &&
1839           pending->will_get_reply == receiving_reply &&
1840           pending->will_send_reply == sending_reply)
1841         {
1842           _dbus_verbose ("Found pending reply with serial %u\n", reply_serial);
1843           break;
1844         }
1845
1846       link = bus_expire_list_get_next_link (connections->pending_replies,
1847                                             link);
1848     }
1849
1850   if (link == NULL)
1851     {
1852       _dbus_verbose ("No pending reply expected\n");
1853
1854       return FALSE;
1855     }
1856
1857   cprd = dbus_new0 (CheckPendingReplyData, 1);
1858   if (cprd == NULL)
1859     {
1860       BUS_SET_OOM (error);
1861       return FALSE;
1862     }
1863
1864   if (!bus_transaction_add_cancel_hook (transaction,
1865                                         cancel_check_pending_reply,
1866                                         cprd,
1867                                         check_pending_reply_data_free))
1868     {
1869       BUS_SET_OOM (error);
1870       dbus_free (cprd);
1871       return FALSE;
1872     }
1873
1874   cprd->link = link;
1875   cprd->connections = connections;
1876
1877   bus_expire_list_unlink (connections->pending_replies,
1878                           link);
1879
1880   _dbus_assert (!bus_expire_list_contains_item (connections->pending_replies, link->data));
1881
1882   return TRUE;
1883 }
1884
1885 /*
1886  * Transactions
1887  *
1888  * Note that this is fairly fragile; in particular, don't try to use
1889  * one transaction across any main loop iterations.
1890  */
1891
1892 typedef struct
1893 {
1894   BusTransaction *transaction;
1895   DBusMessage    *message;
1896   DBusPreallocatedSend *preallocated;
1897 } MessageToSend;
1898
1899 typedef struct
1900 {
1901   BusTransactionCancelFunction cancel_function;
1902   DBusFreeFunction free_data_function;
1903   void *data;
1904 } CancelHook;
1905
1906 struct BusTransaction
1907 {
1908   DBusList *connections;
1909   BusContext *context;
1910   DBusList *cancel_hooks;
1911 };
1912
1913 static void
1914 message_to_send_free (DBusConnection *connection,
1915                       MessageToSend  *to_send)
1916 {
1917   if (to_send->message)
1918     dbus_message_unref (to_send->message);
1919
1920   if (to_send->preallocated)
1921     dbus_connection_free_preallocated_send (connection, to_send->preallocated);
1922
1923   dbus_free (to_send);
1924 }
1925
1926 static void
1927 cancel_hook_cancel (void *element,
1928                     void *data)
1929 {
1930   CancelHook *ch = element;
1931
1932   _dbus_verbose ("Running transaction cancel hook\n");
1933
1934   if (ch->cancel_function)
1935     (* ch->cancel_function) (ch->data);
1936 }
1937
1938 static void
1939 cancel_hook_free (void *element,
1940                   void *data)
1941 {
1942   CancelHook *ch = element;
1943
1944   if (ch->free_data_function)
1945     (* ch->free_data_function) (ch->data);
1946
1947   dbus_free (ch);
1948 }
1949
1950 static void
1951 free_cancel_hooks (BusTransaction *transaction)
1952 {
1953   _dbus_list_foreach (&transaction->cancel_hooks,
1954                       cancel_hook_free, NULL);
1955
1956   _dbus_list_clear (&transaction->cancel_hooks);
1957 }
1958
1959 BusTransaction*
1960 bus_transaction_new (BusContext *context)
1961 {
1962   BusTransaction *transaction;
1963
1964   transaction = dbus_new0 (BusTransaction, 1);
1965   if (transaction == NULL)
1966     return NULL;
1967
1968   transaction->context = context;
1969
1970   return transaction;
1971 }
1972
1973 BusContext*
1974 bus_transaction_get_context (BusTransaction  *transaction)
1975 {
1976   return transaction->context;
1977 }
1978
1979 BusConnections*
1980 bus_transaction_get_connections (BusTransaction  *transaction)
1981 {
1982   return bus_context_get_connections (transaction->context);
1983 }
1984
1985 dbus_bool_t
1986 bus_transaction_send_from_driver (BusTransaction *transaction,
1987                                   DBusConnection *connection,
1988                                   DBusMessage    *message)
1989 {
1990   /* We have to set the sender to the driver, and have
1991    * to check security policy since it was not done in
1992    * dispatch.c
1993    */
1994   _dbus_verbose ("Sending %s %s %s from driver\n",
1995                  dbus_message_get_interface (message) ?
1996                  dbus_message_get_interface (message) : "(no interface)",
1997                  dbus_message_get_member (message) ?
1998                  dbus_message_get_member (message) : "(no member)",
1999                  dbus_message_get_error_name (message) ?
2000                  dbus_message_get_error_name (message) : "(no error name)");
2001
2002   if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
2003     return FALSE;
2004
2005   if (bus_connection_is_active (connection))
2006     {
2007       if (!dbus_message_set_destination (message,
2008                                          bus_connection_get_name (connection)))
2009         return FALSE;
2010     }
2011
2012   /* bus driver never wants a reply */
2013   dbus_message_set_no_reply (message, TRUE);
2014
2015   /* If security policy doesn't allow the message, we silently
2016    * eat it; the driver doesn't care about getting a reply.
2017    */
2018   if (!bus_context_check_security_policy (bus_transaction_get_context (transaction),
2019                                           transaction,
2020                                           NULL, connection, connection, message, NULL))
2021     return TRUE;
2022
2023   return bus_transaction_send (transaction, connection, message);
2024 }
2025
2026 dbus_bool_t
2027 bus_transaction_send (BusTransaction *transaction,
2028                       DBusConnection *connection,
2029                       DBusMessage    *message)
2030 {
2031   MessageToSend *to_send;
2032   BusConnectionData *d;
2033   DBusList *link;
2034
2035   _dbus_verbose ("  trying to add %s interface=%s member=%s error=%s to transaction%s\n",
2036                  dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" :
2037                  dbus_message_get_reply_serial (message) != 0 ? "reply" :
2038                  "message",
2039                  dbus_message_get_interface (message) ?
2040                  dbus_message_get_interface (message) : "(unset)",
2041                  dbus_message_get_member (message) ?
2042                  dbus_message_get_member (message) : "(unset)",
2043                  dbus_message_get_error_name (message) ?
2044                  dbus_message_get_error_name (message) : "(unset)",
2045                  dbus_connection_get_is_connected (connection) ?
2046                  "" : " (disconnected)");
2047
2048   _dbus_assert (dbus_message_get_sender (message) != NULL);
2049
2050   if (!dbus_connection_get_is_connected (connection))
2051     return TRUE; /* silently ignore disconnected connections */
2052
2053   d = BUS_CONNECTION_DATA (connection);
2054   _dbus_assert (d != NULL);
2055
2056   to_send = dbus_new (MessageToSend, 1);
2057   if (to_send == NULL)
2058     {
2059       return FALSE;
2060     }
2061
2062   to_send->preallocated = dbus_connection_preallocate_send (connection);
2063   if (to_send->preallocated == NULL)
2064     {
2065       dbus_free (to_send);
2066       return FALSE;
2067     }
2068
2069   dbus_message_ref (message);
2070   to_send->message = message;
2071   to_send->transaction = transaction;
2072
2073   _dbus_verbose ("about to prepend message\n");
2074
2075   if (!_dbus_list_prepend (&d->transaction_messages, to_send))
2076     {
2077       message_to_send_free (connection, to_send);
2078       return FALSE;
2079     }
2080
2081   _dbus_verbose ("prepended message\n");
2082
2083   /* See if we already had this connection in the list
2084    * for this transaction. If we have a pending message,
2085    * then we should already be in transaction->connections
2086    */
2087   link = _dbus_list_get_first_link (&d->transaction_messages);
2088   _dbus_assert (link->data == to_send);
2089   link = _dbus_list_get_next_link (&d->transaction_messages, link);
2090   while (link != NULL)
2091     {
2092       MessageToSend *m = link->data;
2093       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2094
2095       if (m->transaction == transaction)
2096         break;
2097
2098       link = next;
2099     }
2100
2101   if (link == NULL)
2102     {
2103       if (!_dbus_list_prepend (&transaction->connections, connection))
2104         {
2105           _dbus_list_remove (&d->transaction_messages, to_send);
2106           message_to_send_free (connection, to_send);
2107           return FALSE;
2108         }
2109     }
2110
2111   return TRUE;
2112 }
2113
2114 static void
2115 connection_cancel_transaction (DBusConnection *connection,
2116                                BusTransaction *transaction)
2117 {
2118   DBusList *link;
2119   BusConnectionData *d;
2120
2121   d = BUS_CONNECTION_DATA (connection);
2122   _dbus_assert (d != NULL);
2123
2124   link = _dbus_list_get_first_link (&d->transaction_messages);
2125   while (link != NULL)
2126     {
2127       MessageToSend *m = link->data;
2128       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2129
2130       if (m->transaction == transaction)
2131         {
2132           _dbus_list_remove_link (&d->transaction_messages,
2133                                   link);
2134
2135           message_to_send_free (connection, m);
2136         }
2137
2138       link = next;
2139     }
2140 }
2141
2142 void
2143 bus_transaction_cancel_and_free (BusTransaction *transaction)
2144 {
2145   DBusConnection *connection;
2146
2147   _dbus_verbose ("TRANSACTION: cancelled\n");
2148
2149   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2150     connection_cancel_transaction (connection, transaction);
2151
2152   _dbus_assert (transaction->connections == NULL);
2153
2154   _dbus_list_foreach (&transaction->cancel_hooks,
2155                       cancel_hook_cancel, NULL);
2156
2157   free_cancel_hooks (transaction);
2158
2159   dbus_free (transaction);
2160 }
2161
2162 static void
2163 connection_execute_transaction (DBusConnection *connection,
2164                                 BusTransaction *transaction)
2165 {
2166   DBusList *link;
2167   BusConnectionData *d;
2168
2169   d = BUS_CONNECTION_DATA (connection);
2170   _dbus_assert (d != NULL);
2171
2172   /* Send the queue in order (FIFO) */
2173   link = _dbus_list_get_last_link (&d->transaction_messages);
2174   while (link != NULL)
2175     {
2176       MessageToSend *m = link->data;
2177       DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link);
2178
2179       if (m->transaction == transaction)
2180         {
2181           _dbus_list_remove_link (&d->transaction_messages,
2182                                   link);
2183
2184           _dbus_assert (dbus_message_get_sender (m->message) != NULL);
2185
2186           dbus_connection_send_preallocated (connection,
2187                                              m->preallocated,
2188                                              m->message,
2189                                              NULL);
2190
2191           m->preallocated = NULL; /* so we don't double-free it */
2192
2193           message_to_send_free (connection, m);
2194         }
2195
2196       link = prev;
2197     }
2198 }
2199
2200 void
2201 bus_transaction_execute_and_free (BusTransaction *transaction)
2202 {
2203   /* For each connection in transaction->connections
2204    * send the messages
2205    */
2206   DBusConnection *connection;
2207
2208   _dbus_verbose ("TRANSACTION: executing\n");
2209
2210   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2211     connection_execute_transaction (connection, transaction);
2212
2213   _dbus_assert (transaction->connections == NULL);
2214
2215   free_cancel_hooks (transaction);
2216
2217   dbus_free (transaction);
2218 }
2219
2220 static void
2221 bus_connection_remove_transactions (DBusConnection *connection)
2222 {
2223   MessageToSend *to_send;
2224   BusConnectionData *d;
2225
2226   d = BUS_CONNECTION_DATA (connection);
2227   _dbus_assert (d != NULL);
2228
2229   while ((to_send = _dbus_list_get_first (&d->transaction_messages)))
2230     {
2231       /* only has an effect for the first MessageToSend listing this transaction */
2232       _dbus_list_remove (&to_send->transaction->connections,
2233                          connection);
2234
2235       _dbus_list_remove (&d->transaction_messages, to_send);
2236       message_to_send_free (connection, to_send);
2237     }
2238 }
2239
2240 /**
2241  * Converts the DBusError to a message reply
2242  */
2243 dbus_bool_t
2244 bus_transaction_send_error_reply (BusTransaction  *transaction,
2245                                   DBusConnection  *connection,
2246                                   const DBusError *error,
2247                                   DBusMessage     *in_reply_to)
2248 {
2249   DBusMessage *reply;
2250
2251   _dbus_assert (error != NULL);
2252   _DBUS_ASSERT_ERROR_IS_SET (error);
2253
2254   _dbus_verbose ("Sending error reply %s \"%s\"\n",
2255                  error->name, error->message);
2256
2257   reply = dbus_message_new_error (in_reply_to,
2258                                   error->name,
2259                                   error->message);
2260   if (reply == NULL)
2261     return FALSE;
2262
2263   if (!bus_transaction_send_from_driver (transaction, connection, reply))
2264     {
2265       dbus_message_unref (reply);
2266       return FALSE;
2267     }
2268
2269   dbus_message_unref (reply);
2270
2271   return TRUE;
2272 }
2273
2274 dbus_bool_t
2275 bus_transaction_add_cancel_hook (BusTransaction               *transaction,
2276                                  BusTransactionCancelFunction  cancel_function,
2277                                  void                         *data,
2278                                  DBusFreeFunction              free_data_function)
2279 {
2280   CancelHook *ch;
2281
2282   ch = dbus_new (CancelHook, 1);
2283   if (ch == NULL)
2284     return FALSE;
2285
2286   _dbus_verbose ("     adding cancel hook function = %p data = %p\n",
2287                  cancel_function, data);
2288
2289   ch->cancel_function = cancel_function;
2290   ch->data = data;
2291   ch->free_data_function = free_data_function;
2292
2293   /* It's important that the hooks get run in reverse order that they
2294    * were added
2295    */
2296   if (!_dbus_list_prepend (&transaction->cancel_hooks, ch))
2297     {
2298       dbus_free (ch);
2299       return FALSE;
2300     }
2301
2302   return TRUE;
2303 }