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 #include <dbus/dbus-connection-internal.h>
  37
  38 /* Trim executed commands to this length; we want to keep logs readable */
  39 #define MAX_LOG_COMMAND_LEN 50
  40
  41 static void bus_connection_remove_transactions (DBusConnection *connection);
  42
  43 typedef struct
  44 {
  45   BusExpireItem expire_item;
  46
  47   DBusConnection *will_get_reply;
  48   DBusConnection *will_send_reply;
  49
  50   dbus_uint32_t reply_serial;
  51
  52 } BusPendingReply;
  53
  54 struct BusConnections
  55 {
  56   int refcount;
  57   DBusList *completed;  /**< List of all completed connections */
  58   int n_completed;      /**< Length of completed list */
  59   DBusList *incomplete; /**< List of all not-yet-active connections */
  60   int n_incomplete;     /**< Length of incomplete list */
  61   BusContext *context;
  62   DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */
  63   DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */
  64   int stamp;                   /**< Incrementing number */
  65   BusExpireList *pending_replies; /**< List of pending replies */
  66
  67   /** List of all monitoring connections, a subset of completed.
  68    * Each member is a #DBusConnection. */
  69   DBusList *monitors;
  70   BusMatchmaker *monitor_matchmaker;
  71
  72 #ifdef DBUS_ENABLE_STATS
  73   int total_match_rules;
  74   int peak_match_rules;
  75   int peak_match_rules_per_conn;
  76
  77   int total_bus_names;
  78   int peak_bus_names;
  79   int peak_bus_names_per_conn;
  80 #endif
  81 };
  82
  83 static dbus_int32_t connection_data_slot = -1;
  84
  85 typedef struct
  86 {
  87   BusConnections *connections;
  88   DBusList *link_in_connection_list;
  89   DBusConnection *connection;
  90   DBusList *services_owned;
  91   int n_services_owned;
  92   DBusList *match_rules;
  93   int n_match_rules;
  94   char *name;
  95   DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
  96   DBusMessage *oom_message;
  97   DBusPreallocatedSend *oom_preallocated;
  98   BusClientPolicy *policy;
  99
 100   char *cached_loginfo_string;
 101   BusSELinuxID *selinux_id;
 102
 103   long connection_tv_sec;  /**< Time when we connected (seconds component) */
 104   long connection_tv_usec; /**< Time when we connected (microsec component) */
 105   int stamp;               /**< connections->stamp last time we were traversed */
 106
 107 #ifdef DBUS_ENABLE_STATS
 108   int peak_match_rules;
 109   int peak_bus_names;
 110 #endif
 111   int n_pending_unix_fds;
 112   DBusTimeout *pending_unix_fds_timeout;
 113
 114   /** non-NULL if and only if this is a monitor */
 115   DBusList *link_in_monitors;
 116 } BusConnectionData;
 117
 118 static dbus_bool_t bus_pending_reply_expired (BusExpireList *list,
 119                                               DBusList      *link,
 120                                               void          *data);
 121
 122 static void bus_connection_drop_pending_replies (BusConnections  *connections,
 123                                                  DBusConnection  *connection);
 124
 125 static dbus_bool_t expire_incomplete_timeout (void *data);
 126
 127 #define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
 128
 129 static DBusLoop*
 130 connection_get_loop (DBusConnection *connection)
 131 {
 132   BusConnectionData *d;
 133
 134   d = BUS_CONNECTION_DATA (connection);
 135
 136   return bus_context_get_loop (d->connections->context);
 137 }
 138
 139
 140 static int
 141 get_connections_for_uid (BusConnections *connections,
 142                          dbus_uid_t      uid)
 143 {
 144   void *val;
 145   int current_count;
 146
 147   /* val is NULL is 0 when it isn't in the hash yet */
 148
 149   val = _dbus_hash_table_lookup_uintptr (connections->completed_by_user,
 150                                        uid);
 151
 152   current_count = _DBUS_POINTER_TO_INT (val);
 153
 154   return current_count;
 155 }
 156
 157 static dbus_bool_t
 158 adjust_connections_for_uid (BusConnections *connections,
 159                             dbus_uid_t      uid,
 160                             int             adjustment)
 161 {
 162   int current_count;
 163
 164   current_count = get_connections_for_uid (connections, uid);
 165
 166   _dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT
 167                  ": was %d adjustment %d making %d\n",
 168                  uid, current_count, adjustment, current_count + adjustment);
 169
 170   _dbus_assert (current_count >= 0);
 171
 172   current_count += adjustment;
 173
 174   _dbus_assert (current_count >= 0);
 175
 176   if (current_count == 0)
 177     {
 178       _dbus_hash_table_remove_uintptr (connections->completed_by_user, uid);
 179       return TRUE;
 180     }
 181   else
 182     {
 183       dbus_bool_t retval;
 184
 185       retval = _dbus_hash_table_insert_uintptr (connections->completed_by_user,
 186                                               uid, _DBUS_INT_TO_POINTER (current_count));
 187
 188       /* only positive adjustment can fail as otherwise
 189        * a hash entry should already exist
 190        */
 191       _dbus_assert (adjustment > 0 ||
 192                     (adjustment <= 0 && retval));
 193
 194       return retval;
 195     }
 196 }
 197
 198 void
 199 bus_connection_disconnected (DBusConnection *connection)
 200 {
 201   BusConnectionData *d;
 202   BusService *service;
 203   BusMatchmaker *matchmaker;
 204
 205   d = BUS_CONNECTION_DATA (connection);
 206   _dbus_assert (d != NULL);
 207
 208   _dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n",
 209                  d->name ? d->name : "(inactive)");
 210
 211   /* Delete our match rules */
 212   if (d->n_match_rules > 0)
 213     {
 214       matchmaker = bus_context_get_matchmaker (d->connections->context);
 215       bus_matchmaker_disconnected (matchmaker, connection);
 216     }
 217
 218   /* Drop any service ownership. Unfortunately, this requires
 219    * memory allocation and there doesn't seem to be a good way to
 220    * handle it other than sleeping; we can't "fail" the operation of
 221    * disconnecting a client, and preallocating a broadcast "service is
 222    * now gone" message for every client-service pair seems kind of
 223    * involved.
 224    */
 225   while ((service = _dbus_list_get_last (&d->services_owned)))
 226     {
 227       BusTransaction *transaction;
 228       DBusError error;
 229
 230     retry:
 231
 232       dbus_error_init (&error);
 233
 234       while ((transaction = bus_transaction_new (d->connections->context)) == NULL)
 235         _dbus_wait_for_memory ();
 236
 237       if (!bus_service_remove_owner (service, connection,
 238                                      transaction, &error))
 239         {
 240           _DBUS_ASSERT_ERROR_IS_SET (&error);
 241
 242           if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
 243             {
 244               dbus_error_free (&error);
 245               bus_transaction_cancel_and_free (transaction);
 246               _dbus_wait_for_memory ();
 247               goto retry;
 248             }
 249           else
 250             {
 251               _dbus_verbose ("Failed to remove service owner: %s %s\n",
 252                              error.name, error.message);
 253               _dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason");
 254             }
 255         }
 256
 257       bus_transaction_execute_and_free (transaction);
 258     }
 259
 260   bus_dispatch_remove_connection (connection);
 261
 262   /* no more watching */
 263   if (!dbus_connection_set_watch_functions (connection,
 264                                             NULL, NULL, NULL,
 265                                             connection,
 266                                             NULL))
 267     _dbus_assert_not_reached ("setting watch functions to NULL failed");
 268
 269   if (!dbus_connection_set_timeout_functions (connection,
 270                                               NULL, NULL, NULL,
 271                                               connection,
 272                                               NULL))
 273     _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 274
 275   dbus_connection_set_unix_user_function (connection,
 276                                           NULL, NULL, NULL);
 277   dbus_connection_set_windows_user_function (connection,
 278                                              NULL, NULL, NULL);
 279
 280   dbus_connection_set_dispatch_status_function (connection,
 281                                                 NULL, NULL, NULL);
 282
 283   if (d->pending_unix_fds_timeout)
 284     {
 285       _dbus_loop_remove_timeout (bus_context_get_loop (d->connections->context),
 286                                  d->pending_unix_fds_timeout);
 287       _dbus_timeout_unref (d->pending_unix_fds_timeout);
 288     }
 289   d->pending_unix_fds_timeout = NULL;
 290   _dbus_connection_set_pending_fds_function (connection, NULL, NULL);
 291
 292   bus_connection_remove_transactions (connection);
 293
 294   if (d->link_in_monitors != NULL)
 295     {
 296       BusMatchmaker *mm = d->connections->monitor_matchmaker;
 297
 298       if (mm != NULL)
 299         bus_matchmaker_disconnected (mm, connection);
 300
 301       _dbus_list_remove_link (&d->connections->monitors, d->link_in_monitors);
 302       d->link_in_monitors = NULL;
 303     }
 304
 305   if (d->link_in_connection_list != NULL)
 306     {
 307       if (d->name != NULL)
 308         {
 309           unsigned long uid;
 310
 311           _dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list);
 312           d->link_in_connection_list = NULL;
 313           d->connections->n_completed -= 1;
 314
 315           if (dbus_connection_get_unix_user (connection, &uid))
 316             {
 317               if (!adjust_connections_for_uid (d->connections,
 318                                                uid, -1))
 319                 _dbus_assert_not_reached ("adjusting downward should never fail");
 320             }
 321         }
 322       else
 323         {
 324           _dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list);
 325           d->link_in_connection_list = NULL;
 326           d->connections->n_incomplete -= 1;
 327
 328           /* If we have dropped below the max. number of incomplete
 329            * connections, start accept()ing again */
 330           bus_context_check_all_watches (d->connections->context);
 331         }
 332
 333       _dbus_assert (d->connections->n_incomplete >= 0);
 334       _dbus_assert (d->connections->n_completed >= 0);
 335     }
 336
 337   bus_connection_drop_pending_replies (d->connections, connection);
 338
 339   /* frees "d" as side effect */
 340   dbus_connection_set_data (connection,
 341                             connection_data_slot,
 342                             NULL, NULL);
 343
 344   dbus_connection_unref (connection);
 345 }
 346
 347 static dbus_bool_t
 348 add_connection_watch (DBusWatch      *watch,
 349                       void           *data)
 350 {
 351   DBusConnection *connection = data;
 352
 353   return _dbus_loop_add_watch (connection_get_loop (connection), watch);
 354 }
 355
 356 static void
 357 remove_connection_watch (DBusWatch      *watch,
 358                          void           *data)
 359 {
 360   DBusConnection *connection = data;
 361
 362   _dbus_loop_remove_watch (connection_get_loop (connection), watch);
 363 }
 364
 365 static void
 366 toggle_connection_watch (DBusWatch      *watch,
 367                          void           *data)
 368 {
 369   DBusConnection *connection = data;
 370
 371   _dbus_loop_toggle_watch (connection_get_loop (connection), watch);
 372 }
 373
 374 static dbus_bool_t
 375 add_connection_timeout (DBusTimeout    *timeout,
 376                         void           *data)
 377 {
 378   DBusConnection *connection = data;
 379
 380   return _dbus_loop_add_timeout (connection_get_loop (connection), timeout);
 381 }
 382
 383 static void
 384 remove_connection_timeout (DBusTimeout    *timeout,
 385                            void           *data)
 386 {
 387   DBusConnection *connection = data;
 388
 389   _dbus_loop_remove_timeout (connection_get_loop (connection), timeout);
 390 }
 391
 392 static void
 393 dispatch_status_function (DBusConnection    *connection,
 394                           DBusDispatchStatus new_status,
 395                           void              *data)
 396 {
 397   DBusLoop *loop = data;
 398
 399   if (new_status != DBUS_DISPATCH_COMPLETE)
 400     {
 401       while (!_dbus_loop_queue_dispatch (loop, connection))
 402         _dbus_wait_for_memory ();
 403     }
 404 }
 405
 406 static dbus_bool_t
 407 allow_unix_user_function (DBusConnection *connection,
 408                           unsigned long   uid,
 409                           void           *data)
 410 {
 411   BusConnectionData *d;
 412
 413   d = BUS_CONNECTION_DATA (connection);
 414
 415   _dbus_assert (d != NULL);
 416
 417   return bus_context_allow_unix_user (d->connections->context, uid);
 418 }
 419
 420 static void
 421 free_connection_data (void *data)
 422 {
 423   BusConnectionData *d = data;
 424
 425   /* services_owned should be NULL since we should be disconnected */
 426   _dbus_assert (d->services_owned == NULL);
 427   _dbus_assert (d->n_services_owned == 0);
 428   /* similarly */
 429   _dbus_assert (d->transaction_messages == NULL);
 430
 431   if (d->oom_preallocated)
 432     dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated);
 433
 434   if (d->oom_message)
 435     dbus_message_unref (d->oom_message);
 436
 437   if (d->policy)
 438     bus_client_policy_unref (d->policy);
 439
 440   if (d->selinux_id)
 441     bus_selinux_id_unref (d->selinux_id);
 442
 443   dbus_free (d->cached_loginfo_string);
 444
 445   dbus_free (d->name);
 446
 447   dbus_free (d);
 448 }
 449
 450 BusConnections*
 451 bus_connections_new (BusContext *context)
 452 {
 453   BusConnections *connections;
 454
 455   if (!dbus_connection_allocate_data_slot (&connection_data_slot))
 456     goto failed_0;
 457
 458   connections = dbus_new0 (BusConnections, 1);
 459   if (connections == NULL)
 460     goto failed_1;
 461
 462   connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_UINTPTR,
 463                                                          NULL, NULL);
 464   if (connections->completed_by_user == NULL)
 465     goto failed_2;
 466
 467   connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */
 468                                                    expire_incomplete_timeout,
 469                                                    connections, NULL);
 470   if (connections->expire_timeout == NULL)
 471     goto failed_3;
 472
 473   _dbus_timeout_set_enabled (connections->expire_timeout, FALSE);
 474
 475   connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context),
 476                                                       bus_context_get_reply_timeout (context),
 477                                                       bus_pending_reply_expired,
 478                                                       connections);
 479   if (connections->pending_replies == NULL)
 480     goto failed_4;
 481
 482   if (!_dbus_loop_add_timeout (bus_context_get_loop (context),
 483                                connections->expire_timeout))
 484     goto failed_5;
 485
 486   connections->refcount = 1;
 487   connections->context = context;
 488
 489   return connections;
 490
 491  failed_5:
 492   bus_expire_list_free (connections->pending_replies);
 493  failed_4:
 494   _dbus_timeout_unref (connections->expire_timeout);
 495  failed_3:
 496   _dbus_hash_table_unref (connections->completed_by_user);
 497  failed_2:
 498   dbus_free (connections);
 499  failed_1:
 500   dbus_connection_free_data_slot (&connection_data_slot);
 501  failed_0:
 502   return NULL;
 503 }
 504
 505 BusConnections *
 506 bus_connections_ref (BusConnections *connections)
 507 {
 508   _dbus_assert (connections->refcount > 0);
 509   connections->refcount += 1;
 510
 511   return connections;
 512 }
 513
 514 void
 515 bus_connections_unref (BusConnections *connections)
 516 {
 517   _dbus_assert (connections->refcount > 0);
 518   connections->refcount -= 1;
 519   if (connections->refcount == 0)
 520     {
 521       /* drop all incomplete */
 522       while (connections->incomplete != NULL)
 523         {
 524           DBusConnection *connection;
 525
 526           connection = connections->incomplete->data;
 527
 528           dbus_connection_ref (connection);
 529           dbus_connection_close (connection);
 530           bus_connection_disconnected (connection);
 531           dbus_connection_unref (connection);
 532         }
 533
 534       _dbus_assert (connections->n_incomplete == 0);
 535
 536       /* drop all monitors */
 537       _dbus_list_clear (&connections->monitors);
 538
 539       /* drop all real connections */
 540       while (connections->completed != NULL)
 541         {
 542           DBusConnection *connection;
 543
 544           connection = connections->completed->data;
 545
 546           dbus_connection_ref (connection);
 547           dbus_connection_close (connection);
 548           bus_connection_disconnected (connection);
 549           dbus_connection_unref (connection);
 550         }
 551
 552       _dbus_assert (connections->n_completed == 0);
 553
 554       bus_expire_list_free (connections->pending_replies);
 555
 556       _dbus_loop_remove_timeout (bus_context_get_loop (connections->context),
 557                                  connections->expire_timeout);
 558
 559       _dbus_timeout_unref (connections->expire_timeout);
 560
 561       _dbus_hash_table_unref (connections->completed_by_user);
 562
 563       if (connections->monitor_matchmaker != NULL)
 564         bus_matchmaker_unref (connections->monitor_matchmaker);
 565
 566       dbus_free (connections);
 567
 568       dbus_connection_free_data_slot (&connection_data_slot);
 569     }
 570 }
 571
 572 /* Used for logging */
 573 static dbus_bool_t
 574 cache_peer_loginfo_string (BusConnectionData *d,
 575                            DBusConnection    *connection)
 576 {
 577   DBusString loginfo_buf;
 578   unsigned long uid;
 579   unsigned long pid;
 580   char *windows_sid;
 581   dbus_bool_t prev_added;
 582
 583   if (!_dbus_string_init (&loginfo_buf))
 584     return FALSE;
 585
 586   prev_added = FALSE;
 587   if (dbus_connection_get_unix_user (connection, &uid))
 588     {
 589       if (!_dbus_string_append_printf (&loginfo_buf, "uid=%ld", uid))
 590         goto oom;
 591       else
 592         prev_added = TRUE;
 593     }
 594
 595   if (dbus_connection_get_unix_process_id (connection, &pid))
 596     {
 597       if (prev_added)
 598         {
 599           if (!_dbus_string_append_byte (&loginfo_buf, ' '))
 600             goto oom;
 601         }
 602       if (!_dbus_string_append_printf (&loginfo_buf, "pid=%ld comm=\"", pid))
 603         goto oom;
 604       /* Ignore errors here; we may not have permissions to read the
 605        * proc file. */
 606       _dbus_command_for_pid (pid, &loginfo_buf, MAX_LOG_COMMAND_LEN, NULL);
 607       if (!_dbus_string_append_byte (&loginfo_buf, '"'))
 608         goto oom;
 609     }
 610
 611   if (dbus_connection_get_windows_user (connection, &windows_sid))
 612     {
 613       dbus_bool_t did_append;
 614       did_append = _dbus_string_append_printf (&loginfo_buf,
 615                                                "sid=\"%s\" ", windows_sid);
 616       dbus_free (windows_sid);
 617       if (!did_append)
 618         goto oom;
 619     }
 620
 621   if (!_dbus_string_steal_data (&loginfo_buf, &(d->cached_loginfo_string)))
 622     goto oom;
 623
 624   _dbus_string_free (&loginfo_buf);
 625
 626   return TRUE;
 627 oom:
 628    _dbus_string_free (&loginfo_buf);
 629    return FALSE;
 630 }
 631
 632 static void
 633 check_pending_fds_cb (DBusConnection *connection)
 634 {
 635   BusConnectionData *d = BUS_CONNECTION_DATA (connection);
 636   int n_pending_unix_fds_old = d->n_pending_unix_fds;
 637   int n_pending_unix_fds_new;
 638
 639   n_pending_unix_fds_new = _dbus_connection_get_pending_fds_count (connection);
 640
 641   _dbus_verbose ("Pending fds count changed on connection %p: %d -> %d\n",
 642                  connection, n_pending_unix_fds_old, n_pending_unix_fds_new);
 643
 644   if (n_pending_unix_fds_old == 0 && n_pending_unix_fds_new > 0)
 645     {
 646       _dbus_timeout_set_interval (d->pending_unix_fds_timeout,
 647               bus_context_get_pending_fd_timeout (d->connections->context));
 648       _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, TRUE);
 649     }
 650
 651   if (n_pending_unix_fds_old > 0 && n_pending_unix_fds_new == 0)
 652     {
 653       _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, FALSE);
 654     }
 655
 656
 657   d->n_pending_unix_fds = n_pending_unix_fds_new;
 658 }
 659
 660 static dbus_bool_t
 661 pending_unix_fds_timeout_cb (void *data)
 662 {
 663   DBusConnection *connection = data;
 664   dbus_connection_close (connection);
 665   return TRUE;
 666 }
 667
 668 dbus_bool_t
 669 bus_connections_setup_connection (BusConnections *connections,
 670                                   DBusConnection *connection)
 671 {
 672
 673   BusConnectionData *d;
 674   dbus_bool_t retval;
 675   DBusError error;
 676
 677
 678   d = dbus_new0 (BusConnectionData, 1);
 679
 680   if (d == NULL)
 681     return FALSE;
 682
 683   d->connections = connections;
 684   d->connection = connection;
 685
 686   _dbus_get_monotonic_time (&d->connection_tv_sec,
 687                             &d->connection_tv_usec);
 688
 689   _dbus_assert (connection_data_slot >= 0);
 690
 691   if (!dbus_connection_set_data (connection,
 692                                  connection_data_slot,
 693                                  d, free_connection_data))
 694     {
 695       dbus_free (d);
 696       return FALSE;
 697     }
 698
 699   dbus_connection_set_route_peer_messages (connection, TRUE);
 700
 701   retval = FALSE;
 702
 703   dbus_error_init (&error);
 704   d->selinux_id = bus_selinux_init_connection_id (connection,
 705                                                   &error);
 706   if (dbus_error_is_set (&error))
 707     {
 708       /* This is a bit bogus because we pretend all errors
 709        * are OOM; this is done because we know that in bus.c
 710        * an OOM error disconnects the connection, which is
 711        * the same thing we want on any other error.
 712        */
 713       dbus_error_free (&error);
 714       goto out;
 715     }
 716
 717   if (!dbus_connection_set_watch_functions (connection,
 718                                             add_connection_watch,
 719                                             remove_connection_watch,
 720                                             toggle_connection_watch,
 721                                             connection,
 722                                             NULL))
 723     goto out;
 724
 725   if (!dbus_connection_set_timeout_functions (connection,
 726                                               add_connection_timeout,
 727                                               remove_connection_timeout,
 728                                               NULL,
 729                                               connection, NULL))
 730     goto out;
 731
 732   /* For now we don't need to set a Windows user function because
 733    * there are no policies in the config file controlling what
 734    * Windows users can connect. The default 'same user that owns the
 735    * bus can connect' behavior of DBusConnection is fine on Windows.
 736    */
 737   dbus_connection_set_unix_user_function (connection,
 738                                           allow_unix_user_function,
 739                                           NULL, NULL);
 740
 741   dbus_connection_set_dispatch_status_function (connection,
 742                                                 dispatch_status_function,
 743                                                 bus_context_get_loop (connections->context),
 744                                                 NULL);
 745
 746   d->link_in_connection_list = _dbus_list_alloc_link (connection);
 747   if (d->link_in_connection_list == NULL)
 748     goto out;
 749
 750   /* Setup the connection with the dispatcher */
 751   if (!bus_dispatch_add_connection (connection))
 752     goto out;
 753
 754   if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE)
 755     {
 756       if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection))
 757         {
 758           bus_dispatch_remove_connection (connection);
 759           goto out;
 760         }
 761     }
 762
 763   /* Setup pending fds timeout (see #80559) */
 764   d->pending_unix_fds_timeout = _dbus_timeout_new (100, /* irrelevant */
 765                                                    pending_unix_fds_timeout_cb,
 766                                                    connection, NULL);
 767   if (d->pending_unix_fds_timeout == NULL)
 768     goto out;
 769
 770   _dbus_timeout_set_enabled (d->pending_unix_fds_timeout, FALSE);
 771   if (!_dbus_loop_add_timeout (bus_context_get_loop (connections->context),
 772                                d->pending_unix_fds_timeout))
 773     goto out;
 774
 775   _dbus_connection_set_pending_fds_function (connection,
 776           (DBusPendingFdsChangeFunction) check_pending_fds_cb,
 777           connection);
 778
 779   _dbus_list_append_link (&connections->incomplete, d->link_in_connection_list);
 780   connections->n_incomplete += 1;
 781
 782   dbus_connection_ref (connection);
 783
 784   bus_connections_expire_incomplete (connections);
 785
 786   /* The listening socket is removed from the main loop,
 787    * i.e. does not accept(), while n_incomplete is at its
 788    * maximum value; so we shouldn't get here in that case */
 789   _dbus_assert (connections->n_incomplete <=
 790       bus_context_get_max_incomplete_connections (connections->context));
 791
 792   /* If we have the maximum number of incomplete connections,
 793    * stop accept()ing any more, to avert a DoS. See fd.o #80919 */
 794   bus_context_check_all_watches (d->connections->context);
 795
 796   retval = TRUE;
 797
 798  out:
 799   if (!retval)
 800     {
 801       if (d->selinux_id)
 802         bus_selinux_id_unref (d->selinux_id);
 803       d->selinux_id = NULL;
 804
 805       if (!dbus_connection_set_watch_functions (connection,
 806                                                 NULL, NULL, NULL,
 807                                                 connection,
 808                                                 NULL))
 809         _dbus_assert_not_reached ("setting watch functions to NULL failed");
 810
 811       if (!dbus_connection_set_timeout_functions (connection,
 812                                                   NULL, NULL, NULL,
 813                                                   connection,
 814                                                   NULL))
 815         _dbus_assert_not_reached ("setting timeout functions to NULL failed");
 816
 817       dbus_connection_set_unix_user_function (connection,
 818                                               NULL, NULL, NULL);
 819
 820       dbus_connection_set_windows_user_function (connection,
 821                                                  NULL, NULL, NULL);
 822
 823       dbus_connection_set_dispatch_status_function (connection,
 824                                                     NULL, NULL, NULL);
 825
 826       if (d->pending_unix_fds_timeout)
 827         _dbus_timeout_unref (d->pending_unix_fds_timeout);
 828
 829       d->pending_unix_fds_timeout = NULL;
 830
 831       _dbus_connection_set_pending_fds_function (connection, NULL, NULL);
 832
 833       if (d->link_in_connection_list != NULL)
 834         {
 835           _dbus_assert (d->link_in_connection_list->next == NULL);
 836           _dbus_assert (d->link_in_connection_list->prev == NULL);
 837           _dbus_list_free_link (d->link_in_connection_list);
 838           d->link_in_connection_list = NULL;
 839         }
 840
 841       if (!dbus_connection_set_data (connection,
 842                                      connection_data_slot,
 843                                      NULL, NULL))
 844         _dbus_assert_not_reached ("failed to set connection data to null");
 845
 846       /* "d" has now been freed */
 847     }
 848
 849   return retval;
 850 }
 851
 852 void
 853 bus_connections_expire_incomplete (BusConnections *connections)
 854 {
 855   int next_interval;
 856
 857   next_interval = -1;
 858
 859   if (connections->incomplete != NULL)
 860     {
 861       long tv_sec, tv_usec;
 862       DBusList *link;
 863       int auth_timeout;
 864
 865       _dbus_get_monotonic_time (&tv_sec, &tv_usec);
 866       auth_timeout = bus_context_get_auth_timeout (connections->context);
 867
 868       link = _dbus_list_get_first_link (&connections->incomplete);
 869       while (link != NULL)
 870         {
 871           DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
 872           DBusConnection *connection;
 873           BusConnectionData *d;
 874           double elapsed;
 875
 876           connection = link->data;
 877
 878           d = BUS_CONNECTION_DATA (connection);
 879
 880           _dbus_assert (d != NULL);
 881
 882           elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec,
 883                                                 d->connection_tv_usec,
 884                                                 tv_sec, tv_usec);
 885
 886           if (elapsed >= (double) auth_timeout)
 887             {
 888               /* Unfortunately, we can't identify the connection: it doesn't
 889                * have a unique name yet, we don't know its uid/pid yet,
 890                * and so on. */
 891               bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
 892                   "Connection has not authenticated soon enough, closing it "
 893                   "(auth_timeout=%dms, elapsed: %.0fms)",
 894                   auth_timeout, elapsed);
 895
 896               _dbus_verbose ("Timing out authentication for connection %p\n", connection);
 897               dbus_connection_close (connection);
 898             }
 899           else
 900             {
 901               /* We can end the loop, since the connections are in oldest-first order */
 902               next_interval = ((double)auth_timeout) - elapsed;
 903               _dbus_verbose ("Connection %p authentication expires in %d milliseconds\n",
 904                              connection, next_interval);
 905
 906               break;
 907             }
 908
 909           link = next;
 910         }
 911     }
 912
 913   bus_expire_timeout_set_interval (connections->expire_timeout,
 914                                    next_interval);
 915 }
 916
 917 static dbus_bool_t
 918 expire_incomplete_timeout (void *data)
 919 {
 920   BusConnections *connections = data;
 921
 922   _dbus_verbose ("Running\n");
 923
 924   /* note that this may remove the timeout */
 925   bus_connections_expire_incomplete (connections);
 926
 927   return TRUE;
 928 }
 929
 930 dbus_bool_t
 931 bus_connection_get_unix_groups  (DBusConnection   *connection,
 932                                  unsigned long   **groups,
 933                                  int              *n_groups,
 934                                  DBusError        *error)
 935 {
 936   unsigned long uid;
 937
 938   *groups = NULL;
 939   *n_groups = 0;
 940
 941   if (dbus_connection_get_unix_user (connection, &uid))
 942     {
 943       if (!_dbus_unix_groups_from_uid (uid, groups, n_groups))
 944         {
 945           _dbus_verbose ("Did not get any groups for UID %lu\n",
 946                          uid);
 947           return FALSE;
 948         }
 949       else
 950         {
 951           _dbus_verbose ("Got %d groups for UID %lu\n",
 952                          *n_groups, uid);
 953           return TRUE;
 954         }
 955     }
 956   else
 957     return TRUE; /* successfully got 0 groups */
 958 }
 959
 960 dbus_bool_t
 961 bus_connection_is_in_unix_group (DBusConnection *connection,
 962                                  unsigned long   gid)
 963 {
 964   int i;
 965   unsigned long *group_ids;
 966   int n_group_ids;
 967
 968   if (!bus_connection_get_unix_groups (connection, &group_ids, &n_group_ids,
 969                                        NULL))
 970     return FALSE;
 971
 972   i = 0;
 973   while (i < n_group_ids)
 974     {
 975       if (group_ids[i] == gid)
 976         {
 977           dbus_free (group_ids);
 978           return TRUE;
 979         }
 980       ++i;
 981     }
 982
 983   dbus_free (group_ids);
 984   return FALSE;
 985 }
 986
 987 const char *
 988 bus_connection_get_loginfo (DBusConnection        *connection)
 989 {
 990   BusConnectionData *d;
 991
 992   d = BUS_CONNECTION_DATA (connection);
 993
 994   if (!bus_connection_is_active (connection))
 995     return "inactive";
 996   return d->cached_loginfo_string;
 997 }
 998
 999 BusClientPolicy*
1000 bus_connection_get_policy (DBusConnection *connection)
1001 {
1002   BusConnectionData *d;
1003
1004   d = BUS_CONNECTION_DATA (connection);
1005
1006   _dbus_assert (d != NULL);
1007   _dbus_assert (d->policy != NULL);
1008
1009   return d->policy;
1010 }
1011
1012 static dbus_bool_t
1013 foreach_active (BusConnections               *connections,
1014                 BusConnectionForeachFunction  function,
1015                 void                         *data)
1016 {
1017   DBusList *link;
1018
1019   link = _dbus_list_get_first_link (&connections->completed);
1020   while (link != NULL)
1021     {
1022       DBusConnection *connection = link->data;
1023       DBusList *next = _dbus_list_get_next_link (&connections->completed, link);
1024
1025       if (!(* function) (connection, data))
1026         return FALSE;
1027
1028       link = next;
1029     }
1030
1031   return TRUE;
1032 }
1033
1034 static dbus_bool_t
1035 foreach_inactive (BusConnections               *connections,
1036                   BusConnectionForeachFunction  function,
1037                   void                         *data)
1038 {
1039   DBusList *link;
1040
1041   link = _dbus_list_get_first_link (&connections->incomplete);
1042   while (link != NULL)
1043     {
1044       DBusConnection *connection = link->data;
1045       DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
1046
1047       if (!(* function) (connection, data))
1048         return FALSE;
1049
1050       link = next;
1051     }
1052
1053   return TRUE;
1054 }
1055
1056 /**
1057  * Calls function on each active connection; if the function returns
1058  * #FALSE, stops iterating. Active connections are authenticated
1059  * and have sent a Hello message.
1060  *
1061  * @param connections the connections object
1062  * @param function the function
1063  * @param data data to pass to it as a second arg
1064  */
1065 void
1066 bus_connections_foreach_active (BusConnections               *connections,
1067                                 BusConnectionForeachFunction  function,
1068                                 void                         *data)
1069 {
1070   foreach_active (connections, function, data);
1071 }
1072
1073 /**
1074  * Calls function on each connection; if the function returns
1075  * #FALSE, stops iterating.
1076  *
1077  * @param connections the connections object
1078  * @param function the function
1079  * @param data data to pass to it as a second arg
1080  */
1081 void
1082 bus_connections_foreach (BusConnections               *connections,
1083                          BusConnectionForeachFunction  function,
1084                          void                         *data)
1085 {
1086   if (!foreach_active (connections, function, data))
1087     return;
1088
1089   foreach_inactive (connections, function, data);
1090 }
1091
1092 BusContext*
1093 bus_connections_get_context (BusConnections *connections)
1094 {
1095   return connections->context;
1096 }
1097
1098 /*
1099  * This is used to avoid covering the same connection twice when
1100  * traversing connections. Note that it assumes we will
1101  * bus_connection_mark_stamp() each connection at least once per
1102  * INT_MAX increments of the global stamp, or wraparound would break
1103  * things.
1104  */
1105 void
1106 bus_connections_increment_stamp (BusConnections *connections)
1107 {
1108   connections->stamp += 1;
1109 }
1110
1111 /* Mark connection with current stamp, return TRUE if it
1112  * didn't already have that stamp
1113  */
1114 dbus_bool_t
1115 bus_connection_mark_stamp (DBusConnection *connection)
1116 {
1117   BusConnectionData *d;
1118
1119   d = BUS_CONNECTION_DATA (connection);
1120
1121   _dbus_assert (d != NULL);
1122
1123   if (d->stamp == d->connections->stamp)
1124     return FALSE;
1125   else
1126     {
1127       d->stamp = d->connections->stamp;
1128       return TRUE;
1129     }
1130 }
1131
1132 BusContext*
1133 bus_connection_get_context (DBusConnection *connection)
1134 {
1135   BusConnectionData *d;
1136
1137   d = BUS_CONNECTION_DATA (connection);
1138
1139   _dbus_assert (d != NULL);
1140
1141   return d->connections->context;
1142 }
1143
1144 BusConnections*
1145 bus_connection_get_connections (DBusConnection *connection)
1146 {
1147   BusConnectionData *d;
1148
1149   d = BUS_CONNECTION_DATA (connection);
1150
1151   _dbus_assert (d != NULL);
1152
1153   return d->connections;
1154 }
1155
1156 BusRegistry*
1157 bus_connection_get_registry (DBusConnection *connection)
1158 {
1159   BusConnectionData *d;
1160
1161   d = BUS_CONNECTION_DATA (connection);
1162
1163   _dbus_assert (d != NULL);
1164
1165   return bus_context_get_registry (d->connections->context);
1166 }
1167
1168 BusActivation*
1169 bus_connection_get_activation (DBusConnection *connection)
1170 {
1171   BusConnectionData *d;
1172
1173   d = BUS_CONNECTION_DATA (connection);
1174
1175   _dbus_assert (d != NULL);
1176
1177   return bus_context_get_activation (d->connections->context);
1178 }
1179
1180 BusMatchmaker*
1181 bus_connection_get_matchmaker (DBusConnection *connection)
1182 {
1183   BusConnectionData *d;
1184
1185   d = BUS_CONNECTION_DATA (connection);
1186
1187   _dbus_assert (d != NULL);
1188
1189   return bus_context_get_matchmaker (d->connections->context);
1190 }
1191
1192 BusSELinuxID*
1193 bus_connection_get_selinux_id (DBusConnection *connection)
1194 {
1195   BusConnectionData *d;
1196
1197   d = BUS_CONNECTION_DATA (connection);
1198
1199   _dbus_assert (d != NULL);
1200
1201   return d->selinux_id;
1202 }
1203
1204 /**
1205  * Checks whether the connection is registered with the message bus.
1206  *
1207  * @param connection the connection
1208  * @returns #TRUE if we're an active message bus participant
1209  */
1210 dbus_bool_t
1211 bus_connection_is_active (DBusConnection *connection)
1212 {
1213   BusConnectionData *d;
1214
1215   d = BUS_CONNECTION_DATA (connection);
1216
1217   return d != NULL && d->name != NULL;
1218 }
1219
1220 dbus_bool_t
1221 bus_connection_preallocate_oom_error (DBusConnection *connection)
1222 {
1223   DBusMessage *message;
1224   DBusPreallocatedSend *preallocated;
1225   BusConnectionData *d;
1226
1227   d = BUS_CONNECTION_DATA (connection);
1228
1229   _dbus_assert (d != NULL);
1230
1231   if (d->oom_preallocated != NULL)
1232     return TRUE;
1233
1234   preallocated = dbus_connection_preallocate_send (connection);
1235   if (preallocated == NULL)
1236     return FALSE;
1237
1238   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1239
1240   if (message == NULL)
1241     {
1242       dbus_connection_free_preallocated_send (connection, preallocated);
1243       return FALSE;
1244     }
1245
1246   /* d->name may be NULL, but that is OK */
1247   if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) ||
1248       !dbus_message_set_destination (message, d->name) ||
1249       !dbus_message_set_sender (message,
1250                                 DBUS_SERVICE_DBUS))
1251     {
1252       dbus_connection_free_preallocated_send (connection, preallocated);
1253       dbus_message_unref (message);
1254       return FALSE;
1255     }
1256
1257   /* set reply serial to placeholder value just so space is already allocated
1258    * for it.
1259    */
1260   if (!dbus_message_set_reply_serial (message, 14))
1261     {
1262       dbus_connection_free_preallocated_send (connection, preallocated);
1263       dbus_message_unref (message);
1264       return FALSE;
1265     }
1266
1267   d->oom_message = message;
1268   d->oom_preallocated = preallocated;
1269
1270   return TRUE;
1271 }
1272
1273 void
1274 bus_connection_send_oom_error (DBusConnection *connection,
1275                                DBusMessage    *in_reply_to)
1276 {
1277   BusConnectionData *d;
1278
1279   d = BUS_CONNECTION_DATA (connection);
1280
1281   _dbus_assert (d != NULL);
1282   _dbus_assert (d->oom_message != NULL);
1283
1284   bus_context_log (d->connections->context, DBUS_SYSTEM_LOG_WARNING,
1285                    "dbus-daemon transaction failed (OOM), sending error to "
1286                    "sender %s", bus_connection_get_loginfo (connection));
1287
1288   /* should always succeed since we set it to a placeholder earlier */
1289   if (!dbus_message_set_reply_serial (d->oom_message,
1290                                       dbus_message_get_serial (in_reply_to)))
1291     _dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message");
1292
1293   _dbus_assert (dbus_message_get_sender (d->oom_message) != NULL);
1294
1295   dbus_connection_send_preallocated (connection, d->oom_preallocated,
1296                                      d->oom_message, NULL);
1297
1298   dbus_message_unref (d->oom_message);
1299   d->oom_message = NULL;
1300   d->oom_preallocated = NULL;
1301 }
1302
1303 #ifdef DBUS_ENABLE_STATS
1304 static void
1305 update_peak (int *peak,
1306              int n)
1307 {
1308   if (*peak < n)
1309     *peak = n;
1310 }
1311 #endif
1312
1313 void
1314 bus_connection_add_match_rule_link (DBusConnection *connection,
1315                                     DBusList       *link)
1316 {
1317   BusConnectionData *d;
1318
1319   d = BUS_CONNECTION_DATA (connection);
1320   _dbus_assert (d != NULL);
1321
1322   _dbus_list_append_link (&d->match_rules, link);
1323
1324   d->n_match_rules += 1;
1325
1326 #ifdef DBUS_ENABLE_STATS
1327   update_peak (&d->peak_match_rules, d->n_match_rules);
1328   update_peak (&d->connections->peak_match_rules_per_conn, d->n_match_rules);
1329
1330   d->connections->total_match_rules += 1;
1331   update_peak (&d->connections->peak_match_rules,
1332                d->connections->total_match_rules);
1333 #endif
1334 }
1335
1336 dbus_bool_t
1337 bus_connection_add_match_rule (DBusConnection *connection,
1338                                BusMatchRule   *rule)
1339 {
1340     DBusList *link;
1341
1342   link = _dbus_list_alloc_link (rule);
1343
1344   if (link == NULL)
1345     return FALSE;
1346
1347   bus_connection_add_match_rule_link (connection, link);
1348
1349   return TRUE;
1350 }
1351
1352 void
1353 bus_connection_remove_match_rule (DBusConnection *connection,
1354                                   BusMatchRule   *rule)
1355 {
1356   BusConnectionData *d;
1357
1358   d = BUS_CONNECTION_DATA (connection);
1359   _dbus_assert (d != NULL);
1360
1361   _dbus_list_remove_last (&d->match_rules, rule);
1362
1363   d->n_match_rules -= 1;
1364   _dbus_assert (d->n_match_rules >= 0);
1365
1366 #ifdef DBUS_ENABLE_STATS
1367   d->connections->total_match_rules -= 1;
1368 #endif
1369 }
1370
1371 int
1372 bus_connection_get_n_match_rules (DBusConnection *connection)
1373 {
1374   BusConnectionData *d;
1375
1376   d = BUS_CONNECTION_DATA (connection);
1377   _dbus_assert (d != NULL);
1378
1379   return d->n_match_rules;
1380 }
1381
1382 void
1383 bus_connection_add_owned_service_link (DBusConnection *connection,
1384                                        DBusList       *link)
1385 {
1386   BusConnectionData *d;
1387
1388   d = BUS_CONNECTION_DATA (connection);
1389   _dbus_assert (d != NULL);
1390
1391   _dbus_list_append_link (&d->services_owned, link);
1392
1393   d->n_services_owned += 1;
1394
1395 #ifdef DBUS_ENABLE_STATS
1396   update_peak (&d->peak_bus_names, d->n_services_owned);
1397   update_peak (&d->connections->peak_bus_names_per_conn,
1398                d->n_services_owned);
1399
1400   d->connections->total_bus_names += 1;
1401   update_peak (&d->connections->peak_bus_names,
1402                d->connections->total_bus_names);
1403 #endif
1404 }
1405
1406 dbus_bool_t
1407 bus_connection_add_owned_service (DBusConnection *connection,
1408                                   BusService     *service)
1409 {
1410   DBusList *link;
1411
1412   link = _dbus_list_alloc_link (service);
1413
1414   if (link == NULL)
1415     return FALSE;
1416
1417   bus_connection_add_owned_service_link (connection, link);
1418
1419   return TRUE;
1420 }
1421
1422 void
1423 bus_connection_remove_owned_service (DBusConnection *connection,
1424                                      BusService     *service)
1425 {
1426   BusConnectionData *d;
1427
1428   d = BUS_CONNECTION_DATA (connection);
1429   _dbus_assert (d != NULL);
1430
1431   _dbus_list_remove_last (&d->services_owned, service);
1432
1433   d->n_services_owned -= 1;
1434   _dbus_assert (d->n_services_owned >= 0);
1435
1436 #ifdef DBUS_ENABLE_STATS
1437   d->connections->total_bus_names -= 1;
1438 #endif
1439 }
1440
1441 int
1442 bus_connection_get_n_services_owned (DBusConnection *connection)
1443 {
1444   BusConnectionData *d;
1445
1446   d = BUS_CONNECTION_DATA (connection);
1447   _dbus_assert (d != NULL);
1448
1449   return d->n_services_owned;
1450 }
1451
1452 dbus_bool_t
1453 bus_connection_complete (DBusConnection   *connection,
1454                          const DBusString *name,
1455                          DBusError        *error)
1456 {
1457   BusConnectionData *d;
1458   unsigned long uid;
1459
1460   d = BUS_CONNECTION_DATA (connection);
1461   _dbus_assert (d != NULL);
1462   _dbus_assert (d->name == NULL);
1463   _dbus_assert (d->policy == NULL);
1464
1465   _dbus_assert (!bus_connection_is_active (connection));
1466
1467   if (!_dbus_string_copy_data (name, &d->name))
1468     {
1469       BUS_SET_OOM (error);
1470       return FALSE;
1471     }
1472
1473   _dbus_assert (d->name != NULL);
1474
1475   _dbus_verbose ("Name %s assigned to %p\n", d->name, connection);
1476
1477   d->policy = bus_context_create_client_policy (d->connections->context,
1478                                                 connection,
1479                                                 error);
1480
1481   /* we may have a NULL policy on OOM or error getting list of
1482    * groups for a user. In the latter case we don't handle it so
1483    * well currently, as it will just keep failing over and over.
1484    */
1485
1486   if (d->policy == NULL)
1487     {
1488       _dbus_verbose ("Failed to create security policy for connection %p\n",
1489                      connection);
1490       _DBUS_ASSERT_ERROR_IS_SET (error);
1491       dbus_free (d->name);
1492       d->name = NULL;
1493       return FALSE;
1494     }
1495
1496   if (dbus_connection_get_unix_user (connection, &uid))
1497     {
1498       if (!adjust_connections_for_uid (d->connections,
1499                                        uid, 1))
1500         goto fail;
1501     }
1502
1503   /* Create and cache a string which holds information about the
1504    * peer process; used for logging purposes.
1505    */
1506   if (!cache_peer_loginfo_string (d, connection))
1507     goto fail;
1508
1509   /* Now the connection is active, move it between lists */
1510   _dbus_list_unlink (&d->connections->incomplete,
1511                      d->link_in_connection_list);
1512   d->connections->n_incomplete -= 1;
1513   _dbus_list_append_link (&d->connections->completed,
1514                           d->link_in_connection_list);
1515   d->connections->n_completed += 1;
1516
1517   _dbus_assert (d->connections->n_incomplete >= 0);
1518   _dbus_assert (d->connections->n_completed > 0);
1519
1520   /* If we have dropped below the max. number of incomplete
1521    * connections, start accept()ing again */
1522   bus_context_check_all_watches (d->connections->context);
1523
1524   /* See if we can remove the timeout */
1525   bus_connections_expire_incomplete (d->connections);
1526
1527   _dbus_assert (bus_connection_is_active (connection));
1528
1529   return TRUE;
1530 fail:
1531   BUS_SET_OOM (error);
1532   dbus_free (d->name);
1533   d->name = NULL;
1534   if (d->policy)
1535     bus_client_policy_unref (d->policy);
1536   d->policy = NULL;
1537   return FALSE;
1538 }
1539
1540 dbus_bool_t
1541 bus_connections_reload_policy (BusConnections *connections,
1542                                DBusError      *error)
1543 {
1544   BusConnectionData *d;
1545   DBusConnection *connection;
1546   DBusList *link;
1547
1548   _dbus_assert (connections != NULL);
1549   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
1550
1551   for (link = _dbus_list_get_first_link (&(connections->completed));
1552        link;
1553        link = _dbus_list_get_next_link (&(connections->completed), link))
1554     {
1555       connection = link->data;
1556       d = BUS_CONNECTION_DATA (connection);
1557       _dbus_assert (d != NULL);
1558       _dbus_assert (d->policy != NULL);
1559
1560       bus_client_policy_unref (d->policy);
1561       d->policy = bus_context_create_client_policy (connections->context,
1562                                                     connection,
1563                                                     error);
1564       if (d->policy == NULL)
1565         {
1566           _dbus_verbose ("Failed to create security policy for connection %p\n",
1567                       connection);
1568           _DBUS_ASSERT_ERROR_IS_SET (error);
1569           return FALSE;
1570         }
1571     }
1572
1573   return TRUE;
1574 }
1575
1576 const char *
1577 bus_connection_get_name (DBusConnection *connection)
1578 {
1579   BusConnectionData *d;
1580
1581   d = BUS_CONNECTION_DATA (connection);
1582   _dbus_assert (d != NULL);
1583
1584   return d->name;
1585 }
1586
1587 /**
1588  * Check whether completing the passed-in connection would
1589  * exceed limits, and if so set error and return #FALSE
1590  */
1591 dbus_bool_t
1592 bus_connections_check_limits (BusConnections  *connections,
1593                               DBusConnection  *requesting_completion,
1594                               DBusError       *error)
1595 {
1596   unsigned long uid;
1597
1598   if (connections->n_completed >=
1599       bus_context_get_max_completed_connections (connections->context))
1600     {
1601       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1602                       "The maximum number of active connections has been reached");
1603       return FALSE;
1604     }
1605
1606   if (dbus_connection_get_unix_user (requesting_completion, &uid))
1607     {
1608       if (get_connections_for_uid (connections, uid) >=
1609           bus_context_get_max_connections_per_user (connections->context))
1610         {
1611           dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1612                           "The maximum number of active connections for UID %lu has been reached",
1613                           uid);
1614           return FALSE;
1615         }
1616     }
1617
1618   return TRUE;
1619 }
1620
1621 static void
1622 bus_pending_reply_free (BusPendingReply *pending)
1623 {
1624   _dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n",
1625                  pending,
1626                  pending->will_send_reply,
1627                  pending->will_get_reply,
1628                  pending->reply_serial);
1629
1630   dbus_free (pending);
1631 }
1632
1633 static dbus_bool_t
1634 bus_pending_reply_send_no_reply (BusConnections  *connections,
1635                                  BusTransaction  *transaction,
1636                                  BusPendingReply *pending)
1637 {
1638   DBusMessage *message;
1639   DBusMessageIter iter;
1640   dbus_bool_t retval;
1641   const char *errmsg;
1642
1643   retval = FALSE;
1644
1645   message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
1646   if (message == NULL)
1647     return FALSE;
1648
1649   dbus_message_set_no_reply (message, TRUE);
1650
1651   if (!dbus_message_set_reply_serial (message,
1652                                       pending->reply_serial))
1653     goto out;
1654
1655   if (!dbus_message_set_error_name (message,
1656                                     DBUS_ERROR_NO_REPLY))
1657     goto out;
1658
1659   /* If you change these messages, adjust test/dbus-daemon.c to match */
1660   if (pending->will_send_reply == NULL)
1661     errmsg = "Message recipient disconnected from message bus without replying";
1662   else
1663     errmsg = "Message did not receive a reply (timeout by message bus)";
1664
1665   dbus_message_iter_init_append (message, &iter);
1666   if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg))
1667     goto out;
1668
1669   if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply,
1670                                          message))
1671     goto out;
1672
1673   retval = TRUE;
1674
1675  out:
1676   dbus_message_unref (message);
1677   return retval;
1678 }
1679
1680 static dbus_bool_t
1681 bus_pending_reply_expired (BusExpireList *list,
1682                            DBusList      *link,
1683                            void          *data)
1684 {
1685   BusPendingReply *pending = link->data;
1686   BusConnections *connections = data;
1687   BusTransaction *transaction;
1688
1689   /* No reply is forthcoming. So nuke it if we can. If not,
1690    * leave it in the list to try expiring again later when we
1691    * get more memory.
1692    */
1693
1694   _dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n",
1695                  pending,
1696                  pending->will_send_reply,
1697                  pending->will_get_reply,
1698                  pending->reply_serial);
1699
1700   transaction = bus_transaction_new (connections->context);
1701   if (transaction == NULL)
1702     return FALSE;
1703
1704   if (!bus_pending_reply_send_no_reply (connections,
1705                                         transaction,
1706                                         pending))
1707     {
1708       bus_transaction_cancel_and_free (transaction);
1709       return FALSE;
1710     }
1711
1712   bus_expire_list_remove_link (connections->pending_replies, link);
1713
1714   bus_pending_reply_free (pending);
1715   bus_transaction_execute_and_free (transaction);
1716
1717   return TRUE;
1718 }
1719
1720 static void
1721 bus_connection_drop_pending_replies (BusConnections  *connections,
1722                                      DBusConnection  *connection)
1723 {
1724   /* The DBusConnection is almost 100% finalized here, so you can't
1725    * do anything with it except check for pointer equality
1726    */
1727   DBusList *link;
1728
1729   _dbus_verbose ("Dropping pending replies that involve connection %p\n",
1730                  connection);
1731
1732   link = bus_expire_list_get_first_link (connections->pending_replies);
1733   while (link != NULL)
1734     {
1735       DBusList *next;
1736       BusPendingReply *pending;
1737
1738       next = bus_expire_list_get_next_link (connections->pending_replies,
1739                                             link);
1740       pending = link->data;
1741
1742       if (pending->will_get_reply == connection)
1743         {
1744           /* We don't need to track this pending reply anymore */
1745
1746           _dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n",
1747                          pending,
1748                          pending->will_send_reply,
1749                          pending->will_get_reply,
1750                          pending->reply_serial);
1751
1752           bus_expire_list_remove_link (connections->pending_replies,
1753                                        link);
1754           bus_pending_reply_free (pending);
1755         }
1756       else if (pending->will_send_reply == connection)
1757         {
1758           /* The reply isn't going to be sent, so set things
1759            * up so it will be expired right away
1760            */
1761           _dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n",
1762                          pending,
1763                          pending->will_send_reply,
1764                          pending->will_get_reply,
1765                          pending->reply_serial);
1766
1767           pending->will_send_reply = NULL;
1768           pending->expire_item.added_tv_sec = 0;
1769           pending->expire_item.added_tv_usec = 0;
1770
1771           bus_expire_list_recheck_immediately (connections->pending_replies);
1772         }
1773
1774       link = next;
1775     }
1776 }
1777
1778
1779 typedef struct
1780 {
1781   BusPendingReply *pending;
1782   BusConnections  *connections;
1783 } CancelPendingReplyData;
1784
1785 static void
1786 cancel_pending_reply (void *data)
1787 {
1788   CancelPendingReplyData *d = data;
1789
1790   _dbus_verbose ("d = %p\n", d);
1791
1792   if (!bus_expire_list_remove (d->connections->pending_replies,
1793                                &d->pending->expire_item))
1794     _dbus_assert_not_reached ("pending reply did not exist to be cancelled");
1795
1796   bus_pending_reply_free (d->pending); /* since it's been cancelled */
1797 }
1798
1799 static void
1800 cancel_pending_reply_data_free (void *data)
1801 {
1802   CancelPendingReplyData *d = data;
1803
1804   _dbus_verbose ("d = %p\n", d);
1805
1806   /* d->pending should be either freed or still
1807    * in the list of pending replies (owned by someone
1808    * else)
1809    */
1810
1811   dbus_free (d);
1812 }
1813
1814 /*
1815  * Record that a reply is allowed; return TRUE on success.
1816  */
1817 dbus_bool_t
1818 bus_connections_expect_reply (BusConnections  *connections,
1819                               BusTransaction  *transaction,
1820                               DBusConnection  *will_get_reply,
1821                               DBusConnection  *will_send_reply,
1822                               DBusMessage     *reply_to_this,
1823                               DBusError       *error)
1824 {
1825   BusPendingReply *pending;
1826   dbus_uint32_t reply_serial;
1827   DBusList *link;
1828   CancelPendingReplyData *cprd;
1829   int count;
1830
1831   _dbus_assert (will_get_reply != NULL);
1832   _dbus_assert (will_send_reply != NULL);
1833   _dbus_assert (reply_to_this != NULL);
1834
1835   if (dbus_message_get_no_reply (reply_to_this))
1836     return TRUE; /* we won't allow a reply, since client doesn't care for one. */
1837
1838   reply_serial = dbus_message_get_serial (reply_to_this);
1839
1840   link = bus_expire_list_get_first_link (connections->pending_replies);
1841   count = 0;
1842   while (link != NULL)
1843     {
1844       pending = link->data;
1845
1846       if (pending->reply_serial == reply_serial &&
1847           pending->will_get_reply == will_get_reply &&
1848           pending->will_send_reply == will_send_reply)
1849         {
1850           dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
1851                           "Message has the same reply serial as a currently-outstanding existing method call");
1852           return FALSE;
1853         }
1854
1855       link = bus_expire_list_get_next_link (connections->pending_replies,
1856                                             link);
1857       if (pending->will_get_reply == will_get_reply)
1858         ++count;
1859     }
1860
1861   if (count >=
1862       bus_context_get_max_replies_per_connection (connections->context))
1863     {
1864       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
1865                       "The maximum number of pending replies per connection has been reached");
1866       return FALSE;
1867     }
1868
1869   pending = dbus_new0 (BusPendingReply, 1);
1870   if (pending == NULL)
1871     {
1872       BUS_SET_OOM (error);
1873       return FALSE;
1874     }
1875
1876 #ifdef DBUS_ENABLE_VERBOSE_MODE
1877   /* so we can see a not-yet-added pending reply */
1878   pending->expire_item.added_tv_sec = 1;
1879   pending->expire_item.added_tv_usec = 1;
1880 #endif
1881
1882   pending->will_get_reply = will_get_reply;
1883   pending->will_send_reply = will_send_reply;
1884   pending->reply_serial = reply_serial;
1885
1886   cprd = dbus_new0 (CancelPendingReplyData, 1);
1887   if (cprd == NULL)
1888     {
1889       BUS_SET_OOM (error);
1890       bus_pending_reply_free (pending);
1891       return FALSE;
1892     }
1893
1894   if (!bus_expire_list_add (connections->pending_replies,
1895                             &pending->expire_item))
1896     {
1897       BUS_SET_OOM (error);
1898       dbus_free (cprd);
1899       bus_pending_reply_free (pending);
1900       return FALSE;
1901     }
1902
1903   if (!bus_transaction_add_cancel_hook (transaction,
1904                                         cancel_pending_reply,
1905                                         cprd,
1906                                         cancel_pending_reply_data_free))
1907     {
1908       BUS_SET_OOM (error);
1909       bus_expire_list_remove (connections->pending_replies, &pending->expire_item);
1910       dbus_free (cprd);
1911       bus_pending_reply_free (pending);
1912       return FALSE;
1913     }
1914
1915   cprd->pending = pending;
1916   cprd->connections = connections;
1917
1918   _dbus_get_monotonic_time (&pending->expire_item.added_tv_sec,
1919                             &pending->expire_item.added_tv_usec);
1920
1921   _dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n",
1922                  pending,
1923                  pending->will_send_reply,
1924                  pending->will_get_reply,
1925                  pending->reply_serial);
1926
1927   return TRUE;
1928 }
1929
1930 typedef struct
1931 {
1932   DBusList        *link;
1933   BusConnections  *connections;
1934 } CheckPendingReplyData;
1935
1936 static void
1937 cancel_check_pending_reply (void *data)
1938 {
1939   CheckPendingReplyData *d = data;
1940
1941   _dbus_verbose ("d = %p\n",d);
1942
1943   bus_expire_list_add_link (d->connections->pending_replies,
1944                             d->link);
1945   d->link = NULL;
1946 }
1947
1948 static void
1949 check_pending_reply_data_free (void *data)
1950 {
1951   CheckPendingReplyData *d = data;
1952
1953   _dbus_verbose ("d = %p\n",d);
1954
1955   if (d->link != NULL)
1956     {
1957       BusPendingReply *pending = d->link->data;
1958
1959       _dbus_assert (!bus_expire_list_contains_item (d->connections->pending_replies,
1960                                                     &pending->expire_item));
1961
1962       bus_pending_reply_free (pending);
1963       _dbus_list_free_link (d->link);
1964     }
1965
1966   dbus_free (d);
1967 }
1968
1969 /*
1970  * Check whether a reply is allowed, remove BusPendingReply
1971  * if so, return TRUE if so.
1972  */
1973 dbus_bool_t
1974 bus_connections_check_reply (BusConnections *connections,
1975                              BusTransaction *transaction,
1976                              DBusConnection *sending_reply,
1977                              DBusConnection *receiving_reply,
1978                              DBusMessage    *reply,
1979                              DBusError      *error)
1980 {
1981   CheckPendingReplyData *cprd;
1982   DBusList *link;
1983   dbus_uint32_t reply_serial;
1984
1985   _dbus_assert (sending_reply != NULL);
1986   _dbus_assert (receiving_reply != NULL);
1987
1988   reply_serial = dbus_message_get_reply_serial (reply);
1989
1990   link = bus_expire_list_get_first_link (connections->pending_replies);
1991   while (link != NULL)
1992     {
1993       BusPendingReply *pending = link->data;
1994
1995       if (pending->reply_serial == reply_serial &&
1996           pending->will_get_reply == receiving_reply &&
1997           pending->will_send_reply == sending_reply)
1998         {
1999           _dbus_verbose ("Found pending reply with serial %u\n", reply_serial);
2000           break;
2001         }
2002
2003       link = bus_expire_list_get_next_link (connections->pending_replies,
2004                                             link);
2005     }
2006
2007   if (link == NULL)
2008     {
2009       _dbus_verbose ("No pending reply expected\n");
2010
2011       return FALSE;
2012     }
2013
2014   cprd = dbus_new0 (CheckPendingReplyData, 1);
2015   if (cprd == NULL)
2016     {
2017       BUS_SET_OOM (error);
2018       return FALSE;
2019     }
2020
2021   if (!bus_transaction_add_cancel_hook (transaction,
2022                                         cancel_check_pending_reply,
2023                                         cprd,
2024                                         check_pending_reply_data_free))
2025     {
2026       BUS_SET_OOM (error);
2027       dbus_free (cprd);
2028       return FALSE;
2029     }
2030
2031   cprd->link = link;
2032   cprd->connections = connections;
2033
2034   bus_expire_list_unlink (connections->pending_replies,
2035                           link);
2036
2037   _dbus_assert (!bus_expire_list_contains_item (connections->pending_replies, link->data));
2038
2039   return TRUE;
2040 }
2041
2042 /*
2043  * Transactions
2044  *
2045  * Note that this is fairly fragile; in particular, don't try to use
2046  * one transaction across any main loop iterations.
2047  */
2048
2049 typedef struct
2050 {
2051   BusTransaction *transaction;
2052   DBusMessage    *message;
2053   DBusPreallocatedSend *preallocated;
2054 } MessageToSend;
2055
2056 typedef struct
2057 {
2058   BusTransactionCancelFunction cancel_function;
2059   DBusFreeFunction free_data_function;
2060   void *data;
2061 } CancelHook;
2062
2063 struct BusTransaction
2064 {
2065   DBusList *connections;
2066   BusContext *context;
2067   DBusList *cancel_hooks;
2068 };
2069
2070 static void
2071 message_to_send_free (DBusConnection *connection,
2072                       MessageToSend  *to_send)
2073 {
2074   if (to_send->message)
2075     dbus_message_unref (to_send->message);
2076
2077   if (to_send->preallocated)
2078     dbus_connection_free_preallocated_send (connection, to_send->preallocated);
2079
2080   dbus_free (to_send);
2081 }
2082
2083 static void
2084 cancel_hook_cancel (void *element,
2085                     void *data)
2086 {
2087   CancelHook *ch = element;
2088
2089   _dbus_verbose ("Running transaction cancel hook\n");
2090
2091   if (ch->cancel_function)
2092     (* ch->cancel_function) (ch->data);
2093 }
2094
2095 static void
2096 cancel_hook_free (void *element,
2097                   void *data)
2098 {
2099   CancelHook *ch = element;
2100
2101   if (ch->free_data_function)
2102     (* ch->free_data_function) (ch->data);
2103
2104   dbus_free (ch);
2105 }
2106
2107 static void
2108 free_cancel_hooks (BusTransaction *transaction)
2109 {
2110   _dbus_list_foreach (&transaction->cancel_hooks,
2111                       cancel_hook_free, NULL);
2112
2113   _dbus_list_clear (&transaction->cancel_hooks);
2114 }
2115
2116 BusTransaction*
2117 bus_transaction_new (BusContext *context)
2118 {
2119   BusTransaction *transaction;
2120
2121   transaction = dbus_new0 (BusTransaction, 1);
2122   if (transaction == NULL)
2123     return NULL;
2124
2125   transaction->context = context;
2126
2127   return transaction;
2128 }
2129
2130 BusContext*
2131 bus_transaction_get_context (BusTransaction  *transaction)
2132 {
2133   return transaction->context;
2134 }
2135
2136 /**
2137  * Reserve enough memory to capture the given message if the
2138  * transaction goes through.
2139  */
2140 dbus_bool_t
2141 bus_transaction_capture (BusTransaction *transaction,
2142                          DBusConnection *sender,
2143                          DBusMessage    *message)
2144 {
2145   BusConnections *connections;
2146   BusMatchmaker *mm;
2147   DBusList *link;
2148   DBusList *recipients = NULL;
2149   dbus_bool_t ret = FALSE;
2150
2151   connections = bus_context_get_connections (transaction->context);
2152
2153   /* shortcut: don't compose the message unless someone wants it */
2154   if (connections->monitors == NULL)
2155     return TRUE;
2156
2157   mm = connections->monitor_matchmaker;
2158   /* This is non-null if there has ever been a monitor - we don't GC it.
2159    * There's little point, since there is up to 1 per process. */
2160   _dbus_assert (mm != NULL);
2161
2162   if (!bus_matchmaker_get_recipients (mm, connections, sender, NULL, message,
2163         &recipients))
2164     goto out;
2165
2166   for (link = _dbus_list_get_first_link (&recipients);
2167       link != NULL;
2168       link = _dbus_list_get_next_link (&recipients, link))
2169     {
2170       DBusConnection *recipient = link->data;
2171
2172       if (!bus_transaction_send (transaction, recipient, message))
2173         goto out;
2174     }
2175
2176   ret = TRUE;
2177
2178 out:
2179   _dbus_list_clear (&recipients);
2180   return ret;
2181 }
2182
2183 static dbus_bool_t
2184 bus_transaction_capture_error_reply (BusTransaction  *transaction,
2185                                      const DBusError *error,
2186                                      DBusMessage     *in_reply_to)
2187 {
2188   BusConnections *connections;
2189   DBusMessage *reply;
2190   dbus_bool_t ret = FALSE;
2191
2192   _dbus_assert (error != NULL);
2193   _DBUS_ASSERT_ERROR_IS_SET (error);
2194
2195   connections = bus_context_get_connections (transaction->context);
2196
2197   /* shortcut: don't compose the message unless someone wants it */
2198   if (connections->monitors == NULL)
2199     return TRUE;
2200
2201   reply = dbus_message_new_error (in_reply_to,
2202                                   error->name,
2203                                   error->message);
2204
2205   if (reply == NULL)
2206     return FALSE;
2207
2208   if (!dbus_message_set_sender (reply, DBUS_SERVICE_DBUS))
2209     goto out;
2210
2211   ret = bus_transaction_capture (transaction, NULL, reply);
2212
2213 out:
2214   dbus_message_unref (reply);
2215   return ret;
2216 }
2217
2218 dbus_bool_t
2219 bus_transaction_send_from_driver (BusTransaction *transaction,
2220                                   DBusConnection *connection,
2221                                   DBusMessage    *message)
2222 {
2223   DBusError error = DBUS_ERROR_INIT;
2224
2225   /* We have to set the sender to the driver, and have
2226    * to check security policy since it was not done in
2227    * dispatch.c
2228    */
2229   _dbus_verbose ("Sending %s %s %s from driver\n",
2230                  dbus_message_get_interface (message) ?
2231                  dbus_message_get_interface (message) : "(no interface)",
2232                  dbus_message_get_member (message) ?
2233                  dbus_message_get_member (message) : "(no member)",
2234                  dbus_message_get_error_name (message) ?
2235                  dbus_message_get_error_name (message) : "(no error name)");
2236
2237   if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
2238     return FALSE;
2239
2240   if (bus_connection_is_active (connection))
2241     {
2242       if (!dbus_message_set_destination (message,
2243                                          bus_connection_get_name (connection)))
2244         return FALSE;
2245     }
2246
2247   /* bus driver never wants a reply */
2248   dbus_message_set_no_reply (message, TRUE);
2249
2250   /* Capture it for monitors, even if the real recipient's receive policy
2251    * does not allow it to receive this message from us (which would be odd).
2252    */
2253   if (!bus_transaction_capture (transaction, NULL, message))
2254     return FALSE;
2255
2256   /* If security policy doesn't allow the message, we would silently
2257    * eat it; the driver doesn't care about getting a reply. However,
2258    * if we're actively capturing messages, it's nice to log that we
2259    * tried to send it and did not allow ourselves to do so.
2260    */
2261   if (!bus_context_check_security_policy (bus_transaction_get_context (transaction),
2262                                           transaction,
2263                                           NULL, connection, connection, message, &error))
2264     {
2265       if (!bus_transaction_capture_error_reply (transaction, &error, message))
2266         {
2267           bus_context_log (transaction->context, DBUS_SYSTEM_LOG_WARNING,
2268                            "message from dbus-daemon rejected but not enough "
2269                            "memory to capture it");
2270         }
2271
2272       /* This is not fatal to the transaction so silently eat the disallowed
2273        * message (see reasoning above) */
2274       dbus_error_free (&error);
2275       return TRUE;
2276     }
2277
2278   return bus_transaction_send (transaction, connection, message);
2279 }
2280
2281 dbus_bool_t
2282 bus_transaction_send (BusTransaction *transaction,
2283                       DBusConnection *connection,
2284                       DBusMessage    *message)
2285 {
2286   MessageToSend *to_send;
2287   BusConnectionData *d;
2288   DBusList *link;
2289
2290   _dbus_verbose ("  trying to add %s interface=%s member=%s error=%s to transaction%s\n",
2291                  dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" :
2292                  dbus_message_get_reply_serial (message) != 0 ? "reply" :
2293                  "message",
2294                  dbus_message_get_interface (message) ?
2295                  dbus_message_get_interface (message) : "(unset)",
2296                  dbus_message_get_member (message) ?
2297                  dbus_message_get_member (message) : "(unset)",
2298                  dbus_message_get_error_name (message) ?
2299                  dbus_message_get_error_name (message) : "(unset)",
2300                  dbus_connection_get_is_connected (connection) ?
2301                  "" : " (disconnected)");
2302
2303   _dbus_assert (dbus_message_get_sender (message) != NULL);
2304
2305   if (!dbus_connection_get_is_connected (connection))
2306     return TRUE; /* silently ignore disconnected connections */
2307
2308   d = BUS_CONNECTION_DATA (connection);
2309   _dbus_assert (d != NULL);
2310
2311   to_send = dbus_new (MessageToSend, 1);
2312   if (to_send == NULL)
2313     {
2314       return FALSE;
2315     }
2316
2317   to_send->preallocated = dbus_connection_preallocate_send (connection);
2318   if (to_send->preallocated == NULL)
2319     {
2320       dbus_free (to_send);
2321       return FALSE;
2322     }
2323
2324   dbus_message_ref (message);
2325   to_send->message = message;
2326   to_send->transaction = transaction;
2327
2328   _dbus_verbose ("about to prepend message\n");
2329
2330   if (!_dbus_list_prepend (&d->transaction_messages, to_send))
2331     {
2332       message_to_send_free (connection, to_send);
2333       return FALSE;
2334     }
2335
2336   _dbus_verbose ("prepended message\n");
2337
2338   /* See if we already had this connection in the list
2339    * for this transaction. If we have a pending message,
2340    * then we should already be in transaction->connections
2341    */
2342   link = _dbus_list_get_first_link (&d->transaction_messages);
2343   _dbus_assert (link->data == to_send);
2344   link = _dbus_list_get_next_link (&d->transaction_messages, link);
2345   while (link != NULL)
2346     {
2347       MessageToSend *m = link->data;
2348       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2349
2350       if (m->transaction == transaction)
2351         break;
2352
2353       link = next;
2354     }
2355
2356   if (link == NULL)
2357     {
2358       if (!_dbus_list_prepend (&transaction->connections, connection))
2359         {
2360           _dbus_list_remove (&d->transaction_messages, to_send);
2361           message_to_send_free (connection, to_send);
2362           return FALSE;
2363         }
2364     }
2365
2366   return TRUE;
2367 }
2368
2369 static void
2370 transaction_free (BusTransaction *transaction)
2371 {
2372   _dbus_assert (transaction->connections == NULL);
2373
2374   free_cancel_hooks (transaction);
2375
2376   dbus_free (transaction);
2377 }
2378
2379 static void
2380 connection_cancel_transaction (DBusConnection *connection,
2381                                BusTransaction *transaction)
2382 {
2383   DBusList *link;
2384   BusConnectionData *d;
2385
2386   d = BUS_CONNECTION_DATA (connection);
2387   _dbus_assert (d != NULL);
2388
2389   link = _dbus_list_get_first_link (&d->transaction_messages);
2390   while (link != NULL)
2391     {
2392       MessageToSend *m = link->data;
2393       DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
2394
2395       if (m->transaction == transaction)
2396         {
2397           _dbus_list_remove_link (&d->transaction_messages,
2398                                   link);
2399
2400           message_to_send_free (connection, m);
2401         }
2402
2403       link = next;
2404     }
2405 }
2406
2407 void
2408 bus_transaction_cancel_and_free (BusTransaction *transaction)
2409 {
2410   DBusConnection *connection;
2411
2412   _dbus_verbose ("TRANSACTION: cancelled\n");
2413
2414   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2415     connection_cancel_transaction (connection, transaction);
2416
2417   _dbus_list_foreach (&transaction->cancel_hooks,
2418                       cancel_hook_cancel, NULL);
2419
2420   transaction_free (transaction);
2421 }
2422
2423 static void
2424 connection_execute_transaction (DBusConnection *connection,
2425                                 BusTransaction *transaction)
2426 {
2427   DBusList *link;
2428   BusConnectionData *d;
2429
2430   d = BUS_CONNECTION_DATA (connection);
2431   _dbus_assert (d != NULL);
2432
2433   /* Send the queue in order (FIFO) */
2434   link = _dbus_list_get_last_link (&d->transaction_messages);
2435   while (link != NULL)
2436     {
2437       MessageToSend *m = link->data;
2438       DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link);
2439
2440       if (m->transaction == transaction)
2441         {
2442           _dbus_list_remove_link (&d->transaction_messages,
2443                                   link);
2444
2445           _dbus_assert (dbus_message_get_sender (m->message) != NULL);
2446
2447           dbus_connection_send_preallocated (connection,
2448                                              m->preallocated,
2449                                              m->message,
2450                                              NULL);
2451
2452           m->preallocated = NULL; /* so we don't double-free it */
2453
2454           message_to_send_free (connection, m);
2455         }
2456
2457       link = prev;
2458     }
2459 }
2460
2461 void
2462 bus_transaction_execute_and_free (BusTransaction *transaction)
2463 {
2464   /* For each connection in transaction->connections
2465    * send the messages
2466    */
2467   DBusConnection *connection;
2468
2469   _dbus_verbose ("TRANSACTION: executing\n");
2470
2471   while ((connection = _dbus_list_pop_first (&transaction->connections)))
2472     connection_execute_transaction (connection, transaction);
2473
2474   transaction_free (transaction);
2475 }
2476
2477 static void
2478 bus_connection_remove_transactions (DBusConnection *connection)
2479 {
2480   MessageToSend *to_send;
2481   BusConnectionData *d;
2482
2483   d = BUS_CONNECTION_DATA (connection);
2484   _dbus_assert (d != NULL);
2485
2486   while ((to_send = _dbus_list_get_first (&d->transaction_messages)))
2487     {
2488       /* only has an effect for the first MessageToSend listing this transaction */
2489       _dbus_list_remove (&to_send->transaction->connections,
2490                          connection);
2491
2492       _dbus_list_remove (&d->transaction_messages, to_send);
2493       message_to_send_free (connection, to_send);
2494     }
2495 }
2496
2497 /**
2498  * Converts the DBusError to a message reply
2499  */
2500 dbus_bool_t
2501 bus_transaction_send_error_reply (BusTransaction  *transaction,
2502                                   DBusConnection  *connection,
2503                                   const DBusError *error,
2504                                   DBusMessage     *in_reply_to)
2505 {
2506   DBusMessage *reply;
2507
2508   _dbus_assert (error != NULL);
2509   _DBUS_ASSERT_ERROR_IS_SET (error);
2510
2511   _dbus_verbose ("Sending error reply %s \"%s\"\n",
2512                  error->name, error->message);
2513
2514   reply = dbus_message_new_error (in_reply_to,
2515                                   error->name,
2516                                   error->message);
2517   if (reply == NULL)
2518     return FALSE;
2519
2520   if (!bus_transaction_send_from_driver (transaction, connection, reply))
2521     {
2522       dbus_message_unref (reply);
2523       return FALSE;
2524     }
2525
2526   dbus_message_unref (reply);
2527
2528   return TRUE;
2529 }
2530
2531 dbus_bool_t
2532 bus_transaction_add_cancel_hook (BusTransaction               *transaction,
2533                                  BusTransactionCancelFunction  cancel_function,
2534                                  void                         *data,
2535                                  DBusFreeFunction              free_data_function)
2536 {
2537   CancelHook *ch;
2538
2539   ch = dbus_new (CancelHook, 1);
2540   if (ch == NULL)
2541     return FALSE;
2542
2543   _dbus_verbose ("     adding cancel hook function = %p data = %p\n",
2544                  cancel_function, data);
2545
2546   ch->cancel_function = cancel_function;
2547   ch->data = data;
2548   ch->free_data_function = free_data_function;
2549
2550   /* It's important that the hooks get run in reverse order that they
2551    * were added
2552    */
2553   if (!_dbus_list_prepend (&transaction->cancel_hooks, ch))
2554     {
2555       dbus_free (ch);
2556       return FALSE;
2557     }
2558
2559   return TRUE;
2560 }
2561
2562 int
2563 bus_connections_get_n_active (BusConnections *connections)
2564 {
2565   return connections->n_completed;
2566 }
2567
2568 int
2569 bus_connections_get_n_incomplete (BusConnections *connections)
2570 {
2571   return connections->n_incomplete;
2572 }
2573
2574 #ifdef DBUS_ENABLE_STATS
2575 int
2576 bus_connections_get_total_match_rules (BusConnections *connections)
2577 {
2578   return connections->total_match_rules;
2579 }
2580
2581 int
2582 bus_connections_get_peak_match_rules (BusConnections *connections)
2583 {
2584   return connections->peak_match_rules;
2585 }
2586
2587 int
2588 bus_connections_get_peak_match_rules_per_conn (BusConnections *connections)
2589 {
2590   return connections->peak_match_rules_per_conn;
2591 }
2592
2593 int
2594 bus_connections_get_total_bus_names (BusConnections *connections)
2595 {
2596   return connections->total_bus_names;
2597 }
2598
2599 int
2600 bus_connections_get_peak_bus_names (BusConnections *connections)
2601 {
2602   return connections->peak_bus_names;
2603 }
2604
2605 int
2606 bus_connections_get_peak_bus_names_per_conn (BusConnections *connections)
2607 {
2608   return connections->peak_bus_names_per_conn;
2609 }
2610
2611 int
2612 bus_connection_get_peak_match_rules (DBusConnection *connection)
2613 {
2614   BusConnectionData *d;
2615
2616   d = BUS_CONNECTION_DATA (connection);
2617   return d->peak_match_rules;
2618 }
2619
2620 int
2621 bus_connection_get_peak_bus_names (DBusConnection *connection)
2622 {
2623   BusConnectionData *d;
2624
2625   d = BUS_CONNECTION_DATA (connection);
2626   return d->peak_bus_names;
2627 }
2628 #endif /* DBUS_ENABLE_STATS */
2629
2630 dbus_bool_t
2631 bus_connection_is_monitor (DBusConnection *connection)
2632 {
2633   BusConnectionData *d;
2634
2635   d = BUS_CONNECTION_DATA (connection);
2636
2637   return d != NULL && d->link_in_monitors != NULL;
2638 }
2639
2640 static dbus_bool_t
2641 bcd_add_monitor_rules (BusConnectionData  *d,
2642                        DBusConnection     *connection,
2643                        DBusList          **rules)
2644 {
2645   BusMatchmaker *mm = d->connections->monitor_matchmaker;
2646   DBusList *iter;
2647
2648   if (mm == NULL)
2649     {
2650       mm = bus_matchmaker_new ();
2651
2652       if (mm == NULL)
2653         return FALSE;
2654
2655       d->connections->monitor_matchmaker = mm;
2656     }
2657
2658   for (iter = _dbus_list_get_first_link (rules);
2659       iter != NULL;
2660       iter = _dbus_list_get_next_link (rules, iter))
2661     {
2662       if (!bus_matchmaker_add_rule (mm, iter->data))
2663         {
2664           bus_matchmaker_disconnected (mm, connection);
2665           return FALSE;
2666         }
2667     }
2668
2669   return TRUE;
2670 }
2671
2672 static void
2673 bcd_drop_monitor_rules (BusConnectionData *d,
2674                         DBusConnection *connection)
2675 {
2676   BusMatchmaker *mm = d->connections->monitor_matchmaker;
2677
2678   if (mm != NULL)
2679     bus_matchmaker_disconnected (mm, connection);
2680 }
2681
2682 dbus_bool_t
2683 bus_connection_be_monitor (DBusConnection  *connection,
2684                            BusTransaction  *transaction,
2685                            DBusList       **rules,
2686                            DBusError       *error)
2687 {
2688   BusConnectionData *d;
2689   DBusList *link;
2690   DBusList *tmp;
2691   DBusList *iter;
2692
2693   d = BUS_CONNECTION_DATA (connection);
2694   _dbus_assert (d != NULL);
2695
2696   link = _dbus_list_alloc_link (connection);
2697
2698   if (link == NULL)
2699     {
2700       BUS_SET_OOM (error);
2701       return FALSE;
2702     }
2703
2704   if (!bcd_add_monitor_rules (d, connection, rules))
2705     {
2706       _dbus_list_free_link (link);
2707       BUS_SET_OOM (error);
2708       return FALSE;
2709     }
2710
2711   /* release all its names */
2712   if (!_dbus_list_copy (&d->services_owned, &tmp))
2713     {
2714       bcd_drop_monitor_rules (d, connection);
2715       _dbus_list_free_link (link);
2716       BUS_SET_OOM (error);
2717       return FALSE;
2718     }
2719
2720   for (iter = _dbus_list_get_first_link (&tmp);
2721       iter != NULL;
2722       iter = _dbus_list_get_next_link (&tmp, iter))
2723     {
2724       BusService *service = iter->data;
2725
2726       /* This call is transactional: if there isn't enough memory to
2727        * do everything, then the service gets all its names back when
2728        * the transaction is cancelled due to OOM. */
2729       if (!bus_service_remove_owner (service, connection, transaction, error))
2730         {
2731           bcd_drop_monitor_rules (d, connection);
2732           _dbus_list_free_link (link);
2733           _dbus_list_clear (&tmp);
2734           return FALSE;
2735         }
2736     }
2737
2738   /* We have now done everything that can fail, so there is no problem
2739    * with doing the irrevocable stuff. */
2740
2741   _dbus_list_clear (&tmp);
2742
2743   bus_context_log (transaction->context, DBUS_SYSTEM_LOG_INFO,
2744                    "Connection %s (%s) became a monitor.", d->name,
2745                    d->cached_loginfo_string);
2746
2747   if (d->n_match_rules > 0)
2748     {
2749       BusMatchmaker *mm;
2750
2751       mm = bus_context_get_matchmaker (d->connections->context);
2752       bus_matchmaker_disconnected (mm, connection);
2753     }
2754
2755   /* flag it as a monitor */
2756   d->link_in_monitors = link;
2757   _dbus_list_append_link (&d->connections->monitors, link);
2758
2759   /* it isn't allowed to reply, and it is no longer relevant whether it
2760    * receives replies */
2761   bus_connection_drop_pending_replies (d->connections, connection);
2762
2763   return TRUE;
2764 }