bus/activation.c

   1 /* -*- mode: C; c-file-style: "gnu" -*- */
   2 /* activation.c  Activation of services
   3  *
   4  * Copyright (C) 2003  CodeFactory AB
   5  * Copyright (C) 2003  Red Hat, Inc.
   6  *
   7  * Licensed under the Academic Free License version 1.2
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  */
  24 #include "activation.h"
  25 #include "desktop-file.h"
  26 #include "services.h"
  27 #include "utils.h"
  28 #include <dbus/dbus-internals.h>
  29 #include <dbus/dbus-hash.h>
  30 #include <dbus/dbus-list.h>
  31 #include <dbus/dbus-spawn.h>
  32 #include <dbus/dbus-timeout.h>
  33 #include <sys/types.h>
  34 #include <dirent.h>
  35 #include <errno.h>
  36
  37 #define DBUS_SERVICE_SECTION "D-BUS Service"
  38 #define DBUS_SERVICE_NAME "Name"
  39 #define DBUS_SERVICE_EXEC "Exec"
  40
  41 struct BusActivation
  42 {
  43   int refcount;
  44   DBusHashTable *entries;
  45   DBusHashTable *pending_activations;
  46   char *server_address;
  47   BusContext *context;
  48   int n_pending_activations; /**< This is in fact the number of BusPendingActivationEntry,
  49                               * i.e. number of pending activation requests, not pending
  50                               * activations per se
  51                               */
  52 };
  53
  54 typedef struct
  55 {
  56   char *name;
  57   char *exec;
  58 } BusActivationEntry;
  59
  60 typedef struct BusPendingActivationEntry BusPendingActivationEntry;
  61
  62 struct BusPendingActivationEntry
  63 {
  64   DBusMessage *activation_message;
  65   DBusConnection *connection;
  66 };
  67
  68 typedef struct
  69 {
  70   int refcount;
  71   BusActivation *activation;
  72   char *service_name;
  73   DBusList *entries;
  74   int n_entries;
  75   DBusBabysitter *babysitter;
  76   DBusTimeout *timeout;
  77   unsigned int timeout_added : 1;
  78 } BusPendingActivation;
  79
  80 static void
  81 bus_pending_activation_entry_free (BusPendingActivationEntry *entry)
  82 {
  83   if (entry->activation_message)
  84     dbus_message_unref (entry->activation_message);
  85
  86   if (entry->connection)
  87     dbus_connection_unref (entry->connection);
  88
  89   dbus_free (entry);
  90 }
  91
  92 static void
  93 handle_timeout_callback (DBusTimeout   *timeout,
  94                          void          *data)
  95 {
  96   BusPendingActivation *pending_activation = data;
  97
  98   while (!dbus_timeout_handle (pending_activation->timeout))
  99     _dbus_wait_for_memory ();
 100 }
 101
 102 static void
 103 bus_pending_activation_ref (BusPendingActivation *pending_activation)
 104 {
 105   _dbus_assert (pending_activation->refcount > 0);
 106   pending_activation->refcount += 1;
 107 }
 108
 109 static void
 110 bus_pending_activation_unref (BusPendingActivation *pending_activation)
 111 {
 112   DBusList *link;
 113
 114   if (pending_activation == NULL) /* hash table requires this */
 115     return;
 116
 117   _dbus_assert (pending_activation->refcount > 0);
 118   pending_activation->refcount -= 1;
 119
 120   if (pending_activation->refcount > 0)
 121     return;
 122
 123   if (pending_activation->timeout_added)
 124     {
 125       _dbus_loop_remove_timeout (bus_context_get_loop (pending_activation->activation->context),
 126                                  pending_activation->timeout,
 127                                  handle_timeout_callback, pending_activation);
 128       pending_activation->timeout_added = FALSE;
 129     }
 130
 131   if (pending_activation->timeout)
 132     _dbus_timeout_unref (pending_activation->timeout);
 133
 134   if (pending_activation->babysitter)
 135     {
 136       if (!_dbus_babysitter_set_watch_functions (pending_activation->babysitter,
 137                                                  NULL, NULL, NULL,
 138                                                  pending_activation->babysitter,
 139                                                  NULL))
 140         _dbus_assert_not_reached ("setting watch functions to NULL failed");
 141
 142       _dbus_babysitter_unref (pending_activation->babysitter);
 143     }
 144
 145   dbus_free (pending_activation->service_name);
 146
 147   link = _dbus_list_get_first_link (&pending_activation->entries);
 148
 149   while (link != NULL)
 150     {
 151       BusPendingActivationEntry *entry = link->data;
 152
 153       bus_pending_activation_entry_free (entry);
 154
 155       link = _dbus_list_get_next_link (&pending_activation->entries, link);
 156     }
 157   _dbus_list_clear (&pending_activation->entries);
 158
 159   pending_activation->activation->n_pending_activations -=
 160     pending_activation->n_entries;
 161
 162   _dbus_assert (pending_activation->activation->n_pending_activations >= 0);
 163
 164   dbus_free (pending_activation);
 165 }
 166
 167 static void
 168 bus_activation_entry_free (BusActivationEntry *entry)
 169 {
 170   if (!entry)
 171     return;
 172
 173   dbus_free (entry->name);
 174   dbus_free (entry->exec);
 175
 176   dbus_free (entry);
 177 }
 178
 179 static dbus_bool_t
 180 add_desktop_file_entry (BusActivation  *activation,
 181                         BusDesktopFile *desktop_file,
 182                         DBusError      *error)
 183 {
 184   char *name, *exec;
 185   BusActivationEntry *entry;
 186
 187   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 188
 189   name = NULL;
 190   exec = NULL;
 191   entry = NULL;
 192
 193   if (!bus_desktop_file_get_string (desktop_file,
 194                                     DBUS_SERVICE_SECTION,
 195                                     DBUS_SERVICE_NAME,
 196                                     &name))
 197     {
 198       dbus_set_error (error, DBUS_ERROR_FAILED,
 199                       "No \""DBUS_SERVICE_NAME"\" key in .service file\n");
 200       goto failed;
 201     }
 202
 203   if (!bus_desktop_file_get_string (desktop_file,
 204                                     DBUS_SERVICE_SECTION,
 205                                     DBUS_SERVICE_EXEC,
 206                                     &exec))
 207     {
 208       dbus_set_error (error, DBUS_ERROR_FAILED,
 209                       "No \""DBUS_SERVICE_EXEC"\" key in .service file\n");
 210       goto failed;
 211     }
 212
 213   /* FIXME we need a better-defined algorithm for which service file to
 214    * pick than "whichever one is first in the directory listing"
 215    */
 216   if (_dbus_hash_table_lookup_string (activation->entries, name))
 217     {
 218       dbus_set_error (error, DBUS_ERROR_FAILED,
 219                       "Service %s already exists in activation entry list\n", name);
 220       goto failed;
 221     }
 222
 223   entry = dbus_new0 (BusActivationEntry, 1);
 224   if (entry == NULL)
 225     {
 226       BUS_SET_OOM (error);
 227       goto failed;
 228     }
 229
 230   entry->name = name;
 231   entry->exec = exec;
 232
 233   if (!_dbus_hash_table_insert_string (activation->entries, entry->name, entry))
 234     {
 235       BUS_SET_OOM (error);
 236       goto failed;
 237     }
 238
 239   _dbus_verbose ("Added \"%s\" to list of services\n", entry->name);
 240
 241   return TRUE;
 242
 243  failed:
 244   dbus_free (name);
 245   dbus_free (exec);
 246   dbus_free (entry);
 247
 248   return FALSE;
 249 }
 250
 251 /* warning: this doesn't fully "undo" itself on failure, i.e. doesn't strip
 252  * hash entries it already added.
 253  */
 254 static dbus_bool_t
 255 load_directory (BusActivation *activation,
 256                 const char    *directory,
 257                 DBusError     *error)
 258 {
 259   DBusDirIter *iter;
 260   DBusString dir, filename;
 261   DBusString full_path;
 262   BusDesktopFile *desktop_file;
 263   DBusError tmp_error;
 264   dbus_bool_t retval;
 265
 266   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 267
 268   _dbus_string_init_const (&dir, directory);
 269
 270   iter = NULL;
 271   desktop_file = NULL;
 272
 273   if (!_dbus_string_init (&filename))
 274     {
 275       BUS_SET_OOM (error);
 276       return FALSE;
 277     }
 278
 279   if (!_dbus_string_init (&full_path))
 280     {
 281       BUS_SET_OOM (error);
 282       _dbus_string_free (&filename);
 283       return FALSE;
 284     }
 285
 286   retval = FALSE;
 287
 288   /* from this point it's safe to "goto out" */
 289
 290   iter = _dbus_directory_open (&dir, error);
 291   if (iter == NULL)
 292     {
 293       _dbus_verbose ("Failed to open directory %s: %s\n",
 294                      directory, error ? error->message : "unknown");
 295       goto out;
 296     }
 297
 298   /* Now read the files */
 299   dbus_error_init (&tmp_error);
 300   while (_dbus_directory_get_next_file (iter, &filename, &tmp_error))
 301     {
 302       _dbus_assert (!dbus_error_is_set (&tmp_error));
 303
 304       _dbus_string_set_length (&full_path, 0);
 305
 306       if (!_dbus_string_append (&full_path, directory) ||
 307           !_dbus_concat_dir_and_file (&full_path, &filename))
 308         {
 309           BUS_SET_OOM (error);
 310           goto out;
 311         }
 312
 313       if (!_dbus_string_ends_with_c_str (&filename, ".service"))
 314         {
 315           _dbus_verbose ("Skipping non-.service file %s\n",
 316                          _dbus_string_get_const_data (&filename));
 317           continue;
 318         }
 319
 320       desktop_file = bus_desktop_file_load (&full_path, &tmp_error);
 321
 322       if (desktop_file == NULL)
 323         {
 324           _dbus_verbose ("Could not load %s: %s\n",
 325                          _dbus_string_get_const_data (&full_path),
 326                          tmp_error.message);
 327
 328           if (dbus_error_has_name (&tmp_error, DBUS_ERROR_NO_MEMORY))
 329             {
 330               dbus_move_error (&tmp_error, error);
 331               goto out;
 332             }
 333
 334           dbus_error_free (&tmp_error);
 335           continue;
 336         }
 337
 338       if (!add_desktop_file_entry (activation, desktop_file, &tmp_error))
 339         {
 340           bus_desktop_file_free (desktop_file);
 341           desktop_file = NULL;
 342
 343           _dbus_verbose ("Could not add %s to activation entry list: %s\n",
 344                          _dbus_string_get_const_data (&full_path), tmp_error.message);
 345
 346           if (dbus_error_has_name (&tmp_error, DBUS_ERROR_NO_MEMORY))
 347             {
 348               dbus_move_error (&tmp_error, error);
 349               goto out;
 350             }
 351
 352           dbus_error_free (&tmp_error);
 353           continue;
 354         }
 355       else
 356         {
 357           bus_desktop_file_free (desktop_file);
 358           desktop_file = NULL;
 359           continue;
 360         }
 361     }
 362
 363   if (dbus_error_is_set (&tmp_error))
 364     {
 365       dbus_move_error (&tmp_error, error);
 366       goto out;
 367     }
 368
 369   retval = TRUE;
 370
 371  out:
 372   if (!retval)
 373     _DBUS_ASSERT_ERROR_IS_SET (error);
 374   else
 375     _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 376
 377   if (iter != NULL)
 378     _dbus_directory_close (iter);
 379   if (desktop_file)
 380     bus_desktop_file_free (desktop_file);
 381   _dbus_string_free (&filename);
 382   _dbus_string_free (&full_path);
 383
 384   return retval;
 385 }
 386
 387 BusActivation*
 388 bus_activation_new (BusContext        *context,
 389                     const DBusString  *address,
 390                     DBusList         **directories,
 391                     DBusError         *error)
 392 {
 393   BusActivation *activation;
 394   DBusList *link;
 395
 396   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 397
 398   activation = dbus_new0 (BusActivation, 1);
 399   if (activation == NULL)
 400     {
 401       BUS_SET_OOM (error);
 402       return NULL;
 403     }
 404
 405   activation->refcount = 1;
 406   activation->context = context;
 407   activation->n_pending_activations = 0;
 408
 409   if (!_dbus_string_copy_data (address, &activation->server_address))
 410     {
 411       BUS_SET_OOM (error);
 412       goto failed;
 413     }
 414
 415   activation->entries = _dbus_hash_table_new (DBUS_HASH_STRING, NULL,
 416                                              (DBusFreeFunction)bus_activation_entry_free);
 417   if (activation->entries == NULL)
 418     {
 419       BUS_SET_OOM (error);
 420       goto failed;
 421     }
 422
 423   activation->pending_activations = _dbus_hash_table_new (DBUS_HASH_STRING, NULL,
 424                                                           (DBusFreeFunction)bus_pending_activation_unref);
 425
 426   if (activation->pending_activations == NULL)
 427     {
 428       BUS_SET_OOM (error);
 429       goto failed;
 430     }
 431
 432   /* Load service files */
 433   link = _dbus_list_get_first_link (directories);
 434   while (link != NULL)
 435     {
 436       if (!load_directory (activation, link->data, error))
 437         goto failed;
 438       link = _dbus_list_get_next_link (directories, link);
 439     }
 440
 441   return activation;
 442
 443  failed:
 444   bus_activation_unref (activation);
 445   return NULL;
 446 }
 447
 448 void
 449 bus_activation_ref (BusActivation *activation)
 450 {
 451   _dbus_assert (activation->refcount > 0);
 452
 453   activation->refcount += 1;
 454 }
 455
 456 void
 457 bus_activation_unref (BusActivation *activation)
 458 {
 459   _dbus_assert (activation->refcount > 0);
 460
 461   activation->refcount -= 1;
 462
 463   if (activation->refcount == 0)
 464     {
 465       dbus_free (activation->server_address);
 466       if (activation->entries)
 467         _dbus_hash_table_unref (activation->entries);
 468       if (activation->pending_activations)
 469         _dbus_hash_table_unref (activation->pending_activations);
 470       dbus_free (activation);
 471     }
 472 }
 473
 474 static void
 475 child_setup (void *data)
 476 {
 477   BusActivation *activation = data;
 478   const char *type;
 479
 480   /* If no memory, we simply have the child exit, so it won't try
 481    * to connect to the wrong thing.
 482    */
 483   if (!_dbus_setenv ("DBUS_ACTIVATION_ADDRESS", activation->server_address))
 484     _dbus_exit (1);
 485
 486   type = bus_context_get_type (activation->context);
 487   if (type != NULL)
 488     {
 489       if (!_dbus_setenv ("DBUS_BUS_TYPE", type))
 490         _dbus_exit (1);
 491     }
 492 }
 493
 494 typedef struct
 495 {
 496   BusPendingActivation *pending_activation;
 497   DBusPreallocatedHash *hash_entry;
 498 } RestorePendingData;
 499
 500 static void
 501 restore_pending (void *data)
 502 {
 503   RestorePendingData *d = data;
 504
 505   _dbus_assert (d->pending_activation != NULL);
 506   _dbus_assert (d->hash_entry != NULL);
 507
 508   _dbus_verbose ("Restoring pending activation for service %s, has timeout = %d\n",
 509                  d->pending_activation->service_name,
 510                  d->pending_activation->timeout_added);
 511
 512   _dbus_hash_table_insert_string_preallocated (d->pending_activation->activation->pending_activations,
 513                                                d->hash_entry,
 514                                                d->pending_activation->service_name, d->pending_activation);
 515
 516   bus_pending_activation_ref (d->pending_activation);
 517
 518   d->hash_entry = NULL;
 519 }
 520
 521 static void
 522 free_pending_restore_data (void *data)
 523 {
 524   RestorePendingData *d = data;
 525
 526   if (d->hash_entry)
 527     _dbus_hash_table_free_preallocated_entry (d->pending_activation->activation->pending_activations,
 528                                               d->hash_entry);
 529
 530   bus_pending_activation_unref (d->pending_activation);
 531
 532   dbus_free (d);
 533 }
 534
 535 static dbus_bool_t
 536 add_restore_pending_to_transaction (BusTransaction       *transaction,
 537                                     BusPendingActivation *pending_activation)
 538 {
 539   RestorePendingData *d;
 540
 541   d = dbus_new (RestorePendingData, 1);
 542   if (d == NULL)
 543     return FALSE;
 544
 545   d->pending_activation = pending_activation;
 546   d->hash_entry = _dbus_hash_table_preallocate_entry (d->pending_activation->activation->pending_activations);
 547
 548   bus_pending_activation_ref (d->pending_activation);
 549
 550   if (d->hash_entry == NULL ||
 551       !bus_transaction_add_cancel_hook (transaction, restore_pending, d,
 552                                         free_pending_restore_data))
 553     {
 554       free_pending_restore_data (d);
 555       return FALSE;
 556     }
 557
 558   _dbus_verbose ("Saved pending activation to be restored if the transaction fails\n");
 559
 560   return TRUE;
 561 }
 562
 563 dbus_bool_t
 564 bus_activation_service_created (BusActivation  *activation,
 565                                 const char     *service_name,
 566                                 BusTransaction *transaction,
 567                                 DBusError      *error)
 568 {
 569   BusPendingActivation *pending_activation;
 570   DBusMessage *message;
 571   DBusList *link;
 572
 573   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 574
 575   /* Check if it's a pending activation */
 576   pending_activation = _dbus_hash_table_lookup_string (activation->pending_activations, service_name);
 577
 578   if (!pending_activation)
 579     return TRUE;
 580
 581   link = _dbus_list_get_first_link (&pending_activation->entries);
 582   while (link != NULL)
 583     {
 584       BusPendingActivationEntry *entry = link->data;
 585       DBusList *next = _dbus_list_get_next_link (&pending_activation->entries, link);
 586
 587       if (dbus_connection_get_is_connected (entry->connection))
 588         {
 589           message = dbus_message_new_method_return (entry->activation_message);
 590           if (!message)
 591             {
 592               BUS_SET_OOM (error);
 593               goto error;
 594             }
 595
 596           if (!dbus_message_append_args (message,
 597                                          DBUS_TYPE_UINT32, DBUS_ACTIVATION_REPLY_ACTIVATED,
 598                                          DBUS_TYPE_INVALID))
 599             {
 600               dbus_message_unref (message);
 601               BUS_SET_OOM (error);
 602               goto error;
 603             }
 604
 605           if (!bus_transaction_send_from_driver (transaction, entry->connection, message))
 606             {
 607               dbus_message_unref (message);
 608               BUS_SET_OOM (error);
 609               goto error;
 610             }
 611
 612           dbus_message_unref (message);
 613         }
 614
 615       link = next;
 616     }
 617
 618   if (!add_restore_pending_to_transaction (transaction, pending_activation))
 619     {
 620       _dbus_verbose ("Could not add cancel hook to transaction to revert removing pending activation\n");
 621       BUS_SET_OOM (error);
 622       goto error;
 623     }
 624
 625   _dbus_hash_table_remove_string (activation->pending_activations, service_name);
 626
 627   return TRUE;
 628
 629  error:
 630   return FALSE;
 631 }
 632
 633 /**
 634  * FIXME @todo the error messages here would ideally be preallocated
 635  * so we don't need to allocate memory to send them.
 636  * Using the usual tactic, prealloc an OOM message, then
 637  * if we can't alloc the real error send the OOM error instead.
 638  */
 639 static dbus_bool_t
 640 try_send_activation_failure (BusPendingActivation *pending_activation,
 641                              const DBusError      *how)
 642 {
 643   BusActivation *activation;
 644   DBusList *link;
 645   BusTransaction *transaction;
 646
 647   activation = pending_activation->activation;
 648
 649   transaction = bus_transaction_new (activation->context);
 650   if (transaction == NULL)
 651     return FALSE;
 652
 653   link = _dbus_list_get_first_link (&pending_activation->entries);
 654   while (link != NULL)
 655     {
 656       BusPendingActivationEntry *entry = link->data;
 657       DBusList *next = _dbus_list_get_next_link (&pending_activation->entries, link);
 658
 659       if (dbus_connection_get_is_connected (entry->connection))
 660         {
 661           if (!bus_transaction_send_error_reply (transaction,
 662                                                  entry->connection,
 663                                                  how,
 664                                                  entry->activation_message))
 665             goto error;
 666         }
 667
 668       link = next;
 669     }
 670
 671   bus_transaction_execute_and_free (transaction);
 672
 673   return TRUE;
 674
 675  error:
 676   if (transaction)
 677     bus_transaction_cancel_and_free (transaction);
 678   return FALSE;
 679 }
 680
 681 /**
 682  * Free the pending activation and send an error message to all the
 683  * connections that were waiting for it.
 684  */
 685 static void
 686 pending_activation_failed (BusPendingActivation *pending_activation,
 687                            const DBusError      *how)
 688 {
 689   /* FIXME use preallocated OOM messages instead of bus_wait_for_memory() */
 690   while (!try_send_activation_failure (pending_activation, how))
 691     _dbus_wait_for_memory ();
 692
 693   /* Destroy this pending activation */
 694   _dbus_hash_table_remove_string (pending_activation->activation->pending_activations,
 695                                   pending_activation->service_name);
 696 }
 697
 698 static dbus_bool_t
 699 babysitter_watch_callback (DBusWatch     *watch,
 700                            unsigned int   condition,
 701                            void          *data)
 702 {
 703   BusPendingActivation *pending_activation = data;
 704   dbus_bool_t retval;
 705   DBusBabysitter *babysitter;
 706
 707   babysitter = pending_activation->babysitter;
 708
 709   _dbus_babysitter_ref (babysitter);
 710
 711   retval = dbus_watch_handle (watch, condition);
 712
 713   /* FIXME this is broken in the same way that
 714    * connection watches used to be; there should be
 715    * a separate callback for status change, instead
 716    * of doing "if we handled a watch status might
 717    * have changed"
 718    *
 719    * Fixing this lets us move dbus_watch_handle
 720    * calls into dbus-mainloop.c
 721    */
 722
 723   if (_dbus_babysitter_get_child_exited (babysitter))
 724     {
 725       DBusError error;
 726
 727       dbus_error_init (&error);
 728       _dbus_babysitter_set_child_exit_error (babysitter, &error);
 729
 730       /* Destroys the pending activation */
 731       pending_activation_failed (pending_activation, &error);
 732
 733       dbus_error_free (&error);
 734     }
 735
 736   _dbus_babysitter_unref (babysitter);
 737
 738   return retval;
 739 }
 740
 741 static dbus_bool_t
 742 add_babysitter_watch (DBusWatch      *watch,
 743                       void           *data)
 744 {
 745   BusPendingActivation *pending_activation = data;
 746
 747   return _dbus_loop_add_watch (bus_context_get_loop (pending_activation->activation->context),
 748                                watch, babysitter_watch_callback, pending_activation,
 749                                NULL);
 750 }
 751
 752 static void
 753 remove_babysitter_watch (DBusWatch      *watch,
 754                          void           *data)
 755 {
 756   BusPendingActivation *pending_activation = data;
 757
 758   _dbus_loop_remove_watch (bus_context_get_loop (pending_activation->activation->context),
 759                            watch, babysitter_watch_callback, pending_activation);
 760 }
 761
 762 static dbus_bool_t
 763 pending_activation_timed_out (void *data)
 764 {
 765   BusPendingActivation *pending_activation = data;
 766   DBusError error;
 767
 768   /* Kill the spawned process, since it sucks
 769    * (not sure this is what we want to do, but
 770    * may as well try it for now)
 771    */
 772   _dbus_babysitter_kill_child (pending_activation->babysitter);
 773
 774   dbus_error_init (&error);
 775
 776   dbus_set_error (&error, DBUS_ERROR_TIMED_OUT,
 777                   "Activation of %s timed out",
 778                   pending_activation->service_name);
 779
 780   pending_activation_failed (pending_activation, &error);
 781
 782   dbus_error_free (&error);
 783
 784   return TRUE;
 785 }
 786
 787 static void
 788 cancel_pending (void *data)
 789 {
 790   BusPendingActivation *pending_activation = data;
 791
 792   _dbus_verbose ("Canceling pending activation of %s\n",
 793                  pending_activation->service_name);
 794
 795   if (pending_activation->babysitter)
 796     _dbus_babysitter_kill_child (pending_activation->babysitter);
 797
 798   _dbus_hash_table_remove_string (pending_activation->activation->pending_activations,
 799                                   pending_activation->service_name);
 800 }
 801
 802 static void
 803 free_pending_cancel_data (void *data)
 804 {
 805   BusPendingActivation *pending_activation = data;
 806
 807   bus_pending_activation_unref (pending_activation);
 808 }
 809
 810 static dbus_bool_t
 811 add_cancel_pending_to_transaction (BusTransaction       *transaction,
 812                                    BusPendingActivation *pending_activation)
 813 {
 814   if (!bus_transaction_add_cancel_hook (transaction, cancel_pending,
 815                                         pending_activation,
 816                                         free_pending_cancel_data))
 817     return FALSE;
 818
 819   bus_pending_activation_ref (pending_activation);
 820
 821   _dbus_verbose ("Saved pending activation to be canceled if the transaction fails\n");
 822
 823   return TRUE;
 824 }
 825
 826 dbus_bool_t
 827 bus_activation_activate_service (BusActivation  *activation,
 828                                  DBusConnection *connection,
 829                                  BusTransaction *transaction,
 830                                  DBusMessage    *activation_message,
 831                                  const char     *service_name,
 832                                  DBusError      *error)
 833 {
 834   BusActivationEntry *entry;
 835   BusPendingActivation *pending_activation;
 836   BusPendingActivationEntry *pending_activation_entry;
 837   DBusMessage *message;
 838   DBusString service_str;
 839   char *argv[2];
 840   dbus_bool_t retval;
 841
 842   _DBUS_ASSERT_ERROR_IS_CLEAR (error);
 843
 844   if (activation->n_pending_activations >=
 845       bus_context_get_max_pending_activations (activation->context))
 846     {
 847       dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
 848                       "The maximum number of pending activations has been reached, activation of %s failed",
 849                       service_name);
 850       return FALSE;
 851     }
 852
 853   entry = _dbus_hash_table_lookup_string (activation->entries, service_name);
 854
 855   if (!entry)
 856     {
 857       dbus_set_error (error, DBUS_ERROR_ACTIVATE_SERVICE_NOT_FOUND,
 858                       "The service %s was not found in the activation entry list",
 859                       service_name);
 860       return FALSE;
 861     }
 862
 863   /* Check if the service is active */
 864   _dbus_string_init_const (&service_str, service_name);
 865   if (bus_registry_lookup (bus_context_get_registry (activation->context), &service_str) != NULL)
 866     {
 867       _dbus_verbose ("Service \"%s\" is already active\n", service_name);
 868
 869       message = dbus_message_new_method_return (activation_message);
 870
 871       if (!message)
 872         {
 873           _dbus_verbose ("No memory to create reply to activate message\n");
 874           BUS_SET_OOM (error);
 875           return FALSE;
 876         }
 877
 878       if (!dbus_message_append_args (message,
 879                                      DBUS_TYPE_UINT32, DBUS_ACTIVATION_REPLY_ALREADY_ACTIVE,
 880                                      DBUS_TYPE_INVALID))
 881         {
 882           _dbus_verbose ("No memory to set args of reply to activate message\n");
 883           BUS_SET_OOM (error);
 884           dbus_message_unref (message);
 885           return FALSE;
 886         }
 887
 888       retval = bus_transaction_send_from_driver (transaction, connection, message);
 889       dbus_message_unref (message);
 890       if (!retval)
 891         {
 892           _dbus_verbose ("Failed to send reply\n");
 893           BUS_SET_OOM (error);
 894         }
 895
 896       return retval;
 897     }
 898
 899   pending_activation_entry = dbus_new0 (BusPendingActivationEntry, 1);
 900   if (!pending_activation_entry)
 901     {
 902       _dbus_verbose ("Failed to create pending activation entry\n");
 903       BUS_SET_OOM (error);
 904       return FALSE;
 905     }
 906
 907   pending_activation_entry->activation_message = activation_message;
 908   dbus_message_ref (activation_message);
 909   pending_activation_entry->connection = connection;
 910   dbus_connection_ref (connection);
 911
 912   /* Check if the service is being activated */
 913   pending_activation = _dbus_hash_table_lookup_string (activation->pending_activations, service_name);
 914   if (pending_activation)
 915     {
 916       if (!_dbus_list_append (&pending_activation->entries, pending_activation_entry))
 917         {
 918           _dbus_verbose ("Failed to append a new entry to pending activation\n");
 919
 920           BUS_SET_OOM (error);
 921           bus_pending_activation_entry_free (pending_activation_entry);
 922           return FALSE;
 923         }
 924
 925       pending_activation->n_entries += 1;
 926       pending_activation->activation->n_pending_activations += 1;
 927     }
 928   else
 929     {
 930       pending_activation = dbus_new0 (BusPendingActivation, 1);
 931       if (!pending_activation)
 932         {
 933           _dbus_verbose ("Failed to create pending activation\n");
 934
 935           BUS_SET_OOM (error);
 936           bus_pending_activation_entry_free (pending_activation_entry);
 937           return FALSE;
 938         }
 939
 940       pending_activation->activation = activation;
 941       pending_activation->refcount = 1;
 942
 943       pending_activation->service_name = _dbus_strdup (service_name);
 944       if (!pending_activation->service_name)
 945         {
 946           _dbus_verbose ("Failed to copy service name for pending activation\n");
 947
 948           BUS_SET_OOM (error);
 949           bus_pending_activation_unref (pending_activation);
 950           bus_pending_activation_entry_free (pending_activation_entry);
 951           return FALSE;
 952         }
 953
 954       pending_activation->timeout =
 955         _dbus_timeout_new (bus_context_get_activation_timeout (activation->context),
 956                            pending_activation_timed_out,
 957                            pending_activation,
 958                            NULL);
 959       if (!pending_activation->timeout)
 960         {
 961           _dbus_verbose ("Failed to create timeout for pending activation\n");
 962
 963           BUS_SET_OOM (error);
 964           bus_pending_activation_unref (pending_activation);
 965           bus_pending_activation_entry_free (pending_activation_entry);
 966           return FALSE;
 967         }
 968
 969       if (!_dbus_loop_add_timeout (bus_context_get_loop (activation->context),
 970                                    pending_activation->timeout,
 971                                    handle_timeout_callback,
 972                                    pending_activation,
 973                                    NULL))
 974         {
 975           _dbus_verbose ("Failed to add timeout for pending activation\n");
 976
 977           BUS_SET_OOM (error);
 978           bus_pending_activation_unref (pending_activation);
 979           bus_pending_activation_entry_free (pending_activation_entry);
 980           return FALSE;
 981         }
 982
 983       pending_activation->timeout_added = TRUE;
 984
 985       if (!_dbus_list_append (&pending_activation->entries, pending_activation_entry))
 986         {
 987           _dbus_verbose ("Failed to add entry to just-created pending activation\n");
 988
 989           BUS_SET_OOM (error);
 990           bus_pending_activation_unref (pending_activation);
 991           bus_pending_activation_entry_free (pending_activation_entry);
 992           return FALSE;
 993         }
 994
 995       pending_activation->n_entries += 1;
 996       pending_activation->activation->n_pending_activations += 1;
 997
 998       if (!_dbus_hash_table_insert_string (activation->pending_activations,
 999                                            pending_activation->service_name,
1000                                            pending_activation))
1001         {
1002           _dbus_verbose ("Failed to put pending activation in hash table\n");
1003
1004           BUS_SET_OOM (error);
1005           bus_pending_activation_unref (pending_activation);
1006           return FALSE;
1007         }
1008     }
1009
1010   if (!add_cancel_pending_to_transaction (transaction, pending_activation))
1011     {
1012       _dbus_verbose ("Failed to add pending activation cancel hook to transaction\n");
1013       BUS_SET_OOM (error);
1014       _dbus_hash_table_remove_string (activation->pending_activations,
1015                                       pending_activation->service_name);
1016       return FALSE;
1017     }
1018
1019   /* FIXME we need to support a full command line, not just a single
1020    * argv[0]
1021    */
1022
1023   /* Now try to spawn the process */
1024   argv[0] = entry->exec;
1025   argv[1] = NULL;
1026
1027   if (!_dbus_spawn_async_with_babysitter (&pending_activation->babysitter, argv,
1028                                           child_setup, activation,
1029                                           error))
1030     {
1031       _dbus_verbose ("Failed to spawn child\n");
1032       _DBUS_ASSERT_ERROR_IS_SET (error);
1033       return FALSE;
1034     }
1035
1036   _dbus_assert (pending_activation->babysitter != NULL);
1037
1038   if (!_dbus_babysitter_set_watch_functions (pending_activation->babysitter,
1039                                              add_babysitter_watch,
1040                                              remove_babysitter_watch,
1041                                              NULL,
1042                                              pending_activation,
1043                                              NULL))
1044     {
1045       BUS_SET_OOM (error);
1046       _dbus_verbose ("Failed to set babysitter watch functions\n");
1047       return FALSE;
1048     }
1049
1050   return TRUE;
1051 }