1 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
2 /* dbus-server.c DBusServer object
3  *
4  * Copyright (C) 2002, 2003, 2004, 2005 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 "dbus-server.h"
26 #include "dbus-server-unix.h"
27 #include "dbus-server-socket.h"
28 #include "dbus-string.h"
29 #ifdef DBUS_BUILD_TESTS
30 #include "dbus-server-debug-pipe.h"
31 #endif
32 #include "dbus-address.h"
33 #include "dbus-protocol.h"
34 
35 /**
36  * @defgroup DBusServer DBusServer
37  * @ingroup  DBus
38  * @brief Server that listens for new connections.
39  *
40  * A DBusServer represents a server that other applications
41  * can connect to. Each connection from another application
42  * is represented by a #DBusConnection.
43  *
44  * @todo Thread safety hasn't been tested much for #DBusServer
45  * @todo Need notification to apps of disconnection, may matter for some transports
46  */
47 
48 /**
49  * @defgroup DBusServerInternals DBusServer implementation details
50  * @ingroup  DBusInternals
51  * @brief Implementation details of DBusServer
52  *
53  * @{
54  */
55 
56 #ifndef _dbus_server_trace_ref
57 void
_dbus_server_trace_ref(DBusServer * server,int old_refcount,int new_refcount,const char * why)58 _dbus_server_trace_ref (DBusServer *server,
59     int old_refcount,
60     int new_refcount,
61     const char *why)
62 {
63   static int enabled = -1;
64 
65   _dbus_trace_ref ("DBusServer", server, old_refcount, new_refcount, why,
66       "DBUS_SERVER_TRACE", &enabled);
67 }
68 #endif
69 
70 /* this is a little fragile since it assumes the address doesn't
71  * already have a guid, but it shouldn't
72  */
73 static char*
copy_address_with_guid_appended(const DBusString * address,const DBusString * guid_hex)74 copy_address_with_guid_appended (const DBusString *address,
75                                  const DBusString *guid_hex)
76 {
77   DBusString with_guid;
78   char *retval;
79 
80   if (!_dbus_string_init (&with_guid))
81     return NULL;
82 
83   if (!_dbus_string_copy (address, 0, &with_guid,
84                           _dbus_string_get_length (&with_guid)) ||
85       !_dbus_string_append (&with_guid, ",guid=") ||
86       !_dbus_string_copy (guid_hex, 0,
87                           &with_guid, _dbus_string_get_length (&with_guid)))
88     {
89       _dbus_string_free (&with_guid);
90       return NULL;
91     }
92 
93   retval = NULL;
94   _dbus_string_steal_data (&with_guid, &retval);
95 
96   _dbus_string_free (&with_guid);
97 
98   return retval; /* may be NULL if steal_data failed */
99 }
100 
101 /**
102  * Initializes the members of the DBusServer base class.
103  * Chained up to by subclass constructors.
104  *
105  * @param server the server.
106  * @param vtable the vtable for the subclass.
107  * @param address the server's address
108  * @returns #TRUE on success.
109  */
110 dbus_bool_t
_dbus_server_init_base(DBusServer * server,const DBusServerVTable * vtable,const DBusString * address)111 _dbus_server_init_base (DBusServer             *server,
112                         const DBusServerVTable *vtable,
113                         const DBusString       *address)
114 {
115   server->vtable = vtable;
116 
117 #ifdef DBUS_DISABLE_ASSERT
118   _dbus_atomic_inc (&server->refcount);
119 #else
120     {
121       dbus_int32_t old_refcount = _dbus_atomic_inc (&server->refcount);
122 
123       _dbus_assert (old_refcount == 0);
124     }
125 #endif
126 
127   server->address = NULL;
128   server->watches = NULL;
129   server->timeouts = NULL;
130   server->published_address = FALSE;
131 
132   if (!_dbus_string_init (&server->guid_hex))
133     return FALSE;
134 
135   _dbus_generate_uuid (&server->guid);
136 
137   if (!_dbus_uuid_encode (&server->guid, &server->guid_hex))
138     goto failed;
139 
140   server->address = copy_address_with_guid_appended (address,
141                                                      &server->guid_hex);
142   if (server->address == NULL)
143     goto failed;
144 
145   _dbus_rmutex_new_at_location (&server->mutex);
146   if (server->mutex == NULL)
147     goto failed;
148 
149   server->watches = _dbus_watch_list_new ();
150   if (server->watches == NULL)
151     goto failed;
152 
153   server->timeouts = _dbus_timeout_list_new ();
154   if (server->timeouts == NULL)
155     goto failed;
156 
157   _dbus_data_slot_list_init (&server->slot_list);
158 
159   _dbus_verbose ("Initialized server on address %s\n", server->address);
160 
161   return TRUE;
162 
163  failed:
164   _dbus_rmutex_free_at_location (&server->mutex);
165   server->mutex = NULL;
166   if (server->watches)
167     {
168       _dbus_watch_list_free (server->watches);
169       server->watches = NULL;
170     }
171   if (server->timeouts)
172     {
173       _dbus_timeout_list_free (server->timeouts);
174       server->timeouts = NULL;
175     }
176   if (server->address)
177     {
178       dbus_free (server->address);
179       server->address = NULL;
180     }
181   _dbus_string_free (&server->guid_hex);
182 
183   return FALSE;
184 }
185 
186 /**
187  * Finalizes the members of the DBusServer base class.
188  * Chained up to by subclass finalizers.
189  *
190  * @param server the server.
191  */
192 void
_dbus_server_finalize_base(DBusServer * server)193 _dbus_server_finalize_base (DBusServer *server)
194 {
195   /* We don't have the lock, but nobody should be accessing
196    * concurrently since they don't have a ref
197    */
198 #ifndef DBUS_DISABLE_CHECKS
199   _dbus_assert (!server->have_server_lock);
200 #endif
201   _dbus_assert (server->disconnected);
202 
203   /* calls out to application code... */
204   _dbus_data_slot_list_free (&server->slot_list);
205 
206   dbus_server_set_new_connection_function (server, NULL, NULL, NULL);
207 
208   _dbus_watch_list_free (server->watches);
209   _dbus_timeout_list_free (server->timeouts);
210 
211   _dbus_rmutex_free_at_location (&server->mutex);
212 
213   dbus_free (server->address);
214 
215   dbus_free_string_array (server->auth_mechanisms);
216 
217   _dbus_string_free (&server->guid_hex);
218 }
219 
220 
221 /** Function to be called in protected_change_watch() with refcount held */
222 typedef dbus_bool_t (* DBusWatchAddFunction)     (DBusWatchList *list,
223                                                   DBusWatch     *watch);
224 /** Function to be called in protected_change_watch() with refcount held */
225 typedef void        (* DBusWatchRemoveFunction)  (DBusWatchList *list,
226                                                   DBusWatch     *watch);
227 /** Function to be called in protected_change_watch() with refcount held */
228 typedef void        (* DBusWatchToggleFunction)  (DBusWatchList *list,
229                                                   DBusWatch     *watch,
230                                                   dbus_bool_t    enabled);
231 
232 static dbus_bool_t
protected_change_watch(DBusServer * server,DBusWatch * watch,DBusWatchAddFunction add_function,DBusWatchRemoveFunction remove_function,DBusWatchToggleFunction toggle_function,dbus_bool_t enabled)233 protected_change_watch (DBusServer             *server,
234                         DBusWatch              *watch,
235                         DBusWatchAddFunction    add_function,
236                         DBusWatchRemoveFunction remove_function,
237                         DBusWatchToggleFunction toggle_function,
238                         dbus_bool_t             enabled)
239 {
240   DBusWatchList *watches;
241   dbus_bool_t retval;
242 
243   HAVE_LOCK_CHECK (server);
244 
245   /* This isn't really safe or reasonable; a better pattern is the "do
246    * everything, then drop lock and call out" one; but it has to be
247    * propagated up through all callers
248    */
249 
250   watches = server->watches;
251   if (watches)
252     {
253       server->watches = NULL;
254       _dbus_server_ref_unlocked (server);
255       SERVER_UNLOCK (server);
256 
257       if (add_function)
258         retval = (* add_function) (watches, watch);
259       else if (remove_function)
260         {
261           retval = TRUE;
262           (* remove_function) (watches, watch);
263         }
264       else
265         {
266           retval = TRUE;
267           (* toggle_function) (watches, watch, enabled);
268         }
269 
270       SERVER_LOCK (server);
271       server->watches = watches;
272       _dbus_server_unref_unlocked (server);
273 
274       return retval;
275     }
276   else
277     return FALSE;
278 }
279 
280 /**
281  * Adds a watch for this server, chaining out to application-provided
282  * watch handlers.
283  *
284  * @param server the server.
285  * @param watch the watch to add.
286  */
287 dbus_bool_t
_dbus_server_add_watch(DBusServer * server,DBusWatch * watch)288 _dbus_server_add_watch (DBusServer *server,
289                         DBusWatch  *watch)
290 {
291   HAVE_LOCK_CHECK (server);
292   return protected_change_watch (server, watch,
293                                  _dbus_watch_list_add_watch,
294                                  NULL, NULL, FALSE);
295 }
296 
297 /**
298  * Removes a watch previously added with _dbus_server_remove_watch().
299  *
300  * @param server the server.
301  * @param watch the watch to remove.
302  */
303 void
_dbus_server_remove_watch(DBusServer * server,DBusWatch * watch)304 _dbus_server_remove_watch  (DBusServer *server,
305                             DBusWatch  *watch)
306 {
307   HAVE_LOCK_CHECK (server);
308   protected_change_watch (server, watch,
309                           NULL,
310                           _dbus_watch_list_remove_watch,
311                           NULL, FALSE);
312 }
313 
314 /**
315  * Toggles a watch and notifies app via server's
316  * DBusWatchToggledFunction if available. It's an error to call this
317  * function on a watch that was not previously added.
318  *
319  * @param server the server.
320  * @param watch the watch to toggle.
321  * @param enabled whether to enable or disable
322  */
323 void
_dbus_server_toggle_watch(DBusServer * server,DBusWatch * watch,dbus_bool_t enabled)324 _dbus_server_toggle_watch (DBusServer  *server,
325                            DBusWatch   *watch,
326                            dbus_bool_t  enabled)
327 {
328   _dbus_assert (watch != NULL);
329 
330   HAVE_LOCK_CHECK (server);
331   protected_change_watch (server, watch,
332                           NULL, NULL,
333                           _dbus_watch_list_toggle_watch,
334                           enabled);
335 }
336 
337 /** Function to be called in protected_change_timeout() with refcount held */
338 typedef dbus_bool_t (* DBusTimeoutAddFunction)    (DBusTimeoutList *list,
339                                                    DBusTimeout     *timeout);
340 /** Function to be called in protected_change_timeout() with refcount held */
341 typedef void        (* DBusTimeoutRemoveFunction) (DBusTimeoutList *list,
342                                                    DBusTimeout     *timeout);
343 /** Function to be called in protected_change_timeout() with refcount held */
344 typedef void        (* DBusTimeoutToggleFunction) (DBusTimeoutList *list,
345                                                    DBusTimeout     *timeout,
346                                                    dbus_bool_t      enabled);
347 
348 
349 static dbus_bool_t
protected_change_timeout(DBusServer * server,DBusTimeout * timeout,DBusTimeoutAddFunction add_function,DBusTimeoutRemoveFunction remove_function,DBusTimeoutToggleFunction toggle_function,dbus_bool_t enabled)350 protected_change_timeout (DBusServer               *server,
351                           DBusTimeout              *timeout,
352                           DBusTimeoutAddFunction    add_function,
353                           DBusTimeoutRemoveFunction remove_function,
354                           DBusTimeoutToggleFunction toggle_function,
355                           dbus_bool_t               enabled)
356 {
357   DBusTimeoutList *timeouts;
358   dbus_bool_t retval;
359 
360   HAVE_LOCK_CHECK (server);
361 
362   /* This isn't really safe or reasonable; a better pattern is the "do everything, then
363    * drop lock and call out" one; but it has to be propagated up through all callers
364    */
365 
366   timeouts = server->timeouts;
367   if (timeouts)
368     {
369       server->timeouts = NULL;
370       _dbus_server_ref_unlocked (server);
371       SERVER_UNLOCK (server);
372 
373       if (add_function)
374         retval = (* add_function) (timeouts, timeout);
375       else if (remove_function)
376         {
377           retval = TRUE;
378           (* remove_function) (timeouts, timeout);
379         }
380       else
381         {
382           retval = TRUE;
383           (* toggle_function) (timeouts, timeout, enabled);
384         }
385 
386       SERVER_LOCK (server);
387       server->timeouts = timeouts;
388       _dbus_server_unref_unlocked (server);
389 
390       return retval;
391     }
392   else
393     return FALSE;
394 }
395 
396 /**
397  * Adds a timeout for this server, chaining out to
398  * application-provided timeout handlers. The timeout should be
399  * repeatedly handled with dbus_timeout_handle() at its given interval
400  * until it is removed.
401  *
402  * @param server the server.
403  * @param timeout the timeout to add.
404  */
405 dbus_bool_t
_dbus_server_add_timeout(DBusServer * server,DBusTimeout * timeout)406 _dbus_server_add_timeout (DBusServer  *server,
407 			  DBusTimeout *timeout)
408 {
409   return protected_change_timeout (server, timeout,
410                                    _dbus_timeout_list_add_timeout,
411                                    NULL, NULL, FALSE);
412 }
413 
414 /**
415  * Removes a timeout previously added with _dbus_server_add_timeout().
416  *
417  * @param server the server.
418  * @param timeout the timeout to remove.
419  */
420 void
_dbus_server_remove_timeout(DBusServer * server,DBusTimeout * timeout)421 _dbus_server_remove_timeout (DBusServer  *server,
422 			     DBusTimeout *timeout)
423 {
424   protected_change_timeout (server, timeout,
425                             NULL,
426                             _dbus_timeout_list_remove_timeout,
427                             NULL, FALSE);
428 }
429 
430 /**
431  * Toggles a timeout and notifies app via server's
432  * DBusTimeoutToggledFunction if available. It's an error to call this
433  * function on a timeout that was not previously added.
434  *
435  * @param server the server.
436  * @param timeout the timeout to toggle.
437  * @param enabled whether to enable or disable
438  */
439 void
_dbus_server_toggle_timeout(DBusServer * server,DBusTimeout * timeout,dbus_bool_t enabled)440 _dbus_server_toggle_timeout (DBusServer  *server,
441                              DBusTimeout *timeout,
442                              dbus_bool_t  enabled)
443 {
444   protected_change_timeout (server, timeout,
445                             NULL, NULL,
446                             _dbus_timeout_list_toggle_timeout,
447                             enabled);
448 }
449 
450 
451 /**
452  * Like dbus_server_ref() but does not acquire the lock (must already be held)
453  *
454  * @param server the server.
455  */
456 void
_dbus_server_ref_unlocked(DBusServer * server)457 _dbus_server_ref_unlocked (DBusServer *server)
458 {
459   dbus_int32_t old_refcount;
460 
461   _dbus_assert (server != NULL);
462   HAVE_LOCK_CHECK (server);
463 
464   old_refcount = _dbus_atomic_inc (&server->refcount);
465   _dbus_assert (old_refcount > 0);
466   _dbus_server_trace_ref (server, old_refcount, old_refcount + 1,
467       "ref_unlocked");
468 }
469 
470 /**
471  * Like dbus_server_unref() but does not acquire the lock (must already be held)
472  *
473  * @param server the server.
474  */
475 void
_dbus_server_unref_unlocked(DBusServer * server)476 _dbus_server_unref_unlocked (DBusServer *server)
477 {
478   dbus_int32_t old_refcount;
479 
480   /* Keep this in sync with dbus_server_unref */
481 
482   _dbus_assert (server != NULL);
483 
484   HAVE_LOCK_CHECK (server);
485 
486   old_refcount = _dbus_atomic_dec (&server->refcount);
487   _dbus_assert (old_refcount > 0);
488 
489   _dbus_server_trace_ref (server, old_refcount, old_refcount - 1,
490       "unref_unlocked");
491 
492   if (old_refcount == 1)
493     {
494       _dbus_assert (server->disconnected);
495 
496       SERVER_UNLOCK (server);
497 
498       _dbus_assert (server->vtable->finalize != NULL);
499 
500       (* server->vtable->finalize) (server);
501     }
502 }
503 
504 /** @} */
505 
506 /**
507  * @addtogroup DBusServer
508  *
509  * @{
510  */
511 
512 
513 /**
514  * @typedef DBusServer
515  *
516  * An opaque object representing a server that listens for
517  * connections from other applications. Each time a connection
518  * is made, a new DBusConnection is created and made available
519  * via an application-provided DBusNewConnectionFunction.
520  * The DBusNewConnectionFunction is provided with
521  * dbus_server_set_new_connection_function().
522  *
523  */
524 
525 static const struct {
526   DBusServerListenResult (* func) (DBusAddressEntry *entry,
527                                    DBusServer      **server_p,
528                                    DBusError        *error);
529 } listen_funcs[] = {
530   { _dbus_server_listen_socket }
531   , { _dbus_server_listen_platform_specific }
532 #ifdef DBUS_BUILD_TESTS
533   , { _dbus_server_listen_debug_pipe }
534 #endif
535 };
536 
537 /**
538  * Listens for new connections on the given address.  If there are
539  * multiple semicolon-separated address entries in the address, tries
540  * each one and listens on the first one that works.
541  *
542  * Returns #NULL and sets error if listening fails for any reason.
543  * Otherwise returns a new #DBusServer.
544  * dbus_server_set_new_connection_function(),
545  * dbus_server_set_watch_functions(), and
546  * dbus_server_set_timeout_functions() should be called immediately to
547  * render the server fully functional.
548  *
549  * To free the server, applications must call first
550  * dbus_server_disconnect() and then dbus_server_unref().
551  *
552  * @param address the address of this server.
553  * @param error location to store reason for failure.
554  * @returns a new #DBusServer, or #NULL on failure.
555  *
556  */
557 DBusServer*
dbus_server_listen(const char * address,DBusError * error)558 dbus_server_listen (const char     *address,
559                     DBusError      *error)
560 {
561   DBusServer *server;
562   DBusAddressEntry **entries;
563   int len, i;
564   DBusError first_connect_error = DBUS_ERROR_INIT;
565   dbus_bool_t handled_once;
566 
567   _dbus_return_val_if_fail (address != NULL, NULL);
568   _dbus_return_val_if_error_is_set (error, NULL);
569 
570   if (!dbus_parse_address (address, &entries, &len, error))
571     return NULL;
572 
573   server = NULL;
574   handled_once = FALSE;
575 
576   for (i = 0; i < len; i++)
577     {
578       int j;
579 
580       for (j = 0; j < (int) _DBUS_N_ELEMENTS (listen_funcs); ++j)
581         {
582           DBusServerListenResult result;
583           DBusError tmp_error = DBUS_ERROR_INIT;
584 
585           result = (* listen_funcs[j].func) (entries[i],
586                                              &server,
587                                              &tmp_error);
588 
589           if (result == DBUS_SERVER_LISTEN_OK)
590             {
591               _dbus_assert (server != NULL);
592               _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
593               handled_once = TRUE;
594               goto out;
595             }
596           else if (result == DBUS_SERVER_LISTEN_ADDRESS_ALREADY_USED)
597             {
598               _dbus_assert (server == NULL);
599               dbus_set_error (error,
600                        DBUS_ERROR_ADDRESS_IN_USE,
601                        "Address '%s' already used",
602                        dbus_address_entry_get_method (entries[0]));
603               handled_once = TRUE;
604               goto out;
605             }
606           else if (result == DBUS_SERVER_LISTEN_BAD_ADDRESS)
607             {
608               _dbus_assert (server == NULL);
609               _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
610               dbus_move_error (&tmp_error, error);
611               handled_once = TRUE;
612               goto out;
613             }
614           else if (result == DBUS_SERVER_LISTEN_NOT_HANDLED)
615             {
616               _dbus_assert (server == NULL);
617               _DBUS_ASSERT_ERROR_IS_CLEAR (&tmp_error);
618 
619               /* keep trying addresses */
620             }
621           else if (result == DBUS_SERVER_LISTEN_DID_NOT_CONNECT)
622             {
623               _dbus_assert (server == NULL);
624               _DBUS_ASSERT_ERROR_IS_SET (&tmp_error);
625               if (!dbus_error_is_set (&first_connect_error))
626                 dbus_move_error (&tmp_error, &first_connect_error);
627               else
628                 dbus_error_free (&tmp_error);
629 
630               handled_once = TRUE;
631 
632               /* keep trying addresses */
633             }
634         }
635 
636       _dbus_assert (server == NULL);
637       _DBUS_ASSERT_ERROR_IS_CLEAR (error);
638     }
639 
640  out:
641 
642   if (!handled_once)
643     {
644       _DBUS_ASSERT_ERROR_IS_CLEAR (error);
645       if (len > 0)
646         dbus_set_error (error,
647                        DBUS_ERROR_BAD_ADDRESS,
648                        "Unknown address type '%s'",
649                        dbus_address_entry_get_method (entries[0]));
650       else
651         dbus_set_error (error,
652                         DBUS_ERROR_BAD_ADDRESS,
653                         "Empty address '%s'",
654                         address);
655     }
656 
657   dbus_address_entries_free (entries);
658 
659   if (server == NULL)
660     {
661       _dbus_assert (error == NULL || dbus_error_is_set (&first_connect_error) ||
662                    dbus_error_is_set (error));
663 
664       if (error && dbus_error_is_set (error))
665         {
666           /* already set the error */
667         }
668       else
669         {
670           /* didn't set the error but either error should be
671            * NULL or first_connect_error should be set.
672            */
673           _dbus_assert (error == NULL || dbus_error_is_set (&first_connect_error));
674           dbus_move_error (&first_connect_error, error);
675         }
676 
677       _DBUS_ASSERT_ERROR_IS_CLEAR (&first_connect_error); /* be sure we freed it */
678       _DBUS_ASSERT_ERROR_IS_SET (error);
679 
680       return NULL;
681     }
682   else
683     {
684       _DBUS_ASSERT_ERROR_IS_CLEAR (error);
685       return server;
686     }
687 }
688 
689 /**
690  * Increments the reference count of a DBusServer.
691  *
692  * @param server the server.
693  * @returns the server
694  */
695 DBusServer *
dbus_server_ref(DBusServer * server)696 dbus_server_ref (DBusServer *server)
697 {
698   dbus_int32_t old_refcount;
699 
700   _dbus_return_val_if_fail (server != NULL, NULL);
701 
702   /* can't get the refcount without a side-effect */
703   old_refcount = _dbus_atomic_inc (&server->refcount);
704 
705 #ifndef DBUS_DISABLE_CHECKS
706   if (_DBUS_UNLIKELY (old_refcount <= 0))
707     {
708       /* undo side-effect first */
709       _dbus_atomic_dec (&server->refcount);
710       _dbus_warn_check_failed (_dbus_return_if_fail_warning_format,
711                                _DBUS_FUNCTION_NAME, "old_refcount > 0",
712                                __FILE__, __LINE__);
713       return NULL;
714     }
715 #endif
716 
717   _dbus_server_trace_ref (server, old_refcount, old_refcount + 1, "ref");
718 
719   return server;
720 }
721 
722 /**
723  * Decrements the reference count of a DBusServer.  Finalizes the
724  * server if the reference count reaches zero.
725  *
726  * The server must be disconnected before the refcount reaches zero.
727  *
728  * @param server the server.
729  */
730 void
dbus_server_unref(DBusServer * server)731 dbus_server_unref (DBusServer *server)
732 {
733   dbus_int32_t old_refcount;
734 
735   /* keep this in sync with unref_unlocked */
736 
737   _dbus_return_if_fail (server != NULL);
738 
739   /* can't get the refcount without a side-effect */
740   old_refcount = _dbus_atomic_dec (&server->refcount);
741 
742 #ifndef DBUS_DISABLE_CHECKS
743   if (_DBUS_UNLIKELY (old_refcount <= 0))
744     {
745       /* undo side-effect first */
746       _dbus_atomic_inc (&server->refcount);
747       _dbus_warn_check_failed (_dbus_return_if_fail_warning_format,
748                                _DBUS_FUNCTION_NAME, "old_refcount > 0",
749                                __FILE__, __LINE__);
750       return;
751     }
752 #endif
753 
754   _dbus_server_trace_ref (server, old_refcount, old_refcount - 1, "unref");
755 
756   if (old_refcount == 1)
757     {
758       /* lock not held! */
759       _dbus_assert (server->disconnected);
760 
761       _dbus_assert (server->vtable->finalize != NULL);
762 
763       (* server->vtable->finalize) (server);
764     }
765 }
766 
767 /**
768  * Releases the server's address and stops listening for
769  * new clients. If called more than once, only the first
770  * call has an effect. Does not modify the server's
771  * reference count.
772  *
773  * @param server the server.
774  */
775 void
dbus_server_disconnect(DBusServer * server)776 dbus_server_disconnect (DBusServer *server)
777 {
778   _dbus_return_if_fail (server != NULL);
779 
780 #ifdef DBUS_DISABLE_CHECKS
781   _dbus_atomic_inc (&server->refcount);
782 #else
783     {
784       dbus_int32_t old_refcount = _dbus_atomic_inc (&server->refcount);
785 
786       _dbus_return_if_fail (old_refcount > 0);
787     }
788 #endif
789 
790   SERVER_LOCK (server);
791 
792   _dbus_assert (server->vtable->disconnect != NULL);
793 
794   if (!server->disconnected)
795     {
796       /* this has to be first so recursive calls to disconnect don't happen */
797       server->disconnected = TRUE;
798 
799       (* server->vtable->disconnect) (server);
800     }
801 
802   SERVER_UNLOCK (server);
803   dbus_server_unref (server);
804 }
805 
806 /**
807  * Returns #TRUE if the server is still listening for new connections.
808  *
809  * @param server the server.
810  */
811 dbus_bool_t
dbus_server_get_is_connected(DBusServer * server)812 dbus_server_get_is_connected (DBusServer *server)
813 {
814   dbus_bool_t retval;
815 
816   _dbus_return_val_if_fail (server != NULL, FALSE);
817 
818   SERVER_LOCK (server);
819   retval = !server->disconnected;
820   SERVER_UNLOCK (server);
821 
822   return retval;
823 }
824 
825 /**
826  * Returns the address of the server, as a newly-allocated
827  * string which must be freed by the caller.
828  *
829  * @param server the server
830  * @returns the address or #NULL if no memory
831  */
832 char*
dbus_server_get_address(DBusServer * server)833 dbus_server_get_address (DBusServer *server)
834 {
835   char *retval;
836 
837   _dbus_return_val_if_fail (server != NULL, NULL);
838 
839   SERVER_LOCK (server);
840   retval = _dbus_strdup (server->address);
841   SERVER_UNLOCK (server);
842 
843   return retval;
844 }
845 
846 /**
847  * Returns the unique ID of the server, as a newly-allocated
848  * string which must be freed by the caller. This ID is
849  * normally used by clients to tell when two #DBusConnection
850  * would be equivalent (because the server address passed
851  * to dbus_connection_open() will have the same guid in the
852  * two cases). dbus_connection_open() can re-use an existing
853  * connection with the same ID instead of opening a new
854  * connection.
855  *
856  * This is an ID unique to each #DBusServer. Remember that
857  * a #DBusServer represents only one mode of connecting,
858  * so e.g. a bus daemon can listen on multiple addresses
859  * which will mean it has multiple #DBusServer each with
860  * their own ID.
861  *
862  * The ID is not a UUID in the sense of RFC4122; the details
863  * are explained in the D-Bus specification.
864  *
865  * @param server the server
866  * @returns the id of the server or #NULL if no memory
867  */
868 char*
dbus_server_get_id(DBusServer * server)869 dbus_server_get_id (DBusServer *server)
870 {
871   char *retval;
872 
873   _dbus_return_val_if_fail (server != NULL, NULL);
874 
875   SERVER_LOCK (server);
876   retval = NULL;
877   _dbus_string_copy_data (&server->guid_hex, &retval);
878   SERVER_UNLOCK (server);
879 
880   return retval;
881 }
882 
883 /**
884  * Sets a function to be used for handling new connections.  The given
885  * function is passed each new connection as the connection is
886  * created. If the new connection function increments the connection's
887  * reference count, the connection will stay alive. Otherwise, the
888  * connection will be unreferenced and closed. The new connection
889  * function may also close the connection itself, which is considered
890  * good form if the connection is not wanted.
891  *
892  * The connection here is private in the sense of
893  * dbus_connection_open_private(), so if the new connection function
894  * keeps a reference it must arrange for the connection to be closed.
895  * i.e. libdbus does not own this connection once the new connection
896  * function takes a reference.
897  *
898  * @param server the server.
899  * @param function a function to handle new connections.
900  * @param data data to pass to the new connection handler.
901  * @param free_data_function function to free the data.
902  */
903 void
dbus_server_set_new_connection_function(DBusServer * server,DBusNewConnectionFunction function,void * data,DBusFreeFunction free_data_function)904 dbus_server_set_new_connection_function (DBusServer                *server,
905                                          DBusNewConnectionFunction  function,
906                                          void                      *data,
907                                          DBusFreeFunction           free_data_function)
908 {
909   DBusFreeFunction old_free_function;
910   void *old_data;
911 
912   _dbus_return_if_fail (server != NULL);
913 
914   SERVER_LOCK (server);
915   old_free_function = server->new_connection_free_data_function;
916   old_data = server->new_connection_data;
917 
918   server->new_connection_function = function;
919   server->new_connection_data = data;
920   server->new_connection_free_data_function = free_data_function;
921   SERVER_UNLOCK (server);
922 
923   if (old_free_function != NULL)
924     (* old_free_function) (old_data);
925 }
926 
927 /**
928  * Sets the watch functions for the server. These functions are
929  * responsible for making the application's main loop aware of file
930  * descriptors that need to be monitored for events.
931  *
932  * This function behaves exactly like dbus_connection_set_watch_functions();
933  * see the documentation for that routine.
934  *
935  * @param server the server.
936  * @param add_function function to begin monitoring a new descriptor.
937  * @param remove_function function to stop monitoring a descriptor.
938  * @param toggled_function function to notify when the watch is enabled/disabled
939  * @param data data to pass to add_function and remove_function.
940  * @param free_data_function function to be called to free the data.
941  * @returns #FALSE on failure (no memory)
942  */
943 dbus_bool_t
dbus_server_set_watch_functions(DBusServer * server,DBusAddWatchFunction add_function,DBusRemoveWatchFunction remove_function,DBusWatchToggledFunction toggled_function,void * data,DBusFreeFunction free_data_function)944 dbus_server_set_watch_functions (DBusServer              *server,
945                                  DBusAddWatchFunction     add_function,
946                                  DBusRemoveWatchFunction  remove_function,
947                                  DBusWatchToggledFunction toggled_function,
948                                  void                    *data,
949                                  DBusFreeFunction         free_data_function)
950 {
951   dbus_bool_t result;
952   DBusWatchList *watches;
953 
954   _dbus_return_val_if_fail (server != NULL, FALSE);
955 
956   SERVER_LOCK (server);
957   watches = server->watches;
958   server->watches = NULL;
959   if (watches)
960     {
961       SERVER_UNLOCK (server);
962       result = _dbus_watch_list_set_functions (watches,
963                                                add_function,
964                                                remove_function,
965                                                toggled_function,
966                                                data,
967                                                free_data_function);
968       SERVER_LOCK (server);
969     }
970   else
971     {
972       _dbus_warn_check_failed ("Re-entrant call to %s\n", _DBUS_FUNCTION_NAME);
973       result = FALSE;
974     }
975   server->watches = watches;
976   SERVER_UNLOCK (server);
977 
978   return result;
979 }
980 
981 /**
982  * Sets the timeout functions for the server. These functions are
983  * responsible for making the application's main loop aware of timeouts.
984  *
985  * This function behaves exactly like dbus_connection_set_timeout_functions();
986  * see the documentation for that routine.
987  *
988  * @param server the server.
989  * @param add_function function to add a timeout.
990  * @param remove_function function to remove a timeout.
991  * @param toggled_function function to notify when the timeout is enabled/disabled
992  * @param data data to pass to add_function and remove_function.
993  * @param free_data_function function to be called to free the data.
994  * @returns #FALSE on failure (no memory)
995  */
996 dbus_bool_t
dbus_server_set_timeout_functions(DBusServer * server,DBusAddTimeoutFunction add_function,DBusRemoveTimeoutFunction remove_function,DBusTimeoutToggledFunction toggled_function,void * data,DBusFreeFunction free_data_function)997 dbus_server_set_timeout_functions (DBusServer                *server,
998 				   DBusAddTimeoutFunction     add_function,
999 				   DBusRemoveTimeoutFunction  remove_function,
1000                                    DBusTimeoutToggledFunction toggled_function,
1001 				   void                      *data,
1002 				   DBusFreeFunction           free_data_function)
1003 {
1004   dbus_bool_t result;
1005   DBusTimeoutList *timeouts;
1006 
1007   _dbus_return_val_if_fail (server != NULL, FALSE);
1008 
1009   SERVER_LOCK (server);
1010   timeouts = server->timeouts;
1011   server->timeouts = NULL;
1012   if (timeouts)
1013     {
1014       SERVER_UNLOCK (server);
1015       result = _dbus_timeout_list_set_functions (timeouts,
1016                                                  add_function,
1017                                                  remove_function,
1018                                                  toggled_function,
1019                                                  data,
1020                                                  free_data_function);
1021       SERVER_LOCK (server);
1022     }
1023   else
1024     {
1025       _dbus_warn_check_failed ("Re-entrant call to %s\n", _DBUS_FUNCTION_NAME);
1026       result = FALSE;
1027     }
1028   server->timeouts = timeouts;
1029   SERVER_UNLOCK (server);
1030 
1031   return result;
1032 }
1033 
1034 /**
1035  * Sets the authentication mechanisms that this server offers to
1036  * clients, as a #NULL-terminated array of mechanism names. This
1037  * function only affects connections created <em>after</em> it is
1038  * called.  Pass #NULL instead of an array to use all available
1039  * mechanisms (this is the default behavior).
1040  *
1041  * The D-Bus specification describes some of the supported mechanisms.
1042  *
1043  * @param server the server
1044  * @param mechanisms #NULL-terminated array of mechanisms
1045  * @returns #FALSE if no memory
1046  */
1047 dbus_bool_t
dbus_server_set_auth_mechanisms(DBusServer * server,const char ** mechanisms)1048 dbus_server_set_auth_mechanisms (DBusServer  *server,
1049                                  const char **mechanisms)
1050 {
1051   char **copy;
1052 
1053   _dbus_return_val_if_fail (server != NULL, FALSE);
1054 
1055   SERVER_LOCK (server);
1056 
1057   if (mechanisms != NULL)
1058     {
1059       copy = _dbus_dup_string_array (mechanisms);
1060       if (copy == NULL)
1061         return FALSE;
1062     }
1063   else
1064     copy = NULL;
1065 
1066   dbus_free_string_array (server->auth_mechanisms);
1067   server->auth_mechanisms = copy;
1068 
1069   SERVER_UNLOCK (server);
1070 
1071   return TRUE;
1072 }
1073 
1074 
1075 static DBusDataSlotAllocator slot_allocator;
1076 _DBUS_DEFINE_GLOBAL_LOCK (server_slots);
1077 
1078 /**
1079  * Allocates an integer ID to be used for storing application-specific
1080  * data on any DBusServer. The allocated ID may then be used
1081  * with dbus_server_set_data() and dbus_server_get_data().
1082  * The slot must be initialized with -1. If a nonnegative
1083  * slot is passed in, the refcount is incremented on that
1084  * slot, rather than creating a new slot.
1085  *
1086  * The allocated slot is global, i.e. all DBusServer objects will have
1087  * a slot with the given integer ID reserved.
1088  *
1089  * @param slot_p address of global variable storing the slot ID
1090  * @returns #FALSE on no memory
1091  */
1092 dbus_bool_t
dbus_server_allocate_data_slot(dbus_int32_t * slot_p)1093 dbus_server_allocate_data_slot (dbus_int32_t *slot_p)
1094 {
1095   return _dbus_data_slot_allocator_alloc (&slot_allocator,
1096                                           (DBusRMutex **)&_DBUS_LOCK_NAME (server_slots),
1097                                           slot_p);
1098 }
1099 
1100 /**
1101  * Deallocates a global ID for server data slots.
1102  * dbus_server_get_data() and dbus_server_set_data()
1103  * may no longer be used with this slot.
1104  * Existing data stored on existing DBusServer objects
1105  * will be freed when the server is finalized,
1106  * but may not be retrieved (and may only be replaced
1107  * if someone else reallocates the slot).
1108  *
1109  * @param slot_p address of the slot to deallocate
1110  */
1111 void
dbus_server_free_data_slot(dbus_int32_t * slot_p)1112 dbus_server_free_data_slot (dbus_int32_t *slot_p)
1113 {
1114   _dbus_return_if_fail (*slot_p >= 0);
1115 
1116   _dbus_data_slot_allocator_free (&slot_allocator, slot_p);
1117 }
1118 
1119 /**
1120  * Stores a pointer on a DBusServer, along
1121  * with an optional function to be used for freeing
1122  * the data when the data is set again, or when
1123  * the server is finalized. The slot number
1124  * must have been allocated with dbus_server_allocate_data_slot().
1125  *
1126  * @param server the server
1127  * @param slot the slot number
1128  * @param data the data to store
1129  * @param free_data_func finalizer function for the data
1130  * @returns #TRUE if there was enough memory to store the data
1131  */
1132 dbus_bool_t
dbus_server_set_data(DBusServer * server,int slot,void * data,DBusFreeFunction free_data_func)1133 dbus_server_set_data (DBusServer       *server,
1134                       int               slot,
1135                       void             *data,
1136                       DBusFreeFunction  free_data_func)
1137 {
1138   DBusFreeFunction old_free_func;
1139   void *old_data;
1140   dbus_bool_t retval;
1141 
1142   _dbus_return_val_if_fail (server != NULL, FALSE);
1143 
1144   SERVER_LOCK (server);
1145 
1146   retval = _dbus_data_slot_list_set (&slot_allocator,
1147                                      &server->slot_list,
1148                                      slot, data, free_data_func,
1149                                      &old_free_func, &old_data);
1150 
1151 
1152   SERVER_UNLOCK (server);
1153 
1154   if (retval)
1155     {
1156       /* Do the actual free outside the server lock */
1157       if (old_free_func)
1158         (* old_free_func) (old_data);
1159     }
1160 
1161   return retval;
1162 }
1163 
1164 /**
1165  * Retrieves data previously set with dbus_server_set_data().
1166  * The slot must still be allocated (must not have been freed).
1167  *
1168  * @param server the server
1169  * @param slot the slot to get data from
1170  * @returns the data, or #NULL if not found
1171  */
1172 void*
dbus_server_get_data(DBusServer * server,int slot)1173 dbus_server_get_data (DBusServer   *server,
1174                       int           slot)
1175 {
1176   void *res;
1177 
1178   _dbus_return_val_if_fail (server != NULL, NULL);
1179 
1180   SERVER_LOCK (server);
1181 
1182   res = _dbus_data_slot_list_get (&slot_allocator,
1183                                   &server->slot_list,
1184                                   slot);
1185 
1186   SERVER_UNLOCK (server);
1187 
1188   return res;
1189 }
1190 
1191 /** @} */
1192 
1193 #ifdef DBUS_BUILD_TESTS
1194 #include "dbus-test.h"
1195 #include <string.h>
1196 
1197 dbus_bool_t
_dbus_server_test(void)1198 _dbus_server_test (void)
1199 {
1200   const char *valid_addresses[] = {
1201     "tcp:port=1234",
1202     "tcp:host=localhost,port=1234",
1203     "tcp:host=localhost,port=1234;tcp:port=5678",
1204 #ifdef DBUS_UNIX
1205     "unix:path=./boogie",
1206     "tcp:port=1234;unix:path=./boogie",
1207 #endif
1208   };
1209 
1210   DBusServer *server;
1211   int i;
1212 
1213   for (i = 0; i < _DBUS_N_ELEMENTS (valid_addresses); i++)
1214     {
1215       DBusError error = DBUS_ERROR_INIT;
1216       char *address;
1217       char *id;
1218 
1219       server = dbus_server_listen (valid_addresses[i], &error);
1220       if (server == NULL)
1221         {
1222           _dbus_warn ("server listen error: %s: %s\n", error.name, error.message);
1223           dbus_error_free (&error);
1224           _dbus_assert_not_reached ("Failed to listen for valid address.");
1225         }
1226 
1227       id = dbus_server_get_id (server);
1228       _dbus_assert (id != NULL);
1229       address = dbus_server_get_address (server);
1230       _dbus_assert (address != NULL);
1231 
1232       if (strstr (address, id) == NULL)
1233         {
1234           _dbus_warn ("server id '%s' is not in the server address '%s'\n",
1235                       id, address);
1236           _dbus_assert_not_reached ("bad server id or address");
1237         }
1238 
1239       dbus_free (id);
1240       dbus_free (address);
1241 
1242       dbus_server_disconnect (server);
1243       dbus_server_unref (server);
1244     }
1245 
1246   return TRUE;
1247 }
1248 
1249 #endif /* DBUS_BUILD_TESTS */
1250