]> git.meshlink.io Git - catta/blob - avahi-client/client.c
* Implement client API for arbitrary record browsing
[catta] / avahi-client / client.c
1 /* $Id$ */
2
3 /***
4   This file is part of avahi.
5  
6   avahi is free software; you can redistribute it and/or modify it
7   under the terms of the GNU Lesser General Public License as
8   published by the Free Software Foundation; either version 2.1 of the
9   License, or (at your option) any later version.
10  
11   avahi is distributed in the hope that it will be useful, but WITHOUT
12   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
14   Public License for more details.
15  
16   You should have received a copy of the GNU Lesser General Public
17   License along with avahi; if not, write to the Free Software
18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
19   USA.
20 ***/
21
22 #ifdef HAVE_CONFIG_H
23 #include <config.h>
24 #endif
25
26 #include <stdlib.h>
27 #include <stdio.h>
28 #include <string.h>
29
30 #include <dbus/dbus.h>
31
32 #include <avahi-common/dbus.h>
33 #include <avahi-common/llist.h>
34 #include <avahi-common/error.h>
35 #include <avahi-common/dbus.h>
36 #include <avahi-common/malloc.h>
37 #include <avahi-common/dbus-watch-glue.h>
38
39 #include "client.h"
40 #include "internal.h"
41
42 static int init_server(AvahiClient *client, int *ret_error);
43
44 int avahi_client_set_errno (AvahiClient *client, int error) {
45     assert(client);
46
47     return client->error = error;
48 }
49
50 int avahi_client_set_dbus_error(AvahiClient *client, DBusError *error) {
51     assert(client);
52     assert(error);
53
54     return avahi_client_set_errno(client, avahi_error_dbus_to_number(error->name));
55 }
56
57 static void client_set_state (AvahiClient *client, AvahiServerState state) {
58     assert(client);
59
60     if (client->state == state)
61         return;
62
63     client->state = state;
64
65     switch (client->state) {
66         case AVAHI_CLIENT_FAILURE:
67             if (client->bus) {
68                 dbus_connection_disconnect(client->bus);
69                 dbus_connection_unref(client->bus);
70                 client->bus = NULL;
71             }
72             
73             /* Fall through */
74             
75         case AVAHI_CLIENT_S_COLLISION:
76         case AVAHI_CLIENT_S_REGISTERING:
77
78             /* Clear cached strings */
79             avahi_free(client->host_name);
80             avahi_free(client->host_name_fqdn);
81             avahi_free(client->domain_name);
82
83             client->host_name =  NULL;
84             client->host_name_fqdn = NULL;
85             client->domain_name = NULL;
86             break;
87
88         case AVAHI_CLIENT_S_RUNNING:
89         case AVAHI_CLIENT_CONNECTING:
90             break;
91             
92     }
93     
94     if (client->callback)
95         client->callback (client, state, client->userdata);
96 }
97
98 static DBusHandlerResult filter_func(DBusConnection *bus, DBusMessage *message, void *userdata) {
99     AvahiClient *client = userdata;
100     DBusError error;
101
102     assert(bus);
103     assert(message);
104     
105     dbus_error_init(&error);
106
107 /*     fprintf(stderr, "dbus: interface=%s, path=%s, member=%s\n", */
108 /*             dbus_message_get_interface (message), */
109 /*             dbus_message_get_path (message), */
110 /*             dbus_message_get_member (message)); */
111
112     if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
113
114         /* The DBUS server died or kicked us */
115         avahi_client_set_errno(client, AVAHI_ERR_DISCONNECTED);
116         goto fail;
117
118     } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameAcquired")) {
119
120         /* Ignore this message */
121         
122     } else if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
123         char *name, *old, *new;
124         
125         if (!dbus_message_get_args(
126                   message, &error,
127                   DBUS_TYPE_STRING, &name,
128                   DBUS_TYPE_STRING, &old,
129                   DBUS_TYPE_STRING, &new,
130                   DBUS_TYPE_INVALID) || dbus_error_is_set(&error)) {
131
132             fprintf(stderr, "WARNING: Failed to parse NameOwnerChanged signal: %s\n", error.message);
133             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
134             goto fail;
135         }
136
137         if (strcmp(name, AVAHI_DBUS_NAME) == 0) {
138
139             if (avahi_client_is_connected(client)) {
140
141                 /* Regardless if the server lost or acquired its name or
142                  * if the name was transfered: our services are no longer
143                  * available, so we disconnect ourselves */
144                 avahi_client_set_errno(client, AVAHI_ERR_DISCONNECTED);
145                 goto fail;
146                 
147             } else if (client->state == AVAHI_CLIENT_CONNECTING && (!old || *old == 0)) {
148                 int ret;
149                 
150                 /* Server appeared */
151                 
152                 if ((ret = init_server(client, NULL)) < 0) {
153                     avahi_client_set_errno(client, ret);
154                     goto fail;
155                 }
156             }
157         }
158
159     } else if (!avahi_client_is_connected(client)) {
160         
161         /* Ignore messages we get in unconnected state */
162         
163     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_SERVER, "StateChanged")) {
164         int32_t state;
165         char *e = NULL;
166         int c;
167         
168         if (!dbus_message_get_args(
169                   message, &error,
170                   DBUS_TYPE_INT32, &state,
171                   DBUS_TYPE_STRING, &e,
172                   DBUS_TYPE_INVALID) || dbus_error_is_set (&error)) {
173
174             fprintf(stderr, "WARNING: Failed to parse Server.StateChanged signal: %s\n", error.message);
175             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
176             goto fail;
177         }
178
179         if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
180             avahi_client_set_errno(client, c);
181         
182         client_set_state(client, (AvahiClientState) state);
183
184     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_ENTRY_GROUP, "StateChanged")) {
185         const char *path;
186         AvahiEntryGroup *g;
187         path = dbus_message_get_path(message);
188
189         for (g = client->groups; g; g = g->groups_next)
190             if (strcmp(g->path, path) == 0)
191                 break;
192         
193         if (g) {
194             int32_t state;
195             char *e;
196             int c;
197             
198             if (!dbus_message_get_args(
199                       message, &error,
200                       DBUS_TYPE_INT32, &state,
201                       DBUS_TYPE_STRING, &e,
202                       DBUS_TYPE_INVALID) ||
203                 dbus_error_is_set(&error)) {
204
205                 fprintf(stderr, "WARNING: Failed to parse EntryGroup.StateChanged signal: %s\n", error.message);
206                 avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
207                 goto fail;
208             }
209
210             if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
211                 avahi_client_set_errno(client, c);
212             
213             avahi_entry_group_set_state(g, state);
214         }
215         
216     } else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemNew"))
217         return avahi_domain_browser_event(client, AVAHI_BROWSER_NEW, message);
218     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemRemove")) 
219         return avahi_domain_browser_event(client, AVAHI_BROWSER_REMOVE, message);
220     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "CacheExhausted")) 
221         return avahi_domain_browser_event(client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
222     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "AllForNow")) 
223         return avahi_domain_browser_event(client, AVAHI_BROWSER_ALL_FOR_NOW, message);
224     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "Failure")) 
225         return avahi_domain_browser_event(client, AVAHI_BROWSER_FAILURE, message);
226
227     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemNew")) 
228         return avahi_service_type_browser_event (client, AVAHI_BROWSER_NEW, message);
229     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemRemove")) 
230         return avahi_service_type_browser_event (client, AVAHI_BROWSER_REMOVE, message);
231     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "CacheExhausted")) 
232         return avahi_service_type_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
233     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "AllForNow")) 
234         return avahi_service_type_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
235     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "Failure")) 
236         return avahi_service_type_browser_event (client, AVAHI_BROWSER_FAILURE, message);
237
238     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemNew")) 
239         return avahi_service_browser_event (client, AVAHI_BROWSER_NEW, message);
240     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemRemove")) 
241         return avahi_service_browser_event (client, AVAHI_BROWSER_REMOVE, message);
242     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "CacheExhausted")) 
243         return avahi_service_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
244     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "AllForNow")) 
245         return avahi_service_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
246     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "Failure")) 
247         return avahi_service_browser_event (client, AVAHI_BROWSER_FAILURE, message);
248
249     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Found")) 
250         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
251     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Failure")) 
252         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
253
254     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Found")) 
255         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
256     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Failure")) 
257         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
258
259     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Found")) 
260         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
261     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Failure")) 
262         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
263
264     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_RECORD_BROWSER, "ItemNew")) 
265         return avahi_record_browser_event (client, AVAHI_BROWSER_NEW, message);
266     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_RECORD_BROWSER, "ItemRemove")) 
267         return avahi_record_browser_event (client, AVAHI_BROWSER_REMOVE, message);
268     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_RECORD_BROWSER, "CacheExhausted")) 
269         return avahi_record_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
270     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_RECORD_BROWSER, "AllForNow")) 
271         return avahi_record_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
272     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_RECORD_BROWSER, "Failure")) 
273         return avahi_record_browser_event (client, AVAHI_BROWSER_FAILURE, message);
274
275     else {
276
277         fprintf(stderr, "WARNING: Unhandled message: interface=%s, path=%s, member=%s\n",
278                dbus_message_get_interface(message), 
279                dbus_message_get_path(message),
280                dbus_message_get_member(message));
281         
282         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
283     }
284     
285     return DBUS_HANDLER_RESULT_HANDLED;
286
287 fail:
288
289     if (dbus_error_is_set(&error)) {
290         avahi_client_set_errno(client, avahi_error_dbus_to_number(error.name));
291         dbus_error_free(&error);
292     }
293
294     client_set_state(client, AVAHI_CLIENT_FAILURE);
295     
296     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
297 }
298
299 static int get_server_state(AvahiClient *client, int *ret_error) {
300     DBusMessage *message = NULL, *reply = NULL;
301     DBusError error;
302     int32_t state;
303     int e = AVAHI_ERR_NO_MEMORY;
304     
305     assert(client);
306
307     dbus_error_init(&error);
308
309     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetState")))
310         goto fail;
311
312     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
313
314     if (!reply || dbus_error_is_set (&error))
315         goto fail;
316
317     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INT32, &state, DBUS_TYPE_INVALID) ||
318         dbus_error_is_set (&error))
319         goto fail;
320
321     client_set_state(client, (AvahiServerState) state);
322
323     dbus_message_unref(message);
324     dbus_message_unref(reply);
325     
326     return AVAHI_OK;
327
328 fail:
329     if (dbus_error_is_set(&error)) {
330         e = avahi_error_dbus_to_number (error.name);
331         dbus_error_free(&error);
332     } 
333     
334     if (ret_error)
335         *ret_error = e;
336
337     if (message)
338         dbus_message_unref(message);
339     if (reply)
340         dbus_message_unref(reply);
341     
342     return e;
343 }
344
345 static int check_version(AvahiClient *client, int *ret_error) {
346     DBusMessage *message = NULL, *reply  = NULL;
347     DBusError error;
348     char *version;
349     int e = AVAHI_ERR_NO_MEMORY;
350     
351     assert(client);
352
353     dbus_error_init(&error);
354
355     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetVersionString")))
356         goto fail;
357
358     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
359
360     if (!reply || dbus_error_is_set (&error))
361         goto fail;
362
363     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &version, DBUS_TYPE_INVALID) ||
364         dbus_error_is_set (&error))
365         goto fail;
366
367     if (strcmp(version, PACKAGE_STRING) != 0) {
368         e = AVAHI_ERR_VERSION_MISMATCH;
369         goto fail;
370     }
371
372     dbus_message_unref(message);
373     dbus_message_unref(reply);
374                
375     return AVAHI_OK;
376
377 fail:
378     if (dbus_error_is_set(&error)) {
379         e = avahi_error_dbus_to_number (error.name);
380         dbus_error_free(&error);
381     } 
382
383     if (ret_error)
384         *ret_error = e;
385
386     if (message)
387         dbus_message_unref(message);
388     if (reply)
389         dbus_message_unref(reply);
390     
391     return e;
392 }
393
394 static int init_server(AvahiClient *client, int *ret_error) {
395     int r;
396     
397     if ((r = check_version(client, ret_error)) < 0)
398         return r;
399
400     if ((r = get_server_state(client, ret_error)) < 0)
401         return r;
402
403     return AVAHI_OK;
404 }
405
406 /* This function acts like dbus_bus_get but creates a private
407  * connection instead */
408 static DBusConnection* avahi_dbus_bus_get(DBusError *error) {
409     DBusConnection *c;
410     const char *a;
411
412     if (!(a = getenv("DBUS_SYSTEM_BUS_ADDRESS")) || !*a)
413         a = DBUS_SYSTEM_BUS_DEFAULT_ADDRESS;
414     
415     if (!(c = dbus_connection_open_private(a, error)))
416         return NULL;
417
418     dbus_connection_set_exit_on_disconnect(c, FALSE);
419
420     if (!dbus_bus_register(c, error)) {
421         dbus_connection_close(c);
422         dbus_connection_unref(c);
423         return NULL;
424     }
425
426     return c;
427 }
428
429 AvahiClient *avahi_client_new(const AvahiPoll *poll_api, AvahiClientFlags flags, AvahiClientCallback callback, void *userdata, int *ret_error) {
430     AvahiClient *client = NULL;
431     DBusError error;
432
433     dbus_error_init(&error);
434
435     if (!(client = avahi_new(AvahiClient, 1))) {
436         if (ret_error)
437             *ret_error = AVAHI_ERR_NO_MEMORY;
438         goto fail;
439     }
440
441     client->poll_api = poll_api;
442     client->error = AVAHI_OK;
443     client->callback = callback;
444     client->userdata = userdata;
445     client->state = (AvahiClientState) -1;
446     client->flags = flags;
447     
448     client->host_name = NULL;
449     client->host_name_fqdn = NULL;
450     client->domain_name = NULL;
451     client->version_string = NULL;
452     client->local_service_cookie_valid = 0;
453     
454     AVAHI_LLIST_HEAD_INIT(AvahiEntryGroup, client->groups);
455     AVAHI_LLIST_HEAD_INIT(AvahiDomainBrowser, client->domain_browsers);
456     AVAHI_LLIST_HEAD_INIT(AvahiServiceBrowser, client->service_browsers);
457     AVAHI_LLIST_HEAD_INIT(AvahiServiceTypeBrowser, client->service_type_browsers);
458     AVAHI_LLIST_HEAD_INIT(AvahiServiceResolver, client->service_resolvers);
459     AVAHI_LLIST_HEAD_INIT(AvahiHostNameResolver, client->host_name_resolvers);
460     AVAHI_LLIST_HEAD_INIT(AvahiAddressResolver, client->address_resolvers);
461     AVAHI_LLIST_HEAD_INIT(AvahiRecordBrowser, client->record_browsers);
462
463     if (!(client->bus = avahi_dbus_bus_get(&error)) || dbus_error_is_set(&error)) {
464         if (ret_error)
465             *ret_error = AVAHI_ERR_DBUS_ERROR;
466         goto fail;
467     }
468
469     if (avahi_dbus_connection_glue(client->bus, poll_api) < 0) {
470         if (ret_error)
471             *ret_error = AVAHI_ERR_NO_MEMORY; /* Not optimal */
472         goto fail;
473     }
474
475     if (!dbus_connection_add_filter (client->bus, filter_func, client, NULL)) {
476         if (ret_error)
477             *ret_error = AVAHI_ERR_NO_MEMORY; 
478         goto fail;
479     }
480         
481     dbus_bus_add_match(
482         client->bus,
483         "type='signal', "
484         "interface='" AVAHI_DBUS_INTERFACE_SERVER "', "
485         "sender='" AVAHI_DBUS_NAME "', "
486         "path='" AVAHI_DBUS_PATH_SERVER "'",
487         &error);
488
489     if (dbus_error_is_set(&error))
490         goto fail;
491
492     dbus_bus_add_match (
493         client->bus,
494         "type='signal', "
495         "interface='" DBUS_INTERFACE_DBUS "', "
496         "sender='" DBUS_SERVICE_DBUS "', "
497         "path='" DBUS_PATH_DBUS "'",
498         &error);
499
500     if (dbus_error_is_set(&error))
501         goto fail;
502
503     dbus_bus_add_match (
504         client->bus,
505         "type='signal', "
506         "interface='" DBUS_INTERFACE_LOCAL "'",
507         &error);
508
509     if (dbus_error_is_set(&error))
510         goto fail;
511
512
513     if (!(dbus_bus_name_has_owner(client->bus, AVAHI_DBUS_NAME, &error)) ||
514         dbus_error_is_set(&error)) {
515
516         /* We free the error so its not set, that way the fail target
517          * will return the NO_DAEMON error rather than a DBUS error */
518         dbus_error_free(&error);
519
520         if (!(flags & AVAHI_CLIENT_NO_FAIL)) {
521             
522             if (ret_error)
523                 *ret_error = AVAHI_ERR_NO_DAEMON;
524         
525             goto fail;
526         }
527
528         /* The user doesn't want this call to fail if the daemon is not
529          * available, so let's return succesfully */
530         client_set_state(client, AVAHI_CLIENT_CONNECTING);
531         
532     } else {
533
534         if (init_server(client, ret_error) < 0)
535             goto fail;
536     }
537
538     return client;
539
540 fail:
541
542     if (client)
543         avahi_client_free(client);
544
545     if (dbus_error_is_set(&error)) {
546
547         if (ret_error)
548             *ret_error = avahi_error_dbus_to_number(error.name);
549         
550         dbus_error_free(&error);
551     }
552         
553     return NULL;
554 }
555
556 void avahi_client_free(AvahiClient *client) {
557     assert(client);
558
559     while (client->groups)
560         avahi_entry_group_free(client->groups);
561
562     while (client->domain_browsers)
563         avahi_domain_browser_free(client->domain_browsers);
564
565     while (client->service_browsers)
566         avahi_service_browser_free(client->service_browsers);
567
568     while (client->service_type_browsers)
569         avahi_service_type_browser_free(client->service_type_browsers);
570
571     while (client->service_resolvers)
572         avahi_service_resolver_free(client->service_resolvers);
573
574     while (client->host_name_resolvers)
575         avahi_host_name_resolver_free(client->host_name_resolvers);
576
577     while (client->address_resolvers)
578         avahi_address_resolver_free(client->address_resolvers);
579
580     while (client->record_browsers)
581         avahi_record_browser_free(client->record_browsers);
582     
583     if (client->bus) {
584         dbus_connection_disconnect(client->bus);
585         dbus_connection_unref(client->bus);
586     }
587
588     avahi_free(client->version_string);
589     avahi_free(client->host_name);
590     avahi_free(client->host_name_fqdn);
591     avahi_free(client->domain_name);
592     
593     avahi_free(client);
594 }
595
596 static char* avahi_client_get_string_reply_and_block (AvahiClient *client, const char *method, const char *param) {
597     DBusMessage *message = NULL, *reply = NULL;
598     DBusError error;
599     char *ret, *n;
600
601     assert(client);
602     assert(method);
603
604     dbus_error_init (&error);
605
606     if (!(message = dbus_message_new_method_call (AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, method))) {
607         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
608         goto fail;
609     }
610
611     if (param) {
612         if (!dbus_message_append_args (message, DBUS_TYPE_STRING, &param, DBUS_TYPE_INVALID)) {
613             avahi_client_set_errno (client, AVAHI_ERR_NO_MEMORY);
614             goto fail;
615         }
616     }
617     
618     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
619
620     if (!reply || dbus_error_is_set (&error))
621         goto fail;
622
623     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &ret, DBUS_TYPE_INVALID) ||
624         dbus_error_is_set (&error))
625         goto fail;
626     
627     if (!(n = avahi_strdup(ret))) {
628         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
629         goto fail;
630     }
631
632     dbus_message_unref(message);
633     dbus_message_unref(reply);
634     
635     return n;
636
637 fail:
638
639     if (message)
640         dbus_message_unref(message);
641     if (reply)
642         dbus_message_unref(reply);
643     
644     if (dbus_error_is_set(&error)) {
645         avahi_client_set_dbus_error(client, &error);
646         dbus_error_free(&error);
647     }
648
649     return NULL;
650 }
651
652 const char* avahi_client_get_version_string(AvahiClient *client) {
653     assert(client);
654
655     if (!avahi_client_is_connected(client)) {
656         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
657         return NULL;
658     }
659
660     if (!client->version_string)
661         client->version_string = avahi_client_get_string_reply_and_block(client, "GetVersionString", NULL);
662
663     return client->version_string;
664 }
665
666 const char* avahi_client_get_domain_name(AvahiClient *client) {
667     assert(client);
668
669     if (!avahi_client_is_connected(client)) {
670         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
671         return NULL;
672     }
673
674     if (!client->domain_name)
675         client->domain_name = avahi_client_get_string_reply_and_block(client, "GetDomainName", NULL);
676     
677     return client->domain_name;
678 }
679
680 const char* avahi_client_get_host_name(AvahiClient *client) {
681     assert(client);
682     
683     if (!avahi_client_is_connected(client)) {
684         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
685         return NULL;
686     }
687
688     if (!client->host_name)
689         client->host_name = avahi_client_get_string_reply_and_block(client, "GetHostName", NULL);
690     
691     return client->host_name;
692 }
693
694 const char* avahi_client_get_host_name_fqdn (AvahiClient *client) {
695     assert(client);
696
697     if (!avahi_client_is_connected(client)) {
698         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
699         return NULL;
700     }
701     
702     if (!client->host_name_fqdn)
703         client->host_name_fqdn = avahi_client_get_string_reply_and_block(client, "GetHostNameFqdn", NULL);
704
705     return client->host_name_fqdn;
706 }
707
708 AvahiClientState avahi_client_get_state(AvahiClient *client) {
709     assert(client);
710
711     return client->state;
712 }
713
714 int avahi_client_errno(AvahiClient *client) {
715     assert(client);
716     
717     return client->error;
718 }
719
720 /* Just for internal use */
721 int avahi_client_simple_method_call(AvahiClient *client, const char *path, const char *interface, const char *method) {
722     DBusMessage *message = NULL, *reply = NULL;
723     DBusError error;
724     int r = AVAHI_OK;
725     
726     dbus_error_init(&error);
727
728     assert(client);
729     assert(path);
730     assert(interface);
731     assert(method);
732     
733     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, path, interface, method))) {
734         r = avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
735         goto fail;
736     }
737         
738     if (!(reply = dbus_connection_send_with_reply_and_block(client->bus, message, -1, &error)) ||
739         dbus_error_is_set (&error)) {
740         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
741         goto fail;
742     }
743     
744     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INVALID) ||
745         dbus_error_is_set (&error)) {
746         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
747         goto fail;
748     }
749
750     dbus_message_unref(message);
751     dbus_message_unref(reply);
752
753     return AVAHI_OK;
754     
755 fail:
756     if (dbus_error_is_set(&error)) {
757         r = avahi_client_set_dbus_error(client, &error);
758         dbus_error_free(&error);
759     }
760
761     if (message)
762         dbus_message_unref(message);
763
764     if (reply)
765         dbus_message_unref(reply);
766
767     return r;
768 }
769
770 uint32_t avahi_client_get_local_service_cookie(AvahiClient *client) {
771     DBusMessage *message = NULL, *reply = NULL;
772     DBusError error;
773     assert(client);
774
775     if (!avahi_client_is_connected(client)) {
776         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
777         return AVAHI_SERVICE_COOKIE_INVALID;
778     }
779
780     if (client->local_service_cookie_valid)
781         return client->local_service_cookie;
782
783     dbus_error_init (&error);
784
785     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetLocalServiceCookie"))) {
786         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
787         goto fail;
788     }
789
790     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
791
792     if (!reply || dbus_error_is_set (&error))
793         goto fail;
794
795     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_UINT32, &client->local_service_cookie, DBUS_TYPE_INVALID) ||
796         dbus_error_is_set (&error))
797         goto fail;
798     
799     dbus_message_unref(message);
800     dbus_message_unref(reply);
801
802     client->local_service_cookie_valid = 1;
803     return client->local_service_cookie;
804
805 fail:
806
807     if (message)
808         dbus_message_unref(message);
809     if (reply)
810         dbus_message_unref(reply);
811     
812     if (dbus_error_is_set(&error)) {
813         avahi_client_set_dbus_error(client, &error);
814         dbus_error_free(&error);
815     }
816
817     return AVAHI_SERVICE_COOKIE_INVALID;
818 }
819
820 int avahi_client_is_connected(AvahiClient *client) {
821     assert(client);
822
823     return client->state == AVAHI_CLIENT_S_RUNNING || client->state == AVAHI_CLIENT_S_REGISTERING || client->state == AVAHI_CLIENT_S_COLLISION;
824 }