git.meshlink.io Git - catta/blob - 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     } if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
 119         char *name, *old, *new;
 120
 121         if (!dbus_message_get_args(
 122                   message, &error,
 123                   DBUS_TYPE_STRING, &name,
 124                   DBUS_TYPE_STRING, &old,
 125                   DBUS_TYPE_STRING, &new,
 126                   DBUS_TYPE_INVALID) || dbus_error_is_set(&error)) {
 127
 128             fprintf(stderr, "WARNING: Failed to parse NameOwnerChanged signal: %s\n", error.message);
 129             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 130             goto fail;
 131         }
 132
 133         if (strcmp(name, AVAHI_DBUS_NAME) == 0) {
 134
 135             if (avahi_client_is_connected(client)) {
 136
 137                 /* Regardless if the server lost or acquired its name or
 138                  * if the name was transfered: our services are no longer
 139                  * available, so we disconnect ourselves */
 140                 avahi_client_set_errno(client, AVAHI_ERR_DISCONNECTED);
 141                 goto fail;
 142
 143             } else if (client->state == AVAHI_CLIENT_CONNECTING && (!old || *old == 0)) {
 144                 int ret;
 145
 146                 /* Server appeared */
 147
 148                 if ((ret = init_server(client, NULL)) < 0) {
 149                     avahi_client_set_errno(client, ret);
 150                     goto fail;
 151                 }
 152             }
 153         }
 154
 155     } else if (!avahi_client_is_connected(client)) {
 156
 157         /* Ignore messages, we get in unconnected state */
 158
 159     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_SERVER, "StateChanged")) {
 160         int32_t state;
 161         char *e = NULL;
 162         int c;
 163
 164         if (!dbus_message_get_args(
 165                   message, &error,
 166                   DBUS_TYPE_INT32, &state,
 167                   DBUS_TYPE_STRING, &e,
 168                   DBUS_TYPE_INVALID) || dbus_error_is_set (&error)) {
 169
 170             fprintf(stderr, "WARNING: Failed to parse Server.StateChanged signal: %s\n", error.message);
 171             avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 172             goto fail;
 173         }
 174
 175         if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 176             avahi_client_set_errno(client, c);
 177
 178         client_set_state(client, (AvahiClientState) state);
 179
 180     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_ENTRY_GROUP, "StateChanged")) {
 181         const char *path;
 182         AvahiEntryGroup *g;
 183         path = dbus_message_get_path(message);
 184
 185         for (g = client->groups; g; g = g->groups_next)
 186             if (strcmp(g->path, path) == 0)
 187                 break;
 188
 189         if (g) {
 190             int32_t state;
 191             char *e;
 192             int c;
 193
 194             if (!dbus_message_get_args(
 195                       message, &error,
 196                       DBUS_TYPE_INT32, &state,
 197                       DBUS_TYPE_STRING, &e,
 198                       DBUS_TYPE_INVALID) ||
 199                 dbus_error_is_set(&error)) {
 200
 201                 fprintf(stderr, "WARNING: Failed to parse EntryGroup.StateChanged signal: %s\n", error.message);
 202                 avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 203                 goto fail;
 204             }
 205
 206             if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 207                 avahi_client_set_errno(client, c);
 208
 209             avahi_entry_group_set_state(g, state);
 210         }
 211
 212     } else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemNew"))
 213         return avahi_domain_browser_event(client, AVAHI_BROWSER_NEW, message);
 214     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemRemove"))
 215         return avahi_domain_browser_event(client, AVAHI_BROWSER_REMOVE, message);
 216     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "CacheExhausted"))
 217         return avahi_domain_browser_event(client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 218     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "AllForNow"))
 219         return avahi_domain_browser_event(client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 220     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "Failure"))
 221         return avahi_domain_browser_event(client, AVAHI_BROWSER_FAILURE, message);
 222
 223     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemNew"))
 224         return avahi_service_type_browser_event (client, AVAHI_BROWSER_NEW, message);
 225     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemRemove"))
 226         return avahi_service_type_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 227     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "CacheExhausted"))
 228         return avahi_service_type_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 229     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "AllForNow"))
 230         return avahi_service_type_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 231     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "Failure"))
 232         return avahi_service_type_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 233
 234     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemNew"))
 235         return avahi_service_browser_event (client, AVAHI_BROWSER_NEW, message);
 236     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemRemove"))
 237         return avahi_service_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 238     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "CacheExhausted"))
 239         return avahi_service_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 240     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "AllForNow"))
 241         return avahi_service_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 242     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "Failure"))
 243         return avahi_service_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 244
 245     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Found"))
 246         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 247     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Failure"))
 248         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 249
 250     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Found"))
 251         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 252     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Failure"))
 253         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 254
 255     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Found"))
 256         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 257     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Failure"))
 258         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 259     else {
 260
 261         fprintf(stderr, "WARNING: Unhandled message: interface=%s, path=%s, member=%s\n",
 262                dbus_message_get_interface(message),
 263                dbus_message_get_path(message),
 264                dbus_message_get_member(message));
 265
 266         return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 267     }
 268
 269     return DBUS_HANDLER_RESULT_HANDLED;
 270
 271 fail:
 272
 273     if (dbus_error_is_set(&error)) {
 274         avahi_client_set_errno(client, avahi_error_dbus_to_number(error.name));
 275         dbus_error_free(&error);
 276     }
 277
 278     client_set_state(client, AVAHI_CLIENT_FAILURE);
 279
 280     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 281 }
 282
 283 static int get_server_state(AvahiClient *client, int *ret_error) {
 284     DBusMessage *message = NULL, *reply = NULL;
 285     DBusError error;
 286     int32_t state;
 287     int e = AVAHI_ERR_NO_MEMORY;
 288
 289     assert(client);
 290
 291     dbus_error_init(&error);
 292
 293     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetState")))
 294         goto fail;
 295
 296     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 297
 298     if (!reply || dbus_error_is_set (&error))
 299         goto fail;
 300
 301     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INT32, &state, DBUS_TYPE_INVALID) ||
 302         dbus_error_is_set (&error))
 303         goto fail;
 304
 305     client_set_state(client, (AvahiServerState) state);
 306
 307     dbus_message_unref(message);
 308     dbus_message_unref(reply);
 309
 310     return AVAHI_OK;
 311
 312 fail:
 313     if (dbus_error_is_set(&error)) {
 314         e = avahi_error_dbus_to_number (error.name);
 315         dbus_error_free(&error);
 316     }
 317
 318     if (ret_error)
 319         *ret_error = e;
 320
 321     if (message)
 322         dbus_message_unref(message);
 323     if (reply)
 324         dbus_message_unref(reply);
 325
 326     return e;
 327 }
 328
 329 static int check_version(AvahiClient *client, int *ret_error) {
 330     DBusMessage *message = NULL, *reply  = NULL;
 331     DBusError error;
 332     char *version;
 333     int e = AVAHI_ERR_NO_MEMORY;
 334
 335     assert(client);
 336
 337     dbus_error_init(&error);
 338
 339     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetVersionString")))
 340         goto fail;
 341
 342     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 343
 344     if (!reply || dbus_error_is_set (&error))
 345         goto fail;
 346
 347     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &version, DBUS_TYPE_INVALID) ||
 348         dbus_error_is_set (&error))
 349         goto fail;
 350
 351     if (strcmp(version, PACKAGE_STRING) != 0) {
 352         e = AVAHI_ERR_VERSION_MISMATCH;
 353         goto fail;
 354     }
 355
 356     dbus_message_unref(message);
 357     dbus_message_unref(reply);
 358
 359     return AVAHI_OK;
 360
 361 fail:
 362     if (dbus_error_is_set(&error)) {
 363         e = avahi_error_dbus_to_number (error.name);
 364         dbus_error_free(&error);
 365     }
 366
 367     if (ret_error)
 368         *ret_error = e;
 369
 370     if (message)
 371         dbus_message_unref(message);
 372     if (reply)
 373         dbus_message_unref(reply);
 374
 375     return e;
 376 }
 377
 378 static int init_server(AvahiClient *client, int *ret_error) {
 379     int r;
 380
 381     if ((r = check_version(client, ret_error)) < 0)
 382         return r;
 383
 384     if ((r = get_server_state(client, ret_error)) < 0)
 385         return r;
 386
 387     return AVAHI_OK;
 388 }
 389
 390 /* This function acts like dbus_bus_get but creates a private
 391  * connection instead */
 392 static DBusConnection* avahi_dbus_bus_get(DBusError *error) {
 393     DBusConnection *c;
 394     const char *a;
 395
 396     if (!(a = getenv("DBUS_SYSTEM_BUS_ADDRESS")) || !*a)
 397         a = DBUS_SYSTEM_BUS_DEFAULT_ADDRESS;
 398
 399     if (!(c = dbus_connection_open_private(a, error)))
 400         return NULL;
 401
 402     dbus_connection_set_exit_on_disconnect(c, FALSE);
 403
 404     if (!dbus_bus_register(c, error)) {
 405         dbus_connection_close(c);
 406         dbus_connection_unref(c);
 407         return NULL;
 408     }
 409
 410     return c;
 411 }
 412
 413 AvahiClient *avahi_client_new(const AvahiPoll *poll_api, AvahiClientFlags flags, AvahiClientCallback callback, void *userdata, int *ret_error) {
 414     AvahiClient *client = NULL;
 415     DBusError error;
 416
 417     dbus_error_init(&error);
 418
 419     if (!(client = avahi_new(AvahiClient, 1))) {
 420         if (ret_error)
 421             *ret_error = AVAHI_ERR_NO_MEMORY;
 422         goto fail;
 423     }
 424
 425     client->poll_api = poll_api;
 426     client->error = AVAHI_OK;
 427     client->callback = callback;
 428     client->userdata = userdata;
 429     client->state = (AvahiClientState) -1;
 430     client->flags = flags;
 431
 432     client->host_name = NULL;
 433     client->host_name_fqdn = NULL;
 434     client->domain_name = NULL;
 435     client->version_string = NULL;
 436     client->local_service_cookie_valid = 0;
 437
 438     AVAHI_LLIST_HEAD_INIT(AvahiEntryGroup, client->groups);
 439     AVAHI_LLIST_HEAD_INIT(AvahiDomainBrowser, client->domain_browsers);
 440     AVAHI_LLIST_HEAD_INIT(AvahiServiceBrowser, client->service_browsers);
 441     AVAHI_LLIST_HEAD_INIT(AvahiServiceTypeBrowser, client->service_type_browsers);
 442     AVAHI_LLIST_HEAD_INIT(AvahiServiceResolver, client->service_resolvers);
 443     AVAHI_LLIST_HEAD_INIT(AvahiHostNameResolver, client->host_name_resolvers);
 444     AVAHI_LLIST_HEAD_INIT(AvahiAddressResolver, client->address_resolvers);
 445
 446     if (!(client->bus = avahi_dbus_bus_get(&error)) || dbus_error_is_set(&error)) {
 447         if (ret_error)
 448             *ret_error = AVAHI_ERR_DBUS_ERROR;
 449         goto fail;
 450     }
 451
 452     if (avahi_dbus_connection_glue(client->bus, poll_api) < 0) {
 453         if (ret_error)
 454             *ret_error = AVAHI_ERR_NO_MEMORY; /* Not optimal */
 455         goto fail;
 456     }
 457
 458     if (!dbus_connection_add_filter (client->bus, filter_func, client, NULL)) {
 459         if (ret_error)
 460             *ret_error = AVAHI_ERR_NO_MEMORY;
 461         goto fail;
 462     }
 463
 464     dbus_bus_add_match(
 465         client->bus,
 466         "type='signal', "
 467         "interface='" AVAHI_DBUS_INTERFACE_SERVER "', "
 468         "sender='" AVAHI_DBUS_NAME "', "
 469         "path='" AVAHI_DBUS_PATH_SERVER "'",
 470         &error);
 471
 472     if (dbus_error_is_set(&error))
 473         goto fail;
 474
 475     dbus_bus_add_match (
 476         client->bus,
 477         "type='signal', "
 478         "interface='" DBUS_INTERFACE_DBUS "', "
 479         "sender='" DBUS_SERVICE_DBUS "', "
 480         "path='" DBUS_PATH_DBUS "'",
 481         &error);
 482
 483     if (dbus_error_is_set(&error))
 484         goto fail;
 485
 486     dbus_bus_add_match (
 487         client->bus,
 488         "type='signal', "
 489         "interface='" DBUS_INTERFACE_LOCAL "'",
 490         &error);
 491
 492     if (dbus_error_is_set(&error))
 493         goto fail;
 494
 495
 496     if (!(dbus_bus_name_has_owner(client->bus, AVAHI_DBUS_NAME, &error)) ||
 497         dbus_error_is_set(&error)) {
 498
 499         /* We free the error so its not set, that way the fail target
 500          * will return the NO_DAEMON error rather than a DBUS error */
 501         dbus_error_free(&error);
 502
 503         if (!(flags & AVAHI_CLIENT_NO_FAIL)) {
 504
 505             if (ret_error)
 506                 *ret_error = AVAHI_ERR_NO_DAEMON;
 507
 508             goto fail;
 509         }
 510
 511         /* The user doesn't want this call to fail if the daemon is not
 512          * available, so let's return succesfully */
 513         client_set_state(client, AVAHI_CLIENT_CONNECTING);
 514
 515     } else {
 516
 517         if (init_server(client, ret_error) < 0)
 518             goto fail;
 519     }
 520
 521     return client;
 522
 523 fail:
 524
 525     if (client)
 526         avahi_client_free(client);
 527
 528     if (dbus_error_is_set(&error)) {
 529
 530         if (ret_error)
 531             *ret_error = avahi_error_dbus_to_number(error.name);
 532
 533         dbus_error_free(&error);
 534     }
 535
 536     return NULL;
 537 }
 538
 539 void avahi_client_free(AvahiClient *client) {
 540     assert(client);
 541
 542     while (client->groups)
 543         avahi_entry_group_free(client->groups);
 544
 545     while (client->domain_browsers)
 546         avahi_domain_browser_free(client->domain_browsers);
 547
 548     while (client->service_browsers)
 549         avahi_service_browser_free(client->service_browsers);
 550
 551     while (client->service_type_browsers)
 552         avahi_service_type_browser_free(client->service_type_browsers);
 553
 554     while (client->service_resolvers)
 555         avahi_service_resolver_free(client->service_resolvers);
 556
 557     if (client->bus) {
 558         dbus_connection_disconnect(client->bus);
 559         dbus_connection_unref(client->bus);
 560     }
 561
 562     avahi_free(client->version_string);
 563     avahi_free(client->host_name);
 564     avahi_free(client->host_name_fqdn);
 565     avahi_free(client->domain_name);
 566
 567     avahi_free(client);
 568 }
 569
 570 static char* avahi_client_get_string_reply_and_block (AvahiClient *client, const char *method, const char *param) {
 571     DBusMessage *message = NULL, *reply = NULL;
 572     DBusError error;
 573     char *ret, *n;
 574
 575     assert(client);
 576     assert(method);
 577
 578     dbus_error_init (&error);
 579
 580     if (!(message = dbus_message_new_method_call (AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, method))) {
 581         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 582         goto fail;
 583     }
 584
 585     if (param) {
 586         if (!dbus_message_append_args (message, DBUS_TYPE_STRING, &param, DBUS_TYPE_INVALID)) {
 587             avahi_client_set_errno (client, AVAHI_ERR_NO_MEMORY);
 588             goto fail;
 589         }
 590     }
 591
 592     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 593
 594     if (!reply || dbus_error_is_set (&error))
 595         goto fail;
 596
 597     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &ret, DBUS_TYPE_INVALID) ||
 598         dbus_error_is_set (&error))
 599         goto fail;
 600
 601     if (!(n = avahi_strdup(ret))) {
 602         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 603         goto fail;
 604     }
 605
 606     dbus_message_unref(message);
 607     dbus_message_unref(reply);
 608
 609     return n;
 610
 611 fail:
 612
 613     if (message)
 614         dbus_message_unref(message);
 615     if (reply)
 616         dbus_message_unref(reply);
 617
 618     if (dbus_error_is_set(&error)) {
 619         avahi_client_set_dbus_error(client, &error);
 620         dbus_error_free(&error);
 621     }
 622
 623     return NULL;
 624 }
 625
 626 const char* avahi_client_get_version_string(AvahiClient *client) {
 627     assert(client);
 628
 629     if (!avahi_client_is_connected(client)) {
 630         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 631         return NULL;
 632     }
 633
 634     if (!client->version_string)
 635         client->version_string = avahi_client_get_string_reply_and_block(client, "GetVersionString", NULL);
 636
 637     return client->version_string;
 638 }
 639
 640 const char* avahi_client_get_domain_name(AvahiClient *client) {
 641     assert(client);
 642
 643     if (!avahi_client_is_connected(client)) {
 644         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 645         return NULL;
 646     }
 647
 648     if (!client->domain_name)
 649         client->domain_name = avahi_client_get_string_reply_and_block(client, "GetDomainName", NULL);
 650
 651     return client->domain_name;
 652 }
 653
 654 const char* avahi_client_get_host_name(AvahiClient *client) {
 655     assert(client);
 656
 657     if (!avahi_client_is_connected(client)) {
 658         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 659         return NULL;
 660     }
 661
 662     if (!client->host_name)
 663         client->host_name = avahi_client_get_string_reply_and_block(client, "GetHostName", NULL);
 664
 665     return client->host_name;
 666 }
 667
 668 const char* avahi_client_get_host_name_fqdn (AvahiClient *client) {
 669     assert(client);
 670
 671     if (!avahi_client_is_connected(client)) {
 672         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 673         return NULL;
 674     }
 675
 676     if (!client->host_name_fqdn)
 677         client->host_name_fqdn = avahi_client_get_string_reply_and_block(client, "GetHostNameFqdn", NULL);
 678
 679     return client->host_name_fqdn;
 680 }
 681
 682 AvahiClientState avahi_client_get_state(AvahiClient *client) {
 683     assert(client);
 684
 685     return client->state;
 686 }
 687
 688 int avahi_client_errno(AvahiClient *client) {
 689     assert(client);
 690
 691     return client->error;
 692 }
 693
 694 /* Just for internal use */
 695 int avahi_client_simple_method_call(AvahiClient *client, const char *path, const char *interface, const char *method) {
 696     DBusMessage *message = NULL, *reply = NULL;
 697     DBusError error;
 698     int r = AVAHI_OK;
 699
 700     dbus_error_init(&error);
 701
 702     assert(client);
 703     assert(path);
 704     assert(interface);
 705     assert(method);
 706
 707     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, path, interface, method))) {
 708         r = avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 709         goto fail;
 710     }
 711
 712     if (!(reply = dbus_connection_send_with_reply_and_block(client->bus, message, -1, &error)) ||
 713         dbus_error_is_set (&error)) {
 714         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 715         goto fail;
 716     }
 717
 718     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INVALID) ||
 719         dbus_error_is_set (&error)) {
 720         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 721         goto fail;
 722     }
 723
 724     dbus_message_unref(message);
 725     dbus_message_unref(reply);
 726
 727     return AVAHI_OK;
 728
 729 fail:
 730     if (dbus_error_is_set(&error)) {
 731         r = avahi_client_set_dbus_error(client, &error);
 732         dbus_error_free(&error);
 733     }
 734
 735     if (message)
 736         dbus_message_unref(message);
 737
 738     if (reply)
 739         dbus_message_unref(reply);
 740
 741     return r;
 742 }
 743
 744 uint32_t avahi_client_get_local_service_cookie(AvahiClient *client) {
 745     DBusMessage *message = NULL, *reply = NULL;
 746     DBusError error;
 747     assert(client);
 748
 749     if (!avahi_client_is_connected(client)) {
 750         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 751         return AVAHI_SERVICE_COOKIE_INVALID;
 752     }
 753
 754     if (client->local_service_cookie_valid)
 755         return client->local_service_cookie;
 756
 757     dbus_error_init (&error);
 758
 759     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetLocalServiceCookie"))) {
 760         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 761         goto fail;
 762     }
 763
 764     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 765
 766     if (!reply || dbus_error_is_set (&error))
 767         goto fail;
 768
 769     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_UINT32, &client->local_service_cookie, DBUS_TYPE_INVALID) ||
 770         dbus_error_is_set (&error))
 771         goto fail;
 772
 773     dbus_message_unref(message);
 774     dbus_message_unref(reply);
 775
 776     client->local_service_cookie_valid = 1;
 777     return client->local_service_cookie;
 778
 779 fail:
 780
 781     if (message)
 782         dbus_message_unref(message);
 783     if (reply)
 784         dbus_message_unref(reply);
 785
 786     if (dbus_error_is_set(&error)) {
 787         avahi_client_set_dbus_error(client, &error);
 788         dbus_error_free(&error);
 789     }
 790
 791     return AVAHI_SERVICE_COOKIE_INVALID;
 792 }
 793
 794 int avahi_client_is_connected(AvahiClient *client) {
 795     assert(client);
 796
 797     return client->state == AVAHI_CLIENT_S_RUNNING || client->state == AVAHI_CLIENT_S_REGISTERING || client->state == AVAHI_CLIENT_S_COLLISION;
 798 }