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 int avahi_client_set_errno (AvahiClient *client, int error) {
  43     assert(client);
  44
  45     return client->error = error;
  46 }
  47
  48 int avahi_client_set_dbus_error(AvahiClient *client, DBusError *error) {
  49     assert(client);
  50     assert(error);
  51
  52     return avahi_client_set_errno(client, avahi_error_dbus_to_number(error->name));
  53 }
  54
  55 static void client_set_state (AvahiClient *client, AvahiServerState state) {
  56     assert(client);
  57
  58     if (client->state == state)
  59         return;
  60
  61     client->state = state;
  62
  63     switch (client->state) {
  64         case AVAHI_CLIENT_DISCONNECTED:
  65             if (client->bus) {
  66                 dbus_connection_disconnect(client->bus);
  67                 dbus_connection_unref(client->bus);
  68                 client->bus = NULL;
  69             }
  70
  71             /* Fall through */
  72
  73         case AVAHI_CLIENT_S_COLLISION:
  74         case AVAHI_CLIENT_S_REGISTERING:
  75         case AVAHI_CLIENT_S_FAILURE:
  76
  77             /* Clear cached strings */
  78             avahi_free(client->host_name);
  79             avahi_free(client->host_name_fqdn);
  80             avahi_free(client->domain_name);
  81
  82             client->host_name =  NULL;
  83             client->host_name_fqdn = NULL;
  84             client->domain_name = NULL;
  85             break;
  86
  87         case AVAHI_CLIENT_S_INVALID:
  88         case AVAHI_CLIENT_S_RUNNING:
  89             break;
  90
  91     }
  92
  93     if (client->callback)
  94         client->callback (client, state, client->userdata);
  95 }
  96
  97 static DBusHandlerResult filter_func(DBusConnection *bus, DBusMessage *message, void *userdata) {
  98     AvahiClient *client = userdata;
  99     DBusError error;
 100
 101     assert(bus);
 102     assert(message);
 103
 104     dbus_error_init (&error);
 105
 106 /*     fprintf(stderr, "dbus: interface=%s, path=%s, member=%s\n", */
 107 /*             dbus_message_get_interface (message), */
 108 /*             dbus_message_get_path (message), */
 109 /*             dbus_message_get_member (message)); */
 110
 111     if (client->state == AVAHI_CLIENT_DISCONNECTED)
 112         goto fail;
 113
 114     if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
 115
 116         /* The DBUS server died or kicked us */
 117         client_set_state(client, AVAHI_CLIENT_DISCONNECTED);
 118
 119     } if (dbus_message_is_signal(message, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
 120         char *name, *old, *new;
 121
 122         if (!(dbus_message_get_args(
 123                   message, &error,
 124                   DBUS_TYPE_STRING, &name,
 125                   DBUS_TYPE_STRING, &old,
 126                   DBUS_TYPE_STRING, &new,
 127                   DBUS_TYPE_INVALID) || dbus_error_is_set (&error))) {
 128
 129             fprintf(stderr, "WARNING: Failed to parse NameOwnerChanged signal: %s\n", error.message);
 130             goto fail;
 131         }
 132
 133         if (strcmp(name, AVAHI_DBUS_NAME) == 0)
 134
 135             /* Regardless if the server lost or acquired its name or
 136              * if the name was transfered: our services are no longer
 137              * available, so we disconnect ourselves */
 138
 139             client_set_state(client, AVAHI_CLIENT_DISCONNECTED);
 140
 141     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_SERVER, "StateChanged")) {
 142         int32_t state;
 143         char *e;
 144         int c;
 145
 146         if (!(dbus_message_get_args(
 147                   message, &error,
 148                   DBUS_TYPE_INT32, &state,
 149                   DBUS_TYPE_STRING, &e,
 150                   DBUS_TYPE_INVALID) || dbus_error_is_set (&error))) {
 151             fprintf(stderr, "WARNING: Failed to parse Server.StateChanged signal: %s\n", error.message);
 152             goto fail;
 153         }
 154
 155         if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 156             avahi_client_set_errno(client, c);
 157
 158         client_set_state(client, (AvahiClientState) state);
 159
 160     } else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_ENTRY_GROUP, "StateChanged")) {
 161         const char *path;
 162         AvahiEntryGroup *g;
 163         path = dbus_message_get_path(message);
 164
 165         for (g = client->groups; g; g = g->groups_next)
 166             if (strcmp(g->path, path) == 0)
 167                 break;
 168
 169         if (g) {
 170             int32_t state;
 171             char *e;
 172             int c;
 173
 174             if (!(dbus_message_get_args(
 175                       message, &error,
 176                       DBUS_TYPE_INT32, &state,
 177                       DBUS_TYPE_STRING, &e,
 178                       DBUS_TYPE_INVALID)) ||
 179                 dbus_error_is_set(&error)) {
 180                 fprintf(stderr, "WARNING: Failed to parse EntryGroup.StateChanged signal: %s\n", error.message);
 181                 goto fail;
 182             }
 183
 184             if ((c = avahi_error_dbus_to_number(e)) != AVAHI_OK)
 185                 avahi_client_set_errno(client, c);
 186
 187             avahi_entry_group_set_state(g, state);
 188         }
 189
 190     } else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemNew"))
 191         return avahi_domain_browser_event(client, AVAHI_BROWSER_NEW, message);
 192     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "ItemRemove"))
 193         return avahi_domain_browser_event(client, AVAHI_BROWSER_REMOVE, message);
 194     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "CacheExhausted"))
 195         return avahi_domain_browser_event(client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 196     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "AllForNow"))
 197         return avahi_domain_browser_event(client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 198     else if (dbus_message_is_signal (message, AVAHI_DBUS_INTERFACE_DOMAIN_BROWSER, "Failure"))
 199         return avahi_domain_browser_event(client, AVAHI_BROWSER_FAILURE, message);
 200
 201     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemNew"))
 202         return avahi_service_type_browser_event (client, AVAHI_BROWSER_NEW, message);
 203     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "ItemRemove"))
 204         return avahi_service_type_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 205     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "CacheExhausted"))
 206         return avahi_service_type_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 207     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "AllForNow"))
 208         return avahi_service_type_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 209     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_TYPE_BROWSER, "Failure"))
 210         return avahi_service_type_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 211
 212     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemNew"))
 213         return avahi_service_browser_event (client, AVAHI_BROWSER_NEW, message);
 214     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "ItemRemove"))
 215         return avahi_service_browser_event (client, AVAHI_BROWSER_REMOVE, message);
 216     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "CacheExhausted"))
 217         return avahi_service_browser_event (client, AVAHI_BROWSER_CACHE_EXHAUSTED, message);
 218     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "AllForNow"))
 219         return avahi_service_browser_event (client, AVAHI_BROWSER_ALL_FOR_NOW, message);
 220     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_BROWSER, "Failure"))
 221         return avahi_service_browser_event (client, AVAHI_BROWSER_FAILURE, message);
 222
 223     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Found"))
 224         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 225     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_SERVICE_RESOLVER, "Failure"))
 226         return avahi_service_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 227
 228     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Found"))
 229         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 230     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_HOST_NAME_RESOLVER, "Failure"))
 231         return avahi_host_name_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 232
 233     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Found"))
 234         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FOUND, message);
 235     else if (dbus_message_is_signal(message, AVAHI_DBUS_INTERFACE_ADDRESS_RESOLVER, "Failure"))
 236         return avahi_address_resolver_event (client, AVAHI_RESOLVER_FAILURE, message);
 237
 238     return DBUS_HANDLER_RESULT_HANDLED;
 239
 240 fail:
 241
 242     dbus_error_free (&error);
 243     return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
 244 }
 245
 246 static int get_server_state(AvahiClient *client, int *ret_error) {
 247     DBusMessage *message = NULL, *reply = NULL;
 248     DBusError error;
 249     int32_t state;
 250     int e = AVAHI_ERR_NO_MEMORY;
 251
 252     assert(client);
 253
 254     dbus_error_init(&error);
 255
 256     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetState")))
 257         goto fail;
 258
 259     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 260
 261     if (!reply || dbus_error_is_set (&error))
 262         goto fail;
 263
 264     if (!(dbus_message_get_args(reply, &error, DBUS_TYPE_INT32, &state, DBUS_TYPE_INVALID)) ||
 265         dbus_error_is_set (&error))
 266         goto fail;
 267
 268     client_set_state(client, (AvahiServerState) state);
 269
 270     dbus_message_unref(message);
 271     dbus_message_unref(reply);
 272
 273     return AVAHI_OK;
 274
 275 fail:
 276     if (dbus_error_is_set(&error)) {
 277         e = avahi_error_dbus_to_number (error.name);
 278         dbus_error_free(&error);
 279     }
 280
 281     if (ret_error)
 282         *ret_error = e;
 283
 284     if (message)
 285         dbus_message_unref(message);
 286     if (reply)
 287         dbus_message_unref(reply);
 288
 289     return e;
 290 }
 291
 292 static int check_version(AvahiClient *client, int *ret_error) {
 293     DBusMessage *message = NULL, *reply  = NULL;
 294     DBusError error;
 295     char *version;
 296     int e = AVAHI_ERR_NO_MEMORY;
 297
 298     assert(client);
 299
 300     dbus_error_init(&error);
 301
 302     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetVersionString")))
 303         goto fail;
 304
 305     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 306
 307     if (!reply || dbus_error_is_set (&error))
 308         goto fail;
 309
 310     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &version, DBUS_TYPE_INVALID) ||
 311         dbus_error_is_set (&error))
 312         goto fail;
 313
 314     if (strcmp(version, PACKAGE_STRING) != 0) {
 315         e = AVAHI_ERR_VERSION_MISMATCH;
 316         goto fail;
 317     }
 318
 319     dbus_message_unref(message);
 320     dbus_message_unref(reply);
 321
 322     return AVAHI_OK;
 323
 324 fail:
 325     if (dbus_error_is_set(&error)) {
 326         e = avahi_error_dbus_to_number (error.name);
 327         dbus_error_free(&error);
 328     }
 329
 330     if (ret_error)
 331         *ret_error = e;
 332
 333     if (message)
 334         dbus_message_unref(message);
 335     if (reply)
 336         dbus_message_unref(reply);
 337
 338     return e;
 339 }
 340
 341
 342 /* This function acts like dbus_bus_get but creates a private
 343  * connection instead */
 344 static DBusConnection*
 345 avahi_dbus_bus_get (DBusError *error)
 346 {
 347     DBusConnection *conn;
 348     const char *env_addr;
 349
 350     env_addr = getenv ("DBUS_SYSTEM_BUS_ADDRESS");
 351
 352     if (env_addr == NULL || (*env_addr == 0))
 353     {
 354         env_addr = DBUS_SYSTEM_BUS_DEFAULT_ADDRESS;
 355     }
 356
 357     conn = dbus_connection_open_private (env_addr, error);
 358
 359     if (!conn)
 360         return NULL;
 361
 362     dbus_connection_set_exit_on_disconnect (conn, FALSE);
 363
 364     if (!dbus_bus_register (conn, error))
 365     {
 366         dbus_connection_close (conn);
 367         dbus_connection_unref (conn);
 368
 369         return NULL;
 370     }
 371
 372     return conn;
 373 }
 374
 375 AvahiClient *avahi_client_new(const AvahiPoll *poll_api, AvahiClientCallback callback, void *userdata, int *ret_error) {
 376     AvahiClient *client = NULL;
 377     DBusError error;
 378
 379     dbus_error_init (&error);
 380
 381     if (!(client = avahi_new(AvahiClient, 1))) {
 382         if (ret_error)
 383             *ret_error = AVAHI_ERR_NO_MEMORY;
 384         goto fail;
 385     }
 386
 387     client->poll_api = poll_api;
 388     client->error = AVAHI_OK;
 389     client->callback = callback;
 390     client->userdata = userdata;
 391     client->state = AVAHI_CLIENT_DISCONNECTED;
 392
 393     client->host_name = NULL;
 394     client->host_name_fqdn = NULL;
 395     client->domain_name = NULL;
 396     client->version_string = NULL;
 397     client->local_service_cookie_valid = 0;
 398
 399     AVAHI_LLIST_HEAD_INIT(AvahiEntryGroup, client->groups);
 400     AVAHI_LLIST_HEAD_INIT(AvahiDomainBrowser, client->domain_browsers);
 401     AVAHI_LLIST_HEAD_INIT(AvahiServiceBrowser, client->service_browsers);
 402     AVAHI_LLIST_HEAD_INIT(AvahiServiceTypeBrowser, client->service_type_browsers);
 403     AVAHI_LLIST_HEAD_INIT(AvahiServiceResolver, client->service_resolvers);
 404     AVAHI_LLIST_HEAD_INIT(AvahiHostNameResolver, client->host_name_resolvers);
 405     AVAHI_LLIST_HEAD_INIT(AvahiAddressResolver, client->address_resolvers);
 406
 407     if (!(client->bus = avahi_dbus_bus_get(&error)) ||
 408         dbus_error_is_set (&error))
 409         goto fail;
 410
 411     if (avahi_dbus_connection_glue(client->bus, poll_api) < 0) {
 412         if (ret_error)
 413             *ret_error = AVAHI_ERR_NO_MEMORY; /* Not optimal */
 414         goto fail;
 415     }
 416
 417     if (!dbus_connection_add_filter (client->bus, filter_func, client, NULL)) {
 418         if (ret_error)
 419             *ret_error = AVAHI_ERR_NO_MEMORY;
 420         goto fail;
 421     }
 422
 423     dbus_bus_add_match(
 424         client->bus,
 425         "type='signal', "
 426         "interface='" AVAHI_DBUS_INTERFACE_SERVER "', "
 427         "sender='" AVAHI_DBUS_NAME "', "
 428         "path='" AVAHI_DBUS_PATH_SERVER "'",
 429         &error);
 430
 431     if (dbus_error_is_set (&error))
 432         goto fail;
 433
 434     dbus_bus_add_match (
 435         client->bus,
 436         "type='signal', "
 437         "interface='" DBUS_INTERFACE_DBUS "', "
 438         "sender='" DBUS_SERVICE_DBUS "', "
 439         "path='" DBUS_PATH_DBUS "'",
 440         &error);
 441
 442     if (dbus_error_is_set (&error))
 443         goto fail;
 444
 445         dbus_bus_add_match (
 446         client->bus,
 447         "type='signal', "
 448         "interface='" DBUS_INTERFACE_LOCAL "'",
 449         &error);
 450
 451     if (dbus_error_is_set (&error))
 452         goto fail;
 453
 454     if (!(dbus_bus_name_has_owner(client->bus, AVAHI_DBUS_NAME, &error)) ||
 455         dbus_error_is_set(&error)) {
 456
 457         /* We free the error so its not set, that way the fail target
 458          * will return the NO_DAEMON error rather than a DBUS error */
 459         dbus_error_free (&error);
 460
 461         if (ret_error)
 462             *ret_error = AVAHI_ERR_NO_DAEMON;
 463
 464         goto fail;
 465     }
 466
 467     if (check_version(client, ret_error) < 0)
 468         goto fail;
 469
 470     if (get_server_state(client, ret_error) < 0)
 471         goto fail;
 472
 473     return client;
 474
 475 fail:
 476
 477     if (client)
 478         avahi_client_free(client);
 479
 480     if (dbus_error_is_set(&error)) {
 481
 482         if (ret_error)
 483             *ret_error = avahi_error_dbus_to_number(error.name);
 484
 485         dbus_error_free(&error);
 486     }
 487
 488     return NULL;
 489 }
 490
 491 void avahi_client_free(AvahiClient *client) {
 492     assert(client);
 493
 494     while (client->groups)
 495         avahi_entry_group_free(client->groups);
 496
 497     while (client->domain_browsers)
 498         avahi_domain_browser_free(client->domain_browsers);
 499
 500     while (client->service_browsers)
 501         avahi_service_browser_free(client->service_browsers);
 502
 503     while (client->service_type_browsers)
 504         avahi_service_type_browser_free(client->service_type_browsers);
 505
 506     while (client->service_resolvers)
 507         avahi_service_resolver_free(client->service_resolvers);
 508
 509     if (client->bus) {
 510         dbus_connection_disconnect(client->bus);
 511         dbus_connection_unref(client->bus);
 512     }
 513
 514     avahi_free(client->version_string);
 515     avahi_free(client->host_name);
 516     avahi_free(client->host_name_fqdn);
 517     avahi_free(client->domain_name);
 518
 519     avahi_free(client);
 520 }
 521
 522 static char* avahi_client_get_string_reply_and_block (AvahiClient *client, const char *method, const char *param) {
 523     DBusMessage *message = NULL, *reply = NULL;
 524     DBusError error;
 525     char *ret, *n;
 526
 527     assert(client);
 528     assert(method);
 529
 530     dbus_error_init (&error);
 531
 532     if (!(message = dbus_message_new_method_call (AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, method))) {
 533         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 534         goto fail;
 535     }
 536
 537     if (param) {
 538         if (!dbus_message_append_args (message, DBUS_TYPE_STRING, &param, DBUS_TYPE_INVALID)) {
 539             avahi_client_set_errno (client, AVAHI_ERR_NO_MEMORY);
 540             goto fail;
 541         }
 542     }
 543
 544     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 545
 546     if (!reply || dbus_error_is_set (&error))
 547         goto fail;
 548
 549     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_STRING, &ret, DBUS_TYPE_INVALID) ||
 550         dbus_error_is_set (&error))
 551         goto fail;
 552
 553     if (!(n = avahi_strdup(ret))) {
 554         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 555         goto fail;
 556     }
 557
 558     dbus_message_unref(message);
 559     dbus_message_unref(reply);
 560
 561     return n;
 562
 563 fail:
 564
 565     if (message)
 566         dbus_message_unref(message);
 567     if (reply)
 568         dbus_message_unref(reply);
 569
 570     if (dbus_error_is_set(&error)) {
 571         avahi_client_set_dbus_error(client, &error);
 572         dbus_error_free(&error);
 573     }
 574
 575     return NULL;
 576 }
 577
 578 const char* avahi_client_get_version_string (AvahiClient *client) {
 579     assert(client);
 580
 581     if (client->state == AVAHI_CLIENT_DISCONNECTED) {
 582         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 583         return NULL;
 584     }
 585
 586     if (!client->version_string)
 587         client->version_string = avahi_client_get_string_reply_and_block(client, "GetVersionString", NULL);
 588
 589     return client->version_string;
 590 }
 591
 592 const char* avahi_client_get_domain_name (AvahiClient *client) {
 593     assert(client);
 594
 595     if (client->state == AVAHI_CLIENT_DISCONNECTED) {
 596         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 597         return NULL;
 598     }
 599
 600     if (!client->domain_name)
 601         client->domain_name = avahi_client_get_string_reply_and_block(client, "GetDomainName", NULL);
 602
 603     return client->domain_name;
 604 }
 605
 606 const char* avahi_client_get_host_name (AvahiClient *client) {
 607     assert(client);
 608
 609     if (client->state == AVAHI_CLIENT_DISCONNECTED) {
 610         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 611         return NULL;
 612     }
 613
 614     if (!client->host_name)
 615         client->host_name = avahi_client_get_string_reply_and_block(client, "GetHostName", NULL);
 616
 617     return client->host_name;
 618 }
 619
 620 const char* avahi_client_get_host_name_fqdn (AvahiClient *client) {
 621     assert(client);
 622
 623     if (client->state == AVAHI_CLIENT_DISCONNECTED) {
 624         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 625         return NULL;
 626     }
 627
 628     if (!client->host_name_fqdn)
 629         client->host_name_fqdn = avahi_client_get_string_reply_and_block(client, "GetHostNameFqdn", NULL);
 630
 631     return client->host_name_fqdn;
 632 }
 633
 634 AvahiClientState avahi_client_get_state(AvahiClient *client) {
 635     assert(client);
 636
 637     return client->state;
 638 }
 639
 640 int avahi_client_errno(AvahiClient *client) {
 641     assert(client);
 642
 643     return client->error;
 644 }
 645
 646 /* Just for internal use */
 647 int avahi_client_simple_method_call(AvahiClient *client, const char *path, const char *interface, const char *method) {
 648     DBusMessage *message = NULL, *reply = NULL;
 649     DBusError error;
 650     int r = AVAHI_OK;
 651
 652     dbus_error_init(&error);
 653
 654     assert(client);
 655     assert(path);
 656     assert(interface);
 657     assert(method);
 658
 659     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, path, interface, method))) {
 660         r = avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 661         goto fail;
 662     }
 663
 664     if (!(reply = dbus_connection_send_with_reply_and_block(client->bus, message, -1, &error)) ||
 665         dbus_error_is_set (&error)) {
 666         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 667         goto fail;
 668     }
 669
 670     if (!dbus_message_get_args(reply, &error, DBUS_TYPE_INVALID) ||
 671         dbus_error_is_set (&error)) {
 672         r = avahi_client_set_errno(client, AVAHI_ERR_DBUS_ERROR);
 673         goto fail;
 674     }
 675
 676     dbus_message_unref(message);
 677     dbus_message_unref(reply);
 678
 679     return AVAHI_OK;
 680
 681 fail:
 682     if (dbus_error_is_set(&error)) {
 683         r = avahi_client_set_dbus_error(client, &error);
 684         dbus_error_free(&error);
 685     }
 686
 687     if (message)
 688         dbus_message_unref(message);
 689
 690     if (reply)
 691         dbus_message_unref(reply);
 692
 693     return r;
 694 }
 695
 696 uint32_t avahi_client_get_local_service_cookie(AvahiClient *client) {
 697     DBusMessage *message = NULL, *reply = NULL;
 698     DBusError error;
 699     assert(client);
 700
 701     if (client->state == AVAHI_CLIENT_DISCONNECTED) {
 702         avahi_client_set_errno(client, AVAHI_ERR_BAD_STATE);
 703         return AVAHI_SERVICE_COOKIE_INVALID;
 704     }
 705
 706     if (client->local_service_cookie_valid)
 707         return client->local_service_cookie;
 708
 709     dbus_error_init (&error);
 710
 711     if (!(message = dbus_message_new_method_call(AVAHI_DBUS_NAME, AVAHI_DBUS_PATH_SERVER, AVAHI_DBUS_INTERFACE_SERVER, "GetLocalServiceCookie"))) {
 712         avahi_client_set_errno(client, AVAHI_ERR_NO_MEMORY);
 713         goto fail;
 714     }
 715
 716     reply = dbus_connection_send_with_reply_and_block (client->bus, message, -1, &error);
 717
 718     if (!reply || dbus_error_is_set (&error))
 719         goto fail;
 720
 721     if (!dbus_message_get_args (reply, &error, DBUS_TYPE_UINT32, &client->local_service_cookie, DBUS_TYPE_INVALID) ||
 722         dbus_error_is_set (&error))
 723         goto fail;
 724
 725     dbus_message_unref(message);
 726     dbus_message_unref(reply);
 727
 728     client->local_service_cookie_valid = 1;
 729     return client->local_service_cookie;
 730
 731 fail:
 732
 733     if (message)
 734         dbus_message_unref(message);
 735     if (reply)
 736         dbus_message_unref(reply);
 737
 738     if (dbus_error_is_set(&error)) {
 739         avahi_client_set_dbus_error(client, &error);
 740         dbus_error_free(&error);
 741     }
 742
 743     return AVAHI_SERVICE_COOKIE_INVALID;
 744 }