git.meshlink.io Git - catta/blob - avahi-core/server.c

   1 /***
   2   This file is part of avahi.
   3
   4   avahi is free software; you can redistribute it and/or modify it
   5   under the terms of the GNU Lesser General Public License as
   6   published by the Free Software Foundation; either version 2.1 of the
   7   License, or (at your option) any later version.
   8
   9   avahi is distributed in the hope that it will be useful, but WITHOUT
  10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  11   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
  12   Public License for more details.
  13
  14   You should have received a copy of the GNU Lesser General Public
  15   License along with avahi; if not, write to the Free Software
  16   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  17   USA.
  18 ***/
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include <config.h>
  22 #endif
  23
  24 #include <sys/types.h>
  25 #include <sys/socket.h>
  26 #include <netinet/in.h>
  27 #include <arpa/inet.h>
  28 #include <string.h>
  29 #include <sys/utsname.h>
  30 #include <unistd.h>
  31 #include <errno.h>
  32 #include <stdio.h>
  33 #include <assert.h>
  34 #include <stdlib.h>
  35
  36 #include <avahi-common/domain.h>
  37 #include <avahi-common/timeval.h>
  38 #include <avahi-common/malloc.h>
  39 #include <avahi-common/error.h>
  40
  41 #include "internal.h"
  42 #include "iface.h"
  43 #include "socket.h"
  44 #include "browse.h"
  45 #include "log.h"
  46 #include "util.h"
  47 #include "dns-srv-rr.h"
  48 #include "addr-util.h"
  49 #include "domain-util.h"
  50 #include "rr-util.h"
  51
  52 #define AVAHI_DEFAULT_CACHE_ENTRIES_MAX 4096
  53
  54 static void enum_aux_records(AvahiServer *s, AvahiInterface *i, const char *name, uint16_t type, void (*callback)(AvahiServer *s, AvahiRecord *r, int flush_cache, void* userdata), void* userdata) {
  55     assert(s);
  56     assert(i);
  57     assert(name);
  58     assert(callback);
  59
  60     if (type == AVAHI_DNS_TYPE_ANY) {
  61         AvahiEntry *e;
  62
  63         for (e = s->entries; e; e = e->entries_next)
  64             if (!e->dead &&
  65                 avahi_entry_is_registered(s, e, i) &&
  66                 e->record->key->clazz == AVAHI_DNS_CLASS_IN &&
  67                 avahi_domain_equal(name, e->record->key->name))
  68                 callback(s, e->record, e->flags & AVAHI_PUBLISH_UNIQUE, userdata);
  69
  70     } else {
  71         AvahiEntry *e;
  72         AvahiKey *k;
  73
  74         if (!(k = avahi_key_new(name, AVAHI_DNS_CLASS_IN, type)))
  75             return; /** OOM */
  76
  77         for (e = avahi_hashmap_lookup(s->entries_by_key, k); e; e = e->by_key_next)
  78             if (!e->dead && avahi_entry_is_registered(s, e, i))
  79                 callback(s, e->record, e->flags & AVAHI_PUBLISH_UNIQUE, userdata);
  80
  81         avahi_key_unref(k);
  82     }
  83 }
  84
  85 void avahi_server_enumerate_aux_records(AvahiServer *s, AvahiInterface *i, AvahiRecord *r, void (*callback)(AvahiServer *s, AvahiRecord *r, int flush_cache, void* userdata), void* userdata) {
  86     assert(s);
  87     assert(i);
  88     assert(r);
  89     assert(callback);
  90
  91     /* Call the specified callback far all records referenced by the one specified in *r */
  92
  93     if (r->key->clazz == AVAHI_DNS_CLASS_IN) {
  94         if (r->key->type == AVAHI_DNS_TYPE_PTR) {
  95             enum_aux_records(s, i, r->data.ptr.name, AVAHI_DNS_TYPE_SRV, callback, userdata);
  96             enum_aux_records(s, i, r->data.ptr.name, AVAHI_DNS_TYPE_TXT, callback, userdata);
  97         } else if (r->key->type == AVAHI_DNS_TYPE_SRV) {
  98             enum_aux_records(s, i, r->data.srv.name, AVAHI_DNS_TYPE_A, callback, userdata);
  99             enum_aux_records(s, i, r->data.srv.name, AVAHI_DNS_TYPE_AAAA, callback, userdata);
 100         } else if (r->key->type == AVAHI_DNS_TYPE_CNAME)
 101             enum_aux_records(s, i, r->data.cname.name, AVAHI_DNS_TYPE_ANY, callback, userdata);
 102     }
 103 }
 104
 105 void avahi_server_prepare_response(AvahiServer *s, AvahiInterface *i, AvahiEntry *e, int unicast_response, int auxiliary) {
 106     assert(s);
 107     assert(i);
 108     assert(e);
 109
 110     avahi_record_list_push(s->record_list, e->record, e->flags & AVAHI_PUBLISH_UNIQUE, unicast_response, auxiliary);
 111 }
 112
 113 void avahi_server_prepare_matching_responses(AvahiServer *s, AvahiInterface *i, AvahiKey *k, int unicast_response) {
 114     assert(s);
 115     assert(i);
 116     assert(k);
 117
 118     /* Push all records that match the specified key to the record list */
 119
 120     if (avahi_key_is_pattern(k)) {
 121         AvahiEntry *e;
 122
 123         /* Handle ANY query */
 124
 125         for (e = s->entries; e; e = e->entries_next)
 126             if (!e->dead && avahi_key_pattern_match(k, e->record->key) && avahi_entry_is_registered(s, e, i))
 127                 avahi_server_prepare_response(s, i, e, unicast_response, 0);
 128
 129     } else {
 130         AvahiEntry *e;
 131
 132         /* Handle all other queries */
 133
 134         for (e = avahi_hashmap_lookup(s->entries_by_key, k); e; e = e->by_key_next)
 135             if (!e->dead && avahi_entry_is_registered(s, e, i))
 136                 avahi_server_prepare_response(s, i, e, unicast_response, 0);
 137     }
 138
 139     /* Look for CNAME records */
 140
 141     if ((k->clazz == AVAHI_DNS_CLASS_IN || k->clazz == AVAHI_DNS_CLASS_ANY)
 142         && k->type != AVAHI_DNS_TYPE_CNAME && k->type != AVAHI_DNS_TYPE_ANY) {
 143
 144         AvahiKey *cname_key;
 145
 146         if (!(cname_key = avahi_key_new(k->name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_CNAME)))
 147             return;
 148
 149         avahi_server_prepare_matching_responses(s, i, cname_key, unicast_response);
 150         avahi_key_unref(cname_key);
 151     }
 152 }
 153
 154 static void withdraw_entry(AvahiServer *s, AvahiEntry *e) {
 155     assert(s);
 156     assert(e);
 157
 158     /* Withdraw the specified entry, and if is part of an entry group,
 159      * put that into COLLISION state */
 160
 161     if (e->dead)
 162         return;
 163
 164     if (e->group) {
 165         AvahiEntry *k;
 166
 167         for (k = e->group->entries; k; k = k->by_group_next)
 168             if (!k->dead) {
 169                 avahi_goodbye_entry(s, k, 0, 1);
 170                 k->dead = 1;
 171             }
 172
 173         e->group->n_probing = 0;
 174
 175         avahi_s_entry_group_change_state(e->group, AVAHI_ENTRY_GROUP_COLLISION);
 176     } else {
 177         avahi_goodbye_entry(s, e, 0, 1);
 178         e->dead = 1;
 179     }
 180
 181     s->need_entry_cleanup = 1;
 182 }
 183
 184 static void withdraw_rrset(AvahiServer *s, AvahiKey *key) {
 185     AvahiEntry *e;
 186
 187     assert(s);
 188     assert(key);
 189
 190     /* Withdraw an entry RRSset */
 191
 192     for (e = avahi_hashmap_lookup(s->entries_by_key, key); e; e = e->by_key_next)
 193         withdraw_entry(s, e);
 194 }
 195
 196 static void incoming_probe(AvahiServer *s, AvahiRecord *record, AvahiInterface *i) {
 197     AvahiEntry *e, *n;
 198     int ours = 0, won = 0, lost = 0;
 199
 200     assert(s);
 201     assert(record);
 202     assert(i);
 203
 204     /* Handle incoming probes and check if they conflict our own probes */
 205
 206     for (e = avahi_hashmap_lookup(s->entries_by_key, record->key); e; e = n) {
 207         int cmp;
 208         n = e->by_key_next;
 209
 210         if (e->dead)
 211             continue;
 212
 213         if ((cmp = avahi_record_lexicographical_compare(e->record, record)) == 0) {
 214             ours = 1;
 215             break;
 216         } else {
 217
 218             if (avahi_entry_is_probing(s, e, i)) {
 219                 if (cmp > 0)
 220                     won = 1;
 221                 else /* cmp < 0 */
 222                     lost = 1;
 223             }
 224         }
 225     }
 226
 227     if (!ours) {
 228         char *t = avahi_record_to_string(record);
 229
 230         if (won)
 231             avahi_log_debug("Received conflicting probe [%s]. Local host won.", t);
 232         else if (lost) {
 233             avahi_log_debug("Received conflicting probe [%s]. Local host lost. Withdrawing.", t);
 234             withdraw_rrset(s, record->key);
 235         }
 236
 237         avahi_free(t);
 238     }
 239 }
 240
 241 static int handle_conflict(AvahiServer *s, AvahiInterface *i, AvahiRecord *record, int unique) {
 242     int valid = 1, ours = 0, conflict = 0, withdraw_immediately = 0;
 243     AvahiEntry *e, *n, *conflicting_entry = NULL;
 244
 245     assert(s);
 246     assert(i);
 247     assert(record);
 248
 249     /* Check whether an incoming record conflicts with one of our own */
 250
 251     for (e = avahi_hashmap_lookup(s->entries_by_key, record->key); e; e = n) {
 252         n = e->by_key_next;
 253
 254         if (e->dead)
 255             continue;
 256
 257         /* Check if the incoming is a goodbye record */
 258         if (avahi_record_is_goodbye(record)) {
 259
 260             if (avahi_record_equal_no_ttl(e->record, record)) {
 261                 char *t;
 262
 263                 /* Refresh */
 264                 t = avahi_record_to_string(record);
 265                 avahi_log_debug("Received goodbye record for one of our records [%s]. Refreshing.", t);
 266                 avahi_server_prepare_matching_responses(s, i, e->record->key, 0);
 267
 268                 valid = 0;
 269                 avahi_free(t);
 270                 break;
 271             }
 272
 273             /* If the goodybe packet doesn't match one of our own RRs, we simply ignore it. */
 274             continue;
 275         }
 276
 277         if (!(e->flags & AVAHI_PUBLISH_UNIQUE) && !unique)
 278             continue;
 279
 280         /* Either our entry or the other is intended to be unique, so let's check */
 281
 282         if (avahi_record_equal_no_ttl(e->record, record)) {
 283             ours = 1; /* We have an identical record, so this is no conflict */
 284
 285             /* Check wheter there is a TTL conflict */
 286             if (record->ttl <= e->record->ttl/2 &&
 287                 avahi_entry_is_registered(s, e, i)) {
 288                 char *t;
 289                 /* Refresh */
 290                 t = avahi_record_to_string(record);
 291
 292                 avahi_log_debug("Received record with bad TTL [%s]. Refreshing.", t);
 293                 avahi_server_prepare_matching_responses(s, i, e->record->key, 0);
 294                 valid = 0;
 295
 296                 avahi_free(t);
 297             }
 298
 299             /* There's no need to check the other entries of this RRset */
 300             break;
 301
 302         } else {
 303
 304             if (avahi_entry_is_registered(s, e, i)) {
 305
 306                 /* A conflict => we have to return to probe mode */
 307                 conflict = 1;
 308                 conflicting_entry = e;
 309
 310             } else if (avahi_entry_is_probing(s, e, i)) {
 311
 312                 /* We are currently registering a matching record, but
 313                  * someone else already claimed it, so let's
 314                  * withdraw */
 315                 conflict = 1;
 316                 withdraw_immediately = 1;
 317             }
 318         }
 319     }
 320
 321     if (!ours && conflict) {
 322         char *t;
 323
 324         valid = 0;
 325
 326         t = avahi_record_to_string(record);
 327
 328         if (withdraw_immediately) {
 329             avahi_log_debug("Received conflicting record [%s] with local record to be. Withdrawing.", t);
 330             withdraw_rrset(s, record->key);
 331         } else {
 332             assert(conflicting_entry);
 333             avahi_log_debug("Received conflicting record [%s]. Resetting our record.", t);
 334             avahi_entry_return_to_initial_state(s, conflicting_entry, i);
 335
 336             /* Local unique records are returned to probing
 337              * state. Local shared records are reannounced. */
 338         }
 339
 340         avahi_free(t);
 341     }
 342
 343     return valid;
 344 }
 345
 346 static void append_aux_callback(AvahiServer *s, AvahiRecord *r, int flush_cache, void* userdata) {
 347     int *unicast_response = userdata;
 348
 349     assert(s);
 350     assert(r);
 351     assert(unicast_response);
 352
 353     avahi_record_list_push(s->record_list, r, flush_cache, *unicast_response, 1);
 354 }
 355
 356 static void append_aux_records_to_list(AvahiServer *s, AvahiInterface *i, AvahiRecord *r, int unicast_response) {
 357     assert(s);
 358     assert(r);
 359
 360     avahi_server_enumerate_aux_records(s, i, r, append_aux_callback, &unicast_response);
 361 }
 362
 363 void avahi_server_generate_response(AvahiServer *s, AvahiInterface *i, AvahiDnsPacket *p, const AvahiAddress *a, uint16_t port, int legacy_unicast, int immediately) {
 364
 365     assert(s);
 366     assert(i);
 367     assert(!legacy_unicast || (a && port > 0 && p));
 368
 369     if (legacy_unicast) {
 370         AvahiDnsPacket *reply;
 371         AvahiRecord *r;
 372
 373         if (!(reply = avahi_dns_packet_new_reply(p, 512 + AVAHI_DNS_PACKET_EXTRA_SIZE /* unicast DNS maximum packet size is 512 */ , 1, 1)))
 374             return; /* OOM */
 375
 376         while ((r = avahi_record_list_next(s->record_list, NULL, NULL, NULL))) {
 377
 378             append_aux_records_to_list(s, i, r, 0);
 379
 380             if (avahi_dns_packet_append_record(reply, r, 0, 10))
 381                 avahi_dns_packet_inc_field(reply, AVAHI_DNS_FIELD_ANCOUNT);
 382             else {
 383                 char *t = avahi_record_to_string(r);
 384                 avahi_log_warn("Record [%s] not fitting in legacy unicast packet, dropping.", t);
 385                 avahi_free(t);
 386             }
 387
 388             avahi_record_unref(r);
 389         }
 390
 391         if (avahi_dns_packet_get_field(reply, AVAHI_DNS_FIELD_ANCOUNT) != 0)
 392             avahi_interface_send_packet_unicast(i, reply, a, port);
 393
 394         avahi_dns_packet_free(reply);
 395
 396     } else {
 397         int unicast_response, flush_cache, auxiliary;
 398         AvahiDnsPacket *reply = NULL;
 399         AvahiRecord *r;
 400
 401         /* In case the query packet was truncated never respond
 402         immediately, because known answer suppression records might be
 403         contained in later packets */
 404         int tc = p && !!(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_TC);
 405
 406         while ((r = avahi_record_list_next(s->record_list, &flush_cache, &unicast_response, &auxiliary))) {
 407
 408             int im = immediately;
 409
 410             /* Only send the response immediately if it contains a
 411              * unique entry AND it is not in reply to a truncated
 412              * packet AND it is not an auxiliary record AND all other
 413              * responses for this record are unique too. */
 414
 415             if (flush_cache && !tc && !auxiliary && avahi_record_list_all_flush_cache(s->record_list))
 416                 im = 1;
 417
 418             if (!avahi_interface_post_response(i, r, flush_cache, a, im) && unicast_response) {
 419
 420                 /* Due to some reasons the record has not been scheduled.
 421                  * The client requested an unicast response in that
 422                  * case. Therefore we prepare such a response */
 423
 424                 append_aux_records_to_list(s, i, r, unicast_response);
 425
 426                 for (;;) {
 427
 428                     if (!reply) {
 429                         assert(p);
 430
 431                         if (!(reply = avahi_dns_packet_new_reply(p, i->hardware->mtu, 0, 0)))
 432                             break; /* OOM */
 433                     }
 434
 435                     if (avahi_dns_packet_append_record(reply, r, flush_cache, 0)) {
 436
 437                         /* Appending this record succeeded, so incremeant
 438                          * the specific header field, and return to the caller */
 439
 440                         avahi_dns_packet_inc_field(reply, AVAHI_DNS_FIELD_ANCOUNT);
 441                         break;
 442                     }
 443
 444                     if (avahi_dns_packet_get_field(reply, AVAHI_DNS_FIELD_ANCOUNT) == 0) {
 445                         size_t size;
 446
 447                         /* The record is too large for one packet, so create a larger packet */
 448
 449                         avahi_dns_packet_free(reply);
 450                         size = avahi_record_get_estimate_size(r) + AVAHI_DNS_PACKET_HEADER_SIZE;
 451
 452                         if (!(reply = avahi_dns_packet_new_reply(p, size + AVAHI_DNS_PACKET_EXTRA_SIZE, 0, 1)))
 453                             break; /* OOM */
 454
 455                         if (avahi_dns_packet_append_record(reply, r, flush_cache, 0)) {
 456
 457                             /* Appending this record succeeded, so incremeant
 458                              * the specific header field, and return to the caller */
 459
 460                             avahi_dns_packet_inc_field(reply, AVAHI_DNS_FIELD_ANCOUNT);
 461                             break;
 462
 463                         }  else {
 464
 465                             /* We completely fucked up, there's
 466                              * nothing we can do. The RR just doesn't
 467                              * fit in. Let's ignore it. */
 468
 469                             char *t;
 470                             avahi_dns_packet_free(reply);
 471                             reply = NULL;
 472                             t = avahi_record_to_string(r);
 473                             avahi_log_warn("Record [%s] too large, doesn't fit in any packet!", t);
 474                             avahi_free(t);
 475                             break;
 476                         }
 477                     }
 478
 479                     /* Appending the record didn't succeeed, so let's send this packet, and create a new one */
 480                     avahi_interface_send_packet_unicast(i, reply, a, port);
 481                     avahi_dns_packet_free(reply);
 482                     reply = NULL;
 483                 }
 484             }
 485
 486             avahi_record_unref(r);
 487         }
 488
 489         if (reply) {
 490             if (avahi_dns_packet_get_field(reply, AVAHI_DNS_FIELD_ANCOUNT) != 0)
 491                 avahi_interface_send_packet_unicast(i, reply, a, port);
 492             avahi_dns_packet_free(reply);
 493         }
 494     }
 495
 496     avahi_record_list_flush(s->record_list);
 497 }
 498
 499 static void reflect_response(AvahiServer *s, AvahiInterface *i, AvahiRecord *r, int flush_cache) {
 500     AvahiInterface *j;
 501
 502     assert(s);
 503     assert(i);
 504     assert(r);
 505
 506     if (!s->config.enable_reflector)
 507         return;
 508
 509     for (j = s->monitor->interfaces; j; j = j->interface_next)
 510         if (j != i && (s->config.reflect_ipv || j->protocol == i->protocol))
 511             avahi_interface_post_response(j, r, flush_cache, NULL, 1);
 512 }
 513
 514 static void* reflect_cache_walk_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void* userdata) {
 515     AvahiServer *s = userdata;
 516
 517     assert(c);
 518     assert(pattern);
 519     assert(e);
 520     assert(s);
 521
 522     avahi_record_list_push(s->record_list, e->record, e->cache_flush, 0, 0);
 523     return NULL;
 524 }
 525
 526 static void reflect_query(AvahiServer *s, AvahiInterface *i, AvahiKey *k) {
 527     AvahiInterface *j;
 528
 529     assert(s);
 530     assert(i);
 531     assert(k);
 532
 533     if (!s->config.enable_reflector)
 534         return;
 535
 536     for (j = s->monitor->interfaces; j; j = j->interface_next)
 537         if (j != i && (s->config.reflect_ipv || j->protocol == i->protocol)) {
 538             /* Post the query to other networks */
 539             avahi_interface_post_query(j, k, 1, NULL);
 540
 541             /* Reply from caches of other network. This is needed to
 542              * "work around" known answer suppression. */
 543
 544             avahi_cache_walk(j->cache, k, reflect_cache_walk_callback, s);
 545         }
 546 }
 547
 548 static void reflect_probe(AvahiServer *s, AvahiInterface *i, AvahiRecord *r) {
 549     AvahiInterface *j;
 550
 551     assert(s);
 552     assert(i);
 553     assert(r);
 554
 555     if (!s->config.enable_reflector)
 556         return;
 557
 558     for (j = s->monitor->interfaces; j; j = j->interface_next)
 559         if (j != i && (s->config.reflect_ipv || j->protocol == i->protocol))
 560             avahi_interface_post_probe(j, r, 1);
 561 }
 562
 563 static void handle_query_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, uint16_t port, int legacy_unicast, int from_local_iface) {
 564     size_t n;
 565     int is_probe;
 566
 567     assert(s);
 568     assert(p);
 569     assert(i);
 570     assert(a);
 571
 572     assert(avahi_record_list_is_empty(s->record_list));
 573
 574     is_probe = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) > 0;
 575
 576     /* Handle the questions */
 577     for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); n > 0; n --) {
 578         AvahiKey *key;
 579         int unicast_response = 0;
 580
 581         if (!(key = avahi_dns_packet_consume_key(p, &unicast_response))) {
 582             avahi_log_warn(__FILE__": Packet too short or invalid while reading question key. (Maybe a UTF-8 problem?)");
 583             goto fail;
 584         }
 585
 586         if (!legacy_unicast && !from_local_iface) {
 587             reflect_query(s, i, key);
 588             if (!unicast_response)
 589               avahi_cache_start_poof(i->cache, key, a);
 590         }
 591
 592         if (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0 &&
 593             !(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_TC))
 594             /* Allow our own queries to be suppressed by incoming
 595              * queries only when they do not include known answers */
 596             avahi_query_scheduler_incoming(i->query_scheduler, key);
 597
 598         avahi_server_prepare_matching_responses(s, i, key, unicast_response);
 599         avahi_key_unref(key);
 600     }
 601
 602     if (!legacy_unicast) {
 603
 604         /* Known Answer Suppression */
 605         for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT); n > 0; n --) {
 606             AvahiRecord *record;
 607             int unique = 0;
 608
 609             if (!(record = avahi_dns_packet_consume_record(p, &unique))) {
 610                 avahi_log_warn(__FILE__": Packet too short or invalid while reading known answer record. (Maybe a UTF-8 problem?)");
 611                 goto fail;
 612             }
 613
 614             avahi_response_scheduler_suppress(i->response_scheduler, record, a);
 615             avahi_record_list_drop(s->record_list, record);
 616             avahi_cache_stop_poof(i->cache, record, a);
 617
 618             avahi_record_unref(record);
 619         }
 620
 621         /* Probe record */
 622         for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT); n > 0; n --) {
 623             AvahiRecord *record;
 624             int unique = 0;
 625
 626             if (!(record = avahi_dns_packet_consume_record(p, &unique))) {
 627                 avahi_log_warn(__FILE__": Packet too short or invalid while reading probe record. (Maybe a UTF-8 problem?)");
 628                 goto fail;
 629             }
 630
 631             if (!avahi_key_is_pattern(record->key)) {
 632                 if (!from_local_iface)
 633                     reflect_probe(s, i, record);
 634                 incoming_probe(s, record, i);
 635             }
 636
 637             avahi_record_unref(record);
 638         }
 639     }
 640
 641     if (!avahi_record_list_is_empty(s->record_list))
 642         avahi_server_generate_response(s, i, p, a, port, legacy_unicast, is_probe);
 643
 644     return;
 645
 646 fail:
 647     avahi_record_list_flush(s->record_list);
 648 }
 649
 650 static void handle_response_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, int from_local_iface) {
 651     unsigned n;
 652
 653     assert(s);
 654     assert(p);
 655     assert(i);
 656     assert(a);
 657
 658     for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) +
 659              avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ARCOUNT); n > 0; n--) {
 660         AvahiRecord *record;
 661         int cache_flush = 0;
 662
 663         if (!(record = avahi_dns_packet_consume_record(p, &cache_flush))) {
 664             avahi_log_warn(__FILE__": Packet too short or invalid while reading response record. (Maybe a UTF-8 problem?)");
 665             break;
 666         }
 667
 668         if (!avahi_key_is_pattern(record->key)) {
 669
 670             if (handle_conflict(s, i, record, cache_flush)) {
 671                 if (!from_local_iface && !avahi_record_is_link_local_address(record))
 672                     reflect_response(s, i, record, cache_flush);
 673                 avahi_cache_update(i->cache, record, cache_flush, a);
 674                 avahi_response_scheduler_incoming(i->response_scheduler, record, cache_flush);
 675             }
 676         }
 677
 678         avahi_record_unref(record);
 679     }
 680
 681     /* If the incoming response contained a conflicting record, some
 682        records have been scheduled for sending. We need to flush them
 683        here. */
 684     if (!avahi_record_list_is_empty(s->record_list))
 685         avahi_server_generate_response(s, i, NULL, NULL, 0, 0, 1);
 686 }
 687
 688 static AvahiLegacyUnicastReflectSlot* allocate_slot(AvahiServer *s) {
 689     unsigned n, idx = (unsigned) -1;
 690     AvahiLegacyUnicastReflectSlot *slot;
 691
 692     assert(s);
 693
 694     if (!s->legacy_unicast_reflect_slots)
 695         s->legacy_unicast_reflect_slots = avahi_new0(AvahiLegacyUnicastReflectSlot*, AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX);
 696
 697     for (n = 0; n < AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; n++, s->legacy_unicast_reflect_id++) {
 698         idx = s->legacy_unicast_reflect_id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX;
 699
 700         if (!s->legacy_unicast_reflect_slots[idx])
 701             break;
 702     }
 703
 704     if (idx == (unsigned) -1 || s->legacy_unicast_reflect_slots[idx])
 705         return NULL;
 706
 707     if (!(slot = avahi_new(AvahiLegacyUnicastReflectSlot, 1)))
 708         return NULL; /* OOM */
 709
 710     s->legacy_unicast_reflect_slots[idx] = slot;
 711     slot->id = s->legacy_unicast_reflect_id++;
 712     slot->server = s;
 713
 714     return slot;
 715 }
 716
 717 static void deallocate_slot(AvahiServer *s, AvahiLegacyUnicastReflectSlot *slot) {
 718     unsigned idx;
 719
 720     assert(s);
 721     assert(slot);
 722
 723     idx = slot->id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX;
 724
 725     assert(s->legacy_unicast_reflect_slots[idx] == slot);
 726
 727     avahi_time_event_free(slot->time_event);
 728
 729     avahi_free(slot);
 730     s->legacy_unicast_reflect_slots[idx] = NULL;
 731 }
 732
 733 static void free_slots(AvahiServer *s) {
 734     unsigned idx;
 735     assert(s);
 736
 737     if (!s->legacy_unicast_reflect_slots)
 738         return;
 739
 740     for (idx = 0; idx < AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; idx ++)
 741         if (s->legacy_unicast_reflect_slots[idx])
 742             deallocate_slot(s, s->legacy_unicast_reflect_slots[idx]);
 743
 744     avahi_free(s->legacy_unicast_reflect_slots);
 745     s->legacy_unicast_reflect_slots = NULL;
 746 }
 747
 748 static AvahiLegacyUnicastReflectSlot* find_slot(AvahiServer *s, uint16_t id) {
 749     unsigned idx;
 750
 751     assert(s);
 752
 753     if (!s->legacy_unicast_reflect_slots)
 754         return NULL;
 755
 756     idx = id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX;
 757
 758     if (!s->legacy_unicast_reflect_slots[idx] || s->legacy_unicast_reflect_slots[idx]->id != id)
 759         return NULL;
 760
 761     return s->legacy_unicast_reflect_slots[idx];
 762 }
 763
 764 static void legacy_unicast_reflect_slot_timeout(AvahiTimeEvent *e, void *userdata) {
 765     AvahiLegacyUnicastReflectSlot *slot = userdata;
 766
 767     assert(e);
 768     assert(slot);
 769     assert(slot->time_event == e);
 770
 771     deallocate_slot(slot->server, slot);
 772 }
 773
 774 static void reflect_legacy_unicast_query_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, uint16_t port) {
 775     AvahiLegacyUnicastReflectSlot *slot;
 776     AvahiInterface *j;
 777
 778     assert(s);
 779     assert(p);
 780     assert(i);
 781     assert(a);
 782     assert(port > 0);
 783     assert(i->protocol == a->proto);
 784
 785     if (!s->config.enable_reflector)
 786         return;
 787
 788     /* Reflecting legacy unicast queries is a little more complicated
 789        than reflecting normal queries, since we must route the
 790        responses back to the right client. Therefore we must store
 791        some information for finding the right client contact data for
 792        response packets. In contrast to normal queries legacy
 793        unicast query and response packets are reflected untouched and
 794        are not reassembled into larger packets */
 795
 796     if (!(slot = allocate_slot(s))) {
 797         /* No slot available, we drop this legacy unicast query */
 798         avahi_log_warn("No slot available for legacy unicast reflection, dropping query packet.");
 799         return;
 800     }
 801
 802     slot->original_id = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID);
 803     slot->address = *a;
 804     slot->port = port;
 805     slot->interface = i->hardware->index;
 806
 807     avahi_elapse_time(&slot->elapse_time, 2000, 0);
 808     slot->time_event = avahi_time_event_new(s->time_event_queue, &slot->elapse_time, legacy_unicast_reflect_slot_timeout, slot);
 809
 810     /* Patch the packet with our new locally generatet id */
 811     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->id);
 812
 813     for (j = s->monitor->interfaces; j; j = j->interface_next)
 814         if (j->announcing &&
 815             j != i &&
 816             (s->config.reflect_ipv || j->protocol == i->protocol)) {
 817
 818             if (j->protocol == AVAHI_PROTO_INET && s->fd_legacy_unicast_ipv4 >= 0) {
 819                 avahi_send_dns_packet_ipv4(s->fd_legacy_unicast_ipv4, j->hardware->index, p, NULL, NULL, 0);
 820             } else if (j->protocol == AVAHI_PROTO_INET6 && s->fd_legacy_unicast_ipv6 >= 0)
 821                 avahi_send_dns_packet_ipv6(s->fd_legacy_unicast_ipv6, j->hardware->index, p, NULL, NULL, 0);
 822         }
 823
 824     /* Reset the id */
 825     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->original_id);
 826 }
 827
 828 static int originates_from_local_legacy_unicast_socket(AvahiServer *s, const AvahiAddress *address, uint16_t port) {
 829     assert(s);
 830     assert(address);
 831     assert(port > 0);
 832
 833     if (!s->config.enable_reflector)
 834         return 0;
 835
 836     if (!avahi_address_is_local(s->monitor, address))
 837         return 0;
 838
 839     if (address->proto == AVAHI_PROTO_INET && s->fd_legacy_unicast_ipv4 >= 0) {
 840         struct sockaddr_in lsa;
 841         socklen_t l = sizeof(lsa);
 842
 843         if (getsockname(s->fd_legacy_unicast_ipv4, (struct sockaddr*) &lsa, &l) != 0)
 844             avahi_log_warn("getsockname(): %s", strerror(errno));
 845         else
 846             return avahi_port_from_sockaddr((struct sockaddr*) &lsa) == port;
 847
 848     }
 849
 850     if (address->proto == AVAHI_PROTO_INET6 && s->fd_legacy_unicast_ipv6 >= 0) {
 851         struct sockaddr_in6 lsa;
 852         socklen_t l = sizeof(lsa);
 853
 854         if (getsockname(s->fd_legacy_unicast_ipv6, (struct sockaddr*) &lsa, &l) != 0)
 855             avahi_log_warn("getsockname(): %s", strerror(errno));
 856         else
 857             return avahi_port_from_sockaddr((struct sockaddr*) &lsa) == port;
 858     }
 859
 860     return 0;
 861 }
 862
 863 static int is_mdns_mcast_address(const AvahiAddress *a) {
 864     AvahiAddress b;
 865     assert(a);
 866
 867     avahi_address_parse(a->proto == AVAHI_PROTO_INET ? AVAHI_IPV4_MCAST_GROUP : AVAHI_IPV6_MCAST_GROUP, a->proto, &b);
 868     return avahi_address_cmp(a, &b) == 0;
 869 }
 870
 871 static int originates_from_local_iface(AvahiServer *s, AvahiIfIndex iface, const AvahiAddress *a, uint16_t port) {
 872     assert(s);
 873     assert(iface != AVAHI_IF_UNSPEC);
 874     assert(a);
 875
 876     /* If it isn't the MDNS port it can't be generated by us */
 877     if (port != AVAHI_MDNS_PORT)
 878         return 0;
 879
 880     return avahi_interface_has_address(s->monitor, iface, a);
 881 }
 882
 883 static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddress *src_address, uint16_t port, const AvahiAddress *dst_address, AvahiIfIndex iface, int ttl) {
 884     AvahiInterface *i;
 885     int from_local_iface = 0;
 886
 887     assert(s);
 888     assert(p);
 889     assert(src_address);
 890     assert(dst_address);
 891     assert(iface > 0);
 892     assert(src_address->proto == dst_address->proto);
 893
 894     if (!(i = avahi_interface_monitor_get_interface(s->monitor, iface, src_address->proto)) ||
 895         !i->announcing) {
 896         avahi_log_warn("Received packet from invalid interface.");
 897         return;
 898     }
 899
 900     if (port <= 0) {
 901         /* This fixes RHBZ #475394 */
 902         avahi_log_warn("Received packet from invalid source port %u.", (unsigned) port);
 903         return;
 904     }
 905
 906     if (avahi_address_is_ipv4_in_ipv6(src_address))
 907         /* This is an IPv4 address encapsulated in IPv6, so let's ignore it. */
 908         return;
 909
 910     if (originates_from_local_legacy_unicast_socket(s, src_address, port))
 911         /* This originates from our local reflector, so let's ignore it */
 912         return;
 913
 914     /* We don't want to reflect local traffic, so we check if this packet is generated locally. */
 915     if (s->config.enable_reflector)
 916         from_local_iface = originates_from_local_iface(s, iface, src_address, port);
 917
 918     if (avahi_dns_packet_check_valid_multicast(p) < 0) {
 919         avahi_log_warn("Received invalid packet.");
 920         return;
 921     }
 922
 923     if (avahi_dns_packet_is_query(p)) {
 924         int legacy_unicast = 0;
 925
 926         /* For queries EDNS0 might allow ARCOUNT != 0. We ignore the
 927          * AR section completely here, so far. Until the day we add
 928          * EDNS0 support. */
 929
 930         if (port != AVAHI_MDNS_PORT) {
 931             /* Legacy Unicast */
 932
 933             if ((avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) != 0 ||
 934                  avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) != 0)) {
 935                 avahi_log_warn("Invalid legacy unicast query packet.");
 936                 return;
 937             }
 938
 939             legacy_unicast = 1;
 940         }
 941
 942         if (legacy_unicast)
 943             reflect_legacy_unicast_query_packet(s, p, i, src_address, port);
 944
 945         handle_query_packet(s, p, i, src_address, port, legacy_unicast, from_local_iface);
 946
 947     } else {
 948         char t[AVAHI_ADDRESS_STR_MAX];
 949
 950         if (port != AVAHI_MDNS_PORT) {
 951             avahi_log_warn("Received response from host %s with invalid source port %u on interface '%s.%i'", avahi_address_snprint(t, sizeof(t), src_address), port, i->hardware->name, i->protocol);
 952             return;
 953         }
 954
 955         if (ttl != 255 && s->config.check_response_ttl) {
 956             avahi_log_warn("Received response from host %s with invalid TTL %u on interface '%s.%i'.", avahi_address_snprint(t, sizeof(t), src_address), ttl, i->hardware->name, i->protocol);
 957             return;
 958         }
 959
 960         if (!is_mdns_mcast_address(dst_address) &&
 961             !avahi_interface_address_on_link(i, src_address)) {
 962
 963             avahi_log_warn("Received non-local response from host %s on interface '%s.%i'.", avahi_address_snprint(t, sizeof(t), src_address), i->hardware->name, i->protocol);
 964             return;
 965         }
 966
 967         if (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT) != 0 ||
 968             avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0 ||
 969             avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) != 0) {
 970
 971             avahi_log_warn("Invalid response packet from host %s.", avahi_address_snprint(t, sizeof(t), src_address));
 972             return;
 973         }
 974
 975         handle_response_packet(s, p, i, src_address, from_local_iface);
 976     }
 977 }
 978
 979 static void dispatch_legacy_unicast_packet(AvahiServer *s, AvahiDnsPacket *p) {
 980     AvahiInterface *j;
 981     AvahiLegacyUnicastReflectSlot *slot;
 982
 983     assert(s);
 984     assert(p);
 985
 986     if (avahi_dns_packet_check_valid(p) < 0 || avahi_dns_packet_is_query(p)) {
 987         avahi_log_warn("Received invalid packet.");
 988         return;
 989     }
 990
 991     if (!(slot = find_slot(s, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID)))) {
 992         avahi_log_warn("Received legacy unicast response with unknown id");
 993         return;
 994     }
 995
 996     if (!(j = avahi_interface_monitor_get_interface(s->monitor, slot->interface, slot->address.proto)) ||
 997         !j->announcing)
 998         return;
 999
1000     /* Patch the original ID into this response */
1001     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->original_id);
1002
1003     /* Forward the response to the correct client */
1004     avahi_interface_send_packet_unicast(j, p, &slot->address, slot->port);
1005
1006     /* Undo changes to packet */
1007     avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->id);
1008 }
1009
1010 static void mcast_socket_event(AvahiWatch *w, int fd, AvahiWatchEvent events, void *userdata) {
1011     AvahiServer *s = userdata;
1012     AvahiAddress dest, src;
1013     AvahiDnsPacket *p = NULL;
1014     AvahiIfIndex iface;
1015     uint16_t port;
1016     uint8_t ttl;
1017
1018     assert(w);
1019     assert(fd >= 0);
1020     assert(events & AVAHI_WATCH_IN);
1021
1022     if (fd == s->fd_ipv4) {
1023         dest.proto = src.proto = AVAHI_PROTO_INET;
1024         p = avahi_recv_dns_packet_ipv4(s->fd_ipv4, &src.data.ipv4, &port, &dest.data.ipv4, &iface, &ttl);
1025     } else {
1026         assert(fd == s->fd_ipv6);
1027         dest.proto = src.proto = AVAHI_PROTO_INET6;
1028         p = avahi_recv_dns_packet_ipv6(s->fd_ipv6, &src.data.ipv6, &port, &dest.data.ipv6, &iface, &ttl);
1029     }
1030
1031     if (p) {
1032         if (iface == AVAHI_IF_UNSPEC)
1033             iface = avahi_find_interface_for_address(s->monitor, &dest);
1034
1035         if (iface != AVAHI_IF_UNSPEC)
1036             dispatch_packet(s, p, &src, port, &dest, iface, ttl);
1037         else
1038             avahi_log_error("Incoming packet received on address that isn't local.");
1039
1040         avahi_dns_packet_free(p);
1041
1042         avahi_cleanup_dead_entries(s);
1043     }
1044 }
1045
1046 static void legacy_unicast_socket_event(AvahiWatch *w, int fd, AvahiWatchEvent events, void *userdata) {
1047     AvahiServer *s = userdata;
1048     AvahiDnsPacket *p = NULL;
1049
1050     assert(w);
1051     assert(fd >= 0);
1052     assert(events & AVAHI_WATCH_IN);
1053
1054     if (fd == s->fd_legacy_unicast_ipv4)
1055         p = avahi_recv_dns_packet_ipv4(s->fd_legacy_unicast_ipv4, NULL, NULL, NULL, NULL, NULL);
1056     else {
1057         assert(fd == s->fd_legacy_unicast_ipv6);
1058         p = avahi_recv_dns_packet_ipv6(s->fd_legacy_unicast_ipv6, NULL, NULL, NULL, NULL, NULL);
1059     }
1060
1061     if (p) {
1062         dispatch_legacy_unicast_packet(s, p);
1063         avahi_dns_packet_free(p);
1064
1065         avahi_cleanup_dead_entries(s);
1066     }
1067 }
1068
1069 static void server_set_state(AvahiServer *s, AvahiServerState state) {
1070     assert(s);
1071
1072     if (s->state == state)
1073         return;
1074
1075     s->state = state;
1076
1077     avahi_interface_monitor_update_rrs(s->monitor, 0);
1078
1079     if (s->callback)
1080         s->callback(s, state, s->userdata);
1081 }
1082
1083 static void withdraw_host_rrs(AvahiServer *s) {
1084     assert(s);
1085
1086     if (s->hinfo_entry_group)
1087         avahi_s_entry_group_reset(s->hinfo_entry_group);
1088
1089     if (s->browse_domain_entry_group)
1090         avahi_s_entry_group_reset(s->browse_domain_entry_group);
1091
1092     avahi_interface_monitor_update_rrs(s->monitor, 1);
1093     s->n_host_rr_pending = 0;
1094 }
1095
1096 void avahi_server_decrease_host_rr_pending(AvahiServer *s) {
1097     assert(s);
1098
1099     assert(s->n_host_rr_pending > 0);
1100
1101     if (--s->n_host_rr_pending == 0)
1102         server_set_state(s, AVAHI_SERVER_RUNNING);
1103 }
1104
1105 void avahi_host_rr_entry_group_callback(AvahiServer *s, AvahiSEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) {
1106     assert(s);
1107     assert(g);
1108
1109     if (state == AVAHI_ENTRY_GROUP_REGISTERING &&
1110         s->state == AVAHI_SERVER_REGISTERING)
1111         s->n_host_rr_pending ++;
1112
1113     else if (state == AVAHI_ENTRY_GROUP_COLLISION &&
1114         (s->state == AVAHI_SERVER_REGISTERING || s->state == AVAHI_SERVER_RUNNING)) {
1115         withdraw_host_rrs(s);
1116         server_set_state(s, AVAHI_SERVER_COLLISION);
1117
1118     } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED &&
1119                s->state == AVAHI_SERVER_REGISTERING)
1120         avahi_server_decrease_host_rr_pending(s);
1121 }
1122
1123 static void register_hinfo(AvahiServer *s) {
1124     struct utsname utsname;
1125     AvahiRecord *r;
1126
1127     assert(s);
1128
1129     if (!s->config.publish_hinfo)
1130         return;
1131
1132     if (s->hinfo_entry_group)
1133         assert(avahi_s_entry_group_is_empty(s->hinfo_entry_group));
1134     else
1135         s->hinfo_entry_group = avahi_s_entry_group_new(s, avahi_host_rr_entry_group_callback, NULL);
1136
1137     if (!s->hinfo_entry_group) {
1138         avahi_log_warn("Failed to create HINFO entry group: %s", avahi_strerror(s->error));
1139         return;
1140     }
1141
1142     /* Fill in HINFO rr */
1143     if ((r = avahi_record_new_full(s->host_name_fqdn, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_HINFO, AVAHI_DEFAULT_TTL_HOST_NAME))) {
1144
1145         if (uname(&utsname) < 0)
1146             avahi_log_warn("uname() failed: %s\n", avahi_strerror(errno));
1147         else {
1148
1149             r->data.hinfo.cpu = avahi_strdup(avahi_strup(utsname.machine));
1150             r->data.hinfo.os = avahi_strdup(avahi_strup(utsname.sysname));
1151
1152             avahi_log_info("Registering HINFO record with values '%s'/'%s'.", r->data.hinfo.cpu, r->data.hinfo.os);
1153
1154             if (avahi_server_add(s, s->hinfo_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_UNIQUE, r) < 0) {
1155                 avahi_log_warn("Failed to add HINFO RR: %s", avahi_strerror(s->error));
1156                 return;
1157             }
1158         }
1159
1160         avahi_record_unref(r);
1161     }
1162
1163     if (avahi_s_entry_group_commit(s->hinfo_entry_group) < 0)
1164         avahi_log_warn("Failed to commit HINFO entry group: %s", avahi_strerror(s->error));
1165
1166 }
1167
1168 static void register_localhost(AvahiServer *s) {
1169     AvahiAddress a;
1170     assert(s);
1171
1172     /* Add localhost entries */
1173     avahi_address_parse("127.0.0.1", AVAHI_PROTO_INET, &a);
1174     avahi_server_add_address(s, NULL, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_NO_PROBE|AVAHI_PUBLISH_NO_ANNOUNCE, "localhost", &a);
1175
1176     avahi_address_parse("::1", AVAHI_PROTO_INET6, &a);
1177     avahi_server_add_address(s, NULL, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_NO_PROBE|AVAHI_PUBLISH_NO_ANNOUNCE, "ip6-localhost", &a);
1178 }
1179
1180 static void register_browse_domain(AvahiServer *s) {
1181     assert(s);
1182
1183     if (!s->config.publish_domain)
1184         return;
1185
1186     if (avahi_domain_equal(s->domain_name, "local"))
1187         return;
1188
1189     if (s->browse_domain_entry_group)
1190         assert(avahi_s_entry_group_is_empty(s->browse_domain_entry_group));
1191     else
1192         s->browse_domain_entry_group = avahi_s_entry_group_new(s, NULL, NULL);
1193
1194     if (!s->browse_domain_entry_group) {
1195         avahi_log_warn("Failed to create browse domain entry group: %s", avahi_strerror(s->error));
1196         return;
1197     }
1198
1199     if (avahi_server_add_ptr(s, s->browse_domain_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0, AVAHI_DEFAULT_TTL, "b._dns-sd._udp.local", s->domain_name) < 0) {
1200         avahi_log_warn("Failed to add browse domain RR: %s", avahi_strerror(s->error));
1201         return;
1202     }
1203
1204     if (avahi_s_entry_group_commit(s->browse_domain_entry_group) < 0)
1205         avahi_log_warn("Failed to commit browse domain entry group: %s", avahi_strerror(s->error));
1206 }
1207
1208 static void register_stuff(AvahiServer *s) {
1209     assert(s);
1210
1211     server_set_state(s, AVAHI_SERVER_REGISTERING);
1212     s->n_host_rr_pending ++; /** Make sure that the state isn't changed tp AVAHI_SERVER_RUNNING too early */
1213
1214     register_hinfo(s);
1215     register_browse_domain(s);
1216     avahi_interface_monitor_update_rrs(s->monitor, 0);
1217
1218     assert(s->n_host_rr_pending > 0);
1219     s->n_host_rr_pending --;
1220
1221     if (s->n_host_rr_pending == 0)
1222         server_set_state(s, AVAHI_SERVER_RUNNING);
1223 }
1224
1225 static void update_fqdn(AvahiServer *s) {
1226     char *n;
1227
1228     assert(s);
1229     assert(s->host_name);
1230     assert(s->domain_name);
1231
1232     if (!(n = avahi_strdup_printf("%s.%s", s->host_name, s->domain_name)))
1233         return; /* OOM */
1234
1235     avahi_free(s->host_name_fqdn);
1236     s->host_name_fqdn = n;
1237 }
1238
1239 int avahi_server_set_host_name(AvahiServer *s, const char *host_name) {
1240     char *hn = NULL;
1241     assert(s);
1242
1243     AVAHI_CHECK_VALIDITY(s, !host_name || avahi_is_valid_host_name(host_name), AVAHI_ERR_INVALID_HOST_NAME);
1244
1245     if (!host_name)
1246         hn = avahi_get_host_name_strdup();
1247     else
1248         hn = avahi_normalize_name_strdup(host_name);
1249
1250     hn[strcspn(hn, ".")] = 0;
1251
1252     if (avahi_domain_equal(s->host_name, hn) && s->state != AVAHI_SERVER_COLLISION) {
1253         avahi_free(hn);
1254         return avahi_server_set_errno(s, AVAHI_ERR_NO_CHANGE);
1255     }
1256
1257     withdraw_host_rrs(s);
1258
1259     avahi_free(s->host_name);
1260     s->host_name = hn;
1261
1262     update_fqdn(s);
1263
1264     register_stuff(s);
1265     return AVAHI_OK;
1266 }
1267
1268 int avahi_server_set_domain_name(AvahiServer *s, const char *domain_name) {
1269     char *dn = NULL;
1270     assert(s);
1271
1272     AVAHI_CHECK_VALIDITY(s, !domain_name || avahi_is_valid_domain_name(domain_name), AVAHI_ERR_INVALID_DOMAIN_NAME);
1273
1274     if (!domain_name)
1275         dn = avahi_strdup("local");
1276     else
1277         dn = avahi_normalize_name_strdup(domain_name);
1278
1279     if (avahi_domain_equal(s->domain_name, domain_name)) {
1280         avahi_free(dn);
1281         return avahi_server_set_errno(s, AVAHI_ERR_NO_CHANGE);
1282     }
1283
1284     withdraw_host_rrs(s);
1285
1286     avahi_free(s->domain_name);
1287     s->domain_name = dn;
1288     update_fqdn(s);
1289
1290     register_stuff(s);
1291
1292     avahi_free(dn);
1293     return AVAHI_OK;
1294 }
1295
1296 static int valid_server_config(const AvahiServerConfig *sc) {
1297     AvahiStringList *l;
1298
1299     assert(sc);
1300
1301     if (sc->n_wide_area_servers > AVAHI_WIDE_AREA_SERVERS_MAX)
1302         return AVAHI_ERR_INVALID_CONFIG;
1303
1304     if (sc->host_name && !avahi_is_valid_host_name(sc->host_name))
1305         return AVAHI_ERR_INVALID_HOST_NAME;
1306
1307     if (sc->domain_name && !avahi_is_valid_domain_name(sc->domain_name))
1308         return AVAHI_ERR_INVALID_DOMAIN_NAME;
1309
1310     for (l = sc->browse_domains; l; l = l->next)
1311         if (!avahi_is_valid_domain_name((char*) l->text))
1312             return AVAHI_ERR_INVALID_DOMAIN_NAME;
1313
1314     return AVAHI_OK;
1315 }
1316
1317 static int setup_sockets(AvahiServer *s) {
1318     assert(s);
1319
1320     s->fd_ipv4 = s->config.use_ipv4 ? avahi_open_socket_ipv4(s->config.disallow_other_stacks) : -1;
1321     s->fd_ipv6 = s->config.use_ipv6 ? avahi_open_socket_ipv6(s->config.disallow_other_stacks) : -1;
1322
1323     if (s->fd_ipv6 < 0 && s->fd_ipv4 < 0)
1324         return AVAHI_ERR_NO_NETWORK;
1325
1326     if (s->fd_ipv4 < 0 && s->config.use_ipv4)
1327         avahi_log_notice("Failed to create IPv4 socket, proceeding in IPv6 only mode");
1328     else if (s->fd_ipv6 < 0 && s->config.use_ipv6)
1329         avahi_log_notice("Failed to create IPv6 socket, proceeding in IPv4 only mode");
1330
1331     s->fd_legacy_unicast_ipv4 = s->fd_ipv4 >= 0 && s->config.enable_reflector ? avahi_open_unicast_socket_ipv4() : -1;
1332     s->fd_legacy_unicast_ipv6 = s->fd_ipv6 >= 0 && s->config.enable_reflector ? avahi_open_unicast_socket_ipv6() : -1;
1333
1334     s->watch_ipv4 =
1335         s->watch_ipv6 =
1336         s->watch_legacy_unicast_ipv4 =
1337         s->watch_legacy_unicast_ipv6 = NULL;
1338
1339     if (s->fd_ipv4 >= 0)
1340         s->watch_ipv4 = s->poll_api->watch_new(s->poll_api, s->fd_ipv4, AVAHI_WATCH_IN, mcast_socket_event, s);
1341     if (s->fd_ipv6 >= 0)
1342         s->watch_ipv6 = s->poll_api->watch_new(s->poll_api, s->fd_ipv6, AVAHI_WATCH_IN, mcast_socket_event, s);
1343
1344     if (s->fd_legacy_unicast_ipv4 >= 0)
1345         s->watch_legacy_unicast_ipv4 = s->poll_api->watch_new(s->poll_api, s->fd_legacy_unicast_ipv4, AVAHI_WATCH_IN, legacy_unicast_socket_event, s);
1346     if (s->fd_legacy_unicast_ipv6 >= 0)
1347         s->watch_legacy_unicast_ipv6 = s->poll_api->watch_new(s->poll_api, s->fd_legacy_unicast_ipv6, AVAHI_WATCH_IN, legacy_unicast_socket_event, s);
1348
1349     return 0;
1350 }
1351
1352 AvahiServer *avahi_server_new(const AvahiPoll *poll_api, const AvahiServerConfig *sc, AvahiServerCallback callback, void* userdata, int *error) {
1353     AvahiServer *s;
1354     int e;
1355
1356     if (sc && (e = valid_server_config(sc)) < 0) {
1357         if (error)
1358             *error = e;
1359         return NULL;
1360     }
1361
1362     if (!(s = avahi_new(AvahiServer, 1))) {
1363         if (error)
1364             *error = AVAHI_ERR_NO_MEMORY;
1365
1366         return NULL;
1367     }
1368
1369     s->poll_api = poll_api;
1370
1371     if (sc)
1372         avahi_server_config_copy(&s->config, sc);
1373     else
1374         avahi_server_config_init(&s->config);
1375
1376     if ((e = setup_sockets(s)) < 0) {
1377         if (error)
1378             *error = e;
1379
1380         avahi_server_config_free(&s->config);
1381         avahi_free(s);
1382
1383         return NULL;
1384     }
1385
1386     s->n_host_rr_pending = 0;
1387     s->need_entry_cleanup = 0;
1388     s->need_group_cleanup = 0;
1389     s->need_browser_cleanup = 0;
1390     s->cleanup_time_event = NULL;
1391     s->hinfo_entry_group = NULL;
1392     s->browse_domain_entry_group = NULL;
1393     s->error = AVAHI_OK;
1394     s->state = AVAHI_SERVER_INVALID;
1395
1396     s->callback = callback;
1397     s->userdata = userdata;
1398
1399     s->time_event_queue = avahi_time_event_queue_new(poll_api);
1400
1401     s->entries_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
1402     AVAHI_LLIST_HEAD_INIT(AvahiEntry, s->entries);
1403     AVAHI_LLIST_HEAD_INIT(AvahiGroup, s->groups);
1404
1405     s->record_browser_hashmap = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL);
1406     AVAHI_LLIST_HEAD_INIT(AvahiSRecordBrowser, s->record_browsers);
1407     AVAHI_LLIST_HEAD_INIT(AvahiSHostNameResolver, s->host_name_resolvers);
1408     AVAHI_LLIST_HEAD_INIT(AvahiSAddressResolver, s->address_resolvers);
1409     AVAHI_LLIST_HEAD_INIT(AvahiSDomainBrowser, s->domain_browsers);
1410     AVAHI_LLIST_HEAD_INIT(AvahiSServiceTypeBrowser, s->service_type_browsers);
1411     AVAHI_LLIST_HEAD_INIT(AvahiSServiceBrowser, s->service_browsers);
1412     AVAHI_LLIST_HEAD_INIT(AvahiSServiceResolver, s->service_resolvers);
1413     AVAHI_LLIST_HEAD_INIT(AvahiSDNSServerBrowser, s->dns_server_browsers);
1414
1415     s->legacy_unicast_reflect_slots = NULL;
1416     s->legacy_unicast_reflect_id = 0;
1417
1418     s->record_list = avahi_record_list_new();
1419
1420     /* Get host name */
1421     s->host_name = s->config.host_name ? avahi_normalize_name_strdup(s->config.host_name) : avahi_get_host_name_strdup();
1422     s->host_name[strcspn(s->host_name, ".")] = 0;
1423     s->domain_name = s->config.domain_name ? avahi_normalize_name_strdup(s->config.domain_name) : avahi_strdup("local");
1424     s->host_name_fqdn = NULL;
1425     update_fqdn(s);
1426
1427     do {
1428         s->local_service_cookie = (uint32_t) rand() * (uint32_t) rand();
1429     } while (s->local_service_cookie == AVAHI_SERVICE_COOKIE_INVALID);
1430
1431     if (s->config.enable_wide_area) {
1432         s->wide_area_lookup_engine = avahi_wide_area_engine_new(s);
1433         avahi_wide_area_set_servers(s->wide_area_lookup_engine, s->config.wide_area_servers, s->config.n_wide_area_servers);
1434     } else
1435         s->wide_area_lookup_engine = NULL;
1436
1437     s->multicast_lookup_engine = avahi_multicast_lookup_engine_new(s);
1438
1439     s->monitor = avahi_interface_monitor_new(s);
1440     avahi_interface_monitor_sync(s->monitor);
1441
1442     register_localhost(s);
1443     register_stuff(s);
1444
1445     return s;
1446 }
1447
1448 void avahi_server_free(AvahiServer* s) {
1449     assert(s);
1450
1451     /* Remove all browsers */
1452
1453     while (s->dns_server_browsers)
1454         avahi_s_dns_server_browser_free(s->dns_server_browsers);
1455     while (s->host_name_resolvers)
1456         avahi_s_host_name_resolver_free(s->host_name_resolvers);
1457     while (s->address_resolvers)
1458         avahi_s_address_resolver_free(s->address_resolvers);
1459     while (s->domain_browsers)
1460         avahi_s_domain_browser_free(s->domain_browsers);
1461     while (s->service_type_browsers)
1462         avahi_s_service_type_browser_free(s->service_type_browsers);
1463     while (s->service_browsers)
1464         avahi_s_service_browser_free(s->service_browsers);
1465     while (s->service_resolvers)
1466         avahi_s_service_resolver_free(s->service_resolvers);
1467     while (s->record_browsers)
1468         avahi_s_record_browser_destroy(s->record_browsers);
1469
1470     /* Remove all locally rgeistered stuff */
1471
1472     while(s->entries)
1473         avahi_entry_free(s, s->entries);
1474
1475     avahi_interface_monitor_free(s->monitor);
1476
1477     while (s->groups)
1478         avahi_entry_group_free(s, s->groups);
1479
1480     free_slots(s);
1481
1482     avahi_hashmap_free(s->entries_by_key);
1483     avahi_record_list_free(s->record_list);
1484     avahi_hashmap_free(s->record_browser_hashmap);
1485
1486     if (s->wide_area_lookup_engine)
1487         avahi_wide_area_engine_free(s->wide_area_lookup_engine);
1488     avahi_multicast_lookup_engine_free(s->multicast_lookup_engine);
1489
1490     if (s->cleanup_time_event)
1491         avahi_time_event_free(s->cleanup_time_event);
1492
1493     avahi_time_event_queue_free(s->time_event_queue);
1494
1495     /* Free watches */
1496
1497     if (s->watch_ipv4)
1498         s->poll_api->watch_free(s->watch_ipv4);
1499     if (s->watch_ipv6)
1500         s->poll_api->watch_free(s->watch_ipv6);
1501
1502     if (s->watch_legacy_unicast_ipv4)
1503         s->poll_api->watch_free(s->watch_legacy_unicast_ipv4);
1504     if (s->watch_legacy_unicast_ipv6)
1505         s->poll_api->watch_free(s->watch_legacy_unicast_ipv6);
1506
1507     /* Free sockets */
1508
1509     if (s->fd_ipv4 >= 0)
1510         close(s->fd_ipv4);
1511     if (s->fd_ipv6 >= 0)
1512         close(s->fd_ipv6);
1513
1514     if (s->fd_legacy_unicast_ipv4 >= 0)
1515         close(s->fd_legacy_unicast_ipv4);
1516     if (s->fd_legacy_unicast_ipv6 >= 0)
1517         close(s->fd_legacy_unicast_ipv6);
1518
1519     /* Free other stuff */
1520
1521     avahi_free(s->host_name);
1522     avahi_free(s->domain_name);
1523     avahi_free(s->host_name_fqdn);
1524
1525     avahi_server_config_free(&s->config);
1526
1527     avahi_free(s);
1528 }
1529
1530 const char* avahi_server_get_domain_name(AvahiServer *s) {
1531     assert(s);
1532
1533     return s->domain_name;
1534 }
1535
1536 const char* avahi_server_get_host_name(AvahiServer *s) {
1537     assert(s);
1538
1539     return s->host_name;
1540 }
1541
1542 const char* avahi_server_get_host_name_fqdn(AvahiServer *s) {
1543     assert(s);
1544
1545     return s->host_name_fqdn;
1546 }
1547
1548 void* avahi_server_get_data(AvahiServer *s) {
1549     assert(s);
1550
1551     return s->userdata;
1552 }
1553
1554 void avahi_server_set_data(AvahiServer *s, void* userdata) {
1555     assert(s);
1556
1557     s->userdata = userdata;
1558 }
1559
1560 AvahiServerState avahi_server_get_state(AvahiServer *s) {
1561     assert(s);
1562
1563     return s->state;
1564 }
1565
1566 AvahiServerConfig* avahi_server_config_init(AvahiServerConfig *c) {
1567     assert(c);
1568
1569     memset(c, 0, sizeof(AvahiServerConfig));
1570     c->use_ipv6 = 1;
1571     c->use_ipv4 = 1;
1572     c->allow_interfaces = NULL;
1573     c->deny_interfaces = NULL;
1574     c->host_name = NULL;
1575     c->domain_name = NULL;
1576     c->check_response_ttl = 0;
1577     c->publish_hinfo = 1;
1578     c->publish_addresses = 1;
1579     c->publish_workstation = 1;
1580     c->publish_domain = 1;
1581     c->use_iff_running = 0;
1582     c->enable_reflector = 0;
1583     c->reflect_ipv = 0;
1584     c->add_service_cookie = 0;
1585     c->enable_wide_area = 0;
1586     c->n_wide_area_servers = 0;
1587     c->disallow_other_stacks = 0;
1588     c->browse_domains = NULL;
1589     c->disable_publishing = 0;
1590     c->allow_point_to_point = 0;
1591     c->publish_aaaa_on_ipv4 = 1;
1592     c->publish_a_on_ipv6 = 0;
1593     c->n_cache_entries_max = AVAHI_DEFAULT_CACHE_ENTRIES_MAX;
1594     c->ratelimit_interval = 0;
1595     c->ratelimit_burst = 0;
1596
1597     return c;
1598 }
1599
1600 void avahi_server_config_free(AvahiServerConfig *c) {
1601     assert(c);
1602
1603     avahi_free(c->host_name);
1604     avahi_free(c->domain_name);
1605     avahi_string_list_free(c->browse_domains);
1606     avahi_string_list_free(c->allow_interfaces);
1607     avahi_string_list_free(c->deny_interfaces);
1608 }
1609
1610 AvahiServerConfig* avahi_server_config_copy(AvahiServerConfig *ret, const AvahiServerConfig *c) {
1611     char *d = NULL, *h = NULL;
1612     AvahiStringList *browse = NULL, *allow = NULL, *deny = NULL;
1613     assert(ret);
1614     assert(c);
1615
1616     if (c->host_name)
1617         if (!(h = avahi_strdup(c->host_name)))
1618             return NULL;
1619
1620     if (c->domain_name)
1621         if (!(d = avahi_strdup(c->domain_name))) {
1622             avahi_free(h);
1623             return NULL;
1624         }
1625
1626     if (!(browse = avahi_string_list_copy(c->browse_domains)) && c->browse_domains) {
1627         avahi_free(h);
1628         avahi_free(d);
1629         return NULL;
1630     }
1631
1632     if (!(allow = avahi_string_list_copy(c->allow_interfaces)) && c->allow_interfaces) {
1633         avahi_string_list_free(browse);
1634         avahi_free(h);
1635         avahi_free(d);
1636         return NULL;
1637     }
1638
1639     if (!(deny = avahi_string_list_copy(c->deny_interfaces)) && c->deny_interfaces) {
1640         avahi_string_list_free(allow);
1641         avahi_string_list_free(browse);
1642         avahi_free(h);
1643         avahi_free(d);
1644         return NULL;
1645     }
1646
1647     *ret = *c;
1648     ret->host_name = h;
1649     ret->domain_name = d;
1650     ret->browse_domains = browse;
1651     ret->allow_interfaces = allow;
1652     ret->deny_interfaces = deny;
1653
1654     return ret;
1655 }
1656
1657 int avahi_server_errno(AvahiServer *s) {
1658     assert(s);
1659
1660     return s->error;
1661 }
1662
1663 /* Just for internal use */
1664 int avahi_server_set_errno(AvahiServer *s, int error) {
1665     assert(s);
1666
1667     return s->error = error;
1668 }
1669
1670 uint32_t avahi_server_get_local_service_cookie(AvahiServer *s) {
1671     assert(s);
1672
1673     return s->local_service_cookie;
1674 }
1675
1676 static AvahiEntry *find_entry(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, AvahiKey *key) {
1677     AvahiEntry *e;
1678
1679     assert(s);
1680     assert(key);
1681
1682     for (e = avahi_hashmap_lookup(s->entries_by_key, key); e; e = e->by_key_next)
1683
1684         if ((e->interface == interface || e->interface <= 0 || interface <= 0) &&
1685             (e->protocol == protocol || e->protocol == AVAHI_PROTO_UNSPEC || protocol == AVAHI_PROTO_UNSPEC) &&
1686             (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED || e->group->state == AVAHI_ENTRY_GROUP_REGISTERING))
1687
1688             return e;
1689
1690     return NULL;
1691 }
1692
1693 int avahi_server_get_group_of_service(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, const char *name, const char *type, const char *domain, AvahiSEntryGroup** ret_group) {
1694     AvahiKey *key = NULL;
1695     AvahiEntry *e;
1696     int ret;
1697     char n[AVAHI_DOMAIN_NAME_MAX];
1698
1699     assert(s);
1700     assert(name);
1701     assert(type);
1702     assert(ret_group);
1703
1704     AVAHI_CHECK_VALIDITY(s, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
1705     AVAHI_CHECK_VALIDITY(s, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
1706     AVAHI_CHECK_VALIDITY(s, avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME);
1707     AVAHI_CHECK_VALIDITY(s, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE);
1708     AVAHI_CHECK_VALIDITY(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
1709
1710     if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain) < 0))
1711         return avahi_server_set_errno(s, ret);
1712
1713     if (!(key = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV)))
1714         return avahi_server_set_errno(s, AVAHI_ERR_NO_MEMORY);
1715
1716     e = find_entry(s, interface, protocol, key);
1717     avahi_key_unref(key);
1718
1719     if (e) {
1720         *ret_group = e->group;
1721         return AVAHI_OK;
1722     }
1723
1724     return avahi_server_set_errno(s, AVAHI_ERR_NOT_FOUND);
1725 }
1726
1727 int avahi_server_is_service_local(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, const char *name) {
1728     AvahiKey *key = NULL;
1729     AvahiEntry *e;
1730
1731     assert(s);
1732     assert(name);
1733
1734     if (!s->host_name_fqdn)
1735         return 0;
1736
1737     if (!(key = avahi_key_new(name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV)))
1738         return 0;
1739
1740     e = find_entry(s, interface, protocol, key);
1741     avahi_key_unref(key);
1742
1743     if (!e)
1744         return 0;
1745
1746     return avahi_domain_equal(s->host_name_fqdn, e->record->data.srv.name);
1747 }
1748
1749 int avahi_server_is_record_local(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, AvahiRecord *record) {
1750     AvahiEntry *e;
1751
1752     assert(s);
1753     assert(record);
1754
1755     for (e = avahi_hashmap_lookup(s->entries_by_key, record->key); e; e = e->by_key_next)
1756
1757         if ((e->interface == interface || e->interface <= 0 || interface <= 0) &&
1758             (e->protocol == protocol || e->protocol == AVAHI_PROTO_UNSPEC || protocol == AVAHI_PROTO_UNSPEC) &&
1759             (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED || e->group->state == AVAHI_ENTRY_GROUP_REGISTERING) &&
1760             avahi_record_equal_no_ttl(record, e->record))
1761             return 1;
1762
1763     return 0;
1764 }
1765
1766 /** Set the wide area DNS servers */
1767 int avahi_server_set_wide_area_servers(AvahiServer *s, const AvahiAddress *a, unsigned n) {
1768     assert(s);
1769
1770     if (!s->wide_area_lookup_engine)
1771         return avahi_server_set_errno(s, AVAHI_ERR_INVALID_CONFIG);
1772
1773     avahi_wide_area_set_servers(s->wide_area_lookup_engine, a, n);
1774     return AVAHI_OK;
1775 }
1776
1777 const AvahiServerConfig* avahi_server_get_config(AvahiServer *s) {
1778     assert(s);
1779
1780     return &s->config;
1781 }
1782
1783 /** Set the browsing domains */
1784 int avahi_server_set_browse_domains(AvahiServer *s, AvahiStringList *domains) {
1785     AvahiStringList *l;
1786
1787     assert(s);
1788
1789     for (l = s->config.browse_domains; l; l = l->next)
1790         if (!avahi_is_valid_domain_name((char*) l->text))
1791             return avahi_server_set_errno(s, AVAHI_ERR_INVALID_DOMAIN_NAME);
1792
1793     avahi_string_list_free(s->config.browse_domains);
1794     s->config.browse_domains = avahi_string_list_copy(domains);
1795
1796     return AVAHI_OK;
1797 }