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/avahi-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 AvahiRecord* r; 517 518 assert(c); 519 assert(pattern); 520 assert(e); 521 assert(s); 522 523 /* Don't reflect cache entry with ipv6 link-local addresses. */ 524 r = e->record; 525 if ((r->key->type == AVAHI_DNS_TYPE_AAAA) && 526 (r->data.aaaa.address.address[0] == 0xFE) && 527 (r->data.aaaa.address.address[1] == 0x80)) 528 return NULL; 529 530 avahi_record_list_push(s->record_list, e->record, e->cache_flush, 0, 0); 531 return NULL; 532 } 533 534 static void reflect_query(AvahiServer *s, AvahiInterface *i, AvahiKey *k) { 535 AvahiInterface *j; 536 537 assert(s); 538 assert(i); 539 assert(k); 540 541 if (!s->config.enable_reflector) 542 return; 543 544 for (j = s->monitor->interfaces; j; j = j->interface_next) 545 if (j != i && (s->config.reflect_ipv || j->protocol == i->protocol)) { 546 /* Post the query to other networks */ 547 avahi_interface_post_query(j, k, 1, NULL); 548 549 /* Reply from caches of other network. This is needed to 550 * "work around" known answer suppression. */ 551 552 avahi_cache_walk(j->cache, k, reflect_cache_walk_callback, s); 553 } 554 } 555 556 static void reflect_probe(AvahiServer *s, AvahiInterface *i, AvahiRecord *r) { 557 AvahiInterface *j; 558 559 assert(s); 560 assert(i); 561 assert(r); 562 563 if (!s->config.enable_reflector) 564 return; 565 566 for (j = s->monitor->interfaces; j; j = j->interface_next) 567 if (j != i && (s->config.reflect_ipv || j->protocol == i->protocol)) 568 avahi_interface_post_probe(j, r, 1); 569 } 570 571 static void handle_query_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, uint16_t port, int legacy_unicast, int from_local_iface) { 572 size_t n; 573 int is_probe; 574 575 assert(s); 576 assert(p); 577 assert(i); 578 assert(a); 579 580 assert(avahi_record_list_is_empty(s->record_list)); 581 582 is_probe = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) > 0; 583 584 /* Handle the questions */ 585 for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); n > 0; n --) { 586 AvahiKey *key; 587 int unicast_response = 0; 588 589 if (!(key = avahi_dns_packet_consume_key(p, &unicast_response))) { 590 avahi_log_warn(__FILE__": Packet too short or invalid while reading question key. (Maybe a UTF-8 problem?)"); 591 goto fail; 592 } 593 594 if (!legacy_unicast && !from_local_iface) { 595 reflect_query(s, i, key); 596 if (!unicast_response) 597 avahi_cache_start_poof(i->cache, key, a); 598 } 599 600 if (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0 && 601 !(avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & AVAHI_DNS_FLAG_TC)) 602 /* Allow our own queries to be suppressed by incoming 603 * queries only when they do not include known answers */ 604 avahi_query_scheduler_incoming(i->query_scheduler, key); 605 606 avahi_server_prepare_matching_responses(s, i, key, unicast_response); 607 avahi_key_unref(key); 608 } 609 610 if (!legacy_unicast) { 611 612 /* Known Answer Suppression */ 613 for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT); n > 0; n --) { 614 AvahiRecord *record; 615 int unique = 0; 616 617 if (!(record = avahi_dns_packet_consume_record(p, &unique))) { 618 avahi_log_warn(__FILE__": Packet too short or invalid while reading known answer record. (Maybe a UTF-8 problem?)"); 619 goto fail; 620 } 621 622 avahi_response_scheduler_suppress(i->response_scheduler, record, a); 623 avahi_record_list_drop(s->record_list, record); 624 avahi_cache_stop_poof(i->cache, record, a); 625 626 avahi_record_unref(record); 627 } 628 629 /* Probe record */ 630 for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT); n > 0; n --) { 631 AvahiRecord *record; 632 int unique = 0; 633 634 if (!(record = avahi_dns_packet_consume_record(p, &unique))) { 635 avahi_log_warn(__FILE__": Packet too short or invalid while reading probe record. (Maybe a UTF-8 problem?)"); 636 goto fail; 637 } 638 639 if (!avahi_key_is_pattern(record->key)) { 640 if (!from_local_iface) 641 reflect_probe(s, i, record); 642 incoming_probe(s, record, i); 643 } 644 645 avahi_record_unref(record); 646 } 647 } 648 649 if (!avahi_record_list_is_empty(s->record_list)) 650 avahi_server_generate_response(s, i, p, a, port, legacy_unicast, is_probe); 651 652 return; 653 654 fail: 655 avahi_record_list_flush(s->record_list); 656 } 657 658 static void handle_response_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, int from_local_iface) { 659 unsigned n; 660 661 assert(s); 662 assert(p); 663 assert(i); 664 assert(a); 665 666 for (n = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) + 667 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ARCOUNT); n > 0; n--) { 668 AvahiRecord *record; 669 int cache_flush = 0; 670 671 if (!(record = avahi_dns_packet_consume_record(p, &cache_flush))) { 672 avahi_log_warn(__FILE__": Packet too short or invalid while reading response record. (Maybe a UTF-8 problem?)"); 673 break; 674 } 675 676 if (!avahi_key_is_pattern(record->key)) { 677 678 if (handle_conflict(s, i, record, cache_flush)) { 679 if (!from_local_iface && !avahi_record_is_link_local_address(record)) 680 reflect_response(s, i, record, cache_flush); 681 avahi_cache_update(i->cache, record, cache_flush, a); 682 avahi_response_scheduler_incoming(i->response_scheduler, record, cache_flush); 683 } 684 } 685 686 avahi_record_unref(record); 687 } 688 689 /* If the incoming response contained a conflicting record, some 690 records have been scheduled for sending. We need to flush them 691 here. */ 692 if (!avahi_record_list_is_empty(s->record_list)) 693 avahi_server_generate_response(s, i, NULL, NULL, 0, 0, 1); 694 } 695 696 static AvahiLegacyUnicastReflectSlot* allocate_slot(AvahiServer *s) { 697 unsigned n, idx = (unsigned) -1; 698 AvahiLegacyUnicastReflectSlot *slot; 699 700 assert(s); 701 702 if (!s->legacy_unicast_reflect_slots) 703 s->legacy_unicast_reflect_slots = avahi_new0(AvahiLegacyUnicastReflectSlot*, AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX); 704 705 for (n = 0; n < AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; n++, s->legacy_unicast_reflect_id++) { 706 idx = s->legacy_unicast_reflect_id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; 707 708 if (!s->legacy_unicast_reflect_slots[idx]) 709 break; 710 } 711 712 if (idx == (unsigned) -1 || s->legacy_unicast_reflect_slots[idx]) 713 return NULL; 714 715 if (!(slot = avahi_new(AvahiLegacyUnicastReflectSlot, 1))) 716 return NULL; /* OOM */ 717 718 s->legacy_unicast_reflect_slots[idx] = slot; 719 slot->id = s->legacy_unicast_reflect_id++; 720 slot->server = s; 721 722 return slot; 723 } 724 725 static void deallocate_slot(AvahiServer *s, AvahiLegacyUnicastReflectSlot *slot) { 726 unsigned idx; 727 728 assert(s); 729 assert(slot); 730 731 idx = slot->id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; 732 733 assert(s->legacy_unicast_reflect_slots[idx] == slot); 734 735 avahi_time_event_free(slot->time_event); 736 737 avahi_free(slot); 738 s->legacy_unicast_reflect_slots[idx] = NULL; 739 } 740 741 static void free_slots(AvahiServer *s) { 742 unsigned idx; 743 assert(s); 744 745 if (!s->legacy_unicast_reflect_slots) 746 return; 747 748 for (idx = 0; idx < AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; idx ++) 749 if (s->legacy_unicast_reflect_slots[idx]) 750 deallocate_slot(s, s->legacy_unicast_reflect_slots[idx]); 751 752 avahi_free(s->legacy_unicast_reflect_slots); 753 s->legacy_unicast_reflect_slots = NULL; 754 } 755 756 static AvahiLegacyUnicastReflectSlot* find_slot(AvahiServer *s, uint16_t id) { 757 unsigned idx; 758 759 assert(s); 760 761 if (!s->legacy_unicast_reflect_slots) 762 return NULL; 763 764 idx = id % AVAHI_LEGACY_UNICAST_REFLECT_SLOTS_MAX; 765 766 if (!s->legacy_unicast_reflect_slots[idx] || s->legacy_unicast_reflect_slots[idx]->id != id) 767 return NULL; 768 769 return s->legacy_unicast_reflect_slots[idx]; 770 } 771 772 static void legacy_unicast_reflect_slot_timeout(AvahiTimeEvent *e, void *userdata) { 773 AvahiLegacyUnicastReflectSlot *slot = userdata; 774 775 assert(e); 776 assert(slot); 777 assert(slot->time_event == e); 778 779 deallocate_slot(slot->server, slot); 780 } 781 782 static void reflect_legacy_unicast_query_packet(AvahiServer *s, AvahiDnsPacket *p, AvahiInterface *i, const AvahiAddress *a, uint16_t port) { 783 AvahiLegacyUnicastReflectSlot *slot; 784 AvahiInterface *j; 785 786 assert(s); 787 assert(p); 788 assert(i); 789 assert(a); 790 assert(port > 0); 791 assert(i->protocol == a->proto); 792 793 if (!s->config.enable_reflector) 794 return; 795 796 /* Reflecting legacy unicast queries is a little more complicated 797 than reflecting normal queries, since we must route the 798 responses back to the right client. Therefore we must store 799 some information for finding the right client contact data for 800 response packets. In contrast to normal queries legacy 801 unicast query and response packets are reflected untouched and 802 are not reassembled into larger packets */ 803 804 if (!(slot = allocate_slot(s))) { 805 /* No slot available, we drop this legacy unicast query */ 806 avahi_log_warn("No slot available for legacy unicast reflection, dropping query packet."); 807 return; 808 } 809 810 slot->original_id = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID); 811 slot->address = *a; 812 slot->port = port; 813 slot->interface = i->hardware->index; 814 815 avahi_elapse_time(&slot->elapse_time, 2000, 0); 816 slot->time_event = avahi_time_event_new(s->time_event_queue, &slot->elapse_time, legacy_unicast_reflect_slot_timeout, slot); 817 818 /* Patch the packet with our new locally generatet id */ 819 avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->id); 820 821 for (j = s->monitor->interfaces; j; j = j->interface_next) 822 if (j->announcing && 823 j != i && 824 (s->config.reflect_ipv || j->protocol == i->protocol)) { 825 826 if (j->protocol == AVAHI_PROTO_INET && s->fd_legacy_unicast_ipv4 >= 0) { 827 avahi_send_dns_packet_ipv4(s->fd_legacy_unicast_ipv4, j->hardware->index, p, NULL, NULL, 0); 828 } else if (j->protocol == AVAHI_PROTO_INET6 && s->fd_legacy_unicast_ipv6 >= 0) 829 avahi_send_dns_packet_ipv6(s->fd_legacy_unicast_ipv6, j->hardware->index, p, NULL, NULL, 0); 830 } 831 832 /* Reset the id */ 833 avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->original_id); 834 } 835 836 static int originates_from_local_legacy_unicast_socket(AvahiServer *s, const AvahiAddress *address, uint16_t port) { 837 assert(s); 838 assert(address); 839 assert(port > 0); 840 841 if (!s->config.enable_reflector) 842 return 0; 843 844 if (!avahi_address_is_local(s->monitor, address)) 845 return 0; 846 847 if (address->proto == AVAHI_PROTO_INET && s->fd_legacy_unicast_ipv4 >= 0) { 848 struct sockaddr_in lsa; 849 socklen_t l = sizeof(lsa); 850 851 if (getsockname(s->fd_legacy_unicast_ipv4, (struct sockaddr*) &lsa, &l) != 0) 852 avahi_log_warn("getsockname(): %s", strerror(errno)); 853 else 854 return avahi_port_from_sockaddr((struct sockaddr*) &lsa) == port; 855 856 } 857 858 if (address->proto == AVAHI_PROTO_INET6 && s->fd_legacy_unicast_ipv6 >= 0) { 859 struct sockaddr_in6 lsa; 860 socklen_t l = sizeof(lsa); 861 862 if (getsockname(s->fd_legacy_unicast_ipv6, (struct sockaddr*) &lsa, &l) != 0) 863 avahi_log_warn("getsockname(): %s", strerror(errno)); 864 else 865 return avahi_port_from_sockaddr((struct sockaddr*) &lsa) == port; 866 } 867 868 return 0; 869 } 870 871 static int is_mdns_mcast_address(const AvahiAddress *a) { 872 AvahiAddress b; 873 assert(a); 874 875 avahi_address_parse(a->proto == AVAHI_PROTO_INET ? AVAHI_IPV4_MCAST_GROUP : AVAHI_IPV6_MCAST_GROUP, a->proto, &b); 876 return avahi_address_cmp(a, &b) == 0; 877 } 878 879 static int originates_from_local_iface(AvahiServer *s, AvahiIfIndex iface, const AvahiAddress *a, uint16_t port) { 880 assert(s); 881 assert(iface != AVAHI_IF_UNSPEC); 882 assert(a); 883 884 /* If it isn't the MDNS port it can't be generated by us */ 885 if (port != AVAHI_MDNS_PORT) 886 return 0; 887 888 return avahi_interface_has_address(s->monitor, iface, a); 889 } 890 891 static void dispatch_packet(AvahiServer *s, AvahiDnsPacket *p, const AvahiAddress *src_address, uint16_t port, const AvahiAddress *dst_address, AvahiIfIndex iface, int ttl) { 892 AvahiInterface *i; 893 int from_local_iface = 0; 894 895 assert(s); 896 assert(p); 897 assert(src_address); 898 assert(dst_address); 899 assert(iface > 0); 900 assert(src_address->proto == dst_address->proto); 901 902 if (!(i = avahi_interface_monitor_get_interface(s->monitor, iface, src_address->proto)) || 903 !i->announcing) { 904 avahi_log_warn("Received packet from invalid interface."); 905 return; 906 } 907 908 if (port <= 0) { 909 /* This fixes RHBZ #475394 */ 910 avahi_log_warn("Received packet from invalid source port %u.", (unsigned) port); 911 return; 912 } 913 914 if (avahi_address_is_ipv4_in_ipv6(src_address)) 915 /* This is an IPv4 address encapsulated in IPv6, so let's ignore it. */ 916 return; 917 918 if (originates_from_local_legacy_unicast_socket(s, src_address, port)) 919 /* This originates from our local reflector, so let's ignore it */ 920 return; 921 922 /* We don't want to reflect local traffic, so we check if this packet is generated locally. */ 923 if (s->config.enable_reflector) 924 from_local_iface = originates_from_local_iface(s, iface, src_address, port); 925 926 if (avahi_dns_packet_check_valid_multicast(p) < 0) { 927 avahi_log_warn("Received invalid packet."); 928 return; 929 } 930 931 if (avahi_dns_packet_is_query(p)) { 932 int legacy_unicast = 0; 933 934 /* For queries EDNS0 might allow ARCOUNT != 0. We ignore the 935 * AR section completely here, so far. Until the day we add 936 * EDNS0 support. */ 937 938 if (port != AVAHI_MDNS_PORT) { 939 /* Legacy Unicast */ 940 941 if ((avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) != 0 || 942 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) != 0)) { 943 avahi_log_warn("Invalid legacy unicast query packet."); 944 return; 945 } 946 947 legacy_unicast = 1; 948 } 949 950 if (legacy_unicast) 951 reflect_legacy_unicast_query_packet(s, p, i, src_address, port); 952 953 handle_query_packet(s, p, i, src_address, port, legacy_unicast, from_local_iface); 954 955 } else { 956 char t[AVAHI_ADDRESS_STR_MAX]; 957 958 if (port != AVAHI_MDNS_PORT) { 959 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); 960 return; 961 } 962 963 if (ttl != 255 && s->config.check_response_ttl) { 964 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); 965 return; 966 } 967 968 if (!is_mdns_mcast_address(dst_address) && 969 !avahi_interface_address_on_link(i, src_address)) { 970 971 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); 972 return; 973 } 974 975 if (avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT) != 0 || 976 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0 || 977 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) != 0) { 978 979 avahi_log_warn("Invalid response packet from host %s.", avahi_address_snprint(t, sizeof(t), src_address)); 980 return; 981 } 982 983 handle_response_packet(s, p, i, src_address, from_local_iface); 984 } 985 } 986 987 static void dispatch_legacy_unicast_packet(AvahiServer *s, AvahiDnsPacket *p) { 988 AvahiInterface *j; 989 AvahiLegacyUnicastReflectSlot *slot; 990 991 assert(s); 992 assert(p); 993 994 if (avahi_dns_packet_check_valid(p) < 0 || avahi_dns_packet_is_query(p)) { 995 avahi_log_warn("Received invalid packet."); 996 return; 997 } 998 999 if (!(slot = find_slot(s, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID)))) { 1000 avahi_log_warn("Received legacy unicast response with unknown id"); 1001 return; 1002 } 1003 1004 if (!(j = avahi_interface_monitor_get_interface(s->monitor, slot->interface, slot->address.proto)) || 1005 !j->announcing) 1006 return; 1007 1008 /* Patch the original ID into this response */ 1009 avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->original_id); 1010 1011 /* Forward the response to the correct client */ 1012 avahi_interface_send_packet_unicast(j, p, &slot->address, slot->port); 1013 1014 /* Undo changes to packet */ 1015 avahi_dns_packet_set_field(p, AVAHI_DNS_FIELD_ID, slot->id); 1016 } 1017 1018 static void mcast_socket_event(AvahiWatch *w, int fd, AvahiWatchEvent events, void *userdata) { 1019 AvahiServer *s = userdata; 1020 AvahiAddress dest, src; 1021 AvahiDnsPacket *p = NULL; 1022 AvahiIfIndex iface; 1023 uint16_t port; 1024 uint8_t ttl; 1025 1026 assert(w); 1027 assert(fd >= 0); 1028 assert(events & AVAHI_WATCH_IN); 1029 1030 if (fd == s->fd_ipv4) { 1031 dest.proto = src.proto = AVAHI_PROTO_INET; 1032 p = avahi_recv_dns_packet_ipv4(s->fd_ipv4, &src.data.ipv4, &port, &dest.data.ipv4, &iface, &ttl); 1033 } else { 1034 assert(fd == s->fd_ipv6); 1035 dest.proto = src.proto = AVAHI_PROTO_INET6; 1036 p = avahi_recv_dns_packet_ipv6(s->fd_ipv6, &src.data.ipv6, &port, &dest.data.ipv6, &iface, &ttl); 1037 } 1038 1039 if (p) { 1040 if (iface == AVAHI_IF_UNSPEC) 1041 iface = avahi_find_interface_for_address(s->monitor, &dest); 1042 1043 if (iface != AVAHI_IF_UNSPEC) 1044 dispatch_packet(s, p, &src, port, &dest, iface, ttl); 1045 else 1046 avahi_log_error("Incoming packet received on address that isn't local."); 1047 1048 avahi_dns_packet_free(p); 1049 1050 avahi_cleanup_dead_entries(s); 1051 } 1052 } 1053 1054 static void legacy_unicast_socket_event(AvahiWatch *w, int fd, AvahiWatchEvent events, void *userdata) { 1055 AvahiServer *s = userdata; 1056 AvahiDnsPacket *p = NULL; 1057 1058 assert(w); 1059 assert(fd >= 0); 1060 assert(events & AVAHI_WATCH_IN); 1061 1062 if (fd == s->fd_legacy_unicast_ipv4) 1063 p = avahi_recv_dns_packet_ipv4(s->fd_legacy_unicast_ipv4, NULL, NULL, NULL, NULL, NULL); 1064 else { 1065 assert(fd == s->fd_legacy_unicast_ipv6); 1066 p = avahi_recv_dns_packet_ipv6(s->fd_legacy_unicast_ipv6, NULL, NULL, NULL, NULL, NULL); 1067 } 1068 1069 if (p) { 1070 dispatch_legacy_unicast_packet(s, p); 1071 avahi_dns_packet_free(p); 1072 1073 avahi_cleanup_dead_entries(s); 1074 } 1075 } 1076 1077 static void server_set_state(AvahiServer *s, AvahiServerState state) { 1078 assert(s); 1079 1080 if (s->state == state) 1081 return; 1082 1083 s->state = state; 1084 1085 avahi_interface_monitor_update_rrs(s->monitor, 0); 1086 1087 if (s->callback) 1088 s->callback(s, state, s->userdata); 1089 } 1090 1091 static void withdraw_host_rrs(AvahiServer *s) { 1092 assert(s); 1093 1094 if (s->hinfo_entry_group) 1095 avahi_s_entry_group_reset(s->hinfo_entry_group); 1096 1097 if (s->browse_domain_entry_group) 1098 avahi_s_entry_group_reset(s->browse_domain_entry_group); 1099 1100 avahi_interface_monitor_update_rrs(s->monitor, 1); 1101 s->n_host_rr_pending = 0; 1102 } 1103 1104 void avahi_server_decrease_host_rr_pending(AvahiServer *s) { 1105 assert(s); 1106 1107 assert(s->n_host_rr_pending > 0); 1108 1109 if (--s->n_host_rr_pending == 0) 1110 server_set_state(s, AVAHI_SERVER_RUNNING); 1111 } 1112 1113 void avahi_host_rr_entry_group_callback(AvahiServer *s, AvahiSEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) { 1114 assert(s); 1115 assert(g); 1116 1117 if (state == AVAHI_ENTRY_GROUP_REGISTERING && 1118 s->state == AVAHI_SERVER_REGISTERING) 1119 s->n_host_rr_pending ++; 1120 1121 else if (state == AVAHI_ENTRY_GROUP_COLLISION && 1122 (s->state == AVAHI_SERVER_REGISTERING || s->state == AVAHI_SERVER_RUNNING)) { 1123 withdraw_host_rrs(s); 1124 server_set_state(s, AVAHI_SERVER_COLLISION); 1125 1126 } else if (state == AVAHI_ENTRY_GROUP_ESTABLISHED && 1127 s->state == AVAHI_SERVER_REGISTERING) 1128 avahi_server_decrease_host_rr_pending(s); 1129 } 1130 1131 static void register_hinfo(AvahiServer *s) { 1132 struct utsname utsname; 1133 AvahiRecord *r; 1134 1135 assert(s); 1136 1137 if (!s->config.publish_hinfo) 1138 return; 1139 1140 if (s->hinfo_entry_group) 1141 assert(avahi_s_entry_group_is_empty(s->hinfo_entry_group)); 1142 else 1143 s->hinfo_entry_group = avahi_s_entry_group_new(s, avahi_host_rr_entry_group_callback, NULL); 1144 1145 if (!s->hinfo_entry_group) { 1146 avahi_log_warn("Failed to create HINFO entry group: %s", avahi_strerror(s->error)); 1147 return; 1148 } 1149 1150 /* Fill in HINFO rr */ 1151 if ((r = avahi_record_new_full(s->host_name_fqdn, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_HINFO, AVAHI_DEFAULT_TTL_HOST_NAME))) { 1152 1153 if (uname(&utsname) < 0) 1154 avahi_log_warn("uname() failed: %s\n", avahi_strerror(errno)); 1155 else { 1156 1157 r->data.hinfo.cpu = avahi_strdup(avahi_strup(utsname.machine)); 1158 r->data.hinfo.os = avahi_strdup(avahi_strup(utsname.sysname)); 1159 1160 avahi_log_info("Registering HINFO record with values '%s'/'%s'.", r->data.hinfo.cpu, r->data.hinfo.os); 1161 1162 if (avahi_server_add(s, s->hinfo_entry_group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_UNIQUE, r) < 0) { 1163 avahi_log_warn("Failed to add HINFO RR: %s", avahi_strerror(s->error)); 1164 return; 1165 } 1166 } 1167 1168 avahi_record_unref(r); 1169 } 1170 1171 if (avahi_s_entry_group_commit(s->hinfo_entry_group) < 0) 1172 avahi_log_warn("Failed to commit HINFO entry group: %s", avahi_strerror(s->error)); 1173 1174 } 1175 1176 static void register_localhost(AvahiServer *s) { 1177 AvahiAddress a; 1178 assert(s); 1179 1180 /* Add localhost entries */ 1181 avahi_address_parse("127.0.0.1", AVAHI_PROTO_INET, &a); 1182 avahi_server_add_address(s, NULL, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_NO_PROBE|AVAHI_PUBLISH_NO_ANNOUNCE, "localhost", &a); 1183 1184 avahi_address_parse("::1", AVAHI_PROTO_INET6, &a); 1185 avahi_server_add_address(s, NULL, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_PUBLISH_NO_PROBE|AVAHI_PUBLISH_NO_ANNOUNCE, "ip6-localhost", &a); 1186 } 1187 1188 static void register_browse_domain(AvahiServer *s) { 1189 assert(s); 1190 1191 if (!s->config.publish_domain) 1192 return; 1193 1194 if (avahi_domain_equal(s->domain_name, "local")) 1195 return; 1196 1197 if (s->browse_domain_entry_group) 1198 assert(avahi_s_entry_group_is_empty(s->browse_domain_entry_group)); 1199 else 1200 s->browse_domain_entry_group = avahi_s_entry_group_new(s, NULL, NULL); 1201 1202 if (!s->browse_domain_entry_group) { 1203 avahi_log_warn("Failed to create browse domain entry group: %s", avahi_strerror(s->error)); 1204 return; 1205 } 1206 1207 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) { 1208 avahi_log_warn("Failed to add browse domain RR: %s", avahi_strerror(s->error)); 1209 return; 1210 } 1211 1212 if (avahi_s_entry_group_commit(s->browse_domain_entry_group) < 0) 1213 avahi_log_warn("Failed to commit browse domain entry group: %s", avahi_strerror(s->error)); 1214 } 1215 1216 static void register_stuff(AvahiServer *s) { 1217 assert(s); 1218 1219 server_set_state(s, AVAHI_SERVER_REGISTERING); 1220 s->n_host_rr_pending ++; /** Make sure that the state isn't changed tp AVAHI_SERVER_RUNNING too early */ 1221 1222 register_hinfo(s); 1223 register_browse_domain(s); 1224 avahi_interface_monitor_update_rrs(s->monitor, 0); 1225 1226 assert(s->n_host_rr_pending > 0); 1227 s->n_host_rr_pending --; 1228 1229 if (s->n_host_rr_pending == 0) 1230 server_set_state(s, AVAHI_SERVER_RUNNING); 1231 } 1232 1233 static void update_fqdn(AvahiServer *s) { 1234 char *n; 1235 1236 assert(s); 1237 assert(s->host_name); 1238 assert(s->domain_name); 1239 1240 if (!(n = avahi_strdup_printf("%s.%s", s->host_name, s->domain_name))) 1241 return; /* OOM */ 1242 1243 avahi_free(s->host_name_fqdn); 1244 s->host_name_fqdn = n; 1245 } 1246 1247 int avahi_server_set_host_name(AvahiServer *s, const char *host_name) { 1248 char *hn = NULL; 1249 assert(s); 1250 1251 AVAHI_CHECK_VALIDITY(s, !host_name || avahi_is_valid_host_name(host_name), AVAHI_ERR_INVALID_HOST_NAME); 1252 1253 if (!host_name) 1254 hn = avahi_get_host_name_strdup(); 1255 else 1256 hn = avahi_normalize_name_strdup(host_name); 1257 1258 hn[strcspn(hn, ".")] = 0; 1259 1260 if (avahi_domain_equal(s->host_name, hn) && s->state != AVAHI_SERVER_COLLISION) { 1261 avahi_free(hn); 1262 return avahi_server_set_errno(s, AVAHI_ERR_NO_CHANGE); 1263 } 1264 1265 withdraw_host_rrs(s); 1266 1267 avahi_free(s->host_name); 1268 s->host_name = hn; 1269 1270 update_fqdn(s); 1271 1272 register_stuff(s); 1273 return AVAHI_OK; 1274 } 1275 1276 int avahi_server_set_domain_name(AvahiServer *s, const char *domain_name) { 1277 char *dn = NULL; 1278 assert(s); 1279 1280 AVAHI_CHECK_VALIDITY(s, !domain_name || avahi_is_valid_domain_name(domain_name), AVAHI_ERR_INVALID_DOMAIN_NAME); 1281 1282 if (!domain_name) 1283 dn = avahi_strdup("local"); 1284 else 1285 dn = avahi_normalize_name_strdup(domain_name); 1286 1287 if (avahi_domain_equal(s->domain_name, domain_name)) { 1288 avahi_free(dn); 1289 return avahi_server_set_errno(s, AVAHI_ERR_NO_CHANGE); 1290 } 1291 1292 withdraw_host_rrs(s); 1293 1294 avahi_free(s->domain_name); 1295 s->domain_name = dn; 1296 update_fqdn(s); 1297 1298 register_stuff(s); 1299 1300 avahi_free(dn); 1301 return AVAHI_OK; 1302 } 1303 1304 static int valid_server_config(const AvahiServerConfig *sc) { 1305 AvahiStringList *l; 1306 1307 assert(sc); 1308 1309 if (sc->n_wide_area_servers > AVAHI_WIDE_AREA_SERVERS_MAX) 1310 return AVAHI_ERR_INVALID_CONFIG; 1311 1312 if (sc->host_name && !avahi_is_valid_host_name(sc->host_name)) 1313 return AVAHI_ERR_INVALID_HOST_NAME; 1314 1315 if (sc->domain_name && !avahi_is_valid_domain_name(sc->domain_name)) 1316 return AVAHI_ERR_INVALID_DOMAIN_NAME; 1317 1318 for (l = sc->browse_domains; l; l = l->next) 1319 if (!avahi_is_valid_domain_name((char*) l->text)) 1320 return AVAHI_ERR_INVALID_DOMAIN_NAME; 1321 1322 return AVAHI_OK; 1323 } 1324 1325 static int setup_sockets(AvahiServer *s) { 1326 assert(s); 1327 1328 s->fd_ipv4 = s->config.use_ipv4 ? avahi_open_socket_ipv4(s->config.disallow_other_stacks) : -1; 1329 s->fd_ipv6 = s->config.use_ipv6 ? avahi_open_socket_ipv6(s->config.disallow_other_stacks) : -1; 1330 1331 if (s->fd_ipv6 < 0 && s->fd_ipv4 < 0) 1332 return AVAHI_ERR_NO_NETWORK; 1333 1334 if (s->fd_ipv4 < 0 && s->config.use_ipv4) 1335 avahi_log_notice("Failed to create IPv4 socket, proceeding in IPv6 only mode"); 1336 else if (s->fd_ipv6 < 0 && s->config.use_ipv6) 1337 avahi_log_notice("Failed to create IPv6 socket, proceeding in IPv4 only mode"); 1338 1339 s->fd_legacy_unicast_ipv4 = s->fd_ipv4 >= 0 && s->config.enable_reflector ? avahi_open_unicast_socket_ipv4() : -1; 1340 s->fd_legacy_unicast_ipv6 = s->fd_ipv6 >= 0 && s->config.enable_reflector ? avahi_open_unicast_socket_ipv6() : -1; 1341 1342 s->watch_ipv4 = 1343 s->watch_ipv6 = 1344 s->watch_legacy_unicast_ipv4 = 1345 s->watch_legacy_unicast_ipv6 = NULL; 1346 1347 if (s->fd_ipv4 >= 0) 1348 s->watch_ipv4 = s->poll_api->watch_new(s->poll_api, s->fd_ipv4, AVAHI_WATCH_IN, mcast_socket_event, s); 1349 if (s->fd_ipv6 >= 0) 1350 s->watch_ipv6 = s->poll_api->watch_new(s->poll_api, s->fd_ipv6, AVAHI_WATCH_IN, mcast_socket_event, s); 1351 1352 if (s->fd_legacy_unicast_ipv4 >= 0) 1353 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); 1354 if (s->fd_legacy_unicast_ipv6 >= 0) 1355 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); 1356 1357 return 0; 1358 } 1359 1360 AvahiServer *avahi_server_new(const AvahiPoll *poll_api, const AvahiServerConfig *sc, AvahiServerCallback callback, void* userdata, int *error) { 1361 AvahiServer *s; 1362 int e; 1363 1364 if (sc && (e = valid_server_config(sc)) < 0) { 1365 if (error) 1366 *error = e; 1367 return NULL; 1368 } 1369 1370 if (!(s = avahi_new(AvahiServer, 1))) { 1371 if (error) 1372 *error = AVAHI_ERR_NO_MEMORY; 1373 1374 return NULL; 1375 } 1376 1377 s->poll_api = poll_api; 1378 1379 if (sc) 1380 avahi_server_config_copy(&s->config, sc); 1381 else 1382 avahi_server_config_init(&s->config); 1383 1384 if ((e = setup_sockets(s)) < 0) { 1385 if (error) 1386 *error = e; 1387 1388 avahi_server_config_free(&s->config); 1389 avahi_free(s); 1390 1391 return NULL; 1392 } 1393 1394 s->n_host_rr_pending = 0; 1395 s->need_entry_cleanup = 0; 1396 s->need_group_cleanup = 0; 1397 s->need_browser_cleanup = 0; 1398 s->cleanup_time_event = NULL; 1399 s->hinfo_entry_group = NULL; 1400 s->browse_domain_entry_group = NULL; 1401 s->error = AVAHI_OK; 1402 s->state = AVAHI_SERVER_INVALID; 1403 1404 s->callback = callback; 1405 s->userdata = userdata; 1406 1407 s->time_event_queue = avahi_time_event_queue_new(poll_api); 1408 1409 s->entries_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL); 1410 AVAHI_LLIST_HEAD_INIT(AvahiEntry, s->entries); 1411 AVAHI_LLIST_HEAD_INIT(AvahiGroup, s->groups); 1412 1413 s->record_browser_hashmap = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, NULL, NULL); 1414 AVAHI_LLIST_HEAD_INIT(AvahiSRecordBrowser, s->record_browsers); 1415 AVAHI_LLIST_HEAD_INIT(AvahiSHostNameResolver, s->host_name_resolvers); 1416 AVAHI_LLIST_HEAD_INIT(AvahiSAddressResolver, s->address_resolvers); 1417 AVAHI_LLIST_HEAD_INIT(AvahiSDomainBrowser, s->domain_browsers); 1418 AVAHI_LLIST_HEAD_INIT(AvahiSServiceTypeBrowser, s->service_type_browsers); 1419 AVAHI_LLIST_HEAD_INIT(AvahiSServiceBrowser, s->service_browsers); 1420 AVAHI_LLIST_HEAD_INIT(AvahiSServiceResolver, s->service_resolvers); 1421 AVAHI_LLIST_HEAD_INIT(AvahiSDNSServerBrowser, s->dns_server_browsers); 1422 1423 s->legacy_unicast_reflect_slots = NULL; 1424 s->legacy_unicast_reflect_id = 0; 1425 1426 s->record_list = avahi_record_list_new(); 1427 1428 /* Get host name */ 1429 s->host_name = s->config.host_name ? avahi_normalize_name_strdup(s->config.host_name) : avahi_get_host_name_strdup(); 1430 s->host_name[strcspn(s->host_name, ".")] = 0; 1431 s->domain_name = s->config.domain_name ? avahi_normalize_name_strdup(s->config.domain_name) : avahi_strdup("local"); 1432 s->host_name_fqdn = NULL; 1433 update_fqdn(s); 1434 1435 do { 1436 s->local_service_cookie = (uint32_t) rand() * (uint32_t) rand(); 1437 } while (s->local_service_cookie == AVAHI_SERVICE_COOKIE_INVALID); 1438 1439 if (s->config.enable_wide_area) { 1440 s->wide_area_lookup_engine = avahi_wide_area_engine_new(s); 1441 avahi_wide_area_set_servers(s->wide_area_lookup_engine, s->config.wide_area_servers, s->config.n_wide_area_servers); 1442 } else 1443 s->wide_area_lookup_engine = NULL; 1444 1445 s->multicast_lookup_engine = avahi_multicast_lookup_engine_new(s); 1446 1447 s->monitor = avahi_interface_monitor_new(s); 1448 avahi_interface_monitor_sync(s->monitor); 1449 1450 register_localhost(s); 1451 register_stuff(s); 1452 1453 return s; 1454 } 1455 1456 void avahi_server_free(AvahiServer* s) { 1457 assert(s); 1458 1459 /* Remove all browsers */ 1460 1461 while (s->dns_server_browsers) 1462 avahi_s_dns_server_browser_free(s->dns_server_browsers); 1463 while (s->host_name_resolvers) 1464 avahi_s_host_name_resolver_free(s->host_name_resolvers); 1465 while (s->address_resolvers) 1466 avahi_s_address_resolver_free(s->address_resolvers); 1467 while (s->domain_browsers) 1468 avahi_s_domain_browser_free(s->domain_browsers); 1469 while (s->service_type_browsers) 1470 avahi_s_service_type_browser_free(s->service_type_browsers); 1471 while (s->service_browsers) 1472 avahi_s_service_browser_free(s->service_browsers); 1473 while (s->service_resolvers) 1474 avahi_s_service_resolver_free(s->service_resolvers); 1475 while (s->record_browsers) 1476 avahi_s_record_browser_destroy(s->record_browsers); 1477 1478 /* Remove all locally rgeistered stuff */ 1479 1480 while(s->entries) 1481 avahi_entry_free(s, s->entries); 1482 1483 avahi_interface_monitor_free(s->monitor); 1484 1485 while (s->groups) 1486 avahi_entry_group_free(s, s->groups); 1487 1488 free_slots(s); 1489 1490 avahi_hashmap_free(s->entries_by_key); 1491 avahi_record_list_free(s->record_list); 1492 avahi_hashmap_free(s->record_browser_hashmap); 1493 1494 if (s->wide_area_lookup_engine) 1495 avahi_wide_area_engine_free(s->wide_area_lookup_engine); 1496 avahi_multicast_lookup_engine_free(s->multicast_lookup_engine); 1497 1498 if (s->cleanup_time_event) 1499 avahi_time_event_free(s->cleanup_time_event); 1500 1501 avahi_time_event_queue_free(s->time_event_queue); 1502 1503 /* Free watches */ 1504 1505 if (s->watch_ipv4) 1506 s->poll_api->watch_free(s->watch_ipv4); 1507 if (s->watch_ipv6) 1508 s->poll_api->watch_free(s->watch_ipv6); 1509 1510 if (s->watch_legacy_unicast_ipv4) 1511 s->poll_api->watch_free(s->watch_legacy_unicast_ipv4); 1512 if (s->watch_legacy_unicast_ipv6) 1513 s->poll_api->watch_free(s->watch_legacy_unicast_ipv6); 1514 1515 /* Free sockets */ 1516 1517 if (s->fd_ipv4 >= 0) 1518 close(s->fd_ipv4); 1519 if (s->fd_ipv6 >= 0) 1520 close(s->fd_ipv6); 1521 1522 if (s->fd_legacy_unicast_ipv4 >= 0) 1523 close(s->fd_legacy_unicast_ipv4); 1524 if (s->fd_legacy_unicast_ipv6 >= 0) 1525 close(s->fd_legacy_unicast_ipv6); 1526 1527 /* Free other stuff */ 1528 1529 avahi_free(s->host_name); 1530 avahi_free(s->domain_name); 1531 avahi_free(s->host_name_fqdn); 1532 1533 avahi_server_config_free(&s->config); 1534 1535 avahi_free(s); 1536 } 1537 1538 const char* avahi_server_get_domain_name(AvahiServer *s) { 1539 assert(s); 1540 1541 return s->domain_name; 1542 } 1543 1544 const char* avahi_server_get_host_name(AvahiServer *s) { 1545 assert(s); 1546 1547 return s->host_name; 1548 } 1549 1550 const char* avahi_server_get_host_name_fqdn(AvahiServer *s) { 1551 assert(s); 1552 1553 return s->host_name_fqdn; 1554 } 1555 1556 void* avahi_server_get_data(AvahiServer *s) { 1557 assert(s); 1558 1559 return s->userdata; 1560 } 1561 1562 void avahi_server_set_data(AvahiServer *s, void* userdata) { 1563 assert(s); 1564 1565 s->userdata = userdata; 1566 } 1567 1568 AvahiServerState avahi_server_get_state(AvahiServer *s) { 1569 assert(s); 1570 1571 return s->state; 1572 } 1573 1574 AvahiServerConfig* avahi_server_config_init(AvahiServerConfig *c) { 1575 assert(c); 1576 1577 memset(c, 0, sizeof(AvahiServerConfig)); 1578 c->use_ipv6 = 1; 1579 c->use_ipv4 = 1; 1580 c->allow_interfaces = NULL; 1581 c->deny_interfaces = NULL; 1582 c->host_name = NULL; 1583 c->domain_name = NULL; 1584 c->check_response_ttl = 0; 1585 c->publish_hinfo = 0; 1586 c->publish_addresses = 1; 1587 c->publish_workstation = 0; 1588 c->publish_domain = 1; 1589 c->use_iff_running = 0; 1590 c->enable_reflector = 0; 1591 c->reflect_ipv = 0; 1592 c->add_service_cookie = 0; 1593 c->enable_wide_area = 0; 1594 c->n_wide_area_servers = 0; 1595 c->disallow_other_stacks = 0; 1596 c->browse_domains = NULL; 1597 c->disable_publishing = 0; 1598 c->allow_point_to_point = 0; 1599 c->publish_aaaa_on_ipv4 = 1; 1600 c->publish_a_on_ipv6 = 0; 1601 c->n_cache_entries_max = AVAHI_DEFAULT_CACHE_ENTRIES_MAX; 1602 c->ratelimit_interval = 0; 1603 c->ratelimit_burst = 0; 1604 1605 return c; 1606 } 1607 1608 void avahi_server_config_free(AvahiServerConfig *c) { 1609 assert(c); 1610 1611 avahi_free(c->host_name); 1612 avahi_free(c->domain_name); 1613 avahi_string_list_free(c->browse_domains); 1614 avahi_string_list_free(c->allow_interfaces); 1615 avahi_string_list_free(c->deny_interfaces); 1616 } 1617 1618 AvahiServerConfig* avahi_server_config_copy(AvahiServerConfig *ret, const AvahiServerConfig *c) { 1619 char *d = NULL, *h = NULL; 1620 AvahiStringList *browse = NULL, *allow = NULL, *deny = NULL; 1621 assert(ret); 1622 assert(c); 1623 1624 if (c->host_name) 1625 if (!(h = avahi_strdup(c->host_name))) 1626 return NULL; 1627 1628 if (c->domain_name) 1629 if (!(d = avahi_strdup(c->domain_name))) { 1630 avahi_free(h); 1631 return NULL; 1632 } 1633 1634 if (!(browse = avahi_string_list_copy(c->browse_domains)) && c->browse_domains) { 1635 avahi_free(h); 1636 avahi_free(d); 1637 return NULL; 1638 } 1639 1640 if (!(allow = avahi_string_list_copy(c->allow_interfaces)) && c->allow_interfaces) { 1641 avahi_string_list_free(browse); 1642 avahi_free(h); 1643 avahi_free(d); 1644 return NULL; 1645 } 1646 1647 if (!(deny = avahi_string_list_copy(c->deny_interfaces)) && c->deny_interfaces) { 1648 avahi_string_list_free(allow); 1649 avahi_string_list_free(browse); 1650 avahi_free(h); 1651 avahi_free(d); 1652 return NULL; 1653 } 1654 1655 *ret = *c; 1656 ret->host_name = h; 1657 ret->domain_name = d; 1658 ret->browse_domains = browse; 1659 ret->allow_interfaces = allow; 1660 ret->deny_interfaces = deny; 1661 1662 return ret; 1663 } 1664 1665 int avahi_server_errno(AvahiServer *s) { 1666 assert(s); 1667 1668 return s->error; 1669 } 1670 1671 /* Just for internal use */ 1672 int avahi_server_set_errno(AvahiServer *s, int error) { 1673 assert(s); 1674 1675 return s->error = error; 1676 } 1677 1678 uint32_t avahi_server_get_local_service_cookie(AvahiServer *s) { 1679 assert(s); 1680 1681 return s->local_service_cookie; 1682 } 1683 1684 static AvahiEntry *find_entry(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, AvahiKey *key) { 1685 AvahiEntry *e; 1686 1687 assert(s); 1688 assert(key); 1689 1690 for (e = avahi_hashmap_lookup(s->entries_by_key, key); e; e = e->by_key_next) 1691 1692 if ((e->interface == interface || e->interface <= 0 || interface <= 0) && 1693 (e->protocol == protocol || e->protocol == AVAHI_PROTO_UNSPEC || protocol == AVAHI_PROTO_UNSPEC) && 1694 (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED || e->group->state == AVAHI_ENTRY_GROUP_REGISTERING)) 1695 1696 return e; 1697 1698 return NULL; 1699 } 1700 1701 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) { 1702 AvahiKey *key = NULL; 1703 AvahiEntry *e; 1704 int ret; 1705 char n[AVAHI_DOMAIN_NAME_MAX]; 1706 1707 assert(s); 1708 assert(name); 1709 assert(type); 1710 assert(ret_group); 1711 1712 AVAHI_CHECK_VALIDITY(s, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE); 1713 AVAHI_CHECK_VALIDITY(s, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL); 1714 AVAHI_CHECK_VALIDITY(s, avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME); 1715 AVAHI_CHECK_VALIDITY(s, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE); 1716 AVAHI_CHECK_VALIDITY(s, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); 1717 1718 if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain) < 0)) 1719 return avahi_server_set_errno(s, ret); 1720 1721 if (!(key = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV))) 1722 return avahi_server_set_errno(s, AVAHI_ERR_NO_MEMORY); 1723 1724 e = find_entry(s, interface, protocol, key); 1725 avahi_key_unref(key); 1726 1727 if (e) { 1728 *ret_group = e->group; 1729 return AVAHI_OK; 1730 } 1731 1732 return avahi_server_set_errno(s, AVAHI_ERR_NOT_FOUND); 1733 } 1734 1735 int avahi_server_is_service_local(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, const char *name) { 1736 AvahiKey *key = NULL; 1737 AvahiEntry *e; 1738 1739 assert(s); 1740 assert(name); 1741 1742 if (!s->host_name_fqdn) 1743 return 0; 1744 1745 if (!(key = avahi_key_new(name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV))) 1746 return 0; 1747 1748 e = find_entry(s, interface, protocol, key); 1749 avahi_key_unref(key); 1750 1751 if (!e) 1752 return 0; 1753 1754 return avahi_domain_equal(s->host_name_fqdn, e->record->data.srv.name); 1755 } 1756 1757 int avahi_server_is_record_local(AvahiServer *s, AvahiIfIndex interface, AvahiProtocol protocol, AvahiRecord *record) { 1758 AvahiEntry *e; 1759 1760 assert(s); 1761 assert(record); 1762 1763 for (e = avahi_hashmap_lookup(s->entries_by_key, record->key); e; e = e->by_key_next) 1764 1765 if ((e->interface == interface || e->interface <= 0 || interface <= 0) && 1766 (e->protocol == protocol || e->protocol == AVAHI_PROTO_UNSPEC || protocol == AVAHI_PROTO_UNSPEC) && 1767 (!e->group || e->group->state == AVAHI_ENTRY_GROUP_ESTABLISHED || e->group->state == AVAHI_ENTRY_GROUP_REGISTERING) && 1768 avahi_record_equal_no_ttl(record, e->record)) 1769 return 1; 1770 1771 return 0; 1772 } 1773 1774 /** Set the wide area DNS servers */ 1775 int avahi_server_set_wide_area_servers(AvahiServer *s, const AvahiAddress *a, unsigned n) { 1776 assert(s); 1777 1778 if (!s->wide_area_lookup_engine) 1779 return avahi_server_set_errno(s, AVAHI_ERR_INVALID_CONFIG); 1780 1781 avahi_wide_area_set_servers(s->wide_area_lookup_engine, a, n); 1782 return AVAHI_OK; 1783 } 1784 1785 const AvahiServerConfig* avahi_server_get_config(AvahiServer *s) { 1786 assert(s); 1787 1788 return &s->config; 1789 } 1790 1791 /** Set the browsing domains */ 1792 int avahi_server_set_browse_domains(AvahiServer *s, AvahiStringList *domains) { 1793 AvahiStringList *l; 1794 1795 assert(s); 1796 1797 for (l = s->config.browse_domains; l; l = l->next) 1798 if (!avahi_is_valid_domain_name((char*) l->text)) 1799 return avahi_server_set_errno(s, AVAHI_ERR_INVALID_DOMAIN_NAME); 1800 1801 avahi_string_list_free(s->config.browse_domains); 1802 s->config.browse_domains = avahi_string_list_copy(domains); 1803 1804 return AVAHI_OK; 1805 } 1806
