1/* $Id$ */ 2 3/*** 4 This file is part of avahi. 5 6 avahi is free software; you can redistribute it and/or modify it 7 under the terms of the GNU Lesser General Public License as 8 published by the Free Software Foundation; either version 2.1 of the 9 License, or (at your option) any later version. 10 11 avahi is distributed in the hope that it will be useful, but WITHOUT 12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General 14 Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with avahi; if not, write to the Free Software 18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 19 USA. 20***/ 21 22#ifdef HAVE_CONFIG_H 23#include <config.h> 24#endif 25 26#include <errno.h> 27#include <string.h> 28#include <unistd.h> 29#include <stdlib.h> 30#include <netinet/in.h> 31 32#include <avahi-common/malloc.h> 33#include <avahi-common/error.h> 34#include <avahi-common/timeval.h> 35 36#include "internal.h" 37#include "browse.h" 38#include "socket.h" 39#include "log.h" 40#include "hashmap.h" 41#include "wide-area.h" 42#include "addr-util.h" 43#include "rr-util.h" 44 45#define CACHE_ENTRIES_MAX 500 46 47typedef struct AvahiWideAreaCacheEntry AvahiWideAreaCacheEntry; 48 49struct AvahiWideAreaCacheEntry { 50 AvahiWideAreaLookupEngine *engine; 51 52 AvahiRecord *record; 53 struct timeval timestamp; 54 struct timeval expiry; 55 56 AvahiTimeEvent *time_event; 57 58 AVAHI_LLIST_FIELDS(AvahiWideAreaCacheEntry, by_key); 59 AVAHI_LLIST_FIELDS(AvahiWideAreaCacheEntry, cache); 60}; 61 62struct AvahiWideAreaLookup { 63 AvahiWideAreaLookupEngine *engine; 64 int dead; 65 66 uint32_t id; /* effectively just an uint16_t, but we need it as an index for a hash table */ 67 AvahiTimeEvent *time_event; 68 69 AvahiKey *key, *cname_key; 70 71 int n_send; 72 AvahiDnsPacket *packet; 73 74 AvahiWideAreaLookupCallback callback; 75 void *userdata; 76 77 AvahiAddress dns_server_used; 78 79 AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, lookups); 80 AVAHI_LLIST_FIELDS(AvahiWideAreaLookup, by_key); 81}; 82 83struct AvahiWideAreaLookupEngine { 84 AvahiServer *server; 85 86 int fd_ipv4, fd_ipv6; 87 AvahiWatch *watch_ipv4, *watch_ipv6; 88 89 uint16_t next_id; 90 91 /* Cache */ 92 AVAHI_LLIST_HEAD(AvahiWideAreaCacheEntry, cache); 93 AvahiHashmap *cache_by_key; 94 unsigned cache_n_entries; 95 96 /* Lookups */ 97 AVAHI_LLIST_HEAD(AvahiWideAreaLookup, lookups); 98 AvahiHashmap *lookups_by_id; 99 AvahiHashmap *lookups_by_key; 100 101 int cleanup_dead; 102 103 AvahiAddress dns_servers[AVAHI_WIDE_AREA_SERVERS_MAX]; 104 unsigned n_dns_servers; 105 unsigned current_dns_server; 106}; 107 108static AvahiWideAreaLookup* find_lookup(AvahiWideAreaLookupEngine *e, uint16_t id) { 109 AvahiWideAreaLookup *l; 110 int i = (int) id; 111 112 assert(e); 113 114 if (!(l = avahi_hashmap_lookup(e->lookups_by_id, &i))) 115 return NULL; 116 117 assert(l->id == id); 118 119 if (l->dead) 120 return NULL; 121 122 return l; 123} 124 125static int send_to_dns_server(AvahiWideAreaLookup *l, AvahiDnsPacket *p) { 126 AvahiAddress *a; 127 128 assert(l); 129 assert(p); 130 131 if (l->engine->n_dns_servers <= 0) 132 return -1; 133 134 assert(l->engine->current_dns_server < l->engine->n_dns_servers); 135 136 a = &l->engine->dns_servers[l->engine->current_dns_server]; 137 l->dns_server_used = *a; 138 139 if (a->proto == AVAHI_PROTO_INET) { 140 141 if (l->engine->fd_ipv4 < 0) 142 return -1; 143 144 return avahi_send_dns_packet_ipv4(l->engine->fd_ipv4, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv4, AVAHI_DNS_PORT); 145 146 } else { 147 assert(a->proto == AVAHI_PROTO_INET6); 148 149 if (l->engine->fd_ipv6 < 0) 150 return -1; 151 152 return avahi_send_dns_packet_ipv6(l->engine->fd_ipv6, AVAHI_IF_UNSPEC, p, NULL, &a->data.ipv6, AVAHI_DNS_PORT); 153 } 154} 155 156static void next_dns_server(AvahiWideAreaLookupEngine *e) { 157 assert(e); 158 159 e->current_dns_server++; 160 161 if (e->current_dns_server >= e->n_dns_servers) 162 e->current_dns_server = 0; 163} 164 165static void lookup_stop(AvahiWideAreaLookup *l) { 166 assert(l); 167 168 l->callback = NULL; 169 170 if (l->time_event) { 171 avahi_time_event_free(l->time_event); 172 l->time_event = NULL; 173 } 174} 175 176static void sender_timeout_callback(AvahiTimeEvent *e, void *userdata) { 177 AvahiWideAreaLookup *l = userdata; 178 struct timeval tv; 179 180 assert(l); 181 182 /* Try another DNS server after three retries */ 183 if (l->n_send >= 3 && avahi_address_cmp(&l->engine->dns_servers[l->engine->current_dns_server], &l->dns_server_used) == 0) { 184 next_dns_server(l->engine); 185 186 if (avahi_address_cmp(&l->engine->dns_servers[l->engine->current_dns_server], &l->dns_server_used) == 0) 187 /* There is no other DNS server, fail */ 188 l->n_send = 1000; 189 } 190 191 if (l->n_send >= 6) { 192 avahi_log_warn(__FILE__": Query timed out."); 193 avahi_server_set_errno(l->engine->server, AVAHI_ERR_TIMEOUT); 194 l->callback(l->engine, AVAHI_BROWSER_FAILURE, AVAHI_LOOKUP_RESULT_WIDE_AREA, NULL, l->userdata); 195 lookup_stop(l); 196 return; 197 } 198 199 assert(l->packet); 200 send_to_dns_server(l, l->packet); 201 l->n_send++; 202 203 avahi_time_event_update(e, avahi_elapse_time(&tv, 1000, 0)); 204} 205 206AvahiWideAreaLookup *avahi_wide_area_lookup_new( 207 AvahiWideAreaLookupEngine *e, 208 AvahiKey *key, 209 AvahiWideAreaLookupCallback callback, 210 void *userdata) { 211 212 struct timeval tv; 213 AvahiWideAreaLookup *l, *t; 214 uint8_t *p; 215 216 assert(e); 217 assert(key); 218 assert(callback); 219 assert(userdata); 220 221 l = avahi_new(AvahiWideAreaLookup, 1); 222 l->engine = e; 223 l->dead = 0; 224 l->key = avahi_key_ref(key); 225 l->cname_key = avahi_key_new_cname(l->key); 226 l->callback = callback; 227 l->userdata = userdata; 228 229 /* If more than 65K wide area quries are issued simultaneously, 230 * this will break. This should be limited by some higher level */ 231 232 for (;; e->next_id++) 233 if (!find_lookup(e, e->next_id)) 234 break; /* This ID is not yet used. */ 235 236 l->id = e->next_id++; 237 238 /* We keep the packet around in case we need to repeat our query */ 239 l->packet = avahi_dns_packet_new(0); 240 241 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_ID, (uint16_t) l->id); 242 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_FLAGS, AVAHI_DNS_FLAGS(0, 0, 0, 0, 1, 0, 0, 0, 0, 0)); 243 244 p = avahi_dns_packet_append_key(l->packet, key, 0); 245 assert(p); 246 247 avahi_dns_packet_set_field(l->packet, AVAHI_DNS_FIELD_QDCOUNT, 1); 248 249 if (send_to_dns_server(l, l->packet) < 0) { 250 avahi_log_error(__FILE__": Failed to send packet."); 251 avahi_dns_packet_free(l->packet); 252 avahi_key_unref(l->key); 253 if (l->cname_key) 254 avahi_key_unref(l->cname_key); 255 avahi_free(l); 256 return NULL; 257 } 258 259 l->n_send = 1; 260 261 l->time_event = avahi_time_event_new(e->server->time_event_queue, avahi_elapse_time(&tv, 500, 0), sender_timeout_callback, l); 262 263 avahi_hashmap_insert(e->lookups_by_id, &l->id, l); 264 265 t = avahi_hashmap_lookup(e->lookups_by_key, l->key); 266 AVAHI_LLIST_PREPEND(AvahiWideAreaLookup, by_key, t, l); 267 avahi_hashmap_replace(e->lookups_by_key, avahi_key_ref(l->key), t); 268 269 AVAHI_LLIST_PREPEND(AvahiWideAreaLookup, lookups, e->lookups, l); 270 271 return l; 272} 273 274static void lookup_destroy(AvahiWideAreaLookup *l) { 275 AvahiWideAreaLookup *t; 276 assert(l); 277 278 lookup_stop(l); 279 280 t = avahi_hashmap_lookup(l->engine->lookups_by_key, l->key); 281 AVAHI_LLIST_REMOVE(AvahiWideAreaLookup, by_key, t, l); 282 if (t) 283 avahi_hashmap_replace(l->engine->lookups_by_key, avahi_key_ref(l->key), t); 284 else 285 avahi_hashmap_remove(l->engine->lookups_by_key, l->key); 286 287 AVAHI_LLIST_REMOVE(AvahiWideAreaLookup, lookups, l->engine->lookups, l); 288 289 avahi_hashmap_remove(l->engine->lookups_by_id, &l->id); 290 avahi_dns_packet_free(l->packet); 291 292 if (l->key) 293 avahi_key_unref(l->key); 294 295 if (l->cname_key) 296 avahi_key_unref(l->cname_key); 297 298 avahi_free(l); 299} 300 301void avahi_wide_area_lookup_free(AvahiWideAreaLookup *l) { 302 assert(l); 303 304 if (l->dead) 305 return; 306 307 l->dead = 1; 308 l->engine->cleanup_dead = 1; 309 lookup_stop(l); 310} 311 312void avahi_wide_area_cleanup(AvahiWideAreaLookupEngine *e) { 313 AvahiWideAreaLookup *l, *n; 314 assert(e); 315 316 while (e->cleanup_dead) { 317 e->cleanup_dead = 0; 318 319 for (l = e->lookups; l; l = n) { 320 n = l->lookups_next; 321 322 if (l->dead) 323 lookup_destroy(l); 324 } 325 } 326} 327 328static void cache_entry_free(AvahiWideAreaCacheEntry *c) { 329 AvahiWideAreaCacheEntry *t; 330 assert(c); 331 332 if (c->time_event) 333 avahi_time_event_free(c->time_event); 334 335 AVAHI_LLIST_REMOVE(AvahiWideAreaCacheEntry, cache, c->engine->cache, c); 336 337 t = avahi_hashmap_lookup(c->engine->cache_by_key, c->record->key); 338 AVAHI_LLIST_REMOVE(AvahiWideAreaCacheEntry, by_key, t, c); 339 if (t) 340 avahi_hashmap_replace(c->engine->cache_by_key, avahi_key_ref(c->record->key), t); 341 else 342 avahi_hashmap_remove(c->engine->cache_by_key, c->record->key); 343 344 c->engine->cache_n_entries --; 345 346 avahi_record_unref(c->record); 347 avahi_free(c); 348} 349 350static void expiry_event(AvahiTimeEvent *te, void *userdata) { 351 AvahiWideAreaCacheEntry *e = userdata; 352 353 assert(te); 354 assert(e); 355 356 cache_entry_free(e); 357} 358 359static AvahiWideAreaCacheEntry* find_record_in_cache(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 360 AvahiWideAreaCacheEntry *c; 361 362 assert(e); 363 assert(r); 364 365 for (c = avahi_hashmap_lookup(e->cache_by_key, r->key); c; c = c->by_key_next) 366 if (avahi_record_equal_no_ttl(r, c->record)) 367 return c; 368 369 return NULL; 370} 371 372static void run_callbacks(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 373 AvahiWideAreaLookup *l; 374 375 assert(e); 376 assert(r); 377 378 for (l = avahi_hashmap_lookup(e->lookups_by_key, r->key); l; l = l->by_key_next) { 379 if (l->dead || !l->callback) 380 continue; 381 382 l->callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA, r, l->userdata); 383 } 384 385 if (r->key->clazz == AVAHI_DNS_CLASS_IN && r->key->type == AVAHI_DNS_TYPE_CNAME) { 386 /* It's a CNAME record, so we have to scan the all lookups to see if one matches */ 387 388 for (l = e->lookups; l; l = l->lookups_next) { 389 AvahiKey *key; 390 391 if (l->dead || !l->callback) 392 continue; 393 394 if ((key = avahi_key_new_cname(l->key))) { 395 if (avahi_key_equal(r->key, key)) 396 l->callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA, r, l->userdata); 397 398 avahi_key_unref(key); 399 } 400 } 401 } 402} 403 404static void add_to_cache(AvahiWideAreaLookupEngine *e, AvahiRecord *r) { 405 AvahiWideAreaCacheEntry *c; 406 int is_new; 407 408 assert(e); 409 assert(r); 410 411 if ((c = find_record_in_cache(e, r))) { 412 is_new = 0; 413 414 /* Update the existing entry */ 415 avahi_record_unref(c->record); 416 } else { 417 AvahiWideAreaCacheEntry *t; 418 419 is_new = 1; 420 421 /* Enforce cache size */ 422 if (e->cache_n_entries >= CACHE_ENTRIES_MAX) 423 /* Eventually we should improve the caching algorithm here */ 424 goto finish; 425 426 c = avahi_new(AvahiWideAreaCacheEntry, 1); 427 c->engine = e; 428 c->time_event = NULL; 429 430 AVAHI_LLIST_PREPEND(AvahiWideAreaCacheEntry, cache, e->cache, c); 431 432 /* Add the new entry to the cache entry hash table */ 433 t = avahi_hashmap_lookup(e->cache_by_key, r->key); 434 AVAHI_LLIST_PREPEND(AvahiWideAreaCacheEntry, by_key, t, c); 435 avahi_hashmap_replace(e->cache_by_key, avahi_key_ref(r->key), t); 436 437 e->cache_n_entries ++; 438 } 439 440 c->record = avahi_record_ref(r); 441 442 gettimeofday(&c->timestamp, NULL); 443 c->expiry = c->timestamp; 444 avahi_timeval_add(&c->expiry, r->ttl * 1000000); 445 446 if (c->time_event) 447 avahi_time_event_update(c->time_event, &c->expiry); 448 else 449 c->time_event = avahi_time_event_new(e->server->time_event_queue, &c->expiry, expiry_event, c); 450 451finish: 452 453 if (is_new) 454 run_callbacks(e, r); 455} 456 457static int map_dns_error(uint16_t error) { 458 static const int table[16] = { 459 AVAHI_OK, 460 AVAHI_ERR_DNS_FORMERR, 461 AVAHI_ERR_DNS_SERVFAIL, 462 AVAHI_ERR_DNS_NXDOMAIN, 463 AVAHI_ERR_DNS_NOTIMP, 464 AVAHI_ERR_DNS_REFUSED, 465 AVAHI_ERR_DNS_YXDOMAIN, 466 AVAHI_ERR_DNS_YXRRSET, 467 AVAHI_ERR_DNS_NXRRSET, 468 AVAHI_ERR_DNS_NOTAUTH, 469 AVAHI_ERR_DNS_NOTZONE, 470 AVAHI_ERR_INVALID_DNS_ERROR, 471 AVAHI_ERR_INVALID_DNS_ERROR, 472 AVAHI_ERR_INVALID_DNS_ERROR, 473 AVAHI_ERR_INVALID_DNS_ERROR, 474 AVAHI_ERR_INVALID_DNS_ERROR 475 }; 476 477 assert(error <= 15); 478 479 return table[error]; 480} 481 482static void handle_packet(AvahiWideAreaLookupEngine *e, AvahiDnsPacket *p) { 483 AvahiWideAreaLookup *l = NULL; 484 int i, r; 485 486 AvahiBrowserEvent final_event = AVAHI_BROWSER_ALL_FOR_NOW; 487 488 assert(e); 489 assert(p); 490 491 /* Some superficial validity tests */ 492 if (avahi_dns_packet_check_valid(p) < 0 || avahi_dns_packet_is_query(p)) { 493 avahi_log_warn(__FILE__": Ignoring invalid response for wide area datagram."); 494 goto finish; 495 } 496 497 /* Look for the lookup that issued this query */ 498 if (!(l = find_lookup(e, avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ID))) || l->dead) 499 goto finish; 500 501 /* Check whether this a packet indicating a failure */ 502 if ((r = avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_FLAGS) & 15) != 0 || 503 avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) == 0) { 504 505 avahi_server_set_errno(e->server, r == 0 ? AVAHI_ERR_NOT_FOUND : map_dns_error(r)); 506 /* Tell the user about the failure */ 507 final_event = AVAHI_BROWSER_FAILURE; 508 509 /* We go on here, since some of the records contained in the 510 reply might be interesting in some way */ 511 } 512 513 /* Skip over the question */ 514 for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_QDCOUNT); i > 0; i--) { 515 AvahiKey *k; 516 517 if (!(k = avahi_dns_packet_consume_key(p, NULL))) { 518 avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading question key. (Maybe a UTF-8 problem?)"); 519 avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET); 520 final_event = AVAHI_BROWSER_FAILURE; 521 goto finish; 522 } 523 524 avahi_key_unref(k); 525 } 526 527 /* Process responses */ 528 for (i = (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ANCOUNT) + 529 (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_NSCOUNT) + 530 (int) avahi_dns_packet_get_field(p, AVAHI_DNS_FIELD_ARCOUNT); i > 0; i--) { 531 532 AvahiRecord *rr; 533 534 if (!(rr = avahi_dns_packet_consume_record(p, NULL))) { 535 avahi_log_warn(__FILE__": Wide area response packet too short or invalid while reading response record. (Maybe a UTF-8 problem?)"); 536 avahi_server_set_errno(e->server, AVAHI_ERR_INVALID_PACKET); 537 final_event = AVAHI_BROWSER_FAILURE; 538 goto finish; 539 } 540 541 add_to_cache(e, rr); 542 avahi_record_unref(rr); 543 } 544 545finish: 546 547 if (l && !l->dead) { 548 if (l->callback) 549 l->callback(e, final_event, AVAHI_LOOKUP_RESULT_WIDE_AREA, NULL, l->userdata); 550 551 lookup_stop(l); 552 } 553} 554 555static void socket_event(AVAHI_GCC_UNUSED AvahiWatch *w, int fd, AVAHI_GCC_UNUSED AvahiWatchEvent events, void *userdata) { 556 AvahiWideAreaLookupEngine *e = userdata; 557 AvahiDnsPacket *p = NULL; 558 559 if (fd == e->fd_ipv4) 560 p = avahi_recv_dns_packet_ipv4(e->fd_ipv4, NULL, NULL, NULL, NULL, NULL); 561 else { 562 assert(fd == e->fd_ipv6); 563 p = avahi_recv_dns_packet_ipv6(e->fd_ipv6, NULL, NULL, NULL, NULL, NULL); 564 } 565 566 if (p) { 567 handle_packet(e, p); 568 avahi_dns_packet_free(p); 569 } 570} 571 572AvahiWideAreaLookupEngine *avahi_wide_area_engine_new(AvahiServer *s) { 573 AvahiWideAreaLookupEngine *e; 574 575 assert(s); 576 577 e = avahi_new(AvahiWideAreaLookupEngine, 1); 578 e->server = s; 579 e->cleanup_dead = 0; 580 581 /* Create sockets */ 582 e->fd_ipv4 = s->config.use_ipv4 ? avahi_open_unicast_socket_ipv4() : -1; 583 e->fd_ipv6 = s->config.use_ipv6 ? avahi_open_unicast_socket_ipv6() : -1; 584 585 if (e->fd_ipv4 < 0 && e->fd_ipv6 < 0) { 586 avahi_log_error(__FILE__": Failed to create wide area sockets: %s", strerror(errno)); 587 588 if (e->fd_ipv6 >= 0) 589 close(e->fd_ipv6); 590 591 if (e->fd_ipv4 >= 0) 592 close(e->fd_ipv4); 593 594 avahi_free(e); 595 return NULL; 596 } 597 598 /* Create watches */ 599 600 e->watch_ipv4 = e->watch_ipv6 = NULL; 601 602 if (e->fd_ipv4 >= 0) 603 e->watch_ipv4 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv4, AVAHI_WATCH_IN, socket_event, e); 604 if (e->fd_ipv6 >= 0) 605 e->watch_ipv6 = s->poll_api->watch_new(e->server->poll_api, e->fd_ipv6, AVAHI_WATCH_IN, socket_event, e); 606 607 e->n_dns_servers = e->current_dns_server = 0; 608 e->next_id = (uint16_t) rand(); 609 610 /* Initialize cache */ 611 AVAHI_LLIST_HEAD_INIT(AvahiWideAreaCacheEntry, e->cache); 612 e->cache_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, (AvahiFreeFunc) avahi_key_unref, NULL); 613 e->cache_n_entries = 0; 614 615 /* Initialize lookup list */ 616 e->lookups_by_id = avahi_hashmap_new((AvahiHashFunc) avahi_int_hash, (AvahiEqualFunc) avahi_int_equal, NULL, NULL); 617 e->lookups_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, (AvahiFreeFunc) avahi_key_unref, NULL); 618 AVAHI_LLIST_HEAD_INIT(AvahiWideAreaLookup, e->lookups); 619 620 return e; 621} 622 623void avahi_wide_area_engine_free(AvahiWideAreaLookupEngine *e) { 624 assert(e); 625 626 avahi_wide_area_clear_cache(e); 627 628 while (e->lookups) 629 lookup_destroy(e->lookups); 630 631 avahi_hashmap_free(e->cache_by_key); 632 avahi_hashmap_free(e->lookups_by_id); 633 avahi_hashmap_free(e->lookups_by_key); 634 635 if (e->watch_ipv4) 636 e->server->poll_api->watch_free(e->watch_ipv4); 637 638 if (e->watch_ipv6) 639 e->server->poll_api->watch_free(e->watch_ipv6); 640 641 if (e->fd_ipv6 >= 0) 642 close(e->fd_ipv6); 643 644 if (e->fd_ipv4 >= 0) 645 close(e->fd_ipv4); 646 647 avahi_free(e); 648} 649 650void avahi_wide_area_clear_cache(AvahiWideAreaLookupEngine *e) { 651 assert(e); 652 653 while (e->cache) 654 cache_entry_free(e->cache); 655 656 assert(e->cache_n_entries == 0); 657} 658 659void avahi_wide_area_set_servers(AvahiWideAreaLookupEngine *e, const AvahiAddress *a, unsigned n) { 660 assert(e); 661 662 if (a) { 663 for (e->n_dns_servers = 0; n > 0 && e->n_dns_servers < AVAHI_WIDE_AREA_SERVERS_MAX; a++, n--) 664 if ((a->proto == AVAHI_PROTO_INET && e->fd_ipv4 >= 0) || (a->proto == AVAHI_PROTO_INET6 && e->fd_ipv6 >= 0)) 665 e->dns_servers[e->n_dns_servers++] = *a; 666 } else { 667 assert(n == 0); 668 e->n_dns_servers = 0; 669 } 670 671 e->current_dns_server = 0; 672 673 avahi_wide_area_clear_cache(e); 674} 675 676void avahi_wide_area_cache_dump(AvahiWideAreaLookupEngine *e, AvahiDumpCallback callback, void* userdata) { 677 AvahiWideAreaCacheEntry *c; 678 679 assert(e); 680 assert(callback); 681 682 callback(";; WIDE AREA CACHE ;;; ", userdata); 683 684 for (c = e->cache; c; c = c->cache_next) { 685 char *t = avahi_record_to_string(c->record); 686 callback(t, userdata); 687 avahi_free(t); 688 } 689} 690 691unsigned avahi_wide_area_scan_cache(AvahiWideAreaLookupEngine *e, AvahiKey *key, AvahiWideAreaLookupCallback callback, void *userdata) { 692 AvahiWideAreaCacheEntry *c; 693 AvahiKey *cname_key; 694 unsigned n = 0; 695 696 assert(e); 697 assert(key); 698 assert(callback); 699 700 for (c = avahi_hashmap_lookup(e->cache_by_key, key); c; c = c->by_key_next) { 701 callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA|AVAHI_LOOKUP_RESULT_CACHED, c->record, userdata); 702 n++; 703 } 704 705 if ((cname_key = avahi_key_new_cname(key))) { 706 707 for (c = avahi_hashmap_lookup(e->cache_by_key, cname_key); c; c = c->by_key_next) { 708 callback(e, AVAHI_BROWSER_NEW, AVAHI_LOOKUP_RESULT_WIDE_AREA|AVAHI_LOOKUP_RESULT_CACHED, c->record, userdata); 709 n++; 710 } 711 712 avahi_key_unref(cname_key); 713 } 714 715 return n; 716} 717 718int avahi_wide_area_has_servers(AvahiWideAreaLookupEngine *e) { 719 assert(e); 720 721 return e->n_dns_servers > 0; 722} 723 724 725 726