git.meshlink.io Git - catta/blob - src/resolve-service.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 <string.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27
  28 #include <avahi/domain.h>
  29 #include <avahi/timeval.h>
  30 #include <avahi/malloc.h>
  31 #include <avahi/error.h>
  32
  33 #include "browse.h"
  34 #include <avahi/log.h>
  35
  36 #define TIMEOUT_MSEC 5000
  37
  38 struct AvahiSServiceResolver {
  39     AvahiServer *server;
  40     char *service_name;
  41     char *service_type;
  42     char *domain_name;
  43     AvahiProtocol address_protocol;
  44
  45     AvahiIfIndex interface;
  46     AvahiProtocol protocol;
  47
  48     AvahiSRecordBrowser *record_browser_srv;
  49     AvahiSRecordBrowser *record_browser_txt;
  50     AvahiSRecordBrowser *record_browser_a;
  51     AvahiSRecordBrowser *record_browser_aaaa;
  52
  53     AvahiRecord *srv_record, *txt_record, *address_record;
  54     AvahiLookupResultFlags srv_flags, txt_flags, address_flags;
  55
  56     AvahiSServiceResolverCallback callback;
  57     void* userdata;
  58     AvahiLookupFlags user_flags;
  59
  60     AvahiTimeEvent *time_event;
  61
  62     AVAHI_LLIST_FIELDS(AvahiSServiceResolver, resolver);
  63 };
  64
  65 static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
  66     AvahiLookupResultFlags flags;
  67
  68     assert(r);
  69
  70     if (r->time_event) {
  71         avahi_time_event_free(r->time_event);
  72         r->time_event = NULL;
  73     }
  74
  75     flags =
  76         r->txt_flags |
  77         r->srv_flags |
  78         r->address_flags;
  79
  80     switch (event) {
  81         case AVAHI_RESOLVER_FAILURE:
  82
  83             r->callback(
  84                 r,
  85                 r->interface,
  86                 r->protocol,
  87                 event,
  88                 r->service_name,
  89                 r->service_type,
  90                 r->domain_name,
  91                 NULL,
  92                 NULL,
  93                 0,
  94                 NULL,
  95                 flags,
  96                 r->userdata);
  97
  98             break;
  99
 100         case AVAHI_RESOLVER_FOUND: {
 101             AvahiAddress a;
 102
 103             assert(event == AVAHI_RESOLVER_FOUND);
 104
 105             assert(r->srv_record);
 106
 107             if (r->address_record) {
 108                 switch (r->address_record->key->type) {
 109                     case AVAHI_DNS_TYPE_A:
 110                         a.proto = AVAHI_PROTO_INET;
 111                         a.data.ipv4 = r->address_record->data.a.address;
 112                         break;
 113
 114                     case AVAHI_DNS_TYPE_AAAA:
 115                         a.proto = AVAHI_PROTO_INET6;
 116                         a.data.ipv6 = r->address_record->data.aaaa.address;
 117                         break;
 118
 119                     default:
 120                         assert(0);
 121                 }
 122             }
 123
 124             r->callback(
 125                 r,
 126                 r->interface,
 127                 r->protocol,
 128                 event,
 129                 r->service_name,
 130                 r->service_type,
 131                 r->domain_name,
 132                 r->srv_record->data.srv.name,
 133                 r->address_record ? &a : NULL,
 134                 r->srv_record->data.srv.port,
 135                 r->txt_record ? r->txt_record->data.txt.string_list : NULL,
 136                 flags,
 137                 r->userdata);
 138
 139             break;
 140         }
 141     }
 142 }
 143
 144 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
 145     AvahiSServiceResolver *r = userdata;
 146
 147     assert(e);
 148     assert(r);
 149
 150     avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
 151     finish(r, AVAHI_RESOLVER_FAILURE);
 152 }
 153
 154 static void start_timeout(AvahiSServiceResolver *r) {
 155     struct timeval tv;
 156     assert(r);
 157
 158     if (r->time_event)
 159         return;
 160
 161     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
 162
 163     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 164 }
 165
 166 static void record_browser_callback(
 167     AvahiSRecordBrowser*rr,
 168     AvahiIfIndex interface,
 169     AvahiProtocol protocol,
 170     AvahiBrowserEvent event,
 171     AvahiRecord *record,
 172     AvahiLookupResultFlags flags,
 173     void* userdata) {
 174
 175     AvahiSServiceResolver *r = userdata;
 176
 177     assert(rr);
 178     assert(r);
 179
 180     if (rr == r->record_browser_aaaa || rr == r->record_browser_a)
 181         r->address_flags = flags;
 182     else if (rr == r->record_browser_srv)
 183         r->srv_flags = flags;
 184     else if (rr == r->record_browser_txt)
 185         r->txt_flags = flags;
 186
 187     switch (event) {
 188
 189         case AVAHI_BROWSER_NEW: {
 190             int changed = 0;
 191             assert(record);
 192
 193             if (r->interface > 0 && interface > 0 &&  interface != r->interface)
 194                 return;
 195
 196             if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
 197                 return;
 198
 199             if (r->interface <= 0)
 200                 r->interface = interface;
 201
 202             if (r->protocol == AVAHI_PROTO_UNSPEC)
 203                 r->protocol = protocol;
 204
 205             switch (record->key->type) {
 206                 case AVAHI_DNS_TYPE_SRV:
 207                     if (!r->srv_record) {
 208                         r->srv_record = avahi_record_ref(record);
 209                         changed = 1;
 210
 211                         if (r->record_browser_a) {
 212                             avahi_s_record_browser_free(r->record_browser_a);
 213                             r->record_browser_a = NULL;
 214                         }
 215
 216                         if (r->record_browser_aaaa) {
 217                             avahi_s_record_browser_free(r->record_browser_aaaa);
 218                             r->record_browser_aaaa = NULL;
 219                         }
 220
 221                         if (!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)) {
 222
 223                             if (r->address_protocol == AVAHI_PROTO_INET || r->address_protocol == AVAHI_PROTO_UNSPEC) {
 224                                 AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
 225                                 r->record_browser_a = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
 226                                 avahi_key_unref(k);
 227                             }
 228
 229                             if (r->address_protocol == AVAHI_PROTO_INET6 || r->address_protocol == AVAHI_PROTO_UNSPEC) {
 230                                 AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
 231                                 r->record_browser_aaaa = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
 232                                 avahi_key_unref(k);
 233                             }
 234                         }
 235                     }
 236                     break;
 237
 238                 case AVAHI_DNS_TYPE_TXT:
 239
 240                     assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
 241
 242                     if (!r->txt_record) {
 243                         r->txt_record = avahi_record_ref(record);
 244                         changed = 1;
 245                     }
 246                     break;
 247
 248                 case AVAHI_DNS_TYPE_A:
 249                 case AVAHI_DNS_TYPE_AAAA:
 250
 251                     assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
 252
 253                     if (!r->address_record) {
 254                         r->address_record = avahi_record_ref(record);
 255                         changed = 1;
 256                     }
 257                     break;
 258
 259                 default:
 260                     abort();
 261             }
 262
 263
 264             if (changed &&
 265                 r->srv_record &&
 266                 (r->txt_record || (r->user_flags & AVAHI_LOOKUP_NO_TXT)) &&
 267                 (r->address_record || (r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)))
 268                 finish(r, AVAHI_RESOLVER_FOUND);
 269
 270             break;
 271
 272         }
 273
 274         case AVAHI_BROWSER_REMOVE:
 275
 276             assert(record);
 277
 278             switch (record->key->type) {
 279                 case AVAHI_DNS_TYPE_SRV:
 280
 281                     if (r->srv_record && avahi_record_equal_no_ttl(record, r->srv_record)) {
 282                         avahi_record_unref(r->srv_record);
 283                         r->srv_record = NULL;
 284
 285                         if (r->record_browser_a) {
 286                             avahi_s_record_browser_free(r->record_browser_a);
 287                             r->record_browser_a = NULL;
 288                         }
 289
 290                         if (r->record_browser_aaaa) {
 291                             avahi_s_record_browser_free(r->record_browser_aaaa);
 292                             r->record_browser_aaaa = NULL;
 293                         }
 294
 295                         /** Look for a replacement */
 296                         avahi_s_record_browser_restart(r->record_browser_srv);
 297                         start_timeout(r);
 298                     }
 299
 300                     break;
 301
 302                 case AVAHI_DNS_TYPE_TXT:
 303
 304                     assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
 305
 306                     if (r->txt_record && avahi_record_equal_no_ttl(record, r->txt_record)) {
 307                         avahi_record_unref(r->txt_record);
 308                         r->txt_record = NULL;
 309
 310                         /** Look for a replacement */
 311                         avahi_s_record_browser_restart(r->record_browser_txt);
 312                         start_timeout(r);
 313                     }
 314                     break;
 315
 316                 case AVAHI_DNS_TYPE_A:
 317                 case AVAHI_DNS_TYPE_AAAA:
 318
 319                     assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
 320
 321                     if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
 322                         avahi_record_unref(r->address_record);
 323                         r->address_record = NULL;
 324
 325                         /** Look for a replacement */
 326                         if (r->record_browser_aaaa)
 327                             avahi_s_record_browser_restart(r->record_browser_aaaa);
 328                         if (r->record_browser_a)
 329                             avahi_s_record_browser_restart(r->record_browser_a);
 330                         start_timeout(r);
 331                     }
 332                     break;
 333
 334                 default:
 335                     abort();
 336             }
 337
 338             break;
 339
 340         case AVAHI_BROWSER_CACHE_EXHAUSTED:
 341         case AVAHI_BROWSER_ALL_FOR_NOW:
 342             break;
 343
 344         case AVAHI_BROWSER_FAILURE:
 345
 346             if (rr == r->record_browser_a && r->record_browser_aaaa) {
 347                 /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
 348                 avahi_s_record_browser_free(r->record_browser_a);
 349                 r->record_browser_a = NULL;
 350                 break;
 351             }
 352
 353             if (rr == r->record_browser_aaaa && r->record_browser_a) {
 354                 /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
 355                 avahi_s_record_browser_free(r->record_browser_aaaa);
 356                 r->record_browser_aaaa = NULL;
 357                 break;
 358             }
 359
 360             /* Hmm, everything's lost, tell the user */
 361
 362             if (r->record_browser_srv)
 363                 avahi_s_record_browser_free(r->record_browser_srv);
 364             if (r->record_browser_txt)
 365                 avahi_s_record_browser_free(r->record_browser_txt);
 366             if (r->record_browser_a)
 367                 avahi_s_record_browser_free(r->record_browser_a);
 368             if (r->record_browser_aaaa)
 369                 avahi_s_record_browser_free(r->record_browser_aaaa);
 370
 371             r->record_browser_srv = r->record_browser_txt = r->record_browser_a = r->record_browser_aaaa = NULL;
 372
 373             finish(r, AVAHI_RESOLVER_FAILURE);
 374             break;
 375     }
 376 }
 377
 378 AvahiSServiceResolver *avahi_s_service_resolver_new(
 379     AvahiServer *server,
 380     AvahiIfIndex interface,
 381     AvahiProtocol protocol,
 382     const char *name,
 383     const char *type,
 384     const char *domain,
 385     AvahiProtocol aprotocol,
 386     AvahiLookupFlags flags,
 387     AvahiSServiceResolverCallback callback,
 388     void* userdata) {
 389
 390     AvahiSServiceResolver *r;
 391     AvahiKey *k;
 392     char n[AVAHI_DOMAIN_NAME_MAX];
 393     int ret;
 394
 395     assert(server);
 396     assert(type);
 397     assert(callback);
 398
 399     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
 400     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
 401     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(aprotocol), AVAHI_ERR_INVALID_PROTOCOL);
 402     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
 403     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !name || avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME);
 404     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE);
 405     AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), AVAHI_ERR_INVALID_FLAGS);
 406
 407     if (!domain)
 408         domain = server->domain_name;
 409
 410     if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain)) < 0) {
 411         avahi_server_set_errno(server, ret);
 412         return NULL;
 413     }
 414
 415     if (!(r = avahi_new(AvahiSServiceResolver, 1))) {
 416         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 417         return NULL;
 418     }
 419
 420     r->server = server;
 421     r->service_name = avahi_strdup(name);
 422     r->service_type = avahi_normalize_name_strdup(type);
 423     r->domain_name = avahi_normalize_name_strdup(domain);
 424     r->callback = callback;
 425     r->userdata = userdata;
 426     r->address_protocol = aprotocol;
 427     r->srv_record = r->txt_record = r->address_record = NULL;
 428     r->srv_flags = r->txt_flags = r->address_flags = 0;
 429     r->interface = interface;
 430     r->protocol = protocol;
 431     r->user_flags = flags;
 432     r->record_browser_a = r->record_browser_aaaa = r->record_browser_srv = r->record_browser_txt = NULL;
 433     r->time_event = NULL;
 434     AVAHI_LLIST_PREPEND(AvahiSServiceResolver, resolver, server->service_resolvers, r);
 435
 436     k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
 437     r->record_browser_srv = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
 438     avahi_key_unref(k);
 439
 440     if (!r->record_browser_srv) {
 441         avahi_s_service_resolver_free(r);
 442         return NULL;
 443     }
 444
 445     if (!(flags & AVAHI_LOOKUP_NO_TXT)) {
 446         k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_TXT);
 447         r->record_browser_txt = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS),  record_browser_callback, r);
 448         avahi_key_unref(k);
 449
 450         if (!r->record_browser_txt) {
 451             avahi_s_service_resolver_free(r);
 452             return NULL;
 453         }
 454     }
 455
 456     start_timeout(r);
 457
 458     return r;
 459 }
 460
 461 void avahi_s_service_resolver_free(AvahiSServiceResolver *r) {
 462     assert(r);
 463
 464     AVAHI_LLIST_REMOVE(AvahiSServiceResolver, resolver, r->server->service_resolvers, r);
 465
 466     if (r->time_event)
 467         avahi_time_event_free(r->time_event);
 468
 469     if (r->record_browser_srv)
 470         avahi_s_record_browser_free(r->record_browser_srv);
 471     if (r->record_browser_txt)
 472         avahi_s_record_browser_free(r->record_browser_txt);
 473     if (r->record_browser_a)
 474         avahi_s_record_browser_free(r->record_browser_a);
 475     if (r->record_browser_aaaa)
 476         avahi_s_record_browser_free(r->record_browser_aaaa);
 477
 478     if (r->srv_record)
 479         avahi_record_unref(r->srv_record);
 480     if (r->txt_record)
 481         avahi_record_unref(r->txt_record);
 482     if (r->address_record)
 483         avahi_record_unref(r->address_record);
 484
 485     avahi_free(r->service_name);
 486     avahi_free(r->service_type);
 487     avahi_free(r->domain_name);
 488     avahi_free(r);
 489 }