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 <stdlib.h> 25 26 #include "avahi-common/avahi-malloc.h" 27 #include <avahi-common/timeval.h> 28 29 #include "internal.h" 30 #include "browse.h" 31 #include "socket.h" 32 #include "log.h" 33 #include "hashmap.h" 34 #include "multicast-lookup.h" 35 #include "rr-util.h" 36 37 struct AvahiMulticastLookup { 38 AvahiMulticastLookupEngine *engine; 39 int dead; 40 41 AvahiKey *key, *cname_key; 42 43 AvahiMulticastLookupCallback callback; 44 void *userdata; 45 46 AvahiIfIndex interface; 47 AvahiProtocol protocol; 48 49 int queriers_added; 50 51 AvahiTimeEvent *all_for_now_event; 52 53 AVAHI_LLIST_FIELDS(AvahiMulticastLookup, lookups); 54 AVAHI_LLIST_FIELDS(AvahiMulticastLookup, by_key); 55 }; 56 57 struct AvahiMulticastLookupEngine { 58 AvahiServer *server; 59 60 /* Lookups */ 61 AVAHI_LLIST_HEAD(AvahiMulticastLookup, lookups); 62 AvahiHashmap *lookups_by_key; 63 64 int cleanup_dead; 65 }; 66 67 static void all_for_now_callback(AvahiTimeEvent *e, void* userdata) { 68 AvahiMulticastLookup *l = userdata; 69 70 assert(e); 71 assert(l); 72 73 avahi_time_event_free(l->all_for_now_event); 74 l->all_for_now_event = NULL; 75 76 l->callback(l->engine, l->interface, l->protocol, AVAHI_BROWSER_ALL_FOR_NOW, AVAHI_LOOKUP_RESULT_MULTICAST, NULL, l->userdata); 77 } 78 79 AvahiMulticastLookup *avahi_multicast_lookup_new( 80 AvahiMulticastLookupEngine *e, 81 AvahiIfIndex interface, 82 AvahiProtocol protocol, 83 AvahiKey *key, 84 AvahiMulticastLookupCallback callback, 85 void *userdata) { 86 87 AvahiMulticastLookup *l, *t; 88 struct timeval tv; 89 90 assert(e); 91 assert(AVAHI_IF_VALID(interface)); 92 assert(AVAHI_PROTO_VALID(protocol)); 93 assert(key); 94 assert(callback); 95 96 l = avahi_new(AvahiMulticastLookup, 1); 97 l->engine = e; 98 l->dead = 0; 99 l->key = avahi_key_ref(key); 100 l->cname_key = avahi_key_new_cname(l->key); 101 l->callback = callback; 102 l->userdata = userdata; 103 l->interface = interface; 104 l->protocol = protocol; 105 l->all_for_now_event = NULL; 106 l->queriers_added = 0; 107 108 t = avahi_hashmap_lookup(e->lookups_by_key, l->key); 109 AVAHI_LLIST_PREPEND(AvahiMulticastLookup, by_key, t, l); 110 avahi_hashmap_replace(e->lookups_by_key, avahi_key_ref(l->key), t); 111 112 AVAHI_LLIST_PREPEND(AvahiMulticastLookup, lookups, e->lookups, l); 113 114 avahi_querier_add_for_all(e->server, interface, protocol, l->key, &tv); 115 l->queriers_added = 1; 116 117 /* Add a second */ 118 avahi_timeval_add(&tv, 1000000); 119 120 /* Issue the ALL_FOR_NOW event one second after the querier was initially created */ 121 l->all_for_now_event = avahi_time_event_new(e->server->time_event_queue, &tv, all_for_now_callback, l); 122 123 return l; 124 } 125 126 static void lookup_stop(AvahiMulticastLookup *l) { 127 assert(l); 128 129 l->callback = NULL; 130 131 if (l->queriers_added) { 132 avahi_querier_remove_for_all(l->engine->server, l->interface, l->protocol, l->key); 133 l->queriers_added = 0; 134 } 135 136 if (l->all_for_now_event) { 137 avahi_time_event_free(l->all_for_now_event); 138 l->all_for_now_event = NULL; 139 } 140 } 141 142 static void lookup_destroy(AvahiMulticastLookup *l) { 143 AvahiMulticastLookup *t; 144 assert(l); 145 146 lookup_stop(l); 147 148 t = avahi_hashmap_lookup(l->engine->lookups_by_key, l->key); 149 AVAHI_LLIST_REMOVE(AvahiMulticastLookup, by_key, t, l); 150 if (t) 151 avahi_hashmap_replace(l->engine->lookups_by_key, avahi_key_ref(l->key), t); 152 else 153 avahi_hashmap_remove(l->engine->lookups_by_key, l->key); 154 155 AVAHI_LLIST_REMOVE(AvahiMulticastLookup, lookups, l->engine->lookups, l); 156 157 if (l->key) 158 avahi_key_unref(l->key); 159 160 if (l->cname_key) 161 avahi_key_unref(l->cname_key); 162 163 avahi_free(l); 164 } 165 166 void avahi_multicast_lookup_free(AvahiMulticastLookup *l) { 167 assert(l); 168 169 if (l->dead) 170 return; 171 172 l->dead = 1; 173 l->engine->cleanup_dead = 1; 174 lookup_stop(l); 175 } 176 177 void avahi_multicast_lookup_engine_cleanup(AvahiMulticastLookupEngine *e) { 178 AvahiMulticastLookup *l, *n; 179 assert(e); 180 181 while (e->cleanup_dead) { 182 e->cleanup_dead = 0; 183 184 for (l = e->lookups; l; l = n) { 185 n = l->lookups_next; 186 187 if (l->dead) 188 lookup_destroy(l); 189 } 190 } 191 } 192 193 struct cbdata { 194 AvahiMulticastLookupEngine *engine; 195 AvahiMulticastLookupCallback callback; 196 void *userdata; 197 AvahiKey *key, *cname_key; 198 AvahiInterface *interface; 199 unsigned n_found; 200 }; 201 202 static void* scan_cache_callback(AvahiCache *c, AvahiKey *pattern, AvahiCacheEntry *e, void* userdata) { 203 struct cbdata *cbdata = userdata; 204 205 assert(c); 206 assert(pattern); 207 assert(e); 208 assert(cbdata); 209 210 cbdata->callback( 211 cbdata->engine, 212 cbdata->interface->hardware->index, 213 cbdata->interface->protocol, 214 AVAHI_BROWSER_NEW, 215 AVAHI_LOOKUP_RESULT_CACHED|AVAHI_LOOKUP_RESULT_MULTICAST, 216 e->record, 217 cbdata->userdata); 218 219 cbdata->n_found ++; 220 221 return NULL; 222 } 223 224 static void scan_interface_callback(AvahiInterfaceMonitor *m, AvahiInterface *i, void* userdata) { 225 struct cbdata *cbdata = userdata; 226 227 assert(m); 228 assert(i); 229 assert(cbdata); 230 231 cbdata->interface = i; 232 233 avahi_cache_walk(i->cache, cbdata->key, scan_cache_callback, cbdata); 234 235 if (cbdata->cname_key) 236 avahi_cache_walk(i->cache, cbdata->cname_key, scan_cache_callback, cbdata); 237 238 cbdata->interface = NULL; 239 } 240 241 unsigned avahi_multicast_lookup_engine_scan_cache( 242 AvahiMulticastLookupEngine *e, 243 AvahiIfIndex interface, 244 AvahiProtocol protocol, 245 AvahiKey *key, 246 AvahiMulticastLookupCallback callback, 247 void *userdata) { 248 249 struct cbdata cbdata; 250 251 assert(e); 252 assert(key); 253 assert(callback); 254 255 assert(AVAHI_IF_VALID(interface)); 256 assert(AVAHI_PROTO_VALID(protocol)); 257 258 cbdata.engine = e; 259 cbdata.key = key; 260 cbdata.cname_key = avahi_key_new_cname(key); 261 cbdata.callback = callback; 262 cbdata.userdata = userdata; 263 cbdata.interface = NULL; 264 cbdata.n_found = 0; 265 266 avahi_interface_monitor_walk(e->server->monitor, interface, protocol, scan_interface_callback, &cbdata); 267 268 if (cbdata.cname_key) 269 avahi_key_unref(cbdata.cname_key); 270 271 return cbdata.n_found; 272 } 273 274 void avahi_multicast_lookup_engine_new_interface(AvahiMulticastLookupEngine *e, AvahiInterface *i) { 275 AvahiMulticastLookup *l; 276 277 assert(e); 278 assert(i); 279 280 for (l = e->lookups; l; l = l->lookups_next) { 281 282 if (l->dead || !l->callback) 283 continue; 284 285 if (l->queriers_added && avahi_interface_match(i, l->interface, l->protocol)) 286 avahi_querier_add(i, l->key, NULL); 287 } 288 } 289 290 void avahi_multicast_lookup_engine_notify(AvahiMulticastLookupEngine *e, AvahiInterface *i, AvahiRecord *record, AvahiBrowserEvent event) { 291 AvahiMulticastLookup *l; 292 293 assert(e); 294 assert(record); 295 assert(i); 296 297 for (l = avahi_hashmap_lookup(e->lookups_by_key, record->key); l; l = l->by_key_next) { 298 if (l->dead || !l->callback) 299 continue; 300 301 if (avahi_interface_match(i, l->interface, l->protocol)) 302 l->callback(e, i->hardware->index, i->protocol, event, AVAHI_LOOKUP_RESULT_MULTICAST, record, l->userdata); 303 } 304 305 306 if (record->key->clazz == AVAHI_DNS_CLASS_IN && record->key->type == AVAHI_DNS_TYPE_CNAME) { 307 /* It's a CNAME record, so we have to scan the all lookups to see if one matches */ 308 309 for (l = e->lookups; l; l = l->lookups_next) { 310 AvahiKey *key; 311 312 if (l->dead || !l->callback) 313 continue; 314 315 if ((key = avahi_key_new_cname(l->key))) { 316 if (avahi_key_equal(record->key, key)) 317 l->callback(e, i->hardware->index, i->protocol, event, AVAHI_LOOKUP_RESULT_MULTICAST, record, l->userdata); 318 319 avahi_key_unref(key); 320 } 321 } 322 } 323 } 324 325 AvahiMulticastLookupEngine *avahi_multicast_lookup_engine_new(AvahiServer *s) { 326 AvahiMulticastLookupEngine *e; 327 328 assert(s); 329 330 e = avahi_new(AvahiMulticastLookupEngine, 1); 331 e->server = s; 332 e->cleanup_dead = 0; 333 334 /* Initialize lookup list */ 335 e->lookups_by_key = avahi_hashmap_new((AvahiHashFunc) avahi_key_hash, (AvahiEqualFunc) avahi_key_equal, (AvahiFreeFunc) avahi_key_unref, NULL); 336 AVAHI_LLIST_HEAD_INIT(AvahiWideAreaLookup, e->lookups); 337 338 return e; 339 } 340 341 void avahi_multicast_lookup_engine_free(AvahiMulticastLookupEngine *e) { 342 assert(e); 343 344 while (e->lookups) 345 lookup_destroy(e->lookups); 346 347 avahi_hashmap_free(e->lookups_by_key); 348 avahi_free(e); 349 } 350 351
