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 <string.h> 27 28#include <avahi-common/domain.h> 29#include <avahi-common/malloc.h> 30#include <avahi-common/error.h> 31 32#include "browse.h" 33#include "log.h" 34#include "rr.h" 35 36typedef struct AvahiDNSServerInfo AvahiDNSServerInfo; 37 38struct AvahiDNSServerInfo { 39 AvahiSDNSServerBrowser *browser; 40 41 AvahiIfIndex interface; 42 AvahiProtocol protocol; 43 AvahiRecord *srv_record; 44 AvahiSHostNameResolver *host_name_resolver; 45 AvahiAddress address; 46 AvahiLookupResultFlags flags; 47 48 AVAHI_LLIST_FIELDS(AvahiDNSServerInfo, info); 49}; 50 51struct AvahiSDNSServerBrowser { 52 AvahiServer *server; 53 54 AvahiSRecordBrowser *record_browser; 55 AvahiSDNSServerBrowserCallback callback; 56 void* userdata; 57 AvahiProtocol aprotocol; 58 AvahiLookupFlags user_flags; 59 60 unsigned n_info; 61 62 AVAHI_LLIST_FIELDS(AvahiSDNSServerBrowser, browser); 63 AVAHI_LLIST_HEAD(AvahiDNSServerInfo, info); 64}; 65 66static AvahiDNSServerInfo* get_server_info(AvahiSDNSServerBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol, AvahiRecord *r) { 67 AvahiDNSServerInfo *i; 68 69 assert(b); 70 assert(r); 71 72 for (i = b->info; i; i = i->info_next) 73 if (i->interface == interface && 74 i->protocol == protocol && 75 avahi_record_equal_no_ttl(r, i->srv_record)) 76 return i; 77 78 return NULL; 79} 80 81static void server_info_free(AvahiSDNSServerBrowser *b, AvahiDNSServerInfo *i) { 82 assert(b); 83 assert(i); 84 85 avahi_record_unref(i->srv_record); 86 if (i->host_name_resolver) 87 avahi_s_host_name_resolver_free(i->host_name_resolver); 88 89 AVAHI_LLIST_REMOVE(AvahiDNSServerInfo, info, b->info, i); 90 91 assert(b->n_info >= 1); 92 b->n_info--; 93 94 avahi_free(i); 95} 96 97static void host_name_resolver_callback( 98 AvahiSHostNameResolver *r, 99 AVAHI_GCC_UNUSED AvahiIfIndex interface, 100 AVAHI_GCC_UNUSED AvahiProtocol protocol, 101 AvahiResolverEvent event, 102 const char *host_name, 103 const AvahiAddress *a, 104 AvahiLookupResultFlags flags, 105 void* userdata) { 106 107 AvahiDNSServerInfo *i = userdata; 108 109 assert(r); 110 assert(host_name); 111 assert(i); 112 113 switch (event) { 114 case AVAHI_RESOLVER_FOUND: { 115 i->address = *a; 116 117 i->browser->callback( 118 i->browser, 119 i->interface, 120 i->protocol, 121 AVAHI_BROWSER_NEW, 122 i->srv_record->data.srv.name, 123 &i->address, 124 i->srv_record->data.srv.port, 125 i->flags | flags, 126 i->browser->userdata); 127 128 break; 129 } 130 131 case AVAHI_RESOLVER_FAILURE: 132 /* Ignore */ 133 break; 134 } 135 136 avahi_s_host_name_resolver_free(i->host_name_resolver); 137 i->host_name_resolver = NULL; 138} 139 140static void record_browser_callback( 141 AvahiSRecordBrowser*rr, 142 AvahiIfIndex interface, 143 AvahiProtocol protocol, 144 AvahiBrowserEvent event, 145 AvahiRecord *record, 146 AvahiLookupResultFlags flags, 147 void* userdata) { 148 149 AvahiSDNSServerBrowser *b = userdata; 150 151 assert(rr); 152 assert(b); 153 154 /* Filter flags */ 155 flags &= AVAHI_LOOKUP_RESULT_CACHED | AVAHI_LOOKUP_RESULT_MULTICAST | AVAHI_LOOKUP_RESULT_WIDE_AREA; 156 157 switch (event) { 158 case AVAHI_BROWSER_NEW: { 159 AvahiDNSServerInfo *i; 160 161 assert(record); 162 assert(record->key->type == AVAHI_DNS_TYPE_SRV); 163 164 if (get_server_info(b, interface, protocol, record)) 165 return; 166 167 if (b->n_info >= 10) 168 return; 169 170 if (!(i = avahi_new(AvahiDNSServerInfo, 1))) 171 return; /* OOM */ 172 173 i->browser = b; 174 i->interface = interface; 175 i->protocol = protocol; 176 i->srv_record = avahi_record_ref(record); 177 i->host_name_resolver = avahi_s_host_name_resolver_new( 178 b->server, 179 interface, protocol, 180 record->data.srv.name, 181 b->aprotocol, 182 b->user_flags, 183 host_name_resolver_callback, i); 184 i->flags = flags; 185 186 AVAHI_LLIST_PREPEND(AvahiDNSServerInfo, info, b->info, i); 187 188 b->n_info++; 189 break; 190 } 191 192 case AVAHI_BROWSER_REMOVE: { 193 AvahiDNSServerInfo *i; 194 195 assert(record); 196 assert(record->key->type == AVAHI_DNS_TYPE_SRV); 197 198 if (!(i = get_server_info(b, interface, protocol, record))) 199 return; 200 201 if (!i->host_name_resolver) 202 b->callback( 203 b, 204 interface, 205 protocol, 206 event, 207 i->srv_record->data.srv.name, 208 &i->address, 209 i->srv_record->data.srv.port, 210 i->flags | flags, 211 b->userdata); 212 213 server_info_free(b, i); 214 break; 215 } 216 217 case AVAHI_BROWSER_FAILURE: 218 case AVAHI_BROWSER_ALL_FOR_NOW: 219 case AVAHI_BROWSER_CACHE_EXHAUSTED: 220 221 b->callback( 222 b, 223 interface, 224 protocol, 225 event, 226 NULL, 227 NULL, 228 0, 229 flags, 230 b->userdata); 231 232 break; 233 } 234} 235 236AvahiSDNSServerBrowser *avahi_s_dns_server_browser_new( 237 AvahiServer *server, 238 AvahiIfIndex interface, 239 AvahiProtocol protocol, 240 const char *domain, 241 AvahiDNSServerType type, 242 AvahiProtocol aprotocol, 243 AvahiLookupFlags flags, 244 AvahiSDNSServerBrowserCallback callback, 245 void* userdata) { 246 247 static const char * const type_table[AVAHI_DNS_SERVER_MAX] = { 248 "_domain._udp", 249 "_dns-update._udp" 250 }; 251 252 AvahiSDNSServerBrowser *b; 253 AvahiKey *k = NULL; 254 char n[AVAHI_DOMAIN_NAME_MAX]; 255 int r; 256 257 assert(server); 258 assert(callback); 259 260 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE); 261 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL); 262 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(aprotocol), AVAHI_ERR_INVALID_PROTOCOL); 263 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME); 264 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS); 265 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, type < AVAHI_DNS_SERVER_MAX, AVAHI_ERR_INVALID_FLAGS); 266 267 if (!domain) 268 domain = server->domain_name; 269 270 if ((r = avahi_service_name_join(n, sizeof(n), NULL, type_table[type], domain)) < 0) { 271 avahi_server_set_errno(server, r); 272 return NULL; 273 } 274 275 if (!(b = avahi_new(AvahiSDNSServerBrowser, 1))) { 276 avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY); 277 return NULL; 278 } 279 280 b->server = server; 281 b->callback = callback; 282 b->userdata = userdata; 283 b->aprotocol = aprotocol; 284 b->n_info = 0; 285 b->user_flags = flags; 286 287 AVAHI_LLIST_HEAD_INIT(AvahiDNSServerInfo, b->info); 288 AVAHI_LLIST_PREPEND(AvahiSDNSServerBrowser, browser, server->dns_server_browsers, b); 289 290 if (!(k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV))) { 291 avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY); 292 goto fail; 293 } 294 295 if (!(b->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, b))) 296 goto fail; 297 298 avahi_key_unref(k); 299 300 return b; 301 302fail: 303 304 if (k) 305 avahi_key_unref(k); 306 307 avahi_s_dns_server_browser_free(b); 308 return NULL; 309} 310 311void avahi_s_dns_server_browser_free(AvahiSDNSServerBrowser *b) { 312 assert(b); 313 314 while (b->info) 315 server_info_free(b, b->info); 316 317 AVAHI_LLIST_REMOVE(AvahiSDNSServerBrowser, browser, b->server->dns_server_browsers, b); 318 319 if (b->record_browser) 320 avahi_s_record_browser_free(b->record_browser); 321 322 avahi_free(b); 323} 324 325