git.meshlink.io Git - catta/blob - avahi-core/resolve-service.c

   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 #include <stdio.h>
  28 #include <stdlib.h>
  29
  30 #include <avahi-common/domain.h>
  31 #include <avahi-common/timeval.h>
  32 #include <avahi-common/malloc.h>
  33 #include <avahi-common/error.h>
  34
  35 #include "browse.h"
  36
  37 #define TIMEOUT_MSEC 1000
  38
  39 struct AvahiSServiceResolver {
  40     AvahiServer *server;
  41     char *service_name;
  42     char *service_type;
  43     char *domain_name;
  44     AvahiProtocol address_protocol;
  45
  46     AvahiIfIndex interface;
  47     AvahiProtocol protocol;
  48
  49     AvahiSRecordBrowser *record_browser_srv;
  50     AvahiSRecordBrowser *record_browser_txt;
  51     AvahiSRecordBrowser *record_browser_a;
  52     AvahiSRecordBrowser *record_browser_aaaa;
  53
  54     AvahiRecord *srv_record, *txt_record, *address_record;
  55
  56     AvahiSServiceResolverCallback callback;
  57     void* userdata;
  58
  59     AvahiTimeEvent *time_event;
  60
  61     AVAHI_LLIST_FIELDS(AvahiSServiceResolver, resolver);
  62 };
  63
  64 static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
  65     assert(r);
  66
  67     if (r->time_event) {
  68         avahi_time_event_free(r->time_event);
  69         r->time_event = NULL;
  70     }
  71
  72     if (event == AVAHI_RESOLVER_TIMEOUT)
  73         r->callback(r, r->interface, r->protocol, event, r->service_name, r->service_type, r->domain_name, NULL, NULL, 0, NULL, r->userdata);
  74     else {
  75         AvahiAddress a;
  76         char sn[256], st[256];
  77         size_t i;
  78
  79         assert(event == AVAHI_RESOLVER_FOUND);
  80
  81         assert(r->srv_record);
  82         assert(r->txt_record);
  83         assert(r->address_record);
  84
  85         switch (r->address_record->key->type) {
  86             case AVAHI_DNS_TYPE_A:
  87                 a.family = AVAHI_PROTO_INET;
  88                 a.data.ipv4 = r->address_record->data.a.address;
  89                 break;
  90
  91             case AVAHI_DNS_TYPE_AAAA:
  92                 a.family = AVAHI_PROTO_INET6;
  93                 a.data.ipv6 = r->address_record->data.aaaa.address;
  94                 break;
  95
  96             default:
  97                 assert(0);
  98         }
  99
 100         snprintf(sn, sizeof(sn), r->service_name);
 101         snprintf(st, sizeof(st), r->service_type);
 102
 103         if ((i = strlen(sn)) > 0 && sn[i-1] == '.')
 104             sn[i-1] = 0;
 105
 106         if ((i = strlen(st)) > 0 && st[i-1] == '.')
 107             st[i-1] = 0;
 108
 109         r->callback(r, r->interface, r->protocol, event, sn, st, r->domain_name, r->srv_record->data.srv.name, &a, r->srv_record->data.srv.port, r->txt_record->data.txt.string_list, r->userdata);
 110     }
 111 }
 112
 113 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
 114     AvahiSServiceResolver *r = userdata;
 115
 116     assert(e);
 117     assert(r);
 118
 119     finish(r, AVAHI_RESOLVER_TIMEOUT);
 120 }
 121
 122 static void start_timeout(AvahiSServiceResolver *r) {
 123     struct timeval tv;
 124     assert(r);
 125
 126     if (r->time_event)
 127         return;
 128
 129     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
 130     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 131 }
 132
 133 static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
 134     AvahiSServiceResolver *r = userdata;
 135
 136     assert(rr);
 137     assert(record);
 138     assert(r);
 139
 140     if (event == AVAHI_BROWSER_NEW) {
 141         int changed = 0;
 142
 143         if (r->interface > 0 && interface != r->interface)
 144             return;
 145
 146         if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
 147             return;
 148
 149         if (r->interface <= 0)
 150             r->interface = interface;
 151
 152         if (r->protocol == AVAHI_PROTO_UNSPEC)
 153             r->protocol = protocol;
 154
 155         switch (record->key->type) {
 156             case AVAHI_DNS_TYPE_SRV:
 157                 if (!r->srv_record) {
 158                     r->srv_record = avahi_record_ref(record);
 159                     changed = 1;
 160
 161                     if (r->record_browser_a) {
 162                         avahi_s_record_browser_free(r->record_browser_a);
 163                         r->record_browser_a = NULL;
 164                     }
 165
 166                     if (r->record_browser_aaaa) {
 167                         avahi_s_record_browser_free(r->record_browser_aaaa);
 168                         r->record_browser_aaaa = NULL;
 169                     }
 170
 171                     if (r->address_protocol == AVAHI_PROTO_INET || r->address_protocol == AVAHI_PROTO_UNSPEC) {
 172                         AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
 173                         r->record_browser_a = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, record_browser_callback, r);
 174                         avahi_key_unref(k);
 175                     }
 176
 177                     if (r->address_protocol == AVAHI_PROTO_INET6 || r->address_protocol == AVAHI_PROTO_UNSPEC) {
 178                         AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
 179                         r->record_browser_aaaa = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, record_browser_callback, r);
 180                         avahi_key_unref(k);
 181                     }
 182                 }
 183                 break;
 184
 185             case AVAHI_DNS_TYPE_TXT:
 186                 if (!r->txt_record) {
 187                     r->txt_record = avahi_record_ref(record);
 188                     changed = 1;
 189                 }
 190                 break;
 191
 192             case AVAHI_DNS_TYPE_A:
 193             case AVAHI_DNS_TYPE_AAAA:
 194                 if (!r->address_record) {
 195                     r->address_record = avahi_record_ref(record);
 196                     changed = 1;
 197                 }
 198                 break;
 199
 200             default:
 201                 abort();
 202         }
 203
 204
 205         if (changed && r->txt_record && r->srv_record && r->address_record)
 206             finish(r, AVAHI_RESOLVER_FOUND);
 207
 208     } else {
 209         assert(event == AVAHI_BROWSER_REMOVE);
 210
 211
 212         switch (record->key->type) {
 213             case AVAHI_DNS_TYPE_SRV:
 214
 215                 if (r->srv_record && avahi_record_equal_no_ttl(record, r->srv_record)) {
 216                     avahi_record_unref(r->srv_record);
 217                     r->srv_record = NULL;
 218
 219                     /** Look for a replacement */
 220                     avahi_s_record_browser_restart(r->record_browser_srv);
 221                     start_timeout(r);
 222                 }
 223
 224                 break;
 225
 226             case AVAHI_DNS_TYPE_TXT:
 227
 228                 if (r->txt_record && avahi_record_equal_no_ttl(record, r->txt_record)) {
 229                     avahi_record_unref(r->txt_record);
 230                     r->txt_record = NULL;
 231
 232                     /** Look for a replacement */
 233                     avahi_s_record_browser_restart(r->record_browser_txt);
 234                     start_timeout(r);
 235                 }
 236                 break;
 237
 238             case AVAHI_DNS_TYPE_A:
 239             case AVAHI_DNS_TYPE_AAAA:
 240
 241                 if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
 242                     avahi_record_unref(r->address_record);
 243                     r->address_record = NULL;
 244
 245                     /** Look for a replacement */
 246                     if (r->record_browser_aaaa)
 247                         avahi_s_record_browser_restart(r->record_browser_aaaa);
 248                     if (r->record_browser_a)
 249                         avahi_s_record_browser_restart(r->record_browser_a);
 250                     start_timeout(r);
 251                 }
 252                 break;
 253
 254             default:
 255                 abort();
 256         }
 257     }
 258 }
 259
 260 AvahiSServiceResolver *avahi_s_service_resolver_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const char *name, const char *type, const char *domain, AvahiProtocol aprotocol, AvahiSServiceResolverCallback callback, void* userdata) {
 261     AvahiSServiceResolver *r;
 262     AvahiKey *k;
 263     char t[256], *n;
 264     size_t l;
 265
 266     assert(server);
 267     assert(name);
 268     assert(type);
 269     assert(callback);
 270
 271     assert(aprotocol == AVAHI_PROTO_UNSPEC || aprotocol == AVAHI_PROTO_INET || aprotocol == AVAHI_PROTO_INET6);
 272
 273     if (!avahi_is_valid_service_name(name)) {
 274         avahi_server_set_errno(server, AVAHI_ERR_INVALID_SERVICE_NAME);
 275         return NULL;
 276     }
 277
 278     if (!avahi_is_valid_service_type(type)) {
 279         avahi_server_set_errno(server, AVAHI_ERR_INVALID_SERVICE_TYPE);
 280         return NULL;
 281     }
 282
 283     if (!avahi_is_valid_domain_name(domain)) {
 284         avahi_server_set_errno(server, AVAHI_ERR_INVALID_DOMAIN_NAME);
 285         return NULL;
 286     }
 287
 288     if (!(r = avahi_new(AvahiSServiceResolver, 1))) {
 289         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 290         return NULL;
 291     }
 292
 293     r->server = server;
 294     r->service_name = avahi_strdup(name);
 295     r->service_type = avahi_normalize_name(type);
 296     r->domain_name = avahi_normalize_name(domain);
 297     r->callback = callback;
 298     r->userdata = userdata;
 299     r->address_protocol = aprotocol;
 300     r->srv_record = r->txt_record = r->address_record = NULL;
 301     r->interface = interface;
 302     r->protocol = protocol;
 303
 304     n = t;
 305     l = sizeof(t);
 306     avahi_escape_label((const uint8_t*) name, strlen(name), &n, &l);
 307     snprintf(n, l, ".%s.%s", r->service_type, r->domain_name);
 308
 309     r->time_event = NULL;
 310     start_timeout(r);
 311
 312     AVAHI_LLIST_PREPEND(AvahiSServiceResolver, resolver, server->service_resolvers, r);
 313
 314     r->record_browser_a = r->record_browser_aaaa = r->record_browser_srv = r->record_browser_txt = NULL;
 315
 316     k = avahi_key_new(t, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
 317     r->record_browser_srv = avahi_s_record_browser_new(server, interface, protocol, k, record_browser_callback, r);
 318     avahi_key_unref(k);
 319
 320     if (!r->record_browser_srv) {
 321         avahi_s_service_resolver_free(r);
 322         return NULL;
 323     }
 324
 325     k = avahi_key_new(t, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_TXT);
 326     r->record_browser_txt = avahi_s_record_browser_new(server, interface, protocol, k, record_browser_callback, r);
 327     avahi_key_unref(k);
 328
 329     if (!r->record_browser_txt) {
 330         avahi_s_service_resolver_free(r);
 331         return NULL;
 332     }
 333
 334     return r;
 335 }
 336
 337 void avahi_s_service_resolver_free(AvahiSServiceResolver *r) {
 338     assert(r);
 339
 340     AVAHI_LLIST_REMOVE(AvahiSServiceResolver, resolver, r->server->service_resolvers, r);
 341
 342     if (r->time_event)
 343         avahi_time_event_free(r->time_event);
 344
 345     if (r->record_browser_srv)
 346         avahi_s_record_browser_free(r->record_browser_srv);
 347     if (r->record_browser_txt)
 348         avahi_s_record_browser_free(r->record_browser_txt);
 349     if (r->record_browser_a)
 350         avahi_s_record_browser_free(r->record_browser_a);
 351     if (r->record_browser_aaaa)
 352         avahi_s_record_browser_free(r->record_browser_aaaa);
 353
 354     if (r->srv_record)
 355         avahi_record_unref(r->srv_record);
 356     if (r->txt_record)
 357         avahi_record_unref(r->txt_record);
 358     if (r->address_record)
 359         avahi_record_unref(r->address_record);
 360
 361     avahi_free(r->service_name);
 362     avahi_free(r->service_type);
 363     avahi_free(r->domain_name);
 364     avahi_free(r);
 365 }