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