git.meshlink.io Git - catta/blob - avahi-core/resolve-host-name.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 <stdlib.h>
  27
  28 #include <avahi-common/domain.h>
  29 #include <avahi-common/timeval.h>
  30 #include <avahi-common/malloc.h>
  31 #include <avahi-common/error.h>
  32
  33 #include "browse.h"
  34 #include "log.h"
  35
  36 #define TIMEOUT_MSEC 5000
  37
  38 struct AvahiSHostNameResolver {
  39     AvahiServer *server;
  40     char *host_name;
  41
  42     AvahiSRecordBrowser *record_browser_a;
  43     AvahiSRecordBrowser *record_browser_aaaa;
  44
  45     AvahiSHostNameResolverCallback callback;
  46     void* userdata;
  47
  48     AvahiRecord *address_record;
  49     AvahiIfIndex interface;
  50     AvahiProtocol protocol;
  51     AvahiLookupResultFlags flags;
  52
  53     AvahiTimeEvent *time_event;
  54
  55     AVAHI_LLIST_FIELDS(AvahiSHostNameResolver, resolver);
  56 };
  57
  58 static void finish(AvahiSHostNameResolver *r, AvahiResolverEvent event) {
  59     assert(r);
  60
  61     if (r->time_event) {
  62         avahi_time_event_free(r->time_event);
  63         r->time_event = NULL;
  64     }
  65
  66     switch (event) {
  67         case AVAHI_RESOLVER_FOUND: {
  68             AvahiAddress a;
  69
  70             assert(r->address_record);
  71
  72             switch (r->address_record->key->type) {
  73                 case AVAHI_DNS_TYPE_A:
  74                     a.proto = AVAHI_PROTO_INET;
  75                     a.data.ipv4 = r->address_record->data.a.address;
  76                     break;
  77
  78                 case AVAHI_DNS_TYPE_AAAA:
  79                     a.proto = AVAHI_PROTO_INET6;
  80                     a.data.ipv6 = r->address_record->data.aaaa.address;
  81                     break;
  82
  83                 default:
  84                     abort();
  85             }
  86
  87             r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_FOUND, r->address_record->key->name, &a, r->flags, r->userdata);
  88             break;
  89
  90         }
  91
  92         case AVAHI_RESOLVER_FAILURE:
  93
  94             r->callback(r, r->interface, r->protocol, event, r->host_name, NULL, r->flags, r->userdata);
  95             break;
  96     }
  97 }
  98
  99 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
 100     AvahiSHostNameResolver *r = userdata;
 101
 102     assert(e);
 103     assert(r);
 104
 105     avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
 106     finish(r, AVAHI_RESOLVER_FAILURE);
 107 }
 108
 109 static void start_timeout(AvahiSHostNameResolver *r) {
 110     struct timeval tv;
 111     assert(r);
 112
 113     if (r->time_event)
 114         return;
 115
 116     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
 117
 118     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 119 }
 120
 121 static void record_browser_callback(
 122     AvahiSRecordBrowser*rr,
 123     AvahiIfIndex interface,
 124     AvahiProtocol protocol,
 125     AvahiBrowserEvent event,
 126     AvahiRecord *record,
 127     AvahiLookupResultFlags flags,
 128     void* userdata) {
 129
 130     AvahiSHostNameResolver *r = userdata;
 131
 132     assert(rr);
 133     assert(r);
 134
 135
 136     switch (event) {
 137         case AVAHI_BROWSER_NEW:
 138             assert(record);
 139             assert(record->key->type == AVAHI_DNS_TYPE_A || record->key->type == AVAHI_DNS_TYPE_AAAA);
 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             if (!r->address_record) {
 154                 r->address_record = avahi_record_ref(record);
 155                 r->flags = flags;
 156
 157                 finish(r, AVAHI_RESOLVER_FOUND);
 158             }
 159
 160             break;
 161
 162         case AVAHI_BROWSER_REMOVE:
 163             assert(record);
 164             assert(record->key->type == AVAHI_DNS_TYPE_A || record->key->type == AVAHI_DNS_TYPE_AAAA);
 165
 166             if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
 167                 avahi_record_unref(r->address_record);
 168                 r->address_record = NULL;
 169
 170                 r->flags = flags;
 171
 172
 173                 /** Look for a replacement */
 174                 if (r->record_browser_aaaa)
 175                     avahi_s_record_browser_restart(r->record_browser_aaaa);
 176                 if (r->record_browser_a)
 177                     avahi_s_record_browser_restart(r->record_browser_a);
 178
 179                 start_timeout(r);
 180             }
 181
 182             break;
 183
 184         case AVAHI_BROWSER_CACHE_EXHAUSTED:
 185         case AVAHI_BROWSER_ALL_FOR_NOW:
 186             /* Ignore */
 187             break;
 188
 189         case AVAHI_BROWSER_FAILURE:
 190
 191             /* Stop browsers */
 192
 193             if (r->record_browser_aaaa)
 194                 avahi_s_record_browser_free(r->record_browser_aaaa);
 195             if (r->record_browser_a)
 196                 avahi_s_record_browser_free(r->record_browser_a);
 197
 198             r->record_browser_a = r->record_browser_aaaa = NULL;
 199             r->flags = flags;
 200
 201             finish(r, AVAHI_RESOLVER_FAILURE);
 202             break;
 203     }
 204 }
 205
 206 AvahiSHostNameResolver *avahi_s_host_name_resolver_new(
 207     AvahiServer *server,
 208     AvahiIfIndex interface,
 209     AvahiProtocol protocol,
 210     const char *host_name,
 211     AvahiProtocol aprotocol,
 212     AvahiLookupFlags flags,
 213     AvahiSHostNameResolverCallback callback,
 214     void* userdata) {
 215
 216     AvahiSHostNameResolver *r;
 217     AvahiKey *k;
 218
 219     assert(server);
 220     assert(host_name);
 221     assert(callback);
 222
 223     assert(aprotocol == AVAHI_PROTO_UNSPEC || aprotocol == AVAHI_PROTO_INET || aprotocol == AVAHI_PROTO_INET6);
 224
 225     if (!AVAHI_IF_VALID(interface)) {
 226         avahi_server_set_errno(server, AVAHI_ERR_INVALID_INTERFACE);
 227         return NULL;
 228     }
 229
 230     if (!avahi_is_valid_domain_name(host_name)) {
 231         avahi_server_set_errno(server, AVAHI_ERR_INVALID_HOST_NAME);
 232         return NULL;
 233     }
 234
 235     if (!AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST)) {
 236         avahi_server_set_errno(server, AVAHI_ERR_INVALID_FLAGS);
 237         return NULL;
 238     }
 239
 240     if (!(r = avahi_new(AvahiSHostNameResolver, 1))) {
 241         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 242         return NULL;
 243     }
 244
 245     r->server = server;
 246     r->host_name = avahi_normalize_name_strdup(host_name);
 247     r->callback = callback;
 248     r->userdata = userdata;
 249     r->address_record = NULL;
 250     r->interface = interface;
 251     r->protocol = protocol;
 252     r->flags = 0;
 253
 254     r->record_browser_a = r->record_browser_aaaa = NULL;
 255
 256     r->time_event = NULL;
 257
 258     AVAHI_LLIST_PREPEND(AvahiSHostNameResolver, resolver, server->host_name_resolvers, r);
 259
 260     r->record_browser_aaaa = r->record_browser_a = NULL;
 261
 262
 263     if (aprotocol == AVAHI_PROTO_INET || aprotocol == AVAHI_PROTO_UNSPEC) {
 264         k = avahi_key_new(host_name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
 265         r->record_browser_a = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, r);
 266         avahi_key_unref(k);
 267
 268         if (!r->record_browser_a)
 269             goto fail;
 270     }
 271
 272     if (aprotocol == AVAHI_PROTO_INET6 || aprotocol == AVAHI_PROTO_UNSPEC) {
 273         k = avahi_key_new(host_name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
 274         r->record_browser_aaaa = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, r);
 275         avahi_key_unref(k);
 276
 277         if (!r->record_browser_aaaa)
 278             goto fail;
 279     }
 280
 281     assert(r->record_browser_aaaa || r->record_browser_a);
 282
 283     start_timeout(r);
 284
 285     return r;
 286
 287 fail:
 288     avahi_s_host_name_resolver_free(r);
 289     return NULL;
 290 }
 291
 292 void avahi_s_host_name_resolver_free(AvahiSHostNameResolver *r) {
 293     assert(r);
 294
 295     AVAHI_LLIST_REMOVE(AvahiSHostNameResolver, resolver, r->server->host_name_resolvers, r);
 296
 297     if (r->record_browser_a)
 298         avahi_s_record_browser_free(r->record_browser_a);
 299
 300     if (r->record_browser_aaaa)
 301         avahi_s_record_browser_free(r->record_browser_aaaa);
 302
 303     if (r->time_event)
 304         avahi_time_event_free(r->time_event);
 305
 306     if (r->address_record)
 307         avahi_record_unref(r->address_record);
 308
 309     avahi_free(r->host_name);
 310     avahi_free(r);
 311 }