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 1000
  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
  52     AvahiTimeEvent *time_event;
  53
  54     AVAHI_LLIST_FIELDS(AvahiSHostNameResolver, resolver);
  55 };
  56
  57 static void finish(AvahiSHostNameResolver *r, AvahiResolverEvent event) {
  58     assert(r);
  59
  60     if (r->time_event) {
  61         avahi_time_event_free(r->time_event);
  62         r->time_event = NULL;
  63     }
  64
  65     if (event == AVAHI_RESOLVER_TIMEOUT)
  66         r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_TIMEOUT, r->host_name, NULL, r->userdata);
  67     else {
  68         AvahiAddress a;
  69
  70         assert(event == AVAHI_RESOLVER_FOUND);
  71         assert(r->address_record);
  72
  73         switch (r->address_record->key->type) {
  74             case AVAHI_DNS_TYPE_A:
  75                 a.proto = AVAHI_PROTO_INET;
  76                 a.data.ipv4 = r->address_record->data.a.address;
  77                 break;
  78
  79             case AVAHI_DNS_TYPE_AAAA:
  80                 a.proto = AVAHI_PROTO_INET6;
  81                 a.data.ipv6 = r->address_record->data.aaaa.address;
  82                 break;
  83
  84             default:
  85                 abort();
  86         }
  87
  88         r->callback(r, r->interface, r->protocol, AVAHI_RESOLVER_FOUND, r->address_record->key->name, &a, r->userdata);
  89     }
  90 }
  91
  92 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
  93     AvahiSHostNameResolver *r = userdata;
  94
  95     assert(e);
  96     assert(r);
  97
  98     finish(r, AVAHI_RESOLVER_TIMEOUT);
  99 }
 100
 101 static void start_timeout(AvahiSHostNameResolver *r) {
 102     struct timeval tv;
 103     assert(r);
 104
 105     if (r->time_event)
 106         return;
 107
 108     avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
 109     r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
 110 }
 111
 112 static void record_browser_callback(AvahiSRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
 113     AvahiSHostNameResolver *r = userdata;
 114
 115     assert(rr);
 116     assert(record);
 117     assert(r);
 118
 119     assert(record->key->type == AVAHI_DNS_TYPE_A || record->key->type == AVAHI_DNS_TYPE_AAAA);
 120
 121     if (event == AVAHI_BROWSER_NEW) {
 122
 123         if (r->interface > 0 && interface != r->interface)
 124             return;
 125
 126         if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
 127             return;
 128
 129         if (r->interface <= 0)
 130             r->interface = interface;
 131
 132         if (r->protocol == AVAHI_PROTO_UNSPEC)
 133             r->protocol = protocol;
 134
 135         if (!r->address_record) {
 136             r->address_record = avahi_record_ref(record);
 137
 138             finish(r, AVAHI_RESOLVER_FOUND);
 139         }
 140     } else {
 141
 142         assert(event == AVAHI_BROWSER_REMOVE);
 143
 144         if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
 145             avahi_record_unref(r->address_record);
 146             r->address_record = NULL;
 147
 148             /** Look for a replacement */
 149             if (r->record_browser_aaaa)
 150                 avahi_s_record_browser_restart(r->record_browser_aaaa);
 151             if (r->record_browser_a)
 152                 avahi_s_record_browser_restart(r->record_browser_a);
 153
 154             start_timeout(r);
 155         }
 156     }
 157 }
 158
 159 AvahiSHostNameResolver *avahi_s_host_name_resolver_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const char *host_name, AvahiProtocol aprotocol, AvahiSHostNameResolverCallback callback, void* userdata) {
 160     AvahiSHostNameResolver *r;
 161     AvahiKey *k;
 162
 163     assert(server);
 164     assert(host_name);
 165     assert(callback);
 166
 167     assert(aprotocol == AVAHI_PROTO_UNSPEC || aprotocol == AVAHI_PROTO_INET || aprotocol == AVAHI_PROTO_INET6);
 168
 169     if (!avahi_is_valid_domain_name(host_name)) {
 170         avahi_server_set_errno(server, AVAHI_ERR_INVALID_HOST_NAME);
 171         return NULL;
 172     }
 173
 174     if (!(r = avahi_new(AvahiSHostNameResolver, 1))) {
 175         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 176         return NULL;
 177     }
 178
 179     r->server = server;
 180     r->host_name = avahi_normalize_name(host_name);
 181     r->callback = callback;
 182     r->userdata = userdata;
 183     r->address_record = NULL;
 184     r->interface = interface;
 185     r->protocol = protocol;
 186
 187     r->record_browser_a = r->record_browser_aaaa = NULL;
 188
 189     r->time_event = NULL;
 190     start_timeout(r);
 191
 192     AVAHI_LLIST_PREPEND(AvahiSHostNameResolver, resolver, server->host_name_resolvers, r);
 193
 194     r->record_browser_aaaa = r->record_browser_a = NULL;
 195
 196     if (aprotocol == AVAHI_PROTO_INET || aprotocol == AVAHI_PROTO_UNSPEC) {
 197         k = avahi_key_new(host_name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
 198         r->record_browser_a = avahi_s_record_browser_new(server, interface, protocol, k, record_browser_callback, r);
 199         avahi_key_unref(k);
 200
 201         if (!r->record_browser_a)
 202             goto fail;
 203     }
 204
 205     if (aprotocol == AVAHI_PROTO_INET6 || aprotocol == AVAHI_PROTO_UNSPEC) {
 206         k = avahi_key_new(host_name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
 207         r->record_browser_aaaa = avahi_s_record_browser_new(server, interface, protocol, k, record_browser_callback, r);
 208         avahi_key_unref(k);
 209
 210         if (!r->record_browser_aaaa)
 211             goto fail;
 212     }
 213
 214     assert(r->record_browser_aaaa || r->record_browser_a);
 215
 216     return r;
 217
 218 fail:
 219     avahi_s_host_name_resolver_free(r);
 220     return NULL;
 221 }
 222
 223 void avahi_s_host_name_resolver_free(AvahiSHostNameResolver *r) {
 224     assert(r);
 225
 226     AVAHI_LLIST_REMOVE(AvahiSHostNameResolver, resolver, r->server->host_name_resolvers, r);
 227
 228     if (r->record_browser_a)
 229         avahi_s_record_browser_free(r->record_browser_a);
 230
 231     if (r->record_browser_aaaa)
 232         avahi_s_record_browser_free(r->record_browser_aaaa);
 233
 234     if (r->time_event)
 235         avahi_time_event_free(r->time_event);
 236
 237     if (r->address_record)
 238         avahi_record_unref(r->address_record);
 239
 240     avahi_free(r->host_name);
 241     avahi_free(r);
 242 }