git.meshlink.io Git - catta/blob - avahi-core/browse-dns-server.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
  28 #include <avahi-common/domain.h>
  29 #include <avahi-common/malloc.h>
  30
  31 #include "browse.h"
  32 #include "log.h"
  33 #include "rr.h"
  34
  35 typedef struct AvahiDNSServerInfo AvahiDNSServerInfo;
  36
  37 struct AvahiDNSServerInfo {
  38     AvahiDNSServerBrowser *browser;
  39
  40     AvahiIfIndex interface;
  41     AvahiProtocol protocol;
  42     AvahiRecord *srv_record;
  43     AvahiHostNameResolver *host_name_resolver;
  44     AvahiAddress address;
  45
  46     AVAHI_LLIST_FIELDS(AvahiDNSServerInfo, info);
  47 };
  48
  49 struct AvahiDNSServerBrowser {
  50     AvahiServer *server;
  51     char *domain_name;
  52
  53     AvahiRecordBrowser *record_browser;
  54     AvahiDNSServerBrowserCallback callback;
  55     void* userdata;
  56     AvahiProtocol aprotocol;
  57
  58     unsigned n_info;
  59
  60     AVAHI_LLIST_FIELDS(AvahiDNSServerBrowser, browser);
  61     AVAHI_LLIST_HEAD(AvahiDNSServerInfo, info);
  62 };
  63
  64 static AvahiDNSServerInfo* get_server_info(AvahiDNSServerBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol, AvahiRecord *r) {
  65     AvahiDNSServerInfo *i;
  66
  67     assert(b);
  68     assert(r);
  69
  70     for (i = b->info; i; i = i->info_next)
  71         if (i->interface == interface &&
  72             i->protocol == protocol &&
  73             avahi_record_equal_no_ttl(r, i->srv_record))
  74             return i;
  75
  76     return NULL;
  77 }
  78
  79 static void server_info_free(AvahiDNSServerBrowser *b, AvahiDNSServerInfo *i) {
  80     assert(b);
  81     assert(i);
  82
  83     avahi_record_unref(i->srv_record);
  84     if (i->host_name_resolver)
  85         avahi_host_name_resolver_free(i->host_name_resolver);
  86
  87     AVAHI_LLIST_REMOVE(AvahiDNSServerInfo, info, b->info, i);
  88
  89     assert(b->n_info >= 1);
  90     b->n_info--;
  91
  92     avahi_free(i);
  93 }
  94
  95 static void host_name_resolver_callback(AvahiHostNameResolver *r, AvahiIfIndex interface, AvahiProtocol protocol, AvahiResolverEvent event, const char *host_name, const AvahiAddress *a, void* userdata) {
  96     AvahiDNSServerInfo *i = userdata;
  97
  98     assert(r);
  99     assert(host_name);
 100     assert(i);
 101
 102     if (event == AVAHI_RESOLVER_FOUND) {
 103         i->address = *a;
 104
 105         i->browser->callback(i->browser, i->interface, i->protocol, AVAHI_BROWSER_NEW, i->srv_record->data.srv.name, &i->address, i->srv_record->data.srv.port, i->browser->userdata);
 106     }
 107
 108     avahi_host_name_resolver_free(i->host_name_resolver);
 109     i->host_name_resolver = NULL;
 110 }
 111
 112 static void record_browser_callback(AvahiRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, void* userdata) {
 113     AvahiDNSServerBrowser *b = userdata;
 114
 115     assert(rr);
 116     assert(record);
 117     assert(b);
 118
 119     assert(record->key->type == AVAHI_DNS_TYPE_SRV);
 120
 121     if (event == AVAHI_BROWSER_NEW) {
 122         AvahiDNSServerInfo *i;
 123
 124         if (get_server_info(b, interface, protocol, record))
 125             return;
 126
 127         if (b->n_info >= 10)
 128             return;
 129
 130         if (!(i = avahi_new(AvahiDNSServerInfo, 1)))
 131             return; /* OOM */
 132
 133         i->browser = b;
 134         i->interface = interface;
 135         i->protocol = protocol;
 136         i->srv_record = avahi_record_ref(record);
 137         i->host_name_resolver = avahi_host_name_resolver_new(b->server, interface, protocol, record->data.srv.name, b->aprotocol, host_name_resolver_callback, i);
 138
 139         AVAHI_LLIST_PREPEND(AvahiDNSServerInfo, info, b->info, i);
 140
 141         b->n_info++;
 142     } else if (event == AVAHI_BROWSER_REMOVE) {
 143         AvahiDNSServerInfo *i;
 144
 145         if (!(i = get_server_info(b, interface, protocol, record)))
 146             return;
 147
 148         if (!i->host_name_resolver)
 149             b->callback(b, interface, protocol, event, i->srv_record->data.srv.name, &i->address, i->srv_record->data.srv.port, b->userdata);
 150
 151         server_info_free(b, i);
 152     }
 153 }
 154
 155 AvahiDNSServerBrowser *avahi_dns_server_browser_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const char *domain, AvahiDNSServerType type, AvahiProtocol aprotocol, AvahiDNSServerBrowserCallback callback, void* userdata) {
 156     AvahiDNSServerBrowser *b;
 157     AvahiKey *k;
 158     char *n = NULL;
 159
 160     assert(server);
 161     assert(callback);
 162     assert(type == AVAHI_DNS_SERVER_RESOLVE || type == AVAHI_DNS_SERVER_UPDATE);
 163
 164     if (domain && !avahi_is_valid_domain_name(domain)) {
 165         avahi_server_set_errno(server, AVAHI_ERR_INVALID_DOMAIN_NAME);
 166         return NULL;
 167     }
 168
 169     if (!(b = avahi_new(AvahiDNSServerBrowser, 1))) {
 170         avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
 171         return NULL;
 172     }
 173
 174     b->server = server;
 175     b->domain_name = avahi_normalize_name(domain ? domain : "local");
 176     b->callback = callback;
 177     b->userdata = userdata;
 178     b->aprotocol = aprotocol;
 179     b->n_info = 0;
 180
 181     AVAHI_LLIST_HEAD_INIT(AvahiDNSServerInfo, b->info);
 182     AVAHI_LLIST_PREPEND(AvahiDNSServerBrowser, browser, server->dns_server_browsers, b);
 183
 184     n = avahi_strdup_printf("%s.%s",type == AVAHI_DNS_SERVER_RESOLVE ? "_domain._udp" : "_dns-update._udp", b->domain_name);
 185     k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
 186     avahi_free(n);
 187
 188     b->record_browser = avahi_record_browser_new(server, interface, protocol, k, record_browser_callback, b);
 189     avahi_key_unref(k);
 190
 191     if (!b->record_browser) {
 192         avahi_dns_server_browser_free(b);
 193         return NULL;
 194     }
 195
 196     return b;
 197 }
 198
 199 void avahi_dns_server_browser_free(AvahiDNSServerBrowser *b) {
 200     assert(b);
 201
 202     while (b->info)
 203         server_info_free(b, b->info);
 204
 205     AVAHI_LLIST_REMOVE(AvahiDNSServerBrowser, browser, b->server->dns_server_browsers, b);
 206
 207     if (b->record_browser)
 208         avahi_record_browser_free(b->record_browser);
 209     avahi_free(b->domain_name);
 210     avahi_free(b);
 211 }
 212