browse-dns-server.c revision 0632e854728e8e64552ae08f90852d4a2658539e 
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 "browse.h"
29#include "util.h"
30#include "log.h"
31#include "rr.h"
32
33typedef struct AvahiDNSServerInfo AvahiDNSServerInfo;
34
35struct AvahiDNSServerInfo {
36    AvahiDNSServerBrowser *browser;
37
38    AvahiIfIndex interface;
39    AvahiProtocol protocol;
40    AvahiRecord *srv_record;
41    AvahiHostNameResolver *host_name_resolver;
42    AvahiAddress address;
43
44    AVAHI_LLIST_FIELDS(AvahiDNSServerInfo, info);
45};
46
47struct AvahiDNSServerBrowser {
48    AvahiServer *server;
49    gchar *domain_name;
50
51    AvahiRecordBrowser *record_browser;
52    AvahiDNSServerBrowserCallback callback;
53    gpointer userdata;
54    AvahiProtocol aprotocol;
55
56    guint n_info;
57
58    AVAHI_LLIST_FIELDS(AvahiDNSServerBrowser, browser);
59    AVAHI_LLIST_HEAD(AvahiDNSServerInfo, info);
60};
61
62static AvahiDNSServerInfo* get_server_info(AvahiDNSServerBrowser *b, AvahiIfIndex interface, AvahiProtocol protocol, AvahiRecord *r) {
63    AvahiDNSServerInfo *i;
64
65    g_assert(b);
66    g_assert(r);
67
68    for (i = b->info; i; i = i->info_next)
69        if (i->interface == interface &&
70            i->protocol == protocol &&
71            avahi_record_equal_no_ttl(r, i->srv_record))
72            return i;
73
74    return NULL;
75}
76
77static void server_info_free(AvahiDNSServerBrowser *b, AvahiDNSServerInfo *i) {
78    g_assert(b);
79    g_assert(i);
80
81    avahi_record_unref(i->srv_record);
82    if (i->host_name_resolver)
83        avahi_host_name_resolver_free(i->host_name_resolver);
84
85    AVAHI_LLIST_REMOVE(AvahiDNSServerInfo, info, b->info, i);
86
87    g_assert(b->n_info >= 1);
88    b->n_info--;
89
90    g_free(i);
91}
92
93static void host_name_resolver_callback(AvahiHostNameResolver *r, AvahiIfIndex interface, AvahiProtocol protocol, AvahiResolverEvent event, const gchar *host_name, const AvahiAddress *a, gpointer userdata) {
94    AvahiDNSServerInfo *i = userdata;
95
96    g_assert(r);
97    g_assert(host_name);
98    g_assert(i);
99
100    if (event == AVAHI_RESOLVER_FOUND) {
101        i->address = *a;
102
103        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);
104    }
105
106    avahi_host_name_resolver_free(i->host_name_resolver);
107    i->host_name_resolver = NULL;
108}
109
110static void record_browser_callback(AvahiRecordBrowser*rr, AvahiIfIndex interface, AvahiProtocol protocol, AvahiBrowserEvent event, AvahiRecord *record, gpointer userdata) {
111    AvahiDNSServerBrowser *b = userdata;
112
113    g_assert(rr);
114    g_assert(record);
115    g_assert(b);
116
117    g_assert(record->key->type == AVAHI_DNS_TYPE_SRV);
118
119    if (event == AVAHI_BROWSER_NEW) {
120        AvahiDNSServerInfo *i;
121
122        if (get_server_info(b, interface, protocol, record))
123            return;
124
125        if (b->n_info >= 10)
126            return;
127
128        i = g_new(AvahiDNSServerInfo, 1);
129        i->browser = b;
130        i->interface = interface;
131        i->protocol = protocol;
132        i->srv_record = avahi_record_ref(record);
133        i->host_name_resolver = avahi_host_name_resolver_new(b->server, interface, protocol, record->data.srv.name, b->aprotocol, host_name_resolver_callback, i);
134
135        AVAHI_LLIST_PREPEND(AvahiDNSServerInfo, info, b->info, i);
136
137        b->n_info++;
138    } else if (event == AVAHI_BROWSER_REMOVE) {
139        AvahiDNSServerInfo *i;
140
141        if (!(i = get_server_info(b, interface, protocol, record)))
142            return;
143
144        if (!i->host_name_resolver)
145            b->callback(b, interface, protocol, event, i->srv_record->data.srv.name, &i->address, i->srv_record->data.srv.port, b->userdata);
146
147        server_info_free(b, i);
148    }
149}
150
151AvahiDNSServerBrowser *avahi_dns_server_browser_new(AvahiServer *server, AvahiIfIndex interface, AvahiProtocol protocol, const gchar *domain, AvahiDNSServerType type, AvahiProtocol aprotocol, AvahiDNSServerBrowserCallback callback, gpointer userdata) {
152    AvahiDNSServerBrowser *b;
153    AvahiKey *k;
154    gchar *n = NULL;
155
156    g_assert(server);
157    g_assert(callback);
158    g_assert(type == AVAHI_DNS_SERVER_RESOLVE || type == AVAHI_DNS_SERVER_UPDATE);
159
160    if (domain && !avahi_valid_domain_name(domain)) {
161        avahi_server_set_errno(server, AVAHI_ERR_INVALID_DOMAIN_NAME);
162        return NULL;
163    }
164
165    b = g_new(AvahiDNSServerBrowser, 1);
166    b->server = server;
167    b->domain_name = avahi_normalize_name(domain ? domain : "local");
168    b->callback = callback;
169    b->userdata = userdata;
170    b->aprotocol = aprotocol;
171    b->n_info = 0;
172
173    AVAHI_LLIST_HEAD_INIT(AvahiDNSServerInfo, b->info);
174    AVAHI_LLIST_PREPEND(AvahiDNSServerBrowser, browser, server->dns_server_browsers, b);
175
176    n = g_strdup_printf("%s.%s",type == AVAHI_DNS_SERVER_RESOLVE ? "_domain._udp" : "_dns-update._udp", b->domain_name);
177    k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
178    g_free(n);
179
180    b->record_browser = avahi_record_browser_new(server, interface, protocol, k, record_browser_callback, b);
181    avahi_key_unref(k);
182
183    if (!b->record_browser) {
184        avahi_dns_server_browser_free(b);
185        return NULL;
186    }
187
188    return b;
189}
190
191void avahi_dns_server_browser_free(AvahiDNSServerBrowser *b) {
192    g_assert(b);
193
194    while (b->info)
195        server_info_free(b, b->info);
196
197    AVAHI_LLIST_REMOVE(AvahiDNSServerBrowser, browser, b->server->dns_server_browsers, b);
198
199    if (b->record_browser)
200        avahi_record_browser_free(b->record_browser);
201    g_free(b->domain_name);
202    g_free(b);
203}
204
205