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/malloc.h>
30#include <avahi-common/error.h>
31
32#include "browse.h"
33#include "log.h"
34
35struct AvahiSDomainBrowser {
36    int ref;
37
38    AvahiServer *server;
39
40    AvahiSRecordBrowser *record_browser;
41
42    AvahiDomainBrowserType type;
43    AvahiSDomainBrowserCallback callback;
44    void* userdata;
45
46    AvahiTimeEvent *defer_event;
47
48    int all_for_now_scheduled;
49
50    AVAHI_LLIST_FIELDS(AvahiSDomainBrowser, browser);
51};
52
53static void inc_ref(AvahiSDomainBrowser *b) {
54    assert(b);
55    assert(b->ref >= 1);
56
57    b->ref++;
58}
59
60static void record_browser_callback(
61    AvahiSRecordBrowser*rr,
62    AvahiIfIndex interface,
63    AvahiProtocol protocol,
64    AvahiBrowserEvent event,
65    AvahiRecord *record,
66    AvahiLookupResultFlags flags,
67    void* userdata) {
68
69    AvahiSDomainBrowser *b = userdata;
70    char *n = NULL;
71
72    assert(rr);
73    assert(b);
74
75    if (event == AVAHI_BROWSER_ALL_FOR_NOW &&
76        b->defer_event) {
77
78        b->all_for_now_scheduled = 1;
79        return;
80    }
81
82    /* Filter flags */
83    flags &= AVAHI_LOOKUP_RESULT_CACHED | AVAHI_LOOKUP_RESULT_MULTICAST | AVAHI_LOOKUP_RESULT_WIDE_AREA;
84
85    if (record) {
86        assert(record->key->type == AVAHI_DNS_TYPE_PTR);
87        n = record->data.ptr.name;
88
89        if (b->type == AVAHI_DOMAIN_BROWSER_BROWSE) {
90            AvahiStringList *l;
91
92            /* Filter out entries defined statically */
93
94            for (l = b->server->config.browse_domains; l; l = l->next)
95                if (avahi_domain_equal((char*) l->text, n))
96                    return;
97        }
98
99    }
100
101    b->callback(b, interface, protocol, event, n, flags, b->userdata);
102}
103
104static void defer_callback(AvahiTimeEvent *e, void *userdata) {
105    AvahiSDomainBrowser *b = userdata;
106    AvahiStringList *l;
107
108    assert(e);
109    assert(b);
110
111    assert(b->type == AVAHI_DOMAIN_BROWSER_BROWSE);
112
113    avahi_time_event_free(b->defer_event);
114    b->defer_event = NULL;
115
116    /* Increase ref counter */
117    inc_ref(b);
118
119    for (l = b->server->config.browse_domains; l; l = l->next) {
120
121        /* Check whether this object still exists outside our own
122         * stack frame */
123        if (b->ref <= 1)
124            break;
125
126        b->callback(b, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_BROWSER_NEW, (char*) l->text, AVAHI_LOOKUP_RESULT_STATIC, b->userdata);
127    }
128
129    if (b->ref > 1) {
130        /* If the ALL_FOR_NOW event has already been scheduled, execute it now */
131
132        if (b->all_for_now_scheduled)
133            b->callback(b, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, AVAHI_BROWSER_ALL_FOR_NOW, NULL, 0, b->userdata);
134    }
135
136    /* Decrease ref counter */
137    avahi_s_domain_browser_free(b);
138}
139
140AvahiSDomainBrowser *avahi_s_domain_browser_new(
141    AvahiServer *server,
142    AvahiIfIndex interface,
143    AvahiProtocol protocol,
144    const char *domain,
145    AvahiDomainBrowserType type,
146    AvahiLookupFlags flags,
147    AvahiSDomainBrowserCallback callback,
148    void* userdata) {
149
150    static const char * const type_table[AVAHI_DOMAIN_BROWSER_MAX] = {
151        "b",
152        "db",
153        "r",
154        "dr",
155        "lb"
156    };
157
158    AvahiSDomainBrowser *b;
159    AvahiKey *k = NULL;
160    char n[AVAHI_DOMAIN_NAME_MAX];
161    int r;
162
163    assert(server);
164    assert(callback);
165
166    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
167    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
168    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, type < AVAHI_DOMAIN_BROWSER_MAX, AVAHI_ERR_INVALID_FLAGS);
169    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
170    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST), AVAHI_ERR_INVALID_FLAGS);
171
172    if (!domain)
173        domain = server->domain_name;
174
175    if ((r = avahi_service_name_join(n, sizeof(n), type_table[type], "_dns-sd._udp", domain)) < 0) {
176        avahi_server_set_errno(server, r);
177        return NULL;
178    }
179
180    if (!(b = avahi_new(AvahiSDomainBrowser, 1))) {
181        avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
182        return NULL;
183    }
184
185    b->ref = 1;
186    b->server = server;
187    b->callback = callback;
188    b->userdata = userdata;
189    b->record_browser = NULL;
190    b->type = type;
191    b->all_for_now_scheduled = 0;
192    b->defer_event = NULL;
193
194    AVAHI_LLIST_PREPEND(AvahiSDomainBrowser, browser, server->domain_browsers, b);
195
196    if (!(k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_PTR))) {
197        avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
198        goto fail;
199    }
200
201    if (!(b->record_browser = avahi_s_record_browser_new(server, interface, protocol, k, flags, record_browser_callback, b)))
202        goto fail;
203
204    avahi_key_unref(k);
205
206    if (type == AVAHI_DOMAIN_BROWSER_BROWSE && b->server->config.browse_domains)
207        b->defer_event = avahi_time_event_new(server->time_event_queue, NULL, defer_callback, b);
208
209    return b;
210
211fail:
212
213    if (k)
214        avahi_key_unref(k);
215
216    avahi_s_domain_browser_free(b);
217
218    return NULL;
219}
220
221void avahi_s_domain_browser_free(AvahiSDomainBrowser *b) {
222    assert(b);
223
224    assert(b->ref >= 1);
225    if (--b->ref > 0)
226        return;
227
228    AVAHI_LLIST_REMOVE(AvahiSDomainBrowser, browser, b->server->domain_browsers, b);
229
230    if (b->record_browser)
231        avahi_s_record_browser_free(b->record_browser);
232
233    if (b->defer_event)
234        avahi_time_event_free(b->defer_event);
235
236    avahi_free(b);
237}
238