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#include <stdio.h>
28#include <stdlib.h>
29
30#include <avahi-common/domain.h>
31#include <avahi-common/timeval.h>
32#include <avahi-common/malloc.h>
33#include <avahi-common/error.h>
34
35#include "browse.h"
36#include "log.h"
37
38#define TIMEOUT_MSEC 5000
39
40struct AvahiSServiceResolver {
41    AvahiServer *server;
42    char *service_name;
43    char *service_type;
44    char *domain_name;
45    AvahiProtocol address_protocol;
46
47    AvahiIfIndex interface;
48    AvahiProtocol protocol;
49
50    AvahiSRecordBrowser *record_browser_srv;
51    AvahiSRecordBrowser *record_browser_txt;
52    AvahiSRecordBrowser *record_browser_a;
53    AvahiSRecordBrowser *record_browser_aaaa;
54
55    AvahiRecord *srv_record, *txt_record, *address_record;
56    AvahiLookupResultFlags srv_flags, txt_flags, address_flags;
57
58    AvahiSServiceResolverCallback callback;
59    void* userdata;
60    AvahiLookupFlags user_flags;
61
62    AvahiTimeEvent *time_event;
63
64    AVAHI_LLIST_FIELDS(AvahiSServiceResolver, resolver);
65};
66
67static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
68    AvahiLookupResultFlags flags;
69
70    assert(r);
71
72    if (r->time_event) {
73        avahi_time_event_free(r->time_event);
74        r->time_event = NULL;
75    }
76
77    flags =
78        r->txt_flags |
79        r->srv_flags |
80        r->address_flags;
81
82    switch (event) {
83        case AVAHI_RESOLVER_FAILURE:
84
85            r->callback(
86                r,
87                r->interface,
88                r->protocol,
89                event,
90                r->service_name,
91                r->service_type,
92                r->domain_name,
93                NULL,
94                NULL,
95                0,
96                NULL,
97                flags,
98                r->userdata);
99
100            break;
101
102        case AVAHI_RESOLVER_FOUND: {
103            AvahiAddress a;
104
105            assert(event == AVAHI_RESOLVER_FOUND);
106
107            assert(r->srv_record);
108
109            if (r->address_record) {
110                switch (r->address_record->key->type) {
111                    case AVAHI_DNS_TYPE_A:
112                        a.proto = AVAHI_PROTO_INET;
113                        a.data.ipv4 = r->address_record->data.a.address;
114                        break;
115
116                    case AVAHI_DNS_TYPE_AAAA:
117                        a.proto = AVAHI_PROTO_INET6;
118                        a.data.ipv6 = r->address_record->data.aaaa.address;
119                        break;
120
121                    default:
122                        assert(0);
123                }
124            }
125
126            r->callback(
127                r,
128                r->interface,
129                r->protocol,
130                event,
131                r->service_name,
132                r->service_type,
133                r->domain_name,
134                r->srv_record->data.srv.name,
135                r->address_record ? &a : NULL,
136                r->srv_record->data.srv.port,
137                r->txt_record ? r->txt_record->data.txt.string_list : NULL,
138                flags,
139                r->userdata);
140
141            break;
142        }
143    }
144}
145
146static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
147    AvahiSServiceResolver *r = userdata;
148
149    assert(e);
150    assert(r);
151
152    avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
153    finish(r, AVAHI_RESOLVER_FAILURE);
154}
155
156static void start_timeout(AvahiSServiceResolver *r) {
157    struct timeval tv;
158    assert(r);
159
160    if (r->time_event)
161        return;
162
163    avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
164
165    r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
166}
167
168static void record_browser_callback(
169    AvahiSRecordBrowser*rr,
170    AvahiIfIndex interface,
171    AvahiProtocol protocol,
172    AvahiBrowserEvent event,
173    AvahiRecord *record,
174    AvahiLookupResultFlags flags,
175    void* userdata) {
176
177    AvahiSServiceResolver *r = userdata;
178
179    assert(rr);
180    assert(r);
181
182    if (rr == r->record_browser_aaaa || rr == r->record_browser_a)
183        r->address_flags = flags;
184    else if (rr == r->record_browser_srv)
185        r->srv_flags = flags;
186    else if (rr == r->record_browser_txt)
187        r->txt_flags = flags;
188
189    switch (event) {
190
191        case AVAHI_BROWSER_NEW: {
192            int changed = 0;
193            assert(record);
194
195            if (r->interface > 0 && interface > 0 &&  interface != r->interface)
196                return;
197
198            if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
199                return;
200
201            if (r->interface <= 0)
202                r->interface = interface;
203
204            if (r->protocol == AVAHI_PROTO_UNSPEC)
205                r->protocol = protocol;
206
207            switch (record->key->type) {
208                case AVAHI_DNS_TYPE_SRV:
209                    if (!r->srv_record) {
210                        r->srv_record = avahi_record_ref(record);
211                        changed = 1;
212
213                        if (r->record_browser_a) {
214                            avahi_s_record_browser_free(r->record_browser_a);
215                            r->record_browser_a = NULL;
216                        }
217
218                        if (r->record_browser_aaaa) {
219                            avahi_s_record_browser_free(r->record_browser_aaaa);
220                            r->record_browser_aaaa = NULL;
221                        }
222
223                        if (!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)) {
224
225                            if (r->address_protocol == AVAHI_PROTO_INET || r->address_protocol == AVAHI_PROTO_UNSPEC) {
226                                AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
227                                r->record_browser_a = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
228                                avahi_key_unref(k);
229                            }
230
231                            if (r->address_protocol == AVAHI_PROTO_INET6 || r->address_protocol == AVAHI_PROTO_UNSPEC) {
232                                AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
233                                r->record_browser_aaaa = avahi_s_record_browser_new(r->server, r->interface, r->protocol, k, r->user_flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
234                                avahi_key_unref(k);
235                            }
236                        }
237                    }
238                    break;
239
240                case AVAHI_DNS_TYPE_TXT:
241
242                    assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
243
244                    if (!r->txt_record) {
245                        r->txt_record = avahi_record_ref(record);
246                        changed = 1;
247                    }
248                    break;
249
250                case AVAHI_DNS_TYPE_A:
251                case AVAHI_DNS_TYPE_AAAA:
252
253                    assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
254
255                    if (!r->address_record) {
256                        r->address_record = avahi_record_ref(record);
257                        changed = 1;
258                    }
259                    break;
260
261                default:
262                    abort();
263            }
264
265
266            if (changed &&
267                r->srv_record &&
268                (r->txt_record || (r->user_flags & AVAHI_LOOKUP_NO_TXT)) &&
269                (r->address_record || (r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)))
270                finish(r, AVAHI_RESOLVER_FOUND);
271
272            break;
273
274        }
275
276        case AVAHI_BROWSER_REMOVE:
277
278            assert(record);
279
280            switch (record->key->type) {
281                case AVAHI_DNS_TYPE_SRV:
282
283                    if (r->srv_record && avahi_record_equal_no_ttl(record, r->srv_record)) {
284                        avahi_record_unref(r->srv_record);
285                        r->srv_record = NULL;
286
287                        if (r->record_browser_a) {
288                            avahi_s_record_browser_free(r->record_browser_a);
289                            r->record_browser_a = NULL;
290                        }
291
292                        if (r->record_browser_aaaa) {
293                            avahi_s_record_browser_free(r->record_browser_aaaa);
294                            r->record_browser_aaaa = NULL;
295                        }
296
297                        /** Look for a replacement */
298                        avahi_s_record_browser_restart(r->record_browser_srv);
299                        start_timeout(r);
300                    }
301
302                    break;
303
304                case AVAHI_DNS_TYPE_TXT:
305
306                    assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
307
308                    if (r->txt_record && avahi_record_equal_no_ttl(record, r->txt_record)) {
309                        avahi_record_unref(r->txt_record);
310                        r->txt_record = NULL;
311
312                        /** Look for a replacement */
313                        avahi_s_record_browser_restart(r->record_browser_txt);
314                        start_timeout(r);
315                    }
316                    break;
317
318                case AVAHI_DNS_TYPE_A:
319                case AVAHI_DNS_TYPE_AAAA:
320
321                    assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
322
323                    if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
324                        avahi_record_unref(r->address_record);
325                        r->address_record = NULL;
326
327                        /** Look for a replacement */
328                        if (r->record_browser_aaaa)
329                            avahi_s_record_browser_restart(r->record_browser_aaaa);
330                        if (r->record_browser_a)
331                            avahi_s_record_browser_restart(r->record_browser_a);
332                        start_timeout(r);
333                    }
334                    break;
335
336                default:
337                    abort();
338            }
339
340            break;
341
342        case AVAHI_BROWSER_CACHE_EXHAUSTED:
343        case AVAHI_BROWSER_ALL_FOR_NOW:
344            break;
345
346        case AVAHI_BROWSER_FAILURE:
347
348            if (rr == r->record_browser_a && r->record_browser_aaaa) {
349                /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
350                avahi_s_record_browser_free(r->record_browser_a);
351                r->record_browser_a = NULL;
352                break;
353            }
354
355            if (rr == r->record_browser_aaaa && r->record_browser_a) {
356                /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
357                avahi_s_record_browser_free(r->record_browser_aaaa);
358                r->record_browser_aaaa = NULL;
359                break;
360            }
361
362            /* Hmm, everything's lost, tell the user */
363
364            if (r->record_browser_srv)
365                avahi_s_record_browser_free(r->record_browser_srv);
366            if (r->record_browser_txt)
367                avahi_s_record_browser_free(r->record_browser_txt);
368            if (r->record_browser_a)
369                avahi_s_record_browser_free(r->record_browser_a);
370            if (r->record_browser_aaaa)
371                avahi_s_record_browser_free(r->record_browser_aaaa);
372
373            r->record_browser_srv = r->record_browser_txt = r->record_browser_a = r->record_browser_aaaa = NULL;
374
375            finish(r, AVAHI_RESOLVER_FAILURE);
376            break;
377    }
378}
379
380AvahiSServiceResolver *avahi_s_service_resolver_new(
381    AvahiServer *server,
382    AvahiIfIndex interface,
383    AvahiProtocol protocol,
384    const char *name,
385    const char *type,
386    const char *domain,
387    AvahiProtocol aprotocol,
388    AvahiLookupFlags flags,
389    AvahiSServiceResolverCallback callback,
390    void* userdata) {
391
392    AvahiSServiceResolver *r;
393    AvahiKey *k;
394    char n[AVAHI_DOMAIN_NAME_MAX];
395    int ret;
396
397    assert(server);
398    assert(type);
399    assert(callback);
400
401    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
402    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
403    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(aprotocol), AVAHI_ERR_INVALID_PROTOCOL);
404    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
405    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !name || avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME);
406    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE);
407    AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_FLAGS_VALID(flags, AVAHI_LOOKUP_USE_WIDE_AREA|AVAHI_LOOKUP_USE_MULTICAST|AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), AVAHI_ERR_INVALID_FLAGS);
408
409    if (!domain)
410        domain = server->domain_name;
411
412    if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain)) < 0) {
413        avahi_server_set_errno(server, ret);
414        return NULL;
415    }
416
417    if (!(r = avahi_new(AvahiSServiceResolver, 1))) {
418        avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
419        return NULL;
420    }
421
422    r->server = server;
423    r->service_name = avahi_strdup(name);
424    r->service_type = avahi_normalize_name_strdup(type);
425    r->domain_name = avahi_normalize_name_strdup(domain);
426    r->callback = callback;
427    r->userdata = userdata;
428    r->address_protocol = aprotocol;
429    r->srv_record = r->txt_record = r->address_record = NULL;
430    r->srv_flags = r->txt_flags = r->address_flags = 0;
431    r->interface = interface;
432    r->protocol = protocol;
433    r->user_flags = flags;
434    r->record_browser_a = r->record_browser_aaaa = r->record_browser_srv = r->record_browser_txt = NULL;
435    r->time_event = NULL;
436    AVAHI_LLIST_PREPEND(AvahiSServiceResolver, resolver, server->service_resolvers, r);
437
438    k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
439    r->record_browser_srv = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS), record_browser_callback, r);
440    avahi_key_unref(k);
441
442    if (!r->record_browser_srv) {
443        avahi_s_service_resolver_free(r);
444        return NULL;
445    }
446
447    if (!(flags & AVAHI_LOOKUP_NO_TXT)) {
448        k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_TXT);
449        r->record_browser_txt = avahi_s_record_browser_new(server, interface, protocol, k, flags & ~(AVAHI_LOOKUP_NO_TXT|AVAHI_LOOKUP_NO_ADDRESS),  record_browser_callback, r);
450        avahi_key_unref(k);
451
452        if (!r->record_browser_txt) {
453            avahi_s_service_resolver_free(r);
454            return NULL;
455        }
456    }
457
458    start_timeout(r);
459
460    return r;
461}
462
463void avahi_s_service_resolver_free(AvahiSServiceResolver *r) {
464    assert(r);
465
466    AVAHI_LLIST_REMOVE(AvahiSServiceResolver, resolver, r->server->service_resolvers, r);
467
468    if (r->time_event)
469        avahi_time_event_free(r->time_event);
470
471    if (r->record_browser_srv)
472        avahi_s_record_browser_free(r->record_browser_srv);
473    if (r->record_browser_txt)
474        avahi_s_record_browser_free(r->record_browser_txt);
475    if (r->record_browser_a)
476        avahi_s_record_browser_free(r->record_browser_a);
477    if (r->record_browser_aaaa)
478        avahi_s_record_browser_free(r->record_browser_aaaa);
479
480    if (r->srv_record)
481        avahi_record_unref(r->srv_record);
482    if (r->txt_record)
483        avahi_record_unref(r->txt_record);
484    if (r->address_record)
485        avahi_record_unref(r->address_record);
486
487    avahi_free(r->service_name);
488    avahi_free(r->service_type);
489    avahi_free(r->domain_name);
490    avahi_free(r);
491}
492