1 /***
2 This file is part of avahi.
3
4 avahi is free software; you can redistribute it and/or modify it
5 under the terms of the GNU Lesser General Public License as
6 published by the Free Software Foundation; either version 2.1 of the
7 License, or (at your option) any later version.
8
9 avahi is distributed in the hope that it will be useful, but WITHOUT
10 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12 Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with avahi; if not, write to the Free Software
16 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17 USA.
18 ***/
19
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27
28 #include <avahi-common/domain.h>
29 #include <avahi-common/timeval.h>
30 #include "avahi-common/avahi-malloc.h"
31 #include <avahi-common/error.h>
32
33 #include "browse.h"
34 #include "log.h"
35
36 #define TIMEOUT_MSEC 5000
37
38 struct AvahiSServiceResolver {
39 AvahiServer *server;
40 char *service_name;
41 char *service_type;
42 char *domain_name;
43 AvahiProtocol address_protocol;
44
45 AvahiIfIndex interface;
46 AvahiProtocol protocol;
47
48 AvahiSRecordBrowser *record_browser_srv;
49 AvahiSRecordBrowser *record_browser_txt;
50 AvahiSRecordBrowser *record_browser_a;
51 AvahiSRecordBrowser *record_browser_aaaa;
52
53 AvahiRecord *srv_record, *txt_record, *address_record;
54 AvahiLookupResultFlags srv_flags, txt_flags, address_flags;
55
56 AvahiSServiceResolverCallback callback;
57 void* userdata;
58 AvahiLookupFlags user_flags;
59
60 AvahiTimeEvent *time_event;
61
62 AVAHI_LLIST_FIELDS(AvahiSServiceResolver, resolver);
63 };
64
finish(AvahiSServiceResolver * r,AvahiResolverEvent event)65 static void finish(AvahiSServiceResolver *r, AvahiResolverEvent event) {
66 AvahiLookupResultFlags flags;
67
68 assert(r);
69
70 if (r->time_event) {
71 avahi_time_event_free(r->time_event);
72 r->time_event = NULL;
73 }
74
75 flags =
76 r->txt_flags |
77 r->srv_flags |
78 r->address_flags;
79
80 switch (event) {
81 case AVAHI_RESOLVER_FAILURE:
82
83 r->callback(
84 r,
85 r->interface,
86 r->protocol,
87 event,
88 r->service_name,
89 r->service_type,
90 r->domain_name,
91 NULL,
92 NULL,
93 0,
94 NULL,
95 flags,
96 r->userdata);
97
98 break;
99
100 case AVAHI_RESOLVER_FOUND: {
101 AvahiAddress a;
102
103 assert(event == AVAHI_RESOLVER_FOUND);
104
105 assert(r->srv_record);
106
107 if (r->address_record) {
108 switch (r->address_record->key->type) {
109 case AVAHI_DNS_TYPE_A:
110 a.proto = AVAHI_PROTO_INET;
111 a.data.ipv4 = r->address_record->data.a.address;
112 break;
113
114 case AVAHI_DNS_TYPE_AAAA:
115 a.proto = AVAHI_PROTO_INET6;
116 a.data.ipv6 = r->address_record->data.aaaa.address;
117 break;
118
119 default:
120 assert(0);
121 }
122 }
123
124 r->callback(
125 r,
126 r->interface,
127 r->protocol,
128 event,
129 r->service_name,
130 r->service_type,
131 r->domain_name,
132 r->srv_record->data.srv.name,
133 r->address_record ? &a : NULL,
134 r->srv_record->data.srv.port,
135 r->txt_record ? r->txt_record->data.txt.string_list : NULL,
136 flags,
137 r->userdata);
138
139 break;
140 }
141 }
142 }
143
time_event_callback(AvahiTimeEvent * e,void * userdata)144 static void time_event_callback(AvahiTimeEvent *e, void *userdata) {
145 AvahiSServiceResolver *r = userdata;
146
147 assert(e);
148 assert(r);
149
150 avahi_server_set_errno(r->server, AVAHI_ERR_TIMEOUT);
151 finish(r, AVAHI_RESOLVER_FAILURE);
152 }
153
start_timeout(AvahiSServiceResolver * r)154 static void start_timeout(AvahiSServiceResolver *r) {
155 struct timeval tv;
156 assert(r);
157
158 if (r->time_event)
159 return;
160
161 avahi_elapse_time(&tv, TIMEOUT_MSEC, 0);
162
163 r->time_event = avahi_time_event_new(r->server->time_event_queue, &tv, time_event_callback, r);
164 }
165
record_browser_callback(AvahiSRecordBrowser * rr,AvahiIfIndex interface,AvahiProtocol protocol,AvahiBrowserEvent event,AvahiRecord * record,AvahiLookupResultFlags flags,void * userdata)166 static void record_browser_callback(
167 AvahiSRecordBrowser*rr,
168 AvahiIfIndex interface,
169 AvahiProtocol protocol,
170 AvahiBrowserEvent event,
171 AvahiRecord *record,
172 AvahiLookupResultFlags flags,
173 void* userdata) {
174
175 AvahiSServiceResolver *r = userdata;
176
177 assert(rr);
178 assert(r);
179
180 if (rr == r->record_browser_aaaa || rr == r->record_browser_a)
181 r->address_flags = flags;
182 else if (rr == r->record_browser_srv)
183 r->srv_flags = flags;
184 else if (rr == r->record_browser_txt)
185 r->txt_flags = flags;
186
187 switch (event) {
188
189 case AVAHI_BROWSER_NEW: {
190 int changed = 0;
191 assert(record);
192
193 if (r->interface > 0 && interface > 0 && interface != r->interface)
194 return;
195
196 if (r->protocol != AVAHI_PROTO_UNSPEC && protocol != AVAHI_PROTO_UNSPEC && protocol != r->protocol)
197 return;
198
199 if (r->interface <= 0)
200 r->interface = interface;
201
202 if (r->protocol == AVAHI_PROTO_UNSPEC)
203 r->protocol = protocol;
204
205 switch (record->key->type) {
206 case AVAHI_DNS_TYPE_SRV:
207 if (!r->srv_record) {
208 r->srv_record = avahi_record_ref(record);
209 changed = 1;
210
211 if (r->record_browser_a) {
212 avahi_s_record_browser_free(r->record_browser_a);
213 r->record_browser_a = NULL;
214 }
215
216 if (r->record_browser_aaaa) {
217 avahi_s_record_browser_free(r->record_browser_aaaa);
218 r->record_browser_aaaa = NULL;
219 }
220
221 if (!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)) {
222
223 if (r->address_protocol == AVAHI_PROTO_INET || r->address_protocol == AVAHI_PROTO_UNSPEC) {
224 AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_A);
225 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);
226 avahi_key_unref(k);
227 }
228
229 if (r->address_protocol == AVAHI_PROTO_INET6 || r->address_protocol == AVAHI_PROTO_UNSPEC) {
230 AvahiKey *k = avahi_key_new(r->srv_record->data.srv.name, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_AAAA);
231 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);
232 avahi_key_unref(k);
233 }
234 }
235 }
236 break;
237
238 case AVAHI_DNS_TYPE_TXT:
239
240 assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
241
242 if (!r->txt_record) {
243 r->txt_record = avahi_record_ref(record);
244 changed = 1;
245 }
246 break;
247
248 case AVAHI_DNS_TYPE_A:
249 case AVAHI_DNS_TYPE_AAAA:
250
251 assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
252
253 if (!r->address_record) {
254 r->address_record = avahi_record_ref(record);
255 changed = 1;
256 }
257 break;
258
259 default:
260 abort();
261 }
262
263
264 if (changed &&
265 r->srv_record &&
266 (r->txt_record || (r->user_flags & AVAHI_LOOKUP_NO_TXT)) &&
267 (r->address_record || (r->user_flags & AVAHI_LOOKUP_NO_ADDRESS)))
268 finish(r, AVAHI_RESOLVER_FOUND);
269
270 break;
271
272 }
273
274 case AVAHI_BROWSER_REMOVE:
275
276 assert(record);
277
278 switch (record->key->type) {
279 case AVAHI_DNS_TYPE_SRV:
280
281 if (r->srv_record && avahi_record_equal_no_ttl(record, r->srv_record)) {
282 avahi_record_unref(r->srv_record);
283 r->srv_record = NULL;
284
285 if (r->record_browser_a) {
286 avahi_s_record_browser_free(r->record_browser_a);
287 r->record_browser_a = NULL;
288 }
289
290 if (r->record_browser_aaaa) {
291 avahi_s_record_browser_free(r->record_browser_aaaa);
292 r->record_browser_aaaa = NULL;
293 }
294
295 /** Look for a replacement */
296 avahi_s_record_browser_restart(r->record_browser_srv);
297 start_timeout(r);
298 }
299
300 break;
301
302 case AVAHI_DNS_TYPE_TXT:
303
304 assert(!(r->user_flags & AVAHI_LOOKUP_NO_TXT));
305
306 if (r->txt_record && avahi_record_equal_no_ttl(record, r->txt_record)) {
307 avahi_record_unref(r->txt_record);
308 r->txt_record = NULL;
309
310 /** Look for a replacement */
311 avahi_s_record_browser_restart(r->record_browser_txt);
312 start_timeout(r);
313 }
314 break;
315
316 case AVAHI_DNS_TYPE_A:
317 case AVAHI_DNS_TYPE_AAAA:
318
319 assert(!(r->user_flags & AVAHI_LOOKUP_NO_ADDRESS));
320
321 if (r->address_record && avahi_record_equal_no_ttl(record, r->address_record)) {
322 avahi_record_unref(r->address_record);
323 r->address_record = NULL;
324
325 /** Look for a replacement */
326 if (r->record_browser_aaaa)
327 avahi_s_record_browser_restart(r->record_browser_aaaa);
328 if (r->record_browser_a)
329 avahi_s_record_browser_restart(r->record_browser_a);
330 start_timeout(r);
331 }
332 break;
333
334 default:
335 abort();
336 }
337
338 break;
339
340 case AVAHI_BROWSER_CACHE_EXHAUSTED:
341 case AVAHI_BROWSER_ALL_FOR_NOW:
342 break;
343
344 case AVAHI_BROWSER_FAILURE:
345
346 if (rr == r->record_browser_a && r->record_browser_aaaa) {
347 /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
348 avahi_s_record_browser_free(r->record_browser_a);
349 r->record_browser_a = NULL;
350 break;
351 }
352
353 if (rr == r->record_browser_aaaa && r->record_browser_a) {
354 /* We were looking for both AAAA and A, and the other query is still living, so we'll not die */
355 avahi_s_record_browser_free(r->record_browser_aaaa);
356 r->record_browser_aaaa = NULL;
357 break;
358 }
359
360 /* Hmm, everything's lost, tell the user */
361
362 if (r->record_browser_srv)
363 avahi_s_record_browser_free(r->record_browser_srv);
364 if (r->record_browser_txt)
365 avahi_s_record_browser_free(r->record_browser_txt);
366 if (r->record_browser_a)
367 avahi_s_record_browser_free(r->record_browser_a);
368 if (r->record_browser_aaaa)
369 avahi_s_record_browser_free(r->record_browser_aaaa);
370
371 r->record_browser_srv = r->record_browser_txt = r->record_browser_a = r->record_browser_aaaa = NULL;
372
373 finish(r, AVAHI_RESOLVER_FAILURE);
374 break;
375 }
376 }
377
avahi_s_service_resolver_new(AvahiServer * server,AvahiIfIndex interface,AvahiProtocol protocol,const char * name,const char * type,const char * domain,AvahiProtocol aprotocol,AvahiLookupFlags flags,AvahiSServiceResolverCallback callback,void * userdata)378 AvahiSServiceResolver *avahi_s_service_resolver_new(
379 AvahiServer *server,
380 AvahiIfIndex interface,
381 AvahiProtocol protocol,
382 const char *name,
383 const char *type,
384 const char *domain,
385 AvahiProtocol aprotocol,
386 AvahiLookupFlags flags,
387 AvahiSServiceResolverCallback callback,
388 void* userdata) {
389
390 AvahiSServiceResolver *r;
391 AvahiKey *k;
392 char n[AVAHI_DOMAIN_NAME_MAX];
393 int ret;
394
395 assert(server);
396 assert(type);
397 assert(callback);
398
399 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_IF_VALID(interface), AVAHI_ERR_INVALID_INTERFACE);
400 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(protocol), AVAHI_ERR_INVALID_PROTOCOL);
401 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, AVAHI_PROTO_VALID(aprotocol), AVAHI_ERR_INVALID_PROTOCOL);
402 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !domain || avahi_is_valid_domain_name(domain), AVAHI_ERR_INVALID_DOMAIN_NAME);
403 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, !name || avahi_is_valid_service_name(name), AVAHI_ERR_INVALID_SERVICE_NAME);
404 AVAHI_CHECK_VALIDITY_RETURN_NULL(server, avahi_is_valid_service_type_strict(type), AVAHI_ERR_INVALID_SERVICE_TYPE);
405 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);
406
407 if (!domain)
408 domain = server->domain_name;
409
410 if ((ret = avahi_service_name_join(n, sizeof(n), name, type, domain)) < 0) {
411 avahi_server_set_errno(server, ret);
412 return NULL;
413 }
414
415 if (!(r = avahi_new(AvahiSServiceResolver, 1))) {
416 avahi_server_set_errno(server, AVAHI_ERR_NO_MEMORY);
417 return NULL;
418 }
419
420 r->server = server;
421 r->service_name = avahi_strdup(name);
422 r->service_type = avahi_normalize_name_strdup(type);
423 r->domain_name = avahi_normalize_name_strdup(domain);
424 r->callback = callback;
425 r->userdata = userdata;
426 r->address_protocol = aprotocol;
427 r->srv_record = r->txt_record = r->address_record = NULL;
428 r->srv_flags = r->txt_flags = r->address_flags = 0;
429 r->interface = interface;
430 r->protocol = protocol;
431 r->user_flags = flags;
432 r->record_browser_a = r->record_browser_aaaa = r->record_browser_srv = r->record_browser_txt = NULL;
433 r->time_event = NULL;
434 AVAHI_LLIST_PREPEND(AvahiSServiceResolver, resolver, server->service_resolvers, r);
435
436 k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_SRV);
437 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);
438 avahi_key_unref(k);
439
440 if (!r->record_browser_srv) {
441 avahi_s_service_resolver_free(r);
442 return NULL;
443 }
444
445 if (!(flags & AVAHI_LOOKUP_NO_TXT)) {
446 k = avahi_key_new(n, AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_TXT);
447 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);
448 avahi_key_unref(k);
449
450 if (!r->record_browser_txt) {
451 avahi_s_service_resolver_free(r);
452 return NULL;
453 }
454 }
455
456 start_timeout(r);
457
458 return r;
459 }
460
avahi_s_service_resolver_free(AvahiSServiceResolver * r)461 void avahi_s_service_resolver_free(AvahiSServiceResolver *r) {
462 assert(r);
463
464 AVAHI_LLIST_REMOVE(AvahiSServiceResolver, resolver, r->server->service_resolvers, r);
465
466 if (r->time_event)
467 avahi_time_event_free(r->time_event);
468
469 if (r->record_browser_srv)
470 avahi_s_record_browser_free(r->record_browser_srv);
471 if (r->record_browser_txt)
472 avahi_s_record_browser_free(r->record_browser_txt);
473 if (r->record_browser_a)
474 avahi_s_record_browser_free(r->record_browser_a);
475 if (r->record_browser_aaaa)
476 avahi_s_record_browser_free(r->record_browser_aaaa);
477
478 if (r->srv_record)
479 avahi_record_unref(r->srv_record);
480 if (r->txt_record)
481 avahi_record_unref(r->txt_record);
482 if (r->address_record)
483 avahi_record_unref(r->address_record);
484
485 avahi_free(r->service_name);
486 avahi_free(r->service_type);
487 avahi_free(r->domain_name);
488 avahi_free(r);
489 }
490