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author | lurchi <lurchi@strangeplace.net> | 2018-06-25 18:38:13 +0200 |
---|---|---|
committer | lurchi <lurchi@strangeplace.net> | 2018-06-25 18:38:27 +0200 |
commit | a4186fc2fd00b3fe2899bffcdbbbf8fead31115f (patch) | |
tree | d70c5939cc99d43e29ce63a4faa9ef334de0c81d /src/util/dnsstub.c | |
parent | 7da98cf076e9c5101244dfbbf8c3ddff045d298e (diff) | |
download | gnunet-a4186fc2fd00b3fe2899bffcdbbbf8fead31115f.tar.gz gnunet-a4186fc2fd00b3fe2899bffcdbbbf8fead31115f.zip |
Revert "integrate dnsparser and dnsstub and tun with libgnunetutil"
This reverts commit 7da98cf076e9c5101244dfbbf8c3ddff045d298e.
Diffstat (limited to 'src/util/dnsstub.c')
-rw-r--r-- | src/util/dnsstub.c | 749 |
1 files changed, 0 insertions, 749 deletions
diff --git a/src/util/dnsstub.c b/src/util/dnsstub.c deleted file mode 100644 index 969ff7beb..000000000 --- a/src/util/dnsstub.c +++ /dev/null | |||
@@ -1,749 +0,0 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2012, 2018 GNUnet e.V. | ||
4 | |||
5 | GNUnet is free software: you can redistribute it and/or modify it | ||
6 | under the terms of the GNU Affero General Public License as published | ||
7 | by the Free Software Foundation, either version 3 of the License, | ||
8 | or (at your option) any later version. | ||
9 | |||
10 | GNUnet is distributed in the hope that it will be useful, but | ||
11 | WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
13 | Affero General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU Affero General Public License | ||
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
17 | */ | ||
18 | /** | ||
19 | * @file dns/dnsstub.c | ||
20 | * @brief DNS stub resolver which sends DNS requests to an actual resolver | ||
21 | * @author Christian Grothoff | ||
22 | */ | ||
23 | #include "platform.h" | ||
24 | #include "gnunet_util_lib.h" | ||
25 | #include "gnunet_tun_lib.h" | ||
26 | #include "gnunet_dnsstub_lib.h" | ||
27 | |||
28 | /** | ||
29 | * Timeout for retrying DNS queries. | ||
30 | */ | ||
31 | #define DNS_RETRANSMIT_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 250) | ||
32 | |||
33 | |||
34 | /** | ||
35 | * DNS Server used for resolution. | ||
36 | */ | ||
37 | struct DnsServer; | ||
38 | |||
39 | |||
40 | /** | ||
41 | * UDP socket we are using for sending DNS requests to the Internet. | ||
42 | */ | ||
43 | struct GNUNET_DNSSTUB_RequestSocket | ||
44 | { | ||
45 | |||
46 | /** | ||
47 | * UDP socket we use for this request for IPv4 | ||
48 | */ | ||
49 | struct GNUNET_NETWORK_Handle *dnsout4; | ||
50 | |||
51 | /** | ||
52 | * UDP socket we use for this request for IPv6 | ||
53 | */ | ||
54 | struct GNUNET_NETWORK_Handle *dnsout6; | ||
55 | |||
56 | /** | ||
57 | * Function to call with result. | ||
58 | */ | ||
59 | GNUNET_DNSSTUB_ResultCallback rc; | ||
60 | |||
61 | /** | ||
62 | * Closure for @e rc. | ||
63 | */ | ||
64 | void *rc_cls; | ||
65 | |||
66 | /** | ||
67 | * Task for reading from dnsout4 and dnsout6. | ||
68 | */ | ||
69 | struct GNUNET_SCHEDULER_Task *read_task; | ||
70 | |||
71 | /** | ||
72 | * Task for retrying transmission of the query. | ||
73 | */ | ||
74 | struct GNUNET_SCHEDULER_Task *retry_task; | ||
75 | |||
76 | /** | ||
77 | * Next address we sent the DNS request to. | ||
78 | */ | ||
79 | struct DnsServer *ds_pos; | ||
80 | |||
81 | /** | ||
82 | * Context this request executes in. | ||
83 | */ | ||
84 | struct GNUNET_DNSSTUB_Context *ctx; | ||
85 | |||
86 | /** | ||
87 | * Query we sent to @e addr. | ||
88 | */ | ||
89 | void *request; | ||
90 | |||
91 | /** | ||
92 | * Number of bytes in @a request. | ||
93 | */ | ||
94 | size_t request_len; | ||
95 | |||
96 | }; | ||
97 | |||
98 | |||
99 | /** | ||
100 | * DNS Server used for resolution. | ||
101 | */ | ||
102 | struct DnsServer | ||
103 | { | ||
104 | |||
105 | /** | ||
106 | * Kept in a DLL. | ||
107 | */ | ||
108 | struct DnsServer *next; | ||
109 | |||
110 | /** | ||
111 | * Kept in a DLL. | ||
112 | */ | ||
113 | struct DnsServer *prev; | ||
114 | |||
115 | /** | ||
116 | * IP address of the DNS resolver. | ||
117 | */ | ||
118 | struct sockaddr_storage ss; | ||
119 | }; | ||
120 | |||
121 | |||
122 | /** | ||
123 | * Handle to the stub resolver. | ||
124 | */ | ||
125 | struct GNUNET_DNSSTUB_Context | ||
126 | { | ||
127 | |||
128 | /** | ||
129 | * Array of all open sockets for DNS requests. | ||
130 | */ | ||
131 | struct GNUNET_DNSSTUB_RequestSocket *sockets; | ||
132 | |||
133 | /** | ||
134 | * DLL of DNS resolvers we use. | ||
135 | */ | ||
136 | struct DnsServer *dns_head; | ||
137 | |||
138 | /** | ||
139 | * DLL of DNS resolvers we use. | ||
140 | */ | ||
141 | struct DnsServer *dns_tail; | ||
142 | |||
143 | /** | ||
144 | * How frequently do we retry requests? | ||
145 | */ | ||
146 | struct GNUNET_TIME_Relative retry_freq; | ||
147 | |||
148 | /** | ||
149 | * Length of @e sockets array. | ||
150 | */ | ||
151 | unsigned int num_sockets; | ||
152 | |||
153 | }; | ||
154 | |||
155 | |||
156 | /** | ||
157 | * We're done with a `struct GNUNET_DNSSTUB_RequestSocket`, close it for now. | ||
158 | * | ||
159 | * @param rs request socket to clean up | ||
160 | */ | ||
161 | static void | ||
162 | cleanup_rs (struct GNUNET_DNSSTUB_RequestSocket *rs) | ||
163 | { | ||
164 | if (NULL != rs->dnsout4) | ||
165 | { | ||
166 | GNUNET_NETWORK_socket_close (rs->dnsout4); | ||
167 | rs->dnsout4 = NULL; | ||
168 | } | ||
169 | if (NULL != rs->dnsout6) | ||
170 | { | ||
171 | GNUNET_NETWORK_socket_close (rs->dnsout6); | ||
172 | rs->dnsout6 = NULL; | ||
173 | } | ||
174 | if (NULL != rs->read_task) | ||
175 | { | ||
176 | GNUNET_SCHEDULER_cancel (rs->read_task); | ||
177 | rs->read_task = NULL; | ||
178 | } | ||
179 | if (NULL != rs->retry_task) | ||
180 | { | ||
181 | GNUNET_SCHEDULER_cancel (rs->retry_task); | ||
182 | rs->retry_task = NULL; | ||
183 | } | ||
184 | if (NULL != rs->request) | ||
185 | { | ||
186 | GNUNET_free (rs->request); | ||
187 | rs->request = NULL; | ||
188 | } | ||
189 | } | ||
190 | |||
191 | |||
192 | /** | ||
193 | * Open source port for sending DNS requests | ||
194 | * | ||
195 | * @param af AF_INET or AF_INET6 | ||
196 | * @return #GNUNET_OK on success | ||
197 | */ | ||
198 | static struct GNUNET_NETWORK_Handle * | ||
199 | open_socket (int af) | ||
200 | { | ||
201 | struct sockaddr_in a4; | ||
202 | struct sockaddr_in6 a6; | ||
203 | struct sockaddr *sa; | ||
204 | socklen_t alen; | ||
205 | struct GNUNET_NETWORK_Handle *ret; | ||
206 | |||
207 | ret = GNUNET_NETWORK_socket_create (af, SOCK_DGRAM, 0); | ||
208 | if (NULL == ret) | ||
209 | return NULL; | ||
210 | switch (af) | ||
211 | { | ||
212 | case AF_INET: | ||
213 | memset (&a4, 0, alen = sizeof (struct sockaddr_in)); | ||
214 | sa = (struct sockaddr *) &a4; | ||
215 | break; | ||
216 | case AF_INET6: | ||
217 | memset (&a6, 0, alen = sizeof (struct sockaddr_in6)); | ||
218 | sa = (struct sockaddr *) &a6; | ||
219 | break; | ||
220 | default: | ||
221 | GNUNET_break (0); | ||
222 | GNUNET_NETWORK_socket_close (ret); | ||
223 | return NULL; | ||
224 | } | ||
225 | sa->sa_family = af; | ||
226 | if (GNUNET_OK != GNUNET_NETWORK_socket_bind (ret, | ||
227 | sa, | ||
228 | alen)) | ||
229 | { | ||
230 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
231 | _("Could not bind to any port: %s\n"), | ||
232 | STRERROR (errno)); | ||
233 | GNUNET_NETWORK_socket_close (ret); | ||
234 | return NULL; | ||
235 | } | ||
236 | return ret; | ||
237 | } | ||
238 | |||
239 | |||
240 | /** | ||
241 | * Get a socket of the specified address family to send out a | ||
242 | * UDP DNS request to the Internet. | ||
243 | * | ||
244 | * @param ctx the DNSSTUB context | ||
245 | * @return NULL on error | ||
246 | */ | ||
247 | static struct GNUNET_DNSSTUB_RequestSocket * | ||
248 | get_request_socket (struct GNUNET_DNSSTUB_Context *ctx) | ||
249 | { | ||
250 | struct GNUNET_DNSSTUB_RequestSocket *rs; | ||
251 | |||
252 | for (unsigned int i=0;i<256;i++) | ||
253 | { | ||
254 | rs = &ctx->sockets[GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, | ||
255 | ctx->num_sockets)]; | ||
256 | if (NULL == rs->rc) | ||
257 | break; | ||
258 | } | ||
259 | if (NULL != rs->rc) | ||
260 | { | ||
261 | /* signal "failure" */ | ||
262 | rs->rc (rs->rc_cls, | ||
263 | NULL, | ||
264 | 0); | ||
265 | rs->rc = NULL; | ||
266 | } | ||
267 | if (NULL != rs->read_task) | ||
268 | { | ||
269 | GNUNET_SCHEDULER_cancel (rs->read_task); | ||
270 | rs->read_task = NULL; | ||
271 | } | ||
272 | if (NULL != rs->retry_task) | ||
273 | { | ||
274 | GNUNET_SCHEDULER_cancel (rs->retry_task); | ||
275 | rs->retry_task = NULL; | ||
276 | } | ||
277 | if (NULL != rs->request) | ||
278 | { | ||
279 | GNUNET_free (rs->request); | ||
280 | rs->request = NULL; | ||
281 | } | ||
282 | rs->ctx = ctx; | ||
283 | return rs; | ||
284 | } | ||
285 | |||
286 | |||
287 | /** | ||
288 | * Actually do the reading of a DNS packet from our UDP socket and see | ||
289 | * if we have a valid, matching, pending request. | ||
290 | * | ||
291 | * @param rs request socket with callback details | ||
292 | * @param dnsout socket to read from | ||
293 | * @return #GNUNET_OK on success, #GNUNET_NO on drop, #GNUNET_SYSERR on IO-errors (closed socket) | ||
294 | */ | ||
295 | static int | ||
296 | do_dns_read (struct GNUNET_DNSSTUB_RequestSocket *rs, | ||
297 | struct GNUNET_NETWORK_Handle *dnsout) | ||
298 | { | ||
299 | struct GNUNET_DNSSTUB_Context *ctx = rs->ctx; | ||
300 | ssize_t r; | ||
301 | int len; | ||
302 | |||
303 | #ifndef MINGW | ||
304 | if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), | ||
305 | FIONREAD, | ||
306 | &len)) | ||
307 | { | ||
308 | /* conservative choice: */ | ||
309 | len = UINT16_MAX; | ||
310 | } | ||
311 | #else | ||
312 | /* port the code above? */ | ||
313 | len = UINT16_MAX; | ||
314 | #endif | ||
315 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
316 | "Receiving %d byte DNS reply\n", | ||
317 | len); | ||
318 | { | ||
319 | unsigned char buf[len] GNUNET_ALIGN; | ||
320 | int found; | ||
321 | struct sockaddr_storage addr; | ||
322 | socklen_t addrlen; | ||
323 | struct GNUNET_TUN_DnsHeader *dns; | ||
324 | |||
325 | addrlen = sizeof (addr); | ||
326 | memset (&addr, | ||
327 | 0, | ||
328 | sizeof (addr)); | ||
329 | r = GNUNET_NETWORK_socket_recvfrom (dnsout, | ||
330 | buf, | ||
331 | sizeof (buf), | ||
332 | (struct sockaddr*) &addr, | ||
333 | &addrlen); | ||
334 | if (-1 == r) | ||
335 | { | ||
336 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, | ||
337 | "recvfrom"); | ||
338 | GNUNET_NETWORK_socket_close (dnsout); | ||
339 | return GNUNET_SYSERR; | ||
340 | } | ||
341 | found = GNUNET_NO; | ||
342 | for (struct DnsServer *ds = ctx->dns_head; NULL != ds; ds = ds->next) | ||
343 | { | ||
344 | if (0 == memcmp (&addr, | ||
345 | &ds->ss, | ||
346 | GNUNET_MIN (sizeof (struct sockaddr_storage), | ||
347 | addrlen))) | ||
348 | { | ||
349 | found = GNUNET_YES; | ||
350 | break; | ||
351 | } | ||
352 | } | ||
353 | if (GNUNET_NO == found) | ||
354 | { | ||
355 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
356 | "Received DNS response from server we never asked (ignored)"); | ||
357 | return GNUNET_NO; | ||
358 | } | ||
359 | if (sizeof (struct GNUNET_TUN_DnsHeader) > r) | ||
360 | { | ||
361 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
362 | _("Received DNS response that is too small (%u bytes)"), | ||
363 | (unsigned int) r); | ||
364 | return GNUNET_NO; | ||
365 | } | ||
366 | dns = (struct GNUNET_TUN_DnsHeader *) buf; | ||
367 | if (NULL == rs->rc) | ||
368 | { | ||
369 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
370 | "Request timeout or cancelled; ignoring reply\n"); | ||
371 | return GNUNET_NO; | ||
372 | } | ||
373 | rs->rc (rs->rc_cls, | ||
374 | dns, | ||
375 | r); | ||
376 | } | ||
377 | return GNUNET_OK; | ||
378 | } | ||
379 | |||
380 | |||
381 | /** | ||
382 | * Read a DNS response from the (unhindered) UDP-Socket | ||
383 | * | ||
384 | * @param cls socket to read from | ||
385 | */ | ||
386 | static void | ||
387 | read_response (void *cls); | ||
388 | |||
389 | |||
390 | /** | ||
391 | * Schedule #read_response() task for @a rs. | ||
392 | * | ||
393 | * @param rs request to schedule read operation for | ||
394 | */ | ||
395 | static void | ||
396 | schedule_read (struct GNUNET_DNSSTUB_RequestSocket *rs) | ||
397 | { | ||
398 | struct GNUNET_NETWORK_FDSet *rset; | ||
399 | |||
400 | if (NULL != rs->read_task) | ||
401 | GNUNET_SCHEDULER_cancel (rs->read_task); | ||
402 | rset = GNUNET_NETWORK_fdset_create (); | ||
403 | if (NULL != rs->dnsout4) | ||
404 | GNUNET_NETWORK_fdset_set (rset, | ||
405 | rs->dnsout4); | ||
406 | if (NULL != rs->dnsout6) | ||
407 | GNUNET_NETWORK_fdset_set (rset, | ||
408 | rs->dnsout6); | ||
409 | rs->read_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT, | ||
410 | GNUNET_TIME_UNIT_FOREVER_REL, | ||
411 | rset, | ||
412 | NULL, | ||
413 | &read_response, | ||
414 | rs); | ||
415 | GNUNET_NETWORK_fdset_destroy (rset); | ||
416 | } | ||
417 | |||
418 | |||
419 | /** | ||
420 | * Read a DNS response from the (unhindered) UDP-Socket | ||
421 | * | ||
422 | * @param cls `struct GNUNET_DNSSTUB_RequestSocket` to read from | ||
423 | */ | ||
424 | static void | ||
425 | read_response (void *cls) | ||
426 | { | ||
427 | struct GNUNET_DNSSTUB_RequestSocket *rs = cls; | ||
428 | const struct GNUNET_SCHEDULER_TaskContext *tc; | ||
429 | |||
430 | rs->read_task = NULL; | ||
431 | tc = GNUNET_SCHEDULER_get_task_context (); | ||
432 | /* read and process ready sockets */ | ||
433 | if ( (NULL != rs->dnsout4) && | ||
434 | (GNUNET_NETWORK_fdset_isset (tc->read_ready, | ||
435 | rs->dnsout4)) && | ||
436 | (GNUNET_SYSERR == | ||
437 | do_dns_read (rs, | ||
438 | rs->dnsout4)) ) | ||
439 | rs->dnsout4 = NULL; | ||
440 | if ( (NULL != rs->dnsout6) && | ||
441 | (GNUNET_NETWORK_fdset_isset (tc->read_ready, | ||
442 | rs->dnsout6)) && | ||
443 | (GNUNET_SYSERR == | ||
444 | do_dns_read (rs, | ||
445 | rs->dnsout6)) ) | ||
446 | rs->dnsout6 = NULL; | ||
447 | /* re-schedule read task */ | ||
448 | schedule_read (rs); | ||
449 | } | ||
450 | |||
451 | |||
452 | /** | ||
453 | * Task to (re)transmit the DNS query, possibly repeatedly until | ||
454 | * we succeed. | ||
455 | * | ||
456 | * @param cls our `struct GNUNET_DNSSTUB_RequestSocket *` | ||
457 | */ | ||
458 | static void | ||
459 | transmit_query (void *cls) | ||
460 | { | ||
461 | struct GNUNET_DNSSTUB_RequestSocket *rs = cls; | ||
462 | struct GNUNET_DNSSTUB_Context *ctx = rs->ctx; | ||
463 | const struct sockaddr *sa; | ||
464 | socklen_t salen; | ||
465 | struct DnsServer *ds; | ||
466 | struct GNUNET_NETWORK_Handle *dnsout; | ||
467 | |||
468 | rs->retry_task = GNUNET_SCHEDULER_add_delayed (ctx->retry_freq, | ||
469 | &transmit_query, | ||
470 | rs); | ||
471 | ds = rs->ds_pos; | ||
472 | rs->ds_pos = ds->next; | ||
473 | if (NULL == rs->ds_pos) | ||
474 | rs->ds_pos = ctx->dns_head; | ||
475 | GNUNET_assert (NULL != ds); | ||
476 | dnsout = NULL; | ||
477 | switch (ds->ss.ss_family) | ||
478 | { | ||
479 | case AF_INET: | ||
480 | if (NULL == rs->dnsout4) | ||
481 | rs->dnsout4 = open_socket (AF_INET); | ||
482 | dnsout = rs->dnsout4; | ||
483 | sa = (const struct sockaddr *) &ds->ss; | ||
484 | salen = sizeof (struct sockaddr_in); | ||
485 | break; | ||
486 | case AF_INET6: | ||
487 | if (NULL == rs->dnsout6) | ||
488 | rs->dnsout6 = open_socket (AF_INET6); | ||
489 | dnsout = rs->dnsout6; | ||
490 | sa = (const struct sockaddr *) &ds->ss; | ||
491 | salen = sizeof (struct sockaddr_in6); | ||
492 | break; | ||
493 | default: | ||
494 | return; | ||
495 | } | ||
496 | if (NULL == dnsout) | ||
497 | { | ||
498 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
499 | "Unable to use configure DNS server, skipping\n"); | ||
500 | return; | ||
501 | } | ||
502 | if (GNUNET_SYSERR == | ||
503 | GNUNET_NETWORK_socket_sendto (dnsout, | ||
504 | rs->request, | ||
505 | rs->request_len, | ||
506 | sa, | ||
507 | salen)) | ||
508 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
509 | _("Failed to send DNS request to %s: %s\n"), | ||
510 | GNUNET_a2s (sa, | ||
511 | salen), | ||
512 | STRERROR (errno)); | ||
513 | else | ||
514 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
515 | _("Sent DNS request to %s\n"), | ||
516 | GNUNET_a2s (sa, | ||
517 | salen)); | ||
518 | schedule_read (rs); | ||
519 | } | ||
520 | |||
521 | |||
522 | /** | ||
523 | * Perform DNS resolution using our default IP from init. | ||
524 | * | ||
525 | * @param ctx stub resolver to use | ||
526 | * @param request DNS request to transmit | ||
527 | * @param request_len number of bytes in msg | ||
528 | * @param rc function to call with result | ||
529 | * @param rc_cls closure for 'rc' | ||
530 | * @return socket used for the request, NULL on error | ||
531 | */ | ||
532 | struct GNUNET_DNSSTUB_RequestSocket * | ||
533 | GNUNET_DNSSTUB_resolve (struct GNUNET_DNSSTUB_Context *ctx, | ||
534 | const void *request, | ||
535 | size_t request_len, | ||
536 | GNUNET_DNSSTUB_ResultCallback rc, | ||
537 | void *rc_cls) | ||
538 | { | ||
539 | struct GNUNET_DNSSTUB_RequestSocket *rs; | ||
540 | |||
541 | if (NULL == ctx->dns_head) | ||
542 | { | ||
543 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
544 | "No DNS server configured for resolution\n"); | ||
545 | return NULL; | ||
546 | } | ||
547 | if (NULL == (rs = get_request_socket (ctx))) | ||
548 | { | ||
549 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
550 | "No request socket available for DNS resolution\n"); | ||
551 | return NULL; | ||
552 | } | ||
553 | rs->ds_pos = ctx->dns_head; | ||
554 | rs->rc = rc; | ||
555 | rs->rc_cls = rc_cls; | ||
556 | rs->request = GNUNET_memdup (request, | ||
557 | request_len); | ||
558 | rs->request_len = request_len; | ||
559 | rs->retry_task = GNUNET_SCHEDULER_add_now (&transmit_query, | ||
560 | rs); | ||
561 | return rs; | ||
562 | } | ||
563 | |||
564 | |||
565 | /** | ||
566 | * Cancel DNS resolution. | ||
567 | * | ||
568 | * @param rs resolution to cancel | ||
569 | */ | ||
570 | void | ||
571 | GNUNET_DNSSTUB_resolve_cancel (struct GNUNET_DNSSTUB_RequestSocket *rs) | ||
572 | { | ||
573 | rs->rc = NULL; | ||
574 | if (NULL != rs->retry_task) | ||
575 | { | ||
576 | GNUNET_SCHEDULER_cancel (rs->retry_task); | ||
577 | rs->retry_task = NULL; | ||
578 | } | ||
579 | if (NULL != rs->read_task) | ||
580 | { | ||
581 | GNUNET_SCHEDULER_cancel (rs->read_task); | ||
582 | rs->read_task = NULL; | ||
583 | } | ||
584 | } | ||
585 | |||
586 | |||
587 | /** | ||
588 | * Start a DNS stub resolver. | ||
589 | * | ||
590 | * @param num_sockets how many sockets should we open | ||
591 | * in parallel for DNS queries for this stub? | ||
592 | * @return NULL on error | ||
593 | */ | ||
594 | struct GNUNET_DNSSTUB_Context * | ||
595 | GNUNET_DNSSTUB_start (unsigned int num_sockets) | ||
596 | { | ||
597 | struct GNUNET_DNSSTUB_Context *ctx; | ||
598 | |||
599 | if (0 == num_sockets) | ||
600 | { | ||
601 | GNUNET_break (0); | ||
602 | return NULL; | ||
603 | } | ||
604 | ctx = GNUNET_new (struct GNUNET_DNSSTUB_Context); | ||
605 | ctx->num_sockets = num_sockets; | ||
606 | ctx->sockets = GNUNET_new_array (num_sockets, | ||
607 | struct GNUNET_DNSSTUB_RequestSocket); | ||
608 | ctx->retry_freq = DNS_RETRANSMIT_DELAY; | ||
609 | return ctx; | ||
610 | } | ||
611 | |||
612 | |||
613 | /** | ||
614 | * Add nameserver for use by the DNSSTUB. We will use | ||
615 | * all provided nameservers for resolution (round-robin). | ||
616 | * | ||
617 | * @param ctx resolver context to modify | ||
618 | * @param dns_ip target IP address to use (as string) | ||
619 | * @return #GNUNET_OK on success | ||
620 | */ | ||
621 | int | ||
622 | GNUNET_DNSSTUB_add_dns_ip (struct GNUNET_DNSSTUB_Context *ctx, | ||
623 | const char *dns_ip) | ||
624 | { | ||
625 | struct DnsServer *ds; | ||
626 | struct in_addr i4; | ||
627 | struct in6_addr i6; | ||
628 | |||
629 | ds = GNUNET_new (struct DnsServer); | ||
630 | if (1 == inet_pton (AF_INET, | ||
631 | dns_ip, | ||
632 | &i4)) | ||
633 | { | ||
634 | struct sockaddr_in *s4 = (struct sockaddr_in *) &ds->ss; | ||
635 | |||
636 | s4->sin_family = AF_INET; | ||
637 | s4->sin_port = htons (53); | ||
638 | s4->sin_addr = i4; | ||
639 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
640 | s4->sin_len = (u_char) sizeof (struct sockaddr_in); | ||
641 | #endif | ||
642 | } | ||
643 | else if (1 == inet_pton (AF_INET6, | ||
644 | dns_ip, | ||
645 | &i6)) | ||
646 | { | ||
647 | struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) &ds->ss; | ||
648 | |||
649 | s6->sin6_family = AF_INET6; | ||
650 | s6->sin6_port = htons (53); | ||
651 | s6->sin6_addr = i6; | ||
652 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
653 | s6->sin6_len = (u_char) sizeof (struct sockaddr_in6); | ||
654 | #endif | ||
655 | } | ||
656 | else | ||
657 | { | ||
658 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
659 | "Malformed IP address `%s' for DNS server\n", | ||
660 | dns_ip); | ||
661 | GNUNET_free (ds); | ||
662 | return GNUNET_SYSERR; | ||
663 | } | ||
664 | GNUNET_CONTAINER_DLL_insert (ctx->dns_head, | ||
665 | ctx->dns_tail, | ||
666 | ds); | ||
667 | return GNUNET_OK; | ||
668 | } | ||
669 | |||
670 | |||
671 | /** | ||
672 | * Add nameserver for use by the DNSSTUB. We will use | ||
673 | * all provided nameservers for resolution (round-robin). | ||
674 | * | ||
675 | * @param ctx resolver context to modify | ||
676 | * @param sa socket address of DNS resolver to use | ||
677 | * @return #GNUNET_OK on success | ||
678 | */ | ||
679 | int | ||
680 | GNUNET_DNSSTUB_add_dns_sa (struct GNUNET_DNSSTUB_Context *ctx, | ||
681 | const struct sockaddr *sa) | ||
682 | { | ||
683 | struct DnsServer *ds; | ||
684 | |||
685 | ds = GNUNET_new (struct DnsServer); | ||
686 | switch (sa->sa_family) | ||
687 | { | ||
688 | case AF_INET: | ||
689 | GNUNET_memcpy (&ds->ss, | ||
690 | sa, | ||
691 | sizeof (struct sockaddr_in)); | ||
692 | break; | ||
693 | case AF_INET6: | ||
694 | GNUNET_memcpy (&ds->ss, | ||
695 | sa, | ||
696 | sizeof (struct sockaddr_in6)); | ||
697 | break; | ||
698 | default: | ||
699 | GNUNET_break (0); | ||
700 | GNUNET_free (ds); | ||
701 | return GNUNET_SYSERR; | ||
702 | } | ||
703 | GNUNET_CONTAINER_DLL_insert (ctx->dns_head, | ||
704 | ctx->dns_tail, | ||
705 | ds); | ||
706 | return GNUNET_OK; | ||
707 | } | ||
708 | |||
709 | |||
710 | /** | ||
711 | * How long should we try requests before timing out? | ||
712 | * Only effective for requests issued after this call. | ||
713 | * | ||
714 | * @param ctx resolver context to modify | ||
715 | * @param retry_freq how long to wait between retries | ||
716 | */ | ||
717 | void | ||
718 | GNUNET_DNSSTUB_set_retry (struct GNUNET_DNSSTUB_Context *ctx, | ||
719 | struct GNUNET_TIME_Relative retry_freq) | ||
720 | { | ||
721 | ctx->retry_freq = retry_freq; | ||
722 | } | ||
723 | |||
724 | |||
725 | /** | ||
726 | * Cleanup DNSSTUB resolver. | ||
727 | * | ||
728 | * @param ctx stub resolver to clean up | ||
729 | */ | ||
730 | void | ||
731 | GNUNET_DNSSTUB_stop (struct GNUNET_DNSSTUB_Context *ctx) | ||
732 | { | ||
733 | struct DnsServer *ds; | ||
734 | |||
735 | while (NULL != (ds = ctx->dns_head)) | ||
736 | { | ||
737 | GNUNET_CONTAINER_DLL_remove (ctx->dns_head, | ||
738 | ctx->dns_tail, | ||
739 | ds); | ||
740 | GNUNET_free (ds); | ||
741 | } | ||
742 | for (unsigned int i=0;i<ctx->num_sockets;i++) | ||
743 | cleanup_rs (&ctx->sockets[i]); | ||
744 | GNUNET_free (ctx->sockets); | ||
745 | GNUNET_free (ctx); | ||
746 | } | ||
747 | |||
748 | |||
749 | /* end of dnsstub.c */ | ||