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Diffstat (limited to 'src/gns/gnunet-dns2gns.c')
-rw-r--r-- | src/gns/gnunet-dns2gns.c | 1026 |
1 files changed, 0 insertions, 1026 deletions
diff --git a/src/gns/gnunet-dns2gns.c b/src/gns/gnunet-dns2gns.c deleted file mode 100644 index 46659cdda..000000000 --- a/src/gns/gnunet-dns2gns.c +++ /dev/null | |||
@@ -1,1026 +0,0 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2012-2013 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 | SPDX-License-Identifier: AGPL3.0-or-later | ||
19 | */ | ||
20 | /** | ||
21 | * @file gnunet-dns2gns.c | ||
22 | * @brief DNS server that translates DNS requests to GNS | ||
23 | * @author Christian Grothoff | ||
24 | */ | ||
25 | #include "platform.h" | ||
26 | #include <gnunet_util_lib.h> | ||
27 | #include <gnunet_dnsparser_lib.h> | ||
28 | #include <gnunet_gns_service.h> | ||
29 | #include <gnunet_dnsstub_lib.h> | ||
30 | #include "gnunet_vpn_service.h" | ||
31 | #include "gns.h" | ||
32 | |||
33 | /** | ||
34 | * Timeout for DNS requests. | ||
35 | */ | ||
36 | #define TIMEOUT GNUNET_TIME_UNIT_MINUTES | ||
37 | |||
38 | /** | ||
39 | * Default timeout for VPN redirections. | ||
40 | */ | ||
41 | #define VPN_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30) | ||
42 | |||
43 | |||
44 | struct Request; | ||
45 | |||
46 | /** | ||
47 | * Closure for #vpn_allocation_cb. | ||
48 | */ | ||
49 | struct VpnContext | ||
50 | { | ||
51 | /** | ||
52 | * Which resolution process are we processing. | ||
53 | */ | ||
54 | struct Request *request; | ||
55 | |||
56 | /** | ||
57 | * Handle to the VPN request that we were performing. | ||
58 | */ | ||
59 | struct GNUNET_VPN_RedirectionRequest *vpn_request; | ||
60 | |||
61 | /** | ||
62 | * Number of records serialized in @e rd_data. | ||
63 | */ | ||
64 | unsigned int rd_count; | ||
65 | |||
66 | /** | ||
67 | * Serialized records. | ||
68 | */ | ||
69 | char *rd_data; | ||
70 | |||
71 | /** | ||
72 | * Number of bytes in @e rd_data. | ||
73 | */ | ||
74 | ssize_t rd_data_size; | ||
75 | }; | ||
76 | |||
77 | |||
78 | /** | ||
79 | * Data kept per request. | ||
80 | */ | ||
81 | struct Request | ||
82 | { | ||
83 | /** | ||
84 | * Socket to use for sending the reply. | ||
85 | */ | ||
86 | struct GNUNET_NETWORK_Handle *lsock; | ||
87 | |||
88 | /** | ||
89 | * Destination address to use. | ||
90 | */ | ||
91 | const void *addr; | ||
92 | |||
93 | /** | ||
94 | * Initially, this is the DNS request, it will then be | ||
95 | * converted to the DNS response. | ||
96 | */ | ||
97 | struct GNUNET_DNSPARSER_Packet *packet; | ||
98 | |||
99 | /** | ||
100 | * Our GNS request handle. | ||
101 | */ | ||
102 | struct GNUNET_GNS_LookupWithTldRequest *lookup; | ||
103 | |||
104 | /** | ||
105 | * Our DNS request handle | ||
106 | */ | ||
107 | struct GNUNET_DNSSTUB_RequestSocket *dns_lookup; | ||
108 | |||
109 | /** | ||
110 | * Task run on timeout or shutdown to clean up without | ||
111 | * response. | ||
112 | */ | ||
113 | struct GNUNET_SCHEDULER_Task *timeout_task; | ||
114 | |||
115 | /** | ||
116 | * Vpn resulution context | ||
117 | */ | ||
118 | struct VpnContext *vpn_ctx; | ||
119 | |||
120 | /** | ||
121 | * Original UDP request message. | ||
122 | */ | ||
123 | char *udp_msg; | ||
124 | |||
125 | /** | ||
126 | * Number of bytes in @e addr. | ||
127 | */ | ||
128 | size_t addr_len; | ||
129 | |||
130 | /** | ||
131 | * Number of bytes in @e udp_msg. | ||
132 | */ | ||
133 | size_t udp_msg_size; | ||
134 | |||
135 | /** | ||
136 | * ID of the original request. | ||
137 | */ | ||
138 | uint16_t original_request_id; | ||
139 | |||
140 | }; | ||
141 | |||
142 | /** | ||
143 | * The address to bind to | ||
144 | */ | ||
145 | static in_addr_t address; | ||
146 | |||
147 | /** | ||
148 | * The IPv6 address to bind to | ||
149 | */ | ||
150 | static struct in6_addr address6; | ||
151 | |||
152 | |||
153 | /** | ||
154 | * Handle to GNS resolver. | ||
155 | */ | ||
156 | struct GNUNET_GNS_Handle *gns; | ||
157 | |||
158 | /** | ||
159 | * Our handle to the vpn service | ||
160 | */ | ||
161 | static struct GNUNET_VPN_Handle *vpn_handle; | ||
162 | |||
163 | /** | ||
164 | * Stub resolver | ||
165 | */ | ||
166 | struct GNUNET_DNSSTUB_Context *dns_stub; | ||
167 | |||
168 | /** | ||
169 | * Listen socket for IPv4. | ||
170 | */ | ||
171 | static struct GNUNET_NETWORK_Handle *listen_socket4; | ||
172 | |||
173 | /** | ||
174 | * Listen socket for IPv6. | ||
175 | */ | ||
176 | static struct GNUNET_NETWORK_Handle *listen_socket6; | ||
177 | |||
178 | /** | ||
179 | * Task for IPv4 socket. | ||
180 | */ | ||
181 | static struct GNUNET_SCHEDULER_Task *t4; | ||
182 | |||
183 | /** | ||
184 | * Task for IPv6 socket. | ||
185 | */ | ||
186 | static struct GNUNET_SCHEDULER_Task *t6; | ||
187 | |||
188 | /** | ||
189 | * IP of DNS server | ||
190 | */ | ||
191 | static char *dns_ip; | ||
192 | |||
193 | /** | ||
194 | * UDP Port we listen on for inbound DNS requests. | ||
195 | */ | ||
196 | static unsigned int listen_port = 53; | ||
197 | |||
198 | /** | ||
199 | * Configuration to use. | ||
200 | */ | ||
201 | static const struct GNUNET_CONFIGURATION_Handle *cfg; | ||
202 | |||
203 | |||
204 | /** | ||
205 | * Task run on shutdown. Cleans up everything. | ||
206 | * | ||
207 | * @param cls unused | ||
208 | */ | ||
209 | static void | ||
210 | do_shutdown (void *cls) | ||
211 | { | ||
212 | (void) cls; | ||
213 | if (NULL != t4) | ||
214 | { | ||
215 | GNUNET_SCHEDULER_cancel (t4); | ||
216 | t4 = NULL; | ||
217 | } | ||
218 | if (NULL != t6) | ||
219 | { | ||
220 | GNUNET_SCHEDULER_cancel (t6); | ||
221 | t6 = NULL; | ||
222 | } | ||
223 | if (NULL != listen_socket4) | ||
224 | { | ||
225 | GNUNET_NETWORK_socket_close (listen_socket4); | ||
226 | listen_socket4 = NULL; | ||
227 | } | ||
228 | if (NULL != listen_socket6) | ||
229 | { | ||
230 | GNUNET_NETWORK_socket_close (listen_socket6); | ||
231 | listen_socket6 = NULL; | ||
232 | } | ||
233 | if (NULL != gns) | ||
234 | { | ||
235 | GNUNET_GNS_disconnect (gns); | ||
236 | gns = NULL; | ||
237 | } | ||
238 | if (NULL != vpn_handle) | ||
239 | { | ||
240 | GNUNET_VPN_disconnect (vpn_handle); | ||
241 | vpn_handle = NULL; | ||
242 | } | ||
243 | if (NULL != dns_stub) | ||
244 | { | ||
245 | GNUNET_DNSSTUB_stop (dns_stub); | ||
246 | dns_stub = NULL; | ||
247 | } | ||
248 | } | ||
249 | |||
250 | |||
251 | /** | ||
252 | * Shuffle answers | ||
253 | * Fisher-Yates (aka Knuth) Shuffle | ||
254 | * | ||
255 | * @param request context for the request (with answers) | ||
256 | */ | ||
257 | static void | ||
258 | shuffle_answers (struct Request *request) | ||
259 | { | ||
260 | unsigned int idx = request->packet->num_answers; | ||
261 | unsigned int r_idx; | ||
262 | struct GNUNET_DNSPARSER_Record tmp_answer; | ||
263 | |||
264 | while (0 != idx) | ||
265 | { | ||
266 | r_idx = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, | ||
267 | request->packet->num_answers); | ||
268 | idx--; | ||
269 | tmp_answer = request->packet->answers[idx]; | ||
270 | memcpy (&request->packet->answers[idx], &request->packet->answers[r_idx], | ||
271 | sizeof (struct GNUNET_DNSPARSER_Record)); | ||
272 | memcpy (&request->packet->answers[r_idx], &tmp_answer, | ||
273 | sizeof (struct GNUNET_DNSPARSER_Record)); | ||
274 | } | ||
275 | } | ||
276 | |||
277 | |||
278 | /** | ||
279 | * Send the response for the given request and clean up. | ||
280 | * | ||
281 | * @param request context for the request. | ||
282 | */ | ||
283 | static void | ||
284 | send_response (struct Request *request) | ||
285 | { | ||
286 | char *buf; | ||
287 | size_t size; | ||
288 | ssize_t sret; | ||
289 | |||
290 | shuffle_answers (request); | ||
291 | if (GNUNET_SYSERR == | ||
292 | GNUNET_DNSPARSER_pack (request->packet, | ||
293 | UINT16_MAX /* is this not too much? */, | ||
294 | &buf, | ||
295 | &size)) | ||
296 | { | ||
297 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
298 | _ ("Failed to pack DNS response into UDP packet!\n")); | ||
299 | } | ||
300 | else | ||
301 | { | ||
302 | sret = GNUNET_NETWORK_socket_sendto (request->lsock, | ||
303 | buf, | ||
304 | size, | ||
305 | request->addr, | ||
306 | request->addr_len); | ||
307 | if ((sret < 0) || | ||
308 | (size != (size_t) sret)) | ||
309 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, | ||
310 | "sendto"); | ||
311 | GNUNET_free (buf); | ||
312 | } | ||
313 | GNUNET_SCHEDULER_cancel (request->timeout_task); | ||
314 | GNUNET_DNSPARSER_free_packet (request->packet); | ||
315 | GNUNET_free (request->udp_msg); | ||
316 | GNUNET_free (request); | ||
317 | } | ||
318 | |||
319 | |||
320 | /** | ||
321 | * Task run on timeout. Cleans up request. | ||
322 | * | ||
323 | * @param cls `struct Request *` of the request to clean up | ||
324 | */ | ||
325 | static void | ||
326 | do_timeout (void *cls) | ||
327 | { | ||
328 | struct Request *request = cls; | ||
329 | struct VpnContext *vpn_ctx; | ||
330 | |||
331 | if (NULL != request->packet) | ||
332 | GNUNET_DNSPARSER_free_packet (request->packet); | ||
333 | if (NULL != request->lookup) | ||
334 | GNUNET_GNS_lookup_with_tld_cancel (request->lookup); | ||
335 | if (NULL != request->dns_lookup) | ||
336 | GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup); | ||
337 | GNUNET_free (request->udp_msg); | ||
338 | if (NULL != (vpn_ctx = request->vpn_ctx)) | ||
339 | { | ||
340 | GNUNET_VPN_cancel_request (vpn_ctx->vpn_request); | ||
341 | GNUNET_free (vpn_ctx->rd_data); | ||
342 | GNUNET_free (vpn_ctx); | ||
343 | } | ||
344 | GNUNET_free (request); | ||
345 | } | ||
346 | |||
347 | |||
348 | /** | ||
349 | * Iterator called on obtained result for a DNS lookup | ||
350 | * | ||
351 | * @param cls closure | ||
352 | * @param dns the DNS udp payload | ||
353 | * @param r size of the DNS payload | ||
354 | */ | ||
355 | static void | ||
356 | dns_result_processor (void *cls, | ||
357 | const struct GNUNET_TUN_DnsHeader *dns, | ||
358 | size_t r) | ||
359 | { | ||
360 | struct Request *request = cls; | ||
361 | |||
362 | if (NULL == dns) | ||
363 | { | ||
364 | /* DNSSTUB gave up, so we trigger timeout early */ | ||
365 | GNUNET_SCHEDULER_cancel (request->timeout_task); | ||
366 | do_timeout (request); | ||
367 | return; | ||
368 | } | ||
369 | if (request->original_request_id != dns->id) | ||
370 | { | ||
371 | /* for a another query, ignore */ | ||
372 | return; | ||
373 | } | ||
374 | request->packet = GNUNET_DNSPARSER_parse ((char *) dns, | ||
375 | r); | ||
376 | if (NULL == request->packet) | ||
377 | { | ||
378 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
379 | _ ("Failed to parse DNS response!\n")); | ||
380 | GNUNET_SCHEDULER_cancel (request->timeout_task); | ||
381 | do_timeout (request); | ||
382 | return; | ||
383 | } | ||
384 | GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup); | ||
385 | send_response (request); | ||
386 | } | ||
387 | |||
388 | /** | ||
389 | * Callback invoked from the VPN service once a redirection is | ||
390 | * available. Provides the IP address that can now be used to | ||
391 | * reach the requested destination. Replaces the "VPN" record | ||
392 | * with the respective A/AAAA record and continues processing. | ||
393 | * | ||
394 | * @param cls closure | ||
395 | * @param af address family, AF_INET or AF_INET6; AF_UNSPEC on error; | ||
396 | * will match 'result_af' from the request | ||
397 | * @param address IP address (struct in_addr or struct in_addr6, depending on 'af') | ||
398 | * that the VPN allocated for the redirection; | ||
399 | * traffic to this IP will now be redirected to the | ||
400 | * specified target peer; NULL on error | ||
401 | */ | ||
402 | static void | ||
403 | vpn_allocation_cb (void *cls, | ||
404 | int af, | ||
405 | const void *address) | ||
406 | { | ||
407 | struct VpnContext *vpn_ctx = cls; | ||
408 | struct Request *request = vpn_ctx->request; | ||
409 | struct GNUNET_GNSRECORD_Data rd[vpn_ctx->rd_count]; | ||
410 | unsigned int i; | ||
411 | |||
412 | vpn_ctx->vpn_request = NULL; | ||
413 | request->vpn_ctx = NULL; | ||
414 | GNUNET_assert (GNUNET_OK == | ||
415 | GNUNET_GNSRECORD_records_deserialize ( | ||
416 | (size_t) vpn_ctx->rd_data_size, | ||
417 | vpn_ctx->rd_data, | ||
418 | vpn_ctx->rd_count, | ||
419 | rd)); | ||
420 | for (i = 0; i < vpn_ctx->rd_count; i++) | ||
421 | { | ||
422 | if (GNUNET_GNSRECORD_TYPE_VPN == rd[i].record_type) | ||
423 | { | ||
424 | switch (af) | ||
425 | { | ||
426 | case AF_INET: | ||
427 | rd[i].record_type = GNUNET_DNSPARSER_TYPE_A; | ||
428 | rd[i].data_size = sizeof(struct in_addr); | ||
429 | rd[i].expiration_time = GNUNET_TIME_relative_to_absolute ( | ||
430 | VPN_TIMEOUT).abs_value_us; | ||
431 | rd[i].flags = 0; | ||
432 | rd[i].data = address; | ||
433 | break; | ||
434 | |||
435 | case AF_INET6: | ||
436 | rd[i].record_type = GNUNET_DNSPARSER_TYPE_AAAA; | ||
437 | rd[i].expiration_time = GNUNET_TIME_relative_to_absolute ( | ||
438 | VPN_TIMEOUT).abs_value_us; | ||
439 | rd[i].flags = 0; | ||
440 | rd[i].data = address; | ||
441 | rd[i].data_size = sizeof(struct in6_addr); | ||
442 | break; | ||
443 | |||
444 | default: | ||
445 | GNUNET_assert (0); | ||
446 | } | ||
447 | break; | ||
448 | } | ||
449 | } | ||
450 | GNUNET_assert (i < vpn_ctx->rd_count); | ||
451 | if (0 == vpn_ctx->rd_count) | ||
452 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
453 | _ ("VPN returned empty result for `%s'\n"), | ||
454 | request->packet->queries[0].name); | ||
455 | send_response (request); | ||
456 | GNUNET_free (vpn_ctx->rd_data); | ||
457 | GNUNET_free (vpn_ctx); | ||
458 | } | ||
459 | |||
460 | |||
461 | |||
462 | /** | ||
463 | * Iterator called on obtained result for a GNS lookup. | ||
464 | * | ||
465 | * @param cls closure | ||
466 | * @param was_gns #GNUNET_NO if the TLD is not configured for GNS | ||
467 | * @param rd_count number of records in @a rd | ||
468 | * @param rd the records in reply | ||
469 | */ | ||
470 | static void | ||
471 | result_processor (void *cls, | ||
472 | int was_gns, | ||
473 | uint32_t rd_count, | ||
474 | const struct GNUNET_GNSRECORD_Data *rd) | ||
475 | { | ||
476 | struct Request *request = cls; | ||
477 | struct GNUNET_DNSPARSER_Packet *packet; | ||
478 | struct GNUNET_DNSPARSER_Record rec; | ||
479 | struct VpnContext *vpn_ctx; | ||
480 | const struct GNUNET_TUN_GnsVpnRecord *vpn; | ||
481 | const char *vname; | ||
482 | struct GNUNET_HashCode vhash; | ||
483 | int af; | ||
484 | |||
485 | request->lookup = NULL; | ||
486 | if (GNUNET_NO == was_gns) | ||
487 | { | ||
488 | /* TLD not configured for GNS, fall back to DNS */ | ||
489 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
490 | "Using DNS resolver IP `%s' to resolve `%s'\n", | ||
491 | dns_ip, | ||
492 | request->packet->queries[0].name); | ||
493 | request->original_request_id = request->packet->id; | ||
494 | GNUNET_DNSPARSER_free_packet (request->packet); | ||
495 | request->packet = NULL; | ||
496 | request->dns_lookup = GNUNET_DNSSTUB_resolve (dns_stub, | ||
497 | request->udp_msg, | ||
498 | request->udp_msg_size, | ||
499 | &dns_result_processor, | ||
500 | request); | ||
501 | return; | ||
502 | } | ||
503 | packet = request->packet; | ||
504 | packet->flags.query_or_response = 1; | ||
505 | packet->flags.return_code = GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR; | ||
506 | packet->flags.checking_disabled = 0; | ||
507 | packet->flags.authenticated_data = 1; | ||
508 | packet->flags.zero = 0; | ||
509 | packet->flags.recursion_available = 1; | ||
510 | packet->flags.message_truncated = 0; | ||
511 | packet->flags.authoritative_answer = 0; | ||
512 | // packet->flags.opcode = GNUNET_TUN_DNS_OPCODE_STATUS; // ??? | ||
513 | for (uint32_t i = 0; i < rd_count; i++) | ||
514 | { | ||
515 | rec.expiration_time.abs_value_us = rd[i].expiration_time; | ||
516 | switch (rd[i].record_type) | ||
517 | { | ||
518 | case GNUNET_DNSPARSER_TYPE_A: | ||
519 | GNUNET_assert (sizeof(struct in_addr) == rd[i].data_size); | ||
520 | rec.name = GNUNET_strdup (packet->queries[0].name); | ||
521 | rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; | ||
522 | rec.type = GNUNET_DNSPARSER_TYPE_A; | ||
523 | rec.data.raw.data = GNUNET_new (struct in_addr); | ||
524 | GNUNET_memcpy (rec.data.raw.data, | ||
525 | rd[i].data, | ||
526 | rd[i].data_size); | ||
527 | rec.data.raw.data_len = sizeof(struct in_addr); | ||
528 | GNUNET_array_append (packet->answers, | ||
529 | packet->num_answers, | ||
530 | rec); | ||
531 | break; | ||
532 | |||
533 | case GNUNET_DNSPARSER_TYPE_AAAA: | ||
534 | GNUNET_assert (sizeof(struct in6_addr) == rd[i].data_size); | ||
535 | rec.name = GNUNET_strdup (packet->queries[0].name); | ||
536 | rec.data.raw.data = GNUNET_new (struct in6_addr); | ||
537 | rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; | ||
538 | rec.type = GNUNET_DNSPARSER_TYPE_AAAA; | ||
539 | GNUNET_memcpy (rec.data.raw.data, | ||
540 | rd[i].data, | ||
541 | rd[i].data_size); | ||
542 | rec.data.raw.data_len = sizeof(struct in6_addr); | ||
543 | GNUNET_array_append (packet->answers, | ||
544 | packet->num_answers, | ||
545 | rec); | ||
546 | break; | ||
547 | |||
548 | case GNUNET_DNSPARSER_TYPE_CNAME: | ||
549 | rec.name = GNUNET_strdup (packet->queries[0].name); | ||
550 | rec.data.hostname = GNUNET_strdup (rd[i].data); | ||
551 | rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; | ||
552 | rec.type = GNUNET_DNSPARSER_TYPE_CNAME; | ||
553 | GNUNET_memcpy (rec.data.hostname, | ||
554 | rd[i].data, | ||
555 | rd[i].data_size); | ||
556 | GNUNET_array_append (packet->answers, | ||
557 | packet->num_answers, | ||
558 | rec); | ||
559 | break; | ||
560 | case GNUNET_GNSRECORD_TYPE_VPN: | ||
561 | if ((GNUNET_DNSPARSER_TYPE_A != request->packet->queries[0].type) && | ||
562 | (GNUNET_DNSPARSER_TYPE_AAAA != request->packet->queries[0].type)) | ||
563 | break; | ||
564 | af = (GNUNET_DNSPARSER_TYPE_A == request->packet->queries[0].type) ? AF_INET : | ||
565 | AF_INET6; | ||
566 | if (sizeof(struct GNUNET_TUN_GnsVpnRecord) > | ||
567 | rd[i].data_size) | ||
568 | { | ||
569 | GNUNET_break_op (0); | ||
570 | break; | ||
571 | } | ||
572 | vpn = (const struct GNUNET_TUN_GnsVpnRecord *) rd[i].data; | ||
573 | vname = (const char *) &vpn[1]; | ||
574 | if ('\0' != vname[rd[i].data_size - 1 - sizeof(struct | ||
575 | GNUNET_TUN_GnsVpnRecord) | ||
576 | ]) | ||
577 | { | ||
578 | GNUNET_break_op (0); | ||
579 | break; | ||
580 | } | ||
581 | GNUNET_TUN_service_name_to_hash (vname, | ||
582 | &vhash); | ||
583 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
584 | "Attempting VPN allocation for %s-%s (AF: %d, proto %d)\n", | ||
585 | GNUNET_i2s (&vpn->peer), | ||
586 | vname, | ||
587 | (int) af, | ||
588 | (int) ntohs (vpn->proto)); | ||
589 | vpn_ctx = GNUNET_new (struct VpnContext); | ||
590 | request->vpn_ctx = vpn_ctx; | ||
591 | vpn_ctx->request = request; | ||
592 | vpn_ctx->rd_data_size = GNUNET_GNSRECORD_records_get_size (rd_count, | ||
593 | rd); | ||
594 | if (vpn_ctx->rd_data_size < 0) | ||
595 | { | ||
596 | GNUNET_break_op (0); | ||
597 | GNUNET_free (vpn_ctx); | ||
598 | break; | ||
599 | } | ||
600 | vpn_ctx->rd_data = GNUNET_malloc ((size_t) vpn_ctx->rd_data_size); | ||
601 | vpn_ctx->rd_count = rd_count; | ||
602 | GNUNET_assert (vpn_ctx->rd_data_size == | ||
603 | GNUNET_GNSRECORD_records_serialize (rd_count, | ||
604 | rd, | ||
605 | (size_t) vpn_ctx | ||
606 | ->rd_data_size, | ||
607 | vpn_ctx->rd_data)); | ||
608 | vpn_ctx->vpn_request = GNUNET_VPN_redirect_to_peer (vpn_handle, | ||
609 | af, | ||
610 | ntohs ( | ||
611 | vpn->proto), | ||
612 | &vpn->peer, | ||
613 | &vhash, | ||
614 | GNUNET_TIME_relative_to_absolute ( | ||
615 | VPN_TIMEOUT), | ||
616 | & | ||
617 | vpn_allocation_cb, | ||
618 | vpn_ctx); | ||
619 | return; | ||
620 | |||
621 | |||
622 | default: | ||
623 | /* skip */ | ||
624 | break; | ||
625 | } | ||
626 | } | ||
627 | send_response (request); | ||
628 | } | ||
629 | |||
630 | |||
631 | /** | ||
632 | * Handle DNS request. | ||
633 | * | ||
634 | * @param lsock socket to use for sending the reply | ||
635 | * @param addr address to use for sending the reply | ||
636 | * @param addr_len number of bytes in @a addr | ||
637 | * @param udp_msg DNS request payload | ||
638 | * @param udp_msg_size number of bytes in @a udp_msg | ||
639 | */ | ||
640 | static void | ||
641 | handle_request (struct GNUNET_NETWORK_Handle *lsock, | ||
642 | const void *addr, | ||
643 | size_t addr_len, | ||
644 | const char *udp_msg, | ||
645 | size_t udp_msg_size) | ||
646 | { | ||
647 | struct Request *request; | ||
648 | struct GNUNET_DNSPARSER_Packet *packet; | ||
649 | |||
650 | packet = GNUNET_DNSPARSER_parse (udp_msg, | ||
651 | udp_msg_size); | ||
652 | if (NULL == packet) | ||
653 | { | ||
654 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
655 | _ ("Cannot parse DNS request from %s\n"), | ||
656 | GNUNET_a2s (addr, addr_len)); | ||
657 | return; | ||
658 | } | ||
659 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
660 | "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n", | ||
661 | packet->queries[0].name, | ||
662 | (unsigned int) packet->flags.query_or_response, | ||
663 | (int) packet->num_answers, | ||
664 | (int) packet->num_authority_records, | ||
665 | (int) packet->num_additional_records); | ||
666 | if ((0 != packet->flags.query_or_response) || | ||
667 | (0 != packet->num_answers) || | ||
668 | (0 != packet->num_authority_records)) | ||
669 | { | ||
670 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
671 | _ ("Received malformed DNS request from %s\n"), | ||
672 | GNUNET_a2s (addr, addr_len)); | ||
673 | GNUNET_DNSPARSER_free_packet (packet); | ||
674 | return; | ||
675 | } | ||
676 | if ((1 != packet->num_queries)) | ||
677 | { | ||
678 | GNUNET_log (GNUNET_ERROR_TYPE_WARNING, | ||
679 | _ ("Received unsupported DNS request from %s\n"), | ||
680 | GNUNET_a2s (addr, | ||
681 | addr_len)); | ||
682 | GNUNET_DNSPARSER_free_packet (packet); | ||
683 | return; | ||
684 | } | ||
685 | request = GNUNET_malloc (sizeof(struct Request) + addr_len); | ||
686 | request->lsock = lsock; | ||
687 | request->packet = packet; | ||
688 | request->addr = &request[1]; | ||
689 | request->addr_len = addr_len; | ||
690 | GNUNET_memcpy (&request[1], | ||
691 | addr, | ||
692 | addr_len); | ||
693 | request->udp_msg_size = udp_msg_size; | ||
694 | request->udp_msg = GNUNET_memdup (udp_msg, | ||
695 | udp_msg_size); | ||
696 | request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT, | ||
697 | &do_timeout, | ||
698 | request); | ||
699 | GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, | ||
700 | "Calling GNS on `%s'\n", | ||
701 | packet->queries[0].name); | ||
702 | request->lookup = GNUNET_GNS_lookup_with_tld (gns, | ||
703 | packet->queries[0].name, | ||
704 | packet->queries[0].type, | ||
705 | GNUNET_GNS_LO_DEFAULT, | ||
706 | &result_processor, | ||
707 | request); | ||
708 | } | ||
709 | |||
710 | |||
711 | /** | ||
712 | * Task to read IPv4 DNS packets. | ||
713 | * | ||
714 | * @param cls the 'listen_socket4' | ||
715 | */ | ||
716 | static void | ||
717 | read_dns4 (void *cls) | ||
718 | { | ||
719 | struct sockaddr_in v4; | ||
720 | socklen_t addrlen; | ||
721 | ssize_t size; | ||
722 | const struct GNUNET_SCHEDULER_TaskContext *tc; | ||
723 | |||
724 | GNUNET_assert (listen_socket4 == cls); | ||
725 | t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, | ||
726 | listen_socket4, | ||
727 | &read_dns4, | ||
728 | listen_socket4); | ||
729 | tc = GNUNET_SCHEDULER_get_task_context (); | ||
730 | if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason)) | ||
731 | return; /* shutdown? */ | ||
732 | size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4); | ||
733 | if (0 > size) | ||
734 | { | ||
735 | GNUNET_break (0); | ||
736 | return; /* read error!? */ | ||
737 | } | ||
738 | { | ||
739 | char buf[size + 1]; | ||
740 | ssize_t sret; | ||
741 | |||
742 | addrlen = sizeof(v4); | ||
743 | sret = GNUNET_NETWORK_socket_recvfrom (listen_socket4, | ||
744 | buf, | ||
745 | size + 1, | ||
746 | (struct sockaddr *) &v4, | ||
747 | &addrlen); | ||
748 | if (0 > sret) | ||
749 | { | ||
750 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, | ||
751 | "recvfrom"); | ||
752 | return; | ||
753 | } | ||
754 | GNUNET_break (size == sret); | ||
755 | handle_request (listen_socket4, | ||
756 | &v4, | ||
757 | addrlen, | ||
758 | buf, | ||
759 | size); | ||
760 | } | ||
761 | } | ||
762 | |||
763 | |||
764 | /** | ||
765 | * Task to read IPv6 DNS packets. | ||
766 | * | ||
767 | * @param cls the 'listen_socket6' | ||
768 | */ | ||
769 | static void | ||
770 | read_dns6 (void *cls) | ||
771 | { | ||
772 | struct sockaddr_in6 v6; | ||
773 | socklen_t addrlen; | ||
774 | ssize_t size; | ||
775 | const struct GNUNET_SCHEDULER_TaskContext *tc; | ||
776 | |||
777 | GNUNET_assert (listen_socket6 == cls); | ||
778 | t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, | ||
779 | listen_socket6, | ||
780 | &read_dns6, | ||
781 | listen_socket6); | ||
782 | tc = GNUNET_SCHEDULER_get_task_context (); | ||
783 | if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason)) | ||
784 | return; /* shutdown? */ | ||
785 | size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6); | ||
786 | if (0 > size) | ||
787 | { | ||
788 | GNUNET_break (0); | ||
789 | return; /* read error!? */ | ||
790 | } | ||
791 | { | ||
792 | char buf[size]; | ||
793 | ssize_t sret; | ||
794 | |||
795 | addrlen = sizeof(v6); | ||
796 | sret = GNUNET_NETWORK_socket_recvfrom (listen_socket6, | ||
797 | buf, | ||
798 | size, | ||
799 | (struct sockaddr *) &v6, | ||
800 | &addrlen); | ||
801 | if (0 > sret) | ||
802 | { | ||
803 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, | ||
804 | "recvfrom"); | ||
805 | return; | ||
806 | } | ||
807 | GNUNET_break (size == sret); | ||
808 | handle_request (listen_socket6, | ||
809 | &v6, | ||
810 | addrlen, | ||
811 | buf, | ||
812 | size); | ||
813 | } | ||
814 | } | ||
815 | |||
816 | |||
817 | /** | ||
818 | * Main function that will be run. | ||
819 | * | ||
820 | * @param cls closure | ||
821 | * @param args remaining command-line arguments | ||
822 | * @param cfgfile name of the configuration file used (for saving, can be NULL!) | ||
823 | * @param c configuration | ||
824 | */ | ||
825 | static void | ||
826 | run (void *cls, | ||
827 | char *const *args, | ||
828 | const char *cfgfile, | ||
829 | const struct GNUNET_CONFIGURATION_Handle *c) | ||
830 | { | ||
831 | char *addr_str; | ||
832 | |||
833 | (void) cls; | ||
834 | (void) args; | ||
835 | (void) cfgfile; | ||
836 | cfg = c; | ||
837 | if (NULL == dns_ip) | ||
838 | { | ||
839 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
840 | _ ("No DNS server specified!\n")); | ||
841 | return; | ||
842 | } | ||
843 | GNUNET_SCHEDULER_add_shutdown (&do_shutdown, | ||
844 | NULL); | ||
845 | if (NULL == (gns = GNUNET_GNS_connect (cfg))) | ||
846 | return; | ||
847 | if (NULL == (vpn_handle = GNUNET_VPN_connect (cfg))) | ||
848 | return; | ||
849 | GNUNET_assert (NULL != (dns_stub = GNUNET_DNSSTUB_start (128))); | ||
850 | if (GNUNET_OK != | ||
851 | GNUNET_DNSSTUB_add_dns_ip (dns_stub, | ||
852 | dns_ip)) | ||
853 | { | ||
854 | GNUNET_DNSSTUB_stop (dns_stub); | ||
855 | GNUNET_GNS_disconnect (gns); | ||
856 | gns = NULL; | ||
857 | GNUNET_VPN_disconnect (vpn_handle); | ||
858 | vpn_handle = NULL; | ||
859 | return; | ||
860 | } | ||
861 | |||
862 | /* Get address to bind to */ | ||
863 | if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (c, "dns2gns", | ||
864 | "BIND_TO", | ||
865 | &addr_str)) | ||
866 | { | ||
867 | // No address specified | ||
868 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
869 | "Don't know what to bind to...\n"); | ||
870 | GNUNET_free (addr_str); | ||
871 | GNUNET_SCHEDULER_shutdown (); | ||
872 | return; | ||
873 | } | ||
874 | if (1 != inet_pton (AF_INET, addr_str, &address)) | ||
875 | { | ||
876 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
877 | "Unable to parse address %s\n", | ||
878 | addr_str); | ||
879 | GNUNET_free (addr_str); | ||
880 | GNUNET_SCHEDULER_shutdown (); | ||
881 | return; | ||
882 | } | ||
883 | GNUNET_free (addr_str); | ||
884 | /* Get address to bind to */ | ||
885 | if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (c, "dns2gns", | ||
886 | "BIND_TO6", | ||
887 | &addr_str)) | ||
888 | { | ||
889 | // No address specified | ||
890 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
891 | "Don't know what to bind6 to...\n"); | ||
892 | GNUNET_free (addr_str); | ||
893 | GNUNET_SCHEDULER_shutdown (); | ||
894 | return; | ||
895 | } | ||
896 | if (1 != inet_pton (AF_INET6, addr_str, &address6)) | ||
897 | { | ||
898 | GNUNET_log (GNUNET_ERROR_TYPE_ERROR, | ||
899 | "Unable to parse IPv6 address %s\n", | ||
900 | addr_str); | ||
901 | GNUNET_free (addr_str); | ||
902 | GNUNET_SCHEDULER_shutdown (); | ||
903 | return; | ||
904 | } | ||
905 | GNUNET_free (addr_str); | ||
906 | |||
907 | listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET, | ||
908 | SOCK_DGRAM, | ||
909 | IPPROTO_UDP); | ||
910 | if (NULL != listen_socket4) | ||
911 | { | ||
912 | struct sockaddr_in v4; | ||
913 | |||
914 | memset (&v4, 0, sizeof(v4)); | ||
915 | v4.sin_family = AF_INET; | ||
916 | v4.sin_addr.s_addr = address; | ||
917 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
918 | v4.sin_len = sizeof(v4); | ||
919 | #endif | ||
920 | v4.sin_port = htons (listen_port); | ||
921 | if (GNUNET_OK != | ||
922 | GNUNET_NETWORK_socket_bind (listen_socket4, | ||
923 | (struct sockaddr *) &v4, | ||
924 | sizeof(v4))) | ||
925 | { | ||
926 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind"); | ||
927 | GNUNET_NETWORK_socket_close (listen_socket4); | ||
928 | listen_socket4 = NULL; | ||
929 | } | ||
930 | } | ||
931 | listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6, | ||
932 | SOCK_DGRAM, | ||
933 | IPPROTO_UDP); | ||
934 | if (NULL != listen_socket6) | ||
935 | { | ||
936 | struct sockaddr_in6 v6; | ||
937 | |||
938 | memset (&v6, 0, sizeof(v6)); | ||
939 | v6.sin6_family = AF_INET6; | ||
940 | v6.sin6_addr = address6; | ||
941 | #if HAVE_SOCKADDR_IN_SIN_LEN | ||
942 | v6.sin6_len = sizeof(v6); | ||
943 | #endif | ||
944 | v6.sin6_port = htons (listen_port); | ||
945 | if (GNUNET_OK != | ||
946 | GNUNET_NETWORK_socket_bind (listen_socket6, | ||
947 | (struct sockaddr *) &v6, | ||
948 | sizeof(v6))) | ||
949 | { | ||
950 | GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind"); | ||
951 | GNUNET_NETWORK_socket_close (listen_socket6); | ||
952 | listen_socket6 = NULL; | ||
953 | } | ||
954 | } | ||
955 | if ((NULL == listen_socket4) && | ||
956 | (NULL == listen_socket6)) | ||
957 | { | ||
958 | GNUNET_GNS_disconnect (gns); | ||
959 | gns = NULL; | ||
960 | GNUNET_VPN_disconnect (vpn_handle); | ||
961 | vpn_handle = NULL; | ||
962 | GNUNET_DNSSTUB_stop (dns_stub); | ||
963 | dns_stub = NULL; | ||
964 | return; | ||
965 | } | ||
966 | if (NULL != listen_socket4) | ||
967 | t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, | ||
968 | listen_socket4, | ||
969 | &read_dns4, | ||
970 | listen_socket4); | ||
971 | if (NULL != listen_socket6) | ||
972 | t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, | ||
973 | listen_socket6, | ||
974 | &read_dns6, | ||
975 | listen_socket6); | ||
976 | } | ||
977 | |||
978 | |||
979 | /** | ||
980 | * The main function for the dns2gns daemon. | ||
981 | * | ||
982 | * @param argc number of arguments from the command line | ||
983 | * @param argv command line arguments | ||
984 | * @return 0 ok, 1 on error | ||
985 | */ | ||
986 | int | ||
987 | main (int argc, | ||
988 | char *const *argv) | ||
989 | { | ||
990 | struct GNUNET_GETOPT_CommandLineOption options[] = { | ||
991 | GNUNET_GETOPT_option_string ('d', | ||
992 | "dns", | ||
993 | "IP", | ||
994 | gettext_noop ( | ||
995 | "IP of recursive DNS resolver to use (required)"), | ||
996 | &dns_ip), | ||
997 | GNUNET_GETOPT_option_uint ('p', | ||
998 | "port", | ||
999 | "UDPPORT", | ||
1000 | gettext_noop ( | ||
1001 | "UDP port to listen on for inbound DNS requests; default: 2853"), | ||
1002 | &listen_port), | ||
1003 | GNUNET_GETOPT_OPTION_END | ||
1004 | }; | ||
1005 | int ret; | ||
1006 | |||
1007 | if (GNUNET_OK != | ||
1008 | GNUNET_STRINGS_get_utf8_args (argc, argv, | ||
1009 | &argc, &argv)) | ||
1010 | return 2; | ||
1011 | GNUNET_log_setup ("gnunet-dns2gns", | ||
1012 | "WARNING", | ||
1013 | NULL); | ||
1014 | ret = | ||
1015 | (GNUNET_OK == | ||
1016 | GNUNET_PROGRAM_run (argc, argv, | ||
1017 | "gnunet-dns2gns", | ||
1018 | _ ("GNUnet DNS-to-GNS proxy (a DNS server)"), | ||
1019 | options, | ||
1020 | &run, NULL)) ? 0 : 1; | ||
1021 | GNUNET_free_nz ((void *) argv); | ||
1022 | return ret; | ||
1023 | } | ||
1024 | |||
1025 | |||
1026 | /* end of gnunet-dns2gns.c */ | ||