2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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21 * @file gnunet-dns2gns.c
22 * @brief DNS server that translates DNS requests to GNS
23 * @author Christian Grothoff
26 #include <gnunet_util_lib.h>
27 #include <gnunet_dnsparser_lib.h>
28 #include <gnunet_gns_service.h>
29 #include <gnunet_dnsstub_lib.h>
33 * Timeout for DNS requests.
35 #define TIMEOUT GNUNET_TIME_UNIT_MINUTES
40 #define DNS_SUFFIX ".zkey.eu"
45 #define FCFS_SUFFIX "fcfs.zkey.eu"
48 * Data kept per request.
53 * Socket to use for sending the reply.
55 struct GNUNET_NETWORK_Handle *lsock;
58 * Destination address to use.
63 * Initially, this is the DNS request, it will then be
64 * converted to the DNS response.
66 struct GNUNET_DNSPARSER_Packet *packet;
69 * Our GNS request handle.
71 struct GNUNET_GNS_LookupRequest *lookup;
74 * Our DNS request handle
76 struct GNUNET_DNSSTUB_RequestSocket *dns_lookup;
79 * Task run on timeout or shutdown to clean up without
82 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
85 * Number of bytes in 'addr'.
93 * Handle to GNS resolver.
95 struct GNUNET_GNS_Handle *gns;
100 struct GNUNET_DNSSTUB_Context *dns_stub;
103 * Listen socket for IPv4.
105 static struct GNUNET_NETWORK_Handle *listen_socket4;
108 * Listen socket for IPv6.
110 static struct GNUNET_NETWORK_Handle *listen_socket6;
113 * Task for IPv4 socket.
115 static GNUNET_SCHEDULER_TaskIdentifier t4;
118 * Task for IPv6 socket.
120 static GNUNET_SCHEDULER_TaskIdentifier t6;
125 static char *dns_suffix;
130 static char *fcfs_suffix;
138 * Task run on shutdown. Cleans up everything.
141 * @param tc scheduler context
144 do_shutdown (void *cls,
145 const struct GNUNET_SCHEDULER_TaskContext *tc)
147 if (GNUNET_SCHEDULER_NO_TASK != t4)
148 GNUNET_SCHEDULER_cancel (t4);
149 if (GNUNET_SCHEDULER_NO_TASK != t6)
150 GNUNET_SCHEDULER_cancel (t6);
151 if (NULL != listen_socket4)
153 GNUNET_NETWORK_socket_close (listen_socket4);
154 listen_socket4 = NULL;
156 if (NULL != listen_socket6)
158 GNUNET_NETWORK_socket_close (listen_socket6);
159 listen_socket6 = NULL;
161 GNUNET_GNS_disconnect (gns);
162 GNUNET_DNSSTUB_stop (dns_stub);
168 * Send the response for the given request and clean up.
170 * @param request context for the request.
173 send_response (struct Request *request)
179 GNUNET_DNSPARSER_pack (request->packet,
180 UINT16_MAX /* is this not too much? */,
184 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
185 _("Failed to pack DNS response into UDP packet!\n"));
190 GNUNET_NETWORK_socket_sendto (request->lsock,
194 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
197 GNUNET_SCHEDULER_cancel (request->timeout_task);
198 GNUNET_DNSPARSER_free_packet (request->packet);
199 GNUNET_free (request);
204 * Task run on timeout. Cleans up request.
206 * @param cls 'struct Request' of the request to clean up
207 * @param tc scheduler context
210 do_timeout (void *cls,
211 const struct GNUNET_SCHEDULER_TaskContext *tc)
213 struct Request *request = cls;
215 if (NULL != request->packet)
216 GNUNET_DNSPARSER_free_packet (request->packet);
217 if (NULL != request->lookup)
218 GNUNET_GNS_cancel_lookup_request (request->lookup);
219 GNUNET_free (request);
223 * Iterator called on obtained result for a DNS
227 * @param rs the request socket
228 * @param dns the DNS udp payload
229 * @param r size of the DNS payload
232 dns_result_processor (void *cls,
233 struct GNUNET_DNSSTUB_RequestSocket *rs,
234 const struct GNUNET_TUN_DnsHeader *dns,
237 struct Request *request = cls;
238 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
239 send_response (request);
243 * Iterator called on obtained result for a GNS
247 * @param rd_count number of records
248 * @param rd the records in reply
251 result_processor (void *cls,
253 const struct GNUNET_NAMESTORE_RecordData *rd)
255 struct Request *request = cls;
256 struct GNUNET_DNSPARSER_Packet *packet;
258 struct GNUNET_DNSPARSER_Record rec;
260 request->lookup = NULL;
261 packet = request->packet;
262 packet->flags.query_or_response = 1;
263 packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR;
264 packet->flags.checking_disabled = 0;
265 packet->flags.authenticated_data = 1;
266 packet->flags.zero = 0;
267 packet->flags.recursion_available = 1;
268 packet->flags.message_truncated = 0;
269 packet->flags.authoritative_answer = 0;
270 //packet->flags.opcode = GNUNET_DNSPARSER_OPCODE_STATUS; // ???
271 for (i=0;i<rd_count;i++)
273 switch (rd[i].record_type)
275 case GNUNET_DNSPARSER_TYPE_A:
276 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
277 rec.name = GNUNET_strdup (packet->queries[0].name);
278 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
279 rec.type = GNUNET_DNSPARSER_TYPE_A;
280 rec.data.raw.data = GNUNET_malloc (sizeof (struct in_addr));
281 memcpy (rec.data.raw.data,
284 rec.data.raw.data_len = sizeof (struct in_addr);
285 GNUNET_array_append (packet->answers,
289 case GNUNET_DNSPARSER_TYPE_AAAA:
290 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
291 rec.name = GNUNET_strdup (packet->queries[0].name);
292 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
293 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
294 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
295 memcpy (rec.data.raw.data,
298 rec.data.raw.data_len = sizeof (struct in6_addr);
299 GNUNET_array_append (packet->answers,
303 case GNUNET_DNSPARSER_TYPE_CNAME:
304 rec.name = GNUNET_strdup (packet->queries[0].name);
305 rec.data.hostname = strdup (rd[i].data);
306 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
307 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
308 memcpy (rec.data.hostname,
311 GNUNET_array_append (packet->answers,
320 send_response (request);
325 * Handle DNS request.
327 * @param lsock socket to use for sending the reply
328 * @param addr address to use for sending the reply
329 * @param addr_len number of bytes in addr
330 * @param udp_msg DNS request payload
331 * @param udp_msg_size number of bytes in udp_msg
334 handle_request (struct GNUNET_NETWORK_Handle *lsock,
340 struct Request *request;
341 struct GNUNET_DNSPARSER_Packet *packet;
344 enum GNUNET_GNS_RecordType type;
347 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
350 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
351 _("Cannot parse DNS request from %s\n"),
352 GNUNET_a2s (addr, addr_len));
355 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
357 packet->flags.query_or_response,
359 packet->num_authority_records,
360 packet->num_additional_records);
361 if ( (0 != packet->flags.query_or_response) ||
362 (0 != packet->num_answers) ||
363 (0 != packet->num_authority_records))
365 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
366 _("Received malformed DNS request from %s\n"),
367 GNUNET_a2s (addr, addr_len));
368 GNUNET_DNSPARSER_free_packet (packet);
371 if ( (1 != packet->num_queries) )
373 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
374 _("Received unsupported DNS request from %s\n"),
375 GNUNET_a2s (addr, addr_len));
376 GNUNET_DNSPARSER_free_packet (packet);
379 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
380 request->lsock = lsock;
381 request->packet = packet;
382 request->addr = &request[1];
383 request->addr_len = addr_len;
384 memcpy (&request[1], addr, addr_len);
385 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
388 name = GNUNET_strdup (packet->queries[0].name);
389 name_len = strlen (name);
391 if ( (name_len > strlen (dns_suffix)) &&
392 (0 == strcasecmp (dns_suffix,
393 &name[name_len - strlen (dns_suffix)])) )
395 if (0 == strcasecmp (fcfs_suffix,
396 &name[name_len - strlen (fcfs_suffix)]))
398 name[name_len - strlen (dns_suffix) + 1] = '\0';
399 strcat (name, GNUNET_GNS_TLD);
403 name[name_len - strlen (dns_suffix) + 1] = '\0';
404 strcat (name, GNUNET_GNS_TLD_ZKEY);
406 name_len = strlen (name);
408 if ( (name_len > strlen ((GNUNET_GNS_TLD) + 1)) &&
409 (0 == strcasecmp (GNUNET_GNS_TLD,
410 &name[name_len - strlen (GNUNET_GNS_TLD)])) )
411 use_gns = GNUNET_YES;
413 if ( (name_len > strlen (GNUNET_GNS_TLD_ZKEY)) &&
414 (0 == strcasecmp (GNUNET_GNS_TLD_ZKEY,
415 &name[name_len - strlen (GNUNET_GNS_TLD_ZKEY)])) )
416 use_gns = GNUNET_YES;
418 if (GNUNET_YES == use_gns)
420 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
422 type = packet->queries[0].type;
423 request->lookup = GNUNET_GNS_lookup (gns,
433 /* FIXME: do traditional *DNS* lookup; note that
434 gnunet-service-dns already has code to do this;
435 factor into library to share! Why not use GNUNET_RESOLVER here?*/
436 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
437 "Calling DNS at %s\n", dns_ip);
438 GNUNET_DNSPARSER_free_packet (request->packet);
439 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
442 &dns_result_processor,
453 * Task to read IPv4 DNS packets.
455 * @param cls the 'listen_socket4'
456 * @param tc scheduler context
459 read_dns4 (void *cls,
460 const struct GNUNET_SCHEDULER_TaskContext *tc)
462 struct sockaddr_in v4;
466 GNUNET_assert (listen_socket4 == cls);
467 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
471 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
472 return; /* shutdown? */
473 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
477 return; /* read error!? */
482 addrlen = sizeof (v4);
483 GNUNET_break (size ==
484 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
487 (struct sockaddr *) &v4,
489 handle_request (listen_socket4, &v4, addrlen,
496 * Task to read IPv6 DNS packets.
498 * @param cls the 'listen_socket6'
499 * @param tc scheduler context
502 read_dns6 (void *cls,
503 const struct GNUNET_SCHEDULER_TaskContext *tc)
505 struct sockaddr_in6 v6;
509 GNUNET_assert (listen_socket6 == cls);
510 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
514 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
515 return; /* shutdown? */
516 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
520 return; /* read error!? */
525 addrlen = sizeof (v6);
526 GNUNET_break (size ==
527 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
530 (struct sockaddr *) &v6,
532 handle_request (listen_socket6, &v6, addrlen,
539 * Main function that will be run.
542 * @param args remaining command-line arguments
543 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
544 * @param cfg configuration
547 run (void *cls, char *const *args, const char *cfgfile,
548 const struct GNUNET_CONFIGURATION_Handle *cfg)
552 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
553 "No DNS server specified!\n");
557 if (NULL == dns_suffix)
558 dns_suffix = DNS_SUFFIX;
560 if (NULL == fcfs_suffix)
561 fcfs_suffix = FCFS_SUFFIX;
563 gns = GNUNET_GNS_connect (cfg);
565 dns_stub = GNUNET_DNSSTUB_start (dns_ip);
567 if (NULL == dns_stub)
572 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
575 if (NULL != listen_socket4)
577 struct sockaddr_in v4;
579 memset (&v4, 0, sizeof (v4));
580 v4.sin_family = AF_INET;
581 #if HAVE_SOCKADDR_IN_SIN_LEN
582 v4.sin_len = sizeof (v4);
584 v4.sin_port = htons (53);
586 GNUNET_NETWORK_socket_bind (listen_socket4,
587 (struct sockaddr *) &v4,
590 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
591 GNUNET_NETWORK_socket_close (listen_socket4);
592 listen_socket4 = NULL;
595 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
598 if (NULL != listen_socket6)
600 struct sockaddr_in6 v6;
602 memset (&v6, 0, sizeof (v6));
603 v6.sin6_family = AF_INET6;
604 #if HAVE_SOCKADDR_IN_SIN_LEN
605 v6.sin6_len = sizeof (v6);
607 v6.sin6_port = htons (53);
609 GNUNET_NETWORK_socket_bind (listen_socket6,
610 (struct sockaddr *) &v6,
613 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
614 GNUNET_NETWORK_socket_close (listen_socket6);
615 listen_socket6 = NULL;
618 if ( (NULL == listen_socket4) &&
619 (NULL == listen_socket6) )
621 if (NULL != listen_socket4)
622 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
626 if (NULL != listen_socket6)
627 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
632 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
638 * The main function for the fcfs daemon.
640 * @param argc number of arguments from the command line
641 * @param argv command line arguments
642 * @return 0 ok, 1 on error
648 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
650 gettext_noop ("IP of recursive dns resolver to use (required)"), 1,
651 &GNUNET_GETOPT_set_string, &dns_ip},
652 {'s', "suffix", NULL,
653 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
654 &GNUNET_GETOPT_set_string, &dns_suffix},
656 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
657 &GNUNET_GETOPT_set_string, &fcfs_suffix},
658 GNUNET_GETOPT_OPTION_END
662 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
665 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
668 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
669 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
671 &run, NULL)) ? 0 : 1;
676 /* end of gnunet-dns2gns.c */