2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
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;
123 * DNS suffix, suffix of this gateway in DNS; defaults to '.zkey.eu'
125 static char *dns_suffix;
128 * FCFS suffix, suffix of FCFS-authority in DNS; defaults to 'fcfs.zkey.eu'.
130 static char *fcfs_suffix;
138 * UDP Port we listen on for inbound DNS requests.
140 static unsigned int listen_port = 53;
144 * Task run on shutdown. Cleans up everything.
147 * @param tc scheduler context
150 do_shutdown (void *cls,
151 const struct GNUNET_SCHEDULER_TaskContext *tc)
153 if (GNUNET_SCHEDULER_NO_TASK != t4)
154 GNUNET_SCHEDULER_cancel (t4);
155 if (GNUNET_SCHEDULER_NO_TASK != t6)
156 GNUNET_SCHEDULER_cancel (t6);
157 if (NULL != listen_socket4)
159 GNUNET_NETWORK_socket_close (listen_socket4);
160 listen_socket4 = NULL;
162 if (NULL != listen_socket6)
164 GNUNET_NETWORK_socket_close (listen_socket6);
165 listen_socket6 = NULL;
167 GNUNET_GNS_disconnect (gns);
169 GNUNET_DNSSTUB_stop (dns_stub);
175 * Send the response for the given request and clean up.
177 * @param request context for the request.
180 send_response (struct Request *request)
186 GNUNET_DNSPARSER_pack (request->packet,
187 UINT16_MAX /* is this not too much? */,
191 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
192 _("Failed to pack DNS response into UDP packet!\n"));
197 GNUNET_NETWORK_socket_sendto (request->lsock,
201 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
204 GNUNET_SCHEDULER_cancel (request->timeout_task);
205 GNUNET_DNSPARSER_free_packet (request->packet);
206 GNUNET_free (request);
211 * Task run on timeout. Cleans up request.
213 * @param cls 'struct Request' of the request to clean up
214 * @param tc scheduler context
217 do_timeout (void *cls,
218 const struct GNUNET_SCHEDULER_TaskContext *tc)
220 struct Request *request = cls;
222 if (NULL != request->packet)
223 GNUNET_DNSPARSER_free_packet (request->packet);
224 if (NULL != request->lookup)
225 GNUNET_GNS_cancel_lookup_request (request->lookup);
226 if (NULL != request->dns_lookup)
227 GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup);
228 GNUNET_free (request);
233 * Iterator called on obtained result for a DNS
237 * @param rs the request socket
238 * @param dns the DNS udp payload
239 * @param r size of the DNS payload
242 dns_result_processor (void *cls,
243 struct GNUNET_DNSSTUB_RequestSocket *rs,
244 const struct GNUNET_TUN_DnsHeader *dns,
247 struct Request *request = cls;
249 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
250 send_response (request);
255 * Iterator called on obtained result for a GNS
259 * @param rd_count number of records
260 * @param rd the records in reply
263 result_processor (void *cls,
265 const struct GNUNET_NAMESTORE_RecordData *rd)
267 struct Request *request = cls;
268 struct GNUNET_DNSPARSER_Packet *packet;
270 struct GNUNET_DNSPARSER_Record rec;
272 request->lookup = NULL;
273 packet = request->packet;
274 packet->flags.query_or_response = 1;
275 packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR;
276 packet->flags.checking_disabled = 0;
277 packet->flags.authenticated_data = 1;
278 packet->flags.zero = 0;
279 packet->flags.recursion_available = 1;
280 packet->flags.message_truncated = 0;
281 packet->flags.authoritative_answer = 0;
282 //packet->flags.opcode = GNUNET_DNSPARSER_OPCODE_STATUS; // ???
283 for (i=0;i<rd_count;i++)
285 rec.expiration_time.abs_value = rd[i].expiration_time;
286 switch (rd[i].record_type)
288 case GNUNET_DNSPARSER_TYPE_A:
289 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
290 rec.name = GNUNET_strdup (packet->queries[0].name);
291 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
292 rec.type = GNUNET_DNSPARSER_TYPE_A;
293 rec.data.raw.data = GNUNET_malloc (sizeof (struct in_addr));
294 memcpy (rec.data.raw.data,
297 rec.data.raw.data_len = sizeof (struct in_addr);
298 GNUNET_array_append (packet->answers,
302 case GNUNET_DNSPARSER_TYPE_AAAA:
303 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
304 rec.name = GNUNET_strdup (packet->queries[0].name);
305 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
306 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
307 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
308 memcpy (rec.data.raw.data,
311 rec.data.raw.data_len = sizeof (struct in6_addr);
312 GNUNET_array_append (packet->answers,
316 case GNUNET_DNSPARSER_TYPE_CNAME:
317 rec.name = GNUNET_strdup (packet->queries[0].name);
318 rec.data.hostname = strdup (rd[i].data);
319 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
320 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
321 memcpy (rec.data.hostname,
324 GNUNET_array_append (packet->answers,
333 send_response (request);
338 * Handle DNS request.
340 * @param lsock socket to use for sending the reply
341 * @param addr address to use for sending the reply
342 * @param addr_len number of bytes in addr
343 * @param udp_msg DNS request payload
344 * @param udp_msg_size number of bytes in udp_msg
347 handle_request (struct GNUNET_NETWORK_Handle *lsock,
353 struct Request *request;
354 struct GNUNET_DNSPARSER_Packet *packet;
359 enum GNUNET_GNS_RecordType type;
361 struct GNUNET_CRYPTO_ShortHashCode zone;
363 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
366 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
367 _("Cannot parse DNS request from %s\n"),
368 GNUNET_a2s (addr, addr_len));
371 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
372 "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n",
373 packet->queries[0].name,
374 (unsigned int) packet->flags.query_or_response,
375 (int) packet->num_answers,
376 (int) packet->num_authority_records,
377 (int) packet->num_additional_records);
378 if ( (0 != packet->flags.query_or_response) ||
379 (0 != packet->num_answers) ||
380 (0 != packet->num_authority_records))
382 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
383 _("Received malformed DNS request from %s\n"),
384 GNUNET_a2s (addr, addr_len));
385 GNUNET_DNSPARSER_free_packet (packet);
388 if ( (1 != packet->num_queries) )
390 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
391 _("Received unsupported DNS request from %s\n"),
392 GNUNET_a2s (addr, addr_len));
393 GNUNET_DNSPARSER_free_packet (packet);
396 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
397 request->lsock = lsock;
398 request->packet = packet;
399 request->addr = &request[1];
400 request->addr_len = addr_len;
401 memcpy (&request[1], addr, addr_len);
402 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
405 name = GNUNET_strdup (packet->queries[0].name);
406 name_len = strlen (name);
408 if ( (name_len > strlen (dns_suffix)) &&
409 (0 == strcasecmp (dns_suffix,
410 &name[name_len - strlen (dns_suffix)])) )
412 /* Test if '.zkey' was requested */
413 name[name_len - strlen (dns_suffix)] = '\0';
414 dot = strrchr (name, (int) '.');
415 if ( (NULL != dot) &&
417 GNUNET_CRYPTO_short_hash_from_string (dot + 1, &zone)) )
419 /* valid '.zkey' name */
420 GNUNET_asprintf (&nname,
423 GNUNET_GNS_TLD_ZKEY);
429 /* try '.gads' name */
430 GNUNET_asprintf (&nname,
437 name_len = strlen (name);
439 if ( (name_len >= strlen ((GNUNET_GNS_TLD))) &&
440 (0 == strcasecmp (GNUNET_GNS_TLD,
441 &name[name_len - strlen (GNUNET_GNS_TLD)])) )
442 use_gns = GNUNET_YES;
444 if ( (name_len > strlen (GNUNET_GNS_TLD_ZKEY)) &&
445 (0 == strcasecmp (GNUNET_GNS_TLD_ZKEY,
446 &name[name_len - strlen (GNUNET_GNS_TLD_ZKEY)])) )
447 use_gns = GNUNET_YES;
449 if (GNUNET_YES == use_gns)
451 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
453 type = packet->queries[0].type;
454 request->lookup = GNUNET_GNS_lookup (gns,
464 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
465 "Calling DNS at %s\n", dns_ip);
466 GNUNET_DNSPARSER_free_packet (request->packet);
467 request->packet = NULL;
468 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
471 &dns_result_processor,
479 * Task to read IPv4 DNS packets.
481 * @param cls the 'listen_socket4'
482 * @param tc scheduler context
485 read_dns4 (void *cls,
486 const struct GNUNET_SCHEDULER_TaskContext *tc)
488 struct sockaddr_in v4;
492 GNUNET_assert (listen_socket4 == cls);
493 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
497 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
498 return; /* shutdown? */
499 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
503 return; /* read error!? */
508 addrlen = sizeof (v4);
509 GNUNET_break (size ==
510 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
513 (struct sockaddr *) &v4,
515 handle_request (listen_socket4, &v4, addrlen,
522 * Task to read IPv6 DNS packets.
524 * @param cls the 'listen_socket6'
525 * @param tc scheduler context
528 read_dns6 (void *cls,
529 const struct GNUNET_SCHEDULER_TaskContext *tc)
531 struct sockaddr_in6 v6;
535 GNUNET_assert (listen_socket6 == cls);
536 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
540 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
541 return; /* shutdown? */
542 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
546 return; /* read error!? */
551 addrlen = sizeof (v6);
552 GNUNET_break (size ==
553 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
556 (struct sockaddr *) &v6,
558 handle_request (listen_socket6, &v6, addrlen,
565 * Main function that will be run.
568 * @param args remaining command-line arguments
569 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
570 * @param cfg configuration
573 run (void *cls, char *const *args, const char *cfgfile,
574 const struct GNUNET_CONFIGURATION_Handle *cfg)
578 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
579 "No DNS server specified!\n");
583 if (NULL == dns_suffix)
584 dns_suffix = DNS_SUFFIX;
585 if (NULL == fcfs_suffix)
586 fcfs_suffix = FCFS_SUFFIX;
587 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
589 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
591 GNUNET_GNS_disconnect (gns);
595 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
598 if (NULL != listen_socket4)
600 struct sockaddr_in v4;
602 memset (&v4, 0, sizeof (v4));
603 v4.sin_family = AF_INET;
604 #if HAVE_SOCKADDR_IN_SIN_LEN
605 v4.sin_len = sizeof (v4);
607 v4.sin_port = htons (listen_port);
609 GNUNET_NETWORK_socket_bind (listen_socket4,
610 (struct sockaddr *) &v4,
613 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
614 GNUNET_NETWORK_socket_close (listen_socket4);
615 listen_socket4 = NULL;
618 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
621 if (NULL != listen_socket6)
623 struct sockaddr_in6 v6;
625 memset (&v6, 0, sizeof (v6));
626 v6.sin6_family = AF_INET6;
627 #if HAVE_SOCKADDR_IN_SIN_LEN
628 v6.sin6_len = sizeof (v6);
630 v6.sin6_port = htons (listen_port);
632 GNUNET_NETWORK_socket_bind (listen_socket6,
633 (struct sockaddr *) &v6,
636 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
637 GNUNET_NETWORK_socket_close (listen_socket6);
638 listen_socket6 = NULL;
641 if ( (NULL == listen_socket4) &&
642 (NULL == listen_socket6) )
644 GNUNET_GNS_disconnect (gns);
646 GNUNET_DNSSTUB_stop (dns_stub);
650 if (NULL != listen_socket4)
651 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
655 if (NULL != listen_socket6)
656 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
661 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
667 * The main function for the fcfs daemon.
669 * @param argc number of arguments from the command line
670 * @param argv command line arguments
671 * @return 0 ok, 1 on error
677 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
679 gettext_noop ("IP of recursive DNS resolver to use (required)"), 1,
680 &GNUNET_GETOPT_set_string, &dns_ip},
681 {'s', "suffix", "SUFFIX",
682 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
683 &GNUNET_GETOPT_set_string, &dns_suffix},
684 {'f', "fcfs", "NAME",
685 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
686 &GNUNET_GETOPT_set_string, &fcfs_suffix},
687 {'p', "port", "UDPPORT",
688 gettext_noop ("UDP port to listen on for inbound DNS requests; default: 53"), 1,
689 &GNUNET_GETOPT_set_uint, &listen_port},
690 GNUNET_GETOPT_OPTION_END
694 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
697 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
700 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
701 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
703 &run, NULL)) ? 0 : 1;
704 GNUNET_free ((void*) argv);
708 /* end of gnunet-dns2gns.c */