2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
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
8 option) any later version.
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 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
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 * 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);
163 GNUNET_DNSSTUB_stop (dns_stub);
169 * Send the response for the given request and clean up.
171 * @param request context for the request.
174 send_response (struct Request *request)
180 GNUNET_DNSPARSER_pack (request->packet,
181 UINT16_MAX /* is this not too much? */,
185 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
186 _("Failed to pack DNS response into UDP packet!\n"));
191 GNUNET_NETWORK_socket_sendto (request->lsock,
195 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
198 GNUNET_SCHEDULER_cancel (request->timeout_task);
199 GNUNET_DNSPARSER_free_packet (request->packet);
200 GNUNET_free (request);
205 * Task run on timeout. Cleans up request.
207 * @param cls 'struct Request' of the request to clean up
208 * @param tc scheduler context
211 do_timeout (void *cls,
212 const struct GNUNET_SCHEDULER_TaskContext *tc)
214 struct Request *request = cls;
216 if (NULL != request->packet)
217 GNUNET_DNSPARSER_free_packet (request->packet);
218 if (NULL != request->lookup)
219 GNUNET_GNS_cancel_lookup_request (request->lookup);
220 if (NULL != request->dns_lookup)
221 GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup);
222 GNUNET_free (request);
227 * Iterator called on obtained result for a DNS
231 * @param rs the request socket
232 * @param dns the DNS udp payload
233 * @param r size of the DNS payload
236 dns_result_processor (void *cls,
237 struct GNUNET_DNSSTUB_RequestSocket *rs,
238 const struct GNUNET_TUN_DnsHeader *dns,
241 struct Request *request = cls;
243 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
244 send_response (request);
249 * Iterator called on obtained result for a GNS
253 * @param rd_count number of records
254 * @param rd the records in reply
257 result_processor (void *cls,
259 const struct GNUNET_NAMESTORE_RecordData *rd)
261 struct Request *request = cls;
262 struct GNUNET_DNSPARSER_Packet *packet;
264 struct GNUNET_DNSPARSER_Record rec;
266 request->lookup = NULL;
267 packet = request->packet;
268 packet->flags.query_or_response = 1;
269 packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR;
270 packet->flags.checking_disabled = 0;
271 packet->flags.authenticated_data = 1;
272 packet->flags.zero = 0;
273 packet->flags.recursion_available = 1;
274 packet->flags.message_truncated = 0;
275 packet->flags.authoritative_answer = 0;
276 //packet->flags.opcode = GNUNET_DNSPARSER_OPCODE_STATUS; // ???
277 for (i=0;i<rd_count;i++)
279 rec.expiration_time.abs_value = rd[i].expiration_time;
280 switch (rd[i].record_type)
282 case GNUNET_DNSPARSER_TYPE_A:
283 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
284 rec.name = GNUNET_strdup (packet->queries[0].name);
285 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
286 rec.type = GNUNET_DNSPARSER_TYPE_A;
287 rec.data.raw.data = GNUNET_malloc (sizeof (struct in_addr));
288 memcpy (rec.data.raw.data,
291 rec.data.raw.data_len = sizeof (struct in_addr);
292 GNUNET_array_append (packet->answers,
296 case GNUNET_DNSPARSER_TYPE_AAAA:
297 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
298 rec.name = GNUNET_strdup (packet->queries[0].name);
299 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
300 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
301 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
302 memcpy (rec.data.raw.data,
305 rec.data.raw.data_len = sizeof (struct in6_addr);
306 GNUNET_array_append (packet->answers,
310 case GNUNET_DNSPARSER_TYPE_CNAME:
311 rec.name = GNUNET_strdup (packet->queries[0].name);
312 rec.data.hostname = strdup (rd[i].data);
313 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
314 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
315 memcpy (rec.data.hostname,
318 GNUNET_array_append (packet->answers,
327 send_response (request);
332 * Handle DNS request.
334 * @param lsock socket to use for sending the reply
335 * @param addr address to use for sending the reply
336 * @param addr_len number of bytes in addr
337 * @param udp_msg DNS request payload
338 * @param udp_msg_size number of bytes in udp_msg
341 handle_request (struct GNUNET_NETWORK_Handle *lsock,
347 struct Request *request;
348 struct GNUNET_DNSPARSER_Packet *packet;
353 enum GNUNET_GNS_RecordType type;
355 struct GNUNET_CRYPTO_ShortHashCode zone;
357 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
360 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
361 _("Cannot parse DNS request from %s\n"),
362 GNUNET_a2s (addr, addr_len));
365 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
366 "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n",
367 packet->queries[0].name,
368 (unsigned int) packet->flags.query_or_response,
369 (int) packet->num_answers,
370 (int) packet->num_authority_records,
371 (int) packet->num_additional_records);
372 if ( (0 != packet->flags.query_or_response) ||
373 (0 != packet->num_answers) ||
374 (0 != packet->num_authority_records))
376 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
377 _("Received malformed DNS request from %s\n"),
378 GNUNET_a2s (addr, addr_len));
379 GNUNET_DNSPARSER_free_packet (packet);
382 if ( (1 != packet->num_queries) )
384 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
385 _("Received unsupported DNS request from %s\n"),
386 GNUNET_a2s (addr, addr_len));
387 GNUNET_DNSPARSER_free_packet (packet);
390 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
391 request->lsock = lsock;
392 request->packet = packet;
393 request->addr = &request[1];
394 request->addr_len = addr_len;
395 memcpy (&request[1], addr, addr_len);
396 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
399 name = GNUNET_strdup (packet->queries[0].name);
400 name_len = strlen (name);
402 if ( (name_len > strlen (dns_suffix)) &&
403 (0 == strcasecmp (dns_suffix,
404 &name[name_len - strlen (dns_suffix)])) )
406 /* Test if '.zkey' was requested */
407 name[name_len - strlen (dns_suffix)] = '\0';
408 dot = strrchr (name, (int) '.');
409 if ( (NULL != dot) &&
411 GNUNET_CRYPTO_short_hash_from_string (dot + 1, &zone)) )
413 /* valid '.zkey' name */
414 GNUNET_asprintf (&nname,
417 GNUNET_GNS_TLD_ZKEY);
423 /* try '.gads' name */
424 GNUNET_asprintf (&nname,
431 name_len = strlen (name);
433 if ( (name_len >= strlen ((GNUNET_GNS_TLD))) &&
434 (0 == strcasecmp (GNUNET_GNS_TLD,
435 &name[name_len - strlen (GNUNET_GNS_TLD)])) )
436 use_gns = GNUNET_YES;
438 if ( (name_len > strlen (GNUNET_GNS_TLD_ZKEY)) &&
439 (0 == strcasecmp (GNUNET_GNS_TLD_ZKEY,
440 &name[name_len - strlen (GNUNET_GNS_TLD_ZKEY)])) )
441 use_gns = GNUNET_YES;
443 if (GNUNET_YES == use_gns)
445 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
447 type = packet->queries[0].type;
448 request->lookup = GNUNET_GNS_lookup (gns,
458 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
459 "Calling DNS at %s\n", dns_ip);
460 GNUNET_DNSPARSER_free_packet (request->packet);
461 request->packet = NULL;
462 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
465 &dns_result_processor,
473 * Task to read IPv4 DNS packets.
475 * @param cls the 'listen_socket4'
476 * @param tc scheduler context
479 read_dns4 (void *cls,
480 const struct GNUNET_SCHEDULER_TaskContext *tc)
482 struct sockaddr_in v4;
486 GNUNET_assert (listen_socket4 == cls);
487 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
491 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
492 return; /* shutdown? */
493 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
497 return; /* read error!? */
502 addrlen = sizeof (v4);
503 GNUNET_break (size ==
504 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
507 (struct sockaddr *) &v4,
509 handle_request (listen_socket4, &v4, addrlen,
516 * Task to read IPv6 DNS packets.
518 * @param cls the 'listen_socket6'
519 * @param tc scheduler context
522 read_dns6 (void *cls,
523 const struct GNUNET_SCHEDULER_TaskContext *tc)
525 struct sockaddr_in6 v6;
529 GNUNET_assert (listen_socket6 == cls);
530 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
534 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
535 return; /* shutdown? */
536 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
540 return; /* read error!? */
545 addrlen = sizeof (v6);
546 GNUNET_break (size ==
547 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
550 (struct sockaddr *) &v6,
552 handle_request (listen_socket6, &v6, addrlen,
559 * Main function that will be run.
562 * @param args remaining command-line arguments
563 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
564 * @param cfg configuration
567 run (void *cls, char *const *args, const char *cfgfile,
568 const struct GNUNET_CONFIGURATION_Handle *cfg)
572 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
573 "No DNS server specified!\n");
577 if (NULL == dns_suffix)
578 dns_suffix = DNS_SUFFIX;
579 if (NULL == fcfs_suffix)
580 fcfs_suffix = FCFS_SUFFIX;
581 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
583 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
585 GNUNET_GNS_disconnect (gns);
589 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
592 if (NULL != listen_socket4)
594 struct sockaddr_in v4;
596 memset (&v4, 0, sizeof (v4));
597 v4.sin_family = AF_INET;
598 #if HAVE_SOCKADDR_IN_SIN_LEN
599 v4.sin_len = sizeof (v4);
601 v4.sin_port = htons (53);
603 GNUNET_NETWORK_socket_bind (listen_socket4,
604 (struct sockaddr *) &v4,
607 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
608 GNUNET_NETWORK_socket_close (listen_socket4);
609 listen_socket4 = NULL;
612 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
615 if (NULL != listen_socket6)
617 struct sockaddr_in6 v6;
619 memset (&v6, 0, sizeof (v6));
620 v6.sin6_family = AF_INET6;
621 #if HAVE_SOCKADDR_IN_SIN_LEN
622 v6.sin6_len = sizeof (v6);
624 v6.sin6_port = htons (53);
626 GNUNET_NETWORK_socket_bind (listen_socket6,
627 (struct sockaddr *) &v6,
630 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
631 GNUNET_NETWORK_socket_close (listen_socket6);
632 listen_socket6 = NULL;
635 if ( (NULL == listen_socket4) &&
636 (NULL == listen_socket6) )
638 GNUNET_GNS_disconnect (gns);
640 GNUNET_DNSSTUB_stop (dns_stub);
644 if (NULL != listen_socket4)
645 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
649 if (NULL != listen_socket6)
650 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
655 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
661 * The main function for the fcfs daemon.
663 * @param argc number of arguments from the command line
664 * @param argv command line arguments
665 * @return 0 ok, 1 on error
671 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
673 gettext_noop ("IP of recursive dns resolver to use (required)"), 1,
674 &GNUNET_GETOPT_set_string, &dns_ip},
675 {'s', "suffix", NULL,
676 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
677 &GNUNET_GETOPT_set_string, &dns_suffix},
679 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
680 &GNUNET_GETOPT_set_string, &fcfs_suffix},
681 GNUNET_GETOPT_OPTION_END
685 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
688 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
691 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
692 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
694 &run, NULL)) ? 0 : 1;
699 /* end of gnunet-dns2gns.c */