2 This file is part of GNUnet.
3 (C) 2012-2013 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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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_identity_service.h>
30 #include <gnunet_dnsstub_lib.h>
34 * Timeout for DNS requests.
36 #define TIMEOUT GNUNET_TIME_UNIT_MINUTES
41 #define DNS_SUFFIX ".zkey.eu"
46 #define FCFS_SUFFIX "fcfs.zkey.eu"
49 * Data kept per request.
54 * Socket to use for sending the reply.
56 struct GNUNET_NETWORK_Handle *lsock;
59 * Destination address to use.
64 * Initially, this is the DNS request, it will then be
65 * converted to the DNS response.
67 struct GNUNET_DNSPARSER_Packet *packet;
70 * Our GNS request handle.
72 struct GNUNET_GNS_LookupRequest *lookup;
75 * Our DNS request handle
77 struct GNUNET_DNSSTUB_RequestSocket *dns_lookup;
80 * Task run on timeout or shutdown to clean up without
83 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
86 * Number of bytes in 'addr'.
94 * Handle to GNS resolver.
96 struct GNUNET_GNS_Handle *gns;
101 struct GNUNET_DNSSTUB_Context *dns_stub;
104 * Listen socket for IPv4.
106 static struct GNUNET_NETWORK_Handle *listen_socket4;
109 * Listen socket for IPv6.
111 static struct GNUNET_NETWORK_Handle *listen_socket6;
114 * Task for IPv4 socket.
116 static GNUNET_SCHEDULER_TaskIdentifier t4;
119 * Task for IPv6 socket.
121 static GNUNET_SCHEDULER_TaskIdentifier t6;
124 * DNS suffix, suffix of this gateway in DNS; defaults to '.zkey.eu'
126 static char *dns_suffix;
129 * FCFS suffix, suffix of FCFS-authority in DNS; defaults to 'fcfs.zkey.eu'.
131 static char *fcfs_suffix;
139 * UDP Port we listen on for inbound DNS requests.
141 static unsigned int listen_port = 53;
144 * Which GNS zone do we translate incoming DNS requests to?
146 static struct GNUNET_CRYPTO_EccPublicKey my_zone;
149 * '-z' option with the main zone to use.
151 static char *gns_zone_str;
154 * Configuration to use.
156 static const struct GNUNET_CONFIGURATION_Handle *cfg;
159 * Connection to identity service.
161 static struct GNUNET_IDENTITY_Handle *identity;
164 * Request for our ego.
166 static struct GNUNET_IDENTITY_Operation *id_op;
171 * Task run on shutdown. Cleans up everything.
174 * @param tc scheduler context
177 do_shutdown (void *cls,
178 const struct GNUNET_SCHEDULER_TaskContext *tc)
180 if (GNUNET_SCHEDULER_NO_TASK != t4)
181 GNUNET_SCHEDULER_cancel (t4);
182 if (GNUNET_SCHEDULER_NO_TASK != t6)
183 GNUNET_SCHEDULER_cancel (t6);
184 if (NULL != listen_socket4)
186 GNUNET_NETWORK_socket_close (listen_socket4);
187 listen_socket4 = NULL;
189 if (NULL != listen_socket6)
191 GNUNET_NETWORK_socket_close (listen_socket6);
192 listen_socket6 = NULL;
196 GNUNET_IDENTITY_cancel (id_op);
199 if (NULL != identity)
201 GNUNET_IDENTITY_disconnect (identity);
204 GNUNET_GNS_disconnect (gns);
206 GNUNET_DNSSTUB_stop (dns_stub);
212 * Send the response for the given request and clean up.
214 * @param request context for the request.
217 send_response (struct Request *request)
223 GNUNET_DNSPARSER_pack (request->packet,
224 UINT16_MAX /* is this not too much? */,
228 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
229 _("Failed to pack DNS response into UDP packet!\n"));
234 GNUNET_NETWORK_socket_sendto (request->lsock,
238 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
241 GNUNET_SCHEDULER_cancel (request->timeout_task);
242 GNUNET_DNSPARSER_free_packet (request->packet);
243 GNUNET_free (request);
248 * Task run on timeout. Cleans up request.
250 * @param cls 'struct Request' of the request to clean up
251 * @param tc scheduler context
254 do_timeout (void *cls,
255 const struct GNUNET_SCHEDULER_TaskContext *tc)
257 struct Request *request = cls;
259 if (NULL != request->packet)
260 GNUNET_DNSPARSER_free_packet (request->packet);
261 if (NULL != request->lookup)
262 GNUNET_GNS_lookup_cancel (request->lookup);
263 if (NULL != request->dns_lookup)
264 GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup);
265 GNUNET_free (request);
270 * Iterator called on obtained result for a DNS lookup
273 * @param rs the request socket
274 * @param dns the DNS udp payload
275 * @param r size of the DNS payload
278 dns_result_processor (void *cls,
279 struct GNUNET_DNSSTUB_RequestSocket *rs,
280 const struct GNUNET_TUN_DnsHeader *dns,
283 struct Request *request = cls;
285 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
286 send_response (request);
291 * Iterator called on obtained result for a GNS lookup.
294 * @param rd_count number of records in @a rd
295 * @param rd the records in reply
298 result_processor (void *cls,
300 const struct GNUNET_NAMESTORE_RecordData *rd)
302 struct Request *request = cls;
303 struct GNUNET_DNSPARSER_Packet *packet;
305 struct GNUNET_DNSPARSER_Record rec;
307 request->lookup = NULL;
308 packet = request->packet;
309 packet->flags.query_or_response = 1;
310 packet->flags.return_code = GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR;
311 packet->flags.checking_disabled = 0;
312 packet->flags.authenticated_data = 1;
313 packet->flags.zero = 0;
314 packet->flags.recursion_available = 1;
315 packet->flags.message_truncated = 0;
316 packet->flags.authoritative_answer = 0;
317 //packet->flags.opcode = GNUNET_TUN_DNS_OPCODE_STATUS; // ???
318 for (i=0;i<rd_count;i++)
320 // FIXME: do we need to hanlde #GNUNET_NAMESTORE_RF_SHADOW_RECORD
321 // here? Or should we do this in libgnunetgns?
322 rec.expiration_time.abs_value_us = rd[i].expiration_time;
323 switch (rd[i].record_type)
325 case GNUNET_DNSPARSER_TYPE_A:
326 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
327 rec.name = GNUNET_strdup (packet->queries[0].name);
328 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
329 rec.type = GNUNET_DNSPARSER_TYPE_A;
330 rec.data.raw.data = GNUNET_new (struct in_addr);
331 memcpy (rec.data.raw.data,
334 rec.data.raw.data_len = sizeof (struct in_addr);
335 GNUNET_array_append (packet->answers,
339 case GNUNET_DNSPARSER_TYPE_AAAA:
340 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
341 rec.name = GNUNET_strdup (packet->queries[0].name);
342 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
343 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
344 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
345 memcpy (rec.data.raw.data,
348 rec.data.raw.data_len = sizeof (struct in6_addr);
349 GNUNET_array_append (packet->answers,
353 case GNUNET_DNSPARSER_TYPE_CNAME:
354 rec.name = GNUNET_strdup (packet->queries[0].name);
355 rec.data.hostname = strdup (rd[i].data);
356 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
357 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
358 memcpy (rec.data.hostname,
361 GNUNET_array_append (packet->answers,
370 send_response (request);
375 * Handle DNS request.
377 * @param lsock socket to use for sending the reply
378 * @param addr address to use for sending the reply
379 * @param addr_len number of bytes in @a addr
380 * @param udp_msg DNS request payload
381 * @param udp_msg_size number of bytes in @a udp_msg
384 handle_request (struct GNUNET_NETWORK_Handle *lsock,
390 struct Request *request;
391 struct GNUNET_DNSPARSER_Packet *packet;
397 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
400 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
401 _("Cannot parse DNS request from %s\n"),
402 GNUNET_a2s (addr, addr_len));
405 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
406 "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n",
407 packet->queries[0].name,
408 (unsigned int) packet->flags.query_or_response,
409 (int) packet->num_answers,
410 (int) packet->num_authority_records,
411 (int) packet->num_additional_records);
412 if ( (0 != packet->flags.query_or_response) ||
413 (0 != packet->num_answers) ||
414 (0 != packet->num_authority_records))
416 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
417 _("Received malformed DNS request from %s\n"),
418 GNUNET_a2s (addr, addr_len));
419 GNUNET_DNSPARSER_free_packet (packet);
422 if ( (1 != packet->num_queries) )
424 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
425 _("Received unsupported DNS request from %s\n"),
426 GNUNET_a2s (addr, addr_len));
427 GNUNET_DNSPARSER_free_packet (packet);
430 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
431 request->lsock = lsock;
432 request->packet = packet;
433 request->addr = &request[1];
434 request->addr_len = addr_len;
435 memcpy (&request[1], addr, addr_len);
436 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
439 name = GNUNET_strdup (packet->queries[0].name);
440 name_len = strlen (name);
444 if ( (name_len > strlen (fcfs_suffix)) &&
445 (0 == strcasecmp (fcfs_suffix,
446 &name[name_len - strlen (fcfs_suffix)])) )
448 /* replace ".fcfs.zkey.eu" with ".gnu" */
449 strcpy (&name[name_len - strlen (fcfs_suffix)],
451 use_gns = GNUNET_YES;
452 } else if ( (name_len > strlen (dns_suffix)) &&
453 (0 == strcasecmp (dns_suffix,
454 &name[name_len - strlen (dns_suffix)])) )
456 /* replace ".zkey.eu" with ".zkey" */
457 strcpy (&name[name_len - strlen (dns_suffix)],
459 use_gns = GNUNET_YES;
460 } else if ( (name_len > strlen (".gnu")) &&
461 (0 == strcasecmp (".gnu",
462 &name[name_len - strlen (".gnu")])) )
465 use_gns = GNUNET_YES;
467 if (GNUNET_YES == use_gns)
469 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
470 "Calling GNS on `%s'\n",
472 type = packet->queries[0].type;
473 request->lookup = GNUNET_GNS_lookup (gns,
478 NULL /* no shorten */,
484 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
485 "Using DNS resolver IP `%s' to resolve `%s'\n",
488 GNUNET_DNSPARSER_free_packet (request->packet);
489 request->packet = NULL;
490 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
493 &dns_result_processor,
501 * Task to read IPv4 DNS packets.
503 * @param cls the 'listen_socket4'
504 * @param tc scheduler context
507 read_dns4 (void *cls,
508 const struct GNUNET_SCHEDULER_TaskContext *tc)
510 struct sockaddr_in v4;
514 GNUNET_assert (listen_socket4 == cls);
515 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
519 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
520 return; /* shutdown? */
521 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
525 return; /* read error!? */
530 addrlen = sizeof (v4);
531 GNUNET_break (size ==
532 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
535 (struct sockaddr *) &v4,
537 handle_request (listen_socket4, &v4, addrlen,
544 * Task to read IPv6 DNS packets.
546 * @param cls the 'listen_socket6'
547 * @param tc scheduler context
550 read_dns6 (void *cls,
551 const struct GNUNET_SCHEDULER_TaskContext *tc)
553 struct sockaddr_in6 v6;
557 GNUNET_assert (listen_socket6 == cls);
558 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
562 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
563 return; /* shutdown? */
564 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
568 return; /* read error!? */
573 addrlen = sizeof (v6);
574 GNUNET_break (size ==
575 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
578 (struct sockaddr *) &v6,
580 handle_request (listen_socket6, &v6, addrlen,
592 if (NULL == dns_suffix)
593 dns_suffix = DNS_SUFFIX;
594 if (NULL == fcfs_suffix)
595 fcfs_suffix = FCFS_SUFFIX;
596 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
598 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
600 GNUNET_GNS_disconnect (gns);
604 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
607 if (NULL != listen_socket4)
609 struct sockaddr_in v4;
611 memset (&v4, 0, sizeof (v4));
612 v4.sin_family = AF_INET;
613 #if HAVE_SOCKADDR_IN_SIN_LEN
614 v4.sin_len = sizeof (v4);
616 v4.sin_port = htons (listen_port);
618 GNUNET_NETWORK_socket_bind (listen_socket4,
619 (struct sockaddr *) &v4,
623 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
624 GNUNET_NETWORK_socket_close (listen_socket4);
625 listen_socket4 = NULL;
628 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
631 if (NULL != listen_socket6)
633 struct sockaddr_in6 v6;
635 memset (&v6, 0, sizeof (v6));
636 v6.sin6_family = AF_INET6;
637 #if HAVE_SOCKADDR_IN_SIN_LEN
638 v6.sin6_len = sizeof (v6);
640 v6.sin6_port = htons (listen_port);
642 GNUNET_NETWORK_socket_bind (listen_socket6,
643 (struct sockaddr *) &v6,
647 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
648 GNUNET_NETWORK_socket_close (listen_socket6);
649 listen_socket6 = NULL;
652 if ( (NULL == listen_socket4) &&
653 (NULL == listen_socket6) )
655 GNUNET_GNS_disconnect (gns);
657 GNUNET_DNSSTUB_stop (dns_stub);
661 if (NULL != listen_socket4)
662 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
666 if (NULL != listen_socket6)
667 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
676 * Method called to inform about the egos of this peer.
678 * When used with #GNUNET_IDENTITY_create or #GNUNET_IDENTITY_get,
679 * this function is only called ONCE, and 'NULL' being passed in
680 * @a ego does indicate an error (i.e. name is taken or no default
681 * value is known). If @a ego is non-NULL and if '*ctx'
682 * is set in those callbacks, the value WILL be passed to a subsequent
683 * call to the identity callback of #GNUNET_IDENTITY_connect (if
684 * that one was not NULL).
686 * @param cls closure, NULL
687 * @param ego ego handle
688 * @param ctx context for application to store data for this ego
689 * (during the lifetime of this process, initially NULL)
690 * @param name name assigned by the user for this ego,
691 * NULL if the user just deleted the ego and it
692 * must thus no longer be used
695 identity_cb (void *cls,
696 struct GNUNET_IDENTITY_Ego *ego,
703 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
704 _("No ego configured for `dns2gns` subsystem\n"));
707 GNUNET_IDENTITY_ego_get_public_key (ego,
714 * Main function that will be run.
717 * @param args remaining command-line arguments
718 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
719 * @param c configuration
722 run (void *cls, char *const *args, const char *cfgfile,
723 const struct GNUNET_CONFIGURATION_Handle *c)
729 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
730 _("No DNS server specified!\n"));
733 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
735 if (NULL == gns_zone_str)
737 identity = GNUNET_IDENTITY_connect (cfg,
739 id_op = GNUNET_IDENTITY_get (identity,
745 if ( (NULL == gns_zone_str) ||
747 GNUNET_CRYPTO_ecc_public_key_from_string (gns_zone_str,
748 strlen (gns_zone_str),
751 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
752 _("No valid GNS zone specified!\n"));
753 GNUNET_SCHEDULER_shutdown ();
761 * The main function for the dns2gns daemon.
763 * @param argc number of arguments from the command line
764 * @param argv command line arguments
765 * @return 0 ok, 1 on error
771 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
773 gettext_noop ("IP of recursive DNS resolver to use (required)"), 1,
774 &GNUNET_GETOPT_set_string, &dns_ip},
775 {'f', "fcfs", "NAME",
776 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
777 &GNUNET_GETOPT_set_string, &fcfs_suffix},
778 {'s', "suffix", "SUFFIX",
779 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
780 &GNUNET_GETOPT_set_string, &dns_suffix},
781 {'p', "port", "UDPPORT",
782 gettext_noop ("UDP port to listen on for inbound DNS requests; default: 53"), 1,
783 &GNUNET_GETOPT_set_uint, &listen_port},
784 {'z', "zone", "PUBLICKEY",
785 gettext_noop ("Public key of the GNS zone to use (overrides default)"), 1,
786 &GNUNET_GETOPT_set_string, &gns_zone_str},
787 GNUNET_GETOPT_OPTION_END
791 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
794 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
797 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
798 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
800 &run, NULL)) ? 0 : 1;
801 GNUNET_free ((void*) argv);
805 /* end of gnunet-dns2gns.c */