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
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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_EccPublicSignKey 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;
170 * Task run on shutdown. Cleans up everything.
173 * @param tc scheduler context
176 do_shutdown (void *cls,
177 const struct GNUNET_SCHEDULER_TaskContext *tc)
179 if (GNUNET_SCHEDULER_NO_TASK != t4)
180 GNUNET_SCHEDULER_cancel (t4);
181 if (GNUNET_SCHEDULER_NO_TASK != t6)
182 GNUNET_SCHEDULER_cancel (t6);
183 if (NULL != listen_socket4)
185 GNUNET_NETWORK_socket_close (listen_socket4);
186 listen_socket4 = NULL;
188 if (NULL != listen_socket6)
190 GNUNET_NETWORK_socket_close (listen_socket6);
191 listen_socket6 = NULL;
195 GNUNET_IDENTITY_cancel (id_op);
198 if (NULL != identity)
200 GNUNET_IDENTITY_disconnect (identity);
203 GNUNET_GNS_disconnect (gns);
205 GNUNET_DNSSTUB_stop (dns_stub);
211 * Send the response for the given request and clean up.
213 * @param request context for the request.
216 send_response (struct Request *request)
222 GNUNET_DNSPARSER_pack (request->packet,
223 UINT16_MAX /* is this not too much? */,
227 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
228 _("Failed to pack DNS response into UDP packet!\n"));
233 GNUNET_NETWORK_socket_sendto (request->lsock,
237 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "sendto");
240 GNUNET_SCHEDULER_cancel (request->timeout_task);
241 GNUNET_DNSPARSER_free_packet (request->packet);
242 GNUNET_free (request);
247 * Task run on timeout. Cleans up request.
249 * @param cls 'struct Request' of the request to clean up
250 * @param tc scheduler context
253 do_timeout (void *cls,
254 const struct GNUNET_SCHEDULER_TaskContext *tc)
256 struct Request *request = cls;
258 if (NULL != request->packet)
259 GNUNET_DNSPARSER_free_packet (request->packet);
260 if (NULL != request->lookup)
261 GNUNET_GNS_lookup_cancel (request->lookup);
262 if (NULL != request->dns_lookup)
263 GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup);
264 GNUNET_free (request);
269 * Iterator called on obtained result for a DNS lookup
272 * @param rs the request socket
273 * @param dns the DNS udp payload
274 * @param r size of the DNS payload
277 dns_result_processor (void *cls,
278 struct GNUNET_DNSSTUB_RequestSocket *rs,
279 const struct GNUNET_TUN_DnsHeader *dns,
282 struct Request *request = cls;
284 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
285 send_response (request);
290 * Iterator called on obtained result for a GNS lookup.
293 * @param rd_count number of records in @a rd
294 * @param rd the records in reply
297 result_processor (void *cls,
299 const struct GNUNET_NAMESTORE_RecordData *rd)
301 struct Request *request = cls;
302 struct GNUNET_DNSPARSER_Packet *packet;
304 struct GNUNET_DNSPARSER_Record rec;
306 request->lookup = NULL;
307 packet = request->packet;
308 packet->flags.query_or_response = 1;
309 packet->flags.return_code = GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR;
310 packet->flags.checking_disabled = 0;
311 packet->flags.authenticated_data = 1;
312 packet->flags.zero = 0;
313 packet->flags.recursion_available = 1;
314 packet->flags.message_truncated = 0;
315 packet->flags.authoritative_answer = 0;
316 //packet->flags.opcode = GNUNET_TUN_DNS_OPCODE_STATUS; // ???
317 for (i=0;i<rd_count;i++)
319 // FIXME: do we need to hanlde #GNUNET_NAMESTORE_RF_SHADOW_RECORD
320 // here? Or should we do this in libgnunetgns?
321 rec.expiration_time.abs_value_us = rd[i].expiration_time;
322 switch (rd[i].record_type)
324 case GNUNET_DNSPARSER_TYPE_A:
325 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
326 rec.name = GNUNET_strdup (packet->queries[0].name);
327 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
328 rec.type = GNUNET_DNSPARSER_TYPE_A;
329 rec.data.raw.data = GNUNET_new (struct in_addr);
330 memcpy (rec.data.raw.data,
333 rec.data.raw.data_len = sizeof (struct in_addr);
334 GNUNET_array_append (packet->answers,
338 case GNUNET_DNSPARSER_TYPE_AAAA:
339 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
340 rec.name = GNUNET_strdup (packet->queries[0].name);
341 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
342 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
343 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
344 memcpy (rec.data.raw.data,
347 rec.data.raw.data_len = sizeof (struct in6_addr);
348 GNUNET_array_append (packet->answers,
352 case GNUNET_DNSPARSER_TYPE_CNAME:
353 rec.name = GNUNET_strdup (packet->queries[0].name);
354 rec.data.hostname = strdup (rd[i].data);
355 rec.class = GNUNET_TUN_DNS_CLASS_INTERNET;
356 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
357 memcpy (rec.data.hostname,
360 GNUNET_array_append (packet->answers,
369 send_response (request);
374 * Handle DNS request.
376 * @param lsock socket to use for sending the reply
377 * @param addr address to use for sending the reply
378 * @param addr_len number of bytes in @a addr
379 * @param udp_msg DNS request payload
380 * @param udp_msg_size number of bytes in @a udp_msg
383 handle_request (struct GNUNET_NETWORK_Handle *lsock,
389 struct Request *request;
390 struct GNUNET_DNSPARSER_Packet *packet;
396 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
399 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
400 _("Cannot parse DNS request from %s\n"),
401 GNUNET_a2s (addr, addr_len));
404 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
405 "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n",
406 packet->queries[0].name,
407 (unsigned int) packet->flags.query_or_response,
408 (int) packet->num_answers,
409 (int) packet->num_authority_records,
410 (int) packet->num_additional_records);
411 if ( (0 != packet->flags.query_or_response) ||
412 (0 != packet->num_answers) ||
413 (0 != packet->num_authority_records))
415 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
416 _("Received malformed DNS request from %s\n"),
417 GNUNET_a2s (addr, addr_len));
418 GNUNET_DNSPARSER_free_packet (packet);
421 if ( (1 != packet->num_queries) )
423 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
424 _("Received unsupported DNS request from %s\n"),
425 GNUNET_a2s (addr, addr_len));
426 GNUNET_DNSPARSER_free_packet (packet);
429 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
430 request->lsock = lsock;
431 request->packet = packet;
432 request->addr = &request[1];
433 request->addr_len = addr_len;
434 memcpy (&request[1], addr, addr_len);
435 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
438 name = GNUNET_strdup (packet->queries[0].name);
439 name_len = strlen (name);
443 if ( (name_len > strlen (fcfs_suffix)) &&
444 (0 == strcasecmp (fcfs_suffix,
445 &name[name_len - strlen (fcfs_suffix)])) )
447 /* replace ".fcfs.zkey.eu" with ".gnu" */
448 strcpy (&name[name_len - strlen (fcfs_suffix)],
450 use_gns = GNUNET_YES;
451 } else if ( (name_len > strlen (dns_suffix)) &&
452 (0 == strcasecmp (dns_suffix,
453 &name[name_len - strlen (dns_suffix)])) )
455 /* replace ".zkey.eu" with ".zkey" */
456 strcpy (&name[name_len - strlen (dns_suffix)],
458 use_gns = GNUNET_YES;
459 } else if ( (name_len > strlen (".gnu")) &&
460 (0 == strcasecmp (".gnu",
461 &name[name_len - strlen (".gnu")])) )
464 use_gns = GNUNET_YES;
466 if (GNUNET_YES == use_gns)
468 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
469 "Calling GNS on `%s'\n",
471 type = packet->queries[0].type;
472 request->lookup = GNUNET_GNS_lookup (gns,
477 NULL /* no shorten */,
483 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
484 "Using DNS resolver IP `%s' to resolve `%s'\n",
487 GNUNET_DNSPARSER_free_packet (request->packet);
488 request->packet = NULL;
489 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
492 &dns_result_processor,
500 * Task to read IPv4 DNS packets.
502 * @param cls the 'listen_socket4'
503 * @param tc scheduler context
506 read_dns4 (void *cls,
507 const struct GNUNET_SCHEDULER_TaskContext *tc)
509 struct sockaddr_in v4;
513 GNUNET_assert (listen_socket4 == cls);
514 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
518 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
519 return; /* shutdown? */
520 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
524 return; /* read error!? */
529 addrlen = sizeof (v4);
530 GNUNET_break (size ==
531 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
534 (struct sockaddr *) &v4,
536 handle_request (listen_socket4, &v4, addrlen,
543 * Task to read IPv6 DNS packets.
545 * @param cls the 'listen_socket6'
546 * @param tc scheduler context
549 read_dns6 (void *cls,
550 const struct GNUNET_SCHEDULER_TaskContext *tc)
552 struct sockaddr_in6 v6;
556 GNUNET_assert (listen_socket6 == cls);
557 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
561 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
562 return; /* shutdown? */
563 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
567 return; /* read error!? */
572 addrlen = sizeof (v6);
573 GNUNET_break (size ==
574 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
577 (struct sockaddr *) &v6,
579 handle_request (listen_socket6, &v6, addrlen,
591 if (NULL == dns_suffix)
592 dns_suffix = DNS_SUFFIX;
593 if (NULL == fcfs_suffix)
594 fcfs_suffix = FCFS_SUFFIX;
595 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
597 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
599 GNUNET_GNS_disconnect (gns);
603 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
606 if (NULL != listen_socket4)
608 struct sockaddr_in v4;
610 memset (&v4, 0, sizeof (v4));
611 v4.sin_family = AF_INET;
612 #if HAVE_SOCKADDR_IN_SIN_LEN
613 v4.sin_len = sizeof (v4);
615 v4.sin_port = htons (listen_port);
617 GNUNET_NETWORK_socket_bind (listen_socket4,
618 (struct sockaddr *) &v4,
621 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
622 GNUNET_NETWORK_socket_close (listen_socket4);
623 listen_socket4 = NULL;
626 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
629 if (NULL != listen_socket6)
631 struct sockaddr_in6 v6;
633 memset (&v6, 0, sizeof (v6));
634 v6.sin6_family = AF_INET6;
635 #if HAVE_SOCKADDR_IN_SIN_LEN
636 v6.sin6_len = sizeof (v6);
638 v6.sin6_port = htons (listen_port);
640 GNUNET_NETWORK_socket_bind (listen_socket6,
641 (struct sockaddr *) &v6,
644 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
645 GNUNET_NETWORK_socket_close (listen_socket6);
646 listen_socket6 = NULL;
649 if ( (NULL == listen_socket4) &&
650 (NULL == listen_socket6) )
652 GNUNET_GNS_disconnect (gns);
654 GNUNET_DNSSTUB_stop (dns_stub);
658 if (NULL != listen_socket4)
659 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
663 if (NULL != listen_socket6)
664 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
673 * Method called to inform about the egos of this peer.
675 * When used with #GNUNET_IDENTITY_create or #GNUNET_IDENTITY_get,
676 * this function is only called ONCE, and 'NULL' being passed in
677 * @a ego does indicate an error (i.e. name is taken or no default
678 * value is known). If @a ego is non-NULL and if '*ctx'
679 * is set in those callbacks, the value WILL be passed to a subsequent
680 * call to the identity callback of #GNUNET_IDENTITY_connect (if
681 * that one was not NULL).
683 * @param cls closure, NULL
684 * @param ego ego handle
685 * @param ctx context for application to store data for this ego
686 * (during the lifetime of this process, initially NULL)
687 * @param name name assigned by the user for this ego,
688 * NULL if the user just deleted the ego and it
689 * must thus no longer be used
692 identity_cb (void *cls,
693 struct GNUNET_IDENTITY_Ego *ego,
700 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
701 _("No ego configured for `dns2gns` subsystem\n"));
704 GNUNET_IDENTITY_ego_get_public_key (ego,
711 * Main function that will be run.
714 * @param args remaining command-line arguments
715 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
716 * @param c configuration
719 run (void *cls, char *const *args, const char *cfgfile,
720 const struct GNUNET_CONFIGURATION_Handle *c)
726 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
727 _("No DNS server specified!\n"));
730 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
732 if (NULL == gns_zone_str)
734 identity = GNUNET_IDENTITY_connect (cfg,
736 id_op = GNUNET_IDENTITY_get (identity,
742 if ( (NULL == gns_zone_str) ||
744 GNUNET_CRYPTO_ecc_public_sign_key_from_string (gns_zone_str,
745 strlen (gns_zone_str),
748 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
749 _("No valid GNS zone specified!\n"));
750 GNUNET_SCHEDULER_shutdown ();
758 * The main function for the dns2gns daemon.
760 * @param argc number of arguments from the command line
761 * @param argv command line arguments
762 * @return 0 ok, 1 on error
768 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
770 gettext_noop ("IP of recursive DNS resolver to use (required)"), 1,
771 &GNUNET_GETOPT_set_string, &dns_ip},
772 {'f', "fcfs", "NAME",
773 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
774 &GNUNET_GETOPT_set_string, &fcfs_suffix},
775 {'s', "suffix", "SUFFIX",
776 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
777 &GNUNET_GETOPT_set_string, &dns_suffix},
778 {'p', "port", "UDPPORT",
779 gettext_noop ("UDP port to listen on for inbound DNS requests; default: 53"), 1,
780 &GNUNET_GETOPT_set_uint, &listen_port},
781 {'z', "zone", "PUBLICKEY",
782 gettext_noop ("Public key of the GNS zone to use (overrides default)"), 1,
783 &GNUNET_GETOPT_set_string, &gns_zone_str},
784 GNUNET_GETOPT_OPTION_END
788 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
791 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
794 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
795 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
797 &run, NULL)) ? 0 : 1;
798 GNUNET_free ((void*) argv);
802 /* end of gnunet-dns2gns.c */