2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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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_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);
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 GNUNET_free (request);
224 * Iterator called on obtained result for a DNS
228 * @param rs the request socket
229 * @param dns the DNS udp payload
230 * @param r size of the DNS payload
233 dns_result_processor (void *cls,
234 struct GNUNET_DNSSTUB_RequestSocket *rs,
235 const struct GNUNET_TUN_DnsHeader *dns,
238 struct Request *request = cls;
239 request->packet = GNUNET_DNSPARSER_parse ((char*)dns, r);
240 send_response (request);
244 * Iterator called on obtained result for a GNS
248 * @param rd_count number of records
249 * @param rd the records in reply
252 result_processor (void *cls,
254 const struct GNUNET_NAMESTORE_RecordData *rd)
256 struct Request *request = cls;
257 struct GNUNET_DNSPARSER_Packet *packet;
259 struct GNUNET_DNSPARSER_Record rec;
261 request->lookup = NULL;
262 packet = request->packet;
263 packet->flags.query_or_response = 1;
264 packet->flags.return_code = GNUNET_DNSPARSER_RETURN_CODE_NO_ERROR;
265 packet->flags.checking_disabled = 0;
266 packet->flags.authenticated_data = 1;
267 packet->flags.zero = 0;
268 packet->flags.recursion_available = 1;
269 packet->flags.message_truncated = 0;
270 packet->flags.authoritative_answer = 0;
271 //packet->flags.opcode = GNUNET_DNSPARSER_OPCODE_STATUS; // ???
272 for (i=0;i<rd_count;i++)
274 rec.expiration_time.abs_value = rd[i].expiration_time;
275 switch (rd[i].record_type)
277 case GNUNET_DNSPARSER_TYPE_A:
278 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
279 rec.name = GNUNET_strdup (packet->queries[0].name);
280 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
281 rec.type = GNUNET_DNSPARSER_TYPE_A;
282 rec.data.raw.data = GNUNET_malloc (sizeof (struct in_addr));
283 memcpy (rec.data.raw.data,
286 rec.data.raw.data_len = sizeof (struct in_addr);
287 GNUNET_array_append (packet->answers,
291 case GNUNET_DNSPARSER_TYPE_AAAA:
292 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
293 rec.name = GNUNET_strdup (packet->queries[0].name);
294 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
295 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
296 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
297 memcpy (rec.data.raw.data,
300 rec.data.raw.data_len = sizeof (struct in6_addr);
301 GNUNET_array_append (packet->answers,
305 case GNUNET_DNSPARSER_TYPE_CNAME:
306 rec.name = GNUNET_strdup (packet->queries[0].name);
307 rec.data.hostname = strdup (rd[i].data);
308 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
309 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
310 memcpy (rec.data.hostname,
313 GNUNET_array_append (packet->answers,
322 send_response (request);
327 * Handle DNS request.
329 * @param lsock socket to use for sending the reply
330 * @param addr address to use for sending the reply
331 * @param addr_len number of bytes in addr
332 * @param udp_msg DNS request payload
333 * @param udp_msg_size number of bytes in udp_msg
336 handle_request (struct GNUNET_NETWORK_Handle *lsock,
342 struct Request *request;
343 struct GNUNET_DNSPARSER_Packet *packet;
346 enum GNUNET_GNS_RecordType type;
349 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
352 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
353 _("Cannot parse DNS request from %s\n"),
354 GNUNET_a2s (addr, addr_len));
357 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
358 "Received request with flags %u, #answers %d, #auth %d, #additional %d\n",
359 (unsigned int) packet->flags.query_or_response,
360 (int) packet->num_answers,
361 (int) packet->num_authority_records,
362 (int) packet->num_additional_records);
363 if ( (0 != packet->flags.query_or_response) ||
364 (0 != packet->num_answers) ||
365 (0 != packet->num_authority_records))
367 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
368 _("Received malformed DNS request from %s\n"),
369 GNUNET_a2s (addr, addr_len));
370 GNUNET_DNSPARSER_free_packet (packet);
373 if ( (1 != packet->num_queries) )
375 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
376 _("Received unsupported DNS request from %s\n"),
377 GNUNET_a2s (addr, addr_len));
378 GNUNET_DNSPARSER_free_packet (packet);
381 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
382 request->lsock = lsock;
383 request->packet = packet;
384 request->addr = &request[1];
385 request->addr_len = addr_len;
386 memcpy (&request[1], addr, addr_len);
387 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
390 name = GNUNET_strdup (packet->queries[0].name);
391 name_len = strlen (name);
393 if ( (name_len > strlen (dns_suffix)) &&
394 (0 == strcasecmp (dns_suffix,
395 &name[name_len - strlen (dns_suffix)])) )
397 if ( (name_len > strlen (fcfs_suffix)) &&
398 (0 == strcasecmp (fcfs_suffix,
399 &name[name_len - strlen (fcfs_suffix)])) )
401 name[name_len - strlen (fcfs_suffix) + 1] = '\0';
402 strcat (name, GNUNET_GNS_TLD);
406 name[name_len - strlen (dns_suffix) + 1] = '\0';
407 strcat (name, GNUNET_GNS_TLD_ZKEY);
409 name_len = strlen (name);
411 if ( (name_len > strlen ((GNUNET_GNS_TLD) + 1)) &&
412 (0 == strcasecmp (GNUNET_GNS_TLD,
413 &name[name_len - strlen (GNUNET_GNS_TLD)])) )
414 use_gns = GNUNET_YES;
416 if ( (name_len > strlen (GNUNET_GNS_TLD_ZKEY)) &&
417 (0 == strcasecmp (GNUNET_GNS_TLD_ZKEY,
418 &name[name_len - strlen (GNUNET_GNS_TLD_ZKEY)])) )
419 use_gns = GNUNET_YES;
421 if (GNUNET_YES == use_gns)
423 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
425 type = packet->queries[0].type;
426 request->lookup = GNUNET_GNS_lookup (gns,
436 /* FIXME: do traditional *DNS* lookup; note that
437 gnunet-service-dns already has code to do this;
438 factor into library to share! Why not use GNUNET_RESOLVER here?*/
439 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
440 "Calling DNS at %s\n", dns_ip);
441 GNUNET_DNSPARSER_free_packet (request->packet);
442 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
445 &dns_result_processor,
456 * Task to read IPv4 DNS packets.
458 * @param cls the 'listen_socket4'
459 * @param tc scheduler context
462 read_dns4 (void *cls,
463 const struct GNUNET_SCHEDULER_TaskContext *tc)
465 struct sockaddr_in v4;
469 GNUNET_assert (listen_socket4 == cls);
470 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
474 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
475 return; /* shutdown? */
476 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
480 return; /* read error!? */
485 addrlen = sizeof (v4);
486 GNUNET_break (size ==
487 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
490 (struct sockaddr *) &v4,
492 handle_request (listen_socket4, &v4, addrlen,
499 * Task to read IPv6 DNS packets.
501 * @param cls the 'listen_socket6'
502 * @param tc scheduler context
505 read_dns6 (void *cls,
506 const struct GNUNET_SCHEDULER_TaskContext *tc)
508 struct sockaddr_in6 v6;
512 GNUNET_assert (listen_socket6 == cls);
513 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
517 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
518 return; /* shutdown? */
519 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
523 return; /* read error!? */
528 addrlen = sizeof (v6);
529 GNUNET_break (size ==
530 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
533 (struct sockaddr *) &v6,
535 handle_request (listen_socket6, &v6, addrlen,
542 * Main function that will be run.
545 * @param args remaining command-line arguments
546 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
547 * @param cfg configuration
550 run (void *cls, char *const *args, const char *cfgfile,
551 const struct GNUNET_CONFIGURATION_Handle *cfg)
555 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
556 "No DNS server specified!\n");
560 if (NULL == dns_suffix)
561 dns_suffix = DNS_SUFFIX;
562 if (NULL == fcfs_suffix)
563 fcfs_suffix = FCFS_SUFFIX;
564 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
566 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
568 GNUNET_GNS_disconnect (gns);
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 GNUNET_GNS_disconnect (gns);
623 GNUNET_DNSSTUB_stop (dns_stub);
627 if (NULL != listen_socket4)
628 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
632 if (NULL != listen_socket6)
633 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
638 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
644 * The main function for the fcfs daemon.
646 * @param argc number of arguments from the command line
647 * @param argv command line arguments
648 * @return 0 ok, 1 on error
654 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
656 gettext_noop ("IP of recursive dns resolver to use (required)"), 1,
657 &GNUNET_GETOPT_set_string, &dns_ip},
658 {'s', "suffix", NULL,
659 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
660 &GNUNET_GETOPT_set_string, &dns_suffix},
662 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
663 &GNUNET_GETOPT_set_string, &fcfs_suffix},
664 GNUNET_GETOPT_OPTION_END
668 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
671 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
674 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
675 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
677 &run, NULL)) ? 0 : 1;
682 /* end of gnunet-dns2gns.c */