2 This file is part of GNUnet.
3 (C) 2012 Christian Grothoff (and other contributing authors)
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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 switch (rd[i].record_type)
276 case GNUNET_DNSPARSER_TYPE_A:
277 GNUNET_assert (sizeof (struct in_addr) == rd[i].data_size);
278 rec.name = GNUNET_strdup (packet->queries[0].name);
279 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
280 rec.type = GNUNET_DNSPARSER_TYPE_A;
281 rec.data.raw.data = GNUNET_malloc (sizeof (struct in_addr));
282 memcpy (rec.data.raw.data,
285 rec.data.raw.data_len = sizeof (struct in_addr);
286 GNUNET_array_append (packet->answers,
290 case GNUNET_DNSPARSER_TYPE_AAAA:
291 GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size);
292 rec.name = GNUNET_strdup (packet->queries[0].name);
293 rec.data.raw.data = GNUNET_malloc (sizeof (struct in6_addr));
294 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
295 rec.type = GNUNET_DNSPARSER_TYPE_AAAA;
296 memcpy (rec.data.raw.data,
299 rec.data.raw.data_len = sizeof (struct in6_addr);
300 GNUNET_array_append (packet->answers,
304 case GNUNET_DNSPARSER_TYPE_CNAME:
305 rec.name = GNUNET_strdup (packet->queries[0].name);
306 rec.data.hostname = strdup (rd[i].data);
307 rec.class = GNUNET_DNSPARSER_CLASS_INTERNET;
308 rec.type = GNUNET_DNSPARSER_TYPE_CNAME;
309 memcpy (rec.data.hostname,
312 GNUNET_array_append (packet->answers,
321 send_response (request);
326 * Handle DNS request.
328 * @param lsock socket to use for sending the reply
329 * @param addr address to use for sending the reply
330 * @param addr_len number of bytes in addr
331 * @param udp_msg DNS request payload
332 * @param udp_msg_size number of bytes in udp_msg
335 handle_request (struct GNUNET_NETWORK_Handle *lsock,
341 struct Request *request;
342 struct GNUNET_DNSPARSER_Packet *packet;
345 enum GNUNET_GNS_RecordType type;
348 packet = GNUNET_DNSPARSER_parse (udp_msg, udp_msg_size);
351 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
352 _("Cannot parse DNS request from %s\n"),
353 GNUNET_a2s (addr, addr_len));
356 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
358 packet->flags.query_or_response,
360 packet->num_authority_records,
361 packet->num_additional_records);
362 if ( (0 != packet->flags.query_or_response) ||
363 (0 != packet->num_answers) ||
364 (0 != packet->num_authority_records))
366 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
367 _("Received malformed DNS request from %s\n"),
368 GNUNET_a2s (addr, addr_len));
369 GNUNET_DNSPARSER_free_packet (packet);
372 if ( (1 != packet->num_queries) )
374 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
375 _("Received unsupported DNS request from %s\n"),
376 GNUNET_a2s (addr, addr_len));
377 GNUNET_DNSPARSER_free_packet (packet);
380 request = GNUNET_malloc (sizeof (struct Request) + addr_len);
381 request->lsock = lsock;
382 request->packet = packet;
383 request->addr = &request[1];
384 request->addr_len = addr_len;
385 memcpy (&request[1], addr, addr_len);
386 request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT,
389 name = GNUNET_strdup (packet->queries[0].name);
390 name_len = strlen (name);
392 if ( (name_len > strlen (dns_suffix)) &&
393 (0 == strcasecmp (dns_suffix,
394 &name[name_len - strlen (dns_suffix)])) )
396 if ( (name_len > strlen (fcfs_suffix)) &&
397 (0 == strcasecmp (fcfs_suffix,
398 &name[name_len - strlen (fcfs_suffix)])) )
400 name[name_len - strlen (fcfs_suffix) + 1] = '\0';
401 strcat (name, GNUNET_GNS_TLD);
405 name[name_len - strlen (dns_suffix) + 1] = '\0';
406 strcat (name, GNUNET_GNS_TLD_ZKEY);
408 name_len = strlen (name);
410 if ( (name_len > strlen ((GNUNET_GNS_TLD) + 1)) &&
411 (0 == strcasecmp (GNUNET_GNS_TLD,
412 &name[name_len - strlen (GNUNET_GNS_TLD)])) )
413 use_gns = GNUNET_YES;
415 if ( (name_len > strlen (GNUNET_GNS_TLD_ZKEY)) &&
416 (0 == strcasecmp (GNUNET_GNS_TLD_ZKEY,
417 &name[name_len - strlen (GNUNET_GNS_TLD_ZKEY)])) )
418 use_gns = GNUNET_YES;
420 if (GNUNET_YES == use_gns)
422 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
424 type = packet->queries[0].type;
425 request->lookup = GNUNET_GNS_lookup (gns,
435 /* FIXME: do traditional *DNS* lookup; note that
436 gnunet-service-dns already has code to do this;
437 factor into library to share! Why not use GNUNET_RESOLVER here?*/
438 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
439 "Calling DNS at %s\n", dns_ip);
440 GNUNET_DNSPARSER_free_packet (request->packet);
441 request->dns_lookup = GNUNET_DNSSTUB_resolve2 (dns_stub,
444 &dns_result_processor,
455 * Task to read IPv4 DNS packets.
457 * @param cls the 'listen_socket4'
458 * @param tc scheduler context
461 read_dns4 (void *cls,
462 const struct GNUNET_SCHEDULER_TaskContext *tc)
464 struct sockaddr_in v4;
468 GNUNET_assert (listen_socket4 == cls);
469 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
473 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
474 return; /* shutdown? */
475 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4);
479 return; /* read error!? */
484 addrlen = sizeof (v4);
485 GNUNET_break (size ==
486 GNUNET_NETWORK_socket_recvfrom (listen_socket4,
489 (struct sockaddr *) &v4,
491 handle_request (listen_socket4, &v4, addrlen,
498 * Task to read IPv6 DNS packets.
500 * @param cls the 'listen_socket6'
501 * @param tc scheduler context
504 read_dns6 (void *cls,
505 const struct GNUNET_SCHEDULER_TaskContext *tc)
507 struct sockaddr_in6 v6;
511 GNUNET_assert (listen_socket6 == cls);
512 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
516 if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason))
517 return; /* shutdown? */
518 size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6);
522 return; /* read error!? */
527 addrlen = sizeof (v6);
528 GNUNET_break (size ==
529 GNUNET_NETWORK_socket_recvfrom (listen_socket6,
532 (struct sockaddr *) &v6,
534 handle_request (listen_socket6, &v6, addrlen,
541 * Main function that will be run.
544 * @param args remaining command-line arguments
545 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
546 * @param cfg configuration
549 run (void *cls, char *const *args, const char *cfgfile,
550 const struct GNUNET_CONFIGURATION_Handle *cfg)
554 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
555 "No DNS server specified!\n");
559 if (NULL == dns_suffix)
560 dns_suffix = DNS_SUFFIX;
561 if (NULL == fcfs_suffix)
562 fcfs_suffix = FCFS_SUFFIX;
563 if (NULL == (gns = GNUNET_GNS_connect (cfg)))
565 if (NULL == (dns_stub = GNUNET_DNSSTUB_start (dns_ip)))
567 GNUNET_GNS_disconnect (gns);
571 listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET,
574 if (NULL != listen_socket4)
576 struct sockaddr_in v4;
578 memset (&v4, 0, sizeof (v4));
579 v4.sin_family = AF_INET;
580 #if HAVE_SOCKADDR_IN_SIN_LEN
581 v4.sin_len = sizeof (v4);
583 v4.sin_port = htons (53);
585 GNUNET_NETWORK_socket_bind (listen_socket4,
586 (struct sockaddr *) &v4,
589 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
590 GNUNET_NETWORK_socket_close (listen_socket4);
591 listen_socket4 = NULL;
594 listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6,
597 if (NULL != listen_socket6)
599 struct sockaddr_in6 v6;
601 memset (&v6, 0, sizeof (v6));
602 v6.sin6_family = AF_INET6;
603 #if HAVE_SOCKADDR_IN_SIN_LEN
604 v6.sin6_len = sizeof (v6);
606 v6.sin6_port = htons (53);
608 GNUNET_NETWORK_socket_bind (listen_socket6,
609 (struct sockaddr *) &v6,
612 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
613 GNUNET_NETWORK_socket_close (listen_socket6);
614 listen_socket6 = NULL;
617 if ( (NULL == listen_socket4) &&
618 (NULL == listen_socket6) )
620 GNUNET_GNS_disconnect (gns);
622 GNUNET_DNSSTUB_stop (dns_stub);
626 if (NULL != listen_socket4)
627 t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
631 if (NULL != listen_socket6)
632 t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
637 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
643 * The main function for the fcfs daemon.
645 * @param argc number of arguments from the command line
646 * @param argv command line arguments
647 * @return 0 ok, 1 on error
653 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
655 gettext_noop ("IP of recursive dns resolver to use (required)"), 1,
656 &GNUNET_GETOPT_set_string, &dns_ip},
657 {'s', "suffix", NULL,
658 gettext_noop ("Authoritative DNS suffix to use (optional); default: zkey.eu"), 1,
659 &GNUNET_GETOPT_set_string, &dns_suffix},
661 gettext_noop ("Authoritative FCFS suffix to use (optional); default: fcfs.zkey.eu"), 1,
662 &GNUNET_GETOPT_set_string, &fcfs_suffix},
663 GNUNET_GETOPT_OPTION_END
667 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv,
670 GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL);
673 GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns",
674 _("GNUnet DNS-to-GNS proxy (a DNS server)"),
676 &run, NULL)) ? 0 : 1;
681 /* end of gnunet-dns2gns.c */