2 This file is part of GNUnet.
3 (C) 2009 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.
22 * @file vpn/gnunet-service-dns.c
23 * @author Philipp Toelke
26 #include "gnunet_getopt_lib.h"
27 #include "gnunet_service_lib.h"
28 #include <gnunet_constants.h>
29 #include "gnunet_network_lib.h"
30 #include "gnunet_os_lib.h"
31 #include "gnunet-service-dns-p.h"
32 #include "gnunet_protocols.h"
33 #include "gnunet_applications.h"
34 #include "gnunet-vpn-packet.h"
35 #include "gnunet_container_lib.h"
36 #include "gnunet-dns-parser.h"
37 #include "gnunet_dht_service.h"
38 #include "gnunet_block_lib.h"
39 #include "block_dns.h"
40 #include "gnunet_crypto_lib.h"
41 #include "gnunet_mesh_service.h"
42 #include "gnunet_signatures.h"
44 struct GNUNET_MESH_Handle *mesh_handle;
47 * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
48 * sent through gnunet. The port of this socket will not be hijacked.
50 static struct GNUNET_NETWORK_Handle *dnsout;
53 * The port bound to the socket dnsout
55 static unsigned short dnsoutport;
58 * A handle to the DHT-Service
60 static struct GNUNET_DHT_Handle *dht;
63 * The configuration to use
65 static const struct GNUNET_CONFIGURATION_Handle *cfg;
68 * A list of DNS-Responses that have to be sent to the requesting client
70 static struct answer_packet_list *head;
73 * The tail of the list of DNS-responses
75 static struct answer_packet_list *tail;
78 * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to
79 * some information needed to handle this query
81 * It currently allocates at least
82 * (1 + machine-width + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
89 struct GNUNET_SERVER_Client *client;
90 struct GNUNET_MESH_Tunnel *tunnel;
96 } query_states[UINT16_MAX+1];
99 * A struct used to give more than one value as
100 * closure to receive_dht
102 struct receive_dht_cls
105 struct GNUNET_DHT_GetHandle *handle;
108 struct tunnel_notify_queue
110 struct tunnel_notify_queue *next;
111 struct tunnel_notify_queue *prev;
114 GNUNET_CONNECTION_TransmitReadyNotify cb;
118 * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
122 __attribute__ ((unused)), const struct GNUNET_SCHEDULER_TaskContext *tc)
124 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
129 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
130 "Delaying the hijacking, port is still %d!\n", dnsoutport);
131 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
137 struct GNUNET_OS_Process *proc;
140 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns))
142 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
143 "No entry 'VIRTDNS' in configuration!\n");
147 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
148 snprintf (port_s, 6, "%d", dnsoutport);
151 GNUNET_OS_start_process (NULL, NULL, "gnunet-helper-hijack-dns",
152 "gnunet-hijack-dns", port_s, virt_dns, NULL)))
153 GNUNET_OS_process_close (proc);
154 GNUNET_free (virt_dns);
158 * Delete the hijacking-routes
161 unhijack (unsigned short port)
165 struct GNUNET_OS_Process *proc;
168 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns))
170 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
171 "No entry 'VIRTDNS' in configuration!\n");
175 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
176 snprintf (port_s, 6, "%d", port);
179 GNUNET_OS_start_process (NULL, NULL, "gnunet-helper-hijack-dns",
180 "gnunet-hijack-dns", "-d", port_s, virt_dns,
183 GNUNET_OS_process_wait (proc);
184 GNUNET_OS_process_close (proc);
186 GNUNET_free (virt_dns);
190 * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
194 send_answer (void *cls, size_t size, void *buf)
196 struct answer_packet_list *query = head;
197 size_t len = ntohs (query->pkt.hdr.size);
199 GNUNET_assert (len <= size);
201 memcpy (buf, &query->pkt.hdr, len);
203 GNUNET_CONTAINER_DLL_remove (head, tail, query);
207 /* When more data is to be sent, reschedule */
209 GNUNET_SERVER_notify_transmit_ready (cls, ntohs (head->pkt.hdr.size),
210 GNUNET_TIME_UNIT_FOREVER_REL,
218 struct GNUNET_MESH_Tunnel *tunnel GNUNET_PACKED;
219 struct GNUNET_MessageHeader hdr;
223 struct tunnel_cls *remote_pending[UINT16_MAX];
226 mesh_send_response (void *cls, size_t size, void *buf)
228 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
229 struct GNUNET_MessageHeader *hdr = buf;
231 struct GNUNET_MESH_Tunnel **tunnel = (struct GNUNET_MESH_Tunnel **) (sz + 1);
232 struct dns_pkt *dns = (struct dns_pkt *) (tunnel + 1);
234 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS);
235 hdr->size = htons (*sz + sizeof (struct GNUNET_MessageHeader));
237 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
238 "Sending response, size=%d, sz=%d, sz+hdr=%d\n", size, *sz,
239 *sz + sizeof (struct GNUNET_MessageHeader));
241 GNUNET_assert (size >= (*sz + sizeof (struct GNUNET_MessageHeader)));
243 memcpy (hdr + 1, dns, *sz);
245 if (NULL != GNUNET_MESH_tunnel_get_head (*tunnel))
247 struct tunnel_notify_queue *element = GNUNET_MESH_tunnel_get_head (*tunnel);
248 struct tunnel_notify_queue *head = GNUNET_MESH_tunnel_get_head (*tunnel);
249 struct tunnel_notify_queue *tail = GNUNET_MESH_tunnel_get_tail (*tunnel);
251 GNUNET_CONTAINER_DLL_remove (head, tail, element);
253 GNUNET_MESH_tunnel_set_head (*tunnel, head);
254 GNUNET_MESH_tunnel_set_tail (*tunnel, tail);
255 struct GNUNET_MESH_TransmitHandle *th =
256 GNUNET_MESH_notify_transmit_ready (*tunnel,
259 GNUNET_TIME_relative_divide
260 (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
261 (const struct GNUNET_PeerIdentity *)
263 element->cb, element->cls);
265 /* save the handle */
266 GNUNET_MESH_tunnel_set_data (*tunnel, th);
271 return ntohs (hdr->size);
275 mesh_send (void *cls, size_t size, void *buf)
277 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
279 GNUNET_MESH_tunnel_set_data (cls_->tunnel, NULL);
281 GNUNET_assert (cls_->hdr.size <= size);
283 size = cls_->hdr.size;
284 cls_->hdr.size = htons (cls_->hdr.size);
286 memcpy (buf, &cls_->hdr, size);
288 if (NULL != GNUNET_MESH_tunnel_get_head (cls_->tunnel))
290 struct tunnel_notify_queue *element =
291 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
292 struct tunnel_notify_queue *head =
293 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
294 struct tunnel_notify_queue *tail =
295 GNUNET_MESH_tunnel_get_tail (cls_->tunnel);
297 GNUNET_CONTAINER_DLL_remove (head, tail, element);
299 GNUNET_MESH_tunnel_set_head (cls_->tunnel, head);
300 GNUNET_MESH_tunnel_set_tail (cls_->tunnel, tail);
301 struct GNUNET_MESH_TransmitHandle *th =
302 GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
305 GNUNET_TIME_relative_divide
306 (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
307 (const struct GNUNET_PeerIdentity *)
309 element->cb, element->cls);
311 /* save the handle */
312 GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
313 GNUNET_free (element);
321 mesh_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
322 const struct GNUNET_TRANSPORT_ATS_Information *atsi
323 __attribute__ ((unused)))
327 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
329 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
330 "Connected to peer %s, %x, sending query with id %d\n",
331 GNUNET_i2s (peer), peer, ntohs (cls_->dns.s.id));
333 if (NULL == GNUNET_MESH_tunnel_get_data (cls_->tunnel))
335 struct GNUNET_MESH_TransmitHandle *th =
336 GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
339 GNUNET_TIME_UNIT_MINUTES,
345 GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
349 struct tunnel_notify_queue *head =
350 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
351 struct tunnel_notify_queue *tail =
352 GNUNET_MESH_tunnel_get_tail (cls_->tunnel);
354 struct tunnel_notify_queue *element =
355 GNUNET_malloc (sizeof (struct tunnel_notify_queue));
357 element->len = cls_->hdr.size;
358 element->cb = mesh_send;
360 GNUNET_CONTAINER_DLL_insert_tail (head, tail, element);
361 GNUNET_MESH_tunnel_set_head (cls_->tunnel, head);
362 GNUNET_MESH_tunnel_set_tail (cls_->tunnel, tail);
368 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
370 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
373 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
376 GNUNET_MESH_peer_request_connect_by_type (mesh_handle,
377 GNUNET_TIME_UNIT_HOURS,
378 GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
379 mesh_connect, NULL, cls_);
381 remote_pending[cls_->dns.s.id] = cls_;
385 receive_mesh_query (void *cls
386 __attribute__ ((unused)), struct GNUNET_MESH_Tunnel *tunnel,
388 __attribute__ ((unused)),
389 const struct GNUNET_PeerIdentity *sender
390 __attribute__ ((unused)),
391 const struct GNUNET_MessageHeader *message,
392 const struct GNUNET_TRANSPORT_ATS_Information *atsi
393 __attribute__ ((unused)))
395 struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
397 struct sockaddr_in dest;
399 memset (&dest, 0, sizeof dest);
400 dest.sin_port = htons (53);
402 if (GNUNET_NO == GNUNET_CONFIGURATION_get_value_string(cfg, "dns", "EXTERNAL_DNS", &dns_resolver) ||
403 1 != inet_pton (AF_INET, dns_resolver, &dest.sin_addr))
404 inet_pton (AF_INET, "8.8.8.8", &dest.sin_addr);
406 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Querying for remote, id=%d\n",
408 query_states[dns->s.id].tunnel = tunnel;
409 query_states[dns->s.id].valid = GNUNET_YES;
411 GNUNET_NETWORK_socket_sendto (dnsout, dns,
412 ntohs (message->size) -
413 sizeof (struct GNUNET_MessageHeader),
414 (struct sockaddr *) &dest, sizeof dest);
416 return GNUNET_SYSERR;
420 receive_mesh_answer (void *cls
421 __attribute__ ((unused)),
422 struct GNUNET_MESH_Tunnel *tunnel, void **ctx
423 __attribute__ ((unused)),
424 const struct GNUNET_PeerIdentity *sender,
425 const struct GNUNET_MessageHeader *message,
426 const struct GNUNET_TRANSPORT_ATS_Information *atsi
427 __attribute__ ((unused)))
429 /* TODo: size check */
430 struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
432 /* They sent us a packet we were not waiting for */
433 if (remote_pending[dns->s.id] == NULL ||
434 remote_pending[dns->s.id]->tunnel != tunnel)
437 GNUNET_free (remote_pending[dns->s.id]);
438 remote_pending[dns->s.id] = NULL;
440 if (query_states[dns->s.id].valid != GNUNET_YES)
441 return GNUNET_SYSERR;
442 query_states[dns->s.id].valid = GNUNET_NO;
444 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
445 "Received answer from peer %s, dns-id %d\n", GNUNET_i2s (sender),
448 size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + query_states[dns->s.id].namelen + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */
449 + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
451 struct answer_packet_list *answer =
452 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
454 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
455 answer->pkt.hdr.size = htons (len);
457 struct dns_pkt_parsed *pdns = parse_dns_packet (dns);
459 if (ntohs (pdns->s.ancount) < 1)
461 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer only contains %d answers.\n",
462 ntohs (pdns->s.ancount));
463 free_parsed_dns_packet (pdns);
464 GNUNET_free (answer);
468 answer->pkt.addrsize = ntohs (pdns->answers[0]->data_len);
469 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "The first answer has the addrlen %d\n",
470 answer->pkt.addrsize);
471 memcpy (answer->pkt.addr, pdns->answers[0]->data,
472 ntohs (pdns->answers[0]->data_len));
474 answer->pkt.from = query_states[dns->s.id].remote_ip;
476 answer->pkt.to = query_states[dns->s.id].local_ip;
477 answer->pkt.dst_port = query_states[dns->s.id].local_port;
479 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
481 dpkt->s.id = dns->s.id;
485 dpkt->s.qdcount = htons (1);
486 dpkt->s.ancount = htons (1);
488 memcpy (dpkt->data, query_states[dns->s.id].name,
489 query_states[dns->s.id].namelen);
490 GNUNET_free (query_states[dns->s.id].name);
491 query_states[dns->s.id].name = NULL;
493 struct dns_query_line *dque =
494 (struct dns_query_line *) (dpkt->data +
495 (query_states[dns->s.id].namelen));
497 struct dns_record_line *drec_data =
498 (struct dns_record_line *) (dpkt->data +
499 (query_states[dns->s.id].namelen) +
500 sizeof (struct dns_query_line) + 2);
501 if (16 == answer->pkt.addrsize)
503 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA;
504 dque->type = htons (28); /* AAAA */
505 drec_data->type = htons (28); /* AAAA */
506 drec_data->data_len = htons (16);
510 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_A;
511 dque->type = htons (1); /* A */
512 drec_data->type = htons (1); /* A */
513 drec_data->data_len = htons (4);
515 dque->class = htons (1); /* IN */
518 (char *) (dpkt->data + (query_states[dns->s.id].namelen) +
519 sizeof (struct dns_query_line));
520 memcpy (anname, "\xc0\x0c", 2);
521 drec_data->class = htons (1); /* IN */
523 drec_data->ttl = pdns->answers[0]->ttl;
525 /* Calculate at which offset in the packet the IPv6-Address belongs, it is
526 * filled in by the daemon-vpn */
527 answer->pkt.addroffset =
528 htons ((unsigned short) ((unsigned long) (&drec_data->data) -
529 (unsigned long) (&answer->pkt)));
531 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
533 GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client, len,
534 GNUNET_TIME_UNIT_FOREVER_REL,
536 query_states[dns->s.id].client);
538 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
539 "Sent answer of length %d on to client, addroffset = %d\n", len,
540 answer->pkt.addroffset);
542 free_parsed_dns_packet (pdns);
548 send_rev_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
550 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
553 struct dns_pkt_parsed *pdns = (struct dns_pkt_parsed *) cls;
555 unsigned short id = pdns->s.id;
557 free_parsed_dns_packet (pdns);
559 if (query_states[id].valid != GNUNET_YES)
561 query_states[id].valid = GNUNET_NO;
563 GNUNET_assert (query_states[id].namelen == 74);
565 size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + 74 /* this is the length of a reverse ipv6-lookup */
566 + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */
567 + sizeof (struct dns_record_line) - 1 -
568 2 /* We do not know the lenght of the answer yet */ ;
570 struct answer_packet_list *answer =
571 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
573 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
574 answer->pkt.hdr.size = htons (len);
575 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
577 answer->pkt.from = query_states[id].remote_ip;
579 answer->pkt.to = query_states[id].local_ip;
580 answer->pkt.dst_port = query_states[id].local_port;
582 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
588 dpkt->s.qdcount = htons (1);
589 dpkt->s.ancount = htons (1);
591 memcpy (dpkt->data, query_states[id].name, query_states[id].namelen);
592 GNUNET_free (query_states[id].name);
593 query_states[id].name = NULL;
595 struct dns_query_line *dque =
596 (struct dns_query_line *) (dpkt->data + (query_states[id].namelen));
597 dque->type = htons (12); /* PTR */
598 dque->class = htons (1); /* IN */
601 (char *) (dpkt->data + (query_states[id].namelen) +
602 sizeof (struct dns_query_line));
603 memcpy (anname, "\xc0\x0c", 2);
605 struct dns_record_line *drec_data =
606 (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) +
607 sizeof (struct dns_query_line) + 2);
608 drec_data->type = htons (12); /* AAAA */
609 drec_data->class = htons (1); /* IN */
610 /* FIXME: read the TTL from block:
611 * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
613 * But how to get the seconds out of this?
615 drec_data->ttl = htonl (3600);
617 /* Calculate at which offset in the packet the length of the name and the
618 * name, it is filled in by the daemon-vpn */
619 answer->pkt.addroffset =
620 htons ((unsigned short) ((unsigned long) (&drec_data->data_len) -
621 (unsigned long) (&answer->pkt)));
623 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
625 GNUNET_SERVER_notify_transmit_ready (query_states[id].client, len,
626 GNUNET_TIME_UNIT_FOREVER_REL,
627 &send_answer, query_states[id].client);
631 * Receive a block from the dht.
634 receive_dht (void *cls, struct GNUNET_TIME_Absolute exp
635 __attribute__ ((unused)), const GNUNET_HashCode * key
636 __attribute__ ((unused)),
637 const struct GNUNET_PeerIdentity *const *get_path
638 __attribute__ ((unused)),
639 const struct GNUNET_PeerIdentity *const *put_path
640 __attribute__ ((unused)), enum GNUNET_BLOCK_Type type, size_t size,
644 unsigned short id = ((struct receive_dht_cls *) cls)->id;
645 struct GNUNET_DHT_GetHandle *handle =
646 ((struct receive_dht_cls *) cls)->handle;
649 GNUNET_assert (type == GNUNET_BLOCK_TYPE_DNS);
651 /* If no query with this id is pending, ignore the block */
652 if (query_states[id].valid != GNUNET_YES)
654 query_states[id].valid = GNUNET_NO;
656 const struct GNUNET_DNS_Record *rec = data;
658 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
659 "Got block of size %d, peer: %08x, desc: %08x\n", size,
660 *((unsigned int *) &rec->peer),
661 *((unsigned int *) &rec->service_descriptor));
663 size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + query_states[id].namelen + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */
664 + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
666 struct answer_packet_list *answer =
667 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
669 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
670 answer->pkt.hdr.size = htons (len);
671 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
673 GNUNET_CRYPTO_hash (&rec->peer,
674 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
675 &answer->pkt.service_descr.peer);
677 memcpy (&answer->pkt.service_descr.service_descriptor,
678 &rec->service_descriptor, sizeof (GNUNET_HashCode));
679 memcpy (&answer->pkt.service_descr.service_type, &rec->service_type,
680 sizeof (answer->pkt.service_descr.service_type));
681 memcpy (&answer->pkt.service_descr.ports, &rec->ports,
682 sizeof (answer->pkt.service_descr.ports));
684 answer->pkt.from = query_states[id].remote_ip;
686 answer->pkt.to = query_states[id].local_ip;
687 answer->pkt.dst_port = query_states[id].local_port;
689 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
695 dpkt->s.qdcount = htons (1);
696 dpkt->s.ancount = htons (1);
698 memcpy (dpkt->data, query_states[id].name, query_states[id].namelen);
699 GNUNET_free (query_states[id].name);
700 query_states[id].name = NULL;
702 struct dns_query_line *dque =
703 (struct dns_query_line *) (dpkt->data + (query_states[id].namelen));
704 dque->type = htons (28); /* AAAA */
705 dque->class = htons (1); /* IN */
708 (char *) (dpkt->data + (query_states[id].namelen) +
709 sizeof (struct dns_query_line));
710 memcpy (anname, "\xc0\x0c", 2);
712 struct dns_record_line *drec_data =
713 (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) +
714 sizeof (struct dns_query_line) + 2);
715 drec_data->type = htons (28); /* AAAA */
716 drec_data->class = htons (1); /* IN */
718 /* FIXME: read the TTL from block:
719 * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
721 * But how to get the seconds out of this?
723 drec_data->ttl = htonl (3600);
724 drec_data->data_len = htons (16);
726 /* Calculate at which offset in the packet the IPv6-Address belongs, it is
727 * filled in by the daemon-vpn */
728 answer->pkt.addroffset =
729 htons ((unsigned short) ((unsigned long) (&drec_data->data) -
730 (unsigned long) (&answer->pkt)));
732 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
734 GNUNET_SERVER_notify_transmit_ready (query_states[id].client, len,
735 GNUNET_TIME_UNIT_FOREVER_REL,
736 &send_answer, query_states[id].client);
738 GNUNET_DHT_get_stop (handle);
742 * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
746 __attribute__ ((unused)), struct GNUNET_SERVER_Client *client,
747 const struct GNUNET_MessageHeader *message __attribute__ ((unused)))
749 unhijack (dnsoutport);
750 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
752 GNUNET_SERVER_receive_done (client, GNUNET_OK);
756 * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
759 receive_query (void *cls
760 __attribute__ ((unused)), struct GNUNET_SERVER_Client *client,
761 const struct GNUNET_MessageHeader *message)
763 struct query_packet *pkt = (struct query_packet *) message;
764 struct dns_pkt *dns = (struct dns_pkt *) pkt->data;
765 struct dns_pkt_parsed *pdns = parse_dns_packet (dns);
767 query_states[dns->s.id].valid = GNUNET_YES;
768 query_states[dns->s.id].client = client;
769 query_states[dns->s.id].local_ip = pkt->orig_from;
770 query_states[dns->s.id].local_port = pkt->src_port;
771 query_states[dns->s.id].remote_ip = pkt->orig_to;
772 query_states[dns->s.id].namelen = strlen ((char *) dns->data) + 1;
773 if (query_states[dns->s.id].name != NULL)
774 GNUNET_free (query_states[dns->s.id].name);
775 query_states[dns->s.id].name =
776 GNUNET_malloc (query_states[dns->s.id].namelen);
777 memcpy (query_states[dns->s.id].name, dns->data,
778 query_states[dns->s.id].namelen);
780 /* The query is for a .gnunet-address */
781 if (pdns->queries[0]->namelen > 9 &&
782 0 == strncmp (pdns->queries[0]->name + (pdns->queries[0]->namelen - 9),
785 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
788 GNUNET_CRYPTO_hash (pdns->queries[0]->name, pdns->queries[0]->namelen,
791 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Getting with key %08x, len is %d\n",
792 *((unsigned int *) &key), pdns->queries[0]->namelen);
794 struct receive_dht_cls *cls =
795 GNUNET_malloc (sizeof (struct receive_dht_cls));
799 GNUNET_DHT_get_start (dht, GNUNET_TIME_UNIT_MINUTES,
800 GNUNET_BLOCK_TYPE_DNS, &key,
801 DEFAULT_GET_REPLICATION, GNUNET_DHT_RO_NONE, NULL,
802 0, NULL, 0, receive_dht, cls);
807 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n",
808 pdns->queries[0]->name, pdns->queries[0]->namelen);
810 /* This is a PTR-Query. Check if it is for "our" network */
811 if (htons (pdns->queries[0]->qtype) == 12 && 74 == pdns->queries[0]->namelen)
816 "X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.ip6.arpa.";
818 unsigned long long ipv6prefix;
819 unsigned int comparelen;
821 GNUNET_assert (GNUNET_OK ==
822 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
825 inet_pton (AF_INET6, ipv6addr, ipv6);
826 GNUNET_free (ipv6addr);
828 GNUNET_assert (GNUNET_OK ==
829 GNUNET_CONFIGURATION_get_value_number (cfg, "vpn",
832 GNUNET_assert (ipv6prefix < 127);
833 ipv6prefix = (ipv6prefix + 7) / 8;
835 for (i = ipv6prefix; i < 16; i++)
838 for (i = 0; i < 16; i++)
840 unsigned char c1 = ipv6[i] >> 4;
841 unsigned char c2 = ipv6[i] & 0xf;
844 ipv6rev[62 - (4 * i)] = c1 + '0';
846 ipv6rev[62 - (4 * i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
849 ipv6rev[62 - ((4 * i) + 2)] = c2 + '0';
851 ipv6rev[62 - ((4 * i) + 2)] = c2 + 87;
853 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
854 comparelen = 10 + 4 * ipv6prefix;
856 strncmp (pdns->queries[0]->name +
857 (pdns->queries[0]->namelen - comparelen),
858 ipv6rev + (74 - comparelen), comparelen))
860 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
862 GNUNET_SCHEDULER_add_now (send_rev_query, pdns);
869 unsigned int virt_dns_bytes;
872 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns))
874 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
875 "No entry 'VIRTDNS' in configuration!\n");
879 if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
881 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Error parsing 'VIRTDNS': %s; %m!\n",
886 GNUNET_free (virt_dns);
888 if (virt_dns_bytes == pkt->orig_to)
890 /* This is a packet that was sent directly to the virtual dns-server
892 * This means we have to send this query over gnunet
896 sizeof (struct GNUNET_MESH_Tunnel *) +
897 sizeof (struct GNUNET_MessageHeader) + (ntohs (message->size) -
898 sizeof (struct query_packet) +
900 struct tunnel_cls *cls_ = GNUNET_malloc (size);
902 cls_->hdr.size = size - sizeof (struct GNUNET_MESH_Tunnel *);
904 cls_->hdr.type = ntohs (GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS);
905 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size);
907 memcpy (&cls_->dns, dns,
908 cls_->hdr.size - sizeof (struct GNUNET_MessageHeader));
909 GNUNET_SCHEDULER_add_now (send_mesh_query, cls_);
915 /* The query should be sent to the network */
917 struct sockaddr_in dest;
919 memset (&dest, 0, sizeof dest);
920 dest.sin_port = htons (53);
921 dest.sin_addr.s_addr = pkt->orig_to;
923 GNUNET_NETWORK_socket_sendto (dnsout, dns,
924 ntohs (pkt->hdr.size) -
925 sizeof (struct query_packet) + 1,
926 (struct sockaddr *) &dest, sizeof dest);
929 free_parsed_dns_packet (pdns);
932 GNUNET_SERVER_receive_done (client, GNUNET_OK);
936 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
941 struct sockaddr_in addr;
943 dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
945 return GNUNET_SYSERR;
946 memset (&addr, 0, sizeof (struct sockaddr_in));
948 addr.sin_family = AF_INET;
949 int err = GNUNET_NETWORK_socket_bind (dnsout,
950 (struct sockaddr *) &addr,
951 sizeof (struct sockaddr_in));
953 if (err != GNUNET_OK)
955 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not bind a port: %m\n");
956 return GNUNET_SYSERR;
959 /* Read the port we bound to */
960 socklen_t addrlen = sizeof (struct sockaddr_in);
963 getsockname (GNUNET_NETWORK_get_fd (dnsout), (struct sockaddr *) &addr,
966 dnsoutport = htons (addr.sin_port);
968 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bound to port %d.\n", dnsoutport);
970 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
971 &read_response, NULL);
977 * Read a response-packet of the UDP-Socket
980 read_response (void *cls
981 __attribute__ ((unused)),
982 const struct GNUNET_SCHEDULER_TaskContext *tc)
984 struct sockaddr_in addr;
985 socklen_t addrlen = sizeof (addr);
989 if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
992 memset (&addr, 0, sizeof addr);
995 if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len))
997 unhijack (dnsoutport);
998 if (GNUNET_YES == open_port ())
999 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
1003 /* port the code above? */
1007 unsigned char buf[len];
1008 struct dns_pkt *dns = (struct dns_pkt *) buf;
1010 r = GNUNET_NETWORK_socket_recvfrom (dnsout, buf, sizeof (buf),
1011 (struct sockaddr *) &addr, &addrlen);
1015 unhijack (dnsoutport);
1016 if (GNUNET_YES == open_port ())
1017 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
1021 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d\n",
1024 if (query_states[dns->s.id].valid == GNUNET_YES)
1026 if (query_states[dns->s.id].tunnel != NULL)
1028 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1029 "Answer to query %d for a remote peer!\n",
1031 /* This response should go through a tunnel */
1033 GNUNET_malloc (4 + sizeof (struct GNUNET_MESH_Tunnel *) + r);
1035 struct GNUNET_MESH_Tunnel **t = (struct GNUNET_MESH_Tunnel **) (c + 1);
1037 *t = query_states[dns->s.id].tunnel;
1038 memcpy (t + 1, dns, r);
1040 GNUNET_MESH_tunnel_get_data (query_states[dns->s.id].tunnel))
1042 struct GNUNET_MESH_TransmitHandle *th =
1043 GNUNET_MESH_notify_transmit_ready (query_states[dns->s.id].tunnel,
1046 GNUNET_TIME_UNIT_MINUTES,
1050 GNUNET_MessageHeader),
1051 mesh_send_response, c);
1053 GNUNET_MESH_tunnel_set_data (query_states[dns->s.id].tunnel, th);
1057 struct tunnel_notify_queue *head =
1058 GNUNET_MESH_tunnel_get_head (query_states[dns->s.id].tunnel);
1059 struct tunnel_notify_queue *tail =
1060 GNUNET_MESH_tunnel_get_tail (query_states[dns->s.id].tunnel);
1062 struct tunnel_notify_queue *element =
1063 GNUNET_malloc (sizeof (struct tunnel_notify_queue));
1065 element->len = r + sizeof (struct GNUNET_MessageHeader);
1066 element->cb = mesh_send_response;
1068 GNUNET_CONTAINER_DLL_insert_tail (head, tail, element);
1069 GNUNET_MESH_tunnel_set_head (query_states[dns->s.id].tunnel, head);
1070 GNUNET_MESH_tunnel_set_tail (query_states[dns->s.id].tunnel, tail);
1075 query_states[dns->s.id].valid = GNUNET_NO;
1077 size_t len = sizeof (struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
1078 struct answer_packet_list *answer =
1079 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
1080 answer->pkt.hdr.type =
1081 htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
1082 answer->pkt.hdr.size = htons (len);
1083 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
1084 answer->pkt.from = addr.sin_addr.s_addr;
1085 answer->pkt.to = query_states[dns->s.id].local_ip;
1086 answer->pkt.dst_port = query_states[dns->s.id].local_port;
1087 memcpy (answer->pkt.data, buf, r);
1089 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
1091 GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client,
1092 len, GNUNET_TIME_UNIT_FOREVER_REL,
1094 query_states[dns->s.id].client);
1098 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
1099 &read_response, NULL);
1104 * Task run during shutdown.
1110 cleanup_task (void *cls
1111 __attribute__ ((unused)),
1112 const struct GNUNET_SCHEDULER_TaskContext *tc)
1114 GNUNET_assert (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
1116 unhijack (dnsoutport);
1117 GNUNET_DHT_disconnect (dht);
1118 GNUNET_MESH_disconnect (mesh_handle);
1122 * @brief Create a port-map from udp and tcp redirects
1124 * @param udp_redirects
1125 * @param tcp_redirects
1130 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
1133 char *cpy, *hostname, *redirect;
1135 unsigned int count = 0;
1138 if (NULL != udp_redirects)
1140 cpy = GNUNET_strdup (udp_redirects);
1141 for (redirect = strtok (cpy, " "); redirect != NULL;
1142 redirect = strtok (NULL, " "))
1144 if (NULL == (hostname = strstr (redirect, ":")))
1146 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1147 "Warning: option %s is not formatted correctly!\n",
1152 local_port = atoi (redirect);
1153 if (!((local_port > 0) && (local_port < 65536)))
1154 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1155 "Warning: %s is not a correct port.", redirect);
1157 ret |= (0xFFFF & htons (local_port));
1171 if (NULL != tcp_redirects)
1173 cpy = GNUNET_strdup (tcp_redirects);
1174 for (redirect = strtok (cpy, " "); redirect != NULL;
1175 redirect = strtok (NULL, " "))
1177 if (NULL == (hostname = strstr (redirect, ":")))
1179 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1180 "Warning: option %s is not formatted correctly!\n",
1185 local_port = atoi (redirect);
1186 if (!((local_port > 0) && (local_port < 65536)))
1187 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1188 "Warning: %s is not a correct port.", redirect);
1190 ret |= (0xFFFF & htons (local_port));
1205 GNUNET_free_non_null (cpy);
1210 publish_name (const char *name, uint64_t ports, uint32_t service_type,
1211 struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
1213 size_t size = sizeof (struct GNUNET_DNS_Record);
1214 struct GNUNET_DNS_Record data;
1216 memset (&data, 0, size);
1218 data.purpose.size = htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
1219 data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
1221 GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
1222 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
1223 *((unsigned long long *) &data.service_descriptor));
1225 data.service_type = service_type;
1228 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
1230 data.expiration_time =
1231 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply
1232 (GNUNET_TIME_UNIT_HOURS, 2));
1234 /* Sign the block */
1236 GNUNET_CRYPTO_rsa_sign (my_private_key, &data.purpose, &data.signature))
1238 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
1242 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Putting with key %08x, size = %d\n",
1243 *((unsigned int *) &data.service_descriptor), size);
1245 GNUNET_DHT_put (dht, &data.service_descriptor, DEFAULT_PUT_REPLICATION,
1246 GNUNET_DHT_RO_NONE, GNUNET_BLOCK_TYPE_DNS, size,
1248 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
1249 GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
1254 * @brief Publishes the record defined by the section section
1256 * @param cls closure
1257 * @param section the current section
1260 publish_iterate (void *cls __attribute__ ((unused)), const char *section)
1262 char *udp_redirects;
1263 char *tcp_redirects;
1264 char *alternative_names;
1265 char *alternative_name;
1268 if ((strlen (section) < 8) ||
1269 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
1271 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %s\n", section);
1273 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
1275 udp_redirects = NULL;
1277 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
1279 tcp_redirects = NULL;
1282 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY",
1285 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
1286 if (keyfile != NULL)
1287 GNUNET_free (keyfile);
1291 struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
1292 GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1293 GNUNET_free (keyfile);
1294 GNUNET_assert (my_private_key != NULL);
1296 uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
1297 uint32_t service_type = 0;
1299 if (NULL != udp_redirects)
1300 service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
1302 if (NULL != tcp_redirects)
1303 service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
1305 service_type = htonl (service_type);
1308 publish_name (section, ports, service_type, my_private_key);
1310 GNUNET_CONFIGURATION_get_value_string (cfg, section, "ALTERNATIVE_NAMES",
1311 &alternative_names))
1313 for (alternative_name = strtok (alternative_names, " ");
1314 alternative_name != NULL; alternative_name = strtok (NULL, " "))
1317 alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
1318 strcpy (altname, alternative_name);
1319 strcpy (altname + strlen (alternative_name) + 1, section);
1320 altname[strlen (alternative_name)] = '.';
1322 publish_name (altname, ports, service_type, my_private_key);
1324 GNUNET_free (alternative_names);
1326 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1327 GNUNET_free_non_null (udp_redirects);
1328 GNUNET_free_non_null (tcp_redirects);
1332 * Publish a DNS-record in the DHT.
1335 publish_names (void *cls
1336 __attribute__ ((unused)),
1337 const struct GNUNET_SCHEDULER_TaskContext *tc)
1339 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1342 GNUNET_CONFIGURATION_iterate_sections (cfg, &publish_iterate, NULL);
1344 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS, &publish_names, NULL);
1348 * @param cls closure
1349 * @param server the initialized server
1350 * @param cfg_ configuration to use
1353 run (void *cls, struct GNUNET_SERVER_Handle *server,
1354 const struct GNUNET_CONFIGURATION_Handle *cfg_)
1356 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1357 /* callback, cls, type, size */
1358 {&receive_query, NULL, GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_QUERY_DNS, 0},
1359 {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
1360 sizeof (struct GNUNET_MessageHeader)},
1364 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
1365 {receive_mesh_query, GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS, 0},
1366 {receive_mesh_answer, GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS, 0},
1370 static GNUNET_MESH_ApplicationType apptypes[] = {
1371 GNUNET_APPLICATION_TYPE_END,
1372 GNUNET_APPLICATION_TYPE_END
1376 if (GNUNET_YES != open_port ())
1378 GNUNET_SCHEDULER_shutdown ();
1383 GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT"))
1384 apptypes[0] = GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER;
1385 mesh_handle = GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
1388 dht = GNUNET_DHT_connect (cfg, 1024);
1389 GNUNET_SCHEDULER_add_now (publish_names, NULL);
1390 GNUNET_SERVER_add_handlers (server, handlers);
1391 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup_task,
1396 * The main function for the dns service.
1398 * @param argc number of arguments from the command line
1399 * @param argv command line arguments
1400 * @return 0 ok, 1 on error
1403 main (int argc, char *const *argv)
1405 return (GNUNET_OK ==
1406 GNUNET_SERVICE_run (argc, argv, "dns", GNUNET_SERVICE_OPTION_NONE,
1407 &run, NULL)) ? 0 : 1;