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];
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,
182 GNUNET_OS_process_close (proc);
183 GNUNET_free (virt_dns);
187 * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
191 send_answer (void *cls, size_t size, void *buf)
193 struct answer_packet_list *query = head;
194 size_t len = ntohs (query->pkt.hdr.size);
196 GNUNET_assert (len <= size);
198 memcpy (buf, &query->pkt.hdr, len);
200 GNUNET_CONTAINER_DLL_remove (head, tail, query);
204 /* When more data is to be sent, reschedule */
206 GNUNET_SERVER_notify_transmit_ready (cls, ntohs (head->pkt.hdr.size),
207 GNUNET_TIME_UNIT_FOREVER_REL,
215 struct GNUNET_MESH_Tunnel *tunnel GNUNET_PACKED;
216 struct GNUNET_MessageHeader hdr;
220 struct tunnel_cls *remote_pending[UINT16_MAX];
223 mesh_send_response (void *cls, size_t size, void *buf)
225 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
226 struct GNUNET_MessageHeader *hdr = buf;
228 struct GNUNET_MESH_Tunnel **tunnel = (struct GNUNET_MESH_Tunnel **) (sz + 1);
229 struct dns_pkt *dns = (struct dns_pkt *) (tunnel + 1);
231 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS);
232 hdr->size = htons (*sz + sizeof (struct GNUNET_MessageHeader));
234 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
235 "Sending response, size=%d, sz=%d, sz+hdr=%d\n", size, *sz,
236 *sz + sizeof (struct GNUNET_MessageHeader));
238 GNUNET_assert (size >= (*sz + sizeof (struct GNUNET_MessageHeader)));
240 memcpy (hdr + 1, dns, *sz);
242 if (NULL != GNUNET_MESH_tunnel_get_head (*tunnel))
244 struct tunnel_notify_queue *element = GNUNET_MESH_tunnel_get_head (*tunnel);
245 struct tunnel_notify_queue *head = GNUNET_MESH_tunnel_get_head (*tunnel);
246 struct tunnel_notify_queue *tail = GNUNET_MESH_tunnel_get_tail (*tunnel);
248 GNUNET_CONTAINER_DLL_remove (head, tail, element);
250 GNUNET_MESH_tunnel_set_head (*tunnel, head);
251 GNUNET_MESH_tunnel_set_tail (*tunnel, tail);
252 struct GNUNET_MESH_TransmitHandle *th =
253 GNUNET_MESH_notify_transmit_ready (*tunnel,
256 GNUNET_TIME_relative_divide
257 (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
258 (const struct GNUNET_PeerIdentity *)
260 element->cb, element->cls);
262 /* save the handle */
263 GNUNET_MESH_tunnel_set_data (*tunnel, th);
268 return ntohs (hdr->size);
272 mesh_send (void *cls, size_t size, void *buf)
274 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
276 GNUNET_MESH_tunnel_set_data (cls_->tunnel, NULL);
278 GNUNET_assert (cls_->hdr.size <= size);
280 size = cls_->hdr.size;
281 cls_->hdr.size = htons (cls_->hdr.size);
283 memcpy (buf, &cls_->hdr, size);
285 if (NULL != GNUNET_MESH_tunnel_get_head (cls_->tunnel))
287 struct tunnel_notify_queue *element =
288 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
289 struct tunnel_notify_queue *head =
290 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
291 struct tunnel_notify_queue *tail =
292 GNUNET_MESH_tunnel_get_tail (cls_->tunnel);
294 GNUNET_CONTAINER_DLL_remove (head, tail, element);
296 GNUNET_MESH_tunnel_set_head (cls_->tunnel, head);
297 GNUNET_MESH_tunnel_set_tail (cls_->tunnel, tail);
298 struct GNUNET_MESH_TransmitHandle *th =
299 GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
302 GNUNET_TIME_relative_divide
303 (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
304 (const struct GNUNET_PeerIdentity *)
306 element->cb, element->cls);
308 /* save the handle */
309 GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
310 GNUNET_free (element);
318 mesh_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
319 const struct GNUNET_TRANSPORT_ATS_Information *atsi
320 __attribute__ ((unused)))
324 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
326 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
327 "Connected to peer %s, %x, sending query with id %d\n",
328 GNUNET_i2s (peer), peer, ntohs (cls_->dns.s.id));
330 if (NULL == GNUNET_MESH_tunnel_get_data (cls_->tunnel))
332 struct GNUNET_MESH_TransmitHandle *th =
333 GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
336 GNUNET_TIME_UNIT_MINUTES,
342 GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
346 struct tunnel_notify_queue *head =
347 GNUNET_MESH_tunnel_get_head (cls_->tunnel);
348 struct tunnel_notify_queue *tail =
349 GNUNET_MESH_tunnel_get_tail (cls_->tunnel);
351 struct tunnel_notify_queue *element =
352 GNUNET_malloc (sizeof (struct tunnel_notify_queue));
354 element->len = cls_->hdr.size;
355 element->cb = mesh_send;
357 GNUNET_CONTAINER_DLL_insert_tail (head, tail, element);
358 GNUNET_MESH_tunnel_set_head (cls_->tunnel, head);
359 GNUNET_MESH_tunnel_set_tail (cls_->tunnel, tail);
365 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
367 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
370 struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
373 GNUNET_MESH_peer_request_connect_by_type (mesh_handle,
374 GNUNET_TIME_UNIT_HOURS,
375 GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
376 mesh_connect, NULL, cls_);
378 remote_pending[cls_->dns.s.id] = cls_;
382 receive_mesh_query (void *cls
383 __attribute__ ((unused)), struct GNUNET_MESH_Tunnel *tunnel,
385 __attribute__ ((unused)),
386 const struct GNUNET_PeerIdentity *sender
387 __attribute__ ((unused)),
388 const struct GNUNET_MessageHeader *message,
389 const struct GNUNET_TRANSPORT_ATS_Information *atsi
390 __attribute__ ((unused)))
392 struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
394 struct sockaddr_in dest;
396 memset (&dest, 0, sizeof dest);
397 dest.sin_port = htons (53);
398 /* TODO: read from config */
399 inet_pton (AF_INET, "8.8.8.8", &dest.sin_addr);
401 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Querying for remote, id=%d\n",
403 query_states[dns->s.id].tunnel = tunnel;
404 query_states[dns->s.id].valid = GNUNET_YES;
406 GNUNET_NETWORK_socket_sendto (dnsout, dns,
407 ntohs (message->size) -
408 sizeof (struct GNUNET_MessageHeader),
409 (struct sockaddr *) &dest, sizeof dest);
411 return GNUNET_SYSERR;
415 receive_mesh_answer (void *cls
416 __attribute__ ((unused)),
417 struct GNUNET_MESH_Tunnel *tunnel, void **ctx
418 __attribute__ ((unused)),
419 const struct GNUNET_PeerIdentity *sender,
420 const struct GNUNET_MessageHeader *message,
421 const struct GNUNET_TRANSPORT_ATS_Information *atsi
422 __attribute__ ((unused)))
424 /* TODo: size check */
425 struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
427 /* They sent us a packet we were not waiting for */
428 if (remote_pending[dns->s.id] == NULL ||
429 remote_pending[dns->s.id]->tunnel != tunnel)
432 GNUNET_free (remote_pending[dns->s.id]);
433 remote_pending[dns->s.id] = NULL;
435 if (query_states[dns->s.id].valid != GNUNET_YES)
436 return GNUNET_SYSERR;
437 query_states[dns->s.id].valid = GNUNET_NO;
439 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
440 "Received answer from peer %s, dns-id %d\n", GNUNET_i2s (sender),
443 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 */
444 + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
446 struct answer_packet_list *answer =
447 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
448 memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
450 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
451 answer->pkt.hdr.size = htons (len);
453 struct dns_pkt_parsed *pdns = parse_dns_packet (dns);
455 if (ntohs (pdns->s.ancount) < 1)
457 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer only contains %d answers.\n",
458 ntohs (pdns->s.ancount));
459 free_parsed_dns_packet (pdns);
463 answer->pkt.addrsize = ntohs (pdns->answers[0]->data_len);
464 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "The first answer has the addrlen %d\n",
465 answer->pkt.addrsize);
466 memcpy (answer->pkt.addr, pdns->answers[0]->data,
467 ntohs (pdns->answers[0]->data_len));
469 answer->pkt.from = query_states[dns->s.id].remote_ip;
471 answer->pkt.to = query_states[dns->s.id].local_ip;
472 answer->pkt.dst_port = query_states[dns->s.id].local_port;
474 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
476 dpkt->s.id = dns->s.id;
480 dpkt->s.qdcount = htons (1);
481 dpkt->s.ancount = htons (1);
483 memcpy (dpkt->data, query_states[dns->s.id].name,
484 query_states[dns->s.id].namelen);
485 GNUNET_free (query_states[dns->s.id].name);
486 query_states[dns->s.id].name = NULL;
488 struct dns_query_line *dque =
489 (struct dns_query_line *) (dpkt->data +
490 (query_states[dns->s.id].namelen));
492 struct dns_record_line *drec_data =
493 (struct dns_record_line *) (dpkt->data +
494 (query_states[dns->s.id].namelen) +
495 sizeof (struct dns_query_line) + 2);
496 if (16 == answer->pkt.addrsize)
498 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA;
499 dque->type = htons (28); /* AAAA */
500 drec_data->type = htons (28); /* AAAA */
501 drec_data->data_len = htons (16);
505 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_A;
506 dque->type = htons (1); /* A */
507 drec_data->type = htons (1); /* A */
508 drec_data->data_len = htons (4);
510 dque->class = htons (1); /* IN */
513 (char *) (dpkt->data + (query_states[dns->s.id].namelen) +
514 sizeof (struct dns_query_line));
515 memcpy (anname, "\xc0\x0c", 2);
516 drec_data->class = htons (1); /* IN */
518 drec_data->ttl = pdns->answers[0]->ttl;
520 /* Calculate at which offset in the packet the IPv6-Address belongs, it is
521 * filled in by the daemon-vpn */
522 answer->pkt.addroffset =
523 htons ((unsigned short) ((unsigned long) (&drec_data->data) -
524 (unsigned long) (&answer->pkt)));
526 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
528 GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client, len,
529 GNUNET_TIME_UNIT_FOREVER_REL,
531 query_states[dns->s.id].client);
533 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
534 "Sent answer of length %d on to client, addroffset = %d\n", len,
535 answer->pkt.addroffset);
537 free_parsed_dns_packet (pdns);
543 send_rev_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
545 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
548 struct dns_pkt_parsed *pdns = (struct dns_pkt_parsed *) cls;
550 unsigned short id = pdns->s.id;
552 free_parsed_dns_packet (pdns);
554 if (query_states[id].valid != GNUNET_YES)
556 query_states[id].valid = GNUNET_NO;
558 GNUNET_assert (query_states[id].namelen == 74);
560 size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + 74 /* this is the length of a reverse ipv6-lookup */
561 + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */
562 + sizeof (struct dns_record_line) - 1 -
563 2 /* We do not know the lenght of the answer yet */ ;
565 struct answer_packet_list *answer =
566 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
567 memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
569 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
570 answer->pkt.hdr.size = htons (len);
571 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
573 answer->pkt.from = query_states[id].remote_ip;
575 answer->pkt.to = query_states[id].local_ip;
576 answer->pkt.dst_port = query_states[id].local_port;
578 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
584 dpkt->s.qdcount = htons (1);
585 dpkt->s.ancount = htons (1);
587 memcpy (dpkt->data, query_states[id].name, query_states[id].namelen);
588 GNUNET_free (query_states[id].name);
590 struct dns_query_line *dque =
591 (struct dns_query_line *) (dpkt->data + (query_states[id].namelen));
592 dque->type = htons (12); /* PTR */
593 dque->class = htons (1); /* IN */
596 (char *) (dpkt->data + (query_states[id].namelen) +
597 sizeof (struct dns_query_line));
598 memcpy (anname, "\xc0\x0c", 2);
600 struct dns_record_line *drec_data =
601 (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) +
602 sizeof (struct dns_query_line) + 2);
603 drec_data->type = htons (12); /* AAAA */
604 drec_data->class = htons (1); /* IN */
605 /* FIXME: read the TTL from block:
606 * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
608 * But how to get the seconds out of this?
610 drec_data->ttl = htonl (3600);
612 /* Calculate at which offset in the packet the length of the name and the
613 * name, it is filled in by the daemon-vpn */
614 answer->pkt.addroffset =
615 htons ((unsigned short) ((unsigned long) (&drec_data->data_len) -
616 (unsigned long) (&answer->pkt)));
618 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
620 GNUNET_SERVER_notify_transmit_ready (query_states[id].client, len,
621 GNUNET_TIME_UNIT_FOREVER_REL,
622 &send_answer, query_states[id].client);
626 * Receive a block from the dht.
629 receive_dht (void *cls, struct GNUNET_TIME_Absolute exp
630 __attribute__ ((unused)), const GNUNET_HashCode * key
631 __attribute__ ((unused)),
632 const struct GNUNET_PeerIdentity *const *get_path
633 __attribute__ ((unused)),
634 const struct GNUNET_PeerIdentity *const *put_path
635 __attribute__ ((unused)), enum GNUNET_BLOCK_Type type, size_t size,
639 unsigned short id = ((struct receive_dht_cls *) cls)->id;
640 struct GNUNET_DHT_GetHandle *handle =
641 ((struct receive_dht_cls *) cls)->handle;
644 GNUNET_assert (type == GNUNET_BLOCK_TYPE_DNS);
646 /* If no query with this id is pending, ignore the block */
647 if (query_states[id].valid != GNUNET_YES)
649 query_states[id].valid = GNUNET_NO;
651 const struct GNUNET_DNS_Record *rec = data;
653 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
654 "Got block of size %d, peer: %08x, desc: %08x\n", size,
655 *((unsigned int *) &rec->peer),
656 *((unsigned int *) &rec->service_descriptor));
658 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 */
659 + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
661 struct answer_packet_list *answer =
662 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
663 memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
665 answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
666 answer->pkt.hdr.size = htons (len);
667 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
669 GNUNET_CRYPTO_hash (&rec->peer,
670 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
671 &answer->pkt.service_descr.peer);
673 memcpy (&answer->pkt.service_descr.service_descriptor,
674 &rec->service_descriptor, sizeof (GNUNET_HashCode));
675 memcpy (&answer->pkt.service_descr.service_type, &rec->service_type,
676 sizeof (answer->pkt.service_descr.service_type));
677 memcpy (&answer->pkt.service_descr.ports, &rec->ports,
678 sizeof (answer->pkt.service_descr.ports));
680 answer->pkt.from = query_states[id].remote_ip;
682 answer->pkt.to = query_states[id].local_ip;
683 answer->pkt.dst_port = query_states[id].local_port;
685 struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
691 dpkt->s.qdcount = htons (1);
692 dpkt->s.ancount = htons (1);
694 memcpy (dpkt->data, query_states[id].name, query_states[id].namelen);
695 GNUNET_free (query_states[id].name);
697 struct dns_query_line *dque =
698 (struct dns_query_line *) (dpkt->data + (query_states[id].namelen));
699 dque->type = htons (28); /* AAAA */
700 dque->class = htons (1); /* IN */
703 (char *) (dpkt->data + (query_states[id].namelen) +
704 sizeof (struct dns_query_line));
705 memcpy (anname, "\xc0\x0c", 2);
707 struct dns_record_line *drec_data =
708 (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) +
709 sizeof (struct dns_query_line) + 2);
710 drec_data->type = htons (28); /* AAAA */
711 drec_data->class = htons (1); /* IN */
713 /* FIXME: read the TTL from block:
714 * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
716 * But how to get the seconds out of this?
718 drec_data->ttl = htonl (3600);
719 drec_data->data_len = htons (16);
721 /* Calculate at which offset in the packet the IPv6-Address belongs, it is
722 * filled in by the daemon-vpn */
723 answer->pkt.addroffset =
724 htons ((unsigned short) ((unsigned long) (&drec_data->data) -
725 (unsigned long) (&answer->pkt)));
727 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
729 GNUNET_SERVER_notify_transmit_ready (query_states[id].client, len,
730 GNUNET_TIME_UNIT_FOREVER_REL,
731 &send_answer, query_states[id].client);
733 GNUNET_DHT_get_stop (handle);
737 * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
741 __attribute__ ((unused)), struct GNUNET_SERVER_Client *client,
742 const struct GNUNET_MessageHeader *message __attribute__ ((unused)))
744 unhijack (dnsoutport);
745 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
747 GNUNET_SERVER_receive_done (client, GNUNET_OK);
751 * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
754 receive_query (void *cls
755 __attribute__ ((unused)), struct GNUNET_SERVER_Client *client,
756 const struct GNUNET_MessageHeader *message)
758 struct query_packet *pkt = (struct query_packet *) message;
759 struct dns_pkt *dns = (struct dns_pkt *) pkt->data;
760 struct dns_pkt_parsed *pdns = parse_dns_packet (dns);
762 query_states[dns->s.id].valid = GNUNET_YES;
763 query_states[dns->s.id].client = client;
764 query_states[dns->s.id].local_ip = pkt->orig_from;
765 query_states[dns->s.id].local_port = pkt->src_port;
766 query_states[dns->s.id].remote_ip = pkt->orig_to;
767 query_states[dns->s.id].namelen = strlen ((char *) dns->data) + 1;
768 if (query_states[dns->s.id].name != NULL)
769 GNUNET_free (query_states[dns->s.id].name);
770 query_states[dns->s.id].name =
771 GNUNET_malloc (query_states[dns->s.id].namelen);
772 memcpy (query_states[dns->s.id].name, dns->data,
773 query_states[dns->s.id].namelen);
775 /* The query is for a .gnunet-address */
776 if (pdns->queries[0]->namelen > 9 &&
777 0 == strncmp (pdns->queries[0]->name + (pdns->queries[0]->namelen - 9),
780 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
783 GNUNET_CRYPTO_hash (pdns->queries[0]->name, pdns->queries[0]->namelen,
786 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Getting with key %08x, len is %d\n",
787 *((unsigned int *) &key), pdns->queries[0]->namelen);
789 struct receive_dht_cls *cls =
790 GNUNET_malloc (sizeof (struct receive_dht_cls));
794 GNUNET_DHT_get_start (dht, GNUNET_TIME_UNIT_MINUTES,
795 GNUNET_BLOCK_TYPE_DNS, &key,
796 DEFAULT_GET_REPLICATION, GNUNET_DHT_RO_NONE, NULL,
797 0, NULL, 0, receive_dht, cls);
802 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n",
803 pdns->queries[0]->name, pdns->queries[0]->namelen);
805 /* This is a PTR-Query. Check if it is for "our" network */
806 if (htons (pdns->queries[0]->qtype) == 12 && 74 == pdns->queries[0]->namelen)
811 "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.";
813 unsigned long long ipv6prefix;
814 unsigned int comparelen;
816 GNUNET_assert (GNUNET_OK ==
817 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
820 inet_pton (AF_INET6, ipv6addr, ipv6);
821 GNUNET_free (ipv6addr);
823 GNUNET_assert (GNUNET_OK ==
824 GNUNET_CONFIGURATION_get_value_number (cfg, "vpn",
827 GNUNET_assert (ipv6prefix < 127);
828 ipv6prefix = (ipv6prefix + 7) / 8;
830 for (i = ipv6prefix; i < 16; i++)
833 for (i = 0; i < 16; i++)
835 unsigned char c1 = ipv6[i] >> 4;
836 unsigned char c2 = ipv6[i] & 0xf;
839 ipv6rev[62 - (4 * i)] = c1 + '0';
841 ipv6rev[62 - (4 * i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
844 ipv6rev[62 - ((4 * i) + 2)] = c2 + '0';
846 ipv6rev[62 - ((4 * i) + 2)] = c2 + 87;
848 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
849 comparelen = 10 + 4 * ipv6prefix;
851 strncmp (pdns->queries[0]->name +
852 (pdns->queries[0]->namelen - comparelen),
853 ipv6rev + (74 - comparelen), comparelen))
855 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
857 GNUNET_SCHEDULER_add_now (send_rev_query, pdns);
864 unsigned int virt_dns_bytes;
867 GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns))
869 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
870 "No entry 'VIRTDNS' in configuration!\n");
874 if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
876 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Error parsing 'VIRTDNS': %s; %m!\n",
881 GNUNET_free (virt_dns);
883 if (virt_dns_bytes == pkt->orig_to)
885 /* This is a packet that was sent directly to the virtual dns-server
887 * This means we have to send this query over gnunet
891 sizeof (struct GNUNET_MESH_Tunnel *) +
892 sizeof (struct GNUNET_MessageHeader) + (ntohs (message->size) -
893 sizeof (struct query_packet) +
895 struct tunnel_cls *cls_ = GNUNET_malloc (size);
897 cls_->hdr.size = size - sizeof (struct GNUNET_MESH_Tunnel *);
899 cls_->hdr.type = ntohs (GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS);
900 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size);
902 memcpy (&cls_->dns, dns,
903 cls_->hdr.size - sizeof (struct GNUNET_MessageHeader));
904 GNUNET_SCHEDULER_add_now (send_mesh_query, cls_);
910 /* The query should be sent to the network */
912 struct sockaddr_in dest;
914 memset (&dest, 0, sizeof dest);
915 dest.sin_port = htons (53);
916 dest.sin_addr.s_addr = pkt->orig_to;
918 GNUNET_NETWORK_socket_sendto (dnsout, dns,
919 ntohs (pkt->hdr.size) -
920 sizeof (struct query_packet) + 1,
921 (struct sockaddr *) &dest, sizeof dest);
924 free_parsed_dns_packet (pdns);
927 GNUNET_SERVER_receive_done (client, GNUNET_OK);
930 static void read_response (void *cls,
931 const struct GNUNET_SCHEDULER_TaskContext *tc);
936 struct sockaddr_in addr;
938 dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
940 return GNUNET_SYSERR;
941 memset (&addr, 0, sizeof (struct sockaddr_in));
943 addr.sin_family = AF_INET;
944 int err = GNUNET_NETWORK_socket_bind (dnsout,
945 (struct sockaddr *) &addr,
946 sizeof (struct sockaddr_in));
948 if (err != GNUNET_OK)
950 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not bind a port: %m\n");
951 return GNUNET_SYSERR;
954 /* Read the port we bound to */
955 socklen_t addrlen = sizeof (struct sockaddr_in);
958 getsockname (GNUNET_NETWORK_get_fd (dnsout), (struct sockaddr *) &addr,
961 dnsoutport = htons (addr.sin_port);
963 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bound to port %d.\n", dnsoutport);
965 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
966 &read_response, NULL);
972 * Read a response-packet of the UDP-Socket
975 read_response (void *cls
976 __attribute__ ((unused)),
977 const struct GNUNET_SCHEDULER_TaskContext *tc)
979 struct sockaddr_in addr;
980 socklen_t addrlen = sizeof (addr);
984 if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
987 memset (&addr, 0, sizeof addr);
990 if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len))
992 unhijack (dnsoutport);
993 if (GNUNET_YES == open_port ())
994 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
998 /* port the code above? */
1002 unsigned char buf[len];
1003 struct dns_pkt *dns = (struct dns_pkt *) buf;
1005 r = GNUNET_NETWORK_socket_recvfrom (dnsout, buf, sizeof (buf),
1006 (struct sockaddr *) &addr, &addrlen);
1010 unhijack (dnsoutport);
1011 if (GNUNET_YES == open_port ())
1012 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
1016 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d\n",
1019 if (query_states[dns->s.id].valid == GNUNET_YES)
1021 if (query_states[dns->s.id].tunnel != NULL)
1023 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1024 "Answer to query %d for a remote peer!\n",
1026 /* This response should go through a tunnel */
1028 GNUNET_malloc (4 + sizeof (struct GNUNET_MESH_Tunnel *) + r);
1030 struct GNUNET_MESH_Tunnel **t = (struct GNUNET_MESH_Tunnel **) (c + 1);
1032 *t = query_states[dns->s.id].tunnel;
1033 memcpy (t + 1, dns, r);
1035 GNUNET_MESH_tunnel_get_data (query_states[dns->s.id].tunnel))
1037 struct GNUNET_MESH_TransmitHandle *th =
1038 GNUNET_MESH_notify_transmit_ready (query_states[dns->s.id].tunnel,
1041 GNUNET_TIME_UNIT_MINUTES,
1045 GNUNET_MessageHeader),
1046 mesh_send_response, c);
1048 GNUNET_MESH_tunnel_set_data (query_states[dns->s.id].tunnel, th);
1052 struct tunnel_notify_queue *head =
1053 GNUNET_MESH_tunnel_get_head (query_states[dns->s.id].tunnel);
1054 struct tunnel_notify_queue *tail =
1055 GNUNET_MESH_tunnel_get_tail (query_states[dns->s.id].tunnel);
1057 struct tunnel_notify_queue *element =
1058 GNUNET_malloc (sizeof (struct tunnel_notify_queue));
1060 element->len = r + sizeof (struct GNUNET_MessageHeader);
1061 element->cb = mesh_send_response;
1063 GNUNET_CONTAINER_DLL_insert_tail (head, tail, element);
1064 GNUNET_MESH_tunnel_set_head (query_states[dns->s.id].tunnel, head);
1065 GNUNET_MESH_tunnel_set_tail (query_states[dns->s.id].tunnel, tail);
1070 query_states[dns->s.id].valid = GNUNET_NO;
1072 size_t len = sizeof (struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
1073 struct answer_packet_list *answer =
1074 GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
1075 answer->pkt.hdr.type =
1076 htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
1077 answer->pkt.hdr.size = htons (len);
1078 answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
1079 answer->pkt.from = addr.sin_addr.s_addr;
1080 answer->pkt.to = query_states[dns->s.id].local_ip;
1081 answer->pkt.dst_port = query_states[dns->s.id].local_port;
1082 memcpy (answer->pkt.data, buf, r);
1084 GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
1086 GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client,
1087 len, GNUNET_TIME_UNIT_FOREVER_REL,
1089 query_states[dns->s.id].client);
1093 GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
1094 &read_response, NULL);
1099 * Task run during shutdown.
1105 cleanup_task (void *cls
1106 __attribute__ ((unused)),
1107 const struct GNUNET_SCHEDULER_TaskContext *tc)
1109 GNUNET_assert (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
1111 unhijack (dnsoutport);
1112 GNUNET_DHT_disconnect (dht);
1113 GNUNET_MESH_disconnect (mesh_handle);
1117 * @brief Create a port-map from udp and tcp redirects
1119 * @param udp_redirects
1120 * @param tcp_redirects
1125 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
1128 char *cpy, *hostname, *redirect;
1129 int local_port, count = 0;
1131 if (NULL != udp_redirects)
1133 cpy = GNUNET_strdup (udp_redirects);
1134 for (redirect = strtok (cpy, " "); redirect != NULL;
1135 redirect = strtok (NULL, " "))
1137 if (NULL == (hostname = strstr (redirect, ":")))
1139 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1140 "Warning: option %s is not formatted correctly!\n",
1145 local_port = atoi (redirect);
1146 if (!((local_port > 0) && (local_port < 65536)))
1147 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1148 "Warning: %s is not a correct port.", redirect);
1150 ret |= (0xFFFF & htons (local_port));
1164 if (NULL != tcp_redirects)
1166 cpy = GNUNET_strdup (tcp_redirects);
1167 for (redirect = strtok (cpy, " "); redirect != NULL;
1168 redirect = strtok (NULL, " "))
1170 if (NULL == (hostname = strstr (redirect, ":")))
1172 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1173 "Warning: option %s is not formatted correctly!\n",
1178 local_port = atoi (redirect);
1179 if (!((local_port > 0) && (local_port < 65536)))
1180 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1181 "Warning: %s is not a correct port.", redirect);
1183 ret |= (0xFFFF & htons (local_port));
1204 publish_name (const char *name, uint64_t ports, uint32_t service_type,
1205 struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
1207 size_t size = sizeof (struct GNUNET_DNS_Record);
1208 struct GNUNET_DNS_Record data;
1210 memset (&data, 0, size);
1212 data.purpose.size = htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
1213 data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
1215 GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
1216 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
1217 *((unsigned long long *) &data.service_descriptor));
1219 data.service_type = service_type;
1222 GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
1224 data.expiration_time =
1225 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply
1226 (GNUNET_TIME_UNIT_HOURS, 2));
1228 /* Sign the block */
1230 GNUNET_CRYPTO_rsa_sign (my_private_key, &data.purpose, &data.signature))
1232 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
1236 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Putting with key %08x, size = %d\n",
1237 *((unsigned int *) &data.service_descriptor), size);
1239 GNUNET_DHT_put (dht, &data.service_descriptor, DEFAULT_PUT_REPLICATION,
1240 GNUNET_DHT_RO_NONE, GNUNET_BLOCK_TYPE_DNS, size,
1242 GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
1243 GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
1247 * @brief Publishes the record defined by the section section
1249 * @param cls closure
1250 * @param section the current section
1253 publish_iterate (void *cls __attribute__ ((unused)), const char *section)
1255 if ((strlen (section) < 8) ||
1256 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
1259 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %s\n", section);
1261 char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
1264 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
1266 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
1270 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY",
1273 GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
1274 if (keyfile != NULL)
1275 GNUNET_free (keyfile);
1279 struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
1280 GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1281 GNUNET_free (keyfile);
1282 GNUNET_assert (my_private_key != NULL);
1284 uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
1285 uint32_t service_type = 0;
1287 if (NULL != udp_redirects)
1288 service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
1290 if (NULL != tcp_redirects)
1291 service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
1293 service_type = htonl (service_type);
1296 publish_name (section, ports, service_type, my_private_key);
1298 GNUNET_CONFIGURATION_get_value_string (cfg, section, "ALTERNATIVE_NAMES",
1299 &alternative_names);
1300 for (alternative_name = strtok (alternative_names, " ");
1301 alternative_name != NULL; alternative_name = strtok (NULL, " "))
1304 alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
1305 strcpy (altname, alternative_name);
1306 strcpy (altname + strlen (alternative_name) + 1, section);
1307 altname[strlen (alternative_name)] = '.';
1309 publish_name (altname, ports, service_type, my_private_key);
1312 GNUNET_free_non_null (alternative_names);
1313 GNUNET_CRYPTO_rsa_key_free (my_private_key);
1314 GNUNET_free_non_null (udp_redirects);
1315 GNUNET_free_non_null (tcp_redirects);
1319 * Publish a DNS-record in the DHT.
1322 publish_names (void *cls
1323 __attribute__ ((unused)),
1324 const struct GNUNET_SCHEDULER_TaskContext *tc)
1326 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1329 GNUNET_CONFIGURATION_iterate_sections (cfg, publish_iterate, NULL);
1331 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS, publish_names, NULL);
1335 * @param cls closure
1336 * @param server the initialized server
1337 * @param cfg_ configuration to use
1340 run (void *cls, struct GNUNET_SERVER_Handle *server,
1341 const struct GNUNET_CONFIGURATION_Handle *cfg_)
1343 static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1344 /* callback, cls, type, size */
1345 {&receive_query, NULL, GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_QUERY_DNS, 0},
1346 {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
1347 sizeof (struct GNUNET_MessageHeader)},
1351 static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
1352 {receive_mesh_query, GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS, 0},
1353 {receive_mesh_answer, GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS, 0},
1357 static GNUNET_MESH_ApplicationType apptypes[] = {
1358 GNUNET_APPLICATION_TYPE_END,
1359 GNUNET_APPLICATION_TYPE_END
1363 if (GNUNET_YES != open_port ())
1365 GNUNET_SCHEDULER_shutdown ();
1370 GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT"))
1371 apptypes[0] = GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER;
1372 mesh_handle = GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
1378 for (i = 0; i < 65536; i++)
1380 query_states[i].valid = GNUNET_NO;
1383 dht = GNUNET_DHT_connect (cfg, 1024);
1385 GNUNET_SCHEDULER_add_now (publish_names, NULL);
1387 GNUNET_SERVER_add_handlers (server, handlers);
1388 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup_task,
1393 * The main function for the dns service.
1395 * @param argc number of arguments from the command line
1396 * @param argv command line arguments
1397 * @return 0 ok, 1 on error
1400 main (int argc, char *const *argv)
1402 return (GNUNET_OK ==
1403 GNUNET_SERVICE_run (argc, argv, "dns", GNUNET_SERVICE_OPTION_NONE,
1404 &run, NULL)) ? 0 : 1;