src/vpn/gnunet-service-dns.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 Christian Grothoff (and other contributing authors)
   4
   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.
   9
  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.
  14
  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.
  19 */
  20
  21 /**
  22  * @file vpn/gnunet-service-dns.c
  23  * @author Philipp Toelke
  24  */
  25 #include "platform.h"
  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"
  43
  44 struct GNUNET_MESH_Handle *mesh_handle;
  45
  46 /**
  47  * The tunnel to send queries
  48  */
  49 static struct GNUNET_MESH_Tunnel* dns_tunnel;
  50
  51 char dns_tunnel_connected;
  52
  53 /**
  54  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  55  * sent through gnunet. The port of this socket will not be hijacked.
  56  */
  57 static struct GNUNET_NETWORK_Handle *dnsout;
  58
  59 /**
  60  * The port bound to the socket dnsout
  61  */
  62 static unsigned short dnsoutport;
  63
  64 /**
  65  * A handle to the DHT-Service
  66  */
  67 static struct GNUNET_DHT_Handle *dht;
  68
  69 /**
  70  * The configuration to use
  71  */
  72 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  73
  74 /**
  75  * A list of DNS-Responses that have to be sent to the requesting client
  76  */
  77 static struct answer_packet_list *head;
  78
  79 /**
  80  * The tail of the list of DNS-responses
  81  */
  82 static struct answer_packet_list *tail;
  83
  84 /**
  85  * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to
  86  * some information needed to handle this query
  87  *
  88  * It currently allocates at least
  89  * (1 + machine-width + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  90  * = 17 MiB on 64 bit.
  91  * = 11 MiB on 32 bit.
  92  */
  93 static struct {
  94     unsigned valid:1;
  95     struct GNUNET_SERVER_Client* client;
  96     struct GNUNET_MESH_Tunnel *tunnel;
  97     uint32_t local_ip;
  98     uint32_t remote_ip;
  99     uint16_t local_port;
 100     char* name;
 101     uint8_t namelen;
 102 } query_states[UINT16_MAX];
 103
 104 /**
 105  * A struct used to give more than one value as
 106  * closure to receive_dht
 107  */
 108 struct receive_dht_cls {
 109     uint16_t id;
 110     struct GNUNET_DHT_GetHandle* handle;
 111 };
 112
 113 struct tunnel_notify_queue
 114 {
 115   struct tunnel_notify_queue* next;
 116   struct tunnel_notify_queue* prev;
 117   void* cls;
 118   size_t len;
 119   GNUNET_CONNECTION_TransmitReadyNotify cb;
 120 };
 121
 122 /**
 123  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 124  */
 125 static void
 126 hijack (void *cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext *tc)
 127 {
 128   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 129     return;
 130
 131   if (0 == dnsoutport)
 132     {
 133       GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Delaying the hijacking, port is still %d!\n", dnsoutport);
 134       GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 135       return;
 136     }
 137
 138   char port_s[6];
 139   char *virt_dns;
 140   struct GNUNET_OS_Process *proc;
 141
 142   if (GNUNET_SYSERR ==
 143       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 144                                              &virt_dns))
 145     {
 146       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 147                   "No entry 'VIRTDNS' in configuration!\n");
 148       exit (1);
 149     }
 150
 151   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 152   snprintf (port_s, 6, "%d", dnsoutport);
 153   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 154                                                NULL,
 155                                                "gnunet-helper-hijack-dns",
 156                                                "gnunet-hijack-dns",
 157                                                port_s, virt_dns, NULL)))
 158     GNUNET_OS_process_close (proc);
 159   GNUNET_free (virt_dns);
 160 }
 161
 162 /**
 163  * Delete the hijacking-routes
 164  */
 165 static void
 166 unhijack (unsigned short port)
 167 {
 168   char port_s[6];
 169   char *virt_dns;
 170   struct GNUNET_OS_Process *proc;
 171
 172   if (GNUNET_SYSERR ==
 173       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 174                                              &virt_dns))
 175     {
 176       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 177                   "No entry 'VIRTDNS' in configuration!\n");
 178       exit (1);
 179     }
 180
 181   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 182   snprintf (port_s, 6, "%d", port);
 183   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 184                                                NULL,
 185                                                "gnunet-helper-hijack-dns",
 186                                                "gnunet-hijack-dns",
 187                                                "-d", port_s, virt_dns, NULL)))
 188     GNUNET_OS_process_close (proc);
 189   GNUNET_free (virt_dns);
 190 }
 191
 192 /**
 193  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 194  * system.
 195  */
 196 static size_t
 197 send_answer(void* cls, size_t size, void* buf) {
 198     struct answer_packet_list* query = head;
 199     size_t len = ntohs(query->pkt.hdr.size);
 200
 201     GNUNET_assert(len <= size);
 202
 203     memcpy(buf, &query->pkt.hdr, len);
 204
 205     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 206
 207     GNUNET_free(query);
 208
 209     /* When more data is to be sent, reschedule */
 210     if (head != NULL)
 211       GNUNET_SERVER_notify_transmit_ready(cls,
 212                                           ntohs(head->pkt.hdr.size),
 213                                           GNUNET_TIME_UNIT_FOREVER_REL,
 214                                           &send_answer,
 215                                           cls);
 216
 217     return len;
 218 }
 219
 220 struct tunnel_cls {
 221     struct GNUNET_MESH_Tunnel *tunnel GNUNET_PACKED;
 222     struct GNUNET_MessageHeader hdr;
 223     struct dns_pkt dns;
 224 };
 225
 226 struct tunnel_cls *remote_pending[UINT16_MAX];
 227
 228 static size_t
 229 mesh_send_response (void *cls, size_t size, void *buf)
 230 {
 231   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 232   struct GNUNET_MessageHeader *hdr = buf;
 233   uint32_t *sz = cls;
 234   struct GNUNET_MESH_Tunnel **tunnel = (struct GNUNET_MESH_Tunnel**)(sz+1);
 235   GNUNET_MESH_tunnel_set_data(*tunnel, NULL);
 236   struct dns_pkt *dns = (struct dns_pkt *) (tunnel + 1);
 237   hdr->type = htons (GNUNET_MESSAGE_TYPE_REMOTE_ANSWER_DNS);
 238   hdr->size = htons (*sz + sizeof (struct GNUNET_MessageHeader));
 239
 240   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 241               "Sending response, size=%d, sz=%d, sz+hdr=%d\n", size, *sz,
 242               *sz + sizeof (struct GNUNET_MessageHeader));
 243
 244   GNUNET_assert (size >= (*sz + sizeof (struct GNUNET_MessageHeader)));
 245
 246   memcpy (hdr + 1, dns, *sz);
 247
 248   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 249     {
 250       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 251       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 252       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 253
 254       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 255
 256       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 257       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 258       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 259                                                                                  GNUNET_NO,
 260                                                                                  42,
 261                                                                                  GNUNET_TIME_relative_divide
 262                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 263                                                                                  (const struct GNUNET_PeerIdentity *)
 264                                                                                  NULL, element->len,
 265                                                                                  element->cb, element->cls);
 266       /* save the handle */
 267       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 268     }
 269
 270   GNUNET_free (cls);
 271
 272   return ntohs (hdr->size);
 273 }
 274
 275 static size_t
 276 mesh_send (void *cls, size_t size, void *buf)
 277 {
 278   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 279   GNUNET_MESH_tunnel_set_data(cls_->tunnel, NULL);
 280
 281   GNUNET_assert(cls_->hdr.size <= size);
 282
 283   size = cls_->hdr.size;
 284   cls_->hdr.size = htons(cls_->hdr.size);
 285
 286   memcpy(buf, &cls_->hdr, size);
 287
 288   if (NULL != GNUNET_MESH_tunnel_get_head(cls_->tunnel))
 289     {
 290       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 291       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 292       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(cls_->tunnel);
 293
 294       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 295
 296       GNUNET_MESH_tunnel_set_head(cls_->tunnel, head);
 297       GNUNET_MESH_tunnel_set_tail(cls_->tunnel, tail);
 298       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
 299                                                                                  GNUNET_NO,
 300                                                                                  42,
 301                                                                                  GNUNET_TIME_relative_divide
 302                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 303                                                                                  (const struct GNUNET_PeerIdentity *)
 304                                                                                  NULL, element->len,
 305                                                                                  element->cb, element->cls);
 306       /* save the handle */
 307       GNUNET_MESH_tunnel_set_data(cls_->tunnel, th);
 308       GNUNET_free(element);
 309     }
 310
 311   return size;
 312 }
 313
 314
 315 void
 316 mesh_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
 317               const struct GNUNET_TRANSPORT_ATS_Information *atsi
 318               __attribute__ ((unused)))
 319 {
 320   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "mesh_connect called with %x, %x\n", cls, peer);
 321     return;
 322   if (NULL == peer)
 323     return;
 324   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 325   if ((struct GNUNET_PeerIdentity*)1 != peer)
 326     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 327                 "Connected to peer %s, sending query with id %d\n",
 328                 GNUNET_i2s (peer), ntohs (cls_->dns.s.id));
 329
 330   dns_tunnel_connected = 1;
 331
 332   if (NULL == GNUNET_MESH_tunnel_get_data (cls_->tunnel))
 333     {
 334       struct GNUNET_MESH_TransmitHandle *th =
 335         GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
 336                                            GNUNET_YES,
 337                                            42,
 338                                            GNUNET_TIME_UNIT_MINUTES,
 339                                            NULL,
 340                                            cls_->hdr.size,
 341                                            mesh_send,
 342                                            cls);
 343
 344       GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
 345     }
 346   else
 347     {
 348       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 349       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(cls_->tunnel);
 350
 351       struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
 352       element->cls = cls;
 353       element->len = cls_->hdr.size;
 354       element->cb = mesh_send;
 355
 356       GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 357       GNUNET_MESH_tunnel_set_head(cls_->tunnel, head);
 358       GNUNET_MESH_tunnel_set_tail(cls_->tunnel, tail);
 359     }
 360 }
 361
 362 static void
 363 call_mesh_connect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 364 {
 365   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 366     return;
 367
 368   mesh_connect (cls, (struct GNUNET_PeerIdentity *) 1, NULL);
 369 }
 370
 371
 372 static void
 373 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 374 {
 375   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 376     return;
 377
 378   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 379
 380   if (NULL == dns_tunnel || dns_tunnel_connected == 0)
 381     {
 382       dns_tunnel = GNUNET_MESH_peer_request_connect_by_type(mesh_handle,
 383                                                           GNUNET_TIME_UNIT_HOURS,
 384                                                           GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 385                                                           mesh_connect,
 386                                                           NULL,
 387                                                           cls_);
 388     }
 389   else
 390     GNUNET_SCHEDULER_add_now(call_mesh_connect, cls_);
 391
 392   cls_->tunnel = dns_tunnel;
 393   remote_pending[cls_->dns.s.id] = cls_;
 394 }
 395
 396 static int
 397 receive_mesh_query (void *cls __attribute__((unused)),
 398                     struct GNUNET_MESH_Tunnel *tunnel,
 399                     void **ctx __attribute__((unused)),
 400                     const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 401                     const struct GNUNET_MessageHeader *message,
 402                     const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 403 {
 404   struct dns_pkt *dns = (struct dns_pkt*)(message + 1);
 405
 406   struct sockaddr_in dest;
 407   memset(&dest, 0, sizeof dest);
 408   dest.sin_port = htons(53);
 409   /* TODO: read from config */
 410   inet_pton(AF_INET, "8.8.8.8", &dest.sin_addr);
 411
 412   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Querying for remote, id=%d\n", ntohs(dns->s.id));
 413   query_states[dns->s.id].tunnel = tunnel;
 414   query_states[dns->s.id].valid = GNUNET_YES;
 415
 416   GNUNET_NETWORK_socket_sendto(dnsout,
 417                                dns,
 418                                ntohs(message->size) - sizeof(struct GNUNET_MessageHeader),
 419                                (struct sockaddr*) &dest,
 420                                sizeof dest);
 421
 422   return GNUNET_SYSERR;
 423 }
 424
 425 static int
 426 receive_mesh_answer (void *cls __attribute__((unused)),
 427                      struct GNUNET_MESH_Tunnel *tunnel,
 428                      void **ctx __attribute__((unused)),
 429                      const struct GNUNET_PeerIdentity *sender,
 430                      const struct GNUNET_MessageHeader *message,
 431                      const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 432 {
 433   /* TODo: size check */
 434   struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
 435
 436   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "received dns-answer via %x, id=%d/%\nd\n", tunnel, dns->s.id, ntohs(dns->s.id));
 437
 438   /* They sent us a packet we were not waiting for */
 439   if (remote_pending[dns->s.id] == NULL
 440       || remote_pending[dns->s.id]->tunnel != tunnel)
 441     return GNUNET_OK;
 442
 443   GNUNET_free(remote_pending[dns->s.id]);
 444   remote_pending[dns->s.id] = NULL;
 445
 446   if (query_states[dns->s.id].valid != GNUNET_YES)
 447     return GNUNET_SYSERR;
 448   query_states[dns->s.id].valid = GNUNET_NO;
 449
 450   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Received answer from peer %s, dns-id %d\n", GNUNET_i2s(sender), ntohs(dns->s.id));
 451
 452   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 */
 453     + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
 454
 455   struct answer_packet_list *answer =
 456     GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
 457   memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
 458
 459   answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 460   answer->pkt.hdr.size = htons (len);
 461
 462   struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 463
 464   if (ntohs(pdns->s.ancount) < 1)
 465     {
 466       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer only contains %d answers.\n", ntohs(pdns->s.ancount));
 467       free_parsed_dns_packet(pdns);
 468       return GNUNET_OK;
 469     }
 470
 471   answer->pkt.addrsize = ntohs(pdns->answers[0]->data_len);
 472   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "The first answer has the addrlen %d\n", answer->pkt.addrsize);
 473   memcpy(answer->pkt.addr, pdns->answers[0]->data, ntohs(pdns->answers[0]->data_len));
 474
 475   answer->pkt.from = query_states[dns->s.id].remote_ip;
 476
 477   answer->pkt.to = query_states[dns->s.id].local_ip;
 478   answer->pkt.dst_port = query_states[dns->s.id].local_port;
 479
 480   struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
 481
 482   dpkt->s.id = dns->s.id;
 483   dpkt->s.aa = 1;
 484   dpkt->s.qr = 1;
 485   dpkt->s.ra = 1;
 486   dpkt->s.qdcount = htons (1);
 487   dpkt->s.ancount = htons (1);
 488
 489   memcpy (dpkt->data, query_states[dns->s.id].name,
 490           query_states[dns->s.id].namelen);
 491   GNUNET_free (query_states[dns->s.id].name);
 492
 493   struct dns_query_line *dque =
 494     (struct dns_query_line *) (dpkt->data +
 495                                (query_states[dns->s.id].namelen));
 496
 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)
 502     {
 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);
 507     }
 508   else
 509     {
 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);
 514     }
 515   dque->class = htons (1);      /* IN */
 516
 517   char *anname =
 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 */
 522
 523   drec_data->ttl = pdns->answers[0]->ttl;
 524
 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)));
 530
 531   GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
 532
 533   GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client,
 534                                        len,
 535                                        GNUNET_TIME_UNIT_FOREVER_REL,
 536                                        &send_answer,
 537                                        query_states[dns->s.id].client);
 538
 539   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Sent answer of length %d on to client, addroffset = %d\n", len, answer->pkt.addroffset);
 540
 541   free_parsed_dns_packet(pdns);
 542   return GNUNET_OK;
 543 }
 544
 545
 546 static void
 547 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 548     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 549       return;
 550
 551     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 552
 553     unsigned short id = pdns->s.id;
 554
 555     free_parsed_dns_packet(pdns);
 556
 557     if (query_states[id].valid != GNUNET_YES) return;
 558     query_states[id].valid = GNUNET_NO;
 559
 560     GNUNET_assert(query_states[id].namelen == 74);
 561
 562     size_t len = sizeof(struct answer_packet) - 1 \
 563                  + sizeof(struct dns_static) \
 564                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 565                  + sizeof(struct dns_query_line) \
 566                  + 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*/;
 569
 570     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 571     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 572
 573     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 574     answer->pkt.hdr.size = htons(len);
 575     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 576
 577     answer->pkt.from = query_states[id].remote_ip;
 578
 579     answer->pkt.to = query_states[id].local_ip;
 580     answer->pkt.dst_port = query_states[id].local_port;
 581
 582     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 583
 584     dpkt->s.id = id;
 585     dpkt->s.aa = 1;
 586     dpkt->s.qr = 1;
 587     dpkt->s.ra = 1;
 588     dpkt->s.qdcount = htons(1);
 589     dpkt->s.ancount = htons(1);
 590
 591     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 592     GNUNET_free(query_states[id].name);
 593
 594     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 595     dque->type = htons(12); /* PTR */
 596     dque->class = htons(1); /* IN */
 597
 598     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 599     memcpy(anname, "\xc0\x0c", 2);
 600
 601     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 602     drec_data->type = htons(12); /* AAAA */
 603     drec_data->class = htons(1); /* IN */
 604     /* FIXME: read the TTL from block:
 605      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 606      *
 607      * But how to get the seconds out of this?
 608      */
 609     drec_data->ttl = htonl(3600);
 610
 611     /* Calculate at which offset in the packet the length of the name and the
 612      * name, it is filled in by the daemon-vpn */
 613     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 614
 615     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 616
 617     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 618                                         len,
 619                                         GNUNET_TIME_UNIT_FOREVER_REL,
 620                                         &send_answer,
 621                                         query_states[id].client);
 622 }
 623
 624 /**
 625  * Receive a block from the dht.
 626  */
 627 static void
 628 receive_dht(void *cls,
 629             struct GNUNET_TIME_Absolute exp __attribute__((unused)),
 630             const GNUNET_HashCode *key __attribute__((unused)),
 631             const struct GNUNET_PeerIdentity *const *get_path __attribute__((unused)),
 632             const struct GNUNET_PeerIdentity *const *put_path __attribute__((unused)),
 633             enum GNUNET_BLOCK_Type type,
 634             size_t size,
 635             const void *data) {
 636
 637     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 638     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 639     GNUNET_free(cls);
 640
 641     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 642
 643     /* If no query with this id is pending, ignore the block */
 644     if (query_states[id].valid != GNUNET_YES) return;
 645     query_states[id].valid = GNUNET_NO;
 646
 647     const struct GNUNET_DNS_Record* rec = data;
 648     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 649                "Got block of size %d, peer: %08x, desc: %08x\n",
 650                size,
 651                *((unsigned int*)&rec->peer),
 652                *((unsigned int*)&rec->service_descriptor));
 653
 654     size_t len = sizeof(struct answer_packet) - 1 \
 655                  + sizeof(struct dns_static) \
 656                  + query_states[id].namelen \
 657                  + sizeof(struct dns_query_line) \
 658                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 659                  + sizeof(struct dns_record_line) - 1 \
 660                  + 16; /* To hold the IPv6-Address */
 661
 662     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 663     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 664
 665     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 666     answer->pkt.hdr.size = htons(len);
 667     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 668
 669     GNUNET_CRYPTO_hash(&rec->peer,
 670                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 671                        &answer->pkt.service_descr.peer);
 672
 673     memcpy(&answer->pkt.service_descr.service_descriptor,
 674            &rec->service_descriptor,
 675            sizeof(GNUNET_HashCode));
 676     memcpy(&answer->pkt.service_descr.service_type,
 677            &rec->service_type,
 678            sizeof(answer->pkt.service_descr.service_type));
 679     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 680
 681     answer->pkt.from = query_states[id].remote_ip;
 682
 683     answer->pkt.to = query_states[id].local_ip;
 684     answer->pkt.dst_port = query_states[id].local_port;
 685
 686     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 687
 688     dpkt->s.id = id;
 689     dpkt->s.aa = 1;
 690     dpkt->s.qr = 1;
 691     dpkt->s.ra = 1;
 692     dpkt->s.qdcount = htons(1);
 693     dpkt->s.ancount = htons(1);
 694
 695     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 696     GNUNET_free(query_states[id].name);
 697
 698     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 699     dque->type = htons(28); /* AAAA */
 700     dque->class = htons(1); /* IN */
 701
 702     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 703     memcpy(anname, "\xc0\x0c", 2);
 704
 705     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 706     drec_data->type = htons(28); /* AAAA */
 707     drec_data->class = htons(1); /* IN */
 708
 709     /* FIXME: read the TTL from block:
 710      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 711      *
 712      * But how to get the seconds out of this?
 713      */
 714     drec_data->ttl = htonl(3600);
 715     drec_data->data_len = htons(16);
 716
 717     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 718      * filled in by the daemon-vpn */
 719     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 720
 721     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 722
 723     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 724                                         len,
 725                                         GNUNET_TIME_UNIT_FOREVER_REL,
 726                                         &send_answer,
 727                                         query_states[id].client);
 728
 729     GNUNET_DHT_get_stop(handle);
 730 }
 731
 732 /**
 733  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 734  */
 735 static void
 736 rehijack(void *cls __attribute__((unused)),
 737          struct GNUNET_SERVER_Client *client,
 738          const struct GNUNET_MessageHeader *message __attribute__((unused))) {
 739     unhijack(dnsoutport);
 740     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 741
 742     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 743 }
 744
 745 /**
 746  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 747  */
 748 static void
 749 receive_query(void *cls __attribute__((unused)),
 750               struct GNUNET_SERVER_Client *client,
 751               const struct GNUNET_MessageHeader *message) {
 752     struct query_packet* pkt = (struct query_packet*)message;
 753     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 754     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 755
 756     query_states[dns->s.id].valid = GNUNET_YES;
 757     query_states[dns->s.id].client = client;
 758     query_states[dns->s.id].local_ip = pkt->orig_from;
 759     query_states[dns->s.id].local_port = pkt->src_port;
 760     query_states[dns->s.id].remote_ip = pkt->orig_to;
 761     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 762     if (query_states[dns->s.id].name != NULL)
 763       GNUNET_free(query_states[dns->s.id].name);
 764     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 765     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 766
 767     /* The query is for a .gnunet-address */
 768     if (pdns->queries[0]->namelen > 9 &&
 769         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 770       {
 771         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 772         GNUNET_HashCode key;
 773         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 774
 775         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 776                    "Getting with key %08x, len is %d\n",
 777                    *((unsigned int*)&key),
 778                    pdns->queries[0]->namelen);
 779
 780         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 781         cls->id = dns->s.id;
 782
 783         cls->handle = GNUNET_DHT_get_start(dht,
 784                                            GNUNET_TIME_UNIT_MINUTES,
 785                                            GNUNET_BLOCK_TYPE_DNS,
 786                                            &key,
 787                                            DEFAULT_GET_REPLICATION,
 788                                            GNUNET_DHT_RO_NONE,
 789                                            NULL,
 790                                            0,
 791                                            NULL,
 792                                            0,
 793                                            receive_dht,
 794                                            cls);
 795
 796         goto outfree;
 797       }
 798
 799     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 800
 801     /* This is a PTR-Query. Check if it is for "our" network */
 802     if (htons(pdns->queries[0]->qtype) == 12 &&
 803         74 == pdns->queries[0]->namelen)
 804       {
 805         char* ipv6addr;
 806         char ipv6[16];
 807         char ipv6rev[74] = "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.";
 808         unsigned int i;
 809         unsigned long long ipv6prefix;
 810         unsigned int comparelen;
 811
 812         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 813         inet_pton (AF_INET6, ipv6addr, ipv6);
 814         GNUNET_free(ipv6addr);
 815
 816         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 817         GNUNET_assert(ipv6prefix < 127);
 818         ipv6prefix = (ipv6prefix + 7)/8;
 819
 820         for (i = ipv6prefix; i < 16; i++)
 821           ipv6[i] = 0;
 822
 823         for (i = 0; i < 16; i++)
 824           {
 825             unsigned char c1 = ipv6[i] >> 4;
 826             unsigned char c2 = ipv6[i] & 0xf;
 827
 828             if (c1 <= 9)
 829               ipv6rev[62-(4*i)] = c1 + '0';
 830             else
 831               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 832
 833             if (c2 <= 9)
 834               ipv6rev[62-((4*i)+2)] = c2 + '0';
 835             else
 836               ipv6rev[62-((4*i)+2)] = c2 + 87;
 837           }
 838         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 839         comparelen = 10 + 4*ipv6prefix;
 840         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 841                         ipv6rev + (74 - comparelen),
 842                         comparelen))
 843           {
 844             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 845
 846             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 847
 848             goto out;
 849           }
 850       }
 851
 852     char* virt_dns;
 853     unsigned int virt_dns_bytes;
 854     if (GNUNET_SYSERR ==
 855         GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 856                                                &virt_dns))
 857       {
 858         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 859                     "No entry 'VIRTDNS' in configuration!\n");
 860         exit (1);
 861       }
 862
 863     if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
 864       {
 865         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 866                     "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns);
 867         exit(1);
 868       }
 869
 870     GNUNET_free(virt_dns);
 871
 872     if (virt_dns_bytes == pkt->orig_to)
 873       {
 874         /* This is a packet that was sent directly to the virtual dns-server
 875          *
 876          * This means we have to send this query over gnunet
 877          */
 878
 879         size_t size = sizeof(struct GNUNET_MESH_Tunnel*) + sizeof(struct GNUNET_MessageHeader) + (ntohs(message->size) - sizeof(struct query_packet) + 1);
 880         struct tunnel_cls *cls_ =  GNUNET_malloc(size);
 881         cls_->hdr.size = size - sizeof(struct GNUNET_MESH_Tunnel*);
 882
 883         cls_->hdr.type = ntohs(GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS);
 884         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size);
 885
 886         memcpy(&cls_->dns, dns, cls_->hdr.size - sizeof(struct GNUNET_MessageHeader));
 887         GNUNET_SCHEDULER_add_now(send_mesh_query, cls_);
 888
 889         goto outfree;
 890       }
 891
 892
 893     /* The query should be sent to the network */
 894
 895     struct sockaddr_in dest;
 896     memset(&dest, 0, sizeof dest);
 897     dest.sin_port = htons(53);
 898     dest.sin_addr.s_addr = pkt->orig_to;
 899
 900     GNUNET_NETWORK_socket_sendto(dnsout,
 901                                  dns,
 902                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 903                                  (struct sockaddr*) &dest,
 904                                  sizeof dest);
 905
 906 outfree:
 907     free_parsed_dns_packet(pdns);
 908     pdns = NULL;
 909 out:
 910     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 911 }
 912
 913 static void read_response (void *cls,
 914                            const struct GNUNET_SCHEDULER_TaskContext *tc);
 915
 916 static int
 917 open_port ()
 918 {
 919   struct sockaddr_in addr;
 920
 921   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 922   if (dnsout == NULL)
 923     return GNUNET_SYSERR;
 924   memset (&addr, 0, sizeof (struct sockaddr_in));
 925
 926   addr.sin_family = AF_INET;
 927   int err = GNUNET_NETWORK_socket_bind (dnsout,
 928                                         (struct sockaddr *) &addr,
 929                                         sizeof (struct sockaddr_in));
 930
 931   if (err != GNUNET_OK)
 932     {
 933       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 934                   "Could not bind a port: %m\n");
 935       return GNUNET_SYSERR;
 936     }
 937
 938   /* Read the port we bound to */
 939   socklen_t addrlen = sizeof (struct sockaddr_in);
 940   err = getsockname (GNUNET_NETWORK_get_fd (dnsout),
 941                      (struct sockaddr *) &addr, &addrlen);
 942
 943   dnsoutport = htons (addr.sin_port);
 944
 945   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bound to port %d.\n", dnsoutport);
 946
 947   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
 948                                  &read_response, NULL);
 949
 950   return GNUNET_YES;
 951 }
 952
 953 /**
 954  * Read a response-packet of the UDP-Socket
 955  */
 956 static void
 957 read_response (void *cls
 958                __attribute__ ((unused)),
 959                const struct GNUNET_SCHEDULER_TaskContext *tc)
 960 {
 961   struct sockaddr_in addr;
 962   socklen_t addrlen = sizeof (addr);
 963   int r;
 964   int len;
 965
 966   if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 967     return;
 968
 969   memset (&addr, 0, sizeof addr);
 970
 971 #ifndef MINGW
 972   if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len))
 973     {
 974       unhijack (dnsoutport);
 975       if (GNUNET_YES == open_port ())
 976         GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 977       return;
 978     }
 979 #else
 980   /* port the code above? */
 981   len = 65536;
 982 #endif
 983   {
 984     unsigned char buf[len];
 985     struct dns_pkt *dns = (struct dns_pkt *) buf;
 986
 987     r = GNUNET_NETWORK_socket_recvfrom (dnsout,
 988                                         buf,
 989                                         sizeof (buf),
 990                                         (struct sockaddr *) &addr, &addrlen);
 991
 992     if (r < 0)
 993       {
 994         unhijack (dnsoutport);
 995         if (GNUNET_YES == open_port ())
 996           GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 997         return;
 998       }
 999
1000     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d\n", ntohs(dns->s.id));
1001
1002     if (query_states[dns->s.id].valid == GNUNET_YES)
1003       {
1004         if (query_states[dns->s.id].tunnel != NULL)
1005           {
1006             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d for a remote peer!\n", ntohs(dns->s.id));
1007             /* This response should go through a tunnel */
1008             uint32_t *c = GNUNET_malloc (4 + sizeof(struct GNUNET_MESH_Tunnel*) + r);
1009             *c = r;
1010             struct GNUNET_MESH_Tunnel** t = (struct GNUNET_MESH_Tunnel**)(c + 1);
1011             *t = query_states[dns->s.id].tunnel;
1012             memcpy (t + 1, dns, r);
1013             if (NULL ==
1014                 GNUNET_MESH_tunnel_get_data (query_states[dns->s.id].tunnel))
1015               {
1016                 struct GNUNET_MESH_TransmitHandle *th =
1017                   GNUNET_MESH_notify_transmit_ready (query_states[dns->s.id].tunnel,
1018                                                      GNUNET_YES,
1019                                                      32,
1020                                                      GNUNET_TIME_UNIT_MINUTES,
1021                                                      NULL,
1022                                                      r +
1023                                                      sizeof (struct
1024                                                              GNUNET_MessageHeader),
1025                                                      mesh_send_response, c);
1026                 GNUNET_MESH_tunnel_set_data (query_states[dns->s.id].tunnel,
1027                                              th);
1028               }
1029             else
1030               {
1031                 struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(query_states[dns->s.id].tunnel);
1032                 struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(query_states[dns->s.id].tunnel);
1033
1034                 struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
1035                 element->cls = c;
1036                 element->len = r+sizeof(struct GNUNET_MessageHeader);
1037                 element->cb = mesh_send_response;
1038
1039                 GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
1040                 GNUNET_MESH_tunnel_set_head(query_states[dns->s.id].tunnel, head);
1041                 GNUNET_MESH_tunnel_set_tail(query_states[dns->s.id].tunnel, tail);
1042               }
1043           }
1044         else
1045           {
1046             query_states[dns->s.id].valid = GNUNET_NO;
1047
1048             size_t len = sizeof (struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
1049             struct answer_packet_list *answer =
1050               GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
1051             answer->pkt.hdr.type =
1052               htons (GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
1053             answer->pkt.hdr.size = htons (len);
1054             answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
1055             answer->pkt.from = addr.sin_addr.s_addr;
1056             answer->pkt.to = query_states[dns->s.id].local_ip;
1057             answer->pkt.dst_port = query_states[dns->s.id].local_port;
1058             memcpy (answer->pkt.data, buf, r);
1059
1060             GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
1061
1062             GNUNET_SERVER_notify_transmit_ready (query_states
1063                                                  [dns->s.id].client, len,
1064                                                  GNUNET_TIME_UNIT_FOREVER_REL,
1065                                                  &send_answer,
1066                                                  query_states[dns->s.
1067                                                               id].client);
1068           }
1069       }
1070   }
1071   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
1072                                  dnsout, &read_response, NULL);
1073 }
1074
1075
1076 /**
1077  * Task run during shutdown.
1078  *
1079  * @param cls unused
1080  * @param tc unused
1081  */
1082 static void
1083 cleanup_task (void *cls __attribute__((unused)),
1084               const struct GNUNET_SCHEDULER_TaskContext *tc)
1085 {
1086   GNUNET_assert(0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
1087
1088   unhijack(dnsoutport);
1089   GNUNET_DHT_disconnect(dht);
1090   GNUNET_MESH_disconnect(mesh_handle);
1091 }
1092
1093 /**
1094  * @brief Create a port-map from udp and tcp redirects
1095  *
1096  * @param udp_redirects
1097  * @param tcp_redirects
1098  *
1099  * @return
1100  */
1101 uint64_t
1102 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
1103 {
1104   uint64_t ret = 0;
1105   char* cpy, *hostname, *redirect;
1106   int local_port, count = 0;
1107
1108   if (NULL != udp_redirects)
1109     {
1110       cpy = GNUNET_strdup (udp_redirects);
1111       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
1112         {
1113           if (NULL == (hostname = strstr (redirect, ":")))
1114             {
1115               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
1116               continue;
1117             }
1118           hostname[0] = '\0';
1119           local_port = atoi (redirect);
1120           if (!((local_port > 0) && (local_port < 65536)))
1121             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
1122
1123           ret |= (0xFFFF & htons(local_port));
1124           ret <<= 16;
1125           count ++;
1126
1127           if(count > 4)
1128             {
1129               ret = 0;
1130               goto out;
1131             }
1132         }
1133       GNUNET_free(cpy);
1134       cpy = NULL;
1135     }
1136
1137   if (NULL != tcp_redirects)
1138     {
1139       cpy = GNUNET_strdup (tcp_redirects);
1140       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
1141         {
1142           if (NULL == (hostname = strstr (redirect, ":")))
1143             {
1144               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
1145               continue;
1146             }
1147           hostname[0] = '\0';
1148           local_port = atoi (redirect);
1149           if (!((local_port > 0) && (local_port < 65536)))
1150             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
1151
1152           ret |= (0xFFFF & htons(local_port));
1153           ret <<= 16;
1154           count ++;
1155
1156           if(count > 4)
1157             {
1158               ret = 0;
1159               goto out;
1160             }
1161         }
1162       GNUNET_free(cpy);
1163       cpy = NULL;
1164     }
1165
1166 out:
1167   if (NULL != cpy)
1168     GNUNET_free(cpy);
1169   return ret;
1170 }
1171
1172 void
1173 publish_name (const char *name, uint64_t ports, uint32_t service_type,
1174               struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
1175 {
1176   size_t size = sizeof (struct GNUNET_DNS_Record);
1177   struct GNUNET_DNS_Record data;
1178   memset (&data, 0, size);
1179
1180   data.purpose.size =
1181     htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
1182   data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
1183
1184   GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
1185   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
1186               *((unsigned long long *) &data.service_descriptor));
1187
1188   data.service_type = service_type;
1189   data.ports = ports;
1190
1191   GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
1192
1193   data.expiration_time =
1194     GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 2));
1195
1196   /* Sign the block */
1197   if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key,
1198                                            &data.purpose, &data.signature))
1199     {
1200       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
1201       return;
1202     }
1203
1204   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1205               "Putting with key %08x, size = %d\n",
1206               *((unsigned int *) &data.service_descriptor), size);
1207
1208   GNUNET_DHT_put (dht,
1209                   &data.service_descriptor,
1210                   DEFAULT_PUT_REPLICATION,
1211                   GNUNET_DHT_RO_NONE,
1212                   GNUNET_BLOCK_TYPE_DNS,
1213                   size,
1214                   (char *) &data,
1215                   GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
1216                   GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
1217 }
1218
1219 /**
1220  * @brief Publishes the record defined by the section section
1221  *
1222  * @param cls closure
1223  * @param section the current section
1224  */
1225 void
1226 publish_iterate (void *cls __attribute__((unused)), const char *section)
1227 {
1228   if ((strlen(section) < 8) || (0 != strcmp (".gnunet.", section + (strlen(section) - 8))))
1229     return;
1230
1231   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %s\n", section);
1232
1233   char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
1234     *keyfile;
1235
1236   GNUNET_CONFIGURATION_get_value_string (cfg, section,
1237                                          "UDP_REDIRECTS", &udp_redirects);
1238   GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
1239                                          &tcp_redirects);
1240
1241   if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD",
1242                                                             "HOSTKEY",
1243                                                             &keyfile))
1244     {
1245       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
1246       if (keyfile != NULL)
1247         GNUNET_free (keyfile);
1248       return;
1249     }
1250
1251   struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
1252     GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1253   GNUNET_free (keyfile);
1254   GNUNET_assert (my_private_key != NULL);
1255
1256   uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
1257   uint32_t service_type = 0;
1258
1259   if (NULL != udp_redirects)
1260     service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
1261
1262   if (NULL != tcp_redirects)
1263     service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
1264
1265   service_type = htonl (service_type);
1266
1267
1268   publish_name (section, ports, service_type, my_private_key);
1269
1270   GNUNET_CONFIGURATION_get_value_string (cfg, section,
1271                                          "ALTERNATIVE_NAMES",
1272                                          &alternative_names);
1273   for (alternative_name = strtok (alternative_names, " ");
1274        alternative_name != NULL; alternative_name = strtok (NULL, " "))
1275     {
1276       char *altname =
1277         alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
1278       strcpy (altname, alternative_name);
1279       strcpy (altname + strlen (alternative_name) + 1, section);
1280       altname[strlen (alternative_name)] = '.';
1281
1282       publish_name (altname, ports, service_type, my_private_key);
1283     }
1284
1285   GNUNET_free_non_null(alternative_names);
1286   GNUNET_CRYPTO_rsa_key_free (my_private_key);
1287   GNUNET_free_non_null (udp_redirects);
1288   GNUNET_free_non_null (tcp_redirects);
1289 }
1290
1291 /**
1292  * Publish a DNS-record in the DHT.
1293  */
1294 static void
1295 publish_names (void *cls __attribute__((unused)),
1296                const struct GNUNET_SCHEDULER_TaskContext *tc) {
1297     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1298       return;
1299
1300     GNUNET_CONFIGURATION_iterate_sections(cfg, publish_iterate, NULL);
1301
1302     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
1303                                   publish_names,
1304                                   NULL);
1305 }
1306
1307 /**
1308  * @param cls closure
1309  * @param server the initialized server
1310  * @param cfg_ configuration to use
1311  */
1312 static void
1313 run (void *cls,
1314      struct GNUNET_SERVER_Handle *server,
1315      const struct GNUNET_CONFIGURATION_Handle *cfg_)
1316 {
1317   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1318     /* callback, cls, type, size */
1319     {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
1320     {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
1321      sizeof (struct GNUNET_MessageHeader)},
1322     {NULL, NULL, 0, 0}
1323   };
1324
1325   static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
1326     {receive_mesh_query, GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS, 0},
1327     {receive_mesh_answer, GNUNET_MESSAGE_TYPE_REMOTE_ANSWER_DNS, 0},
1328     {NULL, 0, 0}
1329   };
1330
1331   static GNUNET_MESH_ApplicationType *apptypes;
1332
1333   if (GNUNET_YES != open_port ())
1334     {
1335       GNUNET_SCHEDULER_shutdown();
1336       return;
1337     }
1338
1339   if (GNUNET_YES ==
1340       GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT"))
1341     apptypes = (GNUNET_MESH_ApplicationType[])
1342     {
1343     GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
1344     GNUNET_APPLICATION_TYPE_END};
1345   else
1346   apptypes = (GNUNET_MESH_ApplicationType[])
1347   {
1348   GNUNET_APPLICATION_TYPE_END};
1349
1350   mesh_handle =
1351     GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
1352
1353   cfg = cfg_;
1354
1355   unsigned int i;
1356   for (i = 0; i < 65536; i++)
1357     {
1358       query_states[i].valid = GNUNET_NO;
1359     }
1360
1361   dht = GNUNET_DHT_connect (cfg, 1024);
1362
1363   GNUNET_SCHEDULER_add_now (publish_names, NULL);
1364
1365   GNUNET_SERVER_add_handlers (server, handlers);
1366   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1367                                 &cleanup_task, cls);
1368 }
1369
1370 /**
1371  * The main function for the dns service.
1372  *
1373  * @param argc number of arguments from the command line
1374  * @param argv command line arguments
1375  * @return 0 ok, 1 on error
1376  */
1377 int
1378 main (int argc, char *const *argv)
1379 {
1380   return (GNUNET_OK ==
1381           GNUNET_SERVICE_run (argc,
1382                               argv,
1383                               "dns",
1384                               GNUNET_SERVICE_OPTION_NONE,
1385                               &run, NULL)) ? 0 : 1;
1386 }