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 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.
  49  */
  50 static struct GNUNET_NETWORK_Handle *dnsout;
  51
  52 /**
  53  * The port bound to the socket dnsout
  54  */
  55 static unsigned short dnsoutport;
  56
  57 /**
  58  * A handle to the DHT-Service
  59  */
  60 static struct GNUNET_DHT_Handle *dht;
  61
  62 /**
  63  * The configuration to use
  64  */
  65 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  66
  67 /**
  68  * A list of DNS-Responses that have to be sent to the requesting client
  69  */
  70 static struct answer_packet_list *head;
  71
  72 /**
  73  * The tail of the list of DNS-responses
  74  */
  75 static struct answer_packet_list *tail;
  76
  77 /**
  78  * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to
  79  * some information needed to handle this query
  80  *
  81  * It currently allocates at least
  82  * (1 + machine-width + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  83  * = 17 MiB on 64 bit.
  84  * = 11 MiB on 32 bit.
  85  */
  86 static struct {
  87     unsigned valid:1;
  88     struct GNUNET_SERVER_Client* client;
  89     struct GNUNET_MESH_Tunnel *tunnel;
  90     uint32_t local_ip;
  91     uint32_t remote_ip;
  92     uint16_t local_port;
  93     char* name;
  94     uint8_t namelen;
  95 } query_states[UINT16_MAX];
  96
  97 /**
  98  * A struct used to give more than one value as
  99  * closure to receive_dht
 100  */
 101 struct receive_dht_cls {
 102     uint16_t id;
 103     struct GNUNET_DHT_GetHandle* handle;
 104 };
 105
 106 struct tunnel_notify_queue
 107 {
 108   struct tunnel_notify_queue* next;
 109   struct tunnel_notify_queue* prev;
 110   void* cls;
 111   size_t len;
 112   GNUNET_CONNECTION_TransmitReadyNotify cb;
 113 };
 114
 115 /**
 116  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 117  */
 118 static void
 119 hijack (void *cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext *tc)
 120 {
 121   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 122     return;
 123
 124   if (0 == dnsoutport)
 125     {
 126       GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Delaying the hijacking, port is still %d!\n", dnsoutport);
 127       GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 128       return;
 129     }
 130
 131   char port_s[6];
 132   char *virt_dns;
 133   struct GNUNET_OS_Process *proc;
 134
 135   if (GNUNET_SYSERR ==
 136       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 137                                              &virt_dns))
 138     {
 139       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 140                   "No entry 'VIRTDNS' in configuration!\n");
 141       exit (1);
 142     }
 143
 144   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 145   snprintf (port_s, 6, "%d", dnsoutport);
 146   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 147                                                NULL,
 148                                                "gnunet-helper-hijack-dns",
 149                                                "gnunet-hijack-dns",
 150                                                port_s, virt_dns, NULL)))
 151     GNUNET_OS_process_close (proc);
 152   GNUNET_free (virt_dns);
 153 }
 154
 155 /**
 156  * Delete the hijacking-routes
 157  */
 158 static void
 159 unhijack (unsigned short port)
 160 {
 161   char port_s[6];
 162   char *virt_dns;
 163   struct GNUNET_OS_Process *proc;
 164
 165   if (GNUNET_SYSERR ==
 166       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 167                                              &virt_dns))
 168     {
 169       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 170                   "No entry 'VIRTDNS' in configuration!\n");
 171       exit (1);
 172     }
 173
 174   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 175   snprintf (port_s, 6, "%d", port);
 176   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 177                                                NULL,
 178                                                "gnunet-helper-hijack-dns",
 179                                                "gnunet-hijack-dns",
 180                                                "-d", port_s, virt_dns, NULL)))
 181     GNUNET_OS_process_close (proc);
 182   GNUNET_free (virt_dns);
 183 }
 184
 185 /**
 186  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 187  * system.
 188  */
 189 static size_t
 190 send_answer(void* cls, size_t size, void* buf) {
 191     struct answer_packet_list* query = head;
 192     size_t len = ntohs(query->pkt.hdr.size);
 193
 194     GNUNET_assert(len <= size);
 195
 196     memcpy(buf, &query->pkt.hdr, len);
 197
 198     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 199
 200     GNUNET_free(query);
 201
 202     /* When more data is to be sent, reschedule */
 203     if (head != NULL)
 204       GNUNET_SERVER_notify_transmit_ready(cls,
 205                                           ntohs(head->pkt.hdr.size),
 206                                           GNUNET_TIME_UNIT_FOREVER_REL,
 207                                           &send_answer,
 208                                           cls);
 209
 210     return len;
 211 }
 212
 213 struct tunnel_cls {
 214     struct GNUNET_MESH_Tunnel *tunnel GNUNET_PACKED;
 215     struct GNUNET_MessageHeader hdr;
 216     struct dns_pkt dns;
 217 };
 218
 219 struct tunnel_cls *remote_pending[UINT16_MAX];
 220
 221 static size_t
 222 mesh_send_response (void *cls, size_t size, void *buf)
 223 {
 224   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 225   struct GNUNET_MessageHeader *hdr = buf;
 226   uint32_t *sz = cls;
 227   struct GNUNET_MESH_Tunnel **tunnel = (struct GNUNET_MESH_Tunnel**)(sz+1);
 228   struct dns_pkt *dns = (struct dns_pkt *) (tunnel + 1);
 229   hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS);
 230   hdr->size = htons (*sz + sizeof (struct GNUNET_MessageHeader));
 231
 232   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 233               "Sending response, size=%d, sz=%d, sz+hdr=%d\n", size, *sz,
 234               *sz + sizeof (struct GNUNET_MessageHeader));
 235
 236   GNUNET_assert (size >= (*sz + sizeof (struct GNUNET_MessageHeader)));
 237
 238   memcpy (hdr + 1, dns, *sz);
 239
 240   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 241     {
 242       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 243       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 244       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 245
 246       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 247
 248       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 249       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 250       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 251                                                                                  GNUNET_NO,
 252                                                                                  42,
 253                                                                                  GNUNET_TIME_relative_divide
 254                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 255                                                                                  (const struct GNUNET_PeerIdentity *)
 256                                                                                  NULL, element->len,
 257                                                                                  element->cb, element->cls);
 258       /* save the handle */
 259       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 260     }
 261
 262   GNUNET_free (cls);
 263
 264   return ntohs (hdr->size);
 265 }
 266
 267 static size_t
 268 mesh_send (void *cls, size_t size, void *buf)
 269 {
 270   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 271   GNUNET_MESH_tunnel_set_data(cls_->tunnel, NULL);
 272
 273   GNUNET_assert(cls_->hdr.size <= size);
 274
 275   size = cls_->hdr.size;
 276   cls_->hdr.size = htons(cls_->hdr.size);
 277
 278   memcpy(buf, &cls_->hdr, size);
 279
 280   if (NULL != GNUNET_MESH_tunnel_get_head(cls_->tunnel))
 281     {
 282       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 283       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 284       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(cls_->tunnel);
 285
 286       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 287
 288       GNUNET_MESH_tunnel_set_head(cls_->tunnel, head);
 289       GNUNET_MESH_tunnel_set_tail(cls_->tunnel, tail);
 290       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
 291                                                                                  GNUNET_NO,
 292                                                                                  42,
 293                                                                                  GNUNET_TIME_relative_divide
 294                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 295                                                                                  (const struct GNUNET_PeerIdentity *)
 296                                                                                  NULL, element->len,
 297                                                                                  element->cb, element->cls);
 298       /* save the handle */
 299       GNUNET_MESH_tunnel_set_data(cls_->tunnel, th);
 300       GNUNET_free(element);
 301     }
 302
 303   return size;
 304 }
 305
 306
 307 void
 308 mesh_connect (void *cls, const struct GNUNET_PeerIdentity *peer,
 309               const struct GNUNET_TRANSPORT_ATS_Information *atsi
 310               __attribute__ ((unused)))
 311 {
 312   if (NULL == peer)
 313     return;
 314   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 315   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 316               "Connected to peer %s, %x, sending query with id %d\n",
 317               GNUNET_i2s (peer), peer, ntohs (cls_->dns.s.id));
 318
 319   if (NULL == GNUNET_MESH_tunnel_get_data (cls_->tunnel))
 320     {
 321       struct GNUNET_MESH_TransmitHandle *th =
 322         GNUNET_MESH_notify_transmit_ready (cls_->tunnel,
 323                                            GNUNET_YES,
 324                                            42,
 325                                            GNUNET_TIME_UNIT_MINUTES,
 326                                            NULL,
 327                                            cls_->hdr.size,
 328                                            mesh_send,
 329                                            cls);
 330
 331       GNUNET_MESH_tunnel_set_data (cls_->tunnel, th);
 332     }
 333   else
 334     {
 335       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(cls_->tunnel);
 336       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(cls_->tunnel);
 337
 338       struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
 339       element->cls = cls;
 340       element->len = cls_->hdr.size;
 341       element->cb = mesh_send;
 342
 343       GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 344       GNUNET_MESH_tunnel_set_head(cls_->tunnel, head);
 345       GNUNET_MESH_tunnel_set_tail(cls_->tunnel, tail);
 346     }
 347 }
 348
 349
 350 static void
 351 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 352 {
 353   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 354     return;
 355
 356   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 357
 358   cls_->tunnel = GNUNET_MESH_peer_request_connect_by_type(mesh_handle,
 359                                            GNUNET_TIME_UNIT_HOURS,
 360                                            GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 361                                            mesh_connect,
 362                                            NULL,
 363                                            cls_);
 364
 365   remote_pending[cls_->dns.s.id] = cls_;
 366 }
 367
 368 static int
 369 receive_mesh_query (void *cls __attribute__((unused)),
 370                     struct GNUNET_MESH_Tunnel *tunnel,
 371                     void **ctx __attribute__((unused)),
 372                     const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 373                     const struct GNUNET_MessageHeader *message,
 374                     const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 375 {
 376   struct dns_pkt *dns = (struct dns_pkt*)(message + 1);
 377
 378   struct sockaddr_in dest;
 379   memset(&dest, 0, sizeof dest);
 380   dest.sin_port = htons(53);
 381   /* TODO: read from config */
 382   inet_pton(AF_INET, "8.8.8.8", &dest.sin_addr);
 383
 384   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Querying for remote, id=%d\n", ntohs(dns->s.id));
 385   query_states[dns->s.id].tunnel = tunnel;
 386   query_states[dns->s.id].valid = GNUNET_YES;
 387
 388   GNUNET_NETWORK_socket_sendto(dnsout,
 389                                dns,
 390                                ntohs(message->size) - sizeof(struct GNUNET_MessageHeader),
 391                                (struct sockaddr*) &dest,
 392                                sizeof dest);
 393
 394   return GNUNET_SYSERR;
 395 }
 396
 397 static int
 398 receive_mesh_answer (void *cls __attribute__((unused)),
 399                      struct GNUNET_MESH_Tunnel *tunnel,
 400                      void **ctx __attribute__((unused)),
 401                      const struct GNUNET_PeerIdentity *sender,
 402                      const struct GNUNET_MessageHeader *message,
 403                      const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 404 {
 405   /* TODo: size check */
 406   struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
 407
 408   /* They sent us a packet we were not waiting for */
 409   if (remote_pending[dns->s.id] == NULL
 410       || remote_pending[dns->s.id]->tunnel != tunnel)
 411     return GNUNET_OK;
 412
 413   GNUNET_free(remote_pending[dns->s.id]);
 414   remote_pending[dns->s.id] = NULL;
 415
 416   if (query_states[dns->s.id].valid != GNUNET_YES)
 417     return GNUNET_SYSERR;
 418   query_states[dns->s.id].valid = GNUNET_NO;
 419
 420   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Received answer from peer %s, dns-id %d\n", GNUNET_i2s(sender), ntohs(dns->s.id));
 421
 422   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 */
 423     + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
 424
 425   struct answer_packet_list *answer =
 426     GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
 427   memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
 428
 429   answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
 430   answer->pkt.hdr.size = htons (len);
 431
 432   struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 433
 434   if (ntohs(pdns->s.ancount) < 1)
 435     {
 436       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer only contains %d answers.\n", ntohs(pdns->s.ancount));
 437       free_parsed_dns_packet(pdns);
 438       return GNUNET_OK;
 439     }
 440
 441   answer->pkt.addrsize = ntohs(pdns->answers[0]->data_len);
 442   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "The first answer has the addrlen %d\n", answer->pkt.addrsize);
 443   memcpy(answer->pkt.addr, pdns->answers[0]->data, ntohs(pdns->answers[0]->data_len));
 444
 445   answer->pkt.from = query_states[dns->s.id].remote_ip;
 446
 447   answer->pkt.to = query_states[dns->s.id].local_ip;
 448   answer->pkt.dst_port = query_states[dns->s.id].local_port;
 449
 450   struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
 451
 452   dpkt->s.id = dns->s.id;
 453   dpkt->s.aa = 1;
 454   dpkt->s.qr = 1;
 455   dpkt->s.ra = 1;
 456   dpkt->s.qdcount = htons (1);
 457   dpkt->s.ancount = htons (1);
 458
 459   memcpy (dpkt->data, query_states[dns->s.id].name,
 460           query_states[dns->s.id].namelen);
 461   GNUNET_free (query_states[dns->s.id].name);
 462   query_states[dns->s.id].name = NULL;
 463
 464   struct dns_query_line *dque =
 465     (struct dns_query_line *) (dpkt->data +
 466                                (query_states[dns->s.id].namelen));
 467
 468   struct dns_record_line *drec_data =
 469     (struct dns_record_line *) (dpkt->data +
 470                                 (query_states[dns->s.id].namelen) +
 471                                 sizeof (struct dns_query_line) + 2);
 472   if (16 == answer->pkt.addrsize)
 473     {
 474       answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA;
 475       dque->type = htons (28);      /* AAAA */
 476       drec_data->type = htons (28); /* AAAA */
 477       drec_data->data_len = htons (16);
 478     }
 479   else
 480     {
 481       answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_A;
 482       dque->type = htons (1);      /* A */
 483       drec_data->type = htons (1); /* A*/
 484       drec_data->data_len = htons (4);
 485     }
 486   dque->class = htons (1);      /* IN */
 487
 488   char *anname =
 489     (char *) (dpkt->data + (query_states[dns->s.id].namelen) +
 490               sizeof (struct dns_query_line));
 491   memcpy (anname, "\xc0\x0c", 2);
 492   drec_data->class = htons (1); /* IN */
 493
 494   drec_data->ttl = pdns->answers[0]->ttl;
 495
 496   /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 497    * filled in by the daemon-vpn */
 498   answer->pkt.addroffset =
 499     htons ((unsigned short) ((unsigned long) (&drec_data->data) -
 500                              (unsigned long) (&answer->pkt)));
 501
 502   GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
 503
 504   GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client,
 505                                        len,
 506                                        GNUNET_TIME_UNIT_FOREVER_REL,
 507                                        &send_answer,
 508                                        query_states[dns->s.id].client);
 509
 510   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Sent answer of length %d on to client, addroffset = %d\n", len, answer->pkt.addroffset);
 511
 512   free_parsed_dns_packet(pdns);
 513   return GNUNET_OK;
 514 }
 515
 516
 517 static void
 518 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 519     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 520       return;
 521
 522     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 523
 524     unsigned short id = pdns->s.id;
 525
 526     free_parsed_dns_packet(pdns);
 527
 528     if (query_states[id].valid != GNUNET_YES) return;
 529     query_states[id].valid = GNUNET_NO;
 530
 531     GNUNET_assert(query_states[id].namelen == 74);
 532
 533     size_t len = sizeof(struct answer_packet) - 1 \
 534                  + sizeof(struct dns_static) \
 535                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 536                  + sizeof(struct dns_query_line) \
 537                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 538                  + sizeof(struct dns_record_line) - 1 \
 539                  - 2 /* We do not know the lenght of the answer yet*/;
 540
 541     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 542     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 543
 544     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
 545     answer->pkt.hdr.size = htons(len);
 546     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 547
 548     answer->pkt.from = query_states[id].remote_ip;
 549
 550     answer->pkt.to = query_states[id].local_ip;
 551     answer->pkt.dst_port = query_states[id].local_port;
 552
 553     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 554
 555     dpkt->s.id = id;
 556     dpkt->s.aa = 1;
 557     dpkt->s.qr = 1;
 558     dpkt->s.ra = 1;
 559     dpkt->s.qdcount = htons(1);
 560     dpkt->s.ancount = htons(1);
 561
 562     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 563     GNUNET_free(query_states[id].name);
 564
 565     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 566     dque->type = htons(12); /* PTR */
 567     dque->class = htons(1); /* IN */
 568
 569     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 570     memcpy(anname, "\xc0\x0c", 2);
 571
 572     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 573     drec_data->type = htons(12); /* AAAA */
 574     drec_data->class = htons(1); /* IN */
 575     /* FIXME: read the TTL from block:
 576      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 577      *
 578      * But how to get the seconds out of this?
 579      */
 580     drec_data->ttl = htonl(3600);
 581
 582     /* Calculate at which offset in the packet the length of the name and the
 583      * name, it is filled in by the daemon-vpn */
 584     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 585
 586     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 587
 588     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 589                                         len,
 590                                         GNUNET_TIME_UNIT_FOREVER_REL,
 591                                         &send_answer,
 592                                         query_states[id].client);
 593 }
 594
 595 /**
 596  * Receive a block from the dht.
 597  */
 598 static void
 599 receive_dht(void *cls,
 600             struct GNUNET_TIME_Absolute exp __attribute__((unused)),
 601             const GNUNET_HashCode *key __attribute__((unused)),
 602             const struct GNUNET_PeerIdentity *const *get_path __attribute__((unused)),
 603             const struct GNUNET_PeerIdentity *const *put_path __attribute__((unused)),
 604             enum GNUNET_BLOCK_Type type,
 605             size_t size,
 606             const void *data) {
 607
 608     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 609     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 610     GNUNET_free(cls);
 611
 612     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 613
 614     /* If no query with this id is pending, ignore the block */
 615     if (query_states[id].valid != GNUNET_YES) return;
 616     query_states[id].valid = GNUNET_NO;
 617
 618     const struct GNUNET_DNS_Record* rec = data;
 619     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 620                "Got block of size %d, peer: %08x, desc: %08x\n",
 621                size,
 622                *((unsigned int*)&rec->peer),
 623                *((unsigned int*)&rec->service_descriptor));
 624
 625     size_t len = sizeof(struct answer_packet) - 1 \
 626                  + sizeof(struct dns_static) \
 627                  + query_states[id].namelen \
 628                  + sizeof(struct dns_query_line) \
 629                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 630                  + sizeof(struct dns_record_line) - 1 \
 631                  + 16; /* To hold the IPv6-Address */
 632
 633     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 634     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 635
 636     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
 637     answer->pkt.hdr.size = htons(len);
 638     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 639
 640     GNUNET_CRYPTO_hash(&rec->peer,
 641                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 642                        &answer->pkt.service_descr.peer);
 643
 644     memcpy(&answer->pkt.service_descr.service_descriptor,
 645            &rec->service_descriptor,
 646            sizeof(GNUNET_HashCode));
 647     memcpy(&answer->pkt.service_descr.service_type,
 648            &rec->service_type,
 649            sizeof(answer->pkt.service_descr.service_type));
 650     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 651
 652     answer->pkt.from = query_states[id].remote_ip;
 653
 654     answer->pkt.to = query_states[id].local_ip;
 655     answer->pkt.dst_port = query_states[id].local_port;
 656
 657     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 658
 659     dpkt->s.id = id;
 660     dpkt->s.aa = 1;
 661     dpkt->s.qr = 1;
 662     dpkt->s.ra = 1;
 663     dpkt->s.qdcount = htons(1);
 664     dpkt->s.ancount = htons(1);
 665
 666     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 667     GNUNET_free(query_states[id].name);
 668
 669     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 670     dque->type = htons(28); /* AAAA */
 671     dque->class = htons(1); /* IN */
 672
 673     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 674     memcpy(anname, "\xc0\x0c", 2);
 675
 676     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 677     drec_data->type = htons(28); /* AAAA */
 678     drec_data->class = htons(1); /* IN */
 679
 680     /* FIXME: read the TTL from block:
 681      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 682      *
 683      * But how to get the seconds out of this?
 684      */
 685     drec_data->ttl = htonl(3600);
 686     drec_data->data_len = htons(16);
 687
 688     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 689      * filled in by the daemon-vpn */
 690     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 691
 692     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 693
 694     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 695                                         len,
 696                                         GNUNET_TIME_UNIT_FOREVER_REL,
 697                                         &send_answer,
 698                                         query_states[id].client);
 699
 700     GNUNET_DHT_get_stop(handle);
 701 }
 702
 703 /**
 704  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 705  */
 706 static void
 707 rehijack(void *cls __attribute__((unused)),
 708          struct GNUNET_SERVER_Client *client,
 709          const struct GNUNET_MessageHeader *message __attribute__((unused))) {
 710     unhijack(dnsoutport);
 711     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 712
 713     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 714 }
 715
 716 /**
 717  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 718  */
 719 static void
 720 receive_query(void *cls __attribute__((unused)),
 721               struct GNUNET_SERVER_Client *client,
 722               const struct GNUNET_MessageHeader *message) {
 723     struct query_packet* pkt = (struct query_packet*)message;
 724     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 725     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 726
 727     query_states[dns->s.id].valid = GNUNET_YES;
 728     query_states[dns->s.id].client = client;
 729     query_states[dns->s.id].local_ip = pkt->orig_from;
 730     query_states[dns->s.id].local_port = pkt->src_port;
 731     query_states[dns->s.id].remote_ip = pkt->orig_to;
 732     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 733     if (query_states[dns->s.id].name != NULL)
 734       GNUNET_free(query_states[dns->s.id].name);
 735     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 736     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 737
 738     /* The query is for a .gnunet-address */
 739     if (pdns->queries[0]->namelen > 9 &&
 740         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 741       {
 742         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 743         GNUNET_HashCode key;
 744         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 745
 746         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 747                    "Getting with key %08x, len is %d\n",
 748                    *((unsigned int*)&key),
 749                    pdns->queries[0]->namelen);
 750
 751         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 752         cls->id = dns->s.id;
 753
 754         cls->handle = GNUNET_DHT_get_start(dht,
 755                                            GNUNET_TIME_UNIT_MINUTES,
 756                                            GNUNET_BLOCK_TYPE_DNS,
 757                                            &key,
 758                                            DEFAULT_GET_REPLICATION,
 759                                            GNUNET_DHT_RO_NONE,
 760                                            NULL,
 761                                            0,
 762                                            NULL,
 763                                            0,
 764                                            receive_dht,
 765                                            cls);
 766
 767         goto outfree;
 768       }
 769
 770     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 771
 772     /* This is a PTR-Query. Check if it is for "our" network */
 773     if (htons(pdns->queries[0]->qtype) == 12 &&
 774         74 == pdns->queries[0]->namelen)
 775       {
 776         char* ipv6addr;
 777         char ipv6[16];
 778         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.";
 779         unsigned int i;
 780         unsigned long long ipv6prefix;
 781         unsigned int comparelen;
 782
 783         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 784         inet_pton (AF_INET6, ipv6addr, ipv6);
 785         GNUNET_free(ipv6addr);
 786
 787         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 788         GNUNET_assert(ipv6prefix < 127);
 789         ipv6prefix = (ipv6prefix + 7)/8;
 790
 791         for (i = ipv6prefix; i < 16; i++)
 792           ipv6[i] = 0;
 793
 794         for (i = 0; i < 16; i++)
 795           {
 796             unsigned char c1 = ipv6[i] >> 4;
 797             unsigned char c2 = ipv6[i] & 0xf;
 798
 799             if (c1 <= 9)
 800               ipv6rev[62-(4*i)] = c1 + '0';
 801             else
 802               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 803
 804             if (c2 <= 9)
 805               ipv6rev[62-((4*i)+2)] = c2 + '0';
 806             else
 807               ipv6rev[62-((4*i)+2)] = c2 + 87;
 808           }
 809         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 810         comparelen = 10 + 4*ipv6prefix;
 811         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 812                         ipv6rev + (74 - comparelen),
 813                         comparelen))
 814           {
 815             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 816
 817             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 818
 819             goto out;
 820           }
 821       }
 822
 823     char* virt_dns;
 824     unsigned int virt_dns_bytes;
 825     if (GNUNET_SYSERR ==
 826         GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 827                                                &virt_dns))
 828       {
 829         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 830                     "No entry 'VIRTDNS' in configuration!\n");
 831         exit (1);
 832       }
 833
 834     if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
 835       {
 836         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 837                     "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns);
 838         exit(1);
 839       }
 840
 841     GNUNET_free(virt_dns);
 842
 843     if (virt_dns_bytes == pkt->orig_to)
 844       {
 845         /* This is a packet that was sent directly to the virtual dns-server
 846          *
 847          * This means we have to send this query over gnunet
 848          */
 849
 850         size_t size = sizeof(struct GNUNET_MESH_Tunnel*) + sizeof(struct GNUNET_MessageHeader) + (ntohs(message->size) - sizeof(struct query_packet) + 1);
 851         struct tunnel_cls *cls_ =  GNUNET_malloc(size);
 852         cls_->hdr.size = size - sizeof(struct GNUNET_MESH_Tunnel*);
 853
 854         cls_->hdr.type = ntohs(GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS);
 855         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size);
 856
 857         memcpy(&cls_->dns, dns, cls_->hdr.size - sizeof(struct GNUNET_MessageHeader));
 858         GNUNET_SCHEDULER_add_now(send_mesh_query, cls_);
 859
 860         goto outfree;
 861       }
 862
 863
 864     /* The query should be sent to the network */
 865
 866     struct sockaddr_in dest;
 867     memset(&dest, 0, sizeof dest);
 868     dest.sin_port = htons(53);
 869     dest.sin_addr.s_addr = pkt->orig_to;
 870
 871     GNUNET_NETWORK_socket_sendto(dnsout,
 872                                  dns,
 873                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 874                                  (struct sockaddr*) &dest,
 875                                  sizeof dest);
 876
 877 outfree:
 878     free_parsed_dns_packet(pdns);
 879     pdns = NULL;
 880 out:
 881     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 882 }
 883
 884 static void read_response (void *cls,
 885                            const struct GNUNET_SCHEDULER_TaskContext *tc);
 886
 887 static int
 888 open_port ()
 889 {
 890   struct sockaddr_in addr;
 891
 892   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 893   if (dnsout == NULL)
 894     return GNUNET_SYSERR;
 895   memset (&addr, 0, sizeof (struct sockaddr_in));
 896
 897   addr.sin_family = AF_INET;
 898   int err = GNUNET_NETWORK_socket_bind (dnsout,
 899                                         (struct sockaddr *) &addr,
 900                                         sizeof (struct sockaddr_in));
 901
 902   if (err != GNUNET_OK)
 903     {
 904       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 905                   "Could not bind a port: %m\n");
 906       return GNUNET_SYSERR;
 907     }
 908
 909   /* Read the port we bound to */
 910   socklen_t addrlen = sizeof (struct sockaddr_in);
 911   err = getsockname (GNUNET_NETWORK_get_fd (dnsout),
 912                      (struct sockaddr *) &addr, &addrlen);
 913
 914   dnsoutport = htons (addr.sin_port);
 915
 916   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bound to port %d.\n", dnsoutport);
 917
 918   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
 919                                  &read_response, NULL);
 920
 921   return GNUNET_YES;
 922 }
 923
 924 /**
 925  * Read a response-packet of the UDP-Socket
 926  */
 927 static void
 928 read_response (void *cls
 929                __attribute__ ((unused)),
 930                const struct GNUNET_SCHEDULER_TaskContext *tc)
 931 {
 932   struct sockaddr_in addr;
 933   socklen_t addrlen = sizeof (addr);
 934   int r;
 935   int len;
 936
 937   if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 938     return;
 939
 940   memset (&addr, 0, sizeof addr);
 941
 942 #ifndef MINGW
 943   if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len))
 944     {
 945       unhijack (dnsoutport);
 946       if (GNUNET_YES == open_port ())
 947         GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 948       return;
 949     }
 950 #else
 951   /* port the code above? */
 952   len = 65536;
 953 #endif
 954   {
 955     unsigned char buf[len];
 956     struct dns_pkt *dns = (struct dns_pkt *) buf;
 957
 958     r = GNUNET_NETWORK_socket_recvfrom (dnsout,
 959                                         buf,
 960                                         sizeof (buf),
 961                                         (struct sockaddr *) &addr, &addrlen);
 962
 963     if (r < 0)
 964       {
 965         unhijack (dnsoutport);
 966         if (GNUNET_YES == open_port ())
 967           GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 968         return;
 969       }
 970
 971     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d\n", ntohs(dns->s.id));
 972
 973     if (query_states[dns->s.id].valid == GNUNET_YES)
 974       {
 975         if (query_states[dns->s.id].tunnel != NULL)
 976           {
 977             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d for a remote peer!\n", ntohs(dns->s.id));
 978             /* This response should go through a tunnel */
 979             uint32_t *c = GNUNET_malloc (4 + sizeof(struct GNUNET_MESH_Tunnel*) + r);
 980             *c = r;
 981             struct GNUNET_MESH_Tunnel** t = (struct GNUNET_MESH_Tunnel**)(c + 1);
 982             *t = query_states[dns->s.id].tunnel;
 983             memcpy (t + 1, dns, r);
 984             if (NULL ==
 985                 GNUNET_MESH_tunnel_get_data (query_states[dns->s.id].tunnel))
 986               {
 987                 struct GNUNET_MESH_TransmitHandle *th =
 988                   GNUNET_MESH_notify_transmit_ready (query_states[dns->s.id].tunnel,
 989                                                      GNUNET_YES,
 990                                                      32,
 991                                                      GNUNET_TIME_UNIT_MINUTES,
 992                                                      NULL,
 993                                                      r +
 994                                                      sizeof (struct
 995                                                              GNUNET_MessageHeader),
 996                                                      mesh_send_response, c);
 997                 GNUNET_MESH_tunnel_set_data (query_states[dns->s.id].tunnel,
 998                                              th);
 999               }
1000             else
1001               {
1002                 struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(query_states[dns->s.id].tunnel);
1003                 struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(query_states[dns->s.id].tunnel);
1004
1005                 struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
1006                 element->cls = c;
1007                 element->len = r+sizeof(struct GNUNET_MessageHeader);
1008                 element->cb = mesh_send_response;
1009
1010                 GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
1011                 GNUNET_MESH_tunnel_set_head(query_states[dns->s.id].tunnel, head);
1012                 GNUNET_MESH_tunnel_set_tail(query_states[dns->s.id].tunnel, tail);
1013               }
1014           }
1015         else
1016           {
1017             query_states[dns->s.id].valid = GNUNET_NO;
1018
1019             size_t len = sizeof (struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
1020             struct answer_packet_list *answer =
1021               GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
1022             answer->pkt.hdr.type =
1023               htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS);
1024             answer->pkt.hdr.size = htons (len);
1025             answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
1026             answer->pkt.from = addr.sin_addr.s_addr;
1027             answer->pkt.to = query_states[dns->s.id].local_ip;
1028             answer->pkt.dst_port = query_states[dns->s.id].local_port;
1029             memcpy (answer->pkt.data, buf, r);
1030
1031             GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
1032
1033             GNUNET_SERVER_notify_transmit_ready (query_states
1034                                                  [dns->s.id].client, len,
1035                                                  GNUNET_TIME_UNIT_FOREVER_REL,
1036                                                  &send_answer,
1037                                                  query_states[dns->s.
1038                                                               id].client);
1039           }
1040       }
1041   }
1042   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
1043                                  dnsout, &read_response, NULL);
1044 }
1045
1046
1047 /**
1048  * Task run during shutdown.
1049  *
1050  * @param cls unused
1051  * @param tc unused
1052  */
1053 static void
1054 cleanup_task (void *cls __attribute__((unused)),
1055               const struct GNUNET_SCHEDULER_TaskContext *tc)
1056 {
1057   GNUNET_assert(0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
1058
1059   unhijack(dnsoutport);
1060   GNUNET_DHT_disconnect(dht);
1061   GNUNET_MESH_disconnect(mesh_handle);
1062 }
1063
1064 /**
1065  * @brief Create a port-map from udp and tcp redirects
1066  *
1067  * @param udp_redirects
1068  * @param tcp_redirects
1069  *
1070  * @return
1071  */
1072 uint64_t
1073 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
1074 {
1075   uint64_t ret = 0;
1076   char* cpy, *hostname, *redirect;
1077   int local_port, count = 0;
1078
1079   if (NULL != udp_redirects)
1080     {
1081       cpy = GNUNET_strdup (udp_redirects);
1082       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
1083         {
1084           if (NULL == (hostname = strstr (redirect, ":")))
1085             {
1086               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
1087               continue;
1088             }
1089           hostname[0] = '\0';
1090           local_port = atoi (redirect);
1091           if (!((local_port > 0) && (local_port < 65536)))
1092             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
1093
1094           ret |= (0xFFFF & htons(local_port));
1095           ret <<= 16;
1096           count ++;
1097
1098           if(count > 4)
1099             {
1100               ret = 0;
1101               goto out;
1102             }
1103         }
1104       GNUNET_free(cpy);
1105       cpy = NULL;
1106     }
1107
1108   if (NULL != tcp_redirects)
1109     {
1110       cpy = GNUNET_strdup (tcp_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 out:
1138   if (NULL != cpy)
1139     GNUNET_free(cpy);
1140   return ret;
1141 }
1142
1143 void
1144 publish_name (const char *name, uint64_t ports, uint32_t service_type,
1145               struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
1146 {
1147   size_t size = sizeof (struct GNUNET_DNS_Record);
1148   struct GNUNET_DNS_Record data;
1149   memset (&data, 0, size);
1150
1151   data.purpose.size =
1152     htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
1153   data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
1154
1155   GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
1156   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
1157               *((unsigned long long *) &data.service_descriptor));
1158
1159   data.service_type = service_type;
1160   data.ports = ports;
1161
1162   GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
1163
1164   data.expiration_time =
1165     GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 2));
1166
1167   /* Sign the block */
1168   if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key,
1169                                            &data.purpose, &data.signature))
1170     {
1171       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
1172       return;
1173     }
1174
1175   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1176               "Putting with key %08x, size = %d\n",
1177               *((unsigned int *) &data.service_descriptor), size);
1178
1179   GNUNET_DHT_put (dht,
1180                   &data.service_descriptor,
1181                   DEFAULT_PUT_REPLICATION,
1182                   GNUNET_DHT_RO_NONE,
1183                   GNUNET_BLOCK_TYPE_DNS,
1184                   size,
1185                   (char *) &data,
1186                   GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
1187                   GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
1188 }
1189
1190 /**
1191  * @brief Publishes the record defined by the section section
1192  *
1193  * @param cls closure
1194  * @param section the current section
1195  */
1196 void
1197 publish_iterate (void *cls __attribute__((unused)), const char *section)
1198 {
1199   if ((strlen(section) < 8) || (0 != strcmp (".gnunet.", section + (strlen(section) - 8))))
1200     return;
1201
1202   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %s\n", section);
1203
1204   char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
1205     *keyfile;
1206
1207   GNUNET_CONFIGURATION_get_value_string (cfg, section,
1208                                          "UDP_REDIRECTS", &udp_redirects);
1209   GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
1210                                          &tcp_redirects);
1211
1212   if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD",
1213                                                             "HOSTKEY",
1214                                                             &keyfile))
1215     {
1216       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
1217       if (keyfile != NULL)
1218         GNUNET_free (keyfile);
1219       return;
1220     }
1221
1222   struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
1223     GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1224   GNUNET_free (keyfile);
1225   GNUNET_assert (my_private_key != NULL);
1226
1227   uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
1228   uint32_t service_type = 0;
1229
1230   if (NULL != udp_redirects)
1231     service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
1232
1233   if (NULL != tcp_redirects)
1234     service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
1235
1236   service_type = htonl (service_type);
1237
1238
1239   publish_name (section, ports, service_type, my_private_key);
1240
1241   GNUNET_CONFIGURATION_get_value_string (cfg, section,
1242                                          "ALTERNATIVE_NAMES",
1243                                          &alternative_names);
1244   for (alternative_name = strtok (alternative_names, " ");
1245        alternative_name != NULL; alternative_name = strtok (NULL, " "))
1246     {
1247       char *altname =
1248         alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
1249       strcpy (altname, alternative_name);
1250       strcpy (altname + strlen (alternative_name) + 1, section);
1251       altname[strlen (alternative_name)] = '.';
1252
1253       publish_name (altname, ports, service_type, my_private_key);
1254     }
1255
1256   GNUNET_free_non_null(alternative_names);
1257   GNUNET_CRYPTO_rsa_key_free (my_private_key);
1258   GNUNET_free_non_null (udp_redirects);
1259   GNUNET_free_non_null (tcp_redirects);
1260 }
1261
1262 /**
1263  * Publish a DNS-record in the DHT.
1264  */
1265 static void
1266 publish_names (void *cls __attribute__((unused)),
1267                const struct GNUNET_SCHEDULER_TaskContext *tc) {
1268     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1269       return;
1270
1271     GNUNET_CONFIGURATION_iterate_sections(cfg, publish_iterate, NULL);
1272
1273     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
1274                                   publish_names,
1275                                   NULL);
1276 }
1277
1278 /**
1279  * @param cls closure
1280  * @param server the initialized server
1281  * @param cfg_ configuration to use
1282  */
1283 static void
1284 run (void *cls,
1285      struct GNUNET_SERVER_Handle *server,
1286      const struct GNUNET_CONFIGURATION_Handle *cfg_)
1287 {
1288   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1289     /* callback, cls, type, size */
1290     {&receive_query, NULL, GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_QUERY_DNS, 0},
1291     {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
1292      sizeof (struct GNUNET_MessageHeader)},
1293     {NULL, NULL, 0, 0}
1294   };
1295
1296   static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = {
1297     {receive_mesh_query, GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS, 0},
1298     {receive_mesh_answer, GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS, 0},
1299     {NULL, 0, 0}
1300   };
1301
1302   static GNUNET_MESH_ApplicationType *apptypes;
1303
1304   if (GNUNET_YES != open_port ())
1305     {
1306       GNUNET_SCHEDULER_shutdown();
1307       return;
1308     }
1309
1310   if (GNUNET_YES ==
1311       GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT"))
1312     apptypes = (GNUNET_MESH_ApplicationType[])
1313     {
1314     GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
1315     GNUNET_APPLICATION_TYPE_END};
1316   else
1317   apptypes = (GNUNET_MESH_ApplicationType[])
1318   {
1319   GNUNET_APPLICATION_TYPE_END};
1320
1321   mesh_handle =
1322     GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
1323
1324   cfg = cfg_;
1325
1326   unsigned int i;
1327   for (i = 0; i < 65536; i++)
1328     {
1329       query_states[i].valid = GNUNET_NO;
1330     }
1331
1332   dht = GNUNET_DHT_connect (cfg, 1024);
1333
1334   GNUNET_SCHEDULER_add_now (publish_names, NULL);
1335
1336   GNUNET_SERVER_add_handlers (server, handlers);
1337   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1338                                 &cleanup_task, cls);
1339 }
1340
1341 /**
1342  * The main function for the dns service.
1343  *
1344  * @param argc number of arguments from the command line
1345  * @param argv command line arguments
1346  * @return 0 ok, 1 on error
1347  */
1348 int
1349 main (int argc, char *const *argv)
1350 {
1351   return (GNUNET_OK ==
1352           GNUNET_SERVICE_run (argc,
1353                               argv,
1354                               "dns",
1355                               GNUNET_SERVICE_OPTION_NONE,
1356                               &run, NULL)) ? 0 : 1;
1357 }