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_network_lib.h"
  29 #include "gnunet_os_lib.h"
  30 #include "gnunet-service-dns-p.h"
  31 #include "gnunet_protocols.h"
  32 #include "gnunet_applications.h"
  33 #include "gnunet-vpn-packet.h"
  34 #include "gnunet_container_lib.h"
  35 #include "gnunet-dns-parser.h"
  36 #include "gnunet_dht_service.h"
  37 #include "gnunet_block_lib.h"
  38 #include "block_dns.h"
  39 #include "gnunet_crypto_lib.h"
  40 #include "gnunet_mesh_service.h"
  41 #include "gnunet_signatures.h"
  42
  43 struct GNUNET_MESH_Handle *mesh_handle;
  44
  45 /**
  46  * The UDP-Socket through which DNS-Resolves will be sent if they are not to be
  47  * sent through gnunet. The port of this socket will not be hijacked.
  48  */
  49 static struct GNUNET_NETWORK_Handle *dnsout;
  50
  51 /**
  52  * The port bound to the socket dnsout
  53  */
  54 static unsigned short dnsoutport;
  55
  56 /**
  57  * A handle to the DHT-Service
  58  */
  59 static struct GNUNET_DHT_Handle *dht;
  60
  61 /**
  62  * The configuration to use
  63  */
  64 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  65
  66 /**
  67  * The handle to the service-configuration
  68  */
  69 static struct GNUNET_CONFIGURATION_Handle *servicecfg;
  70
  71 /**
  72  * A list of DNS-Responses that have to be sent to the requesting client
  73  */
  74 static struct answer_packet_list *head;
  75
  76 /**
  77  * The tail of the list of DNS-responses
  78  */
  79 static struct answer_packet_list *tail;
  80
  81 /**
  82  * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to
  83  * some information needed to handle this query
  84  *
  85  * It currently allocates at least
  86  * (1 + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit
  87  * = 1.7 MiB on 64 bit.
  88  * = 1.2 MiB on 32 bit.
  89  */
  90 static struct {
  91     unsigned valid:1;
  92     struct GNUNET_SERVER_Client* client;
  93     uint32_t local_ip;
  94     uint32_t remote_ip;
  95     uint16_t local_port;
  96     char* name;
  97     uint8_t namelen;
  98 } query_states[UINT16_MAX];
  99
 100 /**
 101  * A struct used to give more than one value as
 102  * closure to receive_dht
 103  */
 104 struct receive_dht_cls {
 105     uint16_t id;
 106     struct GNUNET_DHT_GetHandle* handle;
 107 };
 108
 109 /**
 110  * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port.
 111  */
 112 static void
 113 hijack (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 114 {
 115   char port_s[6];
 116   char *virt_dns;
 117   struct GNUNET_OS_Process *proc;
 118
 119   if (GNUNET_SYSERR ==
 120       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 121                                              &virt_dns))
 122     {
 123       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 124                   "No entry 'VIRTDNS' in configuration!\n");
 125       exit (1);
 126     }
 127
 128   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport);
 129   snprintf (port_s, 6, "%d", dnsoutport);
 130   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 131                                                NULL,
 132                                                "gnunet-helper-hijack-dns",
 133                                                "gnunet-hijack-dns",
 134                                                port_s, virt_dns, NULL)))
 135     GNUNET_OS_process_close (proc);
 136   GNUNET_free (virt_dns);
 137 }
 138
 139 /**
 140  * Delete the hijacking-routes
 141  */
 142 static void
 143 unhijack (unsigned short port)
 144 {
 145   char port_s[6];
 146   char *virt_dns;
 147   struct GNUNET_OS_Process *proc;
 148
 149   if (GNUNET_SYSERR ==
 150       GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 151                                              &virt_dns))
 152     {
 153       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 154                   "No entry 'VIRTDNS' in configuration!\n");
 155       exit (1);
 156     }
 157
 158   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port);
 159   snprintf (port_s, 6, "%d", port);
 160   if (NULL != (proc = GNUNET_OS_start_process (NULL,
 161                                                NULL,
 162                                                "gnunet-helper-hijack-dns",
 163                                                "gnunet-hijack-dns",
 164                                                "-d", port_s, virt_dns, NULL)))
 165     GNUNET_OS_process_close (proc);
 166   GNUNET_free (virt_dns);
 167 }
 168
 169 /**
 170  * Send the DNS-Response to the client. Gets called via the notify_transmit_ready-
 171  * system.
 172  */
 173 static size_t
 174 send_answer(void* cls, size_t size, void* buf) {
 175     struct answer_packet_list* query = head;
 176     size_t len = ntohs(query->pkt.hdr.size);
 177
 178     GNUNET_assert(len <= size);
 179
 180     memcpy(buf, &query->pkt.hdr, len);
 181
 182     GNUNET_CONTAINER_DLL_remove (head, tail, query);
 183
 184     GNUNET_free(query);
 185
 186     /* When more data is to be sent, reschedule */
 187     if (head != NULL)
 188       GNUNET_SERVER_notify_transmit_ready(cls,
 189                                           ntohs(head->pkt.hdr.size),
 190                                           GNUNET_TIME_UNIT_FOREVER_REL,
 191                                           &send_answer,
 192                                           cls);
 193
 194     return len;
 195 }
 196
 197 struct tunnel_cls {
 198     struct GNUNET_MESH_Tunnel *tunnel;
 199     struct GNUNET_MessageHeader hdr;
 200     struct dns_pkt dns;
 201 };
 202
 203 struct tunnel_cls *remote_pending[UINT16_MAX];
 204
 205
 206 static size_t
 207 mesh_send (void *cls, size_t size, void *buf)
 208 {
 209   struct tunnel_cls *cls_ = (struct tunnel_cls *) cls;
 210
 211   GNUNET_assert(cls_->hdr.size <= size);
 212
 213   size = cls_->hdr.size;
 214   cls_->hdr.size = htons(cls_->hdr.size);
 215
 216   memcpy(buf, &cls_->hdr, size);
 217   return size;
 218 }
 219
 220
 221 void mesh_connect (void* cls, const struct GNUNET_PeerIdentity* peer, const struct GNUNET_TRANSPORT_ATS_Information *atsi) {
 222   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %x\n", *((unsigned long*)peer));
 223   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 224
 225   GNUNET_MESH_notify_transmit_ready(cls_->tunnel,
 226                                     GNUNET_YES,
 227                                     42,
 228                                     GNUNET_TIME_UNIT_MINUTES,
 229                                     NULL,
 230                                     cls_->hdr.size,
 231                                     mesh_send,
 232                                     cls);
 233 }
 234
 235
 236 static void
 237 send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 238 {
 239   if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 240     return;
 241
 242   struct tunnel_cls *cls_ = (struct tunnel_cls*)cls;
 243
 244   cls_->tunnel = GNUNET_MESH_peer_request_connect_by_type(mesh_handle,
 245                                            GNUNET_TIME_UNIT_HOURS,
 246                                            GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
 247                                            mesh_connect,
 248                                            NULL,
 249                                            cls_);
 250
 251   remote_pending[cls_->dns.s.id] = cls_;
 252
 253   /* TODO
 254    * at receive: walk through pending list, send answer
 255    */
 256 }
 257
 258 static int
 259 receive_mesh_query (void *cls,
 260                     struct GNUNET_MESH_Tunnel *tunnel,
 261                     void **ctx,
 262                     const struct GNUNET_PeerIdentity *sender,
 263                     const struct GNUNET_MessageHeader *message,
 264                     const struct GNUNET_TRANSPORT_ATS_Information *atsi)
 265 {
 266   return GNUNET_SYSERR;
 267 }
 268
 269 static int
 270 receive_mesh_answer (void *cls,
 271                      struct GNUNET_MESH_Tunnel *tunnel,
 272                      void **ctx,
 273                      const struct GNUNET_PeerIdentity *sender,
 274                      const struct GNUNET_MessageHeader *message,
 275                      const struct GNUNET_TRANSPORT_ATS_Information *atsi)
 276 {
 277   /* TODo: size check */
 278   struct dns_pkt *dns = (struct dns_pkt *) (message + 1);
 279
 280   /* They sent us a packet we were not waiting for */
 281   if (remote_pending[dns->s.id] == NULL
 282       || remote_pending[dns->s.id]->tunnel != tunnel)
 283     return GNUNET_SYSERR;
 284   if (query_states[dns->s.id].valid != GNUNET_YES)
 285     return GNUNET_SYSERR;
 286   query_states[dns->s.id].valid = GNUNET_NO;
 287
 288   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 */
 289     + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */
 290
 291   struct answer_packet_list *answer =
 292     GNUNET_malloc (len + 2 * sizeof (struct answer_packet_list *));
 293   memset (answer, 0, len + 2 * sizeof (struct answer_packet_list *));
 294
 295   answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 296   answer->pkt.hdr.size = htons (len);
 297   answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE;
 298
 299   struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 300
 301   if (ntohs(pdns->s.ancount) < 1)
 302     {
 303       free_parsed_dns_packet(pdns);
 304       return GNUNET_OK;
 305     }
 306
 307   answer->pkt.addrsize = pdns->answers[0]->data_len;
 308   memcpy(answer->pkt.addr, pdns->answers[0]->data, ntohs(pdns->answers[0]->data_len));
 309
 310   answer->pkt.from = query_states[dns->s.id].remote_ip;
 311
 312   answer->pkt.to = query_states[dns->s.id].local_ip;
 313   answer->pkt.dst_port = query_states[dns->s.id].local_port;
 314
 315   struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data;
 316
 317   dpkt->s.id = dns->s.id;
 318   dpkt->s.aa = 1;
 319   dpkt->s.qr = 1;
 320   dpkt->s.ra = 1;
 321   dpkt->s.qdcount = htons (1);
 322   dpkt->s.ancount = htons (1);
 323
 324   memcpy (dpkt->data, query_states[dns->s.id].name,
 325           query_states[dns->s.id].namelen);
 326   GNUNET_free (query_states[dns->s.id].name);
 327
 328   struct dns_query_line *dque =
 329     (struct dns_query_line *) (dpkt->data +
 330                                (query_states[dns->s.id].namelen));
 331   dque->type = htons (28);      /* AAAA */
 332   dque->class = htons (1);      /* IN */
 333
 334   char *anname =
 335     (char *) (dpkt->data + (query_states[dns->s.id].namelen) +
 336               sizeof (struct dns_query_line));
 337   memcpy (anname, "\xc0\x0c", 2);
 338
 339   struct dns_record_line *drec_data =
 340     (struct dns_record_line *) (dpkt->data +
 341                                 (query_states[dns->s.id].namelen) +
 342                                 sizeof (struct dns_query_line) + 2);
 343   drec_data->type = htons (28); /* AAAA */
 344   drec_data->class = htons (1); /* IN */
 345
 346   drec_data->ttl = pdns->answers[0]->ttl;
 347   drec_data->data_len = htons (16);
 348
 349   /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 350    * filled in by the daemon-vpn */
 351   answer->pkt.addroffset =
 352     htons ((unsigned short) ((unsigned long) (&drec_data->data) -
 353                              (unsigned long) (&answer->pkt)));
 354
 355   GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer);
 356
 357   GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client,
 358                                        len,
 359                                        GNUNET_TIME_UNIT_FOREVER_REL,
 360                                        &send_answer,
 361                                        query_states[dns->s.id].client);
 362
 363   free_parsed_dns_packet(pdns);
 364   return GNUNET_OK;
 365 }
 366
 367
 368 static void
 369 send_rev_query(void * cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 370     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 371       return;
 372
 373     struct dns_pkt_parsed* pdns = (struct dns_pkt_parsed*) cls;
 374
 375     unsigned short id = pdns->s.id;
 376
 377     free_parsed_dns_packet(pdns);
 378
 379     if (query_states[id].valid != GNUNET_YES) return;
 380     query_states[id].valid = GNUNET_NO;
 381
 382     GNUNET_assert(query_states[id].namelen == 74);
 383
 384     size_t len = sizeof(struct answer_packet) - 1 \
 385                  + sizeof(struct dns_static) \
 386                  + 74 /* this is the length of a reverse ipv6-lookup */ \
 387                  + sizeof(struct dns_query_line) \
 388                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 389                  + sizeof(struct dns_record_line) - 1 \
 390                  - 2 /* We do not know the lenght of the answer yet*/;
 391
 392     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 393     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 394
 395     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 396     answer->pkt.hdr.size = htons(len);
 397     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV;
 398
 399     answer->pkt.from = query_states[id].remote_ip;
 400
 401     answer->pkt.to = query_states[id].local_ip;
 402     answer->pkt.dst_port = query_states[id].local_port;
 403
 404     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 405
 406     dpkt->s.id = id;
 407     dpkt->s.aa = 1;
 408     dpkt->s.qr = 1;
 409     dpkt->s.ra = 1;
 410     dpkt->s.qdcount = htons(1);
 411     dpkt->s.ancount = htons(1);
 412
 413     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 414     GNUNET_free(query_states[id].name);
 415
 416     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 417     dque->type = htons(12); /* PTR */
 418     dque->class = htons(1); /* IN */
 419
 420     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 421     memcpy(anname, "\xc0\x0c", 2);
 422
 423     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 424     drec_data->type = htons(12); /* AAAA */
 425     drec_data->class = htons(1); /* IN */
 426     /* FIXME: read the TTL from block:
 427      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 428      *
 429      * But how to get the seconds out of this?
 430      */
 431     drec_data->ttl = htonl(3600);
 432
 433     /* Calculate at which offset in the packet the length of the name and the
 434      * name, it is filled in by the daemon-vpn */
 435     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data_len)-(unsigned long)(&answer->pkt)));
 436
 437     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 438
 439     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 440                                         len,
 441                                         GNUNET_TIME_UNIT_FOREVER_REL,
 442                                         &send_answer,
 443                                         query_states[id].client);
 444 }
 445
 446 /**
 447  * Receive a block from the dht.
 448  */
 449 static void
 450 receive_dht(void *cls,
 451             struct GNUNET_TIME_Absolute exp,
 452             const GNUNET_HashCode *key,
 453             const struct GNUNET_PeerIdentity *const *get_path,
 454             const struct GNUNET_PeerIdentity *const *put_path,
 455             enum GNUNET_BLOCK_Type type,
 456             size_t size,
 457             const void *data) {
 458
 459     unsigned short id = ((struct receive_dht_cls*)cls)->id;
 460     struct GNUNET_DHT_GetHandle* handle = ((struct receive_dht_cls*)cls)->handle;
 461     GNUNET_free(cls);
 462
 463     GNUNET_assert(type == GNUNET_BLOCK_TYPE_DNS);
 464
 465     /* If no query with this id is pending, ignore the block */
 466     if (query_states[id].valid != GNUNET_YES) return;
 467     query_states[id].valid = GNUNET_NO;
 468
 469     const struct GNUNET_DNS_Record* rec = data;
 470     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 471                "Got block of size %d, peer: %08x, desc: %08x\n",
 472                size,
 473                *((unsigned int*)&rec->peer),
 474                *((unsigned int*)&rec->service_descriptor));
 475
 476     size_t len = sizeof(struct answer_packet) - 1 \
 477                  + sizeof(struct dns_static) \
 478                  + query_states[id].namelen \
 479                  + sizeof(struct dns_query_line) \
 480                  + 2 /* To hold the pointer (as defined in RFC1035) to the name */ \
 481                  + sizeof(struct dns_record_line) - 1 \
 482                  + 16; /* To hold the IPv6-Address */
 483
 484     struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 485     memset(answer, 0, len + 2*sizeof(struct answer_packet_list*));
 486
 487     answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 488     answer->pkt.hdr.size = htons(len);
 489     answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE;
 490
 491     GNUNET_CRYPTO_hash(&rec->peer,
 492                        sizeof(struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 493                        &answer->pkt.service_descr.peer);
 494
 495     memcpy(&answer->pkt.service_descr.service_descriptor,
 496            &rec->service_descriptor,
 497            sizeof(GNUNET_HashCode));
 498     memcpy(&answer->pkt.service_descr.service_type,
 499            &rec->service_type,
 500            sizeof(answer->pkt.service_descr.service_type));
 501     memcpy(&answer->pkt.service_descr.ports, &rec->ports, sizeof(answer->pkt.service_descr.ports));
 502
 503     answer->pkt.from = query_states[id].remote_ip;
 504
 505     answer->pkt.to = query_states[id].local_ip;
 506     answer->pkt.dst_port = query_states[id].local_port;
 507
 508     struct dns_pkt *dpkt = (struct dns_pkt*)answer->pkt.data;
 509
 510     dpkt->s.id = id;
 511     dpkt->s.aa = 1;
 512     dpkt->s.qr = 1;
 513     dpkt->s.ra = 1;
 514     dpkt->s.qdcount = htons(1);
 515     dpkt->s.ancount = htons(1);
 516
 517     memcpy(dpkt->data, query_states[id].name, query_states[id].namelen);
 518     GNUNET_free(query_states[id].name);
 519
 520     struct dns_query_line* dque = (struct dns_query_line*)(dpkt->data+(query_states[id].namelen));
 521     dque->type = htons(28); /* AAAA */
 522     dque->class = htons(1); /* IN */
 523
 524     char* anname = (char*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line));
 525     memcpy(anname, "\xc0\x0c", 2);
 526
 527     struct dns_record_line *drec_data = (struct dns_record_line*)(dpkt->data+(query_states[id].namelen)+sizeof(struct dns_query_line)+2);
 528     drec_data->type = htons(28); /* AAAA */
 529     drec_data->class = htons(1); /* IN */
 530
 531     /* FIXME: read the TTL from block:
 532      * GNUNET_TIME_absolute_get_remaining(rec->expiration_time)
 533      *
 534      * But how to get the seconds out of this?
 535      */
 536     drec_data->ttl = htonl(3600);
 537     drec_data->data_len = htons(16);
 538
 539     /* Calculate at which offset in the packet the IPv6-Address belongs, it is
 540      * filled in by the daemon-vpn */
 541     answer->pkt.addroffset = htons((unsigned short)((unsigned long)(&drec_data->data)-(unsigned long)(&answer->pkt)));
 542
 543     GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 544
 545     GNUNET_SERVER_notify_transmit_ready(query_states[id].client,
 546                                         len,
 547                                         GNUNET_TIME_UNIT_FOREVER_REL,
 548                                         &send_answer,
 549                                         query_states[id].client);
 550
 551     GNUNET_DHT_get_stop(handle);
 552 }
 553
 554 /**
 555  * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS
 556  */
 557 static void
 558 rehijack(void *cls,
 559          struct GNUNET_SERVER_Client *client,
 560          const struct GNUNET_MessageHeader *message) {
 561     unhijack(dnsoutport);
 562     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 563
 564     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 565 }
 566
 567 /**
 568  * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket
 569  */
 570 static void
 571 receive_query(void *cls,
 572               struct GNUNET_SERVER_Client *client,
 573               const struct GNUNET_MessageHeader *message) {
 574     struct query_packet* pkt = (struct query_packet*)message;
 575     struct dns_pkt* dns = (struct dns_pkt*)pkt->data;
 576     struct dns_pkt_parsed* pdns = parse_dns_packet(dns);
 577
 578     query_states[dns->s.id].valid = GNUNET_YES;
 579     query_states[dns->s.id].client = client;
 580     query_states[dns->s.id].local_ip = pkt->orig_from;
 581     query_states[dns->s.id].local_port = pkt->src_port;
 582     query_states[dns->s.id].remote_ip = pkt->orig_to;
 583     query_states[dns->s.id].namelen = strlen((char*)dns->data) + 1;
 584     query_states[dns->s.id].name = GNUNET_malloc(query_states[dns->s.id].namelen);
 585     memcpy(query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen);
 586
 587     /* The query is for a .gnunet-address */
 588     if (pdns->queries[0]->namelen > 9 &&
 589         0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - 9), ".gnunet.", 9))
 590       {
 591         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n");
 592         GNUNET_HashCode key;
 593         GNUNET_CRYPTO_hash(pdns->queries[0]->name, pdns->queries[0]->namelen, &key);
 594
 595         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 596                    "Getting with key %08x, len is %d\n",
 597                    *((unsigned int*)&key),
 598                    pdns->queries[0]->namelen);
 599
 600         struct receive_dht_cls* cls = GNUNET_malloc(sizeof(struct receive_dht_cls));
 601         cls->id = dns->s.id;
 602
 603         cls->handle = GNUNET_DHT_get_start(dht,
 604                                            GNUNET_TIME_UNIT_MINUTES,
 605                                            GNUNET_BLOCK_TYPE_DNS,
 606                                            &key,
 607                                            DEFAULT_GET_REPLICATION,
 608                                            GNUNET_DHT_RO_NONE,
 609                                            NULL,
 610                                            0,
 611                                            NULL,
 612                                            0,
 613                                            receive_dht,
 614                                            cls);
 615
 616         goto outfree;
 617       }
 618
 619     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen);
 620
 621     /* This is a PTR-Query. Check if it is for "our" network */
 622     if (htons(pdns->queries[0]->qtype) == 12 &&
 623         74 == pdns->queries[0]->namelen)
 624       {
 625         char* ipv6addr;
 626         char ipv6[16];
 627         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.";
 628         unsigned int i;
 629         unsigned long long ipv6prefix;
 630         unsigned int comparelen;
 631
 632         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 633         inet_pton (AF_INET6, ipv6addr, ipv6);
 634         GNUNET_free(ipv6addr);
 635
 636         GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 637         GNUNET_assert(ipv6prefix < 127);
 638         ipv6prefix = (ipv6prefix + 7)/8;
 639
 640         for (i = ipv6prefix; i < 16; i++)
 641           ipv6[i] = 0;
 642
 643         for (i = 0; i < 16; i++)
 644           {
 645             unsigned char c1 = ipv6[i] >> 4;
 646             unsigned char c2 = ipv6[i] & 0xf;
 647
 648             if (c1 <= 9)
 649               ipv6rev[62-(4*i)] = c1 + '0';
 650             else
 651               ipv6rev[62-(4*i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */
 652
 653             if (c2 <= 9)
 654               ipv6rev[62-((4*i)+2)] = c2 + '0';
 655             else
 656               ipv6rev[62-((4*i)+2)] = c2 + 87;
 657           }
 658         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev);
 659         comparelen = 10 + 4*ipv6prefix;
 660         if(0 == strncmp(pdns->queries[0]->name+(pdns->queries[0]->namelen - comparelen),
 661                         ipv6rev + (74 - comparelen),
 662                         comparelen))
 663           {
 664             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n");
 665
 666             GNUNET_SCHEDULER_add_now(send_rev_query, pdns);
 667
 668             goto out;
 669           }
 670       }
 671
 672     char* virt_dns;
 673     int virt_dns_bytes;
 674     if (GNUNET_SYSERR ==
 675         GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS",
 676                                                &virt_dns))
 677       {
 678         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 679                     "No entry 'VIRTDNS' in configuration!\n");
 680         exit (1);
 681       }
 682
 683     if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes))
 684       {
 685         GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 686                     "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns);
 687         exit(1);
 688       }
 689
 690     GNUNET_free(virt_dns);
 691
 692     if (virt_dns_bytes == pkt->orig_to)
 693       {
 694         /* This is a packet that was sent directly to the virtual dns-server
 695          *
 696          * This means we have to send this query over gnunet
 697          */
 698
 699         size_t size = sizeof(struct GNUNET_MESH_Tunnel*) + sizeof(struct GNUNET_MessageHeader) + (ntohs(message->size) - sizeof(struct query_packet) + 1);
 700         struct tunnel_cls *cls_ =  GNUNET_malloc(size);
 701         cls_->hdr.size = size - sizeof(struct GNUNET_MESH_Tunnel*);
 702
 703         cls_->hdr.type = ntohs(GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS);
 704
 705         memcpy(&cls_->dns, dns, cls_->hdr.size);
 706         GNUNET_SCHEDULER_add_now(send_mesh_query, cls_);
 707
 708         goto out;
 709       }
 710
 711
 712     /* The query should be sent to the network */
 713
 714     struct sockaddr_in dest;
 715     memset(&dest, 0, sizeof dest);
 716     dest.sin_port = htons(53);
 717     dest.sin_addr.s_addr = pkt->orig_to;
 718
 719     GNUNET_NETWORK_socket_sendto(dnsout,
 720                                  dns,
 721                                  ntohs(pkt->hdr.size) - sizeof(struct query_packet) + 1,
 722                                  (struct sockaddr*) &dest,
 723                                  sizeof dest);
 724
 725 outfree:
 726     free_parsed_dns_packet(pdns);
 727     pdns = NULL;
 728 out:
 729     GNUNET_SERVER_receive_done(client, GNUNET_OK);
 730 }
 731
 732 static void read_response (void *cls,
 733                            const struct GNUNET_SCHEDULER_TaskContext *tc);
 734
 735 static void
 736 open_port ()
 737 {
 738   struct sockaddr_in addr;
 739
 740   dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
 741   if (dnsout == NULL)
 742     return;
 743   memset (&addr, 0, sizeof (struct sockaddr_in));
 744
 745   int err = GNUNET_NETWORK_socket_bind (dnsout,
 746                                         (struct sockaddr *) &addr,
 747                                         sizeof (struct sockaddr_in));
 748
 749   if (err != GNUNET_YES)
 750     {
 751       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
 752                   "Could not bind a port, exiting\n");
 753       return;
 754     }
 755
 756   /* Read the port we bound to */
 757   socklen_t addrlen = sizeof (struct sockaddr_in);
 758   err = getsockname (GNUNET_NETWORK_get_fd (dnsout),
 759                      (struct sockaddr *) &addr, &addrlen);
 760
 761   dnsoutport = htons (addr.sin_port);
 762
 763   GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout,
 764                                  &read_response, NULL);
 765 }
 766
 767 /**
 768  * Read a response-packet of the UDP-Socket
 769  */
 770 static void
 771 read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 772     struct sockaddr_in addr;
 773     socklen_t addrlen = sizeof (addr);
 774     int r;
 775     int len;
 776
 777     if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)
 778       return;
 779
 780     memset(&addr, 0, sizeof addr);
 781
 782 #ifndef MINGW
 783     if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout),
 784                     FIONREAD, &len))
 785       {
 786         unhijack(dnsoutport);
 787         open_port();
 788         GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 789         return;
 790       }
 791 #else
 792     /* port the code above? */
 793     len = 65536;
 794 #endif
 795     {
 796       unsigned char buf[len];
 797       struct dns_pkt* dns = (struct dns_pkt*)buf;
 798
 799       r = GNUNET_NETWORK_socket_recvfrom (dnsout,
 800                                           buf,
 801                                           sizeof (buf),
 802                                           (struct sockaddr*)&addr,
 803                                           &addrlen);
 804
 805       if (r < 0)
 806         {
 807           unhijack(dnsoutport);
 808           open_port();
 809           GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS, hijack, NULL);
 810           return;
 811         }
 812
 813       if (query_states[dns->s.id].valid == GNUNET_YES)
 814         {
 815           query_states[dns->s.id].valid = GNUNET_NO;
 816
 817           size_t len = sizeof(struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */
 818           struct answer_packet_list* answer = GNUNET_malloc(len + 2*sizeof(struct answer_packet_list*));
 819           answer->pkt.hdr.type = htons(GNUNET_MESSAGE_TYPE_LOCAL_RESPONSE_DNS);
 820           answer->pkt.hdr.size = htons(len);
 821           answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 822           answer->pkt.from = addr.sin_addr.s_addr;
 823           answer->pkt.to = query_states[dns->s.id].local_ip;
 824           answer->pkt.dst_port = query_states[dns->s.id].local_port;
 825           memcpy(answer->pkt.data, buf, r);
 826
 827           GNUNET_CONTAINER_DLL_insert_after(head, tail, tail, answer);
 828
 829           GNUNET_SERVER_notify_transmit_ready(query_states[dns->s.id].client,
 830                                               len,
 831                                               GNUNET_TIME_UNIT_FOREVER_REL,
 832                                               &send_answer,
 833                                               query_states[dns->s.id].client);
 834         }
 835     }
 836     GNUNET_SCHEDULER_add_read_net(GNUNET_TIME_UNIT_FOREVER_REL,
 837                                   dnsout,
 838                                   &read_response,
 839                                   NULL);
 840 }
 841
 842
 843 /**
 844  * Task run during shutdown.
 845  *
 846  * @param cls unused
 847  * @param tc unused
 848  */
 849 static void
 850 cleanup_task (void *cls,
 851               const struct GNUNET_SCHEDULER_TaskContext *tc)
 852 {
 853   unhijack(dnsoutport);
 854   GNUNET_DHT_disconnect(dht);
 855 }
 856
 857 /**
 858  * @brief Create a port-map from udp and tcp redirects
 859  *
 860  * @param udp_redirects
 861  * @param tcp_redirects
 862  *
 863  * @return
 864  */
 865 uint64_t
 866 get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects)
 867 {
 868   uint64_t ret = 0;
 869   char* cpy, *hostname, *redirect;
 870   int local_port, count = 0;
 871
 872   if (NULL != udp_redirects)
 873     {
 874       cpy = GNUNET_strdup (udp_redirects);
 875       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 876         {
 877           if (NULL == (hostname = strstr (redirect, ":")))
 878             {
 879               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 880               continue;
 881             }
 882           hostname[0] = '\0';
 883           local_port = atoi (redirect);
 884           if (!((local_port > 0) && (local_port < 65536)))
 885             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 886
 887           ret |= (0xFFFF & htons(local_port));
 888           ret <<= 16;
 889           count ++;
 890
 891           if(count > 4)
 892             {
 893               ret = 0;
 894               goto out;
 895             }
 896         }
 897       GNUNET_free(cpy);
 898       cpy = NULL;
 899     }
 900
 901   if (NULL != tcp_redirects)
 902     {
 903       cpy = GNUNET_strdup (tcp_redirects);
 904       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " "))
 905         {
 906           if (NULL == (hostname = strstr (redirect, ":")))
 907             {
 908               GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect);
 909               continue;
 910             }
 911           hostname[0] = '\0';
 912           local_port = atoi (redirect);
 913           if (!((local_port > 0) && (local_port < 65536)))
 914             GNUNET_log(GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect);
 915
 916           ret |= (0xFFFF & htons(local_port));
 917           ret <<= 16;
 918           count ++;
 919
 920           if(count > 4)
 921             {
 922               ret = 0;
 923               goto out;
 924             }
 925         }
 926       GNUNET_free(cpy);
 927       cpy = NULL;
 928     }
 929
 930 out:
 931   if (NULL != cpy)
 932     GNUNET_free(cpy);
 933   return ret;
 934 }
 935
 936 void
 937 publish_name (const char *name, uint64_t ports, uint32_t service_type,
 938               struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key)
 939 {
 940   size_t size = sizeof (struct GNUNET_DNS_Record);
 941   struct GNUNET_DNS_Record data;
 942   memset (&data, 0, size);
 943
 944   data.purpose.size =
 945     htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature));
 946   data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD;
 947
 948   GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor);
 949   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n",
 950               *((unsigned long long *) &data.service_descriptor));
 951
 952   data.service_type = service_type;
 953   data.ports = ports;
 954
 955   GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer);
 956
 957   data.expiration_time =
 958     GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_HOURS, 2));
 959
 960   /* Sign the block */
 961   if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key,
 962                                            &data.purpose, &data.signature))
 963     {
 964       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n");
 965       return;
 966     }
 967
 968   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 969               "Putting with key %08x, size = %d\n",
 970               *((unsigned int *) &data.service_descriptor), size);
 971
 972   GNUNET_DHT_put (dht,
 973                   &data.service_descriptor,
 974                   DEFAULT_PUT_REPLICATION,
 975                   GNUNET_DHT_RO_NONE,
 976                   GNUNET_BLOCK_TYPE_DNS,
 977                   size,
 978                   (char *) &data,
 979                   GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS),
 980                   GNUNET_TIME_UNIT_MINUTES, NULL, NULL);
 981 }
 982
 983 /**
 984  * @brief Publishes the record defined by the section section
 985  *
 986  * @param cls closure
 987  * @param section the current section
 988  */
 989 void
 990 publish_iterate (void *cls, const char *section)
 991 {
 992   char *udp_redirects, *tcp_redirects, *alternative_names, *alternative_name,
 993     *keyfile;
 994
 995   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
 996                                          "UDP_REDIRECTS", &udp_redirects);
 997   GNUNET_CONFIGURATION_get_value_string (servicecfg, section, "TCP_REDIRECTS",
 998                                          &tcp_redirects);
 999
1000   if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD",
1001                                                             "HOSTKEY",
1002                                                             &keyfile))
1003     {
1004       GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n");
1005       if (keyfile != NULL)
1006         GNUNET_free (keyfile);
1007       return;
1008     }
1009
1010   struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key =
1011     GNUNET_CRYPTO_rsa_key_create_from_file (keyfile);
1012   GNUNET_free (keyfile);
1013   GNUNET_assert (my_private_key != NULL);
1014
1015   uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects);
1016   uint32_t service_type = 0;
1017
1018   if (NULL != udp_redirects)
1019     service_type = GNUNET_DNS_SERVICE_TYPE_UDP;
1020
1021   if (NULL != tcp_redirects)
1022     service_type |= GNUNET_DNS_SERVICE_TYPE_TCP;
1023
1024   service_type = htonl (service_type);
1025
1026
1027   publish_name (section, ports, service_type, my_private_key);
1028
1029   GNUNET_CONFIGURATION_get_value_string (servicecfg, section,
1030                                          "ALTERNATIVE_NAMES",
1031                                          &alternative_names);
1032   for (alternative_name = strtok (alternative_names, " ");
1033        alternative_name != NULL; alternative_name = strtok (NULL, " "))
1034     {
1035       char *altname =
1036         alloca (strlen (alternative_name) + strlen (section) + 1 + 1);
1037       strcpy (altname, alternative_name);
1038       strcpy (altname + strlen (alternative_name) + 1, section);
1039       altname[strlen (alternative_name)] = '.';
1040
1041       publish_name (altname, ports, service_type, my_private_key);
1042     }
1043
1044   GNUNET_free_non_null(alternative_names);
1045   GNUNET_CRYPTO_rsa_key_free (my_private_key);
1046   GNUNET_free_non_null (udp_redirects);
1047   GNUNET_free_non_null (tcp_redirects);
1048 }
1049
1050 /**
1051  * Publish a DNS-record in the DHT. This is up to now just for testing.
1052  */
1053 static void
1054 publish_names (void *cls,
1055                const struct GNUNET_SCHEDULER_TaskContext *tc) {
1056     char *services;
1057     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
1058       return;
1059
1060     if (NULL != servicecfg)
1061       GNUNET_CONFIGURATION_destroy(servicecfg);
1062
1063     GNUNET_CONFIGURATION_get_value_filename(cfg, "dns", "SERVICES", &services);
1064
1065     servicecfg = GNUNET_CONFIGURATION_create();
1066     if (GNUNET_OK == GNUNET_CONFIGURATION_parse(servicecfg, services))
1067       {
1068         GNUNET_log(GNUNET_ERROR_TYPE_INFO, "Parsing services %s\n", services);
1069         GNUNET_CONFIGURATION_iterate_sections(servicecfg, publish_iterate, NULL);
1070       }
1071     if (NULL != services)
1072       GNUNET_free(services);
1073
1074     GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS,
1075                                   publish_names,
1076                                   NULL);
1077 }
1078
1079 /**
1080  * @param cls closure
1081  * @param server the initialized server
1082  * @param cfg_ configuration to use
1083  */
1084 static void
1085 run (void *cls,
1086      struct GNUNET_SERVER_Handle *server,
1087      const struct GNUNET_CONFIGURATION_Handle *cfg_)
1088 {
1089   static const struct GNUNET_SERVER_MessageHandler handlers[] = {
1090     /* callback, cls, type, size */
1091     {&receive_query, NULL, GNUNET_MESSAGE_TYPE_LOCAL_QUERY_DNS, 0},
1092     {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK,
1093      sizeof (struct GNUNET_MessageHeader)},
1094     {NULL, NULL, 0, 0}
1095   };
1096
1097   static struct GNUNET_MESH_MessageHandler *mesh_handlers;
1098
1099   if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno(cfg_, "dns", "PROVIDE_EXIT"))
1100     mesh_handlers = (struct GNUNET_MESH_MessageHandler[]) {
1101           {receive_mesh_query, GNUNET_MESSAGE_TYPE_REMOTE_QUERY_DNS, 0},
1102           {NULL, 0, 0}
1103     };
1104   else
1105     mesh_handlers = (struct GNUNET_MESH_MessageHandler[]) {
1106           {receive_mesh_answer, GNUNET_MESSAGE_TYPE_REMOTE_ANSWER_DNS, 0},
1107           {NULL, 0, 0}
1108     };
1109
1110   const static GNUNET_MESH_ApplicationType apptypes[] =
1111     { GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER,
1112     GNUNET_APPLICATION_TYPE_END
1113   };
1114
1115   mesh_handle = GNUNET_MESH_connect (cfg_, NULL, NULL, mesh_handlers, apptypes);
1116
1117   cfg = cfg_;
1118
1119   unsigned int i;
1120   for (i = 0; i < 65536; i++)
1121     {
1122       query_states[i].valid = GNUNET_NO;
1123     }
1124
1125   dht = GNUNET_DHT_connect (cfg, 1024);
1126
1127   open_port ();
1128
1129   GNUNET_SCHEDULER_add_now (publish_names, NULL);
1130
1131   GNUNET_SERVER_add_handlers (server, handlers);
1132   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
1133                                 &cleanup_task, cls);
1134 }
1135
1136 /**
1137  * The main function for the dns service.
1138  *
1139  * @param argc number of arguments from the command line
1140  * @param argv command line arguments
1141  * @return 0 ok, 1 on error
1142  */
1143 int
1144 main (int argc, char *const *argv)
1145 {
1146   return (GNUNET_OK ==
1147           GNUNET_SERVICE_run (argc,
1148                               argv,
1149                               "dns",
1150                               GNUNET_SERVICE_OPTION_NONE,
1151                               &run, NULL)) ? 0 : 1;
1152 }