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