src/vpn/gnunet-daemon-vpn.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2010 Christian Grothoff
   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-daemon-vpn.c
  23  * @brief
  24  * @author Philipp Toelke
  25  */
  26 #include "platform.h"
  27 #include "gnunet_getopt_lib.h"
  28 #include "gnunet_program_lib.h"
  29 #include "gnunet-vpn-packet.h"
  30 #include "gnunet_common.h"
  31 #include "gnunet_protocols.h"
  32 #include "gnunet_applications.h"
  33 #include <gnunet_mesh_service.h>
  34 #include "gnunet_client_lib.h"
  35 #include "gnunet_container_lib.h"
  36 #include "gnunet_constants.h"
  37 #include <block_dns.h>
  38 #include "gnunet-daemon-vpn-helper.h"
  39 #include "gnunet-daemon-vpn-dns.h"
  40 #include "gnunet-daemon-vpn.h"
  41 #include "gnunet-vpn-checksum.h"
  42
  43 const struct GNUNET_CONFIGURATION_Handle *cfg;
  44 struct GNUNET_MESH_Handle *mesh_handle;
  45 struct GNUNET_CONTAINER_MultiHashMap* hashmap;
  46 static struct GNUNET_CONTAINER_Heap *heap;
  47
  48 struct tunnel_notify_queue
  49 {
  50   struct tunnel_notify_queue* next;
  51   struct tunnel_notify_queue* prev;
  52   size_t len;
  53   void* cls;
  54 };
  55
  56 /**
  57  * If there are at least this many address-mappings, old ones will be removed
  58  */
  59 static long long unsigned int max_mappings = 200;
  60
  61 /**
  62  * Final status code.
  63  */
  64 static int ret;
  65
  66 /**
  67  * This hashmap contains the mapping from peer, service-descriptor,
  68  * source-port and destination-port to a socket
  69  */
  70 static struct GNUNET_CONTAINER_MultiHashMap *udp_connections;
  71
  72 GNUNET_SCHEDULER_TaskIdentifier conn_task;
  73
  74 GNUNET_SCHEDULER_TaskIdentifier shs_task;
  75
  76 /**
  77  * Function scheduled as very last function, cleans up after us
  78  *{{{
  79  */
  80 static void
  81 cleanup(void* cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
  82     GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
  83
  84     /* stop the helper */
  85     cleanup_helper(helper_handle);
  86
  87     /* close the connection to the service-dns */
  88     if (dns_connection != NULL)
  89       {
  90         GNUNET_CLIENT_disconnect (dns_connection, GNUNET_NO);
  91         dns_connection = NULL;
  92       }
  93
  94     if (mesh_handle != NULL)
  95       {
  96         GNUNET_MESH_disconnect(mesh_handle);
  97         mesh_handle = NULL;
  98       }
  99     if (GNUNET_SCHEDULER_NO_TASK != shs_task)
 100       {
 101         GNUNET_SCHEDULER_cancel (shs_task);
 102         shs_task = GNUNET_SCHEDULER_NO_TASK;
 103       }
 104     if (GNUNET_SCHEDULER_NO_TASK != conn_task)
 105       {
 106         GNUNET_SCHEDULER_cancel (conn_task);
 107         conn_task = GNUNET_SCHEDULER_NO_TASK;
 108       }
 109 }
 110 /*}}}*/
 111
 112 /**
 113  * @return the hash of the IP-Address if a mapping exists, NULL otherwise
 114  */
 115 GNUNET_HashCode*
 116 address6_mapping_exists(unsigned char addr[]) {
 117     GNUNET_HashCode* key = GNUNET_malloc(sizeof(GNUNET_HashCode));
 118     unsigned char* k = (unsigned char*)key;
 119     memset(key, 0, sizeof(GNUNET_HashCode));
 120     unsigned int i;
 121     for (i = 0; i < 16; i++)
 122         k[15-i] = addr[i];
 123
 124     if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains(hashmap, key))
 125       return key;
 126     else
 127       {
 128         GNUNET_free(key);
 129         return NULL;
 130       }
 131 }
 132
 133 /**
 134  * @return the hash of the IP-Address if a mapping exists, NULL otherwise
 135  */
 136 GNUNET_HashCode *
 137 address4_mapping_exists (uint32_t addr)
 138 {
 139   GNUNET_HashCode *key = GNUNET_malloc (sizeof (GNUNET_HashCode));
 140   memset (key, 0, sizeof (GNUNET_HashCode));
 141   unsigned char *c = (unsigned char *) &addr;
 142   unsigned char *k = (unsigned char *) key;
 143   unsigned int i;
 144   for (i = 0; i < 4; i++)
 145     k[3 - i] = c[i];
 146
 147   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 148               "a4_m_e: getting with key %08x, addr is %08x, %d.%d.%d.%d\n",
 149               *((uint32_t *) (key)), addr, c[0], c[1], c[2], c[3]);
 150
 151   if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (hashmap, key))
 152     return key;
 153   else
 154     {
 155       GNUNET_free (key);
 156       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Mapping not found!\n");
 157       return NULL;
 158     }
 159 }
 160
 161 static void
 162 collect_mappings(void* cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext* tc) {
 163     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 164       return;
 165
 166     struct map_entry* me = GNUNET_CONTAINER_heap_remove_root(heap);
 167
 168     /* This is free()ed memory! */
 169     me->heap_node = NULL;
 170
 171     /* FIXME! GNUNET_MESH_close_tunnel(me->tunnel); */
 172
 173     GNUNET_CONTAINER_multihashmap_remove(hashmap, &me->hash, me);
 174
 175     GNUNET_free(me);
 176 }
 177
 178 void
 179 send_icmp4_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 180     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 181       return;
 182
 183     struct ip_icmp* request = cls;
 184
 185     struct ip_icmp* response = alloca(ntohs(request->shdr.size));
 186     GNUNET_assert(response != NULL);
 187     memset(response, 0, ntohs(request->shdr.size));
 188
 189     response->shdr.size = request->shdr.size;
 190     response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 191
 192     response->tun.flags = 0;
 193     response->tun.type = htons(0x0800);
 194
 195     response->ip_hdr.hdr_lngth = 5;
 196     response->ip_hdr.version = 4;
 197     response->ip_hdr.proto = 0x01;
 198     response->ip_hdr.dadr = request->ip_hdr.sadr;
 199     response->ip_hdr.sadr = request->ip_hdr.dadr;
 200     response->ip_hdr.tot_lngth = request->ip_hdr.tot_lngth;
 201
 202     response->ip_hdr.chks = calculate_ip_checksum((uint16_t*)&response->ip_hdr, 20);
 203
 204     response->icmp_hdr.code = 0;
 205     response->icmp_hdr.type = 0x0;
 206
 207     /* Magic, more Magic! */
 208     response->icmp_hdr.chks = request->icmp_hdr.chks + 0x8;
 209
 210     /* Copy the rest of the packet */
 211     memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip_icmp));
 212
 213     write_to_helper(response, ntohs(response->shdr.size));
 214
 215     GNUNET_free(request);
 216 }
 217
 218 void
 219 send_icmp6_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 220     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 221       return;
 222
 223     struct ip6_icmp* request = cls;
 224
 225     struct ip6_icmp* response = alloca(ntohs(request->shdr.size));
 226     GNUNET_assert(response != NULL);
 227     memset(response, 0, ntohs(request->shdr.size));
 228
 229     response->shdr.size = request->shdr.size;
 230     response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 231
 232     response->tun.flags = 0;
 233     response->tun.type = htons(0x86dd);
 234
 235     response->ip6_hdr.hoplmt = 255;
 236     response->ip6_hdr.paylgth = request->ip6_hdr.paylgth;
 237     response->ip6_hdr.nxthdr = 0x3a;
 238     response->ip6_hdr.version = 6;
 239     memcpy(&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16);
 240     memcpy(&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16);
 241
 242     response->icmp_hdr.code = 0;
 243     response->icmp_hdr.type = 0x81;
 244
 245     /* Magic, more Magic! */
 246     response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1;
 247
 248     /* Copy the rest of the packet */
 249     memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip6_icmp));
 250
 251     write_to_helper(response, ntohs(response->shdr.size));
 252
 253     GNUNET_free(request);
 254 }
 255
 256 /**
 257  * cls is the pointer to a GNUNET_MessageHeader that is
 258  * followed by the service-descriptor and the packet that should be sent;
 259  */
 260 static size_t
 261 send_pkt_to_peer_notify_callback (void *cls, size_t size, void *buf)
 262 {
 263   struct GNUNET_MESH_Tunnel **tunnel = cls;
 264   GNUNET_MESH_tunnel_set_data(*tunnel, NULL);
 265   struct GNUNET_MessageHeader *hdr =
 266     (struct GNUNET_MessageHeader *) (tunnel + 1);
 267   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "send_pkt_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size);
 268   GNUNET_assert (size >= ntohs (hdr->size));
 269   memcpy (buf, hdr, ntohs (hdr->size));
 270   size = ntohs(hdr->size);
 271   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
 272
 273   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 274     {
 275       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 276       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 277       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 278
 279       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 280
 281       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 282       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 283
 284       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 285                                                                                  GNUNET_NO,
 286                                                                                  42,
 287                                                                                  GNUNET_TIME_relative_divide
 288                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 289                                                                                  (const struct GNUNET_PeerIdentity *)
 290                                                                                  NULL, element->len,
 291                                                                                  send_pkt_to_peer_notify_callback, element->cls);
 292       /* save the handle */
 293       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 294       GNUNET_free(element);
 295     }
 296   GNUNET_free (cls);
 297
 298   return size;
 299 }
 300
 301 unsigned int
 302 port_in_ports (uint64_t ports, uint16_t port)
 303 {
 304   uint16_t *ps = (uint16_t *) & ports;
 305   return ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port;
 306 }
 307
 308 void
 309 send_pkt_to_peer (void *cls,
 310                   const struct GNUNET_PeerIdentity *peer,
 311                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 312 {
 313   /* peer == NULL means that all peers in this request are connected */
 314   if (peer == NULL) return;
 315   struct GNUNET_MESH_Tunnel **tunnel = cls;
 316   struct GNUNET_MessageHeader *hdr =
 317     (struct GNUNET_MessageHeader *) (tunnel + 1);
 318
 319   GNUNET_assert(NULL != tunnel);
 320   GNUNET_assert(NULL != *tunnel);
 321
 322   if (NULL == GNUNET_MESH_tunnel_get_data(*tunnel))
 323     {
 324       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 325                                                                                  GNUNET_NO,
 326                                                                                  42,
 327                                                                                  GNUNET_TIME_relative_divide(GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 328                                                                                  (const struct GNUNET_PeerIdentity *)NULL,
 329                                                                                  ntohs(hdr->size),
 330                                                                                  send_pkt_to_peer_notify_callback,
 331                                                                                  cls);
 332       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 333     }
 334   else
 335     {
 336      struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 337      struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 338      struct tunnel_notify_queue* element = GNUNET_malloc(sizeof *element);
 339
 340      element->cls = cls;
 341      element->len = ntohs(hdr->size);
 342
 343      GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 344
 345      GNUNET_MESH_tunnel_set_head(*tunnel, head);
 346      GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 347     }
 348 }
 349
 350 /**
 351  * Create a new Address from an answer-packet
 352  */
 353 void
 354 new_ip6addr(unsigned char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
 355     char* ipv6addr;
 356     unsigned long long ipv6prefix;
 357     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 358     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 359     GNUNET_assert(ipv6prefix < 127);
 360     ipv6prefix = (ipv6prefix + 7)/8;
 361
 362     inet_pton (AF_INET6, ipv6addr, buf);
 363     GNUNET_free(ipv6addr);
 364
 365     int peer_length = 16 - ipv6prefix - 6;
 366     if (peer_length <= 0)
 367       peer_length = 0;
 368
 369     int service_length = 16 - ipv6prefix - peer_length;
 370     if (service_length <= 0)
 371       service_length = 0;
 372
 373     memcpy(buf+ipv6prefix, service_desc, service_length);
 374     memcpy(buf+ipv6prefix+service_length, peer, peer_length);
 375 }
 376 /*}}}*/
 377
 378
 379 /**
 380  * Create a new Address from an answer-packet
 381  */
 382 void
 383 new_ip6addr_remote (unsigned char *buf, unsigned char *addr, char addrlen)
 384 {                               /* {{{ */
 385   char *ipv6addr;
 386   unsigned long long ipv6prefix;
 387   GNUNET_assert (GNUNET_OK ==
 388                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 389                                                         "IPV6ADDR",
 390                                                         &ipv6addr));
 391   GNUNET_assert (GNUNET_OK ==
 392                  GNUNET_CONFIGURATION_get_value_number (cfg, "vpn",
 393                                                         "IPV6PREFIX",
 394                                                         &ipv6prefix));
 395   GNUNET_assert (ipv6prefix < 127);
 396   ipv6prefix = (ipv6prefix + 7) / 8;
 397
 398   inet_pton (AF_INET6, ipv6addr, buf);
 399   GNUNET_free (ipv6addr);
 400
 401   int local_length = 16 - ipv6prefix;
 402
 403   memcpy (buf + ipv6prefix, addr, GNUNET_MIN (addrlen, local_length));
 404 }
 405 /*}}}*/
 406
 407 /**
 408  * Create a new Address from an answer-packet
 409  */
 410 void
 411 new_ip4addr_remote (unsigned char *buf, unsigned char *addr, char addrlen)
 412 {                               /* {{{ */
 413   char *ipv4addr;
 414   char *ipv4mask;
 415   GNUNET_assert (GNUNET_OK ==
 416                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 417                                                         "IPV4ADDR",
 418                                                         &ipv4addr));
 419   GNUNET_assert (GNUNET_OK ==
 420                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 421                                                         "IPV4MASK",
 422                                                         &ipv4mask));
 423   uint32_t mask;
 424   inet_pton (AF_INET, ipv4addr, buf);
 425   int r = inet_pton (AF_INET, ipv4mask, &mask);
 426   mask = htonl(mask);
 427   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "inet_pton: %d; %m; mask: %08x\n", r, mask);
 428
 429   GNUNET_free (ipv4addr);
 430
 431   int c;
 432
 433   if (mask)
 434     {
 435       mask = (mask ^ (mask - 1)) >> 1;
 436       for (c = 0; mask; c++)
 437         {
 438           mask >>= 1;
 439         }
 440     }
 441   else
 442     {
 443       c = CHAR_BIT * sizeof(mask);
 444     }
 445
 446   c = 32-c;
 447   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "The mask %s has %d leading 1s.\n", ipv4mask, c);
 448
 449   GNUNET_free (ipv4mask);
 450
 451   if (c % 8 == 0)
 452     c = c / 8;
 453   else
 454     GNUNET_assert(0);
 455
 456   memcpy (buf + c, addr, GNUNET_MIN (addrlen, 4-c));
 457 }
 458 /*}}}*/
 459
 460 /**
 461  * This gets scheduled with cls pointing to an answer_packet and does everything
 462  * needed in order to send it to the helper.
 463  *
 464  * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
 465  * doing nothing for "real" services.
 466  */
 467 void
 468 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 469     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 470       return;
 471
 472     struct answer_packet* pkt = cls;
 473     struct answer_packet_list* list;
 474
 475     /* This answer is about a .gnunet-service
 476      *
 477      * It contains an almost complete DNS-Response, we have to fill in the ip
 478      * at the offset pkt->addroffset
 479      */
 480     if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
 481       {
 482         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 483
 484         GNUNET_HashCode key;
 485         memset(&key, 0, sizeof(GNUNET_HashCode));
 486
 487         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 488         unsigned char* k = (unsigned char*)&key;
 489         new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
 490         /*
 491          * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
 492          */
 493         unsigned int i;
 494         for (i = 0; i < 16; i++)
 495             k[15-i] = c[i];
 496
 497         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 498
 499         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 500         char* name = (char*)(value +1);
 501
 502         value->namelen = namelen;
 503         memcpy(name, pkt->data+12, namelen);
 504
 505         memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
 506
 507         memset(value->additional_ports, 0, 8192);
 508
 509         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 510
 511         if (GNUNET_NO ==
 512             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 513           {
 514             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 515                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 516
 517             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 518                                                              GNUNET_TIME_absolute_get ().abs_value);
 519             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 520               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 521           }
 522         else
 523           GNUNET_free(value);
 524
 525
 526         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 527
 528         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 529
 530       }
 531     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
 532       {
 533         GNUNET_HashCode key;
 534         memset(&key, 0, sizeof key);
 535         unsigned char* k = (unsigned char*)&key;
 536         unsigned char* s = pkt->data+12;
 537         int i = 0;
 538         /* Whoever designed the reverse IPv6-lookup is batshit insane */
 539         for (i = 0; i < 16; i++)
 540           {
 541             unsigned char c1 = s[(4*i)+1];
 542             unsigned char c2 = s[(4*i)+3];
 543             if (c1 <= '9')
 544               k[i] = c1 - '0';
 545             else
 546               k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
 547             if (c2 <= '9')
 548               k[i] += 16*(c2 - '0');
 549             else
 550               k[i] += 16*(c2 - 87);
 551           }
 552
 553         struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
 554         uint16_t offset = ntohs(pkt->addroffset);
 555
 556         if (map_entry == NULL)
 557           {
 558             GNUNET_free(pkt);
 559             return;
 560           }
 561
 562         GNUNET_CONTAINER_heap_update_cost (heap, map_entry->heap_node,
 563                                            GNUNET_TIME_absolute_get ().abs_value);
 564
 565
 566         unsigned short namelen = htons(map_entry->namelen);
 567         char* name = (char*)(map_entry + 1);
 568
 569         list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
 570
 571         struct answer_packet* rpkt = &list->pkt;
 572
 573         /* The offset points to the first byte belonging to the address */
 574         memcpy(rpkt, pkt, offset - 1);
 575
 576         rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 577         rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
 578
 579         memcpy(((char*)rpkt)+offset, &namelen, 2);
 580         memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
 581
 582       }
 583     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
 584       {
 585         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 586         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 587       }
 588     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA)
 589       {
 590         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 591
 592         GNUNET_HashCode key;
 593         memset(&key, 0, sizeof(GNUNET_HashCode));
 594
 595         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 596         new_ip6addr_remote(c, pkt->addr, pkt->addrsize);
 597         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "New mapping to %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n",
 598                    c[0],
 599                    c[1],
 600                    c[2],
 601                    c[3],
 602                    c[4],
 603                    c[5],
 604                    c[6],
 605                    c[7],
 606                    c[8],
 607                    c[9],
 608                    c[10],
 609                    c[11],
 610                    c[12],
 611                    c[13],
 612                    c[14],
 613                    c[15]);
 614         unsigned char* k = (unsigned char*)&key;
 615         /*
 616          * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table)
 617          */
 618         unsigned int i;
 619         for (i = 0; i < 16; i++)
 620             k[15-i] = c[i];
 621
 622         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 623
 624         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 625         char* name = (char*)(value +1);
 626
 627         value->namelen = namelen;
 628         memcpy(name, pkt->data+12, namelen);
 629
 630         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize);
 631         value->addrlen = pkt->addrsize;
 632         memcpy(&value->addr, &pkt->addr, pkt->addrsize);
 633         memset(value->additional_ports, 0, 8192);
 634
 635         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 636
 637         if (GNUNET_NO ==
 638             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 639           {
 640             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 641                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 642             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 643                                                              GNUNET_TIME_absolute_get ().abs_value);
 644             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 645               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 646           }
 647         else
 648           GNUNET_free(value);
 649
 650         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 651
 652         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 653       }
 654     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_A)
 655       {
 656         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 657
 658         GNUNET_HashCode key;
 659         memset(&key, 0, sizeof(GNUNET_HashCode));
 660
 661         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 662         new_ip4addr_remote(c, pkt->addr, pkt->addrsize);
 663         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "New mapping to %d.%d.%d.%d\n",
 664                    c[0],
 665                    c[1],
 666                    c[2],
 667                    c[3]);
 668         unsigned char* k = (unsigned char*)&key;
 669         /*
 670          * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table)
 671          */
 672         unsigned int i;
 673         for (i = 0; i < 4; i++)
 674             k[3-i] = c[i];
 675
 676         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 677
 678         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 679         char* name = (char*)(value +1);
 680
 681         value->namelen = namelen;
 682         memcpy(name, pkt->data+12, namelen);
 683
 684         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize);
 685         value->addrlen = pkt->addrsize;
 686         memcpy(&value->addr, &pkt->addr, pkt->addrsize);
 687         memset(value->additional_ports, 0, 8192);
 688
 689         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 690
 691         if (GNUNET_NO ==
 692             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 693           {
 694             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 695                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 696             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 697                                                              GNUNET_TIME_absolute_get ().abs_value);
 698             GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Mapping is saved in the hashmap with key %08x.\n",
 699                        *((uint32_t*)(&key)));
 700             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 701               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 702           }
 703         else
 704           GNUNET_free(value);
 705
 706         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 707
 708         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 709       }
 710     else
 711       {
 712         GNUNET_break(0);
 713         GNUNET_free(pkt);
 714         return;
 715       }
 716
 717     GNUNET_free(pkt);
 718
 719     GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
 720
 721     schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
 722
 723     return;
 724 }
 725
 726 /**
 727  * Sets a bit active in a bitArray.
 728  *
 729  * @param bitArray memory area to set the bit in
 730  * @param bitIdx which bit to set
 731  */
 732 void
 733 setBit (char *bitArray, unsigned int bitIdx)
 734 {
 735   size_t arraySlot;
 736   unsigned int targetBit;
 737
 738   arraySlot = bitIdx / 8;
 739   targetBit = (1L << (bitIdx % 8));
 740   bitArray[arraySlot] |= targetBit;
 741 }
 742
 743 /**
 744  * Clears a bit from bitArray.
 745  *
 746  * @param bitArray memory area to set the bit in
 747  * @param bitIdx which bit to unset
 748  */
 749 void
 750 clearBit (char *bitArray, unsigned int bitIdx)
 751 {
 752   size_t slot;
 753   unsigned int targetBit;
 754
 755   slot = bitIdx / 8;
 756   targetBit = (1L << (bitIdx % 8));
 757   bitArray[slot] = bitArray[slot] & (~targetBit);
 758 }
 759
 760 /**
 761  * Checks if a bit is active in the bitArray
 762  *
 763  * @param bitArray memory area to set the bit in
 764  * @param bitIdx which bit to test
 765  * @return GNUNET_YES if the bit is set, GNUNET_NO if not.
 766  */
 767 int
 768 testBit (char *bitArray, unsigned int bitIdx)
 769 {
 770   size_t slot;
 771   unsigned int targetBit;
 772
 773   slot = bitIdx / 8;
 774   targetBit = (1L << (bitIdx % 8));
 775   if (bitArray[slot] & targetBit)
 776     return GNUNET_YES;
 777   else
 778     return GNUNET_NO;
 779 }
 780
 781 /**
 782  * @brief Add the port to the list of additional ports in the map_entry
 783  *
 784  * @param me the map_entry
 785  * @param port the port in host-byte-order
 786  */
 787 static void
 788 add_additional_port (struct map_entry *me, uint16_t port)
 789 {
 790   setBit(me->additional_ports, port);
 791 }
 792
 793 static int
 794 receive_udp_back (void *cls
 795                   __attribute__ ((unused)), struct GNUNET_MESH_Tunnel *tunnel,
 796                   void **tunnel_ctx __attribute__ ((unused)),
 797                   const struct GNUNET_PeerIdentity *sender __attribute__ ((unused)),
 798                   const struct GNUNET_MessageHeader *message,
 799                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__ ((unused)))
 800 {
 801   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 802   struct remote_addr *s = (struct remote_addr *) desc;
 803   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
 804   const struct GNUNET_PeerIdentity *other = GNUNET_MESH_get_peer (tunnel);
 805
 806   if (16 == s->addrlen)
 807     {
 808       size_t size =
 809         sizeof (struct ip6_udp) + ntohs (pkt->len) - 1 - sizeof (struct udp_pkt);
 810
 811       struct ip6_udp *pkt6 = alloca (size);
 812
 813       GNUNET_assert (pkt6 != NULL);
 814
 815       if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK)
 816         new_ip6addr (pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 817       else
 818         new_ip6addr_remote (pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 819
 820       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 821                   "Relaying calc:%d gnu:%d udp:%d bytes!\n", size,
 822                   ntohs (message->size), ntohs (pkt->len));
 823
 824       pkt6->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
 825       pkt6->shdr.size = htons (size);
 826
 827       pkt6->tun.flags = 0;
 828       pkt6->tun.type = htons (0x86dd);
 829
 830       pkt6->ip6_hdr.version = 6;
 831       pkt6->ip6_hdr.tclass_h = 0;
 832       pkt6->ip6_hdr.tclass_l = 0;
 833       pkt6->ip6_hdr.flowlbl = 0;
 834       pkt6->ip6_hdr.paylgth = pkt->len;
 835       pkt6->ip6_hdr.nxthdr = 0x11;
 836       pkt6->ip6_hdr.hoplmt = 0xff;
 837
 838       {
 839         char *ipv6addr;
 840         GNUNET_assert (GNUNET_OK ==
 841                        GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 842                                                               "IPV6ADDR",
 843                                                               &ipv6addr));
 844         inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
 845         GNUNET_free (ipv6addr);
 846       }
 847       memcpy (&pkt6->udp_hdr, pkt, ntohs (pkt->len));
 848
 849       GNUNET_HashCode *key = address6_mapping_exists (pkt6->ip6_hdr.sadr);
 850       GNUNET_assert (key != NULL);
 851
 852       struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key);
 853       GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 854                                          GNUNET_TIME_absolute_get ().
 855                                          abs_value);
 856
 857       GNUNET_free (key);
 858
 859       GNUNET_assert (me != NULL);
 860       if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK)
 861         {
 862           GNUNET_assert (me->desc.
 863                          service_type & htonl (GNUNET_DNS_SERVICE_TYPE_UDP));
 864           if (!port_in_ports (me->desc.ports, pkt6->udp_hdr.spt)
 865               && !testBit (me->additional_ports, ntohs (pkt6->udp_hdr.spt)))
 866             {
 867               add_additional_port (me, ntohs (pkt6->udp_hdr.spt));
 868             }
 869         }
 870
 871       pkt6->udp_hdr.crc = 0;
 872       uint32_t sum = 0;
 873       sum =
 874         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr,
 875                                    16);
 876       sum =
 877         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr,
 878                                    16);
 879       uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
 880       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 881       tmp = htons (((pkt6->ip6_hdr.nxthdr & 0x00ff)));
 882       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 883
 884       sum =
 885         calculate_checksum_update (sum, (uint16_t *) & pkt6->udp_hdr,
 886                                    ntohs (pkt->len));
 887       pkt6->udp_hdr.crc = calculate_checksum_end (sum);
 888
 889       write_to_helper (pkt6, size);
 890     }
 891   else
 892     {
 893       size_t size =
 894         sizeof (struct ip_udp) + ntohs (pkt->len) - 1 - sizeof (struct udp_pkt);
 895
 896       struct ip_udp *pkt4 = alloca (size);
 897
 898       GNUNET_assert (pkt4 != NULL);
 899
 900       GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK);
 901       uint32_t sadr;
 902       new_ip4addr_remote ((unsigned char*)&sadr, s->addr, s->addrlen);
 903       pkt4->ip_hdr.sadr = sadr;
 904
 905       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 906                   "Relaying calc:%d gnu:%d udp:%d bytes!\n", size,
 907                   ntohs (message->size), ntohs (pkt->len));
 908
 909       pkt4->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
 910       pkt4->shdr.size = htons (size);
 911
 912       pkt4->tun.flags = 0;
 913       pkt4->tun.type = htons (0x0800);
 914
 915       pkt4->ip_hdr.version = 4;
 916       pkt4->ip_hdr.hdr_lngth = 5;
 917       pkt4->ip_hdr.diff_serv = 0;
 918       pkt4->ip_hdr.tot_lngth = htons (20 + ntohs(pkt->len));
 919       pkt4->ip_hdr.ident = 0;
 920       pkt4->ip_hdr.flags = 0;
 921       pkt4->ip_hdr.frag_off = 0;
 922       pkt4->ip_hdr.ttl = 255;
 923       pkt4->ip_hdr.proto = 0x11;
 924       pkt4->ip_hdr.chks = 0;        /* Will be calculated later */
 925
 926       {
 927         char *ipv4addr;
 928         uint32_t dadr;
 929         GNUNET_assert (GNUNET_OK ==
 930                        GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 931                                                               "IPV4ADDR",
 932                                                               &ipv4addr));
 933         inet_pton (AF_INET, ipv4addr, &dadr);
 934         GNUNET_free (ipv4addr);
 935         pkt4->ip_hdr.dadr = dadr;
 936       }
 937       memcpy (&pkt4->udp_hdr, pkt, ntohs (pkt->len));
 938
 939       GNUNET_HashCode *key = address4_mapping_exists (pkt4->ip_hdr.sadr);
 940       GNUNET_assert (key != NULL);
 941
 942       struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key);
 943       GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 944                                          GNUNET_TIME_absolute_get ().
 945                                          abs_value);
 946
 947       GNUNET_free (key);
 948
 949       GNUNET_assert (me != NULL);
 950
 951       pkt4->udp_hdr.crc = 0; /* Optional for IPv4 */
 952
 953       pkt4->ip_hdr.chks =
 954         calculate_ip_checksum ((uint16_t *) & pkt4->ip_hdr, 5 * 4);
 955
 956       write_to_helper (pkt4, size);
 957     }
 958
 959   return GNUNET_OK;
 960 }
 961
 962 static int
 963 receive_tcp_back (void *cls __attribute__((unused)), struct GNUNET_MESH_Tunnel* tunnel,
 964                   void **tunnel_ctx __attribute__((unused)),
 965                   const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 966                   const struct GNUNET_MessageHeader *message,
 967                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 968 {
 969   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 970   struct remote_addr *s = (struct remote_addr *) desc;
 971   struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
 972   const struct GNUNET_PeerIdentity *other = GNUNET_MESH_get_peer (tunnel);
 973
 974   size_t pktlen =
 975     ntohs (message->size) - sizeof (struct GNUNET_MessageHeader) -
 976     sizeof (GNUNET_HashCode);
 977
 978   if (s->addrlen == 16)
 979     {
 980       size_t size = pktlen + sizeof (struct ip6_tcp) - 1;
 981
 982       struct ip6_tcp *pkt6 = alloca (size);
 983       memset (pkt6, 0, size);
 984
 985       GNUNET_assert (pkt6 != NULL);
 986
 987       if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK)
 988         new_ip6addr (pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 989       else
 990         new_ip6addr_remote (pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 991
 992       pkt6->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
 993       pkt6->shdr.size = htons (size);
 994
 995       pkt6->tun.flags = 0;
 996       pkt6->tun.type = htons (0x86dd);
 997
 998       pkt6->ip6_hdr.version = 6;
 999       pkt6->ip6_hdr.tclass_h = 0;
1000       pkt6->ip6_hdr.tclass_l = 0;
1001       pkt6->ip6_hdr.flowlbl = 0;
1002       pkt6->ip6_hdr.paylgth = htons (pktlen);
1003       pkt6->ip6_hdr.nxthdr = 0x06;
1004       pkt6->ip6_hdr.hoplmt = 0xff;
1005
1006       {
1007         char *ipv6addr;
1008         GNUNET_assert (GNUNET_OK ==
1009                        GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
1010                                                               "IPV6ADDR",
1011                                                               &ipv6addr));
1012         inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
1013         GNUNET_free (ipv6addr);
1014       }
1015       memcpy (&pkt6->tcp_hdr, pkt, pktlen);
1016
1017       GNUNET_HashCode *key = address6_mapping_exists (pkt6->ip6_hdr.sadr);
1018       GNUNET_assert (key != NULL);
1019
1020       struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key);
1021       GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
1022                                          GNUNET_TIME_absolute_get ().
1023                                          abs_value);
1024
1025       GNUNET_free (key);
1026
1027       GNUNET_assert (me != NULL);
1028       if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK)
1029         GNUNET_assert (me->desc.
1030                        service_type & htonl (GNUNET_DNS_SERVICE_TYPE_TCP));
1031
1032       pkt6->tcp_hdr.crc = 0;
1033       uint32_t sum = 0;
1034       uint32_t tmp;
1035       sum =
1036         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr,
1037                                    16);
1038       sum =
1039         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr,
1040                                    16);
1041       tmp = htonl (pktlen);
1042       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
1043       tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff)));
1044       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
1045
1046       sum =
1047         calculate_checksum_update (sum, (uint16_t *) & pkt6->tcp_hdr,
1048                                    ntohs (pkt6->ip6_hdr.paylgth));
1049       pkt6->tcp_hdr.crc = calculate_checksum_end (sum);
1050
1051       write_to_helper (pkt6, size);
1052     }
1053   else
1054     {
1055       size_t size = pktlen + sizeof (struct ip_tcp) - 1;
1056
1057       struct ip_tcp *pkt4 = alloca (size);
1058       GNUNET_assert (pkt4 != NULL);
1059       memset (pkt4, 0, size);
1060
1061       GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK);
1062       uint32_t sadr;
1063       new_ip4addr_remote ((unsigned char*)&sadr, s->addr, s->addrlen);
1064       pkt4->ip_hdr.sadr = sadr;
1065
1066       pkt4->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1067       pkt4->shdr.size = htons (size);
1068
1069       pkt4->tun.flags = 0;
1070       pkt4->tun.type = htons (0x0800);
1071
1072       pkt4->ip_hdr.version = 4;
1073       pkt4->ip_hdr.hdr_lngth = 5;
1074       pkt4->ip_hdr.diff_serv = 0;
1075       pkt4->ip_hdr.tot_lngth = htons (20 + pktlen);
1076       pkt4->ip_hdr.ident = 0;
1077       pkt4->ip_hdr.flags = 0;
1078       pkt4->ip_hdr.frag_off = 0;
1079       pkt4->ip_hdr.ttl = 255;
1080       pkt4->ip_hdr.proto = 0x06;
1081       pkt4->ip_hdr.chks = 0;        /* Will be calculated later */
1082
1083       {
1084         char *ipv4addr;
1085         uint32_t dadr;
1086         GNUNET_assert (GNUNET_OK ==
1087                        GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
1088                                                               "IPV4ADDR",
1089                                                               &ipv4addr));
1090         inet_pton (AF_INET, ipv4addr, &dadr);
1091         GNUNET_free (ipv4addr);
1092         pkt4->ip_hdr.dadr = dadr;
1093       }
1094
1095       memcpy (&pkt4->tcp_hdr, pkt, pktlen);
1096
1097       GNUNET_HashCode *key = address4_mapping_exists (pkt4->ip_hdr.sadr);
1098       GNUNET_assert (key != NULL);
1099
1100       struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key);
1101       GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
1102                                          GNUNET_TIME_absolute_get ().
1103                                          abs_value);
1104
1105       GNUNET_free (key);
1106
1107       GNUNET_assert (me != NULL);
1108       pkt4->tcp_hdr.crc = 0;
1109       uint32_t sum = 0;
1110       uint32_t tmp;
1111       tmp = pkt4->ip_hdr.sadr;
1112       sum =
1113         calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
1114       tmp = pkt4->ip_hdr.dadr;
1115       sum =
1116         calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
1117
1118       tmp = (0x06 << 16) | (0xffff & pktlen);
1119
1120       tmp = htonl(tmp);
1121
1122       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
1123
1124       sum =
1125         calculate_checksum_update (sum, (uint16_t *) & pkt4->tcp_hdr, pktlen);
1126       pkt4->tcp_hdr.crc = calculate_checksum_end (sum);
1127
1128       pkt4->ip_hdr.chks =
1129         calculate_ip_checksum ((uint16_t *) & pkt4->ip_hdr, 5 * 4);
1130
1131       write_to_helper (pkt4, size);
1132     }
1133
1134   return GNUNET_OK;
1135 }
1136
1137 /**
1138  * Main function that will be run by the scheduler.
1139  *
1140  * @param cls closure
1141  * @param args remaining command-line arguments
1142  * @param cfgfile name of the configuration file used (for saving, can be NULL!)
1143  * @param cfg_ configuration
1144  */
1145 static void
1146 run (void *cls,
1147      char *const *args __attribute__((unused)),
1148      const char *cfgfilep __attribute__((unused)),
1149      const struct GNUNET_CONFIGURATION_Handle *cfg_)
1150 {
1151     static const struct GNUNET_MESH_MessageHandler handlers[] = {
1152           {receive_udp_back, GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK, 0},
1153           {receive_tcp_back, GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK, 0},
1154           {receive_udp_back, GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK, 0},
1155           {receive_tcp_back, GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK, 0},
1156           {NULL, 0, 0}
1157     };
1158
1159     static const GNUNET_MESH_ApplicationType types[] = {
1160         GNUNET_APPLICATION_TYPE_END
1161     };
1162
1163     mesh_handle = GNUNET_MESH_connect(cfg_,
1164                                       NULL,
1165                                       NULL,
1166                                       handlers,
1167                                       types);
1168     cfg = cfg_;
1169     restart_hijack = 0;
1170     hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
1171     heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
1172     GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "MAX_MAPPINGg",
1173                                            &max_mappings);
1174     udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
1175     conn_task = GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
1176     shs_task = GNUNET_SCHEDULER_add_after (conn_task, start_helper_and_schedule, NULL);
1177     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
1178 }
1179
1180 /**
1181  * The main function to obtain template from gnunetd.
1182  *
1183  * @param argc number of arguments from the command line
1184  * @param argv command line arguments
1185  * @return 0 ok, 1 on error
1186  */
1187 int
1188 main (int argc, char *const *argv) {
1189     static const struct GNUNET_GETOPT_CommandLineOption options[] = {
1190         GNUNET_GETOPT_OPTION_END
1191     };
1192
1193     return (GNUNET_OK ==
1194             GNUNET_PROGRAM_run (argc,
1195                                 argv,
1196                                 "vpn",
1197                                 gettext_noop ("help text"),
1198                                 options, &run, NULL)) ? ret : 1;
1199 }
1200
1201 /* end of gnunet-daemon-vpn.c */
1202