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 address_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 static void
 134 collect_mappings(void* cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext* tc) {
 135     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 136       return;
 137
 138     struct map_entry* me = GNUNET_CONTAINER_heap_remove_root(heap);
 139
 140     /* This is free()ed memory! */
 141     me->heap_node = NULL;
 142
 143     /* FIXME! GNUNET_MESH_close_tunnel(me->tunnel); */
 144
 145     GNUNET_CONTAINER_multihashmap_remove(hashmap, &me->hash, me);
 146
 147     GNUNET_free(me);
 148 }
 149
 150 void
 151 send_icmp_response(void* cls, const struct GNUNET_SCHEDULER_TaskContext *tc) {
 152     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 153       return;
 154
 155     struct ip6_icmp* request = cls;
 156
 157     struct ip6_icmp* response = alloca(ntohs(request->shdr.size));
 158     GNUNET_assert(response != NULL);
 159     memset(response, 0, ntohs(request->shdr.size));
 160
 161     response->shdr.size = request->shdr.size;
 162     response->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 163
 164     response->tun.flags = 0;
 165     response->tun.type = htons(0x86dd);
 166
 167     response->ip6_hdr.hoplmt = 255;
 168     response->ip6_hdr.paylgth = request->ip6_hdr.paylgth;
 169     response->ip6_hdr.nxthdr = 0x3a;
 170     response->ip6_hdr.version = 6;
 171     memcpy(&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16);
 172     memcpy(&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16);
 173
 174     response->icmp_hdr.code = 0;
 175     response->icmp_hdr.type = 0x81;
 176
 177     /* Magic, more Magic! */
 178     response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1;
 179
 180     /* Copy the rest of the packet */
 181     memcpy(response+1, request+1, ntohs(request->shdr.size) - sizeof(struct ip6_icmp));
 182
 183     write_to_helper(response, ntohs(response->shdr.size));
 184
 185     GNUNET_free(request);
 186 }
 187
 188 /**
 189  * cls is the pointer to a GNUNET_MessageHeader that is
 190  * followed by the service-descriptor and the packet that should be sent;
 191  */
 192 static size_t
 193 send_pkt_to_peer_notify_callback (void *cls, size_t size, void *buf)
 194 {
 195   struct GNUNET_MESH_Tunnel **tunnel = cls;
 196   GNUNET_MESH_tunnel_set_data(*tunnel, NULL);
 197   struct GNUNET_MessageHeader *hdr =
 198     (struct GNUNET_MessageHeader *) (tunnel + 1);
 199   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "send_pkt_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size);
 200   GNUNET_assert (size >= ntohs (hdr->size));
 201   memcpy (buf, hdr, ntohs (hdr->size));
 202   size = ntohs(hdr->size);
 203   GNUNET_free (cls);
 204   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
 205
 206   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 207     {
 208       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 209       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 210       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 211
 212       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 213
 214       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 215       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 216
 217       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 218                                                                                  GNUNET_NO,
 219                                                                                  42,
 220                                                                                  GNUNET_TIME_relative_divide
 221                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 222                                                                                  (const struct GNUNET_PeerIdentity *)
 223                                                                                  NULL, element->len,
 224                                                                                  send_pkt_to_peer_notify_callback, element->cls);
 225       /* save the handle */
 226       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 227     }
 228
 229   return size;
 230 }
 231
 232 unsigned int
 233 port_in_ports (uint64_t ports, uint16_t port)
 234 {
 235   uint16_t *ps = (uint16_t *) & ports;
 236   return ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port;
 237 }
 238
 239 void
 240 send_pkt_to_peer (void *cls,
 241                   const struct GNUNET_PeerIdentity *peer,
 242                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 243 {
 244   /* peer == NULL means that all peers in this request are connected */
 245   if (peer == NULL) return;
 246   struct GNUNET_MESH_Tunnel **tunnel = cls;
 247   struct GNUNET_MessageHeader *hdr =
 248     (struct GNUNET_MessageHeader *) (tunnel + 1);
 249
 250   GNUNET_assert(NULL != tunnel);
 251   GNUNET_assert(NULL != *tunnel);
 252
 253   if (NULL == GNUNET_MESH_tunnel_get_data(*tunnel))
 254     {
 255       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 256                                                                                  GNUNET_NO,
 257                                                                                  42,
 258                                                                                  GNUNET_TIME_relative_divide(GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 259                                                                                  (const struct GNUNET_PeerIdentity *)NULL,
 260                                                                                  ntohs(hdr->size),
 261                                                                                  send_pkt_to_peer_notify_callback,
 262                                                                                  cls);
 263       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 264     }
 265   else
 266     {
 267      struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 268      struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 269      struct tunnel_notify_queue* element = GNUNET_malloc(sizeof *element);
 270
 271      element->cls = cls;
 272      element->len = ntohs(hdr->size);
 273
 274      GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 275
 276      GNUNET_MESH_tunnel_set_head(*tunnel, head);
 277      GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 278     }
 279 }
 280
 281 /**
 282  * Create a new Address from an answer-packet
 283  */
 284 void
 285 new_ip6addr(unsigned char* buf, const GNUNET_HashCode *peer, const GNUNET_HashCode *service_desc) { /* {{{ */
 286     char* ipv6addr;
 287     unsigned long long ipv6prefix;
 288     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 289     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_number(cfg, "vpn", "IPV6PREFIX", &ipv6prefix));
 290     GNUNET_assert(ipv6prefix < 127);
 291     ipv6prefix = (ipv6prefix + 7)/8;
 292
 293     inet_pton (AF_INET6, ipv6addr, buf);
 294     GNUNET_free(ipv6addr);
 295
 296     int peer_length = 16 - ipv6prefix - 6;
 297     if (peer_length <= 0)
 298       peer_length = 0;
 299
 300     int service_length = 16 - ipv6prefix - peer_length;
 301     if (service_length <= 0)
 302       service_length = 0;
 303
 304     memcpy(buf+ipv6prefix, service_desc, service_length);
 305     memcpy(buf+ipv6prefix+service_length, peer, peer_length);
 306 }
 307 /*}}}*/
 308
 309
 310 /**
 311  * Create a new Address from an answer-packet
 312  */
 313 void
 314 new_ip6addr_remote (unsigned char *buf, unsigned char *addr, char addrlen)
 315 {                               /* {{{ */
 316   char *ipv6addr;
 317   unsigned long long ipv6prefix;
 318   GNUNET_assert (GNUNET_OK ==
 319                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 320                                                         "IPV6ADDR",
 321                                                         &ipv6addr));
 322   GNUNET_assert (GNUNET_OK ==
 323                  GNUNET_CONFIGURATION_get_value_number (cfg, "vpn",
 324                                                         "IPV6PREFIX",
 325                                                         &ipv6prefix));
 326   GNUNET_assert (ipv6prefix < 127);
 327   ipv6prefix = (ipv6prefix + 7) / 8;
 328
 329   inet_pton (AF_INET6, ipv6addr, buf);
 330   GNUNET_free (ipv6addr);
 331
 332   int local_length = 16 - ipv6prefix;
 333
 334   memcpy (buf + ipv6prefix, addr, GNUNET_MAX (addrlen, local_length));
 335 }
 336 /*}}}*/
 337
 338 /**
 339  * This gets scheduled with cls pointing to an answer_packet and does everything
 340  * needed in order to send it to the helper.
 341  *
 342  * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
 343  * doing nothing for "real" services.
 344  */
 345 void
 346 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 347     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 348       return;
 349
 350     struct answer_packet* pkt = cls;
 351     struct answer_packet_list* list;
 352
 353     /* This answer is about a .gnunet-service
 354      *
 355      * It contains an almost complete DNS-Response, we have to fill in the ip
 356      * at the offset pkt->addroffset
 357      */
 358     if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
 359       {
 360         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 361
 362         GNUNET_HashCode key;
 363         memset(&key, 0, sizeof(GNUNET_HashCode));
 364
 365         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 366         unsigned char* k = (unsigned char*)&key;
 367         new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
 368         /*
 369          * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
 370          */
 371         unsigned int i;
 372         for (i = 0; i < 16; i++)
 373             k[15-i] = c[i];
 374
 375         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 376
 377         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 378         char* name = (char*)(value +1);
 379
 380         value->namelen = namelen;
 381         memcpy(name, pkt->data+12, namelen);
 382
 383         memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
 384
 385         memset(value->additional_ports, 0, 8192);
 386
 387         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 388
 389         if (GNUNET_NO ==
 390             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 391           {
 392             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 393                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 394
 395             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 396                                                              GNUNET_TIME_absolute_get ().abs_value);
 397             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 398               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 399           }
 400         else
 401           GNUNET_free(value);
 402
 403
 404         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 405
 406         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 407
 408       }
 409     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
 410       {
 411         GNUNET_HashCode key;
 412         memset(&key, 0, sizeof key);
 413         unsigned char* k = (unsigned char*)&key;
 414         unsigned char* s = pkt->data+12;
 415         int i = 0;
 416         /* Whoever designed the reverse IPv6-lookup is batshit insane */
 417         for (i = 0; i < 16; i++)
 418           {
 419             unsigned char c1 = s[(4*i)+1];
 420             unsigned char c2 = s[(4*i)+3];
 421             if (c1 <= '9')
 422               k[i] = c1 - '0';
 423             else
 424               k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
 425             if (c2 <= '9')
 426               k[i] += 16*(c2 - '0');
 427             else
 428               k[i] += 16*(c2 - 87);
 429           }
 430
 431         struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
 432         uint16_t offset = ntohs(pkt->addroffset);
 433
 434         if (map_entry == NULL)
 435           {
 436             GNUNET_free(pkt);
 437             return;
 438           }
 439
 440         GNUNET_CONTAINER_heap_update_cost (heap, map_entry->heap_node,
 441                                            GNUNET_TIME_absolute_get ().abs_value);
 442
 443
 444         unsigned short namelen = htons(map_entry->namelen);
 445         char* name = (char*)(map_entry + 1);
 446
 447         list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
 448
 449         struct answer_packet* rpkt = &list->pkt;
 450
 451         /* The offset points to the first byte belonging to the address */
 452         memcpy(rpkt, pkt, offset - 1);
 453
 454         rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 455         rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
 456
 457         memcpy(((char*)rpkt)+offset, &namelen, 2);
 458         memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
 459
 460       }
 461     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
 462       {
 463         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 464         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 465       }
 466     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE)
 467       {
 468         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 469
 470         GNUNET_HashCode key;
 471         memset(&key, 0, sizeof(GNUNET_HashCode));
 472
 473         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 474         new_ip6addr_remote(c, pkt->addr, pkt->addrsize);
 475         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",
 476                    c[0],
 477                    c[1],
 478                    c[2],
 479                    c[3],
 480                    c[4],
 481                    c[5],
 482                    c[6],
 483                    c[7],
 484                    c[8],
 485                    c[9],
 486                    c[10],
 487                    c[11],
 488                    c[12],
 489                    c[13],
 490                    c[14],
 491                    c[15]);
 492         unsigned char* k = (unsigned char*)&key;
 493         /*
 494          * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table)
 495          */
 496         unsigned int i;
 497         for (i = 0; i < 16; i++)
 498             k[15-i] = c[i];
 499
 500         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 501
 502         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 503         char* name = (char*)(value +1);
 504
 505         value->namelen = namelen;
 506         memcpy(name, pkt->data+12, namelen);
 507
 508         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize);
 509         value->addrlen = pkt->addrsize;
 510         memcpy(&value->addr, &pkt->addr, pkt->addrsize);
 511         memset(value->additional_ports, 0, 8192);
 512
 513         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 514
 515         if (GNUNET_NO ==
 516             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 517           {
 518             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 519                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 520             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 521                                                              GNUNET_TIME_absolute_get ().abs_value);
 522             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 523               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 524           }
 525         else
 526           GNUNET_free(value);
 527
 528         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 529
 530         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 531       }
 532     else
 533       {
 534         GNUNET_break(0);
 535         GNUNET_free(pkt);
 536         return;
 537       }
 538
 539     GNUNET_free(pkt);
 540
 541     GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
 542
 543     schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
 544
 545     return;
 546 }
 547
 548 /**
 549  * Sets a bit active in a bitArray.
 550  *
 551  * @param bitArray memory area to set the bit in
 552  * @param bitIdx which bit to set
 553  */
 554 void
 555 setBit (char *bitArray, unsigned int bitIdx)
 556 {
 557   size_t arraySlot;
 558   unsigned int targetBit;
 559
 560   arraySlot = bitIdx / 8;
 561   targetBit = (1L << (bitIdx % 8));
 562   bitArray[arraySlot] |= targetBit;
 563 }
 564
 565 /**
 566  * Clears a bit from bitArray.
 567  *
 568  * @param bitArray memory area to set the bit in
 569  * @param bitIdx which bit to unset
 570  */
 571 void
 572 clearBit (char *bitArray, unsigned int bitIdx)
 573 {
 574   size_t slot;
 575   unsigned int targetBit;
 576
 577   slot = bitIdx / 8;
 578   targetBit = (1L << (bitIdx % 8));
 579   bitArray[slot] = bitArray[slot] & (~targetBit);
 580 }
 581
 582 /**
 583  * Checks if a bit is active in the bitArray
 584  *
 585  * @param bitArray memory area to set the bit in
 586  * @param bitIdx which bit to test
 587  * @return GNUNET_YES if the bit is set, GNUNET_NO if not.
 588  */
 589 int
 590 testBit (char *bitArray, unsigned int bitIdx)
 591 {
 592   size_t slot;
 593   unsigned int targetBit;
 594
 595   slot = bitIdx / 8;
 596   targetBit = (1L << (bitIdx % 8));
 597   if (bitArray[slot] & targetBit)
 598     return GNUNET_YES;
 599   else
 600     return GNUNET_NO;
 601 }
 602
 603 /**
 604  * @brief Add the port to the list of additional ports in the map_entry
 605  *
 606  * @param me the map_entry
 607  * @param port the port in host-byte-order
 608  */
 609 static void
 610 add_additional_port (struct map_entry *me, uint16_t port)
 611 {
 612   setBit(me->additional_ports, port);
 613 }
 614
 615 static int
 616 receive_udp_back (void *cls __attribute__((unused)), struct GNUNET_MESH_Tunnel* tunnel,
 617                   void **tunnel_ctx __attribute__((unused)),
 618                   const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 619                   const struct GNUNET_MessageHeader *message,
 620                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 621 {
 622   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 623   struct remote_addr* s = (struct remote_addr*)desc;
 624   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
 625   const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
 626
 627   size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
 628
 629   struct ip6_udp* pkt6 = alloca(size);
 630
 631   GNUNET_assert(pkt6 != NULL);
 632
 633   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 634     new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 635   else
 636     new_ip6addr_remote(pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 637
 638   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
 639
 640   pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 641   pkt6->shdr.size = htons(size);
 642
 643   pkt6->tun.flags = 0;
 644   pkt6->tun.type = htons(0x86dd);
 645
 646   pkt6->ip6_hdr.version = 6;
 647   pkt6->ip6_hdr.tclass_h = 0;
 648   pkt6->ip6_hdr.tclass_l = 0;
 649   pkt6->ip6_hdr.flowlbl = 0;
 650   pkt6->ip6_hdr.paylgth = pkt->len;
 651   pkt6->ip6_hdr.nxthdr = 0x11;
 652   pkt6->ip6_hdr.hoplmt = 0xff;
 653
 654   {
 655     char* ipv6addr;
 656     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 657     inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
 658     GNUNET_free(ipv6addr);
 659   }
 660   memcpy(&pkt6->udp_hdr, pkt, ntohs(pkt->len));
 661
 662   GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
 663   GNUNET_assert (key != NULL);
 664
 665   struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
 666   GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 667                                      GNUNET_TIME_absolute_get ().abs_value);
 668
 669   GNUNET_free(key);
 670
 671   GNUNET_assert (me != NULL);
 672   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 673     {
 674       GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_UDP));
 675       if (!port_in_ports(me->desc.ports, pkt6->udp_hdr.spt) &&
 676           !testBit(me->additional_ports, ntohs(pkt6->udp_hdr.spt))) {
 677           add_additional_port(me, ntohs(pkt6->udp_hdr.spt));
 678       }
 679     }
 680
 681   pkt6->udp_hdr.crc = 0;
 682   uint32_t sum = 0;
 683   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.sadr, 16);
 684   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.dadr, 16);
 685   uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
 686   sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
 687   tmp = htons(((pkt6->ip6_hdr.nxthdr & 0x00ff)));
 688   sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
 689
 690   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->udp_hdr, ntohs(pkt->len));
 691   pkt6->udp_hdr.crc = calculate_checksum_end(sum);
 692
 693   write_to_helper(pkt6, size);
 694
 695   return GNUNET_OK;
 696 }
 697
 698 static int
 699 receive_tcp_back (void *cls __attribute__((unused)), struct GNUNET_MESH_Tunnel* tunnel,
 700                   void **tunnel_ctx __attribute__((unused)),
 701                   const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 702                   const struct GNUNET_MessageHeader *message,
 703                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 704 {
 705   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 706   struct remote_addr* s = (struct remote_addr*)desc;
 707   struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
 708   const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
 709
 710   size_t pktlen = ntohs(message->size) - sizeof(struct GNUNET_MessageHeader) - sizeof(GNUNET_HashCode);
 711   size_t size = pktlen + sizeof(struct ip6_tcp) - 1;
 712
 713   struct ip6_tcp* pkt6 = alloca(size);
 714   memset(pkt6, 0, size);
 715
 716   GNUNET_assert(pkt6 != NULL);
 717
 718   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_TCP_BACK)
 719     new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 720   else
 721     new_ip6addr_remote(pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 722
 723   pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 724   pkt6->shdr.size = htons(size);
 725
 726   pkt6->tun.flags = 0;
 727   pkt6->tun.type = htons(0x86dd);
 728
 729   pkt6->ip6_hdr.version = 6;
 730   pkt6->ip6_hdr.tclass_h = 0;
 731   pkt6->ip6_hdr.tclass_l = 0;
 732   pkt6->ip6_hdr.flowlbl = 0;
 733   pkt6->ip6_hdr.paylgth = htons(pktlen);
 734   pkt6->ip6_hdr.nxthdr = 0x06;
 735   pkt6->ip6_hdr.hoplmt = 0xff;
 736
 737   {
 738     char* ipv6addr;
 739     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 740     inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
 741     GNUNET_free(ipv6addr);
 742   }
 743   memcpy(&pkt6->tcp_hdr, pkt, pktlen);
 744
 745   GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
 746   GNUNET_assert (key != NULL);
 747
 748   struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
 749   GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 750                                      GNUNET_TIME_absolute_get ().abs_value);
 751
 752   GNUNET_free(key);
 753
 754   GNUNET_assert (me != NULL);
 755   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 756     GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_TCP));
 757
 758   pkt6->tcp_hdr.crc = 0;
 759   uint32_t sum = 0;
 760   uint32_t tmp;
 761   sum =
 762     calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16);
 763   sum =
 764     calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16);
 765   tmp = htonl(pktlen);
 766   sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 767   tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff)));
 768   sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 769
 770   sum =
 771     calculate_checksum_update (sum, (uint16_t *) & pkt6->tcp_hdr,
 772                                ntohs (pkt6->ip6_hdr.paylgth));
 773   pkt6->tcp_hdr.crc = calculate_checksum_end (sum);
 774
 775   write_to_helper(pkt6, size);
 776
 777   return GNUNET_OK;
 778 }
 779
 780 /**
 781  * Main function that will be run by the scheduler.
 782  *
 783  * @param cls closure
 784  * @param args remaining command-line arguments
 785  * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 786  * @param cfg_ configuration
 787  */
 788 static void
 789 run (void *cls,
 790      char *const *args __attribute__((unused)),
 791      const char *cfgfilep __attribute__((unused)),
 792      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 793 {
 794     static const struct GNUNET_MESH_MessageHandler handlers[] = {
 795           {receive_udp_back, GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK, 0},
 796           {receive_tcp_back, GNUNET_MESSAGE_TYPE_SERVICE_TCP_BACK, 0},
 797           {receive_udp_back, GNUNET_MESSAGE_TYPE_REMOTE_UDP_BACK, 0},
 798           {receive_tcp_back, GNUNET_MESSAGE_TYPE_REMOTE_TCP_BACK, 0},
 799           {NULL, 0, 0}
 800     };
 801
 802     static const GNUNET_MESH_ApplicationType types[] = {
 803         GNUNET_APPLICATION_TYPE_END
 804     };
 805
 806     mesh_handle = GNUNET_MESH_connect(cfg_,
 807                                       NULL,
 808                                       NULL,
 809                                       handlers,
 810                                       types);
 811     cfg = cfg_;
 812     restart_hijack = 0;
 813     hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
 814     heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
 815     GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "MAX_MAPPINGg",
 816                                            &max_mappings);
 817     udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
 818     conn_task = GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
 819     shs_task = GNUNET_SCHEDULER_add_after (conn_task, start_helper_and_schedule, NULL);
 820     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
 821 }
 822
 823 /**
 824  * The main function to obtain template from gnunetd.
 825  *
 826  * @param argc number of arguments from the command line
 827  * @param argv command line arguments
 828  * @return 0 ok, 1 on error
 829  */
 830 int
 831 main (int argc, char *const *argv) {
 832     static const struct GNUNET_GETOPT_CommandLineOption options[] = {
 833         GNUNET_GETOPT_OPTION_END
 834     };
 835
 836     return (GNUNET_OK ==
 837             GNUNET_PROGRAM_run (argc,
 838                                 argv,
 839                                 "vpn",
 840                                 gettext_noop ("help text"),
 841                                 options, &run, NULL)) ? ret : 1;
 842 }
 843
 844 /* end of gnunet-daemon-vpn.c */
 845