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_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n");
 204
 205   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 206     {
 207       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 208       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 209       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 210
 211       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 212
 213       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 214       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 215
 216       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 217                                                                                  GNUNET_NO,
 218                                                                                  42,
 219                                                                                  GNUNET_TIME_relative_divide
 220                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 221                                                                                  (const struct GNUNET_PeerIdentity *)
 222                                                                                  NULL, element->len,
 223                                                                                  send_pkt_to_peer_notify_callback, element->cls);
 224       /* save the handle */
 225       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 226     }
 227   GNUNET_free (cls);
 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_MIN (addrlen, local_length));
 335 }
 336 /*}}}*/
 337
 338 /**
 339  * Create a new Address from an answer-packet
 340  */
 341 void
 342 new_ip4addr_remote (unsigned char *buf, unsigned char *addr, char addrlen)
 343 {                               /* {{{ */
 344   char *ipv4addr;
 345   char *ipv4mask;
 346   GNUNET_assert (GNUNET_OK ==
 347                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 348                                                         "IPV4ADDR",
 349                                                         &ipv4addr));
 350   GNUNET_assert (GNUNET_OK ==
 351                  GNUNET_CONFIGURATION_get_value_string (cfg, "vpn",
 352                                                         "IPV4MASK",
 353                                                         &ipv4mask));
 354   uint32_t mask;
 355   inet_pton (AF_INET, ipv4addr, buf);
 356   int r = inet_pton (AF_INET, ipv4mask, &mask);
 357   mask = htonl(mask);
 358   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "inet_pton: %d; %m; mask: %08x\n", r, mask);
 359
 360   GNUNET_free (ipv4addr);
 361
 362   int c;
 363
 364   if (mask)
 365     {
 366       mask = (mask ^ (mask - 1)) >> 1;
 367       for (c = 0; mask; c++)
 368         {
 369           mask >>= 1;
 370         }
 371     }
 372   else
 373     {
 374       c = CHAR_BIT * sizeof(mask);
 375     }
 376
 377   c = 32-c;
 378   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "The mask %s has %d leading 1s.\n", ipv4mask, c);
 379
 380   GNUNET_free (ipv4mask);
 381
 382   if (c % 8 == 0)
 383     c = c / 8;
 384   else
 385     GNUNET_assert(0);
 386
 387   memcpy (buf + c, addr, GNUNET_MIN (addrlen, c));
 388 }
 389 /*}}}*/
 390
 391 /**
 392  * This gets scheduled with cls pointing to an answer_packet and does everything
 393  * needed in order to send it to the helper.
 394  *
 395  * At the moment this means "inventing" and IPv6-Address for .gnunet-services and
 396  * doing nothing for "real" services.
 397  */
 398 void
 399 process_answer(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 400     if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 401       return;
 402
 403     struct answer_packet* pkt = cls;
 404     struct answer_packet_list* list;
 405
 406     /* This answer is about a .gnunet-service
 407      *
 408      * It contains an almost complete DNS-Response, we have to fill in the ip
 409      * at the offset pkt->addroffset
 410      */
 411     if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE)
 412       {
 413         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 414
 415         GNUNET_HashCode key;
 416         memset(&key, 0, sizeof(GNUNET_HashCode));
 417
 418         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 419         unsigned char* k = (unsigned char*)&key;
 420         new_ip6addr(c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor);
 421         /*
 422          * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed)
 423          */
 424         unsigned int i;
 425         for (i = 0; i < 16; i++)
 426             k[15-i] = c[i];
 427
 428         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 429
 430         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 431         char* name = (char*)(value +1);
 432
 433         value->namelen = namelen;
 434         memcpy(name, pkt->data+12, namelen);
 435
 436         memcpy(&value->desc, &pkt->service_descr, sizeof(struct GNUNET_vpn_service_descriptor));
 437
 438         memset(value->additional_ports, 0, 8192);
 439
 440         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 441
 442         if (GNUNET_NO ==
 443             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 444           {
 445             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 446                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 447
 448             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 449                                                              GNUNET_TIME_absolute_get ().abs_value);
 450             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 451               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 452           }
 453         else
 454           GNUNET_free(value);
 455
 456
 457         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 458
 459         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 460
 461       }
 462     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV)
 463       {
 464         GNUNET_HashCode key;
 465         memset(&key, 0, sizeof key);
 466         unsigned char* k = (unsigned char*)&key;
 467         unsigned char* s = pkt->data+12;
 468         int i = 0;
 469         /* Whoever designed the reverse IPv6-lookup is batshit insane */
 470         for (i = 0; i < 16; i++)
 471           {
 472             unsigned char c1 = s[(4*i)+1];
 473             unsigned char c2 = s[(4*i)+3];
 474             if (c1 <= '9')
 475               k[i] = c1 - '0';
 476             else
 477               k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */
 478             if (c2 <= '9')
 479               k[i] += 16*(c2 - '0');
 480             else
 481               k[i] += 16*(c2 - 87);
 482           }
 483
 484         struct map_entry* map_entry = GNUNET_CONTAINER_multihashmap_get(hashmap, &key);
 485         uint16_t offset = ntohs(pkt->addroffset);
 486
 487         if (map_entry == NULL)
 488           {
 489             GNUNET_free(pkt);
 490             return;
 491           }
 492
 493         GNUNET_CONTAINER_heap_update_cost (heap, map_entry->heap_node,
 494                                            GNUNET_TIME_absolute_get ().abs_value);
 495
 496
 497         unsigned short namelen = htons(map_entry->namelen);
 498         char* name = (char*)(map_entry + 1);
 499
 500         list = GNUNET_malloc(2*sizeof(struct answer_packet_list*) + offset + 2 + ntohs(namelen));
 501
 502         struct answer_packet* rpkt = &list->pkt;
 503
 504         /* The offset points to the first byte belonging to the address */
 505         memcpy(rpkt, pkt, offset - 1);
 506
 507         rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 508         rpkt->hdr.size = ntohs(offset + 2 + ntohs(namelen));
 509
 510         memcpy(((char*)rpkt)+offset, &namelen, 2);
 511         memcpy(((char*)rpkt)+offset+2, name, ntohs(namelen));
 512
 513       }
 514     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP)
 515       {
 516         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 517         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 518       }
 519     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA)
 520       {
 521         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 522
 523         GNUNET_HashCode key;
 524         memset(&key, 0, sizeof(GNUNET_HashCode));
 525
 526         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 527         new_ip6addr_remote(c, pkt->addr, pkt->addrsize);
 528         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",
 529                    c[0],
 530                    c[1],
 531                    c[2],
 532                    c[3],
 533                    c[4],
 534                    c[5],
 535                    c[6],
 536                    c[7],
 537                    c[8],
 538                    c[9],
 539                    c[10],
 540                    c[11],
 541                    c[12],
 542                    c[13],
 543                    c[14],
 544                    c[15]);
 545         unsigned char* k = (unsigned char*)&key;
 546         /*
 547          * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table)
 548          */
 549         unsigned int i;
 550         for (i = 0; i < 16; i++)
 551             k[15-i] = c[i];
 552
 553         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 554
 555         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 556         char* name = (char*)(value +1);
 557
 558         value->namelen = namelen;
 559         memcpy(name, pkt->data+12, namelen);
 560
 561         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize);
 562         value->addrlen = pkt->addrsize;
 563         memcpy(&value->addr, &pkt->addr, pkt->addrsize);
 564         memset(value->additional_ports, 0, 8192);
 565
 566         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 567
 568         if (GNUNET_NO ==
 569             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 570           {
 571             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 572                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 573             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 574                                                              GNUNET_TIME_absolute_get ().abs_value);
 575             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 576               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 577           }
 578         else
 579           GNUNET_free(value);
 580
 581         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 582
 583         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 584       }
 585     else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_A)
 586       {
 587         pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP;
 588
 589         GNUNET_HashCode key;
 590         memset(&key, 0, sizeof(GNUNET_HashCode));
 591
 592         unsigned char* c = ((unsigned char*)pkt)+ntohs(pkt->addroffset);
 593         new_ip4addr_remote(c, pkt->addr, pkt->addrsize);
 594         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "New mapping to %d.%d.%d.%d\n",
 595                    c[0],
 596                    c[1],
 597                    c[2],
 598                    c[3]);
 599         unsigned char* k = (unsigned char*)&key;
 600         /*
 601          * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table)
 602          */
 603         unsigned int i;
 604         for (i = 0; i < 4; i++)
 605             k[3-i] = c[i];
 606
 607         uint16_t namelen = strlen((char*)pkt->data+12)+1;
 608
 609         struct map_entry* value = GNUNET_malloc(sizeof(struct map_entry) + namelen);
 610         char* name = (char*)(value +1);
 611
 612         value->namelen = namelen;
 613         memcpy(name, pkt->data+12, namelen);
 614
 615         GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize);
 616         value->addrlen = pkt->addrsize;
 617         memcpy(&value->addr, &pkt->addr, pkt->addrsize);
 618         memset(value->additional_ports, 0, 8192);
 619
 620         memcpy(&value->hash, &key, sizeof(GNUNET_HashCode));
 621
 622         if (GNUNET_NO ==
 623             GNUNET_CONTAINER_multihashmap_contains (hashmap, &key))
 624           {
 625             GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value,
 626                                                GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 627             value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value,
 628                                                              GNUNET_TIME_absolute_get ().abs_value);
 629             if (GNUNET_CONTAINER_heap_get_size(heap) > max_mappings)
 630               GNUNET_SCHEDULER_add_now(collect_mappings, NULL);
 631           }
 632         else
 633           GNUNET_free(value);
 634
 635         list = GNUNET_malloc(htons(pkt->hdr.size) + 2*sizeof(struct answer_packet_list*));
 636
 637         memcpy(&list->pkt, pkt, htons(pkt->hdr.size));
 638       }
 639     else
 640       {
 641         GNUNET_break(0);
 642         GNUNET_free(pkt);
 643         return;
 644       }
 645
 646     GNUNET_free(pkt);
 647
 648     GNUNET_CONTAINER_DLL_insert_after(answer_proc_head, answer_proc_tail, answer_proc_tail, list);
 649
 650     schedule_helper_write(GNUNET_TIME_UNIT_FOREVER_REL, NULL);
 651
 652     return;
 653 }
 654
 655 /**
 656  * Sets a bit active in a bitArray.
 657  *
 658  * @param bitArray memory area to set the bit in
 659  * @param bitIdx which bit to set
 660  */
 661 void
 662 setBit (char *bitArray, unsigned int bitIdx)
 663 {
 664   size_t arraySlot;
 665   unsigned int targetBit;
 666
 667   arraySlot = bitIdx / 8;
 668   targetBit = (1L << (bitIdx % 8));
 669   bitArray[arraySlot] |= targetBit;
 670 }
 671
 672 /**
 673  * Clears a bit from bitArray.
 674  *
 675  * @param bitArray memory area to set the bit in
 676  * @param bitIdx which bit to unset
 677  */
 678 void
 679 clearBit (char *bitArray, unsigned int bitIdx)
 680 {
 681   size_t slot;
 682   unsigned int targetBit;
 683
 684   slot = bitIdx / 8;
 685   targetBit = (1L << (bitIdx % 8));
 686   bitArray[slot] = bitArray[slot] & (~targetBit);
 687 }
 688
 689 /**
 690  * Checks if a bit is active in the bitArray
 691  *
 692  * @param bitArray memory area to set the bit in
 693  * @param bitIdx which bit to test
 694  * @return GNUNET_YES if the bit is set, GNUNET_NO if not.
 695  */
 696 int
 697 testBit (char *bitArray, unsigned int bitIdx)
 698 {
 699   size_t slot;
 700   unsigned int targetBit;
 701
 702   slot = bitIdx / 8;
 703   targetBit = (1L << (bitIdx % 8));
 704   if (bitArray[slot] & targetBit)
 705     return GNUNET_YES;
 706   else
 707     return GNUNET_NO;
 708 }
 709
 710 /**
 711  * @brief Add the port to the list of additional ports in the map_entry
 712  *
 713  * @param me the map_entry
 714  * @param port the port in host-byte-order
 715  */
 716 static void
 717 add_additional_port (struct map_entry *me, uint16_t port)
 718 {
 719   setBit(me->additional_ports, port);
 720 }
 721
 722 static int
 723 receive_udp_back (void *cls __attribute__((unused)), struct GNUNET_MESH_Tunnel* tunnel,
 724                   void **tunnel_ctx __attribute__((unused)),
 725                   const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 726                   const struct GNUNET_MessageHeader *message,
 727                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 728 {
 729   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 730   struct remote_addr* s = (struct remote_addr*)desc;
 731   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
 732   const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
 733
 734   size_t size = sizeof(struct ip6_udp) + ntohs(pkt->len) - 1 - sizeof(struct udp_pkt);
 735
 736   struct ip6_udp* pkt6 = alloca(size);
 737
 738   GNUNET_assert(pkt6 != NULL);
 739
 740   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 741     new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 742   else
 743     new_ip6addr_remote(pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 744
 745   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs(message->size), ntohs(pkt->len));
 746
 747   pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 748   pkt6->shdr.size = htons(size);
 749
 750   pkt6->tun.flags = 0;
 751   pkt6->tun.type = htons(0x86dd);
 752
 753   pkt6->ip6_hdr.version = 6;
 754   pkt6->ip6_hdr.tclass_h = 0;
 755   pkt6->ip6_hdr.tclass_l = 0;
 756   pkt6->ip6_hdr.flowlbl = 0;
 757   pkt6->ip6_hdr.paylgth = pkt->len;
 758   pkt6->ip6_hdr.nxthdr = 0x11;
 759   pkt6->ip6_hdr.hoplmt = 0xff;
 760
 761   {
 762     char* ipv6addr;
 763     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 764     inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
 765     GNUNET_free(ipv6addr);
 766   }
 767   memcpy(&pkt6->udp_hdr, pkt, ntohs(pkt->len));
 768
 769   GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
 770   GNUNET_assert (key != NULL);
 771
 772   struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
 773   GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 774                                      GNUNET_TIME_absolute_get ().abs_value);
 775
 776   GNUNET_free(key);
 777
 778   GNUNET_assert (me != NULL);
 779   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 780     {
 781       GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_UDP));
 782       if (!port_in_ports(me->desc.ports, pkt6->udp_hdr.spt) &&
 783           !testBit(me->additional_ports, ntohs(pkt6->udp_hdr.spt))) {
 784           add_additional_port(me, ntohs(pkt6->udp_hdr.spt));
 785       }
 786     }
 787
 788   pkt6->udp_hdr.crc = 0;
 789   uint32_t sum = 0;
 790   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.sadr, 16);
 791   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->ip6_hdr.dadr, 16);
 792   uint32_t tmp = (pkt6->udp_hdr.len & 0xffff);
 793   sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
 794   tmp = htons(((pkt6->ip6_hdr.nxthdr & 0x00ff)));
 795   sum = calculate_checksum_update(sum, (uint16_t*)&tmp, 4);
 796
 797   sum = calculate_checksum_update(sum, (uint16_t*)&pkt6->udp_hdr, ntohs(pkt->len));
 798   pkt6->udp_hdr.crc = calculate_checksum_end(sum);
 799
 800   write_to_helper(pkt6, size);
 801
 802   return GNUNET_OK;
 803 }
 804
 805 static int
 806 receive_tcp_back (void *cls __attribute__((unused)), struct GNUNET_MESH_Tunnel* tunnel,
 807                   void **tunnel_ctx __attribute__((unused)),
 808                   const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 809                   const struct GNUNET_MessageHeader *message,
 810                   const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 811 {
 812   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 813   struct remote_addr* s = (struct remote_addr*)desc;
 814   struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
 815   const struct GNUNET_PeerIdentity* other = GNUNET_MESH_get_peer(tunnel);
 816
 817   size_t pktlen = ntohs(message->size) - sizeof(struct GNUNET_MessageHeader) - sizeof(GNUNET_HashCode);
 818   size_t size = pktlen + sizeof(struct ip6_tcp) - 1;
 819
 820   struct ip6_tcp* pkt6 = alloca(size);
 821   memset(pkt6, 0, size);
 822
 823   GNUNET_assert(pkt6 != NULL);
 824
 825   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_TCP_BACK)
 826     new_ip6addr(pkt6->ip6_hdr.sadr, &other->hashPubKey, desc);
 827   else
 828     new_ip6addr_remote(pkt6->ip6_hdr.sadr, s->addr, s->addrlen);
 829
 830   pkt6->shdr.type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER);
 831   pkt6->shdr.size = htons(size);
 832
 833   pkt6->tun.flags = 0;
 834   pkt6->tun.type = htons(0x86dd);
 835
 836   pkt6->ip6_hdr.version = 6;
 837   pkt6->ip6_hdr.tclass_h = 0;
 838   pkt6->ip6_hdr.tclass_l = 0;
 839   pkt6->ip6_hdr.flowlbl = 0;
 840   pkt6->ip6_hdr.paylgth = htons(pktlen);
 841   pkt6->ip6_hdr.nxthdr = 0x06;
 842   pkt6->ip6_hdr.hoplmt = 0xff;
 843
 844   {
 845     char* ipv6addr;
 846     GNUNET_assert(GNUNET_OK == GNUNET_CONFIGURATION_get_value_string(cfg, "vpn", "IPV6ADDR", &ipv6addr));
 847     inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr);
 848     GNUNET_free(ipv6addr);
 849   }
 850   memcpy(&pkt6->tcp_hdr, pkt, pktlen);
 851
 852   GNUNET_HashCode* key = address_mapping_exists(pkt6->ip6_hdr.sadr);
 853   GNUNET_assert (key != NULL);
 854
 855   struct map_entry *me = GNUNET_CONTAINER_multihashmap_get(hashmap, key);
 856   GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node,
 857                                      GNUNET_TIME_absolute_get ().abs_value);
 858
 859   GNUNET_free(key);
 860
 861   GNUNET_assert (me != NULL);
 862   if (ntohs(message->type) == GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK)
 863     GNUNET_assert (me->desc.service_type & htonl(GNUNET_DNS_SERVICE_TYPE_TCP));
 864
 865   pkt6->tcp_hdr.crc = 0;
 866   uint32_t sum = 0;
 867   uint32_t tmp;
 868   sum =
 869     calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16);
 870   sum =
 871     calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16);
 872   tmp = htonl(pktlen);
 873   sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 874   tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff)));
 875   sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 876
 877   sum =
 878     calculate_checksum_update (sum, (uint16_t *) & pkt6->tcp_hdr,
 879                                ntohs (pkt6->ip6_hdr.paylgth));
 880   pkt6->tcp_hdr.crc = calculate_checksum_end (sum);
 881
 882   write_to_helper(pkt6, size);
 883
 884   return GNUNET_OK;
 885 }
 886
 887 /**
 888  * Main function that will be run by the scheduler.
 889  *
 890  * @param cls closure
 891  * @param args remaining command-line arguments
 892  * @param cfgfile name of the configuration file used (for saving, can be NULL!)
 893  * @param cfg_ configuration
 894  */
 895 static void
 896 run (void *cls,
 897      char *const *args __attribute__((unused)),
 898      const char *cfgfilep __attribute__((unused)),
 899      const struct GNUNET_CONFIGURATION_Handle *cfg_)
 900 {
 901     static const struct GNUNET_MESH_MessageHandler handlers[] = {
 902           {receive_udp_back, GNUNET_MESSAGE_TYPE_SERVICE_UDP_BACK, 0},
 903           {receive_tcp_back, GNUNET_MESSAGE_TYPE_SERVICE_TCP_BACK, 0},
 904           {receive_udp_back, GNUNET_MESSAGE_TYPE_REMOTE_UDP_BACK, 0},
 905           {receive_tcp_back, GNUNET_MESSAGE_TYPE_REMOTE_TCP_BACK, 0},
 906           {NULL, 0, 0}
 907     };
 908
 909     static const GNUNET_MESH_ApplicationType types[] = {
 910         GNUNET_APPLICATION_TYPE_END
 911     };
 912
 913     mesh_handle = GNUNET_MESH_connect(cfg_,
 914                                       NULL,
 915                                       NULL,
 916                                       handlers,
 917                                       types);
 918     cfg = cfg_;
 919     restart_hijack = 0;
 920     hashmap = GNUNET_CONTAINER_multihashmap_create(65536);
 921     heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
 922     GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "MAX_MAPPINGg",
 923                                            &max_mappings);
 924     udp_connections = GNUNET_CONTAINER_multihashmap_create(65536);
 925     conn_task = GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL);
 926     shs_task = GNUNET_SCHEDULER_add_after (conn_task, start_helper_and_schedule, NULL);
 927     GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
 928 }
 929
 930 /**
 931  * The main function to obtain template from gnunetd.
 932  *
 933  * @param argc number of arguments from the command line
 934  * @param argv command line arguments
 935  * @return 0 ok, 1 on error
 936  */
 937 int
 938 main (int argc, char *const *argv) {
 939     static const struct GNUNET_GETOPT_CommandLineOption options[] = {
 940         GNUNET_GETOPT_OPTION_END
 941     };
 942
 943     return (GNUNET_OK ==
 944             GNUNET_PROGRAM_run (argc,
 945                                 argv,
 946                                 "vpn",
 947                                 gettext_noop ("help text"),
 948                                 options, &run, NULL)) ? ret : 1;
 949 }
 950
 951 /* end of gnunet-daemon-vpn.c */
 952