src/vpn/gnunet-daemon-exit.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-exit.c
  23  * @brief
  24  * @author Philipp Toelke
  25  */
  26 #include <platform.h>
  27 #include <gnunet_common.h>
  28 #include <gnunet_program_lib.h>
  29 #include <gnunet_protocols.h>
  30 #include <gnunet_applications.h>
  31 #include <gnunet_mesh_service.h>
  32 #include <gnunet_constants.h>
  33 #include <string.h>
  34
  35 #include "gnunet-vpn-packet.h"
  36 #include "gnunet-helper-vpn-api.h"
  37 #include "gnunet-vpn-checksum.h"
  38
  39 GNUNET_SCHEDULER_TaskIdentifier shs_task;
  40
  41 /**
  42  * The handle to the configuration used throughout the process
  43  */
  44 static const struct GNUNET_CONFIGURATION_Handle *cfg;
  45
  46 /**
  47  * The handle to the helper
  48  */
  49 struct GNUNET_VPN_HELPER_Handle *helper_handle;
  50
  51 /**
  52  * Final status code.
  53  */
  54 static int ret;
  55
  56 /**
  57  * The handle to mesh
  58  */
  59 static struct GNUNET_MESH_Handle *mesh_handle;
  60
  61 /**
  62  * This hashmaps contains the mapping from peer, service-descriptor,
  63  * source-port and destination-port to a struct redirect_state
  64  */
  65 static struct GNUNET_CONTAINER_MultiHashMap *udp_connections;
  66 static struct GNUNET_CONTAINER_Heap *udp_connections_heap;
  67 static struct GNUNET_CONTAINER_MultiHashMap *tcp_connections;
  68 static struct GNUNET_CONTAINER_Heap *tcp_connections_heap;
  69
  70 /**
  71  * If there are at least this many udp-Connections, old ones will be removed
  72  */
  73 static long long unsigned int max_udp_connections = 200;
  74
  75 /**
  76  * If there are at least this many tcp-Connections, old ones will be removed
  77  */
  78 static long long unsigned int max_tcp_connections = 200;
  79
  80 struct remote_addr
  81 {
  82   char addrlen;
  83   unsigned char addr[16];
  84   char proto;
  85 };
  86
  87 /**
  88  * This struct is saved into the services-hashmap
  89  */
  90 struct redirect_service
  91 {
  92   /**
  93    * One of 4 or 6
  94    */
  95   unsigned int version;
  96   uint16_t my_port;
  97   uint16_t remote_port;
  98
  99   union
 100   {
 101     struct
 102     {
 103       char ip4address[4];
 104     } v4;
 105     struct
 106     {
 107       char ip6address[16];
 108     } v6;
 109   };
 110 };
 111
 112 struct redirect_info
 113 {
 114     /**
 115      * The source-address of this connection. When a packet to this address is
 116      * received, this tunnel is used to forward it.  ipv4-addresses will be put
 117      * here left-aligned */
 118   char addr[16];
 119     /**
 120      * The source-port of this connection
 121      */
 122   uint16_t pt;
 123 };
 124
 125 /**
 126  * This struct is saved into {tcp,udp}_connections;
 127  */
 128 struct redirect_state
 129 {
 130   struct GNUNET_MESH_Tunnel *tunnel;
 131   GNUNET_HashCode desc;
 132   struct redirect_service *serv;
 133   struct remote_addr remote;
 134
 135   struct GNUNET_CONTAINER_HeapNode* heap_node;
 136   struct GNUNET_CONTAINER_MultiHashMap *hashmap;
 137   GNUNET_HashCode hash;
 138
 139   enum { SERVICE, REMOTE } type;
 140
 141   /**
 142    * The source-address and -port of this connection
 143    */
 144   struct redirect_info redirect_info;
 145 };
 146
 147 /**
 148  * This hashmaps saves interesting things about the configured services
 149  */
 150 static struct GNUNET_CONTAINER_MultiHashMap *udp_services;
 151 static struct GNUNET_CONTAINER_MultiHashMap *tcp_services;
 152
 153 struct tunnel_notify_queue
 154 {
 155   struct tunnel_notify_queue* next;
 156   struct tunnel_notify_queue* prev;
 157   void* cls;
 158   size_t len;
 159 };
 160
 161 /**
 162  * Function that frees everything from a hashmap
 163  */
 164 static int
 165 free_iterate(void* cls __attribute__((unused)), const GNUNET_HashCode* hash __attribute__((unused)), void* value)
 166 {
 167   GNUNET_free(value);
 168   return GNUNET_YES;
 169 }
 170
 171 /**
 172  * Function scheduled as very last function, cleans up after us
 173  */
 174 static void
 175 cleanup(void* cls __attribute__((unused)), const struct GNUNET_SCHEDULER_TaskContext* tskctx) {
 176     GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN));
 177
 178     GNUNET_CONTAINER_multihashmap_iterate(udp_connections,
 179                                           free_iterate,
 180                                           NULL);
 181
 182     GNUNET_CONTAINER_multihashmap_iterate(tcp_connections,
 183                                           free_iterate,
 184                                           NULL);
 185
 186     if (mesh_handle != NULL)
 187       {
 188         GNUNET_MESH_disconnect(mesh_handle);
 189         mesh_handle = NULL;
 190       }
 191 }
 192
 193 static void
 194 collect_connections(void* cls, const struct GNUNET_SCHEDULER_TaskContext* tc) {
 195           if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
 196       return;
 197
 198
 199     struct GNUNET_CONTAINER_Heap *heap = cls;
 200
 201     struct redirect_state* state = GNUNET_CONTAINER_heap_remove_root(heap);
 202
 203     /* This is free()ed memory! */
 204     state->heap_node = NULL;
 205
 206     /* FIXME! GNUNET_MESH_close_tunnel(state->tunnel); */
 207
 208     GNUNET_CONTAINER_multihashmap_remove(state->hashmap, &state->hash, state);
 209
 210     GNUNET_free(state);
 211 }
 212
 213 static void
 214 hash_redirect_info(GNUNET_HashCode* hash, struct redirect_info* u_i, size_t addrlen)
 215 {
 216
 217   /* the gnunet hashmap only uses the first sizeof(unsigned int) of the hash
 218    *
 219    * build the hash out of the last bytes of the address and the 2 bytes of
 220    * the port
 221    */
 222   memcpy(hash, &u_i->pt, sizeof(u_i->pt));
 223   memcpy(((unsigned char*)hash)+2, u_i->addr+(addrlen-(sizeof(unsigned int) - 2)), (sizeof(unsigned int) - 2));
 224   memset(((unsigned char*)hash)+sizeof(unsigned int), 0, sizeof(GNUNET_HashCode) - sizeof(unsigned int));
 225 }
 226
 227 /**
 228  * cls is the pointer to a GNUNET_MessageHeader that is
 229  * followed by the service-descriptor and the udp-packet that should be sent;
 230  */
 231 static size_t
 232 send_udp_to_peer_notify_callback (void *cls, size_t size, void *buf)
 233 {
 234   struct GNUNET_MESH_Tunnel** tunnel = cls;
 235   GNUNET_MESH_tunnel_set_data(*tunnel, NULL);
 236   struct GNUNET_MessageHeader *hdr = (struct GNUNET_MessageHeader*)(tunnel + 1);
 237   GNUNET_assert (size >= ntohs (hdr->size));
 238   memcpy (buf, hdr, ntohs (hdr->size));
 239   size = ntohs(hdr->size);
 240
 241   if (NULL != GNUNET_MESH_tunnel_get_head(*tunnel))
 242     {
 243       struct tunnel_notify_queue* element = GNUNET_MESH_tunnel_get_head(*tunnel);
 244       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(*tunnel);
 245       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(*tunnel);
 246
 247       GNUNET_CONTAINER_DLL_remove(head, tail, element);
 248
 249       GNUNET_MESH_tunnel_set_head(*tunnel, head);
 250       GNUNET_MESH_tunnel_set_tail(*tunnel, tail);
 251
 252       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (*tunnel,
 253                                                                                  GNUNET_NO,
 254                                                                                  42,
 255                                                                                  GNUNET_TIME_relative_divide
 256                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 257                                                                                  (const struct GNUNET_PeerIdentity *)
 258                                                                                  NULL, element->len,
 259                                                                                  send_udp_to_peer_notify_callback, element->cls);
 260       /* save the handle */
 261       GNUNET_MESH_tunnel_set_data(*tunnel, th);
 262       GNUNET_free(element);
 263     }
 264
 265   GNUNET_free (cls);
 266
 267   return size;
 268 }
 269
 270 /**
 271  * @brief Handles an UDP-Packet received from the helper.
 272  *
 273  * @param udp A pointer to the Packet
 274  * @param dadr The IP-Destination-address
 275  * @param addrlen The length of the address
 276  * @param version 4 or 6
 277  */
 278 static void
 279 udp_from_helper (struct udp_pkt *udp, unsigned char *dadr, size_t addrlen)
 280 {
 281   struct redirect_info u_i;
 282   struct GNUNET_MESH_Tunnel *tunnel;
 283   uint32_t len;
 284   struct GNUNET_MessageHeader *msg;
 285
 286   memset (&u_i, 0, sizeof (struct redirect_info));
 287
 288   memcpy (&u_i.addr, dadr, addrlen);
 289
 290   u_i.pt = udp->dpt;
 291
 292   /* get tunnel and service-descriptor from this */
 293   GNUNET_HashCode hash;
 294   hash_redirect_info(&hash, &u_i, addrlen);
 295
 296   struct redirect_state *state =
 297     GNUNET_CONTAINER_multihashmap_get (udp_connections, &hash);
 298
 299   /* Mark this connection as freshly used */
 300   GNUNET_CONTAINER_heap_update_cost (udp_connections_heap, state->heap_node,
 301                                      GNUNET_TIME_absolute_get ().abs_value);
 302
 303   tunnel = state->tunnel;
 304
 305   if (state->type == SERVICE)
 306     {
 307       /* check if spt == serv.remote if yes: set spt = serv.myport ("nat") */
 308       if (ntohs (udp->spt) == state->serv->remote_port)
 309         {
 310           udp->spt = htons (state->serv->my_port);
 311         }
 312       else
 313         {
 314           /* otherwise the answer came from a different port (tftp does this)
 315            * add this new port to the list of all services, so that the packets
 316            * coming back from the client to this new port will be routed correctly
 317            */
 318           struct redirect_service *serv =
 319             GNUNET_malloc (sizeof (struct redirect_service));
 320           memcpy (serv, state->serv, sizeof (struct redirect_service));
 321           serv->my_port = ntohs (udp->spt);
 322           serv->remote_port = ntohs (udp->spt);
 323           uint16_t *desc = alloca (sizeof (GNUNET_HashCode) + 2);
 324           memcpy ((GNUNET_HashCode *) (desc + 1), &state->desc,
 325                   sizeof (GNUNET_HashCode));
 326           *desc = ntohs (udp->spt);
 327           GNUNET_assert (GNUNET_OK ==
 328                          GNUNET_CONTAINER_multihashmap_put (udp_services,
 329                                                             (GNUNET_HashCode*)desc, serv,
 330                                                             GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
 331
 332           state->serv = serv;
 333         }
 334     }
 335
 336   /* send udp-packet back */
 337   len =
 338     sizeof (struct GNUNET_MessageHeader) + sizeof (GNUNET_HashCode) +
 339     ntohs (udp->len);
 340   struct GNUNET_MESH_Tunnel** ctunnel = GNUNET_malloc (sizeof(struct GNUNET_MESH_TUNNEL*) + len);
 341   *ctunnel = tunnel;
 342   msg = (struct GNUNET_MessageHeader*)(ctunnel + 1);
 343   msg->size = htons (len);
 344   msg->type = htons (state->type == SERVICE ? GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK : GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK);
 345   GNUNET_HashCode *desc = (GNUNET_HashCode *) (msg + 1);
 346   if (state->type == SERVICE)
 347     memcpy (desc, &state->desc, sizeof (GNUNET_HashCode));
 348   else
 349     memcpy (desc, &state->remote, sizeof (struct remote_addr));
 350   void *_udp = desc + 1;
 351   memcpy (_udp, udp, ntohs (udp->len));
 352
 353   if (NULL == GNUNET_MESH_tunnel_get_data(tunnel))
 354     {
 355       /* No notify is pending */
 356       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (tunnel,
 357                                                                                  GNUNET_NO,
 358                                                                                  42,
 359                                                                                  GNUNET_TIME_relative_divide
 360                                                                                  (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 361                                                                                  (const struct GNUNET_PeerIdentity *)
 362                                                                                  NULL, len,
 363                                                                                  send_udp_to_peer_notify_callback, ctunnel);
 364       /* save the handle */
 365       GNUNET_MESH_tunnel_set_data(tunnel, th);
 366     }
 367   else
 368     {
 369       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(tunnel);
 370       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(tunnel);
 371
 372       struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
 373       element->cls = ctunnel;
 374       element->len = len;
 375
 376       GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 377       GNUNET_MESH_tunnel_set_head(tunnel, head);
 378       GNUNET_MESH_tunnel_set_tail(tunnel, tail);
 379     }
 380 }
 381
 382 /**
 383  * @brief Handles a TCP-Packet received from the helper.
 384  *
 385  * @param tcp A pointer to the Packet
 386  * @param dadr The IP-Destination-address
 387  * @param addrlen The length of the address
 388  * @param version 4 or 6
 389  * @param pktlen the length of the packet, including its header
 390  */
 391 static void
 392 tcp_from_helper (struct tcp_pkt *tcp, unsigned char *dadr, size_t addrlen,
 393                  size_t pktlen)
 394 {
 395   struct redirect_info u_i;
 396   struct GNUNET_MESH_Tunnel *tunnel;
 397   uint32_t len;
 398   struct GNUNET_MessageHeader *msg;
 399
 400   memset (&u_i, 0, sizeof (struct redirect_info));
 401
 402   memcpy (&u_i.addr, dadr, addrlen);
 403   u_i.pt = tcp->dpt;
 404
 405   /* get tunnel and service-descriptor from this */
 406   GNUNET_HashCode hash;
 407   hash_redirect_info(&hash, &u_i, addrlen);
 408
 409   struct redirect_state *state =
 410     GNUNET_CONTAINER_multihashmap_get (tcp_connections, &hash);
 411
 412   if (state == NULL)
 413     {
 414       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "No mapping for this connection; hash is %x\n", *((uint32_t*)&hash));
 415       return;
 416     }
 417
 418   /* Mark this connection as freshly used */
 419   GNUNET_CONTAINER_heap_update_cost (tcp_connections_heap, state->heap_node,
 420                                      GNUNET_TIME_absolute_get ().abs_value);
 421
 422   tunnel = state->tunnel;
 423
 424   if (state->type == SERVICE)
 425     {
 426       /* check if spt == serv.remote if yes: set spt = serv.myport ("nat") */
 427       if (ntohs (tcp->spt) == state->serv->remote_port)
 428         {
 429           tcp->spt = htons (state->serv->my_port);
 430         }
 431       else
 432         {
 433           // This is an illegal packet.
 434           return;
 435         }
 436     }
 437
 438   /* send tcp-packet back */
 439   len =
 440     sizeof (struct GNUNET_MessageHeader) + sizeof (GNUNET_HashCode) + pktlen;
 441   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "len: %d\n", pktlen);
 442   struct GNUNET_MESH_Tunnel** ctunnel = GNUNET_malloc (sizeof(struct GNUNET_MESH_TUNNEL*) + len);
 443   *ctunnel = tunnel;
 444   msg = (struct GNUNET_MessageHeader*)(ctunnel + 1);
 445   msg->size = htons (len);
 446   msg->type = htons (state->type == SERVICE ? GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK : GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK);
 447   GNUNET_HashCode *desc = (GNUNET_HashCode *) (msg + 1);
 448   if (state->type == SERVICE)
 449     memcpy (desc, &state->desc, sizeof (GNUNET_HashCode));
 450   else
 451     memcpy (desc, &state->remote, sizeof (struct remote_addr));
 452   void *_tcp = desc + 1;
 453   memcpy (_tcp, tcp, pktlen);
 454
 455   if (NULL == GNUNET_MESH_tunnel_get_data(tunnel))
 456     {
 457       /* No notify is pending */
 458       struct GNUNET_MESH_TransmitHandle* th = GNUNET_MESH_notify_transmit_ready (tunnel,
 459                                      GNUNET_NO,
 460                                      42,
 461                                      GNUNET_TIME_relative_divide
 462                                      (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2),
 463                                      (const struct GNUNET_PeerIdentity *)NULL,
 464                                      len, send_udp_to_peer_notify_callback,
 465                                      ctunnel);
 466       /* save the handle */
 467       GNUNET_MESH_tunnel_set_data(tunnel, th);
 468     }
 469   else
 470     {
 471       struct tunnel_notify_queue* head = GNUNET_MESH_tunnel_get_head(tunnel);
 472       struct tunnel_notify_queue* tail = GNUNET_MESH_tunnel_get_tail(tunnel);
 473
 474       struct tunnel_notify_queue* element = GNUNET_malloc(sizeof(struct tunnel_notify_queue));
 475       element->cls = ctunnel;
 476       element->len = len;
 477
 478       GNUNET_CONTAINER_DLL_insert_tail(head, tail, element);
 479     }
 480 }
 481
 482
 483 /**
 484  * Receive packets from the helper-process
 485  */
 486 static void
 487 message_token (void *cls __attribute__((unused)),
 488                void *client __attribute__((unused)), const struct GNUNET_MessageHeader *message)
 489 {
 490   GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_HELPER);
 491
 492   struct tun_pkt *pkt_tun = (struct tun_pkt *) message;
 493
 494   /* ethertype is ipv6 */
 495   if (ntohs (pkt_tun->tun.type) == 0x86dd)
 496     {
 497       struct ip6_pkt *pkt6 = (struct ip6_pkt *) pkt_tun;
 498       if (0x11 == pkt6->ip6_hdr.nxthdr)
 499         udp_from_helper (&((struct ip6_udp *) pkt6)->udp_hdr,
 500                          (unsigned char *) &pkt6->ip6_hdr.dadr, 16);
 501       else if (0x06 == pkt6->ip6_hdr.nxthdr)
 502         tcp_from_helper (&((struct ip6_tcp *) pkt6)->tcp_hdr,
 503                          (unsigned char *) &pkt6->ip6_hdr.dadr, 16,
 504                          ntohs (pkt6->ip6_hdr.paylgth));
 505     }
 506   else if (ntohs (pkt_tun->tun.type) == 0x0800)
 507     {
 508       struct ip_pkt *pkt4 = (struct ip_pkt *) pkt_tun;
 509       uint32_t tmp = pkt4->ip_hdr.dadr;
 510       if (0x11 == pkt4->ip_hdr.proto)
 511         udp_from_helper (&((struct ip_udp *) pkt4)->udp_hdr,
 512                          (unsigned char *) &tmp, 4);
 513       else if (0x06 == pkt4->ip_hdr.proto)
 514         {
 515           size_t pktlen = ntohs(pkt4->ip_hdr.tot_lngth);
 516           GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "tot: %d\n", pktlen);
 517           pktlen -= 4*pkt4->ip_hdr.hdr_lngth;
 518           GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "-hdr: %d\n", pktlen);
 519           tcp_from_helper (&((struct ip_tcp *) pkt4)->tcp_hdr,
 520                            (unsigned char *) &tmp, 4, pktlen);
 521         }
 522     }
 523   else
 524     {
 525       return;
 526     }
 527 }
 528
 529 /**
 530  * Reads the configuration servicecfg and populates udp_services
 531  *
 532  * @param cls unused
 533  * @param section name of section in config, equal to hostname
 534  */
 535 static void
 536 read_service_conf (void *cls __attribute__((unused)), const char *section)
 537 {
 538   if ((strlen(section) < 8) || (0 != strcmp (".gnunet.", section + (strlen(section) - 8))))
 539     return;
 540
 541   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %d %s %s\n", strlen(section), section, section + (strlen(section) - 8));
 542
 543   char *cpy;
 544   char *redirect;
 545   char *hostname;
 546   char *hostport;
 547   uint16_t *desc = alloca (sizeof (GNUNET_HashCode) + 2);
 548   GNUNET_CRYPTO_hash (section, strlen (section) + 1,
 549                       (GNUNET_HashCode *) (desc + 1));
 550
 551 #define TCP 2
 552 #define UDP 1
 553
 554   int proto = UDP;
 555
 556   do
 557     {
 558       if (proto == UDP && (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, section, "UDP_REDIRECTS", &cpy)))
 559         goto next;
 560       else if (proto == TCP && (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string(cfg, section, "TCP_REDIRECTS", &cpy)))
 561         goto next;
 562
 563       for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok
 564            (NULL, " "))
 565         {
 566           if (NULL == (hostname = strstr (redirect, ":")))
 567             {
 568               GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n",
 569                           redirect);
 570               continue;
 571             }
 572           hostname[0] = '\0';
 573           hostname++;
 574           if (NULL == (hostport = strstr (hostname, ":")))
 575             {
 576               GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n",
 577                           redirect);
 578               continue;
 579             }
 580           hostport[0] = '\0';
 581           hostport++;
 582
 583           int local_port = atoi (redirect);
 584           if (!((local_port > 0) && (local_port < 65536)))
 585             GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.",
 586                         redirect);
 587
 588           *desc = local_port;
 589
 590           struct redirect_service *serv =
 591             GNUNET_malloc (sizeof (struct redirect_service));
 592           memset (serv, 0, sizeof (struct redirect_service));
 593           serv->my_port = local_port;
 594
 595           if (0 == strcmp ("localhost4", hostname))
 596             {
 597               serv->version = 4;
 598
 599               char *ip4addr;
 600               GNUNET_assert (GNUNET_OK ==
 601                              GNUNET_CONFIGURATION_get_value_string (cfg,
 602                                                                     "exit",
 603                                                                     "IPV4ADDR",
 604                                                                     &ip4addr));
 605               GNUNET_assert (1 ==
 606                              inet_pton (AF_INET, ip4addr,
 607                                         serv->v4.ip4address));
 608               GNUNET_free (ip4addr);
 609             }
 610           else if (0 == strcmp ("localhost6", hostname))
 611             {
 612               serv->version = 6;
 613
 614               char *ip6addr;
 615               GNUNET_assert (GNUNET_OK ==
 616                              GNUNET_CONFIGURATION_get_value_string (cfg,
 617                                                                     "exit",
 618                                                                     "IPV6ADDR",
 619                                                                     &ip6addr));
 620               GNUNET_assert (1 ==
 621                              inet_pton (AF_INET6, ip6addr,
 622                                         serv->v6.ip6address));
 623               GNUNET_free (ip6addr);
 624             }
 625           else
 626             {
 627               // TODO Lookup, yadayadayada
 628               GNUNET_assert (0);
 629             }
 630           serv->remote_port = atoi (hostport);
 631           if (UDP == proto)
 632             GNUNET_assert (GNUNET_OK ==
 633                            GNUNET_CONTAINER_multihashmap_put (udp_services,
 634                                                               (GNUNET_HashCode*)desc, serv,
 635                                                               GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
 636           else
 637             GNUNET_assert (GNUNET_OK ==
 638                            GNUNET_CONTAINER_multihashmap_put (tcp_services,
 639                                                               (GNUNET_HashCode*)desc, serv,
 640                                                               GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
 641
 642         }
 643       GNUNET_free (cpy);
 644 next:
 645       proto = (proto == UDP) ? TCP : UDP;
 646     }
 647   while (proto != UDP);
 648 }
 649
 650 /**
 651  * Start the helper-process
 652  *
 653  * If cls != NULL it is assumed that this function is called as a result of a dying
 654  * helper. cls is then taken as handle to the old helper and is cleaned up.
 655  */
 656 static void
 657 start_helper_and_schedule(void *cls,
 658                           const struct GNUNET_SCHEDULER_TaskContext *tc) {
 659     if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
 660       return;
 661
 662     if (cls != NULL)
 663       cleanup_helper(cls);
 664     cls = NULL;
 665
 666     char* ifname;
 667     char* ipv6addr;
 668     char* ipv6prefix;
 669     char* ipv4addr;
 670     char* ipv4mask;
 671
 672     if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "exit", "IFNAME", &ifname))
 673       {
 674         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IFNAME' in configuration!\n");
 675         exit(1);
 676       }
 677
 678     if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "exit", "IPV6ADDR", &ipv6addr))
 679       {
 680         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV6ADDR' in configuration!\n");
 681         exit(1);
 682       }
 683
 684     if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "exit", "IPV6PREFIX", &ipv6prefix))
 685       {
 686         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV6PREFIX' in configuration!\n");
 687         exit(1);
 688       }
 689
 690     if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "exit", "IPV4ADDR", &ipv4addr))
 691       {
 692         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV4ADDR' in configuration!\n");
 693         exit(1);
 694       }
 695
 696     if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string(cfg, "exit", "IPV4MASK", &ipv4mask))
 697       {
 698         GNUNET_log(GNUNET_ERROR_TYPE_ERROR, "No entry 'IPV4MASK' in configuration!\n");
 699         exit(1);
 700       }
 701
 702     /* Start the helper
 703      * Messages get passed to the function message_token
 704      * When the helper dies, this function will be called again with the
 705      * helper_handle as cls.
 706      */
 707     helper_handle = start_helper(ifname,
 708                                  ipv6addr,
 709                                  ipv6prefix,
 710                                  ipv4addr,
 711                                  ipv4mask,
 712                                  "exit-gnunet",
 713                                  start_helper_and_schedule,
 714                                  message_token,
 715                                  NULL);
 716
 717     GNUNET_free(ipv6addr);
 718     GNUNET_free(ipv6prefix);
 719     GNUNET_free(ipv4addr);
 720     GNUNET_free(ipv4mask);
 721     GNUNET_free(ifname);
 722 }
 723
 724 static void
 725 prepare_ipv4_packet (ssize_t len, ssize_t pktlen, void *payload,
 726                      uint16_t protocol, void *ipaddress, void *tunnel,
 727                      struct redirect_state *state, struct ip_pkt *pkt4)
 728 {
 729   uint32_t tmp, tmp2;
 730
 731   pkt4->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
 732   pkt4->shdr.size = htons (len);
 733   pkt4->tun.flags = 0;
 734   pkt4->tun.type = htons (0x0800);
 735
 736   memcpy (&pkt4->data, payload, pktlen);
 737
 738   pkt4->ip_hdr.version = 4;
 739   pkt4->ip_hdr.hdr_lngth = 5;
 740   pkt4->ip_hdr.diff_serv = 0;
 741   pkt4->ip_hdr.tot_lngth = htons (20 + pktlen);
 742   pkt4->ip_hdr.ident = 0;
 743   pkt4->ip_hdr.flags = 0;
 744   pkt4->ip_hdr.frag_off = 0;
 745   pkt4->ip_hdr.ttl = 255;
 746   pkt4->ip_hdr.proto = protocol;
 747   pkt4->ip_hdr.chks = 0;        /* Will be calculated later */
 748
 749   memcpy (&tmp, ipaddress, 4);
 750   pkt4->ip_hdr.dadr = tmp;
 751
 752   /* Generate a new src-address */
 753   char *ipv4addr;
 754   char *ipv4mask;
 755   GNUNET_assert (GNUNET_OK ==
 756                  GNUNET_CONFIGURATION_get_value_string (cfg, "exit",
 757                                                         "IPV4ADDR",
 758                                                         &ipv4addr));
 759   GNUNET_assert (GNUNET_OK ==
 760                  GNUNET_CONFIGURATION_get_value_string (cfg, "exit",
 761                                                         "IPV4MASK",
 762                                                         &ipv4mask));
 763   inet_pton (AF_INET, ipv4addr, &tmp);
 764   inet_pton (AF_INET, ipv4mask, &tmp2);
 765   GNUNET_free (ipv4addr);
 766   GNUNET_free (ipv4mask);
 767
 768   /* This should be a noop */
 769   tmp = tmp & tmp2;
 770
 771   tmp |= ntohl (*((uint32_t *) tunnel)) & (~tmp2);
 772
 773   pkt4->ip_hdr.sadr = tmp;
 774
 775   memcpy (&state->redirect_info.addr, &tmp, 4);
 776   if (0x11 == protocol)
 777     {
 778       struct ip_udp* pkt4_udp = (struct ip_udp*)pkt4;
 779       state->redirect_info.pt = pkt4_udp->udp_hdr.spt;
 780
 781       pkt4_udp->udp_hdr.crc = 0;        /* Optional for IPv4 */
 782     }
 783   else if (0x06 == protocol)
 784     {
 785       struct ip_tcp* pkt4_tcp = (struct ip_tcp*)pkt4;
 786       state->redirect_info.pt = pkt4_tcp->tcp_hdr.spt;
 787
 788       pkt4_tcp->tcp_hdr.crc = 0;
 789       uint32_t sum = 0;
 790       tmp = pkt4->ip_hdr.sadr;
 791       sum =
 792         calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 793       tmp = pkt4->ip_hdr.dadr;
 794       sum =
 795         calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 796
 797       tmp = (protocol << 16) | (0xffff & pktlen);
 798
 799       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "line: %08x, %x \n", tmp, (0xffff & pktlen));
 800
 801       tmp = htonl(tmp);
 802
 803       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 804
 805       sum =
 806         calculate_checksum_update (sum, (uint16_t *) & pkt4_tcp->tcp_hdr, pktlen);
 807       pkt4_tcp->tcp_hdr.crc = calculate_checksum_end (sum);
 808     }
 809
 810   pkt4->ip_hdr.chks =
 811     calculate_ip_checksum ((uint16_t *) & pkt4->ip_hdr, 5 * 4);
 812 }
 813
 814 static void
 815 prepare_ipv6_packet (ssize_t len, ssize_t pktlen, void *payload,
 816                      uint16_t protocol, void *ipaddress, void *tunnel,
 817                      struct redirect_state *state, struct ip6_pkt *pkt6)
 818 {
 819   uint32_t tmp;
 820
 821   pkt6->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
 822   pkt6->shdr.size = htons (len);
 823   pkt6->tun.flags = 0;
 824
 825   pkt6->tun.type = htons (0x86dd);
 826
 827   memcpy (&pkt6->data, payload, pktlen);
 828
 829   pkt6->ip6_hdr.version = 6;
 830   pkt6->ip6_hdr.nxthdr = protocol;
 831   pkt6->ip6_hdr.paylgth = htons (pktlen);
 832   pkt6->ip6_hdr.hoplmt = 64;
 833
 834   memcpy (pkt6->ip6_hdr.dadr, ipaddress, 16);
 835
 836   /* Generate a new src-address
 837    * This takes as much from the address of the tunnel as fits into
 838    * the host-mask*/
 839   char *ipv6addr;
 840   unsigned long long ipv6prefix;
 841   GNUNET_assert (GNUNET_OK ==
 842                  GNUNET_CONFIGURATION_get_value_string (cfg, "exit",
 843                                                         "IPV6ADDR",
 844                                                         &ipv6addr));
 845   GNUNET_assert (GNUNET_OK ==
 846                  GNUNET_CONFIGURATION_get_value_number (cfg, "exit",
 847                                                         "IPV6PREFIX",
 848                                                         &ipv6prefix));
 849   GNUNET_assert (ipv6prefix < 127);
 850   ipv6prefix = (ipv6prefix + 7) / 8;
 851
 852   inet_pton (AF_INET6, ipv6addr, &pkt6->ip6_hdr.sadr);
 853   GNUNET_free (ipv6addr);
 854
 855   if (ipv6prefix < (16 - sizeof (void *)))
 856     ipv6prefix = 16 - sizeof (void *);
 857
 858   unsigned int offset = ipv6prefix - (16 - sizeof (void *));
 859   memcpy ((((char *) &pkt6->ip6_hdr.sadr)) + ipv6prefix,
 860           ((char *) &tunnel) + offset, 16 - ipv6prefix);
 861
 862   /* copy the needed information into the state */
 863   memcpy (&state->redirect_info.addr, &pkt6->ip6_hdr.sadr, 16);
 864
 865   if (0x11 == protocol)
 866     {
 867       struct ip6_udp* pkt6_udp = (struct ip6_udp*)pkt6;
 868       state->redirect_info.pt = pkt6_udp->udp_hdr.spt;
 869
 870       pkt6_udp->udp_hdr.crc = 0;
 871       uint32_t sum = 0;
 872       sum =
 873         calculate_checksum_update (sum, (uint16_t *) & pkt6_udp->ip6_hdr.sadr, 16);
 874       sum =
 875         calculate_checksum_update (sum, (uint16_t *) & pkt6_udp->ip6_hdr.dadr, 16);
 876       tmp = (htons (pktlen) & 0xffff);
 877       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 878       tmp = htons (((pkt6_udp->ip6_hdr.nxthdr & 0x00ff)));
 879       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 880
 881       sum =
 882         calculate_checksum_update (sum, (uint16_t *) & pkt6_udp->udp_hdr,
 883                                    ntohs (pkt6_udp->udp_hdr.len));
 884       pkt6_udp->udp_hdr.crc = calculate_checksum_end (sum);
 885     }
 886   else if (0x06 == protocol)
 887     {
 888       struct ip6_tcp* pkt6_tcp = (struct ip6_tcp*)pkt6;
 889       state->redirect_info.pt = pkt6_tcp->tcp_hdr.spt;
 890
 891       pkt6_tcp->tcp_hdr.crc = 0;
 892       uint32_t sum = 0;
 893       sum =
 894         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16);
 895       sum =
 896         calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16);
 897       tmp = htonl(pktlen);
 898       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 899       tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff)));
 900       sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4);
 901
 902       sum =
 903         calculate_checksum_update (sum, (uint16_t *) & pkt6_tcp->tcp_hdr,
 904                                    ntohs (pkt6->ip6_hdr.paylgth));
 905       pkt6_tcp->tcp_hdr.crc = calculate_checksum_end (sum);
 906     }
 907 }
 908
 909 /**
 910  * The messages are one GNUNET_HashCode for the service followed by a struct tcp_pkt
 911  */
 912 static int
 913 receive_tcp_service (void *cls __attribute__((unused)),
 914                      struct GNUNET_MESH_Tunnel *tunnel,
 915                      void **tunnel_ctx __attribute__((unused)),
 916                      const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
 917                      const struct GNUNET_MessageHeader *message,
 918                      const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
 919 {
 920   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received TCP-Packet\n");
 921   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
 922   struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
 923   unsigned int pkt_len = ntohs (message->size) - sizeof (struct
 924                                                          GNUNET_MessageHeader)
 925     - sizeof (GNUNET_HashCode);
 926
 927   /** Get the configuration from the services-hashmap.
 928    *
 929    * Which service is needed only depends on the service-descriptor and the
 930    * destination-port
 931    */
 932   uint16_t *tcp_desc = alloca (sizeof (GNUNET_HashCode) + 2);
 933
 934   memcpy (tcp_desc + 1, desc, sizeof (GNUNET_HashCode));
 935   *tcp_desc = ntohs (pkt->dpt);
 936   struct redirect_service *serv =
 937     GNUNET_CONTAINER_multihashmap_get (tcp_services, (GNUNET_HashCode*)tcp_desc);
 938   if (NULL == serv)
 939     {
 940       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 941                   "No service found for TCP dpt %d!\n", *tcp_desc);
 942       return GNUNET_YES;
 943     }
 944
 945   pkt->dpt = htons (serv->remote_port);
 946
 947   /*
 948    * At this point it would be possible to check against some kind of ACL.
 949    */
 950
 951   char *buf;
 952   size_t len;
 953
 954   /* Prepare the state.
 955    * This will be saved in the hashmap, so that the receiving procedure knows
 956    * through which tunnel this connection has to be routed.
 957    */
 958   struct redirect_state *state =
 959     GNUNET_malloc (sizeof (struct redirect_state));
 960   memset (state, 0, sizeof (struct redirect_state));
 961   state->tunnel = tunnel;
 962   state->serv = serv;
 963   state->type = SERVICE;
 964   state->hashmap = tcp_connections;
 965   memcpy (&state->desc, desc, sizeof (GNUNET_HashCode));
 966
 967   len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct pkt_tun) +
 968     sizeof (struct ip6_hdr) + pkt_len;
 969   buf = alloca (len);
 970
 971   memset (buf, 0, len);
 972
 973   switch (serv->version)
 974     {
 975     case 4:
 976       prepare_ipv4_packet (len, pkt_len, pkt, 0x06,     /* TCP */
 977                            &serv->v4.ip4address,
 978                            tunnel, state, (struct ip_pkt *) buf);
 979       break;
 980     case 6:
 981       prepare_ipv6_packet (len, pkt_len, pkt, 0x06,     /* TCP */
 982                            &serv->v6.ip6address,
 983                            tunnel, state, (struct ip6_pkt *) buf);
 984
 985       break;
 986     default:
 987       GNUNET_assert (0);
 988       break;
 989     }
 990
 991   hash_redirect_info(&state->hash, &state->redirect_info, serv->version == 4 ? 4 : 16);
 992
 993   if (GNUNET_NO ==
 994       GNUNET_CONTAINER_multihashmap_contains (tcp_connections, &state->hash))
 995     {
 996       GNUNET_CONTAINER_multihashmap_put (tcp_connections, &state->hash, state,
 997                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
 998
 999       state->heap_node =
1000         GNUNET_CONTAINER_heap_insert (tcp_connections_heap, state,
1001                                       GNUNET_TIME_absolute_get ().abs_value);
1002
1003       if (GNUNET_CONTAINER_heap_get_size(tcp_connections_heap) > max_tcp_connections)
1004         GNUNET_SCHEDULER_add_now(collect_connections, tcp_connections_heap);
1005     }
1006   else
1007     GNUNET_free (state);
1008
1009   (void) GNUNET_DISK_file_write (helper_handle->fh_to_helper, buf, len);
1010   return GNUNET_YES;
1011 }
1012
1013 static int
1014 receive_tcp_remote (void *cls __attribute__((unused)),
1015                      struct GNUNET_MESH_Tunnel *tunnel,
1016                      void **tunnel_ctx __attribute__((unused)),
1017                      const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
1018                      const struct GNUNET_MessageHeader *message,
1019                      const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
1020 {
1021   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
1022   struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1);
1023   struct remote_addr *s = (struct remote_addr *) desc;
1024   char *buf;
1025   size_t len;
1026   unsigned int pkt_len = ntohs (message->size) - sizeof (struct GNUNET_MessageHeader) - sizeof (GNUNET_HashCode);
1027
1028   struct redirect_state *state =
1029     GNUNET_malloc (sizeof (struct redirect_state));
1030   memset (state, 0, sizeof (struct redirect_state));
1031   state->tunnel = tunnel;
1032   state->type = REMOTE;
1033   state->hashmap = tcp_connections;
1034   memcpy (&state->remote, s, sizeof (struct remote_addr));
1035
1036   len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct pkt_tun) +
1037     sizeof (struct ip6_hdr) + pkt_len;
1038   buf = alloca (len);
1039
1040   memset (buf, 0, len);
1041
1042   switch (s->addrlen)
1043     {
1044     case 4:
1045       prepare_ipv4_packet (len, pkt_len, pkt, 0x06,    /* TCP */
1046                            &s->addr, tunnel, state, (struct ip_pkt *) buf);
1047       break;
1048     case 16:
1049       prepare_ipv6_packet (len, pkt_len, pkt, 0x06,    /* TCP */
1050                            &s->addr, tunnel, state, (struct ip6_pkt *) buf);
1051       break;
1052     default:
1053       return GNUNET_SYSERR;
1054       break;
1055     }
1056
1057   hash_redirect_info (&state->hash, &state->redirect_info, s->addrlen);
1058
1059   GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Packet from remote; hash is %x\n", *((uint32_t*)&state->hash));
1060
1061   if (GNUNET_NO ==
1062       GNUNET_CONTAINER_multihashmap_contains (tcp_connections, &state->hash))
1063     {
1064       GNUNET_CONTAINER_multihashmap_put (tcp_connections, &state->hash, state,
1065                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1066
1067       state->heap_node =
1068         GNUNET_CONTAINER_heap_insert (tcp_connections_heap, state,
1069                                       GNUNET_TIME_absolute_get ().abs_value);
1070
1071       if (GNUNET_CONTAINER_heap_get_size (tcp_connections_heap) >
1072           max_tcp_connections)
1073         GNUNET_SCHEDULER_add_now (collect_connections, tcp_connections_heap);
1074     }
1075   else
1076     GNUNET_free (state);
1077
1078   (void) GNUNET_DISK_file_write (helper_handle->fh_to_helper, buf, len);
1079   return GNUNET_YES;
1080
1081 }
1082
1083 static int
1084 receive_udp_remote (void *cls __attribute__((unused)),
1085                     struct GNUNET_MESH_Tunnel *tunnel,
1086                     void **tunnel_ctx __attribute__((unused)),
1087                     const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
1088                     const struct GNUNET_MessageHeader *message,
1089                     const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
1090 {
1091   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
1092   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
1093   struct remote_addr *s = (struct remote_addr *) desc;
1094   char *buf;
1095   size_t len;
1096
1097   GNUNET_assert (ntohs (pkt->len) ==
1098                  ntohs (message->size) -
1099                  sizeof (struct GNUNET_MessageHeader) -
1100                  sizeof (GNUNET_HashCode));
1101
1102   /* Prepare the state.
1103    * This will be saved in the hashmap, so that the receiving procedure knows
1104    * through which tunnel this connection has to be routed.
1105    */
1106   struct redirect_state *state =
1107     GNUNET_malloc (sizeof (struct redirect_state));
1108   memset (state, 0, sizeof (struct redirect_state));
1109   state->tunnel = tunnel;
1110   state->hashmap = udp_connections;
1111   state->type = REMOTE;
1112   memcpy (&state->remote, s, sizeof (struct remote_addr));
1113
1114   len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct pkt_tun) +
1115     sizeof (struct ip6_hdr) + ntohs (pkt->len);
1116   buf = alloca (len);
1117
1118   memset (buf, 0, len);
1119
1120   switch (s->addrlen)
1121     {
1122     case 4:
1123       prepare_ipv4_packet (len, ntohs (pkt->len), pkt, 0x11,    /* UDP */
1124                            &s->addr, tunnel, state, (struct ip_pkt *) buf);
1125       break;
1126     case 16:
1127       prepare_ipv6_packet (len, ntohs (pkt->len), pkt, 0x11,    /* UDP */
1128                            &s->addr, tunnel, state, (struct ip6_pkt *) buf);
1129       break;
1130     default:
1131       GNUNET_assert (0);
1132       break;
1133     }
1134
1135   hash_redirect_info (&state->hash, &state->redirect_info, s->addrlen);
1136
1137   if (GNUNET_NO ==
1138       GNUNET_CONTAINER_multihashmap_contains (udp_connections, &state->hash))
1139     {
1140       GNUNET_CONTAINER_multihashmap_put (udp_connections, &state->hash, state,
1141                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1142
1143       state->heap_node =
1144         GNUNET_CONTAINER_heap_insert (udp_connections_heap, state,
1145                                       GNUNET_TIME_absolute_get ().abs_value);
1146
1147       if (GNUNET_CONTAINER_heap_get_size (udp_connections_heap) >
1148           max_udp_connections)
1149         GNUNET_SCHEDULER_add_now (collect_connections, udp_connections_heap);
1150     }
1151   else
1152     GNUNET_free (state);
1153
1154   (void) GNUNET_DISK_file_write (helper_handle->fh_to_helper, buf, len);
1155   return GNUNET_YES;
1156 }
1157
1158 /**
1159  * The messages are one GNUNET_HashCode for the service, followed by a struct udp_pkt
1160  */
1161 static int
1162 receive_udp_service (void *cls __attribute__((unused)),
1163                      struct GNUNET_MESH_Tunnel *tunnel,
1164                      void **tunnel_ctx __attribute__((unused)),
1165                      const struct GNUNET_PeerIdentity *sender __attribute__((unused)),
1166                      const struct GNUNET_MessageHeader *message,
1167                      const struct GNUNET_TRANSPORT_ATS_Information *atsi __attribute__((unused)))
1168 {
1169   GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1);
1170   struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1);
1171
1172   GNUNET_assert (ntohs (pkt->len) ==
1173                  ntohs (message->size) -
1174                  sizeof (struct GNUNET_MessageHeader) -
1175                  sizeof (GNUNET_HashCode));
1176
1177   /* Get the configuration from the hashmap */
1178   uint16_t *udp_desc = alloca (sizeof (GNUNET_HashCode) + 2);
1179   memcpy (udp_desc + 1, desc, sizeof (GNUNET_HashCode));
1180   *udp_desc = ntohs (pkt->dpt);
1181   struct redirect_service *serv =
1182     GNUNET_CONTAINER_multihashmap_get (udp_services, (GNUNET_HashCode*)udp_desc);
1183   if (NULL == serv)
1184     {
1185       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1186                   "No service found for UDP dpt %d!\n", *udp_desc);
1187       return GNUNET_YES;
1188     }
1189
1190   pkt->dpt = htons (serv->remote_port);
1191
1192   /*
1193    * At this point it would be possible to check against some kind of ACL.
1194    */
1195
1196   char *buf;
1197   size_t len;
1198
1199   /* Prepare the state.
1200    * This will be saved in the hashmap, so that the receiving procedure knows
1201    * through which tunnel this connection has to be routed.
1202    */
1203   struct redirect_state *state =
1204     GNUNET_malloc (sizeof (struct redirect_state));
1205   memset (state, 0, sizeof (struct redirect_state));
1206   state->tunnel = tunnel;
1207   state->serv = serv;
1208   state->type = SERVICE;
1209   state->hashmap = udp_connections;
1210   memcpy (&state->desc, desc, sizeof (GNUNET_HashCode));
1211
1212   len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct pkt_tun) +
1213     sizeof (struct ip6_hdr) + ntohs (pkt->len);
1214   buf = alloca (len);
1215
1216   memset (buf, 0, len);
1217
1218   switch (serv->version)
1219     {
1220     case 4:
1221       prepare_ipv4_packet (len, ntohs (pkt->len), pkt, 0x11,    /* UDP */
1222                            &serv->v4.ip4address,
1223                            tunnel, state, (struct ip_pkt *) buf);
1224       break;
1225     case 6:
1226       prepare_ipv6_packet (len, ntohs (pkt->len), pkt, 0x11,    /* UDP */
1227                            &serv->v6.ip6address,
1228                            tunnel, state, (struct ip6_pkt *) buf);
1229
1230       break;
1231     default:
1232       GNUNET_assert (0);
1233       break;
1234     }
1235
1236   hash_redirect_info(&state->hash, &state->redirect_info, serv->version == 4 ? 4 : 16);
1237
1238   if (GNUNET_NO ==
1239       GNUNET_CONTAINER_multihashmap_contains (udp_connections, &state->hash))
1240     {
1241       GNUNET_CONTAINER_multihashmap_put (udp_connections, &state->hash, state,
1242                                          GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
1243
1244       state->heap_node =
1245         GNUNET_CONTAINER_heap_insert (udp_connections_heap, state,
1246                                       GNUNET_TIME_absolute_get ().abs_value);
1247
1248       if (GNUNET_CONTAINER_heap_get_size(udp_connections_heap) > max_udp_connections)
1249         GNUNET_SCHEDULER_add_now(collect_connections, udp_connections_heap);
1250     }
1251   else
1252     GNUNET_free (state);
1253
1254   (void) GNUNET_DISK_file_write (helper_handle->fh_to_helper, buf, len);
1255   return GNUNET_YES;
1256 }
1257
1258 static void
1259 connect_to_mesh()
1260 {
1261   int udp, tcp;
1262   int handler_idx, app_idx;
1263
1264   udp = GNUNET_CONFIGURATION_get_value_yesno(cfg, "exit", "ENABLE_UDP");
1265   tcp = GNUNET_CONFIGURATION_get_value_yesno(cfg, "exit", "ENABLE_TCP");
1266
1267   static struct GNUNET_MESH_MessageHandler handlers[] = {
1268     {receive_udp_service, GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP, 0},
1269     {receive_tcp_service, GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP, 0},
1270     {NULL, 0, 0},
1271     {NULL, 0, 0},
1272     {NULL, 0, 0}
1273   };
1274
1275   static GNUNET_MESH_ApplicationType apptypes[] =
1276     {
1277       GNUNET_APPLICATION_TYPE_END,
1278       GNUNET_APPLICATION_TYPE_END,
1279       GNUNET_APPLICATION_TYPE_END
1280     };
1281
1282   app_idx = 0;
1283   handler_idx = 2;
1284
1285   if (GNUNET_YES == udp)
1286     {
1287       handlers[handler_idx].callback = receive_udp_remote;
1288       handlers[handler_idx].expected_size = 0;
1289       handlers[handler_idx].type = GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP;
1290       apptypes[app_idx] = GNUNET_APPLICATION_TYPE_INTERNET_UDP_GATEWAY;
1291       handler_idx++;
1292       app_idx++;
1293     }
1294
1295   if (GNUNET_YES == tcp)
1296     {
1297       handlers[handler_idx].callback = receive_tcp_remote;
1298       handlers[handler_idx].expected_size = 0;
1299       handlers[handler_idx].type = GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP;
1300       apptypes[app_idx] = GNUNET_APPLICATION_TYPE_INTERNET_TCP_GATEWAY;
1301       handler_idx++;
1302       app_idx++;
1303     }
1304
1305   mesh_handle = GNUNET_MESH_connect (cfg, NULL, NULL, handlers, apptypes);
1306 }
1307
1308 /**
1309  * @brief Main function that will be run by the scheduler.
1310  *
1311  * @param cls closure
1312  * @param args remaining command-line arguments
1313  * @param cfgfile name of the configuration file used (for saving, can be NULL!)
1314  * @param cfg_ configuration
1315  */
1316 static void
1317 run (void *cls,
1318      char *const *args __attribute__((unused)),
1319      const char *cfgfile __attribute__((unused)), const struct GNUNET_CONFIGURATION_Handle *cfg_)
1320 {
1321   cfg = cfg_;
1322
1323   connect_to_mesh();
1324
1325   udp_connections = GNUNET_CONTAINER_multihashmap_create (65536);
1326   udp_connections_heap =
1327     GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
1328   tcp_connections = GNUNET_CONTAINER_multihashmap_create (65536);
1329   tcp_connections_heap =
1330     GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
1331   udp_services = GNUNET_CONTAINER_multihashmap_create (65536);
1332   tcp_services = GNUNET_CONTAINER_multihashmap_create (65536);
1333
1334   GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_UDP_CONNECTIONS",
1335                                          &max_udp_connections);
1336   GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_TCP_CONNECTIONS",
1337                                          &max_tcp_connections);
1338
1339   GNUNET_CONFIGURATION_iterate_sections (cfg, read_service_conf, NULL);
1340
1341   GNUNET_SCHEDULER_add_now (start_helper_and_schedule, NULL);
1342   GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
1343 }
1344
1345 /**
1346  * The main function to obtain template from gnunetd.
1347  *
1348  * @param argc number of arguments from the command line
1349  * @param argv command line arguments
1350  * @return 0 ok, 1 on error
1351  */
1352 int
1353 main (int argc, char *const *argv) {
1354     static const struct GNUNET_GETOPT_CommandLineOption options[] = {
1355         GNUNET_GETOPT_OPTION_END
1356     };
1357
1358     return (GNUNET_OK ==
1359             GNUNET_PROGRAM_run (argc,
1360                                 argv,
1361                                 "exit",
1362                                 gettext_noop ("help text"),
1363                                 options, &run, NULL)) ? ret : 1;
1364 }
1365
1366 /* end of gnunet-daemon-exit.c */
1367