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