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