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