2 This file is part of GNUnet.
3 (C) 2010, 2012 Christian Grothoff
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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
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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.
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22 * @file exit/gnunet-daemon-exit.c
23 * @brief tool to allow IP traffic exit from the GNUnet mesh to the Internet
24 * @author Philipp Toelke
25 * @author Christian Grothoff
31 * - factor out crc computations from DNS/EXIT/VPN into shared library?
34 * - which code should advertise services? the service model is right
35 * now a bit odd, especially as this code DOES the exit and knows
36 * the DNS "name", but OTOH this is clearly NOT the place to advertise
37 * the service's existence; maybe the daemon should turn into a
38 * service with an API to add local-exit services dynamically?
41 #include "gnunet_util_lib.h"
42 #include "gnunet_protocols.h"
43 #include "gnunet_applications.h"
44 #include "gnunet_mesh_service.h"
45 #include "gnunet_statistics_service.h"
46 #include "gnunet_constants.h"
47 #include "gnunet_tun_lib.h"
51 * Information about an address.
56 * AF_INET or AF_INET6.
61 * Remote address information.
66 * Address, if af is AF_INET.
71 * Address, if af is AF_INET6.
77 * IPPROTO_TCP or IPPROTO_UDP;
82 * Remote port, in host byte order!
89 * This struct is saved into the services-hashmap to represent
90 * a service this peer is specifically offering an exit for
91 * (for a specific domain name).
97 * Remote address to use for the service.
99 struct SocketAddress address;
102 * DNS name of the service.
107 * Port I am listening on within GNUnet for this service, in host
108 * byte order. (as we may redirect ports).
115 * Information we use to track a connection (the classical 6-tuple of
116 * IP-version, protocol, source-IP, destination-IP, source-port and
119 struct RedirectInformation
123 * Address information for the other party (equivalent of the
124 * arguments one would give to "connect").
126 struct SocketAddress remote_address;
129 * Address information we used locally (AF and proto must match
130 * "remote_address"). Equivalent of the arguments one would give to
133 struct SocketAddress local_address;
136 Note 1: additional information might be added here in the
137 future to support protocols that require special handling,
140 Note 2: we might also sometimes not match on all components
141 of the tuple, to support protocols where things do not always
148 * Queue of messages to a tunnel.
150 struct TunnelMessageQueue
153 * This is a doubly-linked list.
155 struct TunnelMessageQueue *next;
158 * This is a doubly-linked list.
160 struct TunnelMessageQueue *prev;
163 * Payload to send via the tunnel.
168 * Number of bytes in 'payload'.
175 * This struct is saved into connections_map to allow finding the
176 * right tunnel given an IP packet from TUN. It is also associated
177 * with the tunnel's closure so we can find it again for the next
178 * message from the tunnel.
183 * Mesh tunnel that is used for this connection.
185 struct GNUNET_MESH_Tunnel *tunnel;
188 * Heap node for this state in the connections_heap.
190 struct GNUNET_CONTAINER_HeapNode *heap_node;
193 * Key this state has in the connections_map.
195 GNUNET_HashCode state_key;
198 * Associated service record, or NULL for no service.
200 struct LocalService *serv;
203 * Head of DLL of messages for this tunnel.
205 struct TunnelMessageQueue *head;
208 * Tail of DLL of messages for this tunnel.
210 struct TunnelMessageQueue *tail;
213 * Active tunnel transmission request (or NULL).
215 struct GNUNET_MESH_TransmitHandle *th;
218 * Primary redirection information for this connection.
220 struct RedirectInformation ri;
226 * The handle to the configuration used throughout the process
228 static const struct GNUNET_CONFIGURATION_Handle *cfg;
231 * The handle to the helper
233 static struct GNUNET_HELPER_Handle *helper_handle;
236 * Arguments to the exit helper.
238 static char *exit_argv[7];
241 * IPv6 prefix (0..127) from configuration file.
243 static unsigned long long ipv6prefix;
248 static struct GNUNET_STATISTICS_Handle *stats;
253 static struct GNUNET_MESH_Handle *mesh_handle;
256 * This hashmaps contains the mapping from peer, service-descriptor,
257 * source-port and destination-port to a struct TunnelState
259 static struct GNUNET_CONTAINER_MultiHashMap *connections_map;
262 * Heap so we can quickly find "old" connections.
264 static struct GNUNET_CONTAINER_Heap *connections_heap;
267 * If there are at least this many connections, old ones will be removed
269 static long long unsigned int max_connections;
272 * This hashmaps saves interesting things about the configured UDP services
274 static struct GNUNET_CONTAINER_MultiHashMap *udp_services;
277 * This hashmaps saves interesting things about the configured TCP services
279 static struct GNUNET_CONTAINER_MultiHashMap *tcp_services;
282 * Are we an IPv4-exit?
284 static int ipv4_exit;
287 * Are we an IPv6-exit?
289 static int ipv6_exit;
292 * Do we support IPv4 at all on the TUN interface?
294 static int ipv4_enabled;
297 * Do we support IPv6 at all on the TUN interface?
299 static int ipv6_enabled;
303 * Given IP information about a connection, calculate the respective
304 * hash we would use for the 'connections_map'.
306 * @param hash resulting hash
307 * @param ri information about the connection
310 hash_redirect_info (GNUNET_HashCode *hash,
311 const struct RedirectInformation *ri)
315 memset (hash, 0, sizeof (GNUNET_HashCode));
316 /* the GNUnet hashmap only uses the first sizeof(unsigned int) of the hash,
317 so we put the IP address in there (and hope for few collisions) */
319 switch (ri->remote_address.af)
322 memcpy (off, &ri->remote_address.address.ipv4, sizeof (struct in_addr));
323 off += sizeof (struct in_addr);
326 memcpy (off, &ri->remote_address.address.ipv6, sizeof (struct in6_addr));
327 off += sizeof (struct in_addr);
332 memcpy (off, &ri->remote_address.port, sizeof (uint16_t));
333 off += sizeof (uint16_t);
334 switch (ri->local_address.af)
337 memcpy (off, &ri->local_address.address.ipv4, sizeof (struct in_addr));
338 off += sizeof (struct in_addr);
341 memcpy (off, &ri->local_address.address.ipv6, sizeof (struct in6_addr));
342 off += sizeof (struct in_addr);
347 memcpy (off, &ri->local_address.port, sizeof (uint16_t));
348 off += sizeof (uint16_t);
349 memcpy (off, &ri->remote_address.proto, sizeof (uint8_t));
350 off += sizeof (uint8_t);
355 * Get our connection tracking state. Warns if it does not exists,
356 * refreshes the timestamp if it does exist.
358 * @param af address family
359 * @param protocol IPPROTO_UDP or IPPROTO_TCP
360 * @param destination_ip target IP
361 * @param destination_port target port
362 * @param local_ip local IP
363 * @param local_port local port
364 * @param state_key set to hash's state if non-NULL
365 * @return NULL if we have no tracking information for this tuple
367 static struct TunnelState *
368 get_redirect_state (int af,
370 const void *destination_ip,
371 uint16_t destination_port,
372 const void *local_ip,
374 GNUNET_HashCode *state_key)
376 struct RedirectInformation ri;
378 struct TunnelState *state;
380 ri.remote_address.af = af;
382 ri.remote_address.address.ipv4 = *((struct in_addr*) destination_ip);
384 ri.remote_address.address.ipv6 = * ((struct in6_addr*) destination_ip);
385 ri.remote_address.port = destination_port;
386 ri.remote_address.proto = protocol;
387 ri.local_address.af = af;
389 ri.local_address.address.ipv4 = *((struct in_addr*) local_ip);
391 ri.local_address.address.ipv6 = * ((struct in6_addr*) local_ip);
392 ri.local_address.port = local_port;
393 ri.local_address.proto = protocol;
394 hash_redirect_info (&key, &ri);
395 if (NULL != state_key)
397 state = GNUNET_CONTAINER_multihashmap_get (connections_map, &key);
400 /* Mark this connection as freshly used */
401 if (NULL == state_key)
402 GNUNET_CONTAINER_heap_update_cost (connections_heap,
404 GNUNET_TIME_absolute_get ().abs_value);
410 * Given a service descriptor and a destination port, find the
411 * respective service entry.
413 * @param service_map map of services (TCP or UDP)
414 * @param desc service descriptor
415 * @param dpt destination port
416 * @return NULL if we are not aware of such a service
418 static struct LocalService *
419 find_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
420 const GNUNET_HashCode *desc,
423 char key[sizeof (GNUNET_HashCode) + sizeof (uint16_t)];
425 memcpy (&key[0], &dpt, sizeof (uint16_t));
426 memcpy (&key[sizeof(uint16_t)], desc, sizeof (GNUNET_HashCode));
427 return GNUNET_CONTAINER_multihashmap_get (service_map,
428 (GNUNET_HashCode *) key);
433 * Free memory associated with a service record.
436 * @param key service descriptor
437 * @param value service record to free
441 free_service_record (void *cls,
442 const GNUNET_HashCode *key,
445 struct LocalService *service = value;
447 GNUNET_free_non_null (service->name);
448 GNUNET_free (service);
454 * Given a service descriptor and a destination port, find the
455 * respective service entry.
457 * @param service_map map of services (TCP or UDP)
458 * @param name name of the service
459 * @param dpt destination port
460 * @param service service information record to store (service->name will be set).
463 store_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
466 struct LocalService *service)
468 char key[sizeof (GNUNET_HashCode) + sizeof (uint16_t)];
469 GNUNET_HashCode desc;
471 GNUNET_CRYPTO_hash (name, strlen (name) + 1, &desc);
472 service->name = GNUNET_strdup (name);
473 memcpy (&key[0], &dpt, sizeof (uint16_t));
474 memcpy (&key[sizeof(uint16_t)], &desc, sizeof (GNUNET_HashCode));
476 GNUNET_CONTAINER_multihashmap_put (service_map,
477 (GNUNET_HashCode *) key,
479 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
481 free_service_record (NULL, (GNUNET_HashCode *) key, service);
482 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
483 _("Got duplicate service records for `%s:%u'\n"),
491 * MESH is ready to receive a message for the tunnel. Transmit it.
493 * @param cls the 'struct TunnelState'.
494 * @param size number of bytes available in buf
495 * @param buf where to copy the message
496 * @return number of bytes copied to buf
499 send_to_peer_notify_callback (void *cls, size_t size, void *buf)
501 struct TunnelState *s = cls;
502 struct GNUNET_MESH_Tunnel *tunnel = s->tunnel;
503 struct TunnelMessageQueue *tnq;
507 GNUNET_assert (size >= tnq->len);
508 memcpy (buf, tnq->payload, tnq->len);
510 GNUNET_CONTAINER_DLL_remove (s->head,
514 if (NULL != (tnq = s->head))
515 s->th = GNUNET_MESH_notify_transmit_ready (tunnel,
516 GNUNET_NO /* corking */,
518 GNUNET_TIME_UNIT_FOREVER_REL,
521 &send_to_peer_notify_callback,
523 GNUNET_STATISTICS_update (stats,
524 gettext_noop ("# Bytes transmitted via mesh tunnels"),
531 * Send the given packet via the mesh tunnel.
533 * @param mesh_tunnel destination
534 * @param payload message to transmit
535 * @param payload_length number of bytes in payload
536 * @param desc descriptor to add before payload (optional)
537 * @param mtype message type to use
540 send_packet_to_mesh_tunnel (struct GNUNET_MESH_Tunnel *mesh_tunnel,
542 size_t payload_length,
543 const GNUNET_HashCode *desc,
546 struct TunnelState *s;
547 struct TunnelMessageQueue *tnq;
548 struct GNUNET_MessageHeader *msg;
552 len = sizeof (struct GNUNET_MessageHeader) + sizeof (GNUNET_HashCode) + payload_length;
553 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
558 tnq = GNUNET_malloc (sizeof (struct TunnelMessageQueue) + len);
559 tnq->payload = &tnq[1];
561 msg = (struct GNUNET_MessageHeader *) &tnq[1];
562 msg->size = htons ((uint16_t) len);
563 msg->type = htons (mtype);
566 dp = (GNUNET_HashCode *) &msg[1];
568 memcpy (&dp[1], payload, payload_length);
572 memcpy (&msg[1], payload, payload_length);
574 s = GNUNET_MESH_tunnel_get_data (mesh_tunnel);
575 GNUNET_assert (NULL != s);
576 GNUNET_CONTAINER_DLL_insert_tail (s->head, s->tail, tnq);
578 s->th = GNUNET_MESH_notify_transmit_ready (mesh_tunnel, GNUNET_NO /* cork */, 0 /* priority */,
579 GNUNET_TIME_UNIT_FOREVER_REL,
581 &send_to_peer_notify_callback,
587 * @brief Handles an UDP packet received from the helper.
589 * @param udp A pointer to the Packet
590 * @param pktlen number of bytes in 'udp'
591 * @param af address family (AFINET or AF_INET6)
592 * @param destination_ip destination IP-address of the IP packet (should
593 * be our local address)
594 * @param source_ip original source IP-address of the IP packet (should
595 * be the original destination address)
598 udp_from_helper (const struct udp_packet *udp,
601 const void *destination_ip,
602 const void *source_ip)
604 struct TunnelState *state;
607 char sbuf[INET6_ADDRSTRLEN];
608 char dbuf[INET6_ADDRSTRLEN];
609 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
610 "Received UDP packet going from %s:%u to %s:%u\n",
613 sbuf, sizeof (sbuf)),
614 (unsigned int) ntohs (udp->spt),
617 dbuf, sizeof (dbuf)),
618 (unsigned int) ntohs (udp->dpt));
620 if (pktlen < sizeof (struct udp_packet))
626 if (pktlen != ntohs (udp->len))
632 state = get_redirect_state (af, IPPROTO_UDP,
640 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
641 _("Packet dropped, have no matching connection information\n"));
644 send_packet_to_mesh_tunnel (state->tunnel,
645 &udp[1], pktlen - sizeof (struct udp_packet),
648 ? GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK
649 : GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK);
654 * @brief Handles a TCP packet received from the helper.
656 * @param tcp A pointer to the Packet
657 * @param pktlen the length of the packet, including its header
658 * @param af address family (AFINET or AF_INET6)
659 * @param destination_ip destination IP-address of the IP packet (should
660 * be our local address)
661 * @param source_ip original source IP-address of the IP packet (should
662 * be the original destination address)
665 tcp_from_helper (const struct tcp_packet *tcp,
668 const void *destination_ip,
669 const void *source_ip)
671 struct TunnelState *state;
673 struct tcp_packet *mtcp;
676 char sbuf[INET6_ADDRSTRLEN];
677 char dbuf[INET6_ADDRSTRLEN];
678 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
679 "Received TCP packet going from %s:%u to %s:%u\n",
682 sbuf, sizeof (sbuf)),
683 (unsigned int) ntohs (tcp->spt),
686 dbuf, sizeof (dbuf)),
687 (unsigned int) ntohs (tcp->dpt));
689 if (pktlen < sizeof (struct tcp_packet))
695 state = get_redirect_state (af, IPPROTO_TCP,
703 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
704 _("Packet dropped, have no matching connection information\n"));
708 /* mug port numbers and crc to avoid information leakage;
709 sender will need to lookup the correct values anyway */
710 memcpy (buf, tcp, pktlen);
711 mtcp = (struct tcp_packet *) buf;
715 send_packet_to_mesh_tunnel (state->tunnel,
719 ? GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK
720 : GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK);
725 * Receive packets from the helper-process
728 * @param client unsued
729 * @param message message received from helper
732 message_token (void *cls GNUNET_UNUSED, void *client GNUNET_UNUSED,
733 const struct GNUNET_MessageHeader *message)
735 const struct tun_header *pkt_tun;
738 GNUNET_STATISTICS_update (stats,
739 gettext_noop ("# Packets received from TUN"),
741 if (ntohs (message->type) != GNUNET_MESSAGE_TYPE_VPN_HELPER)
746 size = ntohs (message->size);
747 if (size < sizeof (struct tun_header) + sizeof (struct GNUNET_MessageHeader))
752 GNUNET_STATISTICS_update (stats,
753 gettext_noop ("# Bytes received from TUN"),
755 pkt_tun = (const struct tun_header *) &message[1];
756 size -= sizeof (struct tun_header) + sizeof (struct GNUNET_MessageHeader);
757 switch (ntohs (pkt_tun->proto))
761 const struct ip6_header *pkt6;
763 if (size < sizeof (struct ip6_header))
765 /* Kernel to blame? */
769 pkt6 = (struct ip6_header *) &pkt_tun[1];
770 if (size != ntohs (pkt6->payload_length))
772 /* Kernel to blame? */
776 size -= sizeof (struct ip6_header);
777 switch (pkt6->next_header)
780 udp_from_helper ((const struct udp_packet *) &pkt6[1], size,
782 &pkt6->destination_address,
783 &pkt6->source_address);
786 tcp_from_helper ((const struct tcp_packet *) &pkt6[1], size,
788 &pkt6->destination_address,
789 &pkt6->source_address);
792 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
793 _("IPv6 packet with unsupported next header received. Ignored.\n"));
800 const struct ip4_header *pkt4;
802 if (size < sizeof (struct ip4_header))
804 /* Kernel to blame? */
808 pkt4 = (const struct ip4_header *) &pkt_tun[1];
809 if (size != ntohs (pkt4->total_length))
811 /* Kernel to blame? */
815 if (pkt4->header_length * 4 != sizeof (struct ip4_header))
817 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
818 _("IPv4 packet options received. Ignored.\n"));
821 size -= sizeof (struct ip4_header);
822 switch (pkt4->protocol)
825 udp_from_helper ((const struct udp_packet *) &pkt4[1], size,
827 &pkt4->destination_address,
828 &pkt4->source_address);
830 tcp_from_helper ((const struct tcp_packet *) &pkt4[1], size,
832 &pkt4->destination_address,
833 &pkt4->source_address);
836 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
837 _("IPv4 packet with unsupported next header received. Ignored.\n"));
843 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
844 _("Packet from unknown protocol %u received. Ignored.\n"),
845 ntohs (pkt_tun->proto));
852 * We need to create a (unique) fresh local address (IP+port).
855 * @param af desired address family
856 * @param proto desired protocol (IPPROTO_UDP or IPPROTO_TCP)
857 * @param local_address address to initialize
860 setup_fresh_address (int af,
862 struct SocketAddress *local_address)
864 local_address->af = af;
865 local_address->proto = (uint8_t) proto;
866 /* default "local" port range is often 32768--61000,
867 so we pick a random value in that range */
869 = (uint16_t) 32768 + GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
875 const char *ipv4addr = exit_argv[4];
876 const char *ipv4mask = exit_argv[5];
881 GNUNET_assert (1 == inet_pton (AF_INET, ipv4addr, &addr));
882 GNUNET_assert (1 == inet_pton (AF_INET, ipv4mask, &mask));
883 if (0 == ~mask.s_addr)
885 /* only one valid IP anyway */
886 local_address->address.ipv4 = addr;
889 /* Given 192.168.0.1/255.255.0.0, we want a mask
890 of '192.168.255.255', thus: */
891 mask.s_addr = addr.s_addr | ~mask.s_addr;
892 /* Pick random IPv4 address within the subnet, except 'addr' or 'mask' itself */
895 rnd.s_addr = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
897 local_address->address.ipv4.s_addr = (addr.s_addr | rnd.s_addr) & mask.s_addr;
899 while ( (local_address->address.ipv4.s_addr == addr.s_addr) ||
900 (local_address->address.ipv4.s_addr == mask.s_addr) );
905 const char *ipv6addr = exit_argv[2];
906 struct in6_addr addr;
907 struct in6_addr mask;
911 GNUNET_assert (1 == inet_pton (AF_INET6, ipv6addr, &addr));
912 GNUNET_assert (ipv6prefix < 128);
913 if (ipv6prefix == 127)
915 /* only one valid IP anyway */
916 local_address->address.ipv6 = addr;
919 /* Given ABCD::/96, we want a mask of 'ABCD::FFFF:FFFF,
922 for (i=127;i>=128-ipv6prefix;i--)
923 mask.s6_addr[i / 8] |= (1 << (i % 8));
925 /* Pick random IPv6 address within the subnet, except 'addr' or 'mask' itself */
930 rnd.s6_addr[i] = (unsigned char) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
932 local_address->address.ipv6.s6_addr[i]
933 = (addr.s6_addr[i] | rnd.s6_addr[i]) & mask.s6_addr[i];
936 while ( (0 == memcmp (&local_address->address.ipv6,
938 sizeof (struct in6_addr))) ||
939 (0 == memcmp (&local_address->address.ipv6,
941 sizeof (struct in6_addr))) );
951 * We are starting a fresh connection (TCP or UDP) and need
952 * to pick a source port and IP address (within the correct
953 * range and address family) to associate replies with the
954 * connection / correct mesh tunnel. This function generates
955 * a "fresh" source IP and source port number for a connection
956 * After picking a good source address, this function sets up
957 * the state in the 'connections_map' and 'connections_heap'
958 * to allow finding the state when needed later. The function
959 * also makes sure that we remain within memory limits by
960 * cleaning up 'old' states.
962 * @param state skeleton state to setup a record for; should
963 * 'state->ri.remote_address' filled in so that
964 * this code can determine which AF/protocol is
965 * going to be used (the 'tunnel' should also
966 * already be set); after calling this function,
967 * heap_node and the local_address will be
968 * also initialized (heap_node != NULL can be
969 * used to test if a state has been fully setup).
972 setup_state_record (struct TunnelState *state)
975 struct TunnelState *s;
977 /* generate fresh, unique address */
980 setup_fresh_address (state->serv->address.af,
981 state->serv->address.proto,
982 &state->ri.local_address);
983 } while (NULL != get_redirect_state (state->ri.remote_address.af,
984 state->ri.remote_address.proto,
985 &state->ri.remote_address.address,
986 state->ri.remote_address.port,
987 &state->ri.local_address.address,
988 state->ri.local_address.port,
991 char buf[INET6_ADDRSTRLEN];
992 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
993 "Picked local address %s:%u for new connection\n",
994 inet_ntop (state->ri.local_address.af,
995 &state->ri.local_address.address,
997 (unsigned int) state->ri.local_address.port);
999 GNUNET_assert (GNUNET_OK ==
1000 GNUNET_CONTAINER_multihashmap_put (connections_map,
1002 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1003 state->heap_node = GNUNET_CONTAINER_heap_insert (connections_heap,
1005 GNUNET_TIME_absolute_get ().abs_value);
1006 while (GNUNET_CONTAINER_heap_get_size (connections_heap) > max_connections)
1008 s = GNUNET_CONTAINER_heap_remove_root (connections_heap);
1009 GNUNET_assert (state != s);
1010 s->heap_node = NULL;
1011 GNUNET_MESH_tunnel_destroy (s->tunnel);
1012 GNUNET_assert (GNUNET_OK ==
1013 GNUNET_CONTAINER_multihashmap_remove (connections_map,
1022 * Prepare an IPv4 packet for transmission via the TUN interface.
1023 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1024 * For UDP, the UDP header will be fully created, whereas for TCP
1025 * only the ports and checksum will be filled in. So for TCP,
1026 * a skeleton TCP header must be part of the provided payload.
1028 * @param payload payload of the packet (starting with UDP payload or
1029 * TCP header, depending on protocol)
1030 * @param payload_length number of bytes in 'payload'
1031 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1032 * @param src_address source address to use (IP and port)
1033 * @param dst_address destination address to use (IP and port)
1034 * @param pkt6 where to write the assembled packet; must
1035 * contain enough space for the IP header, UDP/TCP header
1039 prepare_ipv4_packet (const void *payload, size_t payload_length,
1041 const struct tcp_packet *tcp_header,
1042 const struct SocketAddress *src_address,
1043 const struct SocketAddress *dst_address,
1044 struct ip4_header *pkt4)
1048 len = payload_length;
1052 len += sizeof (struct udp_packet);
1055 len += sizeof (struct tcp_packet);
1056 GNUNET_assert (NULL != tcp_header);
1062 if (len + sizeof (struct ip4_header) > UINT16_MAX)
1069 pkt4->header_length = sizeof (struct ip4_header) / 4;
1070 pkt4->diff_serv = 0;
1071 pkt4->total_length = htons ((uint16_t) (sizeof (struct ip4_header) + len));
1072 pkt4->identification = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1075 pkt4->fragmentation_offset = 0;
1077 pkt4->protocol = protocol;
1079 pkt4->destination_address = dst_address->address.ipv4;
1080 pkt4->source_address = src_address->address.ipv4;
1081 pkt4->checksum = GNUNET_CRYPTO_crc16_n (pkt4, sizeof (struct ip4_header));
1087 struct udp_packet *pkt4_udp = (struct udp_packet *) &pkt4[1];
1089 pkt4_udp->spt = htons (src_address->port);
1090 pkt4_udp->dpt = htons (dst_address->port);
1091 pkt4_udp->crc = 0; /* Optional for IPv4 */
1092 pkt4_udp->len = htons ((uint16_t) payload_length);
1093 memcpy (&pkt4_udp[1], payload, payload_length);
1098 struct tcp_packet *pkt4_tcp = (struct tcp_packet *) &pkt4[1];
1100 memcpy (pkt4_tcp, tcp_header, sizeof (struct tcp_packet));
1101 memcpy (&pkt4_tcp[1], payload, payload_length);
1102 pkt4_tcp->spt = htons (src_address->port);
1103 pkt4_tcp->dpt = htons (dst_address->port);
1106 sum = GNUNET_CRYPTO_crc16_step (sum,
1107 &pkt4->source_address,
1108 sizeof (struct in_addr) * 2);
1109 uint32_t tmp = htonl ((protocol << 16) | (0xffff & len));
1110 sum = GNUNET_CRYPTO_crc16_step (sum, & tmp, sizeof (uint32_t));
1111 sum = GNUNET_CRYPTO_crc16_step (sum, & pkt4_tcp, len);
1112 pkt4_tcp->crc = GNUNET_CRYPTO_crc16_finish (sum);
1122 * Prepare an IPv6 packet for transmission via the TUN interface.
1123 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1124 * For UDP, the UDP header will be fully created, whereas for TCP
1125 * only the ports and checksum will be filled in. So for TCP,
1126 * a skeleton TCP header must be part of the provided payload.
1128 * @param payload payload of the packet (starting with UDP payload or
1129 * TCP header, depending on protocol)
1130 * @param payload_length number of bytes in 'payload'
1131 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1132 * @param src_address source address to use (IP and port)
1133 * @param dst_address destination address to use (IP and port)
1134 * @param pkt6 where to write the assembled packet; must
1135 * contain enough space for the IP header, UDP/TCP header
1139 prepare_ipv6_packet (const void *payload, size_t payload_length,
1141 const struct tcp_packet *tcp_header,
1142 const struct SocketAddress *src_address,
1143 const struct SocketAddress *dst_address,
1144 struct ip6_header *pkt6)
1148 len = payload_length;
1152 len += sizeof (struct udp_packet);
1155 /* tcp_header (with port/crc not set) must be part of payload! */
1156 if (len < sizeof (struct tcp_packet))
1166 if (len > UINT16_MAX)
1173 pkt6->next_header = protocol;
1174 pkt6->payload_length = htons ((uint16_t) (len + sizeof (struct ip6_header)));
1175 pkt6->hop_limit = 255;
1176 pkt6->destination_address = dst_address->address.ipv6;
1177 pkt6->source_address = src_address->address.ipv6;
1183 struct udp_packet *pkt6_udp = (struct udp_packet *) &pkt6[1];
1185 memcpy (&pkt6[1], payload, payload_length);
1187 pkt6_udp->spt = htons (src_address->port);
1188 pkt6_udp->dpt = htons (dst_address->port);
1189 pkt6_udp->len = htons ((uint16_t) payload_length);
1192 sum = GNUNET_CRYPTO_crc16_step (sum,
1193 &pkt6->source_address,
1194 sizeof (struct in6_addr) * 2);
1195 uint32_t tmp = htons (len);
1196 sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
1197 tmp = htonl (pkt6->next_header);
1198 sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
1199 sum = GNUNET_CRYPTO_crc16_step (sum, pkt6_udp, len);
1200 pkt6_udp->crc = GNUNET_CRYPTO_crc16_finish (sum);
1205 struct tcp_packet *pkt6_tcp = (struct tcp_packet *) pkt6;
1207 memcpy (pkt6_tcp, payload, payload_length);
1209 pkt6_tcp->spt = htons (src_address->port);
1210 pkt6_tcp->dpt = htons (dst_address->port);
1213 sum = GNUNET_CRYPTO_crc16_step (sum, &pkt6->source_address,
1214 sizeof (struct in6_addr) * 2);
1215 uint32_t tmp = htonl (len);
1216 sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
1217 tmp = htonl (pkt6->next_header);
1218 sum = GNUNET_CRYPTO_crc16_step (sum, &tmp, sizeof (uint32_t));
1219 sum = GNUNET_CRYPTO_crc16_step (sum, pkt6_tcp, len);
1220 pkt6_tcp->crc = GNUNET_CRYPTO_crc16_finish (sum);
1231 * Send a TCP packet via the TUN interface.
1233 * @param destination_address IP and port to use for the TCP packet's destination
1234 * @param source_address IP and port to use for the TCP packet's source
1235 * @param tcp header template to use
1236 * @param payload payload of the TCP packet
1237 * @param payload_length number of bytes in 'payload'
1240 send_tcp_packet_via_tun (const struct SocketAddress *destination_address,
1241 const struct SocketAddress *source_address,
1242 const struct tcp_packet *tcp_header,
1243 const void *payload, size_t payload_length)
1247 GNUNET_STATISTICS_update (stats,
1248 gettext_noop ("# TCP packets sent via TUN"),
1250 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1251 "Sending packet with %u bytes TCP payload via TUN\n",
1252 (unsigned int) payload_length);
1253 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct tun_header);
1254 switch (source_address->af)
1257 len += sizeof (struct ip4_header);
1260 len += sizeof (struct ip6_header);
1266 len += payload_length;
1267 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1274 struct GNUNET_MessageHeader *hdr;
1275 struct tun_header *tun;
1277 hdr= (struct GNUNET_MessageHeader *) buf;
1278 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1279 hdr->size = htons (len);
1280 tun = (struct tun_header*) &hdr[1];
1281 tun->flags = htons (0);
1282 switch (source_address->af)
1286 struct ip4_header * ipv4 = (struct ip4_header*) &tun[1];
1288 tun->proto = htons (ETH_P_IPV4);
1289 prepare_ipv4_packet (payload, payload_length,
1293 destination_address,
1299 struct ip6_header * ipv6 = (struct ip6_header*) &tun[1];
1301 tun->proto = htons (ETH_P_IPV6);
1302 prepare_ipv6_packet (payload, payload_length,
1306 destination_address,
1314 (void) GNUNET_HELPER_send (helper_handle,
1315 (const struct GNUNET_MessageHeader*) buf,
1323 * Process a request via mesh to send a request to a TCP service
1324 * offered by this system.
1326 * @param cls closure, NULL
1327 * @param tunnel connection to the other end
1328 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1329 * @param sender who sent the message
1330 * @param message the actual message
1331 * @param atsi performance data for the connection
1332 * @return GNUNET_OK to keep the connection open,
1333 * GNUNET_SYSERR to close it (signal serious error)
1336 receive_tcp_service (void *unused GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1337 void **tunnel_ctx GNUNET_UNUSED,
1338 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1339 const struct GNUNET_MessageHeader *message,
1340 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1342 struct TunnelState *state = *tunnel_ctx;
1343 const struct GNUNET_EXIT_TcpServiceStartMessage *start;
1344 uint16_t pkt_len = ntohs (message->size);
1346 GNUNET_STATISTICS_update (stats,
1347 gettext_noop ("# TCP service creation requests received via mesh"),
1349 GNUNET_STATISTICS_update (stats,
1350 gettext_noop ("# Bytes received from MESH"),
1351 pkt_len, GNUNET_NO);
1352 /* check that we got at least a valid header */
1353 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpServiceStartMessage))
1355 GNUNET_break_op (0);
1356 return GNUNET_SYSERR;
1358 start = (const struct GNUNET_EXIT_TcpServiceStartMessage*) message;
1359 pkt_len -= sizeof (struct GNUNET_EXIT_TcpServiceStartMessage);
1360 if ( (NULL == state) ||
1361 (NULL != state->serv) ||
1362 (NULL != state->heap_node) )
1364 GNUNET_break_op (0);
1365 return GNUNET_SYSERR;
1367 GNUNET_break_op (ntohl (start->reserved) == 0);
1368 /* setup fresh connection */
1369 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1370 "Received data from %s for forwarding to TCP service %s on port %u\n",
1371 GNUNET_i2s (sender),
1372 GNUNET_h2s (&start->service_descriptor),
1373 (unsigned int) ntohs (start->tcp_header.dpt));
1374 if (NULL == (state->serv = find_service (tcp_services, &start->service_descriptor,
1375 ntohs (start->tcp_header.dpt))))
1377 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1378 _("No service found for %s on port %d!\n"),
1380 ntohs (start->tcp_header.dpt));
1381 GNUNET_STATISTICS_update (stats,
1382 gettext_noop ("# TCP requests dropped (no such service)"),
1384 return GNUNET_SYSERR;
1386 state->ri.remote_address = state->serv->address;
1387 setup_state_record (state);
1388 send_tcp_packet_via_tun (&state->ri.remote_address,
1389 &state->ri.local_address,
1391 &start[1], pkt_len);
1397 * Process a request to forward TCP data to the Internet via this peer.
1399 * @param cls closure, NULL
1400 * @param tunnel connection to the other end
1401 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1402 * @param sender who sent the message
1403 * @param message the actual message
1404 * @param atsi performance data for the connection
1405 * @return GNUNET_OK to keep the connection open,
1406 * GNUNET_SYSERR to close it (signal serious error)
1409 receive_tcp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1410 void **tunnel_ctx GNUNET_UNUSED,
1411 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1412 const struct GNUNET_MessageHeader *message,
1413 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1415 struct TunnelState *state = *tunnel_ctx;
1416 const struct GNUNET_EXIT_TcpInternetStartMessage *start;
1417 uint16_t pkt_len = ntohs (message->size);
1418 const struct in_addr *v4;
1419 const struct in6_addr *v6;
1420 const void *payload;
1423 GNUNET_STATISTICS_update (stats,
1424 gettext_noop ("# Bytes received from MESH"),
1425 pkt_len, GNUNET_NO);
1426 GNUNET_STATISTICS_update (stats,
1427 gettext_noop ("# TCP IP-exit creation requests received via mesh"),
1429 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpInternetStartMessage))
1431 GNUNET_break_op (0);
1432 return GNUNET_SYSERR;
1434 start = (const struct GNUNET_EXIT_TcpInternetStartMessage*) message;
1435 pkt_len -= sizeof (struct GNUNET_EXIT_TcpInternetStartMessage);
1436 if ( (NULL == state) ||
1437 (NULL != state->serv) ||
1438 (NULL != state->heap_node) )
1440 GNUNET_break_op (0);
1441 return GNUNET_SYSERR;
1443 af = (int) ntohl (start->af);
1444 state->ri.remote_address.af = af;
1448 if (pkt_len < sizeof (struct in_addr))
1450 GNUNET_break_op (0);
1451 return GNUNET_SYSERR;
1455 GNUNET_break_op (0);
1456 return GNUNET_SYSERR;
1458 v4 = (const struct in_addr*) &start[1];
1460 pkt_len -= sizeof (struct in_addr);
1461 state->ri.remote_address.address.ipv4 = *v4;
1464 if (pkt_len < sizeof (struct in6_addr))
1466 GNUNET_break_op (0);
1467 return GNUNET_SYSERR;
1471 GNUNET_break_op (0);
1472 return GNUNET_SYSERR;
1474 v6 = (const struct in6_addr*) &start[1];
1476 pkt_len -= sizeof (struct in_addr);
1477 state->ri.remote_address.address.ipv6 = *v6;
1480 GNUNET_break_op (0);
1481 return GNUNET_SYSERR;
1484 char buf[INET6_ADDRSTRLEN];
1485 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1486 "Received data from %s for starting TCP stream to %s:%u\n",
1487 GNUNET_i2s (sender),
1489 &state->ri.remote_address.address,
1491 (unsigned int) ntohs (start->tcp_header.dpt));
1494 state->ri.remote_address.proto = IPPROTO_TCP;
1495 state->ri.remote_address.port = ntohs (start->tcp_header.dpt);
1496 setup_state_record (state);
1497 send_tcp_packet_via_tun (&state->ri.remote_address,
1498 &state->ri.local_address,
1506 * Process a request to forward TCP data on an established
1507 * connection via this peer.
1509 * @param cls closure, NULL
1510 * @param tunnel connection to the other end
1511 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1512 * @param sender who sent the message
1513 * @param message the actual message
1514 * @param atsi performance data for the connection
1515 * @return GNUNET_OK to keep the connection open,
1516 * GNUNET_SYSERR to close it (signal serious error)
1519 receive_tcp_data (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1520 void **tunnel_ctx GNUNET_UNUSED,
1521 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1522 const struct GNUNET_MessageHeader *message,
1523 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1525 struct TunnelState *state = *tunnel_ctx;
1526 const struct GNUNET_EXIT_TcpDataMessage *data;
1527 uint16_t pkt_len = ntohs (message->size);
1529 GNUNET_STATISTICS_update (stats,
1530 gettext_noop ("# Bytes received from MESH"),
1531 pkt_len, GNUNET_NO);
1532 GNUNET_STATISTICS_update (stats,
1533 gettext_noop ("# TCP data requests received via mesh"),
1535 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpDataMessage))
1537 GNUNET_break_op (0);
1538 return GNUNET_SYSERR;
1540 data = (const struct GNUNET_EXIT_TcpDataMessage*) message;
1541 pkt_len -= sizeof (struct GNUNET_EXIT_TcpDataMessage);
1542 if ( (NULL == state) ||
1543 (NULL == state->heap_node) )
1545 /* connection should have been up! */
1546 GNUNET_STATISTICS_update (stats,
1547 gettext_noop ("# TCP DATA requests dropped (no session)"),
1549 return GNUNET_SYSERR;
1551 GNUNET_break_op (ntohl (data->reserved) == 0);
1553 char buf[INET6_ADDRSTRLEN];
1554 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1555 "Received additional data from %s for TCP stream to %s:%u\n",
1556 GNUNET_i2s (sender),
1557 inet_ntop (state->ri.remote_address.af,
1558 &state->ri.remote_address.address,
1560 (unsigned int) state->ri.remote_address.port);
1563 send_tcp_packet_via_tun (&state->ri.remote_address,
1564 &state->ri.local_address,
1572 * Send a UDP packet via the TUN interface.
1574 * @param destination_address IP and port to use for the UDP packet's destination
1575 * @param source_address IP and port to use for the UDP packet's source
1576 * @param payload payload of the UDP packet (does NOT include UDP header)
1577 * @param payload_length number of bytes of data in payload
1580 send_udp_packet_via_tun (const struct SocketAddress *destination_address,
1581 const struct SocketAddress *source_address,
1582 const void *payload, size_t payload_length)
1586 GNUNET_STATISTICS_update (stats,
1587 gettext_noop ("# UDP packets sent via TUN"),
1589 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1590 "Sending packet with %u bytes UDP payload via TUN\n",
1591 (unsigned int) payload_length);
1592 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct tun_header);
1593 switch (source_address->af)
1596 len += sizeof (struct ip4_header);
1599 len += sizeof (struct ip6_header);
1605 len += sizeof (struct udp_packet);
1606 len += payload_length;
1607 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1614 struct GNUNET_MessageHeader *hdr;
1615 struct tun_header *tun;
1617 hdr= (struct GNUNET_MessageHeader *) buf;
1618 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1619 hdr->size = htons (len);
1620 tun = (struct tun_header*) &hdr[1];
1621 tun->flags = htons (0);
1622 switch (source_address->af)
1626 struct ip4_header * ipv4 = (struct ip4_header*) &tun[1];
1628 tun->proto = htons (ETH_P_IPV4);
1629 prepare_ipv4_packet (payload, payload_length,
1633 destination_address,
1639 struct ip6_header * ipv6 = (struct ip6_header*) &tun[1];
1641 tun->proto = htons (ETH_P_IPV6);
1642 prepare_ipv6_packet (payload, payload_length,
1646 destination_address,
1654 (void) GNUNET_HELPER_send (helper_handle,
1655 (const struct GNUNET_MessageHeader*) buf,
1663 * Process a request to forward UDP data to the Internet via this peer.
1665 * @param cls closure, NULL
1666 * @param tunnel connection to the other end
1667 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1668 * @param sender who sent the message
1669 * @param message the actual message
1670 * @param atsi performance data for the connection
1671 * @return GNUNET_OK to keep the connection open,
1672 * GNUNET_SYSERR to close it (signal serious error)
1675 receive_udp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1676 void **tunnel_ctx GNUNET_UNUSED,
1677 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1678 const struct GNUNET_MessageHeader *message,
1679 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1681 struct TunnelState *state = *tunnel_ctx;
1682 const struct GNUNET_EXIT_UdpInternetMessage *msg;
1683 uint16_t pkt_len = ntohs (message->size);
1684 const struct in_addr *v4;
1685 const struct in6_addr *v6;
1686 const void *payload;
1689 GNUNET_STATISTICS_update (stats,
1690 gettext_noop ("# Bytes received from MESH"),
1691 pkt_len, GNUNET_NO);
1692 GNUNET_STATISTICS_update (stats,
1693 gettext_noop ("# UDP IP-exit requests received via mesh"),
1695 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpInternetMessage))
1697 GNUNET_break_op (0);
1698 return GNUNET_SYSERR;
1700 msg = (const struct GNUNET_EXIT_UdpInternetMessage*) message;
1701 pkt_len -= sizeof (struct GNUNET_EXIT_UdpInternetMessage);
1702 af = (int) ntohl (msg->af);
1703 state->ri.remote_address.af = af;
1707 if (pkt_len < sizeof (struct in_addr))
1709 GNUNET_break_op (0);
1710 return GNUNET_SYSERR;
1714 GNUNET_break_op (0);
1715 return GNUNET_SYSERR;
1717 v4 = (const struct in_addr*) &msg[1];
1719 pkt_len -= sizeof (struct in_addr);
1720 state->ri.remote_address.address.ipv4 = *v4;
1723 if (pkt_len < sizeof (struct in6_addr))
1725 GNUNET_break_op (0);
1726 return GNUNET_SYSERR;
1730 GNUNET_break_op (0);
1731 return GNUNET_SYSERR;
1733 v6 = (const struct in6_addr*) &msg[1];
1735 pkt_len -= sizeof (struct in_addr);
1736 state->ri.remote_address.address.ipv6 = *v6;
1739 GNUNET_break_op (0);
1740 return GNUNET_SYSERR;
1743 char buf[INET6_ADDRSTRLEN];
1744 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1745 "Received data from %s for forwarding to UDP %s:%u\n",
1746 GNUNET_i2s (sender),
1748 &state->ri.remote_address.address,
1750 (unsigned int) ntohs (msg->destination_port));
1752 state->ri.remote_address.proto = IPPROTO_UDP;
1753 state->ri.remote_address.port = msg->destination_port;
1754 if (NULL == state->heap_node)
1755 setup_state_record (state);
1756 if (0 != ntohs (msg->source_port))
1757 state->ri.local_address.port = msg->source_port;
1758 send_udp_packet_via_tun (&state->ri.remote_address,
1759 &state->ri.local_address,
1766 * Process a request via mesh to send a request to a UDP service
1767 * offered by this system.
1769 * @param cls closure, NULL
1770 * @param tunnel connection to the other end
1771 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1772 * @param sender who sent the message
1773 * @param message the actual message
1774 * @param atsi performance data for the connection
1775 * @return GNUNET_OK to keep the connection open,
1776 * GNUNET_SYSERR to close it (signal serious error)
1779 receive_udp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1781 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1782 const struct GNUNET_MessageHeader *message,
1783 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1785 struct TunnelState *state = *tunnel_ctx;
1786 const struct GNUNET_EXIT_UdpServiceMessage *msg;
1787 uint16_t pkt_len = ntohs (message->size);
1789 GNUNET_STATISTICS_update (stats,
1790 gettext_noop ("# Bytes received from MESH"),
1791 pkt_len, GNUNET_NO);
1792 GNUNET_STATISTICS_update (stats,
1793 gettext_noop ("# UDP service requests received via mesh"),
1795 /* check that we got at least a valid header */
1796 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpServiceMessage))
1798 GNUNET_break_op (0);
1799 return GNUNET_SYSERR;
1801 msg = (const struct GNUNET_EXIT_UdpServiceMessage*) message;
1802 pkt_len -= sizeof (struct GNUNET_EXIT_UdpServiceMessage);
1803 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1804 "Received data from %s for forwarding to UDP service %s on port %u\n",
1805 GNUNET_i2s (sender),
1806 GNUNET_h2s (&msg->service_descriptor),
1807 (unsigned int) ntohs (msg->destination_port));
1808 if (NULL == (state->serv = find_service (udp_services, &msg->service_descriptor,
1809 ntohs (msg->destination_port))))
1811 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1812 _("No service found for %s on port %d!\n"),
1814 ntohs (msg->destination_port));
1815 GNUNET_STATISTICS_update (stats,
1816 gettext_noop ("# UDP requests dropped (no such service)"),
1818 return GNUNET_SYSERR;
1820 state->ri.remote_address = state->serv->address;
1821 setup_state_record (state);
1822 if (0 != ntohs (msg->source_port))
1823 state->ri.local_address.port = msg->source_port;
1824 send_udp_packet_via_tun (&state->ri.remote_address,
1825 &state->ri.local_address,
1832 * Callback from GNUNET_MESH for new tunnels.
1834 * @param cls closure
1835 * @param tunnel new handle to the tunnel
1836 * @param initiator peer that started the tunnel
1837 * @param atsi performance information for the tunnel
1838 * @return initial tunnel context for the tunnel
1841 new_tunnel (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1842 const struct GNUNET_PeerIdentity *initiator GNUNET_UNUSED,
1843 const struct GNUNET_ATS_Information *ats GNUNET_UNUSED)
1845 struct TunnelState *s = GNUNET_malloc (sizeof (struct TunnelState));
1847 GNUNET_STATISTICS_update (stats,
1848 gettext_noop ("# Inbound MESH tunnels created"),
1850 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1851 "Received inbound tunnel from `%s'\n",
1852 GNUNET_i2s (initiator));
1859 * Function called by mesh whenever an inbound tunnel is destroyed.
1860 * Should clean up any associated state.
1862 * @param cls closure (set from GNUNET_MESH_connect)
1863 * @param tunnel connection to the other end (henceforth invalid)
1864 * @param tunnel_ctx place where local state associated
1865 * with the tunnel is stored
1868 clean_tunnel (void *cls GNUNET_UNUSED, const struct GNUNET_MESH_Tunnel *tunnel,
1871 struct TunnelState *s = tunnel_ctx;
1872 struct TunnelMessageQueue *tnq;
1874 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1875 "Tunnel destroyed\n");
1876 while (NULL != (tnq = s->head))
1878 GNUNET_CONTAINER_DLL_remove (s->head,
1883 if (s->heap_node != NULL)
1885 GNUNET_assert (GNUNET_YES ==
1886 GNUNET_CONTAINER_multihashmap_remove (connections_map,
1889 GNUNET_CONTAINER_heap_remove_node (s->heap_node);
1890 s->heap_node = NULL;
1894 GNUNET_MESH_notify_transmit_ready_cancel (s->th);
1902 * Function that frees everything from a hashmap
1906 * @param value value to free
1909 free_iterate (void *cls GNUNET_UNUSED,
1910 const GNUNET_HashCode * hash GNUNET_UNUSED, void *value)
1912 GNUNET_free (value);
1918 * Function scheduled as very last function, cleans up after us
1921 cleanup (void *cls GNUNET_UNUSED,
1922 const struct GNUNET_SCHEDULER_TaskContext *tskctx)
1926 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1927 "Exit service is shutting down now\n");
1928 if (helper_handle != NULL)
1930 GNUNET_HELPER_stop (helper_handle);
1931 helper_handle = NULL;
1933 if (mesh_handle != NULL)
1935 GNUNET_MESH_disconnect (mesh_handle);
1938 if (NULL != connections_map)
1940 GNUNET_CONTAINER_multihashmap_iterate (connections_map, &free_iterate, NULL);
1941 GNUNET_CONTAINER_multihashmap_destroy (connections_map);
1942 connections_map = NULL;
1944 if (NULL != connections_heap)
1946 GNUNET_CONTAINER_heap_destroy (connections_heap);
1947 connections_heap = NULL;
1949 if (NULL != tcp_services)
1951 GNUNET_CONTAINER_multihashmap_iterate (tcp_services, &free_service_record, NULL);
1952 GNUNET_CONTAINER_multihashmap_destroy (tcp_services);
1953 tcp_services = NULL;
1955 if (NULL != udp_services)
1957 GNUNET_CONTAINER_multihashmap_iterate (udp_services, &free_service_record, NULL);
1958 GNUNET_CONTAINER_multihashmap_destroy (udp_services);
1959 udp_services = NULL;
1963 GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
1967 GNUNET_free_non_null (exit_argv[i]);
1972 * Add services to the service map.
1974 * @param proto IPPROTO_TCP or IPPROTO_UDP
1975 * @param cpy copy of the service descriptor (can be mutilated)
1976 * @param name DNS name of the service
1979 add_services (int proto,
1986 struct LocalService *serv;
1988 for (redirect = strtok (cpy, " "); redirect != NULL;
1989 redirect = strtok (NULL, " "))
1991 if (NULL == (hostname = strstr (redirect, ":")))
1993 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1994 "option `%s' for domain `%s' is not formatted correctly!\n",
2001 if (NULL == (hostport = strstr (hostname, ":")))
2003 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2004 "option `%s' for domain `%s' is not formatted correctly!\n",
2012 int local_port = atoi (redirect);
2013 int remote_port = atoi (hostport);
2015 if (!((local_port > 0) && (local_port < 65536)))
2017 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2018 "`%s' is not a valid port number (for domain `%s')!", redirect,
2022 if (!((remote_port > 0) && (remote_port < 65536)))
2024 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2025 "`%s' is not a valid port number (for domain `%s')!", hostport,
2030 serv = GNUNET_malloc (sizeof (struct LocalService));
2031 serv->my_port = (uint16_t) local_port;
2032 serv->address.port = remote_port;
2033 if (0 == strcmp ("localhost4", hostname))
2035 const char *ip4addr = exit_argv[4];
2037 serv->address.af = AF_INET;
2038 GNUNET_assert (1 != inet_pton (AF_INET, ip4addr, &serv->address.address.ipv4));
2040 else if (0 == strcmp ("localhost6", hostname))
2042 const char *ip6addr = exit_argv[2];
2044 serv->address.af = AF_INET6;
2045 GNUNET_assert (1 == inet_pton (AF_INET6, ip6addr, &serv->address.address.ipv6));
2049 struct addrinfo *res;
2052 ret = getaddrinfo (hostname, NULL, NULL, &res);
2053 if ( (ret != 0) || (res == NULL) )
2055 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2056 _("No addresses found for hostname `%s' of service `%s'!\n"),
2063 serv->address.af = res->ai_family;
2064 switch (res->ai_family)
2069 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2070 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2076 serv->address.address.ipv4 = ((struct sockaddr_in *) res->ai_addr)->sin_addr;
2081 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2082 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2088 serv->address.address.ipv6 = ((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
2092 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2093 _("No IP addresses found for hostname `%s' of service `%s'!\n"),
2101 store_service ((IPPROTO_UDP == proto) ? udp_services : tcp_services,
2110 * Reads the configuration servicecfg and populates udp_services
2113 * @param section name of section in config, equal to hostname
2116 read_service_conf (void *cls GNUNET_UNUSED, const char *section)
2120 if ((strlen (section) < 8) ||
2121 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
2124 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
2127 add_services (IPPROTO_UDP, cpy, section);
2131 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
2134 add_services (IPPROTO_TCP, cpy, section);
2141 * @brief Main function that will be run by the scheduler.
2143 * @param cls closure
2144 * @param args remaining command-line arguments
2145 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
2146 * @param cfg_ configuration
2149 run (void *cls, char *const *args GNUNET_UNUSED,
2150 const char *cfgfile GNUNET_UNUSED,
2151 const struct GNUNET_CONFIGURATION_Handle *cfg_)
2153 static struct GNUNET_MESH_MessageHandler handlers[] = {
2154 {&receive_udp_service, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_SERVICE, 0},
2155 {&receive_udp_remote, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_INTERNET, 0},
2156 {&receive_tcp_service, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_SERVICE_START, 0},
2157 {&receive_tcp_remote, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_INTERNET_START, 0},
2158 {&receive_tcp_data, GNUNET_MESSAGE_TYPE_VPN_TCP_DATA, 0},
2162 static GNUNET_MESH_ApplicationType apptypes[] = {
2163 GNUNET_APPLICATION_TYPE_END,
2164 GNUNET_APPLICATION_TYPE_END,
2165 GNUNET_APPLICATION_TYPE_END
2167 unsigned int app_idx;
2178 stats = GNUNET_STATISTICS_create ("exit", cfg);
2179 ipv4_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV4");
2180 ipv6_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV6");
2181 ipv4_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV4");
2182 ipv6_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV6");
2183 if (ipv4_exit && (! ipv4_enabled))
2185 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2186 _("Cannot enable IPv4 exit but disable IPv4 on TUN interface, will use ENABLE_IPv4=YES\n"));
2187 ipv4_enabled = GNUNET_YES;
2189 if (ipv6_exit && (! ipv6_enabled))
2191 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2192 _("Cannot enable IPv6 exit but disable IPv6 on TUN interface, will use ENABLE_IPv6=YES\n"));
2193 ipv6_enabled = GNUNET_YES;
2195 if (! (ipv4_enabled || ipv6_enabled))
2197 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2198 _("No useful service enabled. Exiting.\n"));
2199 GNUNET_SCHEDULER_shutdown ();
2203 if (GNUNET_YES == ipv4_exit)
2205 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV4_GATEWAY;
2208 if (GNUNET_YES == ipv6_exit)
2210 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV6_GATEWAY;
2214 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
2217 GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_CONNECTIONS",
2219 max_connections = 1024;
2220 exit_argv[0] = GNUNET_strdup ("exit-gnunet");
2221 if (GNUNET_SYSERR ==
2222 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "TUN_IFNAME", &tun_ifname))
2224 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2225 "No entry 'TUN_IFNAME' in configuration!\n");
2226 GNUNET_SCHEDULER_shutdown ();
2229 exit_argv[1] = tun_ifname;
2232 if (GNUNET_SYSERR ==
2233 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "EXIT_IFNAME", &exit_ifname))
2235 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2236 "No entry 'EXIT_IFNAME' in configuration!\n");
2237 GNUNET_SCHEDULER_shutdown ();
2240 exit_argv[2] = exit_ifname;
2244 exit_argv[2] = GNUNET_strdup ("%");
2246 if (GNUNET_YES == ipv6_enabled)
2248 if ( (GNUNET_SYSERR ==
2249 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6ADDR",
2251 (1 != inet_pton (AF_INET6, ipv6addr, &v6))) )
2253 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2254 "No valid entry 'IPV6ADDR' in configuration!\n");
2255 GNUNET_SCHEDULER_shutdown ();
2258 exit_argv[3] = ipv6addr;
2259 if (GNUNET_SYSERR ==
2260 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6PREFIX",
2263 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2264 "No entry 'IPV6PREFIX' in configuration!\n");
2265 GNUNET_SCHEDULER_shutdown ();
2268 exit_argv[4] = ipv6prefix_s;
2270 GNUNET_CONFIGURATION_get_value_number (cfg, "exit",
2273 (ipv6prefix >= 127) )
2275 GNUNET_SCHEDULER_shutdown ();
2281 /* IPv6 explicitly disabled */
2282 exit_argv[3] = GNUNET_strdup ("-");
2283 exit_argv[4] = GNUNET_strdup ("-");
2285 if (GNUNET_YES == ipv4_enabled)
2287 if ( (GNUNET_SYSERR ==
2288 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4ADDR",
2290 (1 != inet_pton (AF_INET, ipv4addr, &v4))) )
2292 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2293 "No valid entry for 'IPV4ADDR' in configuration!\n");
2294 GNUNET_SCHEDULER_shutdown ();
2297 exit_argv[5] = ipv4addr;
2298 if ( (GNUNET_SYSERR ==
2299 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4MASK",
2301 (1 != inet_pton (AF_INET, ipv4mask, &v4))) )
2303 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
2304 "No valid entry 'IPV4MASK' in configuration!\n");
2305 GNUNET_SCHEDULER_shutdown ();
2308 exit_argv[6] = ipv4mask;
2312 /* IPv4 explicitly disabled */
2313 exit_argv[5] = GNUNET_strdup ("-");
2314 exit_argv[6] = GNUNET_strdup ("-");
2316 exit_argv[7] = NULL;
2318 udp_services = GNUNET_CONTAINER_multihashmap_create (65536);
2319 tcp_services = GNUNET_CONTAINER_multihashmap_create (65536);
2320 GNUNET_CONFIGURATION_iterate_sections (cfg, &read_service_conf, NULL);
2322 connections_map = GNUNET_CONTAINER_multihashmap_create (65536);
2323 connections_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
2325 = GNUNET_MESH_connect (cfg, 42 /* queue size */, NULL,
2327 &clean_tunnel, handlers,
2329 if (NULL == mesh_handle)
2331 GNUNET_SCHEDULER_shutdown ();
2334 helper_handle = GNUNET_HELPER_start ("gnunet-helper-exit",
2336 &message_token, NULL);
2343 * @param argc number of arguments from the command line
2344 * @param argv command line arguments
2345 * @return 0 ok, 1 on error
2348 main (int argc, char *const *argv)
2350 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
2351 GNUNET_GETOPT_OPTION_END
2354 return (GNUNET_OK ==
2355 GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-exit",
2357 ("Daemon to run to provide an IP exit node for the VPN"),
2358 options, &run, NULL)) ? 0 : 1;
2362 /* end of gnunet-daemon-exit.c */