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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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 * - which code should advertise services? the service model is right
32 * now a bit odd, especially as this code DOES the exit and knows
33 * the DNS "name", but OTOH this is clearly NOT the place to advertise
34 * the service's existence; maybe the daemon should turn into a
35 * service with an API to add local-exit services dynamically?
38 #include "gnunet_util_lib.h"
39 #include "gnunet_protocols.h"
40 #include "gnunet_applications.h"
41 #include "gnunet_mesh_service.h"
42 #include "gnunet_statistics_service.h"
43 #include "gnunet_constants.h"
44 #include "gnunet_tun_lib.h"
48 * Information about an address.
53 * AF_INET or AF_INET6.
58 * Remote address information.
63 * Address, if af is AF_INET.
68 * Address, if af is AF_INET6.
74 * IPPROTO_TCP or IPPROTO_UDP;
79 * Remote port, in host byte order!
86 * This struct is saved into the services-hashmap to represent
87 * a service this peer is specifically offering an exit for
88 * (for a specific domain name).
94 * Remote address to use for the service.
96 struct SocketAddress address;
99 * DNS name of the service.
104 * Port I am listening on within GNUnet for this service, in host
105 * byte order. (as we may redirect ports).
112 * Information we use to track a connection (the classical 6-tuple of
113 * IP-version, protocol, source-IP, destination-IP, source-port and
116 struct RedirectInformation
120 * Address information for the other party (equivalent of the
121 * arguments one would give to "connect").
123 struct SocketAddress remote_address;
126 * Address information we used locally (AF and proto must match
127 * "remote_address"). Equivalent of the arguments one would give to
130 struct SocketAddress local_address;
133 Note 1: additional information might be added here in the
134 future to support protocols that require special handling,
137 Note 2: we might also sometimes not match on all components
138 of the tuple, to support protocols where things do not always
145 * Queue of messages to a tunnel.
147 struct TunnelMessageQueue
150 * This is a doubly-linked list.
152 struct TunnelMessageQueue *next;
155 * This is a doubly-linked list.
157 struct TunnelMessageQueue *prev;
160 * Payload to send via the tunnel.
165 * Number of bytes in 'payload'.
172 * This struct is saved into connections_map to allow finding the
173 * right tunnel given an IP packet from TUN. It is also associated
174 * with the tunnel's closure so we can find it again for the next
175 * message from the tunnel.
180 * Mesh tunnel that is used for this connection.
182 struct GNUNET_MESH_Tunnel *tunnel;
185 * Heap node for this state in the connections_heap.
187 struct GNUNET_CONTAINER_HeapNode *heap_node;
190 * Key this state has in the connections_map.
192 GNUNET_HashCode state_key;
195 * Associated service record, or NULL for no service.
197 struct LocalService *serv;
200 * Head of DLL of messages for this tunnel.
202 struct TunnelMessageQueue *head;
205 * Tail of DLL of messages for this tunnel.
207 struct TunnelMessageQueue *tail;
210 * Active tunnel transmission request (or NULL).
212 struct GNUNET_MESH_TransmitHandle *th;
215 * Primary redirection information for this connection.
217 struct RedirectInformation ri;
223 * Return value from 'main'.
225 static int global_ret;
228 * The handle to the configuration used throughout the process
230 static const struct GNUNET_CONFIGURATION_Handle *cfg;
233 * The handle to the helper
235 static struct GNUNET_HELPER_Handle *helper_handle;
238 * Arguments to the exit helper.
240 static char *exit_argv[8];
243 * IPv6 address of our TUN interface.
245 static struct in6_addr exit_ipv6addr;
248 * IPv6 prefix (0..127) from configuration file.
250 static unsigned long long ipv6prefix;
253 * IPv4 address of our TUN interface.
255 static struct in_addr exit_ipv4addr;
258 * IPv4 netmask of our TUN interface.
260 static struct in_addr exit_ipv4mask;
266 static struct GNUNET_STATISTICS_Handle *stats;
271 static struct GNUNET_MESH_Handle *mesh_handle;
274 * This hashmaps contains the mapping from peer, service-descriptor,
275 * source-port and destination-port to a struct TunnelState
277 static struct GNUNET_CONTAINER_MultiHashMap *connections_map;
280 * Heap so we can quickly find "old" connections.
282 static struct GNUNET_CONTAINER_Heap *connections_heap;
285 * If there are at least this many connections, old ones will be removed
287 static long long unsigned int max_connections;
290 * This hashmaps saves interesting things about the configured UDP services
292 static struct GNUNET_CONTAINER_MultiHashMap *udp_services;
295 * This hashmaps saves interesting things about the configured TCP services
297 static struct GNUNET_CONTAINER_MultiHashMap *tcp_services;
300 * Are we an IPv4-exit?
302 static int ipv4_exit;
305 * Are we an IPv6-exit?
307 static int ipv6_exit;
310 * Do we support IPv4 at all on the TUN interface?
312 static int ipv4_enabled;
315 * Do we support IPv6 at all on the TUN interface?
317 static int ipv6_enabled;
321 * Given IP information about a connection, calculate the respective
322 * hash we would use for the 'connections_map'.
324 * @param hash resulting hash
325 * @param ri information about the connection
328 hash_redirect_info (GNUNET_HashCode *hash,
329 const struct RedirectInformation *ri)
333 memset (hash, 0, sizeof (GNUNET_HashCode));
334 /* the GNUnet hashmap only uses the first sizeof(unsigned int) of the hash,
335 so we put the IP address in there (and hope for few collisions) */
337 switch (ri->remote_address.af)
340 memcpy (off, &ri->remote_address.address.ipv4, sizeof (struct in_addr));
341 off += sizeof (struct in_addr);
344 memcpy (off, &ri->remote_address.address.ipv6, sizeof (struct in6_addr));
345 off += sizeof (struct in_addr);
350 memcpy (off, &ri->remote_address.port, sizeof (uint16_t));
351 off += sizeof (uint16_t);
352 switch (ri->local_address.af)
355 memcpy (off, &ri->local_address.address.ipv4, sizeof (struct in_addr));
356 off += sizeof (struct in_addr);
359 memcpy (off, &ri->local_address.address.ipv6, sizeof (struct in6_addr));
360 off += sizeof (struct in_addr);
365 memcpy (off, &ri->local_address.port, sizeof (uint16_t));
366 off += sizeof (uint16_t);
367 memcpy (off, &ri->remote_address.proto, sizeof (uint8_t));
368 off += sizeof (uint8_t);
373 * Get our connection tracking state. Warns if it does not exists,
374 * refreshes the timestamp if it does exist.
376 * @param af address family
377 * @param protocol IPPROTO_UDP or IPPROTO_TCP
378 * @param destination_ip target IP
379 * @param destination_port target port
380 * @param local_ip local IP
381 * @param local_port local port
382 * @param state_key set to hash's state if non-NULL
383 * @return NULL if we have no tracking information for this tuple
385 static struct TunnelState *
386 get_redirect_state (int af,
388 const void *destination_ip,
389 uint16_t destination_port,
390 const void *local_ip,
392 GNUNET_HashCode *state_key)
394 struct RedirectInformation ri;
396 struct TunnelState *state;
398 if (protocol == IPPROTO_ICMP)
401 destination_port = 0;
404 ri.remote_address.af = af;
406 ri.remote_address.address.ipv4 = *((struct in_addr*) destination_ip);
408 ri.remote_address.address.ipv6 = * ((struct in6_addr*) destination_ip);
409 ri.remote_address.port = destination_port;
410 ri.remote_address.proto = protocol;
411 ri.local_address.af = af;
413 ri.local_address.address.ipv4 = *((struct in_addr*) local_ip);
415 ri.local_address.address.ipv6 = * ((struct in6_addr*) local_ip);
416 ri.local_address.port = local_port;
417 ri.local_address.proto = protocol;
418 hash_redirect_info (&key, &ri);
419 if (NULL != state_key)
421 state = GNUNET_CONTAINER_multihashmap_get (connections_map, &key);
424 /* Mark this connection as freshly used */
425 if (NULL == state_key)
426 GNUNET_CONTAINER_heap_update_cost (connections_heap,
428 GNUNET_TIME_absolute_get ().abs_value);
434 * Given a service descriptor and a destination port, find the
435 * respective service entry.
437 * @param service_map map of services (TCP or UDP)
438 * @param desc service descriptor
439 * @param dpt destination port
440 * @return NULL if we are not aware of such a service
442 static struct LocalService *
443 find_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
444 const GNUNET_HashCode *desc,
447 char key[sizeof (GNUNET_HashCode) + sizeof (uint16_t)];
449 memcpy (&key[0], &dpt, sizeof (uint16_t));
450 memcpy (&key[sizeof(uint16_t)], desc, sizeof (GNUNET_HashCode));
451 return GNUNET_CONTAINER_multihashmap_get (service_map,
452 (GNUNET_HashCode *) key);
457 * Free memory associated with a service record.
460 * @param key service descriptor
461 * @param value service record to free
465 free_service_record (void *cls,
466 const GNUNET_HashCode *key,
469 struct LocalService *service = value;
471 GNUNET_free_non_null (service->name);
472 GNUNET_free (service);
478 * Given a service descriptor and a destination port, find the
479 * respective service entry.
481 * @param service_map map of services (TCP or UDP)
482 * @param name name of the service
483 * @param dpt destination port
484 * @param service service information record to store (service->name will be set).
487 store_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
490 struct LocalService *service)
492 char key[sizeof (GNUNET_HashCode) + sizeof (uint16_t)];
493 GNUNET_HashCode desc;
495 GNUNET_CRYPTO_hash (name, strlen (name) + 1, &desc);
496 service->name = GNUNET_strdup (name);
497 memcpy (&key[0], &dpt, sizeof (uint16_t));
498 memcpy (&key[sizeof(uint16_t)], &desc, sizeof (GNUNET_HashCode));
500 GNUNET_CONTAINER_multihashmap_put (service_map,
501 (GNUNET_HashCode *) key,
503 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
505 free_service_record (NULL, (GNUNET_HashCode *) key, service);
506 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
507 _("Got duplicate service records for `%s:%u'\n"),
515 * MESH is ready to receive a message for the tunnel. Transmit it.
517 * @param cls the 'struct TunnelState'.
518 * @param size number of bytes available in buf
519 * @param buf where to copy the message
520 * @return number of bytes copied to buf
523 send_to_peer_notify_callback (void *cls, size_t size, void *buf)
525 struct TunnelState *s = cls;
526 struct GNUNET_MESH_Tunnel *tunnel = s->tunnel;
527 struct TunnelMessageQueue *tnq;
535 s->th = GNUNET_MESH_notify_transmit_ready (tunnel,
536 GNUNET_NO /* corking */,
538 GNUNET_TIME_UNIT_FOREVER_REL,
541 &send_to_peer_notify_callback,
545 GNUNET_assert (size >= tnq->len);
546 memcpy (buf, tnq->payload, tnq->len);
548 GNUNET_CONTAINER_DLL_remove (s->head,
552 if (NULL != (tnq = s->head))
553 s->th = GNUNET_MESH_notify_transmit_ready (tunnel,
554 GNUNET_NO /* corking */,
556 GNUNET_TIME_UNIT_FOREVER_REL,
559 &send_to_peer_notify_callback,
561 GNUNET_STATISTICS_update (stats,
562 gettext_noop ("# Bytes transmitted via mesh tunnels"),
569 * Send the given packet via the mesh tunnel.
571 * @param mesh_tunnel destination
572 * @param tnq message to queue
575 send_packet_to_mesh_tunnel (struct GNUNET_MESH_Tunnel *mesh_tunnel,
576 struct TunnelMessageQueue *tnq)
578 struct TunnelState *s;
580 s = GNUNET_MESH_tunnel_get_data (mesh_tunnel);
581 GNUNET_assert (NULL != s);
582 GNUNET_CONTAINER_DLL_insert_tail (s->head, s->tail, tnq);
584 s->th = GNUNET_MESH_notify_transmit_ready (mesh_tunnel, GNUNET_NO /* cork */, 0 /* priority */,
585 GNUNET_TIME_UNIT_FOREVER_REL,
587 &send_to_peer_notify_callback,
593 * @brief Handles an ICMP packet received from the helper.
595 * @param icmp A pointer to the Packet
596 * @param pktlen number of bytes in 'icmp'
597 * @param af address family (AFINET or AF_INET6)
598 * @param destination_ip destination IP-address of the IP packet (should
599 * be our local address)
600 * @param source_ip original source IP-address of the IP packet (should
601 * be the original destination address)
604 icmp_from_helper (const struct GNUNET_TUN_IcmpHeader *icmp,
607 const void *destination_ip,
608 const void *source_ip)
610 struct TunnelState *state;
611 struct TunnelMessageQueue *tnq;
612 struct GNUNET_EXIT_IcmpToVPNMessage *i2v;
613 const struct GNUNET_TUN_IPv4Header *ipv4;
614 const struct GNUNET_TUN_IPv6Header *ipv6;
615 const struct GNUNET_TUN_UdpHeader *udp;
622 char sbuf[INET6_ADDRSTRLEN];
623 char dbuf[INET6_ADDRSTRLEN];
624 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
625 "Received ICMP packet going from %s to %s\n",
628 sbuf, sizeof (sbuf)),
631 dbuf, sizeof (dbuf)));
633 if (pktlen < sizeof (struct GNUNET_TUN_IcmpHeader))
640 /* Find out if this is an ICMP packet in response to an existing
641 TCP/UDP packet and if so, figure out ports / protocol of the
642 existing session from the IP data in the ICMP payload */
645 protocol = IPPROTO_ICMP;
651 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
652 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
654 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
655 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
656 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
658 sizeof (struct GNUNET_TUN_IcmpHeader) +
659 sizeof (struct GNUNET_TUN_IPv4Header) + 8)
665 ipv4 = (const struct GNUNET_TUN_IPv4Header *) &icmp[1];
666 protocol = ipv4->protocol;
667 /* could be TCP or UDP, but both have the ports in the right
668 place, so that doesn't matter here */
669 udp = (const struct GNUNET_TUN_UdpHeader *) &ipv4[1];
670 spt = ntohs (udp->spt);
671 dpt = ntohs (udp->dpt);
672 /* throw away ICMP payload, won't be useful for the other side anyway */
673 pktlen = sizeof (struct GNUNET_TUN_IcmpHeader);
676 GNUNET_STATISTICS_update (stats,
677 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
685 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
686 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
687 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
688 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
690 sizeof (struct GNUNET_TUN_IcmpHeader) +
691 sizeof (struct GNUNET_TUN_IPv6Header) + 8)
697 ipv6 = (const struct GNUNET_TUN_IPv6Header *) &icmp[1];
698 protocol = ipv6->next_header;
699 /* could be TCP or UDP, but both have the ports in the right
700 place, so that doesn't matter here */
701 udp = (const struct GNUNET_TUN_UdpHeader *) &ipv6[1];
702 spt = ntohs (udp->spt);
703 dpt = ntohs (udp->dpt);
704 /* throw away ICMP payload, won't be useful for the other side anyway */
705 pktlen = sizeof (struct GNUNET_TUN_IcmpHeader);
707 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
708 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
711 GNUNET_STATISTICS_update (stats,
712 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
723 state = get_redirect_state (af, IPPROTO_ICMP,
729 state = get_redirect_state (af, IPPROTO_UDP,
737 state = get_redirect_state (af, IPPROTO_TCP,
745 GNUNET_STATISTICS_update (stats,
746 gettext_noop ("# ICMP packets dropped (not allowed)"),
752 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
753 _("ICMP Packet dropped, have no matching connection information\n"));
756 mlen = sizeof (struct GNUNET_EXIT_IcmpToVPNMessage) + pktlen - sizeof (struct GNUNET_TUN_IcmpHeader);
757 tnq = GNUNET_malloc (sizeof (struct TunnelMessageQueue) + mlen);
758 tnq->payload = &tnq[1];
760 i2v = (struct GNUNET_EXIT_IcmpToVPNMessage *) &tnq[1];
761 i2v->header.size = htons ((uint16_t) mlen);
762 i2v->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_VPN);
763 i2v->af = htonl (af);
764 memcpy (&i2v->icmp_header,
767 send_packet_to_mesh_tunnel (state->tunnel,
773 * @brief Handles an UDP packet received from the helper.
775 * @param udp A pointer to the Packet
776 * @param pktlen number of bytes in 'udp'
777 * @param af address family (AFINET or AF_INET6)
778 * @param destination_ip destination IP-address of the IP packet (should
779 * be our local address)
780 * @param source_ip original source IP-address of the IP packet (should
781 * be the original destination address)
784 udp_from_helper (const struct GNUNET_TUN_UdpHeader *udp,
787 const void *destination_ip,
788 const void *source_ip)
790 struct TunnelState *state;
791 struct TunnelMessageQueue *tnq;
792 struct GNUNET_EXIT_UdpReplyMessage *urm;
796 char sbuf[INET6_ADDRSTRLEN];
797 char dbuf[INET6_ADDRSTRLEN];
798 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
799 "Received UDP packet going from %s:%u to %s:%u\n",
802 sbuf, sizeof (sbuf)),
803 (unsigned int) ntohs (udp->spt),
806 dbuf, sizeof (dbuf)),
807 (unsigned int) ntohs (udp->dpt));
809 if (pktlen < sizeof (struct GNUNET_TUN_UdpHeader))
815 if (pktlen != ntohs (udp->len))
821 state = get_redirect_state (af, IPPROTO_UDP,
829 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
830 _("UDP Packet dropped, have no matching connection information\n"));
833 mlen = sizeof (struct GNUNET_EXIT_UdpReplyMessage) + pktlen - sizeof (struct GNUNET_TUN_UdpHeader);
834 tnq = GNUNET_malloc (sizeof (struct TunnelMessageQueue) + mlen);
835 tnq->payload = &tnq[1];
837 urm = (struct GNUNET_EXIT_UdpReplyMessage *) &tnq[1];
838 urm->header.size = htons ((uint16_t) mlen);
839 urm->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_UDP_REPLY);
840 urm->source_port = htons (0);
841 urm->destination_port = htons (0);
844 pktlen - sizeof (struct GNUNET_TUN_UdpHeader));
845 send_packet_to_mesh_tunnel (state->tunnel,
851 * @brief Handles a TCP packet received from the helper.
853 * @param tcp A pointer to the Packet
854 * @param pktlen the length of the packet, including its TCP header
855 * @param af address family (AFINET or AF_INET6)
856 * @param destination_ip destination IP-address of the IP packet (should
857 * be our local address)
858 * @param source_ip original source IP-address of the IP packet (should
859 * be the original destination address)
862 tcp_from_helper (const struct GNUNET_TUN_TcpHeader *tcp,
865 const void *destination_ip,
866 const void *source_ip)
868 struct TunnelState *state;
870 struct GNUNET_TUN_TcpHeader *mtcp;
871 struct GNUNET_EXIT_TcpDataMessage *tdm;
872 struct TunnelMessageQueue *tnq;
876 char sbuf[INET6_ADDRSTRLEN];
877 char dbuf[INET6_ADDRSTRLEN];
878 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
879 "Received TCP packet with %u bytes going from %s:%u to %s:%u\n",
880 pktlen - sizeof (struct GNUNET_TUN_TcpHeader),
883 sbuf, sizeof (sbuf)),
884 (unsigned int) ntohs (tcp->spt),
887 dbuf, sizeof (dbuf)),
888 (unsigned int) ntohs (tcp->dpt));
890 if (pktlen < sizeof (struct GNUNET_TUN_TcpHeader))
896 state = get_redirect_state (af, IPPROTO_TCP,
904 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
905 _("TCP Packet dropped, have no matching connection information\n"));
909 /* mug port numbers and crc to avoid information leakage;
910 sender will need to lookup the correct values anyway */
911 memcpy (buf, tcp, pktlen);
912 mtcp = (struct GNUNET_TUN_TcpHeader *) buf;
917 mlen = sizeof (struct GNUNET_EXIT_TcpDataMessage) + (pktlen - sizeof (struct GNUNET_TUN_TcpHeader));
918 if (mlen >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
924 tnq = GNUNET_malloc (sizeof (struct TunnelMessageQueue) + mlen);
925 tnq->payload = &tnq[1];
927 tdm = (struct GNUNET_EXIT_TcpDataMessage *) &tnq[1];
928 tdm->header.size = htons ((uint16_t) mlen);
929 tdm->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_TCP_DATA_TO_VPN);
930 tdm->reserved = htonl (0);
931 memcpy (&tdm->tcp_header,
934 send_packet_to_mesh_tunnel (state->tunnel,
940 * Receive packets from the helper-process
943 * @param client unsued
944 * @param message message received from helper
947 message_token (void *cls GNUNET_UNUSED, void *client GNUNET_UNUSED,
948 const struct GNUNET_MessageHeader *message)
950 const struct GNUNET_TUN_Layer2PacketHeader *pkt_tun;
953 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
954 "Got %u-byte message of type %u from gnunet-helper-exit\n",
955 ntohs (message->size),
956 ntohs (message->type));
957 GNUNET_STATISTICS_update (stats,
958 gettext_noop ("# Packets received from TUN"),
960 if (ntohs (message->type) != GNUNET_MESSAGE_TYPE_VPN_HELPER)
965 size = ntohs (message->size);
966 if (size < sizeof (struct GNUNET_TUN_Layer2PacketHeader) + sizeof (struct GNUNET_MessageHeader))
971 GNUNET_STATISTICS_update (stats,
972 gettext_noop ("# Bytes received from TUN"),
974 pkt_tun = (const struct GNUNET_TUN_Layer2PacketHeader *) &message[1];
975 size -= sizeof (struct GNUNET_TUN_Layer2PacketHeader) + sizeof (struct GNUNET_MessageHeader);
976 switch (ntohs (pkt_tun->proto))
980 const struct GNUNET_TUN_IPv4Header *pkt4;
982 if (size < sizeof (struct GNUNET_TUN_IPv4Header))
984 /* Kernel to blame? */
988 pkt4 = (const struct GNUNET_TUN_IPv4Header *) &pkt_tun[1];
989 if (size != ntohs (pkt4->total_length))
991 /* Kernel to blame? */
995 if (pkt4->header_length * 4 != sizeof (struct GNUNET_TUN_IPv4Header))
997 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
998 _("IPv4 packet options received. Ignored.\n"));
1002 size -= sizeof (struct GNUNET_TUN_IPv4Header);
1003 switch (pkt4->protocol)
1006 udp_from_helper ((const struct GNUNET_TUN_UdpHeader *) &pkt4[1], size,
1008 &pkt4->destination_address,
1009 &pkt4->source_address);
1012 tcp_from_helper ((const struct GNUNET_TUN_TcpHeader *) &pkt4[1], size,
1014 &pkt4->destination_address,
1015 &pkt4->source_address);
1018 icmp_from_helper ((const struct GNUNET_TUN_IcmpHeader *) &pkt4[1], size,
1020 &pkt4->destination_address,
1021 &pkt4->source_address);
1024 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1025 _("IPv4 packet with unsupported next header received. Ignored.\n"));
1032 const struct GNUNET_TUN_IPv6Header *pkt6;
1034 if (size < sizeof (struct GNUNET_TUN_IPv6Header))
1036 /* Kernel to blame? */
1040 pkt6 = (struct GNUNET_TUN_IPv6Header *) &pkt_tun[1];
1041 if (size != ntohs (pkt6->payload_length) + sizeof (struct GNUNET_TUN_IPv6Header))
1043 /* Kernel to blame? */
1047 size -= sizeof (struct GNUNET_TUN_IPv6Header);
1048 switch (pkt6->next_header)
1051 udp_from_helper ((const struct GNUNET_TUN_UdpHeader *) &pkt6[1], size,
1053 &pkt6->destination_address,
1054 &pkt6->source_address);
1057 tcp_from_helper ((const struct GNUNET_TUN_TcpHeader *) &pkt6[1], size,
1059 &pkt6->destination_address,
1060 &pkt6->source_address);
1063 icmp_from_helper ((const struct GNUNET_TUN_IcmpHeader *) &pkt6[1], size,
1065 &pkt6->destination_address,
1066 &pkt6->source_address);
1069 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1070 _("IPv6 packet with unsupported next header received. Ignored.\n"));
1076 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1077 _("Packet from unknown protocol %u received. Ignored.\n"),
1078 ntohs (pkt_tun->proto));
1085 * We need to create a (unique) fresh local address (IP+port).
1088 * @param af desired address family
1089 * @param proto desired protocol (IPPROTO_UDP or IPPROTO_TCP)
1090 * @param local_address address to initialize
1093 setup_fresh_address (int af,
1095 struct SocketAddress *local_address)
1097 local_address->af = af;
1098 local_address->proto = (uint8_t) proto;
1099 /* default "local" port range is often 32768--61000,
1100 so we pick a random value in that range */
1101 if (proto == IPPROTO_ICMP)
1102 local_address->port = 0;
1105 = (uint16_t) 32768 + GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1111 struct in_addr addr;
1112 struct in_addr mask;
1115 addr = exit_ipv4addr;
1116 mask = exit_ipv4mask;
1117 if (0 == ~mask.s_addr)
1119 /* only one valid IP anyway */
1120 local_address->address.ipv4 = addr;
1123 /* Given 192.168.0.1/255.255.0.0, we want a mask
1124 of '192.168.255.255', thus: */
1125 mask.s_addr = addr.s_addr | ~mask.s_addr;
1126 /* Pick random IPv4 address within the subnet, except 'addr' or 'mask' itself */
1129 rnd.s_addr = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1131 local_address->address.ipv4.s_addr = (addr.s_addr | rnd.s_addr) & mask.s_addr;
1133 while ( (local_address->address.ipv4.s_addr == addr.s_addr) ||
1134 (local_address->address.ipv4.s_addr == mask.s_addr) );
1139 struct in6_addr addr;
1140 struct in6_addr mask;
1141 struct in6_addr rnd;
1144 addr = exit_ipv6addr;
1145 GNUNET_assert (ipv6prefix < 128);
1146 if (ipv6prefix == 127)
1148 /* only one valid IP anyway */
1149 local_address->address.ipv6 = addr;
1152 /* Given ABCD::/96, we want a mask of 'ABCD::FFFF:FFFF,
1155 for (i=127;i>=ipv6prefix;i--)
1156 mask.s6_addr[i / 8] |= (1 << (i % 8));
1158 /* Pick random IPv6 address within the subnet, except 'addr' or 'mask' itself */
1163 rnd.s6_addr[i] = (unsigned char) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1165 local_address->address.ipv6.s6_addr[i]
1166 = (addr.s6_addr[i] | rnd.s6_addr[i]) & mask.s6_addr[i];
1169 while ( (0 == memcmp (&local_address->address.ipv6,
1171 sizeof (struct in6_addr))) ||
1172 (0 == memcmp (&local_address->address.ipv6,
1174 sizeof (struct in6_addr))) );
1184 * We are starting a fresh connection (TCP or UDP) and need
1185 * to pick a source port and IP address (within the correct
1186 * range and address family) to associate replies with the
1187 * connection / correct mesh tunnel. This function generates
1188 * a "fresh" source IP and source port number for a connection
1189 * After picking a good source address, this function sets up
1190 * the state in the 'connections_map' and 'connections_heap'
1191 * to allow finding the state when needed later. The function
1192 * also makes sure that we remain within memory limits by
1193 * cleaning up 'old' states.
1195 * @param state skeleton state to setup a record for; should
1196 * 'state->ri.remote_address' filled in so that
1197 * this code can determine which AF/protocol is
1198 * going to be used (the 'tunnel' should also
1199 * already be set); after calling this function,
1200 * heap_node and the local_address will be
1201 * also initialized (heap_node != NULL can be
1202 * used to test if a state has been fully setup).
1205 setup_state_record (struct TunnelState *state)
1207 GNUNET_HashCode key;
1208 struct TunnelState *s;
1210 /* generate fresh, unique address */
1213 if (NULL == state->serv)
1214 setup_fresh_address (state->ri.remote_address.af,
1215 state->ri.remote_address.proto,
1216 &state->ri.local_address);
1218 setup_fresh_address (state->serv->address.af,
1219 state->serv->address.proto,
1220 &state->ri.local_address);
1221 } while (NULL != get_redirect_state (state->ri.remote_address.af,
1222 state->ri.remote_address.proto,
1223 &state->ri.remote_address.address,
1224 state->ri.remote_address.port,
1225 &state->ri.local_address.address,
1226 state->ri.local_address.port,
1229 char buf[INET6_ADDRSTRLEN];
1230 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1231 "Picked local address %s:%u for new connection\n",
1232 inet_ntop (state->ri.local_address.af,
1233 &state->ri.local_address.address,
1235 (unsigned int) state->ri.local_address.port);
1237 state->state_key = key;
1238 GNUNET_assert (GNUNET_OK ==
1239 GNUNET_CONTAINER_multihashmap_put (connections_map,
1241 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1242 state->heap_node = GNUNET_CONTAINER_heap_insert (connections_heap,
1244 GNUNET_TIME_absolute_get ().abs_value);
1245 while (GNUNET_CONTAINER_heap_get_size (connections_heap) > max_connections)
1247 s = GNUNET_CONTAINER_heap_remove_root (connections_heap);
1248 GNUNET_assert (state != s);
1249 s->heap_node = NULL;
1250 GNUNET_MESH_tunnel_destroy (s->tunnel);
1251 GNUNET_assert (GNUNET_OK ==
1252 GNUNET_CONTAINER_multihashmap_remove (connections_map,
1261 * Prepare an IPv4 packet for transmission via the TUN interface.
1262 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1263 * For UDP, the UDP header will be fully created, whereas for TCP
1264 * only the ports and checksum will be filled in. So for TCP,
1265 * a skeleton TCP header must be part of the provided payload.
1267 * @param payload payload of the packet (starting with UDP payload or
1268 * TCP header, depending on protocol)
1269 * @param payload_length number of bytes in 'payload'
1270 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1271 * @param tcp_header skeleton of the TCP header, NULL for UDP
1272 * @param src_address source address to use (IP and port)
1273 * @param dst_address destination address to use (IP and port)
1274 * @param pkt6 where to write the assembled packet; must
1275 * contain enough space for the IP header, UDP/TCP header
1279 prepare_ipv4_packet (const void *payload, size_t payload_length,
1281 const struct GNUNET_TUN_TcpHeader *tcp_header,
1282 const struct SocketAddress *src_address,
1283 const struct SocketAddress *dst_address,
1284 struct GNUNET_TUN_IPv4Header *pkt4)
1288 len = payload_length;
1292 len += sizeof (struct GNUNET_TUN_UdpHeader);
1295 len += sizeof (struct GNUNET_TUN_TcpHeader);
1296 GNUNET_assert (NULL != tcp_header);
1302 if (len + sizeof (struct GNUNET_TUN_IPv4Header) > UINT16_MAX)
1308 GNUNET_TUN_initialize_ipv4_header (pkt4,
1311 &src_address->address.ipv4,
1312 &dst_address->address.ipv4);
1317 struct GNUNET_TUN_UdpHeader *pkt4_udp = (struct GNUNET_TUN_UdpHeader *) &pkt4[1];
1319 pkt4_udp->spt = htons (src_address->port);
1320 pkt4_udp->dpt = htons (dst_address->port);
1321 pkt4_udp->len = htons ((uint16_t) payload_length);
1322 GNUNET_TUN_calculate_udp4_checksum (pkt4,
1324 payload, payload_length);
1325 memcpy (&pkt4_udp[1], payload, payload_length);
1330 struct GNUNET_TUN_TcpHeader *pkt4_tcp = (struct GNUNET_TUN_TcpHeader *) &pkt4[1];
1332 *pkt4_tcp = *tcp_header;
1333 pkt4_tcp->spt = htons (src_address->port);
1334 pkt4_tcp->dpt = htons (dst_address->port);
1335 GNUNET_TUN_calculate_tcp4_checksum (pkt4,
1339 memcpy (&pkt4_tcp[1], payload, payload_length);
1349 * Prepare an IPv6 packet for transmission via the TUN interface.
1350 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1351 * For UDP, the UDP header will be fully created, whereas for TCP
1352 * only the ports and checksum will be filled in. So for TCP,
1353 * a skeleton TCP header must be part of the provided payload.
1355 * @param payload payload of the packet (starting with UDP payload or
1356 * TCP header, depending on protocol)
1357 * @param payload_length number of bytes in 'payload'
1358 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1359 * @param src_address source address to use (IP and port)
1360 * @param dst_address destination address to use (IP and port)
1361 * @param pkt6 where to write the assembled packet; must
1362 * contain enough space for the IP header, UDP/TCP header
1366 prepare_ipv6_packet (const void *payload, size_t payload_length,
1368 const struct GNUNET_TUN_TcpHeader *tcp_header,
1369 const struct SocketAddress *src_address,
1370 const struct SocketAddress *dst_address,
1371 struct GNUNET_TUN_IPv6Header *pkt6)
1375 len = payload_length;
1379 len += sizeof (struct GNUNET_TUN_UdpHeader);
1382 len += sizeof (struct GNUNET_TUN_TcpHeader);
1388 if (len > UINT16_MAX)
1394 GNUNET_TUN_initialize_ipv6_header (pkt6,
1397 &src_address->address.ipv6,
1398 &dst_address->address.ipv6);
1404 struct GNUNET_TUN_UdpHeader *pkt6_udp = (struct GNUNET_TUN_UdpHeader *) &pkt6[1];
1406 pkt6_udp->spt = htons (src_address->port);
1407 pkt6_udp->dpt = htons (dst_address->port);
1408 pkt6_udp->len = htons ((uint16_t) payload_length);
1409 GNUNET_TUN_calculate_udp6_checksum (pkt6,
1413 memcpy (&pkt6_udp[1], payload, payload_length);
1418 struct GNUNET_TUN_TcpHeader *pkt6_tcp = (struct GNUNET_TUN_TcpHeader *) &pkt6[1];
1420 /* memcpy first here as some TCP header fields are initialized this way! */
1421 *pkt6_tcp = *tcp_header;
1422 pkt6_tcp->spt = htons (src_address->port);
1423 pkt6_tcp->dpt = htons (dst_address->port);
1424 GNUNET_TUN_calculate_tcp6_checksum (pkt6,
1428 memcpy (&pkt6_tcp[1], payload, payload_length);
1439 * Send a TCP packet via the TUN interface.
1441 * @param destination_address IP and port to use for the TCP packet's destination
1442 * @param source_address IP and port to use for the TCP packet's source
1443 * @param tcp_header header template to use
1444 * @param payload payload of the TCP packet
1445 * @param payload_length number of bytes in 'payload'
1448 send_tcp_packet_via_tun (const struct SocketAddress *destination_address,
1449 const struct SocketAddress *source_address,
1450 const struct GNUNET_TUN_TcpHeader *tcp_header,
1451 const void *payload, size_t payload_length)
1455 GNUNET_STATISTICS_update (stats,
1456 gettext_noop ("# TCP packets sent via TUN"),
1458 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1459 "Sending packet with %u bytes TCP payload via TUN\n",
1460 (unsigned int) payload_length);
1461 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
1462 switch (source_address->af)
1465 len += sizeof (struct GNUNET_TUN_IPv4Header);
1468 len += sizeof (struct GNUNET_TUN_IPv6Header);
1474 len += sizeof (struct GNUNET_TUN_TcpHeader);
1475 len += payload_length;
1476 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1483 struct GNUNET_MessageHeader *hdr;
1484 struct GNUNET_TUN_Layer2PacketHeader *tun;
1486 hdr = (struct GNUNET_MessageHeader *) buf;
1487 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1488 hdr->size = htons (len);
1489 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
1490 tun->flags = htons (0);
1491 switch (source_address->af)
1495 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
1497 tun->proto = htons (ETH_P_IPV4);
1498 prepare_ipv4_packet (payload, payload_length,
1502 destination_address,
1508 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
1510 tun->proto = htons (ETH_P_IPV6);
1511 prepare_ipv6_packet (payload, payload_length,
1515 destination_address,
1523 (void) GNUNET_HELPER_send (helper_handle,
1524 (const struct GNUNET_MessageHeader*) buf,
1532 * Process a request via mesh to send a request to a TCP service
1533 * offered by this system.
1535 * @param cls closure, NULL
1536 * @param tunnel connection to the other end
1537 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1538 * @param sender who sent the message
1539 * @param message the actual message
1540 * @param atsi performance data for the connection
1541 * @return GNUNET_OK to keep the connection open,
1542 * GNUNET_SYSERR to close it (signal serious error)
1545 receive_tcp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1546 void **tunnel_ctx GNUNET_UNUSED,
1547 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1548 const struct GNUNET_MessageHeader *message,
1549 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1551 struct TunnelState *state = *tunnel_ctx;
1552 const struct GNUNET_EXIT_TcpServiceStartMessage *start;
1553 uint16_t pkt_len = ntohs (message->size);
1555 GNUNET_STATISTICS_update (stats,
1556 gettext_noop ("# TCP service creation requests received via mesh"),
1558 GNUNET_STATISTICS_update (stats,
1559 gettext_noop ("# Bytes received from MESH"),
1560 pkt_len, GNUNET_NO);
1561 /* check that we got at least a valid header */
1562 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpServiceStartMessage))
1564 GNUNET_break_op (0);
1565 return GNUNET_SYSERR;
1567 start = (const struct GNUNET_EXIT_TcpServiceStartMessage*) message;
1568 pkt_len -= sizeof (struct GNUNET_EXIT_TcpServiceStartMessage);
1569 if ( (NULL == state) ||
1570 (NULL != state->serv) ||
1571 (NULL != state->heap_node) )
1573 GNUNET_break_op (0);
1574 return GNUNET_SYSERR;
1576 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1578 GNUNET_break_op (0);
1579 return GNUNET_SYSERR;
1581 GNUNET_break_op (ntohl (start->reserved) == 0);
1582 /* setup fresh connection */
1583 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1584 "Received data from %s for forwarding to TCP service %s on port %u\n",
1585 GNUNET_i2s (sender),
1586 GNUNET_h2s (&start->service_descriptor),
1587 (unsigned int) ntohs (start->tcp_header.dpt));
1588 if (NULL == (state->serv = find_service (tcp_services, &start->service_descriptor,
1589 ntohs (start->tcp_header.dpt))))
1591 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1592 _("No service found for %s on port %d!\n"),
1594 ntohs (start->tcp_header.dpt));
1595 GNUNET_STATISTICS_update (stats,
1596 gettext_noop ("# TCP requests dropped (no such service)"),
1598 return GNUNET_SYSERR;
1600 state->ri.remote_address = state->serv->address;
1601 setup_state_record (state);
1602 send_tcp_packet_via_tun (&state->ri.remote_address,
1603 &state->ri.local_address,
1605 &start[1], pkt_len);
1611 * Process a request to forward TCP data to the Internet via this peer.
1613 * @param cls closure, NULL
1614 * @param tunnel connection to the other end
1615 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1616 * @param sender who sent the message
1617 * @param message the actual message
1618 * @param atsi performance data for the connection
1619 * @return GNUNET_OK to keep the connection open,
1620 * GNUNET_SYSERR to close it (signal serious error)
1623 receive_tcp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1624 void **tunnel_ctx GNUNET_UNUSED,
1625 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1626 const struct GNUNET_MessageHeader *message,
1627 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1629 struct TunnelState *state = *tunnel_ctx;
1630 const struct GNUNET_EXIT_TcpInternetStartMessage *start;
1631 uint16_t pkt_len = ntohs (message->size);
1632 const struct in_addr *v4;
1633 const struct in6_addr *v6;
1634 const void *payload;
1637 GNUNET_STATISTICS_update (stats,
1638 gettext_noop ("# Bytes received from MESH"),
1639 pkt_len, GNUNET_NO);
1640 GNUNET_STATISTICS_update (stats,
1641 gettext_noop ("# TCP IP-exit creation requests received via mesh"),
1643 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpInternetStartMessage))
1645 GNUNET_break_op (0);
1646 return GNUNET_SYSERR;
1648 start = (const struct GNUNET_EXIT_TcpInternetStartMessage*) message;
1649 pkt_len -= sizeof (struct GNUNET_EXIT_TcpInternetStartMessage);
1650 if ( (NULL == state) ||
1651 (NULL != state->serv) ||
1652 (NULL != state->heap_node) )
1654 GNUNET_break_op (0);
1655 return GNUNET_SYSERR;
1657 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1659 GNUNET_break_op (0);
1660 return GNUNET_SYSERR;
1662 af = (int) ntohl (start->af);
1663 state->ri.remote_address.af = af;
1667 if (pkt_len < sizeof (struct in_addr))
1669 GNUNET_break_op (0);
1670 return GNUNET_SYSERR;
1674 GNUNET_break_op (0);
1675 return GNUNET_SYSERR;
1677 v4 = (const struct in_addr*) &start[1];
1679 pkt_len -= sizeof (struct in_addr);
1680 state->ri.remote_address.address.ipv4 = *v4;
1683 if (pkt_len < sizeof (struct in6_addr))
1685 GNUNET_break_op (0);
1686 return GNUNET_SYSERR;
1690 GNUNET_break_op (0);
1691 return GNUNET_SYSERR;
1693 v6 = (const struct in6_addr*) &start[1];
1695 pkt_len -= sizeof (struct in6_addr);
1696 state->ri.remote_address.address.ipv6 = *v6;
1699 GNUNET_break_op (0);
1700 return GNUNET_SYSERR;
1703 char buf[INET6_ADDRSTRLEN];
1704 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1705 "Received data from %s for starting TCP stream to %s:%u\n",
1706 GNUNET_i2s (sender),
1708 &state->ri.remote_address.address,
1710 (unsigned int) ntohs (start->tcp_header.dpt));
1712 state->ri.remote_address.proto = IPPROTO_TCP;
1713 state->ri.remote_address.port = ntohs (start->tcp_header.dpt);
1714 setup_state_record (state);
1715 send_tcp_packet_via_tun (&state->ri.remote_address,
1716 &state->ri.local_address,
1724 * Process a request to forward TCP data on an established
1725 * connection via this peer.
1727 * @param cls closure, NULL
1728 * @param tunnel connection to the other end
1729 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1730 * @param sender who sent the message
1731 * @param message the actual message
1732 * @param atsi performance data for the connection
1733 * @return GNUNET_OK to keep the connection open,
1734 * GNUNET_SYSERR to close it (signal serious error)
1737 receive_tcp_data (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1738 void **tunnel_ctx GNUNET_UNUSED,
1739 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1740 const struct GNUNET_MessageHeader *message,
1741 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1743 struct TunnelState *state = *tunnel_ctx;
1744 const struct GNUNET_EXIT_TcpDataMessage *data;
1745 uint16_t pkt_len = ntohs (message->size);
1747 GNUNET_STATISTICS_update (stats,
1748 gettext_noop ("# Bytes received from MESH"),
1749 pkt_len, GNUNET_NO);
1750 GNUNET_STATISTICS_update (stats,
1751 gettext_noop ("# TCP data requests received via mesh"),
1753 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpDataMessage))
1755 GNUNET_break_op (0);
1756 return GNUNET_SYSERR;
1758 data = (const struct GNUNET_EXIT_TcpDataMessage*) message;
1759 pkt_len -= sizeof (struct GNUNET_EXIT_TcpDataMessage);
1760 if ( (NULL == state) ||
1761 (NULL == state->heap_node) )
1763 /* connection should have been up! */
1764 GNUNET_STATISTICS_update (stats,
1765 gettext_noop ("# TCP DATA requests dropped (no session)"),
1767 return GNUNET_SYSERR;
1769 if (data->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1771 GNUNET_break_op (0);
1772 return GNUNET_SYSERR;
1775 GNUNET_break_op (ntohl (data->reserved) == 0);
1777 char buf[INET6_ADDRSTRLEN];
1778 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1779 "Received additional %u bytes of data from %s for TCP stream to %s:%u\n",
1781 GNUNET_i2s (sender),
1782 inet_ntop (state->ri.remote_address.af,
1783 &state->ri.remote_address.address,
1785 (unsigned int) state->ri.remote_address.port);
1788 send_tcp_packet_via_tun (&state->ri.remote_address,
1789 &state->ri.local_address,
1797 * Send an ICMP packet via the TUN interface.
1799 * @param destination_address IP to use for the ICMP packet's destination
1800 * @param source_address IP to use for the ICMP packet's source
1801 * @param icmp_header ICMP header to send
1802 * @param payload payload of the ICMP packet (does NOT include ICMP header)
1803 * @param payload_length number of bytes of data in payload
1806 send_icmp_packet_via_tun (const struct SocketAddress *destination_address,
1807 const struct SocketAddress *source_address,
1808 const struct GNUNET_TUN_IcmpHeader *icmp_header,
1809 const void *payload, size_t payload_length)
1812 struct GNUNET_TUN_IcmpHeader *icmp;
1814 GNUNET_STATISTICS_update (stats,
1815 gettext_noop ("# ICMP packets sent via TUN"),
1817 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1818 "Sending packet with %u bytes ICMP payload via TUN\n",
1819 (unsigned int) payload_length);
1820 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
1821 switch (destination_address->af)
1824 len += sizeof (struct GNUNET_TUN_IPv4Header);
1827 len += sizeof (struct GNUNET_TUN_IPv6Header);
1833 len += sizeof (struct GNUNET_TUN_IcmpHeader);
1834 len += payload_length;
1835 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1842 struct GNUNET_MessageHeader *hdr;
1843 struct GNUNET_TUN_Layer2PacketHeader *tun;
1845 hdr= (struct GNUNET_MessageHeader *) buf;
1846 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1847 hdr->size = htons (len);
1848 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
1849 tun->flags = htons (0);
1850 switch (source_address->af)
1854 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
1856 tun->proto = htons (ETH_P_IPV4);
1857 GNUNET_TUN_initialize_ipv4_header (ipv4,
1859 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
1860 &source_address->address.ipv4,
1861 &destination_address->address.ipv4);
1862 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv4[1];
1867 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
1869 tun->proto = htons (ETH_P_IPV6);
1870 GNUNET_TUN_initialize_ipv6_header (ipv6,
1872 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
1873 &source_address->address.ipv6,
1874 &destination_address->address.ipv6);
1875 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv6[1];
1882 *icmp = *icmp_header;
1886 GNUNET_TUN_calculate_icmp_checksum (icmp,
1889 (void) GNUNET_HELPER_send (helper_handle,
1890 (const struct GNUNET_MessageHeader*) buf,
1898 * Synthesize a plausible ICMP payload for an ICMPv4 error
1899 * response on the given tunnel.
1901 * @param state tunnel information
1902 * @param ipp IPv6 header to fill in (ICMP payload)
1903 * @param udp "UDP" header to fill in (ICMP payload); might actually
1904 * also be the first 8 bytes of the TCP header
1907 make_up_icmpv4_payload (struct TunnelState *state,
1908 struct GNUNET_TUN_IPv4Header *ipp,
1909 struct GNUNET_TUN_UdpHeader *udp)
1911 GNUNET_TUN_initialize_ipv4_header (ipp,
1912 state->ri.remote_address.proto,
1913 sizeof (struct GNUNET_TUN_TcpHeader),
1914 &state->ri.remote_address.address.ipv4,
1915 &state->ri.local_address.address.ipv4);
1916 udp->spt = htons (state->ri.remote_address.port);
1917 udp->dpt = htons (state->ri.local_address.port);
1918 udp->len = htons (0);
1919 udp->crc = htons (0);
1924 * Synthesize a plausible ICMP payload for an ICMPv6 error
1925 * response on the given tunnel.
1927 * @param state tunnel information
1928 * @param ipp IPv6 header to fill in (ICMP payload)
1929 * @param udp "UDP" header to fill in (ICMP payload); might actually
1930 * also be the first 8 bytes of the TCP header
1933 make_up_icmpv6_payload (struct TunnelState *state,
1934 struct GNUNET_TUN_IPv6Header *ipp,
1935 struct GNUNET_TUN_UdpHeader *udp)
1937 GNUNET_TUN_initialize_ipv6_header (ipp,
1938 state->ri.remote_address.proto,
1939 sizeof (struct GNUNET_TUN_TcpHeader),
1940 &state->ri.remote_address.address.ipv6,
1941 &state->ri.local_address.address.ipv6);
1942 udp->spt = htons (state->ri.remote_address.port);
1943 udp->dpt = htons (state->ri.local_address.port);
1944 udp->len = htons (0);
1945 udp->crc = htons (0);
1950 * Process a request to forward ICMP data to the Internet via this peer.
1952 * @param cls closure, NULL
1953 * @param tunnel connection to the other end
1954 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1955 * @param sender who sent the message
1956 * @param message the actual message
1957 * @param atsi performance data for the connection
1958 * @return GNUNET_OK to keep the connection open,
1959 * GNUNET_SYSERR to close it (signal serious error)
1962 receive_icmp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1963 void **tunnel_ctx GNUNET_UNUSED,
1964 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1965 const struct GNUNET_MessageHeader *message,
1966 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1968 struct TunnelState *state = *tunnel_ctx;
1969 const struct GNUNET_EXIT_IcmpInternetMessage *msg;
1970 uint16_t pkt_len = ntohs (message->size);
1971 const struct in_addr *v4;
1972 const struct in6_addr *v6;
1973 const void *payload;
1974 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8];
1977 GNUNET_STATISTICS_update (stats,
1978 gettext_noop ("# Bytes received from MESH"),
1979 pkt_len, GNUNET_NO);
1980 GNUNET_STATISTICS_update (stats,
1981 gettext_noop ("# ICMP IP-exit requests received via mesh"),
1983 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpInternetMessage))
1985 GNUNET_break_op (0);
1986 return GNUNET_SYSERR;
1988 msg = (const struct GNUNET_EXIT_IcmpInternetMessage*) message;
1989 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpInternetMessage);
1991 af = (int) ntohl (msg->af);
1992 if ( (NULL != state->heap_node) &&
1993 (af != state->ri.remote_address.af) )
1995 /* other peer switched AF on this tunnel; not allowed */
1996 GNUNET_break_op (0);
1997 return GNUNET_SYSERR;
2003 if (pkt_len < sizeof (struct in_addr))
2005 GNUNET_break_op (0);
2006 return GNUNET_SYSERR;
2010 GNUNET_break_op (0);
2011 return GNUNET_SYSERR;
2013 v4 = (const struct in_addr*) &msg[1];
2015 pkt_len -= sizeof (struct in_addr);
2016 state->ri.remote_address.address.ipv4 = *v4;
2017 if (NULL == state->heap_node)
2019 state->ri.remote_address.af = af;
2020 state->ri.remote_address.proto = IPPROTO_ICMP;
2021 setup_state_record (state);
2023 /* check that ICMP type is something we want to support
2024 and possibly make up payload! */
2025 switch (msg->icmp_header.type)
2027 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2028 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2030 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2031 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2032 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2035 GNUNET_break_op (0);
2036 return GNUNET_SYSERR;
2038 /* make up payload */
2040 struct GNUNET_TUN_IPv4Header *ipp = (struct GNUNET_TUN_IPv4Header *) buf;
2041 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2043 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2044 pkt_len = sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2045 make_up_icmpv4_payload (state,
2052 GNUNET_break_op (0);
2053 GNUNET_STATISTICS_update (stats,
2054 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2056 return GNUNET_SYSERR;
2061 if (pkt_len < sizeof (struct in6_addr))
2063 GNUNET_break_op (0);
2064 return GNUNET_SYSERR;
2068 GNUNET_break_op (0);
2069 return GNUNET_SYSERR;
2071 v6 = (const struct in6_addr*) &msg[1];
2073 pkt_len -= sizeof (struct in6_addr);
2074 state->ri.remote_address.address.ipv6 = *v6;
2075 if (NULL == state->heap_node)
2077 state->ri.remote_address.af = af;
2078 state->ri.remote_address.proto = IPPROTO_ICMP;
2079 setup_state_record (state);
2081 /* check that ICMP type is something we want to support
2082 and possibly make up payload! */
2083 switch (msg->icmp_header.type)
2085 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2086 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2088 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2089 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2090 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2091 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2094 GNUNET_break_op (0);
2095 return GNUNET_SYSERR;
2097 /* make up payload */
2099 struct GNUNET_TUN_IPv6Header *ipp = (struct GNUNET_TUN_IPv6Header *) buf;
2100 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2102 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2103 pkt_len = sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2104 make_up_icmpv6_payload (state,
2111 GNUNET_break_op (0);
2112 GNUNET_STATISTICS_update (stats,
2113 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2115 return GNUNET_SYSERR;
2121 GNUNET_break_op (0);
2122 return GNUNET_SYSERR;
2126 char buf[INET6_ADDRSTRLEN];
2127 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2128 "Received ICMP data from %s for forwarding to %s\n",
2129 GNUNET_i2s (sender),
2131 &state->ri.remote_address.address,
2132 buf, sizeof (buf)));
2134 send_icmp_packet_via_tun (&state->ri.remote_address,
2135 &state->ri.local_address,
2143 * Setup ICMP payload for ICMP error messages. Called
2144 * for both IPv4 and IPv6 addresses.
2146 * @param state context for creating the IP Packet
2147 * @param buf where to create the payload, has at least
2148 * sizeof (struct GNUNET_TUN_IPv6Header) + 8 bytes
2149 * @return number of bytes of payload we created in buf
2152 make_up_icmp_service_payload (struct TunnelState *state,
2155 switch (state->serv->address.af)
2159 struct GNUNET_TUN_IPv4Header *ipv4;
2160 struct GNUNET_TUN_UdpHeader *udp;
2162 ipv4 = (struct GNUNET_TUN_IPv4Header *)buf;
2163 udp = (struct GNUNET_TUN_UdpHeader *) &ipv4[1];
2164 make_up_icmpv4_payload (state,
2167 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2168 return sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2173 struct GNUNET_TUN_IPv6Header *ipv6;
2174 struct GNUNET_TUN_UdpHeader *udp;
2176 ipv6 = (struct GNUNET_TUN_IPv6Header *)buf;
2177 udp = (struct GNUNET_TUN_UdpHeader *) &ipv6[1];
2178 make_up_icmpv6_payload (state,
2181 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2182 return sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2193 * Process a request via mesh to send ICMP data to a service
2194 * offered by this system.
2196 * @param cls closure, NULL
2197 * @param tunnel connection to the other end
2198 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2199 * @param sender who sent the message
2200 * @param message the actual message
2201 * @param atsi performance data for the connection
2202 * @return GNUNET_OK to keep the connection open,
2203 * GNUNET_SYSERR to close it (signal serious error)
2206 receive_icmp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2208 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2209 const struct GNUNET_MessageHeader *message,
2210 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2212 struct TunnelState *state = *tunnel_ctx;
2213 const struct GNUNET_EXIT_IcmpServiceMessage *msg;
2214 uint16_t pkt_len = ntohs (message->size);
2215 struct GNUNET_TUN_IcmpHeader icmp;
2216 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8];
2217 const void *payload;
2219 GNUNET_STATISTICS_update (stats,
2220 gettext_noop ("# Bytes received from MESH"),
2221 pkt_len, GNUNET_NO);
2222 GNUNET_STATISTICS_update (stats,
2223 gettext_noop ("# ICMP service requests received via mesh"),
2225 /* check that we got at least a valid header */
2226 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpServiceMessage))
2228 GNUNET_break_op (0);
2229 return GNUNET_SYSERR;
2231 msg = (const struct GNUNET_EXIT_IcmpServiceMessage*) message;
2232 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpServiceMessage);
2233 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2234 "Received data from %s for forwarding to ICMP service %s\n",
2235 GNUNET_i2s (sender),
2236 GNUNET_h2s (&msg->service_descriptor));
2237 if (NULL == state->serv)
2239 /* first packet to service must not be ICMP (cannot determine service!) */
2240 GNUNET_break_op (0);
2241 return GNUNET_SYSERR;
2243 icmp = msg->icmp_header;
2245 state->ri.remote_address = state->serv->address;
2246 setup_state_record (state);
2248 /* check that ICMP type is something we want to support,
2249 perform ICMP PT if needed ans possibly make up payload */
2253 switch (msg->icmp_header.type)
2255 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2256 if (state->serv->address.af == AF_INET6)
2257 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REPLY;
2259 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2260 if (state->serv->address.af == AF_INET6)
2261 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST;
2263 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2264 if (state->serv->address.af == AF_INET6)
2265 icmp.type = GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE;
2268 GNUNET_break_op (0);
2269 return GNUNET_SYSERR;
2272 pkt_len = make_up_icmp_service_payload (state, buf);
2274 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2275 if (state->serv->address.af == AF_INET6)
2276 icmp.type = GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED;
2279 GNUNET_break_op (0);
2280 return GNUNET_SYSERR;
2283 pkt_len = make_up_icmp_service_payload (state, buf);
2285 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2286 if (state->serv->address.af == AF_INET6)
2288 GNUNET_STATISTICS_update (stats,
2289 gettext_noop ("# ICMPv4 packets dropped (impossible PT to v6)"),
2295 GNUNET_break_op (0);
2296 return GNUNET_SYSERR;
2299 pkt_len = make_up_icmp_service_payload (state, buf);
2302 GNUNET_break_op (0);
2303 GNUNET_STATISTICS_update (stats,
2304 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2306 return GNUNET_SYSERR;
2308 /* end of AF_INET */
2311 switch (msg->icmp_header.type)
2313 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2314 if (state->serv->address.af == AF_INET)
2315 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REPLY;
2317 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2318 if (state->serv->address.af == AF_INET)
2319 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REQUEST;
2321 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2322 if (state->serv->address.af == AF_INET)
2323 icmp.type = GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE;
2326 GNUNET_break_op (0);
2327 return GNUNET_SYSERR;
2330 pkt_len = make_up_icmp_service_payload (state, buf);
2332 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2333 if (state->serv->address.af == AF_INET)
2334 icmp.type = GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED;
2337 GNUNET_break_op (0);
2338 return GNUNET_SYSERR;
2341 pkt_len = make_up_icmp_service_payload (state, buf);
2343 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2344 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2345 if (state->serv->address.af == AF_INET)
2347 GNUNET_STATISTICS_update (stats,
2348 gettext_noop ("# ICMPv6 packets dropped (impossible PT to v4)"),
2354 GNUNET_break_op (0);
2355 return GNUNET_SYSERR;
2358 pkt_len = make_up_icmp_service_payload (state, buf);
2361 GNUNET_break_op (0);
2362 GNUNET_STATISTICS_update (stats,
2363 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2365 return GNUNET_SYSERR;
2367 /* end of AF_INET6 */
2370 GNUNET_break_op (0);
2371 return GNUNET_SYSERR;
2374 send_icmp_packet_via_tun (&state->ri.remote_address,
2375 &state->ri.local_address,
2383 * Send a UDP packet via the TUN interface.
2385 * @param destination_address IP and port to use for the UDP packet's destination
2386 * @param source_address IP and port to use for the UDP packet's source
2387 * @param payload payload of the UDP packet (does NOT include UDP header)
2388 * @param payload_length number of bytes of data in payload
2391 send_udp_packet_via_tun (const struct SocketAddress *destination_address,
2392 const struct SocketAddress *source_address,
2393 const void *payload, size_t payload_length)
2397 GNUNET_STATISTICS_update (stats,
2398 gettext_noop ("# UDP packets sent via TUN"),
2400 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2401 "Sending packet with %u bytes UDP payload via TUN\n",
2402 (unsigned int) payload_length);
2403 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
2404 switch (source_address->af)
2407 len += sizeof (struct GNUNET_TUN_IPv4Header);
2410 len += sizeof (struct GNUNET_TUN_IPv6Header);
2416 len += sizeof (struct GNUNET_TUN_UdpHeader);
2417 len += payload_length;
2418 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2425 struct GNUNET_MessageHeader *hdr;
2426 struct GNUNET_TUN_Layer2PacketHeader *tun;
2428 hdr= (struct GNUNET_MessageHeader *) buf;
2429 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
2430 hdr->size = htons (len);
2431 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
2432 tun->flags = htons (0);
2433 switch (source_address->af)
2437 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
2439 tun->proto = htons (ETH_P_IPV4);
2440 prepare_ipv4_packet (payload, payload_length,
2444 destination_address,
2450 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
2452 tun->proto = htons (ETH_P_IPV6);
2453 prepare_ipv6_packet (payload, payload_length,
2457 destination_address,
2465 (void) GNUNET_HELPER_send (helper_handle,
2466 (const struct GNUNET_MessageHeader*) buf,
2474 * Process a request to forward UDP data to the Internet via this peer.
2476 * @param cls closure, NULL
2477 * @param tunnel connection to the other end
2478 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2479 * @param sender who sent the message
2480 * @param message the actual message
2481 * @param atsi performance data for the connection
2482 * @return GNUNET_OK to keep the connection open,
2483 * GNUNET_SYSERR to close it (signal serious error)
2486 receive_udp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2487 void **tunnel_ctx GNUNET_UNUSED,
2488 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2489 const struct GNUNET_MessageHeader *message,
2490 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2492 struct TunnelState *state = *tunnel_ctx;
2493 const struct GNUNET_EXIT_UdpInternetMessage *msg;
2494 uint16_t pkt_len = ntohs (message->size);
2495 const struct in_addr *v4;
2496 const struct in6_addr *v6;
2497 const void *payload;
2500 GNUNET_STATISTICS_update (stats,
2501 gettext_noop ("# Bytes received from MESH"),
2502 pkt_len, GNUNET_NO);
2503 GNUNET_STATISTICS_update (stats,
2504 gettext_noop ("# UDP IP-exit requests received via mesh"),
2506 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpInternetMessage))
2508 GNUNET_break_op (0);
2509 return GNUNET_SYSERR;
2511 msg = (const struct GNUNET_EXIT_UdpInternetMessage*) message;
2512 pkt_len -= sizeof (struct GNUNET_EXIT_UdpInternetMessage);
2513 af = (int) ntohl (msg->af);
2514 state->ri.remote_address.af = af;
2518 if (pkt_len < sizeof (struct in_addr))
2520 GNUNET_break_op (0);
2521 return GNUNET_SYSERR;
2525 GNUNET_break_op (0);
2526 return GNUNET_SYSERR;
2528 v4 = (const struct in_addr*) &msg[1];
2530 pkt_len -= sizeof (struct in_addr);
2531 state->ri.remote_address.address.ipv4 = *v4;
2534 if (pkt_len < sizeof (struct in6_addr))
2536 GNUNET_break_op (0);
2537 return GNUNET_SYSERR;
2541 GNUNET_break_op (0);
2542 return GNUNET_SYSERR;
2544 v6 = (const struct in6_addr*) &msg[1];
2546 pkt_len -= sizeof (struct in6_addr);
2547 state->ri.remote_address.address.ipv6 = *v6;
2550 GNUNET_break_op (0);
2551 return GNUNET_SYSERR;
2554 char buf[INET6_ADDRSTRLEN];
2555 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2556 "Received data from %s for forwarding to UDP %s:%u\n",
2557 GNUNET_i2s (sender),
2559 &state->ri.remote_address.address,
2561 (unsigned int) ntohs (msg->destination_port));
2563 state->ri.remote_address.proto = IPPROTO_UDP;
2564 state->ri.remote_address.port = msg->destination_port;
2565 if (NULL == state->heap_node)
2566 setup_state_record (state);
2567 if (0 != ntohs (msg->source_port))
2568 state->ri.local_address.port = msg->source_port;
2569 send_udp_packet_via_tun (&state->ri.remote_address,
2570 &state->ri.local_address,
2577 * Process a request via mesh to send a request to a UDP service
2578 * offered by this system.
2580 * @param cls closure, NULL
2581 * @param tunnel connection to the other end
2582 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2583 * @param sender who sent the message
2584 * @param message the actual message
2585 * @param atsi performance data for the connection
2586 * @return GNUNET_OK to keep the connection open,
2587 * GNUNET_SYSERR to close it (signal serious error)
2590 receive_udp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2592 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2593 const struct GNUNET_MessageHeader *message,
2594 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2596 struct TunnelState *state = *tunnel_ctx;
2597 const struct GNUNET_EXIT_UdpServiceMessage *msg;
2598 uint16_t pkt_len = ntohs (message->size);
2600 GNUNET_STATISTICS_update (stats,
2601 gettext_noop ("# Bytes received from MESH"),
2602 pkt_len, GNUNET_NO);
2603 GNUNET_STATISTICS_update (stats,
2604 gettext_noop ("# UDP service requests received via mesh"),
2606 /* check that we got at least a valid header */
2607 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpServiceMessage))
2609 GNUNET_break_op (0);
2610 return GNUNET_SYSERR;
2612 msg = (const struct GNUNET_EXIT_UdpServiceMessage*) message;
2613 pkt_len -= sizeof (struct GNUNET_EXIT_UdpServiceMessage);
2614 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2615 "Received data from %s for forwarding to UDP service %s on port %u\n",
2616 GNUNET_i2s (sender),
2617 GNUNET_h2s (&msg->service_descriptor),
2618 (unsigned int) ntohs (msg->destination_port));
2619 if (NULL == (state->serv = find_service (udp_services, &msg->service_descriptor,
2620 ntohs (msg->destination_port))))
2622 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2623 _("No service found for %s on port %d!\n"),
2625 ntohs (msg->destination_port));
2626 GNUNET_STATISTICS_update (stats,
2627 gettext_noop ("# UDP requests dropped (no such service)"),
2629 return GNUNET_SYSERR;
2631 state->ri.remote_address = state->serv->address;
2632 setup_state_record (state);
2633 if (0 != ntohs (msg->source_port))
2634 state->ri.local_address.port = msg->source_port;
2635 send_udp_packet_via_tun (&state->ri.remote_address,
2636 &state->ri.local_address,
2643 * Callback from GNUNET_MESH for new tunnels.
2645 * @param cls closure
2646 * @param tunnel new handle to the tunnel
2647 * @param initiator peer that started the tunnel
2648 * @param atsi performance information for the tunnel
2649 * @return initial tunnel context for the tunnel
2652 new_tunnel (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2653 const struct GNUNET_PeerIdentity *initiator GNUNET_UNUSED,
2654 const struct GNUNET_ATS_Information *ats GNUNET_UNUSED)
2656 struct TunnelState *s = GNUNET_malloc (sizeof (struct TunnelState));
2658 GNUNET_STATISTICS_update (stats,
2659 gettext_noop ("# Inbound MESH tunnels created"),
2661 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2662 "Received inbound tunnel from `%s'\n",
2663 GNUNET_i2s (initiator));
2670 * Function called by mesh whenever an inbound tunnel is destroyed.
2671 * Should clean up any associated state.
2673 * @param cls closure (set from GNUNET_MESH_connect)
2674 * @param tunnel connection to the other end (henceforth invalid)
2675 * @param tunnel_ctx place where local state associated
2676 * with the tunnel is stored
2679 clean_tunnel (void *cls GNUNET_UNUSED, const struct GNUNET_MESH_Tunnel *tunnel,
2682 struct TunnelState *s = tunnel_ctx;
2683 struct TunnelMessageQueue *tnq;
2685 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2686 "Tunnel destroyed\n");
2687 while (NULL != (tnq = s->head))
2689 GNUNET_CONTAINER_DLL_remove (s->head,
2694 if (s->heap_node != NULL)
2696 GNUNET_assert (GNUNET_YES ==
2697 GNUNET_CONTAINER_multihashmap_remove (connections_map,
2700 GNUNET_CONTAINER_heap_remove_node (s->heap_node);
2701 s->heap_node = NULL;
2705 GNUNET_MESH_notify_transmit_ready_cancel (s->th);
2713 * Function that frees everything from a hashmap
2717 * @param value value to free
2720 free_iterate (void *cls GNUNET_UNUSED,
2721 const GNUNET_HashCode * hash GNUNET_UNUSED, void *value)
2723 GNUNET_free (value);
2729 * Function scheduled as very last function, cleans up after us
2732 cleanup (void *cls GNUNET_UNUSED,
2733 const struct GNUNET_SCHEDULER_TaskContext *tskctx)
2737 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2738 "Exit service is shutting down now\n");
2739 if (helper_handle != NULL)
2741 GNUNET_HELPER_stop (helper_handle);
2742 helper_handle = NULL;
2744 if (mesh_handle != NULL)
2746 GNUNET_MESH_disconnect (mesh_handle);
2749 if (NULL != connections_map)
2751 GNUNET_CONTAINER_multihashmap_iterate (connections_map, &free_iterate, NULL);
2752 GNUNET_CONTAINER_multihashmap_destroy (connections_map);
2753 connections_map = NULL;
2755 if (NULL != connections_heap)
2757 GNUNET_CONTAINER_heap_destroy (connections_heap);
2758 connections_heap = NULL;
2760 if (NULL != tcp_services)
2762 GNUNET_CONTAINER_multihashmap_iterate (tcp_services, &free_service_record, NULL);
2763 GNUNET_CONTAINER_multihashmap_destroy (tcp_services);
2764 tcp_services = NULL;
2766 if (NULL != udp_services)
2768 GNUNET_CONTAINER_multihashmap_iterate (udp_services, &free_service_record, NULL);
2769 GNUNET_CONTAINER_multihashmap_destroy (udp_services);
2770 udp_services = NULL;
2774 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
2778 GNUNET_free_non_null (exit_argv[i]);
2783 * Add services to the service map.
2785 * @param proto IPPROTO_TCP or IPPROTO_UDP
2786 * @param cpy copy of the service descriptor (can be mutilated)
2787 * @param name DNS name of the service
2790 add_services (int proto,
2797 struct LocalService *serv;
2799 for (redirect = strtok (cpy, " "); redirect != NULL;
2800 redirect = strtok (NULL, " "))
2802 if (NULL == (hostname = strstr (redirect, ":")))
2804 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2805 "option `%s' for domain `%s' is not formatted correctly!\n",
2812 if (NULL == (hostport = strstr (hostname, ":")))
2814 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2815 "option `%s' for domain `%s' is not formatted correctly!\n",
2823 int local_port = atoi (redirect);
2824 int remote_port = atoi (hostport);
2826 if (!((local_port > 0) && (local_port < 65536)))
2828 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2829 "`%s' is not a valid port number (for domain `%s')!", redirect,
2833 if (!((remote_port > 0) && (remote_port < 65536)))
2835 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2836 "`%s' is not a valid port number (for domain `%s')!", hostport,
2841 serv = GNUNET_malloc (sizeof (struct LocalService));
2842 serv->my_port = (uint16_t) local_port;
2843 serv->address.port = remote_port;
2844 if (0 == strcmp ("localhost4", hostname))
2846 const char *ip4addr = exit_argv[4];
2848 serv->address.af = AF_INET;
2849 GNUNET_assert (1 != inet_pton (AF_INET, ip4addr, &serv->address.address.ipv4));
2851 else if (0 == strcmp ("localhost6", hostname))
2853 const char *ip6addr = exit_argv[2];
2855 serv->address.af = AF_INET6;
2856 GNUNET_assert (1 == inet_pton (AF_INET6, ip6addr, &serv->address.address.ipv6));
2860 struct addrinfo *res;
2863 ret = getaddrinfo (hostname, NULL, NULL, &res);
2864 if ( (ret != 0) || (res == NULL) )
2866 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2867 _("No addresses found for hostname `%s' of service `%s'!\n"),
2874 serv->address.af = res->ai_family;
2875 switch (res->ai_family)
2880 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2881 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2887 serv->address.address.ipv4 = ((struct sockaddr_in *) res->ai_addr)->sin_addr;
2892 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2893 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2899 serv->address.address.ipv6 = ((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
2903 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2904 _("No IP addresses found for hostname `%s' of service `%s'!\n"),
2912 store_service ((IPPROTO_UDP == proto) ? udp_services : tcp_services,
2921 * Reads the configuration servicecfg and populates udp_services
2924 * @param section name of section in config, equal to hostname
2927 read_service_conf (void *cls GNUNET_UNUSED, const char *section)
2931 if ((strlen (section) < 8) ||
2932 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
2935 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
2938 add_services (IPPROTO_UDP, cpy, section);
2942 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
2945 add_services (IPPROTO_TCP, cpy, section);
2952 * @brief Main function that will be run by the scheduler.
2954 * @param cls closure
2955 * @param args remaining command-line arguments
2956 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
2957 * @param cfg_ configuration
2960 run (void *cls, char *const *args GNUNET_UNUSED,
2961 const char *cfgfile GNUNET_UNUSED,
2962 const struct GNUNET_CONFIGURATION_Handle *cfg_)
2964 static struct GNUNET_MESH_MessageHandler handlers[] = {
2965 {&receive_icmp_service, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_SERVICE, 0},
2966 {&receive_icmp_remote, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_INTERNET, 0},
2967 {&receive_udp_service, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_SERVICE, 0},
2968 {&receive_udp_remote, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_INTERNET, 0},
2969 {&receive_tcp_service, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_SERVICE_START, 0},
2970 {&receive_tcp_remote, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_INTERNET_START, 0},
2971 {&receive_tcp_data, GNUNET_MESSAGE_TYPE_VPN_TCP_DATA_TO_EXIT, 0},
2975 static GNUNET_MESH_ApplicationType apptypes[] = {
2976 GNUNET_APPLICATION_TYPE_END,
2977 GNUNET_APPLICATION_TYPE_END,
2978 GNUNET_APPLICATION_TYPE_END
2980 unsigned int app_idx;
2989 GNUNET_OS_check_helper_binary ("gnunet-helper-exit"))
2992 "`%s' is not SUID, refusing to run.\n",
2993 "gnunet-helper-exit");
2998 stats = GNUNET_STATISTICS_create ("exit", cfg);
2999 ipv4_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV4");
3000 ipv6_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV6");
3001 ipv4_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV4");
3002 ipv6_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV6");
3003 if (ipv4_exit && (! ipv4_enabled))
3005 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3006 _("Cannot enable IPv4 exit but disable IPv4 on TUN interface, will use ENABLE_IPv4=YES\n"));
3007 ipv4_enabled = GNUNET_YES;
3009 if (ipv6_exit && (! ipv6_enabled))
3011 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3012 _("Cannot enable IPv6 exit but disable IPv6 on TUN interface, will use ENABLE_IPv6=YES\n"));
3013 ipv6_enabled = GNUNET_YES;
3015 if (! (ipv4_enabled || ipv6_enabled))
3017 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3018 _("No useful service enabled. Exiting.\n"));
3019 GNUNET_SCHEDULER_shutdown ();
3023 if (GNUNET_YES == ipv4_exit)
3025 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV4_GATEWAY;
3028 if (GNUNET_YES == ipv6_exit)
3030 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV6_GATEWAY;
3034 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
3037 GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_CONNECTIONS",
3039 max_connections = 1024;
3040 exit_argv[0] = GNUNET_strdup ("exit-gnunet");
3041 if (GNUNET_SYSERR ==
3042 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "TUN_IFNAME", &tun_ifname))
3044 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3045 "No entry 'TUN_IFNAME' in configuration!\n");
3046 GNUNET_SCHEDULER_shutdown ();
3049 exit_argv[1] = tun_ifname;
3052 if (GNUNET_SYSERR ==
3053 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "EXIT_IFNAME", &exit_ifname))
3055 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3056 "No entry 'EXIT_IFNAME' in configuration!\n");
3057 GNUNET_SCHEDULER_shutdown ();
3060 exit_argv[2] = exit_ifname;
3064 exit_argv[2] = GNUNET_strdup ("%");
3066 if (GNUNET_YES == ipv6_enabled)
3068 if ( (GNUNET_SYSERR ==
3069 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6ADDR",
3071 (1 != inet_pton (AF_INET6, ipv6addr, &exit_ipv6addr))) )
3073 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3074 "No valid entry 'IPV6ADDR' in configuration!\n");
3075 GNUNET_SCHEDULER_shutdown ();
3078 exit_argv[3] = ipv6addr;
3079 if (GNUNET_SYSERR ==
3080 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6PREFIX",
3083 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3084 "No entry 'IPV6PREFIX' in configuration!\n");
3085 GNUNET_SCHEDULER_shutdown ();
3088 exit_argv[4] = ipv6prefix_s;
3090 GNUNET_CONFIGURATION_get_value_number (cfg, "exit",
3093 (ipv6prefix >= 127) )
3095 GNUNET_SCHEDULER_shutdown ();
3101 /* IPv6 explicitly disabled */
3102 exit_argv[3] = GNUNET_strdup ("-");
3103 exit_argv[4] = GNUNET_strdup ("-");
3105 if (GNUNET_YES == ipv4_enabled)
3107 if ( (GNUNET_SYSERR ==
3108 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4ADDR",
3110 (1 != inet_pton (AF_INET, ipv4addr, &exit_ipv4addr))) )
3112 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3113 "No valid entry for 'IPV4ADDR' in configuration!\n");
3114 GNUNET_SCHEDULER_shutdown ();
3117 exit_argv[5] = ipv4addr;
3118 if ( (GNUNET_SYSERR ==
3119 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4MASK",
3121 (1 != inet_pton (AF_INET, ipv4mask, &exit_ipv4mask))) )
3123 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3124 "No valid entry 'IPV4MASK' in configuration!\n");
3125 GNUNET_SCHEDULER_shutdown ();
3128 exit_argv[6] = ipv4mask;
3132 /* IPv4 explicitly disabled */
3133 exit_argv[5] = GNUNET_strdup ("-");
3134 exit_argv[6] = GNUNET_strdup ("-");
3136 exit_argv[7] = NULL;
3138 udp_services = GNUNET_CONTAINER_multihashmap_create (65536);
3139 tcp_services = GNUNET_CONTAINER_multihashmap_create (65536);
3140 GNUNET_CONFIGURATION_iterate_sections (cfg, &read_service_conf, NULL);
3142 connections_map = GNUNET_CONTAINER_multihashmap_create (65536);
3143 connections_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3145 = GNUNET_MESH_connect (cfg, 42 /* queue size */, NULL,
3147 &clean_tunnel, handlers,
3149 if (NULL == mesh_handle)
3151 GNUNET_SCHEDULER_shutdown ();
3154 helper_handle = GNUNET_HELPER_start ("gnunet-helper-exit",
3156 &message_token, NULL);
3163 * @param argc number of arguments from the command line
3164 * @param argv command line arguments
3165 * @return 0 ok, 1 on error
3168 main (int argc, char *const *argv)
3170 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
3171 GNUNET_GETOPT_OPTION_END
3174 return (GNUNET_OK ==
3175 GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-exit",
3177 ("Daemon to run to provide an IP exit node for the VPN"),
3178 options, &run, NULL)) ? global_ret : 1;
3182 /* end of gnunet-daemon-exit.c */