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
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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 destination_port 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,
445 uint16_t destination_port)
447 char key[sizeof (GNUNET_HashCode) + sizeof (uint16_t)];
449 memcpy (&key[0], &destination_port, 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 destination_port destination port
484 * @param service service information record to store (service->name will be set).
487 store_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
489 uint16_t destination_port,
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], &destination_port, 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"),
509 (unsigned int) destination_port);
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;
617 uint16_t source_port;
618 uint16_t destination_port;
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 */
644 destination_port = 0;
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 source_port = ntohs (udp->source_port);
671 destination_port = ntohs (udp->destination_port);
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 source_port = ntohs (udp->source_port);
703 destination_port = ntohs (udp->destination_port);
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->source_port),
806 dbuf, sizeof (dbuf)),
807 (unsigned int) ntohs (udp->destination_port));
809 if (pktlen < sizeof (struct GNUNET_TUN_UdpHeader))
815 if (pktlen != ntohs (udp->len))
821 state = get_redirect_state (af, IPPROTO_UDP,
823 ntohs (udp->source_port),
825 ntohs (udp->destination_port),
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->source_port),
887 dbuf, sizeof (dbuf)),
888 (unsigned int) ntohs (tcp->destination_port));
890 if (pktlen < sizeof (struct GNUNET_TUN_TcpHeader))
896 state = get_redirect_state (af, IPPROTO_TCP,
898 ntohs (tcp->source_port),
900 ntohs (tcp->destination_port),
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;
913 mtcp->source_port = 0;
914 mtcp->destination_port = 0;
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 pkt4 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->source_port = htons (src_address->port);
1320 pkt4_udp->destination_port = 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->source_port = htons (src_address->port);
1334 pkt4_tcp->destination_port = 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 tcp_header skeleton TCP header data to send, NULL for UDP
1360 * @param src_address source address to use (IP and port)
1361 * @param dst_address destination address to use (IP and port)
1362 * @param pkt6 where to write the assembled packet; must
1363 * contain enough space for the IP header, UDP/TCP header
1367 prepare_ipv6_packet (const void *payload, size_t payload_length,
1369 const struct GNUNET_TUN_TcpHeader *tcp_header,
1370 const struct SocketAddress *src_address,
1371 const struct SocketAddress *dst_address,
1372 struct GNUNET_TUN_IPv6Header *pkt6)
1376 len = payload_length;
1380 len += sizeof (struct GNUNET_TUN_UdpHeader);
1383 len += sizeof (struct GNUNET_TUN_TcpHeader);
1389 if (len > UINT16_MAX)
1395 GNUNET_TUN_initialize_ipv6_header (pkt6,
1398 &src_address->address.ipv6,
1399 &dst_address->address.ipv6);
1405 struct GNUNET_TUN_UdpHeader *pkt6_udp = (struct GNUNET_TUN_UdpHeader *) &pkt6[1];
1407 pkt6_udp->source_port = htons (src_address->port);
1408 pkt6_udp->destination_port = htons (dst_address->port);
1409 pkt6_udp->len = htons ((uint16_t) payload_length);
1410 GNUNET_TUN_calculate_udp6_checksum (pkt6,
1414 memcpy (&pkt6_udp[1], payload, payload_length);
1419 struct GNUNET_TUN_TcpHeader *pkt6_tcp = (struct GNUNET_TUN_TcpHeader *) &pkt6[1];
1421 /* memcpy first here as some TCP header fields are initialized this way! */
1422 *pkt6_tcp = *tcp_header;
1423 pkt6_tcp->source_port = htons (src_address->port);
1424 pkt6_tcp->destination_port = htons (dst_address->port);
1425 GNUNET_TUN_calculate_tcp6_checksum (pkt6,
1429 memcpy (&pkt6_tcp[1], payload, payload_length);
1440 * Send a TCP packet via the TUN interface.
1442 * @param destination_address IP and port to use for the TCP packet's destination
1443 * @param source_address IP and port to use for the TCP packet's source
1444 * @param tcp_header header template to use
1445 * @param payload payload of the TCP packet
1446 * @param payload_length number of bytes in 'payload'
1449 send_tcp_packet_via_tun (const struct SocketAddress *destination_address,
1450 const struct SocketAddress *source_address,
1451 const struct GNUNET_TUN_TcpHeader *tcp_header,
1452 const void *payload, size_t payload_length)
1456 GNUNET_STATISTICS_update (stats,
1457 gettext_noop ("# TCP packets sent via TUN"),
1459 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1460 "Sending packet with %u bytes TCP payload via TUN\n",
1461 (unsigned int) payload_length);
1462 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
1463 switch (source_address->af)
1466 len += sizeof (struct GNUNET_TUN_IPv4Header);
1469 len += sizeof (struct GNUNET_TUN_IPv6Header);
1475 len += sizeof (struct GNUNET_TUN_TcpHeader);
1476 len += payload_length;
1477 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1484 struct GNUNET_MessageHeader *hdr;
1485 struct GNUNET_TUN_Layer2PacketHeader *tun;
1487 hdr = (struct GNUNET_MessageHeader *) buf;
1488 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1489 hdr->size = htons (len);
1490 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
1491 tun->flags = htons (0);
1492 switch (source_address->af)
1496 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
1498 tun->proto = htons (ETH_P_IPV4);
1499 prepare_ipv4_packet (payload, payload_length,
1503 destination_address,
1509 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
1511 tun->proto = htons (ETH_P_IPV6);
1512 prepare_ipv6_packet (payload, payload_length,
1516 destination_address,
1524 (void) GNUNET_HELPER_send (helper_handle,
1525 (const struct GNUNET_MessageHeader*) buf,
1533 * Process a request via mesh to send a request to a TCP service
1534 * offered by this system.
1536 * @param cls closure, NULL
1537 * @param tunnel connection to the other end
1538 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1539 * @param sender who sent the message
1540 * @param message the actual message
1541 * @param atsi performance data for the connection
1542 * @return GNUNET_OK to keep the connection open,
1543 * GNUNET_SYSERR to close it (signal serious error)
1546 receive_tcp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1547 void **tunnel_ctx GNUNET_UNUSED,
1548 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1549 const struct GNUNET_MessageHeader *message,
1550 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1552 struct TunnelState *state = *tunnel_ctx;
1553 const struct GNUNET_EXIT_TcpServiceStartMessage *start;
1554 uint16_t pkt_len = ntohs (message->size);
1556 GNUNET_STATISTICS_update (stats,
1557 gettext_noop ("# TCP service creation requests received via mesh"),
1559 GNUNET_STATISTICS_update (stats,
1560 gettext_noop ("# Bytes received from MESH"),
1561 pkt_len, GNUNET_NO);
1562 /* check that we got at least a valid header */
1563 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpServiceStartMessage))
1565 GNUNET_break_op (0);
1566 return GNUNET_SYSERR;
1568 start = (const struct GNUNET_EXIT_TcpServiceStartMessage*) message;
1569 pkt_len -= sizeof (struct GNUNET_EXIT_TcpServiceStartMessage);
1570 if ( (NULL == state) ||
1571 (NULL != state->serv) ||
1572 (NULL != state->heap_node) )
1574 GNUNET_break_op (0);
1575 return GNUNET_SYSERR;
1577 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1579 GNUNET_break_op (0);
1580 return GNUNET_SYSERR;
1582 GNUNET_break_op (ntohl (start->reserved) == 0);
1583 /* setup fresh connection */
1584 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1585 "Received data from %s for forwarding to TCP service %s on port %u\n",
1586 GNUNET_i2s (sender),
1587 GNUNET_h2s (&start->service_descriptor),
1588 (unsigned int) ntohs (start->tcp_header.destination_port));
1589 if (NULL == (state->serv = find_service (tcp_services, &start->service_descriptor,
1590 ntohs (start->tcp_header.destination_port))))
1592 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1593 _("No service found for %s on port %d!\n"),
1595 ntohs (start->tcp_header.destination_port));
1596 GNUNET_STATISTICS_update (stats,
1597 gettext_noop ("# TCP requests dropped (no such service)"),
1599 return GNUNET_SYSERR;
1601 state->ri.remote_address = state->serv->address;
1602 setup_state_record (state);
1603 send_tcp_packet_via_tun (&state->ri.remote_address,
1604 &state->ri.local_address,
1606 &start[1], pkt_len);
1612 * Process a request to forward TCP data to the Internet via this peer.
1614 * @param cls closure, NULL
1615 * @param tunnel connection to the other end
1616 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1617 * @param sender who sent the message
1618 * @param message the actual message
1619 * @param atsi performance data for the connection
1620 * @return GNUNET_OK to keep the connection open,
1621 * GNUNET_SYSERR to close it (signal serious error)
1624 receive_tcp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1625 void **tunnel_ctx GNUNET_UNUSED,
1626 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1627 const struct GNUNET_MessageHeader *message,
1628 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1630 struct TunnelState *state = *tunnel_ctx;
1631 const struct GNUNET_EXIT_TcpInternetStartMessage *start;
1632 uint16_t pkt_len = ntohs (message->size);
1633 const struct in_addr *v4;
1634 const struct in6_addr *v6;
1635 const void *payload;
1638 GNUNET_STATISTICS_update (stats,
1639 gettext_noop ("# Bytes received from MESH"),
1640 pkt_len, GNUNET_NO);
1641 GNUNET_STATISTICS_update (stats,
1642 gettext_noop ("# TCP IP-exit creation requests received via mesh"),
1644 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpInternetStartMessage))
1646 GNUNET_break_op (0);
1647 return GNUNET_SYSERR;
1649 start = (const struct GNUNET_EXIT_TcpInternetStartMessage*) message;
1650 pkt_len -= sizeof (struct GNUNET_EXIT_TcpInternetStartMessage);
1651 if ( (NULL == state) ||
1652 (NULL != state->serv) ||
1653 (NULL != state->heap_node) )
1655 GNUNET_break_op (0);
1656 return GNUNET_SYSERR;
1658 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1660 GNUNET_break_op (0);
1661 return GNUNET_SYSERR;
1663 af = (int) ntohl (start->af);
1664 state->ri.remote_address.af = af;
1668 if (pkt_len < sizeof (struct in_addr))
1670 GNUNET_break_op (0);
1671 return GNUNET_SYSERR;
1675 GNUNET_break_op (0);
1676 return GNUNET_SYSERR;
1678 v4 = (const struct in_addr*) &start[1];
1680 pkt_len -= sizeof (struct in_addr);
1681 state->ri.remote_address.address.ipv4 = *v4;
1684 if (pkt_len < sizeof (struct in6_addr))
1686 GNUNET_break_op (0);
1687 return GNUNET_SYSERR;
1691 GNUNET_break_op (0);
1692 return GNUNET_SYSERR;
1694 v6 = (const struct in6_addr*) &start[1];
1696 pkt_len -= sizeof (struct in6_addr);
1697 state->ri.remote_address.address.ipv6 = *v6;
1700 GNUNET_break_op (0);
1701 return GNUNET_SYSERR;
1704 char buf[INET6_ADDRSTRLEN];
1705 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1706 "Received data from %s for starting TCP stream to %s:%u\n",
1707 GNUNET_i2s (sender),
1709 &state->ri.remote_address.address,
1711 (unsigned int) ntohs (start->tcp_header.destination_port));
1713 state->ri.remote_address.proto = IPPROTO_TCP;
1714 state->ri.remote_address.port = ntohs (start->tcp_header.destination_port);
1715 setup_state_record (state);
1716 send_tcp_packet_via_tun (&state->ri.remote_address,
1717 &state->ri.local_address,
1725 * Process a request to forward TCP data on an established
1726 * connection via this peer.
1728 * @param cls closure, NULL
1729 * @param tunnel connection to the other end
1730 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1731 * @param sender who sent the message
1732 * @param message the actual message
1733 * @param atsi performance data for the connection
1734 * @return GNUNET_OK to keep the connection open,
1735 * GNUNET_SYSERR to close it (signal serious error)
1738 receive_tcp_data (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1739 void **tunnel_ctx GNUNET_UNUSED,
1740 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1741 const struct GNUNET_MessageHeader *message,
1742 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1744 struct TunnelState *state = *tunnel_ctx;
1745 const struct GNUNET_EXIT_TcpDataMessage *data;
1746 uint16_t pkt_len = ntohs (message->size);
1748 GNUNET_STATISTICS_update (stats,
1749 gettext_noop ("# Bytes received from MESH"),
1750 pkt_len, GNUNET_NO);
1751 GNUNET_STATISTICS_update (stats,
1752 gettext_noop ("# TCP data requests received via mesh"),
1754 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpDataMessage))
1756 GNUNET_break_op (0);
1757 return GNUNET_SYSERR;
1759 data = (const struct GNUNET_EXIT_TcpDataMessage*) message;
1760 pkt_len -= sizeof (struct GNUNET_EXIT_TcpDataMessage);
1761 if ( (NULL == state) ||
1762 (NULL == state->heap_node) )
1764 /* connection should have been up! */
1765 GNUNET_STATISTICS_update (stats,
1766 gettext_noop ("# TCP DATA requests dropped (no session)"),
1768 return GNUNET_SYSERR;
1770 if (data->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1772 GNUNET_break_op (0);
1773 return GNUNET_SYSERR;
1776 GNUNET_break_op (ntohl (data->reserved) == 0);
1778 char buf[INET6_ADDRSTRLEN];
1779 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1780 "Received additional %u bytes of data from %s for TCP stream to %s:%u\n",
1782 GNUNET_i2s (sender),
1783 inet_ntop (state->ri.remote_address.af,
1784 &state->ri.remote_address.address,
1786 (unsigned int) state->ri.remote_address.port);
1789 send_tcp_packet_via_tun (&state->ri.remote_address,
1790 &state->ri.local_address,
1798 * Send an ICMP packet via the TUN interface.
1800 * @param destination_address IP to use for the ICMP packet's destination
1801 * @param source_address IP to use for the ICMP packet's source
1802 * @param icmp_header ICMP header to send
1803 * @param payload payload of the ICMP packet (does NOT include ICMP header)
1804 * @param payload_length number of bytes of data in payload
1807 send_icmp_packet_via_tun (const struct SocketAddress *destination_address,
1808 const struct SocketAddress *source_address,
1809 const struct GNUNET_TUN_IcmpHeader *icmp_header,
1810 const void *payload, size_t payload_length)
1813 struct GNUNET_TUN_IcmpHeader *icmp;
1815 GNUNET_STATISTICS_update (stats,
1816 gettext_noop ("# ICMP packets sent via TUN"),
1818 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1819 "Sending packet with %u bytes ICMP payload via TUN\n",
1820 (unsigned int) payload_length);
1821 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
1822 switch (destination_address->af)
1825 len += sizeof (struct GNUNET_TUN_IPv4Header);
1828 len += sizeof (struct GNUNET_TUN_IPv6Header);
1834 len += sizeof (struct GNUNET_TUN_IcmpHeader);
1835 len += payload_length;
1836 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1843 struct GNUNET_MessageHeader *hdr;
1844 struct GNUNET_TUN_Layer2PacketHeader *tun;
1846 hdr= (struct GNUNET_MessageHeader *) buf;
1847 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1848 hdr->size = htons (len);
1849 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
1850 tun->flags = htons (0);
1851 switch (source_address->af)
1855 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
1857 tun->proto = htons (ETH_P_IPV4);
1858 GNUNET_TUN_initialize_ipv4_header (ipv4,
1860 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
1861 &source_address->address.ipv4,
1862 &destination_address->address.ipv4);
1863 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv4[1];
1868 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
1870 tun->proto = htons (ETH_P_IPV6);
1871 GNUNET_TUN_initialize_ipv6_header (ipv6,
1873 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
1874 &source_address->address.ipv6,
1875 &destination_address->address.ipv6);
1876 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv6[1];
1883 *icmp = *icmp_header;
1887 GNUNET_TUN_calculate_icmp_checksum (icmp,
1890 (void) GNUNET_HELPER_send (helper_handle,
1891 (const struct GNUNET_MessageHeader*) buf,
1899 * Synthesize a plausible ICMP payload for an ICMPv4 error
1900 * response on the given tunnel.
1902 * @param state tunnel information
1903 * @param ipp IPv6 header to fill in (ICMP payload)
1904 * @param udp "UDP" header to fill in (ICMP payload); might actually
1905 * also be the first 8 bytes of the TCP header
1908 make_up_icmpv4_payload (struct TunnelState *state,
1909 struct GNUNET_TUN_IPv4Header *ipp,
1910 struct GNUNET_TUN_UdpHeader *udp)
1912 GNUNET_TUN_initialize_ipv4_header (ipp,
1913 state->ri.remote_address.proto,
1914 sizeof (struct GNUNET_TUN_TcpHeader),
1915 &state->ri.remote_address.address.ipv4,
1916 &state->ri.local_address.address.ipv4);
1917 udp->source_port = htons (state->ri.remote_address.port);
1918 udp->destination_port = htons (state->ri.local_address.port);
1919 udp->len = htons (0);
1920 udp->crc = htons (0);
1925 * Synthesize a plausible ICMP payload for an ICMPv6 error
1926 * response on the given tunnel.
1928 * @param state tunnel information
1929 * @param ipp IPv6 header to fill in (ICMP payload)
1930 * @param udp "UDP" header to fill in (ICMP payload); might actually
1931 * also be the first 8 bytes of the TCP header
1934 make_up_icmpv6_payload (struct TunnelState *state,
1935 struct GNUNET_TUN_IPv6Header *ipp,
1936 struct GNUNET_TUN_UdpHeader *udp)
1938 GNUNET_TUN_initialize_ipv6_header (ipp,
1939 state->ri.remote_address.proto,
1940 sizeof (struct GNUNET_TUN_TcpHeader),
1941 &state->ri.remote_address.address.ipv6,
1942 &state->ri.local_address.address.ipv6);
1943 udp->source_port = htons (state->ri.remote_address.port);
1944 udp->destination_port = htons (state->ri.local_address.port);
1945 udp->len = htons (0);
1946 udp->crc = htons (0);
1951 * Process a request to forward ICMP data to the Internet via this peer.
1953 * @param cls closure, NULL
1954 * @param tunnel connection to the other end
1955 * @param tunnel_ctx pointer to our 'struct TunnelState *'
1956 * @param sender who sent the message
1957 * @param message the actual message
1958 * @param atsi performance data for the connection
1959 * @return GNUNET_OK to keep the connection open,
1960 * GNUNET_SYSERR to close it (signal serious error)
1963 receive_icmp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
1964 void **tunnel_ctx GNUNET_UNUSED,
1965 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
1966 const struct GNUNET_MessageHeader *message,
1967 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
1969 struct TunnelState *state = *tunnel_ctx;
1970 const struct GNUNET_EXIT_IcmpInternetMessage *msg;
1971 uint16_t pkt_len = ntohs (message->size);
1972 const struct in_addr *v4;
1973 const struct in6_addr *v6;
1974 const void *payload;
1975 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8];
1978 GNUNET_STATISTICS_update (stats,
1979 gettext_noop ("# Bytes received from MESH"),
1980 pkt_len, GNUNET_NO);
1981 GNUNET_STATISTICS_update (stats,
1982 gettext_noop ("# ICMP IP-exit requests received via mesh"),
1984 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpInternetMessage))
1986 GNUNET_break_op (0);
1987 return GNUNET_SYSERR;
1989 msg = (const struct GNUNET_EXIT_IcmpInternetMessage*) message;
1990 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpInternetMessage);
1992 af = (int) ntohl (msg->af);
1993 if ( (NULL != state->heap_node) &&
1994 (af != state->ri.remote_address.af) )
1996 /* other peer switched AF on this tunnel; not allowed */
1997 GNUNET_break_op (0);
1998 return GNUNET_SYSERR;
2004 if (pkt_len < sizeof (struct in_addr))
2006 GNUNET_break_op (0);
2007 return GNUNET_SYSERR;
2011 GNUNET_break_op (0);
2012 return GNUNET_SYSERR;
2014 v4 = (const struct in_addr*) &msg[1];
2016 pkt_len -= sizeof (struct in_addr);
2017 state->ri.remote_address.address.ipv4 = *v4;
2018 if (NULL == state->heap_node)
2020 state->ri.remote_address.af = af;
2021 state->ri.remote_address.proto = IPPROTO_ICMP;
2022 setup_state_record (state);
2024 /* check that ICMP type is something we want to support
2025 and possibly make up payload! */
2026 switch (msg->icmp_header.type)
2028 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2029 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2031 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2032 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2033 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2036 GNUNET_break_op (0);
2037 return GNUNET_SYSERR;
2039 /* make up payload */
2041 struct GNUNET_TUN_IPv4Header *ipp = (struct GNUNET_TUN_IPv4Header *) buf;
2042 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2044 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2045 pkt_len = sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2046 make_up_icmpv4_payload (state,
2053 GNUNET_break_op (0);
2054 GNUNET_STATISTICS_update (stats,
2055 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2057 return GNUNET_SYSERR;
2062 if (pkt_len < sizeof (struct in6_addr))
2064 GNUNET_break_op (0);
2065 return GNUNET_SYSERR;
2069 GNUNET_break_op (0);
2070 return GNUNET_SYSERR;
2072 v6 = (const struct in6_addr*) &msg[1];
2074 pkt_len -= sizeof (struct in6_addr);
2075 state->ri.remote_address.address.ipv6 = *v6;
2076 if (NULL == state->heap_node)
2078 state->ri.remote_address.af = af;
2079 state->ri.remote_address.proto = IPPROTO_ICMP;
2080 setup_state_record (state);
2082 /* check that ICMP type is something we want to support
2083 and possibly make up payload! */
2084 switch (msg->icmp_header.type)
2086 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2087 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2089 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2090 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2091 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2092 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2095 GNUNET_break_op (0);
2096 return GNUNET_SYSERR;
2098 /* make up payload */
2100 struct GNUNET_TUN_IPv6Header *ipp = (struct GNUNET_TUN_IPv6Header *) buf;
2101 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2103 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2104 pkt_len = sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2105 make_up_icmpv6_payload (state,
2112 GNUNET_break_op (0);
2113 GNUNET_STATISTICS_update (stats,
2114 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2116 return GNUNET_SYSERR;
2122 GNUNET_break_op (0);
2123 return GNUNET_SYSERR;
2127 char buf[INET6_ADDRSTRLEN];
2128 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2129 "Received ICMP data from %s for forwarding to %s\n",
2130 GNUNET_i2s (sender),
2132 &state->ri.remote_address.address,
2133 buf, sizeof (buf)));
2135 send_icmp_packet_via_tun (&state->ri.remote_address,
2136 &state->ri.local_address,
2144 * Setup ICMP payload for ICMP error messages. Called
2145 * for both IPv4 and IPv6 addresses.
2147 * @param state context for creating the IP Packet
2148 * @param buf where to create the payload, has at least
2149 * sizeof (struct GNUNET_TUN_IPv6Header) + 8 bytes
2150 * @return number of bytes of payload we created in buf
2153 make_up_icmp_service_payload (struct TunnelState *state,
2156 switch (state->serv->address.af)
2160 struct GNUNET_TUN_IPv4Header *ipv4;
2161 struct GNUNET_TUN_UdpHeader *udp;
2163 ipv4 = (struct GNUNET_TUN_IPv4Header *)buf;
2164 udp = (struct GNUNET_TUN_UdpHeader *) &ipv4[1];
2165 make_up_icmpv4_payload (state,
2168 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2169 return sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2174 struct GNUNET_TUN_IPv6Header *ipv6;
2175 struct GNUNET_TUN_UdpHeader *udp;
2177 ipv6 = (struct GNUNET_TUN_IPv6Header *)buf;
2178 udp = (struct GNUNET_TUN_UdpHeader *) &ipv6[1];
2179 make_up_icmpv6_payload (state,
2182 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2183 return sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2194 * Process a request via mesh to send ICMP data to a service
2195 * offered by this system.
2197 * @param cls closure, NULL
2198 * @param tunnel connection to the other end
2199 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2200 * @param sender who sent the message
2201 * @param message the actual message
2202 * @param atsi performance data for the connection
2203 * @return GNUNET_OK to keep the connection open,
2204 * GNUNET_SYSERR to close it (signal serious error)
2207 receive_icmp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2209 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2210 const struct GNUNET_MessageHeader *message,
2211 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2213 struct TunnelState *state = *tunnel_ctx;
2214 const struct GNUNET_EXIT_IcmpServiceMessage *msg;
2215 uint16_t pkt_len = ntohs (message->size);
2216 struct GNUNET_TUN_IcmpHeader icmp;
2217 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8];
2218 const void *payload;
2220 GNUNET_STATISTICS_update (stats,
2221 gettext_noop ("# Bytes received from MESH"),
2222 pkt_len, GNUNET_NO);
2223 GNUNET_STATISTICS_update (stats,
2224 gettext_noop ("# ICMP service requests received via mesh"),
2226 /* check that we got at least a valid header */
2227 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpServiceMessage))
2229 GNUNET_break_op (0);
2230 return GNUNET_SYSERR;
2232 msg = (const struct GNUNET_EXIT_IcmpServiceMessage*) message;
2233 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpServiceMessage);
2234 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2235 "Received data from %s for forwarding to ICMP service %s\n",
2236 GNUNET_i2s (sender),
2237 GNUNET_h2s (&msg->service_descriptor));
2238 if (NULL == state->serv)
2240 /* first packet to service must not be ICMP (cannot determine service!) */
2241 GNUNET_break_op (0);
2242 return GNUNET_SYSERR;
2244 icmp = msg->icmp_header;
2246 state->ri.remote_address = state->serv->address;
2247 setup_state_record (state);
2249 /* check that ICMP type is something we want to support,
2250 perform ICMP PT if needed ans possibly make up payload */
2254 switch (msg->icmp_header.type)
2256 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2257 if (state->serv->address.af == AF_INET6)
2258 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REPLY;
2260 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2261 if (state->serv->address.af == AF_INET6)
2262 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST;
2264 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2265 if (state->serv->address.af == AF_INET6)
2266 icmp.type = GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE;
2269 GNUNET_break_op (0);
2270 return GNUNET_SYSERR;
2273 pkt_len = make_up_icmp_service_payload (state, buf);
2275 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2276 if (state->serv->address.af == AF_INET6)
2277 icmp.type = GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED;
2280 GNUNET_break_op (0);
2281 return GNUNET_SYSERR;
2284 pkt_len = make_up_icmp_service_payload (state, buf);
2286 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2287 if (state->serv->address.af == AF_INET6)
2289 GNUNET_STATISTICS_update (stats,
2290 gettext_noop ("# ICMPv4 packets dropped (impossible PT to v6)"),
2296 GNUNET_break_op (0);
2297 return GNUNET_SYSERR;
2300 pkt_len = make_up_icmp_service_payload (state, buf);
2303 GNUNET_break_op (0);
2304 GNUNET_STATISTICS_update (stats,
2305 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2307 return GNUNET_SYSERR;
2309 /* end of AF_INET */
2312 switch (msg->icmp_header.type)
2314 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2315 if (state->serv->address.af == AF_INET)
2316 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REPLY;
2318 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2319 if (state->serv->address.af == AF_INET)
2320 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REQUEST;
2322 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2323 if (state->serv->address.af == AF_INET)
2324 icmp.type = GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE;
2327 GNUNET_break_op (0);
2328 return GNUNET_SYSERR;
2331 pkt_len = make_up_icmp_service_payload (state, buf);
2333 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2334 if (state->serv->address.af == AF_INET)
2335 icmp.type = GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED;
2338 GNUNET_break_op (0);
2339 return GNUNET_SYSERR;
2342 pkt_len = make_up_icmp_service_payload (state, buf);
2344 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2345 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2346 if (state->serv->address.af == AF_INET)
2348 GNUNET_STATISTICS_update (stats,
2349 gettext_noop ("# ICMPv6 packets dropped (impossible PT to v4)"),
2355 GNUNET_break_op (0);
2356 return GNUNET_SYSERR;
2359 pkt_len = make_up_icmp_service_payload (state, buf);
2362 GNUNET_break_op (0);
2363 GNUNET_STATISTICS_update (stats,
2364 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2366 return GNUNET_SYSERR;
2368 /* end of AF_INET6 */
2371 GNUNET_break_op (0);
2372 return GNUNET_SYSERR;
2375 send_icmp_packet_via_tun (&state->ri.remote_address,
2376 &state->ri.local_address,
2384 * Send a UDP packet via the TUN interface.
2386 * @param destination_address IP and port to use for the UDP packet's destination
2387 * @param source_address IP and port to use for the UDP packet's source
2388 * @param payload payload of the UDP packet (does NOT include UDP header)
2389 * @param payload_length number of bytes of data in payload
2392 send_udp_packet_via_tun (const struct SocketAddress *destination_address,
2393 const struct SocketAddress *source_address,
2394 const void *payload, size_t payload_length)
2398 GNUNET_STATISTICS_update (stats,
2399 gettext_noop ("# UDP packets sent via TUN"),
2401 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2402 "Sending packet with %u bytes UDP payload via TUN\n",
2403 (unsigned int) payload_length);
2404 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
2405 switch (source_address->af)
2408 len += sizeof (struct GNUNET_TUN_IPv4Header);
2411 len += sizeof (struct GNUNET_TUN_IPv6Header);
2417 len += sizeof (struct GNUNET_TUN_UdpHeader);
2418 len += payload_length;
2419 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2426 struct GNUNET_MessageHeader *hdr;
2427 struct GNUNET_TUN_Layer2PacketHeader *tun;
2429 hdr= (struct GNUNET_MessageHeader *) buf;
2430 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
2431 hdr->size = htons (len);
2432 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
2433 tun->flags = htons (0);
2434 switch (source_address->af)
2438 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
2440 tun->proto = htons (ETH_P_IPV4);
2441 prepare_ipv4_packet (payload, payload_length,
2445 destination_address,
2451 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
2453 tun->proto = htons (ETH_P_IPV6);
2454 prepare_ipv6_packet (payload, payload_length,
2458 destination_address,
2466 (void) GNUNET_HELPER_send (helper_handle,
2467 (const struct GNUNET_MessageHeader*) buf,
2475 * Process a request to forward UDP data to the Internet via this peer.
2477 * @param cls closure, NULL
2478 * @param tunnel connection to the other end
2479 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2480 * @param sender who sent the message
2481 * @param message the actual message
2482 * @param atsi performance data for the connection
2483 * @return GNUNET_OK to keep the connection open,
2484 * GNUNET_SYSERR to close it (signal serious error)
2487 receive_udp_remote (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2488 void **tunnel_ctx GNUNET_UNUSED,
2489 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2490 const struct GNUNET_MessageHeader *message,
2491 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2493 struct TunnelState *state = *tunnel_ctx;
2494 const struct GNUNET_EXIT_UdpInternetMessage *msg;
2495 uint16_t pkt_len = ntohs (message->size);
2496 const struct in_addr *v4;
2497 const struct in6_addr *v6;
2498 const void *payload;
2501 GNUNET_STATISTICS_update (stats,
2502 gettext_noop ("# Bytes received from MESH"),
2503 pkt_len, GNUNET_NO);
2504 GNUNET_STATISTICS_update (stats,
2505 gettext_noop ("# UDP IP-exit requests received via mesh"),
2507 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpInternetMessage))
2509 GNUNET_break_op (0);
2510 return GNUNET_SYSERR;
2512 msg = (const struct GNUNET_EXIT_UdpInternetMessage*) message;
2513 pkt_len -= sizeof (struct GNUNET_EXIT_UdpInternetMessage);
2514 af = (int) ntohl (msg->af);
2515 state->ri.remote_address.af = af;
2519 if (pkt_len < sizeof (struct in_addr))
2521 GNUNET_break_op (0);
2522 return GNUNET_SYSERR;
2526 GNUNET_break_op (0);
2527 return GNUNET_SYSERR;
2529 v4 = (const struct in_addr*) &msg[1];
2531 pkt_len -= sizeof (struct in_addr);
2532 state->ri.remote_address.address.ipv4 = *v4;
2535 if (pkt_len < sizeof (struct in6_addr))
2537 GNUNET_break_op (0);
2538 return GNUNET_SYSERR;
2542 GNUNET_break_op (0);
2543 return GNUNET_SYSERR;
2545 v6 = (const struct in6_addr*) &msg[1];
2547 pkt_len -= sizeof (struct in6_addr);
2548 state->ri.remote_address.address.ipv6 = *v6;
2551 GNUNET_break_op (0);
2552 return GNUNET_SYSERR;
2555 char buf[INET6_ADDRSTRLEN];
2556 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2557 "Received data from %s for forwarding to UDP %s:%u\n",
2558 GNUNET_i2s (sender),
2560 &state->ri.remote_address.address,
2562 (unsigned int) ntohs (msg->destination_port));
2564 state->ri.remote_address.proto = IPPROTO_UDP;
2565 state->ri.remote_address.port = msg->destination_port;
2566 if (NULL == state->heap_node)
2567 setup_state_record (state);
2568 if (0 != ntohs (msg->source_port))
2569 state->ri.local_address.port = msg->source_port;
2570 send_udp_packet_via_tun (&state->ri.remote_address,
2571 &state->ri.local_address,
2578 * Process a request via mesh to send a request to a UDP service
2579 * offered by this system.
2581 * @param cls closure, NULL
2582 * @param tunnel connection to the other end
2583 * @param tunnel_ctx pointer to our 'struct TunnelState *'
2584 * @param sender who sent the message
2585 * @param message the actual message
2586 * @param atsi performance data for the connection
2587 * @return GNUNET_OK to keep the connection open,
2588 * GNUNET_SYSERR to close it (signal serious error)
2591 receive_udp_service (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2593 const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED,
2594 const struct GNUNET_MessageHeader *message,
2595 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2597 struct TunnelState *state = *tunnel_ctx;
2598 const struct GNUNET_EXIT_UdpServiceMessage *msg;
2599 uint16_t pkt_len = ntohs (message->size);
2601 GNUNET_STATISTICS_update (stats,
2602 gettext_noop ("# Bytes received from MESH"),
2603 pkt_len, GNUNET_NO);
2604 GNUNET_STATISTICS_update (stats,
2605 gettext_noop ("# UDP service requests received via mesh"),
2607 /* check that we got at least a valid header */
2608 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpServiceMessage))
2610 GNUNET_break_op (0);
2611 return GNUNET_SYSERR;
2613 msg = (const struct GNUNET_EXIT_UdpServiceMessage*) message;
2614 pkt_len -= sizeof (struct GNUNET_EXIT_UdpServiceMessage);
2615 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2616 "Received data from %s for forwarding to UDP service %s on port %u\n",
2617 GNUNET_i2s (sender),
2618 GNUNET_h2s (&msg->service_descriptor),
2619 (unsigned int) ntohs (msg->destination_port));
2620 if (NULL == (state->serv = find_service (udp_services, &msg->service_descriptor,
2621 ntohs (msg->destination_port))))
2623 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2624 _("No service found for %s on port %d!\n"),
2626 ntohs (msg->destination_port));
2627 GNUNET_STATISTICS_update (stats,
2628 gettext_noop ("# UDP requests dropped (no such service)"),
2630 return GNUNET_SYSERR;
2632 state->ri.remote_address = state->serv->address;
2633 setup_state_record (state);
2634 if (0 != ntohs (msg->source_port))
2635 state->ri.local_address.port = msg->source_port;
2636 send_udp_packet_via_tun (&state->ri.remote_address,
2637 &state->ri.local_address,
2644 * Callback from GNUNET_MESH for new tunnels.
2646 * @param cls closure
2647 * @param tunnel new handle to the tunnel
2648 * @param initiator peer that started the tunnel
2649 * @param atsi performance information for the tunnel
2650 * @return initial tunnel context for the tunnel
2653 new_tunnel (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel,
2654 const struct GNUNET_PeerIdentity *initiator GNUNET_UNUSED,
2655 const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED)
2657 struct TunnelState *s = GNUNET_malloc (sizeof (struct TunnelState));
2659 GNUNET_STATISTICS_update (stats,
2660 gettext_noop ("# Inbound MESH tunnels created"),
2662 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2663 "Received inbound tunnel from `%s'\n",
2664 GNUNET_i2s (initiator));
2671 * Function called by mesh whenever an inbound tunnel is destroyed.
2672 * Should clean up any associated state.
2674 * @param cls closure (set from GNUNET_MESH_connect)
2675 * @param tunnel connection to the other end (henceforth invalid)
2676 * @param tunnel_ctx place where local state associated
2677 * with the tunnel is stored
2680 clean_tunnel (void *cls GNUNET_UNUSED, const struct GNUNET_MESH_Tunnel *tunnel,
2683 struct TunnelState *s = tunnel_ctx;
2684 struct TunnelMessageQueue *tnq;
2686 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2687 "Tunnel destroyed\n");
2688 while (NULL != (tnq = s->head))
2690 GNUNET_CONTAINER_DLL_remove (s->head,
2695 if (s->heap_node != NULL)
2697 GNUNET_assert (GNUNET_YES ==
2698 GNUNET_CONTAINER_multihashmap_remove (connections_map,
2701 GNUNET_CONTAINER_heap_remove_node (s->heap_node);
2702 s->heap_node = NULL;
2706 GNUNET_MESH_notify_transmit_ready_cancel (s->th);
2714 * Function that frees everything from a hashmap
2718 * @param value value to free
2721 free_iterate (void *cls GNUNET_UNUSED,
2722 const GNUNET_HashCode * hash GNUNET_UNUSED, void *value)
2724 GNUNET_free (value);
2730 * Function scheduled as very last function, cleans up after us
2733 cleanup (void *cls GNUNET_UNUSED,
2734 const struct GNUNET_SCHEDULER_TaskContext *tskctx)
2738 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2739 "Exit service is shutting down now\n");
2740 if (helper_handle != NULL)
2742 GNUNET_HELPER_stop (helper_handle);
2743 helper_handle = NULL;
2745 if (mesh_handle != NULL)
2747 GNUNET_MESH_disconnect (mesh_handle);
2750 if (NULL != connections_map)
2752 GNUNET_CONTAINER_multihashmap_iterate (connections_map, &free_iterate, NULL);
2753 GNUNET_CONTAINER_multihashmap_destroy (connections_map);
2754 connections_map = NULL;
2756 if (NULL != connections_heap)
2758 GNUNET_CONTAINER_heap_destroy (connections_heap);
2759 connections_heap = NULL;
2761 if (NULL != tcp_services)
2763 GNUNET_CONTAINER_multihashmap_iterate (tcp_services, &free_service_record, NULL);
2764 GNUNET_CONTAINER_multihashmap_destroy (tcp_services);
2765 tcp_services = NULL;
2767 if (NULL != udp_services)
2769 GNUNET_CONTAINER_multihashmap_iterate (udp_services, &free_service_record, NULL);
2770 GNUNET_CONTAINER_multihashmap_destroy (udp_services);
2771 udp_services = NULL;
2775 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
2779 GNUNET_free_non_null (exit_argv[i]);
2784 * Add services to the service map.
2786 * @param proto IPPROTO_TCP or IPPROTO_UDP
2787 * @param cpy copy of the service descriptor (can be mutilated)
2788 * @param name DNS name of the service
2791 add_services (int proto,
2798 struct LocalService *serv;
2800 for (redirect = strtok (cpy, " "); redirect != NULL;
2801 redirect = strtok (NULL, " "))
2803 if (NULL == (hostname = strstr (redirect, ":")))
2805 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2806 "option `%s' for domain `%s' is not formatted correctly!\n",
2813 if (NULL == (hostport = strstr (hostname, ":")))
2815 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2816 "option `%s' for domain `%s' is not formatted correctly!\n",
2824 int local_port = atoi (redirect);
2825 int remote_port = atoi (hostport);
2827 if (!((local_port > 0) && (local_port < 65536)))
2829 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2830 "`%s' is not a valid port number (for domain `%s')!", redirect,
2834 if (!((remote_port > 0) && (remote_port < 65536)))
2836 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2837 "`%s' is not a valid port number (for domain `%s')!", hostport,
2842 serv = GNUNET_malloc (sizeof (struct LocalService));
2843 serv->my_port = (uint16_t) local_port;
2844 serv->address.port = remote_port;
2845 if (0 == strcmp ("localhost4", hostname))
2847 const char *ip4addr = exit_argv[4];
2849 serv->address.af = AF_INET;
2850 GNUNET_assert (1 != inet_pton (AF_INET, ip4addr, &serv->address.address.ipv4));
2852 else if (0 == strcmp ("localhost6", hostname))
2854 const char *ip6addr = exit_argv[2];
2856 serv->address.af = AF_INET6;
2857 GNUNET_assert (1 == inet_pton (AF_INET6, ip6addr, &serv->address.address.ipv6));
2861 struct addrinfo *res;
2864 ret = getaddrinfo (hostname, NULL, NULL, &res);
2865 if ( (ret != 0) || (res == NULL) )
2867 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2868 _("No addresses found for hostname `%s' of service `%s'!\n"),
2875 serv->address.af = res->ai_family;
2876 switch (res->ai_family)
2881 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2882 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2888 serv->address.address.ipv4 = ((struct sockaddr_in *) res->ai_addr)->sin_addr;
2893 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2894 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
2900 serv->address.address.ipv6 = ((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
2904 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
2905 _("No IP addresses found for hostname `%s' of service `%s'!\n"),
2913 store_service ((IPPROTO_UDP == proto) ? udp_services : tcp_services,
2922 * Reads the configuration servicecfg and populates udp_services
2925 * @param section name of section in config, equal to hostname
2928 read_service_conf (void *cls GNUNET_UNUSED, const char *section)
2932 if ((strlen (section) < 8) ||
2933 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
2936 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
2939 add_services (IPPROTO_UDP, cpy, section);
2943 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
2946 add_services (IPPROTO_TCP, cpy, section);
2953 * Test if the given AF is supported by this system.
2956 * @return GNUNET_OK if the AF is supported
2963 s = socket (af, SOCK_STREAM, 0);
2966 if (EAFNOSUPPORT == errno)
2968 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR,
2970 return GNUNET_SYSERR;
2978 * @brief Main function that will be run by the scheduler.
2980 * @param cls closure
2981 * @param args remaining command-line arguments
2982 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
2983 * @param cfg_ configuration
2986 run (void *cls, char *const *args GNUNET_UNUSED,
2987 const char *cfgfile GNUNET_UNUSED,
2988 const struct GNUNET_CONFIGURATION_Handle *cfg_)
2990 static struct GNUNET_MESH_MessageHandler handlers[] = {
2991 {&receive_icmp_service, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_SERVICE, 0},
2992 {&receive_icmp_remote, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_INTERNET, 0},
2993 {&receive_udp_service, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_SERVICE, 0},
2994 {&receive_udp_remote, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_INTERNET, 0},
2995 {&receive_tcp_service, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_SERVICE_START, 0},
2996 {&receive_tcp_remote, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_INTERNET_START, 0},
2997 {&receive_tcp_data, GNUNET_MESSAGE_TYPE_VPN_TCP_DATA_TO_EXIT, 0},
3001 static GNUNET_MESH_ApplicationType apptypes[] = {
3002 GNUNET_APPLICATION_TYPE_END,
3003 GNUNET_APPLICATION_TYPE_END,
3004 GNUNET_APPLICATION_TYPE_END
3006 unsigned int app_idx;
3015 GNUNET_OS_check_helper_binary ("gnunet-helper-exit"))
3018 "`%s' is not SUID, refusing to run.\n",
3019 "gnunet-helper-exit");
3024 stats = GNUNET_STATISTICS_create ("exit", cfg);
3025 ipv4_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV4");
3026 ipv6_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV6");
3027 ipv4_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV4");
3028 ipv6_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV6");
3030 if ( (ipv4_exit || ipv4_enabled) &&
3031 GNUNET_OK != test_af (AF_INET))
3033 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3034 _("This system does not support IPv4, will disable IPv4 functions despite them being enabled in the configuration\n"));
3035 ipv4_exit = GNUNET_NO;
3036 ipv4_enabled = GNUNET_NO;
3038 if ( (ipv6_exit || ipv6_enabled) &&
3039 GNUNET_OK != test_af (AF_INET6))
3041 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3042 _("This system does not support IPv6, will disable IPv6 functions despite them being enabled in the configuration\n"));
3043 ipv6_exit = GNUNET_NO;
3044 ipv6_enabled = GNUNET_NO;
3046 if (ipv4_exit && (! ipv4_enabled))
3048 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3049 _("Cannot enable IPv4 exit but disable IPv4 on TUN interface, will use ENABLE_IPv4=YES\n"));
3050 ipv4_enabled = GNUNET_YES;
3052 if (ipv6_exit && (! ipv6_enabled))
3054 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3055 _("Cannot enable IPv6 exit but disable IPv6 on TUN interface, will use ENABLE_IPv6=YES\n"));
3056 ipv6_enabled = GNUNET_YES;
3058 if (! (ipv4_enabled || ipv6_enabled))
3060 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3061 _("No useful service enabled. Exiting.\n"));
3062 GNUNET_SCHEDULER_shutdown ();
3066 if (GNUNET_YES == ipv4_exit)
3068 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV4_GATEWAY;
3071 if (GNUNET_YES == ipv6_exit)
3073 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV6_GATEWAY;
3077 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls);
3080 GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_CONNECTIONS",
3082 max_connections = 1024;
3083 exit_argv[0] = GNUNET_strdup ("exit-gnunet");
3084 if (GNUNET_SYSERR ==
3085 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "TUN_IFNAME", &tun_ifname))
3087 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3088 "No entry 'TUN_IFNAME' in configuration!\n");
3089 GNUNET_SCHEDULER_shutdown ();
3092 exit_argv[1] = tun_ifname;
3095 if (GNUNET_SYSERR ==
3096 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "EXIT_IFNAME", &exit_ifname))
3098 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3099 "No entry 'EXIT_IFNAME' in configuration!\n");
3100 GNUNET_SCHEDULER_shutdown ();
3103 exit_argv[2] = exit_ifname;
3107 exit_argv[2] = GNUNET_strdup ("%");
3111 if (GNUNET_YES == ipv6_enabled)
3113 if ( (GNUNET_SYSERR ==
3114 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6ADDR",
3116 (1 != inet_pton (AF_INET6, ipv6addr, &exit_ipv6addr))) )
3118 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3119 "No valid entry 'IPV6ADDR' in configuration!\n");
3120 GNUNET_SCHEDULER_shutdown ();
3123 exit_argv[3] = ipv6addr;
3124 if (GNUNET_SYSERR ==
3125 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6PREFIX",
3128 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3129 "No entry 'IPV6PREFIX' in configuration!\n");
3130 GNUNET_SCHEDULER_shutdown ();
3133 exit_argv[4] = ipv6prefix_s;
3135 GNUNET_CONFIGURATION_get_value_number (cfg, "exit",
3138 (ipv6prefix >= 127) )
3140 GNUNET_SCHEDULER_shutdown ();
3146 /* IPv6 explicitly disabled */
3147 exit_argv[3] = GNUNET_strdup ("-");
3148 exit_argv[4] = GNUNET_strdup ("-");
3150 if (GNUNET_YES == ipv4_enabled)
3152 if ( (GNUNET_SYSERR ==
3153 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4ADDR",
3155 (1 != inet_pton (AF_INET, ipv4addr, &exit_ipv4addr))) )
3157 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3158 "No valid entry for 'IPV4ADDR' in configuration!\n");
3159 GNUNET_SCHEDULER_shutdown ();
3162 exit_argv[5] = ipv4addr;
3163 if ( (GNUNET_SYSERR ==
3164 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4MASK",
3166 (1 != inet_pton (AF_INET, ipv4mask, &exit_ipv4mask))) )
3168 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3169 "No valid entry 'IPV4MASK' in configuration!\n");
3170 GNUNET_SCHEDULER_shutdown ();
3173 exit_argv[6] = ipv4mask;
3177 /* IPv4 explicitly disabled */
3178 exit_argv[5] = GNUNET_strdup ("-");
3179 exit_argv[6] = GNUNET_strdup ("-");
3181 exit_argv[7] = NULL;
3183 udp_services = GNUNET_CONTAINER_multihashmap_create (65536);
3184 tcp_services = GNUNET_CONTAINER_multihashmap_create (65536);
3185 GNUNET_CONFIGURATION_iterate_sections (cfg, &read_service_conf, NULL);
3187 connections_map = GNUNET_CONTAINER_multihashmap_create (65536);
3188 connections_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3190 = GNUNET_MESH_connect (cfg, 42 /* queue size */, NULL,
3192 &clean_tunnel, handlers,
3194 if (NULL == mesh_handle)
3196 GNUNET_SCHEDULER_shutdown ();
3199 helper_handle = GNUNET_HELPER_start ("gnunet-helper-exit",
3201 &message_token, NULL);
3208 * @param argc number of arguments from the command line
3209 * @param argv command line arguments
3210 * @return 0 ok, 1 on error
3213 main (int argc, char *const *argv)
3215 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
3216 GNUNET_GETOPT_OPTION_END
3219 return (GNUNET_OK ==
3220 GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-exit",
3222 ("Daemon to run to provide an IP exit node for the VPN"),
3223 options, &run, NULL)) ? global_ret : 1;
3227 /* end of gnunet-daemon-exit.c */