2 This file is part of GNUnet.
3 Copyright (C) 2010-2013 Christian Grothoff
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file exit/gnunet-daemon-exit.c
23 * @brief tool to allow IP traffic exit from the GNUnet cadet 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_dht_service.h"
42 #include "gnunet_cadet_service.h"
43 #include "gnunet_dnsparser_lib.h"
44 #include "gnunet_dnsstub_lib.h"
45 #include "gnunet_statistics_service.h"
46 #include "gnunet_constants.h"
47 #include "gnunet_signatures.h"
48 #include "gnunet_tun_lib.h"
49 #include "gnunet_regex_service.h"
51 #include "block_dns.h"
55 * Maximum path compression length for cadet regex announcing for IPv4 address
58 #define REGEX_MAX_PATH_LEN_IPV4 4
61 * Maximum path compression length for cadet regex announcing for IPv6 address
64 #define REGEX_MAX_PATH_LEN_IPV6 8
67 * How frequently do we re-announce the regex for the exit?
69 #define REGEX_REFRESH_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 30)
72 * How frequently do we re-announce the DNS exit in the DHT?
74 #define DHT_PUT_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
77 * How long do we typically sign the DNS exit advertisement for?
79 #define DNS_ADVERTISEMENT_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 3)
83 * Generic logging shorthand
85 #define LOG(kind, ...) \
86 GNUNET_log_from (kind, "exit", __VA_ARGS__);
90 * Information about an address.
95 * AF_INET or AF_INET6.
100 * Remote address information.
105 * Address, if af is AF_INET.
110 * Address, if af is AF_INET6.
112 struct in6_addr ipv6;
116 * IPPROTO_TCP or IPPROTO_UDP;
121 * Remote port, in host byte order!
128 * This struct is saved into the services-hashmap to represent
129 * a service this peer is specifically offering an exit for
130 * (for a specific domain name).
136 * Remote address to use for the service.
138 struct SocketAddress address;
141 * DNS name of the service.
146 * Port I am listening on within GNUnet for this service, in host
147 * byte order. (as we may redirect ports).
154 * Information we use to track a connection (the classical 6-tuple of
155 * IP-version, protocol, source-IP, destination-IP, source-port and
158 struct RedirectInformation
162 * Address information for the other party (equivalent of the
163 * arguments one would give to "connect").
165 struct SocketAddress remote_address;
168 * Address information we used locally (AF and proto must match
169 * "remote_address"). Equivalent of the arguments one would give to
172 struct SocketAddress local_address;
175 Note 1: additional information might be added here in the
176 future to support protocols that require special handling,
179 Note 2: we might also sometimes not match on all components
180 of the tuple, to support protocols where things do not always
187 * Queue of messages to a channel.
189 struct ChannelMessageQueue
192 * This is a doubly-linked list.
194 struct ChannelMessageQueue *next;
197 * This is a doubly-linked list.
199 struct ChannelMessageQueue *prev;
202 * Payload to send via the channel.
207 * Number of bytes in 'payload'.
214 * This struct is saved into connections_map to allow finding the
215 * right channel given an IP packet from TUN. It is also associated
216 * with the channel's closure so we can find it again for the next
217 * message from the channel.
222 * Cadet channel that is used for this connection.
224 struct GNUNET_CADET_Channel *channel;
227 * Who is the other end of this channel.
228 * FIXME is this needed? Only used for debugging messages
230 struct GNUNET_PeerIdentity peer;
233 * Active channel transmission request (or NULL).
235 struct GNUNET_CADET_TransmitHandle *th;
238 * #GNUNET_NO if this is a channel for TCP/UDP,
239 * #GNUNET_YES if this is a channel for DNS,
240 * #GNUNET_SYSERR if the channel is not yet initialized.
250 * Heap node for this state in the connections_heap.
252 struct GNUNET_CONTAINER_HeapNode *heap_node;
255 * Key this state has in the connections_map.
257 struct GNUNET_HashCode state_key;
260 * Associated service record, or NULL for no service.
262 struct LocalService *serv;
265 * Head of DLL of messages for this channel.
267 struct ChannelMessageQueue *head;
270 * Tail of DLL of messages for this channel.
272 struct ChannelMessageQueue *tail;
275 * Primary redirection information for this connection.
277 struct RedirectInformation ri;
284 * DNS reply ready for transmission.
289 * Socket we are using to transmit this request (must match if we receive
292 struct GNUNET_DNSSTUB_RequestSocket *rs;
295 * Number of bytes in 'reply'.
300 * Original DNS request ID as used by the client.
302 uint16_t original_id;
305 * DNS request ID that we used for forwarding.
317 * Return value from 'main'.
319 static int global_ret;
322 * Handle to our regex announcement for IPv4.
324 static struct GNUNET_REGEX_Announcement *regex4;
327 * Handle to our regex announcement for IPv4.
329 static struct GNUNET_REGEX_Announcement *regex6;
332 * The handle to the configuration used throughout the process
334 static const struct GNUNET_CONFIGURATION_Handle *cfg;
337 * The handle to the helper
339 static struct GNUNET_HELPER_Handle *helper_handle;
342 * Arguments to the exit helper.
344 static char *exit_argv[8];
347 * IPv6 address of our TUN interface.
349 static struct in6_addr exit_ipv6addr;
352 * IPv6 prefix (0..127) from configuration file.
354 static unsigned long long ipv6prefix;
357 * IPv4 address of our TUN interface.
359 static struct in_addr exit_ipv4addr;
362 * IPv4 netmask of our TUN interface.
364 static struct in_addr exit_ipv4mask;
369 static struct GNUNET_STATISTICS_Handle *stats;
372 * The handle to cadet
374 static struct GNUNET_CADET_Handle *cadet_handle;
377 * This hashmaps contains the mapping from peer, service-descriptor,
378 * source-port and destination-port to a struct ChannelState
380 static struct GNUNET_CONTAINER_MultiHashMap *connections_map;
383 * Heap so we can quickly find "old" connections.
385 static struct GNUNET_CONTAINER_Heap *connections_heap;
388 * If there are at least this many connections, old ones will be removed
390 static unsigned long long max_connections;
393 * This hashmaps saves interesting things about the configured UDP services
395 static struct GNUNET_CONTAINER_MultiHashMap *udp_services;
398 * This hashmaps saves interesting things about the configured TCP services
400 static struct GNUNET_CONTAINER_MultiHashMap *tcp_services;
403 * Array of all open DNS requests from channels.
405 static struct ChannelState *channels[UINT16_MAX + 1];
408 * Handle to the DNS Stub resolver.
410 static struct GNUNET_DNSSTUB_Context *dnsstub;
413 * Handle for ongoing DHT PUT operations to advertise exit service.
415 static struct GNUNET_DHT_PutHandle *dht_put;
420 static struct GNUNET_DHT_Handle *dht;
423 * Task for doing DHT PUTs to advertise exit service.
425 static struct GNUNET_SCHEDULER_Task * dht_task;
428 * Advertisement message we put into the DHT to advertise us
431 static struct GNUNET_DNS_Advertisement dns_advertisement;
434 * Key we store the DNS advertismenet under.
436 static struct GNUNET_HashCode dht_put_key;
439 * Private key for this peer.
441 static struct GNUNET_CRYPTO_EddsaPrivateKey *peer_key;
444 * Are we an IPv4-exit?
446 static int ipv4_exit;
449 * Are we an IPv6-exit?
451 static int ipv6_exit;
454 * Do we support IPv4 at all on the TUN interface?
456 static int ipv4_enabled;
459 * Do we support IPv6 at all on the TUN interface?
461 static int ipv6_enabled;
465 * We got a reply from DNS for a request of a CADET channel. Send it
466 * via the channel (after changing the request ID back).
468 * @param cls the 'struct ChannelState'
469 * @param size number of bytes available in buf
470 * @param buf where to copy the reply
471 * @return number of bytes written to buf
474 transmit_reply_to_cadet (void *cls,
478 struct ChannelState *ts = cls;
482 struct GNUNET_MessageHeader hdr;
483 struct GNUNET_TUN_DnsHeader dns;
485 GNUNET_assert (GNUNET_YES == ts->is_dns);
487 GNUNET_assert (ts->specifics.dns.reply != NULL);
490 ret = sizeof (struct GNUNET_MessageHeader) + ts->specifics.dns.reply_length;
491 GNUNET_assert (ret <= size);
492 hdr.size = htons (ret);
493 hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_FROM_INTERNET);
494 memcpy (&dns, ts->specifics.dns.reply, sizeof (dns));
495 dns.id = ts->specifics.dns.original_id;
497 memcpy (&cbuf[off], &hdr, sizeof (hdr));
499 memcpy (&cbuf[off], &dns, sizeof (dns));
501 memcpy (&cbuf[off], &ts->specifics.dns.reply[sizeof (dns)], ts->specifics.dns.reply_length - sizeof (dns));
502 off += ts->specifics.dns.reply_length - sizeof (dns);
503 GNUNET_free (ts->specifics.dns.reply);
504 ts->specifics.dns.reply = NULL;
505 ts->specifics.dns.reply_length = 0;
506 GNUNET_assert (ret == off);
512 * Callback called from DNSSTUB resolver when a resolution
516 * @param rs the socket that received the response
517 * @param dns the response itself
518 * @param r number of bytes in dns
521 process_dns_result (void *cls,
522 struct GNUNET_DNSSTUB_RequestSocket *rs,
523 const struct GNUNET_TUN_DnsHeader *dns,
526 struct ChannelState *ts;
528 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
529 "Processing DNS result from stub resolver\n");
530 GNUNET_assert (NULL == cls);
531 /* Handle case that this is a reply to a request from a CADET DNS channel */
532 ts = channels[dns->id];
534 (ts->specifics.dns.rs != rs) )
536 LOG (GNUNET_ERROR_TYPE_DEBUG,
537 "Got a response from the stub resolver for DNS request received via CADET!\n");
538 channels[dns->id] = NULL;
539 GNUNET_free_non_null (ts->specifics.dns.reply);
540 ts->specifics.dns.reply = GNUNET_malloc (r);
541 ts->specifics.dns.reply_length = r;
542 memcpy (ts->specifics.dns.reply, dns, r);
544 GNUNET_CADET_notify_transmit_ready_cancel (ts->th);
545 ts->th = GNUNET_CADET_notify_transmit_ready (ts->channel,
547 GNUNET_TIME_UNIT_FOREVER_REL,
548 sizeof (struct GNUNET_MessageHeader) + r,
549 &transmit_reply_to_cadet,
555 * Process a request via cadet to perform a DNS query.
557 * @param cls closure, NULL
558 * @param channel connection to the other end
559 * @param channel_ctx pointer to our `struct ChannelState *`
560 * @param message the actual message
562 * @return #GNUNET_OK to keep the connection open,
563 * #GNUNET_SYSERR to close it (signal serious error)
566 receive_dns_request (void *cls GNUNET_UNUSED, struct GNUNET_CADET_Channel *channel,
568 const struct GNUNET_MessageHeader *message)
570 struct ChannelState *ts = *channel_ctx;
571 const struct GNUNET_TUN_DnsHeader *dns;
572 size_t mlen = ntohs (message->size);
573 size_t dlen = mlen - sizeof (struct GNUNET_MessageHeader);
574 char buf[dlen] GNUNET_ALIGN;
575 struct GNUNET_TUN_DnsHeader *dout;
578 return GNUNET_SYSERR;
579 if (GNUNET_NO == ts->is_dns)
582 return GNUNET_SYSERR;
584 if (GNUNET_SYSERR == ts->is_dns)
586 /* channel is DNS from now on */
587 ts->is_dns = GNUNET_YES;
589 if (dlen < sizeof (struct GNUNET_TUN_DnsHeader))
592 return GNUNET_SYSERR;
594 dns = (const struct GNUNET_TUN_DnsHeader *) &message[1];
595 ts->specifics.dns.original_id = dns->id;
596 if (channels[ts->specifics.dns.my_id] == ts)
597 channels[ts->specifics.dns.my_id] = NULL;
598 ts->specifics.dns.my_id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
600 channels[ts->specifics.dns.my_id] = ts;
601 memcpy (buf, dns, dlen);
602 dout = (struct GNUNET_TUN_DnsHeader *) buf;
603 dout->id = ts->specifics.dns.my_id;
604 ts->specifics.dns.rs = GNUNET_DNSSTUB_resolve2 (dnsstub,
608 if (NULL == ts->specifics.dns.rs)
609 return GNUNET_SYSERR;
615 * Given IP information about a connection, calculate the respective
616 * hash we would use for the 'connections_map'.
618 * @param hash resulting hash
619 * @param ri information about the connection
622 hash_redirect_info (struct GNUNET_HashCode *hash,
623 const struct RedirectInformation *ri)
627 memset (hash, 0, sizeof (struct GNUNET_HashCode));
628 /* the GNUnet hashmap only uses the first sizeof(unsigned int) of the hash,
629 so we put the IP address in there (and hope for few collisions) */
631 switch (ri->remote_address.af)
634 memcpy (off, &ri->remote_address.address.ipv4, sizeof (struct in_addr));
635 off += sizeof (struct in_addr);
638 memcpy (off, &ri->remote_address.address.ipv6, sizeof (struct in6_addr));
639 off += sizeof (struct in_addr);
644 memcpy (off, &ri->remote_address.port, sizeof (uint16_t));
645 off += sizeof (uint16_t);
646 switch (ri->local_address.af)
649 memcpy (off, &ri->local_address.address.ipv4, sizeof (struct in_addr));
650 off += sizeof (struct in_addr);
653 memcpy (off, &ri->local_address.address.ipv6, sizeof (struct in6_addr));
654 off += sizeof (struct in_addr);
659 memcpy (off, &ri->local_address.port, sizeof (uint16_t));
660 off += sizeof (uint16_t);
661 memcpy (off, &ri->remote_address.proto, sizeof (uint8_t));
662 /* off += sizeof (uint8_t); */
667 * Get our connection tracking state. Warns if it does not exists,
668 * refreshes the timestamp if it does exist.
670 * @param af address family
671 * @param protocol IPPROTO_UDP or IPPROTO_TCP
672 * @param destination_ip target IP
673 * @param destination_port target port
674 * @param local_ip local IP
675 * @param local_port local port
676 * @param state_key set to hash's state if non-NULL
677 * @return NULL if we have no tracking information for this tuple
679 static struct ChannelState *
680 get_redirect_state (int af,
682 const void *destination_ip,
683 uint16_t destination_port,
684 const void *local_ip,
686 struct GNUNET_HashCode *state_key)
688 struct RedirectInformation ri;
689 struct GNUNET_HashCode key;
690 struct ChannelState *state;
692 if ( ( (af == AF_INET) && (protocol == IPPROTO_ICMP) ) ||
693 ( (af == AF_INET6) && (protocol == IPPROTO_ICMPV6) ) )
696 destination_port = 0;
699 ri.remote_address.af = af;
701 ri.remote_address.address.ipv4 = *((struct in_addr*) destination_ip);
703 ri.remote_address.address.ipv6 = * ((struct in6_addr*) destination_ip);
704 ri.remote_address.port = destination_port;
705 ri.remote_address.proto = protocol;
706 ri.local_address.af = af;
708 ri.local_address.address.ipv4 = *((struct in_addr*) local_ip);
710 ri.local_address.address.ipv6 = * ((struct in6_addr*) local_ip);
711 ri.local_address.port = local_port;
712 ri.local_address.proto = protocol;
713 hash_redirect_info (&key, &ri);
714 if (NULL != state_key)
716 state = GNUNET_CONTAINER_multihashmap_get (connections_map, &key);
719 /* Mark this connection as freshly used */
720 if (NULL == state_key)
721 GNUNET_CONTAINER_heap_update_cost (connections_heap,
722 state->specifics.tcp_udp.heap_node,
723 GNUNET_TIME_absolute_get ().abs_value_us);
729 * Given a service descriptor and a destination port, find the
730 * respective service entry.
732 * @param service_map map of services (TCP or UDP)
733 * @param desc service descriptor
734 * @param destination_port destination port
735 * @return NULL if we are not aware of such a service
737 static struct LocalService *
738 find_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
739 const struct GNUNET_HashCode *desc,
740 uint16_t destination_port)
742 char key[sizeof (struct GNUNET_HashCode) + sizeof (uint16_t)];
744 memcpy (&key[0], &destination_port, sizeof (uint16_t));
745 memcpy (&key[sizeof(uint16_t)], desc, sizeof (struct GNUNET_HashCode));
746 return GNUNET_CONTAINER_multihashmap_get (service_map,
747 (struct GNUNET_HashCode *) key);
752 * Free memory associated with a service record.
755 * @param key service descriptor
756 * @param value service record to free
760 free_service_record (void *cls,
761 const struct GNUNET_HashCode *key,
764 struct LocalService *service = value;
766 GNUNET_free_non_null (service->name);
767 GNUNET_free (service);
773 * Given a service descriptor and a destination port, find the
774 * respective service entry.
776 * @param service_map map of services (TCP or UDP)
777 * @param name name of the service
778 * @param destination_port destination port
779 * @param service service information record to store (service->name will be set).
782 store_service (struct GNUNET_CONTAINER_MultiHashMap *service_map,
784 uint16_t destination_port,
785 struct LocalService *service)
787 char key[sizeof (struct GNUNET_HashCode) + sizeof (uint16_t)];
788 struct GNUNET_HashCode desc;
790 GNUNET_TUN_service_name_to_hash (name, &desc);
791 service->name = GNUNET_strdup (name);
792 memcpy (&key[0], &destination_port, sizeof (uint16_t));
793 memcpy (&key[sizeof(uint16_t)], &desc, sizeof (struct GNUNET_HashCode));
795 GNUNET_CONTAINER_multihashmap_put (service_map,
796 (struct GNUNET_HashCode *) key,
798 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY))
800 free_service_record (NULL, (struct GNUNET_HashCode *) key, service);
801 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
802 _("Got duplicate service records for `%s:%u'\n"),
804 (unsigned int) destination_port);
810 * CADET is ready to receive a message for the channel. Transmit it.
812 * @param cls the 'struct ChannelState'.
813 * @param size number of bytes available in buf
814 * @param buf where to copy the message
815 * @return number of bytes copied to buf
818 send_to_peer_notify_callback (void *cls, size_t size, void *buf)
820 struct ChannelState *s = cls;
821 struct GNUNET_CADET_Channel *channel = s->channel;
822 struct ChannelMessageQueue *tnq;
825 tnq = s->specifics.tcp_udp.head;
830 s->th = GNUNET_CADET_notify_transmit_ready (channel,
831 GNUNET_NO /* corking */,
832 GNUNET_TIME_UNIT_FOREVER_REL,
834 &send_to_peer_notify_callback,
838 GNUNET_assert (size >= tnq->len);
839 memcpy (buf, tnq->payload, tnq->len);
841 GNUNET_CONTAINER_DLL_remove (s->specifics.tcp_udp.head,
842 s->specifics.tcp_udp.tail,
845 if (NULL != (tnq = s->specifics.tcp_udp.head))
846 s->th = GNUNET_CADET_notify_transmit_ready (channel,
847 GNUNET_NO /* corking */,
848 GNUNET_TIME_UNIT_FOREVER_REL,
850 &send_to_peer_notify_callback,
852 GNUNET_STATISTICS_update (stats,
853 gettext_noop ("# Bytes transmitted via cadet channels"),
860 * Send the given packet via the cadet channel.
862 * @param s channel destination
863 * @param tnq message to queue
866 send_packet_to_cadet_channel (struct ChannelState *s,
867 struct ChannelMessageQueue *tnq)
869 struct GNUNET_CADET_Channel *cadet_channel;
871 cadet_channel = s->channel;
872 GNUNET_assert (NULL != s);
873 GNUNET_CONTAINER_DLL_insert_tail (s->specifics.tcp_udp.head, s->specifics.tcp_udp.tail, tnq);
875 s->th = GNUNET_CADET_notify_transmit_ready (cadet_channel,
876 GNUNET_NO /* cork */,
877 GNUNET_TIME_UNIT_FOREVER_REL,
879 &send_to_peer_notify_callback,
885 * @brief Handles an ICMP packet received from the helper.
887 * @param icmp A pointer to the Packet
888 * @param pktlen number of bytes in 'icmp'
889 * @param af address family (AFINET or AF_INET6)
890 * @param destination_ip destination IP-address of the IP packet (should
891 * be our local address)
892 * @param source_ip original source IP-address of the IP packet (should
893 * be the original destination address)
896 icmp_from_helper (const struct GNUNET_TUN_IcmpHeader *icmp,
899 const void *destination_ip,
900 const void *source_ip)
902 struct ChannelState *state;
903 struct ChannelMessageQueue *tnq;
904 struct GNUNET_EXIT_IcmpToVPNMessage *i2v;
905 const struct GNUNET_TUN_IPv4Header *ipv4;
906 const struct GNUNET_TUN_IPv6Header *ipv6;
907 const struct GNUNET_TUN_UdpHeader *udp;
909 uint16_t source_port;
910 uint16_t destination_port;
914 char sbuf[INET6_ADDRSTRLEN];
915 char dbuf[INET6_ADDRSTRLEN];
916 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
917 "Received ICMP packet going from %s to %s\n",
920 sbuf, sizeof (sbuf)),
923 dbuf, sizeof (dbuf)));
925 if (pktlen < sizeof (struct GNUNET_TUN_IcmpHeader))
932 /* Find out if this is an ICMP packet in response to an existing
933 TCP/UDP packet and if so, figure out ports / protocol of the
934 existing session from the IP data in the ICMP payload */
936 destination_port = 0;
940 protocol = IPPROTO_ICMP;
943 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
944 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
946 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
947 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
948 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
950 sizeof (struct GNUNET_TUN_IcmpHeader) +
951 sizeof (struct GNUNET_TUN_IPv4Header) + 8)
957 ipv4 = (const struct GNUNET_TUN_IPv4Header *) &icmp[1];
958 protocol = ipv4->protocol;
959 /* could be TCP or UDP, but both have the ports in the right
960 place, so that doesn't matter here */
961 udp = (const struct GNUNET_TUN_UdpHeader *) &ipv4[1];
962 /* swap ports, as they are from the original message */
963 destination_port = ntohs (udp->source_port);
964 source_port = ntohs (udp->destination_port);
965 /* throw away ICMP payload, won't be useful for the other side anyway */
966 pktlen = sizeof (struct GNUNET_TUN_IcmpHeader);
969 GNUNET_STATISTICS_update (stats,
970 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
976 protocol = IPPROTO_ICMPV6;
979 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
980 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
981 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
982 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
984 sizeof (struct GNUNET_TUN_IcmpHeader) +
985 sizeof (struct GNUNET_TUN_IPv6Header) + 8)
991 ipv6 = (const struct GNUNET_TUN_IPv6Header *) &icmp[1];
992 protocol = ipv6->next_header;
993 /* could be TCP or UDP, but both have the ports in the right
994 place, so that doesn't matter here */
995 udp = (const struct GNUNET_TUN_UdpHeader *) &ipv6[1];
996 /* swap ports, as they are from the original message */
997 destination_port = ntohs (udp->source_port);
998 source_port = ntohs (udp->destination_port);
999 /* throw away ICMP payload, won't be useful for the other side anyway */
1000 pktlen = sizeof (struct GNUNET_TUN_IcmpHeader);
1002 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
1003 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
1006 GNUNET_STATISTICS_update (stats,
1007 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
1018 state = get_redirect_state (af, IPPROTO_ICMP,
1023 case IPPROTO_ICMPV6:
1024 state = get_redirect_state (af, IPPROTO_ICMPV6,
1030 state = get_redirect_state (af, IPPROTO_UDP,
1038 state = get_redirect_state (af, IPPROTO_TCP,
1046 GNUNET_STATISTICS_update (stats,
1047 gettext_noop ("# ICMP packets dropped (not allowed)"),
1053 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1054 _("ICMP Packet dropped, have no matching connection information\n"));
1057 mlen = sizeof (struct GNUNET_EXIT_IcmpToVPNMessage) + pktlen - sizeof (struct GNUNET_TUN_IcmpHeader);
1058 tnq = GNUNET_malloc (sizeof (struct ChannelMessageQueue) + mlen);
1059 tnq->payload = &tnq[1];
1061 i2v = (struct GNUNET_EXIT_IcmpToVPNMessage *) &tnq[1];
1062 i2v->header.size = htons ((uint16_t) mlen);
1063 i2v->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_VPN);
1064 i2v->af = htonl (af);
1065 memcpy (&i2v->icmp_header,
1068 send_packet_to_cadet_channel (state, tnq);
1073 * @brief Handles an UDP packet received from the helper.
1075 * @param udp A pointer to the Packet
1076 * @param pktlen number of bytes in 'udp'
1077 * @param af address family (AFINET or AF_INET6)
1078 * @param destination_ip destination IP-address of the IP packet (should
1079 * be our local address)
1080 * @param source_ip original source IP-address of the IP packet (should
1081 * be the original destination address)
1084 udp_from_helper (const struct GNUNET_TUN_UdpHeader *udp,
1087 const void *destination_ip,
1088 const void *source_ip)
1090 struct ChannelState *state;
1091 struct ChannelMessageQueue *tnq;
1092 struct GNUNET_EXIT_UdpReplyMessage *urm;
1096 char sbuf[INET6_ADDRSTRLEN];
1097 char dbuf[INET6_ADDRSTRLEN];
1098 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1099 "Received UDP packet going from %s:%u to %s:%u\n",
1102 sbuf, sizeof (sbuf)),
1103 (unsigned int) ntohs (udp->source_port),
1106 dbuf, sizeof (dbuf)),
1107 (unsigned int) ntohs (udp->destination_port));
1109 if (pktlen < sizeof (struct GNUNET_TUN_UdpHeader))
1115 if (pktlen != ntohs (udp->len))
1121 state = get_redirect_state (af, IPPROTO_UDP,
1123 ntohs (udp->source_port),
1125 ntohs (udp->destination_port),
1129 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1130 _("UDP Packet dropped, have no matching connection information\n"));
1133 mlen = sizeof (struct GNUNET_EXIT_UdpReplyMessage) + pktlen - sizeof (struct GNUNET_TUN_UdpHeader);
1134 tnq = GNUNET_malloc (sizeof (struct ChannelMessageQueue) + mlen);
1135 tnq->payload = &tnq[1];
1137 urm = (struct GNUNET_EXIT_UdpReplyMessage *) &tnq[1];
1138 urm->header.size = htons ((uint16_t) mlen);
1139 urm->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_UDP_REPLY);
1140 urm->source_port = htons (0);
1141 urm->destination_port = htons (0);
1144 pktlen - sizeof (struct GNUNET_TUN_UdpHeader));
1145 send_packet_to_cadet_channel (state, tnq);
1150 * @brief Handles a TCP packet received from the helper.
1152 * @param tcp A pointer to the Packet
1153 * @param pktlen the length of the packet, including its TCP header
1154 * @param af address family (AFINET or AF_INET6)
1155 * @param destination_ip destination IP-address of the IP packet (should
1156 * be our local address)
1157 * @param source_ip original source IP-address of the IP packet (should
1158 * be the original destination address)
1161 tcp_from_helper (const struct GNUNET_TUN_TcpHeader *tcp,
1164 const void *destination_ip,
1165 const void *source_ip)
1167 struct ChannelState *state;
1168 char buf[pktlen] GNUNET_ALIGN;
1169 struct GNUNET_TUN_TcpHeader *mtcp;
1170 struct GNUNET_EXIT_TcpDataMessage *tdm;
1171 struct ChannelMessageQueue *tnq;
1175 char sbuf[INET6_ADDRSTRLEN];
1176 char dbuf[INET6_ADDRSTRLEN];
1177 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1178 "Received TCP packet with %u bytes going from %s:%u to %s:%u\n",
1179 pktlen - sizeof (struct GNUNET_TUN_TcpHeader),
1182 sbuf, sizeof (sbuf)),
1183 (unsigned int) ntohs (tcp->source_port),
1186 dbuf, sizeof (dbuf)),
1187 (unsigned int) ntohs (tcp->destination_port));
1189 if (pktlen < sizeof (struct GNUNET_TUN_TcpHeader))
1195 state = get_redirect_state (af, IPPROTO_TCP,
1197 ntohs (tcp->source_port),
1199 ntohs (tcp->destination_port),
1203 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1204 _("TCP Packet dropped, have no matching connection information\n"));
1208 /* mug port numbers and crc to avoid information leakage;
1209 sender will need to lookup the correct values anyway */
1210 memcpy (buf, tcp, pktlen);
1211 mtcp = (struct GNUNET_TUN_TcpHeader *) buf;
1212 mtcp->source_port = 0;
1213 mtcp->destination_port = 0;
1216 mlen = sizeof (struct GNUNET_EXIT_TcpDataMessage) + (pktlen - sizeof (struct GNUNET_TUN_TcpHeader));
1217 if (mlen >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1223 tnq = GNUNET_malloc (sizeof (struct ChannelMessageQueue) + mlen);
1224 tnq->payload = &tnq[1];
1226 tdm = (struct GNUNET_EXIT_TcpDataMessage *) &tnq[1];
1227 tdm->header.size = htons ((uint16_t) mlen);
1228 tdm->header.type = htons (GNUNET_MESSAGE_TYPE_VPN_TCP_DATA_TO_VPN);
1229 tdm->reserved = htonl (0);
1230 memcpy (&tdm->tcp_header,
1233 send_packet_to_cadet_channel (state, tnq);
1238 * Receive packets from the helper-process
1241 * @param client unsued
1242 * @param message message received from helper
1245 message_token (void *cls GNUNET_UNUSED, void *client GNUNET_UNUSED,
1246 const struct GNUNET_MessageHeader *message)
1248 const struct GNUNET_TUN_Layer2PacketHeader *pkt_tun;
1251 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1252 "Got %u-byte message of type %u from gnunet-helper-exit\n",
1253 ntohs (message->size),
1254 ntohs (message->type));
1255 GNUNET_STATISTICS_update (stats,
1256 gettext_noop ("# Packets received from TUN"),
1258 if (ntohs (message->type) != GNUNET_MESSAGE_TYPE_VPN_HELPER)
1263 size = ntohs (message->size);
1264 if (size < sizeof (struct GNUNET_TUN_Layer2PacketHeader) + sizeof (struct GNUNET_MessageHeader))
1269 GNUNET_STATISTICS_update (stats,
1270 gettext_noop ("# Bytes received from TUN"),
1272 pkt_tun = (const struct GNUNET_TUN_Layer2PacketHeader *) &message[1];
1273 size -= sizeof (struct GNUNET_TUN_Layer2PacketHeader) + sizeof (struct GNUNET_MessageHeader);
1274 switch (ntohs (pkt_tun->proto))
1278 const struct GNUNET_TUN_IPv4Header *pkt4;
1280 if (size < sizeof (struct GNUNET_TUN_IPv4Header))
1282 /* Kernel to blame? */
1286 pkt4 = (const struct GNUNET_TUN_IPv4Header *) &pkt_tun[1];
1287 if (size != ntohs (pkt4->total_length))
1289 /* Kernel to blame? */
1293 if (pkt4->header_length * 4 != sizeof (struct GNUNET_TUN_IPv4Header))
1295 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1296 _("IPv4 packet options received. Ignored.\n"));
1300 size -= sizeof (struct GNUNET_TUN_IPv4Header);
1301 switch (pkt4->protocol)
1304 udp_from_helper ((const struct GNUNET_TUN_UdpHeader *) &pkt4[1], size,
1306 &pkt4->destination_address,
1307 &pkt4->source_address);
1310 tcp_from_helper ((const struct GNUNET_TUN_TcpHeader *) &pkt4[1], size,
1312 &pkt4->destination_address,
1313 &pkt4->source_address);
1316 icmp_from_helper ((const struct GNUNET_TUN_IcmpHeader *) &pkt4[1], size,
1318 &pkt4->destination_address,
1319 &pkt4->source_address);
1322 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1323 _("IPv4 packet with unsupported next header %u received. Ignored.\n"),
1324 (int) pkt4->protocol);
1331 const struct GNUNET_TUN_IPv6Header *pkt6;
1333 if (size < sizeof (struct GNUNET_TUN_IPv6Header))
1335 /* Kernel to blame? */
1339 pkt6 = (struct GNUNET_TUN_IPv6Header *) &pkt_tun[1];
1340 if (size != ntohs (pkt6->payload_length) + sizeof (struct GNUNET_TUN_IPv6Header))
1342 /* Kernel to blame? */
1346 size -= sizeof (struct GNUNET_TUN_IPv6Header);
1347 switch (pkt6->next_header)
1350 udp_from_helper ((const struct GNUNET_TUN_UdpHeader *) &pkt6[1], size,
1352 &pkt6->destination_address,
1353 &pkt6->source_address);
1356 tcp_from_helper ((const struct GNUNET_TUN_TcpHeader *) &pkt6[1], size,
1358 &pkt6->destination_address,
1359 &pkt6->source_address);
1361 case IPPROTO_ICMPV6:
1362 icmp_from_helper ((const struct GNUNET_TUN_IcmpHeader *) &pkt6[1], size,
1364 &pkt6->destination_address,
1365 &pkt6->source_address);
1368 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1369 _("IPv6 packet with unsupported next header %d received. Ignored.\n"),
1376 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1377 _("Packet from unknown protocol %u received. Ignored.\n"),
1378 ntohs (pkt_tun->proto));
1386 * We need to create a (unique) fresh local address (IP+port).
1389 * @param af desired address family
1390 * @param proto desired protocol (IPPROTO_UDP or IPPROTO_TCP)
1391 * @param local_address address to initialize
1394 setup_fresh_address (int af,
1396 struct SocketAddress *local_address)
1398 local_address->af = af;
1399 local_address->proto = (uint8_t) proto;
1400 /* default "local" port range is often 32768--61000,
1401 so we pick a random value in that range */
1402 if ( ( (af == AF_INET) && (proto == IPPROTO_ICMP) ) ||
1403 ( (af == AF_INET6) && (proto == IPPROTO_ICMPV6) ) )
1404 local_address->port = 0;
1407 = (uint16_t) 32768 + GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1413 struct in_addr addr;
1414 struct in_addr mask;
1417 addr = exit_ipv4addr;
1418 mask = exit_ipv4mask;
1419 if (0 == ~mask.s_addr)
1421 /* only one valid IP anyway */
1422 local_address->address.ipv4 = addr;
1425 /* Given 192.168.0.1/255.255.0.0, we want a mask
1426 of '192.168.255.255', thus: */
1427 mask.s_addr = addr.s_addr | ~mask.s_addr;
1428 /* Pick random IPv4 address within the subnet, except 'addr' or 'mask' itself */
1431 rnd.s_addr = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1433 local_address->address.ipv4.s_addr = (addr.s_addr | rnd.s_addr) & mask.s_addr;
1435 while ( (local_address->address.ipv4.s_addr == addr.s_addr) ||
1436 (local_address->address.ipv4.s_addr == mask.s_addr) );
1441 struct in6_addr addr;
1442 struct in6_addr mask;
1443 struct in6_addr rnd;
1446 addr = exit_ipv6addr;
1447 GNUNET_assert (ipv6prefix < 128);
1448 if (ipv6prefix == 127)
1450 /* only one valid IP anyway */
1451 local_address->address.ipv6 = addr;
1454 /* Given ABCD::/96, we want a mask of 'ABCD::FFFF:FFFF,
1457 for (i=127;i>=ipv6prefix;i--)
1458 mask.s6_addr[i / 8] |= (1 << (i % 8));
1460 /* Pick random IPv6 address within the subnet, except 'addr' or 'mask' itself */
1465 rnd.s6_addr[i] = (unsigned char) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
1467 local_address->address.ipv6.s6_addr[i]
1468 = (addr.s6_addr[i] | rnd.s6_addr[i]) & mask.s6_addr[i];
1471 while ( (0 == memcmp (&local_address->address.ipv6,
1473 sizeof (struct in6_addr))) ||
1474 (0 == memcmp (&local_address->address.ipv6,
1476 sizeof (struct in6_addr))) );
1486 * We are starting a fresh connection (TCP or UDP) and need
1487 * to pick a source port and IP address (within the correct
1488 * range and address family) to associate replies with the
1489 * connection / correct cadet channel. This function generates
1490 * a "fresh" source IP and source port number for a connection
1491 * After picking a good source address, this function sets up
1492 * the state in the 'connections_map' and 'connections_heap'
1493 * to allow finding the state when needed later. The function
1494 * also makes sure that we remain within memory limits by
1495 * cleaning up 'old' states.
1497 * @param state skeleton state to setup a record for; should
1498 * 'state->specifics.tcp_udp.ri.remote_address' filled in so that
1499 * this code can determine which AF/protocol is
1500 * going to be used (the 'channel' should also
1501 * already be set); after calling this function,
1502 * heap_node and the local_address will be
1503 * also initialized (heap_node != NULL can be
1504 * used to test if a state has been fully setup).
1507 setup_state_record (struct ChannelState *state)
1509 struct GNUNET_HashCode key;
1510 struct ChannelState *s;
1512 /* generate fresh, unique address */
1515 if (NULL == state->specifics.tcp_udp.serv)
1516 setup_fresh_address (state->specifics.tcp_udp.ri.remote_address.af,
1517 state->specifics.tcp_udp.ri.remote_address.proto,
1518 &state->specifics.tcp_udp.ri.local_address);
1520 setup_fresh_address (state->specifics.tcp_udp.serv->address.af,
1521 state->specifics.tcp_udp.serv->address.proto,
1522 &state->specifics.tcp_udp.ri.local_address);
1523 } while (NULL != get_redirect_state (state->specifics.tcp_udp.ri.remote_address.af,
1524 state->specifics.tcp_udp.ri.remote_address.proto,
1525 &state->specifics.tcp_udp.ri.remote_address.address,
1526 state->specifics.tcp_udp.ri.remote_address.port,
1527 &state->specifics.tcp_udp.ri.local_address.address,
1528 state->specifics.tcp_udp.ri.local_address.port,
1531 char buf[INET6_ADDRSTRLEN];
1532 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1533 "Picked local address %s:%u for new connection\n",
1534 inet_ntop (state->specifics.tcp_udp.ri.local_address.af,
1535 &state->specifics.tcp_udp.ri.local_address.address,
1537 (unsigned int) state->specifics.tcp_udp.ri.local_address.port);
1539 state->specifics.tcp_udp.state_key = key;
1540 GNUNET_assert (GNUNET_OK ==
1541 GNUNET_CONTAINER_multihashmap_put (connections_map,
1543 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
1544 state->specifics.tcp_udp.heap_node = GNUNET_CONTAINER_heap_insert (connections_heap,
1546 GNUNET_TIME_absolute_get ().abs_value_us);
1547 while (GNUNET_CONTAINER_heap_get_size (connections_heap) > max_connections)
1549 s = GNUNET_CONTAINER_heap_remove_root (connections_heap);
1550 GNUNET_assert (state != s);
1551 s->specifics.tcp_udp.heap_node = NULL;
1552 GNUNET_CADET_channel_destroy (s->channel);
1553 GNUNET_assert (GNUNET_OK ==
1554 GNUNET_CONTAINER_multihashmap_remove (connections_map,
1555 &s->specifics.tcp_udp.state_key,
1563 * Prepare an IPv4 packet for transmission via the TUN interface.
1564 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1565 * For UDP, the UDP header will be fully created, whereas for TCP
1566 * only the ports and checksum will be filled in. So for TCP,
1567 * a skeleton TCP header must be part of the provided payload.
1569 * @param payload payload of the packet (starting with UDP payload or
1570 * TCP header, depending on protocol)
1571 * @param payload_length number of bytes in 'payload'
1572 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1573 * @param tcp_header skeleton of the TCP header, NULL for UDP
1574 * @param src_address source address to use (IP and port)
1575 * @param dst_address destination address to use (IP and port)
1576 * @param pkt4 where to write the assembled packet; must
1577 * contain enough space for the IP header, UDP/TCP header
1581 prepare_ipv4_packet (const void *payload, size_t payload_length,
1583 const struct GNUNET_TUN_TcpHeader *tcp_header,
1584 const struct SocketAddress *src_address,
1585 const struct SocketAddress *dst_address,
1586 struct GNUNET_TUN_IPv4Header *pkt4)
1590 len = payload_length;
1594 len += sizeof (struct GNUNET_TUN_UdpHeader);
1597 len += sizeof (struct GNUNET_TUN_TcpHeader);
1598 GNUNET_assert (NULL != tcp_header);
1604 if (len + sizeof (struct GNUNET_TUN_IPv4Header) > UINT16_MAX)
1610 GNUNET_TUN_initialize_ipv4_header (pkt4,
1613 &src_address->address.ipv4,
1614 &dst_address->address.ipv4);
1619 struct GNUNET_TUN_UdpHeader *pkt4_udp = (struct GNUNET_TUN_UdpHeader *) &pkt4[1];
1621 pkt4_udp->source_port = htons (src_address->port);
1622 pkt4_udp->destination_port = htons (dst_address->port);
1623 pkt4_udp->len = htons ((uint16_t) payload_length);
1624 GNUNET_TUN_calculate_udp4_checksum (pkt4,
1626 payload, payload_length);
1627 memcpy (&pkt4_udp[1], payload, payload_length);
1632 struct GNUNET_TUN_TcpHeader *pkt4_tcp = (struct GNUNET_TUN_TcpHeader *) &pkt4[1];
1634 *pkt4_tcp = *tcp_header;
1635 pkt4_tcp->source_port = htons (src_address->port);
1636 pkt4_tcp->destination_port = htons (dst_address->port);
1637 GNUNET_TUN_calculate_tcp4_checksum (pkt4,
1641 memcpy (&pkt4_tcp[1], payload, payload_length);
1651 * Prepare an IPv6 packet for transmission via the TUN interface.
1652 * Initializes the IP header and calculates checksums (IP+UDP/TCP).
1653 * For UDP, the UDP header will be fully created, whereas for TCP
1654 * only the ports and checksum will be filled in. So for TCP,
1655 * a skeleton TCP header must be part of the provided payload.
1657 * @param payload payload of the packet (starting with UDP payload or
1658 * TCP header, depending on protocol)
1659 * @param payload_length number of bytes in 'payload'
1660 * @param protocol IPPROTO_UDP or IPPROTO_TCP
1661 * @param tcp_header skeleton TCP header data to send, NULL for UDP
1662 * @param src_address source address to use (IP and port)
1663 * @param dst_address destination address to use (IP and port)
1664 * @param pkt6 where to write the assembled packet; must
1665 * contain enough space for the IP header, UDP/TCP header
1669 prepare_ipv6_packet (const void *payload, size_t payload_length,
1671 const struct GNUNET_TUN_TcpHeader *tcp_header,
1672 const struct SocketAddress *src_address,
1673 const struct SocketAddress *dst_address,
1674 struct GNUNET_TUN_IPv6Header *pkt6)
1678 len = payload_length;
1682 len += sizeof (struct GNUNET_TUN_UdpHeader);
1685 len += sizeof (struct GNUNET_TUN_TcpHeader);
1691 if (len > UINT16_MAX)
1697 GNUNET_TUN_initialize_ipv6_header (pkt6,
1700 &src_address->address.ipv6,
1701 &dst_address->address.ipv6);
1707 struct GNUNET_TUN_UdpHeader *pkt6_udp = (struct GNUNET_TUN_UdpHeader *) &pkt6[1];
1709 pkt6_udp->source_port = htons (src_address->port);
1710 pkt6_udp->destination_port = htons (dst_address->port);
1711 pkt6_udp->len = htons ((uint16_t) payload_length);
1712 GNUNET_TUN_calculate_udp6_checksum (pkt6,
1716 memcpy (&pkt6_udp[1], payload, payload_length);
1721 struct GNUNET_TUN_TcpHeader *pkt6_tcp = (struct GNUNET_TUN_TcpHeader *) &pkt6[1];
1723 /* memcpy first here as some TCP header fields are initialized this way! */
1724 *pkt6_tcp = *tcp_header;
1725 pkt6_tcp->source_port = htons (src_address->port);
1726 pkt6_tcp->destination_port = htons (dst_address->port);
1727 GNUNET_TUN_calculate_tcp6_checksum (pkt6,
1731 memcpy (&pkt6_tcp[1], payload, payload_length);
1742 * Send a TCP packet via the TUN interface.
1744 * @param destination_address IP and port to use for the TCP packet's destination
1745 * @param source_address IP and port to use for the TCP packet's source
1746 * @param tcp_header header template to use
1747 * @param payload payload of the TCP packet
1748 * @param payload_length number of bytes in @a payload
1751 send_tcp_packet_via_tun (const struct SocketAddress *destination_address,
1752 const struct SocketAddress *source_address,
1753 const struct GNUNET_TUN_TcpHeader *tcp_header,
1754 const void *payload, size_t payload_length)
1758 GNUNET_STATISTICS_update (stats,
1759 gettext_noop ("# TCP packets sent via TUN"),
1761 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1762 "Sending packet with %u bytes TCP payload via TUN\n",
1763 (unsigned int) payload_length);
1764 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
1765 switch (source_address->af)
1768 len += sizeof (struct GNUNET_TUN_IPv4Header);
1771 len += sizeof (struct GNUNET_TUN_IPv6Header);
1777 len += sizeof (struct GNUNET_TUN_TcpHeader);
1778 len += payload_length;
1779 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
1785 char buf[len] GNUNET_ALIGN;
1786 struct GNUNET_MessageHeader *hdr;
1787 struct GNUNET_TUN_Layer2PacketHeader *tun;
1789 hdr = (struct GNUNET_MessageHeader *) buf;
1790 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
1791 hdr->size = htons (len);
1792 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
1793 tun->flags = htons (0);
1794 switch (source_address->af)
1798 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
1800 tun->proto = htons (ETH_P_IPV4);
1801 prepare_ipv4_packet (payload, payload_length,
1805 destination_address,
1811 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
1813 tun->proto = htons (ETH_P_IPV6);
1814 prepare_ipv6_packet (payload, payload_length,
1818 destination_address,
1826 if (NULL != helper_handle)
1827 (void) GNUNET_HELPER_send (helper_handle,
1828 (const struct GNUNET_MessageHeader*) buf,
1836 * Process a request via cadet to send a request to a TCP service
1837 * offered by this system.
1839 * @param cls closure, NULL
1840 * @param channel connection to the other end
1841 * @param channel_ctx pointer to our `struct ChannelState *`
1842 * @param message the actual message
1843 * @return #GNUNET_OK to keep the connection open,
1844 * #GNUNET_SYSERR to close it (signal serious error)
1847 receive_tcp_service (void *cls,
1848 struct GNUNET_CADET_Channel *channel,
1850 const struct GNUNET_MessageHeader *message)
1852 struct ChannelState *state = *channel_ctx;
1853 const struct GNUNET_EXIT_TcpServiceStartMessage *start;
1854 uint16_t pkt_len = ntohs (message->size);
1858 GNUNET_break_op (0);
1859 return GNUNET_SYSERR;
1861 if (GNUNET_YES == state->is_dns)
1863 GNUNET_break_op (0);
1864 return GNUNET_SYSERR;
1866 if (GNUNET_SYSERR == state->is_dns)
1868 /* channel is UDP/TCP from now on */
1869 state->is_dns = GNUNET_NO;
1871 GNUNET_STATISTICS_update (stats,
1872 gettext_noop ("# TCP service creation requests received via cadet"),
1874 GNUNET_STATISTICS_update (stats,
1875 gettext_noop ("# Bytes received from CADET"),
1876 pkt_len, GNUNET_NO);
1877 /* check that we got at least a valid header */
1878 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpServiceStartMessage))
1880 GNUNET_break_op (0);
1881 return GNUNET_SYSERR;
1883 start = (const struct GNUNET_EXIT_TcpServiceStartMessage*) message;
1884 pkt_len -= sizeof (struct GNUNET_EXIT_TcpServiceStartMessage);
1885 if ( (NULL != state->specifics.tcp_udp.serv) ||
1886 (NULL != state->specifics.tcp_udp.heap_node) )
1888 GNUNET_break_op (0);
1889 return GNUNET_SYSERR;
1891 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1893 GNUNET_break_op (0);
1894 return GNUNET_SYSERR;
1896 GNUNET_break_op (ntohl (start->reserved) == 0);
1897 /* setup fresh connection */
1898 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1899 "Received data from %s for forwarding to TCP service %s on port %u\n",
1900 GNUNET_i2s (&state->peer),
1901 GNUNET_h2s (&start->service_descriptor),
1902 (unsigned int) ntohs (start->tcp_header.destination_port));
1903 if (NULL == (state->specifics.tcp_udp.serv =
1904 find_service (tcp_services,
1905 &start->service_descriptor,
1906 ntohs (start->tcp_header.destination_port))))
1908 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1909 _("No service %s found for %s on port %d!\n"),
1910 GNUNET_h2s (&start->service_descriptor),
1912 ntohs (start->tcp_header.destination_port));
1913 GNUNET_STATISTICS_update (stats,
1914 gettext_noop ("# TCP requests dropped (no such service)"),
1916 return GNUNET_SYSERR;
1918 state->specifics.tcp_udp.ri.remote_address = state->specifics.tcp_udp.serv->address;
1919 setup_state_record (state);
1920 send_tcp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
1921 &state->specifics.tcp_udp.ri.local_address,
1923 &start[1], pkt_len);
1929 * Process a request to forward TCP data to the Internet via this peer.
1931 * @param cls closure, NULL
1932 * @param channel connection to the other end
1933 * @param channel_ctx pointer to our `struct ChannelState *`
1934 * @param message the actual message
1935 * @return #GNUNET_OK to keep the connection open,
1936 * #GNUNET_SYSERR to close it (signal serious error)
1939 receive_tcp_remote (void *cls GNUNET_UNUSED,
1940 struct GNUNET_CADET_Channel *channel,
1941 void **channel_ctx GNUNET_UNUSED,
1942 const struct GNUNET_MessageHeader *message)
1944 struct ChannelState *state = *channel_ctx;
1945 const struct GNUNET_EXIT_TcpInternetStartMessage *start;
1946 uint16_t pkt_len = ntohs (message->size);
1947 const struct in_addr *v4;
1948 const struct in6_addr *v6;
1949 const void *payload;
1954 GNUNET_break_op (0);
1955 return GNUNET_SYSERR;
1957 if (GNUNET_YES == state->is_dns)
1959 GNUNET_break_op (0);
1960 return GNUNET_SYSERR;
1962 if (GNUNET_SYSERR == state->is_dns)
1964 /* channel is UDP/TCP from now on */
1965 state->is_dns = GNUNET_NO;
1967 GNUNET_STATISTICS_update (stats,
1968 gettext_noop ("# Bytes received from CADET"),
1969 pkt_len, GNUNET_NO);
1970 GNUNET_STATISTICS_update (stats,
1971 gettext_noop ("# TCP IP-exit creation requests received via cadet"),
1973 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpInternetStartMessage))
1975 GNUNET_break_op (0);
1976 return GNUNET_SYSERR;
1978 start = (const struct GNUNET_EXIT_TcpInternetStartMessage*) message;
1979 pkt_len -= sizeof (struct GNUNET_EXIT_TcpInternetStartMessage);
1980 if ( (NULL != state->specifics.tcp_udp.serv) ||
1981 (NULL != state->specifics.tcp_udp.heap_node) )
1983 GNUNET_break_op (0);
1984 return GNUNET_SYSERR;
1986 if (start->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
1988 GNUNET_break_op (0);
1989 return GNUNET_SYSERR;
1991 af = (int) ntohl (start->af);
1992 state->specifics.tcp_udp.ri.remote_address.af = af;
1996 if (pkt_len < sizeof (struct in_addr))
1998 GNUNET_break_op (0);
1999 return GNUNET_SYSERR;
2003 GNUNET_break_op (0);
2004 return GNUNET_SYSERR;
2006 v4 = (const struct in_addr*) &start[1];
2008 pkt_len -= sizeof (struct in_addr);
2009 state->specifics.tcp_udp.ri.remote_address.address.ipv4 = *v4;
2012 if (pkt_len < sizeof (struct in6_addr))
2014 GNUNET_break_op (0);
2015 return GNUNET_SYSERR;
2019 GNUNET_break_op (0);
2020 return GNUNET_SYSERR;
2022 v6 = (const struct in6_addr*) &start[1];
2024 pkt_len -= sizeof (struct in6_addr);
2025 state->specifics.tcp_udp.ri.remote_address.address.ipv6 = *v6;
2028 GNUNET_break_op (0);
2029 return GNUNET_SYSERR;
2032 char buf[INET6_ADDRSTRLEN];
2033 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2034 "Received data from %s for starting TCP stream to %s:%u\n",
2035 GNUNET_i2s (&state->peer),
2037 &state->specifics.tcp_udp.ri.remote_address.address,
2039 (unsigned int) ntohs (start->tcp_header.destination_port));
2041 state->specifics.tcp_udp.ri.remote_address.proto = IPPROTO_TCP;
2042 state->specifics.tcp_udp.ri.remote_address.port = ntohs (start->tcp_header.destination_port);
2043 setup_state_record (state);
2044 send_tcp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
2045 &state->specifics.tcp_udp.ri.local_address,
2053 * Process a request to forward TCP data on an established
2054 * connection via this peer.
2056 * @param cls closure, NULL
2057 * @param channel connection to the other end
2058 * @param channel_ctx pointer to our 'struct ChannelState *'
2059 * @param message the actual message
2060 * @return #GNUNET_OK to keep the connection open,
2061 * #GNUNET_SYSERR to close it (signal serious error)
2064 receive_tcp_data (void *cls GNUNET_UNUSED,
2065 struct GNUNET_CADET_Channel *channel,
2066 void **channel_ctx GNUNET_UNUSED,
2067 const struct GNUNET_MessageHeader *message)
2069 struct ChannelState *state = *channel_ctx;
2070 const struct GNUNET_EXIT_TcpDataMessage *data;
2071 uint16_t pkt_len = ntohs (message->size);
2073 GNUNET_STATISTICS_update (stats,
2074 gettext_noop ("# Bytes received from CADET"),
2075 pkt_len, GNUNET_NO);
2076 GNUNET_STATISTICS_update (stats,
2077 gettext_noop ("# TCP data requests received via cadet"),
2079 if (pkt_len < sizeof (struct GNUNET_EXIT_TcpDataMessage))
2081 GNUNET_break_op (0);
2082 return GNUNET_SYSERR;
2084 data = (const struct GNUNET_EXIT_TcpDataMessage*) message;
2085 pkt_len -= sizeof (struct GNUNET_EXIT_TcpDataMessage);
2086 if ( (NULL == state) ||
2087 (NULL == state->specifics.tcp_udp.heap_node) )
2089 /* connection should have been up! */
2090 GNUNET_STATISTICS_update (stats,
2091 gettext_noop ("# TCP DATA requests dropped (no session)"),
2093 GNUNET_break_op (0);
2094 return GNUNET_SYSERR;
2096 if (data->tcp_header.off * 4 < sizeof (struct GNUNET_TUN_TcpHeader))
2098 GNUNET_break_op (0);
2099 return GNUNET_SYSERR;
2101 if (GNUNET_YES == state->is_dns)
2103 GNUNET_break_op (0);
2104 return GNUNET_SYSERR;
2106 if (GNUNET_SYSERR == state->is_dns)
2108 /* channel is UDP/TCP from now on */
2109 state->is_dns = GNUNET_NO;
2112 GNUNET_break_op (ntohl (data->reserved) == 0);
2114 char buf[INET6_ADDRSTRLEN];
2115 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2116 "Received additional %u bytes of data from %s for TCP stream to %s:%u\n",
2118 GNUNET_i2s (&state->peer),
2119 inet_ntop (state->specifics.tcp_udp.ri.remote_address.af,
2120 &state->specifics.tcp_udp.ri.remote_address.address,
2122 (unsigned int) state->specifics.tcp_udp.ri.remote_address.port);
2125 send_tcp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
2126 &state->specifics.tcp_udp.ri.local_address,
2134 * Send an ICMP packet via the TUN interface.
2136 * @param destination_address IP to use for the ICMP packet's destination
2137 * @param source_address IP to use for the ICMP packet's source
2138 * @param icmp_header ICMP header to send
2139 * @param payload payload of the ICMP packet (does NOT include ICMP header)
2140 * @param payload_length number of bytes of data in @a payload
2143 send_icmp_packet_via_tun (const struct SocketAddress *destination_address,
2144 const struct SocketAddress *source_address,
2145 const struct GNUNET_TUN_IcmpHeader *icmp_header,
2146 const void *payload, size_t payload_length)
2149 struct GNUNET_TUN_IcmpHeader *icmp;
2151 GNUNET_STATISTICS_update (stats,
2152 gettext_noop ("# ICMP packets sent via TUN"),
2154 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2155 "Sending packet with %u bytes ICMP payload via TUN\n",
2156 (unsigned int) payload_length);
2157 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
2158 switch (destination_address->af)
2161 len += sizeof (struct GNUNET_TUN_IPv4Header);
2164 len += sizeof (struct GNUNET_TUN_IPv6Header);
2170 len += sizeof (struct GNUNET_TUN_IcmpHeader);
2171 len += payload_length;
2172 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2178 char buf[len] GNUNET_ALIGN;
2179 struct GNUNET_MessageHeader *hdr;
2180 struct GNUNET_TUN_Layer2PacketHeader *tun;
2182 hdr= (struct GNUNET_MessageHeader *) buf;
2183 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
2184 hdr->size = htons (len);
2185 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
2186 tun->flags = htons (0);
2187 switch (source_address->af)
2191 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
2193 tun->proto = htons (ETH_P_IPV4);
2194 GNUNET_TUN_initialize_ipv4_header (ipv4,
2196 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
2197 &source_address->address.ipv4,
2198 &destination_address->address.ipv4);
2199 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv4[1];
2204 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
2206 tun->proto = htons (ETH_P_IPV6);
2207 GNUNET_TUN_initialize_ipv6_header (ipv6,
2209 sizeof (struct GNUNET_TUN_IcmpHeader) + payload_length,
2210 &source_address->address.ipv6,
2211 &destination_address->address.ipv6);
2212 icmp = (struct GNUNET_TUN_IcmpHeader*) &ipv6[1];
2219 *icmp = *icmp_header;
2223 GNUNET_TUN_calculate_icmp_checksum (icmp,
2226 if (NULL != helper_handle)
2227 (void) GNUNET_HELPER_send (helper_handle,
2228 (const struct GNUNET_MessageHeader*) buf,
2236 * Synthesize a plausible ICMP payload for an ICMPv4 error
2237 * response on the given channel.
2239 * @param state channel information
2240 * @param ipp IPv6 header to fill in (ICMP payload)
2241 * @param udp "UDP" header to fill in (ICMP payload); might actually
2242 * also be the first 8 bytes of the TCP header
2245 make_up_icmpv4_payload (struct ChannelState *state,
2246 struct GNUNET_TUN_IPv4Header *ipp,
2247 struct GNUNET_TUN_UdpHeader *udp)
2249 GNUNET_TUN_initialize_ipv4_header (ipp,
2250 state->specifics.tcp_udp.ri.remote_address.proto,
2251 sizeof (struct GNUNET_TUN_TcpHeader),
2252 &state->specifics.tcp_udp.ri.remote_address.address.ipv4,
2253 &state->specifics.tcp_udp.ri.local_address.address.ipv4);
2254 udp->source_port = htons (state->specifics.tcp_udp.ri.remote_address.port);
2255 udp->destination_port = htons (state->specifics.tcp_udp.ri.local_address.port);
2256 udp->len = htons (0);
2257 udp->crc = htons (0);
2262 * Synthesize a plausible ICMP payload for an ICMPv6 error
2263 * response on the given channel.
2265 * @param state channel information
2266 * @param ipp IPv6 header to fill in (ICMP payload)
2267 * @param udp "UDP" header to fill in (ICMP payload); might actually
2268 * also be the first 8 bytes of the TCP header
2271 make_up_icmpv6_payload (struct ChannelState *state,
2272 struct GNUNET_TUN_IPv6Header *ipp,
2273 struct GNUNET_TUN_UdpHeader *udp)
2275 GNUNET_TUN_initialize_ipv6_header (ipp,
2276 state->specifics.tcp_udp.ri.remote_address.proto,
2277 sizeof (struct GNUNET_TUN_TcpHeader),
2278 &state->specifics.tcp_udp.ri.remote_address.address.ipv6,
2279 &state->specifics.tcp_udp.ri.local_address.address.ipv6);
2280 udp->source_port = htons (state->specifics.tcp_udp.ri.remote_address.port);
2281 udp->destination_port = htons (state->specifics.tcp_udp.ri.local_address.port);
2282 udp->len = htons (0);
2283 udp->crc = htons (0);
2288 * Process a request to forward ICMP data to the Internet via this peer.
2290 * @param cls closure, NULL
2291 * @param channel connection to the other end
2292 * @param channel_ctx pointer to our 'struct ChannelState *'
2293 * @param message the actual message
2294 * @return #GNUNET_OK to keep the connection open,
2295 * #GNUNET_SYSERR to close it (signal serious error)
2298 receive_icmp_remote (void *cls,
2299 struct GNUNET_CADET_Channel *channel,
2301 const struct GNUNET_MessageHeader *message)
2303 struct ChannelState *state = *channel_ctx;
2304 const struct GNUNET_EXIT_IcmpInternetMessage *msg;
2305 uint16_t pkt_len = ntohs (message->size);
2306 const struct in_addr *v4;
2307 const struct in6_addr *v6;
2308 const void *payload;
2309 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8] GNUNET_ALIGN;
2312 if (GNUNET_YES == state->is_dns)
2314 GNUNET_break_op (0);
2315 return GNUNET_SYSERR;
2317 if (GNUNET_SYSERR == state->is_dns)
2319 /* channel is UDP/TCP from now on */
2320 state->is_dns = GNUNET_NO;
2322 GNUNET_STATISTICS_update (stats,
2323 gettext_noop ("# Bytes received from CADET"),
2324 pkt_len, GNUNET_NO);
2325 GNUNET_STATISTICS_update (stats,
2326 gettext_noop ("# ICMP IP-exit requests received via cadet"),
2328 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpInternetMessage))
2330 GNUNET_break_op (0);
2331 return GNUNET_SYSERR;
2333 msg = (const struct GNUNET_EXIT_IcmpInternetMessage*) message;
2334 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpInternetMessage);
2336 af = (int) ntohl (msg->af);
2337 if ( (NULL != state->specifics.tcp_udp.heap_node) &&
2338 (af != state->specifics.tcp_udp.ri.remote_address.af) )
2340 /* other peer switched AF on this channel; not allowed */
2341 GNUNET_break_op (0);
2342 return GNUNET_SYSERR;
2348 if (pkt_len < sizeof (struct in_addr))
2350 GNUNET_break_op (0);
2351 return GNUNET_SYSERR;
2355 GNUNET_break_op (0);
2356 return GNUNET_SYSERR;
2358 v4 = (const struct in_addr*) &msg[1];
2360 pkt_len -= sizeof (struct in_addr);
2361 state->specifics.tcp_udp.ri.remote_address.address.ipv4 = *v4;
2362 if (NULL == state->specifics.tcp_udp.heap_node)
2364 state->specifics.tcp_udp.ri.remote_address.af = af;
2365 state->specifics.tcp_udp.ri.remote_address.proto = IPPROTO_ICMP;
2366 setup_state_record (state);
2368 /* check that ICMP type is something we want to support
2369 and possibly make up payload! */
2370 switch (msg->icmp_header.type)
2372 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2373 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2375 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2376 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2377 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2380 GNUNET_break_op (0);
2381 return GNUNET_SYSERR;
2383 /* make up payload */
2385 struct GNUNET_TUN_IPv4Header *ipp = (struct GNUNET_TUN_IPv4Header *) buf;
2386 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2388 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2389 pkt_len = sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2390 make_up_icmpv4_payload (state,
2397 GNUNET_break_op (0);
2398 GNUNET_STATISTICS_update (stats,
2399 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2401 return GNUNET_SYSERR;
2406 if (pkt_len < sizeof (struct in6_addr))
2408 GNUNET_break_op (0);
2409 return GNUNET_SYSERR;
2413 GNUNET_break_op (0);
2414 return GNUNET_SYSERR;
2416 v6 = (const struct in6_addr*) &msg[1];
2418 pkt_len -= sizeof (struct in6_addr);
2419 state->specifics.tcp_udp.ri.remote_address.address.ipv6 = *v6;
2420 if (NULL == state->specifics.tcp_udp.heap_node)
2422 state->specifics.tcp_udp.ri.remote_address.af = af;
2423 state->specifics.tcp_udp.ri.remote_address.proto = IPPROTO_ICMPV6;
2424 setup_state_record (state);
2426 /* check that ICMP type is something we want to support
2427 and possibly make up payload! */
2428 switch (msg->icmp_header.type)
2430 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2431 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2433 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2434 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2435 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2436 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2439 GNUNET_break_op (0);
2440 return GNUNET_SYSERR;
2442 /* make up payload */
2444 struct GNUNET_TUN_IPv6Header *ipp = (struct GNUNET_TUN_IPv6Header *) buf;
2445 struct GNUNET_TUN_UdpHeader *udp = (struct GNUNET_TUN_UdpHeader *) &ipp[1];
2447 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2448 pkt_len = sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2449 make_up_icmpv6_payload (state,
2456 GNUNET_break_op (0);
2457 GNUNET_STATISTICS_update (stats,
2458 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2460 return GNUNET_SYSERR;
2466 GNUNET_break_op (0);
2467 return GNUNET_SYSERR;
2471 char buf[INET6_ADDRSTRLEN];
2472 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2473 "Received ICMP data from %s for forwarding to %s\n",
2474 GNUNET_i2s (&state->peer),
2476 &state->specifics.tcp_udp.ri.remote_address.address,
2477 buf, sizeof (buf)));
2479 send_icmp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
2480 &state->specifics.tcp_udp.ri.local_address,
2488 * Setup ICMP payload for ICMP error messages. Called
2489 * for both IPv4 and IPv6 addresses.
2491 * @param state context for creating the IP Packet
2492 * @param buf where to create the payload, has at least
2493 * sizeof (struct GNUNET_TUN_IPv6Header) + 8 bytes
2494 * @return number of bytes of payload we created in buf
2497 make_up_icmp_service_payload (struct ChannelState *state,
2500 switch (state->specifics.tcp_udp.serv->address.af)
2504 struct GNUNET_TUN_IPv4Header *ipv4;
2505 struct GNUNET_TUN_UdpHeader *udp;
2507 ipv4 = (struct GNUNET_TUN_IPv4Header *)buf;
2508 udp = (struct GNUNET_TUN_UdpHeader *) &ipv4[1];
2509 make_up_icmpv4_payload (state,
2512 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2513 return sizeof (struct GNUNET_TUN_IPv4Header) + 8;
2518 struct GNUNET_TUN_IPv6Header *ipv6;
2519 struct GNUNET_TUN_UdpHeader *udp;
2521 ipv6 = (struct GNUNET_TUN_IPv6Header *)buf;
2522 udp = (struct GNUNET_TUN_UdpHeader *) &ipv6[1];
2523 make_up_icmpv6_payload (state,
2526 GNUNET_assert (8 == sizeof (struct GNUNET_TUN_UdpHeader));
2527 return sizeof (struct GNUNET_TUN_IPv6Header) + 8;
2538 * Process a request via cadet to send ICMP data to a service
2539 * offered by this system.
2541 * @param cls closure, NULL
2542 * @param channel connection to the other end
2543 * @param channel_ctx pointer to our 'struct ChannelState *'
2544 * @param message the actual message
2545 * @return #GNUNET_OK to keep the connection open,
2546 * #GNUNET_SYSERR to close it (signal serious error)
2549 receive_icmp_service (void *cls,
2550 struct GNUNET_CADET_Channel *channel,
2552 const struct GNUNET_MessageHeader *message)
2554 struct ChannelState *state = *channel_ctx;
2555 const struct GNUNET_EXIT_IcmpServiceMessage *msg;
2556 uint16_t pkt_len = ntohs (message->size);
2557 struct GNUNET_TUN_IcmpHeader icmp;
2558 char buf[sizeof (struct GNUNET_TUN_IPv6Header) + 8] GNUNET_ALIGN;
2559 const void *payload;
2561 if (GNUNET_YES == state->is_dns)
2563 GNUNET_break_op (0);
2564 return GNUNET_SYSERR;
2566 if (GNUNET_SYSERR == state->is_dns)
2568 /* channel is UDP/TCP from now on */
2569 state->is_dns = GNUNET_NO;
2571 GNUNET_STATISTICS_update (stats,
2572 gettext_noop ("# Bytes received from CADET"),
2573 pkt_len, GNUNET_NO);
2574 GNUNET_STATISTICS_update (stats,
2575 gettext_noop ("# ICMP service requests received via cadet"),
2577 /* check that we got at least a valid header */
2578 if (pkt_len < sizeof (struct GNUNET_EXIT_IcmpServiceMessage))
2580 GNUNET_break_op (0);
2581 return GNUNET_SYSERR;
2583 msg = (const struct GNUNET_EXIT_IcmpServiceMessage*) message;
2584 pkt_len -= sizeof (struct GNUNET_EXIT_IcmpServiceMessage);
2585 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2586 "Received data from %s for forwarding to ICMP service %s\n",
2587 GNUNET_i2s (&state->peer),
2588 GNUNET_h2s (&msg->service_descriptor));
2589 if (NULL == state->specifics.tcp_udp.serv)
2591 /* first packet to service must not be ICMP (cannot determine service!) */
2592 GNUNET_break_op (0);
2593 return GNUNET_SYSERR;
2595 icmp = msg->icmp_header;
2597 state->specifics.tcp_udp.ri.remote_address = state->specifics.tcp_udp.serv->address;
2598 setup_state_record (state);
2600 /* check that ICMP type is something we want to support,
2601 perform ICMP PT if needed ans possibly make up payload */
2605 switch (msg->icmp_header.type)
2607 case GNUNET_TUN_ICMPTYPE_ECHO_REPLY:
2608 if (state->specifics.tcp_udp.serv->address.af == AF_INET6)
2609 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REPLY;
2611 case GNUNET_TUN_ICMPTYPE_ECHO_REQUEST:
2612 if (state->specifics.tcp_udp.serv->address.af == AF_INET6)
2613 icmp.type = GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST;
2615 case GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE:
2616 if (state->specifics.tcp_udp.serv->address.af == AF_INET6)
2617 icmp.type = GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE;
2620 GNUNET_break_op (0);
2621 return GNUNET_SYSERR;
2624 pkt_len = make_up_icmp_service_payload (state, buf);
2626 case GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED:
2627 if (state->specifics.tcp_udp.serv->address.af == AF_INET6)
2628 icmp.type = GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED;
2631 GNUNET_break_op (0);
2632 return GNUNET_SYSERR;
2635 pkt_len = make_up_icmp_service_payload (state, buf);
2637 case GNUNET_TUN_ICMPTYPE_SOURCE_QUENCH:
2638 if (state->specifics.tcp_udp.serv->address.af == AF_INET6)
2640 GNUNET_STATISTICS_update (stats,
2641 gettext_noop ("# ICMPv4 packets dropped (impossible PT to v6)"),
2647 GNUNET_break_op (0);
2648 return GNUNET_SYSERR;
2651 pkt_len = make_up_icmp_service_payload (state, buf);
2654 GNUNET_break_op (0);
2655 GNUNET_STATISTICS_update (stats,
2656 gettext_noop ("# ICMPv4 packets dropped (type not allowed)"),
2658 return GNUNET_SYSERR;
2660 /* end of AF_INET */
2663 switch (msg->icmp_header.type)
2665 case GNUNET_TUN_ICMPTYPE6_ECHO_REPLY:
2666 if (state->specifics.tcp_udp.serv->address.af == AF_INET)
2667 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REPLY;
2669 case GNUNET_TUN_ICMPTYPE6_ECHO_REQUEST:
2670 if (state->specifics.tcp_udp.serv->address.af == AF_INET)
2671 icmp.type = GNUNET_TUN_ICMPTYPE_ECHO_REQUEST;
2673 case GNUNET_TUN_ICMPTYPE6_DESTINATION_UNREACHABLE:
2674 if (state->specifics.tcp_udp.serv->address.af == AF_INET)
2675 icmp.type = GNUNET_TUN_ICMPTYPE_DESTINATION_UNREACHABLE;
2678 GNUNET_break_op (0);
2679 return GNUNET_SYSERR;
2682 pkt_len = make_up_icmp_service_payload (state, buf);
2684 case GNUNET_TUN_ICMPTYPE6_TIME_EXCEEDED:
2685 if (state->specifics.tcp_udp.serv->address.af == AF_INET)
2686 icmp.type = GNUNET_TUN_ICMPTYPE_TIME_EXCEEDED;
2689 GNUNET_break_op (0);
2690 return GNUNET_SYSERR;
2693 pkt_len = make_up_icmp_service_payload (state, buf);
2695 case GNUNET_TUN_ICMPTYPE6_PACKET_TOO_BIG:
2696 case GNUNET_TUN_ICMPTYPE6_PARAMETER_PROBLEM:
2697 if (state->specifics.tcp_udp.serv->address.af == AF_INET)
2699 GNUNET_STATISTICS_update (stats,
2700 gettext_noop ("# ICMPv6 packets dropped (impossible PT to v4)"),
2706 GNUNET_break_op (0);
2707 return GNUNET_SYSERR;
2710 pkt_len = make_up_icmp_service_payload (state, buf);
2713 GNUNET_break_op (0);
2714 GNUNET_STATISTICS_update (stats,
2715 gettext_noop ("# ICMPv6 packets dropped (type not allowed)"),
2717 return GNUNET_SYSERR;
2719 /* end of AF_INET6 */
2722 GNUNET_break_op (0);
2723 return GNUNET_SYSERR;
2726 send_icmp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
2727 &state->specifics.tcp_udp.ri.local_address,
2735 * Send a UDP packet via the TUN interface.
2737 * @param destination_address IP and port to use for the UDP packet's destination
2738 * @param source_address IP and port to use for the UDP packet's source
2739 * @param payload payload of the UDP packet (does NOT include UDP header)
2740 * @param payload_length number of bytes of data in @a payload
2743 send_udp_packet_via_tun (const struct SocketAddress *destination_address,
2744 const struct SocketAddress *source_address,
2745 const void *payload, size_t payload_length)
2749 GNUNET_STATISTICS_update (stats,
2750 gettext_noop ("# UDP packets sent via TUN"),
2752 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2753 "Sending packet with %u bytes UDP payload via TUN\n",
2754 (unsigned int) payload_length);
2755 len = sizeof (struct GNUNET_MessageHeader) + sizeof (struct GNUNET_TUN_Layer2PacketHeader);
2756 switch (source_address->af)
2759 len += sizeof (struct GNUNET_TUN_IPv4Header);
2762 len += sizeof (struct GNUNET_TUN_IPv6Header);
2768 len += sizeof (struct GNUNET_TUN_UdpHeader);
2769 len += payload_length;
2770 if (len >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
2776 char buf[len] GNUNET_ALIGN;
2777 struct GNUNET_MessageHeader *hdr;
2778 struct GNUNET_TUN_Layer2PacketHeader *tun;
2780 hdr= (struct GNUNET_MessageHeader *) buf;
2781 hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER);
2782 hdr->size = htons (len);
2783 tun = (struct GNUNET_TUN_Layer2PacketHeader*) &hdr[1];
2784 tun->flags = htons (0);
2785 switch (source_address->af)
2789 struct GNUNET_TUN_IPv4Header * ipv4 = (struct GNUNET_TUN_IPv4Header*) &tun[1];
2791 tun->proto = htons (ETH_P_IPV4);
2792 prepare_ipv4_packet (payload, payload_length,
2796 destination_address,
2802 struct GNUNET_TUN_IPv6Header * ipv6 = (struct GNUNET_TUN_IPv6Header*) &tun[1];
2804 tun->proto = htons (ETH_P_IPV6);
2805 prepare_ipv6_packet (payload, payload_length,
2809 destination_address,
2817 if (NULL != helper_handle)
2818 (void) GNUNET_HELPER_send (helper_handle,
2819 (const struct GNUNET_MessageHeader*) buf,
2827 * Process a request to forward UDP data to the Internet via this peer.
2829 * @param cls closure, NULL
2830 * @param channel connection to the other end
2831 * @param channel_ctx pointer to our 'struct ChannelState *'
2832 * @param message the actual message
2833 * @return #GNUNET_OK to keep the connection open,
2834 * #GNUNET_SYSERR to close it (signal serious error)
2837 receive_udp_remote (void *cls,
2838 struct GNUNET_CADET_Channel *channel,
2840 const struct GNUNET_MessageHeader *message)
2842 struct ChannelState *state = *channel_ctx;
2843 const struct GNUNET_EXIT_UdpInternetMessage *msg;
2844 uint16_t pkt_len = ntohs (message->size);
2845 const struct in_addr *v4;
2846 const struct in6_addr *v6;
2847 const void *payload;
2850 if (GNUNET_YES == state->is_dns)
2852 GNUNET_break_op (0);
2853 return GNUNET_SYSERR;
2855 if (GNUNET_SYSERR == state->is_dns)
2857 /* channel is UDP/TCP from now on */
2858 state->is_dns = GNUNET_NO;
2860 GNUNET_STATISTICS_update (stats,
2861 gettext_noop ("# Bytes received from CADET"),
2862 pkt_len, GNUNET_NO);
2863 GNUNET_STATISTICS_update (stats,
2864 gettext_noop ("# UDP IP-exit requests received via cadet"),
2866 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpInternetMessage))
2868 GNUNET_break_op (0);
2869 return GNUNET_SYSERR;
2871 msg = (const struct GNUNET_EXIT_UdpInternetMessage*) message;
2872 pkt_len -= sizeof (struct GNUNET_EXIT_UdpInternetMessage);
2873 af = (int) ntohl (msg->af);
2874 state->specifics.tcp_udp.ri.remote_address.af = af;
2878 if (pkt_len < sizeof (struct in_addr))
2880 GNUNET_break_op (0);
2881 return GNUNET_SYSERR;
2885 GNUNET_break_op (0);
2886 return GNUNET_SYSERR;
2888 v4 = (const struct in_addr*) &msg[1];
2890 pkt_len -= sizeof (struct in_addr);
2891 state->specifics.tcp_udp.ri.remote_address.address.ipv4 = *v4;
2894 if (pkt_len < sizeof (struct in6_addr))
2896 GNUNET_break_op (0);
2897 return GNUNET_SYSERR;
2901 GNUNET_break_op (0);
2902 return GNUNET_SYSERR;
2904 v6 = (const struct in6_addr*) &msg[1];
2906 pkt_len -= sizeof (struct in6_addr);
2907 state->specifics.tcp_udp.ri.remote_address.address.ipv6 = *v6;
2910 GNUNET_break_op (0);
2911 return GNUNET_SYSERR;
2914 char buf[INET6_ADDRSTRLEN];
2915 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
2916 "Received data from %s for forwarding to UDP %s:%u\n",
2917 GNUNET_i2s (&state->peer),
2919 &state->specifics.tcp_udp.ri.remote_address.address,
2921 (unsigned int) ntohs (msg->destination_port));
2923 state->specifics.tcp_udp.ri.remote_address.proto = IPPROTO_UDP;
2924 state->specifics.tcp_udp.ri.remote_address.port = msg->destination_port;
2925 if (NULL == state->specifics.tcp_udp.heap_node)
2926 setup_state_record (state);
2927 if (0 != ntohs (msg->source_port))
2928 state->specifics.tcp_udp.ri.local_address.port = msg->source_port;
2929 send_udp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
2930 &state->specifics.tcp_udp.ri.local_address,
2937 * Process a request via cadet to send a request to a UDP service
2938 * offered by this system.
2940 * @param cls closure, NULL
2941 * @param channel connection to the other end
2942 * @param channel_ctx pointer to our 'struct ChannelState *'
2943 * @param message the actual message
2944 * @return #GNUNET_OK to keep the connection open,
2945 * #GNUNET_SYSERR to close it (signal serious error)
2948 receive_udp_service (void *cls,
2949 struct GNUNET_CADET_Channel *channel,
2951 const struct GNUNET_MessageHeader *message)
2953 struct ChannelState *state = *channel_ctx;
2954 const struct GNUNET_EXIT_UdpServiceMessage *msg;
2955 uint16_t pkt_len = ntohs (message->size);
2957 if (GNUNET_YES == state->is_dns)
2959 GNUNET_break_op (0);
2960 return GNUNET_SYSERR;
2962 if (GNUNET_SYSERR == state->is_dns)
2964 /* channel is UDP/TCP from now on */
2965 state->is_dns = GNUNET_NO;
2967 GNUNET_STATISTICS_update (stats,
2968 gettext_noop ("# Bytes received from CADET"),
2969 pkt_len, GNUNET_NO);
2970 GNUNET_STATISTICS_update (stats,
2971 gettext_noop ("# UDP service requests received via cadet"),
2973 /* check that we got at least a valid header */
2974 if (pkt_len < sizeof (struct GNUNET_EXIT_UdpServiceMessage))
2976 GNUNET_break_op (0);
2977 return GNUNET_SYSERR;
2979 msg = (const struct GNUNET_EXIT_UdpServiceMessage*) message;
2980 pkt_len -= sizeof (struct GNUNET_EXIT_UdpServiceMessage);
2981 LOG (GNUNET_ERROR_TYPE_DEBUG,
2982 "Received data from %s for forwarding to UDP service %s on port %u\n",
2983 GNUNET_i2s (&state->peer),
2984 GNUNET_h2s (&msg->service_descriptor),
2985 (unsigned int) ntohs (msg->destination_port));
2986 if (NULL == (state->specifics.tcp_udp.serv =
2987 find_service (udp_services,
2988 &msg->service_descriptor,
2989 ntohs (msg->destination_port))))
2991 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
2992 _("No service %s found for %s on port %d!\n"),
2993 GNUNET_h2s (&msg->service_descriptor),
2995 ntohs (msg->destination_port));
2996 GNUNET_STATISTICS_update (stats,
2997 gettext_noop ("# UDP requests dropped (no such service)"),
2999 return GNUNET_SYSERR;
3001 state->specifics.tcp_udp.ri.remote_address = state->specifics.tcp_udp.serv->address;
3002 setup_state_record (state);
3003 if (0 != ntohs (msg->source_port))
3004 state->specifics.tcp_udp.ri.local_address.port = msg->source_port;
3005 send_udp_packet_via_tun (&state->specifics.tcp_udp.ri.remote_address,
3006 &state->specifics.tcp_udp.ri.local_address,
3013 * Callback from CADET for new channels.
3015 * @param cls closure
3016 * @param channel new handle to the channel
3017 * @param initiator peer that started the channel
3018 * @param port destination port
3019 * @param options channel options flags
3020 * @return initial channel context for the channel
3023 new_channel (void *cls,
3024 struct GNUNET_CADET_Channel *channel,
3025 const struct GNUNET_PeerIdentity *initiator,
3027 enum GNUNET_CADET_ChannelOption options)
3029 struct ChannelState *s = GNUNET_new (struct ChannelState);
3031 s->is_dns = GNUNET_SYSERR;
3032 s->peer = *initiator;
3033 GNUNET_STATISTICS_update (stats,
3034 gettext_noop ("# Inbound CADET channels created"),
3036 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3037 "Received inbound channel from `%s'\n",
3038 GNUNET_i2s (initiator));
3039 s->channel = channel;
3045 * Function called by cadet whenever an inbound channel is destroyed.
3046 * Should clean up any associated state.
3048 * @param cls closure (set from #GNUNET_CADET_connect)
3049 * @param channel connection to the other end (henceforth invalid)
3050 * @param channel_ctx place where local state associated
3051 * with the channel is stored
3054 clean_channel (void *cls,
3055 const struct GNUNET_CADET_Channel *channel,
3058 struct ChannelState *s = channel_ctx;
3059 struct ChannelMessageQueue *tnq;
3061 LOG (GNUNET_ERROR_TYPE_DEBUG,
3062 "Channel destroyed\n");
3063 if (GNUNET_SYSERR == s->is_dns)
3068 if (GNUNET_YES == s->is_dns)
3070 if (channels[s->specifics.dns.my_id] == s)
3071 channels[s->specifics.dns.my_id] = NULL;
3072 GNUNET_free_non_null (s->specifics.dns.reply);
3076 while (NULL != (tnq = s->specifics.tcp_udp.head))
3078 GNUNET_CONTAINER_DLL_remove (s->specifics.tcp_udp.head,
3079 s->specifics.tcp_udp.tail,
3083 if (NULL != s->specifics.tcp_udp.heap_node)
3085 GNUNET_assert (GNUNET_YES ==
3086 GNUNET_CONTAINER_multihashmap_remove (connections_map,
3087 &s->specifics.tcp_udp.state_key,
3089 GNUNET_CONTAINER_heap_remove_node (s->specifics.tcp_udp.heap_node);
3090 s->specifics.tcp_udp.heap_node = NULL;
3095 GNUNET_CADET_notify_transmit_ready_cancel (s->th);
3103 * Function that frees everything from a hashmap
3107 * @param value value to free
3110 free_iterate (void *cls,
3111 const struct GNUNET_HashCode * hash,
3114 GNUNET_free (value);
3120 * Function scheduled as very last function if the service
3121 * disabled itself because the helper is not installed
3122 * properly. Does nothing, except for keeping the
3123 * service process alive by virtue of being scheduled.
3126 * @param tc scheduler context
3129 dummy_task (void *cls,
3130 const struct GNUNET_SCHEDULER_TaskContext *tc)
3132 /* just terminate */
3137 * Function scheduled as very last function, cleans up after us
3140 * @param tc scheduler context
3144 const struct GNUNET_SCHEDULER_TaskContext *tc)
3148 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
3149 "Exit service is shutting down now\n");
3151 if (NULL != helper_handle)
3153 GNUNET_HELPER_stop (helper_handle, GNUNET_NO);
3154 helper_handle = NULL;
3158 GNUNET_REGEX_announce_cancel (regex4);
3163 GNUNET_REGEX_announce_cancel (regex6);
3166 if (NULL != cadet_handle)
3168 GNUNET_CADET_disconnect (cadet_handle);
3169 cadet_handle = NULL;
3171 if (NULL != connections_map)
3173 GNUNET_CONTAINER_multihashmap_iterate (connections_map, &free_iterate, NULL);
3174 GNUNET_CONTAINER_multihashmap_destroy (connections_map);
3175 connections_map = NULL;
3177 if (NULL != connections_heap)
3179 GNUNET_CONTAINER_heap_destroy (connections_heap);
3180 connections_heap = NULL;
3182 if (NULL != tcp_services)
3184 GNUNET_CONTAINER_multihashmap_iterate (tcp_services, &free_service_record, NULL);
3185 GNUNET_CONTAINER_multihashmap_destroy (tcp_services);
3186 tcp_services = NULL;
3188 if (NULL != udp_services)
3190 GNUNET_CONTAINER_multihashmap_iterate (udp_services, &free_service_record, NULL);
3191 GNUNET_CONTAINER_multihashmap_destroy (udp_services);
3192 udp_services = NULL;
3194 if (NULL != dnsstub)
3196 GNUNET_DNSSTUB_stop (dnsstub);
3199 if (NULL != peer_key)
3201 GNUNET_free (peer_key);
3204 if (NULL != dht_task)
3206 GNUNET_SCHEDULER_cancel (dht_task);
3209 if (NULL != dht_put)
3211 GNUNET_DHT_put_cancel (dht_put);
3216 GNUNET_DHT_disconnect (dht);
3221 GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
3225 GNUNET_free_non_null (exit_argv[i]);
3230 * Add services to the service map.
3232 * @param proto IPPROTO_TCP or IPPROTO_UDP
3233 * @param cpy copy of the service descriptor (can be mutilated)
3234 * @param name DNS name of the service
3237 add_services (int proto,
3244 struct LocalService *serv;
3248 slen = strlen (name);
3249 GNUNET_assert (slen >= 8);
3250 n = GNUNET_strndup (name, slen - 8 /* remove .gnunet. */);
3252 for (redirect = strtok (cpy, " "); redirect != NULL;
3253 redirect = strtok (NULL, " "))
3255 if (NULL == (hostname = strstr (redirect, ":")))
3257 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3258 _("Option `%s' for domain `%s' is not formatted correctly!\n"),
3265 if (NULL == (hostport = strstr (hostname, ":")))
3267 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3268 _("Option `%s' for domain `%s' is not formatted correctly!\n"),
3276 int local_port = atoi (redirect);
3277 int remote_port = atoi (hostport);
3279 if (!((local_port > 0) && (local_port < 65536)))
3281 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3282 _("`%s' is not a valid port number (for domain `%s')!"),
3287 if (!((remote_port > 0) && (remote_port < 65536)))
3289 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3290 _("`%s' is not a valid port number (for domain `%s')!"),
3296 serv = GNUNET_new (struct LocalService);
3297 serv->address.proto = proto;
3298 serv->my_port = (uint16_t) local_port;
3299 serv->address.port = remote_port;
3300 if (0 == strcmp ("localhost4", hostname))
3302 const char *ip4addr = exit_argv[5];
3304 serv->address.af = AF_INET;
3305 GNUNET_assert (1 == inet_pton (AF_INET, ip4addr, &serv->address.address.ipv4));
3307 else if (0 == strcmp ("localhost6", hostname))
3309 const char *ip6addr = exit_argv[3];
3311 serv->address.af = AF_INET6;
3312 GNUNET_assert (1 == inet_pton (AF_INET6, ip6addr, &serv->address.address.ipv6));
3316 struct addrinfo *res;
3319 ret = getaddrinfo (hostname, NULL, NULL, &res);
3320 if ( (ret != 0) || (res == NULL) )
3322 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3323 _("No addresses found for hostname `%s' of service `%s'!\n"),
3330 serv->address.af = res->ai_family;
3331 switch (res->ai_family)
3336 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3337 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
3343 serv->address.address.ipv4 = ((struct sockaddr_in *) res->ai_addr)->sin_addr;
3348 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3349 _("Service `%s' configured for IPv4, but IPv4 is disabled!\n"),
3355 serv->address.address.ipv6 = ((struct sockaddr_in6 *) res->ai_addr)->sin6_addr;
3359 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
3360 _("No IP addresses found for hostname `%s' of service `%s'!\n"),
3368 store_service ((IPPROTO_UDP == proto) ? udp_services : tcp_services,
3378 * Reads the configuration servicecfg and populates udp_services
3381 * @param section name of section in config, equal to hostname
3384 read_service_conf (void *cls, const char *section)
3388 if ((strlen (section) < 8) ||
3389 (0 != strcmp (".gnunet.", section + (strlen (section) - 8))))
3392 GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS",
3395 add_services (IPPROTO_UDP, cpy, section);
3399 GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS",
3402 add_services (IPPROTO_TCP, cpy, section);
3409 * We are running a DNS exit service, advertise it in the
3410 * DHT. This task is run periodically to do the DHT PUT.
3412 * @param cls closure
3413 * @param tc scheduler context
3416 do_dht_put (void *cls,
3417 const struct GNUNET_SCHEDULER_TaskContext *tc);
3421 * Function called when the DHT PUT operation is complete.
3422 * Schedules the next PUT.
3424 * @param cls closure, NULL
3425 * @param success #GNUNET_OK if the operation worked (unused)
3428 dht_put_cont (void *cls,
3432 dht_task = GNUNET_SCHEDULER_add_delayed (DHT_PUT_FREQUENCY,
3439 * We are running a DNS exit service, advertise it in the
3440 * DHT. This task is run periodically to do the DHT PUT.
3442 * @param cls closure
3443 * @param tc scheduler context
3446 do_dht_put (void *cls,
3447 const struct GNUNET_SCHEDULER_TaskContext *tc)
3449 struct GNUNET_TIME_Absolute expiration;
3452 expiration = GNUNET_TIME_absolute_ntoh (dns_advertisement.expiration_time);
3453 if (GNUNET_TIME_absolute_get_remaining (expiration).rel_value_us <
3454 GNUNET_TIME_UNIT_HOURS.rel_value_us)
3456 /* refresh advertisement */
3457 expiration = GNUNET_TIME_relative_to_absolute (DNS_ADVERTISEMENT_TIMEOUT);
3458 dns_advertisement.expiration_time = GNUNET_TIME_absolute_hton (expiration);
3459 GNUNET_assert (GNUNET_OK ==
3460 GNUNET_CRYPTO_eddsa_sign (peer_key,
3461 &dns_advertisement.purpose,
3462 &dns_advertisement.signature));
3464 dht_put = GNUNET_DHT_put (dht,
3466 1 /* replication */,
3468 GNUNET_BLOCK_TYPE_DNS,
3469 sizeof (struct GNUNET_DNS_Advertisement),
3472 GNUNET_TIME_UNIT_FOREVER_REL,
3473 &dht_put_cont, NULL);
3478 * @brief Main function that will be run by the scheduler.
3480 * @param cls closure
3481 * @param args remaining command-line arguments
3482 * @param cfgfile name of the configuration file used (for saving, can be NULL!)
3483 * @param cfg_ configuration
3488 const char *cfgfile,
3489 const struct GNUNET_CONFIGURATION_Handle *cfg_)
3491 static struct GNUNET_CADET_MessageHandler handlers[] = {
3492 {&receive_icmp_service, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_SERVICE, 0},
3493 {&receive_icmp_remote, GNUNET_MESSAGE_TYPE_VPN_ICMP_TO_INTERNET, 0},
3494 {&receive_udp_service, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_SERVICE, 0},
3495 {&receive_udp_remote, GNUNET_MESSAGE_TYPE_VPN_UDP_TO_INTERNET, 0},
3496 {&receive_tcp_service, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_SERVICE_START, 0},
3497 {&receive_tcp_remote, GNUNET_MESSAGE_TYPE_VPN_TCP_TO_INTERNET_START, 0},
3498 {&receive_tcp_data, GNUNET_MESSAGE_TYPE_VPN_TCP_DATA_TO_EXIT, 0},
3499 {&receive_dns_request, GNUNET_MESSAGE_TYPE_VPN_DNS_TO_INTERNET, 0},
3503 static uint32_t apptypes[] = {
3504 GNUNET_APPLICATION_TYPE_END,
3505 GNUNET_APPLICATION_TYPE_END,
3506 GNUNET_APPLICATION_TYPE_END,
3507 GNUNET_APPLICATION_TYPE_END
3509 unsigned int app_idx;
3519 char *prefixed_regex;
3520 struct in_addr dns_exit4;
3521 struct in6_addr dns_exit6;
3525 ipv4_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV4");
3526 ipv6_exit = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "EXIT_IPV6");
3527 ipv4_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV4");
3528 ipv6_enabled = GNUNET_CONFIGURATION_get_value_yesno (cfg, "exit", "ENABLE_IPV6");
3529 if ( (ipv4_exit) || (ipv6_exit) )
3531 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-exit");
3533 GNUNET_OS_check_helper_binary (binary, GNUNET_YES, "-d gnunet-vpn - - - 169.1.3.3.7 255.255.255.0")) //no nat, ipv4 only
3535 GNUNET_free (binary);
3536 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3537 _("`%s' must be installed SUID, EXIT will not work\n"),
3538 "gnunet-helper-exit");
3539 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
3545 GNUNET_free (binary);
3547 stats = GNUNET_STATISTICS_create ("exit", cfg);
3549 if ( (ipv4_exit || ipv4_enabled) &&
3550 GNUNET_OK != GNUNET_NETWORK_test_pf (PF_INET))
3552 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3553 _("This system does not support IPv4, will disable IPv4 functions despite them being enabled in the configuration\n"));
3554 ipv4_exit = GNUNET_NO;
3555 ipv4_enabled = GNUNET_NO;
3557 if ( (ipv6_exit || ipv6_enabled) &&
3558 GNUNET_OK != GNUNET_NETWORK_test_pf (PF_INET6))
3560 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3561 _("This system does not support IPv6, will disable IPv6 functions despite them being enabled in the configuration\n"));
3562 ipv6_exit = GNUNET_NO;
3563 ipv6_enabled = GNUNET_NO;
3565 if (ipv4_exit && (! ipv4_enabled))
3567 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3568 _("Cannot enable IPv4 exit but disable IPv4 on TUN interface, will use ENABLE_IPv4=YES\n"));
3569 ipv4_enabled = GNUNET_YES;
3571 if (ipv6_exit && (! ipv6_enabled))
3573 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3574 _("Cannot enable IPv6 exit but disable IPv6 on TUN interface, will use ENABLE_IPv6=YES\n"));
3575 ipv6_enabled = GNUNET_YES;
3577 if (! (ipv4_enabled || ipv6_enabled))
3579 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3580 _("No useful service enabled. Exiting.\n"));
3581 GNUNET_SCHEDULER_shutdown ();
3587 GNUNET_CONFIGURATION_get_value_yesno (cfg_, "exit", "EXIT_DNS")) &&
3589 GNUNET_CONFIGURATION_get_value_string (cfg, "exit",
3592 ( (1 != inet_pton (AF_INET, dns_exit, &dns_exit4)) &&
3593 (1 != inet_pton (AF_INET6, dns_exit, &dns_exit6)) ) ) )
3595 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
3596 "dns", "DNS_RESOLVER",
3597 _("need a valid IPv4 or IPv6 address\n"));
3598 GNUNET_free_non_null (dns_exit);
3602 if (GNUNET_YES == ipv4_exit)
3604 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV4_GATEWAY;
3607 if (GNUNET_YES == ipv6_exit)
3609 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_IPV6_GATEWAY;
3612 if (NULL != dns_exit)
3614 dht = GNUNET_DHT_connect (cfg, 1);
3615 peer_key = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
3616 GNUNET_CRYPTO_eddsa_key_get_public (peer_key,
3617 &dns_advertisement.peer.public_key);
3618 dns_advertisement.purpose.size = htonl (sizeof (struct GNUNET_DNS_Advertisement) -
3619 sizeof (struct GNUNET_CRYPTO_EddsaSignature));
3620 dns_advertisement.purpose.purpose = htonl (GNUNET_SIGNATURE_PURPOSE_DNS_RECORD);
3621 GNUNET_CRYPTO_hash ("dns",
3624 dht_task = GNUNET_SCHEDULER_add_now (&do_dht_put,
3626 apptypes[app_idx] = GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER;
3629 GNUNET_free_non_null (dns_exit);
3630 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
3635 GNUNET_CONFIGURATION_get_value_number (cfg, "exit", "MAX_CONNECTIONS",
3637 max_connections = 1024;
3638 exit_argv[0] = GNUNET_strdup ("exit-gnunet");
3639 if (GNUNET_SYSERR ==
3640 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "TUN_IFNAME", &tun_ifname))
3642 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "TUN_IFNAME");
3643 GNUNET_SCHEDULER_shutdown ();
3646 exit_argv[1] = tun_ifname;
3649 if (GNUNET_SYSERR ==
3650 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "EXIT_IFNAME", &exit_ifname))
3652 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "EXIT_IFNAME");
3653 GNUNET_SCHEDULER_shutdown ();
3656 exit_argv[2] = exit_ifname;
3660 exit_argv[2] = GNUNET_strdup ("-");
3664 if (GNUNET_YES == ipv6_enabled)
3666 if ( (GNUNET_SYSERR ==
3667 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6ADDR",
3669 (1 != inet_pton (AF_INET6, ipv6addr, &exit_ipv6addr))) )
3671 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "IPV6ADDR");
3672 GNUNET_SCHEDULER_shutdown ();
3675 exit_argv[3] = ipv6addr;
3676 if (GNUNET_SYSERR ==
3677 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV6PREFIX",
3680 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "IPV6PREFIX");
3681 GNUNET_SCHEDULER_shutdown ();
3684 exit_argv[4] = ipv6prefix_s;
3686 GNUNET_CONFIGURATION_get_value_number (cfg, "exit",
3689 (ipv6prefix >= 127) )
3691 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, "EXIT", "IPV6PREFIX",
3692 _("Must be a number"));
3693 GNUNET_SCHEDULER_shutdown ();
3699 /* IPv6 explicitly disabled */
3700 exit_argv[3] = GNUNET_strdup ("-");
3701 exit_argv[4] = GNUNET_strdup ("-");
3703 if (GNUNET_YES == ipv4_enabled)
3705 if ( (GNUNET_SYSERR ==
3706 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4ADDR",
3708 (1 != inet_pton (AF_INET, ipv4addr, &exit_ipv4addr))) )
3710 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "IPV4ADDR");
3711 GNUNET_SCHEDULER_shutdown ();
3714 exit_argv[5] = ipv4addr;
3716 if ( (GNUNET_SYSERR ==
3717 GNUNET_CONFIGURATION_get_value_string (cfg, "exit", "IPV4MASK",
3719 (1 != inet_pton (AF_INET, ipv4mask, &exit_ipv4mask))) )
3721 GNUNET_log_config_missing (GNUNET_ERROR_TYPE_ERROR, "EXIT", "IPV4MASK");
3722 GNUNET_SCHEDULER_shutdown ();
3723 GNUNET_free_non_null (ipv4mask);
3726 exit_argv[6] = ipv4mask;
3730 /* IPv4 explicitly disabled */
3731 exit_argv[5] = GNUNET_strdup ("-");
3732 exit_argv[6] = GNUNET_strdup ("-");
3734 exit_argv[7] = NULL;
3736 udp_services = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
3737 tcp_services = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
3738 GNUNET_CONFIGURATION_iterate_sections (cfg, &read_service_conf, NULL);
3740 connections_map = GNUNET_CONTAINER_multihashmap_create (65536, GNUNET_NO);
3741 connections_heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
3744 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
3745 _("No useful service enabled. Exiting.\n"));
3746 GNUNET_SCHEDULER_shutdown ();
3750 = GNUNET_CADET_connect (cfg, NULL,
3752 &clean_channel, handlers,
3754 if (NULL == cadet_handle)
3756 GNUNET_SCHEDULER_shutdown ();
3760 /* Cadet handle acquired, now announce regular expressions matching our exit */
3761 if ( (GNUNET_YES == ipv4_enabled) && (GNUNET_YES == ipv4_exit) )
3765 GNUNET_CONFIGURATION_get_value_string (cfg,
3767 "EXIT_RANGE_IPV4_POLICY",
3771 regex = GNUNET_TUN_ipv4policy2regex (policy);
3772 GNUNET_free_non_null (policy);
3775 (void) GNUNET_asprintf (&prefixed_regex,
3777 GNUNET_APPLICATION_TYPE_EXIT_REGEX_PREFIX,
3779 regex4 = GNUNET_REGEX_announce (cfg,
3781 REGEX_REFRESH_FREQUENCY,
3782 REGEX_MAX_PATH_LEN_IPV4);
3783 GNUNET_free (regex);
3784 GNUNET_free (prefixed_regex);
3788 if (GNUNET_YES == ipv6_enabled && GNUNET_YES == ipv6_exit)
3792 GNUNET_CONFIGURATION_get_value_string (cfg,
3794 "EXIT_RANGE_IPV6_POLICY",
3798 regex = GNUNET_TUN_ipv6policy2regex (policy);
3799 GNUNET_free_non_null (policy);
3802 (void) GNUNET_asprintf (&prefixed_regex,
3804 GNUNET_APPLICATION_TYPE_EXIT_REGEX_PREFIX,
3806 regex6 = GNUNET_REGEX_announce (cfg,
3808 REGEX_REFRESH_FREQUENCY,
3809 REGEX_MAX_PATH_LEN_IPV6);
3810 GNUNET_free (regex);
3811 GNUNET_free (prefixed_regex);
3814 if ((ipv4_exit) || (ipv6_exit))
3815 helper_handle = GNUNET_HELPER_start (GNUNET_NO,
3816 "gnunet-helper-exit",
3826 * @param argc number of arguments from the command line
3827 * @param argv command line arguments
3828 * @return 0 ok, 1 on error
3831 main (int argc, char *const *argv)
3833 static const struct GNUNET_GETOPT_CommandLineOption options[] = {
3834 GNUNET_GETOPT_OPTION_END
3837 if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, &argc, &argv))
3840 return (GNUNET_OK ==
3841 GNUNET_PROGRAM_run (argc, argv, "gnunet-daemon-exit",
3843 ("Daemon to run to provide an IP exit node for the VPN"),
3844 options, &run, NULL)) ? global_ret : 1;
3848 /* end of gnunet-daemon-exit.c */