2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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6 it under the terms of the GNU General Public License as published
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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23 * @brief Library handling UPnP and NAT-PMP port forwarding and
24 * external IP address retrieval
25 * @author Milan Bouchet-Valat
26 * @author Christian Grothoff
29 #include "gnunet_util_lib.h"
30 #include "gnunet_resolver_service.h"
31 #include "gnunet_nat_lib.h"
33 #define DEBUG_NAT GNUNET_NO
36 * How often do we scan for changes in our IP address from our local
39 #define IFC_SCAN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
42 * How often do we scan for changes in how our hostname resolves?
44 #define HOSTNAME_DNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 20)
48 * How often do we scan for changes in how our external (dyndns) hostname resolves?
50 #define DYNDNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 7)
53 * How long until we give up trying to resolve our own hostname?
55 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
59 * Where did the given local address originate from?
60 * To be used for debugging as well as in the future
61 * to remove all addresses from a certain source when
62 * we reevaluate the source.
64 enum LocalAddressSource
67 * Address was obtained by DNS resolution of the external hostname
68 * given in the configuration (i.e. hole-punched DynDNS setup).
73 * Address was obtained by looking up our own hostname in DNS.
78 * Address was obtained by scanning our hosts's network interfaces
79 * and taking their address (no DNS involved).
81 LAL_INTERFACE_ADDRESS,
84 * Addresses we were explicitly bound to.
89 * Addresses from UPnP or PMP
101 * List of local addresses that we currently deem valid. Actual
102 * struct is followed by the 'struct sockaddr'. Note that the code
103 * intentionally makes no attempt to ensure that a particular address
104 * is only listed once (especially since it may come from different
105 * sources, and the source is an "internal" construct).
107 struct LocalAddressList
110 * This is a linked list.
112 struct LocalAddressList *next;
117 struct LocalAddressList *prev;
120 * Number of bytes of address that follow.
125 * Origin of the local address.
127 enum LocalAddressSource source;
132 * Handle for miniupnp-based NAT traversal actions.
138 * Doubly-linked list.
140 struct MiniList *next;
143 * Doubly-linked list.
145 struct MiniList *prev;
148 * Handle to mini-action.
150 struct GNUNET_NAT_MiniHandle *mini;
153 * Local port number that was mapped.
161 * Handle for active NAT registrations.
163 struct GNUNET_NAT_Handle
167 * Configuration to use.
169 const struct GNUNET_CONFIGURATION_Handle *cfg;
172 * Function to call when we learn about a new address.
174 GNUNET_NAT_AddressCallback address_callback;
177 * Function to call when we notice another peer asking for
178 * connection reversal.
180 GNUNET_NAT_ReversalCallback reversal_callback;
183 * Closure for 'callback'.
188 * Handle for (DYN)DNS lookup of our external IP.
190 struct GNUNET_RESOLVER_RequestHandle *ext_dns;
193 * Handle for request of hostname resolution, non-NULL if pending.
195 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
198 * stdout pipe handle for the gnunet-helper-nat-server process
200 struct GNUNET_DISK_PipeHandle *server_stdout;
203 * stdout file handle (for reading) for the gnunet-helper-nat-server process
205 const struct GNUNET_DISK_FileHandle *server_stdout_handle;
208 * Linked list of currently valid addresses (head).
210 struct LocalAddressList *lal_head;
213 * Linked list of currently valid addresses (tail).
215 struct LocalAddressList *lal_tail;
218 * How long do we wait for restarting a crashed gnunet-helper-nat-server?
220 struct GNUNET_TIME_Relative server_retry_delay;
223 * ID of select gnunet-helper-nat-server stdout read task
225 GNUNET_SCHEDULER_TaskIdentifier server_read_task;
228 * ID of interface IP-scan task
230 GNUNET_SCHEDULER_TaskIdentifier ifc_task;
233 * ID of hostname DNS lookup task
235 GNUNET_SCHEDULER_TaskIdentifier hostname_task;
238 * ID of DynDNS lookup task
240 GNUNET_SCHEDULER_TaskIdentifier dns_task;
243 * ID of task to add addresses from bind.
245 GNUNET_SCHEDULER_TaskIdentifier bind_task;
248 * How often do we scan for changes in our IP address from our local
251 struct GNUNET_TIME_Relative ifc_scan_frequency;
254 * How often do we scan for changes in how our hostname resolves?
256 struct GNUNET_TIME_Relative hostname_dns_frequency;
259 * How often do we scan for changes in how our external (dyndns) hostname resolves?
261 struct GNUNET_TIME_Relative dyndns_frequency;
264 * The process id of the server process (if behind NAT)
266 struct GNUNET_OS_Process *server_proc;
269 * LAN address as passed by the caller (array).
271 struct sockaddr **local_addrs;
274 * Length of the 'local_addrs'.
276 socklen_t *local_addrlens;
279 * List of handles for UPnP-traversal, one per local port (if
282 struct MiniList *mini_head;
285 * List of handles for UPnP-traversal, one per local port (if
288 struct MiniList *mini_tail;
291 * Number of entries in 'local_addrs' array.
293 unsigned int num_local_addrs;
296 * The our external address (according to config, UPnP may disagree...)
298 char *external_address;
301 * Presumably our internal address (according to config)
303 char *internal_address;
306 * Is this transport configured to be behind a NAT?
311 * Has the NAT been punched? (according to config)
316 * Is this transport configured to allow connections to NAT'd peers?
318 int enable_nat_client;
321 * Should we run the gnunet-helper-nat-server?
323 int enable_nat_server;
326 * Are we allowed to try UPnP/PMP for NAT traversal?
331 * Should we use local addresses (loopback)? (according to config)
333 int use_localaddresses;
336 * Should we do a DNS lookup of our hostname to find out our own IP?
341 * Is using IPv6 disabled?
346 * Is this TCP or UDP?
351 * Port we advertise to the outside.
359 * Try to start the gnunet-helper-nat-server (if it is not
362 * @param h handle to NAT
364 static void start_gnunet_nat_server (struct GNUNET_NAT_Handle *h);
368 * Remove all addresses from the list of 'local' addresses
369 * that originated from the given source.
371 * @param plugin the plugin
372 * @param src source that identifies addresses to remove
375 remove_from_address_list_by_source (struct GNUNET_NAT_Handle *h,
376 enum LocalAddressSource src)
378 struct LocalAddressList *pos;
379 struct LocalAddressList *next;
382 while (NULL != (pos = next))
385 if (pos->source != src)
387 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
388 if (NULL != h->address_callback)
389 h->address_callback (h->callback_cls,
391 (const struct sockaddr *) &pos[1], pos->addrlen);
398 * Add the given address to the list of 'local' addresses, thereby
399 * making it a 'legal' address for this peer to have.
401 * @param plugin the plugin
402 * @param src where did the local address originate from?
403 * @param arg the address, some 'struct sockaddr'
404 * @param arg_size number of bytes in arg
407 add_to_address_list_as_is (struct GNUNET_NAT_Handle *h,
408 enum LocalAddressSource src,
409 const struct sockaddr *arg, socklen_t arg_size)
411 struct LocalAddressList *lal;
413 lal = GNUNET_malloc (sizeof (struct LocalAddressList) + arg_size);
414 memcpy (&lal[1], arg, arg_size);
415 lal->addrlen = arg_size;
417 GNUNET_CONTAINER_DLL_insert (h->lal_head, h->lal_tail, lal);
419 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
421 "Adding address `%s' from source %d\n",
422 GNUNET_a2s (arg, arg_size), src);
424 if (NULL != h->address_callback)
425 h->address_callback (h->callback_cls, GNUNET_YES, arg, arg_size);
430 * Add the given address to the list of 'local' addresses, thereby
431 * making it a 'legal' address for this peer to have. Set the
432 * port number in the process to the advertised port and possibly
433 * also to zero (if we have the gnunet-helper-nat-server).
435 * @param plugin the plugin
436 * @param src where did the local address originate from?
437 * @param arg the address, some 'struct sockaddr'
438 * @param arg_size number of bytes in arg
441 add_to_address_list (struct GNUNET_NAT_Handle *h,
442 enum LocalAddressSource src,
443 const struct sockaddr *arg, socklen_t arg_size)
445 struct sockaddr_in s4;
446 const struct sockaddr_in *in4;
447 struct sockaddr_in6 s6;
448 const struct sockaddr_in6 *in6;
450 if (arg_size == sizeof (struct sockaddr_in))
452 in4 = (const struct sockaddr_in *) arg;
454 s4.sin_port = htons (h->adv_port);
455 add_to_address_list_as_is (h,
457 (const struct sockaddr *) &s4,
458 sizeof (struct sockaddr_in));
459 if (GNUNET_YES == h->enable_nat_server)
461 /* also add with PORT = 0 to indicate NAT server is enabled */
462 s4.sin_port = htons (0);
463 add_to_address_list_as_is (h,
465 (const struct sockaddr *) &s4,
466 sizeof (struct sockaddr_in));
469 else if (arg_size == sizeof (struct sockaddr_in6))
471 if (GNUNET_YES != h->disable_ipv6)
473 in6 = (const struct sockaddr_in6 *) arg;
475 s6.sin6_port = htons (h->adv_port);
476 add_to_address_list_as_is (h,
478 (const struct sockaddr *) &s6,
479 sizeof (struct sockaddr_in6));
490 * Add the given IP address to the list of 'local' addresses, thereby
491 * making it a 'legal' address for this peer to have.
493 * @param plugin the plugin
494 * @param src where did the local address originate from?
495 * @param arg the address, some 'struct in_addr' or 'struct in6_addr'
496 * @param arg_size number of bytes in arg
499 add_ip_to_address_list (struct GNUNET_NAT_Handle *h,
500 enum LocalAddressSource src,
501 const void *addr, socklen_t addrlen)
503 struct sockaddr_in s4;
504 const struct in_addr *in4;
505 struct sockaddr_in6 s6;
506 const struct in6_addr *in6;
508 if (addrlen == sizeof (struct in_addr))
510 in4 = (const struct in_addr *) addr;
511 memset (&s4, 0, sizeof (s4));
512 s4.sin_family = AF_INET;
514 #if HAVE_SOCKADDR_IN_SIN_LEN
515 s4.sin_len = (u_char) sizeof (struct sockaddr_in);
518 add_to_address_list (h,
520 (const struct sockaddr *) &s4,
521 sizeof (struct sockaddr_in));
522 if (GNUNET_YES == h->enable_nat_server)
524 /* also add with PORT = 0 to indicate NAT server is enabled */
525 s4.sin_port = htons (0);
526 add_to_address_list (h,
528 (const struct sockaddr *) &s4,
529 sizeof (struct sockaddr_in));
533 else if (addrlen == sizeof (struct in6_addr))
535 if (GNUNET_YES != h->disable_ipv6)
537 in6 = (const struct in6_addr *) addr;
538 memset (&s6, 0, sizeof (s6));
539 s6.sin6_family = AF_INET6;
540 s6.sin6_port = htons (h->adv_port);
541 #if HAVE_SOCKADDR_IN_SIN_LEN
542 s6.sin6_len = (u_char) sizeof (struct sockaddr_in6);
545 add_to_address_list (h,
547 (const struct sockaddr *) &s6,
548 sizeof (struct sockaddr_in6));
559 * Task to do DNS lookup on our external hostname to
560 * get DynDNS-IP addresses.
562 * @param cls the NAT handle
563 * @param tc scheduler context
566 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
570 * Our (external) hostname was resolved and the configuration says that
571 * the NAT was hole-punched.
573 * @param cls the 'struct Plugin'
574 * @param addr NULL on error, otherwise result of DNS lookup
575 * @param addrlen number of bytes in addr
578 process_external_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
580 struct GNUNET_NAT_Handle *h = cls;
581 struct in_addr dummy;
586 if (1 == inet_pton (AF_INET, h->external_address, &dummy))
587 return; /* repated lookup pointless: was numeric! */
588 h->dns_task = GNUNET_SCHEDULER_add_delayed (h->dyndns_frequency,
592 add_to_address_list (h, LAL_EXTERNAL_IP, addr, addrlen);
597 * Task to do a lookup on our hostname for IP addresses.
599 * @param cls the NAT handle
600 * @param tc scheduler context
603 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
607 * Function called by the resolver for each address obtained from DNS
608 * for our own hostname. Add the addresses to the list of our IP
612 * @param addr one of the addresses of the host, NULL for the last address
613 * @param addrlen length of the address
616 process_hostname_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
618 struct GNUNET_NAT_Handle *h = cls;
622 h->hostname_dns = NULL;
623 h->hostname_task = GNUNET_SCHEDULER_add_delayed (h->hostname_dns_frequency,
624 &resolve_hostname, h);
627 add_to_address_list (h, LAL_HOSTNAME_DNS, addr, addrlen);
632 * Add the IP of our network interface to the list of
635 * @param cls the 'struct GNUNET_NAT_Handle'
636 * @param name name of the interface
637 * @param isDefault do we think this may be our default interface
638 * @param addr address of the interface
639 * @param addrlen number of bytes in addr
640 * @return GNUNET_OK to continue iterating
643 process_interfaces (void *cls,
646 const struct sockaddr *addr, socklen_t addrlen)
648 struct GNUNET_NAT_Handle *h = cls;
649 const struct sockaddr_in *s4;
650 const struct sockaddr_in6 *s6;
652 char buf[INET6_ADDRSTRLEN];
654 switch (addr->sa_family)
657 s4 = (struct sockaddr_in *) addr;
659 if (GNUNET_YES == h->use_localaddresses)
660 add_ip_to_address_list (h,
661 LAL_INTERFACE_ADDRESS,
662 &s4->sin_addr, sizeof (struct in_addr));
665 s6 = (struct sockaddr_in6 *) addr;
666 if (IN6_IS_ADDR_LINKLOCAL (&((struct sockaddr_in6 *) addr)->sin6_addr))
668 /* skip link local addresses */
672 if (GNUNET_YES == h->use_localaddresses)
673 add_ip_to_address_list (h,
674 LAL_INTERFACE_ADDRESS,
675 &s6->sin6_addr, sizeof (struct in6_addr));
681 if ((h->internal_address == NULL) &&
682 (h->server_proc == NULL) &&
683 (h->server_read_task == GNUNET_SCHEDULER_NO_TASK) &&
684 (GNUNET_YES == isDefault) &&
685 ((addr->sa_family == AF_INET) || (addr->sa_family == AF_INET6)))
687 /* no internal address configured, but we found a "default"
688 * interface, try using that as our 'internal' address */
689 h->internal_address = GNUNET_strdup (inet_ntop (addr->sa_family,
690 ip, buf, sizeof (buf)));
691 start_gnunet_nat_server (h);
698 * Task that restarts the gnunet-helper-nat-server process after a crash
699 * after a certain delay.
701 * @param cls the 'struct GNUNET_NAT_Handle'
702 * @param tc scheduler context
705 restart_nat_server (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
707 struct GNUNET_NAT_Handle *h = cls;
709 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
710 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
712 start_gnunet_nat_server (h);
717 * We have been notified that gnunet-helper-nat-server has written something to stdout.
718 * Handle the output, then reschedule this function to be called again once
721 * @param cls the NAT handle
722 * @param tc the scheduling context
725 nat_server_read (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
727 struct GNUNET_NAT_Handle *h = cls;
732 const char *port_start;
733 struct sockaddr_in sin_addr;
735 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
736 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
738 memset (mybuf, 0, sizeof (mybuf));
739 bytes = GNUNET_DISK_file_read (h->server_stdout_handle,
740 mybuf, sizeof (mybuf));
744 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
746 "Finished reading from server stdout with code: %d\n",
749 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
750 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
751 GNUNET_OS_process_wait (h->server_proc);
752 GNUNET_OS_process_close (h->server_proc);
753 h->server_proc = NULL;
754 GNUNET_DISK_pipe_close (h->server_stdout);
755 h->server_stdout = NULL;
756 h->server_stdout_handle = NULL;
757 /* now try to restart it */
758 h->server_retry_delay =
759 GNUNET_TIME_relative_multiply (h->server_retry_delay, 2);
760 h->server_retry_delay =
761 GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_HOURS,
762 h->server_retry_delay);
763 h->server_read_task =
764 GNUNET_SCHEDULER_add_delayed (h->server_retry_delay,
765 &restart_nat_server, h);
770 for (i = 0; i < sizeof (mybuf); i++)
772 if (mybuf[i] == '\n')
777 if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf)))
780 port_start = &mybuf[i + 1];
784 /* construct socket address of sender */
785 memset (&sin_addr, 0, sizeof (sin_addr));
786 sin_addr.sin_family = AF_INET;
787 #if HAVE_SOCKADDR_IN_SIN_LEN
788 sin_addr.sin_len = sizeof (sin_addr);
790 if ((NULL == port_start) ||
791 (1 != sscanf (port_start, "%d", &port)) ||
792 (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr)))
794 /* should we restart gnunet-helper-nat-server? */
795 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
798 ("gnunet-helper-nat-server generated malformed address `%s'\n"),
800 h->server_read_task =
801 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
802 h->server_stdout_handle,
803 &nat_server_read, h);
806 sin_addr.sin_port = htons ((uint16_t) port);
808 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
810 "gnunet-helper-nat-server read: %s:%d\n", mybuf, port);
812 h->reversal_callback (h->callback_cls,
813 (const struct sockaddr *) &sin_addr, sizeof (sin_addr));
814 h->server_read_task =
815 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
816 h->server_stdout_handle,
817 &nat_server_read, h);
822 * Try to start the gnunet-helper-nat-server (if it is not
825 * @param h handle to NAT
828 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h)
830 if ((h->behind_nat == GNUNET_YES) &&
831 (h->enable_nat_server == GNUNET_YES) &&
832 (h->internal_address != NULL) &&
833 (NULL != (h->server_stdout = GNUNET_DISK_pipe (GNUNET_YES,
834 GNUNET_NO, GNUNET_YES))))
837 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
839 "Starting %s at `%s'\n",
840 "gnunet-helper-nat-server", h->internal_address);
842 /* Start the server process */
843 h->server_proc = GNUNET_OS_start_process (NULL,
845 "gnunet-helper-nat-server",
846 "gnunet-helper-nat-server",
847 h->internal_address, NULL);
848 if (h->server_proc == NULL)
850 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
852 _("Failed to start %s\n"), "gnunet-helper-nat-server");
853 GNUNET_DISK_pipe_close (h->server_stdout);
854 h->server_stdout = NULL;
858 /* Close the write end of the read pipe */
859 GNUNET_DISK_pipe_close_end (h->server_stdout, GNUNET_DISK_PIPE_END_WRITE);
860 h->server_stdout_handle
861 = GNUNET_DISK_pipe_handle (h->server_stdout,
862 GNUNET_DISK_PIPE_END_READ);
864 = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
865 h->server_stdout_handle,
866 &nat_server_read, h);
873 * Task to scan the local network interfaces for IP addresses.
875 * @param cls the NAT handle
876 * @param tc scheduler context
879 list_interfaces (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
881 struct GNUNET_NAT_Handle *h = cls;
883 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
884 remove_from_address_list_by_source (h, LAL_INTERFACE_ADDRESS);
885 GNUNET_OS_network_interfaces_list (&process_interfaces, h);
886 h->ifc_task = GNUNET_SCHEDULER_add_delayed (h->ifc_scan_frequency,
887 &list_interfaces, h);
892 * Task to do a lookup on our hostname for IP addresses.
894 * @param cls the NAT handle
895 * @param tc scheduler context
898 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
900 struct GNUNET_NAT_Handle *h = cls;
902 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
903 remove_from_address_list_by_source (h, LAL_HOSTNAME_DNS);
904 h->hostname_dns = GNUNET_RESOLVER_hostname_resolve (AF_UNSPEC,
905 HOSTNAME_RESOLVE_TIMEOUT,
906 &process_hostname_ip, h);
911 * Task to do DNS lookup on our external hostname to
912 * get DynDNS-IP addresses.
914 * @param cls the NAT handle
915 * @param tc scheduler context
918 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
920 struct GNUNET_NAT_Handle *h = cls;
922 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
923 remove_from_address_list_by_source (h, LAL_EXTERNAL_IP);
924 h->ext_dns = GNUNET_RESOLVER_ip_get (h->external_address,
926 GNUNET_TIME_UNIT_MINUTES,
927 &process_external_ip, h);
932 * Add or remove UPnP-mapped addresses.
934 * @param cls the GNUNET_NAT_Handle
935 * @param add_remove GNUNET_YES to mean the new public IP address, GNUNET_NO to mean
936 * the previous (now invalid) one
937 * @param addr either the previous or the new public IP address
938 * @param addrlen actual lenght of the address
942 int add_remove, const struct sockaddr *addr, socklen_t addrlen)
944 struct GNUNET_NAT_Handle *h = cls;
945 struct LocalAddressList *pos;
946 struct LocalAddressList *next;
948 if (GNUNET_YES == add_remove)
950 add_to_address_list (h, LAL_UPNP, addr, addrlen);
955 while (NULL != (pos = next))
958 if ((pos->source != LAL_UPNP) ||
959 (pos->addrlen != addrlen) || (0 != memcmp (&pos[1], addr, addrlen)))
961 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
962 if (NULL != h->address_callback)
963 h->address_callback (h->callback_cls,
965 (const struct sockaddr *) &pos[1], pos->addrlen);
967 return; /* only remove once */
969 /* asked to remove address that does not exist */
975 * Try to add a port mapping using UPnP.
977 * @param h overall NAT handle
978 * @param port port to map with UPnP
981 add_minis (struct GNUNET_NAT_Handle *h, uint16_t port)
988 if (port == ml->port)
989 return; /* already got this port */
992 ml = GNUNET_malloc (sizeof (struct MiniList));
994 ml->mini = GNUNET_NAT_mini_map_start (port, h->is_tcp, &upnp_add, h);
995 GNUNET_CONTAINER_DLL_insert (h->mini_head, h->mini_tail, ml);
1000 * Task to add addresses from original bind to set of valid addrs.
1002 * @param cls the NAT handle
1003 * @param tc scheduler context
1006 add_from_bind (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1008 static struct in6_addr any = IN6ADDR_ANY_INIT;
1009 struct GNUNET_NAT_Handle *h = cls;
1011 struct sockaddr *sa;
1012 const struct sockaddr_in *v4;
1014 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1015 for (i = 0; i < h->num_local_addrs; i++)
1017 sa = h->local_addrs[i];
1018 switch (sa->sa_family)
1021 if (sizeof (struct sockaddr_in) != h->local_addrlens[i])
1026 v4 = (const struct sockaddr_in *) sa;
1027 if (0 != v4->sin_addr.s_addr)
1028 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1029 sizeof (struct sockaddr_in));
1031 add_minis (h, ntohs (v4->sin_port));
1034 if (sizeof (struct sockaddr_in6) != h->local_addrlens[i])
1039 if (0 != memcmp (&((const struct sockaddr_in6 *) sa)->sin6_addr,
1040 &any, sizeof (struct in6_addr)))
1041 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1042 sizeof (struct sockaddr_in6));
1053 * Attempt to enable port redirection and detect public IP address contacting
1054 * UPnP or NAT-PMP routers on the local network. Use addr to specify to which
1055 * of the local host's addresses should the external port be mapped. The port
1056 * is taken from the corresponding sockaddr_in[6] field.
1058 * @param cfg configuration to use
1059 * @param is_tcp GNUNET_YES for TCP, GNUNET_NO for UDP
1060 * @param adv_port advertised port (port we are either bound to or that our OS
1061 * locally performs redirection from to our bound port).
1062 * @param num_addrs number of addresses in 'addrs'
1063 * @param addr the local address packets should be redirected to
1064 * @param addrlen actual lenght of the address
1065 * @param address_callback function to call everytime the public IP address changes
1066 * @param reversal_callback function to call if someone wants connection reversal from us
1067 * @param callback_cls closure for callbacks
1068 * @return NULL on error, otherwise handle that can be used to unregister
1070 struct GNUNET_NAT_Handle *
1071 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
1074 unsigned int num_addrs,
1075 const struct sockaddr **addrs,
1076 const socklen_t * addrlens,
1077 GNUNET_NAT_AddressCallback address_callback,
1078 GNUNET_NAT_ReversalCallback reversal_callback,
1081 struct GNUNET_NAT_Handle *h;
1082 struct in_addr in_addr;
1086 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1088 "Registered with NAT service at port %u with %u IP bound local addresses\n",
1089 (unsigned int) adv_port, num_addrs);
1091 h = GNUNET_malloc (sizeof (struct GNUNET_NAT_Handle));
1092 h->server_retry_delay = GNUNET_TIME_UNIT_SECONDS;
1095 h->address_callback = address_callback;
1096 h->reversal_callback = reversal_callback;
1097 h->callback_cls = callback_cls;
1098 h->num_local_addrs = num_addrs;
1099 h->adv_port = adv_port;
1102 h->local_addrs = GNUNET_malloc (num_addrs * sizeof (struct sockaddr *));
1103 h->local_addrlens = GNUNET_malloc (num_addrs * sizeof (socklen_t));
1104 for (i = 0; i < num_addrs; i++)
1106 GNUNET_assert (addrlens[i] > 0);
1107 GNUNET_assert (addrs[i] != NULL);
1108 h->local_addrlens[i] = addrlens[i];
1109 h->local_addrs[i] = GNUNET_malloc (addrlens[i]);
1110 memcpy (h->local_addrs[i], addrs[i], addrlens[i]);
1113 h->bind_task = GNUNET_SCHEDULER_add_now (&add_from_bind, h);
1115 GNUNET_CONFIGURATION_have_value (cfg, "nat", "INTERNAL_ADDRESS"))
1117 (void) GNUNET_CONFIGURATION_get_value_string (cfg,
1120 &h->internal_address);
1122 if ((h->internal_address != NULL) &&
1123 (inet_pton (AF_INET, h->internal_address, &in_addr) != 1))
1125 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1127 _("Malformed %s `%s' given in configuration!\n"),
1128 "INTERNAL_ADDRESS", h->internal_address);
1129 GNUNET_free (h->internal_address);
1130 h->internal_address = NULL;
1134 GNUNET_CONFIGURATION_have_value (cfg, "nat", "EXTERNAL_ADDRESS"))
1136 (void) GNUNET_CONFIGURATION_get_value_string (cfg,
1139 &h->external_address);
1141 if ((h->external_address != NULL) &&
1142 (inet_pton (AF_INET, h->external_address, &in_addr) != 1))
1144 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1146 _("Malformed %s `%s' given in configuration!\n"),
1147 "EXTERNAL_ADDRESS", h->external_address);
1148 GNUNET_free (h->external_address);
1149 h->external_address = NULL;
1151 h->behind_nat = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1152 "nat", "BEHIND_NAT");
1153 h->nat_punched = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1154 "nat", "PUNCHED_NAT");
1155 h->enable_nat_client = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1157 "ENABLE_NAT_CLIENT");
1158 h->enable_nat_server = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1160 "ENABLE_NAT_SERVER");
1161 h->enable_upnp = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1162 "nat", "ENABLE_UPNP");
1163 h->use_localaddresses = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1166 h->use_hostname = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1169 h->disable_ipv6 = GNUNET_CONFIGURATION_get_value_yesno (cfg,
1170 "nat", "DISABLEV6");
1172 GNUNET_CONFIGURATION_get_value_time (cfg,
1175 &h->dyndns_frequency))
1176 h->dyndns_frequency = DYNDNS_FREQUENCY;
1178 GNUNET_CONFIGURATION_get_value_time (cfg,
1180 "IFC_SCAN_FREQUENCY",
1181 &h->ifc_scan_frequency))
1182 h->ifc_scan_frequency = IFC_SCAN_FREQUENCY;
1184 GNUNET_CONFIGURATION_get_value_time (cfg,
1186 "HOSTNAME_DNS_FREQUENCY",
1187 &h->hostname_dns_frequency))
1188 h->hostname_dns_frequency = HOSTNAME_DNS_FREQUENCY;
1190 if (NULL == reversal_callback)
1191 h->enable_nat_server = GNUNET_NO;
1193 /* Check if NAT was hole-punched */
1194 if ((NULL != h->address_callback) &&
1195 (h->external_address != NULL) && (h->nat_punched == GNUNET_YES))
1197 h->dns_task = GNUNET_SCHEDULER_add_now (&resolve_dns, h);
1198 h->enable_nat_server = GNUNET_NO;
1199 h->enable_upnp = GNUNET_NO;
1202 /* Test for SUID binaries */
1203 if ((h->behind_nat == GNUNET_YES) &&
1204 (GNUNET_YES == h->enable_nat_server) &&
1206 GNUNET_OS_check_helper_binary ("gnunet-helper-nat-server")))
1208 h->enable_nat_server = GNUNET_NO;
1209 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1211 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1212 "gnunet-helper-nat-server");
1214 if ((GNUNET_YES == h->enable_nat_client) &&
1216 GNUNET_OS_check_helper_binary ("gnunet-helper-nat-client")))
1218 h->enable_nat_client = GNUNET_NO;
1219 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1221 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1222 "gnunet-helper-nat-client");
1225 start_gnunet_nat_server (h);
1227 /* FIXME: add support for UPnP, etc */
1229 if (NULL != h->address_callback)
1231 h->ifc_task = GNUNET_SCHEDULER_add_now (&list_interfaces, h);
1232 if (GNUNET_YES == h->use_hostname)
1233 h->hostname_task = GNUNET_SCHEDULER_add_now (&resolve_hostname, h);
1241 * Stop port redirection and public IP address detection for the given handle.
1242 * This frees the handle, after having sent the needed commands to close open ports.
1244 * @param h the handle to stop
1247 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h)
1250 struct LocalAddressList *lal;
1251 struct MiniList *ml;
1253 while (NULL != (ml = h->mini_head))
1255 GNUNET_CONTAINER_DLL_remove (h->mini_head, h->mini_tail, ml);
1256 if (NULL != ml->mini)
1257 GNUNET_NAT_mini_map_stop (ml->mini);
1260 if (h->ext_dns != NULL)
1262 GNUNET_RESOLVER_request_cancel (h->ext_dns);
1265 if (NULL != h->hostname_dns)
1267 GNUNET_RESOLVER_request_cancel (h->hostname_dns);
1268 h->hostname_dns = NULL;
1270 if (GNUNET_SCHEDULER_NO_TASK != h->server_read_task)
1272 GNUNET_SCHEDULER_cancel (h->server_read_task);
1273 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
1275 if (GNUNET_SCHEDULER_NO_TASK != h->bind_task)
1277 GNUNET_SCHEDULER_cancel (h->bind_task);
1278 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1280 if (GNUNET_SCHEDULER_NO_TASK != h->ifc_task)
1282 GNUNET_SCHEDULER_cancel (h->ifc_task);
1283 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
1285 if (GNUNET_SCHEDULER_NO_TASK != h->hostname_task)
1287 GNUNET_SCHEDULER_cancel (h->hostname_task);
1288 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
1290 if (GNUNET_SCHEDULER_NO_TASK != h->dns_task)
1292 GNUNET_SCHEDULER_cancel (h->dns_task);
1293 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
1295 if (NULL != h->server_proc)
1297 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
1298 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
1299 GNUNET_OS_process_wait (h->server_proc);
1300 GNUNET_OS_process_close (h->server_proc);
1301 h->server_proc = NULL;
1302 GNUNET_DISK_pipe_close (h->server_stdout);
1303 h->server_stdout = NULL;
1304 h->server_stdout_handle = NULL;
1306 if (NULL != h->server_stdout)
1308 GNUNET_DISK_pipe_close (h->server_stdout);
1309 h->server_stdout = NULL;
1310 h->server_stdout_handle = NULL;
1312 while (NULL != (lal = h->lal_head))
1314 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, lal);
1315 if (NULL != h->address_callback)
1316 h->address_callback (h->callback_cls,
1318 (const struct sockaddr *) &lal[1], lal->addrlen);
1321 for (i = 0; i < h->num_local_addrs; i++)
1322 GNUNET_free (h->local_addrs[i]);
1323 GNUNET_free_non_null (h->local_addrs);
1324 GNUNET_free_non_null (h->local_addrlens);
1325 GNUNET_free_non_null (h->external_address);
1326 GNUNET_free_non_null (h->internal_address);
1332 * We learned about a peer (possibly behind NAT) so run the
1333 * gnunet-helper-nat-client to send dummy ICMP responses to cause
1334 * that peer to connect to us (connection reversal).
1336 * @param h NAT handle for us (largely used for configuration)
1337 * @param sa the address of the peer (IPv4-only)
1340 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
1341 const struct sockaddr_in *sa)
1343 char inet4[INET_ADDRSTRLEN];
1344 char port_as_string[6];
1345 struct GNUNET_OS_Process *proc;
1347 if (GNUNET_YES != h->enable_nat_client)
1348 return; /* not permitted / possible */
1350 if (h->internal_address == NULL)
1352 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING,
1355 ("Internal IP address not known, cannot use ICMP NAT traversal method\n"));
1358 GNUNET_assert (sa->sin_family == AF_INET);
1359 if (NULL == inet_ntop (AF_INET, &sa->sin_addr, inet4, INET_ADDRSTRLEN))
1361 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
1364 GNUNET_snprintf (port_as_string, sizeof (port_as_string), "%d", h->adv_port);
1366 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG,
1368 _("Running gnunet-helper-nat-client %s %s %u\n"),
1369 h->internal_address, inet4, (unsigned int) h->adv_port);
1371 proc = GNUNET_OS_start_process (NULL,
1373 "gnunet-helper-nat-client",
1374 "gnunet-helper-nat-client",
1375 h->internal_address,
1376 inet4, port_as_string, NULL);
1379 /* we know that the gnunet-helper-nat-client will terminate virtually
1381 GNUNET_OS_process_wait (proc);
1382 GNUNET_OS_process_close (proc);
1387 * Test if the given address is (currently) a plausible IP address for this peer.
1389 * @param h the handle returned by register
1390 * @param addr IP address to test (IPv4 or IPv6)
1391 * @param addrlen number of bytes in addr
1392 * @return GNUNET_YES if the address is plausible,
1393 * GNUNET_NO if the address is not plausible,
1394 * GNUNET_SYSERR if the address is malformed
1397 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h,
1398 const void *addr, socklen_t addrlen)
1400 struct LocalAddressList *pos;
1401 const struct sockaddr_in *in4;
1402 const struct sockaddr_in6 *in6;
1404 if ((addrlen != sizeof (struct in_addr)) &&
1405 (addrlen != sizeof (struct in6_addr)))
1408 return GNUNET_SYSERR;
1413 if (pos->addrlen == sizeof (struct sockaddr_in))
1415 in4 = (struct sockaddr_in *) &pos[1];
1416 if ((addrlen == sizeof (struct in_addr)) &&
1417 (0 == memcmp (&in4->sin_addr, addr, sizeof (struct in_addr))))
1420 else if (pos->addrlen == sizeof (struct sockaddr_in6))
1422 in6 = (struct sockaddr_in6 *) &pos[1];
1423 if ((addrlen == sizeof (struct in6_addr)) &&
1424 (0 == memcmp (&in6->sin6_addr, addr, sizeof (struct in6_addr))))
1433 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1434 "Asked to validate one of my addresses and validation failed!\n");