2 This file is part of GNUnet.
3 (C) 2009, 2010, 2011 Christian Grothoff (and other contributing authors)
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.
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"
34 #define LOG(kind,...) GNUNET_log_from (kind, "nat", __VA_ARGS__)
37 * How often do we scan for changes in our IP address from our local
40 #define IFC_SCAN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
43 * How often do we scan for changes in how our hostname resolves?
45 #define HOSTNAME_DNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 20)
49 * How often do we scan for changes in how our external (dyndns) hostname resolves?
51 #define DYNDNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 7)
54 * How long until we give up trying to resolve our own hostname?
56 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
60 * Where did the given local address originate from?
61 * To be used for debugging as well as in the future
62 * to remove all addresses from a certain source when
63 * we reevaluate the source.
65 enum LocalAddressSource
68 * Address was obtained by DNS resolution of the external hostname
69 * given in the configuration (i.e. hole-punched DynDNS setup).
74 * Address was obtained by looking up our own hostname in DNS.
79 * Address was obtained by scanning our hosts's network interfaces
80 * and taking their address (no DNS involved).
82 LAL_INTERFACE_ADDRESS,
85 * Addresses we were explicitly bound to.
90 * Addresses from UPnP or PMP
102 * List of local addresses that we currently deem valid. Actual
103 * struct is followed by the 'struct sockaddr'. Note that the code
104 * intentionally makes no attempt to ensure that a particular address
105 * is only listed once (especially since it may come from different
106 * sources, and the source is an "internal" construct).
108 struct LocalAddressList
111 * This is a linked list.
113 struct LocalAddressList *next;
118 struct LocalAddressList *prev;
121 * Number of bytes of address that follow.
126 * Origin of the local address.
128 enum LocalAddressSource source;
133 * Handle for miniupnp-based NAT traversal actions.
139 * Doubly-linked list.
141 struct MiniList *next;
144 * Doubly-linked list.
146 struct MiniList *prev;
149 * Handle to mini-action.
151 struct GNUNET_NAT_MiniHandle *mini;
154 * Local port number that was mapped.
162 * Handle for active NAT registrations.
164 struct GNUNET_NAT_Handle
168 * Configuration to use.
170 const struct GNUNET_CONFIGURATION_Handle *cfg;
173 * Function to call when we learn about a new address.
175 GNUNET_NAT_AddressCallback address_callback;
178 * Function to call when we notice another peer asking for
179 * connection reversal.
181 GNUNET_NAT_ReversalCallback reversal_callback;
184 * Closure for 'callback'.
189 * Handle for (DYN)DNS lookup of our external IP.
191 struct GNUNET_RESOLVER_RequestHandle *ext_dns;
194 * Handle for request of hostname resolution, non-NULL if pending.
196 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
199 * stdout pipe handle for the gnunet-helper-nat-server process
201 struct GNUNET_DISK_PipeHandle *server_stdout;
204 * stdout file handle (for reading) for the gnunet-helper-nat-server process
206 const struct GNUNET_DISK_FileHandle *server_stdout_handle;
209 * Linked list of currently valid addresses (head).
211 struct LocalAddressList *lal_head;
214 * Linked list of currently valid addresses (tail).
216 struct LocalAddressList *lal_tail;
219 * How long do we wait for restarting a crashed gnunet-helper-nat-server?
221 struct GNUNET_TIME_Relative server_retry_delay;
224 * ID of select gnunet-helper-nat-server stdout read task
226 GNUNET_SCHEDULER_TaskIdentifier server_read_task;
229 * ID of interface IP-scan task
231 GNUNET_SCHEDULER_TaskIdentifier ifc_task;
234 * ID of hostname DNS lookup task
236 GNUNET_SCHEDULER_TaskIdentifier hostname_task;
239 * ID of DynDNS lookup task
241 GNUNET_SCHEDULER_TaskIdentifier dns_task;
244 * ID of task to add addresses from bind.
246 GNUNET_SCHEDULER_TaskIdentifier bind_task;
249 * How often do we scan for changes in our IP address from our local
252 struct GNUNET_TIME_Relative ifc_scan_frequency;
255 * How often do we scan for changes in how our hostname resolves?
257 struct GNUNET_TIME_Relative hostname_dns_frequency;
260 * How often do we scan for changes in how our external (dyndns) hostname resolves?
262 struct GNUNET_TIME_Relative dyndns_frequency;
265 * The process id of the server process (if behind NAT)
267 struct GNUNET_OS_Process *server_proc;
270 * LAN address as passed by the caller (array).
272 struct sockaddr **local_addrs;
275 * Length of the 'local_addrs'.
277 socklen_t *local_addrlens;
280 * List of handles for UPnP-traversal, one per local port (if
283 struct MiniList *mini_head;
286 * List of handles for UPnP-traversal, one per local port (if
289 struct MiniList *mini_tail;
292 * Number of entries in 'local_addrs' array.
294 unsigned int num_local_addrs;
297 * Our external address (according to config, UPnP may disagree...),
298 * in dotted decimal notation, IPv4-only. Or NULL if not known.
300 char *external_address;
303 * Presumably our internal address (according to config)
305 char *internal_address;
308 * Is this transport configured to be behind a NAT?
313 * Has the NAT been punched? (according to config)
318 * Is this transport configured to allow connections to NAT'd peers?
320 int enable_nat_client;
323 * Should we run the gnunet-helper-nat-server?
325 int enable_nat_server;
328 * Are we allowed to try UPnP/PMP for NAT traversal?
333 * Should we use local addresses (loopback)? (according to config)
335 int use_localaddresses;
338 * Should we return local addresses to clients
340 int return_localaddress;
343 * Should we do a DNS lookup of our hostname to find out our own IP?
348 * Is using IPv6 disabled?
353 * Is this TCP or UDP?
358 * Port we advertise to the outside.
366 * Try to start the gnunet-helper-nat-server (if it is not
369 * @param h handle to NAT
372 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h);
376 * Remove all addresses from the list of 'local' addresses
377 * that originated from the given source.
379 * @param h handle to NAT
380 * @param src source that identifies addresses to remove
383 remove_from_address_list_by_source (struct GNUNET_NAT_Handle *h,
384 enum LocalAddressSource src)
386 struct LocalAddressList *pos;
387 struct LocalAddressList *next;
390 while (NULL != (pos = next))
393 if (pos->source != src)
395 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
396 if (NULL != h->address_callback)
397 h->address_callback (h->callback_cls, GNUNET_NO,
398 (const struct sockaddr *) &pos[1], pos->addrlen);
405 * Add the given address to the list of 'local' addresses, thereby
406 * making it a 'legal' address for this peer to have.
408 * @param h handle to NAT
409 * @param src where did the local address originate from?
410 * @param arg the address, some 'struct sockaddr'
411 * @param arg_size number of bytes in arg
414 add_to_address_list_as_is (struct GNUNET_NAT_Handle *h,
415 enum LocalAddressSource src,
416 const struct sockaddr *arg, socklen_t arg_size)
418 struct LocalAddressList *lal;
420 lal = GNUNET_malloc (sizeof (struct LocalAddressList) + arg_size);
421 memcpy (&lal[1], arg, arg_size);
422 lal->addrlen = arg_size;
424 GNUNET_CONTAINER_DLL_insert (h->lal_head, h->lal_tail, lal);
425 LOG (GNUNET_ERROR_TYPE_DEBUG, "Adding address `%s' from source %d\n",
426 GNUNET_a2s (arg, arg_size), src);
427 if (NULL != h->address_callback)
428 h->address_callback (h->callback_cls, GNUNET_YES, arg, arg_size);
433 * Add the given address to the list of 'local' addresses, thereby
434 * making it a 'legal' address for this peer to have. Set the
435 * port number in the process to the advertised port and possibly
436 * also to zero (if we have the gnunet-helper-nat-server).
438 * @param h handle to NAT
439 * @param src where did the local address originate from?
440 * @param arg the address, some 'struct sockaddr'
441 * @param arg_size number of bytes in arg
444 add_to_address_list (struct GNUNET_NAT_Handle *h, enum LocalAddressSource src,
445 const struct sockaddr *arg, socklen_t arg_size)
447 struct sockaddr_in s4;
448 const struct sockaddr_in *in4;
449 struct sockaddr_in6 s6;
450 const struct sockaddr_in6 *in6;
452 if (arg_size == sizeof (struct sockaddr_in))
454 in4 = (const struct sockaddr_in *) arg;
456 s4.sin_port = htons (h->adv_port);
457 add_to_address_list_as_is (h, src, (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, src, (const struct sockaddr *) &s4,
464 sizeof (struct sockaddr_in));
467 else if (arg_size == sizeof (struct sockaddr_in6))
469 if (GNUNET_YES != h->disable_ipv6)
471 in6 = (const struct sockaddr_in6 *) arg;
473 s6.sin6_port = htons (h->adv_port);
474 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s6,
475 sizeof (struct sockaddr_in6));
486 * Add the given IP address to the list of 'local' addresses, thereby
487 * making it a 'legal' address for this peer to have.
489 * @param h handle to NAT
490 * @param src where did the local address originate from?
491 * @param addr the address, some 'struct in_addr' or 'struct in6_addr'
492 * @param addrlen number of bytes in addr
495 add_ip_to_address_list (struct GNUNET_NAT_Handle *h,
496 enum LocalAddressSource src, const void *addr,
499 struct sockaddr_in s4;
500 const struct in_addr *in4;
501 struct sockaddr_in6 s6;
502 const struct in6_addr *in6;
504 if (addrlen == sizeof (struct in_addr))
506 in4 = (const struct in_addr *) addr;
507 memset (&s4, 0, sizeof (s4));
508 s4.sin_family = AF_INET;
510 #if HAVE_SOCKADDR_IN_SIN_LEN
511 s4.sin_len = (u_char) sizeof (struct sockaddr_in);
514 add_to_address_list (h, src, (const struct sockaddr *) &s4,
515 sizeof (struct sockaddr_in));
516 if (GNUNET_YES == h->enable_nat_server)
518 /* also add with PORT = 0 to indicate NAT server is enabled */
519 s4.sin_port = htons (0);
520 add_to_address_list (h, src, (const struct sockaddr *) &s4,
521 sizeof (struct sockaddr_in));
525 else if (addrlen == sizeof (struct in6_addr))
527 if (GNUNET_YES != h->disable_ipv6)
529 in6 = (const struct in6_addr *) addr;
530 memset (&s6, 0, sizeof (s6));
531 s6.sin6_family = AF_INET6;
532 s6.sin6_port = htons (h->adv_port);
533 #if HAVE_SOCKADDR_IN_SIN_LEN
534 s6.sin6_len = (u_char) sizeof (struct sockaddr_in6);
537 add_to_address_list (h, src, (const struct sockaddr *) &s6,
538 sizeof (struct sockaddr_in6));
549 * Task to do DNS lookup on our external hostname to
550 * get DynDNS-IP addresses.
552 * @param cls the NAT handle
553 * @param tc scheduler context
556 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
560 * Our (external) hostname was resolved and the configuration says that
561 * the NAT was hole-punched.
563 * @param cls the 'struct Plugin'
564 * @param addr NULL on error, otherwise result of DNS lookup
565 * @param addrlen number of bytes in addr
568 process_external_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
570 struct GNUNET_NAT_Handle *h = cls;
571 struct in_addr dummy;
576 if (1 == inet_pton (AF_INET, h->external_address, &dummy))
577 return; /* repated lookup pointless: was numeric! */
579 GNUNET_SCHEDULER_add_delayed (h->dyndns_frequency, &resolve_dns, h);
582 add_to_address_list (h, LAL_EXTERNAL_IP, addr, addrlen);
587 * Task to do a lookup on our hostname for IP addresses.
589 * @param cls the NAT handle
590 * @param tc scheduler context
593 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
597 * Function called by the resolver for each address obtained from DNS
598 * for our own hostname. Add the addresses to the list of our IP
602 * @param addr one of the addresses of the host, NULL for the last address
603 * @param addrlen length of the address
606 process_hostname_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
608 struct GNUNET_NAT_Handle *h = cls;
612 h->hostname_dns = NULL;
614 GNUNET_SCHEDULER_add_delayed (h->hostname_dns_frequency,
615 &resolve_hostname, h);
618 add_to_address_list (h, LAL_HOSTNAME_DNS, addr, addrlen);
623 * Add the IP of our network interface to the list of
626 * @param cls the 'struct GNUNET_NAT_Handle'
627 * @param name name of the interface
628 * @param isDefault do we think this may be our default interface
629 * @param addr address of the interface
630 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
631 * @param netmask the network mask (can be NULL for unknown or unassigned))
632 * @param addrlen number of bytes in addr
633 * @return GNUNET_OK to continue iterating
636 process_interfaces (void *cls, const char *name, int isDefault,
637 const struct sockaddr *addr,
638 const struct sockaddr *broadcast_addr,
639 const struct sockaddr *netmask, socklen_t addrlen)
641 const static struct in6_addr any6 = IN6ADDR_ANY_INIT;
642 struct GNUNET_NAT_Handle *h = cls;
643 const struct sockaddr_in *s4;
644 const struct sockaddr_in6 *s6;
646 char buf[INET6_ADDRSTRLEN];
650 switch (addr->sa_family)
653 /* check if we're bound to the "ANY" IP address */
654 have_any = GNUNET_NO;
655 for (i=0;i<h->num_local_addrs;i++)
657 if (h->local_addrs[i]->sa_family != AF_INET)
662 if (INADDR_ANY == ((struct sockaddr_in*) h->local_addrs[i])->sin_addr.s_addr)
664 have_any = GNUNET_YES;
668 if (GNUNET_NO == have_any)
669 return GNUNET_OK; /* not bound to IP 0.0.0.0 but to specific IP addresses,
670 do not use those from interfaces */
671 s4 = (struct sockaddr_in *) addr;
674 /* Check if address is in 127.0.0.0/8 */
675 uint32_t address = ntohl ((uint32_t) (s4->sin_addr.s_addr));
676 uint32_t value = (address & 0xFF000000) ^ 0x7F000000;
678 if ((h->return_localaddress == GNUNET_NO) && (value == 0))
682 if (GNUNET_YES == h->use_localaddresses)
684 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s4->sin_addr,
685 sizeof (struct in_addr));
689 /* check if we're bound to the "ANY" IP address */
690 have_any = GNUNET_NO;
691 for (i=0;i<h->num_local_addrs;i++)
693 if (h->local_addrs[i]->sa_family != AF_INET6)
695 if (0 == memcmp (&any6,
696 &((struct sockaddr_in6*) h->local_addrs[i])->sin6_addr,
697 sizeof (struct in6_addr)))
699 have_any = GNUNET_YES;
703 if (GNUNET_NO == have_any)
704 return GNUNET_OK; /* not bound to "ANY" IP (::0) but to specific IP addresses,
705 do not use those from interfaces */
707 s6 = (struct sockaddr_in6 *) addr;
708 if (IN6_IS_ADDR_LINKLOCAL (&((struct sockaddr_in6 *) addr)->sin6_addr))
710 /* skip link local addresses */
713 if ((h->return_localaddress == GNUNET_NO) &&
714 (IN6_IS_ADDR_LOOPBACK (&((struct sockaddr_in6 *) addr)->sin6_addr)))
719 if (GNUNET_YES == h->use_localaddresses)
721 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s6->sin6_addr,
722 sizeof (struct in6_addr));
729 if ((h->internal_address == NULL) && (h->server_proc == NULL) &&
730 (h->server_read_task == GNUNET_SCHEDULER_NO_TASK) &&
731 (GNUNET_YES == isDefault) && ((addr->sa_family == AF_INET) ||
732 (addr->sa_family == AF_INET6)))
734 /* no internal address configured, but we found a "default"
735 * interface, try using that as our 'internal' address */
736 h->internal_address =
737 GNUNET_strdup (inet_ntop (addr->sa_family, ip, buf, sizeof (buf)));
738 start_gnunet_nat_server (h);
745 * Task that restarts the gnunet-helper-nat-server process after a crash
746 * after a certain delay.
748 * @param cls the 'struct GNUNET_NAT_Handle'
749 * @param tc scheduler context
752 restart_nat_server (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
754 struct GNUNET_NAT_Handle *h = cls;
756 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
757 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
759 start_gnunet_nat_server (h);
764 * We have been notified that gnunet-helper-nat-server has written something to stdout.
765 * Handle the output, then reschedule this function to be called again once
768 * @param cls the NAT handle
769 * @param tc the scheduling context
772 nat_server_read (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
774 struct GNUNET_NAT_Handle *h = cls;
779 const char *port_start;
780 struct sockaddr_in sin_addr;
782 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
783 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
785 memset (mybuf, 0, sizeof (mybuf));
787 GNUNET_DISK_file_read (h->server_stdout_handle, mybuf, sizeof (mybuf));
790 LOG (GNUNET_ERROR_TYPE_DEBUG,
791 "Finished reading from server stdout with code: %d\n", bytes);
792 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
793 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill");
794 GNUNET_OS_process_wait (h->server_proc);
795 GNUNET_OS_process_destroy (h->server_proc);
796 h->server_proc = NULL;
797 GNUNET_DISK_pipe_close (h->server_stdout);
798 h->server_stdout = NULL;
799 h->server_stdout_handle = NULL;
800 /* now try to restart it */
801 h->server_retry_delay = GNUNET_TIME_STD_BACKOFF (h->server_retry_delay);
802 h->server_read_task =
803 GNUNET_SCHEDULER_add_delayed (h->server_retry_delay,
804 &restart_nat_server, h);
809 for (i = 0; i < sizeof (mybuf); i++)
811 if (mybuf[i] == '\n')
816 if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf)))
819 port_start = &mybuf[i + 1];
823 /* construct socket address of sender */
824 memset (&sin_addr, 0, sizeof (sin_addr));
825 sin_addr.sin_family = AF_INET;
826 #if HAVE_SOCKADDR_IN_SIN_LEN
827 sin_addr.sin_len = sizeof (sin_addr);
829 if ((NULL == port_start) || (1 != SSCANF (port_start, "%d", &port)) ||
830 (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr)))
832 /* should we restart gnunet-helper-nat-server? */
833 LOG (GNUNET_ERROR_TYPE_WARNING, "nat",
834 _("gnunet-helper-nat-server generated malformed address `%s'\n"),
836 h->server_read_task =
837 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
838 h->server_stdout_handle,
839 &nat_server_read, h);
842 sin_addr.sin_port = htons ((uint16_t) port);
843 LOG (GNUNET_ERROR_TYPE_DEBUG, "gnunet-helper-nat-server read: %s:%d\n", mybuf,
845 h->reversal_callback (h->callback_cls, (const struct sockaddr *) &sin_addr,
847 h->server_read_task =
848 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
849 h->server_stdout_handle, &nat_server_read,
855 * Try to start the gnunet-helper-nat-server (if it is not
858 * @param h handle to NAT
861 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h)
865 if ((h->behind_nat == GNUNET_YES) && (h->enable_nat_server == GNUNET_YES) &&
866 (h->internal_address != NULL) &&
869 GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES, GNUNET_NO, GNUNET_YES))))
871 LOG (GNUNET_ERROR_TYPE_DEBUG, "Starting `%s' at `%s'\n",
872 "gnunet-helper-nat-server", h->internal_address);
873 /* Start the server process */
874 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
876 GNUNET_OS_start_process (GNUNET_NO, 0, NULL, h->server_stdout,
878 "gnunet-helper-nat-server",
879 h->internal_address, NULL);
880 GNUNET_free (binary);
881 if (h->server_proc == NULL)
883 LOG (GNUNET_ERROR_TYPE_WARNING, "nat", _("Failed to start %s\n"),
884 "gnunet-helper-nat-server");
885 GNUNET_DISK_pipe_close (h->server_stdout);
886 h->server_stdout = NULL;
890 /* Close the write end of the read pipe */
891 GNUNET_DISK_pipe_close_end (h->server_stdout, GNUNET_DISK_PIPE_END_WRITE);
892 h->server_stdout_handle =
893 GNUNET_DISK_pipe_handle (h->server_stdout, GNUNET_DISK_PIPE_END_READ);
894 h->server_read_task =
895 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
896 h->server_stdout_handle,
897 &nat_server_read, h);
904 * Task to scan the local network interfaces for IP addresses.
906 * @param cls the NAT handle
907 * @param tc scheduler context
910 list_interfaces (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
912 struct GNUNET_NAT_Handle *h = cls;
914 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
915 remove_from_address_list_by_source (h, LAL_INTERFACE_ADDRESS);
916 GNUNET_OS_network_interfaces_list (&process_interfaces, h);
918 GNUNET_SCHEDULER_add_delayed (h->ifc_scan_frequency, &list_interfaces, h);
923 * Task to do a lookup on our hostname for IP addresses.
925 * @param cls the NAT handle
926 * @param tc scheduler context
929 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
931 struct GNUNET_NAT_Handle *h = cls;
933 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
934 remove_from_address_list_by_source (h, LAL_HOSTNAME_DNS);
936 GNUNET_RESOLVER_hostname_resolve (AF_UNSPEC, HOSTNAME_RESOLVE_TIMEOUT,
937 &process_hostname_ip, h);
942 * Task to do DNS lookup on our external hostname to
943 * get DynDNS-IP addresses.
945 * @param cls the NAT handle
946 * @param tc scheduler context
949 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
951 struct GNUNET_NAT_Handle *h = cls;
953 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
954 remove_from_address_list_by_source (h, LAL_EXTERNAL_IP);
956 GNUNET_RESOLVER_ip_get (h->external_address, AF_INET,
957 GNUNET_TIME_UNIT_MINUTES, &process_external_ip,
963 * Add or remove UPnP-mapped addresses.
965 * @param cls the GNUNET_NAT_Handle
966 * @param add_remove GNUNET_YES to mean the new public IP address, GNUNET_NO to mean
967 * the previous (now invalid) one
968 * @param addr either the previous or the new public IP address
969 * @param addrlen actual lenght of the address
972 upnp_add (void *cls, int add_remove, const struct sockaddr *addr,
975 struct GNUNET_NAT_Handle *h = cls;
976 struct LocalAddressList *pos;
977 struct LocalAddressList *next;
979 if (GNUNET_YES == add_remove)
981 add_to_address_list (h, LAL_UPNP, addr, addrlen);
986 while (NULL != (pos = next))
989 if ((pos->source != LAL_UPNP) || (pos->addrlen != addrlen) ||
990 (0 != memcmp (&pos[1], addr, addrlen)))
992 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
993 if (NULL != h->address_callback)
994 h->address_callback (h->callback_cls, GNUNET_NO,
995 (const struct sockaddr *) &pos[1], pos->addrlen);
997 return; /* only remove once */
999 /* asked to remove address that does not exist */
1005 * Try to add a port mapping using UPnP.
1007 * @param h overall NAT handle
1008 * @param port port to map with UPnP
1011 add_minis (struct GNUNET_NAT_Handle *h, uint16_t port)
1013 struct MiniList *ml;
1018 if (port == ml->port)
1019 return; /* already got this port */
1022 ml = GNUNET_malloc (sizeof (struct MiniList));
1024 ml->mini = GNUNET_NAT_mini_map_start (port, h->is_tcp, &upnp_add, h);
1025 GNUNET_CONTAINER_DLL_insert (h->mini_head, h->mini_tail, ml);
1030 * Task to add addresses from original bind to set of valid addrs.
1032 * @param cls the NAT handle
1033 * @param tc scheduler context
1036 add_from_bind (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1038 static struct in6_addr any = IN6ADDR_ANY_INIT;
1039 struct GNUNET_NAT_Handle *h = cls;
1041 struct sockaddr *sa;
1042 const struct sockaddr_in *v4;
1044 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1045 for (i = 0; i < h->num_local_addrs; i++)
1047 sa = h->local_addrs[i];
1048 switch (sa->sa_family)
1051 if (sizeof (struct sockaddr_in) != h->local_addrlens[i])
1056 v4 = (const struct sockaddr_in *) sa;
1057 if (0 != v4->sin_addr.s_addr)
1058 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1059 sizeof (struct sockaddr_in));
1061 add_minis (h, ntohs (v4->sin_port));
1064 if (sizeof (struct sockaddr_in6) != h->local_addrlens[i])
1070 memcmp (&((const struct sockaddr_in6 *) sa)->sin6_addr, &any,
1071 sizeof (struct in6_addr)))
1072 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1073 sizeof (struct sockaddr_in6));
1084 * Attempt to enable port redirection and detect public IP address contacting
1085 * UPnP or NAT-PMP routers on the local network. Use addr to specify to which
1086 * of the local host's addresses should the external port be mapped. The port
1087 * is taken from the corresponding sockaddr_in[6] field.
1089 * @param cfg configuration to use
1090 * @param is_tcp GNUNET_YES for TCP, GNUNET_NO for UDP
1091 * @param adv_port advertised port (port we are either bound to or that our OS
1092 * locally performs redirection from to our bound port).
1093 * @param num_addrs number of addresses in 'addrs'
1094 * @param addrs the local addresses packets should be redirected to
1095 * @param addrlens actual lengths of the addresses
1096 * @param address_callback function to call everytime the public IP address changes
1097 * @param reversal_callback function to call if someone wants connection reversal from us
1098 * @param callback_cls closure for callbacks
1099 * @return NULL on error, otherwise handle that can be used to unregister
1101 struct GNUNET_NAT_Handle *
1102 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg, int is_tcp,
1103 uint16_t adv_port, unsigned int num_addrs,
1104 const struct sockaddr **addrs, const socklen_t * addrlens,
1105 GNUNET_NAT_AddressCallback address_callback,
1106 GNUNET_NAT_ReversalCallback reversal_callback,
1109 struct GNUNET_NAT_Handle *h;
1110 struct in_addr in_addr;
1114 LOG (GNUNET_ERROR_TYPE_DEBUG,
1115 "Registered with NAT service at port %u with %u IP bound local addresses\n",
1116 (unsigned int) adv_port, num_addrs);
1117 h = GNUNET_malloc (sizeof (struct GNUNET_NAT_Handle));
1118 h->server_retry_delay = GNUNET_TIME_UNIT_SECONDS;
1121 h->address_callback = address_callback;
1122 h->reversal_callback = reversal_callback;
1123 h->callback_cls = callback_cls;
1124 h->num_local_addrs = num_addrs;
1125 h->adv_port = adv_port;
1128 h->local_addrs = GNUNET_malloc (num_addrs * sizeof (struct sockaddr *));
1129 h->local_addrlens = GNUNET_malloc (num_addrs * sizeof (socklen_t));
1130 for (i = 0; i < num_addrs; i++)
1132 GNUNET_assert (addrlens[i] > 0);
1133 GNUNET_assert (addrs[i] != NULL);
1134 h->local_addrlens[i] = addrlens[i];
1135 h->local_addrs[i] = GNUNET_malloc (addrlens[i]);
1136 memcpy (h->local_addrs[i], addrs[i], addrlens[i]);
1139 h->bind_task = GNUNET_SCHEDULER_add_now (&add_from_bind, h);
1141 GNUNET_CONFIGURATION_have_value (cfg, "nat", "INTERNAL_ADDRESS"))
1143 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1145 &h->internal_address);
1147 if ((h->internal_address != NULL) &&
1148 (inet_pton (AF_INET, h->internal_address, &in_addr) != 1))
1150 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1151 "nat", "INTERNAL_ADDRESS",
1153 GNUNET_free (h->internal_address);
1154 h->internal_address = NULL;
1158 GNUNET_CONFIGURATION_have_value (cfg, "nat", "EXTERNAL_ADDRESS"))
1160 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1162 &h->external_address);
1165 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT");
1167 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "PUNCHED_NAT");
1168 h->enable_nat_client =
1169 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_CLIENT");
1170 h->enable_nat_server =
1171 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_SERVER");
1173 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_UPNP");
1174 h->use_localaddresses =
1175 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_LOCALADDR");
1176 h->return_localaddress =
1177 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat",
1178 "RETURN_LOCAL_ADDRESSES");
1181 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_HOSTNAME");
1183 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "DISABLEV6");
1185 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "DYNDNS_FREQUENCY",
1186 &h->dyndns_frequency))
1187 h->dyndns_frequency = DYNDNS_FREQUENCY;
1189 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "IFC_SCAN_FREQUENCY",
1190 &h->ifc_scan_frequency))
1191 h->ifc_scan_frequency = IFC_SCAN_FREQUENCY;
1193 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "HOSTNAME_DNS_FREQUENCY",
1194 &h->hostname_dns_frequency))
1195 h->hostname_dns_frequency = HOSTNAME_DNS_FREQUENCY;
1197 if (NULL == reversal_callback)
1198 h->enable_nat_server = GNUNET_NO;
1200 /* Check if NAT was hole-punched */
1201 if ((NULL != h->address_callback) && (h->external_address != NULL) &&
1202 (h->nat_punched == GNUNET_YES))
1204 h->dns_task = GNUNET_SCHEDULER_add_now (&resolve_dns, h);
1205 h->enable_nat_server = GNUNET_NO;
1206 h->enable_upnp = GNUNET_NO;
1209 /* Test for SUID binaries */
1210 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
1211 if ((h->behind_nat == GNUNET_YES) && (GNUNET_YES == h->enable_nat_server) &&
1213 GNUNET_OS_check_helper_binary (binary, GNUNET_YES, "-d 127.0.0.1" ))) // use localhost as source for that one udp-port, ok for testing
1215 h->enable_nat_server = GNUNET_NO;
1216 LOG (GNUNET_ERROR_TYPE_WARNING,
1218 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1219 "gnunet-helper-nat-server");
1221 GNUNET_free (binary);
1222 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client");
1223 if ((GNUNET_YES == h->enable_nat_client) &&
1225 GNUNET_OS_check_helper_binary (binary, GNUNET_YES, "-d 127.0.0.1 127.0.0.2 42"))) // none of these parameters are actually used in privilege testing mode
1227 h->enable_nat_client = GNUNET_NO;
1228 LOG (GNUNET_ERROR_TYPE_WARNING,
1230 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1231 "gnunet-helper-nat-client");
1233 GNUNET_free (binary);
1234 start_gnunet_nat_server (h);
1236 /* FIXME: add support for UPnP, etc */
1238 if (NULL != h->address_callback)
1240 h->ifc_task = GNUNET_SCHEDULER_add_now (&list_interfaces, h);
1241 if (GNUNET_YES == h->use_hostname)
1242 h->hostname_task = GNUNET_SCHEDULER_add_now (&resolve_hostname, h);
1250 * Stop port redirection and public IP address detection for the given handle.
1251 * This frees the handle, after having sent the needed commands to close open ports.
1253 * @param h the handle to stop
1256 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h)
1259 struct LocalAddressList *lal;
1260 struct MiniList *ml;
1262 while (NULL != (ml = h->mini_head))
1264 GNUNET_CONTAINER_DLL_remove (h->mini_head, h->mini_tail, ml);
1265 if (NULL != ml->mini)
1266 GNUNET_NAT_mini_map_stop (ml->mini);
1269 if (h->ext_dns != NULL)
1271 GNUNET_RESOLVER_request_cancel (h->ext_dns);
1274 if (NULL != h->hostname_dns)
1276 GNUNET_RESOLVER_request_cancel (h->hostname_dns);
1277 h->hostname_dns = NULL;
1279 if (GNUNET_SCHEDULER_NO_TASK != h->server_read_task)
1281 GNUNET_SCHEDULER_cancel (h->server_read_task);
1282 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
1284 if (GNUNET_SCHEDULER_NO_TASK != h->bind_task)
1286 GNUNET_SCHEDULER_cancel (h->bind_task);
1287 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1289 if (GNUNET_SCHEDULER_NO_TASK != h->ifc_task)
1291 GNUNET_SCHEDULER_cancel (h->ifc_task);
1292 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
1294 if (GNUNET_SCHEDULER_NO_TASK != h->hostname_task)
1296 GNUNET_SCHEDULER_cancel (h->hostname_task);
1297 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
1299 if (GNUNET_SCHEDULER_NO_TASK != h->dns_task)
1301 GNUNET_SCHEDULER_cancel (h->dns_task);
1302 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
1304 if (NULL != h->server_proc)
1306 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
1307 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill");
1308 GNUNET_OS_process_wait (h->server_proc);
1309 GNUNET_OS_process_destroy (h->server_proc);
1310 h->server_proc = NULL;
1311 GNUNET_DISK_pipe_close (h->server_stdout);
1312 h->server_stdout = NULL;
1313 h->server_stdout_handle = NULL;
1315 if (NULL != h->server_stdout)
1317 GNUNET_DISK_pipe_close (h->server_stdout);
1318 h->server_stdout = NULL;
1319 h->server_stdout_handle = NULL;
1321 while (NULL != (lal = h->lal_head))
1323 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, lal);
1324 if (NULL != h->address_callback)
1325 h->address_callback (h->callback_cls, GNUNET_NO,
1326 (const struct sockaddr *) &lal[1], lal->addrlen);
1329 for (i = 0; i < h->num_local_addrs; i++)
1330 GNUNET_free (h->local_addrs[i]);
1331 GNUNET_free_non_null (h->local_addrs);
1332 GNUNET_free_non_null (h->local_addrlens);
1333 GNUNET_free_non_null (h->external_address);
1334 GNUNET_free_non_null (h->internal_address);
1340 * We learned about a peer (possibly behind NAT) so run the
1341 * gnunet-helper-nat-client to send dummy ICMP responses to cause
1342 * that peer to connect to us (connection reversal).
1344 * @return GNUNET_SYSERR on error, GNUNET_NO if nat client is disabled,
1345 * GNUNET_OK otherwise
1348 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
1349 const struct sockaddr_in *sa)
1353 char inet4[INET_ADDRSTRLEN];
1354 char port_as_string[6];
1355 struct GNUNET_OS_Process *proc;
1358 if (GNUNET_YES != h->enable_nat_client)
1359 return GNUNET_NO; /* not permitted / possible */
1361 if (h->internal_address == NULL)
1363 LOG (GNUNET_ERROR_TYPE_WARNING, "nat",
1365 ("Internal IP address not known, cannot use ICMP NAT traversal method\n"));
1366 return GNUNET_SYSERR;
1368 GNUNET_assert (sa->sin_family == AF_INET);
1369 if (NULL == inet_ntop (AF_INET, &sa->sin_addr, inet4, INET_ADDRSTRLEN))
1371 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "inet_ntop");
1372 return GNUNET_SYSERR;
1374 GNUNET_snprintf (port_as_string, sizeof (port_as_string), "%d", h->adv_port);
1375 LOG (GNUNET_ERROR_TYPE_DEBUG,
1376 _("Running gnunet-helper-nat-client %s %s %u\n"), h->internal_address,
1377 inet4, (unsigned int) h->adv_port);
1378 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client");
1380 GNUNET_OS_start_process (GNUNET_NO, 0, NULL, NULL,
1382 "gnunet-helper-nat-client", h->internal_address,
1383 inet4, port_as_string, NULL);
1384 GNUNET_free (binary);
1386 return GNUNET_SYSERR;
1387 /* we know that the gnunet-helper-nat-client will terminate virtually
1389 GNUNET_OS_process_wait (proc);
1390 GNUNET_OS_process_destroy (proc);
1396 * Test if the given address is (currently) a plausible IP address for this peer.
1398 * @param h the handle returned by register
1399 * @param addr IP address to test (IPv4 or IPv6)
1400 * @param addrlen number of bytes in addr
1401 * @return GNUNET_YES if the address is plausible,
1402 * GNUNET_NO if the address is not plausible,
1403 * GNUNET_SYSERR if the address is malformed
1406 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h, const void *addr,
1409 struct LocalAddressList *pos;
1410 const struct sockaddr_in *in4;
1411 const struct sockaddr_in6 *in6;
1413 if ((addrlen != sizeof (struct in_addr)) &&
1414 (addrlen != sizeof (struct in6_addr)))
1417 return GNUNET_SYSERR;
1422 if (pos->addrlen == sizeof (struct sockaddr_in))
1424 in4 = (struct sockaddr_in *) &pos[1];
1425 if ((addrlen == sizeof (struct in_addr)) &&
1426 (0 == memcmp (&in4->sin_addr, addr, sizeof (struct in_addr))))
1429 else if (pos->addrlen == sizeof (struct sockaddr_in6))
1431 in6 = (struct sockaddr_in6 *) &pos[1];
1432 if ((addrlen == sizeof (struct in6_addr)) &&
1433 (0 == memcmp (&in6->sin6_addr, addr, sizeof (struct in6_addr))))
1442 LOG (GNUNET_ERROR_TYPE_WARNING,
1443 "Asked to validate one of my addresses and validation failed!\n");