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
7 by the Free Software Foundation; either version 3, or (at your
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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 DNS resolution of the external hostname
75 * given in the configuration (i.e. hole-punched DynDNS setup)
76 * during the previous iteration (see #3213).
81 * Address was obtained by looking up our own hostname in DNS.
86 * Address was obtained by scanning our hosts's network interfaces
87 * and taking their address (no DNS involved).
89 LAL_INTERFACE_ADDRESS,
92 * Addresses we were explicitly bound to.
97 * Addresses from UPnP or PMP
109 * List of local addresses that we currently deem valid. Actual
110 * struct is followed by the 'struct sockaddr'. Note that the code
111 * intentionally makes no attempt to ensure that a particular address
112 * is only listed once (especially since it may come from different
113 * sources, and the source is an "internal" construct).
115 struct LocalAddressList
118 * This is a linked list.
120 struct LocalAddressList *next;
125 struct LocalAddressList *prev;
128 * Number of bytes of address that follow.
133 * Origin of the local address.
135 enum LocalAddressSource source;
140 * Handle for miniupnp-based NAT traversal actions.
146 * Doubly-linked list.
148 struct MiniList *next;
151 * Doubly-linked list.
153 struct MiniList *prev;
156 * Handle to mini-action.
158 struct GNUNET_NAT_MiniHandle *mini;
161 * Local port number that was mapped.
169 * Handle for active NAT registrations.
171 struct GNUNET_NAT_Handle
175 * Configuration to use.
177 const struct GNUNET_CONFIGURATION_Handle *cfg;
180 * Function to call when we learn about a new address.
182 GNUNET_NAT_AddressCallback address_callback;
185 * Function to call when we notice another peer asking for
186 * connection reversal.
188 GNUNET_NAT_ReversalCallback reversal_callback;
191 * Closure for callbacks (@e address_callback and @e reversal_callback)
196 * Handle for (DYN)DNS lookup of our external IP.
198 struct GNUNET_RESOLVER_RequestHandle *ext_dns;
201 * Handle for request of hostname resolution, non-NULL if pending.
203 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
206 * stdout pipe handle for the gnunet-helper-nat-server process
208 struct GNUNET_DISK_PipeHandle *server_stdout;
211 * stdout file handle (for reading) for the gnunet-helper-nat-server process
213 const struct GNUNET_DISK_FileHandle *server_stdout_handle;
216 * Linked list of currently valid addresses (head).
218 struct LocalAddressList *lal_head;
221 * Linked list of currently valid addresses (tail).
223 struct LocalAddressList *lal_tail;
226 * How long do we wait for restarting a crashed gnunet-helper-nat-server?
228 struct GNUNET_TIME_Relative server_retry_delay;
231 * ID of select gnunet-helper-nat-server stdout read task
233 GNUNET_SCHEDULER_TaskIdentifier server_read_task;
236 * ID of interface IP-scan task
238 GNUNET_SCHEDULER_TaskIdentifier ifc_task;
241 * ID of hostname DNS lookup task
243 GNUNET_SCHEDULER_TaskIdentifier hostname_task;
246 * ID of DynDNS lookup task
248 GNUNET_SCHEDULER_TaskIdentifier dns_task;
251 * ID of task to add addresses from bind.
253 GNUNET_SCHEDULER_TaskIdentifier bind_task;
256 * How often do we scan for changes in our IP address from our local
259 struct GNUNET_TIME_Relative ifc_scan_frequency;
262 * How often do we scan for changes in how our hostname resolves?
264 struct GNUNET_TIME_Relative hostname_dns_frequency;
267 * How often do we scan for changes in how our external (dyndns) hostname resolves?
269 struct GNUNET_TIME_Relative dyndns_frequency;
272 * The process id of the server process (if behind NAT)
274 struct GNUNET_OS_Process *server_proc;
277 * LAN address as passed by the caller (array).
279 struct sockaddr **local_addrs;
282 * Length of the @e local_addrs.
284 socklen_t *local_addrlens;
287 * List of handles for UPnP-traversal, one per local port (if
290 struct MiniList *mini_head;
293 * List of handles for UPnP-traversal, one per local port (if
296 struct MiniList *mini_tail;
299 * Number of entries in 'local_addrs' array.
301 unsigned int num_local_addrs;
304 * Our external address (according to config, UPnP may disagree...),
305 * in dotted decimal notation, IPv4-only. Or NULL if not known.
307 char *external_address;
310 * Presumably our internal address (according to config)
312 char *internal_address;
315 * Is this transport configured to be behind a NAT?
320 * Has the NAT been punched? (according to config)
325 * Is this transport configured to allow connections to NAT'd peers?
327 int enable_nat_client;
330 * Should we run the gnunet-helper-nat-server?
332 int enable_nat_server;
335 * Are we allowed to try UPnP/PMP for NAT traversal?
340 * Should we use local addresses (loopback)? (according to config)
342 int use_localaddresses;
345 * Should we return local addresses to clients
347 int return_localaddress;
350 * Should we do a DNS lookup of our hostname to find out our own IP?
355 * Is using IPv6 disabled?
360 * Is this TCP or UDP?
365 * Port we advertise to the outside.
373 * Try to start the gnunet-helper-nat-server (if it is not
376 * @param h handle to NAT
379 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h);
383 * Remove all addresses from the list of 'local' addresses
384 * that originated from the given source.
386 * @param h handle to NAT
387 * @param src source that identifies addresses to remove
390 remove_from_address_list_by_source (struct GNUNET_NAT_Handle *h,
391 enum LocalAddressSource src)
393 struct LocalAddressList *pos;
394 struct LocalAddressList *next;
397 while (NULL != (pos = next))
400 if (pos->source != src)
402 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
403 if (NULL != h->address_callback)
404 h->address_callback (h->callback_cls, GNUNET_NO,
405 (const struct sockaddr *) &pos[1], pos->addrlen);
412 * Add the given address to the list of 'local' addresses, thereby
413 * making it a 'legal' address for this peer to have.
415 * @param h handle to NAT
416 * @param src where did the local address originate from?
417 * @param arg the address, some `struct sockaddr`
418 * @param arg_size number of bytes in @a arg
421 add_to_address_list_as_is (struct GNUNET_NAT_Handle *h,
422 enum LocalAddressSource src,
423 const struct sockaddr *arg, socklen_t arg_size)
425 struct LocalAddressList *lal;
427 lal = GNUNET_malloc (sizeof (struct LocalAddressList) + arg_size);
428 memcpy (&lal[1], arg, arg_size);
429 lal->addrlen = arg_size;
431 GNUNET_CONTAINER_DLL_insert (h->lal_head, h->lal_tail, lal);
432 LOG (GNUNET_ERROR_TYPE_DEBUG,
433 "Adding address `%s' from source %d\n",
434 GNUNET_a2s (arg, arg_size),
436 if (NULL != h->address_callback)
437 h->address_callback (h->callback_cls, GNUNET_YES, arg, arg_size);
442 * Add the given address to the list of 'local' addresses, thereby
443 * making it a 'legal' address for this peer to have. Set the
444 * port number in the process to the advertised port and possibly
445 * also to zero (if we have the gnunet-helper-nat-server).
447 * @param h handle to NAT
448 * @param src where did the local address originate from?
449 * @param arg the address, some `struct sockaddr`
450 * @param arg_size number of bytes in @a arg
453 add_to_address_list (struct GNUNET_NAT_Handle *h,
454 enum LocalAddressSource src,
455 const struct sockaddr *arg,
458 struct sockaddr_in s4;
459 const struct sockaddr_in *in4;
460 struct sockaddr_in6 s6;
461 const struct sockaddr_in6 *in6;
463 if (arg_size == sizeof (struct sockaddr_in))
465 in4 = (const struct sockaddr_in *) arg;
467 s4.sin_port = htons (h->adv_port);
468 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4,
469 sizeof (struct sockaddr_in));
470 if (GNUNET_YES == h->enable_nat_server)
472 /* also add with PORT = 0 to indicate NAT server is enabled */
473 s4.sin_port = htons (0);
474 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4,
475 sizeof (struct sockaddr_in));
478 else if (arg_size == sizeof (struct sockaddr_in6))
480 if (GNUNET_YES != h->disable_ipv6)
482 in6 = (const struct sockaddr_in6 *) arg;
484 s6.sin6_port = htons (h->adv_port);
485 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s6,
486 sizeof (struct sockaddr_in6));
497 * Add the given IP address to the list of 'local' addresses, thereby
498 * making it a 'legal' address for this peer to have.
500 * @param h handle to NAT
501 * @param src where did the local address originate from?
502 * @param addr the address, some `struct in_addr` or `struct in6_addr`
503 * @param addrlen number of bytes in addr
506 add_ip_to_address_list (struct GNUNET_NAT_Handle *h,
507 enum LocalAddressSource src, const void *addr,
510 struct sockaddr_in s4;
511 const struct in_addr *in4;
512 struct sockaddr_in6 s6;
513 const struct in6_addr *in6;
515 if (addrlen == sizeof (struct in_addr))
517 in4 = (const struct in_addr *) addr;
518 memset (&s4, 0, sizeof (s4));
519 s4.sin_family = AF_INET;
521 #if HAVE_SOCKADDR_IN_SIN_LEN
522 s4.sin_len = (u_char) sizeof (struct sockaddr_in);
525 add_to_address_list (h, src, (const struct sockaddr *) &s4,
526 sizeof (struct sockaddr_in));
527 if (GNUNET_YES == h->enable_nat_server)
529 /* also add with PORT = 0 to indicate NAT server is enabled */
530 s4.sin_port = htons (0);
531 add_to_address_list (h, src, (const struct sockaddr *) &s4,
532 sizeof (struct sockaddr_in));
536 else if (addrlen == sizeof (struct in6_addr))
538 if (GNUNET_YES != h->disable_ipv6)
540 in6 = (const struct in6_addr *) addr;
541 memset (&s6, 0, sizeof (s6));
542 s6.sin6_family = AF_INET6;
543 s6.sin6_port = htons (h->adv_port);
544 #if HAVE_SOCKADDR_IN_SIN_LEN
545 s6.sin6_len = (u_char) sizeof (struct sockaddr_in6);
548 add_to_address_list (h, src, (const struct sockaddr *) &s6,
549 sizeof (struct sockaddr_in6));
560 * Task to do DNS lookup on our external hostname to
561 * get DynDNS-IP addresses.
563 * @param cls the NAT handle
564 * @param tc scheduler context
567 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
571 * Our (external) hostname was resolved and the configuration says that
572 * the NAT was hole-punched.
574 * @param cls the `struct GNUNET_NAT_Handle`
575 * @param addr NULL on error, otherwise result of DNS lookup
576 * @param addrlen number of bytes in @a addr
579 process_external_ip (void *cls,
580 const struct sockaddr *addr,
583 struct GNUNET_NAT_Handle *h = cls;
584 struct in_addr dummy;
589 /* Current iteration is over, remove 'old' IPs now */
590 LOG (GNUNET_ERROR_TYPE_DEBUG,
591 "Purging old IPs for external address\n");
592 remove_from_address_list_by_source (h, LAL_EXTERNAL_IP_OLD);
593 if (1 == inet_pton (AF_INET,
597 LOG (GNUNET_ERROR_TYPE_DEBUG,
598 "Got numeric IP for external address, not repeating lookup\n");
599 return; /* repated lookup pointless: was numeric! */
602 GNUNET_SCHEDULER_add_delayed (h->dyndns_frequency,
606 LOG (GNUNET_ERROR_TYPE_DEBUG,
607 "Got IP `%s' for external address `%s'\n",
608 GNUNET_a2s (addr, addrlen),
609 h->external_address);
610 add_to_address_list (h, LAL_EXTERNAL_IP, addr, addrlen);
615 * Task to do a lookup on our hostname for IP addresses.
617 * @param cls the NAT handle
618 * @param tc scheduler context
621 resolve_hostname (void *cls,
622 const struct GNUNET_SCHEDULER_TaskContext *tc);
626 * Function called by the resolver for each address obtained from DNS
627 * for our own hostname. Add the addresses to the list of our IP
631 * @param addr one of the addresses of the host, NULL for the last address
632 * @param addrlen length of the @a addr
635 process_hostname_ip (void *cls,
636 const struct sockaddr *addr,
639 struct GNUNET_NAT_Handle *h = cls;
643 h->hostname_dns = NULL;
645 GNUNET_SCHEDULER_add_delayed (h->hostname_dns_frequency,
646 &resolve_hostname, h);
649 add_to_address_list (h, LAL_HOSTNAME_DNS, addr, addrlen);
654 * Add the IP of our network interface to the list of
657 * @param cls the `struct GNUNET_NAT_Handle`
658 * @param name name of the interface
659 * @param isDefault do we think this may be our default interface
660 * @param addr address of the interface
661 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
662 * @param netmask the network mask (can be NULL for unknown or unassigned))
663 * @param addrlen number of bytes in @a addr and @a broadcast_addr
664 * @return #GNUNET_OK to continue iterating
667 process_interfaces (void *cls, const char *name, int isDefault,
668 const struct sockaddr *addr,
669 const struct sockaddr *broadcast_addr,
670 const struct sockaddr *netmask, socklen_t addrlen)
672 const static struct in6_addr any6 = IN6ADDR_ANY_INIT;
673 struct GNUNET_NAT_Handle *h = cls;
674 const struct sockaddr_in *s4;
675 const struct sockaddr_in6 *s6;
677 char buf[INET6_ADDRSTRLEN];
681 switch (addr->sa_family)
684 /* check if we're bound to the "ANY" IP address */
685 have_any = GNUNET_NO;
686 for (i=0;i<h->num_local_addrs;i++)
688 if (h->local_addrs[i]->sa_family != AF_INET)
693 if (INADDR_ANY == ((struct sockaddr_in*) h->local_addrs[i])->sin_addr.s_addr)
695 have_any = GNUNET_YES;
699 if (GNUNET_NO == have_any)
700 return GNUNET_OK; /* not bound to IP 0.0.0.0 but to specific IP addresses,
701 do not use those from interfaces */
702 s4 = (struct sockaddr_in *) addr;
705 /* Check if address is in 127.0.0.0/8 */
706 uint32_t address = ntohl ((uint32_t) (s4->sin_addr.s_addr));
707 uint32_t value = (address & 0xFF000000) ^ 0x7F000000;
709 if ((h->return_localaddress == GNUNET_NO) && (value == 0))
713 if ((GNUNET_YES == h->use_localaddresses) || (value != 0))
715 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s4->sin_addr,
716 sizeof (struct in_addr));
720 /* check if we're bound to the "ANY" IP address */
721 have_any = GNUNET_NO;
722 for (i=0;i<h->num_local_addrs;i++)
724 if (h->local_addrs[i]->sa_family != AF_INET6)
726 if (0 == memcmp (&any6,
727 &((struct sockaddr_in6*) h->local_addrs[i])->sin6_addr,
728 sizeof (struct in6_addr)))
730 have_any = GNUNET_YES;
734 if (GNUNET_NO == have_any)
735 return GNUNET_OK; /* not bound to "ANY" IP (::0) but to specific IP addresses,
736 do not use those from interfaces */
738 s6 = (struct sockaddr_in6 *) addr;
739 if (IN6_IS_ADDR_LINKLOCAL (&((struct sockaddr_in6 *) addr)->sin6_addr))
741 /* skip link local addresses */
744 if ((h->return_localaddress == GNUNET_NO) &&
745 (IN6_IS_ADDR_LOOPBACK (&((struct sockaddr_in6 *) addr)->sin6_addr)))
750 if (GNUNET_YES == h->use_localaddresses)
752 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s6->sin6_addr,
753 sizeof (struct in6_addr));
760 if ((h->internal_address == NULL) && (h->server_proc == NULL) &&
761 (h->server_read_task == GNUNET_SCHEDULER_NO_TASK) &&
762 (GNUNET_YES == isDefault) && ((addr->sa_family == AF_INET) ||
763 (addr->sa_family == AF_INET6)))
765 /* no internal address configured, but we found a "default"
766 * interface, try using that as our 'internal' address */
767 h->internal_address =
768 GNUNET_strdup (inet_ntop (addr->sa_family, ip, buf, sizeof (buf)));
769 start_gnunet_nat_server (h);
776 * Task that restarts the gnunet-helper-nat-server process after a crash
777 * after a certain delay.
779 * @param cls the `struct GNUNET_NAT_Handle`
780 * @param tc scheduler context
783 restart_nat_server (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
785 struct GNUNET_NAT_Handle *h = cls;
787 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
788 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
790 start_gnunet_nat_server (h);
795 * We have been notified that gnunet-helper-nat-server has written
796 * something to stdout. Handle the output, then reschedule this
797 * function to be called again once more is available.
799 * @param cls the NAT handle
800 * @param tc the scheduling context
803 nat_server_read (void *cls,
804 const struct GNUNET_SCHEDULER_TaskContext *tc)
806 struct GNUNET_NAT_Handle *h = cls;
811 const char *port_start;
812 struct sockaddr_in sin_addr;
814 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
815 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
817 memset (mybuf, 0, sizeof (mybuf));
819 GNUNET_DISK_file_read (h->server_stdout_handle, mybuf, sizeof (mybuf));
822 LOG (GNUNET_ERROR_TYPE_DEBUG,
823 "Finished reading from server stdout with code: %d\n",
825 if (0 != GNUNET_OS_process_kill (h->server_proc, GNUNET_TERM_SIG))
826 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill");
827 GNUNET_OS_process_wait (h->server_proc);
828 GNUNET_OS_process_destroy (h->server_proc);
829 h->server_proc = NULL;
830 GNUNET_DISK_pipe_close (h->server_stdout);
831 h->server_stdout = NULL;
832 h->server_stdout_handle = NULL;
833 /* now try to restart it */
834 h->server_retry_delay = GNUNET_TIME_STD_BACKOFF (h->server_retry_delay);
835 h->server_read_task =
836 GNUNET_SCHEDULER_add_delayed (h->server_retry_delay,
837 &restart_nat_server, h);
842 for (i = 0; i < sizeof (mybuf); i++)
844 if (mybuf[i] == '\n')
849 if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf)))
852 port_start = &mybuf[i + 1];
856 /* construct socket address of sender */
857 memset (&sin_addr, 0, sizeof (sin_addr));
858 sin_addr.sin_family = AF_INET;
859 #if HAVE_SOCKADDR_IN_SIN_LEN
860 sin_addr.sin_len = sizeof (sin_addr);
862 if ((NULL == port_start) || (1 != SSCANF (port_start, "%d", &port)) ||
863 (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr)))
865 /* should we restart gnunet-helper-nat-server? */
866 LOG (GNUNET_ERROR_TYPE_WARNING, "nat",
867 _("gnunet-helper-nat-server generated malformed address `%s'\n"),
869 h->server_read_task =
870 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
871 h->server_stdout_handle,
872 &nat_server_read, h);
875 sin_addr.sin_port = htons ((uint16_t) port);
876 LOG (GNUNET_ERROR_TYPE_DEBUG, "gnunet-helper-nat-server read: %s:%d\n", mybuf,
878 h->reversal_callback (h->callback_cls, (const struct sockaddr *) &sin_addr,
880 h->server_read_task =
881 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
882 h->server_stdout_handle, &nat_server_read,
888 * Try to start the gnunet-helper-nat-server (if it is not
891 * @param h handle to NAT
894 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h)
898 if ((h->behind_nat == GNUNET_YES) && (h->enable_nat_server == GNUNET_YES) &&
899 (h->internal_address != NULL) &&
902 GNUNET_DISK_pipe (GNUNET_YES, GNUNET_YES, GNUNET_NO, GNUNET_YES))))
904 LOG (GNUNET_ERROR_TYPE_DEBUG,
905 "Starting `%s' at `%s'\n",
906 "gnunet-helper-nat-server", h->internal_address);
907 /* Start the server process */
908 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
910 GNUNET_OS_start_process (GNUNET_NO, 0, NULL, h->server_stdout, NULL,
912 "gnunet-helper-nat-server",
913 h->internal_address, NULL);
914 GNUNET_free (binary);
915 if (h->server_proc == NULL)
917 LOG (GNUNET_ERROR_TYPE_WARNING, "nat", _("Failed to start %s\n"),
918 "gnunet-helper-nat-server");
919 GNUNET_DISK_pipe_close (h->server_stdout);
920 h->server_stdout = NULL;
924 /* Close the write end of the read pipe */
925 GNUNET_DISK_pipe_close_end (h->server_stdout, GNUNET_DISK_PIPE_END_WRITE);
926 h->server_stdout_handle =
927 GNUNET_DISK_pipe_handle (h->server_stdout, GNUNET_DISK_PIPE_END_READ);
928 h->server_read_task =
929 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
930 h->server_stdout_handle,
931 &nat_server_read, h);
938 * Task to scan the local network interfaces for IP addresses.
940 * @param cls the NAT handle
941 * @param tc scheduler context
944 list_interfaces (void *cls,
945 const struct GNUNET_SCHEDULER_TaskContext *tc)
947 struct GNUNET_NAT_Handle *h = cls;
949 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
950 remove_from_address_list_by_source (h, LAL_INTERFACE_ADDRESS);
951 GNUNET_OS_network_interfaces_list (&process_interfaces, h);
953 GNUNET_SCHEDULER_add_delayed (h->ifc_scan_frequency,
954 &list_interfaces, h);
959 * Task to do a lookup on our hostname for IP addresses.
961 * @param cls the NAT handle
962 * @param tc scheduler context
965 resolve_hostname (void *cls,
966 const struct GNUNET_SCHEDULER_TaskContext *tc)
968 struct GNUNET_NAT_Handle *h = cls;
970 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
971 remove_from_address_list_by_source (h, LAL_HOSTNAME_DNS);
973 GNUNET_RESOLVER_hostname_resolve (AF_UNSPEC, HOSTNAME_RESOLVE_TIMEOUT,
974 &process_hostname_ip, h);
979 * Task to do DNS lookup on our external hostname to
980 * get DynDNS-IP addresses.
982 * @param cls the NAT handle
983 * @param tc scheduler context
986 resolve_dns (void *cls,
987 const struct GNUNET_SCHEDULER_TaskContext *tc)
989 struct GNUNET_NAT_Handle *h = cls;
990 struct LocalAddressList *pos;
992 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
993 for (pos = h->lal_head; NULL != pos; pos = pos->next)
994 if (pos->source == LAL_EXTERNAL_IP)
995 pos->source = LAL_EXTERNAL_IP_OLD;
996 LOG (GNUNET_ERROR_TYPE_DEBUG,
997 "Resolving external address `%s'\n",
998 h->external_address);
1000 GNUNET_RESOLVER_ip_get (h->external_address, AF_INET,
1001 GNUNET_TIME_UNIT_MINUTES,
1002 &process_external_ip, h);
1007 * Add or remove UPnP-mapped addresses.
1009 * @param cls the `struct GNUNET_NAT_Handle`
1010 * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
1011 * the previous (now invalid) one
1012 * @param addr either the previous or the new public IP address
1013 * @param addrlen actual lenght of @a addr
1014 * @param ret GNUNET_NAT_ERROR_SUCCESS on success, otherwise an error code
1017 upnp_add (void *cls,
1019 const struct sockaddr *addr,
1021 enum GNUNET_NAT_StatusCode ret)
1023 struct GNUNET_NAT_Handle *h = cls;
1024 struct LocalAddressList *pos;
1025 struct LocalAddressList *next;
1028 if (GNUNET_NAT_ERROR_SUCCESS != ret)
1030 /* Error while running upnp client */
1031 LOG (GNUNET_ERROR_TYPE_ERROR,
1032 _("Error while running upnp client:\n"));
1034 //FIXME: convert error code to string
1039 if (GNUNET_YES == add_remove)
1041 add_to_address_list (h, LAL_UPNP, addr, addrlen);
1044 else if (GNUNET_NO == add_remove)
1046 /* remove address */
1048 while (NULL != (pos = next))
1051 if ((pos->source != LAL_UPNP) || (pos->addrlen != addrlen) ||
1052 (0 != memcmp (&pos[1], addr, addrlen)))
1054 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
1055 if (NULL != h->address_callback)
1056 h->address_callback (h->callback_cls, GNUNET_NO,
1057 (const struct sockaddr *) &pos[1], pos->addrlen);
1059 return; /* only remove once */
1061 /* asked to remove address that does not exist */
1062 LOG (GNUNET_ERROR_TYPE_ERROR,
1063 "Asked to remove unkown address `%s'\n",
1064 GNUNET_a2s(addr, addrlen));
1076 * Try to add a port mapping using UPnP.
1078 * @param h overall NAT handle
1079 * @param port port to map with UPnP
1082 add_minis (struct GNUNET_NAT_Handle *h,
1085 struct MiniList *ml;
1090 if (port == ml->port)
1091 return; /* already got this port */
1095 ml = GNUNET_new (struct MiniList);
1097 ml->mini = GNUNET_NAT_mini_map_start (port, h->is_tcp, &upnp_add, h);
1099 if (NULL == ml->mini)
1101 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1102 _("Failed to run upnp client for port %u\n"), ml->port);
1107 GNUNET_CONTAINER_DLL_insert (h->mini_head, h->mini_tail, ml);
1112 * Task to add addresses from original bind to set of valid addrs.
1114 * @param cls the NAT handle
1115 * @param tc scheduler context
1118 add_from_bind (void *cls,
1119 const struct GNUNET_SCHEDULER_TaskContext *tc)
1121 static struct in6_addr any = IN6ADDR_ANY_INIT;
1122 struct GNUNET_NAT_Handle *h = cls;
1124 struct sockaddr *sa;
1125 const struct sockaddr_in *v4;
1127 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1128 for (i = 0; i < h->num_local_addrs; i++)
1130 sa = h->local_addrs[i];
1131 switch (sa->sa_family)
1134 if (sizeof (struct sockaddr_in) != h->local_addrlens[i])
1139 v4 = (const struct sockaddr_in *) sa;
1140 if (0 != v4->sin_addr.s_addr)
1141 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1142 sizeof (struct sockaddr_in));
1145 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1146 "Running upnp client for address `%s'\n",
1147 GNUNET_a2s (sa,sizeof (struct sockaddr_in)));
1148 add_minis (h, ntohs (v4->sin_port));
1152 if (sizeof (struct sockaddr_in6) != h->local_addrlens[i])
1158 memcmp (&((const struct sockaddr_in6 *) sa)->sin6_addr, &any,
1159 sizeof (struct in6_addr)))
1160 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1161 sizeof (struct sockaddr_in6));
1172 * Attempt to enable port redirection and detect public IP address contacting
1173 * UPnP or NAT-PMP routers on the local network. Use addr to specify to which
1174 * of the local host's addresses should the external port be mapped. The port
1175 * is taken from the corresponding sockaddr_in[6] field.
1177 * @param cfg configuration to use
1178 * @param is_tcp #GNUNET_YES for TCP, #GNUNET_NO for UDP
1179 * @param adv_port advertised port (port we are either bound to or that our OS
1180 * locally performs redirection from to our bound port).
1181 * @param num_addrs number of addresses in 'addrs'
1182 * @param addrs the local addresses packets should be redirected to
1183 * @param addrlens actual lengths of the addresses
1184 * @param address_callback function to call everytime the public IP address changes
1185 * @param reversal_callback function to call if someone wants connection reversal from us
1186 * @param callback_cls closure for callbacks
1187 * @return NULL on error, otherwise handle that can be used to unregister
1189 struct GNUNET_NAT_Handle *
1190 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
1193 unsigned int num_addrs,
1194 const struct sockaddr **addrs,
1195 const socklen_t * addrlens,
1196 GNUNET_NAT_AddressCallback address_callback,
1197 GNUNET_NAT_ReversalCallback reversal_callback,
1200 struct GNUNET_NAT_Handle *h;
1201 struct in_addr in_addr;
1205 LOG (GNUNET_ERROR_TYPE_DEBUG,
1206 "Registered with NAT service at port %u with %u IP bound local addresses\n",
1207 (unsigned int) adv_port, num_addrs);
1208 h = GNUNET_new (struct GNUNET_NAT_Handle);
1209 h->server_retry_delay = GNUNET_TIME_UNIT_SECONDS;
1212 h->address_callback = address_callback;
1213 h->reversal_callback = reversal_callback;
1214 h->callback_cls = callback_cls;
1215 h->num_local_addrs = num_addrs;
1216 h->adv_port = adv_port;
1219 h->local_addrs = GNUNET_malloc (num_addrs * sizeof (struct sockaddr *));
1220 h->local_addrlens = GNUNET_malloc (num_addrs * sizeof (socklen_t));
1221 for (i = 0; i < num_addrs; i++)
1223 GNUNET_assert (addrlens[i] > 0);
1224 GNUNET_assert (addrs[i] != NULL);
1225 h->local_addrlens[i] = addrlens[i];
1226 h->local_addrs[i] = GNUNET_malloc (addrlens[i]);
1227 memcpy (h->local_addrs[i], addrs[i], addrlens[i]);
1230 h->bind_task = GNUNET_SCHEDULER_add_now (&add_from_bind, h);
1232 GNUNET_CONFIGURATION_have_value (cfg, "nat", "INTERNAL_ADDRESS"))
1234 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1236 &h->internal_address);
1238 if ((h->internal_address != NULL) &&
1239 (inet_pton (AF_INET, h->internal_address, &in_addr) != 1))
1241 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
1242 "nat", "INTERNAL_ADDRESS",
1244 GNUNET_free (h->internal_address);
1245 h->internal_address = NULL;
1249 GNUNET_CONFIGURATION_have_value (cfg, "nat", "EXTERNAL_ADDRESS"))
1251 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1253 &h->external_address);
1256 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT");
1258 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "PUNCHED_NAT");
1259 h->enable_nat_client =
1260 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_CLIENT");
1261 h->enable_nat_server =
1262 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_ICMP_SERVER");
1264 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_UPNP");
1265 h->use_localaddresses =
1266 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_LOCALADDR");
1267 h->return_localaddress =
1268 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat",
1269 "RETURN_LOCAL_ADDRESSES");
1272 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_HOSTNAME");
1274 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "DISABLEV6");
1276 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "DYNDNS_FREQUENCY",
1277 &h->dyndns_frequency))
1278 h->dyndns_frequency = DYNDNS_FREQUENCY;
1280 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "IFC_SCAN_FREQUENCY",
1281 &h->ifc_scan_frequency))
1282 h->ifc_scan_frequency = IFC_SCAN_FREQUENCY;
1284 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "HOSTNAME_DNS_FREQUENCY",
1285 &h->hostname_dns_frequency))
1286 h->hostname_dns_frequency = HOSTNAME_DNS_FREQUENCY;
1288 if (NULL == reversal_callback)
1289 h->enable_nat_server = GNUNET_NO;
1291 /* Check for UPnP client, disable immediately if not available */
1292 if ( (GNUNET_YES == h->enable_upnp) &&
1294 GNUNET_OS_check_helper_binary ("upnpc", GNUNET_NO, NULL)) )
1296 LOG (GNUNET_ERROR_TYPE_ERROR,
1297 _("UPnP enabled in configuration, but UPnP client `upnpc` command not found, disabling UPnP \n"));
1298 h->enable_upnp = GNUNET_NO;
1301 /* Check if NAT was hole-punched */
1302 if ((NULL != h->address_callback) &&
1303 (NULL != h->external_address) &&
1304 (GNUNET_YES == h->nat_punched))
1306 h->dns_task = GNUNET_SCHEDULER_add_now (&resolve_dns, h);
1307 h->enable_nat_server = GNUNET_NO;
1308 h->enable_upnp = GNUNET_NO;
1312 LOG (GNUNET_ERROR_TYPE_DEBUG,
1313 "No external IP address given to add to our list of addresses\n");
1316 /* Test for SUID binaries */
1317 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
1318 if ((h->behind_nat == GNUNET_YES) && (GNUNET_YES == h->enable_nat_server) &&
1320 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
1322 h->enable_nat_server = GNUNET_NO;
1323 LOG (GNUNET_ERROR_TYPE_WARNING,
1324 _("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1325 "gnunet-helper-nat-server");
1327 GNUNET_free (binary);
1328 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client");
1329 if ((GNUNET_YES == h->enable_nat_client) &&
1331 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
1333 h->enable_nat_client = GNUNET_NO;
1334 LOG (GNUNET_ERROR_TYPE_WARNING,
1336 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1337 "gnunet-helper-nat-client");
1339 GNUNET_free (binary);
1340 start_gnunet_nat_server (h);
1342 /* FIXME: add support for UPnP, etc */
1344 if (NULL != h->address_callback)
1346 h->ifc_task = GNUNET_SCHEDULER_add_now (&list_interfaces, h);
1347 if (GNUNET_YES == h->use_hostname)
1348 h->hostname_task = GNUNET_SCHEDULER_add_now (&resolve_hostname, h);
1356 * Stop port redirection and public IP address detection for the given handle.
1357 * This frees the handle, after having sent the needed commands to close open ports.
1359 * @param h the handle to stop
1362 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h)
1365 struct LocalAddressList *lal;
1366 struct MiniList *ml;
1368 LOG (GNUNET_ERROR_TYPE_DEBUG,
1369 "NAT unregister called\n");
1370 while (NULL != (ml = h->mini_head))
1372 GNUNET_CONTAINER_DLL_remove (h->mini_head, h->mini_tail, ml);
1373 if (NULL != ml->mini)
1374 GNUNET_NAT_mini_map_stop (ml->mini);
1377 if (NULL != h->ext_dns)
1379 GNUNET_RESOLVER_request_cancel (h->ext_dns);
1382 if (NULL != h->hostname_dns)
1384 GNUNET_RESOLVER_request_cancel (h->hostname_dns);
1385 h->hostname_dns = NULL;
1387 if (GNUNET_SCHEDULER_NO_TASK != h->server_read_task)
1389 GNUNET_SCHEDULER_cancel (h->server_read_task);
1390 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
1392 if (GNUNET_SCHEDULER_NO_TASK != h->bind_task)
1394 GNUNET_SCHEDULER_cancel (h->bind_task);
1395 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1397 if (GNUNET_SCHEDULER_NO_TASK != h->ifc_task)
1399 GNUNET_SCHEDULER_cancel (h->ifc_task);
1400 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
1402 if (GNUNET_SCHEDULER_NO_TASK != h->hostname_task)
1404 GNUNET_SCHEDULER_cancel (h->hostname_task);
1405 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
1407 if (GNUNET_SCHEDULER_NO_TASK != h->dns_task)
1409 GNUNET_SCHEDULER_cancel (h->dns_task);
1410 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
1412 if (NULL != h->server_proc)
1414 if (0 != GNUNET_OS_process_kill (h->server_proc, GNUNET_TERM_SIG))
1415 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING, "nat", "kill");
1416 GNUNET_OS_process_wait (h->server_proc);
1417 GNUNET_OS_process_destroy (h->server_proc);
1418 h->server_proc = NULL;
1419 GNUNET_DISK_pipe_close (h->server_stdout);
1420 h->server_stdout = NULL;
1421 h->server_stdout_handle = NULL;
1423 if (NULL != h->server_stdout)
1425 GNUNET_DISK_pipe_close (h->server_stdout);
1426 h->server_stdout = NULL;
1427 h->server_stdout_handle = NULL;
1429 while (NULL != (lal = h->lal_head))
1431 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, lal);
1432 if (NULL != h->address_callback)
1433 h->address_callback (h->callback_cls, GNUNET_NO,
1434 (const struct sockaddr *) &lal[1], lal->addrlen);
1437 for (i = 0; i < h->num_local_addrs; i++)
1438 GNUNET_free (h->local_addrs[i]);
1439 GNUNET_free_non_null (h->local_addrs);
1440 GNUNET_free_non_null (h->local_addrlens);
1441 GNUNET_free_non_null (h->external_address);
1442 GNUNET_free_non_null (h->internal_address);
1448 * We learned about a peer (possibly behind NAT) so run the
1449 * gnunet-helper-nat-client to send dummy ICMP responses to cause
1450 * that peer to connect to us (connection reversal).
1452 * @param h handle (used for configuration)
1453 * @param sa the address of the peer (IPv4-only)
1454 * @return #GNUNET_SYSERR on error, #GNUNET_NO if nat client is disabled,
1455 * #GNUNET_OK otherwise
1458 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
1459 const struct sockaddr_in *sa)
1463 char inet4[INET_ADDRSTRLEN];
1464 char port_as_string[6];
1465 struct GNUNET_OS_Process *proc;
1468 if (GNUNET_YES != h->enable_nat_client)
1469 return GNUNET_NO; /* not permitted / possible */
1471 if (h->internal_address == NULL)
1473 LOG (GNUNET_ERROR_TYPE_WARNING, "nat",
1474 _("Internal IP address not known, cannot use ICMP NAT traversal method\n"));
1475 return GNUNET_SYSERR;
1477 GNUNET_assert (sa->sin_family == AF_INET);
1478 if (NULL == inet_ntop (AF_INET, &sa->sin_addr, inet4, INET_ADDRSTRLEN))
1480 GNUNET_log_from_strerror (GNUNET_ERROR_TYPE_WARNING,
1483 return GNUNET_SYSERR;
1485 GNUNET_snprintf (port_as_string,
1486 sizeof (port_as_string),
1489 LOG (GNUNET_ERROR_TYPE_DEBUG,
1490 _("Running gnunet-helper-nat-client %s %s %u\n"),
1491 h->internal_address,
1493 (unsigned int) h->adv_port);
1494 binary = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client");
1496 GNUNET_OS_start_process (GNUNET_NO, 0, NULL, NULL, NULL,
1498 "gnunet-helper-nat-client",
1499 h->internal_address,
1500 inet4, port_as_string, NULL);
1501 GNUNET_free (binary);
1503 return GNUNET_SYSERR;
1504 /* we know that the gnunet-helper-nat-client will terminate virtually
1506 GNUNET_OS_process_wait (proc);
1507 GNUNET_OS_process_destroy (proc);
1513 * Test if the given address is (currently) a plausible IP address for this peer.
1515 * @param h the handle returned by register
1516 * @param addr IP address to test (IPv4 or IPv6)
1517 * @param addrlen number of bytes in @a addr
1518 * @return #GNUNET_YES if the address is plausible,
1519 * #GNUNET_NO if the address is not plausible,
1520 * #GNUNET_SYSERR if the address is malformed
1523 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h,
1527 struct LocalAddressList *pos;
1528 const struct sockaddr_in *in4;
1529 const struct sockaddr_in6 *in6;
1531 if ((addrlen != sizeof (struct in_addr)) &&
1532 (addrlen != sizeof (struct in6_addr)))
1535 return GNUNET_SYSERR;
1537 for (pos = h->lal_head; NULL != pos; pos = pos->next)
1539 if (pos->addrlen == sizeof (struct sockaddr_in))
1541 in4 = (struct sockaddr_in *) &pos[1];
1542 if ((addrlen == sizeof (struct in_addr)) &&
1543 (0 == memcmp (&in4->sin_addr, addr, sizeof (struct in_addr))))
1546 else if (pos->addrlen == sizeof (struct sockaddr_in6))
1548 in6 = (struct sockaddr_in6 *) &pos[1];
1549 if ((addrlen == sizeof (struct in6_addr)) &&
1550 (0 == memcmp (&in6->sin6_addr, addr, sizeof (struct in6_addr))))
1558 LOG (GNUNET_ERROR_TYPE_WARNING,
1559 "Asked to validate one of my addresses and validation failed!\n");
1565 * Converts enum GNUNET_NAT_StatusCode to a string
1567 * @param err error code to resolve to a string
1568 * @return point to a static string containing the error code
1571 GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err){
1573 case GNUNET_NAT_ERROR_SUCCESS:
1574 return _("Operation Successful");
1577 return "unknown status code";