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
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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"
35 * How often do we scan for changes in our IP address from our local
38 #define IFC_SCAN_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
41 * How often do we scan for changes in how our hostname resolves?
43 #define HOSTNAME_DNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 20)
47 * How often do we scan for changes in how our external (dyndns) hostname resolves?
49 #define DYNDNS_FREQUENCY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 7)
52 * How long until we give up trying to resolve our own hostname?
54 #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)
58 * Where did the given local address originate from?
59 * To be used for debugging as well as in the future
60 * to remove all addresses from a certain source when
61 * we reevaluate the source.
63 enum LocalAddressSource
66 * Address was obtained by DNS resolution of the external hostname
67 * given in the configuration (i.e. hole-punched DynDNS setup).
72 * Address was obtained by looking up our own hostname in DNS.
77 * Address was obtained by scanning our hosts's network interfaces
78 * and taking their address (no DNS involved).
80 LAL_INTERFACE_ADDRESS,
83 * Addresses we were explicitly bound to.
88 * Addresses from UPnP or PMP
100 * List of local addresses that we currently deem valid. Actual
101 * struct is followed by the 'struct sockaddr'. Note that the code
102 * intentionally makes no attempt to ensure that a particular address
103 * is only listed once (especially since it may come from different
104 * sources, and the source is an "internal" construct).
106 struct LocalAddressList
109 * This is a linked list.
111 struct LocalAddressList *next;
116 struct LocalAddressList *prev;
119 * Number of bytes of address that follow.
124 * Origin of the local address.
126 enum LocalAddressSource source;
131 * Handle for miniupnp-based NAT traversal actions.
137 * Doubly-linked list.
139 struct MiniList *next;
142 * Doubly-linked list.
144 struct MiniList *prev;
147 * Handle to mini-action.
149 struct GNUNET_NAT_MiniHandle *mini;
152 * Local port number that was mapped.
160 * Handle for active NAT registrations.
162 struct GNUNET_NAT_Handle
166 * Configuration to use.
168 const struct GNUNET_CONFIGURATION_Handle *cfg;
171 * Function to call when we learn about a new address.
173 GNUNET_NAT_AddressCallback address_callback;
176 * Function to call when we notice another peer asking for
177 * connection reversal.
179 GNUNET_NAT_ReversalCallback reversal_callback;
182 * Closure for 'callback'.
187 * Handle for (DYN)DNS lookup of our external IP.
189 struct GNUNET_RESOLVER_RequestHandle *ext_dns;
192 * Handle for request of hostname resolution, non-NULL if pending.
194 struct GNUNET_RESOLVER_RequestHandle *hostname_dns;
197 * stdout pipe handle for the gnunet-helper-nat-server process
199 struct GNUNET_DISK_PipeHandle *server_stdout;
202 * stdout file handle (for reading) for the gnunet-helper-nat-server process
204 const struct GNUNET_DISK_FileHandle *server_stdout_handle;
207 * Linked list of currently valid addresses (head).
209 struct LocalAddressList *lal_head;
212 * Linked list of currently valid addresses (tail).
214 struct LocalAddressList *lal_tail;
217 * How long do we wait for restarting a crashed gnunet-helper-nat-server?
219 struct GNUNET_TIME_Relative server_retry_delay;
222 * ID of select gnunet-helper-nat-server stdout read task
224 GNUNET_SCHEDULER_TaskIdentifier server_read_task;
227 * ID of interface IP-scan task
229 GNUNET_SCHEDULER_TaskIdentifier ifc_task;
232 * ID of hostname DNS lookup task
234 GNUNET_SCHEDULER_TaskIdentifier hostname_task;
237 * ID of DynDNS lookup task
239 GNUNET_SCHEDULER_TaskIdentifier dns_task;
242 * ID of task to add addresses from bind.
244 GNUNET_SCHEDULER_TaskIdentifier bind_task;
247 * How often do we scan for changes in our IP address from our local
250 struct GNUNET_TIME_Relative ifc_scan_frequency;
253 * How often do we scan for changes in how our hostname resolves?
255 struct GNUNET_TIME_Relative hostname_dns_frequency;
258 * How often do we scan for changes in how our external (dyndns) hostname resolves?
260 struct GNUNET_TIME_Relative dyndns_frequency;
263 * The process id of the server process (if behind NAT)
265 struct GNUNET_OS_Process *server_proc;
268 * LAN address as passed by the caller (array).
270 struct sockaddr **local_addrs;
273 * Length of the 'local_addrs'.
275 socklen_t *local_addrlens;
278 * List of handles for UPnP-traversal, one per local port (if
281 struct MiniList *mini_head;
284 * List of handles for UPnP-traversal, one per local port (if
287 struct MiniList *mini_tail;
290 * Number of entries in 'local_addrs' array.
292 unsigned int num_local_addrs;
295 * Our external address (according to config, UPnP may disagree...),
296 * in dotted decimal notation, IPv4-only. Or NULL if not known.
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
365 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h);
369 * Remove all addresses from the list of 'local' addresses
370 * that originated from the given source.
372 * @param h handle to NAT
373 * @param src source that identifies addresses to remove
376 remove_from_address_list_by_source (struct GNUNET_NAT_Handle *h,
377 enum LocalAddressSource src)
379 struct LocalAddressList *pos;
380 struct LocalAddressList *next;
383 while (NULL != (pos = next))
386 if (pos->source != src)
388 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
389 if (NULL != h->address_callback)
390 h->address_callback (h->callback_cls, GNUNET_NO,
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 h handle to NAT
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, "nat",
420 "Adding address `%s' from source %d\n", GNUNET_a2s (arg,
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 h handle to NAT
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, enum LocalAddressSource src,
442 const struct sockaddr *arg, socklen_t arg_size)
444 struct sockaddr_in s4;
445 const struct sockaddr_in *in4;
446 struct sockaddr_in6 s6;
447 const struct sockaddr_in6 *in6;
449 if (arg_size == sizeof (struct sockaddr_in))
451 in4 = (const struct sockaddr_in *) arg;
453 s4.sin_port = htons (h->adv_port);
454 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4,
455 sizeof (struct sockaddr_in));
456 if (GNUNET_YES == h->enable_nat_server)
458 /* also add with PORT = 0 to indicate NAT server is enabled */
459 s4.sin_port = htons (0);
460 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s4,
461 sizeof (struct sockaddr_in));
464 else if (arg_size == sizeof (struct sockaddr_in6))
466 if (GNUNET_YES != h->disable_ipv6)
468 in6 = (const struct sockaddr_in6 *) arg;
470 s6.sin6_port = htons (h->adv_port);
471 add_to_address_list_as_is (h, src, (const struct sockaddr *) &s6,
472 sizeof (struct sockaddr_in6));
483 * Add the given IP address to the list of 'local' addresses, thereby
484 * making it a 'legal' address for this peer to have.
486 * @param h handle to NAT
487 * @param src where did the local address originate from?
488 * @param addr the address, some 'struct in_addr' or 'struct in6_addr'
489 * @param addrlen number of bytes in addr
492 add_ip_to_address_list (struct GNUNET_NAT_Handle *h,
493 enum LocalAddressSource src, const void *addr,
496 struct sockaddr_in s4;
497 const struct in_addr *in4;
498 struct sockaddr_in6 s6;
499 const struct in6_addr *in6;
501 if (addrlen == sizeof (struct in_addr))
503 in4 = (const struct in_addr *) addr;
504 memset (&s4, 0, sizeof (s4));
505 s4.sin_family = AF_INET;
507 #if HAVE_SOCKADDR_IN_SIN_LEN
508 s4.sin_len = (u_char) sizeof (struct sockaddr_in);
511 add_to_address_list (h, src, (const struct sockaddr *) &s4,
512 sizeof (struct sockaddr_in));
513 if (GNUNET_YES == h->enable_nat_server)
515 /* also add with PORT = 0 to indicate NAT server is enabled */
516 s4.sin_port = htons (0);
517 add_to_address_list (h, src, (const struct sockaddr *) &s4,
518 sizeof (struct sockaddr_in));
522 else if (addrlen == sizeof (struct in6_addr))
524 if (GNUNET_YES != h->disable_ipv6)
526 in6 = (const struct in6_addr *) addr;
527 memset (&s6, 0, sizeof (s6));
528 s6.sin6_family = AF_INET6;
529 s6.sin6_port = htons (h->adv_port);
530 #if HAVE_SOCKADDR_IN_SIN_LEN
531 s6.sin6_len = (u_char) sizeof (struct sockaddr_in6);
534 add_to_address_list (h, src, (const struct sockaddr *) &s6,
535 sizeof (struct sockaddr_in6));
546 * Task to do DNS lookup on our external hostname to
547 * get DynDNS-IP addresses.
549 * @param cls the NAT handle
550 * @param tc scheduler context
553 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
557 * Our (external) hostname was resolved and the configuration says that
558 * the NAT was hole-punched.
560 * @param cls the 'struct Plugin'
561 * @param addr NULL on error, otherwise result of DNS lookup
562 * @param addrlen number of bytes in addr
565 process_external_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
567 struct GNUNET_NAT_Handle *h = cls;
568 struct in_addr dummy;
573 if (1 == inet_pton (AF_INET, h->external_address, &dummy))
574 return; /* repated lookup pointless: was numeric! */
576 GNUNET_SCHEDULER_add_delayed (h->dyndns_frequency, &resolve_dns, h);
579 add_to_address_list (h, LAL_EXTERNAL_IP, addr, addrlen);
584 * Task to do a lookup on our hostname for IP addresses.
586 * @param cls the NAT handle
587 * @param tc scheduler context
590 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);
594 * Function called by the resolver for each address obtained from DNS
595 * for our own hostname. Add the addresses to the list of our IP
599 * @param addr one of the addresses of the host, NULL for the last address
600 * @param addrlen length of the address
603 process_hostname_ip (void *cls, const struct sockaddr *addr, socklen_t addrlen)
605 struct GNUNET_NAT_Handle *h = cls;
609 h->hostname_dns = NULL;
611 GNUNET_SCHEDULER_add_delayed (h->hostname_dns_frequency,
612 &resolve_hostname, h);
615 add_to_address_list (h, LAL_HOSTNAME_DNS, addr, addrlen);
620 * Add the IP of our network interface to the list of
623 * @param cls the 'struct GNUNET_NAT_Handle'
624 * @param name name of the interface
625 * @param isDefault do we think this may be our default interface
626 * @param addr address of the interface
627 * @param addrlen number of bytes in addr
628 * @return GNUNET_OK to continue iterating
631 process_interfaces (void *cls, const char *name, int isDefault,
632 const struct sockaddr *addr, socklen_t addrlen)
634 struct GNUNET_NAT_Handle *h = cls;
635 const struct sockaddr_in *s4;
636 const struct sockaddr_in6 *s6;
638 char buf[INET6_ADDRSTRLEN];
640 switch (addr->sa_family)
643 s4 = (struct sockaddr_in *) addr;
645 if (GNUNET_YES == h->use_localaddresses)
646 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s4->sin_addr,
647 sizeof (struct in_addr));
650 s6 = (struct sockaddr_in6 *) addr;
651 if (IN6_IS_ADDR_LINKLOCAL (&((struct sockaddr_in6 *) addr)->sin6_addr))
653 /* skip link local addresses */
657 if (GNUNET_YES == h->use_localaddresses)
658 add_ip_to_address_list (h, LAL_INTERFACE_ADDRESS, &s6->sin6_addr,
659 sizeof (struct in6_addr));
665 if ((h->internal_address == NULL) && (h->server_proc == NULL) &&
666 (h->server_read_task == GNUNET_SCHEDULER_NO_TASK) &&
667 (GNUNET_YES == isDefault) && ((addr->sa_family == AF_INET) ||
668 (addr->sa_family == AF_INET6)))
670 /* no internal address configured, but we found a "default"
671 * interface, try using that as our 'internal' address */
672 h->internal_address =
673 GNUNET_strdup (inet_ntop (addr->sa_family, ip, buf, sizeof (buf)));
674 start_gnunet_nat_server (h);
681 * Task that restarts the gnunet-helper-nat-server process after a crash
682 * after a certain delay.
684 * @param cls the 'struct GNUNET_NAT_Handle'
685 * @param tc scheduler context
688 restart_nat_server (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
690 struct GNUNET_NAT_Handle *h = cls;
692 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
693 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
695 start_gnunet_nat_server (h);
700 * We have been notified that gnunet-helper-nat-server has written something to stdout.
701 * Handle the output, then reschedule this function to be called again once
704 * @param cls the NAT handle
705 * @param tc the scheduling context
708 nat_server_read (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
710 struct GNUNET_NAT_Handle *h = cls;
715 const char *port_start;
716 struct sockaddr_in sin_addr;
718 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
719 if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0)
721 memset (mybuf, 0, sizeof (mybuf));
723 GNUNET_DISK_file_read (h->server_stdout_handle, mybuf, sizeof (mybuf));
727 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "nat",
728 "Finished reading from server stdout with code: %d\n",
731 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
732 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
733 GNUNET_OS_process_wait (h->server_proc);
734 GNUNET_OS_process_close (h->server_proc);
735 h->server_proc = NULL;
736 GNUNET_DISK_pipe_close (h->server_stdout);
737 h->server_stdout = NULL;
738 h->server_stdout_handle = NULL;
739 /* now try to restart it */
740 h->server_retry_delay =
741 GNUNET_TIME_relative_multiply (h->server_retry_delay, 2);
742 h->server_retry_delay =
743 GNUNET_TIME_relative_max (GNUNET_TIME_UNIT_HOURS,
744 h->server_retry_delay);
745 h->server_read_task =
746 GNUNET_SCHEDULER_add_delayed (h->server_retry_delay,
747 &restart_nat_server, h);
752 for (i = 0; i < sizeof (mybuf); i++)
754 if (mybuf[i] == '\n')
759 if ((mybuf[i] == ':') && (i + 1 < sizeof (mybuf)))
762 port_start = &mybuf[i + 1];
766 /* construct socket address of sender */
767 memset (&sin_addr, 0, sizeof (sin_addr));
768 sin_addr.sin_family = AF_INET;
769 #if HAVE_SOCKADDR_IN_SIN_LEN
770 sin_addr.sin_len = sizeof (sin_addr);
772 if ((NULL == port_start) || (1 != sscanf (port_start, "%d", &port)) ||
773 (-1 == inet_pton (AF_INET, mybuf, &sin_addr.sin_addr)))
775 /* should we restart gnunet-helper-nat-server? */
776 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "nat",
778 ("gnunet-helper-nat-server generated malformed address `%s'\n"),
780 h->server_read_task =
781 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
782 h->server_stdout_handle,
783 &nat_server_read, h);
786 sin_addr.sin_port = htons ((uint16_t) port);
788 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "nat",
789 "gnunet-helper-nat-server read: %s:%d\n", mybuf, port);
791 h->reversal_callback (h->callback_cls, (const struct sockaddr *) &sin_addr,
793 h->server_read_task =
794 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
795 h->server_stdout_handle, &nat_server_read,
801 * Try to start the gnunet-helper-nat-server (if it is not
804 * @param h handle to NAT
807 start_gnunet_nat_server (struct GNUNET_NAT_Handle *h)
809 if ((h->behind_nat == GNUNET_YES) && (h->enable_nat_server == GNUNET_YES) &&
810 (h->internal_address != NULL) &&
813 GNUNET_DISK_pipe (GNUNET_YES, GNUNET_NO, GNUNET_YES))))
816 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "nat" "Starting %s at `%s'\n",
817 "gnunet-helper-nat-server", h->internal_address);
819 /* Start the server process */
821 GNUNET_OS_start_process (NULL, h->server_stdout,
822 "gnunet-helper-nat-server",
823 "gnunet-helper-nat-server",
824 h->internal_address, NULL);
825 if (h->server_proc == NULL)
827 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "nat",
828 _("Failed to start %s\n"), "gnunet-helper-nat-server");
829 GNUNET_DISK_pipe_close (h->server_stdout);
830 h->server_stdout = NULL;
834 /* Close the write end of the read pipe */
835 GNUNET_DISK_pipe_close_end (h->server_stdout, GNUNET_DISK_PIPE_END_WRITE);
836 h->server_stdout_handle =
837 GNUNET_DISK_pipe_handle (h->server_stdout, GNUNET_DISK_PIPE_END_READ);
838 h->server_read_task =
839 GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
840 h->server_stdout_handle,
841 &nat_server_read, h);
848 * Task to scan the local network interfaces for IP addresses.
850 * @param cls the NAT handle
851 * @param tc scheduler context
854 list_interfaces (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
856 struct GNUNET_NAT_Handle *h = cls;
858 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
859 remove_from_address_list_by_source (h, LAL_INTERFACE_ADDRESS);
860 GNUNET_OS_network_interfaces_list (&process_interfaces, h);
862 GNUNET_SCHEDULER_add_delayed (h->ifc_scan_frequency, &list_interfaces, h);
867 * Task to do a lookup on our hostname for IP addresses.
869 * @param cls the NAT handle
870 * @param tc scheduler context
873 resolve_hostname (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
875 struct GNUNET_NAT_Handle *h = cls;
877 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
878 remove_from_address_list_by_source (h, LAL_HOSTNAME_DNS);
880 GNUNET_RESOLVER_hostname_resolve (AF_UNSPEC, HOSTNAME_RESOLVE_TIMEOUT,
881 &process_hostname_ip, h);
886 * Task to do DNS lookup on our external hostname to
887 * get DynDNS-IP addresses.
889 * @param cls the NAT handle
890 * @param tc scheduler context
893 resolve_dns (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
895 struct GNUNET_NAT_Handle *h = cls;
897 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
898 remove_from_address_list_by_source (h, LAL_EXTERNAL_IP);
900 GNUNET_RESOLVER_ip_get (h->external_address, AF_INET,
901 GNUNET_TIME_UNIT_MINUTES, &process_external_ip,
907 * Add or remove UPnP-mapped addresses.
909 * @param cls the GNUNET_NAT_Handle
910 * @param add_remove GNUNET_YES to mean the new public IP address, GNUNET_NO to mean
911 * the previous (now invalid) one
912 * @param addr either the previous or the new public IP address
913 * @param addrlen actual lenght of the address
916 upnp_add (void *cls, int add_remove, const struct sockaddr *addr,
919 struct GNUNET_NAT_Handle *h = cls;
920 struct LocalAddressList *pos;
921 struct LocalAddressList *next;
923 if (GNUNET_YES == add_remove)
925 add_to_address_list (h, LAL_UPNP, addr, addrlen);
930 while (NULL != (pos = next))
933 if ((pos->source != LAL_UPNP) || (pos->addrlen != addrlen) ||
934 (0 != memcmp (&pos[1], addr, addrlen)))
936 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, pos);
937 if (NULL != h->address_callback)
938 h->address_callback (h->callback_cls, GNUNET_NO,
939 (const struct sockaddr *) &pos[1], pos->addrlen);
941 return; /* only remove once */
943 /* asked to remove address that does not exist */
949 * Try to add a port mapping using UPnP.
951 * @param h overall NAT handle
952 * @param port port to map with UPnP
955 add_minis (struct GNUNET_NAT_Handle *h, uint16_t port)
962 if (port == ml->port)
963 return; /* already got this port */
966 ml = GNUNET_malloc (sizeof (struct MiniList));
968 ml->mini = GNUNET_NAT_mini_map_start (port, h->is_tcp, &upnp_add, h);
969 GNUNET_CONTAINER_DLL_insert (h->mini_head, h->mini_tail, ml);
974 * Task to add addresses from original bind to set of valid addrs.
976 * @param cls the NAT handle
977 * @param tc scheduler context
980 add_from_bind (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
982 static struct in6_addr any = IN6ADDR_ANY_INIT;
983 struct GNUNET_NAT_Handle *h = cls;
986 const struct sockaddr_in *v4;
988 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
989 for (i = 0; i < h->num_local_addrs; i++)
991 sa = h->local_addrs[i];
992 switch (sa->sa_family)
995 if (sizeof (struct sockaddr_in) != h->local_addrlens[i])
1000 v4 = (const struct sockaddr_in *) sa;
1001 if (0 != v4->sin_addr.s_addr)
1002 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1003 sizeof (struct sockaddr_in));
1005 add_minis (h, ntohs (v4->sin_port));
1008 if (sizeof (struct sockaddr_in6) != h->local_addrlens[i])
1014 memcmp (&((const struct sockaddr_in6 *) sa)->sin6_addr, &any,
1015 sizeof (struct in6_addr)))
1016 add_to_address_list (h, LAL_BINDTO_ADDRESS, sa,
1017 sizeof (struct sockaddr_in6));
1028 * Attempt to enable port redirection and detect public IP address contacting
1029 * UPnP or NAT-PMP routers on the local network. Use addr to specify to which
1030 * of the local host's addresses should the external port be mapped. The port
1031 * is taken from the corresponding sockaddr_in[6] field.
1033 * @param cfg configuration to use
1034 * @param is_tcp GNUNET_YES for TCP, GNUNET_NO for UDP
1035 * @param adv_port advertised port (port we are either bound to or that our OS
1036 * locally performs redirection from to our bound port).
1037 * @param num_addrs number of addresses in 'addrs'
1038 * @param addrs the local addresses packets should be redirected to
1039 * @param addrlens actual lengths of the addresses
1040 * @param address_callback function to call everytime the public IP address changes
1041 * @param reversal_callback function to call if someone wants connection reversal from us
1042 * @param callback_cls closure for callbacks
1043 * @return NULL on error, otherwise handle that can be used to unregister
1045 struct GNUNET_NAT_Handle *
1046 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg, int is_tcp,
1047 uint16_t adv_port, unsigned int num_addrs,
1048 const struct sockaddr **addrs, const socklen_t * addrlens,
1049 GNUNET_NAT_AddressCallback address_callback,
1050 GNUNET_NAT_ReversalCallback reversal_callback,
1053 struct GNUNET_NAT_Handle *h;
1054 struct in_addr in_addr;
1058 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "nat",
1059 "Registered with NAT service at port %u with %u IP bound local addresses\n",
1060 (unsigned int) adv_port, num_addrs);
1062 h = GNUNET_malloc (sizeof (struct GNUNET_NAT_Handle));
1063 h->server_retry_delay = GNUNET_TIME_UNIT_SECONDS;
1066 h->address_callback = address_callback;
1067 h->reversal_callback = reversal_callback;
1068 h->callback_cls = callback_cls;
1069 h->num_local_addrs = num_addrs;
1070 h->adv_port = adv_port;
1073 h->local_addrs = GNUNET_malloc (num_addrs * sizeof (struct sockaddr *));
1074 h->local_addrlens = GNUNET_malloc (num_addrs * sizeof (socklen_t));
1075 for (i = 0; i < num_addrs; i++)
1077 GNUNET_assert (addrlens[i] > 0);
1078 GNUNET_assert (addrs[i] != NULL);
1079 h->local_addrlens[i] = addrlens[i];
1080 h->local_addrs[i] = GNUNET_malloc (addrlens[i]);
1081 memcpy (h->local_addrs[i], addrs[i], addrlens[i]);
1084 h->bind_task = GNUNET_SCHEDULER_add_now (&add_from_bind, h);
1086 GNUNET_CONFIGURATION_have_value (cfg, "nat", "INTERNAL_ADDRESS"))
1088 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1090 &h->internal_address);
1092 if ((h->internal_address != NULL) &&
1093 (inet_pton (AF_INET, h->internal_address, &in_addr) != 1))
1095 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "nat",
1096 _("Malformed %s `%s' given in configuration!\n"),
1097 "INTERNAL_ADDRESS", h->internal_address);
1098 GNUNET_free (h->internal_address);
1099 h->internal_address = NULL;
1103 GNUNET_CONFIGURATION_have_value (cfg, "nat", "EXTERNAL_ADDRESS"))
1105 (void) GNUNET_CONFIGURATION_get_value_string (cfg, "nat",
1107 &h->external_address);
1110 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT");
1112 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "PUNCHED_NAT");
1113 h->enable_nat_client =
1114 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_NAT_CLIENT");
1115 h->enable_nat_server =
1116 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_NAT_SERVER");
1118 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "ENABLE_UPNP");
1119 h->use_localaddresses =
1120 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_LOCALADDR");
1122 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "USE_HOSTNAME");
1124 GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "DISABLEV6");
1126 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "DYNDNS_FREQUENCY",
1127 &h->dyndns_frequency))
1128 h->dyndns_frequency = DYNDNS_FREQUENCY;
1130 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "IFC_SCAN_FREQUENCY",
1131 &h->ifc_scan_frequency))
1132 h->ifc_scan_frequency = IFC_SCAN_FREQUENCY;
1134 GNUNET_CONFIGURATION_get_value_time (cfg, "nat", "HOSTNAME_DNS_FREQUENCY",
1135 &h->hostname_dns_frequency))
1136 h->hostname_dns_frequency = HOSTNAME_DNS_FREQUENCY;
1138 if (NULL == reversal_callback)
1139 h->enable_nat_server = GNUNET_NO;
1141 /* Check if NAT was hole-punched */
1142 if ((NULL != h->address_callback) && (h->external_address != NULL) &&
1143 (h->nat_punched == GNUNET_YES))
1145 h->dns_task = GNUNET_SCHEDULER_add_now (&resolve_dns, h);
1146 h->enable_nat_server = GNUNET_NO;
1147 h->enable_upnp = GNUNET_NO;
1150 /* Test for SUID binaries */
1151 if ((h->behind_nat == GNUNET_YES) && (GNUNET_YES == h->enable_nat_server) &&
1153 GNUNET_OS_check_helper_binary ("gnunet-helper-nat-server")))
1155 h->enable_nat_server = GNUNET_NO;
1156 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1158 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1159 "gnunet-helper-nat-server");
1161 if ((GNUNET_YES == h->enable_nat_client) &&
1163 GNUNET_OS_check_helper_binary ("gnunet-helper-nat-client")))
1165 h->enable_nat_client = GNUNET_NO;
1166 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1168 ("Configuration requires `%s', but binary is not installed properly (SUID bit not set). Option disabled.\n"),
1169 "gnunet-helper-nat-client");
1172 start_gnunet_nat_server (h);
1174 /* FIXME: add support for UPnP, etc */
1176 if (NULL != h->address_callback)
1178 h->ifc_task = GNUNET_SCHEDULER_add_now (&list_interfaces, h);
1179 if (GNUNET_YES == h->use_hostname)
1180 h->hostname_task = GNUNET_SCHEDULER_add_now (&resolve_hostname, h);
1188 * Stop port redirection and public IP address detection for the given handle.
1189 * This frees the handle, after having sent the needed commands to close open ports.
1191 * @param h the handle to stop
1194 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h)
1197 struct LocalAddressList *lal;
1198 struct MiniList *ml;
1200 while (NULL != (ml = h->mini_head))
1202 GNUNET_CONTAINER_DLL_remove (h->mini_head, h->mini_tail, ml);
1203 if (NULL != ml->mini)
1204 GNUNET_NAT_mini_map_stop (ml->mini);
1207 if (h->ext_dns != NULL)
1209 GNUNET_RESOLVER_request_cancel (h->ext_dns);
1212 if (NULL != h->hostname_dns)
1214 GNUNET_RESOLVER_request_cancel (h->hostname_dns);
1215 h->hostname_dns = NULL;
1217 if (GNUNET_SCHEDULER_NO_TASK != h->server_read_task)
1219 GNUNET_SCHEDULER_cancel (h->server_read_task);
1220 h->server_read_task = GNUNET_SCHEDULER_NO_TASK;
1222 if (GNUNET_SCHEDULER_NO_TASK != h->bind_task)
1224 GNUNET_SCHEDULER_cancel (h->bind_task);
1225 h->bind_task = GNUNET_SCHEDULER_NO_TASK;
1227 if (GNUNET_SCHEDULER_NO_TASK != h->ifc_task)
1229 GNUNET_SCHEDULER_cancel (h->ifc_task);
1230 h->ifc_task = GNUNET_SCHEDULER_NO_TASK;
1232 if (GNUNET_SCHEDULER_NO_TASK != h->hostname_task)
1234 GNUNET_SCHEDULER_cancel (h->hostname_task);
1235 h->hostname_task = GNUNET_SCHEDULER_NO_TASK;
1237 if (GNUNET_SCHEDULER_NO_TASK != h->dns_task)
1239 GNUNET_SCHEDULER_cancel (h->dns_task);
1240 h->dns_task = GNUNET_SCHEDULER_NO_TASK;
1242 if (NULL != h->server_proc)
1244 if (0 != GNUNET_OS_process_kill (h->server_proc, SIGTERM))
1245 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
1246 GNUNET_OS_process_wait (h->server_proc);
1247 GNUNET_OS_process_close (h->server_proc);
1248 h->server_proc = NULL;
1249 GNUNET_DISK_pipe_close (h->server_stdout);
1250 h->server_stdout = NULL;
1251 h->server_stdout_handle = NULL;
1253 if (NULL != h->server_stdout)
1255 GNUNET_DISK_pipe_close (h->server_stdout);
1256 h->server_stdout = NULL;
1257 h->server_stdout_handle = NULL;
1259 while (NULL != (lal = h->lal_head))
1261 GNUNET_CONTAINER_DLL_remove (h->lal_head, h->lal_tail, lal);
1262 if (NULL != h->address_callback)
1263 h->address_callback (h->callback_cls, GNUNET_NO,
1264 (const struct sockaddr *) &lal[1], lal->addrlen);
1267 for (i = 0; i < h->num_local_addrs; i++)
1268 GNUNET_free (h->local_addrs[i]);
1269 GNUNET_free_non_null (h->local_addrs);
1270 GNUNET_free_non_null (h->local_addrlens);
1271 GNUNET_free_non_null (h->external_address);
1272 GNUNET_free_non_null (h->internal_address);
1278 * We learned about a peer (possibly behind NAT) so run the
1279 * gnunet-helper-nat-client to send dummy ICMP responses to cause
1280 * that peer to connect to us (connection reversal).
1282 * @param h NAT handle for us (largely used for configuration)
1283 * @param sa the address of the peer (IPv4-only)
1286 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
1287 const struct sockaddr_in *sa)
1289 char inet4[INET_ADDRSTRLEN];
1290 char port_as_string[6];
1291 struct GNUNET_OS_Process *proc;
1293 if (GNUNET_YES != h->enable_nat_client)
1294 return; /* not permitted / possible */
1296 if (h->internal_address == NULL)
1298 GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "nat",
1300 ("Internal IP address not known, cannot use ICMP NAT traversal method\n"));
1303 GNUNET_assert (sa->sin_family == AF_INET);
1304 if (NULL == inet_ntop (AF_INET, &sa->sin_addr, inet4, INET_ADDRSTRLEN))
1306 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
1309 GNUNET_snprintf (port_as_string, sizeof (port_as_string), "%d", h->adv_port);
1311 GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "nat",
1312 _("Running gnunet-helper-nat-client %s %s %u\n"),
1313 h->internal_address, inet4, (unsigned int) h->adv_port);
1316 GNUNET_OS_start_process (NULL, NULL, "gnunet-helper-nat-client",
1317 "gnunet-helper-nat-client", h->internal_address,
1318 inet4, port_as_string, NULL);
1321 /* we know that the gnunet-helper-nat-client will terminate virtually
1323 GNUNET_OS_process_wait (proc);
1324 GNUNET_OS_process_close (proc);
1329 * Test if the given address is (currently) a plausible IP address for this peer.
1331 * @param h the handle returned by register
1332 * @param addr IP address to test (IPv4 or IPv6)
1333 * @param addrlen number of bytes in addr
1334 * @return GNUNET_YES if the address is plausible,
1335 * GNUNET_NO if the address is not plausible,
1336 * GNUNET_SYSERR if the address is malformed
1339 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h, const void *addr,
1342 struct LocalAddressList *pos;
1343 const struct sockaddr_in *in4;
1344 const struct sockaddr_in6 *in6;
1346 if ((addrlen != sizeof (struct in_addr)) &&
1347 (addrlen != sizeof (struct in6_addr)))
1350 return GNUNET_SYSERR;
1355 if (pos->addrlen == sizeof (struct sockaddr_in))
1357 in4 = (struct sockaddr_in *) &pos[1];
1358 if ((addrlen == sizeof (struct in_addr)) &&
1359 (0 == memcmp (&in4->sin_addr, addr, sizeof (struct in_addr))))
1362 else if (pos->addrlen == sizeof (struct sockaddr_in6))
1364 in6 = (struct sockaddr_in6 *) &pos[1];
1365 if ((addrlen == sizeof (struct in6_addr)) &&
1366 (0 == memcmp (&in6->sin6_addr, addr, sizeof (struct in6_addr))))
1375 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1376 "Asked to validate one of my addresses and validation failed!\n");