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18 SPDX-License-Identifier: AGPL3.0-or-later
22 * @file nat/nat_auto.c
23 * @brief functions for auto-configuration of the network
24 * @author Christian Grothoff
25 * @author Bruno Cabral
28 #include "gnunet_util_lib.h"
29 #include "gnunet_resolver_service.h"
30 #include "gnunet_nat_lib.h"
33 #define LOG(kind,...) GNUNET_log_from (kind, "nat", __VA_ARGS__)
37 * How long do we wait for the NAT test to report success?
39 #define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 15)
41 #define NAT_SERVER_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 10)
44 * Phases of the auto configuration.
49 * Initial start value.
54 * Test our external IP.
59 * Test our external IP.
64 * Test our internal IP.
69 * Test if NAT was punched.
74 * Test if UPnP is working.
79 * Test if ICMP server works.
84 * Test if ICMP client works.
89 * Last phase, we're done.
97 * Handle to auto-configuration in progress.
99 struct GNUNET_NAT_AutoHandle
103 * Handle to the active NAT test.
105 struct GNUNET_NAT_Test *tst;
108 * Function to call when done.
110 GNUNET_NAT_AutoResultCallback fin_cb;
113 * Closure for @e fin_cb.
118 * Handle for active 'GNUNET_NAT_mini_get_external_ipv4'-operation.
120 struct GNUNET_NAT_ExternalHandle *eh;
123 * Current configuration (with updates from previous phases)
125 struct GNUNET_CONFIGURATION_Handle *cfg;
128 * Original configuration (used to calculate differences)
130 struct GNUNET_CONFIGURATION_Handle *initial_cfg;
133 * Task identifier for the timeout.
135 struct GNUNET_SCHEDULER_Task *task;
138 * Message queue to the gnunet-nat-server.
140 struct GNUNET_MQ_Handle *mq;
143 * Where are we in the test?
145 enum AutoPhase phase;
148 * Situation of the NAT
150 enum GNUNET_NAT_Type type;
158 * UPnP already set the external ip address ?
160 int upnp_set_external_address;
163 * Did the external server connected back ?
168 * Address detected by STUN
172 unsigned int stun_port;
175 * Internal IP is the same as the public one ?
177 int internal_ip_is_public;
180 * Error code for better debugging and user feedback
182 enum GNUNET_NAT_StatusCode ret;
187 * The listen socket of the service for IPv4
189 static struct GNUNET_NETWORK_Handle *lsock4;
192 * The listen task ID for IPv4
194 static struct GNUNET_SCHEDULER_Task *ltask4;
197 * The port the test service is running on (default 7895)
199 static unsigned long long port = 7895;
201 static char *stun_server = "stun.ekiga.net";
203 static unsigned int stun_port = 3478;
207 * Run the next phase of the auto test.
209 * @param ah auto test handle
212 next_phase (struct GNUNET_NAT_AutoHandle *ah);
216 process_stun_reply(struct sockaddr_in *answer,
217 struct GNUNET_NAT_AutoHandle *ah)
219 ah->stun_ip = inet_ntoa(answer->sin_addr);
220 ah->stun_port = ntohs (answer->sin_port);
221 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
222 "External IP is: %s , with port %u\n",
230 * Function that terminates the test.
235 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
236 "Stopping STUN and quitting...\n");
240 GNUNET_SCHEDULER_cancel (ltask4);
246 GNUNET_NETWORK_socket_close (lsock4);
253 * Activity on our incoming socket. Read data from the
254 * incoming connection.
259 do_udp_read (void *cls)
261 struct GNUNET_NAT_AutoHandle *ah = cls;
262 unsigned char reply_buf[1024];
264 struct sockaddr_in answer;
265 const struct GNUNET_SCHEDULER_TaskContext *tc;
267 tc = GNUNET_SCHEDULER_get_task_context ();
268 if ((0 != (tc->reason & GNUNET_SCHEDULER_REASON_READ_READY)) &&
269 (GNUNET_NETWORK_fdset_isset (tc->read_ready,
272 rlen = GNUNET_NETWORK_socket_recv (lsock4,
276 //Lets handle the packet
277 memset (&answer, 0, sizeof(struct sockaddr_in));
278 if (ah->phase == AUTO_NAT_PUNCHED)
280 //Destroy the connection
281 GNUNET_NETWORK_socket_close (lsock4);
282 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
283 "The external server was able to connect back");
284 ah->connected_back = GNUNET_YES;
290 GNUNET_NAT_stun_handle_packet (reply_buf, rlen, &answer))
293 process_stun_reply (&answer, ah);
303 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
304 "TIMEOUT while waiting for an answer\n");
305 if (ah->phase == AUTO_NAT_PUNCHED)
316 * Create an IPv4 listen socket bound to our port.
318 * @return NULL on error
320 static struct GNUNET_NETWORK_Handle *
323 struct GNUNET_NETWORK_Handle *ls;
324 struct sockaddr_in sa4;
327 memset (&sa4, 0, sizeof (sa4));
328 sa4.sin_family = AF_INET;
329 sa4.sin_port = htons (port);
330 #if HAVE_SOCKADDR_IN_SIN_LEN
331 sa4.sin_len = sizeof (sa4);
333 ls = GNUNET_NETWORK_socket_create (AF_INET,
339 GNUNET_NETWORK_socket_bind (ls, (const struct sockaddr *) &sa4,
343 GNUNET_NETWORK_socket_close (ls);
352 request_callback (void *cls,
353 enum GNUNET_NAT_StatusCode result)
355 // struct GNUNET_NAT_AutoHandle *ah = cls;
357 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
358 "Request callback: stop and quit\n");
361 // next_phase (ah); FIXME this always will be NULL, as called in test_stun()
366 * Function called by NAT to report the outcome of the nat-test.
367 * Clean up and update GUI.
369 * @param cls the auto handle
370 * @param success currently always #GNUNET_OK
371 * @param emsg NULL on success, otherwise an error message
374 result_callback (void *cls,
375 enum GNUNET_NAT_StatusCode ret)
377 struct GNUNET_NAT_AutoHandle *ah = cls;
379 if (GNUNET_NAT_ERROR_SUCCESS == ret)
380 GNUNET_NAT_test_stop (ah->tst);
383 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
384 GNUNET_NAT_ERROR_SUCCESS == ret
385 ? _("NAT traversal with ICMP Server succeeded.\n")
386 : _("NAT traversal with ICMP Server failed.\n"));
387 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "ENABLE_ICMP_SERVER",
388 GNUNET_NAT_ERROR_SUCCESS == ret ? "NO" : "YES");
394 * Main function for the connection reversal test.
396 * @param cls the `struct GNUNET_NAT_AutoHandle`
399 reversal_test (void *cls)
401 struct GNUNET_NAT_AutoHandle *ah = cls;
404 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
405 _("Testing connection reversal with ICMP server.\n"));
406 GNUNET_RESOLVER_connect (ah->cfg);
407 ah->tst = GNUNET_NAT_test_start (ah->cfg, GNUNET_YES, 0, 0, TIMEOUT,
408 &result_callback, ah);
413 * Set our external IPv4 address based on the UPnP.
416 * @param cls closure with our setup context
417 * @param addr the address, NULL on errors
418 * @param emsg NULL on success, otherwise an error message
421 set_external_ipv4 (void *cls,
422 const struct in_addr *addr,
423 enum GNUNET_NAT_StatusCode ret)
425 struct GNUNET_NAT_AutoHandle *ah = cls;
426 char buf[INET_ADDRSTRLEN];
430 if (GNUNET_NAT_ERROR_SUCCESS != ret)
435 /* enable 'behind nat' */
436 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
437 _("Detected external IP `%s'\n"),
442 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "BEHIND_NAT", "YES");
444 /* set external IP address */
445 if (NULL == inet_ntop (AF_INET, addr, buf, sizeof (buf)))
448 /* actually, this should never happen, as the caller already executed just
449 * this check, but for consistency (eg: future changes in the caller)
450 * we still need to report this error...
452 ah->ret = GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID;
456 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "EXTERNAL_ADDRESS",
458 ah->upnp_set_external_address = GNUNET_YES;
464 * Determine our external IPv4 address.
466 * @param ah auto setup context
469 test_external_ip (struct GNUNET_NAT_AutoHandle *ah)
471 if (GNUNET_NAT_ERROR_SUCCESS != ah->ret)
475 /* try to detect external IP */
476 ah->eh = GNUNET_NAT_mini_get_external_ipv4 (TIMEOUT,
477 &set_external_ipv4, ah);
482 * Determine our external IPv4 address and port using an external STUN server
484 * @param ah auto setup context
487 test_stun (struct GNUNET_NAT_AutoHandle *ah)
490 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Running STUN test\n");
492 /* Get port from the configuration */
494 GNUNET_CONFIGURATION_get_value_number (ah->cfg,
502 //Lets create the socket
506 GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind");
512 //Lets call our function now when it accepts
513 ltask4 = GNUNET_SCHEDULER_add_read_net (NAT_SERVER_TIMEOUT,
520 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
521 "STUN service listens on port %u\n",
522 (unsigned int) port);
524 GNUNET_NAT_stun_make_request (stun_server,
530 /*An error happened*/
531 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "STUN error, stopping\n");
539 * Process list of local IP addresses. Find and set the
540 * one of the default interface.
542 * @param cls our `struct GNUNET_NAT_AutoHandle`
543 * @param name name of the interface (can be NULL for unknown)
544 * @param isDefault is this presumably the default interface
545 * @param addr address of this interface (can be NULL for unknown or unassigned)
546 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
547 * @param netmask the network mask (can be NULL for unknown or unassigned))
548 * @param addrlen length of the @a addr and @a broadcast_addr
549 * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
552 process_if (void *cls,
555 const struct sockaddr *addr,
556 const struct sockaddr *broadcast_addr,
557 const struct sockaddr *netmask,
560 struct GNUNET_NAT_AutoHandle *ah = cls;
561 const struct sockaddr_in *in;
562 char buf[INET_ADDRSTRLEN];
565 if ( (sizeof (struct sockaddr_in6) == addrlen) &&
566 (0 != GNUNET_memcmp (&in6addr_loopback, &((const struct sockaddr_in6 *) addr)->sin6_addr)) &&
567 (! IN6_IS_ADDR_LINKLOCAL(&((const struct sockaddr_in6 *) addr)->sin6_addr)) )
569 ah->have_v6 = GNUNET_YES;
570 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
571 _("This system has a global IPv6 address, setting IPv6 to supported.\n"));
575 if (addrlen != sizeof (struct sockaddr_in))
577 in = (const struct sockaddr_in *) addr;
580 /* set internal IP address */
581 if (NULL == inet_ntop (AF_INET, &in->sin_addr, buf, sizeof (buf)))
586 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "INTERNAL_ADDRESS",
588 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
589 _("Detected internal network address `%s'.\n"),
593 ah->ret = GNUNET_NAT_ERROR_SUCCESS;
595 /* Check if our internal IP is the same as the External detect by STUN*/
596 if(ah->stun_ip && (strcmp(buf, ah->stun_ip) == 0) )
598 ah->internal_ip_is_public = GNUNET_YES;
599 GNUNET_log (GNUNET_ERROR_TYPE_INFO,"A internal IP is the sameas the external");
600 /* No need to continue*/
601 return GNUNET_SYSERR;
604 /* no need to continue iteration if we found the default */
608 return GNUNET_SYSERR;
613 * Determine our local IP addresses; detect internal IP & IPv6-support
615 * @param ah auto setup context
618 test_local_ip (struct GNUNET_NAT_AutoHandle *ah)
620 ah->have_v6 = GNUNET_NO;
621 ah->ret = GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO; // reset to success if any of the IFs in below iterator has a valid IP
622 GNUNET_OS_network_interfaces_list (&process_if, ah);
624 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "DISABLEV6",
625 (GNUNET_YES == ah->have_v6) ? "NO" : "YES");
631 * We got disconnected from the NAT server. Stop
632 * waiting for a reply.
634 * @param cls the `struct GNUNET_NAT_AutoHandle`
635 * @param error error code
638 mq_error_handler (void *cls,
639 enum GNUNET_MQ_Error error)
641 struct GNUNET_NAT_AutoHandle *ah = cls;
643 GNUNET_MQ_destroy (ah->mq);
645 /* wait a bit first? */
651 * Test if NAT has been punched
653 * @param ah auto setup context
656 test_nat_punched (struct GNUNET_NAT_AutoHandle *ah)
658 struct GNUNET_NAT_TestMessage *msg;
659 struct GNUNET_MQ_Envelope *env;
663 LOG (GNUNET_ERROR_TYPE_INFO,
664 "We don't have a STUN IP");
669 LOG (GNUNET_ERROR_TYPE_INFO,
670 "Asking gnunet-nat-server to connect to `%s'\n",
672 ah->mq = GNUNET_CLIENT_connect (ah->cfg,
679 GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
680 _("Failed to connect to `gnunet-nat-server'\n"));
684 env = GNUNET_MQ_msg (msg,
685 GNUNET_MESSAGE_TYPE_NAT_TEST);
686 msg->dst_ipv4 = inet_addr (ah->stun_ip);
687 msg->dport = htons (ah->stun_port);
689 msg->is_tcp = htonl ((uint32_t) GNUNET_NO);
690 GNUNET_MQ_send (ah->mq,
694 GNUNET_SCHEDULER_cancel (ltask4);
695 ltask4 = GNUNET_SCHEDULER_add_read_net (NAT_SERVER_TIMEOUT,
704 * Test if UPnPC works.
706 * @param ah auto setup context
709 test_upnpc (struct GNUNET_NAT_AutoHandle *ah)
714 if (GNUNET_NAT_ERROR_SUCCESS != ah->ret)
717 // test if upnpc is available
718 have_upnpc = (GNUNET_SYSERR !=
719 GNUNET_OS_check_helper_binary ("upnpc", GNUNET_NO, NULL));
720 //FIXME: test if upnpc is actually working, that is, if transports start to work once we use UPnP
721 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
723 ? _("upnpc found, enabling its use\n")
724 : _("upnpc not found\n"));
725 GNUNET_CONFIGURATION_set_value_string (ah->cfg, "nat", "ENABLE_UPNP",
726 (GNUNET_YES == have_upnpc) ? "YES" : "NO");
733 * Test if ICMP server is working
735 * @param ah auto setup context
738 test_icmp_server (struct GNUNET_NAT_AutoHandle *ah)
751 helper = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-server");
753 GNUNET_CONFIGURATION_get_value_string (ah->cfg,
760 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
761 _("test_icmp_server not possible, as we have no public IPv4 address\n"));
767 GNUNET_CONFIGURATION_get_value_yesno (ah->cfg,
772 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
773 _("test_icmp_server not possible, as we are not behind NAT\n"));
779 GNUNET_OS_check_helper_binary (helper,
783 binary = GNUNET_OK; // use localhost as source for that one udp-port, ok for testing
784 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
785 _("No working gnunet-helper-nat-server found\n"));
788 GNUNET_free_non_null (tmp);
789 GNUNET_free (helper);
791 if ( (GNUNET_OK == ext_ip) &&
792 (GNUNET_YES == nated) &&
793 (GNUNET_OK == binary) )
794 ah->task = GNUNET_SCHEDULER_add_now (&reversal_test,
802 * Test if ICMP client is working
804 * @param ah auto setup context
807 test_icmp_client (struct GNUNET_NAT_AutoHandle *ah)
813 helper = GNUNET_OS_get_libexec_binary_path ("gnunet-helper-nat-client");
815 GNUNET_CONFIGURATION_get_value_string (ah->cfg,
821 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
822 _("test_icmp_client not possible, as we have no internal IPv4 address\n"));
828 GNUNET_CONFIGURATION_get_value_yesno (ah->cfg,
832 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
833 _("test_icmp_server not possible, as we are not behind NAT\n"));
839 GNUNET_OS_check_helper_binary (helper,
841 "-d 127.0.0.1 127.0.0.2 42"))
843 // none of these parameters are actually used in privilege testing mode
844 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
845 _("No working gnunet-helper-nat-server found\n"));
848 GNUNET_free_non_null (tmp);
849 GNUNET_free (helper);
856 * Run the next phase of the auto test.
859 next_phase (struct GNUNET_NAT_AutoHandle *ah)
861 struct GNUNET_CONFIGURATION_Handle *diff;
869 case AUTO_EXTERNAL_IP:
870 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
871 "Will run AUTO_EXTERNAL_IP\n");
872 test_external_ip (ah);
875 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
876 "Will run AUTO_STUN\n");
880 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
881 "Will run AUTO_LOCAL_IP\n");
884 case AUTO_NAT_PUNCHED:
885 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
886 "Will run AUTO_NAT_PUNCHED\n");
887 test_nat_punched (ah);
890 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
891 "Will run AUTO_UPNPC\n");
894 case AUTO_ICMP_SERVER:
895 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
896 "Will run AUTO_ICMP_SERVER\n");
897 test_icmp_server (ah);
899 case AUTO_ICMP_CLIENT:
900 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
901 "Will run AUTO_ICMP_CLIENT\n");
902 test_icmp_client (ah);
905 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
906 "Done with tests\n");
907 if (!ah->internal_ip_is_public)
909 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
914 if (ah->connected_back)
916 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
923 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
931 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
935 if (ah->connected_back)
937 ah->type = GNUNET_NAT_TYPE_STUN_PUNCHED_NAT;
938 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
945 ah->type = GNUNET_NAT_TYPE_UNREACHABLE_NAT;
946 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
953 if (0 != ah->stun_port)
955 GNUNET_CONFIGURATION_set_value_number (ah->cfg,
964 //The internal IP is the same as public, but we didn't got a incoming connection
965 if (ah->connected_back)
967 ah->type = GNUNET_NAT_TYPE_NO_NAT;
968 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
975 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
979 ah->type = GNUNET_NAT_TYPE_UNREACHABLE_NAT;
982 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
987 if (0 != ah->stun_port)
989 GNUNET_CONFIGURATION_set_value_number (ah->cfg,
998 diff = GNUNET_CONFIGURATION_get_diff (ah->initial_cfg,
1002 ah->fin_cb (ah->fin_cb_cls,
1006 GNUNET_CONFIGURATION_destroy (diff);
1007 GNUNET_NAT_autoconfig_cancel (ah);
1013 * Start auto-configuration routine. The resolver service should
1014 * be available when this function is called.
1016 * @param cfg initial configuration
1017 * @param cb function to call with autoconfiguration result
1018 * @param cb_cls closure for @a cb
1019 * @return handle to cancel operation
1021 struct GNUNET_NAT_AutoHandle *
1022 GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
1023 GNUNET_NAT_AutoResultCallback cb,
1026 struct GNUNET_NAT_AutoHandle *ah;
1028 ah = GNUNET_new (struct GNUNET_NAT_AutoHandle);
1030 ah->fin_cb_cls = cb_cls;
1031 ah->ret = GNUNET_NAT_ERROR_SUCCESS;
1032 ah->cfg = GNUNET_CONFIGURATION_dup (cfg);
1033 ah->initial_cfg = GNUNET_CONFIGURATION_dup (cfg);
1035 /* never use loopback addresses if user wanted autoconfiguration */
1036 GNUNET_CONFIGURATION_set_value_string (ah->cfg,
1047 * Abort autoconfiguration.
1049 * @param ah handle for operation to abort
1052 GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah)
1054 if (NULL != ah->tst)
1056 GNUNET_NAT_test_stop (ah->tst);
1061 GNUNET_NAT_mini_get_external_ipv4_cancel (ah->eh);
1066 GNUNET_MQ_destroy (ah->mq);
1069 if (NULL != ah->task)
1071 GNUNET_SCHEDULER_cancel (ah->task);
1074 GNUNET_CONFIGURATION_destroy (ah->cfg);
1075 GNUNET_CONFIGURATION_destroy (ah->initial_cfg);
1080 /* end of nat_auto.c */