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3 Copyright (C) 2007-2014 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_nat_lib.h
23 * @brief Library handling UPnP and NAT-PMP port forwarding and
24 * external IP address retrieval
25 * @author Christian Grothoff
26 * @author Milan Bouchet-Valat
29 #ifndef GNUNET_NAT_LIB_H
30 #define GNUNET_NAT_LIB_H
32 #include "gnunet_util_lib.h"
36 * Signature of the callback passed to #GNUNET_NAT_register() for
37 * a function to call whenever our set of 'valid' addresses changes.
40 * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
41 * the previous (now invalid) one
42 * @param addr either the previous or the new public IP address
43 * @param addrlen actual length of the @a addr
46 (*GNUNET_NAT_AddressCallback) (void *cls,
48 const struct sockaddr *addr,
53 * Signature of the callback passed to #GNUNET_NAT_register().
54 * for a function to call whenever someone asks us to do connection
58 * @param addr public IP address of the other peer
59 * @param addrlen actual lenght of the @a addr
62 (*GNUNET_NAT_ReversalCallback) (void *cls,
63 const struct sockaddr *addr,
68 * Handle for active NAT registrations.
70 struct GNUNET_NAT_Handle;
75 * What the situation of the NAT connectivity
80 * We have a direct connection
82 GNUNET_NAT_TYPE_NO_NAT = GNUNET_OK,
85 * We are under a NAT but cannot traverse it
87 GNUNET_NAT_TYPE_UNREACHABLE_NAT,
90 * We can traverse using STUN
92 GNUNET_NAT_TYPE_STUN_PUNCHED_NAT,
95 * WE can traverse using UPNP
97 GNUNET_NAT_TYPE_UPNP_NAT
102 * Error Types for the NAT subsystem (which can then later be converted/resolved to a string)
104 enum GNUNET_NAT_StatusCode
109 GNUNET_NAT_ERROR_SUCCESS = GNUNET_OK,
114 GNUNET_NAT_ERROR_IPC_FAILURE,
117 * Failure in network subsystem, check permissions
119 GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR,
124 GNUNET_NAT_ERROR_TIMEOUT,
127 * detected that we are offline
129 GNUNET_NAT_ERROR_NOT_ONLINE,
132 * `upnpc` command not found
134 GNUNET_NAT_ERROR_UPNPC_NOT_FOUND,
137 * Failed to run `upnpc` command
139 GNUNET_NAT_ERROR_UPNPC_FAILED,
142 * `upnpc' command took too long, process killed
144 GNUNET_NAT_ERROR_UPNPC_TIMEOUT,
147 * `upnpc' command failed to establish port mapping
149 GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED,
152 * `external-ip' command not found
154 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND,
157 * Failed to run `external-ip` command
159 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED,
162 * `external-ip' command output invalid
164 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID,
167 * "no valid address was returned by `external-ip'"
169 GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID,
172 * Could not determine interface with internal/local network address
174 GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO,
177 * No working gnunet-helper-nat-server found
179 GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND,
182 * NAT test could not be initialized
184 GNUNET_NAT_ERROR_NAT_TEST_START_FAILED,
189 GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT,
192 * NAT test failed to initiate
194 GNUNET_NAT_ERROR_NAT_REGISTER_FAILED,
199 GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND,
209 * Converts `enum GNUNET_NAT_StatusCode` to string
211 * @param err error code to resolve to a string
212 * @return point to a static string containing the error code
215 GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err);
219 * Attempt to enable port redirection and detect public IP address
220 * contacting UPnP or NAT-PMP routers on the local network. Use addr
221 * to specify to which of the local host's addresses should the
222 * external port be mapped. The port is taken from the corresponding
223 * sockaddr_in[6] field. The NAT module should call the given
224 * callback for any 'plausible' external address.
226 * @param cfg configuration to use
227 * @param is_tcp #GNUNET_YES for TCP, #GNUNET_NO for UDP
228 * @param adv_port advertised port (port we are either bound to or that our OS
229 * locally performs redirection from to our bound port).
230 * @param num_addrs number of addresses in @a addrs
231 * @param addrs list of local addresses packets should be redirected to
232 * @param addrlens actual lengths of the addresses in @a addrs
233 * @param address_callback function to call everytime the public IP address changes
234 * @param reversal_callback function to call if someone wants connection reversal from us,
235 * NULL if connection reversal is not supported
236 * @param callback_cls closure for callbacks
237 * @return NULL on error, otherwise handle that can be used to unregister
239 struct GNUNET_NAT_Handle *
240 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
243 unsigned int num_addrs,
244 const struct sockaddr **addrs,
245 const socklen_t *addrlens,
246 GNUNET_NAT_AddressCallback address_callback,
247 GNUNET_NAT_ReversalCallback reversal_callback,
249 struct GNUNET_NETWORK_Handle* sock);
253 * Test if the given address is (currently) a plausible IP address for
256 * @param h the handle returned by register
257 * @param addr IP address to test (IPv4 or IPv6)
258 * @param addrlen number of bytes in @a addr
259 * @return #GNUNET_YES if the address is plausible,
260 * #GNUNET_NO if the address is not plausible,
261 * #GNUNET_SYSERR if the address is malformed
264 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h,
270 * We learned about a peer (possibly behind NAT) so run the
271 * gnunet-nat-client to send dummy ICMP responses to cause
272 * that peer to connect to us (connection reversal).
274 * @param h handle (used for configuration)
275 * @param sa the address of the peer (IPv4-only)
276 * @return #GNUNET_SYSERR on error, #GNUNET_NO if nat client is disabled,
277 * #GNUNET_OK otherwise
280 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
281 const struct sockaddr_in *sa);
285 * Stop port redirection and public IP address detection for the given
286 * handle. This frees the handle, after having sent the needed
287 * commands to close open ports.
289 * @param h the handle to stop
292 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h);
296 * Handle to a NAT test.
298 struct GNUNET_NAT_Test;
302 * Function called to report success or failure for
303 * NAT configuration test.
306 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
308 typedef void (*GNUNET_NAT_TestCallback) (void *cls,
309 enum GNUNET_NAT_StatusCode result);
313 * Start testing if NAT traversal works using the
314 * given configuration (IPv4-only).
316 * @param cfg configuration for the NAT traversal
317 * @param is_tcp #GNUNET_YES to test TCP, #GNUNET_NO to test UDP
318 * @param bnd_port port to bind to, 0 for connection reversal
319 * @param adv_port externally advertised port to use
320 * @param timeout delay after which the test should be aborted
321 * @param report function to call with the result of the test;
322 * you still must call #GNUNET_NAT_test_stop().
323 * @param report_cls closure for @a report
324 * @return handle to cancel NAT test
326 struct GNUNET_NAT_Test *
327 GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
331 struct GNUNET_TIME_Relative timeout,
332 GNUNET_NAT_TestCallback report,
337 * Stop an active NAT test.
339 * @param tst test to stop.
342 GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst);
346 * Signature of a callback that is given an IP address.
349 * @param addr the address, NULL on errors
350 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
353 (*GNUNET_NAT_IPCallback) (void *cls,
354 const struct in_addr *addr,
355 enum GNUNET_NAT_StatusCode result);
360 * Opaque handle to cancel #GNUNET_NAT_mini_get_external_ipv4() operation.
362 struct GNUNET_NAT_ExternalHandle;
366 * Try to get the external IPv4 address of this peer.
368 * @param timeout when to fail
369 * @param cb function to call with result
370 * @param cb_cls closure for @a cb
371 * @return handle for cancellation (can only be used until @a cb is called), NULL on error
373 struct GNUNET_NAT_ExternalHandle *
374 GNUNET_NAT_mini_get_external_ipv4 (struct GNUNET_TIME_Relative timeout,
375 GNUNET_NAT_IPCallback cb,
382 * @param eh operation to cancel
385 GNUNET_NAT_mini_get_external_ipv4_cancel (struct GNUNET_NAT_ExternalHandle *eh);
389 * Handle to a mapping created with upnpc.
391 struct GNUNET_NAT_MiniHandle;
395 * Signature of the callback passed to #GNUNET_NAT_register() for
396 * a function to call whenever our set of 'valid' addresses changes.
399 * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
400 * the previous (now invalid) one, #GNUNET_SYSERR indicates an error
401 * @param addr either the previous or the new public IP address
402 * @param addrlen actual length of the @a addr
403 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
406 (*GNUNET_NAT_MiniAddressCallback) (void *cls,
408 const struct sockaddr *addr,
410 enum GNUNET_NAT_StatusCode result);
414 * Start mapping the given port using (mini)upnpc. This function
415 * should typically not be used directly (it is used within the
416 * general-purpose #GNUNET_NAT_register() code). However, it can be
417 * used if specifically UPnP-based NAT traversal is to be used or
420 * @param port port to map
421 * @param is_tcp #GNUNET_YES to map TCP, #GNUNET_NO for UDP
422 * @param ac function to call with mapping result
423 * @param ac_cls closure for @a ac
424 * @return NULL on error
426 struct GNUNET_NAT_MiniHandle *
427 GNUNET_NAT_mini_map_start (uint16_t port,
429 GNUNET_NAT_MiniAddressCallback ac,
434 * Remove a mapping created with (mini)upnpc. Calling
435 * this function will give 'upnpc' 1s to remove the mapping,
436 * so while this function is non-blocking, a task will be
437 * left with the scheduler for up to 1s past this call.
439 * @param mini the handle
442 GNUNET_NAT_mini_map_stop (struct GNUNET_NAT_MiniHandle *mini);
446 * Handle to auto-configuration in progress.
448 struct GNUNET_NAT_AutoHandle;
452 * Function called with the result from the autoconfiguration.
455 * @param diff minimal suggested changes to the original configuration
456 * to make it work (as best as we can)
457 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
458 * @param type what the situation of the NAT
461 (*GNUNET_NAT_AutoResultCallback)(void *cls,
462 const struct GNUNET_CONFIGURATION_Handle *diff,
463 enum GNUNET_NAT_StatusCode result,
464 enum GNUNET_NAT_Type type);
468 * Start auto-configuration routine. The resolver service should
469 * be available when this function is called.
471 * @param cfg initial configuration
472 * @param cb function to call with autoconfiguration result
473 * @param cb_cls closure for @a cb
474 * @return handle to cancel operation
476 struct GNUNET_NAT_AutoHandle *
477 GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
478 GNUNET_NAT_AutoResultCallback cb,
483 * Abort autoconfiguration.
485 * @param ah handle for operation to abort
488 GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah);
491 * Handle for active STUN Requests.
493 struct GNUNET_NAT_STUN_Handle;
499 * Function called with the result if an error happened during STUN request.
502 * @param result the specific error code
505 (*GNUNET_NAT_STUN_ErrorCallback)(void *cls,
506 enum GNUNET_NAT_StatusCode error);
510 * Handle to a request given to the resolver. Can be used to cancel
511 * the request prior to the timeout or successful execution. Also
512 * used to track our internal state for the request.
514 struct GNUNET_NAT_STUN_Handle;
518 * Make generic STUN request. Sends a generic stun request to the
519 * server specified using the specified socket. The caller must
520 * wait for a reply on the @a sock and call
521 * #GNUNET_NAT_stun_handle_packet() if a reply is received.
523 * @param server the address of the stun server
524 * @param port port of the stun server
525 * @param sock the socket used to send the request
526 * @param cb callback in case of error (or completion)
527 * @param cb_cls closure for @a cb
528 * @return NULL on error
530 struct GNUNET_NAT_STUN_Handle *
531 GNUNET_NAT_stun_make_request (const char *server,
533 struct GNUNET_NETWORK_Handle *sock,
534 GNUNET_NAT_STUN_ErrorCallback cb,
539 * Cancel active STUN request. Frees associated resources
540 * and ensures that the callback is no longer invoked.
542 * @param rh request to cancel
545 GNUNET_NAT_stun_make_request_cancel (struct GNUNET_NAT_STUN_Handle *rh);
549 * Handle an incoming STUN message. Do some basic sanity checks on
550 * packet size and content, try to extract a bit of information, and
551 * possibly reply. At the moment this only processes BIND requests,
552 * and returns the externally visible address of the request. If a
553 * callback is specified, invoke it with the attribute.
555 * @param data the packet
556 * @param len the length of the packet
557 * @param arg sockaddr_in where we will set our discovered packet
558 * @return #GNUNET_OK on OK,
559 * #GNUNET_NO if the packet is not a stun packet
562 GNUNET_NAT_stun_handle_packet (const void *data,
564 struct sockaddr_in *arg);
568 * CHECK if is a valid STUN packet sending to #GNUNET_NAT_stun_handle_packet().
569 * It also check if it can handle the packet based on the NAT handler.
570 * You don't need to call anything else to check if the packet is valid,
572 * @param cls the NAT handle
573 * @param data, packet
574 * @param len, packet length
576 * @return #GNUNET_NO if it can't decode, #GNUNET_YES if is a packet
579 GNUNET_NAT_is_valid_stun_packet (void *cls,
587 /* end of gnunet_nat_lib.h */