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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,
84 * We are under a NAT but cannot traverse it
86 GNUNET_NAT_TYPE_UNREACHABLE_NAT,
88 * We can traverse using STUN
90 GNUNET_NAT_TYPE_STUN_PUNCHED_NAT,
92 * WE can traverse using UPNP
94 GNUNET_NAT_TYPE_UPNP_NAT
99 * Error Types for the NAT subsystem (which can then later be converted/resolved to a string)
101 enum GNUNET_NAT_StatusCode
106 GNUNET_NAT_ERROR_SUCCESS = GNUNET_OK,
111 GNUNET_NAT_ERROR_IPC_FAILURE,
114 * Failure in network subsystem, check permissions
116 GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR,
121 GNUNET_NAT_ERROR_TIMEOUT,
124 * detected that we are offline
126 GNUNET_NAT_ERROR_NOT_ONLINE,
129 * `upnpc` command not found
131 GNUNET_NAT_ERROR_UPNPC_NOT_FOUND,
134 * Failed to run `upnpc` command
136 GNUNET_NAT_ERROR_UPNPC_FAILED,
139 * `upnpc' command took too long, process killed
141 GNUNET_NAT_ERROR_UPNPC_TIMEOUT,
144 * `upnpc' command failed to establish port mapping
146 GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED,
149 * `external-ip' command not found
151 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND,
154 * Failed to run `external-ip` command
156 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED,
159 * `external-ip' command output invalid
161 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID,
164 * "no valid address was returned by `external-ip'"
166 GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID,
169 * Could not determine interface with internal/local network address
171 GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO,
174 * No working gnunet-helper-nat-server found
176 GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND,
179 * NAT test could not be initialized
181 GNUNET_NAT_ERROR_NAT_TEST_START_FAILED,
186 GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT,
189 * NAT test failed to initiate
191 GNUNET_NAT_ERROR_NAT_REGISTER_FAILED,
196 GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND,
208 * Converts `enum GNUNET_NAT_StatusCode` to string
210 * @param err error code to resolve to a string
211 * @return point to a static string containing the error code
214 GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err);
218 * Attempt to enable port redirection and detect public IP address
219 * contacting UPnP or NAT-PMP routers on the local network. Use addr
220 * to specify to which of the local host's addresses should the
221 * external port be mapped. The port is taken from the corresponding
222 * sockaddr_in[6] field. The NAT module should call the given
223 * callback for any 'plausible' external address.
225 * @param cfg configuration to use
226 * @param is_tcp #GNUNET_YES for TCP, #GNUNET_NO for UDP
227 * @param adv_port advertised port (port we are either bound to or that our OS
228 * locally performs redirection from to our bound port).
229 * @param num_addrs number of addresses in @a addrs
230 * @param addrs list of local addresses packets should be redirected to
231 * @param addrlens actual lengths of the addresses in @a addrs
232 * @param address_callback function to call everytime the public IP address changes
233 * @param reversal_callback function to call if someone wants connection reversal from us,
234 * NULL if connection reversal is not supported
235 * @param callback_cls closure for callbacks
236 * @return NULL on error, otherwise handle that can be used to unregister
238 struct GNUNET_NAT_Handle *
239 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
242 unsigned int num_addrs,
243 const struct sockaddr **addrs,
244 const socklen_t *addrlens,
245 GNUNET_NAT_AddressCallback address_callback,
246 GNUNET_NAT_ReversalCallback reversal_callback,
248 struct GNUNET_NETWORK_Handle* sock);
252 * Test if the given address is (currently) a plausible IP address for
255 * @param h the handle returned by register
256 * @param addr IP address to test (IPv4 or IPv6)
257 * @param addrlen number of bytes in @a addr
258 * @return #GNUNET_YES if the address is plausible,
259 * #GNUNET_NO if the address is not plausible,
260 * #GNUNET_SYSERR if the address is malformed
263 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h,
269 * We learned about a peer (possibly behind NAT) so run the
270 * gnunet-nat-client to send dummy ICMP responses to cause
271 * that peer to connect to us (connection reversal).
273 * @param h handle (used for configuration)
274 * @param sa the address of the peer (IPv4-only)
275 * @return #GNUNET_SYSERR on error, #GNUNET_NO if nat client is disabled,
276 * #GNUNET_OK otherwise
279 GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
280 const struct sockaddr_in *sa);
284 * Stop port redirection and public IP address detection for the given
285 * handle. This frees the handle, after having sent the needed
286 * commands to close open ports.
288 * @param h the handle to stop
291 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h);
295 * Handle to a NAT test.
297 struct GNUNET_NAT_Test;
301 * Function called to report success or failure for
302 * NAT configuration test.
305 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
307 typedef void (*GNUNET_NAT_TestCallback) (void *cls,
308 enum GNUNET_NAT_StatusCode result);
312 * Start testing if NAT traversal works using the
313 * given configuration (IPv4-only).
315 * @param cfg configuration for the NAT traversal
316 * @param is_tcp #GNUNET_YES to test TCP, #GNUNET_NO to test UDP
317 * @param bnd_port port to bind to, 0 for connection reversal
318 * @param adv_port externally advertised port to use
319 * @param timeout delay after which the test should be aborted
320 * @param report function to call with the result of the test;
321 * you still must call #GNUNET_NAT_test_stop().
322 * @param report_cls closure for @a report
323 * @return handle to cancel NAT test
325 struct GNUNET_NAT_Test *
326 GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
330 struct GNUNET_TIME_Relative timeout,
331 GNUNET_NAT_TestCallback report,
336 * Stop an active NAT test.
338 * @param tst test to stop.
341 GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst);
345 * Signature of a callback that is given an IP address.
348 * @param addr the address, NULL on errors
349 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
351 typedef void (*GNUNET_NAT_IPCallback) (void *cls,
352 const struct in_addr *addr,
353 enum GNUNET_NAT_StatusCode result);
358 * Opaque handle to cancel #GNUNET_NAT_mini_get_external_ipv4() operation.
360 struct GNUNET_NAT_ExternalHandle;
364 * Try to get the external IPv4 address of this peer.
366 * @param timeout when to fail
367 * @param cb function to call with result
368 * @param cb_cls closure for @a cb
369 * @return handle for cancellation (can only be used until @a cb is called), NULL on error
371 struct GNUNET_NAT_ExternalHandle *
372 GNUNET_NAT_mini_get_external_ipv4 (struct GNUNET_TIME_Relative timeout,
373 GNUNET_NAT_IPCallback cb,
380 * @param eh operation to cancel
383 GNUNET_NAT_mini_get_external_ipv4_cancel (struct GNUNET_NAT_ExternalHandle *eh);
387 * Handle to a mapping created with upnpc.
389 struct GNUNET_NAT_MiniHandle;
393 * Signature of the callback passed to #GNUNET_NAT_register() for
394 * a function to call whenever our set of 'valid' addresses changes.
397 * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
398 * the previous (now invalid) one, #GNUNET_SYSERR indicates an error
399 * @param addr either the previous or the new public IP address
400 * @param addrlen actual length of the @a addr
401 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
404 (*GNUNET_NAT_MiniAddressCallback) (void *cls,
406 const struct sockaddr *addr,
408 enum GNUNET_NAT_StatusCode result);
412 * Start mapping the given port using (mini)upnpc. This function
413 * should typically not be used directly (it is used within the
414 * general-purpose #GNUNET_NAT_register() code). However, it can be
415 * used if specifically UPnP-based NAT traversal is to be used or
418 * @param port port to map
419 * @param is_tcp #GNUNET_YES to map TCP, #GNUNET_NO for UDP
420 * @param ac function to call with mapping result
421 * @param ac_cls closure for @a ac
422 * @return NULL on error
424 struct GNUNET_NAT_MiniHandle *
425 GNUNET_NAT_mini_map_start (uint16_t port,
427 GNUNET_NAT_MiniAddressCallback ac,
432 * Remove a mapping created with (mini)upnpc. Calling
433 * this function will give 'upnpc' 1s to remove the mapping,
434 * so while this function is non-blocking, a task will be
435 * left with the scheduler for up to 1s past this call.
437 * @param mini the handle
440 GNUNET_NAT_mini_map_stop (struct GNUNET_NAT_MiniHandle *mini);
444 * Handle to auto-configuration in progress.
446 struct GNUNET_NAT_AutoHandle;
450 * Function called with the result from the autoconfiguration.
453 * @param diff minimal suggested changes to the original configuration
454 * to make it work (as best as we can)
455 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
456 * @param type what the situation of the NAT
459 (*GNUNET_NAT_AutoResultCallback)(void *cls,
460 const struct GNUNET_CONFIGURATION_Handle *diff,
461 enum GNUNET_NAT_StatusCode result,
462 enum GNUNET_NAT_Type type);
466 * Start auto-configuration routine. The resolver service should
467 * be available when this function is called.
469 * @param cfg initial configuration
470 * @param cb function to call with autoconfiguration result
471 * @param cb_cls closure for @a cb
472 * @return handle to cancel operation
474 struct GNUNET_NAT_AutoHandle *
475 GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
476 GNUNET_NAT_AutoResultCallback cb,
481 * Abort autoconfiguration.
483 * @param ah handle for operation to abort
486 GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah);
489 * Handle for active STUN Requests.
491 struct GNUNET_NAT_STUN_Handle;
497 * Function called with the result if an error happened during STUN request.
500 * @param result the specific error code
503 (*GNUNET_NAT_STUN_ErrorCallback)(void *cls,
504 enum GNUNET_NAT_StatusCode error);
508 * Make Generic STUN request and
509 * Send a generic stun request to the server specified using the specified socket.
510 * possibly waiting for a reply and filling the 'reply' field with
511 * the externally visible address.
514 * @param server, the address of the stun server
515 * @param port, port of the stun server
516 * @param sock the socket used to send the request
517 * @param cb callback in case of error
518 * @return #GNUNET_OK success, #GNUNET_NO on error.
521 GNUNET_NAT_stun_make_request(char * server,
523 struct GNUNET_NETWORK_Handle * sock, GNUNET_NAT_STUN_ErrorCallback cb,
529 * Handle an incoming STUN message, Do some basic sanity checks on packet size and content,
530 * try to extract a bit of information, and possibly reply.
531 * At the moment this only processes BIND requests, and returns
532 * the externally visible address of the request.
533 * If a callback is specified, invoke it with the attribute.
535 * @param data, the packet
536 * @param len, the length of the packet
537 * @param arg, sockaddr_in where we will set our discovered packet
539 * @return, #GNUNET_OK on OK, #GNUNET_NO if the packet is invalid ( not a stun packet)
542 GNUNET_NAT_stun_handle_packet(const void *data,
544 struct sockaddr_in *arg);
547 * CHECK if is a valid STUN packet sending to GNUNET_NAT_stun_handle_packet.
548 * It also check if it can handle the packet based on the NAT handler.
549 * You don't need to call anything else to check if the packet is valid,
551 * @param cls the NAT handle
552 * @param data, packet
553 * @param len, packet length
555 * @return #GNUNET_NO if it can't decode,# GNUNET_YES if is a packet
558 GNUNET_NAT_is_valid_stun_packet(void *cls,
566 /* end of gnunet_nat_lib.h */