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22 * @author Christian Grothoff
23 * @author Milan Bouchet-Valat
26 * Service for handling UPnP and NAT-PMP port forwarding
27 * and external IP address retrieval
29 * @defgroup nat NAT library
30 * Service for handling UPnP and NAT-PMP port forwarding
31 * and external IP address retrieval
36 #ifndef GNUNET_NAT_SERVICE_H
37 #define GNUNET_NAT_SERVICE_H
39 #include "gnunet_util_lib.h"
43 * Some addresses contain sensitive information or are
44 * not suitable for global distribution. We use address
45 * classes to filter addresses by which domain they make
46 * sense to be used in. These are used in a bitmask.
48 * FIXME: might want to define this elsewhere; we have
49 * an equivalent enum in gnunet_transport_hello_service.h;
50 * might ultimately belong with the new HELLO definition.
52 enum GNUNET_NAT_AddressClass
58 GNUNET_NAT_AC_NONE = 0,
61 * Addresses that fall into no other category
62 * (i.e. incoming which we cannot use elsewhere).
64 GNUNET_NAT_AC_OTHER = 1,
67 * Flag for addresses that are highly sensitive
68 * (i.e. IPv6 with our MAC).
70 GNUNET_NAT_AC_PRIVATE = 2,
73 * Addresses that are global (i.e. IPv4).
75 GNUNET_NAT_AC_GLOBAL = 4,
78 * Addresses that are global and are sensitive
79 * (i.e. IPv6 with our MAC).
81 GNUNET_NAT_AC_GLOBAL_PRIVATE = 6,
84 * Addresses useful in the local wired network,
85 * i.e. a MAC. Sensitive, but obvious to people nearby.
87 * Useful for broadcasts.
89 GNUNET_NAT_AC_LAN = 8,
92 * Addresses useful in the local wired network,
93 * i.e. a MAC. Sensitive, but obvious to people nearby.
94 * Useful for broadcasts.
96 GNUNET_NAT_AC_LAN_PRIVATE = 10,
99 * Addresses useful in the local wireless network,
100 * i.e. a MAC. Sensitive, but obvious to people nearby.
101 * Useful for broadcasts.
103 GNUNET_NAT_AC_WLAN = 16,
106 * Addresses useful in the local bluetooth network. Sensitive, but
107 * obvious to people nearby. Useful for broadcasts.
109 GNUNET_NAT_AC_BT = 32,
112 * Loopback addresses, only useful under special cirumstances.
114 GNUNET_NAT_AC_LOOPBACK = 64,
117 * Addresses that should be our external IP address
118 * on the outside of a NAT. Might be incorrectly determined.
119 * Used as a bit in combination with #GNUNET_NAT_AC_GLOBAL,
120 * or in case of double-NAT with
121 * #GNUNET_NAT_AC_LAN.
123 GNUNET_NAT_AC_EXTERN = 128,
126 * Bitmask for "any" address.
128 GNUNET_NAT_AC_ANY = 65535
134 * Signature of the callback passed to #GNUNET_NAT_register() for
135 * a function to call whenever our set of 'valid' addresses changes.
138 * @param add_remove #GNUNET_YES to add a new public IP address,
139 * #GNUNET_NO to remove a previous (now invalid) one
140 * @param ac address class the address belongs to
141 * @param addr either the previous or the new public IP address
142 * @param addrlen actual length of the @a addr
145 (*GNUNET_NAT_AddressCallback) (void *cls,
147 enum GNUNET_NAT_AddressClass ac,
148 const struct sockaddr *addr,
153 * Signature of the callback passed to #GNUNET_NAT_register().
154 * for a function to call whenever someone asks us to do connection
158 * @param remote_addr public IP address of the other peer
159 * @param remote_addrlen actual length of the @a remote_addr
162 (*GNUNET_NAT_ReversalCallback) (void *cls,
163 const struct sockaddr *remote_addr,
164 socklen_t remote_addrlen);
168 * Handle for active NAT registrations.
170 struct GNUNET_NAT_Handle;
174 * Attempt to enable port redirection and detect public IP address
175 * contacting UPnP or NAT-PMP routers on the local network. Use @a
176 * addr to specify to which of the local host's addresses should the
177 * external port be mapped. The port is taken from the corresponding
178 * sockaddr_in[6] field. The NAT module should call the given @a
179 * address_callback for any 'plausible' external address.
181 * @param cfg configuration to use
182 * @param proto protocol this is about, IPPROTO_TCP or IPPROTO_UDP
183 * @param hole_external hostname and port of manually punched hole in NAT, otherwise NULL (or empty string)
184 * @param num_addrs number of addresses in @a addrs
185 * @param addrs list of local addresses packets should be redirected to
186 * @param addrlens actual lengths of the addresses in @a addrs
187 * @param address_callback function to call everytime the public IP address changes
188 * @param reversal_callback function to call if someone wants connection reversal from us,
189 * NULL if connection reversal is not supported
190 * @param callback_cls closure for callbacks
191 * @return NULL on error, otherwise handle that can be used to unregister
193 struct GNUNET_NAT_Handle *
194 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
196 const char *hole_external,
197 unsigned int num_addrs,
198 const struct sockaddr **addrs,
199 const socklen_t *addrlens,
200 GNUNET_NAT_AddressCallback address_callback,
201 GNUNET_NAT_ReversalCallback reversal_callback,
206 * Test if the given address is (currently) a plausible IP address for
207 * this peer. Mostly a convenience function so that clients do not
208 * have to explicitly track all IPs that the #GNUNET_NAT_AddressCallback
209 * has returned so far.
211 * @param nh the handle returned by register
212 * @param addr IP address to test (IPv4 or IPv6)
213 * @param addrlen number of bytes in @a addr
214 * @return #GNUNET_YES if the address is plausible,
215 * #GNUNET_NO if the address is not plausible,
216 * #GNUNET_SYSERR if the address is malformed
219 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *nh,
225 * We learned about a peer (possibly behind NAT) so run the
226 * gnunet-nat-client to send dummy ICMP responses to cause
227 * that peer to connect to us (connection reversal).
229 * @param nh handle (used for configuration)
230 * @param local_sa our local address of the peer (IPv4-only)
231 * @param remote_sa the remote address of the peer (IPv4-only)
232 * @return #GNUNET_SYSERR on error,
233 * #GNUNET_NO if connection reversal is unavailable,
234 * #GNUNET_OK otherwise (presumably in progress)
237 GNUNET_NAT_request_reversal (struct GNUNET_NAT_Handle *nh,
238 const struct sockaddr_in *local_sa,
239 const struct sockaddr_in *remote_sa);
243 * Stop port redirection and public IP address detection for the given
244 * handle. This frees the handle, after having sent the needed
245 * commands to close open ports.
247 * @param nh the handle to unregister
250 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *nh);
254 * Handle to a NAT test.
256 struct GNUNET_NAT_Test;
260 * Error Types for the NAT subsystem (which can then later be converted/resolved to a string)
262 enum GNUNET_NAT_StatusCode
267 GNUNET_NAT_ERROR_SUCCESS = GNUNET_OK,
272 GNUNET_NAT_ERROR_IPC_FAILURE,
275 * Failure in network subsystem, check permissions
277 GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR,
282 GNUNET_NAT_ERROR_TIMEOUT,
285 * detected that we are offline
287 GNUNET_NAT_ERROR_NOT_ONLINE,
290 * `upnpc` command not found
292 GNUNET_NAT_ERROR_UPNPC_NOT_FOUND,
295 * Failed to run `upnpc` command
297 GNUNET_NAT_ERROR_UPNPC_FAILED,
300 * `upnpc' command took too long, process killed
302 GNUNET_NAT_ERROR_UPNPC_TIMEOUT,
305 * `upnpc' command failed to establish port mapping
307 GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED,
310 * `external-ip' command not found
312 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND,
315 * Failed to run `external-ip` command
317 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED,
320 * `external-ip' command output invalid
322 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID,
325 * "no valid address was returned by `external-ip'"
327 GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID,
330 * Could not determine interface with internal/local network address
332 GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO,
335 * No working gnunet-helper-nat-server found
337 GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND,
340 * NAT test could not be initialized
342 GNUNET_NAT_ERROR_NAT_TEST_START_FAILED,
347 GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT,
350 * NAT test failed to initiate
352 GNUNET_NAT_ERROR_NAT_REGISTER_FAILED,
357 GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND
363 * Function called to report success or failure for
364 * NAT configuration test.
367 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
370 (*GNUNET_NAT_TestCallback) (void *cls,
371 enum GNUNET_NAT_StatusCode result);
375 * Handle an incoming STUN message. This function is useful as
376 * some GNUnet service may be listening on a UDP port and might
377 * thus receive STUN messages while trying to receive other data.
378 * In this case, this function can be used to process replies
381 * The function does some basic sanity checks on packet size and
382 * content, try to extract a bit of information.
384 * At the moment this only processes BIND requests, and returns the
385 * externally visible address of the request to the rest of the
388 * @param nh handle to the NAT service
389 * @param sender_addr address from which we got @a data
390 * @param sender_addr_len number of bytes in @a sender_addr
391 * @param data the packet
392 * @param data_size number of bytes in @a data
393 * @return #GNUNET_OK on success
394 * #GNUNET_NO if the packet is not a STUN packet
395 * #GNUNET_SYSERR on internal error handling the packet
398 GNUNET_NAT_stun_handle_packet (struct GNUNET_NAT_Handle *nh,
399 const struct sockaddr *sender_addr,
400 size_t sender_addr_len,
406 * Handle to a request given to the resolver. Can be used to cancel
407 * the request prior to the timeout or successful execution. Also
408 * used to track our internal state for the request.
410 struct GNUNET_NAT_STUN_Handle;
414 * Make Generic STUN request. Sends a generic stun request to the
415 * server specified using the specified socket. If we do this,
416 * we need to watch for possible responses and call
417 * #GNUNET_NAT_stun_handle_packet() on incoming packets.
419 * @param server the address of the stun server
420 * @param port port of the stun server, in host byte order
421 * @param sock the socket used to send the request, must be a
423 * @param cb callback in case of error
424 * @param cb_cls closure for @a cb
425 * @return NULL on error
427 struct GNUNET_NAT_STUN_Handle *
428 GNUNET_NAT_stun_make_request (const char *server,
430 struct GNUNET_NETWORK_Handle *sock,
431 GNUNET_NAT_TestCallback cb,
436 * Cancel active STUN request. Frees associated resources
437 * and ensures that the callback is no longer invoked.
439 * @param rh request to cancel
442 GNUNET_NAT_stun_make_request_cancel (struct GNUNET_NAT_STUN_Handle *rh);
446 * Start testing if NAT traversal works using the given configuration
447 * (IPv4-only). The transport adapters should be down while using
450 * @param cfg configuration for the NAT traversal
451 * @param proto protocol to test, i.e. IPPROTO_TCP or IPPROTO_UDP
452 * @param bind_ip IPv4 address to bind to
453 * @param bnd_port port to bind to, 0 to test connection reversal
454 * @param extern_ip IPv4 address to externally advertise
455 * @param extern_port externally advertised port to use
456 * @param report function to call with the result of the test
457 * @param report_cls closure for @a report
458 * @return handle to cancel NAT test
460 struct GNUNET_NAT_Test *
461 GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
463 struct in_addr bind_ip,
465 struct in_addr extern_ip,
466 uint16_t extern_port,
467 GNUNET_NAT_TestCallback report,
472 * Stop an active NAT test.
474 * @param tst test to stop.
477 GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst);
481 * Handle to auto-configuration in progress.
483 struct GNUNET_NAT_AutoHandle;
487 * What the situation of the NAT connectivity
492 * We have a direct connection
494 GNUNET_NAT_TYPE_NO_NAT = GNUNET_OK,
497 * We are under a NAT but cannot traverse it
499 GNUNET_NAT_TYPE_UNREACHABLE_NAT,
502 * We can traverse using STUN
504 GNUNET_NAT_TYPE_STUN_PUNCHED_NAT,
507 * We can traverse using UPNP
509 GNUNET_NAT_TYPE_UPNP_NAT,
512 * We know nothing about the NAT.
514 GNUNET_NAT_TYPE_UNKNOWN
520 * Converts `enum GNUNET_NAT_StatusCode` to string
522 * @param err error code to resolve to a string
523 * @return point to a static string containing the error code
526 GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err);
530 * Function called with the result from the autoconfiguration.
533 * @param diff minimal suggested changes to the original configuration
534 * to make it work (as best as we can)
535 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
536 * @param type what the situation of the NAT
539 (*GNUNET_NAT_AutoResultCallback)(void *cls,
540 const struct GNUNET_CONFIGURATION_Handle *diff,
541 enum GNUNET_NAT_StatusCode result,
542 enum GNUNET_NAT_Type type);
546 * Start auto-configuration routine. The transport adapters should
547 * be stopped while this function is called.
549 * @param cfg initial configuration
550 * @param cb function to call with autoconfiguration result
551 * @param cb_cls closure for @a cb
552 * @return handle to cancel operation
554 struct GNUNET_NAT_AutoHandle *
555 GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
556 GNUNET_NAT_AutoResultCallback cb,
561 * Abort autoconfiguration.
563 * @param ah handle for operation to abort
566 GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah);
571 /** @} */ /* end of group */
573 /* end of gnunet_nat_service.h */