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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 * Addresses that are global and are insensitive
70 GNUNET_NAT_AC_GLOBAL = 2,
73 * Addresses that are global and are sensitive
74 * (i.e. IPv6 with our MAC).
76 GNUNET_NAT_AC_GLOBAL_PRIVATE = 4,
79 * Addresses useful in the local wired network,
80 * i.e. a MAC. Sensitive, but obvious to people nearby.
81 * Useful for broadcasts.
83 GNUNET_NAT_AC_LAN = 8,
86 * Addresses useful in the local wireless network,
87 * i.e. a MAC. Sensitive, but obvious to people nearby.
88 * Useful for broadcasts.
90 GNUNET_NAT_AC_WLAN = 16,
93 * Addresses useful in the local bluetooth network. Sensitive, but
94 * obvious to people nearby. Useful for broadcasts.
96 GNUNET_NAT_AC_BT = 32,
99 * Bitmask for "any" address.
101 GNUNET_NAT_AC_ANY = 65535
107 * Signature of the callback passed to #GNUNET_NAT_register() for
108 * a function to call whenever our set of 'valid' addresses changes.
111 * @param add_remove #GNUNET_YES to add a new public IP address,
112 * #GNUNET_NO to remove a previous (now invalid) one
113 * @param ac address class the address belongs to
114 * @param addr either the previous or the new public IP address
115 * @param addrlen actual length of the @a addr
118 (*GNUNET_NAT_AddressCallback) (void *cls,
120 enum GNUNET_NAT_AddressClass ac,
121 const struct sockaddr *addr,
126 * Signature of the callback passed to #GNUNET_NAT_register().
127 * for a function to call whenever someone asks us to do connection
131 * @param local_addr address where we received the request
132 * @param local_addrlen actual length of the @a local_addr
133 * @param remote_addr public IP address of the other peer
134 * @param remote_addrlen actual length of the @a remote_addr
137 (*GNUNET_NAT_ReversalCallback) (void *cls,
138 const struct sockaddr *local_addr,
139 socklen_t local_addrlen,
140 const struct sockaddr *remote_addr,
141 socklen_t remote_addrlen);
145 * Handle for active NAT registrations.
147 struct GNUNET_NAT_Handle;
151 * Attempt to enable port redirection and detect public IP address
152 * contacting UPnP or NAT-PMP routers on the local network. Use @a
153 * addr to specify to which of the local host's addresses should the
154 * external port be mapped. The port is taken from the corresponding
155 * sockaddr_in[6] field. The NAT module should call the given @a
156 * address_callback for any 'plausible' external address.
158 * @param cfg configuration to use
159 * @param proto protocol this is about, IPPROTO_TCP or IPPROTO_UDP
160 * @param adv_port advertised port (port we are either bound to or that our OS
161 * locally performs redirection from to our bound port).
162 * @param num_addrs number of addresses in @a addrs
163 * @param addrs list of local addresses packets should be redirected to
164 * @param addrlens actual lengths of the addresses in @a addrs
165 * @param address_callback function to call everytime the public IP address changes
166 * @param reversal_callback function to call if someone wants connection reversal from us,
167 * NULL if connection reversal is not supported
168 * @param callback_cls closure for callbacks
169 * @return NULL on error, otherwise handle that can be used to unregister
171 struct GNUNET_NAT_Handle *
172 GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
175 unsigned int num_addrs,
176 const struct sockaddr **addrs,
177 const socklen_t *addrlens,
178 GNUNET_NAT_AddressCallback address_callback,
179 GNUNET_NAT_ReversalCallback reversal_callback,
184 * Handle an incoming STUN message. This function is useful as
185 * some GNUnet service may be listening on a UDP port and might
186 * thus receive STUN messages while trying to receive other data.
187 * In this case, this function can be used to act as a proper
188 * STUN server (if desired).
190 * The function does some basic sanity checks on packet size and
191 * content, try to extract a bit of information, and possibly replies
192 * if this is an actual STUN message.
194 * At the moment this only processes BIND requests, and returns the
195 * externally visible address of the request.
197 * @param nh handle to the NAT service
198 * @param sender_addr address from which we got @a data
199 * @param sender_addr_len number of bytes in @a sender_addr
200 * @param data the packet
201 * @param data_size number of bytes in @a data
202 * @return #GNUNET_OK on success
203 * #GNUNET_NO if the packet is not a STUN packet
204 * #GNUNET_SYSERR on internal error handling the packet
207 GNUNET_NAT_stun_handle_packet (struct GNUNET_NAT_Handle *nh,
208 const struct sockaddr *sender_addr,
209 size_t sender_addr_len,
215 * Test if the given address is (currently) a plausible IP address for
216 * this peer. Mostly a convenience function so that clients do not
217 * have to explicitly track all IPs that the #GNUNET_NAT_AddressCallback
218 * has returned so far.
220 * @param nh the handle returned by register
221 * @param addr IP address to test (IPv4 or IPv6)
222 * @param addrlen number of bytes in @a addr
223 * @return #GNUNET_YES if the address is plausible,
224 * #GNUNET_NO if the address is not plausible,
225 * #GNUNET_SYSERR if the address is malformed
228 GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *nh,
234 * We learned about a peer (possibly behind NAT) so run the
235 * gnunet-nat-client to send dummy ICMP responses to cause
236 * that peer to connect to us (connection reversal).
238 * @param nh handle (used for configuration)
239 * @param local_sa our local address of the peer (IPv4-only)
240 * @param remote_sa the remote address of the peer (IPv4-only)
241 * @return #GNUNET_SYSERR on error,
242 * #GNUNET_NO if connection reversal is unavailable,
243 * #GNUNET_OK otherwise (presumably in progress)
246 GNUNET_NAT_request_reversal (struct GNUNET_NAT_Handle *nh,
247 const struct sockaddr_in *local_sa,
248 const struct sockaddr_in *remote_sa);
252 * Stop port redirection and public IP address detection for the given
253 * handle. This frees the handle, after having sent the needed
254 * commands to close open ports.
256 * @param nh the handle to unregister
259 GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *nh);
263 * Handle to a NAT test.
265 struct GNUNET_NAT_Test;
269 * Error Types for the NAT subsystem (which can then later be converted/resolved to a string)
271 enum GNUNET_NAT_StatusCode
276 GNUNET_NAT_ERROR_SUCCESS = GNUNET_OK,
281 GNUNET_NAT_ERROR_IPC_FAILURE,
284 * Failure in network subsystem, check permissions
286 GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR,
291 GNUNET_NAT_ERROR_TIMEOUT,
294 * detected that we are offline
296 GNUNET_NAT_ERROR_NOT_ONLINE,
299 * `upnpc` command not found
301 GNUNET_NAT_ERROR_UPNPC_NOT_FOUND,
304 * Failed to run `upnpc` command
306 GNUNET_NAT_ERROR_UPNPC_FAILED,
309 * `upnpc' command took too long, process killed
311 GNUNET_NAT_ERROR_UPNPC_TIMEOUT,
314 * `upnpc' command failed to establish port mapping
316 GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED,
319 * `external-ip' command not found
321 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND,
324 * Failed to run `external-ip` command
326 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED,
329 * `external-ip' command output invalid
331 GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID,
334 * "no valid address was returned by `external-ip'"
336 GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID,
339 * Could not determine interface with internal/local network address
341 GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO,
344 * No working gnunet-helper-nat-server found
346 GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND,
349 * NAT test could not be initialized
351 GNUNET_NAT_ERROR_NAT_TEST_START_FAILED,
356 GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT,
359 * NAT test failed to initiate
361 GNUNET_NAT_ERROR_NAT_REGISTER_FAILED,
366 GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND
372 * Function called to report success or failure for
373 * NAT configuration test.
376 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
379 (*GNUNET_NAT_TestCallback) (void *cls,
380 enum GNUNET_NAT_StatusCode result);
384 * Start testing if NAT traversal works using the given configuration
385 * (IPv4-only). The transport adapters should be down while using
388 * @param cfg configuration for the NAT traversal
389 * @param proto protocol to test, i.e. IPPROTO_TCP or IPPROTO_UDP
390 * @param bind_ip IPv4 address to bind to
391 * @param bnd_port port to bind to, 0 to test connection reversal
392 * @param extern_ip IPv4 address to externally advertise
393 * @param extern_port externally advertised port to use
394 * @param report function to call with the result of the test
395 * @param report_cls closure for @a report
396 * @return handle to cancel NAT test
398 struct GNUNET_NAT_Test *
399 GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
401 struct in_addr bind_ip,
403 struct in_addr extern_ip,
404 uint16_t extern_port,
405 GNUNET_NAT_TestCallback report,
410 * Stop an active NAT test.
412 * @param tst test to stop.
415 GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst);
419 * Handle to auto-configuration in progress.
421 struct GNUNET_NAT_AutoHandle;
425 * What the situation of the NAT connectivity
430 * We have a direct connection
432 GNUNET_NAT_TYPE_NO_NAT = GNUNET_OK,
435 * We are under a NAT but cannot traverse it
437 GNUNET_NAT_TYPE_UNREACHABLE_NAT,
440 * We can traverse using STUN
442 GNUNET_NAT_TYPE_STUN_PUNCHED_NAT,
445 * We can traverse using UPNP
447 GNUNET_NAT_TYPE_UPNP_NAT,
450 * We know nothing about the NAT.
452 GNUNET_NAT_TYPE_UNKNOWN
458 * Converts `enum GNUNET_NAT_StatusCode` to string
460 * @param err error code to resolve to a string
461 * @return point to a static string containing the error code
464 GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err);
468 * Function called with the result from the autoconfiguration.
471 * @param diff minimal suggested changes to the original configuration
472 * to make it work (as best as we can)
473 * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
474 * @param type what the situation of the NAT
477 (*GNUNET_NAT_AutoResultCallback)(void *cls,
478 const struct GNUNET_CONFIGURATION_Handle *diff,
479 enum GNUNET_NAT_StatusCode result,
480 enum GNUNET_NAT_Type type);
484 * Start auto-configuration routine. The transport adapters should
485 * be stopped while this function is called.
487 * @param cfg initial configuration
488 * @param cb function to call with autoconfiguration result
489 * @param cb_cls closure for @a cb
490 * @return handle to cancel operation
492 struct GNUNET_NAT_AutoHandle *
493 GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
494 GNUNET_NAT_AutoResultCallback cb,
499 * Abort autoconfiguration.
501 * @param ah handle for operation to abort
504 GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah);
509 /** @} */ /* end of group */
511 /* end of gnunet_nat_service.h */