/*
This file is part of GNUnet.
- (C) 2007, 2008, 2009 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2007-2014 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
- * @file include/gnunet_nat_lib.h
- * @brief Library handling UPnP and NAT-PMP port forwarding and
- * external IP address retrieval
- *
+ * @author Christian Grothoff
* @author Milan Bouchet-Valat
+ *
+ * @file
+ * Library handling UPnP and NAT-PMP port forwarding
+ * and external IP address retrieval
+ *
+ * @defgroup nat NAT library
+ * Library handling UPnP and NAT-PMP port forwarding
+ * and external IP address retrieval
+ *
+ * @{
*/
#ifndef GNUNET_NAT_LIB_H
-#define GNUNET_NAT_LIB_H 1
+#define GNUNET_NAT_LIB_H
-#include "platform.h"
#include "gnunet_util_lib.h"
-#include "upnp.h"
-#include "natpmp.h"
-#include <inttypes.h>
/**
- * Used to communicate with the UPnP and NAT-PMP plugins
- * FIXME: move to src/nat/common.h
+ * Signature of the callback passed to #GNUNET_NAT_register() for
+ * a function to call whenever our set of 'valid' addresses changes.
+ *
+ * @param cls closure
+ * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
+ * the previous (now invalid) one
+ * @param addr either the previous or the new public IP address
+ * @param addrlen actual length of the @a addr
*/
-enum GNUNET_NAT_port_forwarding
- {
- GNUNET_NAT_PORT_ERROR,
- GNUNET_NAT_PORT_UNMAPPED,
- GNUNET_NAT_PORT_UNMAPPING,
- GNUNET_NAT_PORT_MAPPING,
- GNUNET_NAT_PORT_MAPPED
- };
+typedef void
+(*GNUNET_NAT_AddressCallback) (void *cls,
+ int add_remove,
+ const struct sockaddr *addr,
+ socklen_t addrlen);
/**
- * Signature of the callback passed to GNUNET_NAT_register.
+ * Signature of the callback passed to #GNUNET_NAT_register().
+ * for a function to call whenever someone asks us to do connection
+ * reversal.
*
* @param cls closure
- * @param add_remove GNUNET_YES to mean the new public IP address, GNUNET_NO to mean
- * the previous (now invalid) one
- * @param addr either the previous or the new public IP address
- * @param addrlen actual lenght of the address
+ * @param addr public IP address of the other peer
+ * @param addrlen actual lenght of the @a addr
*/
-typedef void (*GNUNET_NAT_AddressCallback) (void *cls, int add_remove,
- const struct sockaddr * addr,
- socklen_t addrlen);
+typedef void
+(*GNUNET_NAT_ReversalCallback) (void *cls,
+ const struct sockaddr *addr,
+ socklen_t addrlen);
+
/**
* Handle for active NAT registrations.
*/
struct GNUNET_NAT_Handle;
+
+
+/**
+ * What the situation of the NAT connectivity
+ */
+enum GNUNET_NAT_Type
+{
+ /**
+ * We have a direct connection
+ */
+ GNUNET_NAT_TYPE_NO_NAT = GNUNET_OK,
+
+ /**
+ * We are under a NAT but cannot traverse it
+ */
+ GNUNET_NAT_TYPE_UNREACHABLE_NAT,
+
+ /**
+ * We can traverse using STUN
+ */
+ GNUNET_NAT_TYPE_STUN_PUNCHED_NAT,
+
+ /**
+ * WE can traverse using UPNP
+ */
+ GNUNET_NAT_TYPE_UPNP_NAT
+
+};
+
+/**
+ * Error Types for the NAT subsystem (which can then later be converted/resolved to a string)
+ */
+enum GNUNET_NAT_StatusCode
+{
+ /**
+ * Just the default
+ */
+ GNUNET_NAT_ERROR_SUCCESS = GNUNET_OK,
+
+ /**
+ * IPC Failure
+ */
+ GNUNET_NAT_ERROR_IPC_FAILURE,
+
+ /**
+ * Failure in network subsystem, check permissions
+ */
+ GNUNET_NAT_ERROR_INTERNAL_NETWORK_ERROR,
+
+ /**
+ * test timed out
+ */
+ GNUNET_NAT_ERROR_TIMEOUT,
+
+ /**
+ * detected that we are offline
+ */
+ GNUNET_NAT_ERROR_NOT_ONLINE,
+
+ /**
+ * `upnpc` command not found
+ */
+ GNUNET_NAT_ERROR_UPNPC_NOT_FOUND,
+
+ /**
+ * Failed to run `upnpc` command
+ */
+ GNUNET_NAT_ERROR_UPNPC_FAILED,
+
+ /**
+ * `upnpc' command took too long, process killed
+ */
+ GNUNET_NAT_ERROR_UPNPC_TIMEOUT,
+
+ /**
+ * `upnpc' command failed to establish port mapping
+ */
+ GNUNET_NAT_ERROR_UPNPC_PORTMAP_FAILED,
+
+ /**
+ * `external-ip' command not found
+ */
+ GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_NOT_FOUND,
+
+ /**
+ * Failed to run `external-ip` command
+ */
+ GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_FAILED,
+
+ /**
+ * `external-ip' command output invalid
+ */
+ GNUNET_NAT_ERROR_EXTERNAL_IP_UTILITY_OUTPUT_INVALID,
+
+ /**
+ * "no valid address was returned by `external-ip'"
+ */
+ GNUNET_NAT_ERROR_EXTERNAL_IP_ADDRESS_INVALID,
+
+ /**
+ * Could not determine interface with internal/local network address
+ */
+ GNUNET_NAT_ERROR_NO_VALID_IF_IP_COMBO,
+
+ /**
+ * No working gnunet-helper-nat-server found
+ */
+ GNUNET_NAT_ERROR_HELPER_NAT_SERVER_NOT_FOUND,
+
+ /**
+ * NAT test could not be initialized
+ */
+ GNUNET_NAT_ERROR_NAT_TEST_START_FAILED,
+
+ /**
+ * NAT test timeout
+ */
+ GNUNET_NAT_ERROR_NAT_TEST_TIMEOUT,
+
+ /**
+ * NAT test failed to initiate
+ */
+ GNUNET_NAT_ERROR_NAT_REGISTER_FAILED,
+
+ /**
+ *
+ */
+ GNUNET_NAT_ERROR_HELPER_NAT_CLIENT_NOT_FOUND,
+
+ /**
+ *
+ */
+ GNUNET_NAT_ERROR_
+};
+
+
/**
- * Attempt to enable port redirection and detect public IP address contacting
- * UPnP or NAT-PMP routers on the local network. Use addr to specify to which
- * of the local host's addresses should the external port be mapped. The port
- * is taken from the corresponding sockaddr_in[6] field.
+ * Converts `enum GNUNET_NAT_StatusCode` to string
*
- * @param sched the sheduler used in the program
- * @param addr the local address packets should be redirected to
- * @param addrlen actual lenght of the address
- * @param callback function to call everytime the public IP address changes
- * @param callback_cls closure for callback
- * @return NULL on error, otherwise handle that can be used to unregister
+ * @param err error code to resolve to a string
+ * @return point to a static string containing the error code
*/
-struct GNUNET_NAT_Handle *GNUNET_NAT_register (struct GNUNET_SCHEDULER_Handle
- *sched,
- const struct sockaddr *addr,
- socklen_t addrlen,
- GNUNET_NAT_AddressCallback
- callback, void *callback_cls);
+const char *
+GNUNET_NAT_status2string (enum GNUNET_NAT_StatusCode err);
+
+
+/**
+ * Attempt to enable port redirection and detect public IP address
+ * contacting UPnP or NAT-PMP routers on the local network. Use addr
+ * to specify to which of the local host's addresses should the
+ * external port be mapped. The port is taken from the corresponding
+ * sockaddr_in[6] field. The NAT module should call the given
+ * callback for any 'plausible' external address.
+ *
+ * @param cfg configuration to use
+ * @param is_tcp #GNUNET_YES for TCP, #GNUNET_NO for UDP
+ * @param adv_port advertised port (port we are either bound to or that our OS
+ * locally performs redirection from to our bound port).
+ * @param num_addrs number of addresses in @a addrs
+ * @param addrs list of local addresses packets should be redirected to
+ * @param addrlens actual lengths of the addresses in @a addrs
+ * @param address_callback function to call everytime the public IP address changes
+ * @param reversal_callback function to call if someone wants connection reversal from us,
+ * NULL if connection reversal is not supported
+ * @param callback_cls closure for callbacks
+ * @return NULL on error, otherwise handle that can be used to unregister
+ */
+struct GNUNET_NAT_Handle *
+GNUNET_NAT_register (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ int is_tcp,
+ uint16_t adv_port,
+ unsigned int num_addrs,
+ const struct sockaddr **addrs,
+ const socklen_t *addrlens,
+ GNUNET_NAT_AddressCallback address_callback,
+ GNUNET_NAT_ReversalCallback reversal_callback,
+ void *callback_cls,
+ struct GNUNET_NETWORK_Handle* sock);
+
+
+/**
+ * Test if the given address is (currently) a plausible IP address for
+ * this peer.
+ *
+ * @param h the handle returned by register
+ * @param addr IP address to test (IPv4 or IPv6)
+ * @param addrlen number of bytes in @a addr
+ * @return #GNUNET_YES if the address is plausible,
+ * #GNUNET_NO if the address is not plausible,
+ * #GNUNET_SYSERR if the address is malformed
+ */
+int
+GNUNET_NAT_test_address (struct GNUNET_NAT_Handle *h,
+ const void *addr,
+ socklen_t addrlen);
+
/**
- * Stop port redirection and public IP address detection for the given handle.
- * This frees the handle, after having sent the needed commands to close open ports.
+ * We learned about a peer (possibly behind NAT) so run the
+ * gnunet-nat-client to send dummy ICMP responses to cause
+ * that peer to connect to us (connection reversal).
+ *
+ * @param h handle (used for configuration)
+ * @param sa the address of the peer (IPv4-only)
+ * @return #GNUNET_SYSERR on error, #GNUNET_NO if nat client is disabled,
+ * #GNUNET_OK otherwise
+ */
+int
+GNUNET_NAT_run_client (struct GNUNET_NAT_Handle *h,
+ const struct sockaddr_in *sa);
+
+
+/**
+ * Stop port redirection and public IP address detection for the given
+ * handle. This frees the handle, after having sent the needed
+ * commands to close open ports.
*
* @param h the handle to stop
*/
-void GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h);
+void
+GNUNET_NAT_unregister (struct GNUNET_NAT_Handle *h);
+
+
+/**
+ * Handle to a NAT test.
+ */
+struct GNUNET_NAT_Test;
+
+
+/**
+ * Function called to report success or failure for
+ * NAT configuration test.
+ *
+ * @param cls closure
+ * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
+ */
+typedef void (*GNUNET_NAT_TestCallback) (void *cls,
+ enum GNUNET_NAT_StatusCode result);
+
+
+/**
+ * Start testing if NAT traversal works using the
+ * given configuration (IPv4-only).
+ *
+ * @param cfg configuration for the NAT traversal
+ * @param is_tcp #GNUNET_YES to test TCP, #GNUNET_NO to test UDP
+ * @param bnd_port port to bind to, 0 for connection reversal
+ * @param adv_port externally advertised port to use
+ * @param timeout delay after which the test should be aborted
+ * @param report function to call with the result of the test;
+ * you still must call #GNUNET_NAT_test_stop().
+ * @param report_cls closure for @a report
+ * @return handle to cancel NAT test
+ */
+struct GNUNET_NAT_Test *
+GNUNET_NAT_test_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ int is_tcp,
+ uint16_t bnd_port,
+ uint16_t adv_port,
+ struct GNUNET_TIME_Relative timeout,
+ GNUNET_NAT_TestCallback report,
+ void *report_cls);
+
+
+/**
+ * Stop an active NAT test.
+ *
+ * @param tst test to stop.
+ */
+void
+GNUNET_NAT_test_stop (struct GNUNET_NAT_Test *tst);
+
+
+/**
+ * Signature of a callback that is given an IP address.
+ *
+ * @param cls closure
+ * @param addr the address, NULL on errors
+ * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
+ */
+typedef void
+(*GNUNET_NAT_IPCallback) (void *cls,
+ const struct in_addr *addr,
+ enum GNUNET_NAT_StatusCode result);
+
/**
- * Compare the sin(6)_addr fields of AF_INET or AF_INET(6) sockaddr.
- * FIXME: move to src/nat/common.h or so.
- *
- * @param a first sockaddr
- * @param b second sockaddr
- * @return 0 if addresses are equal, non-null value otherwise
+ * Opaque handle to cancel #GNUNET_NAT_mini_get_external_ipv4() operation.
*/
-int GNUNET_NAT_cmp_addr (const struct sockaddr *a,
- const struct sockaddr *b);
+struct GNUNET_NAT_ExternalHandle;
+
+
+/**
+ * Try to get the external IPv4 address of this peer.
+ *
+ * @param timeout when to fail
+ * @param cb function to call with result
+ * @param cb_cls closure for @a cb
+ * @return handle for cancellation (can only be used until @a cb is called), NULL on error
+ */
+struct GNUNET_NAT_ExternalHandle *
+GNUNET_NAT_mini_get_external_ipv4 (struct GNUNET_TIME_Relative timeout,
+ GNUNET_NAT_IPCallback cb,
+ void *cb_cls);
+
+
+/**
+ * Cancel operation.
+ *
+ * @param eh operation to cancel
+ */
+void
+GNUNET_NAT_mini_get_external_ipv4_cancel (struct GNUNET_NAT_ExternalHandle *eh);
+
+
+/**
+ * Handle to a mapping created with upnpc.
+ */
+struct GNUNET_NAT_MiniHandle;
+
+
+/**
+ * Signature of the callback passed to #GNUNET_NAT_register() for
+ * a function to call whenever our set of 'valid' addresses changes.
+ *
+ * @param cls closure
+ * @param add_remove #GNUNET_YES to mean the new public IP address, #GNUNET_NO to mean
+ * the previous (now invalid) one, #GNUNET_SYSERR indicates an error
+ * @param addr either the previous or the new public IP address
+ * @param addrlen actual length of the @a addr
+ * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
+ */
+typedef void
+(*GNUNET_NAT_MiniAddressCallback) (void *cls,
+ int add_remove,
+ const struct sockaddr *addr,
+ socklen_t addrlen,
+ enum GNUNET_NAT_StatusCode result);
+
+
+/**
+ * Start mapping the given port using (mini)upnpc. This function
+ * should typically not be used directly (it is used within the
+ * general-purpose #GNUNET_NAT_register() code). However, it can be
+ * used if specifically UPnP-based NAT traversal is to be used or
+ * tested.
+ *
+ * @param port port to map
+ * @param is_tcp #GNUNET_YES to map TCP, #GNUNET_NO for UDP
+ * @param ac function to call with mapping result
+ * @param ac_cls closure for @a ac
+ * @return NULL on error
+ */
+struct GNUNET_NAT_MiniHandle *
+GNUNET_NAT_mini_map_start (uint16_t port,
+ int is_tcp,
+ GNUNET_NAT_MiniAddressCallback ac,
+ void *ac_cls);
+
+
+/**
+ * Remove a mapping created with (mini)upnpc. Calling
+ * this function will give 'upnpc' 1s to remove the mapping,
+ * so while this function is non-blocking, a task will be
+ * left with the scheduler for up to 1s past this call.
+ *
+ * @param mini the handle
+ */
+void
+GNUNET_NAT_mini_map_stop (struct GNUNET_NAT_MiniHandle *mini);
+
+
+/**
+ * Handle to auto-configuration in progress.
+ */
+struct GNUNET_NAT_AutoHandle;
+
+
+/**
+ * Function called with the result from the autoconfiguration.
+ *
+ * @param cls closure
+ * @param diff minimal suggested changes to the original configuration
+ * to make it work (as best as we can)
+ * @param result #GNUNET_NAT_ERROR_SUCCESS on success, otherwise the specific error code
+ * @param type what the situation of the NAT
+ */
+typedef void
+(*GNUNET_NAT_AutoResultCallback)(void *cls,
+ const struct GNUNET_CONFIGURATION_Handle *diff,
+ enum GNUNET_NAT_StatusCode result,
+ enum GNUNET_NAT_Type type);
+
+
+/**
+ * Start auto-configuration routine. The resolver service should
+ * be available when this function is called.
+ *
+ * @param cfg initial configuration
+ * @param cb function to call with autoconfiguration result
+ * @param cb_cls closure for @a cb
+ * @return handle to cancel operation
+ */
+struct GNUNET_NAT_AutoHandle *
+GNUNET_NAT_autoconfig_start (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ GNUNET_NAT_AutoResultCallback cb,
+ void *cb_cls);
+
+
+/**
+ * Abort autoconfiguration.
+ *
+ * @param ah handle for operation to abort
+ */
+void
+GNUNET_NAT_autoconfig_cancel (struct GNUNET_NAT_AutoHandle *ah);
+
+/**
+ * Handle for active STUN Requests.
+ */
+struct GNUNET_NAT_STUN_Handle;
+
+
+/**
+ * Function called with the result if an error happened during STUN request.
+ *
+ * @param cls closure
+ * @param result the specific error code
+ */
+typedef void
+(*GNUNET_NAT_STUN_ErrorCallback)(void *cls,
+ enum GNUNET_NAT_StatusCode error);
+
+
+/**
+ * Handle to a request given to the resolver. Can be used to cancel
+ * the request prior to the timeout or successful execution. Also
+ * used to track our internal state for the request.
+ */
+struct GNUNET_NAT_STUN_Handle;
+
+
+/**
+ * Make generic STUN request. Sends a generic stun request to the
+ * server specified using the specified socket. The caller must
+ * wait for a reply on the @a sock and call
+ * #GNUNET_NAT_stun_handle_packet() if a reply is received.
+ *
+ * @param server the address of the stun server
+ * @param port port of the stun server
+ * @param sock the socket used to send the request
+ * @param cb callback in case of error (or completion)
+ * @param cb_cls closure for @a cb
+ * @return NULL on error
+ */
+struct GNUNET_NAT_STUN_Handle *
+GNUNET_NAT_stun_make_request (const char *server,
+ uint16_t port,
+ struct GNUNET_NETWORK_Handle *sock,
+ GNUNET_NAT_STUN_ErrorCallback cb,
+ void *cb_cls);
+
+
+/**
+ * Cancel active STUN request. Frees associated resources
+ * and ensures that the callback is no longer invoked.
+ *
+ * @param rh request to cancel
+ */
+void
+GNUNET_NAT_stun_make_request_cancel (struct GNUNET_NAT_STUN_Handle *rh);
+
+
+/**
+ * Handle an incoming STUN message. Do some basic sanity checks on
+ * packet size and content, try to extract a bit of information, and
+ * possibly reply. At the moment this only processes BIND requests,
+ * and returns the externally visible address of the request. If a
+ * callback is specified, invoke it with the attribute.
+ *
+ * @param data the packet
+ * @param len the length of the packet
+ * @param arg sockaddr_in where we will set our discovered packet
+ * @return #GNUNET_OK on OK,
+ * #GNUNET_NO if the packet is not a stun packet
+ */
+int
+GNUNET_NAT_stun_handle_packet (const void *data,
+ size_t len,
+ struct sockaddr_in *arg);
+
+
+/**
+ * CHECK if is a valid STUN packet sending to #GNUNET_NAT_stun_handle_packet().
+ * It also check if it can handle the packet based on the NAT handler.
+ * You don't need to call anything else to check if the packet is valid,
+ *
+ * @param cls the NAT handle
+ * @param data packet
+ * @param len length of @a data
+ * @return #GNUNET_NO if it can't decode, #GNUNET_YES if is a packet
+ */
+int
+GNUNET_NAT_is_valid_stun_packet (void *cls,
+ const void *data,
+ size_t len);
+
+#endif
-#endif
+/** @} */ /* end of group */
/* end of gnunet_nat_lib.h */