BadVPN – Rev 1
?pathlinks?
/**
* @file BSocksClient.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* SOCKS5 client. TCP only, no authentication.
*/
#ifndef BADVPN_SOCKS_BSOCKSCLIENT_H
#define BADVPN_SOCKS_BSOCKSCLIENT_H
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <misc/debug.h>
#include <misc/debugerror.h>
#include <misc/socks_proto.h>
#include <misc/packed.h>
#include <base/DebugObject.h>
#include <base/BPending.h>
#include <system/BConnection.h>
#include <flow/PacketStreamSender.h>
#define BSOCKSCLIENT_EVENT_ERROR 1
#define BSOCKSCLIENT_EVENT_UP 2
#define BSOCKSCLIENT_EVENT_ERROR_CLOSED 3
#define BSOCKSCLIENT_EVENT_CONNECTED 4
/**
* Handler for events generated by the SOCKS client.
*
* The event is one of the following:
* - BSOCKSCLIENT_EVENT_ERROR: An error has occured. The object must be freed from the
* job closure of the handler and no further I/O must be attempted.
* - BSOCKSCLIENT_EVENT_ERROR_CLOSED: The server has closed the connection. This event
* can only be reported after BSOCKSCLIENT_EVENT_UP. The object must be freed from
* the job closure of the handler and no further I/O must be attempted.
* - BSOCKSCLIENT_EVENT_UP: The CONNECT or UDP ASSOCIATE operation was successful. In
* the case of CONNECT, application I/O may now begin.
* - BSOCKSCLIENT_EVENT_CONNECTED: The TCP connection to the server has been established
* and the SOCKS protocol is about to begin. The local address of the TCP connection is
* now available via @ref BSocksClient_GetLocalAddr. The job closure of this callback
* is the last chance to call @ref BSocksClient_SetDestAddr.
*
* @param user as in {@link BSocksClient_Init}
* @param event See above.
*/
typedef void (*BSocksClient_handler) (void *user, int event);
struct BSocksClient_auth_info {
int auth_type;
union {
struct {
const char *username;
size_t username_len;
const char *password;
size_t password_len;
} password;
};
};
typedef struct {
const struct BSocksClient_auth_info *auth_info;
size_t num_auth_info;
BAddr dest_addr;
bool udp;
BAddr bind_addr;
BSocksClient_handler handler;
void *user;
BReactor *reactor;
int state;
char *buffer;
BConnector connector;
BConnection con;
BPending continue_job;
union {
struct {
PacketPassInterface *send_if;
PacketStreamSender send_sender;
StreamRecvInterface *recv_if;
uint8_t *recv_dest;
int recv_len;
int recv_total;
} control;
};
DebugError d_err;
DebugObject d_obj;
} BSocksClient;
struct BSocksClient_auth_info BSocksClient_auth_none (void);
struct BSocksClient_auth_info BSocksClient_auth_password (const char *username, size_t username_len, const char *password, size_t password_len);
/**
* Initializes the object.
*
* This object connects to a SOCKS5 server and performs a CONNECT or UDP ASSOCIATE
* operation. In any case, the object reports the BSOCKSCLIENT_EVENT_UP event via the
* handler when the operation was completed successfully. In the case of CONNECT, the
* user may then use the send and receive interfaces to exchange data through the
* connection (@ref BSocksClient_GetSendInterface and @ref BSocksClient_GetRecvInterface).
*
* @param o the object
* @param server_addr SOCKS5 server address
* @param auth_info List of supported authentication methods and associated parameters.
* Initialize these using functions such as BSocksClient_auth_none() and
* BSocksClient_auth_password(). The pointer must remain valid while this object
* exists, the data is not copied.
* @param num_auth_info Number of the above. There should be at least one, otherwise it
* certainly won't work.
* @param dest_addr Address to send as DST.ADDR in the CONNECT or UDP ASSOCIATE request.
* It is also possible to specify it later from the BSOCKSCLIENT_EVENT_CONNECTED
* event callback using @ref BSocksClient_SetDestAddr; this is necessary for UDP
* if the local TCP connection address must be known to bind the UDP socket.
* @param udp false to perform a CONNECT, true to perform a UDP ASSOCIATE
* @param handler handler for up and error events
* @param user value passed to handler
* @param reactor reactor we live in
* @return 1 on success, 0 on failure
*/
int BSocksClient_Init (BSocksClient *o, BAddr server_addr,
const struct BSocksClient_auth_info *auth_info, size_t num_auth_info, BAddr dest_addr,
bool udp, BSocksClient_handler handler, void *user, BReactor *reactor) WARN_UNUSED;
/**
* Frees the object.
*
* @param o the object
*/
void BSocksClient_Free (BSocksClient *o);
/**
* Get the local address of the TCP socket for the SOCKS server connection.
*
* This may only be called after the BSOCKSCLIENT_EVENT_CONNECTED event was reported.
*
* @param o the object
* @param local_addr On success the local address is returned here.
* @return 1 on success, 0 on failure
*/
int BSocksClient_GetLocalAddr (BSocksClient *o, BAddr *local_addr);
/**
* Set the DST.ADDR to send, overriding that specified in @ref BSocksClient_Init.
*
* The last chance to call this function is in the job closure of the
* BSOCKSCLIENT_EVENT_CONNECTED event, this must not be called after that.
*
* @param o the object
* @param dest_addr DST.ADDR to set.
*/
void BSocksClient_SetDestAddr (BSocksClient *o, BAddr dest_addr);
/**
* Return the BND.ADDR that the SOCKS server reported.
*
* This may only be called after the BSOCKSCLIENT_EVENT_UP event was reported.
* This address is needed for UDP ASSOCIATE because it is the address that the
* client should send UDP packets to.
*
* @param o the object
* @return The BND.ADDR, of type BADDR_TYPE_IPV4 or BADDR_TYPE_IPV6.
*/
BAddr BSocksClient_GetBindAddr (BSocksClient *o);
/**
* Returns the send interface.
* The object must be in up state. Additionally this must not be called if the
* object was initialized in UDP ASSOCIATE mode.
*
* @param o the object
* @return send interface
*/
StreamPassInterface * BSocksClient_GetSendInterface (BSocksClient *o);
/**
* Returns the receive interface.
* The object must be in up state. Additionally this must not be called if the
* object was initialized in UDP ASSOCIATE mode.
*
* @param o the object
* @return receive interface
*/
StreamRecvInterface * BSocksClient_GetRecvInterface (BSocksClient *o);
#endif