/*
 * pqisslproxy.cc
 *
 * 3P/PQI network interface for RetroShare.
 *
 * Copyright 2004-2013 by Robert Fernie.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License Version 2.1 as published by the Free Software Foundation.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA.
 *
 * Please report all bugs and problems to "retroshare@lunamutt.com".
 *
 */



#include "pqi/pqisslproxy.h"
#include "pqi/pqinetwork.h"

#include <errno.h>
#include <openssl/err.h>

#include <sstream>

#include "util/rsdebug.h"
#include "util/rsnet.h"

#include "pqi/p3linkmgr.h"

const int pqisslproxyzone = 3517;

#define PROXY_DEBUG	1

#define PROXY_STATE_FAILED			0
#define PROXY_STATE_INIT			1
#define PROXY_STATE_WAITING_METHOD_RESPONSE	2
#define PROXY_STATE_WAITING_SOCKS_RESPONSE	3
#define PROXY_STATE_CONNECTION_COMPLETE		4

pqisslproxy::pqisslproxy(pqissllistener *l, PQInterface *parent, p3LinkMgr *lm)
        :pqissl(l, parent, lm)
{
	sockaddr_clear(&remote_addr);
	return;
}


pqisslproxy::~pqisslproxy()
{ 
        rslog(RSL_ALERT, pqisslproxyzone,  
            "pqisslproxy::~pqisslproxy -> destroying pqisslproxy");
	return;
}

int 	pqisslproxy::Initiate_Connection()
{

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Initiate_Connection()";
	std::cerr << std::endl;
#endif

  	rslog(RSL_DEBUG_BASIC, pqisslproxyzone, 
		 "pqisslproxy::Initiate_Connection() Connection to Proxy");
	/* init proxy state */
	mProxyState = PROXY_STATE_INIT;

	/* call standard Init_Conn() */
	return pqissl::Initiate_Connection();
}


/********* VERY DIFFERENT **********/
int 	pqisslproxy::Basic_Connection_Complete()
{
	rslog(RSL_DEBUG_BASIC, pqisslproxyzone, 
	  "pqisslproxy::Basic_Connection_Complete()...");

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Basic_Connection_Complete() STATE: " << mProxyState;
	std::cerr << std::endl;
#endif

	int ret = 0;
	switch(mProxyState)
	{
		case PROXY_STATE_INIT:
			ret = Proxy_Send_Method(); // checks basic conn, sends Method when able.
			break;

		case PROXY_STATE_WAITING_METHOD_RESPONSE:
			ret = Proxy_Send_Address(); // waits for Method Response, send Address when able.
			break;

		case PROXY_STATE_WAITING_SOCKS_RESPONSE: 
			ret = Proxy_Connection_Complete(); // wait for ACK.
			break;

		case PROXY_STATE_CONNECTION_COMPLETE:

#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Basic_Connection_Complete() COMPLETED";
			std::cerr << std::endl;
#endif

			return 1;

		case PROXY_STATE_FAILED:

#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Basic_Connection_Complete() FAILED";
			std::cerr << std::endl;
#endif

			return -1;
	}

	if (ret < 0)
	{

#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Basic_Connection_Complete() FAILED(2)";
			std::cerr << std::endl;
#endif

		return -1; // FAILURE.
	}


#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Basic_Connection_Complete() IN PROGRESS";
	std::cerr << std::endl;
#endif

	// In Progress.
	return 0;
}


int 	pqisslproxy::Proxy_Send_Method()
{

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Method() Checking pqissl::Basic_Connection_Complete()";
	std::cerr << std::endl;
#endif

	int ret = pqissl::Basic_Connection_Complete();
	if (ret != 1)
	{
		return ret; // basic connection not complete.
	}

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Method() Basic complete, sending Method";
	std::cerr << std::endl;
#endif

	/* send hello to proxy server */
	uint8_t method_hello_data[3] = { 0x05, 0x01, 0x00 };  // [ Ver | nMethods (1) | No Auth Method ]

	int sent = send(sockfd, method_hello_data, 3, 0);
	if (sent != 3)
	{

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Send_Method() Send Failure";
		std::cerr << std::endl;
#endif
		return -1;
	}

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Method() Send Method Okay";
	std::cerr << std::endl;
#endif

	mProxyState = PROXY_STATE_WAITING_METHOD_RESPONSE;

	return 1;
}

int 	pqisslproxy::Proxy_Method_Response()
{

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Method_Response()";
	std::cerr << std::endl;
#endif

	/* get response from proxy server */

	uint8_t method_response[2];

	// read from the socket.
	int recvd = recv(sockfd, method_response, 2, MSG_WAITALL);
	if (recvd != 2)
	{
		if ((recvd == -1) && (errno == EAGAIN))
		{

#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Method_Response() EAGAIN";
			std::cerr << std::endl;
#endif

			return 0;
		}

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Method_Response() Error recving response";
		std::cerr << std::endl;
#endif
		return -1;
	}

	// does it make sense?
	if (method_response[0] != 0x05)
	{

		// Error.
#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Method_Response() Error response[0] != 0x05. Is: ";
		std::cerr << (uint32_t) method_response[0];
		std::cerr << std::endl;
#endif
		return -1;
	}

	if (method_response[1] != 0x00)
	{

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Method_Response() Error response[0] != 0x00. Is: ";
		std::cerr << (uint32_t) method_response[1];
		std::cerr << std::endl;
#endif
		// Error.
		return -1;
	}


#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Method_Response() Response Okay";
	std::cerr << std::endl;
#endif

	return 1;
}

#define MAX_SOCKS_REQUEST_LEN  262  // 4 + 1 + 255 + 2.

int 	pqisslproxy::Proxy_Send_Address()
{

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Address() Checking Method Response";
	std::cerr << std::endl;
#endif

	// Check Method Response.
	int ret = Proxy_Method_Response();
	if (ret != 1)
	{
		return ret; // Method Response not complete.
	}

	uint8_t socks_request[MAX_SOCKS_REQUEST_LEN] = 
		{ 0x05, // SOCKS VERSION.
		0x01, // CONNECT (Tor doesn't support BIND or UDP).
		0x00, // RESERVED.
		0x03, // ADDRESS TYPE (Domain Name)
		0x00, // Length of Domain name... the rest is variable so can't hard code it!
		};

	/* get the length of the domain name, pack so we can't overflow uint8_t */
	uint8_t len = mDomainAddress.length();
	socks_request[4] = len;
	for(int i = 0; i < len; i++)
	{
		socks_request[5 + i] = mDomainAddress[i];
	}

	/* now add the port, being careful with packing */
	uint16_t net_port = htons(mRemotePort);
	socks_request[5 + len] = ((uint8_t *) &net_port)[0];
	socks_request[5 + len + 1] = ((uint8_t *) &net_port)[1];

	int pkt_len = 5 + len + 2;

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Address() Sending String: ";
	for(int i = 0; i < pkt_len; i++)
		std::cerr << (uint32_t) socks_request[i];
	std::cerr << std::endl;
#endif
	int sent = send(sockfd, socks_request, pkt_len, 0);
	if (sent != pkt_len)
	{

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Send_Address() Send Error";
		std::cerr << std::endl;
#endif

		return -1;
	}


#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Send_Address() Sent Okay";
	std::cerr << std::endl;
#endif

	mProxyState = PROXY_STATE_WAITING_SOCKS_RESPONSE;
	return 1;
}

int 	pqisslproxy::Proxy_Connection_Complete()
{
	/* get response from proxy server */
	/* response is similar format to request - with variable length data */

	uint8_t socks_response[MAX_SOCKS_REQUEST_LEN];

	int recvd = recv(sockfd, socks_response, 5, MSG_WAITALL); 
	if (recvd != 5)
	{
		if ((recvd == -1) && (errno == EAGAIN))
		{
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() EAGAIN";
			std::cerr << std::endl;
#endif
			return 0;
		}

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Connection_Complete() recv error";
		std::cerr << std::endl;
#endif
		return -1;
	}
			
	// error checking.
	if (socks_response[0] != 0x05)
	{

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Connection_Complete() ERROR socks_response[0] != 0x05. is: ";
		std::cerr << (uint32_t) socks_response[0];
		std::cerr << std::endl;
#endif

		// error.
		return -1;
	}

	if (socks_response[1] != 0x00)
	{

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Connection_Complete() ERROR socks_response[1] != 0x00. is: ";
		std::cerr << (uint32_t) socks_response[1];
		std::cerr << std::endl;
#endif

		// connection failed.
		return -1;
	}

	int address_bytes = 0;
	switch(socks_response[3]) // Address Type.
	{
		case 0x01:
			// IPv4 4 address bytes.
			address_bytes = 4;
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() IPv4 Address Type";
			std::cerr << std::endl;
#endif
			break;
		case 0x04:
			// IPv6 16 address bytes.
			address_bytes = 16;
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() IPv6 Address Type";
			std::cerr << std::endl;
#endif
			break;
		case 0x03:
			// Variable address bytes - specified in next byte.
			address_bytes = 1 + socks_response[4];
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() Domain Address Type. len: " << address_bytes;
			std::cerr << std::endl;
#endif
			break;
		default:
			// unknown error.
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() ERROR Unknown Address Type";
			std::cerr << std::endl;
#endif
			return -1;
			break;
	}


	// read the remaining bytes.
	recvd = recv(sockfd, &(socks_response[5]), address_bytes + 1, MSG_WAITALL); // address_bytes - 1 + 2...
	if (recvd != address_bytes + 1)
	{
		if ((recvd == -1) && (errno == EAGAIN))
		{
#ifdef PROXY_DEBUG
			std::cerr << "pqisslproxy::Proxy_Connection_Complete() ERROR EAGAIN at end.";
			std::cerr << std::endl;
#endif
			// Waiting - shouldn't happen.
			return 0;
		}

#ifdef PROXY_DEBUG
		std::cerr << "pqisslproxy::Proxy_Connection_Complete() ERROR recving(2)";
		std::cerr << std::endl;
#endif
		return -1;
	}

#ifdef PROXY_DEBUG
	std::cerr << "pqisslproxy::Proxy_Connection_Complete() Received String: ";
	for(int i = 0; i < 4 + address_bytes + 2; i++)
		std::cerr << (uint32_t) socks_response[i];
	std::cerr << std::endl;
#endif

	// should print address.
	// if we get here - connection is good!.
	mProxyState = PROXY_STATE_CONNECTION_COMPLETE;
	return 1;

}

bool pqisslproxy::connect_parameter(uint32_t type, const std::string &value)
{
        if (type == NET_PARAM_CONNECT_DOMAIN_ADDRESS)
        {
                std::string out;
                rs_sprintf(out, "pqisslproxy::connect_parameter() Peer: %s DOMAIN_ADDRESS: %s", PeerId().c_str(), value.c_str());
                rslog(RSL_WARNING, pqisslproxyzone, out);

                mDomainAddress = value;
                std::cerr << out << std::endl;
                return true;
        }
        return pqissl::connect_parameter(type, value);
}

bool pqisslproxy::connect_parameter(uint32_t type, uint32_t value)
{
        if (type == NET_PARAM_CONNECT_REMOTE_PORT)
        {
                std::string out;
                rs_sprintf(out, "pqisslproxy::connect_parameter() Peer: %s REMOTE_PORT: %lu", PeerId().c_str(), value);
                rslog(RSL_WARNING, pqisslproxyzone, out);

        	mRemotePort = value;
                std::cerr << out << std::endl;
                return true;
        }
        return pqissl::connect_parameter(type, value);
}