#!/usr/bin/python
import sys
import socket
import threading
def server_loop(local_host,local_port,remote_host,remote_port,receive_first):

    server = socket.socket(socket.AF_INET,socket.SOCK_STREAM)

    try:
        server.bind((local_host,local_port))
    except:
        print "[!!]Failed to listen on %s:%d" % (local_host,local_port)
        print "[!!]check for other listening sockets or correct permissions."
        sys.exit(0)

    print "[*]Listening on %s:%d" % (local_host,local_port)

    server.listen(5)

    while True:
        client_socket, addr = server.accept()

        print "[==>]Receive incoming connect from %s:%d" % (addr[0],addr[1])

        proxy_thread = threading.Thread(target=proxy_handler, args =(client_socket,remote_host,remote_port,receive_first))

        proxy_thread.start()

def main():

    if len(sys.argv[1:]) != 5:
        print "Usage: ./tcpProxy.py [localhost][localport][remotehost][remoteport][receive_port]"
        print "Example: ./tcpProxy.py 127.0.0.1 9000 10.12.132.1 9000 True"
        sys.exit(0)

    local_host = sys.argv[1]
    local_port = int(sys.argv[2])

    remote_host = sys.argv[3]
    remote_port = int(sys.argv[4])

    receive_first = sys.argv[5]

    if "True" in receive_first:
        receive_first = True
    else:
        receive_first = False

    server_loop(local_host,local_port,remote_host,remote_port,receive_first)

def proxy_handler(client_socket, remote_host, remote_port, receive_first):

        remote_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

        remote_socket.connect((remote_host, remote_port))

        if receive_first:
            remote_buffer = receive_from(remote_socket)
            hexdump(remote_buffer)

            remote_buffer = response_handler(remote_buffer)

            if len(remote_buffer):
                print "[<==]Sending %d bytes to localhost." % len(remote_buffer)
                client_socket.send(remote_buffer)

        while True:
            local_buffer = receive_from(client_socket)

            if len(local_buffer):

                print "[==>] Received %d bytes from localhost." % len(local_buffer)
                hexdump(local_buffer)

                local_buffer = request_handler(local_buffer)

                remote_socket.send(local_buffer)
                print "[==>] Sent to remote."

            remote_buffer = receive_from(remote_socket)

            if len(remote_buffer):

                print "[<==]Received %d bytes from remote." % len(remote_buffer)
                hexdump(remote_buffer)

                remote_buffer = response_handler(remote_buffer)

                client_socket.send(remote_buffer)

                print "[<==]Sent to localhost."

                if not len(local_buffer) or not len(remote_buffer):
                    client_socket.close()
                    remote_socket.close()
                    print "[*]No More data. Closing connections."

                    break


def hexdump(src, length=16):
    result = []
    digits = 4 if isinstance(src, unicode) else 2
    for i in xrange(0, len(src), length):
        s = src[i:i + length]
        hexa = b' '.join(["%0*X" % (digits, ord(x)) for x in s])
        text = b''.join([x if 0x20 <= ord(x) < 0x7F else b'.' for x in s])
        result.append(b"%04X %-*s %s" % (i, length * (digits + 1), hexa, text))

        print b'\n'.join(result)


def receive_from(connection):
    buffer = ""

    connection.settimeout(2)

    try:

        while True:
            data = connection.recv(4096)

            if not data:
                break

            buffer += data
    except:
        pass

    return buffer


def request_handler(buffer):
    return buffer


def response_handler(buffer):
    return buffer

main()