Python Forwarding Proxy

web_proxy.py

# *-* coding: utf-8 *-*
import socket, sys
import threading

def tratando_host(host_proxy):
    host_proxy = host_proxy.replace("Host: ", "")
    index_prota_proxy = host_proxy.find(":")
    port_proxy = host_proxy[index_prota_proxy:].replace(":","").replace("\r\n","") if index_prota_proxy != -1 else 80
    port_proxy = int(port_proxy)
    return (host_proxy, port_proxy)

def tratativa_data(data, webserver, port):
    comeco = data[data.find("\r\n")+2:]
    host_proxy = comeco[:comeco.find("\r\n")+2]
    host_novo = "Host: "
    if port != 80:
        host_novo += webserver + ":" + str(port)
    else:
        host_novo += webserver
    host_novo += "\r\n"

    addr_proxy = tratando_host(host_proxy)
    return (data.replace(host_proxy, host_novo), addr_proxy)

def tratativa_retornodata(data, webserver):
    location = data[data.find("Location:"):]
    location = location[:location.find("\r\n")]
    location = location[location.find('http://'):]

    host_novo = "Location: http://"
    host_novo += webserver.replace("\r\n", "")
    host_novo += location[7:][ (location[7:].find('/')) :]

    return data.replace(location, host_novo)

def proxy_server(webserver, port, conn, addr, data):
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.connect((webserver, port))
        data, addr_proxy = tratativa_data(data, webserver, port)
        print("Dados:",data)
        print("Para:",webserver)
        s.send(data)

        while True:
            reply = s.recv(buffer_size)
            if len(reply) > 0:
                # falta tratar o retorno pelo proxy
                reply = tratativa_retornodata(reply, addr_proxy[0])
                conn.send(reply)

                dar = float(len(reply))
                dar = float(dar / 1024.0)
                dar = "%.3s" %( str(dar) )
                dar = "%s KB" %( dar)

                print("[*] Request Done: %s => %s <= " %( str(addr[0] ) , str(dar) ) )
            else:
                break
        s.close()
        conn.close()
    except socket.error as e:
        print("Erro no proxy_server")
        print(e)
        s.close()
        conn.close()
        sys.exit(1)


class Connexao(threading.Thread):

    def __init__(self, conn, data, addr):
        threading.Thread.__init__(self)
        self.conn = conn
        self.data = data
        self.addr = addr

    def run(self):
        conn = self.conn
        data = self.data
        addr = self.addr
        try:
            first_line = data.split("\n")[0]
            url = first_line.split(" ")[1]

            http_pos = url.find("://")
            if http_pos == -1:
                temp = url
            else:
                temp = url[(http_pos+3):]

            port_pos = temp.find(":")

            webserver_pos = temp.find("/")
            if webserver_pos == -1:
                webserver_pos = len(temp)
            webserver = ""
            port = -1
            if port_pos == -1 or webserver_pos < port_pos:
                port = 80
                webserver = temp[:webserver_pos]
            else:
                port = int ( ( temp[ ( port_pos + 1 ) :]) [:webserver_pos - port_pos -1 ] )
                webserver = temp[:port_pos]
            webserver = "www.google.com"
            port = 80
            proxy_server(webserver, port, conn, addr, data)
        except Exception as e:
            print("Erro no run")
            print(e)
            conn.close()
            pass

def start():
    try:
        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        s.bind(('', listening_port))
        s.listen(max_conn)
        print("[*] Initializing Sockets ...Done")
        print("[*] Sockets Binded Succefully ...")
        print("[*] Sockets Started Succefully [%d]\n"%(listening_port))
    except Exception:
        print("[*] Unable to Initialize Socket")
        sys.exit(2)
    while True:
        try:
            conn, addr = s.accept()
            data = conn.recv(buffer_size)
            conexao = Connexao(conn, data, addr)
            conexao.run()
        except KeyboardInterrupt:
            print("\n[*] Proxy Server is Shuting Down ...")
            s.close()
            sys.exit(1)

try:
    listening_port = int(input("[*] Enter Listening Port Number: "))
except KeyboardInterrupt:
    print("\n[*] User registration An Interrupt")
    print("[*] Application Exiting")
    sys.exit()

max_conn = 5
buffer_size = 8129

start()