not network answer

proxy.py

# 50.012 network lab 1
# Adapted from K & R's original code

from socket import *
import sys
import _thread as thread
import os
import functools


proxy_port = 8079


@functools.lru_cache(maxsize=1024)
def proxy_cache(webServer, port, message):
    # Create a socket on the proxyserver
    c = socket(AF_INET, SOCK_STREAM)
    print("[i] Created:", c)
    c.connect((webServer, port))
    print("[i] Connected:", webServer, port)

    webServer = bytes(webServer, encoding="ascii")
    message = bytes(message, encoding="ascii")

    print("[i] Send message:", message)
    c.sendall(message)

    chunks = []

    print("[i] Start recv...", end=" ")
    while True:
        buff = c.recv(1024)
        print(len(buff), end=" ... ")
        if len(buff) < 1:
            break
        else:
            chunks.append(buff)

    # Close the socket after use
    c.close()

    buff = b"".join(chunks)

    return buff


def client_thread(tcpCliSock):
    tcpCliSock.settimeout(5.0)
    try:
        message = tcpCliSock.recv(4096).decode("ascii")
    except:
        print("error", str(sys.exc_info()[0]))
        tcpCliSock.close()
        return

    print("[i] Recieved message:", message)

    # Extract the following info from the received message
    #   webServer: the web server's host name
    #   resource: the web resource requested
    #   file_to_use: a valid file name to cache the requested resource
    #   Assume the HTTP reques is in the format of:
    #      GET http://www.ucla.edu/img/apple-touch-icon.png HTTP/1.1\r\n
    #      Host: www.ucla.edu\r\n
    #      User-Agent: .....
    #      Accept:  ......

    msgElements = message.split()

    if len(msgElements) < 5:
        print("[e] Non-supported request: ", msgElements)
        tcpCliSock.close()
        return

    if msgElements[0].upper() != 'GET' or msgElements[3].upper() != 'HOST:':
        print("[e] Non-supported request:", msgElements[0], msgElements[3])
        tcpCliSock.close()
        return

    resource = msgElements[1].replace("http://", "", 1)

    webServer = msgElements[4]

    port = 80

    print("[i] webServer:", webServer)
    print("[i] resource:", resource)

    message = message.replace("Connection: keep-alive", "Connection: close")

    if ":443" in resource:
        port = 443
        print("[e] Sorry, so far our program cannot deal with HTTPS yet")
        tcpCliSock.close()
        return
    
    print("[i] Ask for the buffer...")
    buffer = proxy_cache(webServer, port, message)
    print("\n[i] Got the buffer:", proxy_cache.cache_info())

    tcpCliSock.send(buffer)


if len(sys.argv) <= 1:
    print(
        'Usage : "python ProxyServer.py server_ip"\n[server_ip : It is the IP Address Of Proxy Server')
    sys.exit(2)

# Create a server socket, bind it to a port and start listening
tcpSerSock = socket(AF_INET, SOCK_STREAM)

# Fill in start
tcpSerSock.bind((sys.argv[1], proxy_port))
tcpSerSock.listen(1)
# Fill in end

print('[i] Proxy ready to serve at', sys.argv[1], proxy_port)

try:
    while True:
        # Start receiving data from the client
        tcpCliSock, addr = tcpSerSock.accept()
        print('[i] Received a connection from:', addr)
        # the following function starts a new thread, taking the function name as the first argument, and a tuple of arguments to the function as its second argument
        thread.start_new_thread(client_thread, (tcpCliSock, ))

except KeyboardInterrupt:
    print('[i] End')

finally:
    # Close the socket after use
    tcpSerSock.close()
    tcpCliSock.close()