update,

hk1234566/python_networking/new/NetworkApplications-full.py

@@ -0,0 +1,587 @@
+#!/usr/bin/env python3
+# -*- coding: UTF-8 -*-
+
+import argparse
+import socket
+import os
+import sys
+import struct
+import time
+import random
+import traceback  # useful for exception handling
+import threading
+
+from pprint import pprint
+
+
+# config
+INCOMING_BUFFER = 1024
+OUTGOING_BUFFER = INCOMING_BUFFER * 10
+ICMP_TYPE = 8
+
+
+def setupArgumentParser() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description='A collection of Network Applications developed for SCC.203.')
+    parser.set_defaults(func=ICMPPing, hostname='lancaster.ac.uk')
+    subparsers = parser.add_subparsers(help='sub-command help')
+
+    parser_p = subparsers.add_parser('ping', aliases=['p'], help='run ping')
+    parser_p.set_defaults(timeout=4)
+    parser_p.add_argument('hostname', type=str, help='host to ping towards')
+    parser_p.add_argument(
+        '--count',
+        '-c',
+        nargs='?',
+        type=int,
+        help='number of times to ping the host before stopping')
+    parser_p.add_argument(
+        '--timeout',
+        '-t',
+        nargs='?',
+        type=int,
+        help='maximum timeout before considering request lost')
+    parser_p.set_defaults(func=ICMPPing)
+
+    parser_t = subparsers.add_parser('traceroute', aliases=['t'],
+                                     help='run traceroute')
+    parser_t.set_defaults(timeout=4, protocol='icmp')
+    parser_t.add_argument(
+        'hostname',
+        type=str,
+        help='host to traceroute towards')
+    parser_t.add_argument(
+        '--timeout',
+        '-t',
+        nargs='?',
+        type=int,
+        help='maximum timeout before considering request lost')
+    parser_t.add_argument('--protocol', '-p', nargs='?', type=str,
+                          help='protocol to send request with (UDP/ICMP)')
+    parser_t.set_defaults(func=Traceroute)
+
+    parser_pt = subparsers.add_parser('paris-traceroute', aliases=['pt'],
+                                      help='run paris-traceroute')
+    parser_pt.set_defaults(timeout=4, protocol='icmp')
+    parser_pt.add_argument(
+        'hostname',
+        type=str,
+        help='host to traceroute towards')
+    parser_pt.add_argument(
+        '--timeout',
+        '-t',
+        nargs='?',
+        type=int,
+        help='maximum timeout before considering request lost')
+    parser_pt.add_argument('--protocol', '-p', nargs='?', type=str,
+                           help='protocol to send request with (UDP/ICMP)')
+    parser_pt.set_defaults(func=ParisTraceroute)
+
+    parser_w = subparsers.add_parser(
+        'web', aliases=['w'], help='run web server')
+    parser_w.set_defaults(port=8080)
+    parser_w.add_argument('--port', '-p', type=int, nargs='?',
+                          help='port number to start web server listening on')
+    parser_w.set_defaults(func=WebServer)
+
+    parser_x = subparsers.add_parser('proxy', aliases=['x'], help='run proxy')
+    parser_x.set_defaults(port=8000)
+    parser_x.add_argument('--port', '-p', type=int, nargs='?',
+                          help='port number to start web server listening on')
+    parser_x.set_defaults(func=Proxy)
+
+    args = parser.parse_args()
+    return args
+
+
+class NetworkApplication:
+
+    def checksum(self, dataToChecksum: str) -> str:
+        csum = 0
+        countTo = (len(dataToChecksum) // 2) * 2
+        count = 0
+
+        while count < countTo:
+            thisVal = dataToChecksum[count + 1] * 256 + dataToChecksum[count]
+            csum = csum + thisVal
+            csum = csum & 0xffffffff
+            count = count + 2
+
+        if countTo < len(dataToChecksum):
+            csum = csum + dataToChecksum[len(dataToChecksum) - 1]
+            csum = csum & 0xffffffff
+
+        csum = (csum >> 16) + (csum & 0xffff)
+        csum = csum + (csum >> 16)
+        answer = ~csum
+        answer = answer & 0xffff
+        answer = answer >> 8 | (answer << 8 & 0xff00)
+
+        answer = socket.htons(answer)
+
+        return answer
+
+    def printOneResult(
+            self,
+            destinationAddress: str,
+            packetLength: int,
+            time: float,
+            ttl: int,
+            destinationHostname=''):
+        if destinationHostname:
+            print(
+                "%d bytes from %s (%s): ttl=%d time=%.2f ms" %
+                (packetLength, destinationHostname, destinationAddress, ttl, time))
+        else:
+            print("%d bytes from %s: ttl=%d time=%.2f ms" %
+                  (packetLength, destinationAddress, ttl, time))
+
+    def printAdditionalDetails(
+            self,
+            packetLoss=0.0,
+            minimumDelay=0.0,
+            averageDelay=0.0,
+            maximumDelay=0.0):
+        print("%.2f%% packet loss" % (packetLoss))
+        if minimumDelay > 0 and averageDelay > 0 and maximumDelay > 0:
+            print("rtt min/avg/max = %.2f/%.2f/%.2f ms" %
+                  (minimumDelay, averageDelay, maximumDelay))
+
+    def printMultipleResults(
+            self,
+            ttl: int,
+            destinationAddress: str,
+            measurements: list,
+            destinationHostname=''):
+        latencies = ''
+        noResponse = True
+        for rtt in measurements:
+            if rtt is not None:
+                latencies += str(round(rtt, 3))
+                latencies += ' ms  '
+                noResponse = False
+            else:
+                latencies += '* '
+
+        if noResponse is False:
+            print(
+                "%d %s (%s) %s" %
+                (ttl,
+                 destinationHostname,
+                 destinationAddress,
+                 latencies))
+        else:
+            print("%d %s" % (ttl, latencies))
+
+
+class ICMPPing(NetworkApplication):
+    # Task 1.1: ICMP Ping
+
+    def receiveOnePing(self, icmpSocket, destinationAddress, ID, timeout):
+        # 1. Wait for the socket to receive a reply
+        icmpSocket.settimeout(timeout)
+
+        try:
+            reply, addr = icmpSocket.recvfrom(2048)
+        except socket.timeout as msg:
+            print("No data received from socket within timeout period. Message: " + str(msg))
+            sys.exit(1)
+
+        # 2. Once received, record time of receipt, otherwise, handle a timeout
+        recv_time = time.time()
+
+        # 4. Unpack the packet header for useful information, including the ID
+        # icmp header of the received packet,
+        # bottom of packet because of network byte-order
+        # align offset to include the layer 2 encap = 14
+        reply_size = struct.unpack(">H", reply[16 - 14:18 - 14])[0]
+        reply_ttl = struct.unpack(">B", reply[22 - 14:23 - 14])[0]
+        reply_id = struct.unpack(">B", reply[38 - 14:39 - 14])[0]
+
+        # 5. Check that the ID matches between the request and reply
+        if reply_id != ID:
+            print("Received packet ID not match")
+            sys.exit(1)
+
+        # 6. Return recv time + packet size
+        return (recv_time, reply_size, reply_ttl)
+
+    def sendOnePing(self, icmpSocket, destinationAddress, ID):
+        # 1. Build ICMP header
+        header = struct.pack('BBHHH', ICMP_TYPE, 0, 0, ID, 1)
+        data = bytes("Task 1.1: ICMP Ping", 'utf-8')
+
+        # 2. Checksum ICMP packet using given function
+        new_checksum = self.checksum(header + data)
+
+        # 3. Insert checksum into packet
+        header = struct.pack('BBHHH', ICMP_TYPE, 0, new_checksum, ID, 1)
+        packet = header + data
+
+        # 4. Send packet using socket
+        while packet:
+            sent = icmpSocket.sendto(packet, (destinationAddress, 1500))  # 1500 = Port number
+            packet = packet[sent:]
+
+        # 5. Record time of sending
+        sendTime = time.time()
+        return sendTime
+
+    def doOnePing(self, destinationAddress, timeout):
+        # 1. Create ICMP socket
+        # Sends raw packets to ipv4 addresses
+        new_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.getprotobyname('icmp'))
+        ID = 1
+
+        # 2. Call sendOnePing function
+        sendTime = self.sendOnePing(new_socket, destinationAddress, ID)
+
+        # 3. Call receiveOnePing function
+        (recv_time, reply_len, reply_size) = self.receiveOnePing(new_socket, destinationAddress, ID, 1)
+
+        # 4. Close ICMP socket
+        new_socket.close()
+
+        # 5. Return total network delay
+        send_time_ms = sendTime * 1000
+        recv_time_ms = recv_time * 1000
+
+        total_delay = recv_time_ms - send_time_ms
+
+        return (total_delay, reply_len, reply_size)
+
+    def __init__(self, args):
+        print('Ping to: %s...' % (args.hostname))
+        # 1. Look up hostname, resolving it to an IP address
+
+        # # 2. Call doOnePing function, approximately every second
+        try:
+            destinationAddress = socket.gethostbyname(args.hostname)
+
+            while True:
+                (total_delay, reply_len, reply_size) = self.doOnePing(destinationAddress, 1)
+                # 3. Print out the returned delay (and other relevant details) using the printOneResult method
+                self.printOneResult(destinationAddress, reply_len, total_delay, reply_size, args.hostname)
+                time.sleep(1)
+
+                # 4. Continue this process until stopped
+
+        except BaseException:
+            print("Host name not recognised")
+
+
+class Traceroute(NetworkApplication):
+    # Task 1.2: Traceroute
+
+    def __init__(self, args):
+        # Please ensure you print each result using the printOneResult method!
+        print('Traceroute to: %s...' % (args.hostname))
+
+        # Get IP of destination
+        dest_address = socket.gethostbyname(args.hostname)
+
+        # ​init ttl_count_up
+        ttl_count_up = 1
+        while True:
+            # Creates sockets
+            recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
+            send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_ICMP)
+            send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl_count_up)
+
+            # COnstruct and send packet
+            header = struct.pack('BBHHH', ICMP_TYPE, 0, 0, 5, 1)
+            data = "Task 1.2: Traceroute".encode()
+
+            # NOTE: the direction constrainted by checksum generating function, so the above BBHHH will not be modified
+            new_checksum = self.checksum(header + data)
+            header = struct.pack('BBHHH', ICMP_TYPE, 0, new_checksum, 5, 1)
+            packet = header + data
+            send_socket.sendto(packet, (dest_address, 1024 * 10))
+
+            send_time = time.time()  # Record beginning time
+
+            # Loop until packet received
+            run = True
+            while run:
+                recv_packet, address = recv_socket.recvfrom(1024 * 4)
+                address = address[0]
+
+                run = False
+
+            send_socket.close()
+            recv_socket.close()
+
+            recv_time = time.time()
+
+            # try best to resolv hostname
+            try:
+                hostname = socket.gethostbyaddr(address)[0]
+            except BaseException:
+                hostname = address
+
+            self.printOneResult(address, sys.getsizeof(packet), (recv_time - send_time) * 1000, ttl_count_up, hostname)
+            ttl_count_up += 1
+
+            # dest reach, exit loop
+            if address == dest_address:
+                break
+
+
+
+
+class ParisTraceroute(NetworkApplication):
+    # Task 1.3: Paris-Traceroute
+    # A well-known limitation of trace route is that it may indicate a path that does not actually
+    # exist in the presence of “load-balancers” in the network. Consider the example below where
+    # a source host Src sends traceroute traffic to a destination host Dst.
+
+    def getIdentifier(self, checkSumWanted):
+        return 0xf7ff - checkSumWanted
+
+    def __init__(self, args):
+
+        try:
+            print('Paris-Traceroute to: %s...' % (args.hostname))
+
+            # Get IP of destination
+            dest_ip = socket.gethostbyname(args.hostname)
+
+            ttl_count_up = 1
+            # in paris-traceroute, use checksum as identifier
+            check_sum_count_up = 1
+
+            while True:
+                # Creates sockets
+                recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
+                send_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)
+
+                # Limit ttl of socket
+                send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl_count_up)
+
+                # COnstruct and send packet
+                # Header is type (8), code (8), checksum (16), id (16), sequence (16)
+                header = struct.pack('!BBHHH', ICMP_TYPE, 0, 0, 0, 0)
+
+                # NOTE: the checksum acts as a identifier, get the apporiate identifier to get the wanted checksum
+                # BE(big endian) used here
+                # checked with opensource from https://paris-traceroute.net
+                new_identifier = self.getIdentifier(check_sum_count_up)
+                header = struct.pack('!BBHHH', ICMP_TYPE, 0, check_sum_count_up, new_identifier, 0)
+
+                packet = header
+                send_socket.sendto(packet, (dest_ip, OUTGOING_BUFFER))
+
+                # jot down start time for diff
+                start_time = time.time()
+
+                # Loop until packet received
+                run = True
+                while run:
+                    recv_packet, address = recv_socket.recvfrom(INCOMING_BUFFER)
+                    address = address[0]
+
+                    run = False
+
+                # close socket after done
+                send_socket.close()
+                recv_socket.close()
+
+                recv_time = time.time()
+
+                # try best to resolv hostname
+                try:
+                    try_res_hostname = socket.gethostbyaddr(address)[0]
+                except BaseException:
+                    # bypass if cannot resolv hostname
+                    try_res_hostname = address
+
+                self.printOneResult(address, sys.getsizeof(packet), (recv_time - start_time) * 1000, ttl_count_up, try_res_hostname)
+                ttl_count_up += 1
+                check_sum_count_up += 1
+
+                # dest reach, exit loop
+                if address == dest_ip:
+                    break
+
+        except BaseException as err:
+            print('error occured', err)
+            sys.exit(1)
+
+
+class WebServer(NetworkApplication):
+
+    def handleRequest(self, tcpSocket):
+        # 1. Receive request message from the client on connection socket
+        getrequest = tcpSocket.recv(INCOMING_BUFFER).decode()
+        print(getrequest)
+
+        # 2. Extract the path of the requested object from the message (second
+        # part of the HTTP header)
+        headers = getrequest.split('\n')
+        filename = headers[0].split()[1]
+
+        try:
+            # 3. Read the corresponding file from disk
+            filetosend = open(filename.replace('/', ''))
+            content = filetosend.read()
+            filetosend.close()
+
+            # 4. Store in temporary buffer
+            response = 'HTTP/1.0 200 OK\n\n' + content
+
+        # 5. Send the correct HTTP response error
+        except FileNotFoundError:
+            response = 'HTTP/1.0 404 NOT FOUND\n\nFile Not Found'
+
+        # 6. Send the content of the file to the socket
+        tcpSocket.sendall(response.encode())
+
+        # 7. Close the connection socket
+        tcpSocket.close()
+        pass
+
+    def __init__(self, args):
+        print('Web Server starting on port: %i...' % (args.port))
+        # 1. Create server socket
+        server_socket = socket.socket()
+        server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+
+        # 2. Bind the server socket to server address and server port
+        server_socket.bind(("127.0.0.1", args.port))
+
+        # 3. Continuously listen for connections to server socket
+        server_socket.listen()
+
+        # 4. When a connection is accepted, call handleRequest function,
+        # passing new connection socket
+        # (see https://docs.python.org/3/library/socket.html#socket.socket.accept)
+        run = True
+        while run:
+            client_socket, client_address = server_socket.accept()
+            self.handleRequest(client_socket)
+
+            # 5. Close server socket
+            server_socket.close()
+            run = False
+
+
+
+
+class Proxy(NetworkApplication):
+    # Task 2.2: Web Proxy
+    # As with Task 2.1, there are a number of ways to test your Web Proxy. For example, to
+    # generate requests using curl, we can use the following:
+    # curl neverssl.com - -proxy 127.0.0.1: 8000
+    # This assumes that the Web Proxy is running on the local machine and bound to port 8000.
+    # In this case, the URL requested from the proxy is neverssl.com.
+    def handleRequest(self, tcp_socket):
+        dst_host = ''
+
+        # receive request from client
+        full_req = tcp_socket.recv(INCOMING_BUFFER).decode('utf-8')
+        # print("Full req =", full_req)
+
+        first_line = full_req.split('\r\n')[0]
+        [http_action, full_url, http_ver] = first_line.split(' ')
+        sainted_url = full_url.split('://')[1].replace('/', '')
+        try_split_port = sainted_url.split(':')
+        if (len(try_split_port) > 1):
+            dst_host, dst_port = try_split_port
+        else:
+            dst_host = sainted_url
+            dst_port = 80
+
+        try:
+            # try convert to ip, if not emit gaierror
+            dst_ip = socket.gethostbyname(dst_host)
+
+            # create new socket for sending request
+            outgoing_req_socket = socket.socket(
+                socket.AF_INET, socket.SOCK_STREAM)
+            outgoing_req_socket.settimeout(2)
+
+            # connect to dst server
+            outgoing_req_socket.connect((dst_ip, dst_port))
+
+            # forward request getting from proxy
+            outgoing_req_socket.send(full_req.encode('utf-8'))
+            # print("forwarded the request")
+
+            # receive data from the server
+            while True:
+                reply = outgoing_req_socket.recv(INCOMING_BUFFER)
+
+                if len(reply) > 0:
+                    # forward reply to originator
+                    tcp_socket.send(reply)
+
+                else:
+                    # buffer empty, forward reply done
+                    break
+
+            # close port
+            outgoing_req_socket.close()
+
+        # handle cannot convert hostname to ip
+        except socket.gaierror as msg:
+            print("Couldn't convert domain to ip", dst_host, msg)
+
+            if tcp_socket:
+                tcp_socket.close()
+            sys.exit(1)
+
+        # handle socket timeout
+        except socket.timeout:
+            print("Connection timeout")
+            if outgoing_req_socket:
+                outgoing_req_socket.close()
+            return
+
+        # final overflow for any error
+        except socket.error as msg:
+            print("Socket error:", msg)
+            if outgoing_req_socket:
+                outgoing_req_socket.close()
+            if tcp_socket:
+                tcp_socket.close()
+            sys.exit(1)
+
+    def __init__(self, args):
+        server_ip = '127.0.0.1'
+        server_port = args.port
+        print('Task 2.2: Web Proxy, starting on port: %i...' % (server_port))
+
+        # 1. Create server socket
+        server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+        # 2. Bind the server socket to server address and server port
+        server_socket.bind((server_ip, server_port))
+
+        # 3. Continuously listen for connections to server socket
+        server_socket.listen(1)
+        serving = True
+        try:
+            while serving:
+                # 4. When a connection is accepted,
+                #   -> call handleIncomingRequest function,
+                #   -> passing new connection socket
+                # (see https://docs.python.org/3/library/socket.html#socket.socket.accept)
+                connection, address = server_socket.accept()
+                self.handleRequest(connection)
+
+        except socket.error as msg:
+            if server_socket:
+                server_socket.close()
+            print("Socket error:", msg)
+            sys.exit(1)
+
+        finally:
+            # 5. Close server socket
+            if server_socket:
+                server_socket.close()
+            sys.exit(0)
+
+
+if __name__ == "__main__":
+    args = setupArgumentParser()
+    args.func(args)