update,

hk1234566/python_networking/sample1.py

@@ -0,0 +1,409 @@
+#!/usr/bin/env python3
+
+# -*- coding: UTF-8 -*-
+
+######
+import argparse
+import socket
+import os
+import sys
+import struct
+import time
+
+
+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.add_argument('hostname', type=str,
+                          help='host to ping towards')
+    parser_p.add_argument('count', nargs='?', type=int,
+                          help='number of times to ping the host before stopping')
+    parser_p.add_argument('timeout', 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.add_argument('hostname', type=str,
+                          help='host to traceroute towards')
+    parser_t.add_argument('timeout', nargs='?', type=int,
+                          help='maximum timeout before considering request lost')
+    parser_t.add_argument('protocol', nargs='?', type=str,
+                          help='protocol to send request with (UDP/ICMP)')
+    parser_t.set_defaults(func=Traceroute)
+
+    parser_w = subparsers.add_parser(
+        'web', aliases=['w'], help='run web server')
+    parser_w.set_defaults(port=8080)
+    parser_w.add_argument('port', 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', 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=%dtime=%.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/%.2fms" %
+                  (minimumDelay, averageDelay, maximumDelay))
+
+
+class ICMPPing(NetworkApplication):
+
+    def receiveOnePing(self, icmpSocket, destinationAddress, ID, timeout):
+
+        # 1. Wait for the socket to receive a reply. #2. Once received, record time of receipt, otherwise, handle a timeout
+        try:
+            timeRecieved = time.time()
+            information, address = icmpSocket.recvfrom(1024)
+            timeSent = information.split()[2]
+            
+            # 3. Compare the time of receipt to time of sending, producing the total network delay
+            timeSent= self.sendOnePing(icmpSocket, destinationAddress, 111)
+            totalNetworkDelay = (timeRecieved*1000) - timeSent
+            
+            # 4. Unpack the packet header for useful information, including the ID
+            icmpType, icmpCode, icmpChecksum, icmpPacketID, icmpSeqNumber = struct.unpack("bbHHh", icmpHeader)
+
+            # 5. Check that the ID matches between the request and reply AND THEN 6. Return total network delay
+            if(icmpPacketID == self.ID):
+                return totalNetworkDelay
+
+            else:
+                return 0
+
+        except timeout: # No response received, print the timeout message
+            print("Request timed out")
+
+
+
+    def sendOnePing(self, icmpSocket, destinationAddress, ID):
+        # 1. Build ICMP header
+        icmpHeader=struct.pack("bbHHh", 8, 0, 0, ID, 1)
+
+        # 2. Checksum ICMP packet using given function
+        icmpChecksum = self.checksum(icmpHeader)
+
+        # 3. Insert checksum into packet
+        icmpHeader = struct.pack("bbHHh", 8, 0, icmpChecksum, ID, 1)
+
+        # 4. Send packet using socket- double check this //run with wireshark
+        icmpSocket.sendto(icmpHeader, (destinationAddress, 1))
+        
+        # 5. Record time of sending
+        timeSent=time.time()
+        return timeSent
+
+    def doOnePing(self, destinationAddress, timeout):
+        # 1. Create ICMP socket
+        # Translate an Internet protocol name (for example, 'icmp') to a constant suitable for passing as the (optional) third argument to the socket() function.
+        icmp_proto = socket.getprotobyname("icmp") #debugging
+        icmpSocket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp_proto)
+        #icmpSocket = socket.socket(socket.AF_INET,socket.SOCK_RAW, socket.IPPROTO_ICMP)
+
+        # 2. Call sendOnePing function
+        timeSent = self.sendOnePing(icmpSocket, destinationAddress, 111)
+
+        # 3. Call receiveOnePing function
+        networkDelay = self.receiveOnePing(icmpSocket, destinationAddress, 111, 1000, timeSent)
+
+        # 4. Close ICMP socket
+        icmpSocket.close()
+
+        # 5. Return total network delay
+        return networkDelay
+
+    def __init__(self, args):
+        print('Ping to: %s...' % (args.hostname))
+        # 1. Look up hostname, resolving it to an IP address
+        ipAddress = socket.gethostbyname(args.hostname)
+
+        # 2. Call doOnePing function approximately every second
+        while True:
+            time.sleep(1)
+            debuggingTimeout = args.timeout
+            print("testing:", ipAddress, debuggingTimeout)
+            returnedDelay = self.doOnePing(ipAddress, debuggingTimeout)
+            # 3. Print out the returned delay (and other relevant details) using the printOneResult method
+            self.printOneResult(ipAddress, 50, returnedDelay, 150)
+            #Example use of printOneResult - complete as appropriate
+            # 4. Continue this process until stopped - did this through the while True
+
+
+class Traceroute(NetworkApplication):
+
+    def __init__(self, args):
+    #
+        # Please ensure you print each result using the printOneResult method!
+        print('Traceroute to: %s...' % (args.hostname))
+        # 1. Look up hostname, resolving it to an IP address
+        ipAddress= socket.gethostbyname(args.hostname)
+        numberofNodes= 0  # create variable and initialise
+        # 2. Call PingOneNode function approximately every second
+        while True:
+            time.sleep(1)
+            #nodalDelay = self.pingOneNode(ipAddress, args.timeout, 1)
+            
+            nodalDelay = self.pingOneNode()
+            self.printOneResult(ipAddress, 50, nodalDelay[1]*1000, 150)
+            numberofNodes = numberofNodes + 1  # increments number of nodes
+            
+            # 4. Continue this process until stopped - until ICMP = 0
+            if self.ICMP_CODE == 0:
+                break
+            # 3. Print out the returned delay (and other relevant details) using the printOneResult method
+            # check this don't think its right
+            self.printOneResult(ipAddress, 50, nodalDelay[1]*1000, 150)
+
+    def pingOneNode(self):
+        # 1. Create ICMP socket
+        icmp_proto = socket.getprotobyname("icmp") #debugging
+        icmpSocket= socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp_proto)
+        # 2. Call sendNodePing function
+        timeSent= self.sendNodePing(icmpSocket, self.ipAddress, 111)
+        # 3. Call recieveNodePing function
+        networkDelay= self.recieveNodePing(icmpSocket, self.ipAddress, 111, 1000, timeSent)
+         # 4. Close ICMP socket
+        icmpSocket.close()
+        # 5. Return total network delay- add up all the nodes
+        x = 0 
+        for x in self.numberOfNodes:
+            totalDelay = (networkDelay[x] + networkDelay[x + 1])
+            x = x + 1
+            if x == self.numberOfNodes:
+                break
+            return totalDelay
+
+    def sendNodePing(icmpSocket):
+         # 1. Build ICMP header
+        icmpHeader= struct.pack("bbHHh", 8, 0, 0, ID, 1)
+        # 2. Checksum ICMP packet using given function
+        icmpChecksum= self.checksum(icmpHeader)
+         # 3. Insert checksum into packet
+        packetHeader= struct.pack("bbHHh", 8, 0, icmpChecksum, ID, 1)
+        packet= packetHeader
+        # 4. Send packet using socket
+        # double check this //run with wireshark
+        icmpSocket.sendto(packet, (self.icmpAddress, 1))
+        # 5. Record time of sending
+        sentTime= time.time()
+        return sentTime
+
+    def recieveNodePing(icmpSocket):
+        # 1. Wait for the socket to receive a reply- TTL = 0
+        sentTime= time.time()
+        ## Set the TTL for messages to 1 so they do not go past the local network segment
+        #TTL = socket.recvmessage()
+        
+        TTL = struct.pack('b', 1)
+        icmpSocket.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_TTL, TTL)
+        # 2. Once received, record time of receipt, otherwise, handle a timeout
+        try:  # TTL == 0
+            timeRecieved = time.time()
+            # 3. Compare the time of receipt to time of sending, producing the total network delay- did when calculated RTT? 
+            totalNetworkDelay = (timeRecieved * 1000) - sentTime
+            # 4. Unpack the packet header for useful information, including the ID
+            icmpType, icmpCode, icmpChecksum, icmpPacketID, icmpSeqNumber= struct.unpack("bbHHh", icmpHeader)
+            # 5. Check that the ID matches between the request and reply and # 6. Return total network delay
+            if(icmpPacketID == self.ID):
+                return totalNetworkDelay
+            else:
+                return 0     
+        
+        except TTL != 0:  #if nothing is recieved, handle a timeout
+            print("TTL is 0 - socket has not recieved a reply")
+            return None
+        
+
+
+class WebServer(NetworkApplication):
+
+    def handleRequest(tcpSocket):
+        # 1. Receive request message from the client on connection (tcp?) socket
+        tcpSocket = serverSocket.accept() # acceptrequest
+        bufferSize = tcpSocket.CMSG_SPACE(4) # IPv4 address is 4 bytes in length - calculates the size of the buffer that should be allocated for receiving the ancillary data.
+        #recieve message in buffer size allocated 
+        requestMessage = tcpSocket.recvmsg(bufferSize[0, [0]])
+        # 2. Extract the path of the requested object from the message (second part of the HTTP header)
+        file = requestMessage.unpack_from(bufferSize)  # returns a tuple
+        # 3. Read the corresponding file from disk
+        socket.sendfile(file)
+        # 4. Store in temporary buffer
+        tempBuffer = socket.makefile( mode = 'r', buffering =None, encoding=None, errors=None, newline=None)
+        tempFile = struct.pack_into(format, self.tempBuffer, 0, file)
+        # 5. Send the correct HTTP response error
+        httpResponseError= ("HTTP/1.1 404 Not Found\r\n")
+        tcpSocket.sendmsg(httpResponseError)
+        # 6. Send the content of the file to the socket
+        tcpSocket.recvmsg(bufferSize[0, 0])
+        # 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
+        serverSocket= socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        print("creating server socket")
+        # 2. Bind the server socket to server address and server port
+        #serverSocket.bind((socket.gethostname(), 80))
+        serverSocket.bind((sys.argv[1],80))
+        print("binding socket")
+        # 3. Continuously listen for connections to server socket
+        serverSocket.listen(5)
+        # 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)
+        newSocket= socket.accept()
+        while True:
+            handleRequest(newSocket)
+            print("calling handleRequest")
+            # 5. Close server socket
+            serverSocket.close()
+
+
+class Proxy(NetworkApplication):
+
+    def __init__(self, args):
+        print('Web Proxy starting on port: %i...' % (args.port))
+
+        #if __name__ == "__main__":
+        #    args=setupArgumentParser()
+        #    args.func(args)
+            
+        #1. create server socket and listen - connectionless socket: used to establish a TCP connection with the HTTP server
+        serverSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        #2. Bind the server socket to server address and server port
+        serverSocket.bind((socket.gethostname(), 80))
+        #serverSocket.bind(('', args.port))
+        #serverSocket.bind((sys.argv[1],80))
+        print("binding socket")
+        serverSocket.listen(5)
+        #3. create proxy
+        proxySocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        proxySocket.bind((socket.gethostname(), args.port))
+        # become a server socket
+        proxySocket.listen(5)
+        #4. Continuously listen for connections to server socket and proxy
+        #5. When a connection is accepted, call handleRequest function, passing new connection socket  (?)
+        while 1:
+            connectionSocket, addr = serverSocket.accept() # accept TCP connection from client 
+            with serverSocket.accept()[0] as connectionSocket: #pass new connection socket
+                print("recieved connection from ", addr)
+                handleRequest(proxySocket)
+                print("calling handleRequest")
+                # 5. Close server socket? 
+                serverSocket.close()
+        
+
+    def handleRequest(connectionSocket):
+        #1. Receive request message from the client on connection socket
+        # IPv4 address is 4 bytes in length
+        bufferSize = connectionSocket.CMSG_SPACE(4)
+        requestMessage = connectionSocket.recvmsg(bufferSize[0, [0]])
+        #2. forward to proxy
+        proxySocket.recvmsg(requestMessage)
+        #3. proxy extracts the path of the requested object from the message (second part of the HTTP header)
+        file = requestMessage.unpack_from( format, buffer, offset = 1)  # returns a tuple
+        filename= requestMessage.split()[1]
+        #4. Read the corresponding file from disk: proxy server checks to see if object is stored locally 
+        try:
+            fileOpen = open(filename[1:], "r")  # open file in text mode
+            outputdata = fileOpen.readlines()
+            isObjectLocal == True
+            # 1.  if it does, the proxy server returns the object within a HTTP response message to the client browser
+            httpResponse= ("GET /" + file + " HTTP/1.1\r\n\r\n")
+            # 3. Read the corresponding file from disk
+            socket.sendfile(object, offset = 0, count =None)
+            #send via HTTP response message to client Browser
+
+        except IOError:
+            if isObjectLocal == False:
+                # 2.  if it doesn’t, the proxy server opens a TCP connection to the origin server??
+                originIP = serverSocket.gethostbyname(args.hostname)
+                proxySocket.connect(originIP, port)
+                # proxySocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+                # bind the socket to a public host, and a well-known port
+                # proxySocket.bind((socket.gethostname(), 80))
+                #sends HTTP request for object
+                httpRequest= ("GET /" + file + " HTTP/1.1\r\n\r\n")
+                proxySocket.send(httpRequest.encode())
+                #origin server recieves request
+                connectionSocket.recvmessage(httpRequest.encode())
+            
+                #5. Store in temporary buffer
+                hostn = filename.split('/')[0].replace("www.","",1)
+                connectionSocket.connect((hostn,80))
+                # Create a temporary file on this socket
+                tempObject = proxySocket.makefile('r', 0)
+                tempObject.write("GET "+"http://" + filename + " HTTP/1.0\n\n")
+    
+                #6. Send the correct HTTP response error
+                httpRequest= ("GET /" + file + " HTTP/1.1\r\n\r\n")
+                connectionSocket.send(httpRequest.encode())
+                #connctionSocket.send("HTTP/1.1 200 OK\r\n\r\n")
+                print("Request message sent")
+                #7. send content to webserver
+                object = connectionSocket.send(bufferSize[0, 0])
+                serverSocket.recvmsg(object)
+                #8. Send the content of the file to the socket
+        
+                #9. Close the connection socket  
+                connectionSocket.close()
+        
+        
+
+if __name__ == "__main__":
+    args= setupArgumentParser()
+    args.func(args)
+
+def main():
+    print("running")
+    NetworkApplication()