In this lab, you will gain a better understanding of Internet Control Message Protocol (ICMP). You will learn to implement a Ping application using ICMP request and reply messages.
from socket import *
import os
import sys
import struct
import time
import select
import binascii
ICMP_ECHO_REQUEST = 8
packageSent = 0
packageReceive = 0
def checksum(string):
csum = 0
countTo = (len(string) // 2) * 2
count = 0
while count < countTo> thisVal = (string[count + 1]) * 256 + (string[count])
csum += thisVal
csum &= 0xffffffff
count += 2
if countTo < len> csum += (string[len(string) - 1])
csum &= 0xffffffff
csum = (csum >> 16) + (csum & 0xffff)
csum = csum + (csum >> 16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8> return answer
def receiveOnePing(mySocket, ID, timeout, destAddr):
global packageReceive
timeLeft = timeout
while 1:
startedSelect = time.time()
whatReady = select.select([mySocket], [], [], timeLeft)
howLongInSelect = (time.time() - startedSelect)
if whatReady[0] == []: # Timeout
return "Request timed out."
timeReceived = time.time()
recPacket, addr = mySocket.recvfrom(1024)
# Fill in start
# Fetch the ICMP header from the IP packet
header = recPacket[20:28]
type, code, checksum, packageID, sequence = struct.unpack("bbHHh", header)
if packageID == ID:
time_offset = struct.calcsize("d")
timeSent = struct.unpack("d", recPacket[28:28 + time_offset])[0]
packageReceive += 1
return timeReceived - timeSent
# Fill in end
timeLeft = timeLeft - howLongInSelect
if timeLeft <= 0:
return "Request timed out."
def sendOnePing(mySocket, destAddr, ID):
# Header is type (8), code (8), checksum (16), id (16), sequence (16)
global packageSent
myChecksum = 0
# Make a dummy header with a 0 checksum
# struct -- Interpret strings as packed binary data
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, myChecksum, ID, 1)
data = struct.pack("d", time.time())
# Calculate the checksum on the data and the dummy header.
myChecksum = checksum(header + data)
# Get the right checksum, and put in the header
if sys.platform == 'darwin':
# Convert 16-bit integers from host to network byte order
myChecksum = htons(myChecksum) & 0xffff
else:
myChecksum = htons(myChecksum)
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST, 0, myChecksum, ID, 1)
packet = header + data
mySocket.sendto(packet, (destAddr, 1)) # AF_INET address must be tuple, not str
packageSent += 1
# Both LISTS and TUPLES consist of a number of objects
# which can be referenced by their position number within the object.
def doOnePing(destAddr, timeout):
icmp = getprotobyname("icmp")
# SOCK_RAW is a powerful socket type. For more details: http://sockraw.org/papers/sock_raw
mySocket = socket(AF_INET, SOCK_RAW, icmp)
myID = os.getpid() & 0xFFFF # Return the current process i
sendOnePing(mySocket, destAddr, myID)
delay = receiveOnePing(mySocket, myID, timeout, destAddr)
mySocket.close()
return delay
def average(arrays):
avg_sum = 0
for i in arrays:
avg_sum += i
return (avg_sum / len(arrays))
def ping(host, timeout=1):
# timeout=1 means: If one second goes by without a reply from the server, # the client assumes that either the client's ping or the server's pong is lost
dest = gethostbyname(host)
print("Pinging " + dest + " aka " + host + " using Python:")
print("")
delays = []
# Send ping requests to a server separated by approximately one second
count = 5
while count:
delay = doOnePing(dest, timeout)
print("Ping times " + str(count) + " RTT = " + str(delay))
time.sleep(1) # one second
count -= 1
delays.append(delay)
print("")
print("The maximum RTT is: " + str(max(delays)))
print("The minimum RTT is: " + str(min(delays)))
print("The average RTT is " + str(sum(delays)/len(delays)))
print("The package loss rate is " + str(1 - packageReceive/packageSent))
return delays
host = input("Enter address want to ping: ")
ping(host)
#ping("google.com")
