Python traceroute doesn't work

Question

I have found a python project that implements Traceroute, however it doesn't work. Here is the project:

import socket
import sys

class TraceRoute(object):

    BADDR = "0.0.0.0" # default bind address - (all IPs)
    PORT = 33434 # default port
    ICMP = socket.getprotobyname('icmp')
    UDP = socket.getprotobyname('udp')

    destination = ""
    ttl = 0 # increase ttl by one each time. 

    # sockets
    reciever = None
    sender = None

    # finished?
    finished = False

    def __init__(self, addr):
        self.destination = socket.gethostbyname(addr)

        self.reciever = socket.socket(socket.AF_INET, socket.SOCK_RAW, self.ICMP)
        self.sender = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, self.UDP)

        # bind to reciever so we can listen for replies
        self.reciever.bind(('', self.PORT))

    def next_server(self):
        """ Connects to next server 1 hop away from current server (i.e. server[ttl + 1]) """
        if self.finished:
            # we have nothing to do, just return
            return

        # first job increment the ttl on the socket
        self.ttl += 1
        self.sender.setsockopt(socket.SOL_IP, socket.IP_TTL, self.ttl)

        self.sender.sendto("", (self.destination, self.PORT))

        current_server = self.reciever.recvfrom(512)[1][0] # get 512 bytes from the reciever
        print current_server
        self.display(current_server)

        if current_server == self.destination:
            self.finished = True

    def display(self, address):
        """ Gets the hostname (if we can) and displays """
        try:
            name = socket.gethostbyaddr(address)[0]
            print "%s) %s (%s)" % (self.ttl, name, address)
        except socket.error:
            # we couldn't - we'll just tell them the IP address
            print "%s) %s" % (self.ttl, address)

    def __del__(self):
        """ close our sockets """
        try:
            self.reciever.close()
        except socket.error:
            # already closed
            pass

        try:
            self.sender.close()
        except socket.error:
            # already closed
            pass

if __name__ == "__main__":
    # lets get the address from the commandline args
    if len(sys.argv) <= 1:
        # nothing been specified
        print "You need to give an address"
        print "%s <server>" % sys.argv[0]
        sys.exit() # we can't do anything.

    tracert = TraceRoute(sys.argv[1])
    while not tracert.finished:
        tracert.next_server()

I run the project and it gets stuck on this line:

current_server = self.reciever.recvfrom(512)[1][0]

After looking at Wireshark I figured that I'm recieving the ICMP response but my python project doesn't catch and recieve it for some reason, therefore it cannot continue and pass that line.

Help?

FWIW, the above code works perfectly for me, on Ubuntu 14.04, Python 2.7.6. — Robᵩ, Jun 09 '14 at 20:11

score 0 · Answer 1 · answered Mar 14 '19 at 17:44

I'm writing a traceroute project on Windows currently, and I have faced the exact same problem as you did, socket.recvfrom doesn't receive anything on my computer, however, it works fine on other computers.

I found out that it was actually Windows Defender blocking the reply message the whole time. After I shut down Windows Defender, I started to receive all those blocked messages. Hopefully this helps you(though it might be a bit too late).

Python traceroute doesn't work

1 Answers1