I recently learned, how to write a traceroute using socket programming in python. I am sharing it below. I don't take any credit for the code. I may have picked bits and pieces from various different resources on the Internet, as a part of my learning process. It's not very elegant but demonstrates the purpose. Perhaps, some day I can improve it and add few enhancements to it.
Can be executed as -
>sudo ./traceroute.py xharpreetx.com
#!/usr/bin/python
import sys
import socket
def traceroute(dest_name):
dest_addr = socket.gethostbyname(dest_name)
port = 33434
max_hops = 30
print dest_name
icmp = socket.getprotobyname('icmp')
udp = socket.getprotobyname('udp')
ttl = 1
while True:
print ttl,
recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
recv_socket.bind(("", port))
send_socket.sendto("", (dest_name, port))
curr_addr = None
curr_name = None
try:
_, curr_addr = recv_socket.recvfrom(512)
curr_addr = curr_addr[0]
try:
curr_name = socket.gethostbyaddr(curr_addr)[0]
except socket.error:
curr_name = curr_addr
except socket.error:
pass
finally:
send_socket.close()
recv_socket.close()
if curr_addr is not None:
curr_host = "%s (%s)" % (curr_name, curr_addr)
else:
curr_host = "*"
print "%d\t%s" % (ttl, curr_host)
ttl += 1
if curr_addr == dest_addr or ttl > max_hops:
break
if __name__ == "__main__":
traceroute(sys.argv[1])
import sys
import socket
def traceroute(dest_name):
dest_addr = socket.gethostbyname(dest_name)
port = 33434
max_hops = 30
print dest_name
icmp = socket.getprotobyname('icmp')
udp = socket.getprotobyname('udp')
ttl = 1
while True:
print ttl,
recv_socket = socket.socket(socket.AF_INET, socket.SOCK_RAW, icmp)
send_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, udp)
send_socket.setsockopt(socket.SOL_IP, socket.IP_TTL, ttl)
recv_socket.bind(("", port))
send_socket.sendto("", (dest_name, port))
curr_addr = None
curr_name = None
try:
_, curr_addr = recv_socket.recvfrom(512)
curr_addr = curr_addr[0]
try:
curr_name = socket.gethostbyaddr(curr_addr)[0]
except socket.error:
curr_name = curr_addr
except socket.error:
pass
finally:
send_socket.close()
recv_socket.close()
if curr_addr is not None:
curr_host = "%s (%s)" % (curr_name, curr_addr)
else:
curr_host = "*"
print "%d\t%s" % (ttl, curr_host)
ttl += 1
if curr_addr == dest_addr or ttl > max_hops:
break
if __name__ == "__main__":
traceroute(sys.argv[1])
Can be executed as -
>sudo ./traceroute.py xharpreetx.com