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#!/usr/bin/env python
# Thu, 13 Mar 14 (PDT)
# ip.py: Demonstrate IP objects
# Copyright (C) 2015, Nevil Brownlee, U Auckland | WAND
from plt_testing import *
t = get_example_trace('anon-v4.pcap')
n = 0
for pkt in t:
n += 1 # Wireshark uses 1-org packet numbers
ip = pkt.ip
if not ip:
continue
print "%03d: checksum=%04x, OK=%s" % (n, ip.checksum, ip.test_l3_cksm())
if not ip.test_l3_cksm():
ip.set_l3_cksm()
else:
ip.checksum = 0xCDEF
print " checksum=%04x, OK=%s" % (ip.checksum, ip.test_l3_cksm())
tcp = ip.tcp
if tcp:
try:
print " tcp checksum=%04x, ok=%s" % (
tcp.checksum, tcp.test_trans_cksm())
if not tcp.test_trans_cksm():
tcp.set_trans_cksm()
else:
tcp.checksum = 0x1234
print " tcp checksum=%04x, ok=%s" % (
tcp.checksum, tcp.test_trans_cksm())
except ValueError, e:
print " .tcp. %s" % e
udp = ip.udp
if udp:
#continue
try:
# Only packet 236 is short enough for plt to check it's correct
print " udp checksum=%04x, ok=%s" % (
udp.checksum, udp.test_trans_cksm())
if not udp.test_trans_cksm():
udp.set_trans_cksm()
else:
udp.checksum = 0x5678
print " udp checksum=%04x, ok=%s" % (
udp.checksum, udp.test_trans_cksm())
except ValueError, e:
print " .udp. %s" % e
#if n == 20:
# break
print "%5d packets accepted" % (t.pkt_accepts())
print "%5d packets dropped" % (t.pkt_drops())
t.close() # Don't do this inside the loop!
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