pmcgleenon / ip-ttl

IP ECN/TTL modifier as a linux netfilter module

ip-ttl

ttl is a linux netfilter kernel module that rewrites either of the:

• Diff Serv ECN field.
• the IP Time To Live (TTL) field or

Download:

$ git clone https://github.com/pmcgleenon/ip-ttl

Building:

you'll need to install the kernel-devel rpm

$ make clean all

Running:

Parameters are described with modinfo ttl.ko:

debug_enabled: Debug mode enabled (int)
ttl_value: new ttl value (5-255) (int)
perc_11: percentage of ECN 11 traffic required (0-100) (int)
perc_10: percentage of ECN 10 traffic required (0-100) (int)
perc_10: percentage of ECN 01 traffic required (0-100) (int)
ecn_enabled: Rewrite ECN IP hdr bits (int)
filter_mode:Behaviour is consistent on 0: Flow Affinity, 1: Source IP Affinity (int)

$ modinfo ttl.ko

you can load the module with no parameters, in which case it will rewrite 100% of the traffic with the IP TTL value set to one less than the current default value (i.e. ttl = ttl - 1):

insmod ttl.ko

specify a ttl_value to use this as the TTL; the debug_enabled argument enables debug logs:

insmod ttl.ko debug_enabled=1 ttl_value=40

modify ECN based on Source IP Affinity on with ECN 11, 10, 01 on 20% of the traffic. ECN 00 will be the remainder (40%)

insmod ttl.ko perc11=20 perc10=20 perc01=20 ecn_enabled=1 filter_mode=1

License

Copyright (C) 2009-2014 The Apache Software Foundation

Licensed under the Apache License, Version 2.0