TRUNCATE target module for iptables
-- To compile and install module -- Type "sudo make" then "sudo make install"
-- To uninstall module -- Type "sudo make uninstall"
-- To run -- Type "iptables -t mangle -A $CHAIN -j TRUNCATE --at-byte=$NUM [--drop-tcp-opts]", where $CHAIN is OUTPUT, FORWARD, POSTROUTING or PREROUTING, and $NUM is the number of bytes to keep.
The --at-byte argument must be specified, while the --drop-tcp-opts option is optional (optional TCP options after the first 20 bytes of the TCP header are kept by default).
-- To clean -- Type "sudo make clean"