CONFIG_IP_NF_MATCH_TOS
psd match support
CONFIG_IP_NF_MATCH_PSD
  This option adds a `psd' match, which allows you to create rules in
  any iptables table wich will detect TCP and UDP port scans.
 
  If you want to compile it as a module, say M here and read
  Documentation/modules.txt.  If unsure, say `N'.