ipfirewall = "ipfirewall" line .

line	= flush | command [ iface ] action protocol [ flags ] from to .
  
flush	= "flush" | "freeze" .
command	= "addb" | "addblocking" | "addf" | "addforwarding" | "copyright"
	  | "checkb" | "checkblocking" | "checkf" | "checkforwarding" .
action	= "accept" | "reject" | "log" .
protocol = "all" | "tcp" [ tcp_connect ] | "udp" | "icmp" | protoname .

iface	= ifname .

tcp_connect = "connection" | "tcp_connection" .

flags	= flag [ flags ] .
flag	= "ip_head_fragment" | "ip_headfragment" | "ip_tail_fragment"
	  | "ip_tailfragment" | "ip_option" | "ip_recroute_option"
	  | "ip_misc_option" | "ip_fragment" .

from	= "from" maskaddr .
to	= "to" maskaddr .

maskaddr = ipaddress "/" ipmask | ipaddress ":" masknum .
