#!/usr/bin/perl
# $c command add/del/list
# $lip open ip
# $lp open port
# $rip connect ip
# $rp connect port

$c = $ARGV[0];
$lip = $ARGV[1];
$lp = $ARGV[2];
$rip = $ARGV[3];
$rp = $ARGV[4];

if ($c eq "add") {  
    system ("iptables -t nat -A PREROUTING -d $lip -p tcp --dport $lp -j DNAT --to-destination $rip:$rp");  
#    system ("iptables -t nat -A POSTROUTING -p tcp --dport $rp -d $rip -j SNAT --to-source $lip:$lp");  
    }

if ($c eq "del") {  
    system ("iptables -t nat -D PREROUTING --dst $lip -p tcp --dport $lp -j DNAT --to-destination $rip:$rp");  
#    system ("iptables -t nat -D POSTROUTING -p tcp --dport $rp -d $rip -j SNAT --to-source $lip:$lp");  

#    system ("iptables -t nat -D PREROUTING --dst $lip -p tcp --dport $lp -j DNAT --to-destination $rip:$rp");  
#    system ("iptables -t nat -D POSTROUTING -p tcp --dport $rp -d $rip -j SNAT --to-source $lip:$lp");  
    }

if ($c eq "list") {  system ("iptables -L -n -t nat -v | grep \"tcp dpt\""); }