$ipmac = "SELECT ip,mac FROM control WHERE ativo=1 ORDER by ip";
        $resultipmac = mysql_query($ipmac)
     or die ("Nao foi possivel realizar a consulta.");


while ($linha=mysql_fetch_array($resultipmac))
{
   $ip  = $linha['ip'];
   $mac = $linha['mac'];
   echo shell_exec("sudo iptables -I INPUT -i eth0 -s $ip -d 0/0 -m mac --mac-source $mac");
   echo "";
   echo "$ip<br>";
   echo "$mac<br>";
   echo "";
}


Feb 14 12:44:11 mail sudo:   nobody : TTY=unknown ; PWD=/home/control/public_html/src ; USER=root ; COMMAND=/usr/sbin/iptables -I INPUT -i eth0 -s [ip] -d 0/0 -m mac --mac-source [mac] -j ACCEPT