JPsiotp/sio1/siotp/sisr1/TP7/scriptsnft/fw_part5.nft

define netif = enp0s3
define dmzif = enp0s8
define lanif = enp0s9

define firewall = 192.168.0.140
define ipdmz = 172.16.0.254
define iplan = 10.0.0.254

define lan-ntw = 10.0.0.0/24

define dns-server = {10.121.38.7 , 10.121.38.8}

define proxy-lyc = 10.121.38.1
define proxy-port = 8080

table ip ipfilter{
	chain prerouting {
                type filter hook prerouting priority filter; policy drop;
		icmp type echo-reply accept
		ct state established, related accept
		icmp type echo-request iif {$lanif} ip daddr 172.16.0.1-172.16.0.254 accept
		icmp type echo-request iif {$lanif} ip daddr {$iplan} accept
                tcp dport 20 accept
                tcp dport 21 accept
                tcp dport {80, 443} accept
		tcp dport 22 accept
		ip saddr $proxy-lyc tcp dport {80, 443} accept
		ct state {established,related} accept
		tcp sport {80,443} ip saddr $lan-ntw accept
		tcp dport {80,443} ip saddr $lan-ntw accept
        }

	chain system_in {
                type filter hook input priority filter; policy drop;
		icmp type echo-reply accept
		icmp type echo-request iif {$lanif} accept
		ct state established, related accept
                tcp dport 20 accept
                tcp dport 21 accept
                tcp dport {80, 443} accept
                tcp dport 22 accept
		ip saddr $proxy-lyc tcp dport {80, 443} accept
        }
 	chain routing {
                type filter hook forward priority filter; policy drop;
        	icmp type echo-request iif {$lanif} oif {$dmzif} accept
		icmp type echo-reply iif {$dmzif} oif {$lanif} accept
		ct state {established,related} accept
		tcp sport {80,443} ip saddr $lan-ntw accept
		tcp dport {80,443} ip saddr $lan-ntw accept
	}

 	chain system_out {
                type filter hook output priority filter; policy drop;
                ip daddr $dns-server accept
                ip daddr $proxy-lyc tcp dport $proxy-port accept
		icmp type echo-reply oif {$lanif} accept
		icmp type echo-request accept
                tcp dport 20 accept
		tcp sport 20 accept
                tcp dport 21 accept
		tcp sport 21 accept
                tcp dport {80, 443} accept
		tcp sport {80, 443} accept
		tcp sport 22 accept
        }
	chain postrouting {
                type filter hook postrouting priority filter; policy drop;
		ip daddr $dns-server accept
		ip daddr $proxy-lyc tcp dport $proxy-port accept
		icmp type echo-request ip saddr {$iplan, $ipdmz, $firewall} accept
		icmp type echo-reply iif {$dmzif}  oif {$lanif} accept
		icmp type echo-request iif {$lanif} oif {$dmzif} accept
		icmp type echo-request ip saddr $iplan oif $lanif accept
                tcp dport 20 accept
                tcp sport 20 accept
                tcp dport 21 accept
                tcp sport 21 accept
                tcp dport {80, 443} accept
                tcp sport {80, 443} accept
		tcp sport 22 accept
        	ct state {established,related} accept
	}
}
table ip nat {
	chain prerouting {
		type nat hook prerouting priority filter; policy accept;
	}

	chain postrouting {
		type nat hook postrouting priority filter; policy accept;
		ip saddr $lan-ntw oif $netif snat $firewall
	}
}