-IPTABLES=/sbin/iptables
PATH=/sbin:/bin:/usr/sbin:/usr/bin
my_ip() {
MYIP=$1
# Allow everything from this host
- $IPTABLES -A INPUT -s $MYIP -j ACCEPT
+ nft add rule ip filter input saddr $MYIP counter accept
# Allow ICMP
- $IPTABLES -A INPUT -d $MYIP -p icmp -j ACCEPT
+ nft add rule ip filter input daddr $MYIP proto icmp counter accept
# Allow ports >1024
- $IPTABLES -A INPUT -d $MYIP -p tcp --dport 1024: ! --syn -j ACCEPT
- $IPTABLES -A INPUT -d $MYIP -p udp --dport 1024: -j ACCEPT
+ nft add rule ip filter input daddr $MYIP dport 1024- proto tcp tcp flags & syn != syn counter accept
+ nft add rule ip filter input daddr $MYIP dport 1024- proto udp counter accept
}
start_firewall() {
# Allow everything from localhost
- $IPTABLES -A INPUT -s 127.0.0.1 -j ACCEPT
+ nft add rule ip filter input saddr 127.0.0.1 counter accept
# Specifically block access to NFS and XWindows. Neccessary because these are ports >1024
- $IPTABLES -A INPUT -p tcp --dport 2049 -j DROP
- $IPTABLES -A INPUT -p udp --dport 2049 -j DROP
- $IPTABLES -A INPUT -p tcp --dport 6000:6063 -j DROP
- $IPTABLES -A INPUT -p udp --dport 6000:6063 -j DROP
+ nft add rule ip filter input dport 2049 proto tcp counter drop
+ nft add rule ip filter input dport 2049 proto udp counter drop
+ nft add rule ip filter input dport 6000-6063 proto tcp counter drop
+ nft add rule ip filter input dport 6000-6063 proto udp counter drop
# Allow incoming ssh, smtp, dns, dhcp, www, ident, ntp, smb, OpenVPN, git-daemon
- $IPTABLES -A INPUT -p tcp --dport 22 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 25 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 53 -j ACCEPT
- $IPTABLES -A INPUT -p udp --dport 53 -j ACCEPT
- $IPTABLES -A INPUT -p udp --sport 53 --dport 1024: -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 80 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 113 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 123 -j ACCEPT
- $IPTABLES -A INPUT -p udp --dport 123 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 137:139 -j ACCEPT
- $IPTABLES -A INPUT -p udp --dport 137:139 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 443 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 445 -j ACCEPT
- $IPTABLES -A INPUT -p udp --dport 1194 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 9418 -j ACCEPT
+ nft add rule ip filter input dport 22 proto tcp counter accept
+ nft add rule ip filter input dport 25 proto tcp counter accept
+ nft add rule ip filter input dport 53 proto tcp counter accept
+ nft add rule ip filter input dport 53 proto udp counter accept
+ nft add rule ip filter input sport 53 dport 1024- proto udp counter accept
+ nft add rule ip filter input dport 80 proto tcp counter accept
+ nft add rule ip filter input dport 113 proto tcp counter accept
+ nft add rule ip filter input dport 123 proto tcp counter accept
+ nft add rule ip filter input dport 123 proto udp counter accept
+ nft add rule ip filter input dport 137-139 proto tcp counter accept
+ nft add rule ip filter input dport 137-139 proto udp counter accept
+ nft add rule ip filter input dport 443 proto tcp counter accept
+ nft add rule ip filter input dport 445 proto tcp counter accept
+ nft add rule ip filter input dport 1194 proto udp counter accept
+ nft add rule ip filter input dport 9418 proto tcp counter accept
# FTP
- $IPTABLES -A INPUT -p tcp --dport 20 -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 21 -j ACCEPT
+ nft add rule ip filter input dport 20 proto tcp counter accept
+ nft add rule ip filter input dport 21 proto tcp counter accept
# Allow ftp-data for active connections
- #$IPTABLES -A INPUT -p tcp --sport 20 --dport 1024: -j ACCEPT
+ #nft add rule ip filter input sport 20 dport 1024- proto tcp counter accept
# Track FTP connections to allow active and passive mode FTP
- $IPTABLES -A INPUT -p tcp --sport 20 -m state --state ESTABLISHED,RELATED -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 20 -m state --state ESTABLISHED,RELATED -j ACCEPT
- $IPTABLES -A INPUT -p tcp --sport 21 -m state --state NEW,ESTABLISHED -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 21 -m state --state ESTABLISHED,RELATED -j ACCEPT
- $IPTABLES -A INPUT -p tcp --sport 1024:65535 -m state --state ESTABLISHED,RELATED -j ACCEPT
- $IPTABLES -A INPUT -p tcp --dport 1024:65535 -m state --state ESTABLISHED,RELATED -j ACCEPT
+ nft add rule ip filter input sport 20 proto tcp ct mstate state state state established,related counter accept
+ nft add rule ip filter input dport 20 proto tcp ct mstate state state state established,related counter accept
+ nft add rule ip filter input sport 21 proto tcp ct mstate state state state new,established counter accept
+ nft add rule ip filter input dport 21 proto tcp ct mstate state state state established,related counter accept
+ nft add rule ip filter input sport 1024-65535 proto tcp ct mstate state state state established,related counter accept
+ nft add rule ip filter input dport 1024-65535 proto tcp ct mstate state state state established,related counter accept
MY_IP=$(ip --oneline -4 address show up | awk '{split($4,a,/\//); if (a[1] != "127.0.0.1") print a[1]}')
for ip in $MY_IP; do my_ip "$ip"; done