linux域名白名单实现仅能访问指定网站

# 编辑DNS配置文件 /etc/named.conf
zone "example.com" IN {
    type master;
    file "/etc/named/zones/db.example.com";
};

# 编辑区域文件 /etc/named/zones/db.example.com
$TTL 86400
@       IN      SOA     ns1.example.com. admin.example.com. (
                        2023010101 ; serial
                        3600       ; refresh
                        1800       ; retry
                        604800     ; expire
                        86400      ; minimum
                )
        IN      NS      ns1.example.com.
        IN      NS      ns2.example.com.

example.com.    IN      A       192.168.1.1
www.example.com.    IN      A       192.168.1.1

sudo systemctl restart named

# 允许访问特定域名
iptables -A INPUT -p tcp --dport 80 -m string --string "example.com" --algo bm -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -m string --string "example.com" --algo bm -j ACCEPT

# 拒绝其他所有访问
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP

sudo iptables-save > /etc/iptables/rules.v4

sudo systemd-resolve --flush-caches

sudo iptables -L -v -n