#!/bin/sh
# IRCd Firewall - Developed by acidvegas (https://git.acid.vegas/supertools)

# nano /etc/default/grub
# Add ipv6.disable=1 to GRUB_CMDLINE_LINUX_DEFAULT then run update-grub

# Configuration
IP_MAIN="10.0.0.1" # Change this to your IP
IP_HUB="10.0.0.2"  # Change this to your hub IP
PORT_SSH=22        # Default 22
PORT_HUB=5900      # Default 5900

# Kernel hardening settings
mkdir -p /etc/sysctl.d
{
  printf "net.ipv4.conf.all.accept_source_route = 0\n"
  printf "net.ipv6.conf.all.accept_source_route = 0\n"
  printf "net.ipv4.conf.all.rp_filter = 1\n"
  printf "net.ipv4.conf.default.rp_filter = 1\n"
  printf "net.ipv4.conf.all.accept_redirects = 0\n"
  printf "net.ipv6.conf.all.accept_redirects = 0\n"
  printf "net.ipv4.conf.default.accept_redirects = 0\n"
  printf "net.ipv6.conf.default.accept_redirects = 0\n"
  printf "net.ipv4.conf.all.log_martians = 1\n"
  printf "kernel.randomize_va_space = 2\n"
  printf "fs.suid_dumpable = 0\n"
} > /etc/sysctl.d/99-custom-hardening.conf

# Apply hardening settings
sysctl -p /etc/sysctl.d/99-custom-hardening.conf

# Flush existing rules
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X

# Default chain policies
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT

# Common Firewall rules
iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p icmp --icmp-type echo-request -j DROP
iptables -A INPUT -i lo -j ACCEPT

# Allow SSH
iptables -A INPUT -p tcp -s $IP_MAIN --dport $PORT_SSH -j ACCEPT

# Allow IRCd Hub
iptables -A INPUT -p tcp -s $IP_HUB  --dport $PORT_HUB -j ACCEPT

# Allow IRCd Ports
iptables -A INPUT -p tcp --dport 6660:6669 -j ACCEPT
iptables -A INPUT -p tcp --dport 7000 -j ACCEPT

# Allow IRCd TLS Ports
iptables -A INPUT -p tcp --dport 6697 -j ACCEPT
iptables -A INPUT -p tcp --dport 9999 -j ACCEPT

# Save rules
apt-get install -y iptables-persistent
netfilter-persistent save
systemctl enable netfilter-persistent && systemctl start netfilter-persistent

# Show rules
iptables -L -v -n