#!/bin/bash -xu

#Define the policies to accept in order to avoid being cut out running this remotely via SSH
  sudo iptables -P INPUT   ACCEPT
  sudo iptables -P FORWARD ACCEPT
  sudo iptables -P OUTPUT  ACCEPT

#To begin with, flush the tables
  sudo iptables -t mangle -F
  sudo iptables -t nat    -F
  sudo iptables -t filter -F
  sudo iptables -X


# Allow Access Point NAT
sudo iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE


# Allows all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
sudo iptables -t filter -A INPUT -i lo -j ACCEPT
sudo iptables -t filter -A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

# Accepts all established inbound connections
sudo iptables -t filter -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT

#Drop all multicast traffic
sudo iptables -t filter -A INPUT -d 224.0.0.0/4 -j DROP
sudo iptables -t filter -A OUTPUT -d 224.0.0.0/4 -j DROP

# Allows all outbound traffic
sudo iptables -t filter -A OUTPUT -j ACCEPT

# Allows HTTP and HTTPS connections from anywhere (the normal ports for websites)
sudo iptables -t filter -A INPUT -p tcp --dport 80 -j ACCEPT
sudo iptables -t filter -A INPUT -p tcp --dport 443 -j ACCEPT

# Allows SSH connections
sudo iptables -t filter -A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT
sudo iptables -t filter -A INPUT -p tcp -m state --state NEW -m recent --dport 22 --set --name ssh --rsource
sudo iptables -t filter -A INPUT -p tcp -m state --state NEW -m recent --dport 22 ! --rcheck --seconds 60 --hitcount 4 --name ssh --rsource -j ACCEPT

# Allow ping and other icmp traffic
sudo iptables -t filter -A INPUT -p icmp -j ACCEPT

# Allow forwarded the following forwards
sudo iptables -t filter -A FORWARD -o wlan0 -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -t filter -A FORWARD -o eth0 -i wlan0 -j ACCEPT

# log iptables denied calls
sudo iptables -t filter -A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7

# Reject all other inbound
sudo iptables -t filter -A INPUT -j DROP
sudo iptables -t filter -A FORWARD -j DROP

#Reset the policies
sudo iptables -P INPUT DROP
sudo iptables -P FORWARD DROP
sudo iptables -P OUTPUT DROP

sudo dmesg -c
clear