network_ap.sh

#!/bin/bash
# Ref: http://www.contextis.com/resources/blog/wireless-phishing-captive-portals/
# 
# Steps :
# ./network_ap.sh
# ./create_ap wlan0 eth0 AccessPoint -g 10.0.0.1

killall hostapd
killall dnsmasq

#
# First, delete all existing rules
#
iptables --flush
iptables --delete-chain
iptables --table nat --delete-chain
iptables --table nat -F
iptables --table nat -X


#
# Captive Portal
#
# - Replace `10.0.0.1` to `192.168.1.5:3000` to access remove server
#
iptables -t mangle -N localhost
iptables -t mangle -A PREROUTING -i wlan0 -p udp --dport 53 -j RETURN
iptables -t mangle -A PREROUTING -i wlan0 -j localhost
iptables -t mangle -A localhost -j MARK --set-mark 1
iptables -t nat -A PREROUTING -i wlan0 -p tcp -m mark --mark 1 -j DNAT --to-destination 10.0.0.1
sysctl -w net.ipv4.ip_forward=1
iptables -A FORWARD -i wlan0 -j ACCEPT
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE