VFREE HijackFilter

VFREE HijackFilter is a free software to protect you from unwanted Internet hijacking.

Copyright (C) 2016 Rayson Zhu vfreex@gmail.com

If you encountered Internet hijacking, call your ISP to stop it! This software should be your last choice for preventing Internet hijacking.

1. Installation

1.1 Build

• Ubuntu / Debian

apt install make gcc iptables-dev linux-headers-`uname -r` pkg-config
make

• Fedora

dnf install make gcc iptables-devel kernel-devel-`uname -r` pkgconfig
make

• RHEL / CentOS

yum install make gcc iptables-devel kernel-devel-`uname -r` pkgconfig
make

1.2 Install

make install
depmod

1.3. Uninstall

make uninstall
depmod

2. Usage

2.1 DNSFilter

DNSFilter is a Netfilter extension to help you match and filter proofed DNS responses.

Suppose your ISP redirects nonexistent domain names to 192.0.2.1 and 198.51.100.1. To match and drop those spoofed DNS responses, we can use following commands:

# for IPv4 network
iptables -t mangle -A PREROUTING -p udp --sport 53 -m vfree_dns \
  --a 192.0.2.1,198.51.100.1\
  -j DROP
# for IPv6 network
ip6tables -t mangle -A PREROUTING -p udp --sport 53 -m vfree_dns \
  --a 192.0.2.1,198.51.100.1\
  -j DROP

Use -h option for help.

iptables -m vfree_dns -h

3. TO-DO

• HTTPFilter: a netfilter module to match and filter proofed HTTP messages

4. LICENSE

This program is distributed under GNU GENERAL PUBLIC LICENSE Version 3.