as-d/chinadns

Protect yourself against DNS poisoning in China.

ChinaDNS

Protect yourself against DNS poisoning in China.

In order to bypass IP blocking, you also need VPN software like ShadowVPN.

Install

• Linux / Unix

  Download a release.

    ./configure && make
    src/chinadns -m -c chnroute.txt
  

• OpenWRT

  • Download precompiled for OpenWRT trunk and CPU: ar71xx, brcm63xx, brcm47xx, ramips_24kec. Open an issue if you think your CPU is a popular one but not listed here.

  • If you use other CPU or other OpenWRT versions, build yourself: cd into SDK root, then

      pushd package
      git clone https://github.com/clowwindy/ChinaDNS.git
      popd
      make menuconfig # select Network/ChinaDNS
      make -j
      make V=99 package/ChinaDNS/openwrt/compile
    

• Tomoto

  • Download Tomato toolchain, build by yourself.

  • Uncompress the downloaded file to ~/.

  • Copy the brcm directory under ~/WRT54GL-US_v4.30.11_11/tools/ to /opt, then

      export PATH=/opt/brcm/hndtools-mipsel-uclibc/bin/:/opt/brcm/hndtools-mipsel-linux/bin/:$PATH
      git clone https://github.com/clowwindy/ChinaDNS.git
      cd ChinaDNS
      ./autogen.sh && ./configure --host=mipsel-linux --enable-static && make
    

• Windows

  Download Python exe version.

Usage

• Linux / Unix Recommand using with option "-m" (DNS pointer mutation method) Run sudo chinadns -m -c chnroute.txt on your local machine. ChinaDNS creates a UDP DNS Server at 0.0.0.0:53.

• OpenWRT

    opkg install ChinaDNS_1.x.x_ar71xx.ipk
    /etc/init.d/chinadns start
    /etc/init.d/chinadns enable
  

  Invoke the "enable" command to run the initscript on boot

  (Optional) We strongly recommend you to set ChinaDNS as a upstream DNS server for dnsmasq instead of using ChinaDNS directly:

  1. Run /etc/init.d/chinadns stop

  2. Remove the 2 lines containing iptables in /etc/init.d/chinadns.

  3. Update /etc/dnsmasq.conf to use only 127.0.0.1#5353:

      no-resolv
      server=127.0.0.1#5353
     

  4. Restart chinadns and dnsmasq

Test if it works correctly:

$ dig @192.168.1.1 www.youtube.com -p5353
; <<>> DiG 9.8.3-P1 <<>> @127.0.0.1 www.google.com -p5353
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29845
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.youtube.com.		IN	A

;; ANSWER SECTION:
www.youtube.com.	21569	IN	CNAME	youtube-ui.l.google.com.
youtube-ui.l.google.com. 269	IN	A	216.58.220.174

;; Query time: 74 msec
;; SERVER: 127.0.0.1#5353(127.0.0.1)
;; WHEN: Fri Jan 30 18:37:57 2015
;; MSG SIZE  rcvd: 83

Currently ChinaDNS only supports UDP. Builtin OpenWRT init script works with dnsmasq, which handles TCP. If you use it directly without dnsmasq, you need to add a redirect rule for TCP:

iptables -t nat -A PREROUTING -p tcp --dport 53 -j DNAT --to-destination 8.8.8.8:53

Advanced

usage: chinadns [-h] [-l IPLIST_FILE] [-b BIND_ADDR] [-p BIND_PORT]
       [-c CHNROUTE_FILE] [-s DNS] [-v]
Forward DNS requests.

-h, --help            show this help message and exit
-l IPLIST_FILE        path to ip blacklist file
-c CHNROUTE_FILE      path to china route file
                      if not specified, CHNRoute will be turned off
-d                    enable bi-directional CHNRoute filter
-y                    delay time for suspects, default: 0.3
-b BIND_ADDR          address that listens, default: 127.0.0.1
-p BIND_PORT          port that listens, default: 53
-s DNS                DNS servers to use, default:
                      114.114.114.114,208.67.222.222:443,8.8.8.8
-m                    Using DNS compression pointer mutation
                      (backlist and delaying would be disabled)
-v                    verbose logging

About chnroute

You can generate latest chnroute.txt using this command:

curl 'http://ftp.apnic.net/apnic/stats/apnic/delegated-apnic-latest' | grep ipv4 | grep CN | awk -F\| '{ printf("%s/%d\n", $4, 32-log($5)/log(2)) }' > chnroute.txt

License

Copyright (C) 2015 clowwindy

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Bugs and Issues

Please visit Issue Tracker

Mailing list: http://groups.google.com/group/shadowsocks