Features

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• DNS query forwarding, supports TCP DNS protocol and UDP DNS protocol
• DNS server speed test, choose the fastest servers
• DNS query local acceleration, use lru cache
• DNS server automatic switching, when multiple query errors, automatically try to switch
• Private Host, equivalent to modifying the hosts file
• Support intranet DNS server, resolve internal domain names

How to use this python script ?

---

• change your dns server to 127.0.0.1

$ vi /etc/resolve.conf  
  nameserver 127.0.0.1

• restart the network

$ sudo /etc/init.d/networking restart

• run the script

$ sudo python tcpdns.py -f tcpdns.json.example

Commandline

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usage: tcpdns.py [-h] -f CONFIG_JSON [-d]
TCP DNS Proxy
optional arguments:   -h, --help      show this help message and exit   -f CONFIG_JSON  Json config file   -d              Print debug message

Configuration file

---

json
{
    "socket_timeout": 20,
    "host": "0.0.0.0",
    "port": 53,
    "tcpdnsserver": ["8.8.8.8:53",
                       "8.8.4.4:53",
                       "156.154.70.1:53",
                       "156.154.71.1:53",
                       "208.67.222.222:53",
                       "208.67.220.220:53",
                       "209.244.0.3:53"],
    "udpdnsserver": ["208.67.222.222:5353"],
    "enableserverswitch": true,
    "speed_test": true,
    "enablelrucache": true,
    "lrucachesize"  : 500,
    "udp_mode"        : false,
    "daemon_process"  : false,
    "internaldnsserver": ["192.168.1.1:53"],
    "internal_domain": ["intra"],
    "private_host"    : {"*google.com": "203.117.34.162"}
}

• enableserverswitch: switch dns servers if network is slow
• speed_test : test dns server speed on startup
• enablelrucache : use lru cache to store dns server responses
• udp_mode : use udp dns procotol, default is tcp dns protocol

daemon_process : daemon process on nix platform

• internaldnsserver : internal dns server on internal network
• internal_domain : internal domains which use internal dns server to get ip address

private_host : like /etc/hosts on nix platform

Dependencies

---

libraries

* [libev] (http://libevent.org/)

python moudules

* [gevent] (https://github.com/surfly/gevent) * [pylru] (https://github.com/jlhutch/pylru) * [python-daemon] (https://pagure.io/python-daemon/) (Windows does not need)

INSTALL

---

Linux system

python3 -m venv .venv
source .venv/bin/activate
pip3 install -r requirements.txt
sudo .venv/bin/python3 tcpdns.py -f tcpdns.json.example -d

Windows system

Use tcpdns.exe in win directory. (I haven't tested it on Windows 10 or 11.)

LICENSE

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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 2 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/