This is free, open source RethinkDNS serverless DoH and DoT resolvers with custom blocklists that can be hosted on cloudflare, fly.io and deno-deploy. This initiative is to provide first level of anti-censorship and data privacy to every person on the earth.

For the People

Easiest way to host this serverless dns would be to use Cloudflare. Click the below button to deploy. User will be liable for cloudflare billing.

Instructions for configuring, like changing recursive resolver and other platforms available to host are linked from the table below.

Platform	Difficulty	Resolver Protocol	Instructions
⛅ Cloudflare	Easy	HTTPS	Hosting on Cloudflare Workers
🦕 Deno Deploy	Moderate	HTTPS	Hostng on Deno.com
🪰 Fly	Hard	TLS & HTTPS	Hosting on Fly.io

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Rest of this README is intended for software developers.

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For the Developers

Style Guide

This repository enforces a certain style guide as configured in .eslintrc.cjs file.

To help with style guide, there exists a git pre-commit hook that runs eslint on .js files before a commit is made. This may fix a few issues & format the code with prettier.

Commit will fail if there are any "error" level style guide violations which couldn't be fixed automatically.

Run npm i or npm prepare to set up the hook.

Use git commit --no-verify to bypass this hook.

Pull requests are also checked for style guide violations and fixed automatically if possible.

Runtimes

Deno

Run:

deno run --allow-net --allow-env --allow-read --import-map=import_map.json src/server-deno.ts

List of environment variables can be found in .env.example file. Load them as required. For convenience, you can also put them in a .env file and they will also be loaded into the environment.

Runtime API:

• https://doc.deno.land/deno/stable
• https://doc.deno.land/deno/unstable

NOTE: Runtime API of deno-deploy differs from that of Deno. See below.

Node

Run:

node src/server-node.js

Proxies DNS over HTTPS & DNS over TLS requests to the main app (index.js).

List of environment variables can be found in .env.example file. Load them as required. For convenience in non-production environment, you can also put them in a .env file and they will be loaded into the environment if not already present.

Platforms

Deno Deploy

Runtime API: https://deno.com/deploy/docs/runtime-api

Flow

The flow of rethink dns is based on plugin module, current plugin flow is as below. Five plugins are currently loaded.

1. CommandControl
   This is optional plugin used to provide command to rethink serverless dns using GET request.
2. UserOperation
   This plugin loads current user details if not found in cache.
   e.g. dns resolve google.com request to rethink serverless cloudflare resolver https://example.com/1:AIAA7g==, configuration string 1:AIAA7g== is treated as user id and loads selected blocklists files for configuration string and cache it under user id.
3. DNSBlock
   This is optional plugin used to check whether requested domain should be blocked or processed further.
4. DNSResolver
   This plugin forward dns request to upstream resolver based on environment variable CF_DNS_RESOLVER_URL if not blocked by DNSBlock plugin.
5. DNSCnameBlock
   This is optional plugin used to check whether dns resolved response contains cname and cname has blocked domain name, if cname has blocked domain name then request is blocked.

Custom Plugin

Custom plugins can be developed by adding following function to class

export class CustomPlugin {
	constructor() {
	}
	async RethinkModule(param) {
		let response = {};
		response.isException = false;
		response.exceptionStack = "";
		response.exceptionFrom = "";
		response.data = {};
		try {
		} catch (e) {
			response.isException = true;
			response.exceptionStack = e.stack;
			response.exceptionFrom = "CustomPlugin RethinkModule";
		}
		return response;
	}
}

• RethinkModule(param) is entry point for every plugin.
• Inside RethinkModule method your custom logic can be build for your rethink serverless dns.
• example if published to npm as @your-plugin/plugin
• add your plugin to rethink serverless dns at src/helpers/plugin.js

/**
 * Import and Initialize plugins
 */
import { CustomPlugin } from "@your-plugin/plugin";
const customPlugin = new CustomPlugin();

// Start RethinkPlugin constructor

/**
 * Here, register the plugins that should run before custom plugin if any.
 * So as if any of it's output is available to the next plugin. For example,
 * "userBlocklistInfo" is the output of "userOperation" plugin and is only
 * available after it's run.
 */

/**
 * custom plugin registration
 */
this.registerPlugin(
	"customPlugin",
	customPlugin,
	["event", "userBlocklistInfo", "dnsResolverResponse"],
	customCallBack,
	false,
);

/**
 * Here, register the plugins that should run after custom plugin if any.
 */

// End RethinkPlugin constructor

/**
 * custom plugin call back after execution
 */
function customCallBack(response, currentRequest) {
	if (response.isException) {
		loadException(response, currentRequest);
	} else if (response.data.decision) {
		currentRequest.stopProcessing = true;
	} else {
		// "customResponse" param can be registered and passed onto next plugin
		this.registerParameter("customResponse", response.data);
	}
}

• this.registerPlugin(Plugin_Name, Plugin_Object , [Parameters_to_Plugin], Plugin_Callback_Function, Plugin_Execution_After_StopProcessing)
  • Plugin_Name - string denotes name of the plugin.
  • Plugin_Object - object of plugin class, which implements RethinkModule function within class.
  • Parameters_to_Plugin - list of parameters passed to RethinkModule function.
  • Plugin_Callback_Function - function that will be called back after plugin execution with plugin response and current request object.
  • Plugin_Execution_After_StopProcessing - boolean indicates the plugin execution status after currentRequest.stopProcessing is set.
• In the example snippet above, three parameters are passed to custom rethink module
  • event parameter passed by worker
  • userBlocklistInfo is output of userOperation plugin
  • dnsResolverResponse is output of dnsResolver plugin
• Once plugin execution is done customCallBack function is initiated with plugin response and currentRequest.
• Inside the plugin call-back based on the plugin response dns process can be stopped or moved further by saving response this.registerParameter("parameter-name", parameter data).
• By setting currentRequest.stopProcessing = true, no further plugin will be executed except if Plugin Execution After StopProcessing is set to true.
• Publish to cloudflare with updated plugin which will reflect to all your pointed devices.