Add blacklist env

src/client.js

@@ -1,10 +1,10 @@
 const record_prefix = 'forward-domain=';
-const path = require('path');
 const {
     client
 } = require('./sni');
 const {
-    findTxtRecord
+    findTxtRecord,
+    isHostBlacklisted
 } = require('./util');
 const combineURLs = require('axios/lib/helpers/combineURLs');
 
@@ -26,13 +26,14 @@ async function buildCache(host) {
     return {
         url,
         expand,
+        blacklisted: isHostBlacklisted(host),
         expire: Date.now() + 86400 * 1000,
     };
 }
 
 const acme_prefix = '/.well-known/acme-challenge/';
 
-const listener = async function (/** @type {import('http').IncomingMessage} */ req, /** @type {import('http').ServerResponse} */ res) {
+const listener = async function ( /** @type {import('http').IncomingMessage} */ req, /** @type {import('http').ServerResponse} */ res) {
     try {
         if (req.url.startsWith(acme_prefix)) {
             if (client.challengeCallbacks) {
@@ -52,6 +53,12 @@ const listener = async function (/** @type {import('http').IncomingMessage} */ r
             cache = await buildCache(req.headers.host);
             resolveCache[req.headers.host] = cache;
         }
+        if (cache.blacklisted) {
+            res.writeHead(301, {
+                'Location': process.env.BLACKLIST_REDIRECT || 'https://forwarddomain.net/blacklisted',
+            });
+            return;
+        }
         res.writeHead(301, {
             'Location': cache.expand ? combineURLs(cache.url, req.url) : cache.url,
         });

src/sni.js

@@ -5,7 +5,6 @@ const path = require('path');
 const {
     md5,
     ensureDir,
-    findTxtRecord
 } = require('./util');
 const {
     default: AwaitLock

src/util.js

@@ -1,11 +1,26 @@
-const { default: axios } = require('axios');
+const {
+    default: axios
+} = require('axios');
 var crypto = require('crypto');
 const fs = require('fs');
+const blacklistURL = (process.env.BLACKLIST_HOSTS || "").split(',').reduce((acc, host) => {
+    acc[host] = true;
+    return acc;
+}, {});
 
 function md5(str) {
     return crypto.createHash('md5').update(str).digest('hex');
 }
 
+function isHostBlacklisted(domain = '') {
+    if (domain.length > 6) {
+        let p = domain.lastIndexOf('.', domain.length - 6);
+        if (p > 0) {
+            domain = domain.substring(p + 1);
+        }
+    }
+    return blacklistURL[domain];
+}
 
 async function ensureDir(dir) {
     try {
@@ -40,4 +55,5 @@ module.exports = {
     md5,
     ensureDir,
     findTxtRecord,
+    isHostBlacklisted,
 }