From 10f9e1b5f2e0048cfbd043da7d19771f3af2e20f Mon Sep 17 00:00:00 2001
From: Dorian Niemiec <dorian.niemiec@svrjs.org>
Date: Mon, 28 Aug 2023 03:44:04 +0200
Subject: [PATCH] Add reverse DNS lookup support

---
 config.json |  4 +--
 svr.js      | 77 +++++++++++++++++++++++++++++++++++------------------
 2 files changed, 53 insertions(+), 28 deletions(-)

diff --git a/config.json b/config.json
index 76fd53d..e8d3ae7 100644
--- a/config.json
+++ b/config.json
@@ -3,7 +3,7 @@
   "port": 80,
   "pubport": 80,
   "page404": "404.html",
-  "timestamp": 1692915666757,
+  "timestamp": 1693186939816,
   "blacklist": [],
   "nonStandardCodes": [],
   "enableCompression": true,
@@ -90,4 +90,4 @@
   "enableETag": true,
   "disableUnusedWorkerTermination": false,
   "rewriteDirtyURLs": true
-}
\ No newline at end of file
+}
diff --git a/svr.js b/svr.js
index 85d1e30..8f6d783 100644
--- a/svr.js
+++ b/svr.js
@@ -357,6 +357,7 @@ http.STATUS_CODES[497] = "HTTP Request Sent to HTTPS Port";
 http.STATUS_CODES[598] = "Network Read Timeout Error";
 http.STATUS_CODES[599] = "Network Connect Timeout Error";
 var url = require("url");
+var dns = require("dns");
 try {
   var gracefulFs = require("graceful-fs");
   if (!process.isBun) gracefulFs.gracefulify(fs); //Bun + graceful-fs + SVR.JS + requests about static content = 500 Internal Server Error!
@@ -865,21 +866,33 @@ if (host != "[offline]" || ifaceEx) {
         return;
       }
       pubip = d.toString();
-      if (!domain) {
-        if (pubip.indexOf(":") == -1) {
-          var parts = pubip.split(".");
-          var p1 = parseInt(parts[0]).toString(16);
-          var p2 = parseInt(parts[1]).toString(16);
-          var p3 = parseInt(parts[2]).toString(16);
-          var p4 = parseInt(parts[3]).toString(16);
-          var pp = parseInt(pubport).toString(16);
-          domain = p1 + p2 + p3 + p4 + pp + ".nodesvr.doriantech.com";
-        } else {
-          domain = pubip.replace(/[^0-9a-zA-Z]/gi, "").toLowerCase() + ".nodesvrip6.doriantech.com";
+      if (domain) {
+        ipRequestCompleted = true;
+        process.emit("ipRequestCompleted");
+      } else {
+        var callbackDone = false;
+
+        var dnsTimeout = setTimeout(function() {
+          callbackDone = true;
+          ipRequestCompleted = true;
+          process.emit("ipRequestCompleted");
+        }, 3000);
+
+        try {
+          dns.reverse(pubip, function(err, hostnames) {
+            if(callbackDone) return;
+            clearTimeout(dnsTimeout);
+            if(!err && hostnames.length > 0) domain = hostnames[0];
+            ipRequestCompleted = true;
+            process.emit("ipRequestCompleted");
+          });
+        } catch(err) {
+          clearTimeout(dnsTimeout);
+          callbackDone = true;
+          ipRequestCompleted = true;
+          process.emit("ipRequestCompleted");
         }
       }
-      ipRequestCompleted = true;
-      process.emit("ipRequestCompleted");
     });
   });
   ipRequest.on("error", function () {
@@ -917,21 +930,33 @@ if (host != "[offline]" || ifaceEx) {
           return;
         }
         pubip = d.toString();
-        if (!domain) {
-          if (pubip.indexOf(":") == -1) {
-            var parts = pubip.split(".");
-            var p1 = parseInt(parts[0]).toString(16);
-            var p2 = parseInt(parts[1]).toString(16);
-            var p3 = parseInt(parts[2]).toString(16);
-            var p4 = parseInt(parts[3]).toString(16);
-            var pp = parseInt(pubport).toString(16);
-            domain = p1 + p2 + p3 + p4 + pp + ".nodesvr.doriantech.com";
-          } else {
-            domain = pubip.replace(/[^0-9a-zA-Z]/gi, "").toLowerCase() + ".nodesvrip6.doriantech.com";
+        if (domain) {
+          ipRequestCompleted = true;
+          process.emit("ipRequestCompleted");
+        } else {
+          var callbackDone = false;
+
+          var dnsTimeout = setTimeout(function() {
+            callbackDone = true;
+            ipRequestCompleted = true;
+            process.emit("ipRequestCompleted");
+          }, 3000);
+
+          try {
+            dns.reverse(pubip, function(err, hostnames) {
+              if(callbackDone) return;
+              clearTimeout(dnsTimeout);
+              if(!err && hostnames.length > 0) domain = hostnames[0];
+              ipRequestCompleted = true;
+              process.emit("ipRequestCompleted");
+            });
+          } catch(err) {
+            clearTimeout(dnsTimeout);
+            callbackDone = true;
+            ipRequestCompleted = true;
+            process.emit("ipRequestCompleted");
           }
         }
-        ipRequestCompleted = true;
-        process.emit("ipRequestCompleted");
       });
     });
     ipRequest2.on("error", function () {