From bbc49c6dee671d040dff7a733d70b92eaa26d44e Mon Sep 17 00:00:00 2001
From: ray-1337 <33544674+ray-1337@users.noreply.github.com>
Date: Mon, 11 Apr 2022 21:16:08 +0200
Subject: [PATCH] support net mask

---
 src/Util.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/Util.js b/src/Util.js
index e683286..e1963de 100644
--- a/src/Util.js
+++ b/src/Util.js
@@ -93,8 +93,9 @@ module.exports.checkAppropriateIP = function(address) {
     throw new Error("The address must be type of number.");
   };
 
-  // https://stackoverflow.com/a/5284410
-  let regex = new RegExp(/\b((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.|$)){4}\b/gi);
+  // https://blog.markhatton.co.uk/2011/03/15/regular-expressions-for-ip-addresses-cidr-ranges-and-hostnames/
+  // also support subnet/net mask
+  let regex = new RegExp(/^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(3[0-2]|[1-2][0-9]|[0-9]))?$/gi);
   if (!address.match(regex)) {
     throw new Error(`The IP address is not matched with ${regex.toString()} regular expressions.`);
   };