improvement of ipv4 regex and test cases (#73)

* improvement of ipv4 regex and test cases

* require utils test

* change example

---------

Co-authored-by: Markus Frindt <m.frindt@cognigy.com>

lib/sip-trunk-register.js

@@ -7,6 +7,7 @@ const {
 } = require('./config');
 const assert = require('assert');
 const short = require('short-uuid');
+const {isValidIPv4} = require('./utils');
 const DEFAULT_EXPIRES = (parseInt(JAMBONES_REGBOT_DEFAULT_EXPIRES_INTERVAL) || 3600);
 const MIN_EXPIRES = (parseInt(JAMBONES_REGBOT_MIN_EXPIRES_INTERVAL) || 30);
 const MAX_INITIAL_DELAY = 15;
@@ -124,7 +125,7 @@ class Regbot {
       }
 
       this.logger.debug(`sending REGISTER for ${this.aor}`);
-      const isIPv4 = /^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$/.test(this.ipv4);
+      const isIPv4 = isValidIPv4(this.ipv4);
 
       const proxy = `sip:${this.ipv4}${isIPv4 ? `:${this.port}` : ''};transport=${transport}`;
       this.logger.debug({isIPv4}, `sending via proxy ${proxy}`);

lib/utils.js

@@ -27,9 +27,23 @@ async function addSipGatewayToBlacklist(client, logger, sip_gateway_sid, expired
   }
 }
 
+/* Regex pattern to match valid IPv4 addresses (0.0.0.0 to 255.255.255.255) */
+const ipv4Pattern = /^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$/;
+
+/**
+ * Checks if the given input string represents a valid IPv4 address.
+ *
+ * @param {string} ip - The string to be validated.
+ * @returns {boolean} - `true` if the input is a valid IPv4 address, `false` otherwise.
+ */
+function isValidIPv4(ip) {
+  return ipv4Pattern.test(ip);
+}
+
 module.exports = {
   isUacBehindNat,
   getSipProtocol,
   addSipGatewayToBlacklist,
-  NAT_EXPIRES: 30
+  NAT_EXPIRES: 30,
+  isValidIPv4,
 };