From 83750044c5506fa6be3fd5b389b520067697cb7f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?David=20Majdand=C5=BEi=C4=87?=
 <david.majdandzic@hotmail.com>
Date: Thu, 9 Nov 2023 14:50:56 +0100
Subject: [PATCH] Implement random smppid generation

---
 center.js     | 13 ++++++++++---
 cliOptions.js |  6 ++++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/center.js b/center.js
index 007713b..3e14e02 100644
--- a/center.js
+++ b/center.js
@@ -5,6 +5,7 @@ const NanoTimer = require("nanotimer");
 const { createBaseLogger, createSessionLogger } = require("./logger");
 const { verifyDefaults, verifyExists } = require("./utils");
 const { centerOptions } = require("./cliOptions");
+const crypto = require("crypto");
 
 const logger = createBaseLogger();
 const options = commandLineArgs(centerOptions);
@@ -121,7 +122,13 @@ const server = smpp.createServer(
 
 			sessionLogger.info("Generating DR for incoming submit_sm");
 			let response = pdu.response();
-			response.message_id = (messageid++).toString(16);
+
+			let smppid = messageid++;
+			if (options.randid) {
+				smppid = crypto.randomBytes(12).toString("hex");
+			}
+
+			response.message_id = smppid.toString(16);
 			session.send(response);
 
 			let drMessage = "";
@@ -143,8 +150,8 @@ const server = smpp.createServer(
 			drMessage += "text:";
 
 			const DRPdu = {
-				source_addr: pdu.source_addr,
-				destination_addr: pdu.destination_addr,
+				source_addr: pdu.destination_addr,
+				destination_addr: pdu.source_addr,
 				short_message: drMessage,
 				esm_class: 4,
 			};
diff --git a/cliOptions.js b/cliOptions.js
index 9d6fc3f..79c2c96 100644
--- a/cliOptions.js
+++ b/cliOptions.js
@@ -58,6 +58,12 @@ const centerOptions = [
 	{ name: "systemid", alias: "s", type: String, description: "SMPP related login info." },
 	{ name: "password", alias: "w", type: String, description: "SMPP related login info." },
 	{ name: "dr", type: Boolean, description: "Whether or not to send Delivery Reports.", defaultOption: false },
+	{
+		name: "randid",
+		type: Boolean,
+		description: "SMPP ID generation is entirely random instead of sequential.",
+		defaultOption: false,
+	},
 	{
 		name: "sessions",
 		type: Number,