From 509846fa0b9e27f7adec0895dcf351795814d7f4 Mon Sep 17 00:00:00 2001
From: Robert Langhammer <rlanghammer@web.de>
Date: Sun, 24 Nov 2019 23:42:28 +0100
Subject: [PATCH] It is possible to DoS the server with massiv call of simple
 babelweb.

Here we generate the dumpfile only once per minute and a short description top optimize apache2 on Debian (i don't know what you can do, if you use nginx)

Signed-off-by: christiand <fff@chrisi01.de>
Signed-off-by: Robert Langhammer <rlanghammer@web.de>
---
 README.md | 4 ++++
 index.php | 5 ++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 1ce0abe..023707c 100644
--- a/README.md
+++ b/README.md
@@ -13,3 +13,7 @@ The haserl version for slim devices without php
 ### Requirements
 * haserl
 * netcat with ipv6 support
+
+## Apache 2 settings
+To avoid OOM Killer it's usefull to reduce the MaxConnectionsPerChild on apache2. On Debian open /etc/apache2/mods-enabled/mpm_prefork.conf and reduce MaxConnectionsPerChild.
+Do not use more then 10 MaxConnectionsPerChild per Gigabyte RAM on your System.
diff --git a/index.php b/index.php
index 6eb81f9..56b242b 100644
--- a/index.php
+++ b/index.php
@@ -23,7 +23,10 @@
 		<?php
 		error_reporting(0);
 		$file="/tmp/babeldump";
-		shell_exec('echo "dump" | nc ::1 33123 -q 1 > '.$file.'');
+
+		if (filemtime($file) < time()-10) {
+			shell_exec('echo "dump" | nc ::1 33123 -q 1 > '.$file.'');
+		}
 
 		$file_handle = fopen($file, 'r');
 		$set=0;