From 75fa1a6e88ef2cc1d9572788152e025fc5305f1b Mon Sep 17 00:00:00 2001
From: Christian Weiske <cweiske@cweiske.de>
Date: Wed, 4 May 2016 13:14:33 +0200
Subject: [PATCH]

---
 ping.php | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/ping.php b/ping.php
index ca5a562..f1df4b1 100644
--- a/ping.php
+++ b/ping.php
@@ -3,6 +3,16 @@
  * Pings a given host and returns a red or green image.
  * Green when the host is online, red when offline.
  *
+ * Error: ping: socket: Operation not permitted
+ *        (raw socket required by specified options).
+ *
+ * Solution:
+ *     $ chmod +s /path/to/ping
+ * Alternative:
+ *     $ setcap cap_net_raw+ep /path/to/ping
+ * Alternative:
+ *     make it passwordless sudo
+ *
  * Keywords: http image ping online check
  *
  * @author Christian Weiske <weiske@mogic.com>
@@ -21,13 +31,18 @@ if (!isset($_GET['size'])) {
     $size = intval($_GET['size']);
 }
 
-exec('ping -c 1 -w 1 -W 1 ' . escapeshellarg($host), $output, $retval);
+exec('ping -c 1 -w 1 -W 1 ' . escapeshellarg($host) . ' 2>&1', $output, $retval);
 if ($retval == 0) {
     //all fine
     sendSvg($size, 'fill: green');
-} else {
-    //error
+} else if ($retval == 1) {
+    //no reply
     sendSvg($size, 'fill: red');
+} else {
+    //some other error, e.g. permissions
+    header('HTTP/1.0 500 Internal server error');
+    header('Content-type: text/plain');
+    echo implode("\n", $output) . "\n";
 }
 
 function sendSvg($size, $style)
@@ -35,8 +50,8 @@ function sendSvg($size, $style)
     $half = intval($size / 2);
     header('HTTP/1.0 200 OK');
     header('Content-type: image/svg+xml');
+    echo '<' . '?xml version="1.0"?>' . "\n";
     echo <<<XML
-<?xml version="1.0"?>
 <svg xmlns="http://www.w3.org/2000/svg" width="$size" height="$size">
   <circle cx="$half" cy="$half" r="$half" style="$style"/>
 </svg>
-- 
2.30.2