// below we set up some silly defaults; it is recommended to save your
// own settings in $configfile; if readable it will override our defaults;
// for a list of configuration variables see https://wox.at/as/_/netstat_php
$configfile = 'netstat.conf.php';

// title (as in HTML) and headline of the page
$title = "Our Network Status";
$headline = $title;

// including $configfile if available
if (file_exists($configfile) && is_readable($configfile)) include($configfile);

// all configuration variables are set only if not already set
function defaults(&$var, $value) {
isset($var) || $var = $value;
}

// Report no PHP errors (to be safe we include this very early)
defaults($error_reporting, 0); error_reporting($error_reporting);

// if $alertfile exists the contents will be included()/shown (use HTML!)
defaults($alertfile, 'netstat.txt');

// checks (use pipes (|) with care ;)
// syntax: host or IP to check | port | description
// if $port = 'ping' an ICMP ping will be executed
// if $port = 'headline' $host is printed as a headline
defaults($checks, array(

'Examples testing localhost |headline',
'localhost | ping| ICMP ping (ping)',
'localhost | 80 | WWW server (port 80)',
'127.0.0.2 | 443 | WWW server (SSL, port 443)',
'127.0.0.1 | 22 | SSH server (port 22)',
'[::1] | 22 | SSH server IPv6 (port 22)',
'127.0.0.3 | 21 | FTP server (port 21)',
'-------------------------------------------------',
'Some more examples with errors or not :)|headline',
'www.unknown.example.com| 80|www.unknown.example.com',
'example.com| 23|example.com:23 (telnet is dead)',
'Empty and negative ports are ignored||',
'So are lines without pipe delimiter',
'www.google.com | 80 | WWW server @ google.com',
'localhost |-ping| Disabled ping',
'www.example.com | -80 | WWW server @ www.example.com',

));

// exec commands for ping: -l3 (preload) is recommended but
//defaults($ping_command, 'ping -l3 -c3 -w1 -q'); // might not work everywhere
defaults($ping_command, 'ping -c3 -w1 -q');
defaults($ping6_command, 'ping6 -c3 -w1 -q');

// fsockopen timeout; might need adjustment depending on network
defaults($timeout, 4);

// show a very simple progress indicator (requires Javascript)
// may be disabled also by adding '?noprogress' to the script's URL
defaults($progressindicator, true);

// diagnostics and errors are added by default as title attributes
// they are shown by browsers in tooltips upon mouse over
// with ?showdiagnostics, ?diags or $showdiagnostics=true diagnostics
// will be shown in their own table rows
defaults($showdiagnostics, false);

// output buffering can be a PITA (see below), in some cases it can help
// to send "garbage" to get browsers to display the first parts of a page
// (like the title + progress indicator) while the rest is still loading.
// consider $bufferfill="\n";
defaults($bufferfill,'');

// strings for online and offline (by default these are used for CSS, too)
defaults($online, 'Online');
defaults($offline, 'Offline');

// print date and/or time (leave empty to show no timestamp)
defaults($datetime, 'l, F j, Y, H:i:s T');

// RSS alert feed
defaults($rssfeed, true); // enable/disable RSS feed
// URL of RSS feed
defaults($rssfeedurl, '//'.$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME'].'?rss');
// RSS feed title
defaults($rsstitle, "RSS alert feed of $title");
// RSS header e.g. to include in $htmlheader; set to '' to offer no RSS
defaults($rssheader, '");
// RSS alert link (might point e.g. to your network status homepage)
defaults($rsslink, '//'.$_SERVER['HTTP_HOST'].$_SERVER['SCRIPT_NAME'].'?noprogress');
// RSS date and/or time format (here we use a ISO 8601 format)
defaults($rssdatetime, 'o-m-d H:i:s T');

// HTML/page header (_tmp variable just used for readability)
$htmlheader_tmp = <<





$rssheader

\n\n");

// ------------------------------------------------- main part of script

// if RSS feed is requested send $alertfile and quit
if ((isset($_REQUEST['rss']) && ($rssfeed))
|| (isset($argv[1]) && $argv[1] == 'rss'))
{
header("Content-Type: application/rss+xml");
echo "\n";
echo "\n\n";
echo "\n$rsslink\n";
echo "$rsstitle\n";
echo "en\n";
if (file_exists($alertfile) && is_readable($alertfile))
{
echo "\n\n";
echo ''.date("r", filemtime($alertfile))."\n";
echo "$rsslink\n";
echo '#'.date("Ymd\THi", filemtime($alertfile))."\n";
echo '\n\n";
}
echo "\n\n";
exit;
} else if (isset($_REQUEST['rss'])) {
// if RSS was requested even though it was disabled
exit;
}

// output HTML/page header
echo $htmlheader;

// headline, date and time and start of table
echo "

$headline

\n";
if ($datetime) echo '

as of ' . date($datetime) . "

\n";

// show the contents of $alertfile if it is readable and larger than 7 bytes
if (file_exists($alertfile))
{
clearstatcache(true, $alertfile);
if ((is_readable($alertfile) && (filesize($alertfile) > 7)))
{
echo "

\n";
}
}

// show a simple progress indicator
if (isset($_REQUEST['noprogress'])
|| (isset($argv[1]) && $argv[1] == 'noprogress'))
{
$progressindicator = false;
}
if ($progressindicator)
{
echo '\n";
}

// flush output buffers (if any)/send content to browser
// note that this won't work if output is buffered by filters, proxies
// etc. of is gzip'ed; cf. https://stackoverflow.com/q/4191385/196133
// + https://stackoverflow.com/q/3445222/196133
// + https://stackoverflow.com/q/4481235/196133
echo $bufferfill;
@ob_flush(); @flush();

// $showdiagnostics is true w/ ?diags, and false with ?diags=off
if (isset($_GET['showdiagnostics']) || isset($_GET['diags']))
{
if ($_GET['showdiagnostics'] == 'off' || $_GET['diags'] == 'off')
{
$showdiagnostics = false;
} else {
$showdiagnostics = true;
}
}

echo "

// main loop of checks
foreach ($checks as $check)
{
$status = $offline; // default state
$diagnostics = ''; // mouse-over for tooltips
$output = true; // print a line or print no line
list($host,$port,$description) = explode('|',"$check||"); // the 2 extra '|'s are to avoid notices about undefined offsets
$host = trim($host);
$port = trim($port);

switch ($port)
{
case '': // ignore lines with empty or no "ports", and ignore ...
case (substr($port,0,1)=='-'): // negative ports, '-ping', and
// any "port" starting with '-' is considered a disabled check
$output = false; break;
case 'headline': // print a headline within the status table
// we enclose it with invisible
== == for nicer text output
echo '

\n";
$output = false; break;
case 'ping': // do an ICMP ping
$ping=exec("$ping_command $host",$pingoutput,$pingreturn);
// Continues on into ping6 as they share all but the command.
case 'ping6': // do an ICMP IPv6 ping
if (!isset($ping))
{
$ping=exec("$ping6_command $host",$pingoutput,$pingreturn);
}
if(strlen($ping)>10)
{
// strlen($ping)>10 works around a bug in Debian ping (", pipe 3")
// https://bugs.debian.org/456192
$status = $online; $diagnostics = "$ping :: $pingreturn";
}
else $diagnostics = "$ping :: $pingreturn";
// uncomment this if you want the full output as HTML comment
//echo "\n\n";
//unset($pingoutput);
// *nix ping command's return value meanings:
// 0: all OK; 1: an error occured; 2: host unknown
unset($ping);
break;
default: // look if a TCP connection to port can be opened
$time_start = microtime(true);
$fp = @fsockopen($host, $port, $errno, $errstr, $timeout);
$time_end = microtime(true);
$time = number_format(($time_end - $time_start)*1000,1);

if ($fp)
{
// fsockopen worked, service is online
$status = $online;
$diagnostics = "$time ms";
fclose($fp);
}
else if ($errno<0) { $diagnostics = "errno=$errno; Host unknown?"; } else { $diagnostics = $errstr; } } // output results if ($output) { $diagnostics = htmlspecialchars($diagnostics); if ($showdiagnostics && $diagnostics) { if ($status == $online && ($port != 'ping' && $port != 'ping6')) { echo "

\n";
} else {
echo "

\n";
echo "

\n";
}
} else {
echo "

\n";
}
}

// flush output buffers (if any)/send content to browser
@ob_flush(); @flush();
}

echo "

\n";

// make progress indicator disappear by means of Javascript
if ($progressindicator) {
echo << progressindicator = document.getElementById("progress"); progressindicator.innerHTML = "Checks finished"; progressindicator.style.visibility = 'hidden';
EOT;
}

// output $version and HTML/page footer
if (!empty($version)) echo "

$version

\n";
echo "$htmlfooter\n";

/*
* License
*
* This script is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This script is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this script; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA