April 17th, 2006
Perform a Trace Route (tracert) with PHP
This is a handy little code snippet to trace a packet's route from the web server to a remote host. The code uses regualr expressions to validate the IP address of the remote host, and the code also protects against form submission spoofing.
<?php
ini_set('display_errors', 1);
error_reporting(E_ALL ^ E_NOTICE);
// Obtain POST data.
$trace_ip_addr = $_POST['trace_ip_addr']; // input
// Remove any slashes if Magic Quotes GPC is enabled.
if (get_magic_quotes_gpc())
{
$trace_ip_addr = stripslashes($trace_ip_addr);
}
if ($_POST['submit'] == 'Trace') // Form has been submitted.
{
echo '<div class="output">' . "\n";
if (strlen($trace_ip_addr) <= 15)
{
// use regular expression to check for valid IP adress
if (ereg('^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$', $trace_ip_addr))
{
// Display result.
echo '<pre>' . "\n" .
'traceroute ' . $trace_ip_addr . "\n\n";
system('traceroute ' . $trace_ip_addr); // Trace IP address.
echo '</pre>' . "\n" .
'<p>Trace complete.</p>' . "\n";
}
else
{
// regular expression determined invalid IP adress
echo '<p>Please enter a valid IP address.</p>' . "\n";
}
}
else
{
echo '<p>An illegal operation was encountered.</p>' . "\n";
}
echo '</div>' . "\n";
}
?>
<html>
<head>
<title>Trace</title>
</head>
<body>
<h1>Trace</h1>
<form method="post">
<p><label for="trace_ip_addr">IP address:</label><br />
<input name="trace_ip_addr" id="trace_ip_addr" type="text" value="<?php echo $_POST['submit'] == 'Trace' ? htmlentities($trace_ip_addr, ENT_QUOTES) : '127.0.0.1'; ?>" size="40" maxlength="15" /></p>
<p><input type="submit" name="submit" value="Trace" /></p>
</form>
<p>Trace may take a while, please be patient.</p>
</body>
</html>
This code is adapted from a snippet I found on DaniWeb
