<?php
/*
	Copyright (C) 2014 Deciso B.V.
	Copyright (C) 2009 Jim Pingle (jpingle@gmail.com)
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions are met:

	1. Redistributions of source code must retain the above copyright notice,
	this list of conditions and the following disclaimer.

	2. Redistributions in binary form must reproduce the above copyright
	notice, this list of conditions and the following disclaimer in the
	documentation and/or other materials provided with the distribution.

	THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
	INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
	AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
	OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	POSSIBILITY OF SUCH DAMAGE.
*/

$pgtitle = array(gettext("Diagnostics"),gettext("DNS Lookup"));
require("guiconfig.inc");

$host = trim($_REQUEST['host'], " \t\n\r\0\x0B[];\"'");
$host_esc = escapeshellarg($host);

if (is_array($config['aliases']['alias'])) {
	$a_aliases = &$config['aliases']['alias'];
} else {
	$a_aliases = array();
}
$aliasname = str_replace(array(".","-"), "_", $host);
$alias_exists = false;
$counter=0;
foreach($a_aliases as $a) {
	if($a['name'] == $aliasname) {
		$alias_exists = true;
		$id=$counter;
	}
	$counter++;
}

if(isset($_POST['create_alias']) && (is_hostname($host) || is_ipaddr($host))) {
	if($_POST['override'])
		$override = true;
	$resolved = gethostbyname($host);
	$type = "hostname";
	if($resolved) {
		$resolved = array();
		exec("/usr/bin/drill {$host_esc} A | /usr/bin/grep {$host_esc} | /usr/bin/grep -v ';' | /usr/bin/awk '{ print $5 }'", $resolved);
		$isfirst = true;
		foreach($resolved as $re) {
			if($re <> "") {
				if(!$isfirst)
					$addresses .= " ";
				$addresses .= rtrim($re) . "/32";
				$isfirst = false;
			}
		}
		$newalias = array();
		if($override)
			$alias_exists = false;
		if($alias_exists == false) {
			$newalias['name'] = $aliasname;
			$newalias['type'] = "network";
			$newalias['address'] = $addresses;
			$newalias['descr'] = "Created from Diagnostics-> DNS Lookup";
			if($override)
				$a_aliases[$id] = $newalias;
			else
				$a_aliases[] = $newalias;
			write_config();
			$createdalias = true;
		}
	}
}

if ($_POST) {
	unset($input_errors);

	$reqdfields = explode(" ", "host");
	$reqdfieldsn = explode(",", "Host");

	do_input_validation($_POST, $reqdfields, $reqdfieldsn, $input_errors);

	if (!is_hostname($host) && !is_ipaddr($host)) {
		$input_errors[] = gettext("Host must be a valid hostname or IP address.");
	} else {
		// Test resolution speed of each DNS server.
		$dns_speeds = array();
		$dns_servers = array();
		exec("/usr/bin/grep nameserver /etc/resolv.conf | /usr/bin/cut -f2 -d' '", $dns_servers);
		foreach ($dns_servers as $dns_server) {
			$query_time = exec("/usr/bin/drill {$host_esc} " . escapeshellarg("@" . trim($dns_server)) . " | /usr/bin/grep Query | /usr/bin/cut -d':' -f2");
			if($query_time == "")
				$query_time = gettext("No response");
			$new_qt = array();
			$new_qt['dns_server'] = $dns_server;
			$new_qt['query_time'] = $query_time;
			$dns_speeds[] = $new_qt;
			unset($new_qt);
		}
	}

	$type = "unknown";
	$resolved = "";
	$ipaddr = "";
	$hostname = "";
	if (!$input_errors) {
		if (is_ipaddr($host)) {
			$type = "ip";
			$resolved = gethostbyaddr($host);
			$ipaddr = $host;
			if ($host != $resolved)
				$hostname = $resolved;
		} elseif (is_hostname($host)) {
			$type = "hostname";
			$resolved = gethostbyname($host);
			if($resolved) {
				$resolved = array();
				exec("/usr/bin/drill {$host_esc} A | /usr/bin/grep {$host_esc} | /usr/bin/grep -v ';' | /usr/bin/awk '{ print $5 }'", $resolved);
			}
			$hostname = $host;
			if ($host != $resolved)
				$ipaddr = $resolved[0];
		}

		if ($host == $resolved) {
			$resolved = gettext("No record found");
		}
	}
}

if( ($_POST['host']) && ($_POST['dialog_output']) ) {
	display_host_results ($host,$resolved,$dns_speeds);
	exit;
}

function display_host_results ($address,$hostname,$dns_speeds) {
	$map_lengths = function($element) { return strlen($element[0]); };

	echo gettext("IP Address") . ": {$address} \n";
	echo gettext("Host Name") . ": {$hostname} \n";
	echo "\n";
	$text_table = array();
	$text_table[] = array(gettext("Server"), gettext("Query Time"));
	if (is_array($dns_speeds)) {
		foreach ($dns_speeds as $qt) {
			$text_table[] = array(trim($qt['dns_server']), trim($qt['query_time']));
		}
	}
	$col0_padlength = max(array_map($map_lengths, $text_table)) + 4;
	foreach ($text_table as $text_row) {
		echo str_pad($text_row[0], $col0_padlength) . $text_row[1] . "\n";
	}
}

include("head.inc"); ?>
<body>
<?php include("fbegin.inc"); ?>

<section class="page-content-main">
	<div class="container-fluid">
		<div class="row">

		    <form action="<?=$_SERVER['REQUEST_URI'];?>" method="post" name="iform" id="iform">
			<section class="col-xs-12">
                <div class="content-box">

					<?php if ($input_errors) print_input_errors($input_errors); ?>

                    <header class="content-box-head container-fluid">
				        <h3><?=gettext("Resolve DNS hostname or IP");?></h3>
				    </header>

				    <div class="content-box-main">
				    <div class="table-responsive">
				        <table class="table table-striped">
					        <tbody>
					        <tr>
					          <td><?=gettext("Hostname or IP");?></td>
					          <td><?=$mandfldhtml;?><input name="host" type="text" class="form-control" id="host" size="20" value="<?=htmlspecialchars($host);?>" /></td>
					          <?php if ($resolved && $type): ?>
					          <td>
						      <?php
										$found = 0;
										if(is_array($resolved)) {
											foreach($resolved as $hostitem) {
												if($hostitem <> "") {
													echo $hostitem . "<br />";
													$found++;
												}
											}
										} else {
											echo $resolved;
										}
									  ?>
					          </td>
					          <td>
						      <? if($found > 0): ?>
									  <?PHP	if($alias_exists): ?>
										An alias already exists for the hostname <?= htmlspecialchars($host) ?>. <br />
										<input type="hidden" name="override" value="true"/>
										<input type="submit" class="btn btn-default" name="create_alias" value="Overwrite Alias"/>
									  <?php else: ?>
									  <?php if(!$createdalias): ?>
										<input type="submit" class="btn btn-default" name="create_alias" value="Create Alias"/>
									  <?php else: ?>
									   Alias created with name <?= htmlspecialchars($newalias['name']) ?>
									  <? endif; endif; endif; ?>
									  </td>
					          <? else: ?>
					          <td></td><td></td>
					          <? endif; ?>
					        </tr>
					        <?php if (!empty($_POST)): ?>
					        <tr>
					          <td><?=gettext("Resolution time per server");?></td>
					          <td colspan="3">

					            <table class="table table-striped">
						            <tr>
						            <th><?=gettext("Server");?></th>
						            <th><?=gettext("Query time");?></th>
						            </tr>
						            <?php if(is_array($dns_speeds)): foreach($dns_speeds as $qt): ?>
											<tr>
												<td>
													<?=$qt['dns_server']?>
												</td>
												<td>
													<?=$qt['query_time']?>
												</td>
											</tr>
											<?php endforeach; endif; ?>
					            </table>
					          </td>
					        </tr>
					        <?php endif; ?>
					        <?php if (!$input_errors && $ipaddr): ?>
					        <tr>
					          <td><?=gettext("More Information:");?></td>
					          <td colspan="3"><a href ="/diag_ping.php?host=<?=htmlspecialchars($host)?>&amp;interface=wan&amp;count=3"><?=gettext("Ping");?></a> <br />
											<a href ="/diag_traceroute.php?host=<?=htmlspecialchars($host)?>&amp;ttl=18"><?=gettext("Traceroute");?></a>
											<p>
											<?=gettext("NOTE: The following links are to external services, so their reliability cannot be guaranteed.");?><br /><br />
											<a target="_blank" href="http://private.dnsstuff.com/tools/whois.ch?ip=<?php echo $ipaddr; ?>"><?=gettext("IP WHOIS @ DNS Stuff");?></a><br />
											<a target="_blank" href="http://private.dnsstuff.com/tools/ipall.ch?ip=<?php echo $ipaddr; ?>"><?=gettext("IP Info @ DNS Stuff");?></a>
											</p>
										</td>
					        </tr>
					        <?php endif; ?>
					        </tbody>
					    </table>
				    </div>
				    <div class="container-fluid">

				    <input type="submit" class="btn btn-primary btn-fixed pull-right" value="<?=gettext("DNS Lookup");?>" />
				    </div>
				    </div>

				</div>
			</section>

		</div>

	</div>
</section>
