<?php

/*
    Copyright (C) 2016 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.
*/

require_once("guiconfig.inc");

$resolved = array();
$dns_speeds = array();
if (!empty($_REQUEST['host'])) {
    $host = trim($_REQUEST['host'], " \t\n\r\0\x0B[];\"'");
    $host_esc = escapeshellarg($host);

    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_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");
            }
            $dns_speeds[] = array('dns_server' => $dns_server, 'query_time' => $query_time);
        }
    }

    $ipaddr = "";
    if (count($input_errors) == 0) {
        if (is_ipaddr($host)) {
            $resolved[] = " " . gethostbyaddr($host); // add a space to provide an empty type field
            $ipaddr = $host;
        } elseif (is_hostname($host)) {
            exec("/usr/bin/drill {$host_esc} A | /usr/bin/grep 'IN' | /usr/bin/grep -v ';' | /usr/bin/awk '{ print $4 \" \" $5 }'", $resolved);
            $ipaddr = explode(" ", $resolved[count($resolved)-1])[1];
        }
    }
}

include("head.inc"); ?>
<body>
<?php include("fbegin.inc"); ?>
<section class="page-content-main">
  <div class="container-fluid">
    <div class="row">
      <form method="post" name="iform" id="iform">
        <section class="col-xs-12">
          <div class="content-box">
            <?php if (isset($input_errors) && count($input_errors) > 0) print_input_errors($input_errors); ?>
            <header class="content-box-head container-fluid">
              <h3><?=gettext("Resolve DNS hostname or IP");?></h3>
            </header>
            <div class="table-responsive">
              <table class="table table-striped">
                <tbody>
                  <tr>
                    <td><?=gettext("Hostname or IP");?></td>
                    <td>
                      <input name="host" type="text" value="<?=htmlspecialchars($host);?>" />
                    </td>
                  </tr>
<?php
                  if (count($resolved) > 0):?>
                  <tr>
                    <td><?=gettext("Response");?></td>
                    <td>
                      <table class="table table-striped table-condensed">
                        <tr>
                          <th><?=gettext("Type");?></th>
                          <th><?=gettext("Address");?></th>
                        </tr>
<?php
                        foreach($resolved as $hostitem):?>
                        <tr>
                          <td><?=explode(' ',$hostitem)[0];?></td>
                          <td><?=explode(' ',$hostitem)[1];?></td>
                        </tr>
<?php
                        endforeach;?>
                      </table>
                    </td>
                  </tr>
                  <tr>
                    <td><?=gettext("Resolution time per server");?></td>
                    <td colspan="2">
                      <table class="table table-striped table-condensed">
                        <tr>
                          <th><?=gettext("Server");?></th>
                          <th><?=gettext("Query time");?></th>
                        </tr>

<?php
                        foreach($dns_speeds as $qt): ?>
                        <tr>
                          <td><?=$qt['dns_server']?></td>
                          <td><?=$qt['query_time']?></td>
                        </tr>
<?php
                        endforeach; ?>
                      </table>
                    </td>
                  </tr>
<?php
                  endif;
                  if (!empty($ipaddr)):?>
                  <tr>
                    <td><?=gettext("More Information:");?></td>
                    <td>
                      <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=<?=$ipaddr; ?>"><?=gettext("IP WHOIS @ DNS Stuff");?></a><br />
                      <a target="_blank" href="http://private.dnsstuff.com/tools/ipall.ch?ip=<?=$ipaddr; ?>"><?=gettext("IP Info @ DNS Stuff");?></a>
                      </p>
                    </td>
                  </tr>
<?php
                  endif; ?>
                </tbody>
                <tfoot>
                  <tr>
                    <td></td>
                    <td>
                      <input type="submit" class="btn btn-primary btn-fixed" value="<?=gettext("DNS Lookup");?>" />
                    </td>
                  </tr>
                </tfoot>
              </table>
            </div>
          </div>
        </section>
      </form>
    </div>
  </div>
</section>
<?php include("foot.inc"); ?>
