[phpmix-cvs] drupal/modules/smtp_checker INSTALL.txt, NONE, 1.1 LICENSE.txt, NONE, 1.1 README.txt, NONE, 1.1 smtp_checker.module, NONE, 1.1

[<php...@li...>]

Update of /cvsroot/phpmix/drupal/modules/smtp_checker
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv6821/smtp_checker

Added Files:
	INSTALL.txt LICENSE.txt README.txt smtp_checker.module 
Log Message:
Initial import.

--- NEW FILE: INSTALL.txt ---
$Id: INSTALL.txt,v 1.1 2006/06/03 16:12:33 markus_petrux Exp $
********************************************************************
                    D R U P A L    M O D U L E                     
********************************************************************
Name  : smtp_checker
Author: markus_petrux  [ http://www.phpmix.org ]
Drupal: 4.7

********************************************************************
INSTALLATION:

1. Create the folder 'modules/smtp_checker'

2. Copy all modules files, keeping directory structure, to the
   folder 'modules/smtp_checker'

3. Enable the smtp_checker module in 'admin/modules'

4. Forms fields to check using this module can be specified at:
   admin/settings/smtp_checker

5. You're done.

********************************************************************
Please, see the file README.txt for further information.
--- NEW FILE: LICENSE.txt ---
		    GNU GENERAL PUBLIC LICENSE
		       Version 2, June 1991

 Copyright (C) 1989, 1991 Free Software Foundation, Inc.
 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

			    Preamble

  The licenses for most software are designed to take away your
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Public License instead of this License.

--- NEW FILE: smtp_checker.module ---
<?php
// $Id: smtp_checker.module,v 1.1 2006/06/03 16:12:33 markus_petrux Exp $

/**
 * @file
 * Enable validation of e-mail addresses by checking the SMTP server.
 */

/**
 * Some external URLs used as reference in this module
 */
define(SMTP_CHECKER_DRUPAL_FORM_API_DOCS, 'http://drupal.org/node/33338');
define(SMTP_CHECKER_RFC2821, 'http://www.faqs.org/rfcs/rfc2821');

/**
 * Implementation of hook_perm().
 */
function smtp_checker_perm() {
  return array('use smtp checker assistant');
}

/**
 * Implementation of hook_help().
 */
function smtp_checker_help($section) {
  switch ($section) {
    case 'admin/help#smtp_checker':
      $output = t('<p>The <strong>SMTP Checker</strong> module allows you to enable validation of e-mail addresses supplied by the user through any form, that uses the standard <a href="%form-api" target="_blank">drupal Form API</a>, by checking the related SMTP servers.</p>
<p>The validation process works as follows:
<ul>
<li>The hostname part is extracted from the e-mail address (note: e-mail addresses are expected to be supplied in simple format: username@hostname).</li>
<li>An attempt to obtain the list of mail servers associated with the e-mail address is made. The list is obtained by performing a lookup of the <em>MX records</em> defined for that <em>hostname</em> (note: according to <a href="%rfc2821" target="_blank">RFC 2821</a>, when no mail exchangers are defined, the hostname itself should be used).</li>
<li>For each mail server, a SMTP connection is attempted to perform a mail delivery check to the specified e-mail address (note: no e-mail is sent, only an attempt to do so is made).</li>
<li>If a mail server responds successfully, then the e-mail address is accepted, otherwise it is rejected with an error message.</li>
</ul></p>
<p>For the administrator\'s convenience, failed attempts are <a href="%admin-logs">logged</a> to make it as easy as possible to diagnose any error that might occur during the process.</p>
<p>You can define which forms to apply this validation process using the <a href="%settings">settings panel</a> for this module.</p>
', array('%form-api' => url(SMTP_CHECKER_DRUPAL_FORM_API_DOCS), '%rfc2821' => url(SMTP_CHECKER_RFC2821), '%admin-logs' => url('admin/logs', 'filter=smtp checker'), '%settings' => url('admin/settings/smtp_checker')));
      break;
    case 'admin/settings/smtp_checker':
      $output = t('<p>This panel allows you to specify which form fields you wish to hook in order to validate e-mail addresses <a href="%help">using the <strong>SMTP Checker</strong> module</a>.
For each form you can specify its internal identifier and the fields that you wish to check, using the following format:</p>
<p>&nbsp;&nbsp;&nbsp;&nbsp;form_id:fieldname_list</p>
<p>Where:</p>
<ul>
<li><strong>form_id</strong> is a drupal form identifier. You should be able to find this information by looking at the source code of the page that contains the form and searching for the <em>value</em> of an input element of type <em>hidden</em> and name is <em>edit[form_id]</em>.</li>
<li><strong>fieldname_list</strong> is a comma separated list of field names on the specified form that you wish to check.</li>
</ul>
<p>Note: The validation process performs a special handling for textarea fields, where more than one e-mail address can be specified using a comma separated list (such as in the recipients field of the contact module). For simple text fields, only a single e-mail address is expected.</p>
', array('%help' => url('admin/help/smtp_checker')));
      break;
    case 'admin/modules#description':
      $output = t('Enables validation of e-mail addresses by checking the SMTP server.');
      break;
  }
  return $output;
}

/**
 * Implementation of hook_settings().
 */
function smtp_checker_settings() {
  $form = array(
    'smtp_checker_forminfo' => array(
      '#type' => 'textarea', '#title' => t('Where to apply SMTP validation'),
      '#default_value' => variable_get('smtp_checker_forminfo', ''),
      '#rows' => 10,
      '#description' => t('Please, enter information about each form using separate lines.')
    ),
    'smtp_checker_assistant' => array(
      '#type' => 'radios', '#title' => t('Enable SMTP Checker assistant in forms'),
      '#default_value' => variable_get('smtp_checker_assistant', 0),
      '#options' => array('1' => t('Enabled'), '0' => t('Disabled')),
      '#description' => t('<p>When this option is enabled all Drupal forms
that have input fields of type text or textarea (except those that are critical such as the login form)
will be disabled for normal operation and a special checkbox will be shown next to all text fields.
You can then visit any form and check the fields that are aimed to accept e-mail addresses and that
you wish to protect using the SMTP Checker module.
Next to each checkbox there is a button that you have to press in order to update the module settings.
This is an alternative (and hopefully easier) method to configure the <em>Where to apply SMTP validation</em> option.</p>
<p>By default, this assistant is enabled to site administrators only.
However, from the <a href="%access-control">access control panel</a>, you can grant the <em>"%use-assistant"</em> permission to any user role, if the need arises.
In that way, you can visit a from as (say) a guest, and be able to see fields that are otherwise hidden, so you can activate the SMTP checker module for them.
An example of this possible scenario is the comment form. Here, anonymous users may be requested to enter their e-mail address.
That is, if you need to use the assistant to activate the SMTP checker module for fields that are only available to non-administrators,
you need to grant the <em>"%use-assistant"</em> permission for them.</p>
<p><strong>IMPORTANT:</strong> Remeber that, in order to restore forms to normal operation,
you need to disable the assitant as soon as you get ready setting up the SMTP checker module.</p>',
array('%access-control' => url('admin/access'), '%use-assistant' => t('use smtp checker assistant')))
    )
  );
  return $form;
}

/**
 * Extract references to form fields of the specified types.
 *
 * @param $form
 *   A $form array (note it is passed by reference).
 * @param $field_types
 *   An array of field types, such as array('textfield','textarea'), the default.
 * @param $field_prefix
 *   Used when the function is called recursivelly.
 * @return
 *   An array of references to form fields of the specified types.
 */
function _smtp_checker_extract_fields(&$form, $field_types = array('textfield','textarea'), $field_prefix = '') {
  $result = array();
  if (is_array($form)) {
    foreach ($form as $field_name => $field_data) {
      if ($field_name[0] != '#' && is_array($field_data)) {
        if (isset($field_data['#type']) && in_array($field_data['#type'], $field_types)) {
          $result[$field_prefix . $field_name] = &$form[$field_name];
        }
        else {
          $tmp = _smtp_checker_extract_fields($form[$field_name], $field_types, $field_prefix . $field_name .'/');
          if (is_array($tmp)) {
            $result = array_merge($result, $tmp);
          }
        }
      }
    }
  }
  return $result;
}

/**
 * Implement form_alter hook.
 */
function smtp_checker_form_alter($form_id, &$form) {
  static $forminfo = FALSE;

  // Extract forms/fields where we should check e-mail addresses.
  if (!$forminfo) {
    $tmp_string = variable_get('smtp_checker_forminfo', '');
    $tmp_array = preg_split("/\r?\n|\r/", $tmp_string);
    $forminfo = array();
    for ($i=0; $i<count($tmp_array); $i++) {
      $formline = explode(':', $tmp_array[$i]);
      if (count($formline) >= 2) {
        $formline[1] = explode(',', $formline[1]);
        array_map('trim', $formline[1]);
        $forminfo[$formline[0]] = $formline[1];
      }
    }
    unset($tmp_string, $tmp_array, $formline);
  }

  // Check to see if we have to display the assistant.
  $show_assistant = FALSE;
  if (variable_get('smtp_checker_assistant', 0) && user_access('use smtp checker assistant') && $_GET['q'] != 'admin/settings/smtp_checker') {
    // This is a quick hack to ignore certain forms. That is, there are some forms that
    // we know there are no mail related fields.
    // This is specially important for the search_box, but there may be more.
    $ignored_forms = array('search_box','user_login');
    if (!preg_match('#('. implode('|', $ignored_forms) .')#i', $form_id)) {
      // Now, extract references to form fields of type textfield/textarea
      $form_fields = _smtp_checker_extract_fields($form);
      // Is there any field of type textfield/textarea here?
      if (count($form_fields)) {
        // Ok, let's activate the assistant for this form.
        $show_assistant = TRUE;
      }
    }
  }

  // Should we display the assistant for this form?
  if ($show_assistant) {
    // Save a copy of the current form, unaltered.
    global $smtp_checker_form;
    $smtp_checker_form = $form;
    // Alter the form to add our checkboxes.
    form_set_error('', t('<p>This form has been temporarily disabled!</p>'));
    $smtp_checkbox_count = 0;
    foreach ($form_fields as $field_name => $field_data) {
      $checkbox_name = 'smtp-checker-'. $smtp_checkbox_count++;
      $checkbox_form = theme('checkbox', array(
        '#title' => '<span class="marker">'. t('SMTP Check field: %title', array('%title' => $form_fields[$field_name]['#title'])) .'</span>',
        '#name' => $checkbox_name,
        '#id' => $checkbox_name,
        '#return_value' => 1, '#value' => (isset($forminfo[$form_id]) && in_array($field_name, $forminfo[$form_id]) ? 1 : 0)
      ));
      $checkbox_form .= theme('submit', array(
        '#name' => $checkbox_name .'-button',
        '#button_type' => 'submit',
        '#attributes' => array('class' => 'form-submit'),
        '#value' => t('Update SMTP Checker settings')
      ));
      $form_fields[$field_name]['#prefix'] = $checkbox_form . $form_fields[$field_name]['#prefix'];
      $form_fields[$field_name]['#validate']['smtp_checker_form_disabled'] = array('form_id' => $form_id);
    }
  }
  else {
    // ok, this is 'normal' operation, is this form one of our targets?
    if( isset($forminfo[$form_id]) ) {
      // Extract references to form fields of type textfield/textarea
      $form_fields = _smtp_checker_extract_fields($form);
      // Perform the check if there are possible target fields only.
      if (count($form_fields)) {
        // Find the specified fields in this form.
        foreach ($forminfo[$form_id] as $field_name) {
          // Does the specified field exist in this form?
          if (isset($form_fields[$field_name])) {
            // Since they seem to wish to check for valid e-mail addresses
            // we should make sure the field is actually required.
            $form_fields[$field_name]['#required'] = TRUE;
            // Inject our validation routine
            if (!isset($form_fields[$field_name]['#validate'])) {
              $form_fields[$field_name]['#validate'] = array();
            }
            $form_fields[$field_name]['#validate']['smtp_checker_form_validate'] = array('fieldname' => $field_name);
          }
        }
      }
    }
  }
}

/**
 * This handler is called when the assistant has been enabled.
 * We will deal here with any options specified by the user.
 * The user will be redirected to the same path and no other changes will take effect.
 * The form has been temporarily disabled.
 */
function smtp_checker_form_disabled($element, $form_id) {
  // Validate form_id
  global $smtp_checker_form;
  $form = $smtp_checker_form;
  if ($form_id == $form['form_id']) {
    form_set_error('', t('Internal error while checking form_id!'));
    return;
  }

  // Extract list of checked fields in current form
  $form_fields = _smtp_checker_extract_fields($form);
  $smtp_checkbox_count = 0;
  $smtp_fields = array();
  foreach ($form_fields as $field_name => $field_data) {
    $checkbox_name = 'smtp-checker-'. $smtp_checkbox_count++;
    if (isset($_POST[$checkbox_name])) {
      $smtp_fields[$field_name] = $field_data['#title'];
    }
  }

  // Update SMTP Checker settings accordingly
  $tmp_string = variable_get('smtp_checker_forminfo', '');
  $tmp_array = preg_split("/\r?\n|\r/", $tmp_string);
  $forminfo = array();
  if (count($smtp_fields) > 0) {
    $forminfo[] = $form_id .':'. implode(',', array_keys($smtp_fields));
  }
  for ($i=0; $i<count($tmp_array); $i++) {
    $formline = explode(':', $tmp_array[$i]);
    if (count($formline) >= 2) {
      if ($form_id != $formline[0]) {
        $forminfo[] = $formline[0] .':'. $formline[1];
      }
    }
  }
  variable_set('smtp_checker_forminfo', implode("\n", $forminfo));

  // Void the real form!
  drupal_get_messages();
  drupal_goto($_GET['q']);
}

/**
 * Form callback used to invoke the real validation functions
 *
 * Note we perform a special handling for textarea fields
 * where more than one e-mail address can be specified
 * using a comma separated list.
 */
function smtp_checker_form_validate($element, $field_name) {
  if ($element['#type'] == 'textarea') {
    $email_addresses = explode(',', $element['#value']);
    array_map('trim', $email_addresses);
  }
  else {
    $email_addresses = array($element['#value']);
  }

  foreach($email_addresses as $email) {
    if (!_smtp_checker_validate($email)) {
      form_set_error($field_name, t('The e-mail address %mail is not valid, it was rejected by the mail server or the mail server failed to respond successfully. Please, check your input, verify that your e-mail address is active or try it again later.', array('%mail' => theme('placeholder', $email))));
    }
  }
}

/**
 * Validate an e-mail address by checking the SMTP server, obtained from the related MX host(s)
 */
function _smtp_checker_validate($email) {
  if (!ini_get('safe_mode')) {
    set_time_limit(60);
  }

  // Separate hostname from e-mail address
  list($username, $hostname) = explode('@', $email);

  if (empty($username) || empty($hostname)) {
    $message = t('e-mail: %e-mail | invalid e-mail address format specified', array('%e-mail' => $email));
    watchdog('smtp checker', $message);
    return FALSE;
  }

  // Try to find all MX records defined for the specified hostname
  $mxhosts = array();
  $weights = array();

  // We'll be using a different method depending on the Operating System we're running under
  $is_win = @preg_match("/Microsoft|Win32|IIS|WebSTAR|Xitami/", getenv('SERVER_SOFTWARE'));

  if ($is_win) {

    // Note this method won't work when safe_mode is on!
    // @TODO: There is an alternative method here:
    // http://www.php.net/manual/en/function.getmxrr.php#49290

    if (!ini_get('safe_mode')) {
      @exec("nslookup -type=mx $hostname", $output);
      foreach ($output as $line) {
        if (preg_match("#^.*MX preference = (\d{1,10}), mail exchanger = (.*)$#i", $line, $match)) {
          $weights[] = $match[1];
          $mxhosts[] = $match[2];
        }
      }
    }
  }
  else {

    // a) First check for an MX record, but if it fails we still want
    //    to try getmxrr() it if we can find ANY other DNS record.
    // b) If we found a DNS record then we'll attempt to get all
    //    MX records using http://www.php.net/getmxrr

    if (checkdnsrr($hostname, 'MX') || checkdnsrr($hostname, 'ANY')) {
      getmxrr($hostname, $mxhosts, $weights);
    }
  }

  // NOTE: according to RFC 2821 http://www.faqs.org/rfcs/rfc2821
  // when no mail exchangers are listed, hostname itself should be used
  if (count($mxhosts) <= 0) {
    $mxhosts[] = $hostname;
  }
  else {
    // Sort found MX hosts in order of lowest weight first, in addition
    // elements with the same weight are sorted in alphabetic order
    array_multisort($weights, $mxhosts);
  }

  // Test mail delivery against all MX host until one succeeds
  foreach ($mxhosts as $mxhost) {
    if (_smtp_checker_validate_mailbox($email, $mxhost)) {
      return TRUE;
    }
  }
  return FALSE;
}

/**
 * Test mail delivery through the specified SMTP host
 */
function _smtp_checker_validate_mailbox($email, $hostname)
{
  // @TODO: Some of these values could probably be defined somewhere else (maybe by the user)
  $server_name = $_SERVER['SERVER_NAME'];
  $sendmail_from = @ini_get('sendmail_from');
  $smtp_port = 25;
  $fsock_timeout = 15;

  // Attempt to prevent fsockopen to try out an invalid host.
  if (!is_array(gethostbynamel($hostname))) {
    $message = t('e-mail: %e-mail | DNS lookup failed', array('%e-mail' => $email));
    watchdog('smtp checker', $message);
    return FALSE;
  }

  if (!($fp = @fsockopen($hostname, $smtp_port, $errno, $errmsg, $fsock_timeout))) {
    if (!is_numeric($errno)) {
      $errno = '(?)';
    }
    if (empty($errmsg)) {
      $errmsg = ( !is_resource($fp) ? t('fsockopen returned an invalid resource') : t('(null)') );
    }
    $message = t('e-mail: %e-mail | fsockopen failed to connect | Error #%errno "%message"',
      array('%e-mail' => $email, '%errno' => $errno, '%message' => $errmsg));
    watchdog('smtp checker', $message);
    return FALSE;
  }

  usleep(888);
  $out = fgetss($fp, 1024);

  if (!ereg('^220', $out)) {
    @fclose($fp);
    $message = t('e-mail: %e-mail | Invalid fsockopen response "%message"',
      array('%e-mail' => $email, '%message' => $out));
    watchdog('smtp checker', $message);
    return FALSE;
  }

  fputs($fp, "HELO {$server_name}\r\n");
  while (ereg('^220', $out)) {
    $out = fgetss($fp, 1024);
  }
  fputs($fp, "VRFY <{$email}>\r\n");
  $verify = fgetss($fp, 1024);
  fputs($fp, "MAIL FROM: <{$sendmail_from}>\r\n");
  $From = fgetss($fp, 1024);
  fputs($fp, "RCPT TO: <{$email}>\r\n");
  $To = fgetss($fp, 1024);

  fputs($fp, "QUIT\r\n");
  fclose($fp);

  if (ereg('^250', $From) && ereg('^250', $To) && !ereg('^550', $verify)) {
    return TRUE;
  }

  $message = t('e-mail: %e-mail | VRFY: %verify | MAIL FROM: %from | RCPT TO: %to',
    array('%e-mail' => $email, '%verify' => $verify, '%from' => $From, '%to' => str_replace('-"', ' ', $To)));
  watchdog('smtp checker', $message);
  return FALSE;
}

--- NEW FILE: README.txt ---
$Id: README.txt,v 1.1 2006/06/03 16:12:33 markus_petrux Exp $
********************************************************************
                    D R U P A L    M O D U L E                     
********************************************************************
Name  : smtp_checker
Author: markus_petrux  [ http://www.phpmix.org ]
Drupal: 4.7

********************************************************************
DESCRIPTION:

The SMTP Checker module allows you to enable validation of email
addresses supplied by the user through any form, that uses the
standard drupal Form API (see [1]), by checking the related SMTP
servers.

The validation process works as follows:

* The hostname part is extracted from the email address (note: email
  addresses are expected to be supplied in simple format:
  username@hostname).
* An attempt to obtain the list of mail servers associated with the
  email address is made. The list is obtained by performing a lookup
  of the MX records defined for that hostname (note: according to
  RFC 2821, see [2], when no mail exchangers are defined, the
  hostname itself should be used).
* For each mail server, a SMTP connection is attempted to perform a
  mail delivery check to the specified email address (note: no email
  is sent, only an attempt to do so is made).
* If a mail server responds successfully, then the email address is
  accepted, otherwise it is rejected with an error message.

For the administrator's convenience, failed attempts are logged to
make it as easy as possible to diagnose any error that might occur
during the process.

You can define which forms to apply this validation process using
the settings panel for this module (admin/settings/smtp_checker).

********************************************************************
REFERENCES:

[1] Drupal Form API:
    http://drupal.org/node/33338

[2] RFC 2821 - Simple Mail Transfer Protocol
    http://www.faqs.org/rfcs/rfc2821

********************************************************************
INSTALLATION:

Please, see the file INSTALL.txt in this directory.

********************************************************************