<?php
// $Id: troll.module,v 1.26.2.8 2008-04-24 05:46:14 jaydub Exp $

/**
 * @file
 * Search users by IP address, banning IP addresses, advanced user
 * searching, blocking user by role, and blacklisting by IP block.
 *
 * @author David Kent Norman
 * @author Aaron Welch
 * @link http://deekayen.net/
 * @link http://advomatic.com/
 */

/**
 * Implementation of hook_init.
 */
function troll_init() {
  if (troll_is_blacklisted()) {
    $alt_page = variable_get('troll_blacklist_alt_page', 0);
    if ($alt_page) {
      switch ($alt_page) {
        case 'blank':
          exit;
          break;
        case '404':
          // drupal_not_found() can make a mess in admin logs with watchdog()
          drupal_set_header('HTTP/1.0 404 Not Found');
          drupal_set_title(t('Page not found'));
          print theme('page', $return);
          exit;
          break;
        case 'redirect':
          header('Location: '. variable_get('troll_blacklist_alt_url', ''));
          exit;
          break;
      }
    }

    $req_mod = variable_get('troll_blacklist_mod_requests', 0);
    if ($req_mod == 'notice_post_drop' && !empty($_POST)) {
      $_POST = array();
      drupal_set_message(t('Your data submission was ignored because you are visiting from a blacklisted location.'));
    }
    else if ($req_mod == 'silent_post_drop') {
      $_POST = array();
    }

    if (variable_get('troll_blacklist_stutter', 0)) {
      sleep(rand(1, 5));
    }
  }

  global $user;

  if ($user->uid) {
    $track = db_fetch_object(db_query("SELECT * FROM {troll_ip_track} WHERE uid = %d AND ip_address = '%s'", $user->uid, $_SERVER['REMOTE_ADDR']));
    if ($track->uid) {
      // record for this IP exists, update accessed timestamp
      db_query("UPDATE {troll_ip_track} SET accessed = %d WHERE uid = %d AND ip_address = '%s'", time(), $user->uid, $_SERVER['REMOTE_ADDR']);
    }
    else {
      // insert new IP record for user
      db_query("INSERT INTO {troll_ip_track} (uid, ip_address, created, accessed) VALUES (%d, '%s', %d, %d)", $user->uid, $_SERVER['REMOTE_ADDR'], time(), time());
    }
  }

  if (variable_get('troll_enable_ip_ban', FALSE)) {
    $ban = db_fetch_object(db_query('SELECT * FROM {troll_ip_ban} WHERE (expires > %d OR expires = 0) AND ip_address = \'%s\'', time(), $_SERVER['REMOTE_ADDR']));
    if ($ban->ip_address) {
      global $base_url;
      watchdog('troll', 'IP Ban: '. $_SERVER['REMOTE_ADDR'], l(t('administer'), 'admin/settings/troll/ip_ban/'), WATCHDOG_NOTICE);
      $troll_ip_ban_redirect = variable_get('troll_ip_ban_redirect', '');
      $page = (empty($troll_ip_ban_redirect) ? drupal_get_path('module', 'troll') .'/blocked.html' : $troll_ip_ban_redirect);
      header('location: '. $base_url .'/'. $page);
      die();
    }
  }
}

/**
 * Implementation of hook_help.
 *
 * @param $section string
 */
function troll_help($section = 'admin/help#legal') {
  switch ($section) {
    case 'admin/settings/troll/ip_ban':
      if (!variable_get('troll_enable_ip_ban', FALSE)) {
        return theme('error', t('IP banning is currently disabled, you can enable it in the !settings page', array('!settings' => l(t('settings'), 'admin/settings/troll/settings'))));
      }
      break;
  }
}

/**
 * Implementation of hook_settings().
 *
 * @return array
 */
function troll_admin_settings() {
  $form['ip_settings'] = array(
    '#type' => 'fieldset',
    '#title' => 'IP Address Banning'
  );
  $form['ip_settings']['troll_enable_ip_ban'] = array(
    '#type' => 'radios',
    '#title' => t('IP Address Banning'),
    '#default_value' => variable_get('troll_enable_ip_ban', 1),
    '#options' => array('1' => t('Enable banning by IP address'), '0' => t('Disable banning by IP address'))
  );
  $form['ip_settings']['troll_ip_ban_redirect'] = array(
    '#type' => 'textfield',
    '#title' => t('IP Ban Relocation Page'),
    '#default_value' => variable_get('troll_ip_ban_redirect', ''),
    '#description' => t("Page for relocating users banned based on their IP address or domain name.  If left blank, users will be redirected to blocked.html in the troll module's directory. Do not use a drupal path here! You will cause a loop since IP banning completely blocks all access to the site! Edit the blocked.html file, or redirect to http://localhost."),
  );

  $roles = user_roles();
  $form['role_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('User Blocking')
  );
  $form['role_settings']['troll_block_role'] = array(
    '#type' => 'select',
    '#title' => t('Troll Block Role'),
    '#default_value' => variable_get('troll_block_role', ''),
    '#options' => $roles,
    '#description' => t('Select the role to set users to when blocking from the troll adminstration screens')
  );

  return system_settings_form($form);
}

/**
 * Implementation of hook_perm().
 */
function troll_perm() {
  return array('administer troll');
}

/**
 * Implementation of hook_menu().
 *
 * @return array
 */
function troll_menu($may_cache) {
  $items = array();

  $access = user_access('administer troll');
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/troll',
      'title' => t('Troll'),
      'description' => t('Manage visitor IP banning.'),
      'callback' => 'troll_search_users',
      'access' => $access,
      'weight' => 0,
    );
    $items[] = array(
      'path' => 'admin/settings/troll/search',
      'title' => t('Search Users'),
      'callback' => 'troll_search_users',
      'type' => MENU_DEFAULT_LOCAL_TASK,
      'access' => $access,
      'weight' => 0
    );
    $items[] = array(
      'path' => 'admin/settings/troll/ip_ban',
      'title' => t('IP Banning'),
      'callback' => 'troll_ip_ban',
      'type' => MENU_LOCAL_TASK,
      'access' => $access,
      'weight' => 1
    );
    $items[] = array(
      'path' => 'admin/settings/troll/ip_blacklist',
      'title' => t('Blacklists'),
      'callback' => 'troll_blacklist',
      'type' => MENU_LOCAL_TASK,
      'access' => $access,
      'weight' => 2
    );
    $items[] = array(
      'path' => 'admin/settings/troll/settings',
      'title' => t('Settings'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('troll_admin_settings'),
      'type' => MENU_LOCAL_TASK,
      'access' => user_access('administer site configuration'), 
      'weight' => 3
    );
    $items[] = array(
      'path' => 'admin/settings/troll/ip_ban/edit',
      'title' => t('IP Ban Form'),
      'callback' => 'drupal_get_form',
      'callback arguments' => 'troll_ip_ban_form',
      'type' => MENU_CALLBACK,
      'access' => $access
    );
  }
  return $items;
}

/**
 *
 * MENU CALLBACKS
 *
**/

/**
 * User IP banning page callback function.
 */
function troll_ip_ban($op = NULL, $iid = NULL) {
  $op   = $_POST['op'] ? $_POST['op'] : $op;
  $edit = $_POST ? $_POST : $edit;

  switch ($op) {
    case 'user':
      $ip = db_fetch_object(db_query('SELECT ip_address FROM {troll_ip_track} WHERE uid = %d ORDER BY accessed DESC', $iid));
      $edit['ip_address'] = $ip->ip_address;
      troll_insert_ip($edit);
      drupal_goto('admin/settings/troll/ip_ban');
      break;
    case t('Ban IP'):
      troll_insert_ip($edit);
      drupal_goto('admin/settings/troll/ip_ban');
      break;
    case t('Update Banned IP'):
      troll_update_ip($edit);
      drupal_goto('admin/settings/troll/ip_ban');
      break;
    case 'delete':
      $output = troll_confirm_delete_ip($iid);
      break;
    case t('Confirm'):
      troll_remove_ip($iid);
      drupal_goto('admin/settings/troll/ip_ban');
      break;
    case t('Cancel'):
      drupal_goto('admin/settings/troll/ip_ban');
      break;
    default:
      $form['banform'] = array(
        '#type' => 'fieldset',
        '#title' => t('Add IP Ban'),
        '#value' => drupal_get_form('troll_ip_ban_form'),
        '#weight' => -1,
        '#collapsible' => true
      );
      $form['ipdisplay'] = array(
        '#type' => 'fieldset',
        '#title' => t('Banned IPs'),
        '#value' => troll_display_ip(),
        '#weight' => 0,
        '#collapsible' => true
      );
      $output = drupal_render($form);
      break;
  }
  return $output;
}

/**
 * Central function to display Blacklists tab and fire
 * off functions for Blacklist-related form submissions
 *
 * @param string $op
 * @param array $edit
 * @return string
 */
function troll_blacklist($op = NULL, $edit = NULL) {
  $op = $_POST['op'] ? $_POST['op'] : $op;

  switch ($op) {
    case t('Update Blacklist Punishments'):
      variable_set('troll_blacklist_mod_requests', $_POST['mod_requests']);
      variable_set('troll_blacklist_stutter', $_POST['stutter']);
      variable_set('troll_blacklist_alt_page', $_POST['alt_page']);
      variable_set('troll_blacklist_alt_url', $_POST['alt_url']);
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    case t('Import List'):
      if (!empty($_POST['truncate_list'])) {
        if (db_query('TRUNCATE TABLE {troll_blacklist}')) {
          drupal_set_message(t('Blacklist table truncated.'));
        }
      }
      if (!empty($_POST['select_list'])) {
        troll_blacklist_import_list($_POST['select_list']);
      }
      if (!empty($_POST['custom_list'])) {
        troll_blacklist_import_url($_POST['custom_list']);
      }
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    case t('Search Blacklisted IPs'):
      return troll_blacklist_search($_POST['ip_address']);
      break;
    case t('Insert Whitelist IPs'):
      troll_whitelist_insert_ips($_POST['whitelist_addr1'], $_POST['whitelist_addr2']);
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    case t('Update Whitelist IPs'):
      troll_whitelist_insert_ips($_POST['whitelist_addr1'], $_POST['whitelist_addr2']);
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    case 'deletewhite':
      $output = troll_confirm_delete_white_block(arg(5), arg(6));
      break;
    case t('Confirm Whitelist Removal'):
      troll_remove_whitelist($_POST['net'], $_POST['bcast']);
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    case 'deleteblack':
      $output = troll_confirm_delete_black_block(arg(5), arg(6));
      break;
    case t('Confirm Blacklist Removal'):
      troll_remove_blacklist($_POST['net'], $_POST['bcast']);
      drupal_goto('admin/settings/troll/ip_blacklist');
      break;
    default:
      $form['blacklist_info'] = array(
        '#type' => 'fieldset',
        '#title' => t('Blacklist Summary'),
        '#value' => troll_blacklist_summary(),
        '#weight' => -4,
        '#collapsible' => true,
        '#collapsed' => false
      );
      $form['blacklist_punishment'] = array(
        '#type' => 'fieldset',
        '#title' => t('Blacklist Visitor Punishment'),
        '#value' => troll_blacklist_punishment(),
        '#weight' => -3,
        '#collapsible' => true,
        '#collapsed' => true
      );
      $form['blacklist_import'] = array(
        '#type' => 'fieldset',
        '#title' => t('Import Blacklist'),
        '#value' => troll_blacklist_import(),
        '#weight' => -2,
        '#collapsible' => true,
        '#collapsed' => true
      );
      $form['search_blacklist'] = array(
        '#type' => 'fieldset',
        '#title' => t('Search Blacklisted IPs'),
        '#value' => troll_blacklist_search_blacklist(),
        '#weight' => 0,
        '#collapsible' => true,
        '#collapsed' => true
      );
      $form['whitelist_form'] = array(
        '#type' => 'fieldset',
        '#title' => t('Whitelist IPs'),
        '#value' => troll_whitelist(),
        '#description' => t('Whitelisted IPs override the blacklist. Does not apply to the IP Ban feature.'),
        '#weight' => 1,
        '#collapsible' => true,
        '#collapsed' => true
      );
      $output = drupal_render($form);
      break;
  }
  return $output;
}

/**
 * Summary of how many IP blocks are filtered
 *
 * @return string
 */
function troll_blacklist_summary() {
  $count = db_result(db_query('SELECT COUNT(net) FROM {troll_blacklist}'));
  return t('%d address blocks filtered.', array('%d' => $count));
}

/**
 * Form builder function
 *
 * @uses troll_blacklist_punishment_form()
 * @return string
 */
function troll_blacklist_punishment() {
  return drupal_get_form('troll_blacklist_punishment_form');
}

/**
 * Gives admins a choice of how to punish blacklisted visitors
 *
 * @return array
 */
function troll_blacklist_punishment_form() {
  $form['stutter'] = array(
    '#type' => 'checkbox',
    '#title' => t('Randomly stutter output'),
    '#default_value' => variable_get('troll_blacklist_stutter', 0),
    '#description' => t('While outputting content, the troll module will cause Drupal to "sleep" for random intervals of 1-5 seconds to delay output.')
  );
  $form['mod_requests'] = array(
    '#type' => 'radios',
    '#title' => t('Page request modification'),
    '#options' => array(t('none'), 'silent_post_drop' => 'Silently drop form post submission data', 'notice_post_drop' => 'Drop form post submission data and give a notice'),
    '#default_value' => variable_get('troll_blacklist_mod_requests', '0'),
    '#description' => t('Modifies data sent by visitors from blacklisted IPs before Drupal even has a chance to process it.')
  );
  $form['alt_page_output'] = array(
    '#type' => 'fieldset',
    '#title' => 'Alternate page output'
  );
  $form['alt_page_output']['alt_page'] = array(
    '#type' => 'radios',
    '#title' => 'Alternate pages',
    '#options' => array(t('none'), 'blank' => t('Blank pages'), '404' => t('404 every page request'), 'redirect' => t('Redirect to alternate URL')),
    '#default_value' => variable_get('troll_blacklist_alt_page', '0'),
    '#description' => t('Sends alternate page output, whether the visitor hits a real URL or not.')
  );
  $form['alt_page_output']['alt_url'] = array(
    '#type' => 'textfield',
    '#title' => t('Redirection URL'),
    '#default_value' => variable_get('troll_blacklist_alt_url', ''),
    '#description' => t('URL to redirect blacklisted visitors to if "Redirect to alternate URL" is selected. Start with the appropriate prefix (e.g. http://)')
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Update Blacklist Punishments'),
    '#weight' => 1
  );
  return $form;
}

/**
 * Form builder function
 *
 * @uses troll_blacklist_import_form()
 * @return string
 */
function troll_blacklist_import() {
  return drupal_get_form('troll_blacklist_import_form');
}

/**
 * Builds form array for admin to select how to import a new blacklist.
 *
 * @return array
 */
function troll_blacklist_import_form() {
  $form['truncate_list'] = array(
    '#type' => 'checkbox',
    '#title' => t('Truncate/delete existing blacklist before import')
    );
  $options = array();
  $options[0] = '';
  if (function_exists('gzopen')) {
    $options['S1gz'] = 'OpenBSD mirror: SPEWS.org Level 1 bzip archive';
    $options['S2gz'] = 'OpenBSD mirror: SPEWS.org Level 2 bzip archive';
    $options['OCgz'] = 'OpenBSD mirror: okean.com China bzip archive';
    $options['OKgz'] = 'OpenBSD mirror: okean.com Korea bzip archive';
  }
  $options['S1tx'] = 'SPEWS.org Level 1 text file';
  $options['S2tx'] = 'SPEWS.org Level 2 text file';
  $options['OTtx'] = 'okean.com China and Korea text file';
  $options['OCtx'] = 'okean.com China text file';
  $options['OKtx'] = 'okean.com Korea text file';
  $form['select_list'] = array(
    '#type' => 'select',
    '#title' => t('Download and import'),
    '#options' => $options,
    '#description' => t('Downloads supported blacklist from the internet. Please select a mirror when possible.'),
    );
  $form['custom_list'] = array(
    '#type' => 'textfield',
    '#title' => t('List URL'),
    '#description' => t('URL of a list to import. List files should have one address per line in Classless Internet Domain Routing CIDR format (x.x.x.x/x). Individual IPs should still have /32.'),
    );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Import List'),
    '#weight' => 1,
  );
  return $form;
}

/**
 * Decyphers what dropdown selection was chosen to send for parsing out IP blocks
 *
 * @see troll_blacklist_import_form()
 * @see troll_blacklist_parse_save()
 * @param array $edit
 */
function troll_blacklist_import_list($list) {
  $files = array('S1gz' => array('gz' => 'http://www.openbsd.org/spamd/spews_list_level1.txt.gz'),
    'S2gz' => array('gz' => 'http://www.openbsd.org/spamd/spews_list_level2.txt.gz'),
    'OCgz' => array('gz' => 'http://www.openbsd.org/spamd/chinacidr.txt.gz'),
    'OKgz' => array('gz' => 'http://www.openbsd.org/spamd/koreacidr.txt.gz'),
    'S1tx' => array('txt' => 'http://www.spews.org/spews_list_level1.txt'),
    'S2tx' => array('txt' => 'http://www.spews.org/spews_list_level2.txt'),
    'OTtx' => array('txt' => 'http://www.okean.com/sinokoreacidr.txt'),
    'OCtx' => array('txt' => 'http://www.okean.com/chinacidr.txt'),
    'OKtx' => array('txt' => 'http://www.okean.com/koreacidr.txt'));

  if (!isset($files[$list])) {
    drupal_set_message(t('Form input not valid'));
    return false;
  }

  $file_type = array_keys($files[$list]);
  troll_blacklist_parse_save($files[$list][$file_type[0]], $file_type[0]);
}

/**
 * Parses a URL to send for parsing out IP blocks
 *
 * @see troll_blacklist_parse_save()
 * @param array $edit
 */
function troll_blacklist_import_url($edit) {
  $url_parts = parse_url($edit['custom_list']);
  $file_parts = pathinfo($url_parts['path']);
  troll_blacklist_parse_save($edit['custom_list'], $file_parts['extension']);
}

/**
 * Parses input file, line by line, searching for IP blocks in CIDR
 * format (x.x.x.x/x). Understands files in text, bzip, and bzip2 format,
 * where the PHP installation supports it. Writes what it finds to the
 * database as long integers.
 *
 * @todo should probably function_exists() the compression file functions
 * @param $file_name string
 * @param $file_type string
 */
function troll_blacklist_parse_save($file_name, $file_type) {
  $netmasks = array(
    0, -2147483648, -1073741824, -536870912, -268435456, -134217728,
    -67108864, -33554432, -16777216, -8388608, -4194304, -2097152, -1048576,
    -524288, -262144, -131072, -65536, -32768, -16384, -8192, -4096, -2048,
    -1024, -512, -256, -128, -64, -32, -16, -8, -4, -2, -1);

  switch ($file_type) {
    case 'gz':
      $fp = gzopen($file_name, 'r');
      break;
    default:
      $fp = fopen($file_name, 'r');
      break;
  }

  if (is_resource($fp)) {
    $i = 0;
    while (!feof($fp)) {
      $buffer = fgets($fp);
      if ($buffer{0} != '#' && ($buffer{0} != '/' && $buffer{1} != '/') && !empty($buffer)) {
        preg_match("/([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})\/([0-9]{1,2})/", $buffer, $matches);
        // $matches array
        // 0 = whole string
        // 1 = i.i.i.i
        // 2 = s
        $longip = ip2long($matches[1]);
        unset($buffer, $matches[0], $matches[1]);

        if ($matches[2] == 32) {
          $net = $bcast = $longip;
        }
        else {
          $net = $longip & $netmasks[$matches[2]];
          $bcast = $longip | ($netmasks[$matches[2]] ^ -1);
        }
        db_query('DELETE FROM {troll_blacklist} WHERE net = %d AND bcast = %d', $net, $bcast);
        db_query('INSERT INTO {troll_blacklist} (net, bcast) VALUES (%d, %d)', $net, $bcast);
        $i++;
      }
    }
    switch ($file_type) {
      case 'gz':
        gzclose($fp);
        break;
      default:
        fclose($fp);
        break;
    }
    drupal_set_message(t('%i IP blocks imported', array('%i' => $i)));
  }
  else {
    drupal_set_message(t('Import failed! File could not be read.'));
  }
}

/**
 * Form builder function
 *
 * @uses troll_blacklist_search_blacklist_form()
 * @return string
 */
function troll_blacklist_search_blacklist() {
  return drupal_get_form('troll_blacklist_search_blacklist_form');
}

/**
 * Form to search blacklist to see if an IP matches
 *
 * @return array
 */
function troll_blacklist_search_blacklist_form() {
  $form['ip_address'] = array(
    '#type' => 'textfield',
    '#title' => t('IP Address'),
    '#size' => 15,
    '#maxlength' => 15,
    '#description' => t('Address to search for in the database of imported IP blocks.'),
    '#required' => TRUE
    );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Search Blacklisted IPs'),
    '#weight' => 1
  );
  return $form;
}

/**
 * Perform search to see if an IP address matches a blacklisted IP block.
 * If no results are found, get redirected to the blacklist management
 * page instead of seeing results.
 *
 * @param $edit array
 * @return string
 */
function troll_blacklist_search($ip_address) {
  $longip = _troll_longip($ip_address);
  $sql = "SELECT net, bcast FROM {troll_blacklist} WHERE net <= %d AND bcast >= %d";

  $headers = array(
    array('data' => t('Network Address'), 'field' => 'net', 'sort' => 'asc'),
    array('data' => t('Broadcast Address'), 'field' => 'bcast'),
    array('data' => t('Actions'), 'field' => 'delete')
  );

  $sql .= tablesort_sql($headers);
  $result = pager_query($sql, 25, 0, NULL, $longip, $longip);
  if (db_num_rows($result) == 0) {
    drupal_set_message(t('No matches found in blacklist search.'));
    drupal_goto('admin/settings/troll/ip_blacklist');
  }
  while ($row = db_fetch_object($result)) {
    $printnet = long2ip($row->net);
    $printbcast = long2ip($row->bcast);
    $action = l(t('remove'), "admin/settings/troll/ip_blacklist/deleteblack/{$row->net}/{$row->bcast}");
    $rows[] = array($printnet, $printbcast, $action);
  }

  $pager = theme('pager', NULL, 25, 0);
  if (!empty($pager)) {
    $rows[] = array(array('data' => $pager, 'colspan' => 3));
  }

  return theme('table', $headers, $rows);
}

/**
 * Form builder function
 *
 * @param $net string Not used, here for later implementation of whitelist editing
 * @param $bcast string Not used, here for later implementation of whitelist editing
 * @uses troll_whitelist_form()
 * @return string
 */
function troll_whitelist($net = NULL, $bcast = NULL) {
  $output = drupal_get_form('troll_whitelist_form', $net, $bcast);
  $sql = 'SELECT net, bcast FROM {troll_whitelist}';

  $headers = array(
    array('data' => t('Start/Network Address'), 'field' => 'net', 'sort' => 'asc'),
    array('data' => t('End/Broadcast Address'), 'field' => 'bcast'),
    array('data' => t('Actions'), 'field' => 'delete')
  );

  $sql .= tablesort_sql($headers);
  $result = pager_query($sql, 25);
  while($row = db_fetch_object($result)) {
    $printnet = long2ip($row->net);
    $printbcast = long2ip($row->bcast);
    $action = l(t('remove'), "admin/settings/troll/ip_blacklist/deletewhite/{$row->net}/{$row->bcast}");
    $rows[] = array($printnet, $printbcast, $action);
  }

  $pager = theme('pager', NULL, 25, 0);
  if (!empty($pager)) {
    $rows[] = array(array('data' => $pager, 'colspan' => 3));
  }

  return $output . theme('table', $headers, $rows);
}

/**
 * Display form for creating new whitelist block and table of current whitelisted IPs
 *
 * @return array
 */
function troll_whitelist_form($net, $bcast) {
  $form['whitelist_addr1'] = array(
    '#type' => 'textfield',
    '#title' => t('Starting IP Address'),
    '#size' => 15,
    '#maxlength' => 15,
    '#default_value' => $net ? long2ip($net) : '',
    '#description' => t('IP or start to range of IPs to whitelist.'),
    '#required' => TRUE
  );
  $form['whitelist_addr2'] = array(
    '#type' => 'textfield',
    '#title' => t('Ending IP Address'),
    '#size' => 15,
    '#maxlength' => 15,
    '#default_value' => $bcast ? long2ip($bcast) : '',
    '#description' => t('End of IP range to whitelist. If whitelisting a single IP, leave this blank.'),
    '#required' => false
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => ($net && $bcast) ? t('Update Whitelist IPs') : t('Insert Whitelist IPs'),
    '#weight' => 1
  );
  $form['#action'] = url('admin/settings/troll/ip_blacklist');

  return $form;
}

/**
 * Insert a new IP block into the whitelist
 *
 * @param array $edit
 */
function troll_whitelist_insert_ips($whitelist_addr1, $whitelist_addr2) {
  $longip1 = _troll_longip($whitelist_addr1);
  $longip2 = _troll_longip(empty($whitelist_addr2) ? $whitelist_addr1 : $whitelist_addr2);
  if ($longip1 > $longip2) {
    $temp = $longip1;
    $longip1 = $longip2;
    $longip2 = $temp;
    unset($temp);
  }
  db_query("REPLACE INTO {troll_whitelist} (net, bcast) VALUES (%d, %d)", $longip1, $longip2);
  drupal_set_message(t('IP range %ip1 to %ip2 whitelisted.', array('%ip1' => long2ip($longip1), '%ip2' => long2ip($longip2))));
}

/**
 * Convert dotted decimal IP to long integer and check for validity
 *
 * @param $ip string
 * @return integer
 */
function _troll_longip($ip) {
  $longip = ip2long($ip);
  if ($longip === false || $longip == -1) {
    drupal_set_message(t('IP %ip not valid!', array('%ip' => $ip)));
    drupal_goto('admin/settings/troll/ip_blacklist');
  }
  return $longip;
}

/**
 * User search page callback function.
 *
 * @param $op array
 * @param $uid
 * @return string
 */
function troll_search_users($op = NULL, $uid = NULL) {
  $form_values = $_POST;

  $output = '';
  switch ($op) {
    case 'view':
      $output = troll_search_user_detail($uid);
      break;
    case 'block':
      troll_block_user($uid);
      drupal_goto('admin/settings/troll/search');
      break;
    default:
      $output = troll_search();
      $output .= troll_list_users($form_values);
      break;
  }
  return $output;
}

/**
 *
 * FORM FUNCTIONS
 *
**/

/**
 * IP banning form.
 *
 * @param $iid int
 * @return array
 */
function troll_ip_ban_form($iid = NULL) {
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => ($iid) ? t('Update Banned IP') : t('Ban IP'),
    '#weight' => 1,
  );

  $ip = db_fetch_object(db_query('SELECT * FROM {troll_ip_ban} WHERE iid = %d', $iid));
  $form['iid'] = array(
    '#type' => 'hidden',
    '#value' => $ip->iid,
  );
  $form['ip_address'] = array(
    '#type' => 'textfield',
    '#title' => t('IP Address'),
    '#default_value' => $ip->ip_address,
    '#description' => t('The IP address to ban.'),
    '#required' => TRUE
  );
  $form['domain_name'] = array(
    '#type' => 'textfield',
    '#title' => t('Domain Name'),
    '#default_value' => ($ip->domain_name ? $ip->domain_name : ($ip->ip_address ? gethostbyaddr($ip->ip_address) : '')),
    '#description' => t('The Domain Name of the IP address to ban - for reference only.')
  );

  $timestamp = ($ip->expires ? $ip->expires : time());

  $date = getdate( gmmktime() );
  $curyear = $date['year'];
  while ($i < 10) {
    $years[$curyear+$i] = $curyear+$i;
    $i++;
  }
  $months = array(1 => t('January'), t('February'), t('March'), t('April'), t('May'), t('June'), t('July'), t('August'), t('September'), t('October'), t('November'), t('December'));
  for ($i = 1; $i <= 31; $i++) {
    $days[$i] = $i;
  }

  $form['timestamp'] = array(
    '#type' => 'fieldset',
    '#title' => t('Expires'),
    '#prefix' => '<div class="container-inline"><div class="day">',
    '#suffix' => '</div></div>',
    '#description' => t('The ban will be removed after this day.')
  );
  $form['timestamp']['expires'] = array(
    '#type' => 'checkbox',
    '#default_value' => ($ip->expires ? TRUE : FALSE)
  );
  $form['timestamp']['month'] = array(
    '#type' => 'select',
    '#default_value' => date('n', $timestamp),
    '#options' => $months
  );
  $form['timestamp']['day'] = array(
    '#type' => 'select',
    '#default_value' => date('j', $timestamp),
    '#options' => $days
  );
  $form['timestamp']['year'] = array(
    '#type' => 'select',
    '#default_value' => date('Y', $timestamp),
    '#options' => $years
  );

  $form['#action'] = url('admin/settings/troll/ip_ban');
  return $form;
}

/**
 * troll_ip_ban form validate callback function.
 *
 * @param $form_id
 * @param $edit array
 */
function troll_ip_ban_validate($form_id, $edit) {
  if (!preg_match('([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})', $edit['ip_address'])) {
    form_set_error('ip_address', t('Please include an valid IP address'));
  }
}

/**
 * IP ban information form.
 */
function troll_display_ip() {

  $sql = 'SELECT iid, ip_address, domain_name, expires, uid FROM {troll_ip_ban}';

  $headers = array(
    array('data' => t('IP Address'), 'field' => 'ip_address'),
    array('data' => t('Domain Name'), 'field' => 'domain_name'),
    array('data' => t('Expires'), 'field' => 'expires', 'sort' => 'desc'),
    array('data' => t('Actions'), 'field' => 'delete')
  );

  $sql .= tablesort_sql($headers);
  $result = pager_query($sql, 25);
  while ($row = db_fetch_object($result)) {
    $thisip = l($row->ip_address, 'admin/settings/troll/ip_ban/edit/'. $row->iid);
    $thisdom = l(($row->domain_name ? $row->domain_name : gethostbyname($row->ip_address)), 'admin/settings/troll/ip_ban/edit/'. $row->iid);
    $expires = ($row->expires ? date('M d, Y', $row->expires) : t('never'));
    $action = l(t('remove'), 'admin/settings/troll/ip_ban/delete/'. $row->iid);
    $rows[] = array($thisip, $thisdom, $expires, $action);
  }

  $pager = theme('pager', NULL, 25, 0);
  if (!empty($pager)) {
    $rows[] = array(array('data' => $pager, 'colspan' => 5));
  }

  return theme('table', $headers, $rows);
}

/**
 * IP ban delete confirmation.
 */
function troll_confirm_delete_ip($iid) {
  return drupal_get_form('troll_confirm_delete_ip_form', $iid);
}

/**
 * IP ban delete confirmation form.
 */
function troll_confirm_delete_ip_form($iid) {
  $ip = db_fetch_object(db_query('SELECT * FROM {troll_ip_ban} WHERE iid = %d', $iid));
  return confirm_form(array(), t('Remove Ban for IP %ip?', array('%ip' => $ip->ip_address)), 'admin/settings/troll/ip_ban'. $edit['field_id'], t('Are you sure you want to remove the ban on this IP?'));
}

/**
 * Confirmation before deleting a blacklist IP block
 *
 * @param integer $net IP in long format
 * @param integer $bcast IP in long format
 * @return string
 */
function troll_confirm_delete_black_block($net, $bcast) {
  $result = db_result(db_query('SELECT COUNT(net) FROM {troll_blacklist} WHERE net = %d AND bcast = %d', $net, $bcast));
  if (empty($result)) {
    drupal_set_message(t('No such IP range found in the database.'));
    drupal_goto('admin/settings/troll/ip_blacklist');
  }
  return drupal_get_form('troll_confirm_delete_black_block_form', $net, $bcast);
}

/**
 * Confirmation form for deleting a blacklist IP block
 *
 * @param integer $net IP in long format
 * @param integer $bcast IP in long format
 */
function troll_confirm_delete_black_block_form($net, $bcast) {
  return confirm_form(array(
    'net' => array(
      '#type' => 'hidden',
      '#value' => $net),
      'bcast' => array(
        '#type' => 'hidden',
        '#value' => $bcast)
      ),
      t('Remove listing for IP block %ip1 to %ip2?', array('%ip1' => long2ip($net), '%ip2' => long2ip($bcast))
    ),
    'admin/settings/troll/ip_blacklist',
    t('Are you sure you want to remove this IP block from the blacklist?'),
    t('Confirm Blacklist Removal')
  );
}

/**
 * Confirmation before deleting a whitelist IP block
 *
 * @param integer $net IP in long format
 * @param integer $bcast IP in long format
 * @return string
 */
function troll_confirm_delete_white_block($net, $bcast) {
  $result = db_result(db_query('SELECT COUNT(net) FROM {troll_whitelist} WHERE net = %d AND bcast = %d', $net, $bcast));
  if (empty($result)) {
    drupal_set_message(t('No such IP range found in the database.'));
    drupal_goto('admin/settings/troll/ip_blacklist');
  }
  return drupal_get_form('troll_confirm_delete_white_block_form', $net, $bcast);
}

/**
 * Confirmation form for deleting a whitelist IP block
 *
 * @param integer $net IP in long format
 * @param integer $bcast IP in long format
 */
function troll_confirm_delete_white_block_form($net, $bcast) {
  return confirm_form(array(
    'net' => array(
      '#type' => 'hidden',
      '#value' => $net),
      'bcast' => array(
        '#type' => 'hidden',
        '#value' => $bcast)
    ),
    t('Remove listing for IP block %ip1 to %ip2?', array('%ip1' => long2ip($net), '%ip2' => long2ip($bcast))),
    'admin/settings/troll/ip_blacklist',
    t('Are you sure you want to remove this IP block from the whitelist?'),
    t('Confirm Whitelist Removal')
  );
}

/**
 * Form builder function
 *
 * @uses troll_search_form()
 * @return sring
 */
function troll_search() {
  return drupal_get_form('troll_search_form');
}

/**
 * User search form.
 *
 * @return array
 */
function troll_search_form() {
  $form['#action'] = url('admin/settings/troll/search');
  $form['#redirect'] = FALSE;
  $form['search'] = array(
    '#type' => 'fieldset',
    '#title' => t('Search Users'),
    '#collapsible' => true
  );
  $form['search']['username'] = array(
    '#type' => 'textfield',
    '#title' => t('Username'),
    '#description' => t('You can use % for wildcard, so to get all usernames with \'A\' in them, use %A%')
  );
  $form['search']['mail'] = array(
    '#type' => 'textfield',
    '#title' => t('Email')
  );
  $form['search']['ip_address'] = array(
    '#type' => 'textfield',
    '#title' => t('IP Address')
  );
  $form['search']['date_created'] = array(
    '#type' => 'textfield',
    '#title' => t('Account Date Created'),
    '#description' => t('Enter date in mm/dd/yyyy format. Returns all users created after the date entered.')
  );
  $form['search']['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Search Users')
  );

  return $form;
}

/**
 * User list form.
 *
 * @param $edit array
 */
function troll_list_users($edit) {

  $where[] = 'u.uid <> 0';

  if (strlen($edit['username']) > 0) {
    $where[] = "LOWER(u.name) LIKE '%%%s%%' ";
    $args[] = drupal_strtolower($edit['username']);
  }
  if (strlen($edit['mail']) > 0) {
    $where[] = "LOWER(u.mail) LIKE '%%%s%%' ";
    $args[] = drupal_strtolower($edit['mail']);
  }
  if (strlen($edit['ip_address']) > 0) {
    $where[] = "LOWER(t.ip_address) LIKE '%%%s%%' ";
    $args[] = drupal_strtolower($edit['ip_address']);
  }
  if (strlen($edit['date_created']) > 0) {
    $where[] = "u.created > %d ";
    $args[] = drupal_strtotime($edit['date_created']);
  }

  $sql = "SELECT u.uid, u.name, u.mail, u.status, t.ip_address, MAX(t.accessed) AS recorded, u.created FROM {users} u LEFT JOIN {troll_ip_track} t ON u.uid = t.uid";

  $sql .= ' WHERE '. implode(' AND ', $where);

  $headers = array(
    array('data' => t('Username'), 'field' => 'u.name'),
    array('data' => t('Email'), 'field' => 'u.mail'),
    array('data' => t('Status'), 'field' => 'u.status'),
    array('data' => t('IP Address'), 'field' => 't.ip_address'),
    array('data' => t('Last Access'), 'field' => 't.created'),
    array('data' => t('Account Created'), 'field' => 'u.created'),
    array('data' => t('Actions'), 'field' => 'actions')
  );

  $sql .= ' GROUP BY u.uid, u.name, u.mail, u.status, t.ip_address, u.created';
  $sql .= tablesort_sql($headers);

  $count = 'SELECT COUNT(*) FROM {users} u LEFT JOIN {troll_ip_track} t ON u.uid = t.uid WHERE '. implode(' AND ', $where) .' AND u.uid <> 0';
  $result = pager_query($sql, 25, 0, $count, $args);

  while($user = db_fetch_object($result)) {
    $name = l($user->name, 'admin/settings/troll/search/view/'. $user->uid, array('title' => t('View detailed user information')));
    $email = $user->mail;
    $status = ($user->status ? t('Active') : t('Blocked'));
    $ip = ($user->ip_address ? l($user->ip_address, 'admin/settings/troll/search/view/'. $user->uid, array('title' => t('View detailed user information'))) : t('none'));
    $recorded = ($user->recorded ? date('M d, Y', $user->recorded) : t('none recorded'));
    $created = date('M d, Y', $user->created);
    $actions = array();

    if (!$user->status) {
      $actions[] = array('title' => t('Edit User'), 'href' => "user/{$user->uid}/edit");
    }
    else if (variable_get('troll_block_role', NULL)) {
      $actions[] = array('title' => t('Block User'), 'href' => 'admin/settings/troll/search/block/'. $user->uid);
    }
    else {
      $actions[] = array('title' => t('Setup Block Role'), 'href' => 'admin/settings/troll/settings');
    }
    if ($user->ip_address) {
      $actions[] = array('title' => t('Ban IP'), 'href' => 'admin/settings/troll/ip_ban/user/'. $user->uid);
    }
    $action = theme('links', $actions);
    $rows[] = array($name, $email, $status, $ip, $recorded, $created, $action);
  }

  $pager = theme('pager', NULL, 25);

  if (!empty($pager)) {
    $rows[] = array(array('data' => $pager, 'colspan' => 7));
  }

  return theme('table', $headers, $rows);
}

/**
 * User detail form.
 *
 * @param $uid int
 * @return string
 */
function troll_search_user_detail($uid) {
  $u = user_load(array('uid' => $uid));
  $u->ip = db_fetch_object(db_query('SELECT t.ip_address FROM {troll_ip_track} t WHERE t.uid = %d GROUP BY t.uid, t.ip_address', $uid));

  $roles = $u->roles;

  $form['details'] = array(
    '#type' => 'fieldset',
    '#title' => t('Account Details for %username', array('%username' => $u->name))
  );

  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('User Name'),
    '#value' => theme('username', $u),
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('Email'),
    '#value' => $u->mail
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('User ID'),
    '#value' => $uid
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('Account Created'),
    '#value' => format_date($u->created, 'long')
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('Last Access'),
    '#value' => format_date($u->changed, 'long')
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('Status'),
    '#value' => ($u->status ? t('Active') : t('Blocked'))
  );
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('User Roles'),
    '#value' => implode(', ', $u->roles)
  );
  if ($u->status) {
    $links[] = array('title' => t('Block User'), 'href' => "admin/settings/troll/search/block/$uid");
  }
  else {
    $links[] = array('title' => t('Edit User'), 'href' => "user/$uid/edit");
  }
  if ($u->ip->ip_address) {
    $links[] = array('title' => t('Ban IP'), 'href' => "admin/settings/troll/ip_ban/user/$uid");
  }
  $form['details'][] = array(
    '#type' => 'item',
    '#title' => t('Actions'),
    '#value' => theme('links', $links)
  );

  $content = drupal_render($form);

  // get IP history
  $results = db_query('SELECT * FROM {troll_ip_track} WHERE uid = %d ORDER BY created DESC', $uid);
  while ($ip = db_fetch_object($results)) {
    $banned = db_fetch_object(db_query('SELECT * FROM {troll_ip_ban} WHERE ip_address = \'%s\'', $ip->ip_address));
    if ($banned->ip_address) {
      if ($banned->expires && $banned->expires < time()) {
        $status = l(t('expired'), 'admin/settings/troll/ip_ban/edit/'. $banned->iid, array('title' => t('Edit IP ban information')));
      }
      else {
        $status = l(t('banned'), 'admin/settings/troll/ip_ban/edit/'. $banned->iid, array('title' => t('Edit IP ban information')));
      }
    }
    else {
      $status = l(t('not banned'), 'admin/settings/troll/ip_ban/ip/'. $ip->ip_address, array('title' => t('Ban this IP')));
    }
    $rows[] = array($ip->ip_address, $status, format_date($ip->accessed, 'long'), format_date($ip->created, 'long'), exec('host '. $ip->ip_address));
  }

  if ($rows) {
    $pheader = array(t('IP'), t('Status'), t('Last Access'), t('First Access'), t('Host Information'));
    $posts = theme('table', $pheader, $rows);
  }
  $content .= theme('box', t('IP History'), ($posts ? $posts : t('No ip history')));

  // get recent posts
  $rdat = db_query("SELECT * FROM {node} WHERE uid = %d ORDER BY created DESC LIMIT 5", $uid);

  $posts = NULL;
  $rows = array();
  while ($node = db_fetch_object($rdat)) {
    $rows[] = array(l($node->title, "node/{$node->nid}") .' '. theme('mark', node_mark($node->nid, $node->changed)), $node->type, date('M d, Y', $node->created), ($node->status ? t('published') : t('not published')));
  }
  if ($rows) {
    $pheader = array(t('Title'), t('Type'), t('Created'), t('Status'));
    $posts = theme('table', $pheader, $rows);
  }

  $content .= theme('box', t('Recent Posts'), ($posts ? $posts : t('No recent posts')));

  // Get recent comments
  $cp = 'SELECT * FROM {comments} WHERE uid = %d ORDER BY timestamp DESC';
  $cdat = db_query($cp, $uid);

  $rows = array();
  $posts = NULL;
  while ($comment = db_fetch_object($cdat)) {
    $rows[] = array(l($comment->subject, 'node/'. $comment->nid, NULL, NULL, 'comment-'. $comment->cid) .' '. theme('mark', node_mark($comment->nid, $comment->changed)), date('M d, Y', $comment->timestamp), ($comment->status ? t('not published') : t('published')));
  }

  if ($rows) {
    $cheader = array(t('Subject'), t('Date Created'), t('Status'));
    $posts = theme('table', $cheader, $rows);
  }
  $content .= theme('box', t('Recent Comments'), ($posts ? $posts : t('No recent comments')));

  return $content;
}

/**
 *
 * DATABASE FUNCTIONS
 *
**/

/**
 * Removes an IP ban from the database.
 */
function troll_remove_ip($iid) {
  if (db_query('DELETE FROM {troll_ip_ban} WHERE iid = %d', $iid)) {
    drupal_set_message(t('IP ban removed'));
  }
  else {
    drupal_set_message(t('An error occurred, IP ban not removed'));
  }
}

/**
 * Removes IP block from the blacklist
 *
 * @param $edit array
 */
function troll_remove_blacklist($net, $bcast) {
  if (db_query('DELETE FROM {troll_blacklist} WHERE net = %d AND bcast = %d', $net, $bcast)) {
    drupal_set_message(t('Blacklist block removed'));
  }
  else {
    drupal_set_message(t('An error occurred, blacklist block not removed'));
  }
}

/**
 * Removes IP block from the whitelist
 *
 * @param $edit array
 */
function troll_remove_whitelist($net, $bcast) {
  if (db_query('DELETE FROM {troll_whitelist} WHERE net = %d AND bcast = %d', $net, $bcast)) {
    drupal_set_message(t('IP whitelist removed'));
  }
  else {
    drupal_set_message(t('An error occurred, IP whitelist not removed'));
  }
}

/**
 * Inserts an IP ban into the database.
 *
 * @param $edit array
 */
function troll_insert_ip($edit) {
  global $user;

  $expires = ($edit['expires'] ? mktime(23, 59, 0, $edit['month'], $edit['day'], $edit['year']) : 0);

  db_query("DELETE FROM {troll_ip_ban} WHERE ip_address = '%s'", $edit['ip_address']);
  if (db_query("INSERT INTO {troll_ip_ban} (ip_address, domain_name, created, expires, uid) VALUES ('%s', '%s', %d, %d, %d)", $edit['ip_address'], $edit['domain_name'], time(), $expires, $user->uid)) {
    drupal_set_message(t('IP ban added: %ip', array('%ip' => $edit['ip_address'])));
  }
  else {
    drupal_set_message(t('An error occurred, IP ban not created'));
  }
  drupal_goto('admin/settings/troll/ip_ban');
}

/**
 * Updates an IP ban in the database.
 *
 * @param $edit array
 */
function troll_update_ip($edit) {
  global $user;

  $expires = ($edit['expires'] ? mktime(23, 59, 0, $edit['month'], $edit['day'], $edit['year']) : 0);

  if (db_query("UPDATE {troll_ip_ban} SET ip_address = '%s', domain_name = '%s', expires = %d, uid = %d WHERE iid = %d", $edit['ip_address'], $edit['domain_name'], $expires, $user->uid, $edit['iid'])) {
    drupal_set_message(t('IP ban updated: %ip', array('%ip' => $edit['ip_address'])));
  }
  else {
    drupal_set_message(t('An error occurred, IP ban not updated'));
  }
}


/**
 * Logs IP information for users in the database.
 */
function troll_check_ip(){
  global $user;
  $sql = "SELECT uid FROM {troll_ip_track} WHERE ip_address = '%s' AND uid = %d";
  $chk = db_query($sql, $_SERVER['REMOTE_ADDR'], $user->uid);
  $check = db_fetch_array($chk);
  if (!isset($check['uid'])){
    $isql = "INSERT INTO {troll_ip_track} (uid, ip_address, created) VALUES (%d, '%s', %d)";
    db_query($isql, $user->uid, $_SERVER['REMOTE_ADDR'], time());
  }
}

/**
 * Checks remote IP to see if it is blacklisted.
 *
 * @todo declare $blacklisted to be static if this function is called more than once, and figure out a proper table join
 * @return integer zero if whitelisted or not blacklisted, otherwise the number of IP blacklist block matches
 */
function troll_is_blacklisted() {
  $longip = ip2long($_SERVER['REMOTE_ADDR']);
  if ($longip === FALSE || $longip == -1) {
    return FALSE;
  }
  else {
    $blacklisted = db_result(db_query('SELECT COUNT(b.net) FROM {troll_blacklist} b WHERE b.net <= %d AND b.bcast >= %d', $longip, $longip));
    $whitelisted = db_result(db_query('SELECT COUNT(w.net) FROM {troll_whitelist} w WHERE w.net <= %d AND w.bcast >= %d', $longip, $longip));
    return $whitelisted ? FALSE : $blacklisted;
  }
}

/**
 * Bans a user.
 *
 * @param $uid int
 */
function troll_block_user($uid) {
  db_query('UPDATE {users} SET status = 0 WHERE uid = %d', $uid);
  db_query('DELETE FROM {users_roles} WHERE uid = %d', $uid);
  sess_destroy_uid($uid);
  if (variable_get('troll_block_role', NULL)) {
    db_query('INSERT INTO {users_roles} (uid, rid) VALUES (%d, %d)', $uid, variable_get('troll_block_role', '0'));
  }
  drupal_set_message(t('Blocked user !link', array('!link' => l($uid, "admin/settings/troll/search/view/$uid"))));
}

/**
 * For functions that need tables that only exist after updates
 *
 * @return bool
 */
function _troll_updated_schema() {
  if (!preg_match("/update\.php$/", $_SERVER['PHP_SELF'])) {
    return db_result(db_query("SELECT schema_version FROM {system} WHERE name = 'troll' AND type = 'module' AND status = 1"));
  }
  return false;
}