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spambot.module in Spambot 6.3

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File

spambot.module
View source 
<?php

define('SPAMBOT_ACTION_NONE', 0);
define('SPAMBOT_ACTION_BLOCK', 1);
define('SPAMBOT_ACTION_DELETE', 2);
define('SPAMBOT_DEFAULT_BLOCKED_MESSAGE', 'Your email address or username or IP address is blacklisted.');
define('SPAMBOT_MAX_EVIDENCE_LENGTH', 1024);

/**
 * Implementation of hook_perm()
 */
function spambot_perm() {
  return array(
    'protected from spambot scans',
  );
}

/**
 * Implementation of hook_menu()
 */
function spambot_menu() {
  $items = array();
  $items['admin/settings/spambot'] = array(
    'title' => 'Spambot',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'spambot_settings_form',
    ),
    'access arguments' => array(
      'administer site configuration',
    ),
    'file' => 'spambot.admin.inc',
  );
  $items['user/%user/spambot'] = array(
    'title' => 'Spam',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'spambot_user_spam_admin_form',
      1,
    ),
    'access arguments' => array(
      'administer users',
    ),
    'type' => MENU_LOCAL_TASK,
    'file' => 'spambot.pages.inc',
  );
  return $items;
}

/**
 * Implementation of hook_form_alter()
 */
function spambot_form_alter(&$form, $form_state, $form_id) {
  if ($form_id == 'user_register' && variable_get('spambot_user_register_protect', TRUE) && !user_access('administer users')) {
    $form['#validate'][] = 'spambot_user_register_validate';
  }
}

/**
 * Validate the user_register form
 */
function spambot_user_register_validate($form, &$form_state) {
  $email_threshold = variable_get('spambot_criteria_email', 1);
  $username_threshold = variable_get('spambot_criteria_username', 0);
  $ip_threshold = variable_get('spambot_criteria_ip', 20);

  // Build request parameters according to the criteria to use
  $request = array();
  if (!empty($form_state['values']['mail']) && $email_threshold > 0) {
    $request['email'] = $form_state['values']['mail'];
  }
  if (!empty($form_state['values']['name']) && $username_threshold > 0) {
    $request['username'] = $form_state['values']['name'];
  }
  if ($ip_threshold > 0) {
    $ip = ip_address();

    // Don't check the loopback interface
    if ($ip != '127.0.0.1') {

      // Make sure we have a valid IPv4 address (API doesn't support IPv6 yet)
      if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) === FALSE) {
        watchdog('spambot', 'Invalid IP address on registration: @ip. Spambot will not rely on it.', array(
          '@ip' => $ip,
        ));
      }
      else {
        $request['ip'] = $ip;
      }
    }
  }

  // Only do a remote API request if there is anything to check
  if (count($request)) {
    $data = array();
    if (spambot_sfs_request($request, $data)) {
      $substitutions = array(
        '@email' => $form_state['values']['mail'],
        '%email' => $form_state['values']['mail'],
        '@username' => $form_state['values']['name'],
        '%username' => $form_state['values']['name'],
        '@ip' => ip_address(),
        '%ip' => ip_address(),
      );
      $reasons = array();
      if ($email_threshold > 0 && !empty($data['email']['appears']) && $data['email']['frequency'] >= $email_threshold) {
        form_set_error('mail', t(variable_get('spambot_blocked_message_email', t(SPAMBOT_DEFAULT_BLOCKED_MESSAGE)), $substitutions));
        $reasons[] = t('email=@value', array(
          '@value' => $request['email'],
        ));
      }
      if ($username_threshold > 0 && !empty($data['username']['appears']) && $data['username']['frequency'] >= $username_threshold) {
        form_set_error('name', t(variable_get('spambot_blocked_message_username', t(SPAMBOT_DEFAULT_BLOCKED_MESSAGE)), $substitutions));
        $reasons[] = t('username=@value', array(
          '@value' => $request['username'],
        ));
      }
      if ($ip_threshold > 0 && !empty($data['ip']['appears']) && $data['ip']['frequency'] >= $ip_threshold) {
        form_set_error('', t(variable_get('spambot_blocked_message_ip', t(SPAMBOT_DEFAULT_BLOCKED_MESSAGE)), $substitutions));
        $reasons[] = t('ip=@value', array(
          '@value' => $request['ip'],
        ));
      }
      if (count($reasons)) {
        watchdog('spambot', t('Blocked registration: @reasons', array(
          '@reasons' => join(',', $reasons),
        )));

        // Slow them down if configured
        $delay = variable_get('spambot_blacklisted_delay', 0);
        if ($delay) {
          sleep($delay);
        }
      }
    }
  }
}

/**
 * Implementation of hook_nodeapi()
 *
 * Updates the node_spambot table to remember the ip address of node creation.
 */
function spambot_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  global $user;
  switch ($op) {
    case 'insert':
      db_query("INSERT INTO {node_spambot} (nid, uid, hostname) VALUES (%d, %d, '%s')", $node->nid, $node->uid, ip_address());
      break;
    case 'delete':
      db_query("DELETE FROM {node_spambot} where nid = %d", $node->nid);
      break;
  }
}

/**
 * Implementation of hook_cron
 */
function spambot_cron() {
  $limit = variable_get('spambot_cron_user_limit', 0);
  if ($limit) {
    $last_uid = variable_get('spambot_last_checked_uid', 0);
    if ($last_uid < 1) {

      // Skip scanning the first account
      $last_uid = 1;
    }
    $result = db_query("SELECT uid FROM {users} WHERE uid > %d ORDER BY uid LIMIT %d", $last_uid, $limit);
    $uids = array();
    while ($object = db_fetch_object($result)) {
      $uids[$object->uid] = $object->uid;
    }
    $action = variable_get('spambot_spam_account_action', SPAMBOT_ACTION_NONE);
    foreach ($uids as $uid) {
      $account = user_load($uid);
      if ($account->status || variable_get('spambot_check_blocked_accounts', FALSE)) {
        $result = spambot_account_is_spammer($account);
        if ($result > 0) {
          $link = l(t('spammer'), 'user/' . $account->uid);
          switch (user_access('protected from spambot scans', $account) ? SPAMBOT_ACTION_NONE : $action) {
            case SPAMBOT_ACTION_BLOCK:
              if ($account->status) {
                user_save($account, array(
                  'status' => 0,
                ));
                watchdog('spambot', t('Blocked spam account: @name &lt;@email&gt; (uid @uid)', array(
                  '@name' => $account->name,
                  '@email' => $account->mail,
                  '@uid' => $account->uid,
                )), array(), WATCHDOG_NOTICE, $link);
              }
              else {

                // Don't block an already blocked account
                watchdog('spambot', t('Spam account already blocked: @name &lt;@email&gt; (uid @uid)', array(
                  '@name' => $account->name,
                  '@email' => $account->mail,
                  '@uid' => $account->uid,
                )), array(), WATCHDOG_NOTICE, $link);
              }
              break;
            case SPAMBOT_ACTION_DELETE:
              user_delete(array(), $account->uid);
              watchdog('spambot', t('Deleted spam account: @name &lt;@email&gt; (uid @uid)', array(
                '@name' => $account->name,
                '@email' => $account->mail,
                '@uid' => $account->uid,
              )), array(), WATCHDOG_NOTICE, $link);
              break;
            default:
              watchdog('spambot', t('Found spam account: @name &lt;@email&gt; (uid @uid)', array(
                '@name' => $account->name,
                '@email' => $account->mail,
                '@uid' => $account->uid,
              )), array(), WATCHDOG_NOTICE, $link);
              break;
          }

          // Mark this uid as successfully checked
          variable_set('spambot_last_checked_uid', $uid);
        }
        else {
          if ($result == 0) {

            // Mark this uid as successfully checked
            variable_set('spambot_last_checked_uid', $uid);
          }
          else {
            if ($result < 0) {

              // Error contacting service, so pause processing
              break;
            }
          }
        }
      }
    }
  }
}

/**
 * Invoke www.stopforumspam.com's api
 *
 * @param $query
 *   A keyed array of url parameters ie. array('email' => 'blah@blah.com')
 * @param $data
 *   An array that will be filled with the data from www.stopforumspam.com. 
 *
 * @return
 *   TRUE on successful request (and $data will contain the data), FALSE if error
 * 
 * $data should be an array of the following form: 
 * Array
 * (
 *     [success] => 1
 *     [email] => Array
 *         (
 *             [lastseen] => 2010-01-10 08:41:26
 *             [frequency] => 2
 *             [appears] => 1
 *         )
 * 
 *     [username] => Array
 *         (
 *             [frequency] => 0
 *             [appears] => 0
 *         )
 * )
 *
 */
function spambot_sfs_request($query, &$data) {

  // An empty request results in no match
  if (empty($query)) {
    return FALSE;
  }

  // Use php serialisation format
  $query['f'] = 'serial';

  // Change to use http_build_query() once PHP 4.x can be dropped
  $params = array();
  foreach ($query as $key => $value) {
    $params[] = $key . '=' . urlencode($value);
  }
  $url = 'http://www.stopforumspam.com/api?' . join('&', $params);
  $result = drupal_http_request($url);
  if (!empty($result->code) && $result->code == 200 && empty($result->error) && !empty($result->data)) {
    $data = unserialize($result->data);
    if (!empty($data['success'])) {
      return TRUE;
    }
    else {
      watchdog('spambot', t("Request unsuccessful: @url <pre>\n@dump</pre>", array(
        '@url' => $url,
        '@dump' => print_r($data, TRUE),
      )));
    }
  }
  else {
    watchdog('spambot', t("Error contacting service: @url <pre>\n@dump</pre>", array(
      '@url' => $url,
      '@dump' => print_r($result, TRUE),
    )));
  }
  return FALSE;
}

/**
 * Checks an account to see if it's a spammer.
 * This one uses configurable automated criteria checking of email and username only
 *
 * @return
 *   positive if spammer, 0 if not spammer, negative if error
 */
function spambot_account_is_spammer($account) {
  $email_threshold = variable_get('spambot_criteria_email', 1);
  $username_threshold = variable_get('spambot_criteria_username', 0);
  $ip_threshold = variable_get('spambot_criteria_ip', 20);

  // Build request parameters according to the criteria to use
  $request = array();
  if (!empty($account->mail) && $email_threshold > 0) {
    $request['email'] = $account->mail;
  }
  if (!empty($account->name) && $username_threshold > 0) {
    $request['username'] = $account->name;
  }

  // Only do a remote API request if there is anything to check
  if (count($request)) {
    $data = array();
    if (spambot_sfs_request($request, $data)) {
      if ($email_threshold > 0 && !empty($data['email']['appears']) && $data['email']['frequency'] >= $email_threshold || $username_threshold > 0 && !empty($data['username']['appears']) && $data['username']['frequency'] >= $username_threshold) {
        return 1;
      }
    }
    else {

      // Return error
      return -1;
    }
  }

  // Now check IP's
  // If any IP matches the threshold, then flag as a spammer
  if ($ip_threshold > 0) {
    $ips = spambot_account_ip_addresses($account);
    foreach ($ips as $ip) {

      // Skip the loopback interface
      if ($ip == '127.0.0.1') {
        continue;
      }
      elseif (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) === FALSE) {
        $link = l(t('user'), 'user/' . $account->uid);
        watchdog('spambot', 'Invalid IP address: @ip (uid=@uid, name=@name, email=@email). Spambot will not rely on it.', array(
          '@ip' => $ip,
          '@name' => $account->name,
          '@email' => $account->mail,
          '@uid' => $account->uid,
        ), WATCHDOG_NOTICE, $link);
        continue;
      }
      $request = array(
        'ip' => $ip,
      );
      $data = array();
      if (spambot_sfs_request($request, $data)) {
        if (!empty($data['ip']['appears']) && $data['ip']['frequency'] >= $ip_threshold) {
          return 1;
        }
      }
      else {

        // Abort on error
        return -1;
      }
    }
  }

  // Return no match
  return 0;
}

/**
 * Retrieves a list of IP addresses for an account
 *
 * @param $account
 *   Account to retrieve IP addresses for
 *
 * @return
 *   An array of IP addresses, or an empty array if none found
 */
function spambot_account_ip_addresses($account) {
  $hostnames = array();

  // Retrieve IPs from node_spambot table
  $result = db_query("SELECT DISTINCT hostname FROM {node_spambot} WHERE uid = %d", $account->uid);
  while ($object = db_fetch_object($result)) {
    $hostnames[] = $object->hostname;
  }

  // Retrieve IPs from any sessions which may still exist
  $result = db_query("SELECT DISTINCT hostname FROM {sessions} WHERE uid = %d", $account->uid);
  while ($object = db_fetch_object($result)) {
    $hostnames[] = $object->hostname;
  }

  // Retrieve IPs from comments
  if (module_exists('comment')) {
    $result = db_query("SELECT DISTINCT hostname FROM {comments} WHERE uid = %d", $account->uid);
    while ($object = db_fetch_object($result)) {
      $hostnames[] = $object->hostname;
    }
  }

  // Retrieve IPs from statistics
  if (module_exists('statistics')) {
    $result = db_query("SELECT DISTINCT hostname FROM {accesslog} WHERE uid = %d", $account->uid);
    while ($object = db_fetch_object($result)) {
      $hostnames[] = $object->hostname;
    }
  }

  // Retrieve IPs from user stats
  if (module_exists('user_stats')) {
    $result = db_query("SELECT DISTINCT ip_address FROM {user_stats_ips} WHERE uid = %d", $account->uid);
    while ($object = db_fetch_object($result)) {
      $hostnames[] = $object->ip_address;
    }
  }
  $hostnames = array_unique($hostnames);
  return $hostnames;
}

/**
 * Reports an account as a spammer. Requires ip address and evidence of a single incident
 *
 * @param $account
 *   Account to report
 * @param $ip
 *   IP address to report
 * @param $evidence
 *   Evidence to report
 *
 * @return
 *   TRUE if successful, FALSE if error
 */
function spambot_report_account($account, $ip, $evidence) {
  $success = FALSE;
  $key = variable_get('spambot_sfs_api_key', FALSE);
  if ($key) {
    $query['api_key'] = $key;
    $query['email'] = $account->mail;
    $query['username'] = $account->name;
    $query['ip_addr'] = $ip;
    $query['evidence'] = mb_strimwidth($evidence, 0, SPAMBOT_MAX_EVIDENCE_LENGTH);

    // Change to use http_build_query() once PHP 4.x can be dropped
    $params = array();
    foreach ($query as $key => $value) {
      $params[] = $key . '=' . urlencode($value);
    }
    $url = 'http://www.stopforumspam.com/add.php';
    $result = drupal_http_request($url, array(
      'Content-type' => 'application/x-www-form-urlencoded',
    ), 'POST', join('&', $params));
    if (!empty($result->code) && $result->code == 200 && !empty($result->data) && stripos($result->data, 'data submitted successfully') !== FALSE) {
      $success = TRUE;
    }
    else {
      if (stripos($result->data, 'duplicate') !== FALSE) {

        // www.stopforumspam.com can return a 503 code with data = '<p>recent duplicate entry</p>'
        //   which we will treat as successful.
        $success = TRUE;
      }
      else {
        watchdog('spambot', t("Error reporting account: @url <pre>\n@dump</pre>", array(
          '@url' => $url,
          '@dump' => print_r($result, TRUE),
        )));
      }
    }
  }
  return $success;
}

Functions

Namesort descending Description
spambot_account_ip_addresses Retrieves a list of IP addresses for an account
spambot_account_is_spammer Checks an account to see if it's a spammer. This one uses configurable automated criteria checking of email and username only
spambot_cron Implementation of hook_cron
spambot_form_alter Implementation of hook_form_alter()
spambot_menu Implementation of hook_menu()
spambot_nodeapi Implementation of hook_nodeapi()
spambot_perm Implementation of hook_perm()
spambot_report_account Reports an account as a spammer. Requires ip address and evidence of a single incident
spambot_sfs_request Invoke www.stopforumspam.com's api
spambot_user_register_validate Validate the user_register form

Constants

Namesort descending Description
SPAMBOT_ACTION_BLOCK
SPAMBOT_ACTION_DELETE
SPAMBOT_ACTION_NONE
SPAMBOT_DEFAULT_BLOCKED_MESSAGE
SPAMBOT_MAX_EVIDENCE_LENGTH