diff options
Diffstat (limited to 'system/libraries/Session/drivers/Session_database_driver.php')
| -rw-r--r-- | system/libraries/Session/drivers/Session_database_driver.php | 420 |
1 files changed, 420 insertions, 0 deletions
diff --git a/system/libraries/Session/drivers/Session_database_driver.php b/system/libraries/Session/drivers/Session_database_driver.php new file mode 100644 index 000000000..b519b782f --- /dev/null +++ b/system/libraries/Session/drivers/Session_database_driver.php @@ -0,0 +1,420 @@ +<?php +/** + * CodeIgniter + * + * An open source application development framework for PHP + * + * This content is released under the MIT License (MIT) + * + * Copyright (c) 2014 - 2017, British Columbia Institute of Technology + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + * + * @package CodeIgniter + * @author EllisLab Dev Team + * @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/) + * @copyright Copyright (c) 2014 - 2017, British Columbia Institute of Technology (http://bcit.ca/) + * @license http://opensource.org/licenses/MIT MIT License + * @link https://codeigniter.com + * @since Version 3.0.0 + * @filesource + */ +defined('BASEPATH') OR exit('No direct script access allowed'); + +/** + * CodeIgniter Session Database Driver + * + * @package CodeIgniter + * @subpackage Libraries + * @category Sessions + * @author Andrey Andreev + * @link https://codeigniter.com/user_guide/libraries/sessions.html + */ +class CI_Session_database_driver extends CI_Session_driver implements SessionHandlerInterface { + + /** + * DB object + * + * @var object + */ + protected $_db; + + /** + * Row exists flag + * + * @var bool + */ + protected $_row_exists = FALSE; + + /** + * Lock "driver" flag + * + * @var string + */ + protected $_platform; + + // ------------------------------------------------------------------------ + + /** + * Class constructor + * + * @param array $params Configuration parameters + * @return void + */ + public function __construct(&$params) + { + parent::__construct($params); + + $CI =& get_instance(); + isset($CI->db) OR $CI->load->database(); + $this->_db = $CI->db; + + if ( ! $this->_db instanceof CI_DB_query_builder) + { + throw new Exception('Query Builder not enabled for the configured database. Aborting.'); + } + elseif ($this->_db->pconnect) + { + throw new Exception('Configured database connection is persistent. Aborting.'); + } + elseif ($this->_db->cache_on) + { + throw new Exception('Configured database connection has cache enabled. Aborting.'); + } + + $db_driver = $this->_db->dbdriver.(empty($this->_db->subdriver) ? '' : '_'.$this->_db->subdriver); + if (strpos($db_driver, 'mysql') !== FALSE) + { + $this->_platform = 'mysql'; + } + elseif (in_array($db_driver, array('postgre', 'pdo_pgsql'), TRUE)) + { + $this->_platform = 'postgre'; + } + + // Note: BC work-around for the old 'sess_table_name' setting, should be removed in the future. + if ( ! isset($this->_config['save_path']) && ($this->_config['save_path'] = config_item('sess_table_name'))) + { + log_message('debug', 'Session: "sess_save_path" is empty; using BC fallback to "sess_table_name".'); + } + } + + // ------------------------------------------------------------------------ + + /** + * Open + * + * Initializes the database connection + * + * @param string $save_path Table name + * @param string $name Session cookie name, unused + * @return bool + */ + public function open($save_path, $name) + { + if (empty($this->_db->conn_id) && ! $this->_db->db_connect()) + { + return $this->_fail(); + } + + return $this->_success; + } + + // ------------------------------------------------------------------------ + + /** + * Read + * + * Reads session data and acquires a lock + * + * @param string $session_id Session ID + * @return string Serialized session data + */ + public function read($session_id) + { + if ($this->_get_lock($session_id) !== FALSE) + { + // Prevent previous QB calls from messing with our queries + $this->_db->reset_query(); + + // Needed by write() to detect session_regenerate_id() calls + $this->_session_id = $session_id; + + $this->_db + ->select('data') + ->from($this->_config['save_path']) + ->where('id', $session_id); + + if ($this->_config['match_ip']) + { + $this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']); + } + + if ( ! ($result = $this->_db->get()) OR ($result = $result->row()) === NULL) + { + // PHP7 will reuse the same SessionHandler object after + // ID regeneration, so we need to explicitly set this to + // FALSE instead of relying on the default ... + $this->_row_exists = FALSE; + $this->_fingerprint = md5(''); + return ''; + } + + // PostgreSQL's variant of a BLOB datatype is Bytea, which is a + // PITA to work with, so we use base64-encoded data in a TEXT + // field instead. + $result = ($this->_platform === 'postgre') + ? base64_decode(rtrim($result->data)) + : $result->data; + + $this->_fingerprint = md5($result); + $this->_row_exists = TRUE; + return $result; + } + + $this->_fingerprint = md5(''); + return ''; + } + + // ------------------------------------------------------------------------ + + /** + * Write + * + * Writes (create / update) session data + * + * @param string $session_id Session ID + * @param string $session_data Serialized session data + * @return bool + */ + public function write($session_id, $session_data) + { + // Prevent previous QB calls from messing with our queries + $this->_db->reset_query(); + + // Was the ID regenerated? + if (isset($this->_session_id) && $session_id !== $this->_session_id) + { + if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id)) + { + return $this->_fail(); + } + + $this->_row_exists = FALSE; + $this->_session_id = $session_id; + } + elseif ($this->_lock === FALSE) + { + return $this->_fail(); + } + + if ($this->_row_exists === FALSE) + { + $insert_data = array( + 'id' => $session_id, + 'ip_address' => $_SERVER['REMOTE_ADDR'], + 'timestamp' => time(), + 'data' => ($this->_platform === 'postgre' ? base64_encode($session_data) : $session_data) + ); + + if ($this->_db->insert($this->_config['save_path'], $insert_data)) + { + $this->_fingerprint = md5($session_data); + $this->_row_exists = TRUE; + return $this->_success; + } + + return $this->_fail(); + } + + $this->_db->where('id', $session_id); + if ($this->_config['match_ip']) + { + $this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']); + } + + $update_data = array('timestamp' => time()); + if ($this->_fingerprint !== md5($session_data)) + { + $update_data['data'] = ($this->_platform === 'postgre') + ? base64_encode($session_data) + : $session_data; + } + + if ($this->_db->update($this->_config['save_path'], $update_data)) + { + $this->_fingerprint = md5($session_data); + return $this->_success; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * Close + * + * Releases locks + * + * @return bool + */ + public function close() + { + return ($this->_lock && ! $this->_release_lock()) + ? $this->_fail() + : $this->_success; + } + + // ------------------------------------------------------------------------ + + /** + * Destroy + * + * Destroys the current session. + * + * @param string $session_id Session ID + * @return bool + */ + public function destroy($session_id) + { + if ($this->_lock) + { + // Prevent previous QB calls from messing with our queries + $this->_db->reset_query(); + + $this->_db->where('id', $session_id); + if ($this->_config['match_ip']) + { + $this->_db->where('ip_address', $_SERVER['REMOTE_ADDR']); + } + + if ( ! $this->_db->delete($this->_config['save_path'])) + { + return $this->_fail(); + } + } + + if ($this->close() === $this->_success) + { + $this->_cookie_destroy(); + return $this->_success; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * Garbage Collector + * + * Deletes expired sessions + * + * @param int $maxlifetime Maximum lifetime of sessions + * @return bool + */ + public function gc($maxlifetime) + { + // Prevent previous QB calls from messing with our queries + $this->_db->reset_query(); + + return ($this->_db->delete($this->_config['save_path'], 'timestamp < '.(time() - $maxlifetime))) + ? $this->_success + : $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * Get lock + * + * Acquires a lock, depending on the underlying platform. + * + * @param string $session_id Session ID + * @return bool + */ + protected function _get_lock($session_id) + { + if ($this->_platform === 'mysql') + { + $arg = md5($session_id.($this->_config['match_ip'] ? '_'.$_SERVER['REMOTE_ADDR'] : '')); + if ($this->_db->query("SELECT GET_LOCK('".$arg."', 300) AS ci_session_lock")->row()->ci_session_lock) + { + $this->_lock = $arg; + return TRUE; + } + + return FALSE; + } + elseif ($this->_platform === 'postgre') + { + $arg = "hashtext('".$session_id."')".($this->_config['match_ip'] ? ", hashtext('".$_SERVER['REMOTE_ADDR']."')" : ''); + if ($this->_db->simple_query('SELECT pg_advisory_lock('.$arg.')')) + { + $this->_lock = $arg; + return TRUE; + } + + return FALSE; + } + + return parent::_get_lock($session_id); + } + + // ------------------------------------------------------------------------ + + /** + * Release lock + * + * Releases a previously acquired lock + * + * @return bool + */ + protected function _release_lock() + { + if ( ! $this->_lock) + { + return TRUE; + } + + if ($this->_platform === 'mysql') + { + if ($this->_db->query("SELECT RELEASE_LOCK('".$this->_lock."') AS ci_session_lock")->row()->ci_session_lock) + { + $this->_lock = FALSE; + return TRUE; + } + + return FALSE; + } + elseif ($this->_platform === 'postgre') + { + if ($this->_db->simple_query('SELECT pg_advisory_unlock('.$this->_lock.')')) + { + $this->_lock = FALSE; + return TRUE; + } + + return FALSE; + } + + return parent::_release_lock(); + } +} |