diff options
Diffstat (limited to 'system/libraries/Session/drivers/Session_redis_driver.php')
| -rw-r--r-- | system/libraries/Session/drivers/Session_redis_driver.php | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/system/libraries/Session/drivers/Session_redis_driver.php b/system/libraries/Session/drivers/Session_redis_driver.php new file mode 100644 index 000000000..e220a2951 --- /dev/null +++ b/system/libraries/Session/drivers/Session_redis_driver.php @@ -0,0 +1,395 @@ +<?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 Redis Driver + * + * @package CodeIgniter + * @subpackage Libraries + * @category Sessions + * @author Andrey Andreev + * @link https://codeigniter.com/user_guide/libraries/sessions.html + */ +class CI_Session_redis_driver extends CI_Session_driver implements SessionHandlerInterface { + + /** + * phpRedis instance + * + * @var Redis + */ + protected $_redis; + + /** + * Key prefix + * + * @var string + */ + protected $_key_prefix = 'ci_session:'; + + /** + * Lock key + * + * @var string + */ + protected $_lock_key; + + /** + * Key exists flag + * + * @var bool + */ + protected $_key_exists = FALSE; + + // ------------------------------------------------------------------------ + + /** + * Class constructor + * + * @param array $params Configuration parameters + * @return void + */ + public function __construct(&$params) + { + parent::__construct($params); + + if (empty($this->_config['save_path'])) + { + log_message('error', 'Session: No Redis save path configured.'); + } + elseif (preg_match('#(?:tcp://)?([^:?]+)(?:\:(\d+))?(\?.+)?#', $this->_config['save_path'], $matches)) + { + isset($matches[3]) OR $matches[3] = ''; // Just to avoid undefined index notices below + $this->_config['save_path'] = array( + 'host' => $matches[1], + 'port' => empty($matches[2]) ? NULL : $matches[2], + 'password' => preg_match('#auth=([^\s&]+)#', $matches[3], $match) ? $match[1] : NULL, + 'database' => preg_match('#database=(\d+)#', $matches[3], $match) ? (int) $match[1] : NULL, + 'timeout' => preg_match('#timeout=(\d+\.\d+)#', $matches[3], $match) ? (float) $match[1] : NULL + ); + + preg_match('#prefix=([^\s&]+)#', $matches[3], $match) && $this->_key_prefix = $match[1]; + } + else + { + log_message('error', 'Session: Invalid Redis save path format: '.$this->_config['save_path']); + } + + if ($this->_config['match_ip'] === TRUE) + { + $this->_key_prefix .= $_SERVER['REMOTE_ADDR'].':'; + } + } + + // ------------------------------------------------------------------------ + + /** + * Open + * + * Sanitizes save_path and initializes connection. + * + * @param string $save_path Server path + * @param string $name Session cookie name, unused + * @return bool + */ + public function open($save_path, $name) + { + if (empty($this->_config['save_path'])) + { + return $this->_fail(); + } + + $redis = new Redis(); + if ( ! $redis->connect($this->_config['save_path']['host'], $this->_config['save_path']['port'], $this->_config['save_path']['timeout'])) + { + log_message('error', 'Session: Unable to connect to Redis with the configured settings.'); + } + elseif (isset($this->_config['save_path']['password']) && ! $redis->auth($this->_config['save_path']['password'])) + { + log_message('error', 'Session: Unable to authenticate to Redis instance.'); + } + elseif (isset($this->_config['save_path']['database']) && ! $redis->select($this->_config['save_path']['database'])) + { + log_message('error', 'Session: Unable to select Redis database with index '.$this->_config['save_path']['database']); + } + else + { + $this->_redis = $redis; + return $this->_success; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * 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 (isset($this->_redis) && $this->_get_lock($session_id)) + { + // Needed by write() to detect session_regenerate_id() calls + $this->_session_id = $session_id; + + $session_data = $this->_redis->get($this->_key_prefix.$session_id); + + is_string($session_data) + ? $this->_key_exists = TRUE + : $session_data = ''; + + $this->_fingerprint = md5($session_data); + return $session_data; + } + + return $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * 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, $session_data) + { + if ( ! isset($this->_redis, $this->_lock_key)) + { + return $this->_fail(); + } + // Was the ID regenerated? + elseif ($session_id !== $this->_session_id) + { + if ( ! $this->_release_lock() OR ! $this->_get_lock($session_id)) + { + return $this->_fail(); + } + + $this->_key_exists = FALSE; + $this->_session_id = $session_id; + } + + $this->_redis->setTimeout($this->_lock_key, 300); + if ($this->_fingerprint !== ($fingerprint = md5($session_data)) OR $this->_key_exists === FALSE) + { + if ($this->_redis->set($this->_key_prefix.$session_id, $session_data, $this->_config['expiration'])) + { + $this->_fingerprint = $fingerprint; + $this->_key_exists = TRUE; + return $this->_success; + } + + return $this->_fail(); + } + + return ($this->_redis->setTimeout($this->_key_prefix.$session_id, $this->_config['expiration'])) + ? $this->_success + : $this->_fail(); + } + + // ------------------------------------------------------------------------ + + /** + * Close + * + * Releases locks and closes connection. + * + * @return bool + */ + public function close() + { + if (isset($this->_redis)) + { + try { + if ($this->_redis->ping() === '+PONG') + { + $this->_release_lock(); + if ($this->_redis->close() === FALSE) + { + return $this->_fail(); + } + } + } + catch (RedisException $e) + { + log_message('error', 'Session: Got RedisException on close(): '.$e->getMessage()); + } + + $this->_redis = NULL; + return $this->_success; + } + + return $this->_success; + } + + // ------------------------------------------------------------------------ + + /** + * Destroy + * + * Destroys the current session. + * + * @param string $session_id Session ID + * @return bool + */ + public function destroy($session_id) + { + if (isset($this->_redis, $this->_lock_key)) + { + if (($result = $this->_redis->delete($this->_key_prefix.$session_id)) !== 1) + { + log_message('debug', 'Session: Redis::delete() expected to return 1, got '.var_export($result, TRUE).' instead.'); + } + + $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) + { + // Not necessary, Redis takes care of that. + return $this->_success; + } + + // ------------------------------------------------------------------------ + + /** + * Get lock + * + * Acquires an (emulated) lock. + * + * @param string $session_id Session ID + * @return bool + */ + protected function _get_lock($session_id) + { + // PHP 7 reuses the SessionHandler object on regeneration, + // so we need to check here if the lock key is for the + // correct session ID. + if ($this->_lock_key === $this->_key_prefix.$session_id.':lock') + { + return $this->_redis->setTimeout($this->_lock_key, 300); + } + + // 30 attempts to obtain a lock, in case another request already has it + $lock_key = $this->_key_prefix.$session_id.':lock'; + $attempt = 0; + do + { + if (($ttl = $this->_redis->ttl($lock_key)) > 0) + { + sleep(1); + continue; + } + + if ( ! $this->_redis->setex($lock_key, 300, time())) + { + log_message('error', 'Session: Error while trying to obtain lock for '.$this->_key_prefix.$session_id); + return FALSE; + } + + $this->_lock_key = $lock_key; + break; + } + while (++$attempt < 30); + + if ($attempt === 30) + { + log_message('error', 'Session: Unable to obtain lock for '.$this->_key_prefix.$session_id.' after 30 attempts, aborting.'); + return FALSE; + } + elseif ($ttl === -1) + { + log_message('debug', 'Session: Lock for '.$this->_key_prefix.$session_id.' had no TTL, overriding.'); + } + + $this->_lock = TRUE; + return TRUE; + } + + // ------------------------------------------------------------------------ + + /** + * Release lock + * + * Releases a previously acquired lock + * + * @return bool + */ + protected function _release_lock() + { + if (isset($this->_redis, $this->_lock_key) && $this->_lock) + { + if ( ! $this->_redis->delete($this->_lock_key)) + { + log_message('error', 'Session: Error while trying to free lock for '.$this->_lock_key); + return FALSE; + } + + $this->_lock_key = NULL; + $this->_lock = FALSE; + } + + return TRUE; + } + +} |