Implement custom Redis session backend

2 files changed, 146 insertions, 13 deletions

diff --git a/Zotlabs/Web/Session.php b/Zotlabs/Web/Session.php
index fe0a3fbf9..6f92a0319 100644
--- a/Zotlabs/Web/Session.php
+++ b/Zotlabs/Web/Session.php
@@ -29,34 +29,44 @@ class Session {
 		/*
 		 * Set our session storage functions.
 		 */
-		
+
 		if($this->custom_handler) {
 			/* Custom handler (files, memached, redis..) */
 
 			$session_save_handler = strval(get_config('system', 'session_save_handler', Null));
 			$session_save_path = strval(get_config('system', 'session_save_path', Null));
-			$session_gc_probability = intval(get_config('system', 'session_gc_probability', 1));
-			$session_gc_divisor = intval(get_config('system', 'session_gc_divisor', 100));
-			if(!$session_save_handler || !$session_save_path) {
-				logger('Session save handler or path not set.',LOGGER_NORMAL,LOG_ERR);
+
+			if(is_null($session_save_handler) || is_null($session_save_path)) {
+				logger('Session save handler or path not set', LOGGER_NORMAL, LOG_ERR);
 			}
 			else {
-				ini_set('session.save_handler', $session_save_handler);
-				ini_set('session.save_path', $session_save_path);
-				ini_set('session.gc_probability', $session_gc_probability);
-				ini_set('session.gc_divisor', $session_gc_divisor);
+				// Check if custom sessions backend exists
+				$clsname = '\Zotlabs\Web\Session' . ucfirst(strtolower($session_save_handler));
+				if (class_exists($clsname)) {
+					$handler = new $clsname($session_save_path);
+				}
+				else {
+					ini_set('session.save_handler', $session_save_handler);
+					ini_set('session.save_path', $session_save_path);
+					ini_set('session.gc_probability', intval(get_config('system', 'session_gc_probability', 1)));
+					ini_set('session.gc_divisor', intval(get_config('system', 'session_gc_divisor', 100)));
+				}
 			}
 		}
 		else {
-			$handler = new \Zotlabs\Web\SessionHandler();
+			$handler = new SessionHandler();
+		}
+
+		if (isset($handler)) {
 
 			$this->handler = $handler;
 
-		   	$x = session_set_save_handler($handler,false);
-		   	if(! $x)
-		   		logger('Session save handler initialisation failed.',LOGGER_NORMAL,LOG_ERR);
+			$x = session_set_save_handler($handler, false);
+			if(! $x)
+				logger('Session save handler initialisation failed.',LOGGER_NORMAL,LOG_ERR);
 		}
 
+
 		// Force cookies to be secure (https only) if this site is SSL enabled. 
 		// Must be done before session_start().
 
diff --git a/Zotlabs/Web/SessionRedis.php b/Zotlabs/Web/SessionRedis.php
new file mode 100644
index 000000000..b4f5d54b3
--- /dev/null
+++ b/Zotlabs/Web/SessionRedis.php
@@ -0,0 +1,123 @@
+<?php
+
+namespace Zotlabs\Web;
+
+
+class SessionRedis implements \SessionHandlerInterface {
+
+        private $redis = null;
+
+
+        function __construct($connection) {
+
+                $this->redis = new \Redis();
+
+                $credentials = parse_url($connection);
+
+                try {
+                        if (isset($credentials['path']))
+                                $this->redis->connect($credentials['path']);
+                        else {
+
+                                if (isset($credentials['query']))
+                                        $vars = parse_str($credentials['query']);
+                                else
+                                        $vars = [];
+
+                                $this->redis->connect(
+                                        (isset($credentials['scheme']) ? $credentials['scheme'] . '://' : '') . $credentials['host'],
+                                        (isset($credentials['port']) ? $credentials['port'] : 6379),
+                                        (isset($vars['timeout']) ? $vars['timeout'] : 1),
+                                        null,
+                                        0,
+                                        (isset($vars['read_timeout']) ? $vars['read_timeout'] : 0)
+                                );
+
+                                if (isset($vars['auth']))
+                                        $this->redis->auth($vars['auth']);
+                        }
+                }
+                catch(\RedisException $ex) {
+                        logger('Error connecting to Redis: ' . $ex->getMessage());
+                }
+        }
+
+
+        function open($s, $n) {
+
+                return true;
+        }
+
+        // IMPORTANT: if we read the session and it doesn't exist, create an empty record.
+        // We rely on this due to differing PHP implementation of session_regenerate_id()
+        // some which call read explicitly and some that do not. So we call it explicitly
+        // just after sid regeneration to force a record to exist.
+
+        function read($id) {
+
+                if ($id) {
+                        $data = $this->redis->get($id);
+
+                        if ($data)
+                                return $data;
+                        else
+                                $this->redis->setEx($id, 300, '');
+                }
+
+                return '';
+        }
+
+
+        function write($id, $data) {
+
+                // Pretend everything is hunky-dory, even though it isn't.
+                // There probably isn't anything we can do about it in any event.
+                // See: https://stackoverflow.com/a/43636110
+
+                if(! $id || ! $data)
+                        return true;
+
+
+                // Unless we authenticate somehow, only keep a session for 5 minutes
+                // The viewer can extend this by performing any web action using the
+                // original cookie, but this allows us to cleanup the hundreds or
+                // thousands of empty sessions left around from web crawlers which are
+                // assigned cookies on each page that they never use.
+
+                $expire = 300;
+
+                if($_SESSION) {
+                        if(array_key_exists('remember_me',$_SESSION) && intval($_SESSION['remember_me']))
+                                $expire = 60 * 60 * 24 * 365;
+                        elseif(local_channel())
+                                $expire = 60 * 60 * 24 * 3;
+                        elseif(remote_channel())
+                                $expire = 60 * 60 * 24 * 1;
+                }
+
+                $this->redis->setEx($id, $expire, $data);
+
+                return true;
+        }
+
+
+        function close() {
+
+                return true;
+        }
+
+
+        function destroy ($id) {
+
+                $this->redis->del($id);
+
+                return true;
+        }
+
+
+        function gc($expire) {
+
+                return true;
+        }
+
+}