Add support for getting the real client IP behind proxies

config/config.sample.php

@@ -62,6 +62,12 @@
 /* List of trusted domains, to prevent host header poisoning ownCloud is only using these Host headers */
 'trusted_domains' => array('demo.owncloud.org', 'otherdomain.owncloud.org:8080'),
 
+/* List of trusted proxy servers */
+'trusted_proxies' => array('203.0.113.45', '198.51.100.128'),
+
+/* Headers that should be trusted as client IP address in combination with `trusted_proxies` */
+'forwarded_for_headers' => array('HTTP_X_FORWARDED', 'HTTP_FORWARDED_FOR'),
+
 /* Theme to use for ownCloud */
 "theme" => "",
 

lib/private/allconfig.php

@@ -28,7 +28,7 @@ public function setSystemValue($key, $value) {
 	 *
 	 * @param string $key the key of the value, under which it was saved
 	 * @param mixed $default the default value to be returned if the value isn't set
-	 * @return string the saved value
+	 * @return mixed the value or $default
 	 */
 	public function getSystemValue($key, $default = '') {
 		return \OCP\Config::getSystemValue($key, $default);

lib/private/request.php

@@ -15,6 +15,34 @@ class OC_Request {
 
 	const REGEX_LOCALHOST = '/^(127\.0\.0\.1|localhost)(:[0-9]+|)$/';
 
+	/**
+	 * Returns the remote address, if the connection came from a trusted proxy and `forwarded_for_headers` has been configured
+	 * then the IP address specified in this header will be returned instead.
+	 * Do always use this instead of $_SERVER['REMOTE_ADDR']
+	 * @return string IP address
+	 */
+	public static function getRemoteAddress() {
+		$remoteAddress = $_SERVER['REMOTE_ADDR'];
+		$trustedProxies = \OC::$server->getConfig()->getSystemValue('trusted_proxies', array());
+
+		if(is_array($trustedProxies) && in_array($remoteAddress, $trustedProxies)) {
+			$forwardedForHeaders = \OC::$server->getConfig()->getSystemValue('forwarded_for_headers', array());
+
+			foreach($forwardedForHeaders as $header) {
+				if (array_key_exists($header, $_SERVER) === true) {
+					foreach (explode(',', $_SERVER[$header]) as $IP) {
+						$IP = trim($IP);
+						if (filter_var($IP, FILTER_VALIDATE_IP) !== false) {
+							return $IP;
+						}
+					}
+				}
+			}
+		}
+
+		return $remoteAddress;
+	}
+
 	/**
 	 * Check overwrite condition
 	 * @param string $type

lib/public/config.php

@@ -43,7 +43,7 @@ class Config {
 	 * Gets a value from config.php
 	 * @param string $key key
 	 * @param mixed $default = null default value
-	 * @return string the value or $default
+	 * @return mixed the value or $default
 	 *
 	 * This function gets the value from config.php. If it does not exist,
 	 * $default will be returned.

lib/public/iconfig.php

@@ -47,7 +47,7 @@ public function setSystemValue($key, $value);
 	 *
 	 * @param string $key the key of the value, under which it was saved
 	 * @param string $default the default value to be returned if the value isn't set
-	 * @return string the saved value
+	 * @return mixed the value or $default
 	 */
 	public function getSystemValue($key, $default = '');
 

tests/lib/request.php

@@ -9,21 +9,53 @@
 class Test_Request extends PHPUnit_Framework_TestCase {
 
 	public function setUp() {
-		OC_Config::setValue('overwritewebroot', '/domain.tld/ownCloud');
+		OC::$server->getConfig()->setSystemValue('overwritewebroot', '/domain.tld/ownCloud');
+
+		OC::$server->getConfig()->setSystemValue('trusted_proxies', array());
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array());
 	}
 
 	public function tearDown() {
-		OC_Config::setValue('overwritewebroot', '');
+		OC::$server->getConfig()->setSystemValue('overwritewebroot', '');
+		OC::$server->getConfig()->setSystemValue('trusted_proxies', array());
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array());
 	}
 
 	public function testScriptNameOverWrite() {
 		$_SERVER['REMOTE_ADDR'] = '10.0.0.1';
-		$_SERVER["SCRIPT_FILENAME"] = __FILE__;
+		$_SERVER['SCRIPT_FILENAME'] = __FILE__;
 
 		$scriptName = OC_Request::scriptName();
 		$this->assertEquals('/domain.tld/ownCloud/tests/lib/request.php', $scriptName);
 	}
 
+	public function testGetRemoteAddress() {
+		$_SERVER['REMOTE_ADDR'] = '10.0.0.2';
+		$_SERVER['HTTP_X_FORWARDED'] = '10.4.0.5, 10.4.0.4';
+		$_SERVER['HTTP_X_FORWARDED_FOR'] = '192.168.0.233';
+
+		// Without having specified a trusted remote address
+		$this->assertEquals('10.0.0.2', OC_Request::getRemoteAddress());
+
+		// With specifying a trusted remote address but no trusted header
+		OC::$server->getConfig()->setSystemValue('trusted_proxies', array('10.0.0.2'));
+		$this->assertEquals('10.0.0.2', OC_Request::getRemoteAddress());
+
+		// With specifying a trusted remote address and trusted headers
+		OC::$server->getConfig()->setSystemValue('trusted_proxies', array('10.0.0.2'));
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array('HTTP_X_FORWARDED'));
+		$this->assertEquals('10.4.0.5', OC_Request::getRemoteAddress());
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array('HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED'));
+		$this->assertEquals('192.168.0.233', OC_Request::getRemoteAddress());
+
+		// With specifying multiple trusted remote addresses and trusted headers
+		OC::$server->getConfig()->setSystemValue('trusted_proxies', array('10.3.4.2', '10.0.0.2', '127.0.3.3'));
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array('HTTP_X_FORWARDED'));
+		$this->assertEquals('10.4.0.5', OC_Request::getRemoteAddress());
+		OC::$server->getConfig()->setSystemValue('forwarded_for_headers', array('HTTP_CLIENT_IP', 'HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED'));
+		$this->assertEquals('192.168.0.233', OC_Request::getRemoteAddress());
+	}
+
 	/**
 	 * @dataProvider rawPathInfoProvider
 	 * @param $expected