add LDAP ConfigHandler for external storages and "$home" var

* handler registered upon OCA\\Files_External::loadAdditionalBackends
  event as user_ldap is loaded before files_external
* new configuration field "ldapExtStorageHomeAttribute" (not in GUI yet)

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

7 files changed, 171 insertions, 0 deletions

diff --git a/apps/user_ldap/lib/AppInfo/Application.php b/apps/user_ldap/lib/AppInfo/Application.php
index 59d7cdb4924..7e0c3534488 100644
--- a/apps/user_ldap/lib/AppInfo/Application.php
+++ b/apps/user_ldap/lib/AppInfo/Application.php
@@ -23,7 +23,9 @@
 
 namespace OCA\User_LDAP\AppInfo;
 
+use OCA\Files_External\Service\BackendService;
 use OCA\User_LDAP\Controller\RenewPasswordController;
+use OCA\User_LDAP\Handler\ExtStorageConfigHandler;
 use OCA\User_LDAP\ILDAPWrapper;
 use OCA\User_LDAP\LDAP;
 use OCP\AppFramework\App;
@@ -57,4 +59,18 @@ class Application extends App {
 			return new LDAP();
 		});
 	}
+
+	public function registerBackendDependents() {
+		$container = $this->getContainer();
+
+		$container->getServer()->getEventDispatcher()->addListener(
+			'OCA\\Files_External::loadAdditionalBackends',
+			function() use ($container) {
+				$storagesBackendService = $container->query(BackendService::class);
+				$storagesBackendService->registerConfigHandler('home', function () use ($container) {
+					return $container->query(ExtStorageConfigHandler::class);
+				});
+			}
+		);
+	}
 }
diff --git a/apps/user_ldap/lib/Configuration.php b/apps/user_ldap/lib/Configuration.php
index c912d30b49b..ee77702a090 100644
--- a/apps/user_ldap/lib/Configuration.php
+++ b/apps/user_ldap/lib/Configuration.php
@@ -106,6 +106,7 @@ class Configuration {
 		'turnOnPasswordChange' => false,
 		'ldapDynamicGroupMemberURL' => null,
 		'ldapDefaultPPolicyDN' => null,
+		'ldapExtStorageHomeAttribute' => null,
 	);
 
 	/**
@@ -477,6 +478,7 @@ class Configuration {
 			'ldap_dynamic_group_member_url'     => '',
 			'ldap_default_ppolicy_dn'           => '',
 			'ldap_user_avatar_rule'             => 'default',
+			'ldap_ext_storage_home_attribute'   => '',
 		);
 	}
 
@@ -537,6 +539,7 @@ class Configuration {
 			'ldap_experienced_admin'            => 'ldapExperiencedAdmin',
 			'ldap_dynamic_group_member_url'     => 'ldapDynamicGroupMemberURL',
 			'ldap_default_ppolicy_dn'           => 'ldapDefaultPPolicyDN',
+			'ldap_ext_storage_home_attribute'   => 'ldapExtStorageHomeAttribute',
 			'ldapIgnoreNamingRules'             => 'ldapIgnoreNamingRules',	// sysconfig
 		);
 		return $array;
diff --git a/apps/user_ldap/lib/Connection.php b/apps/user_ldap/lib/Connection.php
index 7becf311a22..ba393dffc12 100644
--- a/apps/user_ldap/lib/Connection.php
+++ b/apps/user_ldap/lib/Connection.php
@@ -60,6 +60,8 @@ use OCP\ILogger;
  * @property string ldapQuotaAttribute
  * @property string ldapQuotaDefault
  * @property string ldapEmailAttribute
+ * @property string ldapExtStorageHomeAttribute
+ * @property string homeFolderNamingRule
  */
 class Connection extends LDAPUtility {
 	private $ldapConnectionRes = null;
diff --git a/apps/user_ldap/lib/Exceptions/AttributeNotSet.php b/apps/user_ldap/lib/Exceptions/AttributeNotSet.php
new file mode 100644
index 00000000000..540b65c1820
--- /dev/null
+++ b/apps/user_ldap/lib/Exceptions/AttributeNotSet.php
@@ -0,0 +1,26 @@
+<?php
+/**
+ * @copyright Copyright (c) 2019 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\User_LDAP\Exceptions;
+
+class AttributeNotSet extends \RuntimeException {}
diff --git a/apps/user_ldap/lib/Handler/ExtStorageConfigHandler.php b/apps/user_ldap/lib/Handler/ExtStorageConfigHandler.php
new file mode 100644
index 00000000000..98a3cc71263
--- /dev/null
+++ b/apps/user_ldap/lib/Handler/ExtStorageConfigHandler.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * @copyright Copyright (c) 2019 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\User_LDAP\Handler;
+
+use OCA\Files_External\Config\IConfigHandler;
+use OCA\Files_External\Config\SimpleSubstitutionTrait;
+use OCA\User_LDAP\User_Proxy;
+use OCP\IUserSession;
+
+class ExtStorageConfigHandler implements IConfigHandler {
+	use SimpleSubstitutionTrait;
+
+	/** @var IUserSession */
+	private $session;
+
+	public function __construct(IUserSession $session) {
+		$this->placeholder = 'home';
+		$this->session = $session;
+	}
+
+	/**
+	 * @param mixed $optionValue
+	 * @return mixed the same type as $optionValue
+	 * @since 16.0.0
+	 * @throws \Exception
+	 */
+	public function handle($optionValue) {
+		$user = $this->session->getUser();
+		if($user === null) {
+			return $optionValue;
+		}
+
+		$backend = $user->getBackend();
+		if(!$backend instanceof User_Proxy) {
+			return $optionValue;
+		}
+
+		$access = $backend->getLDAPAccess($user->getUID());
+		if(!$access) {
+			return $optionValue;
+		}
+
+		$attribute = $access->connection->ldapExtStorageHomeAttribute;
+		if(empty($attribute)) {
+			return $optionValue;
+		}
+
+		$ldapUser = $access->userManager->get($user->getUID());
+		$extHome = $ldapUser->getExtStorageHome();
+
+		return $this->processInput($optionValue, $extHome);
+	}
+}
diff --git a/apps/user_ldap/lib/User/Manager.php b/apps/user_ldap/lib/User/Manager.php
index 6185c0da45c..046b42551b6 100644
--- a/apps/user_ldap/lib/User/Manager.php
+++ b/apps/user_ldap/lib/User/Manager.php
@@ -176,6 +176,7 @@ class Manager {
 			$this->access->getConnection()->ldapEmailAttribute,
 			$this->access->getConnection()->ldapUserDisplayName,
 			$this->access->getConnection()->ldapUserDisplayName2,
+			$this->access->getConnection()->ldapExtStorageHomeAttribute,
 		];
 
 		$homeRule = $this->access->getConnection()->homeFolderNamingRule;
diff --git a/apps/user_ldap/lib/User/User.php b/apps/user_ldap/lib/User/User.php
index 0d8f993746f..d68d8b35d14 100644
--- a/apps/user_ldap/lib/User/User.php
+++ b/apps/user_ldap/lib/User/User.php
@@ -32,6 +32,7 @@ namespace OCA\User_LDAP\User;
 
 use OCA\User_LDAP\Access;
 use OCA\User_LDAP\Connection;
+use OCA\User_LDAP\Exceptions\AttributeNotSet;
 use OCA\User_LDAP\FilesystemHelper;
 use OCA\User_LDAP\LogWrapper;
 use OCP\IAvatarManager;
@@ -244,6 +245,13 @@ class User {
 		}
 		$this->connection->writeToCache($cacheKey, $groups);
 
+		//external storage var
+		$attr = strtolower($this->connection->ldapExtStorageHomeAttribute);
+		if(isset($ldapEntry[$attr])) {
+			$this->updateExtStorageHome($ldapEntry[$attr][0]);
+		}
+		unset($attr);
+
 		//Avatar
 		/** @var Connection $connection */
 		$connection = $this->access->getConnection();
@@ -617,6 +625,47 @@ class User {
 	}
 
 	/**
+	 * @throws AttributeNotSet
+	 * @throws \OC\ServerNotAvailableException
+	 * @throws \OCP\PreConditionNotMetException
+	 */
+	public function getExtStorageHome():string {
+		$value = $this->config->getUserValue($this->getUsername(), 'user_ldap', 'extStorageHome', '');
+		if ($value !== '') {
+			return $value;
+		}
+
+		$value = $this->updateExtStorageHome();
+		if ($value !== '') {
+			return $value;
+		}
+
+		throw new AttributeNotSet(sprintf(
+			'external home storage attribute yield no value for %s', $this->getUsername()
+		));
+	}
+
+	/**
+	 * @throws \OCP\PreConditionNotMetException
+	 * @throws \OC\ServerNotAvailableException
+	 */
+	public function updateExtStorageHome(string $valueFromLDAP = null):string {
+		if($valueFromLDAP === null) {
+			$extHomeValues = $this->access->readAttribute($this->getDN(), $this->connection->ldapExtStorageHomeAttribute);
+		} else {
+			$extHomeValues = [$valueFromLDAP];
+		}
+		if ($extHomeValues && isset($extHomeValues[0])) {
+			$extHome = $extHomeValues[0];
+			$this->config->setUserValue($this->getUsername(), 'user_ldap', 'extStorageHome', $extHome);
+			return $extHome;
+		} else {
+			$this->config->deleteUserValue($this->getUsername(), 'user_ldap', 'extStorageHome');
+			return '';
+		}
+	}
+
+	/**
 	 * called by a post_login hook to handle password expiry
 	 *
 	 * @param array $params