Improved http error handling

bin/auth_ejabberd.php

@@ -51,9 +51,10 @@
  *
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 use Dice\Dice;

bin/console.php

@@ -20,9 +20,10 @@
  *
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 use Dice\Dice;

bin/daemon.php

@@ -23,9 +23,10 @@
  * This script was taken from http://php.net/manual/en/function.pcntl-fork.php
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 use Dice\Dice;

bin/testargs.php

@@ -26,9 +26,10 @@
  *
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 if (($_SERVER["argc"] > 1) && isset($_SERVER["argv"][1])) {

bin/wait-for-connection

@@ -24,9 +24,10 @@
  * Usage: php bin/wait-for-connection {HOST} {PORT} [{TIMEOUT}]
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 $timeout = 60;

bin/worker.php

@@ -21,9 +21,10 @@
  * Starts the background processing
  */
 
+use Friendica\Network\HTTPException\ForbiddenException;
+
 if (php_sapi_name() !== 'cli') {
-	header($_SERVER["SERVER_PROTOCOL"] . ' 403 Forbidden');
+	throw new ForbiddenException();
-	exit();
 }
 
 use Dice\Dice;

include/api.php

@@ -246,8 +246,6 @@ function api_login(App $a)
 	if (!DBA::isResult($record)) {
 		Logger::debug(API_LOG_PREFIX . 'failed', ['module' => 'api', 'action' => 'login', 'parameters' => $_SERVER]);
 		header('WWW-Authenticate: Basic realm="Friendica"');
-		//header('HTTP/1.0 401 Unauthorized');
-		//die('This api requires login');
 		throw new UnauthorizedException("This API requires login");
 	}
 

src/App/Module.php

@@ -29,6 +29,7 @@ use Friendica\Module\Home;
 use Friendica\Module\HTTPException\MethodNotAllowed;
 use Friendica\Module\HTTPException\PageNotFound;
 use Friendica\Network\HTTPException\MethodNotAllowedException;
+use Friendica\Network\HTTPException\NoContentException;
 use Friendica\Network\HTTPException\NotFoundException;
 use Friendica\Util\Profiler;
 use Psr\Log\LoggerInterface;
@@ -291,9 +292,8 @@ class Module
 		// @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/OPTIONS
 		// @todo Check allowed methods per requested path
 		if ($server['REQUEST_METHOD'] === Router::OPTIONS) {
-			header('HTTP/1.1 204 No Content');
 			header('Allow: ' . implode(',', Router::ALLOWED_METHODS));
-			exit();
+			throw new NoContentException();
 		}
 
 		$placeholder = '';

src/Core/Cache/TraitMemcacheCommand.php

@@ -21,7 +21,7 @@
 
 namespace Friendica\Core\Cache;
 
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\ServiceUnavailableException;
 
 /**
  * Trait for Memcache to add a custom version of the
@@ -52,7 +52,7 @@ trait TraitMemcacheCommand
 	 *
 	 * @return array All keys of the memcache instance
 	 *
-	 * @throws InternalServerErrorException
+	 * @throws ServiceUnavailableException
 	 */
 	protected function getMemcacheKeys()
 	{
@@ -88,13 +88,13 @@ trait TraitMemcacheCommand
 	 *
 	 * @return string The returned buffer result
 	 *
-	 * @throws InternalServerErrorException In case the memcache server isn't available (anymore)
+	 * @throws ServiceUnavailableException In case the memcache server isn't available (anymore)
 	 */
 	protected function sendMemcacheCommand(string $command)
 	{
 		$s = @fsockopen($this->server, $this->port);
 		if (!$s) {
-			throw new InternalServerErrorException("Cant connect to:" . $this->server . ':' . $this->port);
+			throw new ServiceUnavailableException("Cant connect to:" . $this->server . ':' . $this->port);
 		}
 
 		fwrite($s, $command . "\r\n");

src/Core/Renderer.php

@@ -23,7 +23,7 @@ namespace Friendica\Core;
 
 use Exception;
 use Friendica\DI;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\ServiceUnavailableException;
 use Friendica\Render\TemplateEngine;
 
 /**
@@ -69,7 +69,7 @@ class Renderer
 	 * @param string $template
 	 * @param array  $vars
 	 * @return string
-	 * @throws InternalServerErrorException
+	 * @throws ServiceUnavailableException
 	 */
 	public static function replaceMacros(string $template, array $vars = [])
 	{
@@ -87,7 +87,7 @@ class Renderer
 			$message = is_site_admin() ?
 				$e->getMessage() :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
-			throw new InternalServerErrorException($message);
+			throw new ServiceUnavailableException($message);
 		}
 
 		DI::profiler()->stopRecording();
@@ -102,7 +102,7 @@ class Renderer
 	 * @param string $subDir Subdirectory (Optional)
 	 *
 	 * @return string template.
-	 * @throws InternalServerErrorException
+	 * @throws ServiceUnavailableException
 	 */
 	public static function getMarkupTemplate($file, $subDir = '')
 	{
@@ -116,7 +116,7 @@ class Renderer
 			$message = is_site_admin() ?
 				$e->getMessage() :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
-			throw new InternalServerErrorException($message);
+			throw new ServiceUnavailableException($message);
 		}
 
 		DI::profiler()->stopRecording();
@@ -128,7 +128,7 @@ class Renderer
 	 * Register template engine class
 	 *
 	 * @param string $class
-	 * @throws InternalServerErrorException
+	 * @throws ServiceUnavailableException
 	 */
 	public static function registerTemplateEngine($class)
 	{
@@ -143,7 +143,7 @@ class Renderer
 			$message = is_site_admin() ?
 				$admin_message :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
-			throw new InternalServerErrorException($message);
+			throw new ServiceUnavailableException($message);
 		}
 	}
 
@@ -154,7 +154,7 @@ class Renderer
 	 * or default
 	 *
 	 * @return TemplateEngine Template Engine instance
-	 * @throws InternalServerErrorException
+	 * @throws ServiceUnavailableException
 	 */
 	public static function getTemplateEngine()
 	{
@@ -177,7 +177,7 @@ class Renderer
 		$message = is_site_admin() ?
 			$admin_message :
 			DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
-		throw new InternalServerErrorException($message);
+		throw new ServiceUnavailableException($message);
 	}
 
 	/**

src/Core/System.php

@@ -22,7 +22,10 @@
 namespace Friendica\Core;
 
 use Friendica\DI;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\BadRequestException;
+use Friendica\Network\HTTPException\FoundException;
+use Friendica\Network\HTTPException\MovedPermanentlyException;
+use Friendica\Network\HTTPException\TemporaryRedirectException;
 use Friendica\Util\XML;
 
 /**
@@ -122,7 +125,9 @@ class System
 	 */
 	public static function httpExit($val, $message = '', $content = '')
 	{
-		Logger::log('http_status_exit ' . $val);
+		if ($val >= 400) {
+			Logger::debug('Exit with error', ['code' => $val, 'message' => $message, 'callstack' => System::callstack(20), 'method' => $_SERVER['REQUEST_METHOD'], 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '']);
+		}
 		header($_SERVER["SERVER_PROTOCOL"] . ' ' . $val . ' ' . $message);
 
 		echo $content;
@@ -132,6 +137,9 @@ class System
 
 	public static function jsonError($httpCode, $data, $content_type = 'application/json')
 	{
+		if ($httpCode >= 400) {
+			Logger::debug('Exit with error', ['code' => $httpCode, 'content_type' => $content_type, 'callstack' => System::callstack(20), 'method' => $_SERVER['REQUEST_METHOD'], 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '']);
+		}
 		header($_SERVER["SERVER_PROTOCOL"] . ' ' . $httpCode);
 		self::jsonExit($data, $content_type);
 	}
@@ -222,28 +230,25 @@ class System
 	 * @param string $url  The new Location to redirect
 	 * @param int    $code The redirection code, which is used (Default is 302)
 	 *
-	 * @throws InternalServerErrorException If the URL is not fully qualified
+	 * @throws BadRequestException If the URL is not fully qualified
 	 */
 	public static function externalRedirect($url, $code = 302)
 	{
 		if (empty(parse_url($url, PHP_URL_SCHEME))) {
-			throw new InternalServerErrorException("'$url' is not a fully qualified URL, please use App->internalRedirect() instead");
+			throw new BadRequestException("'$url' is not a fully qualified URL, please use App->internalRedirect() instead");
-		}
-
-		switch ($code) {
-			case 302:
-				// this is the default code for a REDIRECT
-				// We don't need a extra header here
-				break;
-			case 301:
-				header('HTTP/1.1 301 Moved Permanently');
-				break;
-			case 307:
-				header('HTTP/1.1 307 Temporary Redirect');
-				break;
 		}
 
 		header("Location: $url");
+
+		switch ($code) {
+			case 302:
+				throw new FoundException();
+			case 301:
+				throw new MovedPermanentlyException();
+			case 307:
+				throw new TemporaryRedirectException();
+		}
+
 		exit();
 	}
 

src/Database/Database.php

@@ -23,7 +23,7 @@ namespace Friendica\Database;
 
 use Friendica\Core\Config\Cache;
 use Friendica\Core\System;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\ServiceUnavailableException;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\Profiler;
 use mysqli;
@@ -520,7 +520,7 @@ class Database
 		$called_from_e = ($called_from['function'] == 'e');
 
 		if (!isset($this->connection)) {
-			throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
+			throw new ServiceUnavailableException('The Connection is empty, although connected is set true.');
 		}
 
 		switch ($this->driver) {

src/Factory/Api/Mastodon/Application.php

@@ -23,7 +23,7 @@ namespace Friendica\Factory\Api\Mastodon;
 
 use Friendica\BaseFactory;
 use Friendica\Database\Database;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\UnprocessableEntityException;
 use Psr\Log\LoggerInterface;
 
 class Application extends BaseFactory
@@ -42,13 +42,13 @@ class Application extends BaseFactory
 	 *
 	 * @return \Friendica\Object\Api\Mastodon\Application
 	 *
-	 * @throws InternalServerErrorException
+	 * @throws UnprocessableEntityException
 	 */
 	public function createFromApplicationId(int $id): \Friendica\Object\Api\Mastodon\Application
 	{
 		$application = $this->dba->selectFirst('application', ['client_id', 'client_secret', 'id', 'name', 'redirect_uri', 'website'], ['id' => $id]);
 		if (!$this->dba->isResult($application)) {
-			throw new InternalServerErrorException(sprintf("ID '%s' not found", $id));
+			throw new UnprocessableEntityException(sprintf("ID '%s' not found", $id));
 		}
 
 		return new \Friendica\Object\Api\Mastodon\Application(

src/Module/Admin/Summary.php

@@ -32,8 +32,7 @@ use Friendica\DI;
 use Friendica\Factory\ConfigFactory;
 use Friendica\Model\Register;
 use Friendica\Module\BaseAdmin;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\ServiceUnavailableException;
-use Friendica\Util\ConfigFileLoader;
 use Friendica\Util\DateTimeFormat;
 
 class Summary extends BaseAdmin
@@ -129,7 +128,7 @@ class Summary extends BaseAdmin
 				$stream = $fileSystem->createStream($file);
 
 				if (!isset($stream)) {
-					throw new InternalServerErrorException('Stream is null.');
+					throw new ServiceUnavailableException('Stream is null.');
 				}
 
 			} catch (\Throwable $exception) {
@@ -143,7 +142,7 @@ class Summary extends BaseAdmin
 					$stream = $fileSystem->createStream($file);
 
 					if (!isset($stream)) {
-						throw new InternalServerErrorException('Stream is null.');
+						throw new ServiceUnavailableException('Stream is null.');
 					}
 				}
 			} catch (\Throwable $exception) {

src/Module/Diaspora/Receive.php

@@ -96,7 +96,9 @@ class Receive extends BaseModule
 		if (Diaspora::dispatch($importer, $msg)) {
 			throw new HTTPException\OKException();
 		} else {
-			throw new HTTPException\InternalServerErrorException();
+			// We couldn't process the content.
+			// To avoid the remote system trying again we send the message that we accepted the content.
+			throw new HTTPException\AcceptedException();
 		}
 	}
 

src/Module/Friendica.php

@@ -30,6 +30,7 @@ use Friendica\Database\PostUpdate;
 use Friendica\DI;
 use Friendica\Model\User;
 use Friendica\Network\HTTPException;
+use Friendica\Network\HTTPException\ImATeapotException;
 use Friendica\Protocol\ActivityPub;
 
 /**

src/Module/Photo.php

@@ -33,6 +33,7 @@ use Friendica\Model\Storage\ExternalResource;
 use Friendica\Model\Storage\SystemResource;
 use Friendica\Model\User;
 use Friendica\Network\HTTPException;
+use Friendica\Network\HTTPException\NotModifiedException;
 use Friendica\Object\Image;
 use Friendica\Util\Images;
 use Friendica\Util\Network;
@@ -55,7 +56,6 @@ class Photo extends BaseModule
 		$totalstamp = microtime(true);
 
 		if (isset($_SERVER["HTTP_IF_MODIFIED_SINCE"])) {
-			header("HTTP/1.1 304 Not Modified");
 			header("Last-Modified: " . gmdate("D, d M Y H:i:s", time()) . " GMT");
 			if (!empty($_SERVER["HTTP_IF_NONE_MATCH"])) {
 				header("Etag: " . $_SERVER["HTTP_IF_NONE_MATCH"]);
@@ -67,7 +67,7 @@ class Photo extends BaseModule
 				header_remove("Expires");
 				header_remove("Cache-Control");
 			}
-			exit;
+			throw new NotModifiedException();
 		}
 
 		Profile::addVisitorCookieForHTTPSigner();

src/Module/Proxy.php

@@ -25,6 +25,7 @@ use Friendica\BaseModule;
 use Friendica\Core\Logger;
 use Friendica\Core\System;
 use Friendica\DI;
+use Friendica\Network\HTTPException\NotModifiedException;
 use Friendica\Object\Image;
 use Friendica\Util\HTTPSignature;
 use Friendica\Util\Images;
@@ -53,7 +54,6 @@ class Proxy extends BaseModule
 		}
 
 		if (isset($_SERVER["HTTP_IF_MODIFIED_SINCE"])) {
-			header("HTTP/1.1 304 Not Modified");
 			header("Last-Modified: " . gmdate("D, d M Y H:i:s", time()) . " GMT");
 			if (!empty($_SERVER["HTTP_IF_NONE_MATCH"])) {
 				header("Etag: " . $_SERVER["HTTP_IF_NONE_MATCH"]);
@@ -65,7 +65,7 @@ class Proxy extends BaseModule
 				header_remove("Expires");
 				header_remove("Cache-Control");
 			}
-			exit;
+			throw new NotModifiedException();
 		}
 
 		if (empty($request['url'])) {

src/Module/Special/HTTPException.php

@@ -21,6 +21,7 @@
 
 namespace Friendica\Module\Special;
 
+use Friendica\Core\Logger;
 use Friendica\Core\Renderer;
 use Friendica\Core\System;
 use Friendica\DI;
@@ -42,36 +43,10 @@ class HTTPException
 	 */
 	private static function getVars(\Friendica\Network\HTTPException $e)
 	{
-		$message = $e->getMessage();
+		// Explanations are mostly taken from https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
-
-		$titles = [
-			200 => 'OK',
-			400 => DI::l10n()->t('Bad Request'),
-			401 => DI::l10n()->t('Unauthorized'),
-			403 => DI::l10n()->t('Forbidden'),
-			404 => DI::l10n()->t('Not Found'),
-			500 => DI::l10n()->t('Internal Server Error'),
-			503 => DI::l10n()->t('Service Unavailable'),
-		];
-		$title = ($titles[$e->getCode()] ?? '') ?: 'Error ' . $e->getCode();
-
-		if (empty($message)) {
-			// Explanations are taken from https://en.wikipedia.org/wiki/List_of_HTTP_status_codes
-			$explanation = [
-				400 => DI::l10n()->t('The server cannot or will not process the request due to an apparent client error.'),
-				401 => DI::l10n()->t('Authentication is required and has failed or has not yet been provided.'),
-				403 => DI::l10n()->t('The request was valid, but the server is refusing action. The user might not have the necessary permissions for a resource, or may need an account.'),
-				404 => DI::l10n()->t('The requested resource could not be found but may be available in the future.'),
-				500 => DI::l10n()->t('An unexpected condition was encountered and no more specific message is suitable.'),
-				503 => DI::l10n()->t('The server is currently unavailable (because it is overloaded or down for maintenance). Please try again later.'),
-			];
-
-			$message = $explanation[$e->getCode()] ?? '';
-		}
-
 		$vars = [
-			'$title' => $title,
+			'$title' => $e->httpdesc ?: 'Error ' . $e->getCode(),
-			'$message' => $message,
+			'$message' => $e->getMessage() ?: $e->explanation,
 			'$back' => DI::l10n()->t('Go back'),
 			'$stack_trace' => DI::l10n()->t('Stack trace:'),
 		];
@@ -113,6 +88,10 @@ class HTTPException
 	{
 		header($_SERVER["SERVER_PROTOCOL"] . ' ' . $e->getCode() . ' ' . $e->httpdesc);
 
+		if ($e->getCode() >= 400) {
+			Logger::debug('Exit with error', ['code' => $e->getCode(), 'description' => $e->httpdesc, 'query' => DI::args()->getQueryString(), 'callstack' => System::callstack(20), 'method' => $_SERVER['REQUEST_METHOD'], 'agent' => $_SERVER['HTTP_USER_AGENT'] ?? '']);
+		}
+
 		$tpl = Renderer::getMarkupTemplate('exception.tpl');
 
 		return Renderer::replaceMacros($tpl, self::getVars($e));

src/Network/CurlResult.php

@@ -22,8 +22,7 @@
 namespace Friendica\Network;
 
 use Friendica\Core\Logger;
-use Friendica\Core\System;
+use Friendica\Network\HTTPException\UnprocessableEntityException;
-use Friendica\Network\HTTPException\InternalServerErrorException;
 use Friendica\Util\Network;
 
 /**
@@ -102,7 +101,7 @@ class CurlResult implements IHTTPResult
 	 * @param string $url optional URL
 	 *
 	 * @return IHTTPResult a CURL with error response
-	 * @throws InternalServerErrorException
+	 * @throws UnprocessableEntityException
 	 */
 	public static function createErrorCurl($url = '')
 	{
@@ -117,12 +116,12 @@ class CurlResult implements IHTTPResult
 	 * @param int $errorNumber the error number or 0 (zero) if no error
 	 * @param string $error the error message or '' (the empty string) if no
 	 *
-	 * @throws InternalServerErrorException when HTTP code of the CURL response is missing
+	 * @throws UnprocessableEntityException when HTTP code of the CURL response is missing
 	 */
 	public function __construct($url, $result, $info, $errorNumber = 0, $error = '')
 	{
 		if (!array_key_exists('http_code', $info)) {
-			throw new InternalServerErrorException('CURL response doesn\'t contains a response HTTP code');
+			throw new UnprocessableEntityException('CURL response doesn\'t contains a response HTTP code');
 		}
 
 		$this->returnCode = $info['http_code'];

src/Network/HTTPException.php

@@ -31,15 +31,11 @@ use Exception;
  */
 abstract class HTTPException extends Exception
 {
-	public $httpdesc = '';
+	public $httpdesc    = '';
+	public $explanation = '';
 
 	public function __construct($message = '', Exception $previous = null)
 	{
 		parent::__construct($message, $this->code, $previous);
-
-		if (empty($this->httpdesc)) {
-			$classname = str_replace('Exception', '', str_replace('Friendica\Network\HTTPException\\', '', get_class($this)));
-			$this->httpdesc = preg_replace("|([a-z])([A-Z])|",'$1 $2', $classname);
-		}
 	}
 }

src/Network/HTTPException/AcceptedException.php

@@ -26,4 +26,5 @@ use Friendica\Network\HTTPException;
 class AcceptedException extends HTTPException
 {
 	protected $code = 202;
+	var $httpdesc   = 'Accepted';
 }

src/Network/HTTPException/BadGatewayException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class BadGatewayException extends HTTPException
 {
-	protected $code = 502;
+	protected $code  = 502;
+	var $httpdesc    = 'Bad Gateway';
+	var $explanation = 'The server was acting as a gateway or proxy and received an invalid response from the upstream server.';
 }

src/Network/HTTPException/BadRequestException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class BadRequestException extends HTTPException
 {
-	protected $code = 400;
+	protected $code  = 400;
+	var $httpdesc    = 'Bad Request';
+	var $explanation = 'The server cannot or will not process the request due to an apparent client error.';
 }

src/Network/HTTPException/ConflictException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class ConflictException extends HTTPException
 {
-	protected $code = 409;
+	protected $code  = 409;
+	var $httpdesc    = 'Conflict ';
+	var $explanation = 'Indicates that the request could not be processed because of conflict in the current state of the resource, such as an edit conflict between multiple simultaneous updates.';
 }

src/Network/HTTPException/ExpectationFailedException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class ExpectationFailedException extends HTTPException
 {
-	protected $code = 417;
+	protected $code  = 417;
+	var $httpdesc    = 'Expectation Failed';
+	var $explanation = 'The server cannot meet the requirements of the Expect request-header field.';
 }

src/Network/HTTPException/ForbiddenException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class ForbiddenException extends HTTPException
 {
-	protected $code = 403;
+	protected $code  = 403;
+	var $httpdesc    = 'Forbidden';
+	var $explanation = 'The request was valid, but the server is refusing action. The user might not have the necessary permissions for a resource, or may need an account.';
 }

src/Network/HTTPException/FoundException.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Network\HTTPException;
+
+use Friendica\Network\HTTPException;
+
+class FoundException extends HTTPException
+{
+	protected $code = 302;
+	var $httpdesc   = 'Found (Moved Temporarily)';
+}

src/Network/HTTPException/GatewayTimeoutException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class GatewayTimeoutException extends HTTPException
 {
-	protected $code = 504;
+	protected $code  = 504;
+	var $httpdesc    = 'Gateway Timeout';
+	var $explanation = 'The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.';
 }

src/Network/HTTPException/GoneException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class GoneException extends HTTPException
 {
-	protected $code = 410;
+	protected $code  = 410;
+	var $httpdesc    = 'Gone';
+	var $explanation = 'Indicates that the resource requested is no longer available and will not be available again.';
 }

src/Network/HTTPException/ImATeapotException.php

@@ -25,6 +25,7 @@ use Friendica\Network\HTTPException;
 
 class ImATeapotException extends HTTPException
 {
-	protected $code = 418;
+	protected $code  = 418;
-	var $httpdesc = "I'm A Teapot";
+	var $httpdesc    = "I'm A Teapot";
+	var $explanation = 'This is a teapot that is requested to brew coffee.';
 }

src/Network/HTTPException/InternalServerErrorException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class InternalServerErrorException extends HTTPException
 {
-	protected $code = 500;
+	protected $code  = 500;
+	var $httpdesc    = 'Internal Server Error';
+	var $explanation = 'An unexpected condition was encountered and no more specific message is suitable.';
 }

src/Network/HTTPException/LenghtRequiredException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class LenghtRequiredException extends HTTPException
 {
-	protected $code = 411;
+	protected $code  = 411;
+	var $httpdesc    = 'Length Required';
+	var $explanation = 'The request did not specify the length of its content, which is required by the requested resource.';
 }

src/Network/HTTPException/MethodNotAllowedException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class MethodNotAllowedException extends HTTPException
 {
-	protected $code = 405;
+	protected $code  = 405;
+	var $httpdesc    = 'Method Not Allowed';
+	var $explanation = 'A request method is not supported for the requested resource; for example, a GET request on a form that requires data to be presented via POST, or a PUT request on a read-only resource.';
 }

src/Network/HTTPException/MovedPermanently.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Network\HTTPException;
+
+use Friendica\Network\HTTPException;
+
+class MovedPermanentlyException extends HTTPException
+{
+	protected $code = 301;
+	var $httpdesc   = 'Moved Permanently';
+}

src/Network/HTTPException/NoContentException.php

@@ -26,4 +26,5 @@ use Friendica\Network\HTTPException;
 class NoContentException extends HTTPException
 {
 	protected $code = 204;
+	var $httpdesc   = 'No Content';
 }

src/Network/HTTPException/NonAcceptableException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class NonAcceptableException extends HTTPException
 {
-	protected $code = 406;
+	protected $code  = 406;
+	var $httpdesc    = 'Not Acceptable';
+	var $explanation = 'The requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request.';
 }

src/Network/HTTPException/NotFoundException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class NotFoundException extends HTTPException
 {
-	protected $code = 404;
+	protected $code  = 404;
+	var $httpdesc    = 'Not Found';
+	var $explanation = 'The requested resource could not be found but may be available in the future.';
 }

src/Network/HTTPException/NotImplementedException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class NotImplementedException extends HTTPException
 {
-	protected $code = 501;
+	protected $code  = 501;
+	var $httpdesc    = 'Not Implemented';
+	var $explanation = 'The server either does not recognize the request method, or it lacks the ability to fulfil the request. Usually this implies future availability (e.g., a new feature of a web-service API).';
 }

src/Network/HTTPException/NotModifiedException.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Network\HTTPException;
+
+use Friendica\Network\HTTPException;
+
+class NotModifiedException extends HTTPException
+{
+	protected $code = 304;
+	var $httpdesc   = 'Not Modified';
+}

src/Network/HTTPException/OKException.php

@@ -26,4 +26,5 @@ use Friendica\Network\HTTPException;
 class OKException extends HTTPException
 {
 	protected $code = 200;
+	var $httpdesc   = 'OK';
 }

src/Network/HTTPException/PreconditionFailedException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class PreconditionFailedException extends HTTPException
 {
-	protected $code = 412;
+	protected $code  = 412;
+	var $httpdesc    = 'Precondition Failed';
+	var $explanation = 'The server does not meet one of the preconditions that the requester put on the request header fields.';
 }

src/Network/HTTPException/ServiceUnavailableException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class ServiceUnavailableException extends HTTPException
 {
-	protected $code = 503;
+	protected $code  = 503;
+	var $httpdesc    = 'Service Unavailable';
+	var $explanation = 'The server is currently unavailable (because it is overloaded or down for maintenance). Please try again later.';
 }

src/Network/HTTPException/TemporaryRedirectException.php

@@ -0,0 +1,30 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2021, the Friendica project
+ *
+ * @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 <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Network\HTTPException;
+
+use Friendica\Network\HTTPException;
+
+class TemporaryRedirectException extends HTTPException
+{
+	protected $code = 307;
+	var $httpdesc   = 'Temporary Redirect';
+}

src/Network/HTTPException/TooManyRequestsException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class TooManyRequestsException extends HTTPException
 {
-	protected $code = 429;
+	protected $code  = 429;
+	var $httpdesc    = 'Too Many Requests';
+	var $explanation = 'The user has sent too many requests in a given amount of time.';
 }

src/Network/HTTPException/UnauthorizedException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class UnauthorizedException extends HTTPException
 {
-	protected $code = 401;
+	protected $code  = 401;
+	var $httpdesc    = 'Unauthorized';
+	var $explanation = 'Authentication is required and has failed or has not yet been provided.';
 }

src/Network/HTTPException/UnprocessableEntityException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class UnprocessableEntityException extends HTTPException
 {
-	protected $code = 422;
+	protected $code  = 422;
+	var $httpdesc    = 'Unprocessable Entity';
+	var $explanation = 'The request was well-formed but was unable to be followed due to semantic errors.';
 }

src/Network/HTTPException/UnsupportedMediaTypeException.php

@@ -25,5 +25,7 @@ use Friendica\Network\HTTPException;
 
 class UnsupportedMediaTypeException extends HTTPException
 {
-	protected $code = 415;
+	protected $code  = 415;
+	var $httpdesc    = 'Unsupported Media Type';
+	var $explanation = 'The request entity has a media type which the server or resource does not support. For example, the client uploads an image as image/svg+xml, but the server requires that images use a different format.';
 }

src/Render/FriendicaSmartyEngine.php

@@ -23,7 +23,7 @@ namespace Friendica\Render;
 
 use Friendica\Core\Hook;
 use Friendica\DI;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\ServiceUnavailableException;
 use Friendica\Util\Strings;
 
 /**
@@ -54,7 +54,7 @@ final class FriendicaSmartyEngine extends TemplateEngine
 			$message = is_site_admin() ?
 				$admin_message :
 				DI::l10n()->t('Friendica can\'t display this page at the moment, please contact the administrator.');
-			throw new InternalServerErrorException($message);
+			throw new ServiceUnavailableException($message);
 		}
 	}
 

src/Util/EMailer/MailBuilder.php

@@ -27,7 +27,7 @@ use Friendica\Core\Config\IConfig;
 use Friendica\Core\L10n;
 use Friendica\Core\Renderer;
 use Friendica\Model\User;
-use Friendica\Network\HTTPException\InternalServerErrorException;
+use Friendica\Network\HTTPException\UnprocessableEntityException;
 use Friendica\Object\Email;
 use Friendica\Object\EMail\IEmail;
 use Psr\Log\LoggerInterface;
@@ -226,7 +226,7 @@ abstract class MailBuilder
 	 *
 	 * @return IEmail A new generated email
 	 *
-	 * @throws InternalServerErrorException
+	 * @throws UnprocessableEntityException
 	 * @throws Exception
 	 */
 	public function build(bool $raw = false)
@@ -241,11 +241,11 @@ abstract class MailBuilder
 		}
 
 		if (empty($this->recipientAddress)) {
-			throw new InternalServerErrorException('Recipient address is missing.');
+			throw new UnprocessableEntityException('Recipient address is missing.');
 		}
 
 		if (empty($this->senderAddress) || empty($this->senderName)) {
-			throw new InternalServerErrorException('Sender address or name is missing.');
+			throw new UnprocessableEntityException('Sender address or name is missing.');
 		}
 
 		$this->senderNoReply = $this->senderNoReply ?? $this->senderAddress;

src/Util/HTTPSignature.php

@@ -476,7 +476,7 @@ class HTTPSignature
 	public static function getSigner($content, $http_headers)
 	{
 		if (empty($http_headers['HTTP_SIGNATURE'])) {
-			Logger::info('No HTTP_SIGNATURE header');
+			Logger::debug('No HTTP_SIGNATURE header');
 			return false;
 		}
 

src/Util/Network.php

@@ -25,6 +25,7 @@ use Friendica\Core\Hook;
 use Friendica\Core\Logger;
 use Friendica\DI;
 use Friendica\Model\Contact;
+use Friendica\Network\HTTPException\NotModifiedException;
 
 class Network
 {
@@ -544,8 +545,7 @@ class Network
 		header('Last-Modified: ' . $last_modified);
 
 		if ($flag_not_modified) {
-			header("HTTP/1.1 304 Not Modified");
+			throw new NotModifiedException();
-			exit;
 		}
 	}
 

src/Worker/Notifier.php

@@ -693,7 +693,7 @@ class Notifier
 	private static function notifySelfRemoval($self_user_id, $priority, $created)
 	{
 		$owner = User::getOwnerDataById($self_user_id);
-		if (!$owner) {
+		if (empty($self_user_id) || empty($owner)) {
 			return false;
 		}
 

view/theme/frio/style.php

@@ -20,6 +20,7 @@
  */
 
 use Friendica\DI;
+use Friendica\Network\HTTPException\NotModifiedException;
 use Friendica\Util\Strings;
 
 require_once 'view/theme/frio/theme.php';
@@ -225,8 +226,7 @@ if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && isset($_SERVER['HTTP_IF_NONE_MA
 				stripslashes($_SERVER['HTTP_IF_NONE_MATCH']));
 
 	if (($cached_modified == $modified) && ($cached_etag == $etag)) {
-		header('HTTP/1.1 304 Not Modified');
+		throw new NotModifiedException();
-		exit();
 	}
 }
 

view/theme/vier/style.php

@@ -21,6 +21,7 @@
 
 use Friendica\Core\Logger;
 use Friendica\DI;
+use Friendica\Network\HTTPException\NotModifiedException;
 
 $uid = $_REQUEST['puid'] ?? 0;
 
@@ -67,8 +68,7 @@ if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && isset($_SERVER['HTTP_IF_NONE_MA
 				stripslashes($_SERVER['HTTP_IF_NONE_MATCH']));
 
 	if (($cached_modified == $modified) && ($cached_etag == $etag)) {
-		header('HTTP/1.1 304 Not Modified');
+		throw new NotModifiedException();
-		exit();
 	}
 }
 echo $stylecss;