From 28395d55e5d3e7a1c7b302a3a5d34459803db12d Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Sun, 4 Feb 2024 12:42:21 +0100
Subject: [PATCH 1/4] Refactor the logging system

---
 inc/config.php            |  17 +++-
 inc/driver/log-driver.php | 189 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+), 2 deletions(-)
 create mode 100644 inc/driver/log-driver.php

diff --git a/inc/config.php b/inc/config.php
index ffd1b544..c34eb034 100644
--- a/inc/config.php
+++ b/inc/config.php
@@ -65,8 +65,21 @@
 	// been generated. This keeps the script from querying the database and causing strain when not needed.
 	$config['has_installed'] = '.installed';
 
-	// Use syslog() for logging all error messages and unauthorized login attempts.
-	$config['syslog'] = false;
+	// Deprecated, use 'log_system'.
+	// $config['syslog'] = false;
+
+	$config['log_system'] = [];
+	// Log all error messages and unauthorized login attempts.
+	// Can be "syslog", "error_log" (default), "file", "stderr" or "none".
+	$config['log_system']['type'] = 'error_log';
+	// The application name used by the logging system. Defaults to "tinyboard" for backwards compatibility.
+	$config['log_system']['name'] = 'tinyboard';
+	// Only relevant if 'log_system' is set to "syslog". If true, double print the logs also in stderr.
+	// Defaults to false.
+	$config['log_system']['syslog_stderr'] = false;
+	// Only relevant if "log_system" is set to `file`. Sets the file that vichan will log to.
+	// Defaults to '/var/log/vichan.log'.
+	$config['log_system']['file_path'] = '/var/log/vichan.log';
 
 	// Use `host` via shell_exec() to lookup hostnames, avoiding query timeouts. May not work on your system.
 	// Requires safe_mode to be disabled.
diff --git a/inc/driver/log-driver.php b/inc/driver/log-driver.php
new file mode 100644
index 00000000..0026f009
--- /dev/null
+++ b/inc/driver/log-driver.php
@@ -0,0 +1,189 @@
+<?php // Logging
+namespace Vichan\Driver;
+
+use InvalidArgumentException;
+use RuntimeException;
+
+defined('TINYBOARD') or exit;
+
+
+class LogDrivers {
+	public static function levelToString(int $level): string {
+		switch ($level) {
+			case Log::EMERG:
+				return 'EMERG';
+			case Log::ERROR:
+				return 'ERROR';
+			case Log::WARNING:
+				return 'WARNING';
+			case Log::NOTICE:
+				return 'NOTICE';
+			case Log::INFO:
+				return 'INFO';
+			case Log::DEBUG:
+				return 'DEBUG';
+			default:
+				throw new InvalidArgumentException('Not a logging level');
+		}
+	}
+
+	/**
+	 * Log to syslog.
+	 */
+	public static function syslog(string $name, int $level, bool $print_stderr): Log {
+		$flags = LOG_ODELAY;
+		if ($print_stderr) {
+			$flags |= LOG_PERROR;
+		}
+
+		if (!openlog($name, $flags, LOG_USER)) {
+			throw new RuntimeException('Unable to open syslog');
+		}
+
+		return new class($level) implements Log {
+			private $level;
+
+			public function __construct(int $level) {
+				$this->level = $level;
+			}
+
+			public function log(int $level, string $message): void {
+				if ($level <= $this->level) {
+					if (isset($_SERVER['REMOTE_ADDR'], $_SERVER['REQUEST_METHOD'], $_SERVER['REQUEST_URI'])) {
+						// CGI
+						syslog($level, "$message - client: {$_SERVER['REMOTE_ADDR']}, request: \"{$_SERVER['REQUEST_METHOD']} {$_SERVER['REQUEST_URI']}\"");
+					} else {
+						syslog($level, $message);
+					}
+				}
+			}
+		};
+	}
+
+	/**
+	 * Log via the php function error_log.
+	 */
+	public static function error_log(string $name, int $level): Log {
+		return new class($name, $level) implements Log {
+			private string $name;
+			private int $level;
+
+			public function __construct(string $name, int $level) {
+				$this->name = $name;
+				$this->level = $level;
+			}
+
+			public function log(int $level, string $message): void {
+				if ($level <= $this->level) {
+					$lv = LogDrivers::levelToString($level);
+					$line = "{$this->name} $lv: $message";
+					error_log($line, 0, null, null);
+				}
+			}
+		};
+	}
+
+	/**
+	 * Log to a file.
+	 */
+	public static function file(string $name, int $level, string $file_path): Log {
+		/*
+		 * error_log is slow as hell in it's 3rd mode, so use fopen + file locking instead.
+		 * https://grobmeier.solutions/performance-ofnonblocking-write-to-files-via-php-21082009.html
+		 *
+		 * Whatever file appending is atomic is contentious:
+		 *  - There are no POSIX guarantees: https://stackoverflow.com/a/7237901
+		 *  - But linus suggested they are on linux, on some filesystems: https://web.archive.org/web/20151201111541/http://article.gmane.org/gmane.linux.kernel/43445
+		 *  - But it doesn't seem to be always the case: https://www.notthewizard.com/2014/06/17/are-files-appends-really-atomic/
+		 *
+		 * So we just use file locking to be sure.
+		 */
+
+		$fd = fopen($file_path, 'a');
+		if ($fd === false) {
+			throw new RuntimeException("Unable to open log file at $file_path");
+		}
+
+		$logger = new class($name, $level, $fd) implements Log {
+			private string $name;
+			private int $level;
+			private mixed $fd;
+
+			public function __construct(string $name, int $level, mixed $fd) {
+				$this->name = $name;
+				$this->level = $level;
+				$this->fd = $fd;
+			}
+
+			public function log(int $level, string $message): void {
+				if ($level <= $this->level) {
+					$lv = LogDrivers::levelToString($level);
+					$line = "{$this->name} $lv: $message\n";
+					flock($this->fd, LOCK_EX);
+					fwrite($this->fd, $line);
+					flock($this->fd, LOCK_UN);
+				}
+			}
+
+			public function close() {
+				fclose($this->fd);
+			}
+		};
+
+		// Close the file on shutdown.
+		register_shutdown_function([$logger, 'close']);
+
+		return $logger;
+	}
+
+	/**
+	 * Log to php's standard error file stream.
+	 */
+	public static function stderr(string $name, int $level): Log {
+		return new class($name, $level) implements Log {
+			private $name;
+			private $level;
+
+			public function __construct(string $name, int $level) {
+				$this->name = $name;
+				$this->level = $level;
+			}
+
+			public function log(int $level, string $message): void {
+				if ($level <= $this->level) {
+					$lv = LogDrivers::levelToString($level);
+					fwrite(STDERR, "{$this->name} $lv: $message\n");
+				}
+			}
+		};
+	}
+
+	/**
+	 * No-op logging system.
+	 */
+	public static function none(): Log {
+		return new class() implements Log {
+			public function log($level, $message): void {
+				// No-op.
+			}
+		};
+	}
+}
+
+interface Log {
+	public const EMERG = LOG_EMERG;
+	public const ERROR = LOG_ERR;
+	public const WARNING = LOG_WARNING;
+	public const NOTICE = LOG_NOTICE;
+	public const INFO = LOG_INFO;
+	public const DEBUG = LOG_DEBUG;
+
+
+	/**
+	 * Log a message if the level of relevancy is at least the minimum.
+	 *
+	 * @param int $level Message level. Use Log interface constants.
+	 * @param string $message The message to log.
+	 */
+	public function log(int $level, string $message): void;
+}

From f05c290b67ed5a359a0e8170ac5177eddbb70ad9 Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Thu, 4 Apr 2024 09:56:59 +0200
Subject: [PATCH 2/4] log-driver.php: autoload the logging dirver

---
 composer.json | 1 +
 1 file changed, 1 insertion(+)

diff --git a/composer.json b/composer.json
index e1951679..b06ff6a1 100644
--- a/composer.json
+++ b/composer.json
@@ -34,6 +34,7 @@
             "inc/queue.php",
             "inc/functions.php",
             "inc/driver/http-driver.php",
+            "inc/driver/log-driver.php",
             "inc/service/captcha-queries.php"
         ]
     },

From 55cb6bc400513ea5ca23ea0aac6cefa7c212f122 Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Wed, 3 Apr 2024 23:42:05 +0200
Subject: [PATCH 3/4] context.php: add log driver

---
 inc/context.php | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/inc/context.php b/inc/context.php
index 5e540bab..3e52b569 100644
--- a/inc/context.php
+++ b/inc/context.php
@@ -1,24 +1,53 @@
 <?php
 namespace Vichan;
 
-defined('TINYBOARD') or exit;
+use Vichan\Driver\{HttpDriver, HttpDrivers, Log, LogDrivers};
 
-use Vichan\Driver\{HttpDriver, HttpDrivers};
+defined('TINYBOARD') or exit;
 
 
 interface Context {
+	public function getLog(): Log;
 	public function getHttpDriver(): HttpDriver;
 }
 
 class AppContext implements Context {
 	private array $config;
+	private ?Log $log;
 	private ?HttpDriver $http;
 
 
+	private function initLogDriver(): Log {
+		$name = $this->config['log_system']['name'];
+		$level = $this->config['debug'] ? Log::DEBUG : Log::NOTICE;
+		$backend = $this->config['log_system']['type'];
+
+		// Check 'syslog' for backwards compatibility.
+		if ((isset($this->config['syslog']) && $this->config['syslog']) || $backend === 'syslog') {
+			return LogDrivers::syslog($name, $level, $this->config['log_system']['syslog_stderr']);
+		} elseif ($backend === 'file') {
+			return LogDrivers::file($name, $level, $this->config['log_system']['file_path']);
+		} elseif ($backend === 'stderr') {
+			return LogDrivers::stderr($name, $level);
+		} elseif ($backend === 'none') {
+			return LogDrivers::none();
+		} else {
+			return LogDrivers::error_log($name, $level);
+		}
+	}
+
+
 	public function __construct(array $config) {
 		$this->config = $config;
 	}
 
+	public function getLog(): Log {
+		if (is_null($this->log)) {
+			$this->log = $this->initLogDriver();
+		}
+		return $this->log;
+	}
+
 	public function getHttpDriver(): HttpDriver {
 		if (is_null($this->http)) {
 			$this->http = HttpDrivers::getHttpDriver($this->config['upload_by_url_timeout'], $this->config['max_filesize']);

From 710f6aa6c2983dee3295e7586b19782c7f2fa88c Mon Sep 17 00:00:00 2001
From: Zankaria <zankaria.auxa@skiff.com>
Date: Wed, 3 Apr 2024 23:51:02 +0200
Subject: [PATCH 4/4] post.php: use logger

---
 post.php | 54 +++++++++++++++++++++++-------------------------------
 1 file changed, 23 insertions(+), 31 deletions(-)

diff --git a/post.php b/post.php
index 387b1a97..487cf2dc 100644
--- a/post.php
+++ b/post.php
@@ -7,6 +7,7 @@ require_once 'inc/bootstrap.php';
 
 use Vichan\AppContext;
 use Vichan\Driver\HttpDriver;
+use Vichan\Driver\Log;
 use Vichan\Service\{RemoteCaptchaQuery, NativeCaptchaQuery};
 
 /**
@@ -250,7 +251,7 @@ if (isset($_GET['Newsgroups']) && $config['nntpchan']['enabled']) {
 		$content = file_get_contents("php://input");
 	}
 	elseif ($ct == 'multipart/mixed' || $ct == 'multipart/form-data') {
-		_syslog(LOG_INFO, "MM: Files: ".print_r($GLOBALS, true)); // Debug
+		$context->getLog()->log(Log::DEBUG, 'MM: Files: ' . print_r($GLOBALS, true));
 
 		$content = '';
 
@@ -415,8 +416,9 @@ if (isset($_POST['delete'])) {
 				modLog("User at $ip deleted their own post #$id");
 			}
 
-			_syslog(LOG_INFO, 'Deleted post: ' .
-				'/' . $board['dir'] . $config['dir']['res'] . link_for($post) . ($post['thread'] ? '#' . $id : '')
+			$context->getLog()->log(
+				Log::INFO,
+				'Deleted post: /' . $board['dir'] . $config['dir']['res'] . link_for($post) . ($post['thread'] ? '#' . $id : '')
 			);
 		}
 	}
@@ -491,9 +493,7 @@ if (isset($_POST['delete'])) {
 				error($config['error']['captcha']);
 			}
 		} catch (RuntimeException $e) {
-			if ($config['syslog']) {
-				_syslog(LOG_ERR, "Native captcha IO exception: {$e->getMessage()}");
-			}
+			$context->getLog()->log(Log::ERROR, "Native captcha IO exception: {$e->getMessage()}");
 			error($config['error']['local_io_error']);
 		}
 	}
@@ -512,9 +512,7 @@ if (isset($_POST['delete'])) {
 
 		$post = $query->fetch(PDO::FETCH_ASSOC);
 		if ($post === false) {
-			if ($config['syslog']) {
-				_syslog(LOG_INFO, "Failed to report non-existing post #{$id} in {$board['dir']}");
-			}
+			$context->getLog()->log(Log::INFO, "Failed to report non-existing post #{$id} in {$board['dir']}");
 			error($config['error']['nopost']);
 		}
 
@@ -523,11 +521,12 @@ if (isset($_POST['delete'])) {
 			error($error);
 		}
 
-		if ($config['syslog'])
-			_syslog(LOG_INFO, 'Reported post: ' .
-				'/' . $board['dir'] . $config['dir']['res'] . link_for($post) . ($post['thread'] ? '#' . $id : '') .
-				' for "' . $reason . '"'
-			);
+		$context->getLog()->log(
+			Log::INFO,
+			'Reported post: /'
+				 . $board['dir'] . $config['dir']['res'] . link_for($post) . ($post['thread'] ? '#' . $id : '')
+				 . " for \"$reason\""
+		);
 		$query = prepare("INSERT INTO ``reports`` VALUES (NULL, :time, :ip, :board, :post, :reason)");
 		$query->bindValue(':time', time(), PDO::PARAM_INT);
 		$query->bindValue(':ip', $_SERVER['REMOTE_ADDR'], PDO::PARAM_STR);
@@ -637,14 +636,10 @@ if (isset($_POST['delete'])) {
 				}
 			}
 		} catch (RuntimeException $e) {
-			if ($config['syslog']) {
-				_syslog(LOG_ERR, "Captcha IO exception: {$e->getMessage()}");
-			}
+			$context->getLog()->log(Log::ERROR, "Captcha IO exception: {$e->getMessage()}");
 			error($config['error']['remote_io_error']);
 		} catch (JsonException $e) {
-			if ($config['syslog']) {
-				_syslog(LOG_ERR, "Bad JSON reply to captcha: {$e->getMessage()}");
-			}
+			$context->getLog()->log(Log::ERROR, "Bad JSON reply to captcha: {$e->getMessage()}");
 			error($config['error']['remote_io_error']);
 		}
 
@@ -1128,11 +1123,9 @@ if (isset($_POST['delete'])) {
 					try {
 						$file['size'] = strip_image_metadata($file['tmp_name']);
 					} catch (RuntimeException $e) {
-						if ($config['syslog']) {
-							_syslog(LOG_ERR, "Could not strip image metadata: {$e->getMessage()}");
-							// Since EXIF metadata can countain sensible info, fail the request.
-							error(_('Could not strip EXIF metadata!'), null, $error);
-						}
+						$context->getLog()->log(Log::ERROR, "Could not strip image metadata: {$e->getMessage()}");
+						// Since EXIF metadata can countain sensible info, fail the request.
+						error(_('Could not strip EXIF metadata!'), null, $error);
 					}
 				} else {
 					$image->to($file['file']);
@@ -1168,9 +1161,7 @@ if (isset($_POST['delete'])) {
 						$post['body_nomarkup'] .= "<tinyboard ocr image $key>" . htmlspecialchars($value) . "</tinyboard>";
 					}
 				} catch (RuntimeException $e) {
-					if ($config['syslog']) {
-						_syslog(LOG_ERR, "Could not OCR image: {$e->getMessage()}");
-					}
+					$context->getLog()->log(Log::ERROR, "Could not OCR image: {$e->getMessage()}");
 				}
 			}
 		}
@@ -1360,9 +1351,10 @@ if (isset($_POST['delete'])) {
 
 	buildThread($post['op'] ? $id : $post['thread']);
 
-	if ($config['syslog'])
-		_syslog(LOG_INFO, 'New post: /' . $board['dir'] . $config['dir']['res'] .
-			link_for($post) . (!$post['op'] ? '#' . $id : ''));
+	$context->getLog()->log(
+		Log::INFO,
+		'New post: /' . $board['dir'] . $config['dir']['res'] . link_for($post) . (!$post['op'] ? '#' . $id : '')
+	);
 
 	if (!$post['mod']) header('X-Associated-Content: "' . $redirect . '"');