server/lib/files.php

<?php

/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @copyright 2012 Frank Karlitschek frank@owncloud.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * Class for fileserver access
 *
 */
class OC_Files {
	static $tmpFiles = array();

	/**
	 * return the content of a file or return a zip file containning multiply files
	 *
	 * @param string $dir
	 * @param string $file ; seperated list of files to download
	 * @param boolean $only_header ; boolean to only send header of the request
	 */
	public static function get($dir, $files, $only_header = false) {
		if (strpos($files, ';')) {
			$files = explode(';', $files);
		}

		if (is_array($files)) {
			self::validateZipDownload($dir, $files);
			$executionTime = intval(ini_get('max_execution_time'));
			set_time_limit(0);
			$zip = new ZipArchive();
			$filename = OC_Helper::tmpFile('.zip');
			if ($zip->open($filename, ZIPARCHIVE::CREATE | ZIPARCHIVE::OVERWRITE) !== true) {
				exit("cannot open <$filename>\n");
			}
			foreach ($files as $file) {
				$file = $dir . '/' . $file;
				if (\OC\Files\Filesystem::is_file($file)) {
					$tmpFile = \OC\Files\Filesystem::toTmpFile($file);
					self::$tmpFiles[] = $tmpFile;
					$zip->addFile($tmpFile, basename($file));
				} elseif (\OC\Files\Filesystem::is_dir($file)) {
					self::zipAddDir($file, $zip);
				}
			}
			$zip->close();
			set_time_limit($executionTime);
		} elseif (\OC\Files\Filesystem::is_dir($dir . '/' . $files)) {
			self::validateZipDownload($dir, $files);
			$executionTime = intval(ini_get('max_execution_time'));
			set_time_limit(0);
			$zip = new ZipArchive();
			$filename = OC_Helper::tmpFile('.zip');
			if ($zip->open($filename, ZIPARCHIVE::CREATE | ZIPARCHIVE::OVERWRITE) !== true) {
				exit("cannot open <$filename>\n");
			}
			$file = $dir . '/' . $files;
			self::zipAddDir($file, $zip);
			$zip->close();
			set_time_limit($executionTime);
		} else {
			$zip = false;
			$filename = $dir . '/' . $files;
		}
		@ob_end_clean();
		if ($zip or \OC\Files\Filesystem::isReadable($filename)) {
			header('Content-Disposition: attachment; filename="' . basename($filename) . '"');
			header('Content-Transfer-Encoding: binary');
			OC_Response::disableCaching();
			if ($zip) {
				ini_set('zlib.output_compression', 'off');
				header('Content-Type: application/zip');
				header('Content-Length: ' . filesize($filename));
			} else {
				header('Content-Type: ' . \OC\Files\Filesystem::getMimeType($filename));
			}
		} elseif ($zip or !\OC\Files\Filesystem::file_exists($filename)) {
			header("HTTP/1.0 404 Not Found");
			$tmpl = new OC_Template('', '404', 'guest');
			$tmpl->assign('file', $filename);
			$tmpl->printPage();
		} else {
			header("HTTP/1.0 403 Forbidden");
			die('403 Forbidden');
		}
		if ($only_header) {
			if (!$zip)
				header("Content-Length: " . \OC\Files\Filesystem::filesize($filename));
			return;
		}
		if ($zip) {
			$handle = fopen($filename, 'r');
			if ($handle) {
				$chunkSize = 8 * 1024; // 1 MB chunks
				while (!feof($handle)) {
					echo fread($handle, $chunkSize);
					flush();
				}
			}
			unlink($filename);
		} else {
			\OC\Files\Filesystem::readfile($filename);
		}
		foreach (self::$tmpFiles as $tmpFile) {
			if (file_exists($tmpFile) and is_file($tmpFile)) {
				unlink($tmpFile);
			}
		}
	}

	public static function zipAddDir($dir, $zip, $internalDir = '') {
		$dirname = basename($dir);
		$zip->addEmptyDir($internalDir . $dirname);
		$internalDir .= $dirname .= '/';
		$files = \OC\Files\Filesystem::getDirectoryContent($dir);
		foreach ($files as $file) {
			$filename = $file['name'];
			$file = $dir . '/' . $filename;
			if (\OC\Files\Filesystem::is_file($file)) {
				$tmpFile = \OC\Files\Filesystem::toTmpFile($file);
				OC_Files::$tmpFiles[] = $tmpFile;
				$zip->addFile($tmpFile, $internalDir . $filename);
			} elseif (\OC\Files\Filesystem::is_dir($file)) {
				self::zipAddDir($file, $zip, $internalDir);
			}
		}
	}

	/**
	 * checks if the selected files are within the size constraint. If not, outputs an error page.
	 *
	 * @param dir   $dir
	 * @param files $files
	 */
	static function validateZipDownload($dir, $files) {
		if (!OC_Config::getValue('allowZipDownload', true)) {
			$l = OC_L10N::get('lib');
			header("HTTP/1.0 409 Conflict");
			$tmpl = new OC_Template('', 'error', 'user');
			$errors = array(
				array(
					'error' => $l->t('ZIP download is turned off.'),
					'hint' => $l->t('Files need to be downloaded one by one.') . '<br/><a href="javascript:history.back()">' . $l->t('Back to Files') . '</a>',
				)
			);
			$tmpl->assign('errors', $errors);
			$tmpl->printPage();
			exit;
		}

		$zipLimit = OC_Config::getValue('maxZipInputSize', OC_Helper::computerFileSize('800 MB'));
		if ($zipLimit > 0) {
			$totalsize = 0;
			if (is_array($files)) {
				foreach ($files as $file) {
					$totalsize += \OC\Files\Filesystem::filesize($dir . '/' . $file);
				}
			} else {
				$totalsize += \OC\Files\Filesystem::filesize($dir . '/' . $files);
			}
			if ($totalsize > $zipLimit) {
				$l = OC_L10N::get('lib');
				header("HTTP/1.0 409 Conflict");
				$tmpl = new OC_Template('', 'error', 'user');
				$errors = array(
					array(
						'error' => $l->t('Selected files too large to generate zip file.'),
						'hint' => 'Download the files in smaller chunks, seperately or kindly ask your administrator.<br/><a href="javascript:history.back()">' . $l->t('Back to Files') . '</a>',
					)
				);
				$tmpl->assign('errors', $errors);
				$tmpl->printPage();
				exit;
			}
		}
	}

	/**
	 * set the maximum upload size limit for apache hosts using .htaccess
	 *
	 * @param int size filesisze in bytes
	 * @return false on failure, size on success
	 */
	static function setUploadLimit($size) {
		//don't allow user to break his config -- upper boundary
		if ($size > PHP_INT_MAX) {
			//max size is always 1 byte lower than computerFileSize returns
			if ($size > PHP_INT_MAX + 1)
				return false;
			$size -= 1;
		} else {
			$size = OC_Helper::humanFileSize($size);
			$size = substr($size, 0, -1); //strip the B
			$size = str_replace(' ', '', $size); //remove the space between the size and the postfix
		}

		//don't allow user to break his config -- broken or malicious size input
		if (intval($size) == 0) {
			return false;
		}

		$htaccess = @file_get_contents(OC::$SERVERROOT . '/.htaccess'); //supress errors in case we don't have permissions for
		if (!$htaccess) {
			return false;
		}

		$phpValueKeys = array(
			'upload_max_filesize',
			'post_max_size'
		);

		foreach ($phpValueKeys as $key) {
			$pattern = '/php_value ' . $key . ' (\S)*/';
			$setting = 'php_value ' . $key . ' ' . $size;
			$hasReplaced = 0;
			$content = preg_replace($pattern, $setting, $htaccess, 1, $hasReplaced);
			if ($content !== null) {
				$htaccess = $content;
			}
			if ($hasReplaced == 0) {
				$htaccess .= "\n" . $setting;
			}
		}

		//check for write permissions
		if (is_writable(OC::$SERVERROOT . '/.htaccess')) {
			file_put_contents(OC::$SERVERROOT . '/.htaccess', $htaccess);
			return OC_Helper::computerFileSize($size);
		} else {
			OC_Log::write('files', 'Can\'t write upload limit to ' . OC::$SERVERROOT . '/.htaccess. Please check the file permissions', OC_Log::WARN);
		}

		return false;
	}
}