gorrion/gemini.class.php

<?php
error_reporting(E_ALL);
set_time_limit(-1);
ob_implicit_flush();

class Gemini {

	function __construct($config) {
		try {
			if(empty($config['certificate_file']))
				die("Missing certificate file.  Edit config.php\n");
			$this->ip = "0";
			$this->port = "1965";
			$this->data_dir = "hosts/";
			$this->default_host_dir = "default/";
			$this->default_index_file = "index.gemini";
			$this->logging = 1;
			$this->log_file = "logs/gemini-php.log";
			$this->log_sep = "\t";
			$settings = array('ip', 'port', 'data_dir', 'default_host_dir', 'default_index_file',
					'certificate_file', 'certificate_passphrase');
			foreach($settings as $setting_key) {
				if(!empty($config[$setting_key]))
					$this->$setting_key = $config[$setting_key];
			}
			// append the required filepath slashes if they're missing
			if(substr($this->data_dir, -1) != "/")
				$this->data_dir .= "/";
			if(substr($this->default_host_dir, -1) != "/")
				$this->default_host_dir .= "/";
			if($this->logging) {
				if(!file_exists($this->log_file)) {
					$this->log_to_file("Log created", null, null, null, null);
				}
				if(!is_writable($this->log_file)) {
					die("{$this->log_file} is not writable.\n");
				}
			}
			if(!is_readable($this->certificate_file)) {
				die("Certificate file {$this->certificate_file} not readable.\n");
			}
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	function parse_request($request) {
		try {
			$url = trim($request); // strip <CR><LF> from the end
			return parse_url($url);
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	function get_valid_hosts() {
		try {
			$dirs = array_map('basename', glob($this->data_dir.'*', GLOB_ONLYDIR));
			return $dirs;
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	function get_status_code($filepath) {
		try {
			if(is_file($filepath) and file_exists($filepath))
				return "20";
			if(!file_exists($filepath))
				return "51";
			return "50";
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	function get_mime_type($filepath) {
		try {
			$type = mime_content_type($filepath);
			// we need a way to detect gemini file types, which PHP doesn't
			// so.. if it ends with gemini (or if it has no extension), assume
			$path_parts = pathinfo($filepath);
			if(empty($path_parts['extension']) or $path_parts['extension'] == "gemini")
				$type = "text/gemini";
			return $type;
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	/**
	* Gets the full file path (assumes directory structure based on host)
	*
	* This function determines where the requested file is stored
	* based on the hostname supplied in the request from the client.
	* If no host is supplied, the default directory is assumed.
	*
	* @param array $url An array returned by the parse_request() method
	*
	* @return string
	*/
	function get_filepath($url) {
		try {
			$hostname = "";
			if(!is_array($url))
				return false;
			if(!empty($url['host']))
				$hostname = $url['host'];

			$valid_hosts = $this->get_valid_hosts();
			if(!in_array($hostname, $valid_hosts))
				$hostname = "default";

			// Kristall Browser is adding "__" to the end of the filenames
			// wtf am I missing?
			// also removing ".." to mitigate against directory traversal
			$url['path'] = str_replace(array("..", "__"), "", $url['path']);
			// force an index file to be appended if a filename is missing
			if(empty($url['path'])) {
				$url['path'] = "/".$this->default_index_file;
			} elseif(substr($url['path'], -1) == "/") {
				$url['path'] .= $this->default_index_file;
			}

			$valid_data_dir = dirname(__FILE__)."/".$this->data_dir;
			$return_path = $this->data_dir.$hostname.$url['path'];
			// check the real path is in the data_dir (path traversal sanity check)
			if(substr(realpath($return_path),0, strlen($valid_data_dir)) == $valid_data_dir) {
				return $return_path;
			}
			return false;
		}
		catch(exception $e) {
			error_log($e);
		}
	}

	function log_to_file($ip, $status_code, $meta, $filepath, $filesize) {
		try {
			$ts = date("Y-m-d H:i:s", strtotime('now'));
			$this->log_sep;
			$str = $ts.$this->log_sep.$ip.$this->log_sep.$status_code.$this->log_sep.
			$meta.$this->log_sep.$filepath.$this->log_sep.$filesize."\n";
			file_put_contents($this->log_file, $str, FILE_APPEND);
		}
		catch(exception $e) {
			error_log($e);
		}
	}
}

?>