utils.js

/*
    ***** BEGIN LICENSE BLOCK *****
    
    Copyright © 2015 Zotero
                     https://www.zotero.org
    
    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/>.
    
    ***** END LICENSE BLOCK *****
*/

"use strict";

var config = require('config');
var log = require('./log');

module.exports = function () {
	//
	// Private functions
	//
	function WSError (code, message) {
		if (code < 1000) {
			code += 4000;
		}
		this.code = code;
		this.message = message || "";
	}
	WSError.prototype = new Error; // e instanceof Error == true
	
	
	//
	// Public methods
	//
	return {
		end: function (req, res, code, msg) {
			if (!code) {
				log.warn("Response code not provided to utils.end()")
				code = 500;
			}
			
			var logMessage = msg instanceof Error ? msg.stack : msg;
			log.info('"' + req.method + " " + req.url + '" ' + code
				+ (logMessage ? " - " + logMessage : ""), req);
			
			res.writeHead(
				code,
				{
					'Content-Type': 'text/plain',
					'Connection': 'close'
				}
			);
			
			// For 500 errors, hide real error message unless this is a dev site
			if (this.isServerError(code) && (!config.has('dev') || !config.get('dev'))) {
				msg = "Error";
			}
			res.end(msg);
		},
		
		wsEnd: function (ws, code, msg) {
			if (!code) {
				code = 4500;
			}
			else if (code < 1000) {
				code += 4000;
			}
			
			if (msg instanceof Error) {
				var logMessage = msg.stack;
				msg = msg.message;
			}
			else {
				var logMessage = msg;
			}
			log.info(code + " - " + logMessage, ws);
			
			// For 500 errors other than 503, hide real error message unless this is a dev site
			if (this.isServerError(code - 4000) && code != 4503 && (!config.has('dev') || !config.get('dev'))) {
				msg = "Error";
			}
			// Close frame is 125, and we can only use 123
			const MAX_PAYLOAD = 123;
			// Up to first newline or max payload, whichever comes first
			ws.close(code, msg.match(/^[^\n]+/, msg)[0].substring(0, MAX_PAYLOAD));
		},
		
		getIPAddressFromRequest: function (request) {
			try {
				let addr = request.socket.clientAddress || request.socket.remoteAddress;
				return addr;
			}
			catch (e) {
				log.error(e);
				return "";
			}
		},
		
		plural: function (str, num) {
			return str + (num != 1 ? 's' : '');
		},
		
		isClientError: function (code) {
			return code >= 400 && code < 500;
		},
		
		isServerError: function (code) {
			return code >= 500 && code < 600;
		},
		
		WSError: WSError
	};
}()