const dns = require('dns') const minecraftJavaPing = require('mc-ping-updated') const minecraftBedrockPing = require('mcpe-ping-fixed') const logger = require('./logger') const MessageOf = require('./message') const config = require('../config') function ping (host, port, type, timeout, callback, version) { switch (type) { case 'PC': unfurlSrv(host, port, (host, port) => { minecraftJavaPing(host, port || 25565, (err, res) => { if (err) { callback(err) } else { const payload = { players: { online: capPlayerCount(host, parseInt(res.players.online)) }, version: parseInt(res.version.protocol) } // Ensure the returned favicon is a data URI if (res.favicon && res.favicon.startsWith('data:image/')) { payload.favicon = res.favicon } callback(null, payload) } }, timeout, version) }) break case 'PE': minecraftBedrockPing(host, port || 19132, (err, res) => { if (err) { callback(err) } else { callback(null, { players: { online: capPlayerCount(host, parseInt(res.currentPlayers)) } }) } }, timeout) break default: throw new Error('Unsupported type: ' + type) } } function unfurlSrv (hostname, port, callback) { dns.resolveSrv('_minecraft._tcp.' + hostname, (_, records) => { if (!records || records.length < 1) { callback(hostname, port) } else { callback(records[0].name, records[0].port) } }) } // player count can be up to 1^32-1, which is a massive scale and destroys browser performance when rendering graphs // Artificially cap and warn to prevent propogating garbage function capPlayerCount (host, playerCount) { const maxPlayerCount = 250000 if (playerCount !== Math.min(playerCount, maxPlayerCount)) { logger.log('warn', '%s returned a player count of %d, Minetrack has capped it to %d to prevent browser performance issues with graph rendering. If this is in error, please edit maxPlayerCount in ping.js!', host, playerCount, maxPlayerCount) return maxPlayerCount } else if (playerCount !== Math.max(playerCount, 0)) { logger.log('warn', '%s returned an invalid player count of %d, setting to 0.', host, playerCount) return 0 } return playerCount } class PingController { constructor (app) { this._app = app } schedule () { setInterval(this.pingAll, config.rates.pingAll) this.pingAll() } pingAll = () => { for (const serverRegistration of this._app.serverRegistrations) { const version = serverRegistration.getNextProtocolVersion() ping(serverRegistration.data.ip, serverRegistration.data.port, serverRegistration.data.type, config.rates.connectTimeout, (err, resp) => { if (err) { logger.log('error', 'Failed to ping %s: %s', serverRegistration.data.ip, err.message) } this.handlePing(serverRegistration, resp, err, version) }, version.protocolId) } } handlePing (serverRegistration, resp, err, version) { const timestamp = new Date().getTime() serverRegistration.addPing(timestamp, resp) let updateHistoryGraph = false if (config.logToDatabase) { const playerCount = resp ? resp.players.online : 0 // Log to database this._app.database.insertPing(serverRegistration.data.ip, timestamp, playerCount) if (serverRegistration.addGraphPoint(resp !== undefined, playerCount, timestamp)) { updateHistoryGraph = true } } // Generate a combined update payload // This includes any modified fields and flags used by the frontend // This will not be cached and can contain live metadata const updateMessage = serverRegistration.getUpdate(timestamp, resp, err, version, updateHistoryGraph) this._app.server.broadcast(MessageOf('updateServer', updateMessage)) } } module.exports = PingController