mirror of
https://github.com/webtorrent/bittorrent-tracker.git
synced 2024-12-13 19:06:27 +00:00
615 lines
18 KiB
JavaScript
615 lines
18 KiB
JavaScript
module.exports = Server
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var bencode = require('bencode')
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var debug = require('debug')('bittorrent-tracker')
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var dgram = require('dgram')
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var EventEmitter = require('events').EventEmitter
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var http = require('http')
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var inherits = require('inherits')
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var series = require('run-series')
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var string2compact = require('string2compact')
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var WebSocketServer = require('ws').Server
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var common = require('./lib/common')
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var Swarm = require('./lib/server/swarm')
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var parseHttpRequest = require('./lib/server/parse-http')
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var parseUdpRequest = require('./lib/server/parse-udp')
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var parseWebSocketRequest = require('./lib/server/parse-websocket')
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inherits(Server, EventEmitter)
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/**
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* BitTorrent tracker server.
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*
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* HTTP service which responds to GET requests from torrent clients. Requests include
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* metrics from clients that help the tracker keep overall statistics about the torrent.
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* Responses include a peer list that helps the client participate in the torrent.
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*
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* @param {Object} opts options object
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* @param {Number} opts.interval tell clients to announce on this interval (ms)
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* @param {Number} opts.trustProxy trust 'x-forwarded-for' header from reverse proxy
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* @param {boolean} opts.http start an http server? (default: true)
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* @param {boolean} opts.udp start a udp server? (default: true)
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* @param {boolean} opts.ws start a websocket server? (default: true)
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* @param {function} opts.filter black/whitelist fn for disallowing/allowing torrents
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*/
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function Server (opts) {
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var self = this
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if (!(self instanceof Server)) return new Server(opts)
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EventEmitter.call(self)
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if (!opts) opts = {}
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debug('new server %s', JSON.stringify(opts))
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self.intervalMs = opts.interval
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? opts.interval
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: 10 * 60 * 1000 // 10 min
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self._trustProxy = !!opts.trustProxy
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if (typeof opts.filter === 'function') self._filter = opts.filter
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self._listenCalled = false
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self.listening = false
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self.destroyed = false
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self.torrents = {}
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self.http = null
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self.udp4 = null
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self.udp6 = null
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self.ws = null
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// start an http tracker unless the user explictly says no
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if (opts.http !== false) {
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self.http = http.createServer()
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self.http.on('error', function (err) { self._onError(err) })
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self.http.on('listening', onListening)
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// Add default http request handler on next tick to give user the chance to add
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// their own handler first. Handle requests untouched by user's handler.
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process.nextTick(function () {
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self.http.on('request', function (req, res) {
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if (res.headersSent) return
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self.onHttpRequest(req, res)
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})
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})
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}
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// start a udp tracker unless the user explicitly says no
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if (opts.udp !== false) {
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var isNode10 = /^v0.10./.test(process.version)
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self.udp4 = self.udp = dgram.createSocket(
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isNode10 ? 'udp4' : { type: 'udp4', reuseAddr: true }
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)
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self.udp4.on('message', function (msg, rinfo) { self.onUdpRequest(msg, rinfo) })
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self.udp4.on('error', function (err) { self._onError(err) })
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self.udp4.on('listening', onListening)
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self.udp6 = dgram.createSocket(
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isNode10 ? 'udp6' : { type: 'udp6', reuseAddr: true }
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)
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self.udp6.on('message', function (msg, rinfo) { self.onUdpRequest(msg, rinfo) })
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self.udp6.on('error', function (err) { self._onError(err) })
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self.udp6.on('listening', onListening)
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}
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// start a websocket tracker (for WebTorrent) unless the user explicitly says no
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if (opts.ws !== false) {
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if (!self.http) {
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self.http = http.createServer()
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self.http.on('error', function (err) { self._onError(err) })
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self.http.on('listening', onListening)
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// Add default http request handler on next tick to give user the chance to add
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// their own handler first. Handle requests untouched by user's handler.
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process.nextTick(function () {
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self.http.on('request', function (req, res) {
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if (res.headersSent) return
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// For websocket trackers, we only need to handle the UPGRADE http method.
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// Return 404 for all other request types.
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res.statusCode = 404
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res.end('404 Not Found')
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})
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})
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}
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self.ws = new WebSocketServer({ server: self.http })
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self.ws.address = self.http.address.bind(self.http)
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self.ws.on('error', function (err) { self._onError(err) })
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self.ws.on('connection', function (socket) { self.onWebSocketConnection(socket) })
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}
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var num = !!self.http + !!self.udp4 + !!self.udp6
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function onListening () {
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num -= 1
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if (num === 0) {
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self.listening = true
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debug('listening')
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self.emit('listening')
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}
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}
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}
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Server.prototype._onError = function (err) {
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var self = this
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self.emit('error', err)
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}
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Server.prototype.listen = function (/* port, hostname, onlistening */) {
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var self = this
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if (self._listenCalled || self.listening) throw new Error('server already listening')
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self._listenCalled = true
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var lastArg = arguments[arguments.length - 1]
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if (typeof lastArg === 'function') self.once('listening', lastArg)
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var port = toNumber(arguments[0]) || arguments[0] || 0
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var hostname = typeof arguments[1] !== 'function' ? arguments[1] : undefined
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debug('listen (port: %o hostname: %o)', port, hostname)
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function isObject (obj) {
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return typeof obj === 'object' && obj !== null
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}
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var httpPort = isObject(port) ? (port.http || 0) : port
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var udpPort = isObject(port) ? (port.udp || 0) : port
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// binding to :: only receives IPv4 connections if the bindv6only sysctl is set 0,
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// which is the default on many operating systems
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var httpHostname = isObject(hostname) ? hostname.http : hostname
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var udp4Hostname = isObject(hostname) ? hostname.udp : hostname
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var udp6Hostname = isObject(hostname) ? hostname.udp6 : hostname
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if (self.http) self.http.listen(httpPort, httpHostname)
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if (self.udp4) self.udp4.bind(udpPort, udp4Hostname)
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if (self.udp6) self.udp6.bind(udpPort, udp6Hostname)
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}
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Server.prototype.close = function (cb) {
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var self = this
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if (!cb) cb = function () {}
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debug('close')
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self.listening = false
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self.destroyed = true
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if (self.udp4) {
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try {
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self.udp4.close()
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} catch (err) {}
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}
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if (self.udp6) {
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try {
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self.udp6.close()
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} catch (err) {}
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}
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if (self.ws) {
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try {
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self.ws.close()
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} catch (err) {}
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}
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if (self.http) self.http.close(cb)
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else cb(null)
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}
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Server.prototype.createSwarm = function (infoHash, cb) {
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var self = this
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if (Buffer.isBuffer(infoHash)) infoHash = infoHash.toString('hex')
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process.nextTick(function () {
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var swarm = self.torrents[infoHash] = new Swarm(infoHash, self)
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cb(null, swarm)
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})
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}
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Server.prototype.getSwarm = function (infoHash, cb) {
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var self = this
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if (Buffer.isBuffer(infoHash)) infoHash = infoHash.toString('hex')
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process.nextTick(function () {
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cb(null, self.torrents[infoHash])
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})
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}
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Server.prototype.onHttpRequest = function (req, res, opts) {
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var self = this
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if (!opts) opts = {}
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opts.trustProxy = opts.trustProxy || self._trustProxy
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var params
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try {
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params = parseHttpRequest(req, opts)
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params.httpReq = req
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params.httpRes = res
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} catch (err) {
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res.end(bencode.encode({
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'failure reason': err.message
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}))
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// even though it's an error for the client, it's just a warning for the server.
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// don't crash the server because a client sent bad data :)
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self.emit('warning', err)
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return
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}
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self._onRequest(params, function (err, response) {
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if (err) {
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self.emit('warning', err)
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response = {
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'failure reason': err.message
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}
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}
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if (self.destroyed) return res.end()
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delete response.action // only needed for UDP encoding
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res.end(bencode.encode(response))
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if (params.action === common.ACTIONS.ANNOUNCE) {
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self.emit(common.EVENT_NAMES[params.event], params.addr, params)
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}
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})
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}
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Server.prototype.onUdpRequest = function (msg, rinfo) {
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var self = this
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var params
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try {
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params = parseUdpRequest(msg, rinfo)
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} catch (err) {
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self.emit('warning', err)
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// Do not reply for parsing errors
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return
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}
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self._onRequest(params, function (err, response) {
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if (err) {
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self.emit('warning', err)
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response = {
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action: common.ACTIONS.ERROR,
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'failure reason': err.message
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}
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}
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if (self.destroyed) return
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response.transactionId = params.transactionId
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response.connectionId = params.connectionId
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var buf = makeUdpPacket(response)
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try {
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var udp = (rinfo.family === 'IPv4') ? self.udp4 : self.udp6
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udp.send(buf, 0, buf.length, rinfo.port, rinfo.address)
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} catch (err) {
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self.emit('warning', err)
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}
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if (params.action === common.ACTIONS.ANNOUNCE) {
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self.emit(common.EVENT_NAMES[params.event], params.addr, params)
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}
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})
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}
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Server.prototype.onWebSocketConnection = function (socket) {
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var self = this
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socket.peerId = null // as hex
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socket.infoHashes = []
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socket.onSend = self._onWebSocketSend.bind(self, socket)
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socket.on('message', self._onWebSocketRequest.bind(self, socket))
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socket.on('error', self._onWebSocketError.bind(self, socket))
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socket.on('close', self._onWebSocketClose.bind(self, socket))
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}
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Server.prototype._onWebSocketRequest = function (socket, params) {
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var self = this
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try {
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params = parseWebSocketRequest(socket, params)
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} catch (err) {
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socket.send(JSON.stringify({
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'failure reason': err.message,
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info_hash: common.hexToBinary(params.info_hash)
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}), socket.onSend)
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// even though it's an error for the client, it's just a warning for the server.
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// don't crash the server because a client sent bad data :)
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self.emit('warning', err)
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return
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}
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if (!socket.peerId) socket.peerId = params.peer_id // as hex
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self._onRequest(params, function (err, response) {
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if (err) {
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self.emit('warning', err)
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response = {
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'failure reason': err.message
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}
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}
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if (self.destroyed) return
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if (socket.infoHashes.indexOf(params.info_hash) === -1) {
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socket.infoHashes.push(params.info_hash)
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}
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var peers = response.peers
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delete response.peers
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// WebSocket tracker should have a shorter interval – default: 2 minutes
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response.interval = Math.ceil(self.intervalMs / 1000 / 5)
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response.info_hash = common.hexToBinary(params.info_hash)
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socket.send(JSON.stringify(response), socket.onSend)
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debug('sent response %s to %s', JSON.stringify(response), params.peer_id)
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if (params.numwant) {
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debug('got offers %s from %s', JSON.stringify(params.offers), params.peer_id)
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debug('got %s peers from swarm %s', peers.length, params.info_hash)
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peers.forEach(function (peer, i) {
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peer.socket.send(JSON.stringify({
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offer: params.offers[i].offer,
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offer_id: params.offers[i].offer_id,
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peer_id: common.hexToBinary(params.peer_id),
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info_hash: common.hexToBinary(params.info_hash)
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}), peer.socket.onSend)
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debug('sent offer to %s from %s', peer.peerId, params.peer_id)
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})
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}
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if (params.answer) {
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debug('got answer %s from %s', JSON.stringify(params.answer), params.peer_id)
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self.getSwarm(params.info_hash, function (err, swarm) {
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if (err) return self.emit('warning', err)
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if (!swarm) {
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return self.emit('warning', new Error('no swarm with that `info_hash`'))
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}
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var toPeer = swarm.peers[params.to_peer_id]
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if (!toPeer) {
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return self.emit('warning', new Error('no peer with that `to_peer_id`'))
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}
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toPeer.socket.send(JSON.stringify({
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answer: params.answer,
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offer_id: params.offer_id,
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peer_id: common.hexToBinary(params.peer_id),
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info_hash: common.hexToBinary(params.info_hash)
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}), toPeer.socket.onSend)
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debug('sent answer to %s from %s', toPeer.peerId, params.peer_id)
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done()
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})
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} else {
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done()
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}
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function done () {
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// emit event once the announce is fully "processed"
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if (params.action === common.ACTIONS.ANNOUNCE) {
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self.emit(common.EVENT_NAMES[params.event], params.peer_id, params)
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}
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}
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})
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}
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Server.prototype._onRequest = function (params, cb) {
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var self = this
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if (params && params.action === common.ACTIONS.CONNECT) {
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cb(null, { action: common.ACTIONS.CONNECT })
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} else if (params && params.action === common.ACTIONS.ANNOUNCE) {
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self._onAnnounce(params, cb)
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} else if (params && params.action === common.ACTIONS.SCRAPE) {
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self._onScrape(params, cb)
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} else {
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cb(new Error('Invalid action'))
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}
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}
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Server.prototype._onAnnounce = function (params, cb) {
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var self = this
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self.getSwarm(params.info_hash, function (err, swarm) {
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if (err) return cb(err)
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if (swarm) {
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announce(swarm)
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} else {
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createSwarm()
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}
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})
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function createSwarm () {
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if (self._filter) {
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self._filter(params.info_hash, params, function (allowed) {
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if (allowed instanceof Error) {
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cb(allowed)
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} else if (!allowed) {
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cb(new Error('disallowed info_hash'))
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} else {
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self.createSwarm(params.info_hash, function (err, swarm) {
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if (err) return cb(err)
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announce(swarm)
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})
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}
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})
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} else {
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self.createSwarm(params.info_hash, function (err, swarm) {
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if (err) return cb(err)
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announce(swarm)
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})
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}
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}
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function announce (swarm) {
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if (!params.event || params.event === 'empty') params.event = 'update'
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swarm.announce(params, function (err, response) {
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if (err) return cb(err)
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if (!response.action) response.action = common.ACTIONS.ANNOUNCE
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if (!response.interval) response.interval = Math.ceil(self.intervalMs / 1000)
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if (params.compact === 1) {
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var peers = response.peers
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// Find IPv4 peers
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response.peers = string2compact(peers.filter(function (peer) {
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return common.IPV4_RE.test(peer.ip)
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}).map(function (peer) {
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return peer.ip + ':' + peer.port
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}))
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// Find IPv6 peers
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response.peers6 = string2compact(peers.filter(function (peer) {
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return common.IPV6_RE.test(peer.ip)
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}).map(function (peer) {
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return '[' + peer.ip + ']:' + peer.port
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}))
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} else if (params.compact === 0) {
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// IPv6 peers are not separate for non-compact responses
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response.peers = response.peers.map(function (peer) {
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return {
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'peer id': common.hexToBinary(peer.peerId),
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ip: peer.ip,
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port: peer.port
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}
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})
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} // else, return full peer objects (used for websocket responses)
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cb(null, response)
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})
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}
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}
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Server.prototype._onScrape = function (params, cb) {
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var self = this
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if (params.info_hash == null) {
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// if info_hash param is omitted, stats for all torrents are returned
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// TODO: make this configurable!
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params.info_hash = Object.keys(self.torrents)
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}
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series(params.info_hash.map(function (infoHash) {
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return function (cb) {
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self.getSwarm(infoHash, function (err, swarm) {
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if (err) return cb(err)
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if (swarm) {
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swarm.scrape(params, function (err, scrapeInfo) {
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if (err) return cb(err)
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cb(null, {
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infoHash: infoHash,
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complete: (scrapeInfo && scrapeInfo.complete) || 0,
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incomplete: (scrapeInfo && scrapeInfo.incomplete) || 0
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})
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})
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} else {
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cb(null, { infoHash: infoHash, complete: 0, incomplete: 0 })
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}
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})
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}
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}), function (err, results) {
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||
if (err) return cb(err)
|
||
|
||
var response = {
|
||
action: common.ACTIONS.SCRAPE,
|
||
files: {},
|
||
flags: { min_request_interval: Math.ceil(self.intervalMs / 1000) }
|
||
}
|
||
|
||
results.forEach(function (result) {
|
||
response.files[common.hexToBinary(result.infoHash)] = {
|
||
complete: result.complete || 0,
|
||
incomplete: result.incomplete || 0,
|
||
downloaded: result.complete || 0 // TODO: this only provides a lower-bound
|
||
}
|
||
})
|
||
|
||
cb(null, response)
|
||
})
|
||
}
|
||
|
||
function makeUdpPacket (params) {
|
||
var packet
|
||
switch (params.action) {
|
||
case common.ACTIONS.CONNECT:
|
||
packet = Buffer.concat([
|
||
common.toUInt32(common.ACTIONS.CONNECT),
|
||
common.toUInt32(params.transactionId),
|
||
params.connectionId
|
||
])
|
||
break
|
||
case common.ACTIONS.ANNOUNCE:
|
||
packet = Buffer.concat([
|
||
common.toUInt32(common.ACTIONS.ANNOUNCE),
|
||
common.toUInt32(params.transactionId),
|
||
common.toUInt32(params.interval),
|
||
common.toUInt32(params.incomplete),
|
||
common.toUInt32(params.complete),
|
||
params.peers
|
||
])
|
||
break
|
||
case common.ACTIONS.SCRAPE:
|
||
var scrapeResponse = [
|
||
common.toUInt32(common.ACTIONS.SCRAPE),
|
||
common.toUInt32(params.transactionId)
|
||
]
|
||
for (var infoHash in params.files) {
|
||
var file = params.files[infoHash]
|
||
scrapeResponse.push(
|
||
common.toUInt32(file.complete),
|
||
common.toUInt32(file.downloaded), // TODO: this only provides a lower-bound
|
||
common.toUInt32(file.incomplete)
|
||
)
|
||
}
|
||
packet = Buffer.concat(scrapeResponse)
|
||
break
|
||
case common.ACTIONS.ERROR:
|
||
packet = Buffer.concat([
|
||
common.toUInt32(common.ACTIONS.ERROR),
|
||
common.toUInt32(params.transactionId || 0),
|
||
new Buffer(params['failure reason'], 'utf8')
|
||
])
|
||
break
|
||
default:
|
||
throw new Error('Action not implemented: ' + params.action)
|
||
}
|
||
return packet
|
||
}
|
||
|
||
Server.prototype._onWebSocketSend = function (socket, err) {
|
||
var self = this
|
||
if (err) self._onWebSocketError(socket, err)
|
||
}
|
||
|
||
Server.prototype._onWebSocketClose = function (socket) {
|
||
var self = this
|
||
if (!socket.peerId || !socket.infoHashes) return
|
||
debug('websocket close')
|
||
|
||
socket.infoHashes.forEach(function (infoHash) {
|
||
var swarm = self.torrents[infoHash]
|
||
if (swarm) {
|
||
swarm.announce({
|
||
event: 'stopped',
|
||
numwant: 0,
|
||
peer_id: socket.peerId
|
||
}, function () {})
|
||
}
|
||
})
|
||
}
|
||
|
||
Server.prototype._onWebSocketError = function (socket, err) {
|
||
var self = this
|
||
debug('websocket error %s', err.message || err)
|
||
self.emit('warning', err)
|
||
self._onWebSocketClose(socket)
|
||
}
|
||
|
||
function toNumber (x) {
|
||
x = Number(x)
|
||
return x >= 0 ? x : false
|
||
}
|