server/controllers/tracker.ts

   1 import { logger } from '../helpers/logger'
   2 import * as express from 'express'
   3 import * as http from 'http'
   4 import * as bitTorrentTracker from 'bittorrent-tracker'
   5 import * as proxyAddr from 'proxy-addr'
   6 import { Server as WebSocketServer } from 'ws'
   7 import { CONFIG, TRACKER_RATE_LIMITS } from '../initializers/constants'
   8
   9 const TrackerServer = bitTorrentTracker.Server
  10
  11 const trackerRouter = express.Router()
  12
  13 let peersIps = {}
  14 let peersIpInfoHash = {}
  15 runPeersChecker()
  16
  17 const trackerServer = new TrackerServer({
  18   http: false,
  19   udp: false,
  20   ws: false,
  21   dht: false,
  22   filter: function (infoHash, params, cb) {
  23     let ip: string
  24
  25     if (params.type === 'ws') {
  26       ip = params.socket.ip
  27     } else {
  28       ip = params.httpReq.ip
  29     }
  30
  31     const key = ip + '-' + infoHash
  32
  33     peersIps[ip] = peersIps[ip] ? peersIps[ip] + 1 : 1
  34     peersIpInfoHash[key] = peersIpInfoHash[key] ? peersIpInfoHash[key] + 1 : 1
  35
  36     if (peersIpInfoHash[key] > TRACKER_RATE_LIMITS.ANNOUNCES_PER_IP_PER_INFOHASH) {
  37       return cb(new Error(`Too many requests (${peersIpInfoHash[ key ]} of ip ${ip} for torrent ${infoHash}`))
  38     }
  39
  40     return cb()
  41   }
  42 })
  43
  44 trackerServer.on('error', function (err) {
  45   logger.error('Error in tracker.', { err })
  46 })
  47
  48 trackerServer.on('warning', function (err) {
  49   logger.warn('Warning in tracker.', { err })
  50 })
  51
  52 const onHttpRequest = trackerServer.onHttpRequest.bind(trackerServer)
  53 trackerRouter.get('/tracker/announce', (req, res) => onHttpRequest(req, res, { action: 'announce' }))
  54 trackerRouter.get('/tracker/scrape', (req, res) => onHttpRequest(req, res, { action: 'scrape' }))
  55
  56 function createWebsocketServer (app: express.Application) {
  57   const server = http.createServer(app)
  58   const wss = new WebSocketServer({ server: server, path: '/tracker/socket' })
  59   wss.on('connection', function (ws, req) {
  60     const ip = proxyAddr(req, CONFIG.TRUST_PROXY)
  61     ws['ip'] = ip
  62
  63     trackerServer.onWebSocketConnection(ws)
  64   })
  65
  66   return server
  67 }
  68
  69 // ---------------------------------------------------------------------------
  70
  71 export {
  72   trackerRouter,
  73   createWebsocketServer
  74 }
  75
  76 // ---------------------------------------------------------------------------
  77
  78 function runPeersChecker () {
  79   setInterval(() => {
  80     logger.debug('Checking peers.')
  81
  82     for (const ip of Object.keys(peersIpInfoHash)) {
  83       if (peersIps[ip] > TRACKER_RATE_LIMITS.ANNOUNCES_PER_IP) {
  84         logger.warn('Peer %s made abnormal requests (%d).', ip, peersIps[ip])
  85       }
  86     }
  87
  88     peersIpInfoHash = {}
  89     peersIps = {}
  90   }, TRACKER_RATE_LIMITS.INTERVAL)
  91 }