diff --git a/server.js b/server.js index 3370b56..26b12e0 100644 --- a/server.js +++ b/server.js @@ -1,4 +1,5 @@ module.exports = Server +module.exports.parseHttpRequest = parseHttpRequest var bencode = require('bencode') var bufferEqual = require('buffer-equal') @@ -138,48 +139,43 @@ Server.prototype._getSwarm = function (binaryInfoHash) { Server.prototype._onHttpRequest = function (req, res) { var self = this - var s = req.url.split('?') - var params = common.querystringParse(s[1]) + + var params + try { + params = parseHttpRequest(req, { + trustProxy: self._trustProxy + }) + } catch (err) { + debug('sent error %s', err.message) + res.end(bencode.encode({ + 'failure reason': err.message + })) + + // even though it's an error for the client, it's just a warning for the server. + // don't crash the server because a client sent bad data :) + self.emit('warning', err) + + return + } + var response - if (s[0] === '/announce') { - var infoHash = typeof params.info_hash === 'string' && params.info_hash - var peerId = typeof params.peer_id === 'string' && common.binaryToUtf8(params.peer_id) - var port = Number(params.port) - - if (!infoHash) return error('invalid info_hash') - if (infoHash.length !== 20) return error('invalid info_hash') - if (!peerId) return error('invalid peer_id') - if (peerId.length !== 20) return error('invalid peer_id') - if (!port) return error('invalid port') - - var left = Number(params.left) - var compact = Number(params.compact) - - var ip = self._trustProxy - ? req.headers['x-forwarded-for'] || req.connection.remoteAddress - : req.connection.remoteAddress.replace(REMOVE_IPV6_RE, '') // force ipv4 - var addr = ip + ':' + port - var swarm = self._getSwarm(infoHash) - var peer = swarm.peers[addr] - - var numWant = Math.min( - Number(params.numwant) || NUM_ANNOUNCE_PEERS, - MAX_ANNOUNCE_PEERS - ) + if (params && params.request === 'announce') { + var swarm = self._getSwarm(params.info_hash) + var peer = swarm.peers[params.addr] var start = function () { if (peer) { debug('unexpected `started` event from peer that is already in swarm') return update() // treat as an update } - if (left === 0) swarm.complete += 1 + if (params.left === 0) swarm.complete += 1 else swarm.incomplete += 1 - peer = swarm.peers[addr] = { - ip: ip, - port: port, - peerId: peerId + peer = swarm.peers[params.addr] = { + ip: params.ip, + port: params.port, + peerId: params.peer_id } - self.emit('start', addr) + self.emit('start', params.addr) } var stop = function () { @@ -189,8 +185,8 @@ Server.prototype._onHttpRequest = function (req, res) { } if (peer.complete) swarm.complete -= 1 else swarm.incomplete -= 1 - swarm.peers[addr] = null - self.emit('stop', addr) + swarm.peers[params.addr] = null + self.emit('stop', params.addr) } var complete = function () { @@ -205,7 +201,7 @@ Server.prototype._onHttpRequest = function (req, res) { swarm.complete += 1 swarm.incomplete -= 1 peer.complete = true - self.emit('complete', addr) + self.emit('complete', params.addr) } var update = function () { @@ -213,7 +209,7 @@ Server.prototype._onHttpRequest = function (req, res) { debug('unexpected `update` event from peer that is not in swarm') return start() // treat as a start } - self.emit('update', addr) + self.emit('update', params.addr) } switch (params.event) { @@ -233,12 +229,12 @@ Server.prototype._onHttpRequest = function (req, res) { return error('invalid event') // early return } - if (left === 0 && peer) peer.complete = true + if (params.left === 0 && peer) peer.complete = true // send peers - var peers = compact === 1 - ? self._getPeersCompact(swarm, numWant) - : self._getPeers(swarm, numWant) + var peers = params.compact === 1 + ? self._getPeersCompact(swarm, params.numwant) + : self._getPeers(swarm, params.numwant) response = { complete: swarm.complete, @@ -250,11 +246,12 @@ Server.prototype._onHttpRequest = function (req, res) { res.end(bencode.encode(response)) debug('sent response %s', response) - } else if (s[0] === '/scrape') { // unofficial scrape message + } else if (params.request === 'scrape') { // unofficial scrape message if (typeof params.info_hash === 'string') { params.info_hash = [ params.info_hash ] } else if (params.info_hash == null) { // if info_hash param is omitted, stats for all torrents are returned + // TODO: make this configurable! params.info_hash = Object.keys(self.torrents) } @@ -268,11 +265,6 @@ Server.prototype._onHttpRequest = function (req, res) { } params.info_hash.some(function (infoHash) { - if (infoHash.length !== 20) { - error('invalid info_hash') - return true // early return - } - var swarm = self._getSwarm(infoHash) response.files[infoHash] = { @@ -338,7 +330,7 @@ Server.prototype._onUdpRequest = function (msg, rinfo) { var event = msg.readUInt32BE(80) var ip = msg.readUInt32BE(84) // optional var key = msg.readUInt32BE(88) // TODO: what is this for? - var numWant = msg.readUInt32BE(92) // optional + var numwant = msg.readUInt32BE(92) // optional var port = msg.readUInt16BE(96) // optional if (ip) { @@ -358,7 +350,7 @@ Server.prototype._onUdpRequest = function (msg, rinfo) { // never send more than MAX_ANNOUNCE_PEERS or else the UDP packet will get bigger than // 512 bytes which is not safe - numWant = Math.min(numWant || NUM_ANNOUNCE_PEERS, MAX_ANNOUNCE_PEERS) + numwant = Math.min(numwant || NUM_ANNOUNCE_PEERS, MAX_ANNOUNCE_PEERS) var start = function () { if (peer) { @@ -429,7 +421,7 @@ Server.prototype._onUdpRequest = function (msg, rinfo) { if (left === 0 && peer) peer.complete = true // send peers - var peers = self._getPeersCompact(swarm, numWant) + var peers = self._getPeersCompact(swarm, numwant) send(Buffer.concat([ common.toUInt32(common.ACTIONS.ANNOUNCE), @@ -479,10 +471,10 @@ Server.prototype._onUdpRequest = function (msg, rinfo) { } } -Server.prototype._getPeers = function (swarm, numWant) { +Server.prototype._getPeers = function (swarm, numwant) { var peers = [] for (var peerId in swarm.peers) { - if (peers.length >= numWant) break + if (peers.length >= numwant) break var peer = swarm.peers[peerId] if (!peer) continue // ignore null values peers.push({ @@ -494,11 +486,11 @@ Server.prototype._getPeers = function (swarm, numWant) { return peers } -Server.prototype._getPeersCompact = function (swarm, numWant) { +Server.prototype._getPeersCompact = function (swarm, numwant) { var peers = [] for (var peerId in swarm.peers) { - if (peers.length >= numWant) break + if (peers.length >= numwant) break var peer = swarm.peers[peerId] if (!peer) continue // ignore null values peers.push(peer.ip + ':' + peer.port) @@ -507,6 +499,61 @@ Server.prototype._getPeersCompact = function (swarm, numWant) { return string2compact(peers) } + +function parseHttpRequest (req, options) { + var s = req.url.split('?') + var params = common.querystringParse(s[1]) + + if (s[0] === '/announce') { + params.request = 'announce' + + params.peer_id = typeof params.peer_id === 'string' && common.binaryToUtf8(params.peer_id) + params.port = Number(params.port) + + if (typeof params.info_hash !== 'string') throw new Error('invalid info_hash') + if (params.info_hash.length !== 20) throw new Error('invalid info_hash length') + if (typeof params.peer_id !== 'string') throw new Error('invalid peer_id') + if (params.peer_id.length !== 20) throw new Error('invalid peer_id length') + if (!params.port) throw new Error('invalid port') + + params.left = Number(params.left) + params.compact = Number(params.compact) + + params.ip = options.trustProxy + ? req.headers['x-forwarded-for'] || req.connection.remoteAddress + : req.connection.remoteAddress.replace(REMOVE_IPV6_RE, '') // force ipv4 + params.addr = params.ip + ':' + params.port // TODO: ipv6 brackets? + + params.numwant = Math.min( + Number(params.numwant) || NUM_ANNOUNCE_PEERS, + MAX_ANNOUNCE_PEERS + ) + + return params + } else if (s[0] === '/scrape') { // unofficial scrape message + params.request = 'scrape' + + if (typeof params.info_hash === 'string') { + params.info_hash = [ params.info_hash ] + } + + if (params.info_hash) { + if (!Array.isArray(params.info_hash)) throw new Error('invalid info_hash') + + params.info_hash.some(function (infoHash) { + if (infoHash.length !== 20) { + throw new Error('invalid info_hash') + } + }) + } + + return params + } else { + return null + } +} + + // HELPER FUNCTIONS var TWO_PWR_32 = (1 << 16) * 2