Allow proxying tracker calls and peer connexions in node (TCP/UDP)

depends on webtorrent/bittorrent-tracker#157

index.js

@@ -16,6 +16,7 @@ var parseTorrent = require('parse-torrent')
 var path = require('path')
 var Peer = require('simple-peer')
 var randombytes = require('randombytes')
+var Socks = require('socks')
 var speedometer = require('speedometer')
 var zeroFill = require('zero-fill')
 
@@ -106,6 +107,26 @@ function WebTorrent (opts) {
     if (global.WRTC && !self.tracker.wrtc) self.tracker.wrtc = global.WRTC
   }
 
+  // Proxy
+  self.proxyOpts = opts.proxyOpts
+  if (self.proxyOpts) {
+    self.proxyOpts.proxyTrackerConnections = self.proxyOpts.proxyTrackerConnections !== false
+    self.proxyOpts.proxyPeerConnections = self.proxyOpts.proxyPeerConnections !== false
+
+    if (self.proxyOpts.socksProxy) {
+      if (!self.proxyOpts.socksProxy.proxy) self.proxyOpts.socksProxy.proxy = {}
+      if (!self.proxyOpts.socksProxy.proxy.type) self.proxyOpts.socksProxy.proxy.type = 5
+
+      // Create HTTP agents from socks proxy if needed
+      if (!self.proxyOpts.httpAgent) {
+        self.proxyOpts.httpAgent = new Socks.Agent(self.proxyOpts.socksProxy, false)
+      }
+      if (!self.proxyOpts.httpsAgent) {
+        self.proxyOpts.httpsAgent = new Socks.Agent(self.proxyOpts.socksProxy, true)
+      }
+    }
+  }
+
   if (typeof TCPPool === 'function') {
     self._tcpPool = new TCPPool(self)
   } else {

lib/torrent.js

@@ -26,6 +26,7 @@ var Piece = require('torrent-piece')
 var pump = require('pump')
 var randomIterate = require('random-iterate')
 var sha1 = require('simple-sha1')
+var Socks = require('socks')
 var speedometer = require('speedometer')
 var uniq = require('uniq')
 var utMetadata = require('ut_metadata')
@@ -1658,38 +1659,56 @@ Torrent.prototype._drain = function () {
     port: parts[1]
   }
 
-  var conn = peer.conn = net.connect(opts)
+  if (self.client.proxyOpts && self.client.proxyOpts.socksProxy && self.client.proxyOpts.proxyPeerConnections) {
+    var proxyOpts = extend(self.client.proxyOpts.socksProxy, {
+      command: 'connect',
+      target: opts
+    })
 
-  conn.once('connect', function () { peer.onConnect() })
-  conn.once('error', function (err) { peer.destroy(err) })
-  peer.startConnectTimeout()
+    Socks.createConnection(proxyOpts, onGotSocket)
+  } else {
+    onGotSocket(null, net.connect(opts))
+  }
 
-  // When connection closes, attempt reconnect after timeout (with exponential backoff)
-  conn.on('close', function () {
-    if (self.destroyed) return
+  function onGotSocket (err, socket) {
+    if (err) return peer.destroy(err)
 
-    // TODO: If torrent is done, do not try to reconnect after a timeout
+    var conn = peer.conn = socket
 
-    if (peer.retries >= RECONNECT_WAIT.length) {
-      self._debug(
-        'conn %s closed: will not re-add (max %s attempts)',
-        peer.addr, RECONNECT_WAIT.length
-      )
-      return
+    if (self.client.proxyOpts && self.client.proxyOpts.proxyPeerConnections) {
+      peer.onConnect()
     }
+    conn.once('connect', function () { peer.onConnect() })
+    conn.once('error', function (err) { peer.destroy(err) })
+    peer.startConnectTimeout()
 
-    var ms = RECONNECT_WAIT[peer.retries]
-    self._debug(
-      'conn %s closed: will re-add to queue in %sms (attempt %s)',
-      peer.addr, ms, peer.retries + 1
-    )
+    // When connection closes, attempt reconnect after timeout (with exponential backoff)
+    conn.on('close', function () {
+      if (self.destroyed) return
 
-    var reconnectTimeout = setTimeout(function reconnectTimeout () {
-      var newPeer = self._addPeer(peer.addr)
-      if (newPeer) newPeer.retries = peer.retries + 1
-    }, ms)
-    if (reconnectTimeout.unref) reconnectTimeout.unref()
-  })
+      // TODO: If torrent is done, do not try to reconnect after a timeout
+
+      if (peer.retries >= RECONNECT_WAIT.length) {
+        self._debug(
+            'conn %s closed: will not re-add (max %s attempts)',
+            peer.addr, RECONNECT_WAIT.length
+        )
+        return
+      }
+
+      var ms = RECONNECT_WAIT[peer.retries]
+      self._debug(
+          'conn %s closed: will re-add to queue in %sms (attempt %s)',
+          peer.addr, ms, peer.retries + 1
+      )
+
+      var reconnectTimeout = setTimeout(function reconnectTimeout () {
+        var newPeer = self._addPeer(peer.addr)
+        if (newPeer) newPeer.retries = peer.retries + 1
+      }, ms)
+      if (reconnectTimeout.unref) reconnectTimeout.unref()
+    })
+  }
 }
 
 /**

lib/webconn.js

@@ -6,6 +6,7 @@ var debug = require('debug')('webtorrent:webconn')
 var get = require('simple-get')
 var inherits = require('inherits')
 var sha1 = require('simple-sha1')
+var url = require('url')
 var Wire = require('bittorrent-protocol')
 
 var VERSION = require('../package.json').version
@@ -109,20 +110,27 @@ WebConn.prototype.httpRequest = function (pieceIndex, offset, length, cb) {
   }
 
   requests.forEach(function (request) {
-    var url = request.url
+    var parsedUrl = url.parse(request.url)
     var start = request.start
     var end = request.end
     debug(
       'Requesting url=%s pieceIndex=%d offset=%d length=%d start=%d end=%d',
-      url, pieceIndex, offset, length, start, end
+      request.url, pieceIndex, offset, length, start, end
     )
+
+    var agent
+    if (self._torrent.client.proxyOpts && self._torrent.client.proxyOpts.proxyPeerConnections) {
+      agent = parsedUrl.protocol === 'https:'
+        ? self._torrent.client.proxyOpts.httpsAgent : self._torrent.client.proxyOpts.httpAgent
+    }
     var opts = {
-      url: url,
+      url: parsedUrl,
       method: 'GET',
       headers: {
         'user-agent': 'WebTorrent/' + VERSION + ' (https://webtorrent.io)',
         range: 'bytes=' + start + '-' + end
-      }
+      },
+      agent: agent
     }
     get.concat(opts, function (err, res, data) {
       if (hasError) return

package.json

@@ -15,6 +15,7 @@
     "load-ip-set": false,
     "net": false,
     "os": false,
+    "socks": false,
     "ut_pex": false
   },
   "browserify": {
@@ -56,6 +57,7 @@
     "simple-get": "^2.2.1",
     "simple-peer": "^6.0.4",
     "simple-sha1": "^2.0.8",
+    "socks": "^1.1.9",
     "speedometer": "^1.0.0",
     "stream-to-blob": "^1.0.0",
     "stream-to-blob-url": "^2.1.0",