Decode and validate version message in transports

lib/net/base.js

@@ -12,8 +12,10 @@
 
 var inherits = require("inherits");
 var EventEmitter = require("events").EventEmitter;
+var util = require("../_util");
 var PPromise = require("../platform").Promise;
 var structs = require("../structs");
+var messages = require("../messages");
 
 /**
  * Base transport class. Allows to use single class for both client and
@@ -91,8 +93,9 @@ BaseTransport.prototype.close = function() {
   throw new Error("Not implemented");
 };
 
-// Static private helpers.
+// Private helpers.
 
+// Make a message from variable number of arguments.
 BaseTransport._getmsg = function(args) {
   if (typeof args[0] === "string") {
     return structs.message.encode(args[0], args[1]);
@@ -110,4 +113,53 @@ BaseTransport._unmap = function(addr) {
   }
 };
 
+// Check whether two given arrays intersect.
+// NOTE(Kagami): It has O(n*m) complexity in the worst case but:
+// * Max length of stream list = 160,000
+// * One of the arrays (our streams) should have reasonable length
+function intersects(a, b) {
+  var alen = a.length;
+  var blen = b.length;
+  if (!alen || !blen) {
+    return false;
+  }
+  var i, j;
+  for (i = 0; i < alen; ++i) {
+    for (j = 0; j < blen; ++j) {
+      if (a[i] === b[j]) {
+        return true;
+      }
+    }
+  }
+}
+
+// Decode and validate version message.
+BaseTransport.prototype._decodeVersion = function(payload) {
+  var version;
+  try {
+    version = messages.version.decodePayload(payload);
+  } catch(err) {
+    throw new Error("Version decode error: " + err.message);
+  }
+  if (version.version < util.PROTOCOL_VERSION) {
+    throw new Error("Peer uses old protocol v" + version.version);
+  }
+  // TODO(Kagami): We may want to send error message describing the time
+  // offset problem to this node as PyBitmessage.
+  var delta = (version.time.getTime() - new Date().getTime()) / 1000;
+  if (delta > 3600) {
+    throw new Error("Peer's time is too far in the future: +" + delta + "s");
+  }
+  if (delta < -3600) {
+    throw new Error("Peer's time is too far in the past: " + delta + "s");
+  }
+  if (!intersects(this.streamNumbers, version.streamNumbers)) {
+    throw new Error(
+      "Peer isn't interested in our streams; " +
+      "first 10 peer's streams: " + version.streamNumbers.slice(0, 10)
+    );
+  }
+  return version;
+};
+
 module.exports = BaseTransport;

lib/net/tcp.js

@@ -38,12 +38,14 @@ var objectAssign = Object.assign || require("object-assign");
 var inherits = require("inherits");
 var net = require("net");
 var dns = require("dns");
-var assert = require("../_util").assert;
+var util = require("../_util");
 var PPromise = require("../platform").Promise;
 var structs = require("../structs");
 var messages = require("../messages");
 var BaseTransport = require("./base");
 
+var assert = util.assert;
+var ServicesBitfield = structs.ServicesBitfield;
 var getmsg = BaseTransport._getmsg;
 var unmap = BaseTransport._unmap;
 
@@ -58,9 +60,9 @@ var unmap = BaseTransport._unmap;
  * provided by this node (`NODE_NETWORK` by default)
  * @param {(Array|string|Buffer)} opts.userAgent -
  * [User agent]{@link module:bitmessage/user-agent} of this node
- * (bitmessage's by default)
+ * (user agent of bitmessage library by default)
  * @param {number[]} opts.streamNumbers - Streams accepted by this node
- * (1 by default)
+ * ([1] by default)
  * @param {number} opts.port - Incoming port of this node (8444 by
  * default)
  * @constructor
@@ -71,6 +73,7 @@ function TcpTransport(opts) {
   objectAssign(this, opts);
   this.seeds = this.seeds || [];
   this.dnsSeeds = this.dnsSeeds || [];
+  this.streamNumbers = this.streamNumbers || [1];
   this._clients = {};
 }
 
@@ -140,25 +143,38 @@ TcpTransport.prototype._setupClient = function(client, incoming) {
   });
 
   // High-level message processing.
-  self.on("message", function(command) {
+  self.on("message", function(command, payload) {
+    var version;
     if (!established) {
-      // TODO: Process version data.
-      // TODO: Disconnect if proto version < 3.
       if (command === "version") {
         if (verackSent) {
           return;
         }
+
+        try {
+          version = self._decodeVersion(payload);
+        } catch(err) {
+          self.emit("error", err);
+          return client.end();
+        }
+        if (!version.services.get(ServicesBitfield.NODE_NETWORK)) {
+          self.emit("error", new Error(
+            "Not a normal network node: " + version.services
+          ));
+          return client.end();
+        }
+
         self.send("verack");
         verackSent = true;
         if (incoming) {
           self._sendVersion();
         } else if (verackReceived) {
-          self.emit("established");
+          self.emit("established", version);
         }
       } else if (command === "verack") {
         verackReceived = true;
         if (verackSent) {
-          self.emit("established");
+          self.emit("established", version);
         }
       }
     }

lib/net/ws.browser.js

@@ -12,10 +12,17 @@ var structs = require("../structs");
 var messages = require("../messages");
 var BaseTransport = require("./base");
 
+var ServicesBitfield = structs.ServicesBitfield;
+var getmsg = BaseTransport._getmsg;
+
 function WsTransport(opts) {
   WsTransport.super_.call(this);
   objectAssign(this, opts);
   this.seeds = this.seeds || [];
+  this.services = this.services || ServicesBitfield().set([
+    ServicesBitfield.NODE_MOBILE,
+  ]);
+  this.streamNumbers = this.streamNumbers || [1];
 }
 
 inherits(WsTransport, BaseTransport);
@@ -62,25 +69,38 @@ WsTransport.prototype.connect = function(url, protocols) {
   };
 
   // High-level message processing.
-  self.on("message", function(command) {
+  self.on("message", function(command, payload) {
+    var version;
     if (!established) {
-      // TODO: Process version data.
-      // TODO: Disconnect if proto version < 3.
       if (command === "version") {
         if (verackSent) {
           return;
         }
+
+        try {
+          version = self._decodeVersion(payload);
+        } catch(err) {
+          self.emit("error", err);
+          return client.close();
+        }
+        if (!version.services.get(ServicesBitfield.NODE_GATEWAY)) {
+          self.emit("error", new Error(
+            "Not a gateway node: " + version.services
+          ));
+          return client.close();
+        }
+
         self.send("verack");
         verackSent = true;
         if (verackReceived) {
           established = true;
-          self.emit("established");
+          self.emit("established", version);
         }
       } else if (command === "verack") {
         verackReceived = true;
         if (verackSent) {
           established = true;
-          self.emit("established");
+          self.emit("established", version);
         }
       }
     }
@@ -98,7 +118,7 @@ WsTransport.prototype.connect = function(url, protocols) {
 
 WsTransport.prototype.send = function() {
   if (this._client) {
-    this._client.send(BaseTransport._getmsg(arguments));
+    this._client.send(getmsg(arguments));
   } else {
     throw new Error("Not connected");
   }

lib/net/ws.js

@@ -19,6 +19,7 @@ var messages = require("../messages");
 var BaseTransport = require("./base");
 
 var WebSocketServer = WebSocket.Server;
+var ServicesBitfield = structs.ServicesBitfield;
 var getmsg = BaseTransport._getmsg;
 var unmap = BaseTransport._unmap;
 
@@ -30,12 +31,13 @@ var unmap = BaseTransport._unmap;
  * @param {Array} opts.seeds - Bootstrap nodes (none by default)
  * @param {Object} opts.services -
  * [Service features]{@link module:bitmessage/structs.ServicesBitfield}
- * provided by this node (`NODE_NETWORK` by default)
+ * provided by this node (`NODE_MOBILE` for Browser and `NODE_MOBILE` +
+ * `NODE_GATEWAY` for Node by default)
  * @param {(Array|string|Buffer)} opts.userAgent -
  * [User agent]{@link module:bitmessage/user-agent} of this node
- * (bitmessage's by default)
+ * (user agent of bitmessage library by default)
  * @param {number[]} opts.streamNumbers - Streams accepted by this node
- * (1 by default)
+ * ([1] by default)
  * @param {number} opts.port - Incoming port of this node, makes sence
  * only on Node platform (18444 by default)
  * @constructor
@@ -45,6 +47,11 @@ function WsTransport(opts) {
   WsTransport.super_.call(this);
   objectAssign(this, opts);
   this.seeds = this.seeds || [];
+  this.services = this.services || ServicesBitfield().set([
+    ServicesBitfield.NODE_MOBILE,
+    ServicesBitfield.NODE_GATEWAY,
+  ]);
+  this.streamNumbers = this.streamNumbers || [1];
   this.port = this.port || 18444;
 }
 
@@ -114,27 +121,46 @@ WsTransport.prototype._setupClient = function(client, incoming) {
   });
 
   // High-level message processing.
-  self.on("message", function(command) {
+  self.on("message", function(command, payload) {
+    var version;
     if (!established) {
-      // TODO: Process version data.
-      // TODO: Disconnect if proto version < 3.
       if (command === "version") {
         if (verackSent) {
           return;
         }
+
+        try {
+          version = self._decodeVersion(payload);
+        } catch(err) {
+          self.emit("error", err);
+          return client.close();
+        }
+        if (incoming && !version.services.get(ServicesBitfield.NODE_MOBILE)) {
+          self.emit("error", new Error(
+            "Not a mobile node: " + version.services
+          ));
+          return client.close();
+        }
+        if (!incoming && !version.services.get(ServicesBitfield.NODE_GATEWAY)) {
+          self.emit("error", new Error(
+            "Not a gateway node: " + version.services
+          ));
+          return client.close();
+        }
+
         self.send("verack");
         verackSent = true;
         if (incoming) {
           self._sendVersion();
         } else if (verackReceived) {
           established = true;
-          self.emit("established");
+          self.emit("established", version);
         }
       } else if (command === "verack") {
         verackReceived = true;
         if (verackSent) {
           established = true;
-          self.emit("established");
+          self.emit("established", version);
         }
       }
     }

lib/user-agent.js

@@ -92,7 +92,7 @@ var encode = exports.encode = function(software) {
 };
 
 /**
- * Encode bitmessage's library user agent.
+ * Encode user agent of bitmessage library.
  * @return {Buffer} Encoded user agent.
  */
 exports.encodeSelf = function() {
@@ -100,7 +100,7 @@ exports.encodeSelf = function() {
 };
 
 /**
- * Encode user agent with bitmessage's library user agent underneath.
+ * Encode user agent with user agent of bitmessage library underneath.
  * Most underlying software comes first.
  * @param {(Object[]|string[]|Object|string)} software - List of
  * software to encode

tests/functional.js

@@ -2,6 +2,7 @@ var expect = require("chai").expect;
 
 var bitmessage = require("../lib");
 var structs = bitmessage.structs;
+var ServicesBitfield = structs.ServicesBitfield;
 var message = structs.message;
 var WsTransport = require("../lib/net/ws");
 
@@ -62,7 +63,13 @@ if (!process.browser) {
     });
 
     it("should automatically establish connection", function(done) {
-      tcp.once("established", function() {
+      tcp.once("established", function(version) {
+        expect(version.version).to.equal(3);
+        expect(version.services.get(ServicesBitfield.NODE_NETWORK)).to.be.true;
+        expect(version.remoteHost).to.equal("127.0.0.1");
+        expect(version.port).to.equal(22333);
+        expect(version.userAgent).to.be.a("string");
+        expect(version.streamNumbers).to.deep.equal([1]);
         done();
       });
     });
@@ -119,7 +126,12 @@ describe("WebSocket transport", function() {
   });
 
   it("should automatically establish connection", function(done) {
-    ws.once("established", function() {
+    ws.once("established", function(version) {
+      expect(version.services.get(ServicesBitfield.NODE_GATEWAY)).to.be.true;
+      expect(version.remoteHost).to.equal("127.0.0.1");
+      expect(version.port).to.equal(22334);
+      expect(version.userAgent).to.be.a("string");
+      expect(version.streamNumbers).to.deep.equal([1]);
       done();
     });
   });

tests/tcp-node.js

@@ -1,7 +1,7 @@
 var TcpTransport = require("../lib/net/tcp");
 
 function start() {
-  var server = new TcpTransport();
+  var server = new TcpTransport({port: 22333});
   // In node 0.12/io 1.0 we can use {host: x, port: y} syntax so it'll
   // be more compatible with the ws transport options.
   server.listen(22333, "127.0.0.1");

tests/ws-node.js

@@ -1,7 +1,7 @@
 var WsTransport = require("../lib/net/ws");
 
 function start() {
-  var server = new WsTransport();
+  var server = new WsTransport({port: 22334});
   server.listen({host: "127.0.0.1", port: 22334});
   server.on("connection", function(client) {
     client.on("message", function(command, payload) {