Merge pull request #9 from Unity-Technologies/bugfix/protocol-version-size-check

Protocol version size check

Author: stephen-palmer

lib/constants.js

@@ -1,6 +1,7 @@
 const constants = {
     VERSION: "5.4.0",
     PROTOCOL_VERSION: 254,
+    PROTOCOL_VERSION_MIN_SIZE: 2,
     UINT32_SIZE: 8,                             // hex
     UINT64_SIZE: 16,                            // hex
     HASH_SIZE: 16,                              // bin

lib/server.js

@@ -73,6 +73,13 @@ class CacheServer {
             // Get the version as the first thing
             var idx = 0;
             if (!socket.protocolVersion) {
+                if (data.length < consts.PROTOCOL_VERSION_MIN_SIZE)
+                {
+                    // We need more data
+                    socket.pendingData = data;
+                    return false;
+                }
+
                 socket.protocolVersion = helpers.readUInt32(data);
                 let buf = Buffer.allocUnsafe(consts.UINT32_SIZE);
                 if (socket.protocolVersion == consts.PROTOCOL_VERSION) {

package.json

@@ -11,6 +11,7 @@
   },
   "scripts": {
     "test": "mocha test",
+    "coverage": "istanbul cover ./node_modules/mocha/bin/_mocha; open coverage/lcov-report/index.html",
     "start": "node main.js",
     "coveralls": "istanbul cover ./node_modules/mocha/bin/_mocha --report lcovonly -- -R spec && cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js && rm -rf ./coverage"
   },

test/server.js

@@ -122,6 +122,20 @@ describe("CacheServer protocol", function() {
 
             client.write(helpers.encodeInt32(consts.PROTOCOL_VERSION + 1));
         });
+
+        it("should recognize a 2 byte version sent 1 byte at a time", function (done) {
+            this.slow(250);
+
+            client.on('data', function(data) {
+                var ver = helpers.readUInt32(data);
+                assert(ver == consts.PROTOCOL_VERSION, "Expected " + consts.PROTOCOL_VERSION + " Received " + ver);
+                done();
+            });
+
+            var ver = "fe";
+            client.write(ver[0]);
+            sleep(50).then(() => { client.write(ver[1]); });
+        });
     });
 
     describe("Transactions", function () {