Refactor error code classes and support 1009 code

* Renamed DataError to WSProtocolError to be consistent with the specification terminology, and made it clear that this always represents a closing scenario
* Added comments to other errors to clarify their use
* Added WSMessageTooBigError with associated 1009 error code

lib/em-websocket/connection.rb

@@ -75,10 +75,10 @@ def receive_data(data)
         trigger_on_error(e)
         # Errors during the handshake require the connection to be aborted
         abort
-      rescue WebSocketError => e
+      rescue WSProtocolError => e
         debug [:error, e]
         trigger_on_error(e)
-        close_websocket_private(1002) # 1002 indicates a protocol error
+        close_websocket_private(e.code)
       rescue => e
         debug [:error, e]
         # These are application errors - raise unless onerror defined

lib/em-websocket/framing03.rb

@@ -59,7 +59,7 @@ def process_data(newdata)
 
           # Addition to the spec to protect against malicious requests
           if payload_length > MAXIMUM_FRAME_LENGTH
-            raise DataError, "Frame length too long (#{payload_length} bytes)"
+            raise WSMessageTooBigError, "Frame length too long (#{payload_length} bytes)"
           end
 
           # Check buffer size
@@ -78,7 +78,7 @@ def process_data(newdata)
           frame_type = opcode_to_type(opcode)
 
           if frame_type == :continuation && !@frame_type
-            raise WebSocketError, 'Continuation frame not expected'
+            raise WSProtocolError, 'Continuation frame not expected'
           end
 
           if more
@@ -156,7 +156,7 @@ def type_to_opcode(frame_type)
       end
 
       def opcode_to_type(opcode)
-        FRAME_TYPES_INVERSE[opcode] || raise(DataError, "Unknown opcode")
+        FRAME_TYPES_INVERSE[opcode] || raise(WSProtocolError, "Unknown opcode")
       end
 
       def data_frame?(type)

lib/em-websocket/framing05.rb

@@ -62,7 +62,7 @@ def process_data(newdata)
 
           # Addition to the spec to protect against malicious requests
           if payload_length > MAXIMUM_FRAME_LENGTH
-            raise DataError, "Frame length too long (#{payload_length} bytes)"
+            raise WSMessageTooBigError, "Frame length too long (#{payload_length} bytes)"
           end
 
           # Check buffer size
@@ -83,7 +83,7 @@ def process_data(newdata)
           frame_type = opcode_to_type(opcode)
 
           if frame_type == :continuation && !@frame_type
-            raise WebSocketError, 'Continuation frame not expected'
+            raise WSProtocolError, 'Continuation frame not expected'
           end
 
           if !fin
@@ -157,7 +157,7 @@ def type_to_opcode(frame_type)
       end
 
       def opcode_to_type(opcode)
-        FRAME_TYPES_INVERSE[opcode] || raise(DataError, "Unknown opcode")
+        FRAME_TYPES_INVERSE[opcode] || raise(WSProtocolError, "Unknown opcode")
       end
 
       def data_frame?(type)

lib/em-websocket/framing07.rb

@@ -83,7 +83,7 @@ def process_data(newdata)
           frame_type = opcode_to_type(opcode)
 
           if frame_type == :continuation && !@frame_type
-            raise WebSocketError, 'Continuation frame not expected'
+            raise WSProtocolError, 'Continuation frame not expected'
           end
 
           if !fin
@@ -158,7 +158,7 @@ def type_to_opcode(frame_type)
       end
 
       def opcode_to_type(opcode)
-        FRAME_TYPES_INVERSE[opcode] || raise(DataError, "Unknown opcode")
+        FRAME_TYPES_INVERSE[opcode] || raise(WSProtocolError, "Unknown opcode")
       end
 
       def data_frame?(type)

lib/em-websocket/framing76.rb

@@ -42,7 +42,7 @@ def process_data(newdata)
 
             # Addition to the spec to protect against malicious requests
             if length > MAXIMUM_FRAME_LENGTH
-              raise DataError, "Frame length too long (#{length} bytes)"
+              raise WSMessageTooBigError, "Frame length too long (#{length} bytes)"
             end
 
             if @data.getbyte(pointer+length-1) == nil
@@ -69,12 +69,12 @@ def process_data(newdata)
 
             if @data.getbyte(0) != 0x00
               # Close the connection since this buffer can never match
-              raise DataError, "Invalid frame received"
+              raise WSProtocolError, "Invalid frame received"
             end
 
             # Addition to the spec to protect against malicious requests
             if @data.size > MAXIMUM_FRAME_LENGTH
-              raise DataError, "Frame length too long (#{@data.size} bytes)"
+              raise WSMessageTooBigError, "Frame length too long (#{@data.size} bytes)"
             end
 
             # Optimization to avoid calling slice! unnecessarily

lib/em-websocket/handler_factory.rb

@@ -99,7 +99,7 @@ def self.build_with_request(connection, request, remains, secure = false, debug
           Handler13.new(connection, request, debug)
         else
           # According to spec should abort the connection
-          raise WebSocketError, "Protocol version #{version} not supported"
+          raise HandshakeError, "Protocol version #{version} not supported"
         end
       end
     end

lib/em-websocket/message_processor_06.rb

@@ -12,7 +12,7 @@ def message(message_type, extension_data, application_data)
             nil
           when 1
             # Illegal close frame
-            raise DataError, "Close frames with a body must contain a 2 byte status code"
+            raise WSProtocolError, "Close frames with a body must contain a 2 byte status code"
           else
             application_data.slice!(0, 2).unpack('n').first
           end

lib/em-websocket/websocket.rb

@@ -1,8 +1,24 @@
 module EventMachine
   module WebSocket
+    # All errors raised by em-websocket should descend from this class
+    #
     class WebSocketError < RuntimeError; end
+
+    # Used for errors that occur during WebSocket handshake
+    #
     class HandshakeError < WebSocketError; end
-    class DataError < WebSocketError; end
+
+    # Used for errors which should cause the connection to close.
+    # See RFC6455 §7.4.1 for a full description of meanings
+    #
+    class WSProtocolError < WebSocketError
+      def code; 1002; end
+    end
+
+    # 1009: Message too big to process
+    class WSMessageTooBigError < WSProtocolError
+      def code; 1009; end
+    end
 
     def self.start(options, &blk)
       EM.epoll

spec/integration/draft76_spec.rb

@@ -140,7 +140,7 @@ def start_client
     em {
       EventMachine::WebSocket.start(:host => "0.0.0.0", :port => 12345) { |server|
         server.onerror { |error|
-          error.should be_an_instance_of EM::WebSocket::DataError
+          error.should be_an_instance_of EM::WebSocket::WSMessageTooBigError
           error.message.should == "Frame length too long (1180591620717411303296 bytes)"
           done
         }
@@ -164,7 +164,7 @@ def start_client
     em {
       EventMachine::WebSocket.start(:host => "0.0.0.0", :port => 12345) { |server|
         server.onerror { |error|
-          error.should be_an_instance_of EM::WebSocket::DataError
+          error.should be_an_instance_of EM::WebSocket::WSProtocolError
           error.message.should == "Invalid frame received"
           done
         }

spec/unit/framing_spec.rb

@@ -240,11 +240,11 @@ def debug(*args); end
   end
 
   describe "other tests" do
-    it "should raise a DataError if an invalid frame type is requested" do
+    it "should raise a WSProtocolError if an invalid frame type is requested" do
       lambda {
         # Opcode 3 is not supported by this draft
         @f << "\x83\x05Hello"
-      }.should raise_error(EventMachine::WebSocket::DataError, "Unknown opcode")
+      }.should raise_error(EventMachine::WebSocket::WSProtocolError, "Unknown opcode")
     end
 
     it "should accept a fragmented unmasked text message in 3 frames" do