Added protocol negotiation

This is primarily for backwards compatibility for when
or if the protocol is changed in future versions.

If the server fails to respond with an acceptable
protocol, the client disconnects and disables
the monitor.

4 files changed, 21 insertions, 7 deletions

diff --git a/actioncable/lib/action_cable/connection/base.rb b/actioncable/lib/action_cable/connection/base.rb
index b4488265cb..43c83b4b78 100644
--- a/actioncable/lib/action_cable/connection/base.rb
+++ b/actioncable/lib/action_cable/connection/base.rb
@@ -48,7 +48,7 @@ module ActionCable
       include InternalChannel
       include Authorization
 
-      attr_reader :server, :env, :subscriptions, :logger, :worker_pool
+      attr_reader :server, :env, :subscriptions, :logger, :worker_pool, :protocol
       delegate :event_loop, :pubsub, to: :server
 
       def initialize(server, env)
@@ -153,6 +153,7 @@ module ActionCable
 
       private
         def handle_open
+          @protocol = websocket.protocol
           connect if respond_to?(:connect)
           subscribe_to_internal_channel
           send_welcome_message
diff --git a/actioncable/lib/action_cable/connection/client_socket.rb b/actioncable/lib/action_cable/connection/client_socket.rb
index 9e4dbcd6e6..cf529ebd81 100644
--- a/actioncable/lib/action_cable/connection/client_socket.rb
+++ b/actioncable/lib/action_cable/connection/client_socket.rb
@@ -29,7 +29,7 @@ module ActionCable
 
       attr_reader :env, :url
 
-      def initialize(env, event_target, event_loop)
+      def initialize(env, event_target, event_loop, protocols)
         @env          = env
         @event_target = event_target
         @event_loop   = event_loop
@@ -42,7 +42,7 @@ module ActionCable
         @ready_state = CONNECTING
 
         # The driver calls +env+, +url+, and +write+
-        @driver = ::WebSocket::Driver.rack(self)
+        @driver = ::WebSocket::Driver.rack(self, protocols: protocols)
 
         @driver.on(:open)    { |e| open }
         @driver.on(:message) { |e| receive_message(e.data) }
@@ -109,6 +109,10 @@ module ActionCable
         @ready_state == OPEN
       end
 
+      def protocol
+        @driver.protocol
+      end
+
       private
         def open
           return unless @ready_state == CONNECTING
diff --git a/actioncable/lib/action_cable/connection/faye_client_socket.rb b/actioncable/lib/action_cable/connection/faye_client_socket.rb
index c9139b6858..09834ca39d 100644
--- a/actioncable/lib/action_cable/connection/faye_client_socket.rb
+++ b/actioncable/lib/action_cable/connection/faye_client_socket.rb
@@ -3,9 +3,10 @@ require 'faye/websocket'
 module ActionCable
   module Connection
     class FayeClientSocket
-      def initialize(env, event_target, stream_event_loop)
+      def initialize(env, event_target, stream_event_loop, protocols)
         @env = env
         @event_target = event_target
+        @protocols = protocols
 
         @faye = nil
       end
@@ -23,6 +24,10 @@ module ActionCable
         @faye && @faye.close
       end
 
+      def protocol
+        @faye && @faye.protocol
+      end
+
       def rack_response
         connect
         @faye.rack_response
@@ -31,7 +36,7 @@ module ActionCable
       private
         def connect
           return if @faye
-          @faye = Faye::WebSocket.new(@env)
+          @faye = Faye::WebSocket.new(@env, @protocols)
 
           @faye.on(:open)    { |event| @event_target.on_open }
           @faye.on(:message) { |event| @event_target.on_message(event.data) }
diff --git a/actioncable/lib/action_cable/connection/web_socket.rb b/actioncable/lib/action_cable/connection/web_socket.rb
index 0bec9b6a96..11f28c37e8 100644
--- a/actioncable/lib/action_cable/connection/web_socket.rb
+++ b/actioncable/lib/action_cable/connection/web_socket.rb
@@ -4,8 +4,8 @@ module ActionCable
   module Connection
     # Wrap the real socket to minimize the externally-presented API
     class WebSocket
-      def initialize(env, event_target, event_loop, client_socket_class)
-        @websocket = ::WebSocket::Driver.websocket?(env) ? client_socket_class.new(env, event_target, event_loop) : nil
+      def initialize(env, event_target, event_loop, client_socket_class, protocols: ActionCable::INTERNAL[:protocols])
+        @websocket = ::WebSocket::Driver.websocket?(env) ? client_socket_class.new(env, event_target, event_loop, protocols) : nil
       end
 
       def possible?
@@ -24,6 +24,10 @@ module ActionCable
         websocket.close
       end
 
+      def protocol
+        websocket.protocol
+      end
+
       def rack_response
         websocket.rack_response
       end