endpoint MUST discard unsupported (unknown) frame

5 files changed, 23 insertions, 3 deletions

diff --git a/lib/plum/frame.rb b/lib/plum/frame.rb
index 1cb2933..67316b5 100644
--- a/lib/plum/frame.rb
+++ b/lib/plum/frame.rb
@@ -89,7 +89,7 @@ module Plum
     # Returns the type of the frame in Symbol.
     # @return [Symbol] The type.
     def type
-      @_type ||= FRAME_TYPES.key(type_value)
+      @_type ||= FRAME_TYPES.key(type_value) || ("unknown_%01A" % type_value).to_sym
     end
 
     # Returns the set flags on the frame.
diff --git a/lib/plum/server_connection.rb b/lib/plum/server_connection.rb
index de5c3e2..d75947f 100644
--- a/lib/plum/server_connection.rb
+++ b/lib/plum/server_connection.rb
@@ -186,8 +186,10 @@ module Plum
         process_ping(frame)
       when :goaway
         close
-      else # :data, :headers, :priority, :rst_stream, :push_promise, :continuation
+      when :data, :headers, :priority, :rst_stream, :push_promise, :continuation
         raise Plum::ConnectionError.new(:protocol_error)
+      else
+        # MUST ignore unknown frame type.
       end
     end
 
diff --git a/lib/plum/stream.rb b/lib/plum/stream.rb
index b7e3029..98df787 100644
--- a/lib/plum/stream.rb
+++ b/lib/plum/stream.rb
@@ -46,8 +46,10 @@ module Plum
         process_window_update(frame)
       when :continuation
         process_continuation(frame)
-      else # :ping, :goaway, :settings, :push_promise
+      when :ping, :goaway, :settings, :push_promise
         raise Plum::ConnectionError.new(:protocol_error) # stream_id MUST be 0x00
+      else
+        # MUST ignore unknown frame
       end
     rescue Plum::StreamError => e
       callback(:stream_error, e)
diff --git a/test/plum/test_server_connection.rb b/test/plum/test_server_connection.rb
index 032275a..5bfdf98 100644
--- a/test/plum/test_server_connection.rb
+++ b/test/plum/test_server_connection.rb
@@ -24,6 +24,14 @@ class ServerConnectionTest < Minitest::Test
     end
   end
 
+  def test_server_ignore_unknown_frame_type
+    open_server_connection {|con|
+      refute_raises {
+        con << Frame.new(type_value: 0x0f, stream_id: 0).assemble
+      }
+    }
+  end
+
   def test_server_raise_cprotocol_error_client_start_even_stream_id
     con = open_server_connection
     assert_connection_error(:protocol_error) {
diff --git a/test/plum/test_stream.rb b/test/plum/test_stream.rb
index 19162e7..ebe881f 100644
--- a/test/plum/test_stream.rb
+++ b/test/plum/test_stream.rb
@@ -11,6 +11,14 @@ class StreamTest < Minitest::Test
     }
   end
 
+  def test_stream_unknown_frame_type
+    open_new_stream {|stream|
+      refute_raises {
+        stream.process_frame(Frame.new(type_value: 0x0f, stream_id: stream.id, payload: "\x00\x00\x00\x00"))
+      }
+    }
+  end
+
   def test_stream_close
     open_new_stream(state: :half_closed_local) {|stream|
       stream.close(StreamError.new(:frame_size_error).http2_error_code)