diff -r 01361be9e2dc -r 55b5ba8d4e68 mercurial/wireprotoframing.py
--- a/mercurial/wireprotoframing.py	Mon Apr 09 15:32:01 2018 -0700
+++ b/mercurial/wireprotoframing.py	Mon Apr 09 16:54:20 2018 -0700
@@ -922,6 +922,7 @@
         self._outgoingstream = stream(1)
         self._pendingrequests = collections.deque()
         self._activerequests = {}
+        self._incomingstreams = {}
 
     def callcommand(self, name, args, datafh=None):
         """Request that a command be executed.
@@ -1007,3 +1008,63 @@
             yield frame
 
         request.state = 'sent'
+
+    def onframerecv(self, frame):
+        """Process a frame that has been received off the wire.
+
+        Returns a 2-tuple of (action, meta) describing further action the
+        caller needs to take as a result of receiving this frame.
+        """
+        if frame.streamid % 2:
+            return 'error', {
+                'message': (
+                    _('received frame with odd numbered stream ID: %d') %
+                    frame.streamid),
+            }
+
+        if frame.streamid not in self._incomingstreams:
+            if not frame.streamflags & STREAM_FLAG_BEGIN_STREAM:
+                return 'error', {
+                    'message': _('received frame on unknown stream '
+                                 'without beginning of stream flag set'),
+                }
+
+        if frame.streamflags & STREAM_FLAG_ENCODING_APPLIED:
+            raise error.ProgrammingError('support for decoding stream '
+                                         'payloads not yet implemneted')
+
+        if frame.streamflags & STREAM_FLAG_END_STREAM:
+            del self._incomingstreams[frame.streamid]
+
+        if frame.requestid not in self._activerequests:
+            return 'error', {
+                'message': (_('received frame for inactive request ID: %d') %
+                            frame.requestid),
+            }
+
+        request = self._activerequests[frame.requestid]
+        request.state = 'receiving'
+
+        handlers = {
+            FRAME_TYPE_BYTES_RESPONSE: self._onbytesresponseframe,
+        }
+
+        meth = handlers.get(frame.typeid)
+        if not meth:
+            raise error.ProgrammingError('unhandled frame type: %d' %
+                                         frame.typeid)
+
+        return meth(request, frame)
+
+    def _onbytesresponseframe(self, request, frame):
+        if frame.flags & FLAG_BYTES_RESPONSE_EOS:
+            request.state = 'received'
+            del self._activerequests[request.requestid]
+
+        return 'responsedata', {
+            'request': request,
+            'expectmore': frame.flags & FLAG_BYTES_RESPONSE_CONTINUATION,
+            'eos': frame.flags & FLAG_BYTES_RESPONSE_EOS,
+            'cbor': frame.flags & FLAG_BYTES_RESPONSE_CBOR,
+            'data': frame.payload,
+        }