core: refactor facedancer core to use 'control_send' for control endp…

…oint transfers.

facedancer/device.py

@@ -257,6 +257,21 @@ def clear_halt(self, endpoint_number: int, direction: USBDirection):
         self.backend.clear_halt(endpoint_number, direction)
 
 
+    def control_send(self, endpoint_number: int, in_request: USBControlRequest, data: bytes, *, blocking: bool = False):
+        """ Queues sending data on the provided control endpoint in
+            response to a IN control request.
+
+        Args:
+            endpoint_number : The endpoint number to send data upon.
+            in_request      : The control request being responded to.
+            data            : The data to send.
+            blocking        : If provided and true, this function will block
+                               until the backend indicates the send is complete.
+
+        """
+        self.backend.send_on_control_endpoint(endpoint_number, in_request, data, blocking=blocking)
+
+
     def send(self, endpoint_number: int, data: bytes, *, blocking: bool = False):
         """ Queues sending data on the IN endpoint with the provided number.
 
@@ -267,13 +282,9 @@ def send(self, endpoint_number: int, data: bytes, *, blocking: bool = False):
                                until the backend indicates the send is complete.
         """
 
-        # EP0 is special, as it conceptually belongs to the whole device, as it's used
-        # for control requests and configuration. We'll handle it directly, here.
-        #
-        # All of our backends currently automatically handle packetization and ZLPs for
-        # the control endpoint, so we'll skip packetizing it (which would generate spurious ZLPs).
         if endpoint_number == 0:
-            self.backend.send_on_endpoint(0, data, blocking=blocking)
+            # TODO upgrade to an exception with the release of Facedancer 3.1.0
+            log.warning("Please use USBDevice::control_send() for control transfers")
         elif self.configuration:
             endpoint = self.configuration.get_endpoint(endpoint_number, USBDirection.IN)
             endpoint.send(data, blocking=blocking)

facedancer/endpoint.py

@@ -100,7 +100,7 @@ def get_device(self):
         return self.parent.get_device()
 
 
-    def send(self, data: bytes, *, blocking: bool =False):
+    def send(self, data: bytes, *, blocking: bool = False):
         """ Sends data on this endpoint. Valid only for IN endpoints.
 
         Args:

facedancer/proxy.py

@@ -245,7 +245,7 @@ def _proxy_in_control_request(self, request: USBControlRequest):
             self.backend.stall_endpoint(0, USBDirection.IN)
         else:
             # TODO: support control endpoints other than 0
-            self.send(0, data)
+            self.control_send(0, request, data)
 
 
     def _proxy_out_control_request(self, request: USBControlRequest):

facedancer/request.py

@@ -251,7 +251,7 @@ def from_raw_bytes(cls, raw_bytes: bytes, *, device = None):
 
     def reply(self, data: bytes):
         """ Replies to the given request with a given set of bytes. """
-        self.device.send(endpoint_number=0, data=data)
+        self.device.control_send(endpoint_number=0, in_request=self, data=data)
 
 
     def acknowledge(self, *, blocking: bool = False):
@@ -260,7 +260,7 @@ def acknowledge(self, *, blocking: bool = False):
         Args:
             blocking : If true, the relevant control request will complete before returning.
         """
-        self.device.send(endpoint_number=0, data=b"", blocking=blocking)
+        self.device.control_send(endpoint_number=0, in_request=self, data=b"", blocking=blocking)
 
 
     def ack(self, *, blocking: bool = False):