pylibschc.fragmenter: fix non-ACK handling for Fragmenter

anr-bmbf-pivot · Feb 16, 2023 · 6cbffa1 · 6cbffa1
1 parent 061de8a
commit 6cbffa1
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Showing 3 changed files with 10 additions and 3 deletions.
diff --git a/pylibschc/__init__.py b/pylibschc/__init__.py
@@ -9,4 +9,4 @@
 __copyright__ = "Copyright 2023 Freie Universität Berlin"
 __license__ = "GPLv3"
 __email__ = "[email protected]"
-__version__ = "0.0.1b2"
+__version__ = "0.0.1b3"
diff --git a/pylibschc/fragmenter.py b/pylibschc/fragmenter.py
@@ -98,8 +98,11 @@ def input(self, data: typing.Union[bytes, BitArray]) -> ReassemblyStatus:
         """Handle incoming an ACK.
 
         :param data: An ACK.
-        :raise RuntimeError: if ``data`` was not an ACK.
+        :raise RuntimeError: if ``data`` was not an ACK or if the fragmenter never sent
+            a fragment for which the ACK should be handled.
         :retval ACK_HANDLED: when the ACK was handled."""
+        if not self._tx_conn:
+            raise RuntimeError("Unexpected state, you did not send a fragment yet")
         if isinstance(data, BitArray):
             bit_array = data
         else:
@@ -115,7 +118,7 @@ def input(self, data: typing.Union[bytes, BitArray]) -> ReassemblyStatus:
                     self.end_rx(new_conn)
                 new_conn.reset()
             assert RuntimeError(
-                b"Unexpected state, input {data.hex()} should be an ACK"
+                f"Unexpected state, input {data.hex()} should be an ACK"
             )
         return ReassemblyStatus.ACK_HANDLED  # pragma: no cover
 

diff --git a/tests/test_fragmenter.py b/tests/test_fragmenter.py
@@ -298,6 +298,8 @@ def test_fragmenter_reassembler_threaded(  # pylint: disable=too-many-arguments
             end_tx=self.end_tx,
             remove_timer_entry=self.remove_timer_entry,
         )
+        with pytest.raises(RuntimeError):
+            self.fragmenter.input(b"\x03\x03")
         self.reassembler = pylibschc.fragmenter.Reassembler(
             device=device,
             post_timer_task=self.post_timer_task,
@@ -426,6 +428,8 @@ async def output(buffer):
             end_tx=self.end_tx,
             remove_timer_entry=self.remove_timer_entry,
         )
+        with pytest.raises(RuntimeError):
+            self.fragmenter.input(b"\x03\x03")
         self.reassembler = pylibschc.fragmenter.Reassembler(
             device=device,
             post_timer_task=self.post_timer_task,