Merge pull request #77 from mwolter805/fix/transport-symmetry

fix: symmetric disconnect signaling, serial timeout, BLE callback, oversize-frame recovery

src/meshcore/ble_cx.py

@@ -124,9 +124,12 @@ class BLEConnection:
                     await self.client.pair()
                     logger.info("BLE pairing successful")
                 except Exception as e:
-                    logger.warning(f"BLE pairing failed: {e}")
-                    # Don't fail the connection if pairing fails, as the device
-                    # might already be paired or not require pairing
+                    logger.error(f"BLE pairing failed: {e}")
+                    # A failed pairing leaves the transport in a half-usable
+                    # state — re-raise so the caller gets a clean failure
+                    # instead of a silently degraded connection.
+                    await self.client.disconnect()
+                    raise
                     
         except BleakDeviceNotFoundError:
             return None
@@ -162,6 +165,17 @@ class BLEConnection:
         self.client = self._user_provided_client
         self.device = self._user_provided_device
 
+        # Re-register disconnect callback on the reset client so subsequent
+        # disconnects after a reconnect cycle are still detected.
+        if self.client is not None and hasattr(self.client, 'set_disconnected_callback'):
+            try:
+                self.client.set_disconnected_callback(self.handle_disconnect)
+            except Exception:
+                # set_disconnected_callback may not be available on all bleak
+                # versions; the next connect() call will re-create the client
+                # with the callback anyway.
+                pass
+
         if self._disconnect_callback:
             self._spawn_background(self._disconnect_callback("ble_disconnect"))
 
@@ -179,11 +193,19 @@ class BLEConnection:
     async def send(self, data):
         if not self.client:
             logger.error("Client is not connected")
+            if self._disconnect_callback:
+                await self._disconnect_callback("ble_transport_lost")
             return False
         if not self.rx_char:
             logger.error("RX characteristic not found")
             return False
-        await self.client.write_gatt_char(self.rx_char, bytes(data), response=True)
+        try:
+            await self.client.write_gatt_char(self.rx_char, bytes(data), response=True)
+        except Exception as exc:
+            logger.warning(f"BLE write failed: {exc}")
+            if self._disconnect_callback:
+                await self._disconnect_callback(f"ble_write_failed: {exc}")
+            return False
 
     async def disconnect(self):
         """Disconnect from the BLE device."""

src/meshcore/serial_cx.py

@@ -60,12 +60,16 @@ class SerialConnection:
         def resume_writing(self):
             logger.debug("resume writing")
 
-    async def connect(self):
+    async def connect(self, timeout: float = 10.0):
         """
-        Connects to the device
+        Connects to the device.
+
+        Args:
+            timeout: Maximum seconds to wait for connection_made callback.
+                     Defaults to 10.0. Raises asyncio.TimeoutError on expiry.
         """
         self._connected_event.clear()
-        
+
         loop = asyncio.get_running_loop()
         await serial_asyncio.create_serial_connection(
             loop,
@@ -74,7 +78,7 @@ class SerialConnection:
             baudrate=self.baudrate,
         )
 
-        await self._connected_event.wait()
+        await asyncio.wait_for(self._connected_event.wait(), timeout=timeout)
         logger.info("Serial Connection started")
         return self.port
 
@@ -110,7 +114,7 @@ class SerialConnection:
                 self.frame_expected_size = 0
                 if len(data) > 0: # rerun handle_rx on remaining data
                     self.handle_rx(data)
-                    return
+                return  # nothing left to process after reset
 
         upbound = self.frame_expected_size - len(self.inframe)
         if len(data) < upbound:
@@ -133,11 +137,18 @@ class SerialConnection:
     async def send(self, data):
         if not self.transport:
             logger.error("Transport not connected, cannot send data")
+            if self._disconnect_callback:
+                await self._disconnect_callback("serial_transport_lost")
             return
         size = len(data)
         pkt = b"\x3c" + size.to_bytes(2, byteorder="little") + data
         logger.debug(f"sending pkt : {pkt}")
-        self.transport.write(pkt)
+        try:
+            self.transport.write(pkt)
+        except OSError as exc:
+            logger.warning(f"Serial write failed: {exc}")
+            if self._disconnect_callback:
+                await self._disconnect_callback(f"serial_write_failed: {exc}")
 
     async def disconnect(self):
         """Close the serial connection."""

src/meshcore/tcp_cx.py

@@ -46,7 +46,6 @@ class TCPConnection:
 
         def data_received(self, data):
             logger.debug("data received")
-            self.cx._receive_count += 1
             self.cx.handle_rx(data)
 
         def error_received(self, exc):
@@ -101,7 +100,7 @@ class TCPConnection:
                 self.frame_expected_size = 0
                 if len(data) > 0: # rerun handle_rx on remaining data
                     self.handle_rx(data)
-                    return
+                return  # nothing left to process after reset
 
         upbound = self.frame_expected_size - len(self.inframe)
         if len(data) < upbound :
@@ -111,6 +110,10 @@ class TCPConnection:
 
         self.inframe = self.inframe + data[0:upbound]
         data = data[upbound:]
+        # Increment per completed MeshCore frame, not per TCP segment (N04).
+        # The threshold heuristic in send() compares _send_count vs
+        # _receive_count — counting per-segment skews it under fragmentation.
+        self._receive_count += 1
         if self.reader is not None:
             # feed meshcore reader
             self._spawn_background(self.reader.handle_rx(self.inframe))
@@ -142,7 +145,12 @@ class TCPConnection:
         size = len(data)
         pkt = b"\x3c" + size.to_bytes(2, byteorder="little") + data
         logger.debug(f"sending pkt : {pkt}")
-        self.transport.write(pkt)
+        try:
+            self.transport.write(pkt)
+        except (OSError, ConnectionResetError) as exc:
+            logger.warning(f"TCP write failed: {exc}")
+            if self._disconnect_callback:
+                await self._disconnect_callback(f"tcp_write_failed: {exc}")
 
     async def disconnect(self):
         """Close the TCP connection."""