apps: Add a controller loopback throughput test app

apps/controller_loopback.py

@@ -0,0 +1,198 @@
+# Copyright 2024 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import asyncio
+import logging
+import os
+import time
+from typing import Optional
+from bumble.colors import color
+from bumble.hci import (
+    HCI_READ_LOOPBACK_MODE_COMMAND,
+    HCI_Read_Loopback_Mode_Command,
+    HCI_WRITE_LOOPBACK_MODE_COMMAND,
+    HCI_Write_Loopback_Mode_Command,
+    LoopbackMode,
+)
+from bumble.host import Host
+from bumble.transport import open_transport_or_link
+import click
+
+
+class Loopback:
+    """Send and receive ACL data packets in local loopback mode"""
+
+    def __init__(self, packet_size: int, packet_count: int, transport: str):
+        self.transport = transport
+        self.packet_size = packet_size
+        self.packet_count = packet_count
+        self.connection_handle: Optional[int] = None
+        self.connection_event = asyncio.Event()
+        self.done = asyncio.Event()
+        self.expected_cid = 0
+        self.bytes_received = 0
+        self.start_timestamp = 0.0
+        self.last_timestamp = 0.0
+
+    def on_connection(self, connection_handle: int, *args):
+        """Retrieve connection handle from new connection event"""
+        if not self.connection_event.is_set():
+            # save first connection handle for ACL
+            # subsequent connections are SCO
+            self.connection_handle = connection_handle
+            self.connection_event.set()
+
+    def on_l2cap_pdu(self, connection_handle: int, cid: int, pdu: bytes):
+        """Calculate packet receive speed"""
+        now = time.time()
+        print(f'<<< Received packet {cid}: {len(pdu)} bytes')
+        assert connection_handle == self.connection_handle
+        assert cid == self.expected_cid
+        self.expected_cid += 1
+        if cid == 0:
+            self.start_timestamp = now
+            self.last_timestamp = now
+        else:
+            elapsed_since_start = now - self.start_timestamp
+            elapsed_since_last = now - self.last_timestamp
+            self.bytes_received += len(pdu)
+            instant_rx_speed = len(pdu) / elapsed_since_last
+            average_rx_speed = self.bytes_received / elapsed_since_start
+            print(
+                color(
+                    f'@@@ RX speed: instant={instant_rx_speed:.4f},'
+                    f' average={average_rx_speed:.4f}',
+                    'cyan',
+                )
+            )
+        if self.expected_cid == self.packet_count:
+            print(color('@@@ Received last packet', 'green'))
+            self.done.set()
+
+    async def run(self):
+        """Run a loopback throughput test"""
+        print(color('>>> Connecting to HCI...', 'green'))
+        async with await open_transport_or_link(self.transport) as (
+            hci_source,
+            hci_sink,
+        ):
+            print(color('>>> Connected', 'green'))
+
+            host = Host(hci_source, hci_sink)
+            await host.reset()
+
+            # make sure data can fit in one l2cap pdu
+            l2cap_header_size = 4
+            max_packet_size = host.hc_acl_data_packet_length - l2cap_header_size
+            if self.packet_size > max_packet_size:
+                print(
+                    color(
+                        f'!!! Packet size ({self.packet_size}) larger than max supported'
+                        f' size ({max_packet_size})',
+                        'red',
+                    )
+                )
+                return
+
+            if not host.supports_command(
+                HCI_WRITE_LOOPBACK_MODE_COMMAND
+            ) or not host.supports_command(HCI_READ_LOOPBACK_MODE_COMMAND):
+                print(color('!!! Loopback mode not supported', 'red'))
+                return
+
+            # set event callbacks
+            host.on('connection', self.on_connection)
+            host.on('l2cap_pdu', self.on_l2cap_pdu)
+
+            loopback_mode = LoopbackMode.LOCAL
+
+            print(color('### Setting loopback mode', 'blue'))
+            await host.send_command(
+                HCI_Write_Loopback_Mode_Command(loopback_mode=LoopbackMode.LOCAL),
+                check_result=True,
+            )
+
+            print(color('### Checking loopback mode', 'blue'))
+            response = await host.send_command(
+                HCI_Read_Loopback_Mode_Command(), check_result=True
+            )
+            if response.return_parameters.loopback_mode != loopback_mode:
+                print(color('!!! Loopback mode mismatch', 'red'))
+                return
+
+            await self.connection_event.wait()
+            print(color('### Connected', 'cyan'))
+
+            print(color('=== Start sending', 'magenta'))
+            start_time = time.time()
+            bytes_sent = 0
+            for cid in range(0, self.packet_count):
+                # using the cid as an incremental index
+                host.send_l2cap_pdu(
+                    self.connection_handle, cid, bytes(self.packet_size)
+                )
+                print(
+                    color(
+                        f'>>> Sending packet {cid}: {self.packet_size} bytes', 'yellow'
+                    )
+                )
+                bytes_sent += self.packet_size  # don't count L2CAP or HCI header sizes
+                await asyncio.sleep(0)  # yield to allow packet receive
+
+            await self.done.wait()
+            print(color('=== Done!', 'magenta'))
+
+            elapsed = time.time() - start_time
+            average_tx_speed = bytes_sent / elapsed
+            print(
+                color(
+                    f'@@@ TX speed: average={average_tx_speed:.4f} ({bytes_sent} bytes'
+                    f' in {elapsed:.2f} seconds)',
+                    'green',
+                )
+            )
+
+
+# -----------------------------------------------------------------------------
+@click.command()
+@click.option(
+    '--packet-size',
+    '-s',
+    metavar='SIZE',
+    type=click.IntRange(8, 4096),
+    default=500,
+    help='Packet size',
+)
+@click.option(
+    '--packet-count',
+    '-c',
+    metavar='COUNT',
+    type=int,
+    default=10,
+    help='Packet count',
+)
+@click.argument('transport')
+def main(packet_size, packet_count, transport):
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'WARNING').upper())
+
+    loopback = Loopback(packet_size, packet_count, transport)
+    asyncio.run(loopback.run())
+
+
+# -----------------------------------------------------------------------------
+if __name__ == '__main__':
+    main()

bumble/hci.py

@@ -1987,6 +1987,17 @@ def type_spec(cls):
         return {'size': 1, 'mapper': lambda x: OwnAddressType(x).name}
 
 
+# -----------------------------------------------------------------------------
+class LoopbackMode(enum.IntEnum):
+    DISABLED = 0
+    LOCAL = 1
+    REMOTE = 2
+
+    @classmethod
+    def type_spec(cls):
+        return {'size': 1, 'mapper': lambda x: LoopbackMode(x).name}
+
+
 # -----------------------------------------------------------------------------
 class HCI_Packet:
     '''
@@ -3313,6 +3324,27 @@ class HCI_Read_Encryption_Key_Size_Command(HCI_Command):
     '''
 
 
+# -----------------------------------------------------------------------------
+@HCI_Command.command(
+    return_parameters_fields=[
+        ('status', STATUS_SPEC),
+        ('loopback_mode', LoopbackMode.type_spec()),
+    ],
+)
+class HCI_Read_Loopback_Mode_Command(HCI_Command):
+    '''
+    See Bluetooth spec @ 7.6.1 Read Loopback Mode Command
+    '''
+
+
+# -----------------------------------------------------------------------------
+@HCI_Command.command([('loopback_mode', 1)])
+class HCI_Write_Loopback_Mode_Command(HCI_Command):
+    '''
+    See Bluetooth spec @ 7.6.2 Write Loopback Mode Command
+    '''
+
+
 # -----------------------------------------------------------------------------
 @HCI_Command.command([('le_event_mask', 8)])
 class HCI_LE_Set_Event_Mask_Command(HCI_Command):