fix linter config

2026-04-16 00:25:31 +00:00 · 2025-02-03 18:02:14 -05:00
parent 6d9a0bf4e1
commit 5293d32dc6
10 changed files with 656 additions and 293 deletions
--- a/extras/android/BtBench/app/build.gradle.kts
+++ b/extras/android/BtBench/app/build.gradle.kts
@@ -10,7 +10,7 @@ android {

    defaultConfig {
        applicationId = "com.github.google.bumble.btbench"
-        minSdk = 30
+        minSdk = 33
        targetSdk = 34
        versionCode = 1
        versionName = "1.0"
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Connection.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Connection.kt
@@ -0,0 +1,109 @@
+package com.github.google.bumble.btbench
+
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCallback
+import android.bluetooth.BluetoothManager
+import android.bluetooth.BluetoothProfile
+import android.content.Context
+import android.os.Build
+import androidx.core.content.ContextCompat
+import java.util.logging.Logger
+
+private val Log = Logger.getLogger("btbench.connection")
+
+open class Connection(
+    private val viewModel: AppViewModel,
+    private val bluetoothAdapter: BluetoothAdapter,
+    private val context: Context
+) : BluetoothGattCallback() {
+    var remoteDevice: BluetoothDevice? = null
+    var gatt: BluetoothGatt? = null
+
+    @SuppressLint("MissingPermission")
+    open fun connect() {
+        val addressIsPublic = viewModel.peerBluetoothAddress.endsWith("/P")
+        val address = viewModel.peerBluetoothAddress.take(17)
+        remoteDevice = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            bluetoothAdapter.getRemoteLeDevice(
+                address,
+                if (addressIsPublic) {
+                    BluetoothDevice.ADDRESS_TYPE_PUBLIC
+                } else {
+                    BluetoothDevice.ADDRESS_TYPE_RANDOM
+                }
+            )
+        } else {
+            bluetoothAdapter.getRemoteDevice(address)
+        }
+
+        gatt = remoteDevice?.connectGatt(
+            context,
+            false,
+            this,
+            BluetoothDevice.TRANSPORT_LE,
+            if (viewModel.use2mPhy) BluetoothDevice.PHY_LE_2M_MASK else BluetoothDevice.PHY_LE_1M_MASK
+        )
+    }
+
+    @SuppressLint("MissingPermission")
+    fun disconnect() {
+        gatt?.disconnect()
+    }
+
+    override fun onMtuChanged(gatt: BluetoothGatt, mtu: Int, status: Int) {
+        Log.info("MTU update: mtu=$mtu status=$status")
+        viewModel.mtu = mtu
+    }
+
+    override fun onPhyUpdate(gatt: BluetoothGatt, txPhy: Int, rxPhy: Int, status: Int) {
+        Log.info("PHY update: tx=$txPhy, rx=$rxPhy, status=$status")
+        viewModel.txPhy = txPhy
+        viewModel.rxPhy = rxPhy
+    }
+
+    override fun onPhyRead(gatt: BluetoothGatt, txPhy: Int, rxPhy: Int, status: Int) {
+        Log.info("PHY: tx=$txPhy, rx=$rxPhy, status=$status")
+        viewModel.txPhy = txPhy
+        viewModel.rxPhy = rxPhy
+    }
+
+    @SuppressLint("MissingPermission")
+    override fun onConnectionStateChange(
+        gatt: BluetoothGatt?, status: Int, newState: Int
+    ) {
+        if (status != BluetoothGatt.GATT_SUCCESS) {
+            Log.warning("onConnectionStateChange status=$status")
+        }
+
+        if (gatt != null && newState == BluetoothProfile.STATE_CONNECTED) {
+            if (viewModel.use2mPhy) {
+                Log.info("requesting 2M PHY")
+                gatt.setPreferredPhy(
+                    BluetoothDevice.PHY_LE_2M_MASK,
+                    BluetoothDevice.PHY_LE_2M_MASK,
+                    BluetoothDevice.PHY_OPTION_NO_PREFERRED
+                )
+            }
+            gatt.readPhy()
+
+            // Request an MTU update, even though we don't use GATT, because Android
+            // won't request a larger link layer maximum data length otherwise.
+            gatt.requestMtu(517)
+
+            // Request a specific connection priority
+            val connectionPriority = when (viewModel.connectionPriority) {
+                "BALANCED" -> BluetoothGatt.CONNECTION_PRIORITY_BALANCED
+                "LOW_POWER" -> BluetoothGatt.CONNECTION_PRIORITY_LOW_POWER
+                "HIGH" -> BluetoothGatt.CONNECTION_PRIORITY_HIGH
+                "DCK" -> BluetoothGatt.CONNECTION_PRIORITY_DCK
+                else -> 0
+            }
+            if (!gatt.requestConnectionPriority(connectionPriority)) {
+                Log.warning("requestConnectionPriority failed")
+            }
+        }
+    }
+}
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/GattClient.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/GattClient.kt
@@ -0,0 +1,219 @@
+// 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.
+
+package com.github.google.bumble.btbench
+
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothGattDescriptor
+import android.bluetooth.BluetoothProfile
+import android.content.Context
+import java.io.IOException
+import java.util.UUID
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.Semaphore
+import java.util.logging.Logger
+import kotlin.concurrent.thread
+
+private val Log = Logger.getLogger("btbench.gatt-client")
+
+private var CCCD_UUID = UUID.fromString("00002902-0000-1000-8000-00805F9B34FB")
+
+private val SPEED_SERVICE_UUID = UUID.fromString("50DB505C-8AC4-4738-8448-3B1D9CC09CC5")
+private val SPEED_TX_UUID = UUID.fromString("E789C754-41A1-45F4-A948-A0A1A90DBA53")
+private val SPEED_RX_UUID = UUID.fromString("016A2CC7-E14B-4819-935F-1F56EAE4098D")
+
+
+class GattClientConnection(
+    viewModel: AppViewModel,
+    bluetoothAdapter: BluetoothAdapter,
+    context: Context
+) : Connection(viewModel, bluetoothAdapter, context), PacketIO {
+    override var packetSink: PacketSink? = null
+    private val discoveryDone: CountDownLatch = CountDownLatch(1)
+    private val writeSemaphore: Semaphore = Semaphore(1)
+    var rxCharacteristic: BluetoothGattCharacteristic? = null
+    var txCharacteristic: BluetoothGattCharacteristic? = null
+
+    override fun connect() {
+        super.connect()
+
+        // Check if we're already connected and have discovered the services
+        if (gatt?.getService(SPEED_SERVICE_UUID) != null) {
+            onServicesDiscovered(gatt, BluetoothGatt.GATT_SUCCESS)
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    override fun onConnectionStateChange(
+        gatt: BluetoothGatt?, status: Int, newState: Int
+    ) {
+        super.onConnectionStateChange(gatt, status, newState)
+        if (status != BluetoothGatt.GATT_SUCCESS) {
+            discoveryDone.countDown()
+            return
+        }
+        if (gatt != null && newState == BluetoothProfile.STATE_CONNECTED) {
+            if (!gatt.discoverServices()) {
+                Log.warning("discoverServices could not start")
+                discoveryDone.countDown()
+            }
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    override fun onServicesDiscovered(gatt: BluetoothGatt?, status: Int) {
+        if (status != BluetoothGatt.GATT_SUCCESS) {
+            Log.warning("failed to discover services: ${status}")
+            discoveryDone.countDown()
+            return
+        }
+
+        // Find the service
+        val service = gatt!!.getService(SPEED_SERVICE_UUID)
+        if (service == null) {
+            Log.warning("GATT Service not found")
+            discoveryDone.countDown()
+            return
+        }
+
+        // Find the RX and TX characteristics
+        rxCharacteristic = service.getCharacteristic(SPEED_RX_UUID)
+        if (rxCharacteristic == null) {
+            Log.warning("GATT RX Characteristics not found")
+            discoveryDone.countDown()
+            return
+        }
+        txCharacteristic = service.getCharacteristic(SPEED_TX_UUID)
+        if (txCharacteristic == null) {
+            Log.warning("GATT TX Characteristics not found")
+            discoveryDone.countDown()
+            return
+        }
+
+        // Subscribe to the RX characteristic
+        gatt.setCharacteristicNotification(rxCharacteristic, true)
+        val cccdDescriptor = rxCharacteristic!!.getDescriptor(CCCD_UUID)
+        gatt.writeDescriptor(cccdDescriptor, BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
+
+        Log.info("GATT discovery complete")
+        discoveryDone.countDown()
+    }
+
+    override fun onCharacteristicWrite(
+        gatt: BluetoothGatt?,
+        characteristic: BluetoothGattCharacteristic?,
+        status: Int
+    ) {
+        // Now we can write again
+        writeSemaphore.release()
+
+        if (status != BluetoothGatt.GATT_SUCCESS) {
+            Log.warning("onCharacteristicWrite failed: $status")
+            return
+        }
+    }
+
+    override fun onCharacteristicChanged(
+        gatt: BluetoothGatt,
+        characteristic: BluetoothGattCharacteristic,
+        value: ByteArray
+    ) {
+        if (characteristic.uuid == SPEED_RX_UUID && packetSink != null) {
+            val packet = Packet.from(value)
+            packetSink!!.onPacket(packet)
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    override fun sendPacket(packet: Packet) {
+        if (txCharacteristic == null) {
+            Log.warning("No TX characteristic, dropping")
+            return
+        }
+
+        // Wait until we can write
+        writeSemaphore.acquire()
+
+        // Write the data
+        val data = packet.toBytes()
+        val clampedData = if (data.size > 512) {
+            // Clamp the data to the maximum allowed characteristic data size
+            data.copyOf(512)
+        } else {
+            data
+        }
+        gatt?.writeCharacteristic(
+            txCharacteristic!!,
+            clampedData,
+            BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE
+        )
+    }
+
+    fun waitForDiscoveryCompletion() {
+        discoveryDone.await()
+    }
+}
+
+class GattClient(
+    private val viewModel: AppViewModel,
+    bluetoothAdapter: BluetoothAdapter,
+    context: Context,
+    private val createIoClient: (packetIo: PacketIO) -> IoClient
+) : Mode {
+    private var connection: GattClientConnection =
+        GattClientConnection(viewModel, bluetoothAdapter, context)
+    private var clientThread: Thread? = null
+
+    @SuppressLint("MissingPermission")
+    override fun run() {
+        viewModel.running = true
+
+        clientThread = thread(name = "GattClient") {
+            connection.connect()
+
+            viewModel.aborter = {
+                connection.disconnect()
+            }
+
+            // Discover the rx and tx characteristics
+            connection.waitForDiscoveryCompletion()
+            if (connection.rxCharacteristic == null || connection.txCharacteristic == null) {
+                connection.disconnect()
+                viewModel.running = false
+                return@thread
+            }
+
+            val ioClient = createIoClient(connection)
+
+            try {
+                ioClient.run()
+                viewModel.status = "OK"
+            } catch (error: IOException) {
+                Log.info("run ended abruptly")
+                viewModel.status = "ABORTED"
+                viewModel.lastError = "IO_ERROR"
+            } finally {
+                connection.disconnect()
+                viewModel.running = false
+            }
+        }
+    }
+
+    override fun waitForCompletion() {
+        clientThread?.join()
+    }
+}
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/L2capClient.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/L2capClient.kt
@@ -16,101 +16,25 @@ package com.github.google.bumble.btbench

 import android.annotation.SuppressLint
 import android.bluetooth.BluetoothAdapter
-import android.bluetooth.BluetoothDevice
-import android.bluetooth.BluetoothGatt
-import android.bluetooth.BluetoothGattCallback
-import android.bluetooth.BluetoothProfile
 import android.content.Context
-import android.os.Build
 import java.util.logging.Logger

 private val Log = Logger.getLogger("btbench.l2cap-client")

 class L2capClient(
    private val viewModel: AppViewModel,
-    private val bluetoothAdapter: BluetoothAdapter,
-    private val context: Context,
+    bluetoothAdapter: BluetoothAdapter,
+    context: Context,
    private val createIoClient: (packetIo: PacketIO) -> IoClient
 ) : Mode {
+    private var connection: Connection = Connection(viewModel, bluetoothAdapter, context)
    private var socketClient: SocketClient? = null

    @SuppressLint("MissingPermission")
    override fun run() {
        viewModel.running = true
-        val addressIsPublic = viewModel.peerBluetoothAddress.endsWith("/P")
-        val address = viewModel.peerBluetoothAddress.take(17)
-        val remoteDevice = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
-            bluetoothAdapter.getRemoteLeDevice(
-                address,
-                if (addressIsPublic) {
-                    BluetoothDevice.ADDRESS_TYPE_PUBLIC
-                } else {
-                    BluetoothDevice.ADDRESS_TYPE_RANDOM
-                }
-            )
-        } else {
-            bluetoothAdapter.getRemoteDevice(address)
-        }
-
-        val gatt = remoteDevice.connectGatt(
-            context,
-            false,
-            object : BluetoothGattCallback() {
-                override fun onMtuChanged(gatt: BluetoothGatt, mtu: Int, status: Int) {
-                    Log.info("MTU update: mtu=$mtu status=$status")
-                    viewModel.mtu = mtu
-                }
-
-                override fun onPhyUpdate(gatt: BluetoothGatt, txPhy: Int, rxPhy: Int, status: Int) {
-                    Log.info("PHY update: tx=$txPhy, rx=$rxPhy, status=$status")
-                    viewModel.txPhy = txPhy
-                    viewModel.rxPhy = rxPhy
-                }
-
-                override fun onPhyRead(gatt: BluetoothGatt, txPhy: Int, rxPhy: Int, status: Int) {
-                    Log.info("PHY: tx=$txPhy, rx=$rxPhy, status=$status")
-                    viewModel.txPhy = txPhy
-                    viewModel.rxPhy = rxPhy
-                }
-
-                override fun onConnectionStateChange(
-                    gatt: BluetoothGatt?, status: Int, newState: Int
-                ) {
-                    if (gatt != null && newState == BluetoothProfile.STATE_CONNECTED) {
-                        if (viewModel.use2mPhy) {
-                            Log.info("requesting 2M PHY")
-                            gatt.setPreferredPhy(
-                                BluetoothDevice.PHY_LE_2M_MASK,
-                                BluetoothDevice.PHY_LE_2M_MASK,
-                                BluetoothDevice.PHY_OPTION_NO_PREFERRED
-                            )
-                        }
-                        gatt.readPhy()
-
-                        // Request an MTU update, even though we don't use GATT, because Android
-                        // won't request a larger link layer maximum data length otherwise.
-                        gatt.requestMtu(517)
-
-                        // Request a specific connection priority
-                        val connectionPriority = when (viewModel.connectionPriority) {
-                            "BALANCED" -> BluetoothGatt.CONNECTION_PRIORITY_BALANCED
-                            "LOW_POWER" -> BluetoothGatt.CONNECTION_PRIORITY_LOW_POWER
-                            "HIGH" -> BluetoothGatt.CONNECTION_PRIORITY_HIGH
-                            "DCK" -> BluetoothGatt.CONNECTION_PRIORITY_DCK
-                            else -> 0
-                        }
-                        if (!gatt.requestConnectionPriority(connectionPriority)) {
-                            Log.warning("requestConnectionPriority failed")
-                        }
-                    }
-                }
-            },
-            BluetoothDevice.TRANSPORT_LE,
-            if (viewModel.use2mPhy) BluetoothDevice.PHY_LE_2M_MASK else BluetoothDevice.PHY_LE_1M_MASK
-        )
-
-        val socket = remoteDevice.createInsecureL2capChannel(viewModel.l2capPsm)
-
+        connection.connect()
+        val socket = connection.remoteDevice!!.createInsecureL2capChannel(viewModel.l2capPsm)
        socketClient = SocketClient(viewModel, socket, createIoClient)
        socketClient!!.run()
    }
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/MainActivity.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/MainActivity.kt
@@ -146,9 +146,7 @@ class MainActivity : ComponentActivity() {
        initBluetooth()
        setContent {
            MainView(
-                appViewModel,
-                ::becomeDiscoverable,
-                ::runScenario
+                appViewModel, ::becomeDiscoverable, ::runScenario
            )
        }

@@ -184,6 +182,8 @@ class MainActivity : ComponentActivity() {
                "rfcomm-server" -> appViewModel.mode = RFCOMM_SERVER_MODE
                "l2cap-client" -> appViewModel.mode = L2CAP_CLIENT_MODE
                "l2cap-server" -> appViewModel.mode = L2CAP_SERVER_MODE
+                "gatt-client" -> appViewModel.mode = GATT_CLIENT_MODE
+                "gatt-server" -> appViewModel.mode = GATT_SERVER_MODE
            }
        }
        intent.getStringExtra("autostart")?.let {
@@ -204,12 +204,14 @@ class MainActivity : ComponentActivity() {
            RFCOMM_CLIENT_MODE -> RfcommClient(appViewModel, bluetoothAdapter!!, ::createIoClient)
            RFCOMM_SERVER_MODE -> RfcommServer(appViewModel, bluetoothAdapter!!, ::createIoClient)
            L2CAP_CLIENT_MODE -> L2capClient(
-                appViewModel,
-                bluetoothAdapter!!,
-                baseContext,
-                ::createIoClient
+                appViewModel, bluetoothAdapter!!, baseContext, ::createIoClient
            )
+
            L2CAP_SERVER_MODE -> L2capServer(appViewModel, bluetoothAdapter!!, ::createIoClient)
+            GATT_CLIENT_MODE -> GattClient(
+                appViewModel, bluetoothAdapter!!, baseContext, ::createIoClient
+            )
+
            else -> throw IllegalStateException()
        }
        runner.run()
@@ -283,7 +285,7 @@ fun MainView(
                        keyboardController?.hide()
                        focusManager.clearFocus()
                    }),
-                    enabled = (appViewModel.mode == RFCOMM_CLIENT_MODE) or (appViewModel.mode == L2CAP_CLIENT_MODE)
+                    enabled = (appViewModel.mode == RFCOMM_CLIENT_MODE || appViewModel.mode == L2CAP_CLIENT_MODE || appViewModel.mode == GATT_CLIENT_MODE)
                )
                Divider()
                TextField(
@@ -351,43 +353,36 @@ fun MainView(
                        keyboardController?.hide()
                        focusManager.clearFocus()
                    }),
-                    enabled = (appViewModel.scenario == PING_SCENARIO)
+                    enabled = (appViewModel.scenario == PING_SCENARIO || appViewModel.scenario == SEND_SCENARIO)
                )
                Divider()
-                ActionButton(
-                    text = "Become Discoverable", onClick = becomeDiscoverable, true
-                )
                Row(
                    horizontalArrangement = Arrangement.SpaceBetween,
                    verticalAlignment = Alignment.CenterVertically
                ) {
                    Text(text = "2M PHY")
                    Spacer(modifier = Modifier.padding(start = 8.dp))
-                    Switch(
-                        enabled = (appViewModel.mode == L2CAP_CLIENT_MODE || appViewModel.mode == L2CAP_SERVER_MODE),
+                    Switch(enabled = (appViewModel.mode == L2CAP_CLIENT_MODE || appViewModel.mode == L2CAP_SERVER_MODE || appViewModel.mode == GATT_CLIENT_MODE || appViewModel.mode == GATT_SERVER_MODE),
                        checked = appViewModel.use2mPhy,
-                        onCheckedChange = { appViewModel.use2mPhy = it }
-                    )
+                        onCheckedChange = { appViewModel.use2mPhy = it })
                    Column(Modifier.selectableGroup()) {
                        listOf(
-                            "BALANCED",
-                            "LOW",
-                            "HIGH",
-                            "DCK"
+                            "BALANCED", "LOW", "HIGH", "DCK"
                        ).forEach { text ->
                            Row(
                                Modifier
                                    .selectable(
                                        selected = (text == appViewModel.connectionPriority),
                                        onClick = { appViewModel.updateConnectionPriority(text) },
-                                        role = Role.RadioButton
+                                        role = Role.RadioButton,
                                    )
                                    .padding(horizontal = 16.dp),
                                verticalAlignment = Alignment.CenterVertically
                            ) {
                                RadioButton(
                                    selected = (text == appViewModel.connectionPriority),
-                                    onClick = null
+                                    onClick = null,
+                                    enabled = (appViewModel.mode == L2CAP_CLIENT_MODE || appViewModel.mode == L2CAP_SERVER_MODE || appViewModel.mode == GATT_CLIENT_MODE || appViewModel.mode == GATT_SERVER_MODE)
                                )
                                Text(
                                    text = text,
@@ -404,7 +399,9 @@ fun MainView(
                            RFCOMM_CLIENT_MODE,
                            RFCOMM_SERVER_MODE,
                            L2CAP_CLIENT_MODE,
-                            L2CAP_SERVER_MODE
+                            L2CAP_SERVER_MODE,
+                            GATT_CLIENT_MODE,
+                            GATT_SERVER_MODE
                        ).forEach { text ->
                            Row(
                                Modifier
@@ -417,8 +414,7 @@ fun MainView(
                                verticalAlignment = Alignment.CenterVertically
                            ) {
                                RadioButton(
-                                    selected = (text == appViewModel.mode),
-                                    onClick = null
+                                    selected = (text == appViewModel.mode), onClick = null
                                )
                                Text(
                                    text = text,
@@ -430,10 +426,7 @@ fun MainView(
                    }
                    Column(Modifier.selectableGroup()) {
                        listOf(
-                            SEND_SCENARIO,
-                            RECEIVE_SCENARIO,
-                            PING_SCENARIO,
-                            PONG_SCENARIO
+                            SEND_SCENARIO, RECEIVE_SCENARIO, PING_SCENARIO, PONG_SCENARIO
                        ).forEach { text ->
                            Row(
                                Modifier
@@ -446,8 +439,7 @@ fun MainView(
                                verticalAlignment = Alignment.CenterVertically
                            ) {
                                RadioButton(
-                                    selected = (text == appViewModel.scenario),
-                                    onClick = null
+                                    selected = (text == appViewModel.scenario), onClick = null
                                )
                                Text(
                                    text = text,
@@ -465,20 +457,29 @@ fun MainView(
                    ActionButton(
                        text = "Stop", onClick = appViewModel::abort, enabled = appViewModel.running
                    )
+                    ActionButton(
+                        text = "Become Discoverable", onClick = becomeDiscoverable, true
+                    )
                }
                Divider()
-                Text(
-                    text = if (appViewModel.mtu != 0) "MTU: ${appViewModel.mtu}" else ""
-                )
-                Text(
-                    text = if (appViewModel.rxPhy != 0 || appViewModel.txPhy != 0) "PHY: tx=${appViewModel.txPhy}, rx=${appViewModel.rxPhy}" else ""
-                )
+                if (appViewModel.mtu != 0) {
+                    Text(
+                        text = "MTU: ${appViewModel.mtu}"
+                    )
+                }
+                if (appViewModel.rxPhy != 0) {
+                    Text(
+                        text = "PHY: tx=${appViewModel.txPhy}, rx=${appViewModel.rxPhy}"
+                    )
+                }
                Text(
                    text = "Status: ${appViewModel.status}"
                )
-                Text(
-                    text = "Last Error: ${appViewModel.lastError}"
-                )
+                if (appViewModel.lastError.isNotEmpty()) {
+                    Text(
+                        text = "Last Error: ${appViewModel.lastError}"
+                    )
+                }
                Text(
                    text = "Packets Sent: ${appViewModel.packetsSent}"
                )
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Model.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Model.kt
@@ -35,6 +35,8 @@ const val L2CAP_CLIENT_MODE = "L2CAP Client"
 const val L2CAP_SERVER_MODE = "L2CAP Server"
 const val RFCOMM_CLIENT_MODE = "RFCOMM Client"
 const val RFCOMM_SERVER_MODE = "RFCOMM Server"
+const val GATT_CLIENT_MODE = "GATT Client"
+const val GATT_SERVER_MODE = "GATT Server"

 const val SEND_SCENARIO = "Send"
 const val RECEIVE_SCENARIO = "Receive"
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Packet.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Packet.kt
@@ -17,6 +17,7 @@ package com.github.google.bumble.btbench
 import android.bluetooth.BluetoothSocket
 import java.io.IOException
 import java.nio.ByteBuffer
+import java.nio.ByteOrder
 import java.util.logging.Logger
 import kotlin.math.min

@@ -37,11 +38,16 @@ abstract class Packet(val type: Int, val payload: ByteArray = ByteArray(0)) {
                RESET -> ResetPacket()
                SEQUENCE -> SequencePacket(
                    data[1].toInt(),
-                    ByteBuffer.wrap(data, 2, 4).getInt(),
-                    data.sliceArray(6..<data.size)
+                    ByteBuffer.wrap(data, 2, 4).order(ByteOrder.LITTLE_ENDIAN).getInt(),
+                    ByteBuffer.wrap(data, 6, 4).order(ByteOrder.LITTLE_ENDIAN).getInt(),
+                    data.sliceArray(10..<data.size)
+                )
+
+                ACK -> AckPacket(
+                    data[1].toInt(),
+                    ByteBuffer.wrap(data, 2, 4).order(ByteOrder.LITTLE_ENDIAN).getInt()
                )

-                ACK -> AckPacket(data[1].toInt(), ByteBuffer.wrap(data, 2, 4).getInt())
                else -> GenericPacket(data[0].toInt(), data.sliceArray(1..<data.size))
            }
        }
@@ -57,16 +63,24 @@ class ResetPacket : Packet(RESET)

 class AckPacket(val flags: Int, val sequenceNumber: Int) : Packet(ACK) {
    override fun toBytes(): ByteArray {
-        return ByteBuffer.allocate(1 + 1 + 4).put(type.toByte()).put(flags.toByte())
+        return ByteBuffer.allocate(6).order(
+            ByteOrder.LITTLE_ENDIAN
+        ).put(type.toByte()).put(flags.toByte())
            .putInt(sequenceNumber).array()
    }
 }

-class SequencePacket(val flags: Int, val sequenceNumber: Int, payload: ByteArray) :
+class SequencePacket(
+    val flags: Int,
+    val sequenceNumber: Int,
+    val timestamp: Int,
+    payload: ByteArray
+) :
    Packet(SEQUENCE, payload) {
    override fun toBytes(): ByteArray {
-        return ByteBuffer.allocate(1 + 1 + 4 + payload.size).put(type.toByte()).put(flags.toByte())
-            .putInt(sequenceNumber).put(payload).array()
+        return ByteBuffer.allocate(10 + payload.size).order(ByteOrder.LITTLE_ENDIAN)
+            .put(type.toByte()).put(flags.toByte())
+            .putInt(sequenceNumber).putInt(timestamp).put(payload).array()
    }
 }

--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Pinger.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Pinger.kt
@@ -46,19 +46,23 @@ class Pinger(private val viewModel: AppViewModel, private val packetIO: PacketIO

        val startTime = TimeSource.Monotonic.markNow()
        for (i in 0..<packetCount) {
-            val now = TimeSource.Monotonic.markNow()
-            val targetTime = startTime + (i * viewModel.senderPacketInterval).milliseconds
-            val delay = targetTime - now
-            if (delay.isPositive()) {
-                Log.info("sleeping ${delay.inWholeMilliseconds} ms")
-                Thread.sleep(delay.inWholeMilliseconds)
+            var now = TimeSource.Monotonic.markNow()
+            if (viewModel.senderPacketInterval > 0) {
+                val targetTime = startTime + (i * viewModel.senderPacketInterval).milliseconds
+                val delay = targetTime - now
+                if (delay.isPositive()) {
+                    Log.info("sleeping ${delay.inWholeMilliseconds} ms")
+                    Thread.sleep(delay.inWholeMilliseconds)
+                    now = TimeSource.Monotonic.markNow()
+                }
            }
            pingTimes.add(TimeSource.Monotonic.markNow())
            packetIO.sendPacket(
                SequencePacket(
                    if (i < packetCount - 1) 0 else Packet.LAST_FLAG,
                    i,
-                    ByteArray(packetSize - 6)
+                    (now - startTime).inWholeMicroseconds.toInt(),
+                    ByteArray(packetSize - 10)
                )
            )
            viewModel.packetsSent = i + 1
--- a/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Sender.kt
+++ b/extras/android/BtBench/app/src/main/java/com/github/google/bumble/btbench/Sender.kt
@@ -16,6 +16,7 @@ package com.github.google.bumble.btbench

 import java.util.concurrent.Semaphore
 import java.util.logging.Logger
+import kotlin.time.Duration.Companion.milliseconds
 import kotlin.time.DurationUnit
 import kotlin.time.TimeSource

@@ -45,20 +46,32 @@ class Sender(private val viewModel: AppViewModel, private val packetIO: PacketIO

        val packetCount = viewModel.senderPacketCount
        val packetSize = viewModel.senderPacketSize
-        for (i in 0..<packetCount - 1) {
-            packetIO.sendPacket(SequencePacket(0, i, ByteArray(packetSize - 6)))
+        for (i in 0..<packetCount) {
+            var now = TimeSource.Monotonic.markNow()
+            if (viewModel.senderPacketInterval > 0) {
+                val targetTime = startTime + (i * viewModel.senderPacketInterval).milliseconds
+                val delay = targetTime - now
+                if (delay.isPositive()) {
+                    Log.info("sleeping ${delay.inWholeMilliseconds} ms")
+                    Thread.sleep(delay.inWholeMilliseconds)
+                }
+                now = TimeSource.Monotonic.markNow()
+            }
+            val flags = when (i) {
+                packetCount - 1 -> Packet.LAST_FLAG
+                else -> 0
+            }
+            packetIO.sendPacket(
+                SequencePacket(
+                    flags,
+                    i,
+                    (now - startTime).inWholeMicroseconds.toInt(),
+                    ByteArray(packetSize - 10)
+                )
+            )
            bytesSent += packetSize
            viewModel.packetsSent = i + 1
        }
-        packetIO.sendPacket(
-            SequencePacket(
-                Packet.LAST_FLAG,
-                packetCount - 1,
-                ByteArray(packetSize - 6)
-            )
-        )
-        bytesSent += packetSize
-        viewModel.packetsSent = packetCount

        // Wait for the ACK
        Log.info("waiting for ACK")