Merge pull request #10 from element-hq/kegan/tun

Add VpnService in developer settings

Author: kegsay

AGENTS.md

@@ -8,6 +8,8 @@
 
 You are running in a sandbox unless told otherwise.
 Builds/tests Android projects OFFLINE. Host SDK + Gradle caches are mounted read-only. Use './gradlew --offline testDebugUnitTest' for unit tests, './gradlew --offline assembleDebug' to build, './gradlew --offline lintDebug' for lint. Instrumented tests (connectedAndroidTest) are NOT supported — no device/KVM.
+You may be unable to write cache entries (chmod EPERM) in which case `--no-configuration-cache`.
+Run ktlint, detekt, lintGplayDebug, lintFdroidDebug and fix any issues before declaring work is done.
 
 ## Strong Conventions
 

app/build.gradle.kts

@@ -38,7 +38,9 @@ plugins {
 // 26.05.2-r1234+neutrino.0.3.0. The build number is the git commit count; the Neutrino
 // version comes from the version catalog. Used for both versionName and the APK file name.
 val neutrinoVersion = libs.versions.neutrino.get()
-val buildNumber = providers.of(GitCommitCountValueSource::class.java) {}.get()
+val buildNumber = providers.of(GitCommitCountValueSource::class.java) {
+    parameters.workingDir.set(rootProject.layout.projectDirectory)
+}.get()
 val fullVersionName = "${Versions.VERSION_NAME}-r$buildNumber+neutrino.$neutrinoVersion"
 
 base {
@@ -255,8 +257,12 @@ dependencies {
 
 tasks.withType<GenerateBuildConfig>().configureEach {
     outputs.upToDateWhen { false }
-    val gitRevision = providers.of(GitRevisionValueSource::class.java) {}.get()
-    val gitBranchName = providers.of(GitBranchNameValueSource::class.java) {}.get()
+    val gitRevision = providers.of(GitRevisionValueSource::class.java) {
+        parameters.workingDir.set(rootProject.layout.projectDirectory)
+    }.get()
+    val gitBranchName = providers.of(GitBranchNameValueSource::class.java) {
+        parameters.workingDir.set(rootProject.layout.projectDirectory)
+    }.get()
     android.defaultConfig.buildConfigFieldStr("GIT_REVISION", gitRevision)
     android.defaultConfig.buildConfigFieldStr("GIT_BRANCH_NAME", gitBranchName)
 }

features/preferences/impl/build.gradle.kts

@@ -84,6 +84,7 @@ dependencies {
     implementation(projects.services.analytics.api)
     implementation(projects.services.analytics.compose)
     implementation(projects.services.appnavstate.api)
+    implementation(projects.services.neutrino.api)
     implementation(projects.services.toolbox.api)
     implementation(libs.datetime)
     implementation(libs.coil.compose)

features/preferences/impl/src/main/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsEvents.kt

@@ -15,4 +15,6 @@ sealed interface DeveloperSettingsEvents {
     data class ChangeBrandColor(val color: Color?) : DeveloperSettingsEvents
     data object ClearCache : DeveloperSettingsEvents
     data object VacuumStores : DeveloperSettingsEvents
+    data class SetPacketTunnelEnabled(val enabled: Boolean) : DeveloperSettingsEvents
+    data class OnPacketTunnelConsentResult(val granted: Boolean) : DeveloperSettingsEvents
 }

features/preferences/impl/src/main/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsPresenter.kt

@@ -8,6 +8,7 @@
 
 package io.element.android.features.preferences.impl.developer
 
+import android.content.Intent
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.MutableState
@@ -31,6 +32,7 @@ import io.element.android.libraries.architecture.runCatchingUpdatingState
 import io.element.android.libraries.core.data.ByteUnit
 import io.element.android.libraries.matrix.api.analytics.GetDatabaseSizesUseCase
 import io.element.android.libraries.matrix.api.core.SessionId
+import io.element.android.services.neutrino.api.NeutrinoTunnel
 import kotlinx.collections.immutable.ImmutableMap
 import kotlinx.collections.immutable.toImmutableMap
 import kotlinx.coroutines.CoroutineScope
@@ -46,6 +48,7 @@ class DeveloperSettingsPresenter(
     private val vacuumStoresUseCase: VacuumStoresUseCase,
     private val databaseSizesUseCase: GetDatabaseSizesUseCase,
     private val fileSizeFormatter: FileSizeFormatter,
+    private val neutrinoTunnel: NeutrinoTunnel,
 ) : Presenter<DeveloperSettingsState> {
     @Composable
     override fun present(): DeveloperSettingsState {
@@ -61,6 +64,14 @@ class DeveloperSettingsPresenter(
         var showColorPicker by remember {
             mutableStateOf(false)
         }
+        // Initialise from the actual tunnel state so the toggle reflects reality on
+        // (re)entry, rather than a presenter-local flag that resets to false.
+        var packetTunnelEnabled by remember {
+            mutableStateOf(neutrinoTunnel.isRunning())
+        }
+        var packetTunnelConsentIntent by remember {
+            mutableStateOf<Intent?>(null)
+        }
         LaunchedEffect(Unit) {
             computeDatabaseSizes(databaseSizes)
         }
@@ -88,6 +99,29 @@ class DeveloperSettingsPresenter(
                 DeveloperSettingsEvents.VacuumStores -> coroutineScope.launch {
                     vacuumStoresUseCase()
                 }
+                is DeveloperSettingsEvents.SetPacketTunnelEnabled -> {
+                    if (event.enabled) {
+                        val consentIntent = neutrinoTunnel.consentIntent()
+                        if (consentIntent == null) {
+                            // Consent already granted: start immediately.
+                            neutrinoTunnel.start()
+                            packetTunnelEnabled = true
+                        } else {
+                            // Ask the View to launch the system VPN consent dialog.
+                            packetTunnelConsentIntent = consentIntent
+                        }
+                    } else {
+                        neutrinoTunnel.stop()
+                        packetTunnelEnabled = false
+                    }
+                }
+                is DeveloperSettingsEvents.OnPacketTunnelConsentResult -> {
+                    packetTunnelConsentIntent = null
+                    if (event.granted) {
+                        neutrinoTunnel.start()
+                        packetTunnelEnabled = true
+                    }
+                }
             }
         }
 
@@ -99,6 +133,8 @@ class DeveloperSettingsPresenter(
             clearCacheAction = clearCacheAction.value,
             isEnterpriseBuild = enterpriseService.isEnterpriseBuild,
             showColorPicker = showColorPicker,
+            packetTunnelEnabled = packetTunnelEnabled,
+            packetTunnelConsentIntent = packetTunnelConsentIntent,
             eventSink = ::handleEvent,
         )
     }

features/preferences/impl/src/main/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsState.kt

@@ -8,6 +8,7 @@
 
 package io.element.android.features.preferences.impl.developer
 
+import android.content.Intent
 import io.element.android.features.preferences.impl.developer.appsettings.AppDeveloperSettingsState
 import io.element.android.libraries.architecture.AsyncAction
 import io.element.android.libraries.architecture.AsyncData
@@ -20,6 +21,10 @@ data class DeveloperSettingsState(
     val clearCacheAction: AsyncAction<Unit>,
     val isEnterpriseBuild: Boolean,
     val showColorPicker: Boolean,
+    val packetTunnelEnabled: Boolean,
+    // When non-null, the View must launch this VPN consent Intent and report the
+    // result back via [DeveloperSettingsEvents.OnPacketTunnelConsentResult].
+    val packetTunnelConsentIntent: Intent?,
     val eventSink: (DeveloperSettingsEvents) -> Unit
 ) {
     val showLoader = clearCacheAction is AsyncAction.Loading

features/preferences/impl/src/main/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsStateProvider.kt

@@ -39,6 +39,7 @@ fun aDeveloperSettingsState(
     clearCacheAction: AsyncAction<Unit> = AsyncAction.Uninitialized,
     isEnterpriseBuild: Boolean = false,
     showColorPicker: Boolean = false,
+    packetTunnelEnabled: Boolean = false,
     eventSink: (DeveloperSettingsEvents) -> Unit = {},
 ) = DeveloperSettingsState(
     appDeveloperSettingsState = appDeveloperSettingsState,
@@ -47,5 +48,7 @@ fun aDeveloperSettingsState(
     clearCacheAction = clearCacheAction,
     isEnterpriseBuild = isEnterpriseBuild,
     showColorPicker = showColorPicker,
+    packetTunnelEnabled = packetTunnelEnabled,
+    packetTunnelConsentIntent = null,
     eventSink = eventSink,
 )

features/preferences/impl/src/main/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsView.kt

@@ -8,11 +8,15 @@
 
 package io.element.android.features.preferences.impl.developer
 
+import android.app.Activity
 import androidx.activity.compose.BackHandler
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.progressSemantics
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.ui.ExperimentalComposeUiApi
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
@@ -45,6 +49,16 @@ fun DeveloperSettingsView(
     if (state.showLoader) {
         ProgressDialog()
     }
+    // The packet tunnel needs system VPN consent before it can start. When the
+    // presenter surfaces a consent Intent, launch it and report the result back.
+    val packetTunnelConsentLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.StartActivityForResult()
+    ) { result ->
+        state.eventSink(DeveloperSettingsEvents.OnPacketTunnelConsentResult(result.resultCode == Activity.RESULT_OK))
+    }
+    LaunchedEffect(state.packetTunnelConsentIntent) {
+        state.packetTunnelConsentIntent?.let { packetTunnelConsentLauncher.launch(it) }
+    }
     BackHandler(
         enabled = !state.showLoader,
         onBack = onBackClick,
@@ -65,6 +79,23 @@ fun DeveloperSettingsView(
         )
         NotificationCategory(onPushHistoryClick)
 
+        PreferenceCategory(title = "Neutrino") {
+            ListItem(
+                headlineContent = {
+                    Text("Packet tunnel")
+                },
+                supportingContent = {
+                    Text("Capture this app's traffic to the virtual subnet over a TUN interface (logs packets only)")
+                },
+                trailingContent = ListItemContent.Switch(
+                    checked = state.packetTunnelEnabled,
+                ),
+                onClick = {
+                    state.eventSink(DeveloperSettingsEvents.SetPacketTunnelEnabled(!state.packetTunnelEnabled))
+                }
+            )
+        }
+
         if (state.isEnterpriseBuild) {
             PreferenceCategory(title = "Theme") {
                 ListItem(

features/preferences/impl/src/test/kotlin/io/element/android/features/preferences/impl/developer/DeveloperSettingsPresenterTest.kt

@@ -27,6 +27,7 @@ import io.element.android.libraries.matrix.api.analytics.SdkStoreSizes
 import io.element.android.libraries.matrix.api.core.SessionId
 import io.element.android.libraries.matrix.test.A_SESSION_ID
 import io.element.android.tests.testutils.WarmUpRule
+import io.element.android.tests.testutils.consumeItemsUntilPredicate
 import io.element.android.tests.testutils.lambda.lambdaRecorder
 import io.element.android.tests.testutils.lambda.value
 import io.element.android.tests.testutils.test
@@ -144,13 +145,56 @@ class DeveloperSettingsPresenterTest {
         }
     }
 
+    @Test
+    fun `present - enabling packet tunnel with consent already granted starts it`() = runTest {
+        val neutrinoTunnel = FakeNeutrinoTunnel(consentIntentResult = null)
+        val presenter = createDeveloperSettingsPresenter(neutrinoTunnel = neutrinoTunnel)
+        presenter.test {
+            val initialState = consumeItemsUntilPredicate { !it.packetTunnelEnabled }.last()
+            initialState.eventSink(DeveloperSettingsEvents.SetPacketTunnelEnabled(true))
+            val enabledState = consumeItemsUntilPredicate { it.packetTunnelEnabled }.last()
+            assertThat(enabledState.packetTunnelEnabled).isTrue()
+            assertThat(enabledState.packetTunnelConsentIntent).isNull()
+            assertThat(neutrinoTunnel.startCount).isEqualTo(1)
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
+    @Test
+    fun `present - packet tunnel toggle reflects the already-running tunnel on entry`() = runTest {
+        val neutrinoTunnel = FakeNeutrinoTunnel(initiallyRunning = true)
+        val presenter = createDeveloperSettingsPresenter(neutrinoTunnel = neutrinoTunnel)
+        presenter.test {
+            assertThat(awaitItem().packetTunnelEnabled).isTrue()
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
+    @Test
+    fun `present - disabling packet tunnel stops it`() = runTest {
+        val neutrinoTunnel = FakeNeutrinoTunnel(consentIntentResult = null)
+        val presenter = createDeveloperSettingsPresenter(neutrinoTunnel = neutrinoTunnel)
+        presenter.test {
+            val initialState = consumeItemsUntilPredicate { !it.packetTunnelEnabled }.last()
+            initialState.eventSink(DeveloperSettingsEvents.SetPacketTunnelEnabled(true))
+            consumeItemsUntilPredicate { it.packetTunnelEnabled }
+                .last()
+                .eventSink(DeveloperSettingsEvents.SetPacketTunnelEnabled(false))
+            val disabledState = consumeItemsUntilPredicate { !it.packetTunnelEnabled }.last()
+            assertThat(disabledState.packetTunnelEnabled).isFalse()
+            assertThat(neutrinoTunnel.stopCount).isEqualTo(1)
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
     private fun createDeveloperSettingsPresenter(
         sessionId: SessionId = A_SESSION_ID,
         cacheSizeUseCase: FakeComputeCacheSizeUseCase = FakeComputeCacheSizeUseCase(),
         clearCacheUseCase: FakeClearCacheUseCase = FakeClearCacheUseCase(),
         enterpriseService: EnterpriseService = FakeEnterpriseService(),
         vacuumStoresUseCase: VacuumStoresUseCase = VacuumStoresUseCase {},
         databaseSizesUseCase: GetDatabaseSizesUseCase = GetDatabaseSizesUseCase { Result.success(SdkStoreSizes(null, null, null, null)) },
+        neutrinoTunnel: FakeNeutrinoTunnel = FakeNeutrinoTunnel(),
     ): DeveloperSettingsPresenter {
         return DeveloperSettingsPresenter(
             appDeveloperSettingsPresenter = { anAppDeveloperSettingsState() },
@@ -161,6 +205,7 @@ class DeveloperSettingsPresenterTest {
             vacuumStoresUseCase = vacuumStoresUseCase,
             databaseSizesUseCase = databaseSizesUseCase,
             fileSizeFormatter = FakeFileSizeFormatter(),
+            neutrinoTunnel = neutrinoTunnel,
         )
     }
 }

features/preferences/impl/src/test/kotlin/io/element/android/features/preferences/impl/developer/FakeNeutrinoTunnel.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2026 Element Creations Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+package io.element.android.features.preferences.impl.developer
+
+import android.content.Intent
+import io.element.android.services.neutrino.api.NeutrinoTunnel
+
+class FakeNeutrinoTunnel(
+    private val consentIntentResult: Intent? = null,
+    initiallyRunning: Boolean = false,
+) : NeutrinoTunnel {
+    var startCount = 0
+        private set
+    var stopCount = 0
+        private set
+    private var running = initiallyRunning
+
+    override fun consentIntent(): Intent? = consentIntentResult
+
+    override fun start() {
+        startCount++
+        running = true
+    }
+
+    override fun stop() {
+        stopCount++
+        running = false
+    }
+
+    override fun isRunning(): Boolean = running
+}