Merge changes I76b0a7ba,If7308f1a,Ica8faced,Ia8f42ed0,I975afb45, ... into main
* changes:
Add some documentation to EthernetInterfaceStateMachine
Add support for link state tracking
Add unit test class for EthernetInterfaceStateMachine
Add missing call to add states to state machine
Make class testable
Log.wtf if block times out
Wait on IpClient#onQuit in StartedState#exit
Use TAG instead
Introduce CMD_ON_NETWORK_NEEDED and CMD_ON_NETWORK_UNNEEDED messages
Clean up and document state lifecycle
Add convenience method for processMessage with no arguments
Implement NetworkOffer in EthernetInterfaceStateMachine
Add boilerplate to represent interface states in state machine
Fix typo in SyncStateMachineTest
Move SyncStateMachine to staticlibs
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 9e0c970..01f5393 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -75,6 +75,7 @@
import com.android.net.module.util.NetdUtils;
import com.android.net.module.util.SdkUtil.LateSdk;
import com.android.net.module.util.SharedLog;
+import com.android.net.module.util.SyncStateMachine.StateInfo;
import com.android.net.module.util.ip.InterfaceController;
import com.android.net.module.util.ip.IpNeighborMonitor;
import com.android.net.module.util.ip.IpNeighborMonitor.NeighborEvent;
@@ -87,7 +88,6 @@
import com.android.networkstack.tethering.util.InterfaceSet;
import com.android.networkstack.tethering.util.PrefixUtils;
import com.android.networkstack.tethering.util.StateMachineShim;
-import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo;
import java.net.Inet4Address;
import java.net.Inet6Address;
diff --git a/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java b/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java
index 078a35f..c236188 100644
--- a/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java
+++ b/Tethering/src/com/android/networkstack/tethering/util/StateMachineShim.java
@@ -22,7 +22,8 @@
import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.util.State;
import com.android.internal.util.StateMachine;
-import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo;
+import com.android.net.module.util.SyncStateMachine;
+import com.android.net.module.util.SyncStateMachine.StateInfo;
import java.util.List;
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt b/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt
index f8e98e3..2417385 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/util/StateMachineShimTest.kt
@@ -19,9 +19,10 @@
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.SmallTest
import com.android.internal.util.State
+import com.android.net.module.util.SyncStateMachine
+import com.android.net.module.util.SyncStateMachine.StateInfo
import com.android.networkstack.tethering.util.StateMachineShim.AsyncStateMachine
import com.android.networkstack.tethering.util.StateMachineShim.Dependencies
-import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo
import kotlin.test.assertFailsWith
import org.junit.Test
import org.junit.runner.RunWith
diff --git a/service-t/src/com/android/server/ethernet/EthernetInterfaceStateMachine.java b/service-t/src/com/android/server/ethernet/EthernetInterfaceStateMachine.java
new file mode 100644
index 0000000..b8f6859
--- /dev/null
+++ b/service-t/src/com/android/server/ethernet/EthernetInterfaceStateMachine.java
@@ -0,0 +1,344 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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
+ *
+ * http://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.android.server.ethernet;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.net.NetworkCapabilities;
+import android.net.NetworkProvider;
+import android.net.NetworkProvider.NetworkOfferCallback;
+import android.net.NetworkRequest;
+import android.net.NetworkScore;
+import android.net.ip.IIpClient;
+import android.net.ip.IpClientCallbacks;
+import android.net.ip.IpClientManager;
+import android.os.ConditionVariable;
+import android.os.Handler;
+import android.os.Message;
+import android.util.ArraySet;
+import android.util.Log;
+
+import com.android.internal.util.State;
+import com.android.net.module.util.SyncStateMachine;
+import com.android.net.module.util.SyncStateMachine.StateInfo;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+/**
+ * EthernetInterfaceStateMachine manages the lifecycle of an ethernet-like network interface which
+ * includes managing a NetworkOffer, IpClient, and NetworkAgent as well as making the interface
+ * available as a tethering downstream.
+ *
+ * All methods exposed by this class *must* be called on the Handler thread provided in the
+ * constructor.
+ */
+class EthernetInterfaceStateMachine extends SyncStateMachine {
+ private static final String TAG = EthernetInterfaceStateMachine.class.getSimpleName();
+
+ private static final int CMD_ON_LINK_UP = 1;
+ private static final int CMD_ON_LINK_DOWN = 2;
+ private static final int CMD_ON_NETWORK_NEEDED = 3;
+ private static final int CMD_ON_NETWORK_UNNEEDED = 4;
+ private static final int CMD_ON_IPCLIENT_CREATED = 5;
+
+ private class EthernetNetworkOfferCallback implements NetworkOfferCallback {
+ private final Set<Integer> mRequestIds = new ArraySet<>();
+
+ @Override
+ public void onNetworkNeeded(@NonNull NetworkRequest request) {
+ if (this != mNetworkOfferCallback) {
+ return;
+ }
+
+ mRequestIds.add(request.requestId);
+ if (mRequestIds.size() == 1) {
+ processMessage(CMD_ON_NETWORK_NEEDED);
+ }
+ }
+
+ @Override
+ public void onNetworkUnneeded(@NonNull NetworkRequest request) {
+ if (this != mNetworkOfferCallback) {
+ return;
+ }
+
+ if (!mRequestIds.remove(request.requestId)) {
+ // This can only happen if onNetworkNeeded was not called for a request or if
+ // the requestId changed. Both should *never* happen.
+ Log.wtf(TAG, "onNetworkUnneeded called for unknown request");
+ }
+ if (mRequestIds.isEmpty()) {
+ processMessage(CMD_ON_NETWORK_UNNEEDED);
+ }
+ }
+ }
+
+ private class EthernetIpClientCallback extends IpClientCallbacks {
+ private final ConditionVariable mOnQuitCv = new ConditionVariable(false);
+
+ private void safelyPostOnHandler(Runnable r) {
+ mHandler.post(() -> {
+ if (this != mIpClientCallback) {
+ return;
+ }
+ r.run();
+ });
+ }
+
+ @Override
+ public void onIpClientCreated(IIpClient ipClient) {
+ safelyPostOnHandler(() -> {
+ // TODO: add a SyncStateMachine#processMessage(cmd, obj) overload.
+ processMessage(CMD_ON_IPCLIENT_CREATED, 0, 0,
+ mDependencies.makeIpClientManager(ipClient));
+ });
+ }
+
+ public void waitOnQuit() {
+ if (!mOnQuitCv.block(5_000 /* timeoutMs */)) {
+ Log.wtf(TAG, "Timed out waiting on IpClient to shutdown.");
+ }
+ }
+
+ @Override
+ public void onQuit() {
+ mOnQuitCv.open();
+ }
+ }
+
+ private @Nullable EthernetNetworkOfferCallback mNetworkOfferCallback;
+ private @Nullable EthernetIpClientCallback mIpClientCallback;
+ private @Nullable IpClientManager mIpClient;
+ private final String mIface;
+ private final Handler mHandler;
+ private final Context mContext;
+ private final NetworkCapabilities mCapabilities;
+ private final NetworkProvider mNetworkProvider;
+ private final EthernetNetworkFactory.Dependencies mDependencies;
+ private boolean mLinkUp = false;
+
+ /** Interface is in tethering mode. */
+ private class TetheringState extends State {
+ @Override
+ public boolean processMessage(Message msg) {
+ switch (msg.what) {
+ case CMD_ON_LINK_UP:
+ case CMD_ON_LINK_DOWN:
+ // TODO: think about what to do here.
+ return HANDLED;
+ }
+ return NOT_HANDLED;
+ }
+ }
+
+ /** Link is down */
+ private class LinkDownState extends State {
+ @Override
+ public boolean processMessage(Message msg) {
+ switch (msg.what) {
+ case CMD_ON_LINK_UP:
+ transitionTo(mStoppedState);
+ return HANDLED;
+ case CMD_ON_LINK_DOWN:
+ // do nothing, already in the correct state.
+ return HANDLED;
+ }
+ return NOT_HANDLED;
+ }
+ }
+
+ /** Parent states of all states that do not cause a NetworkOffer to be extended. */
+ private class NetworkOfferExtendedState extends State {
+ @Override
+ public void enter() {
+ if (mNetworkOfferCallback != null) {
+ // This should never happen. If it happens anyway, log and move on.
+ Log.wtf(TAG, "Previous NetworkOffer was never retracted");
+ }
+
+ mNetworkOfferCallback = new EthernetNetworkOfferCallback();
+ final NetworkScore defaultScore = new NetworkScore.Builder().build();
+ mNetworkProvider.registerNetworkOffer(defaultScore,
+ new NetworkCapabilities(mCapabilities), cmd -> mHandler.post(cmd),
+ mNetworkOfferCallback);
+ }
+
+ @Override
+ public boolean processMessage(Message msg) {
+ switch (msg.what) {
+ case CMD_ON_LINK_UP:
+ // do nothing, already in the correct state.
+ return HANDLED;
+ case CMD_ON_LINK_DOWN:
+ transitionTo(mLinkDownState);
+ return HANDLED;
+ }
+ return NOT_HANDLED;
+ }
+
+ @Override
+ public void exit() {
+ mNetworkProvider.unregisterNetworkOffer(mNetworkOfferCallback);
+ mNetworkOfferCallback = null;
+ }
+ }
+
+ /**
+ * Offer is extended but has not been requested.
+ *
+ * StoppedState's sole purpose is to react to a CMD_ON_NETWORK_NEEDED and transition to
+ * StartedState when that happens. Note that StoppedState could be rolled into
+ * NetworkOfferExtendedState. However, keeping the states separate provides some additional
+ * protection by logging a Log.wtf if a CMD_ON_NETWORK_NEEDED is received in an unexpected state
+ * (i.e. StartedState or RunningState). StoppedState is a child of NetworkOfferExtendedState.
+ */
+ private class StoppedState extends State {
+ @Override
+ public boolean processMessage(Message msg) {
+ switch (msg.what) {
+ case CMD_ON_NETWORK_NEEDED:
+ transitionTo(mStartedState);
+ return HANDLED;
+ }
+ return NOT_HANDLED;
+ }
+ }
+
+ /** Network is needed, starts IpClient and manages its lifecycle */
+ private class StartedState extends State {
+ @Override
+ public void enter() {
+ mIpClientCallback = new EthernetIpClientCallback();
+ mDependencies.makeIpClient(mContext, mIface, mIpClientCallback);
+ }
+
+ @Override
+ public boolean processMessage(Message msg) {
+ switch (msg.what) {
+ case CMD_ON_NETWORK_UNNEEDED:
+ transitionTo(mStoppedState);
+ return HANDLED;
+ case CMD_ON_IPCLIENT_CREATED:
+ mIpClient = (IpClientManager) msg.obj;
+ transitionTo(mRunningState);
+ return HANDLED;
+ }
+ return NOT_HANDLED;
+ }
+
+ @Override
+ public void exit() {
+ if (mIpClient != null) {
+ mIpClient.shutdown();
+ // TODO: consider adding a StoppingState and making the shutdown operation
+ // asynchronous.
+ mIpClientCallback.waitOnQuit();
+ }
+ mIpClientCallback = null;
+ }
+ }
+
+ /** IpClient is running, starts provisioning and registers NetworkAgent */
+ private class RunningState extends State {
+
+ }
+
+ private final TetheringState mTetheringState = new TetheringState();
+ private final LinkDownState mLinkDownState = new LinkDownState();
+ private final NetworkOfferExtendedState mOfferExtendedState = new NetworkOfferExtendedState();
+ private final StoppedState mStoppedState = new StoppedState();
+ private final StartedState mStartedState = new StartedState();
+ private final RunningState mRunningState = new RunningState();
+
+ public EthernetInterfaceStateMachine(String iface, Handler handler, Context context,
+ NetworkCapabilities capabilities, NetworkProvider provider,
+ EthernetNetworkFactory.Dependencies deps) {
+ super(TAG + "." + iface, handler.getLooper().getThread());
+
+ mIface = iface;
+ mHandler = handler;
+ mContext = context;
+ mCapabilities = capabilities;
+ mNetworkProvider = provider;
+ mDependencies = deps;
+
+ // Interface lifecycle:
+ // [ LinkDownState ]
+ // |
+ // v
+ // *link comes up*
+ // |
+ // v
+ // [ StoppedState ]
+ // |
+ // v
+ // *network is needed*
+ // |
+ // v
+ // [ StartedState ]
+ // |
+ // v
+ // *IpClient is created*
+ // |
+ // v
+ // [ RunningState ]
+ // |
+ // v
+ // *interface is requested for tethering*
+ // |
+ // v
+ // [TetheringState]
+ //
+ // Tethering mode is special as the interface is configured by Tethering, rather than the
+ // ethernet module.
+ final List<StateInfo> states = new ArrayList<>();
+ states.add(new StateInfo(mTetheringState, null));
+
+ // CHECKSTYLE:OFF IndentationCheck
+ // Initial state
+ states.add(new StateInfo(mLinkDownState, null));
+ states.add(new StateInfo(mOfferExtendedState, null));
+ states.add(new StateInfo(mStoppedState, mOfferExtendedState));
+ states.add(new StateInfo(mStartedState, mOfferExtendedState));
+ states.add(new StateInfo(mRunningState, mStartedState));
+ // CHECKSTYLE:ON IndentationCheck
+ addAllStates(states);
+
+ // TODO: set initial state to TetheringState if a tethering interface has been requested and
+ // this is the first interface to be added.
+ start(mLinkDownState);
+ }
+
+ public boolean updateLinkState(boolean up) {
+ if (mLinkUp == up) {
+ return false;
+ }
+
+ // TODO: consider setting mLinkUp as part of processMessage().
+ mLinkUp = up;
+ if (!up) { // was up, goes down
+ processMessage(CMD_ON_LINK_DOWN);
+ } else { // was down, comes up
+ processMessage(CMD_ON_LINK_UP);
+ }
+
+ return true;
+ }
+}
diff --git a/staticlibs/Android.bp b/staticlibs/Android.bp
index e2834b0..71f388d 100644
--- a/staticlibs/Android.bp
+++ b/staticlibs/Android.bp
@@ -39,12 +39,13 @@
"device/com/android/net/module/util/DeviceConfigUtils.java",
"device/com/android/net/module/util/DomainUtils.java",
"device/com/android/net/module/util/FdEventsReader.java",
+ "device/com/android/net/module/util/FeatureVersions.java",
+ "device/com/android/net/module/util/HandlerUtils.java",
"device/com/android/net/module/util/NetworkMonitorUtils.java",
"device/com/android/net/module/util/PacketReader.java",
"device/com/android/net/module/util/SharedLog.java",
"device/com/android/net/module/util/SocketUtils.java",
- "device/com/android/net/module/util/FeatureVersions.java",
- "device/com/android/net/module/util/HandlerUtils.java",
+ "device/com/android/net/module/util/SyncStateMachine.java",
// This library is used by system modules, for which the system health impact of Kotlin
// has not yet been evaluated. Annotations may need jarjar'ing.
// "src_devicecommon/**/*.kt",
@@ -68,6 +69,7 @@
"//packages/modules/CaptivePortalLogin",
],
static_libs: [
+ "modules-utils-statemachine",
"net-utils-framework-common",
],
libs: [
diff --git a/Tethering/src/com/android/networkstack/tethering/util/SyncStateMachine.java b/staticlibs/device/com/android/net/module/util/SyncStateMachine.java
similarity index 96%
rename from Tethering/src/com/android/networkstack/tethering/util/SyncStateMachine.java
rename to staticlibs/device/com/android/net/module/util/SyncStateMachine.java
index a17eb26..da184d3 100644
--- a/Tethering/src/com/android/networkstack/tethering/util/SyncStateMachine.java
+++ b/staticlibs/device/com/android/net/module/util/SyncStateMachine.java
@@ -14,7 +14,7 @@
* limitations under the License.
*/
-package com.android.networkstack.tethering.util;
+package com.android.net.module.util;
import android.annotation.NonNull;
import android.annotation.Nullable;
@@ -165,6 +165,11 @@
* The message is processed sequentially, so calling this method recursively is not permitted.
* In other words, using this method inside State#enter, State#exit, or State#processMessage
* is incorrect and will result in an IllegalStateException.
+ *
+ * @param what is assigned to Message.what
+ * @param arg1 is assigned to Message.arg1
+ * @param arg2 is assigned to Message.arg2
+ * @param obj is assigned to Message.obj
*/
public final void processMessage(int what, int arg1, int arg2, @Nullable Object obj) {
ensureCorrectThread();
@@ -189,6 +194,15 @@
mCurrentlyProcessing = Integer.MIN_VALUE;
}
+ /**
+ * Synchronously process a message and perform state transition.
+ *
+ * @param what is assigned to Message.what.
+ */
+ public final void processMessage(int what) {
+ processMessage(what, 0, 0, null);
+ }
+
private void maybeProcessSelfMessageQueue() {
while (!mSelfMsgQueue.isEmpty()) {
currentStateProcessMessageThenPerformTransitions(mSelfMsgQueue.poll());
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/util/SyncStateMachineTest.kt b/staticlibs/tests/unit/src/com/android/net/module/util/SyncStateMachineTest.kt
similarity index 98%
rename from Tethering/tests/unit/src/com/android/networkstack/tethering/util/SyncStateMachineTest.kt
rename to staticlibs/tests/unit/src/com/android/net/module/util/SyncStateMachineTest.kt
index 3a57fdd..d534054 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/util/SyncStateMachineTest.kt
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/SyncStateMachineTest.kt
@@ -13,13 +13,13 @@
* See the License for the specific language governing permissions and
* limitations under the License.
*/
-package com.android.networkstack.tethering.util
+package com.android.net.module.util
import android.os.Message
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.SmallTest
import com.android.internal.util.State
-import com.android.networkstack.tethering.util.SyncStateMachine.StateInfo
+import com.android.net.module.util.SyncStateMachine.StateInfo
import java.util.ArrayDeque
import java.util.ArrayList
import kotlin.test.assertFailsWith
@@ -45,7 +45,7 @@
@RunWith(AndroidJUnit4::class)
@SmallTest
-class SynStateMachineTest {
+class SyncStateMachineTest {
private val mState1 = spy(object : TestState(MSG_1) {})
private val mState2 = spy(object : TestState(MSG_2) {})
private val mState3 = spy(object : TestState(MSG_3) {})
diff --git a/tests/unit/java/com/android/server/ethernet/EthernetInterfaceStateMachineTest.kt b/tests/unit/java/com/android/server/ethernet/EthernetInterfaceStateMachineTest.kt
new file mode 100644
index 0000000..c8b2f65
--- /dev/null
+++ b/tests/unit/java/com/android/server/ethernet/EthernetInterfaceStateMachineTest.kt
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * 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
+ *
+ * http://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.
+ */
+// ktlint does not allow annotating function argument literals inline. Disable the specific rule
+// since this negatively affects readability.
+@file:Suppress("ktlint:standard:comment-wrapping")
+
+package com.android.server.ethernet
+
+import android.content.Context
+import android.net.NetworkCapabilities
+import android.net.NetworkProvider
+import android.net.NetworkProvider.NetworkOfferCallback
+import android.os.Build
+import android.os.Handler
+import android.os.test.TestLooper
+import androidx.test.filters.SmallTest
+import com.android.testutils.DevSdkIgnoreRule
+import com.android.testutils.DevSdkIgnoreRunner
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.any
+import org.mockito.ArgumentMatchers.eq
+import org.mockito.Mock
+import org.mockito.Mockito.inOrder
+import org.mockito.Mockito.verify
+import org.mockito.MockitoAnnotations
+
+private const val IFACE = "eth0"
+private val CAPS = NetworkCapabilities.Builder().build()
+
+@SmallTest
+@RunWith(DevSdkIgnoreRunner::class)
+@DevSdkIgnoreRule.IgnoreUpTo(Build.VERSION_CODES.S_V2)
+class EthernetInterfaceStateMachineTest {
+ private lateinit var looper: TestLooper
+ private lateinit var handler: Handler
+ private lateinit var ifaceState: EthernetInterfaceStateMachine
+
+ @Mock private lateinit var context: Context
+ @Mock private lateinit var provider: NetworkProvider
+ @Mock private lateinit var deps: EthernetNetworkFactory.Dependencies
+
+ // There seems to be no (obvious) way to force execution of @Before and @Test annotation on the
+ // same thread. Since SyncStateMachine requires all interactions to be called from the same
+ // thread that is provided at construction time (in this case, the thread that TestLooper() is
+ // called on), setUp() must be called directly from the @Test method.
+ // TODO: find a way to fix this in the test runner.
+ fun setUp() {
+ looper = TestLooper()
+ handler = Handler(looper.looper)
+ MockitoAnnotations.initMocks(this)
+
+ ifaceState = EthernetInterfaceStateMachine(IFACE, handler, context, CAPS, provider, deps)
+ }
+
+ @Test
+ fun testUpdateLinkState_networkOfferRegisteredAndRetracted() {
+ setUp()
+
+ ifaceState.updateLinkState(/* up= */ true)
+
+ // link comes up: validate the NetworkOffer is registered and capture callback object.
+ val inOrder = inOrder(provider)
+ val networkOfferCb = ArgumentCaptor.forClass(NetworkOfferCallback::class.java).also {
+ inOrder.verify(provider).registerNetworkOffer(any(), any(), any(), it.capture())
+ }.value
+
+ ifaceState.updateLinkState(/* up */ false)
+
+ // link goes down: validate the NetworkOffer is retracted
+ inOrder.verify(provider).unregisterNetworkOffer(eq(networkOfferCb))
+ }
+}