Adding middleware to support EthernetSettings

Adds EthernetInterface class and its unit tests. This class encapsulates
all operations performed on an EthernetInterface. EthernetManager and
ConnectivityManager are its dependencies to execute operations.

Flag: com.android.settings.connectivity.ethernet_settings

Test: atest SettingsRoboTests:com.android.settings.network.EthernetInterfaceTest

Change-Id: I640a607c8d9705a10dc4c4c609e036a1afa6b5f7

src/com/android/settings/network/ethernet/EthernetInterface.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2025 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.settings.network.ethernet
+
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.EthernetManager
+import android.net.EthernetManager.STATE_ABSENT
+import android.net.EthernetNetworkManagementException
+import android.net.EthernetNetworkUpdateRequest
+import android.net.IpConfiguration
+import android.os.OutcomeReceiver
+import android.util.Log
+import androidx.core.content.ContextCompat
+import java.util.concurrent.Executor
+
+class EthernetInterface(private val context: Context, private val id: String) :
+    EthernetManager.InterfaceStateListener {
+    private val ethernetManager =
+        context.getSystemService(EthernetManager::class.java)
+    private val connectivityManager =
+        context.getSystemService(ConnectivityManager::class.java)
+    private val executor = ContextCompat.getMainExecutor(context)
+
+    private val TAG = "EthernetInterface"
+
+    private var interfaceState = STATE_ABSENT
+    private var ipConfiguration = IpConfiguration()
+
+    fun getInterfaceState() = interfaceState
+
+    fun getConfiguration(): IpConfiguration {
+        return ipConfiguration
+    }
+
+    fun setConfiguration(ipConfiguration: IpConfiguration) {
+        val request =
+            EthernetNetworkUpdateRequest.Builder().setIpConfiguration(ipConfiguration).build()
+        ethernetManager.updateConfiguration(
+            id,
+            request,
+            executor,
+            object : OutcomeReceiver<String, EthernetNetworkManagementException> {
+                override fun onError(e: EthernetNetworkManagementException) {
+                    Log.e(TAG, "Failed to updateConfiguration: ", e)
+                }
+
+                override fun onResult(id: String) {
+                    Log.d(TAG, "Successfully updated configuration: " + id)
+                }
+            },
+        )
+    }
+
+    override fun onInterfaceStateChanged(id: String, state: Int, role: Int, cfg: IpConfiguration?) {
+        if (id == this.id) {
+            ipConfiguration = cfg ?: IpConfiguration()
+            interfaceState = state
+        }
+    }
+}

tests/robotests/src/com/android/settings/network/ethernet/EthernetInterfaceTest.kt

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2025 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.settings.network.ethernet
+
+import android.content.Context
+import android.content.ContextWrapper
+import android.net.EthernetManager
+import android.net.EthernetManager.STATE_ABSENT
+import android.net.EthernetManager.STATE_LINK_DOWN
+import android.net.EthernetManager.STATE_LINK_UP
+import android.net.IpConfiguration
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.kotlin.mock
+
+@RunWith(AndroidJUnit4::class)
+class EthernetInterfaceTest {
+
+    private val mockEthernetManager = mock<EthernetManager>()
+
+    private val context: Context =
+        object : ContextWrapper(ApplicationProvider.getApplicationContext()) {
+            override fun getSystemService(name: String): Any? =
+                when (name) {
+                    Context.ETHERNET_SERVICE -> mockEthernetManager
+                    else -> super.getSystemService(name)
+                }
+        }
+
+    private val ethernetInterface = EthernetInterface(context, "eth0")
+
+    @Test
+    fun getInterfaceState_shouldReturnDefaultState() {
+        assertEquals(ethernetInterface.getInterfaceState(), STATE_ABSENT)
+    }
+
+    @Test
+    fun getConfiguration_shouldReturnDefaultIpConfig() {
+        val ipConfiguration: IpConfiguration = ethernetInterface.getConfiguration()
+
+        assertEquals(ipConfiguration.getIpAssignment(), IpConfiguration.IpAssignment.UNASSIGNED)
+    }
+
+    @Test
+    fun interfaceStateChanged_shouldUpdateState() {
+        val testConfig = IpConfiguration()
+        testConfig.setIpAssignment(IpConfiguration.IpAssignment.STATIC)
+
+        ethernetInterface.onInterfaceStateChanged("eth0", STATE_LINK_UP, 0, testConfig)
+
+        assertEquals(ethernetInterface.getInterfaceState(), STATE_LINK_UP)
+        assertEquals(
+            ethernetInterface.getConfiguration().getIpAssignment(),
+            IpConfiguration.IpAssignment.STATIC,
+        )
+    }
+
+    @Test
+    fun interfaceStateChanged_iddoesnotmatch_shouldNotUpdateState() {
+        val testConfig = IpConfiguration()
+        testConfig.setIpAssignment(IpConfiguration.IpAssignment.STATIC)
+
+        ethernetInterface.onInterfaceStateChanged("eth1", STATE_LINK_DOWN, 0, testConfig)
+
+        assertEquals(ethernetInterface.getInterfaceState(), STATE_ABSENT)
+        assertEquals(
+            ethernetInterface.getConfiguration().getIpAssignment(),
+            IpConfiguration.IpAssignment.UNASSIGNED,
+        )
+    }
+}