Add createSetLinkStateMessage method at RtNetlinkLinkMessage
This CL mainly adds the createSetLinkStateMessage() method at the
RtNetlinkLinkMessage class, that creates a link message to set the
interface up or down. The functionality is the same as
"ip link set $interface up" or "ip link set $interface down".
Bug: 364501824
Test: atest NetworkStaticLibTests
Change-Id: Id9232851f6d9a7f99f857fd5b8d4eae506de2c7c
diff --git a/staticlibs/device/com/android/net/module/util/netlink/OsAccess.java b/staticlibs/device/com/android/net/module/util/netlink/OsAccess.java
new file mode 100644
index 0000000..7591d5c
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/netlink/OsAccess.java
@@ -0,0 +1,37 @@
+/*
+ * 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.net.module.util.netlink;
+
+import android.system.Os;
+
+import androidx.annotation.NonNull;
+
+/**
+ * This class wraps the static methods of {@link android.system.Os} for mocking and testing.
+ */
+public class OsAccess {
+ /**
+ * Constant indicating that the {@code if_nametoindex()} function could not find the network
+ * interface index corresponding to the given interface name.
+ */
+ public static int INVALID_INTERFACE_INDEX = 0;
+
+ /** Wraps {@link Os#if_nametoindex(String)}. */
+ public int if_nametoindex(@NonNull String name) {
+ return Os.if_nametoindex(name);
+ }
+}
diff --git a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java
index 72c770a..887a701 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java
@@ -16,7 +16,12 @@
package com.android.net.module.util.netlink;
+import static android.system.OsConstants.AF_UNSPEC;
+
import static com.android.net.module.util.NetworkStackConstants.ETHER_ADDR_LEN;
+import static com.android.net.module.util.netlink.NetlinkConstants.IFF_UP;
+import static com.android.net.module.util.netlink.NetlinkConstants.RTM_NEWLINK;
+import static com.android.net.module.util.netlink.StructNlMsgHdr.NLM_F_REQUEST_ACK;
import android.net.MacAddress;
import android.system.OsConstants;
@@ -218,6 +223,35 @@
return length;
}
+ /**
+ * Create a link message to set the operational state (up or down) of a network interface.
+ *
+ * @param interfaceName The network interface name.
+ * @param sequenceNumber The sequence number to use for the Netlink message.
+ * @param isUp {@code true} to set the interface up, {@code false} to set it down.
+ * @return A `RtNetlinkLinkMessage` instance configured to set the link state.
+ */
+ @Nullable
+ public static RtNetlinkLinkMessage createSetLinkStateMessage(@NonNull String interfaceName,
+ int sequenceNumber, boolean isUp) {
+ return createSetLinkStateMessage(interfaceName, sequenceNumber, isUp, new OsAccess());
+ }
+
+ @VisibleForTesting
+ @Nullable
+ protected static RtNetlinkLinkMessage createSetLinkStateMessage(@NonNull String interfaceName,
+ int sequenceNumber, boolean isUp, OsAccess osAccess) {
+ final int interfaceIndex = osAccess.if_nametoindex(interfaceName);
+ if (interfaceIndex == OsAccess.INVALID_INTERFACE_INDEX) {
+ return null;
+ }
+
+ return RtNetlinkLinkMessage.build(
+ new StructNlMsgHdr(0, RTM_NEWLINK, NLM_F_REQUEST_ACK, sequenceNumber),
+ new StructIfinfoMsg((short) AF_UNSPEC, (short) 0, interfaceIndex,
+ isUp ? IFF_UP : 0, IFF_UP), DEFAULT_MTU, null, null);
+ }
+
@Override
public String toString() {
return "RtNetlinkLinkMessage{ "
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
index 5272366..7cc95de 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructNlMsgHdr.java
@@ -32,10 +32,11 @@
// Already aligned.
public static final int STRUCT_SIZE = 16;
- public static final short NLM_F_REQUEST = 0x0001;
- public static final short NLM_F_MULTI = 0x0002;
- public static final short NLM_F_ACK = 0x0004;
- public static final short NLM_F_ECHO = 0x0008;
+ public static final short NLM_F_REQUEST = 0x0001;
+ public static final short NLM_F_MULTI = 0x0002;
+ public static final short NLM_F_ACK = 0x0004;
+ public static final short NLM_F_ECHO = 0x0008;
+ public static final short NLM_F_REQUEST_ACK = NLM_F_REQUEST | NLM_F_ACK;
// Flags for a GET request.
public static final short NLM_F_ROOT = 0x0100;
public static final short NLM_F_MATCH = 0x0200;
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkLinkMessageTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkLinkMessageTest.java
index afe220f..b9f3661 100644
--- a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkLinkMessageTest.java
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/RtNetlinkLinkMessageTest.java
@@ -24,24 +24,29 @@
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
+import static org.mockito.Mockito.when;
+import android.annotation.SuppressLint;
import android.net.MacAddress;
import android.system.OsConstants;
import androidx.test.filters.SmallTest;
-import androidx.test.runner.AndroidJUnit4;
import com.android.net.module.util.HexDump;
import org.junit.Test;
import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnitRunner;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
-@RunWith(AndroidJUnit4.class)
+@RunWith(MockitoJUnitRunner.class)
@SmallTest
public class RtNetlinkLinkMessageTest {
+ @Mock
+ private OsAccess mOsAccess;
// An example of the full RTM_NEWLINK message.
private static final String RTM_NEWLINK_HEX =
@@ -186,6 +191,57 @@
}
@Test
+ public void testCreateSetLinkUpMessage() {
+ final String expectedHexBytes =
+ "20000000100005006824000000000000" // struct nlmsghdr
+ + "00000000080000000100000001000000"; // struct ifinfomsg
+ final String interfaceName = "wlan0";
+ final int interfaceIndex = 8;
+ final int sequenceNumber = 0x2468;
+ final boolean isUp = true;
+
+ when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(interfaceIndex);
+
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkStateMessage(
+ interfaceName, sequenceNumber, isUp, mOsAccess);
+ assertNotNull(msg);
+ final byte[] bytes = msg.pack(ByteOrder.LITTLE_ENDIAN); // For testing.
+ assertEquals(expectedHexBytes, HexDump.toHexString(bytes));
+ }
+
+ @Test
+ public void testCreateSetLinkDownMessage() {
+ final String expectedHexBytes =
+ "20000000100005006824000000000000" // struct nlmsghdr
+ + "00000000080000000000000001000000"; // struct ifinfomsg
+ final String interfaceName = "wlan0";
+ final int interfaceIndex = 8;
+ final int sequenceNumber = 0x2468;
+ final boolean isUp = false;
+
+ when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(interfaceIndex);
+
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkStateMessage(
+ interfaceName, sequenceNumber, isUp, mOsAccess);
+ assertNotNull(msg);
+ final byte[] bytes = msg.pack(ByteOrder.LITTLE_ENDIAN); // For testing.
+ assertEquals(expectedHexBytes, HexDump.toHexString(bytes));
+ }
+
+ @Test
+ public void testCreateSetLinkStateMessage_InvalidInterface() {
+ final String interfaceName = "wlan0";
+ final int sequenceNumber = 0x2468;
+ final boolean isUp = false;
+
+ when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(OsAccess.INVALID_INTERFACE_INDEX);
+
+ final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkStateMessage(
+ interfaceName, sequenceNumber, isUp, mOsAccess);
+ assertNull(msg);
+ }
+
+ @Test
public void testToString() {
final ByteBuffer byteBuffer = toByteBuffer(RTM_NEWLINK_HEX);
byteBuffer.order(ByteOrder.LITTLE_ENDIAN); // For testing.