Merge "Add createSetLinkNameMessage method at RtNetlinkLinkMessage" into main am: 5fdce4d932 am: 0dd7646adf

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3256558

Change-Id: I851fbe13f02c45bdcd009e5405b15d1bcc422b6b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
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 887a701..27869ef 100644
--- a/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java
+++ b/staticlibs/device/com/android/net/module/util/netlink/RtNetlinkLinkMessage.java
@@ -252,6 +252,35 @@
                                     isUp ? IFF_UP : 0, IFF_UP), DEFAULT_MTU, null, null);
     }
 
+    /**
+     * Create a link message to rename the network interface.
+     *
+     * @param interfaceName  The network interface name.
+     * @param sequenceNumber The sequence number to use for the Netlink message.
+     * @param newName        The new name of the network interface.
+     * @return A `RtNetlinkLinkMessage` instance configured to rename the network interface.
+     */
+    @Nullable
+    public static RtNetlinkLinkMessage createSetLinkNameMessage(@NonNull String interfaceName,
+            int sequenceNumber, @NonNull String newName) {
+        return createSetLinkNameMessage(interfaceName, sequenceNumber, newName, new OsAccess());
+    }
+
+    @VisibleForTesting
+    @Nullable
+    protected static RtNetlinkLinkMessage createSetLinkNameMessage(@NonNull String interfaceName,
+            int sequenceNumber, @NonNull String newName, 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, 0, 0),
+                DEFAULT_MTU, null, newName);
+    }
+
     @Override
     public String toString() {
         return "RtNetlinkLinkMessage{ "
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 b9f3661..ee74468 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
@@ -242,6 +242,53 @@
     }
 
     @Test
+    public void testCreateSetLinkNameMessage() {
+        final String expectedHexBytes =
+                "2C000000100005006824000000000000"   // struct nlmsghdr
+                + "00000000080000000000000000000000" // struct ifinfomsg
+                + "0A000300776C616E31000000";        // IFLA_IFNAME(wlan1)
+        final String interfaceName = "wlan0";
+        final int interfaceIndex = 8;
+        final int sequenceNumber = 0x2468;
+        final String newName = "wlan1";
+
+        when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(interfaceIndex);
+
+        final RtNetlinkLinkMessage msg = RtNetlinkLinkMessage.createSetLinkNameMessage(
+                interfaceName, sequenceNumber, newName, mOsAccess);
+        assertNotNull(msg);
+        final byte[] bytes = msg.pack(ByteOrder.LITTLE_ENDIAN);  // For testing.
+        assertEquals(expectedHexBytes, HexDump.toHexString(bytes));
+    }
+
+    @Test
+    public void testCreateSetLinkNameMessage_InterfaceNotFound() {
+        final String interfaceName = "wlan0";
+        final int sequenceNumber = 0x2468;
+        final String newName = "wlan1";
+
+        when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(OsAccess.INVALID_INTERFACE_INDEX);
+
+        assertNull(RtNetlinkLinkMessage.createSetLinkNameMessage(
+                interfaceName, sequenceNumber, newName, mOsAccess));
+    }
+
+    @Test
+    public void testCreateSetLinkNameMessage_InvalidNewName() {
+        final String interfaceName = "wlan0";
+        final int interfaceIndex = 8;
+        final int sequenceNumber = 0x2468;
+
+        when(mOsAccess.if_nametoindex(interfaceName)).thenReturn(interfaceIndex);
+
+        final String[] invalidNames = {"", "interface_name_longer_than_limit"};
+        for (String invalidName : invalidNames) {
+            assertNull(RtNetlinkLinkMessage.createSetLinkNameMessage(
+                    interfaceName, sequenceNumber, invalidName, mOsAccess));
+        }
+    }
+
+    @Test
     public void testToString() {
         final ByteBuffer byteBuffer = toByteBuffer(RTM_NEWLINK_HEX);
         byteBuffer.order(ByteOrder.LITTLE_ENDIAN);  // For testing.