Add netlink rta_cacheinfo structure.

Bug: 183601771
Test: m
Change-Id: Iaa65425fa875a9dde4d4b7c1b110d9a2a406f444
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructRtaCacheInfo.java b/staticlibs/device/com/android/net/module/util/netlink/StructRtaCacheInfo.java
new file mode 100644
index 0000000..fef1f9e
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructRtaCacheInfo.java
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2023 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 androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.Struct.Field;
+import com.android.net.module.util.Struct.Type;
+
+import java.nio.ByteBuffer;
+
+/**
+ * struct rta_cacheinfo
+ *
+ * see also:
+ *
+ *     include/uapi/linux/rtnetlink.h
+ *
+ * @hide
+ */
+public class StructRtaCacheInfo extends Struct {
+    // Already aligned.
+    public static final int STRUCT_SIZE = 32;
+
+    @Field(order = 0, type = Type.U32)
+    public final long clntref;
+    @Field(order = 1, type = Type.U32)
+    public final long lastuse;
+    @Field(order = 2, type = Type.S32)
+    public final int expires;
+    @Field(order = 3, type = Type.U32)
+    public final long error;
+    @Field(order = 4, type = Type.U32)
+    public final long used;
+    @Field(order = 5, type = Type.U32)
+    public final long id;
+    @Field(order = 6, type = Type.U32)
+    public final long ts;
+    @Field(order = 7, type = Type.U32)
+    public final long tsage;
+
+    StructRtaCacheInfo(long clntref, long lastuse, int expires, long error, long used, long id,
+            long ts, long tsage) {
+        this.clntref = clntref;
+        this.lastuse = lastuse;
+        this.expires = expires;
+        this.error = error;
+        this.used = used;
+        this.id = id;
+        this.ts = ts;
+        this.tsage = tsage;
+    }
+
+    /**
+     * Parse an rta_cacheinfo struct from a {@link ByteBuffer}.
+     *
+     * @param byteBuffer The buffer from which to parse the rta_cacheinfo.
+     * @return the parsed rta_cacheinfo struct, or {@code null} if the rta_cacheinfo struct
+     *         could not be parsed successfully (for example, if it was truncated).
+     */
+    @Nullable
+    public static StructRtaCacheInfo parse(@NonNull final ByteBuffer byteBuffer) {
+        if (byteBuffer.remaining() < STRUCT_SIZE) return null;
+
+        // The ByteOrder must already have been set to native order.
+        return Struct.parse(StructRtaCacheInfo.class, byteBuffer);
+    }
+
+    /**
+     * Write a rta_cacheinfo struct to {@link ByteBuffer}.
+     */
+    public void pack(@NonNull final ByteBuffer byteBuffer) {
+        // The ByteOrder must already have been set to native order.
+        this.writeToByteBuffer(byteBuffer);
+    }
+}