Add prefixmsg struct to parse RTM_NEWPREFIX message header.
Bug: 315069348
Test: TH
Change-Id: I8bc5bee20f3043203f591bdfe31a4879a09d1565
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructPrefixMsg.java b/staticlibs/device/com/android/net/module/util/netlink/StructPrefixMsg.java
new file mode 100644
index 0000000..504d6c7
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructPrefixMsg.java
@@ -0,0 +1,94 @@
+/*
+ * 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 androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+
+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 prefixmsg {
+ * unsigned char prefix_family;
+ * unsigned char prefix_pad1;
+ * unsigned short prefix_pad2;
+ * int prefix_ifindex;
+ * unsigned char prefix_type;
+ * unsigned char prefix_len;
+ * unsigned char prefix_flags;
+ * unsigned char prefix_pad3;
+ * }
+ *
+ * see also:
+ *
+ * include/uapi/linux/rtnetlink.h
+ *
+ * @hide
+ */
+public class StructPrefixMsg extends Struct {
+ // Already aligned.
+ public static final int STRUCT_SIZE = 12;
+
+ @Field(order = 0, type = Type.U8, padding = 3)
+ public final short prefix_family;
+ @Field(order = 1, type = Type.S32)
+ public final int prefix_ifindex;
+ @Field(order = 2, type = Type.U8)
+ public final short prefix_type;
+ @Field(order = 3, type = Type.U8)
+ public final short prefix_len;
+ @Field(order = 4, type = Type.U8, padding = 1)
+ public final short prefix_flags;
+
+ @VisibleForTesting
+ public StructPrefixMsg(short family, int ifindex, short type, short len, short flags) {
+ this.prefix_family = family;
+ this.prefix_ifindex = ifindex;
+ this.prefix_type = type;
+ this.prefix_len = len;
+ this.prefix_flags = flags;
+ }
+
+ /**
+ * Parse a prefixmsg struct from a {@link ByteBuffer}.
+ *
+ * @param byteBuffer The buffer from which to parse the prefixmsg.
+ * @return the parsed prefixmsg struct, or throw IllegalArgumentException if the prefixmsg
+ * struct could not be parsed successfully (for example, if it was truncated).
+ */
+ public static StructPrefixMsg parse(@NonNull final ByteBuffer byteBuffer) {
+ if (byteBuffer.remaining() < STRUCT_SIZE) {
+ throw new IllegalArgumentException("Invalid bytebuffer remaining size "
+ + byteBuffer.remaining() + "for prefix_msg struct.");
+ }
+
+ // The ByteOrder must already have been set to native order.
+ return Struct.parse(StructPrefixMsg.class, byteBuffer);
+ }
+
+ /**
+ * Write a prefixmsg struct to {@link ByteBuffer}.
+ */
+ public void pack(@NonNull final ByteBuffer byteBuffer) {
+ // The ByteOrder must already have been set to native order.
+ writeToByteBuffer(byteBuffer);
+ }
+}