Add RouteInformation option Struct.
This structure is useful when building an RA with RIO for integration
tests and verify the device's provisioning behavior, for example, check
if devices in ULA networks can recover its IPv6 connectivity from
receiving a normal RA after losing IPv6 default route (e.g. received RA
with zero router lifetime).
Bug: 183601771
Test: m
Change-Id: I13b85000ea1633f56edc74e3d62b7a38b9a851bf
diff --git a/staticlibs/device/com/android/net/module/util/structs/RouteInformationOption.java b/staticlibs/device/com/android/net/module/util/structs/RouteInformationOption.java
new file mode 100644
index 0000000..49bafed
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/structs/RouteInformationOption.java
@@ -0,0 +1,97 @@
+/*
+ * 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.structs;
+
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ND_OPTION_RIO;
+
+import android.net.IpPrefix;
+
+import androidx.annotation.NonNull;
+
+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;
+import java.nio.ByteOrder;
+
+/**
+ * ICMPv6 route information option, as per https://tools.ietf.org/html/rfc4191.
+ *
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Type | Length | Prefix Length |Resvd|Prf|Resvd|
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Route Lifetime |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Prefix (Variable Length) |
+ * . .
+ * . .
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+public class RouteInformationOption extends Struct {
+ public enum Preference {
+ HIGH((byte) 0x1),
+ MEDIUM((byte) 0x0),
+ LOW((byte) 0x3),
+ RESERVED((byte) 0x2);
+
+ final byte mValue;
+ Preference(byte value) {
+ this.mValue = value;
+ }
+ }
+
+ @Field(order = 0, type = Type.S8)
+ public final byte type;
+ @Field(order = 1, type = Type.S8)
+ public final byte length; // Length in 8-byte octets
+ @Field(order = 2, type = Type.U8)
+ public final short prefixLen;
+ @Field(order = 3, type = Type.S8)
+ public final byte prf;
+ @Field(order = 4, type = Type.U32)
+ public final long routeLifetime;
+ @Field(order = 5, type = Type.ByteArray, arraysize = 16)
+ public final byte[] prefix;
+
+ RouteInformationOption(final byte type, final byte length, final short prefixLen,
+ final byte prf, final long routeLifetime, @NonNull final byte[] prefix) {
+ this.type = type;
+ this.length = length;
+ this.prefixLen = prefixLen;
+ this.prf = prf;
+ this.routeLifetime = routeLifetime;
+ this.prefix = prefix;
+ }
+
+ /**
+ * Build a Route Information option from the required specified parameters.
+ */
+ public static ByteBuffer build(final IpPrefix prefix, final Preference prf,
+ final long routeLifetime) {
+ // The prefix field is always assumed to have 16 bytes, but the number of leading
+ // bits in this prefix depends on IpPrefix#prefixLength, then we can simply set the
+ // option length to 3.
+ final RouteInformationOption option = new RouteInformationOption(
+ (byte) ICMPV6_ND_OPTION_RIO, (byte) 3 /* option length */,
+ (short) prefix.getPrefixLength(), (byte) (prf.mValue << 3), routeLifetime,
+ prefix.getRawAddress());
+ return ByteBuffer.wrap(option.writeToBytes(ByteOrder.BIG_ENDIAN));
+ }
+}
diff --git a/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java b/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
index 6a6f5e1..24aabbc 100644
--- a/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
+++ b/staticlibs/framework/com/android/net/module/util/NetworkStackConstants.java
@@ -140,6 +140,7 @@
* ICMPv6 constants.
*
* See also:
+ * - https://tools.ietf.org/html/rfc4191
* - https://tools.ietf.org/html/rfc4443
* - https://tools.ietf.org/html/rfc4861
*/
@@ -157,6 +158,7 @@
public static final int ICMPV6_ND_OPTION_TLLA = 2;
public static final int ICMPV6_ND_OPTION_PIO = 3;
public static final int ICMPV6_ND_OPTION_MTU = 5;
+ public static final int ICMPV6_ND_OPTION_RIO = 24;
public static final int ICMPV6_ND_OPTION_RDNSS = 25;
public static final int ICMPV6_ND_OPTION_PREF64 = 38;