Add PrefixInformation option struct to parse nduser option.
This is helpful for user space to get the PIO option via netlink message
and check whether the P flag is set or not, this bit flag determines if
we should start DHCPv6 PD process for IPv6 provisioning.
Bug: 315069348
Test: atest NetworkStaticLibTests
Change-Id: Id94b6538c5d88fe43c262ab23c30ccd53c766a62
diff --git a/staticlibs/device/com/android/net/module/util/netlink/StructNdOptPio.java b/staticlibs/device/com/android/net/module/util/netlink/StructNdOptPio.java
new file mode 100644
index 0000000..65541eb
--- /dev/null
+++ b/staticlibs/device/com/android/net/module/util/netlink/StructNdOptPio.java
@@ -0,0 +1,120 @@
+/*
+ * 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.net.IpPrefix;
+import android.util.Log;
+
+import androidx.annotation.NonNull;
+
+import com.android.net.module.util.HexDump;
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.structs.PrefixInformationOption;
+
+import java.nio.BufferUnderflowException;
+import java.nio.ByteBuffer;
+import java.util.Objects;
+
+/**
+ * The Prefix Information Option. RFC 4861.
+ *
+ * 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 |L|A|R|P| Rsvd1 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Valid Lifetime |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Preferred Lifetime |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | Reserved2 |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ * | |
+ * + +
+ * | |
+ * + Prefix +
+ * | |
+ * + +
+ * | |
+ * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+public class StructNdOptPio extends NdOption {
+ private static final String TAG = StructNdOptPio.class.getSimpleName();
+ public static final int TYPE = 3;
+ public static final byte LENGTH = 4; // Length in 8-byte units
+
+ public final byte flags;
+ public final long preferred;
+ public final long valid;
+ @NonNull
+ public final IpPrefix prefix;
+
+ public StructNdOptPio(byte flags, long preferred, long valid, @NonNull final IpPrefix prefix) {
+ super((byte) TYPE, LENGTH);
+ this.prefix = Objects.requireNonNull(prefix, "prefix must not be null");
+ this.flags = flags;
+ this.preferred = preferred;
+ this.valid = valid;
+ }
+
+ /**
+ * Parses a PrefixInformation option from a {@link ByteBuffer}.
+ *
+ * @param buf The buffer from which to parse the option. The buffer's byte order must be
+ * {@link java.nio.ByteOrder#BIG_ENDIAN}.
+ * @return the parsed option, or {@code null} if the option could not be parsed successfully.
+ */
+ public static StructNdOptPio parse(@NonNull ByteBuffer buf) {
+ if (buf == null || buf.remaining() < LENGTH * 8) return null;
+ try {
+ final PrefixInformationOption pio = Struct.parse(PrefixInformationOption.class, buf);
+ if (pio.type != TYPE) {
+ throw new IllegalArgumentException("Invalid type " + pio.type);
+ }
+ if (pio.length != LENGTH) {
+ throw new IllegalArgumentException("Invalid length " + pio.length);
+ }
+ return new StructNdOptPio(pio.flags, pio.preferredLifetime, pio.validLifetime,
+ pio.getIpPrefix());
+ } catch (IllegalArgumentException | BufferUnderflowException e) {
+ // Not great, but better than throwing an exception that might crash the caller.
+ // Convention in this package is that null indicates that the option was truncated
+ // or malformed, so callers must already handle it.
+ Log.d(TAG, "Invalid PIO option: " + e);
+ return null;
+ }
+ }
+
+ protected void writeToByteBuffer(ByteBuffer buf) {
+ buf.put(PrefixInformationOption.build(prefix, flags, valid, preferred));
+ }
+
+ /** Outputs the wire format of the option to a new big-endian ByteBuffer. */
+ public ByteBuffer toByteBuffer() {
+ final ByteBuffer buf = ByteBuffer.allocate(Struct.getSize(PrefixInformationOption.class));
+ writeToByteBuffer(buf);
+ buf.flip();
+ return buf;
+ }
+
+ @Override
+ @NonNull
+ public String toString() {
+ return String.format("NdOptPio(flags:%s, preferred lft:%s, valid lft:%s, prefix:%s)",
+ HexDump.toHexString(flags), preferred, valid, prefix);
+ }
+}
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNdOptPioTest.java b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNdOptPioTest.java
new file mode 100644
index 0000000..0d88829
--- /dev/null
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/netlink/StructNdOptPioTest.java
@@ -0,0 +1,205 @@
+/*
+ * 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 static com.android.net.module.util.NetworkStackConstants.INFINITE_LEASE;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import android.net.IpPrefix;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import com.android.net.module.util.structs.PrefixInformationOption;
+
+import libcore.util.HexEncoding;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class StructNdOptPioTest {
+ private static final IpPrefix TEST_PREFIX = new IpPrefix("2a00:79e1:abc:f605::/64");
+ private static final byte TEST_PIO_FLAGS_P_UNSET = (byte) 0xC0; // L=1,A=1
+ private static final byte TEST_PIO_FLAGS_P_SET = (byte) 0xD0; // L=1,A=1,P=1
+ private static final String PIO_BYTES =
+ "0304" // type=3, length=4
+ + "40" // prefix length=64
+ + "C0" // L=1,A=1
+ + "00278D00" // valid=259200
+ + "00093A80" // preferred=604800
+ + "00000000" // Reserved2
+ + "2A0079E10ABCF6050000000000000000"; // prefix=2a00:79e1:abc:f605::
+
+ private static final String PIO_WITH_P_FLAG_BYTES =
+ "0304" // type=3, length=4
+ + "40" // prefix length=64
+ + "D0" // L=1,A=1,P=1
+ + "00278D00" // valid=2592000
+ + "00093A80" // preferred=604800
+ + "00000000" // Reserved2
+ + "2A0079E10ABCF6050000000000000000"; // prefix=2a00:79e1:abc:f605::
+
+ private static final String PIO_WITH_P_FLAG_INFINITY_LIFETIME_BYTES =
+ "0304" // type=3, length=4
+ + "40" // prefix length=64
+ + "D0" // L=1,A=1,P=1
+ + "FFFFFFFF" // valid=infinity
+ + "FFFFFFFF" // preferred=infintiy
+ + "00000000" // Reserved2
+ + "2A0079E10ABCF6050000000000000000"; // prefix=2a00:79e1:abc:f605::
+
+ private static void assertPioOptMatches(final StructNdOptPio opt, int length, byte flags,
+ long preferred, long valid, final IpPrefix prefix) {
+ assertEquals(StructNdOptPio.TYPE, opt.type);
+ assertEquals(length, opt.length);
+ assertEquals(flags, opt.flags);
+ assertEquals(preferred, opt.preferred);
+ assertEquals(valid, opt.valid);
+ assertEquals(prefix, opt.prefix);
+ }
+
+ private static void assertToByteBufferMatches(final StructNdOptPio opt, final String expected) {
+ String actual = HexEncoding.encodeToString(opt.toByteBuffer().array());
+ assertEquals(expected, actual);
+ }
+
+ private static void doPioParsingTest(final String optionHexString, int length, byte flags,
+ long preferred, long valid, final IpPrefix prefix) {
+ final byte[] rawBytes = HexEncoding.decode(optionHexString);
+ final StructNdOptPio opt = StructNdOptPio.parse(ByteBuffer.wrap(rawBytes));
+ assertPioOptMatches(opt, length, flags, preferred, valid, prefix);
+ assertToByteBufferMatches(opt, optionHexString);
+ }
+
+ @Test
+ public void testParsingPioWithoutPFlag() {
+ doPioParsingTest(PIO_BYTES, 4 /* length */, TEST_PIO_FLAGS_P_UNSET,
+ 604800 /* preferred */, 2592000 /* valid */, TEST_PREFIX);
+ }
+
+ @Test
+ public void testParsingPioWithPFlag() {
+ doPioParsingTest(PIO_WITH_P_FLAG_BYTES, 4 /* length */, TEST_PIO_FLAGS_P_SET,
+ 604800 /* preferred */, 2592000 /* valid */, TEST_PREFIX);
+ }
+
+ @Test
+ public void testParsingPioWithPFlag_infinityLifetime() {
+ doPioParsingTest(PIO_WITH_P_FLAG_INFINITY_LIFETIME_BYTES, 4 /* length */,
+ TEST_PIO_FLAGS_P_SET,
+ Integer.toUnsignedLong(INFINITE_LEASE) /* preferred */,
+ Integer.toUnsignedLong(INFINITE_LEASE) /* valid */,
+ TEST_PREFIX);
+ }
+
+ @Test
+ public void testToByteBuffer() {
+ final StructNdOptPio pio =
+ new StructNdOptPio(TEST_PIO_FLAGS_P_UNSET, 604800 /* preferred */,
+ 2592000 /* valid */, TEST_PREFIX);
+ assertToByteBufferMatches(pio, PIO_BYTES);
+ }
+
+ @Test
+ public void testToByteBuffer_withPFlag() {
+ final StructNdOptPio pio =
+ new StructNdOptPio(TEST_PIO_FLAGS_P_SET, 604800 /* preferred */,
+ 2592000 /* valid */, TEST_PREFIX);
+ assertToByteBufferMatches(pio, PIO_WITH_P_FLAG_BYTES);
+ }
+
+ @Test
+ public void testToByteBuffer_infinityLifetime() {
+ final StructNdOptPio pio =
+ new StructNdOptPio(TEST_PIO_FLAGS_P_SET,
+ Integer.toUnsignedLong(INFINITE_LEASE) /* preferred */,
+ Integer.toUnsignedLong(INFINITE_LEASE) /* valid */, TEST_PREFIX);
+ assertToByteBufferMatches(pio, PIO_WITH_P_FLAG_INFINITY_LIFETIME_BYTES);
+ }
+
+ private static ByteBuffer makePioOption(byte type, byte length, byte prefixLen, byte flags,
+ long valid, long preferred, final byte[] prefix) {
+ final PrefixInformationOption pio = new PrefixInformationOption(type, length, prefixLen,
+ flags, valid, preferred, 0 /* reserved */, prefix);
+ return ByteBuffer.wrap(pio.writeToBytes(ByteOrder.BIG_ENDIAN));
+ }
+
+ @Test
+ public void testParsing_invalidOptionType() {
+ final ByteBuffer buf = makePioOption((byte) 24 /* wrong type:RIO */,
+ (byte) 4 /* length */, (byte) 64 /* prefixLen */, TEST_PIO_FLAGS_P_SET,
+ 2592000 /* valid */, 604800 /* preferred */, TEST_PREFIX.getRawAddress());
+ assertNull(StructNdOptPio.parse(buf));
+ }
+
+ @Test
+ public void testParsing_invalidOptionLength() {
+ final ByteBuffer buf = makePioOption((byte) 24 /* wrong type:RIO */,
+ (byte) 3 /* wrong length */, (byte) 64 /* prefixLen */,
+ TEST_PIO_FLAGS_P_SET, 2592000 /* valid */, 604800 /* preferred */,
+ TEST_PREFIX.getRawAddress());
+ assertNull(StructNdOptPio.parse(buf));
+ }
+
+ @Test
+ public void testParsing_truncatedByteBuffer() {
+ final ByteBuffer buf = makePioOption((byte) 3 /* type */, (byte) 4 /* length */,
+ (byte) 64 /* prefixLen */, TEST_PIO_FLAGS_P_SET,
+ 2592000 /* valid */, 604800 /* preferred */, TEST_PREFIX.getRawAddress());
+ final int len = buf.limit();
+ for (int i = 0; i < buf.limit() - 1; i++) {
+ buf.flip();
+ buf.limit(i);
+ assertNull("Option truncated to " + i + " bytes, should have returned null",
+ StructNdOptPio.parse(buf));
+ }
+ buf.flip();
+ buf.limit(len);
+
+ final StructNdOptPio opt = StructNdOptPio.parse(buf);
+ assertPioOptMatches(opt, (byte) 4 /* length */, TEST_PIO_FLAGS_P_SET,
+ 604800 /* preferred */, 2592000 /* valid */, TEST_PREFIX);
+ }
+
+ @Test
+ public void testParsing_invalidByteBufferLength() {
+ final ByteBuffer buf = makePioOption((byte) 3 /* type */, (byte) 4 /* length */,
+ (byte) 64 /* prefixLen */, TEST_PIO_FLAGS_P_SET,
+ 2592000 /* valid */, 604800 /* preferred */, TEST_PREFIX.getRawAddress());
+ buf.limit(31); // less than 4 * 8
+ assertNull(StructNdOptPio.parse(buf));
+ }
+
+ @Test
+ public void testToString() {
+ final ByteBuffer buf = makePioOption((byte) 3 /* type */, (byte) 4 /* length */,
+ (byte) 64 /* prefixLen */, TEST_PIO_FLAGS_P_SET,
+ 2592000 /* valid */, 604800 /* preferred */, TEST_PREFIX.getRawAddress());
+ final StructNdOptPio opt = StructNdOptPio.parse(buf);
+ final String expected = "NdOptPio"
+ + "(flags:D0, preferred lft:604800, valid lft:2592000,"
+ + " prefix:2a00:79e1:abc:f605::/64)";
+ assertEquals(expected, opt.toString());
+ }
+}