Add class to support TcpInfo parsing (ac1bf661) · Commits · e / os / android_packages_modules_NetworkStack

src/com/android/networkstack/netlink/TcpInfo.java

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		/*
		* Copyright (C) 2019 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.networkstack.netlink;

		import android.util.Log;
		import android.util.Range;

		import androidx.annotation.NonNull;
		import androidx.annotation.Nullable;

		import com.android.internal.annotations.VisibleForTesting;

		import java.nio.BufferUnderflowException;
		import java.nio.ByteBuffer;
		import java.util.HashMap;
		import java.util.LinkedHashMap;
		import java.util.Objects;

		/**
		* Class for tcp_info.
		*
		* Corresponds to {@code struct tcp_info} from bionic/libc/kernel/uapi/linux/tcp.h
		*/
		public class TcpInfo {
		public enum Field {
		STATE(Byte.BYTES),
		CASTATE(Byte.BYTES),
		RETRANSMITS(Byte.BYTES),
		PROBES(Byte.BYTES),
		BACKOFF(Byte.BYTES),
		OPTIONS(Byte.BYTES),
		WSCALE(Byte.BYTES),
		DELIVERY_RATE_APP_LIMITED(Byte.BYTES),
		RTO(Integer.BYTES),
		ATO(Integer.BYTES),
		SND_MSS(Integer.BYTES),
		RCV_MSS(Integer.BYTES),
		UNACKED(Integer.BYTES),
		SACKED(Integer.BYTES),
		LOST(Integer.BYTES),
		RETRANS(Integer.BYTES),
		FACKETS(Integer.BYTES),
		LAST_DATA_SENT(Integer.BYTES),
		LAST_ACK_SENT(Integer.BYTES),
		LAST_DATA_RECV(Integer.BYTES),
		LAST_ACK_RECV(Integer.BYTES),
		PMTU(Integer.BYTES),
		RCV_SSTHRESH(Integer.BYTES),
		RTT(Integer.BYTES),
		RTTVAR(Integer.BYTES),
		SND_SSTHRESH(Integer.BYTES),
		SND_CWND(Integer.BYTES),
		ADVMSS(Integer.BYTES),
		REORDERING(Integer.BYTES),
		RCV_RTT(Integer.BYTES),
		RCV_SPACE(Integer.BYTES),
		TOTAL_RETRANS(Integer.BYTES),
		PACING_RATE(Long.BYTES),
		MAX_PACING_RATE(Long.BYTES),
		BYTES_ACKED(Long.BYTES),
		BYTES_RECEIVED(Long.BYTES),
		SEGS_OUT(Integer.BYTES),
		SEGS_IN(Integer.BYTES),
		NOTSENT_BYTES(Integer.BYTES),
		MIN_RTT(Integer.BYTES),
		DATA_SEGS_IN(Integer.BYTES),
		DATA_SEGS_OUT(Integer.BYTES),
		DELIVERY_RATE(Long.BYTES),
		BUSY_TIME(Long.BYTES),
		RWND_LIMITED(Long.BYTES),
		SNDBUF_LIMITED(Long.BYTES);

		public final int size;

		Field(int s) {
		size = s;
		}
		}

		private static final String TAG = "TcpInfo";
		private final LinkedHashMap<Field, Number> mFieldsValues = new LinkedHashMap<Field, Number>();

		private TcpInfo(@NonNull ByteBuffer bytes, int infolen) {
		final int start = bytes.position();
		for (final Field field : Field.values()) {
		switch (field.size) {
		case Byte.BYTES:
		mFieldsValues.put(field, getByte(bytes, start, infolen));
		break;
		case Integer.BYTES:
		mFieldsValues.put(field, getInt(bytes, start, infolen));
		break;
		case Long.BYTES:
		mFieldsValues.put(field, getLong(bytes, start, infolen));
		break;
		default:
		Log.e(TAG, "Unexpected size:" + field.size);
		}
		}

		}

		@VisibleForTesting
		public TcpInfo(@NonNull HashMap<Field, Number> info) {
		for (final Field field : Field.values()) {
		mFieldsValues.put(field, info.get(field));
		}
		}

		/** Parse a TcpInfo from a giving ByteBuffer with a specific length. */
		@Nullable
		public static TcpInfo parse(@NonNull ByteBuffer bytes, int infolen) {
		try {
		TcpInfo info = new TcpInfo(bytes, infolen);
		return info;
		} catch (BufferUnderflowException e) {
		Log.e(TAG, "parsing error.", e);
		return null;
		}
		}

		/**
		* Helper function for handling different struct tcp_info versions in the kernel.
		*/
		private static boolean isValidOffset(int start, int len, int pos, int targetBytes) {
		final Range a = new Range(start, start + len);
		final Range b = new Range(pos, pos + targetBytes);
		return a.contains(b);
		}

		/** Get value for specific key. */
		@Nullable
		public Number getValue(@NonNull Field key) {
		return mFieldsValues.get(key);
		}

		@Nullable
		private static Byte getByte(@NonNull ByteBuffer buffer, int start, int len) {
		if (!isValidOffset(start, len, buffer.position(), Byte.BYTES)) return null;

		return buffer.get();
		}

		@Nullable
		private static Integer getInt(@NonNull ByteBuffer buffer, int start, int len) {
		if (!isValidOffset(start, len, buffer.position(), Integer.BYTES)) return null;

		return buffer.getInt();
		}

		@Nullable
		private static Long getLong(@NonNull ByteBuffer buffer, int start, int len) {
		if (!isValidOffset(start, len, buffer.position(), Long.BYTES)) return null;

		return buffer.getLong();
		}

		private static String decodeWscale(byte num) {
		return String.valueOf((num >> 4) & 0x0f) + ":" + String.valueOf(num & 0x0f);
		}

		/**
		* Returns a string representing a given tcp state.
		* Map to enum in bionic/libc/include/netinet/tcp.h
		*/
		@VisibleForTesting
		public static String getTcpStateName(int state) {
		switch (state) {
		case 1: return "TCP_ESTABLISHED";
		case 2: return "TCP_SYN_SENT";
		case 3: return "TCP_SYN_RECV";
		case 4: return "TCP_FIN_WAIT1";
		case 5: return "TCP_FIN_WAIT2";
		case 6: return "TCP_TIME_WAIT";
		case 7: return "TCP_CLOSE";
		case 8: return "TCP_CLOSE_WAIT";
		case 9: return "TCP_LAST_ACK";
		case 10: return "TCP_LISTEN";
		case 11: return "TCP_CLOSING";
		default: return "UNKNOWN:" + Integer.toString(state);
		}
		}

		@Override
		public boolean equals(Object obj) {
		if (!(obj instanceof TcpInfo)) return false;
		TcpInfo other = (TcpInfo) obj;

		for (final Field key : mFieldsValues.keySet()) {
		if (!Objects.equals(mFieldsValues.get(key), other.mFieldsValues.get(key))) {
		return false;
		}
		}
		return true;
		}

		@Override
		public int hashCode() {
		return Objects.hash(mFieldsValues.values().toArray());
		}

		@Override
		public String toString() {
		String str = "TcpInfo{ ";
		for (final Field key : mFieldsValues.keySet()) {
		str += key.name().toLowerCase() + "=";
		if (key == Field.STATE) {
		str += getTcpStateName(mFieldsValues.get(key).intValue()) + " ";
		} else if (key == Field.WSCALE) {
		str += decodeWscale(mFieldsValues.get(key).byteValue()) + " ";
		} else {
		str += mFieldsValues.get(key) + " ";
		}
		}
		str += "}";
		return str;
		}
		}

tests/unit/src/android/networkstack/netlink/TcpInfoTest.java

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+227 −0

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		/*
		* Copyright (C) 2019 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 android.networkstack.netlink;

		import static org.junit.Assert.assertEquals;

		import androidx.test.filters.SmallTest;
		import androidx.test.runner.AndroidJUnit4;

		import com.android.networkstack.netlink.TcpInfo;

		import libcore.util.HexEncoding;

		import org.junit.Test;
		import org.junit.runner.RunWith;

		import java.nio.ByteBuffer;
		import java.util.HashMap;

		@RunWith(AndroidJUnit4.class)
		@SmallTest
		public class TcpInfoTest {
		private static final int TCP_INFO_LENGTH_V1 = 192;
		private static final int SHORT_TEST_TCP_INFO = 8;
		private static final String TCP_ESTABLISHED = "TCP_ESTABLISHED";
		private static final String TCP_FIN_WAIT1 = "TCP_FIN_WAIT1";
		private static final String TCP_SYN_SENT = "TCP_SYN_SENT";
		private static final String UNKNOWN_20 = "UNKNOWN:20";
		// Refer to rfc793 for the value definition.
		private static final String TCP_INFO_HEX =
		"01" + // state = TCP_ESTABLISHED
		"00" + // ca_state = TCP_CA_OPEN
		"00" + // retransmits = 0
		"00" + // probes = 0
		"00" + // backoff = 0
		"07" + // option = TCPI_OPT_WSCALE\|TCPI_OPT_SACK\|TCPI_OPT_TIMESTAMPS
		"88" + // wscale = 8
		"00" + // delivery_rate_app_limited = 0
		"001B914A" + // rto = 1806666
		"00000000" + // ato = 0
		"0000052E" + // sndMss = 1326
		"00000218" + // rcvMss = 536
		"00000000" + // unsacked = 0
		"00000000" + // acked = 0
		"00000000" + // lost = 0
		"00000000" + // retrans = 0
		"00000000" + // fackets = 0
		"000000BB" + // lastDataSent = 187
		"00000000" + // lastAckSent = 0
		"000000BB" + // lastDataRecv = 187
		"000000BB" + // lastDataAckRecv = 187
		"000005DC" + // pmtu = 1500
		"00015630" + // rcvSsthresh = 87600
		"00092C3E" + // rttt = 601150
		"0004961F" + // rttvar = 300575
		"00000578" + // sndSsthresh = 1400
		"0000000A" + // sndCwnd = 10
		"000005A8" + // advmss = 1448
		"00000003" + // reordering = 3
		"00000000" + // rcvrtt = 0
		"00015630" + // rcvspace = 87600
		"00000000" + // totalRetrans = 0
		"000000000000AC53" + // pacingRate = 44115
		"FFFFFFFFFFFFFFFF" + // maxPacingRate = 18446744073709551615
		"0000000000000001" + // bytesAcked = 1
		"0000000000000000" + // bytesReceived = 0
		"00000002" + // SegsOut = 2
		"00000001" + // SegsIn = 1
		"00000000" + // NotSentBytes = 0
		"00092C3E" + // minRtt = 601150
		"00000000" + // DataSegsIn = 0
		"00000000" + // DataSegsOut = 0
		"0000000000000000" + // deliverRate = 0
		"0000000000000000" + // busyTime = 0
		"0000000000000000" + // RwndLimited = 0
		"0000000000000000"; // sndBufLimited = 0
		private static final byte[] TCP_INFO_BYTES =
		HexEncoding.decode(TCP_INFO_HEX.toCharArray(), false);

		@Test
		public void testParseTcpInfo() {
		final ByteBuffer buffer = ByteBuffer.wrap(TCP_INFO_BYTES);
		final HashMap<TcpInfo.Field, Number> expected = makeTestTcpInfoHash();
		final TcpInfo parsedInfo = TcpInfo.parse(buffer, TCP_INFO_LENGTH_V1);

		assertEquals(parsedInfo, new TcpInfo(expected));
		}

		@Test
		public void testValidOffset() {
		final ByteBuffer buffer = ByteBuffer.wrap(TCP_INFO_BYTES);

		final HashMap<TcpInfo.Field, Number> expected = makeShortTestTcpInfoHash();
		final TcpInfo parsedInfo = TcpInfo.parse(buffer, SHORT_TEST_TCP_INFO);

		assertEquals(parsedInfo, new TcpInfo(expected));
		}

		@Test
		public void testTcpStateName() {
		assertEquals(TcpInfo.getTcpStateName(4), TCP_FIN_WAIT1);
		assertEquals(TcpInfo.getTcpStateName(1), TCP_ESTABLISHED);
		assertEquals(TcpInfo.getTcpStateName(2), TCP_SYN_SENT);
		assertEquals(TcpInfo.getTcpStateName(20), UNKNOWN_20);
		}

		private static final String MALFORMED_TCP_INFO_HEX =
		"01" + // state = TCP_ESTABLISHED
		"00" + // ca_state = TCP_CA_OPEN
		"00" + // retransmits = 0
		"00" + // probes = 0
		"00" + // backoff = 0
		"07" + // option = TCPI_OPT_WSCALE\|TCPI_OPT_SACK\|TCPI_OPT_TIMESTAMPS
		"88" + // wscale = 8
		"00" + // delivery_rate_app_limited = 0
		"001B"; // Incomplete bytes, expect to be an int.
		private static final byte[] MALFORMED_TCP_INFO_BYTES =
		HexEncoding.decode(MALFORMED_TCP_INFO_HEX.toCharArray(), false);
		@Test
		public void testMalformedTcpInfo() {
		final ByteBuffer buffer = ByteBuffer.wrap(MALFORMED_TCP_INFO_BYTES);
		final HashMap<TcpInfo.Field, Number> expected = makeShortTestTcpInfoHash();

		TcpInfo parsedInfo = TcpInfo.parse(buffer, SHORT_TEST_TCP_INFO);
		assertEquals(parsedInfo, new TcpInfo(expected));

		parsedInfo = TcpInfo.parse(buffer, TCP_INFO_LENGTH_V1);
		assertEquals(parsedInfo, null);
		}

		@Test
		public void testGetValue() {
		ByteBuffer buffer = ByteBuffer.wrap(TCP_INFO_BYTES);

		final HashMap<TcpInfo.Field, Number> expected = makeShortTestTcpInfoHash();
		expected.put(TcpInfo.Field.MAX_PACING_RATE, 10_000L);
		expected.put(TcpInfo.Field.FACKETS, 10);

		final TcpInfo expectedInfo = new TcpInfo(expected);
		assertEquals((byte) 0x01, expectedInfo.getValue(TcpInfo.Field.STATE));
		assertEquals((byte) 0x00, expectedInfo.getValue(TcpInfo.Field.CASTATE));
		assertEquals((byte) 0x00, expectedInfo.getValue(TcpInfo.Field.RETRANSMITS));
		assertEquals((byte) 0x00, expectedInfo.getValue(TcpInfo.Field.PROBES));
		assertEquals((byte) 0x00, expectedInfo.getValue(TcpInfo.Field.BACKOFF));
		assertEquals((byte) 0x07, expectedInfo.getValue(TcpInfo.Field.OPTIONS));
		assertEquals((byte) 0x88, expectedInfo.getValue(TcpInfo.Field.WSCALE));
		assertEquals((byte) 0x00, expectedInfo.getValue(TcpInfo.Field.DELIVERY_RATE_APP_LIMITED));

		assertEquals(10_000L, expectedInfo.getValue(TcpInfo.Field.MAX_PACING_RATE));
		assertEquals(10, expectedInfo.getValue(TcpInfo.Field.FACKETS));
		assertEquals(null, expectedInfo.getValue(TcpInfo.Field.RTT));

		}

		// Make a TcpInfo contains only first 8 bytes.
		private HashMap<TcpInfo.Field, Number> makeShortTestTcpInfoHash() {
		final HashMap<TcpInfo.Field, Number> info = new HashMap<TcpInfo.Field, Number>();
		info.put(TcpInfo.Field.STATE, (byte) 0x01);
		info.put(TcpInfo.Field.CASTATE, (byte) 0x00);
		info.put(TcpInfo.Field.RETRANSMITS, (byte) 0x00);
		info.put(TcpInfo.Field.PROBES, (byte) 0x00);
		info.put(TcpInfo.Field.BACKOFF, (byte) 0x00);
		info.put(TcpInfo.Field.OPTIONS, (byte) 0x07);
		info.put(TcpInfo.Field.WSCALE, (byte) 0x88);
		info.put(TcpInfo.Field.DELIVERY_RATE_APP_LIMITED, (byte) 0x00);

		return info;
		}

		private HashMap<TcpInfo.Field, Number> makeTestTcpInfoHash() {
		final HashMap<TcpInfo.Field, Number> info = makeShortTestTcpInfoHash();
		info.put(TcpInfo.Field.RTO, 1806666);
		info.put(TcpInfo.Field.ATO, 0);
		info.put(TcpInfo.Field.SND_MSS, 1326);
		info.put(TcpInfo.Field.RCV_MSS, 536);
		info.put(TcpInfo.Field.UNACKED, 0);
		info.put(TcpInfo.Field.SACKED, 0);
		info.put(TcpInfo.Field.LOST, 0);
		info.put(TcpInfo.Field.RETRANS, 0);
		info.put(TcpInfo.Field.FACKETS, 0);
		info.put(TcpInfo.Field.LAST_DATA_SENT, 187);
		info.put(TcpInfo.Field.LAST_ACK_SENT, 0);
		info.put(TcpInfo.Field.LAST_DATA_RECV, 187);
		info.put(TcpInfo.Field.LAST_ACK_RECV, 187);
		info.put(TcpInfo.Field.PMTU, 1500);
		info.put(TcpInfo.Field.RCV_SSTHRESH, 87600);
		info.put(TcpInfo.Field.RTT, 601150);
		info.put(TcpInfo.Field.RTTVAR, 300575);
		info.put(TcpInfo.Field.SND_SSTHRESH, 1400);
		info.put(TcpInfo.Field.SND_CWND, 10);
		info.put(TcpInfo.Field.ADVMSS, 1448);
		info.put(TcpInfo.Field.REORDERING, 3);
		info.put(TcpInfo.Field.RCV_RTT, 0);
		info.put(TcpInfo.Field.RCV_SPACE, 87600);
		info.put(TcpInfo.Field.TOTAL_RETRANS, 0);
		info.put(TcpInfo.Field.PACING_RATE, 44115L);
		info.put(TcpInfo.Field.MAX_PACING_RATE, -1L);
		info.put(TcpInfo.Field.BYTES_ACKED, 1L);
		info.put(TcpInfo.Field.BYTES_RECEIVED, 0L);
		info.put(TcpInfo.Field.SEGS_OUT, 2);
		info.put(TcpInfo.Field.SEGS_IN, 1);
		info.put(TcpInfo.Field.NOTSENT_BYTES, 0);
		info.put(TcpInfo.Field.MIN_RTT, 601150);
		info.put(TcpInfo.Field.DATA_SEGS_IN, 0);
		info.put(TcpInfo.Field.DATA_SEGS_OUT, 0);
		info.put(TcpInfo.Field.DELIVERY_RATE, 0L);
		info.put(TcpInfo.Field.BUSY_TIME, 0L);
		info.put(TcpInfo.Field.RWND_LIMITED, 0L);
		info.put(TcpInfo.Field.SNDBUF_LIMITED, 0L);

		return info;
		}
		}