Deprecate IPv6 prefixes no longer in use. (9d6ba6bd) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/connectivity/tethering/IPv6TetheringInterfaceServices.java

+13 −1

Original line number	Diff line number	Diff line
		@@ -176,9 +176,21 @@ class IPv6TetheringInterfaceServices {

		private void updateRaParams(RaParams params) {
		if (mRaDaemon != null) {
		HashSet<IpPrefix> deprecated = null;

		if (mLastRaParams != null) {
		deprecated = new HashSet<>();

		for (IpPrefix ipp : mLastRaParams.prefixes) {
		if (params == null \|\| !params.prefixes.contains(ipp)) {
		deprecated.add(ipp);
		}
		}
		}

		// Currently, we send spurious RAs (5) whenever there's any update.
		// TODO: Compare params with mLastParams to avoid spurious updates.
		mRaDaemon.buildNewRa(params);
		mRaDaemon.buildNewRa(params, deprecated);
		}

		mLastRaParams = params;

services/net/java/android/net/ip/RouterAdvertisementDaemon.java

+97 −36

Original line number	Diff line number	Diff line
		@@ -45,7 +45,9 @@ import java.nio.BufferOverflowException;
		import java.nio.ByteBuffer;
		import java.nio.ByteOrder;
		import java.util.ArrayList;
		import java.util.HashMap;
		import java.util.HashSet;
		import java.util.Map;
		import java.util.Random;
		import java.util.Set;
		import java.util.concurrent.atomic.AtomicInteger;
		@@ -109,6 +111,11 @@ public class RouterAdvertisementDaemon {
		private final byte[] mRA = new byte[IPV6_MIN_MTU];
		@GuardedBy("mLock")
		private int mRaLength;
		@GuardedBy("mLock")
		private final HashMap<IpPrefix, Integer> mDeprecatedPrefixes;

		@GuardedBy("mLock")
		private RaParams mRaParams;

		private volatile FileDescriptor mSocket;
		private volatile MulticastTransmitter mMulticastTransmitter;
		@@ -141,45 +148,29 @@ public class RouterAdvertisementDaemon {
		mIfIndex = ifindex;
		mHwAddr = hwaddr;
		mAllNodes = new InetSocketAddress(getAllNodesForScopeId(mIfIndex), 0);
		mDeprecatedPrefixes = new HashMap<>();
		}

		public void buildNewRa(RaParams params) {
		public void buildNewRa(RaParams params, HashSet<IpPrefix> newlyDeprecated) {
		if (newlyDeprecated != null) {
		synchronized (mLock) {
		for (IpPrefix ipp : newlyDeprecated) {
		mDeprecatedPrefixes.put(ipp, MAX_URGENT_RTR_ADVERTISEMENTS);
		}
		}
		}

		// TODO: Send MAX_URGENT_RTR_ADVERTISEMENTS zero router lifetime RAs,
		// iff. we have already sent an RA.
		if (params == null \|\| params.prefixes.isEmpty()) {
		// No RA to be served at this time.
		clearRa();
		return;
		}

		if (params.mtu < IPV6_MIN_MTU) {
		params.mtu = IPV6_MIN_MTU;
		}

		final ByteBuffer ra = ByteBuffer.wrap(mRA);
		ra.order(ByteOrder.BIG_ENDIAN);

		synchronized (mLock) {
		try {
		putHeader(ra, params.hasDefaultRoute);
		putSlla(ra, mHwAddr);
		// https://tools.ietf.org/html/rfc5175#section-4 says:
		//
		// "MUST NOT be added to a Router Advertisement message
		// if no flags in the option are set."
		//
		// putExpandedFlagsOption(ra);
		putMtu(ra, params.mtu);
		for (IpPrefix ipp : params.prefixes) {
		putPio(ra, ipp);
		}
		if (params.dnses.size() > 0) {
		putRdnss(ra, params.dnses);
		}
		mRaLength = ra.position();
		} catch (BufferOverflowException e) {
		Log.e(TAG, "Could not construct new RA: " + e);
		mRaLength = 0;
		return;
		}
		mRaParams = params;
		assembleRa();
		}

		maybeNotifyMulticastTransmitter();
		@@ -216,6 +207,64 @@ public class RouterAdvertisementDaemon {
		}
		}

		private void assembleRa() {
		final ByteBuffer ra = ByteBuffer.wrap(mRA);
		ra.order(ByteOrder.BIG_ENDIAN);

		synchronized (mLock) {
		try {
		putHeader(ra, mRaParams.hasDefaultRoute);

		putSlla(ra, mHwAddr);

		// https://tools.ietf.org/html/rfc5175#section-4 says:
		//
		// "MUST NOT be added to a Router Advertisement message
		// if no flags in the option are set."
		//
		// putExpandedFlagsOption(ra);

		putMtu(ra, mRaParams.mtu);

		for (IpPrefix ipp : mRaParams.prefixes) {
		putPio(ra, ipp, DEFAULT_LIFETIME, DEFAULT_LIFETIME);
		mDeprecatedPrefixes.remove(ipp);
		}

		for (IpPrefix ipp : mDeprecatedPrefixes.keySet()) {
		putPio(ra, ipp, 0, 0);
		}

		if (mRaParams.dnses.size() > 0) {
		putRdnss(ra, mRaParams.dnses);
		}

		mRaLength = ra.position();
		} catch (BufferOverflowException e) {
		Log.e(TAG, "Could not construct new RA: " + e);
		mRaLength = 0;
		return;
		}
		}
		}

		private int decrementDeprecatedPrefixes() {
		int removed = 0;

		synchronized (mLock) {
		for (Map.Entry<IpPrefix, Integer> kv : mDeprecatedPrefixes.entrySet()) {
		if (kv.getValue() == 0) {
		mDeprecatedPrefixes.remove(kv.getKey());
		removed++;
		} else {
		kv.setValue(kv.getValue() - 1);
		}
		}
		}

		return removed;
		}

		private void maybeNotifyMulticastTransmitter() {
		final MulticastTransmitter m = mMulticastTransmitter;
		if (m != null) {
		@@ -325,10 +374,11 @@ public class RouterAdvertisementDaemon {
		ra.put(ND_OPTION_MTU)
		.put(MTU_NUM_8OCTETS)
		.putShort(asShort(0))
		.putInt(mtu);
		.putInt((mtu < IPV6_MIN_MTU) ? IPV6_MIN_MTU : mtu);
		}

		private static void putPio(ByteBuffer ra, IpPrefix ipp) {
		private static void putPio(ByteBuffer ra, IpPrefix ipp,
		int validTime, int preferredTime) {
		/**
		Prefix Information

		@@ -359,13 +409,17 @@ public class RouterAdvertisementDaemon {
		final byte ND_OPTION_PIO = 3;
		final byte PIO_NUM_8OCTETS = 4;

		if (validTime < 0) validTime = 0;
		if (preferredTime < 0) preferredTime = 0;
		if (preferredTime > validTime) preferredTime = validTime;

		final byte[] addr = ipp.getAddress().getAddress();
		ra.put(ND_OPTION_PIO)
		.put(PIO_NUM_8OCTETS)
		.put(asByte(prefixLength))
		.put(asByte(0xc0)) // L&A set
		.putInt(DEFAULT_LIFETIME)
		.putInt(DEFAULT_LIFETIME)
		.put(asByte(0xc0)) /* L & A set */
		.putInt(validTime)
		.putInt(preferredTime)
		.putInt(0)
		.put(addr);
		}
		@@ -547,6 +601,11 @@ public class RouterAdvertisementDaemon {
		}

		maybeSendRA(mAllNodes);
		if (decrementDeprecatedPrefixes() > 0) {
		// At least one deprecated PIO has been removed;
		// reassemble the RA.
		assembleRa();
		}
		}
		}

		@@ -560,15 +619,17 @@ public class RouterAdvertisementDaemon {
		}

		private int getNextMulticastTransmitDelaySec() {
		int countDeprecatedPrefixes = 0;
		synchronized (mLock) {
		if (mRaLength < MIN_RA_HEADER_SIZE) {
		// No actual RA to send; just sleep for 1 day.
		return DAY_IN_SECONDS;
		}
		countDeprecatedPrefixes = mDeprecatedPrefixes.size();
		}

		final int urgentPending = mUrgentAnnouncements.getAndDecrement();
		if (urgentPending > 0) {
		if (urgentPending > 0 \|\| countDeprecatedPrefixes > 0) {
		return MIN_DELAY_BETWEEN_RAS_SEC;
		}