Merge "Unremove DnsResolver#query method used by external developers" (3206b80b) · Commits · e / os / android_frameworks_base

api/current.txt

+1 −0

Original line number	Diff line number	Diff line
		@@ -27231,6 +27231,7 @@ package android.net {
		method @NonNull public static android.net.DnsResolver getInstance();
		method public <T> void query(@Nullable android.net.Network, @NonNull byte[], int, @NonNull java.util.concurrent.Executor, @Nullable android.os.CancellationSignal, @NonNull android.net.DnsResolver.AnswerCallback<T>);
		method public <T> void query(@Nullable android.net.Network, @NonNull String, int, int, int, @NonNull java.util.concurrent.Executor, @Nullable android.os.CancellationSignal, @NonNull android.net.DnsResolver.AnswerCallback<T>);
		method public void query(@Nullable android.net.Network, @NonNull String, int, @NonNull java.util.concurrent.Executor, @Nullable android.os.CancellationSignal, @NonNull android.net.DnsResolver.InetAddressAnswerCallback);
		field public static final int CLASS_IN = 1; // 0x1
		field public static final int FLAG_EMPTY = 0; // 0x0
		field public static final int FLAG_NO_CACHE_LOOKUP = 4; // 0x4

core/java/android/net/DnsResolver.java

+194 −13

Original line number	Diff line number	Diff line
		@@ -22,6 +22,10 @@ import static android.net.NetworkUtils.resNetworkResult;
		import static android.net.NetworkUtils.resNetworkSend;
		import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_ERROR;
		import static android.os.MessageQueue.OnFileDescriptorEventListener.EVENT_INPUT;
		import static android.system.OsConstants.AF_INET;
		import static android.system.OsConstants.AF_INET6;
		import static android.system.OsConstants.IPPROTO_UDP;
		import static android.system.OsConstants.SOCK_DGRAM;

		import android.annotation.CallbackExecutor;
		import android.annotation.IntDef;
		@@ -30,12 +34,18 @@ import android.annotation.Nullable;
		import android.os.CancellationSignal;
		import android.os.Looper;
		import android.system.ErrnoException;
		import android.system.Os;
		import android.util.Log;

		import libcore.io.IoUtils;

		import java.io.FileDescriptor;
		import java.io.IOException;
		import java.lang.annotation.Retention;
		import java.lang.annotation.RetentionPolicy;
		import java.net.InetAddress;
		import java.net.InetSocketAddress;
		import java.net.SocketAddress;
		import java.net.UnknownHostException;
		import java.util.ArrayList;
		import java.util.List;
		@@ -52,6 +62,7 @@ public final class DnsResolver {
		private static final String TAG = "DnsResolver";
		private static final int FD_EVENTS = EVENT_INPUT \| EVENT_ERROR;
		private static final int MAXPACKET = 8 * 1024;
		private static final int SLEEP_TIME = 2;

		@IntDef(prefix = { "CLASS_" }, value = {
		CLASS_IN
		@@ -188,9 +199,9 @@ public final class DnsResolver {
		* Send a raw DNS query.
		* The answer will be provided asynchronously through the provided {@link AnswerCallback}.
		*
		* @param network {@link Network} specifying which network for querying.
		* @param network {@link Network} specifying which network to query on.
		* {@code null} for query on default network.
		* @param query blob message
		* @param query blob message to query
		* @param flags flags as a combination of the FLAGS_* constants
		* @param executor The {@link Executor} that the callback should be executed on.
		* @param cancellationSignal used by the caller to signal if the query should be
		@@ -211,21 +222,23 @@ public final class DnsResolver {
		queryfd = resNetworkSend((network != null
		? network.netId : NETID_UNSET), query, query.length, flags);
		} catch (ErrnoException e) {
		executor.execute(() -> {
		callback.onQueryException(e);
		});
		return;
		}

		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		registerFDListener(executor, queryfd, callback, cancellationSignal, lock);
		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		}

		/**
		* Send a DNS query with the specified name, class and query type.
		* The answer will be provided asynchronously through the provided {@link AnswerCallback}.
		*
		* @param network {@link Network} specifying which network for querying.
		* @param network {@link Network} specifying which network to query on.
		* {@code null} for query on default network.
		* @param domain domain name for querying
		* @param domain domain name to query
		* @param nsClass dns class as one of the CLASS_* constants
		* @param nsType dns resource record (RR) type as one of the TYPE_* constants
		* @param flags flags as a combination of the FLAGS_* constants
		@@ -249,12 +262,145 @@ public final class DnsResolver {
		queryfd = resNetworkQuery((network != null
		? network.netId : NETID_UNSET), domain, nsClass, nsType, flags);
		} catch (ErrnoException e) {
		executor.execute(() -> {
		callback.onQueryException(e);
		});
		return;
		}

		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		registerFDListener(executor, queryfd, callback, cancellationSignal, lock);
		maybeAddCancellationSignal(cancellationSignal, queryfd, lock);
		}

		private class InetAddressAnswerAccumulator extends InetAddressAnswerCallback {
		private final List<InetAddress> mAllAnswers;
		private ParseException mParseException;
		private ErrnoException mErrnoException;
		private final InetAddressAnswerCallback mUserCallback;
		private final int mTargetAnswerCount;
		private int mReceivedAnswerCount = 0;

		InetAddressAnswerAccumulator(int size, @NonNull InetAddressAnswerCallback callback) {
		mTargetAnswerCount = size;
		mAllAnswers = new ArrayList<>();
		mUserCallback = callback;
		}

		private boolean maybeReportException() {
		if (mErrnoException != null) {
		mUserCallback.onQueryException(mErrnoException);
		return true;
		}
		if (mParseException != null) {
		mUserCallback.onParseException(mParseException);
		return true;
		}
		return false;
		}

		private void maybeReportAnswer() {
		if (++mReceivedAnswerCount != mTargetAnswerCount) return;
		if (mAllAnswers.isEmpty() && maybeReportException()) return;
		// TODO: Do RFC6724 sort.
		mUserCallback.onAnswer(mAllAnswers);
		}

		@Override
		public void onAnswer(@NonNull List<InetAddress> answer) {
		mAllAnswers.addAll(answer);
		maybeReportAnswer();
		}

		@Override
		public void onParseException(@NonNull ParseException e) {
		mParseException = e;
		maybeReportAnswer();
		}

		@Override
		public void onQueryException(@NonNull ErrnoException e) {
		mErrnoException = e;
		maybeReportAnswer();
		}
		}

		/**
		* Send a DNS query with the specified name, get back a set of InetAddresses asynchronously.
		* The answer will be provided asynchronously through the provided
		* {@link InetAddressAnswerCallback}.
		*
		* @param network {@link Network} specifying which network to query on.
		* {@code null} for query on default network.
		* @param domain domain name to query
		* @param flags flags as a combination of the FLAGS_* constants
		* @param executor The {@link Executor} that the callback should be executed on.
		* @param cancellationSignal used by the caller to signal if the query should be
		* cancelled. May be {@code null}.
		* @param callback an {@link InetAddressAnswerCallback} which will be called to notify the
		* caller of the result of dns query.
		*/
		public void query(@Nullable Network network, @NonNull String domain, @QueryFlag int flags,
		@NonNull @CallbackExecutor Executor executor,
		@Nullable CancellationSignal cancellationSignal,
		@NonNull InetAddressAnswerCallback callback) {
		if (cancellationSignal != null && cancellationSignal.isCanceled()) {
		return;
		}
		final Object lock = new Object();
		final boolean queryIpv6 = haveIpv6(network);
		final boolean queryIpv4 = haveIpv4(network);

		final FileDescriptor v4fd;
		final FileDescriptor v6fd;

		int queryCount = 0;

		if (queryIpv6) {
		try {
		v6fd = resNetworkQuery((network != null
		? network.netId : NETID_UNSET), domain, CLASS_IN, TYPE_AAAA, flags);
		} catch (ErrnoException e) {
		executor.execute(() -> {
		callback.onQueryException(e);
		});
		return;
		}
		queryCount++;
		} else v6fd = null;

		// TODO: Use device flag to controll the sleep time.
		// Avoiding gateways drop packets if queries are sent too close together
		try {
		Thread.sleep(SLEEP_TIME);
		} catch (InterruptedException ex) { }

		if (queryIpv4) {
		try {
		v4fd = resNetworkQuery((network != null
		? network.netId : NETID_UNSET), domain, CLASS_IN, TYPE_A, flags);
		} catch (ErrnoException e) {
		if (queryIpv6) resNetworkCancel(v6fd); // Closes fd, marks it invalid.
		executor.execute(() -> {
		callback.onQueryException(e);
		});
		return;
		}
		queryCount++;
		} else v4fd = null;

		final InetAddressAnswerAccumulator accumulator =
		new InetAddressAnswerAccumulator(queryCount, callback);

		if (queryIpv6) registerFDListener(executor, v6fd, accumulator, cancellationSignal, lock);
		if (queryIpv4) registerFDListener(executor, v4fd, accumulator, cancellationSignal, lock);

		if (cancellationSignal == null) return;
		cancellationSignal.setOnCancelListener(() -> {
		synchronized (lock) {
		if (queryIpv4) cancelQuery(v4fd);
		if (queryIpv6) cancelQuery(v6fd);
		}
		});
		}

		private <T> void registerFDListener(@NonNull Executor executor,
		@@ -271,7 +417,7 @@ public final class DnsResolver {
		}
		byte[] answerbuf = null;
		try {
		answerbuf = resNetworkResult(fd);
		answerbuf = resNetworkResult(fd); // Closes fd, marks it invalid.
		} catch (ErrnoException e) {
		Log.e(TAG, "resNetworkResult:" + e.toString());
		answerCallback.onQueryException(e);
		@@ -291,19 +437,54 @@ public final class DnsResolver {
		});
		}

		private void cancelQuery(@NonNull FileDescriptor queryfd) {
		if (!queryfd.valid()) return;
		Looper.getMainLooper().getQueue().removeOnFileDescriptorEventListener(queryfd);
		resNetworkCancel(queryfd); // Closes fd, marks it invalid.
		}

		private void maybeAddCancellationSignal(@Nullable CancellationSignal cancellationSignal,
		@NonNull FileDescriptor queryfd, @NonNull Object lock) {
		if (cancellationSignal == null) return;
		cancellationSignal.setOnCancelListener(() -> {
		synchronized (lock) {
		if (!queryfd.valid()) return;
		Looper.getMainLooper().getQueue()
		.removeOnFileDescriptorEventListener(queryfd);
		resNetworkCancel(queryfd);
		cancelQuery(queryfd);
		}
		});
		}

		// These two functions match the behaviour of have_ipv4 and have_ipv6 in the native resolver.
		private boolean haveIpv4(@Nullable Network network) {
		final SocketAddress addrIpv4 =
		new InetSocketAddress(InetAddresses.parseNumericAddress("8.8.8.8"), 0);
		return checkConnectivity(network, AF_INET, addrIpv4);
		}

		private boolean haveIpv6(@Nullable Network network) {
		final SocketAddress addrIpv6 =
		new InetSocketAddress(InetAddresses.parseNumericAddress("2000::"), 0);
		return checkConnectivity(network, AF_INET6, addrIpv6);
		}

		private boolean checkConnectivity(@Nullable Network network,
		int domain, @NonNull SocketAddress addr) {
		final FileDescriptor socket;
		try {
		socket = Os.socket(domain, SOCK_DGRAM, IPPROTO_UDP);
		} catch (ErrnoException e) {
		return false;
		}
		try {
		if (network != null) network.bindSocket(socket);
		Os.connect(socket, addr);
		} catch (IOException \| ErrnoException e) {
		return false;
		} finally {
		IoUtils.closeQuietly(socket);
		}
		return true;
		}

		private static class DnsAddressAnswer extends DnsPacket {
		private static final String TAG = "DnsResolver.DnsAddressAnswer";
		private static final boolean DBG = false;