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Add Rfc6724 style sort for DnsResolver and fix potential bug

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1. pass default network explicitly to fix potential
   mis-sync network problem in DnsResolver#query
2. Add rfc6724 sort and related test
3. DnsResolver do rfc6724 sort before response InetAddress answers
4. move haveIpv* function from DnsResolver to DnsUtils

Bug: 129530368
Test: atest DnsResolverTest DnsUtilsTest
Change-Id: I4efa599c0605f6a9e4ef2dd1a36572c69b3c433f
This commit is contained in:
Luke Huang 2019-04-17 22:27:56 +08:00
commit 26c1cdb19d
1 changed files with 665 additions and 72 deletions
Download patch file Download diff file Expand all files Collapse all files

106
core/java/android/net/DnsResolver.java
View file

@ -16,16 +16,17 @@
package android.net;
import static android.net.NetworkUtils.getDnsNetId;
import static android.net.NetworkUtils.resNetworkCancel;
import static android.net.NetworkUtils.resNetworkQuery;
import static android.net.NetworkUtils.resNetworkResult;
import static android.net.NetworkUtils.resNetworkSend;
import static android.net.util.DnsUtils.haveIpv4;
import static android.net.util.DnsUtils.haveIpv6;
import static android.net.util.DnsUtils.rfc6724Sort;
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 static android.system.OsConstants.ENONET;
import android.annotation.CallbackExecutor;
import android.annotation.IntDef;
@ -34,18 +35,12 @@ 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;
@ -196,8 +191,8 @@ public final class DnsResolver {
final Object lock = new Object();
final FileDescriptor queryfd;
try {
queryfd = resNetworkSend((network != null
? network.getNetIdForResolv() : NETID_UNSET), query, query.length, flags);
queryfd = resNetworkSend((network != null)
? network.getNetIdForResolv() : NETID_UNSET, query, query.length, flags);
} catch (ErrnoException e) {
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
return;
@ -237,8 +232,8 @@ public final class DnsResolver {
final Object lock = new Object();
final FileDescriptor queryfd;
try {
queryfd = resNetworkQuery((network != null
? network.getNetIdForResolv() : NETID_UNSET), domain, nsClass, nsType, flags);
queryfd = resNetworkQuery((network != null)
? network.getNetIdForResolv() : NETID_UNSET, domain, nsClass, nsType, flags);
} catch (ErrnoException e) {
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
return;
@ -252,14 +247,16 @@ public final class DnsResolver {
private class InetAddressAnswerAccumulator implements Callback<byte[]> {
private final List<InetAddress> mAllAnswers;
private final Network mNetwork;
private int mRcode;
private DnsException mDnsException;
private final Callback<? super List<InetAddress>> mUserCallback;
private final int mTargetAnswerCount;
private int mReceivedAnswerCount = 0;
InetAddressAnswerAccumulator(int size,
InetAddressAnswerAccumulator(@NonNull Network network, int size,
@NonNull Callback<? super List<InetAddress>> callback) {
mNetwork = network;
mTargetAnswerCount = size;
mAllAnswers = new ArrayList<>();
mUserCallback = callback;
@ -280,8 +277,7 @@ public final class DnsResolver {
private void maybeReportAnswer() {
if (++mReceivedAnswerCount != mTargetAnswerCount) return;
if (mAllAnswers.isEmpty() && maybeReportError()) return;
// TODO: Do RFC6724 sort.
mUserCallback.onAnswer(mAllAnswers, mRcode);
mUserCallback.onAnswer(rfc6724Sort(mNetwork, mAllAnswers), mRcode);
}
@Override
@ -308,7 +304,7 @@ public final class DnsResolver {
/**
* Send a DNS query with the specified name on a network with both IPv4 and IPv6,
* get back a set of InetAddresses asynchronously.
* get back a set of InetAddresses with rfc6724 sorting style asynchronously.
*
* This method will examine the connection ability on given network, and query IPv4
* and IPv6 if connection is available.
@ -335,8 +331,23 @@ public final class DnsResolver {
return;
}
final Object lock = new Object();
final boolean queryIpv6 = haveIpv6(network);
final boolean queryIpv4 = haveIpv4(network);
final Network queryNetwork;
try {
queryNetwork = (network != null) ? network : new Network(getDnsNetId());
} catch (ErrnoException e) {
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
return;
}
final boolean queryIpv6 = haveIpv6(queryNetwork);
final boolean queryIpv4 = haveIpv4(queryNetwork);
// This can only happen if queryIpv4 and queryIpv6 are both false.
// This almost certainly means that queryNetwork does not exist or no longer exists.
if (!queryIpv6 && !queryIpv4) {
executor.execute(() -> callback.onError(
new DnsException(ERROR_SYSTEM, new ErrnoException("resNetworkQuery", ENONET))));
return;
}
final FileDescriptor v4fd;
final FileDescriptor v6fd;
@ -345,9 +356,8 @@ public final class DnsResolver {
if (queryIpv6) {
try {
v6fd = resNetworkQuery((network != null
? network.getNetIdForResolv() : NETID_UNSET),
domain, CLASS_IN, TYPE_AAAA, flags);
v6fd = resNetworkQuery(queryNetwork.getNetIdForResolv(), domain, CLASS_IN,
TYPE_AAAA, flags);
} catch (ErrnoException e) {
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
return;
@ -355,7 +365,6 @@ public final class DnsResolver {
queryCount++;
} else v6fd = null;
// TODO: Use device flag to control the sleep time.
// Avoiding gateways drop packets if queries are sent too close together
try {
Thread.sleep(SLEEP_TIME_MS);
@ -365,9 +374,8 @@ public final class DnsResolver {
if (queryIpv4) {
try {
v4fd = resNetworkQuery((network != null
? network.getNetIdForResolv() : NETID_UNSET),
domain, CLASS_IN, TYPE_A, flags);
v4fd = resNetworkQuery(queryNetwork.getNetIdForResolv(), domain, CLASS_IN, TYPE_A,
flags);
} catch (ErrnoException e) {
if (queryIpv6) resNetworkCancel(v6fd); // Closes fd, marks it invalid.
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
@ -377,7 +385,7 @@ public final class DnsResolver {
} else v4fd = null;
final InetAddressAnswerAccumulator accumulator =
new InetAddressAnswerAccumulator(queryCount, callback);
new InetAddressAnswerAccumulator(queryNetwork, queryCount, callback);
synchronized (lock) {
if (queryIpv6) {
@ -398,7 +406,7 @@ public final class DnsResolver {
/**
* Send a DNS query with the specified name and query type, get back a set of
* InetAddresses asynchronously.
* InetAddresses with rfc6724 sorting style asynchronously.
*
* The answer will be provided asynchronously through the provided {@link Callback}.
*
@ -423,15 +431,17 @@ public final class DnsResolver {
}
final Object lock = new Object();
final FileDescriptor queryfd;
final Network queryNetwork;
try {
queryfd = resNetworkQuery((network != null
? network.getNetIdForResolv() : NETID_UNSET), domain, CLASS_IN, nsType, flags);
queryNetwork = (network != null) ? network : new Network(getDnsNetId());
queryfd = resNetworkQuery(queryNetwork.getNetIdForResolv(), domain, CLASS_IN, nsType,
flags);
} catch (ErrnoException e) {
executor.execute(() -> callback.onError(new DnsException(ERROR_SYSTEM, e)));
return;
}
final InetAddressAnswerAccumulator accumulator =
new InetAddressAnswerAccumulator(1, callback);
new InetAddressAnswerAccumulator(queryNetwork, 1, callback);
synchronized (lock) {
registerFDListener(executor, queryfd, accumulator, cancellationSignal, lock);
if (cancellationSignal == null) return;
@ -500,38 +510,6 @@ public final class DnsResolver {
});
}
// 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;