Merge pull request #222 from trustin/dns_lookup

Do not send an AAAA DNS query when -Djava.net.preferIPv4Stack=true (0.21)
line · Aug 9, 2016 · 3337679 · 3337679
2 parents c8048c9 + 52773a0
commit 3337679
Showing 1 changed file with 30 additions and 2 deletions.
diff --git a/src/main/java/com/linecorp/armeria/client/NonDecoratingClientFactory.java b/src/main/java/com/linecorp/armeria/client/NonDecoratingClientFactory.java
@@ -18,6 +18,7 @@
 
 import static java.util.Objects.requireNonNull;
 
+import java.net.InetAddress;
 import java.util.Optional;
 import java.util.concurrent.ThreadFactory;
 import java.util.function.Function;
@@ -27,6 +28,7 @@
 import com.linecorp.armeria.common.util.NativeLibraries;
 
 import io.netty.bootstrap.Bootstrap;
+import io.netty.channel.ChannelFactory;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.EventLoop;
 import io.netty.channel.EventLoopGroup;
@@ -35,10 +37,13 @@
 import io.netty.channel.epoll.EpollSocketChannel;
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.DatagramChannel;
+import io.netty.channel.socket.InternetProtocolFamily;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioDatagramChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
+import io.netty.resolver.NameResolver;
 import io.netty.resolver.dns.DnsAddressResolverGroup;
+import io.netty.resolver.dns.DnsNameResolverBuilder;
 import io.netty.resolver.dns.DnsServerAddresses;
 import io.netty.util.concurrent.DefaultThreadFactory;
 
@@ -89,8 +94,7 @@ private NonDecoratingClientFactory(SessionOptions options,
         baseBootstrap.channel(channelType());
         baseBootstrap.resolver(
                 options.addressResolverGroup()
-                       .orElseGet(() -> new DnsAddressResolverGroup(
-                               datagramChannelType(), DnsServerAddresses.defaultAddresses())));
+                       .orElseGet(DnsAddressResolverGroup5657::new));
 
         baseBootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS,
                              ConvertUtils.safeLongToInt(options.connectTimeoutMillis()));
@@ -148,4 +152,28 @@ public void close() {
             eventLoopGroup.shutdownGracefully().syncUninterruptibly();
         }
     }
+
+    private static class DnsAddressResolverGroup5657 extends DnsAddressResolverGroup {
+
+        DnsAddressResolverGroup5657() {
+            super(datagramChannelType(), DnsServerAddresses.defaultAddresses());
+        }
+
+        @Override
+        protected NameResolver<InetAddress> newNameResolver(
+                EventLoop eventLoop, ChannelFactory<? extends DatagramChannel> channelFactory,
+                DnsServerAddresses nameServerAddresses) throws Exception {
+
+            final DnsNameResolverBuilder builder = new DnsNameResolverBuilder(eventLoop);
+            builder.channelFactory(channelFactory);
+            builder.nameServerAddresses(nameServerAddresses);
+            if (Boolean.getBoolean("java.net.preferIPv4Stack")) {
+                // Resolve IPv4 addresses only when -Djava.net.preferIPv4Stack is enabled,
+                // because JDK will fail or refuse connecting to an IPv6 address at all.
+                // See: https://github.com/netty/netty/issues/5657
+                builder.resolvedAddressTypes(InternetProtocolFamily.IPv4);
+            }
+            return builder.build();
+        }
+    }
 }