Try all resolved IP addresses for hostname (Fixes #834)

src/main/java/com/hierynomus/protocol/commons/HostResolver.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright (C)2016 - SMBJ Contributors
+ *
+ * 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.hierynomus.protocol.commons;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+public interface HostResolver {
+    public static final HostResolver DEFAULT = new DefaultHostResolver();
+
+    InetAddress[] resolveHost(String host) throws UnknownHostException;
+
+    public static class DefaultHostResolver implements HostResolver {
+        @Override
+        public InetAddress[] resolveHost(String host) throws UnknownHostException {
+            return InetAddress.getAllByName(host);
+        }
+    }
+}
+

src/main/java/com/hierynomus/smbj/SmbConfig.java

@@ -37,6 +37,7 @@
 import com.hierynomus.mssmb2.SMB2GlobalCapability;
 import com.hierynomus.ntlm.NtlmConfig;
 import com.hierynomus.protocol.commons.Factory;
+import com.hierynomus.protocol.commons.HostResolver;
 import com.hierynomus.protocol.commons.socket.ProxySocketFactory;
 import com.hierynomus.security.SecurityProvider;
 import com.hierynomus.security.bc.BCSecurityProvider;
@@ -74,6 +75,7 @@ public final class SmbConfig {
     private Set<SMB2Dialect> dialects;
     private List<Factory.Named<Authenticator>> authenticators;
     private SocketFactory socketFactory;
+    private HostResolver hostResolver;
     private Random random;
     private UUID clientGuid;
     private boolean signingRequired;
@@ -102,6 +104,7 @@ public static Builder builder() {
                 .withClientGuid(UUID.randomUUID())
                 .withSecurityProvider(getDefaultSecurityProvider())
                 .withSocketFactory(new ProxySocketFactory())
+                .withHostResolver(HostResolver.DEFAULT)
                 .withSigningRequired(false)
                 .withDfsEnabled(false)
                 .withMultiProtocolNegotiate(false)
@@ -153,6 +156,7 @@ private SmbConfig(SmbConfig other) {
         dialects.addAll(other.dialects);
         authenticators.addAll(other.authenticators);
         socketFactory = other.socketFactory;
+        hostResolver = other.hostResolver;
         random = other.random;
         clientGuid = other.clientGuid;
         signingRequired = other.signingRequired;
@@ -244,6 +248,10 @@ public SocketFactory getSocketFactory() {
         return socketFactory;
     }
 
+    public HostResolver getHostResolver() {
+        return hostResolver;
+    }
+
     public GSSContextConfig getClientGSSContextConfig() {
         return clientGSSContextConfig;
     }
@@ -317,6 +325,14 @@ public Builder withSocketFactory(SocketFactory socketFactory) {
             return this;
         }
 
+        public Builder withHostResolver(HostResolver hostResolver) {
+            if (hostResolver == null) {
+                throw new IllegalArgumentException("Host resolver may not be null");
+            }
+            config.hostResolver = hostResolver;
+            return this;
+        }
+
         public Builder withDialects(SMB2Dialect... dialects) {
             return withDialects(Arrays.asList(dialects));
         }

src/main/java/com/hierynomus/smbj/connection/Connection.java

@@ -20,6 +20,7 @@
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.util.UUID;
 import java.util.concurrent.Future;
@@ -29,6 +30,7 @@
 import com.hierynomus.mssmb.SMB1PacketFactory;
 import com.hierynomus.mssmb2.*;
 import com.hierynomus.mssmb2.messages.SMB2Cancel;
+import com.hierynomus.protocol.commons.HostResolver;
 import com.hierynomus.protocol.commons.buffer.Buffer;
 import com.hierynomus.protocol.commons.concurrent.CancellableFuture;
 import com.hierynomus.protocol.commons.concurrent.Futures;
@@ -43,6 +45,7 @@
 import com.hierynomus.smbj.SmbConfig;
 import com.hierynomus.smbj.auth.AuthenticationContext;
 import com.hierynomus.smbj.common.Pooled;
+import com.hierynomus.smbj.common.SMBRuntimeException;
 import com.hierynomus.smbj.connection.packet.DeadLetterPacketHandler;
 import com.hierynomus.smbj.connection.packet.IncomingPacketHandler;
 import com.hierynomus.smbj.connection.packet.SMB1PacketHandler;
@@ -95,13 +98,14 @@ public SMBClient getClient() {
 
     private SmbConfig config;
     TransportLayer<SMBPacket<?, ?>> transport;
+    private final HostResolver hostResolver;
     private final SMBEventBus bus;
     private final ReentrantLock lock = new ReentrantLock();
 
     public Connection(SmbConfig config, SMBClient client, SMBEventBus bus, ServerList serverList) {
         this.config = config;
         this.client = client;
-        this.transport = config.getTransportLayerFactory().createTransportLayer(new PacketHandlers<>(new SMBPacketSerializer(), this, converter), config);
+        this.hostResolver = config.getHostResolver();
         this.bus = bus;
         this.serverList = serverList;
         init();
@@ -127,6 +131,7 @@ public Connection(Connection connection) {
         this.client = connection.client;
         this.config = connection.config;
         this.transport = connection.transport;
+        this.hostResolver = connection.hostResolver;
         this.bus = connection.bus;
         this.serverList = connection.serverList;
         init();
@@ -136,7 +141,27 @@ public void connect(String hostname, int port) throws IOException {
         if (isConnected()) {
             throw new IllegalStateException(format("This connection is already connected to %s", getRemoteHostname()));
         }
-        transport.connect(new InetSocketAddress(hostname, port));
+        try {
+            InetAddress[] address = hostResolver.resolveHost(hostname);
+            for (InetAddress inetAddress : address) {
+                try {
+                    transport.connect(new InetSocketAddress(inetAddress, port));
+                    onConnect(hostname, port);
+                    return;
+                } catch (IOException e) {
+                    logger.debug("Failed to connect to {} on address {}", hostname, inetAddress.getHostAddress(), e);
+                }
+            }
+            transport.connect(new InetSocketAddress(hostname, port));
+        } catch (IOException e) {
+            throw new IOException("Failed to resolve hostname " + hostname, e);
+        }
+
+        logger.error("Failed to connect to {}", hostname);
+        throw new SMBRuntimeException("Failed to connect to " + hostname);
+    }
+
+    private void onConnect(String hostname, int port) throws IOException {
         this.connectionContext = new ConnectionContext(config.getClientGuid(), hostname, port, config);
         new SMBProtocolNegotiator(this, config, connectionContext).negotiateDialect();
         this.signatory.init();

src/test/groovy/com/hierynomus/smbj/SMBClientSpec.groovy

@@ -17,12 +17,13 @@ package com.hierynomus.smbj
 
 import com.hierynomus.smbj.testing.PacketProcessor.DefaultPacketProcessor
 import com.hierynomus.smbj.testing.StubTransportLayerFactory
+import com.hierynomus.smbj.testing.StubHostResolver
 import spock.lang.Specification
 
 class SMBClientSpec extends Specification {
 
   def processor = new DefaultPacketProcessor()
-  def config = SmbConfig.builder().withTransportLayerFactory(new StubTransportLayerFactory(processor)).build()
+  def config = SmbConfig.builder().withTransportLayerFactory(new StubTransportLayerFactory(processor)).withHostResolver(StubHostResolver.INSTANCE).build()
 
   def "should return same connection for same host/port combo"() {
     given:

src/test/groovy/com/hierynomus/smbj/connection/ConnectionSpec.groovy

@@ -39,6 +39,7 @@ import com.hierynomus.smbj.testing.PacketProcessor.NoOpPacketProcessor
 import com.hierynomus.smbj.testing.PacketProcessor.DefaultPacketProcessor
 import com.hierynomus.smbj.testing.StubAuthenticator
 import com.hierynomus.smbj.testing.StubTransportLayerFactory
+import com.hierynomus.smbj.testing.StubHostResolver
 import net.engio.mbassy.listener.Handler
 import spock.lang.Specification
 
@@ -51,6 +52,7 @@ class ConnectionSpec extends Specification {
   private SmbConfig smbConfig(packetProcessor) {
     SmbConfig.builder()
       .withTransportLayerFactory(new StubTransportLayerFactory(new DefaultPacketProcessor().wrap(packetProcessor)))
+      .withHostResolver(new StubHostResolver())
       .withAuthenticators(new StubAuthenticator.Factory())
       .build()
   }

src/test/java/com/hierynomus/smbj/testing/StubHostResolver.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C)2016 - SMBJ Contributors
+ *
+ * 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.hierynomus.smbj.testing;
+
+import java.net.InetAddress;
+
+import com.hierynomus.protocol.commons.HostResolver;
+
+public class StubHostResolver implements HostResolver {
+    public static final StubHostResolver INSTANCE = new StubHostResolver();
+
+    public InetAddress[] resolveHost(String host) {
+        return new InetAddress[]{
+            InetAddress.getLoopbackAddress()
+        };
+    }
+}

src/test/java/com/hierynomus/smbj/testing/Utils.java

@@ -21,7 +21,9 @@
 public class Utils {
     public static SmbConfig config(PacketProcessor processor) {
         return SmbConfig.builder()
-                .withTransportLayerFactory(new StubTransportLayerFactory<>(new DefaultPacketProcessor().wrap(processor)))
+                .withTransportLayerFactory(
+                        new StubTransportLayerFactory<>(new DefaultPacketProcessor().wrap(processor)))
+                .withHostResolver(StubHostResolver.INSTANCE)
                 .withAuthenticators(new StubAuthenticator.Factory()).build();
     }
 }