forked from netty/netty
-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
DNS Resolve ambiguity in which DNS servers are used during resolution
Motivation: Recently DnsServerAddressStreamProvider was introduced to allow control for each query as to which DNS server should be used for resolution to respect the local host's default DNS server configuration. However resolver-dns also accepts a stream of DNS servers to use by default, but this stream is not host name aware. This creates an ambiguity as to which method is used to determine the DNS server to user during resolution, and in which order. We can remove this ambiguity and provide a more general API by just supporting DnsServerAddressStreamProvider. Modifications: - Remove the fixed DnsServerAddresses and instead only accept a DnsServerAddressStreamProvider. - Add utility methods to help use DnsServerAddressStreamProvider for a single entry, a list of entries, and get the default for the current machine. Result: Fixes netty#6573.
- Loading branch information
1 parent
4f465db
commit e5d3152
Showing
14 changed files
with
205 additions
and
81 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
43 changes: 43 additions & 0 deletions
43
resolver-dns/src/main/java/io/netty/resolver/dns/DnsServerAddressStreamProviders.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,43 @@ | ||
| /* | ||
| * Copyright 2017 The Netty Project | ||
| * | ||
| * The Netty Project licenses this file to you 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 io.netty.resolver.dns; | ||
|
|
||
| import io.netty.util.internal.UnstableApi; | ||
|
|
||
| /** | ||
| * Utility methods related to {@link DnsServerAddressStreamProvider}. | ||
| */ | ||
| @UnstableApi | ||
| public final class DnsServerAddressStreamProviders { | ||
| // TODO(scott): how is this done on Windows? This may require a JNI call to GetNetworkParams | ||
| // https://msdn.microsoft.com/en-us/library/aa365968(VS.85).aspx. | ||
| private static final DnsServerAddressStreamProvider DEFAULT_DNS_SERVER_ADDRESS_STREAM_PROVIDER = | ||
| UnixResolverDnsServerAddressStreamProvider.parseSilently(); | ||
|
|
||
| private DnsServerAddressStreamProviders() { | ||
| } | ||
|
|
||
| /** | ||
| * A {@link DnsServerAddressStreamProvider} which inherits the DNS servers from your local host's configuration. | ||
| * <p> | ||
| * Note that only macOS and Linux are currently supported. | ||
| * @return A {@link DnsServerAddressStreamProvider} which inherits the DNS servers from your local host's | ||
| * configuration. | ||
| */ | ||
| public static DnsServerAddressStreamProvider platformDefault() { | ||
| return DEFAULT_DNS_SERVER_ADDRESS_STREAM_PROVIDER; | ||
| } | ||
| } |
56 changes: 56 additions & 0 deletions
56
resolver-dns/src/main/java/io/netty/resolver/dns/MultiDnsServerAddressStreamProvider.java
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,56 @@ | ||
| /* | ||
| * Copyright 2017 The Netty Project | ||
| * | ||
| * The Netty Project licenses this file to you 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 io.netty.resolver.dns; | ||
|
|
||
| import io.netty.util.internal.UnstableApi; | ||
|
|
||
| import java.util.List; | ||
|
|
||
| /** | ||
| * A {@link DnsServerAddressStreamProvider} which iterates through a collection of | ||
| * {@link DnsServerAddressStreamProvider} until the first non-{@code null} result is found. | ||
| */ | ||
| @UnstableApi | ||
| public final class MultiDnsServerAddressStreamProvider implements DnsServerAddressStreamProvider { | ||
| private final DnsServerAddressStreamProvider[] providers; | ||
|
|
||
| /** | ||
| * Create a new instance. | ||
| * @param providers The providers to use for DNS resolution. They will be queried in order. | ||
| */ | ||
| public MultiDnsServerAddressStreamProvider(List<DnsServerAddressStreamProvider> providers) { | ||
| this.providers = providers.toArray(new DnsServerAddressStreamProvider[0]); | ||
| } | ||
|
|
||
| /** | ||
| * Create a new instance. | ||
| * @param providers The providers to use for DNS resolution. They will be queried in order. | ||
| */ | ||
| public MultiDnsServerAddressStreamProvider(DnsServerAddressStreamProvider... providers) { | ||
| this.providers = providers.clone(); | ||
| } | ||
|
|
||
| @Override | ||
| public DnsServerAddressStream nameServerAddressStream(String hostname) { | ||
| for (DnsServerAddressStreamProvider provider : providers) { | ||
| DnsServerAddressStream stream = provider.nameServerAddressStream(hostname); | ||
| if (stream != null) { | ||
| return stream; | ||
| } | ||
| } | ||
| return null; | ||
| } | ||
| } |
Oops, something went wrong.