Package io.netty.resolver.dns

Class DnsNameResolver

java.lang.Object

io.netty.resolver.SimpleNameResolver<InetAddress>

io.netty.resolver.InetNameResolver

io.netty.resolver.dns.DnsNameResolver

All Implemented Interfaces:

NameResolver<InetAddress>, Closeable, AutoCloseable

public class DnsNameResolver
extends InetNameResolver

A DNS-based InetNameResolver.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	DnsNameResolver.DnsResolveChannelPerResolutionProvider
private static final class	DnsNameResolver.DnsResolveChannelPerResolverProvider
private static interface	DnsNameResolver.DnsResolveChannelProvider
private static final class	DnsNameResolver.DnsResponseHandler

Field Summary

Fields

Modifier and Type	Field	Description
private final AuthoritativeDnsServerCache	authoritativeDnsServerCache
private final DnsCnameCache	cnameCache
private final boolean	completeOncePreferredResolved
private static final DatagramDnsResponseDecoder	DATAGRAM_DECODER
private static final DatagramDnsQueryEncoder	DATAGRAM_ENCODER
private final boolean	decodeIdn
private static final UnixResolverOptions	DEFAULT_OPTIONS
(package private) static final ResolvedAddressTypes	DEFAULT_RESOLVE_ADDRESS_TYPES
(package private) static final String[]	DEFAULT_SEARCH_DOMAINS
static final AttributeKey<Boolean>	DNS_PIPELINE_ATTRIBUTE	An attribute used to mark all channels created by the DnsNameResolver.
private final DnsQueryLifecycleObserverFactory	dnsQueryLifecycleObserverFactory
private final DnsServerAddressStreamProvider	dnsServerAddressStreamProvider
private static final DnsRecord[]	EMPTY_ADDITIONALS
private final HostsFileEntriesResolver	hostsFileEntriesResolver
private final Map<String,Future<List<InetAddress>>>	inflightLookups
private static final InternetProtocolFamily[]	IPV4_ONLY_RESOLVED_PROTOCOL_FAMILIES
private static final DnsRecordType[]	IPV4_ONLY_RESOLVED_RECORD_TYPES
private static final InternetProtocolFamily[]	IPV4_PREFERRED_RESOLVED_PROTOCOL_FAMILIES
private static final DnsRecordType[]	IPV4_PREFERRED_RESOLVED_RECORD_TYPES
private static final InternetProtocolFamily[]	IPV6_ONLY_RESOLVED_PROTOCOL_FAMILIES
private static final DnsRecordType[]	IPV6_ONLY_RESOLVED_RECORD_TYPES
private static final InternetProtocolFamily[]	IPV6_PREFERRED_RESOLVED_PROTOCOL_FAMILIES
private static final DnsRecordType[]	IPV6_PREFERRED_RESOLVED_RECORD_TYPES
private static final String	LOCALHOST
private static final InetAddress	LOCALHOST_ADDRESS
private static final InternalLogger	logger
private final int	maxNumConsolidation
private final int	maxPayloadSize
private final int	maxQueriesPerResolve
private final Comparator<InetSocketAddress>	nameServerComparator
private final int	ndots
private static final ChannelHandler	NOOP_HANDLER
private final boolean	optResourceEnabled
private final InternetProtocolFamily	preferredAddressType
private final DnsQueryContextManager	queryContextManager	Manages the DnsQueryContexts in progress and their query IDs.
private final DnsServerAddressStream	queryDnsServerAddressStream
private final long	queryTimeoutMillis
private final boolean	recursionDesired
private final DnsCache	resolveCache	Cache for doResolve(String, Promise) and doResolveAll(String, Promise).
private final DnsNameResolver.DnsResolveChannelProvider	resolveChannelProvider
private final ResolvedAddressTypes	resolvedAddressTypes
private final InternetProtocolFamily[]	resolvedInternetProtocolFamilies
private final DnsRecordType[]	resolveRecordTypes
private final boolean	retryWithTcpOnTimeout
private final String[]	searchDomains
private final Bootstrap	socketBootstrap
private final boolean	supportsAAAARecords
private final boolean	supportsARecords
private static final String	WINDOWS_HOST_NAME

Constructor Summary

Constructors

Constructor	Description
DnsNameResolver(EventLoop eventLoop, ChannelFactory<? extends DatagramChannel> channelFactory, ChannelFactory<? extends SocketChannel> socketChannelFactory, boolean retryWithTcpOnTimeout, DnsCache resolveCache, DnsCnameCache cnameCache, AuthoritativeDnsServerCache authoritativeDnsServerCache, SocketAddress localAddress, DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory, long queryTimeoutMillis, ResolvedAddressTypes resolvedAddressTypes, boolean recursionDesired, int maxQueriesPerResolve, boolean traceEnabled, int maxPayloadSize, boolean optResourceEnabled, HostsFileEntriesResolver hostsFileEntriesResolver, DnsServerAddressStreamProvider dnsServerAddressStreamProvider, DnsServerAddressStream queryDnsServerAddressStream, String[] searchDomains, int ndots, boolean decodeIdn, boolean completeOncePreferredResolved, int maxNumConsolidation, DnsNameResolverChannelStrategy datagramChannelStrategy)
DnsNameResolver(EventLoop eventLoop, ChannelFactory<? extends DatagramChannel> channelFactory, DnsCache resolveCache, AuthoritativeDnsServerCache authoritativeDnsServerCache, DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory, long queryTimeoutMillis, ResolvedAddressTypes resolvedAddressTypes, boolean recursionDesired, int maxQueriesPerResolve, boolean traceEnabled, int maxPayloadSize, boolean optResourceEnabled, HostsFileEntriesResolver hostsFileEntriesResolver, DnsServerAddressStreamProvider dnsServerAddressStreamProvider, String[] searchDomains, int ndots, boolean decodeIdn)	Deprecated. Use DnsNameResolverBuilder.
DnsNameResolver(EventLoop eventLoop, ChannelFactory<? extends DatagramChannel> channelFactory, DnsCache resolveCache, DnsCache authoritativeDnsServerCache, DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory, long queryTimeoutMillis, ResolvedAddressTypes resolvedAddressTypes, boolean recursionDesired, int maxQueriesPerResolve, boolean traceEnabled, int maxPayloadSize, boolean optResourceEnabled, HostsFileEntriesResolver hostsFileEntriesResolver, DnsServerAddressStreamProvider dnsServerAddressStreamProvider, String[] searchDomains, int ndots, boolean decodeIdn)	Deprecated. Use DnsNameResolverBuilder.

Method Summary

Modifier and Type	Method	Description
private static boolean	anyInterfaceSupportsIpV6()	Returns true if any NetworkInterface supports IPv6, false otherwise.
AuthoritativeDnsServerCache	authoritativeDnsServerCache()	Returns the cache used for authoritative DNS servers for a domain.
private static Promise<AddressedEnvelope<DnsResponse,InetSocketAddress>>	cast(Promise<?> promise)
void	close()	Closes the internal datagram channel used for sending and receiving DNS messages, and clears all DNS resource records from the cache.
DnsCnameCache	cnameCache()	Returns the DnsCnameCache.
(package private) final DnsQueryLifecycleObserverFactory	dnsQueryLifecycleObserverFactory()
(package private) final Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	doQuery(Channel channel, InetSocketAddress nameServerAddr, DnsQuestion question, DnsQueryLifecycleObserver queryLifecycleObserver, DnsRecord[] additionals, boolean flush, Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)
protected void	doResolve(String inetHost, DnsRecord[] additionals, Promise<InetAddress> promise, DnsCache resolveCache)	Hook designed for extensibility so one can pass a different cache on each resolution attempt instead of using the global one.
protected void	doResolve(String inetHost, Promise<InetAddress> promise)	Invoked by SimpleNameResolver.resolve(String) to perform the actual name resolution.
protected void	doResolveAll(String inetHost, DnsRecord[] additionals, Promise<List<InetAddress>> promise, DnsCache resolveCache)	Hook designed for extensibility so one can pass a different cache on each resolution attempt instead of using the global one.
protected void	doResolveAll(String inetHost, Promise<List<InetAddress>> promise)	Invoked by SimpleNameResolver.resolveAll(String) to perform the actual name resolution.
(package private) static boolean	doResolveAllCached(String hostname, DnsRecord[] additionals, Promise<List<InetAddress>> promise, DnsCache resolveCache, String[] searchDomains, int ndots, InternetProtocolFamily[] resolvedInternetProtocolFamilies)
private void	doResolveAllNow(ChannelFuture f, String hostname, DnsRecord[] additionals, Promise<List<InetAddress>> promise, DnsCache resolveCache)
private void	doResolveAllUncached(Channel channel, String hostname, DnsRecord[] additionals, Promise<?> originalPromise, Promise<List<InetAddress>> promise, DnsCache resolveCache, boolean completeEarlyIfPossible)
private void	doResolveAllUncached0(Channel channel, String hostname, DnsRecord[] additionals, Promise<?> originalPromise, Promise<List<InetAddress>> promise, DnsCache resolveCache, boolean completeEarlyIfPossible)
private boolean	doResolveCached(String hostname, DnsRecord[] additionals, Promise<InetAddress> promise, DnsCache resolveCache)
private void	doResolveNow(ChannelFuture f, String hostname, DnsRecord[] additionals, Promise<InetAddress> promise, DnsCache resolveCache)
private void	doResolveUncached(Channel channel, String hostname, DnsRecord[] additionals, Promise<InetAddress> promise, DnsCache resolveCache, boolean completeEarlyIfPossible)
protected EventLoop	executor()	Returns the EventExecutor which is used to notify the listeners of the Future returned by SimpleNameResolver.resolve(String).
private static List<String>	getSearchDomainsHack()
private static boolean	hasEntries(List<? extends DnsCacheEntry> cachedEntries)
private static String	hostname(String inetHost)
HostsFileEntriesResolver	hostsFileEntriesResolver()	Returns the component that tries to resolve hostnames against the hosts file prior to asking to remotes DNS servers.
(package private) final boolean	isDecodeIdn()
private static boolean	isLocalWindowsHost(String hostname)	Checks whether the given hostname is the localhost/host (computer) name on Windows OS.
boolean	isOptResourceEnabled()	Returns the automatic inclusion of a optional records that tries to give the remote DNS server a hint about how much data the resolver can read per response is enabled.
boolean	isRecursionDesired()	Returns true if and only if this resolver sends a DNS query with the RD (recursion desired) flag set.
static boolean	isTimeoutError(Throwable cause)	Returns true if the Throwable was caused by an timeout.
static boolean	isTransportOrTimeoutError(Throwable cause)	Returns true if the Throwable was caused by an timeout or transport error.
private InetAddress	loopbackAddress()
int	maxPayloadSize()	Returns the capacity of the datagram packet buffer (in bytes).
int	maxQueriesPerResolve()	Returns the maximum allowed number of DNS queries to send when resolving a host name.
(package private) final int	ndots()
(package private) final DnsServerAddressStream	newNameServerAddressStream(String hostname)
private static DnsNameResolver.DnsResolveChannelProvider	newProvider(DnsNameResolverChannelStrategy channelStrategy, Bootstrap bootstrap, SocketAddress localAddress)
protected DnsServerAddressStream	newRedirectDnsServerStream(String hostname, List<InetSocketAddress> nameservers)	Creates a new DnsServerAddressStream to following a redirected DNS query.
(package private) InetSocketAddress	newRedirectServerAddress(InetAddress server)
private InetSocketAddress	nextNameServerAddress()
(package private) final InternetProtocolFamily	preferredAddressType()
(package private) static InternetProtocolFamily	preferredAddressType(ResolvedAddressTypes resolvedAddressTypes)
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(DnsQuestion question)	Sends a DNS query with the specified question.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(DnsQuestion question, Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)	Sends a DNS query with the specified question.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(DnsQuestion question, Iterable<DnsRecord> additionals)	Sends a DNS query with the specified question with additional records.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(InetSocketAddress nameServerAddr, DnsQuestion question)	Sends a DNS query with the specified question using the specified name server list.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(InetSocketAddress nameServerAddr, DnsQuestion question, Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)	Sends a DNS query with the specified question using the specified name server list.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(InetSocketAddress nameServerAddr, DnsQuestion question, Iterable<DnsRecord> additionals)	Sends a DNS query with the specified question with additional records using the specified name server list.
Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>	query(InetSocketAddress nameServerAddr, DnsQuestion question, Iterable<DnsRecord> additionals, Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)	Sends a DNS query with the specified question with additional records using the specified name server list.
DnsServerAddressStream	queryDnsServerAddressStream()	Returns the dns server address stream used for DNS queries (not resolve).
long	queryTimeoutMillis()	Returns the timeout of each DNS query performed by this resolver (in milliseconds).
private static ChannelFuture	registerOrBind(Bootstrap bootstrap, SocketAddress localAddress)
final Future<InetAddress>	resolve(String inetHost, Iterable<DnsRecord> additionals)	Resolves the specified name into an address.
final Future<InetAddress>	resolve(String inetHost, Iterable<DnsRecord> additionals, Promise<InetAddress> promise)	Resolves the specified name into an address.
final Future<List<DnsRecord>>	resolveAll(DnsQuestion question)	Resolves the DnsRecords that are matched by the specified DnsQuestion.
private Future<List<DnsRecord>>	resolveAll(DnsQuestion question, DnsRecord[] additionals, Promise<List<DnsRecord>> promise)
final Future<List<DnsRecord>>	resolveAll(DnsQuestion question, Iterable<DnsRecord> additionals)	Resolves the DnsRecords that are matched by the specified DnsQuestion.
final Future<List<DnsRecord>>	resolveAll(DnsQuestion question, Iterable<DnsRecord> additionals, Promise<List<DnsRecord>> promise)	Resolves the DnsRecords that are matched by the specified DnsQuestion.
final Future<List<InetAddress>>	resolveAll(String inetHost, Iterable<DnsRecord> additionals)	Resolves the specified host name and port into a list of address.
final Future<List<InetAddress>>	resolveAll(String inetHost, Iterable<DnsRecord> additionals, Promise<List<InetAddress>> promise)	Resolves the specified host name and port into a list of address.
private void	resolveAllNow(ChannelFuture f, String hostname, DnsQuestion question, DnsRecord[] additionals, Promise<List<DnsRecord>> promise)
DnsCache	resolveCache()	Returns the resolution cache.
ResolvedAddressTypes	resolvedAddressTypes()	Returns the ResolvedAddressTypes resolved by SimpleNameResolver.resolve(String).
(package private) InternetProtocolFamily[]	resolvedInternetProtocolFamiliesUnsafe()
private List<InetAddress>	resolveHostsFileEntries(String hostname)
private InetAddress	resolveHostsFileEntry(String hostname)
private void	resolveNow(Channel channel, String hostname, DnsRecord[] additionals, Promise<?> originalPromise, Promise<List<InetAddress>> promise, DnsCache resolveCache, boolean completeEarlyIfPossible)
(package private) final DnsRecordType[]	resolveRecordTypes()
(package private) final String[]	searchDomains()
(package private) final boolean	supportsAAAARecords()
(package private) final boolean	supportsARecords()
private static DnsRecord[]	toArray(Iterable<DnsRecord> additionals, boolean validateType)
private static UnknownHostException	toException(ChannelFuture f, String hostname, DnsQuestion question, DnsRecord[] additionals)
private static void	tryFailure(Promise<?> promise, Throwable cause)
(package private) static <T> boolean	trySuccess(Promise<T> promise, T result)
private static void	validateAdditional(DnsRecord record, boolean validateType)

Methods inherited from class io.netty.resolver.InetNameResolver

asAddressResolver

Methods inherited from class io.netty.resolver.SimpleNameResolver

resolve, resolve, resolveAll, resolveAll

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DNS_PIPELINE_ATTRIBUTE

public static final AttributeKey<Boolean> DNS_PIPELINE_ATTRIBUTE

An attribute used to mark all channels created by the DnsNameResolver.

logger

private static final InternalLogger logger

LOCALHOST

private static final String LOCALHOST

See Also:

• Constant Field Values

WINDOWS_HOST_NAME

private static final String WINDOWS_HOST_NAME

LOCALHOST_ADDRESS

private static final InetAddress LOCALHOST_ADDRESS

EMPTY_ADDITIONALS

private static final DnsRecord[] EMPTY_ADDITIONALS

IPV4_ONLY_RESOLVED_RECORD_TYPES

private static final DnsRecordType[] IPV4_ONLY_RESOLVED_RECORD_TYPES

IPV4_ONLY_RESOLVED_PROTOCOL_FAMILIES

private static final InternetProtocolFamily[] IPV4_ONLY_RESOLVED_PROTOCOL_FAMILIES

IPV4_PREFERRED_RESOLVED_RECORD_TYPES

private static final DnsRecordType[] IPV4_PREFERRED_RESOLVED_RECORD_TYPES

IPV4_PREFERRED_RESOLVED_PROTOCOL_FAMILIES

private static final InternetProtocolFamily[] IPV4_PREFERRED_RESOLVED_PROTOCOL_FAMILIES

IPV6_ONLY_RESOLVED_RECORD_TYPES

private static final DnsRecordType[] IPV6_ONLY_RESOLVED_RECORD_TYPES

IPV6_ONLY_RESOLVED_PROTOCOL_FAMILIES

private static final InternetProtocolFamily[] IPV6_ONLY_RESOLVED_PROTOCOL_FAMILIES

IPV6_PREFERRED_RESOLVED_RECORD_TYPES

private static final DnsRecordType[] IPV6_PREFERRED_RESOLVED_RECORD_TYPES

IPV6_PREFERRED_RESOLVED_PROTOCOL_FAMILIES

private static final InternetProtocolFamily[] IPV6_PREFERRED_RESOLVED_PROTOCOL_FAMILIES

NOOP_HANDLER

private static final ChannelHandler NOOP_HANDLER

DEFAULT_RESOLVE_ADDRESS_TYPES

static final ResolvedAddressTypes DEFAULT_RESOLVE_ADDRESS_TYPES

DEFAULT_SEARCH_DOMAINS

static final String[] DEFAULT_SEARCH_DOMAINS

DEFAULT_OPTIONS

private static final UnixResolverOptions DEFAULT_OPTIONS

DATAGRAM_DECODER

private static final DatagramDnsResponseDecoder DATAGRAM_DECODER

DATAGRAM_ENCODER

private static final DatagramDnsQueryEncoder DATAGRAM_ENCODER

nameServerComparator

private final Comparator<InetSocketAddress> nameServerComparator

queryContextManager

private final DnsQueryContextManager queryContextManager

Manages the DnsQueryContexts in progress and their query IDs.

resolveCache

private final DnsCache resolveCache

Cache for doResolve(String, Promise) and doResolveAll(String, Promise).

authoritativeDnsServerCache

private final AuthoritativeDnsServerCache authoritativeDnsServerCache

cnameCache

private final DnsCnameCache cnameCache

queryDnsServerAddressStream

private final DnsServerAddressStream queryDnsServerAddressStream

queryTimeoutMillis

private final long queryTimeoutMillis

maxQueriesPerResolve

private final int maxQueriesPerResolve

resolvedAddressTypes

private final ResolvedAddressTypes resolvedAddressTypes

resolvedInternetProtocolFamilies

private final InternetProtocolFamily[] resolvedInternetProtocolFamilies

recursionDesired

private final boolean recursionDesired

maxPayloadSize

private final int maxPayloadSize

optResourceEnabled

private final boolean optResourceEnabled

hostsFileEntriesResolver

private final HostsFileEntriesResolver hostsFileEntriesResolver

dnsServerAddressStreamProvider

private final DnsServerAddressStreamProvider dnsServerAddressStreamProvider

searchDomains

private final String[] searchDomains

ndots

private final int ndots

supportsAAAARecords

private final boolean supportsAAAARecords

supportsARecords

private final boolean supportsARecords

preferredAddressType

private final InternetProtocolFamily preferredAddressType

resolveRecordTypes

private final DnsRecordType[] resolveRecordTypes

decodeIdn

private final boolean decodeIdn

dnsQueryLifecycleObserverFactory

private final DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory

completeOncePreferredResolved

private final boolean completeOncePreferredResolved

resolveChannelProvider

private final DnsNameResolver.DnsResolveChannelProvider resolveChannelProvider

socketBootstrap

private final Bootstrap socketBootstrap

retryWithTcpOnTimeout

private final boolean retryWithTcpOnTimeout

maxNumConsolidation

private final int maxNumConsolidation

inflightLookups

private final Map<String,Future<List<InetAddress>>> inflightLookups

Constructor Details

DnsNameResolver

@Deprecated
public DnsNameResolver(EventLoop eventLoop,
 ChannelFactory<? extends DatagramChannel> channelFactory,
 DnsCache resolveCache,
 DnsCache authoritativeDnsServerCache,
 DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory,
 long queryTimeoutMillis,
 ResolvedAddressTypes resolvedAddressTypes,
 boolean recursionDesired,
 int maxQueriesPerResolve,
 boolean traceEnabled,
 int maxPayloadSize,
 boolean optResourceEnabled,
 HostsFileEntriesResolver hostsFileEntriesResolver,
 DnsServerAddressStreamProvider dnsServerAddressStreamProvider,
 String[] searchDomains,
 int ndots,
 boolean decodeIdn)

Deprecated.

Use DnsNameResolverBuilder.

Creates a new DNS-based name resolver that communicates with the specified list of DNS servers.

Parameters:

eventLoop - the EventLoop which will perform the communication with the DNS servers

channelFactory - the ChannelFactory that will create a DatagramChannel

resolveCache - the DNS resolved entries cache

authoritativeDnsServerCache - the cache used to find the authoritative DNS server for a domain

dnsQueryLifecycleObserverFactory - used to generate new instances of DnsQueryLifecycleObserver which can be used to track metrics for DNS servers.

queryTimeoutMillis - timeout of each DNS query in millis. 0 disables the timeout. If not set or a negative number is set, the default timeout is used.

resolvedAddressTypes - the preferred address types

recursionDesired - if recursion desired flag must be set

maxQueriesPerResolve - the maximum allowed number of DNS queries for a given name resolution

traceEnabled - if trace is enabled

maxPayloadSize - the capacity of the datagram packet buffer

optResourceEnabled - if automatic inclusion of a optional records is enabled

hostsFileEntriesResolver - the HostsFileEntriesResolver used to check for local aliases

dnsServerAddressStreamProvider - The DnsServerAddressStreamProvider used to determine the name servers for each hostname lookup.

searchDomains - the list of search domain (can be null, if so, will try to default to the underlying platform ones)

ndots - the ndots value

decodeIdn - true if domain / host names should be decoded to unicode when received. See rfc3492.

DnsNameResolver

@Deprecated
public DnsNameResolver(EventLoop eventLoop,
 ChannelFactory<? extends DatagramChannel> channelFactory,
 DnsCache resolveCache,
 AuthoritativeDnsServerCache authoritativeDnsServerCache,
 DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory,
 long queryTimeoutMillis,
 ResolvedAddressTypes resolvedAddressTypes,
 boolean recursionDesired,
 int maxQueriesPerResolve,
 boolean traceEnabled,
 int maxPayloadSize,
 boolean optResourceEnabled,
 HostsFileEntriesResolver hostsFileEntriesResolver,
 DnsServerAddressStreamProvider dnsServerAddressStreamProvider,
 String[] searchDomains,
 int ndots,
 boolean decodeIdn)

Deprecated.

Use DnsNameResolverBuilder.

Creates a new DNS-based name resolver that communicates with the specified list of DNS servers.

Parameters:

eventLoop - the EventLoop which will perform the communication with the DNS servers

channelFactory - the ChannelFactory that will create a DatagramChannel

resolveCache - the DNS resolved entries cache

authoritativeDnsServerCache - the cache used to find the authoritative DNS server for a domain

dnsQueryLifecycleObserverFactory - used to generate new instances of DnsQueryLifecycleObserver which can be used to track metrics for DNS servers.

queryTimeoutMillis - timeout of each DNS query in millis. 0 disables the timeout. If not set or a negative number is set, the default timeout is used.

resolvedAddressTypes - the preferred address types

recursionDesired - if recursion desired flag must be set

maxQueriesPerResolve - the maximum allowed number of DNS queries for a given name resolution

traceEnabled - if trace is enabled

maxPayloadSize - the capacity of the datagram packet buffer

optResourceEnabled - if automatic inclusion of a optional records is enabled

hostsFileEntriesResolver - the HostsFileEntriesResolver used to check for local aliases

dnsServerAddressStreamProvider - The DnsServerAddressStreamProvider used to determine the name servers for each hostname lookup.

searchDomains - the list of search domain (can be null, if so, will try to default to the underlying platform ones)

ndots - the ndots value

decodeIdn - true if domain / host names should be decoded to unicode when received. See rfc3492.

DnsNameResolver

DnsNameResolver(EventLoop eventLoop,
 ChannelFactory<? extends DatagramChannel> channelFactory,
 ChannelFactory<? extends SocketChannel> socketChannelFactory,
 boolean retryWithTcpOnTimeout,
 DnsCache resolveCache,
 DnsCnameCache cnameCache,
 AuthoritativeDnsServerCache authoritativeDnsServerCache,
 SocketAddress localAddress,
 DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory,
 long queryTimeoutMillis,
 ResolvedAddressTypes resolvedAddressTypes,
 boolean recursionDesired,
 int maxQueriesPerResolve,
 boolean traceEnabled,
 int maxPayloadSize,
 boolean optResourceEnabled,
 HostsFileEntriesResolver hostsFileEntriesResolver,
 DnsServerAddressStreamProvider dnsServerAddressStreamProvider,
 DnsServerAddressStream queryDnsServerAddressStream,
 String[] searchDomains,
 int ndots,
 boolean decodeIdn,
 boolean completeOncePreferredResolved,
 int maxNumConsolidation,
 DnsNameResolverChannelStrategy datagramChannelStrategy)

Method Details

anyInterfaceSupportsIpV6

private static boolean anyInterfaceSupportsIpV6()

Returns true if any NetworkInterface supports IPv6, false otherwise.

getSearchDomainsHack

private static List<String> getSearchDomainsHack()
                                          throws Exception

Throws:

Exception

newProvider

private static DnsNameResolver.DnsResolveChannelProvider newProvider(DnsNameResolverChannelStrategy channelStrategy,
 Bootstrap bootstrap,
 SocketAddress localAddress)

preferredAddressType

static InternetProtocolFamily preferredAddressType(ResolvedAddressTypes resolvedAddressTypes)

newRedirectServerAddress

InetSocketAddress newRedirectServerAddress(InetAddress server)

dnsQueryLifecycleObserverFactory

final DnsQueryLifecycleObserverFactory dnsQueryLifecycleObserverFactory()

newRedirectDnsServerStream

protected DnsServerAddressStream newRedirectDnsServerStream(String hostname,
 List<InetSocketAddress> nameservers)

Creates a new DnsServerAddressStream to following a redirected DNS query. By overriding this it provides the opportunity to sort the name servers before following a redirected DNS query.

Parameters:

hostname - the hostname.

nameservers - The addresses of the DNS servers which are used in the event of a redirect. This may contain resolved and unresolved addresses so the used DnsServerAddressStream must allow unresolved addresses if you want to include these as well.

Returns:

A DnsServerAddressStream which will be used to follow the DNS redirect or null if none should be followed.

resolveCache

public DnsCache resolveCache()

Returns the resolution cache.

cnameCache

public DnsCnameCache cnameCache()

Returns the DnsCnameCache.

authoritativeDnsServerCache

public AuthoritativeDnsServerCache authoritativeDnsServerCache()

Returns the cache used for authoritative DNS servers for a domain.

queryTimeoutMillis

public long queryTimeoutMillis()

Returns the timeout of each DNS query performed by this resolver (in milliseconds). The default value is 5 seconds.

queryDnsServerAddressStream

public DnsServerAddressStream queryDnsServerAddressStream()

Returns the dns server address stream used for DNS queries (not resolve).

resolvedAddressTypes

public ResolvedAddressTypes resolvedAddressTypes()

Returns the ResolvedAddressTypes resolved by SimpleNameResolver.resolve(String). The default value depends on the value of the system property "java.net.preferIPv6Addresses".

resolvedInternetProtocolFamiliesUnsafe

InternetProtocolFamily[] resolvedInternetProtocolFamiliesUnsafe()

searchDomains

final String[] searchDomains()

ndots

final int ndots()

supportsAAAARecords

final boolean supportsAAAARecords()

supportsARecords

final boolean supportsARecords()

preferredAddressType

final InternetProtocolFamily preferredAddressType()

resolveRecordTypes

final DnsRecordType[] resolveRecordTypes()

isDecodeIdn

final boolean isDecodeIdn()

isRecursionDesired

public boolean isRecursionDesired()

Returns true if and only if this resolver sends a DNS query with the RD (recursion desired) flag set. The default value is true.

maxQueriesPerResolve

public int maxQueriesPerResolve()

Returns the maximum allowed number of DNS queries to send when resolving a host name. The default value is 8.

maxPayloadSize

public int maxPayloadSize()

Returns the capacity of the datagram packet buffer (in bytes). The default value is 4096 bytes.

isOptResourceEnabled

public boolean isOptResourceEnabled()

Returns the automatic inclusion of a optional records that tries to give the remote DNS server a hint about how much data the resolver can read per response is enabled.

hostsFileEntriesResolver

public HostsFileEntriesResolver hostsFileEntriesResolver()

Returns the component that tries to resolve hostnames against the hosts file prior to asking to remotes DNS servers.

close

public void close()

Closes the internal datagram channel used for sending and receiving DNS messages, and clears all DNS resource records from the cache. Attempting to send a DNS query or to resolve a domain name will fail once this method has been called.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface NameResolver<InetAddress>

Overrides:

close in class SimpleNameResolver<InetAddress>

executor

protected EventLoop executor()

Description copied from class: SimpleNameResolver

Returns the EventExecutor which is used to notify the listeners of the Future returned by SimpleNameResolver.resolve(String).

Overrides:

executor in class SimpleNameResolver<InetAddress>

resolveHostsFileEntry

private InetAddress resolveHostsFileEntry(String hostname)

resolveHostsFileEntries

private List<InetAddress> resolveHostsFileEntries(String hostname)

isLocalWindowsHost

private static boolean isLocalWindowsHost(String hostname)

Checks whether the given hostname is the localhost/host (computer) name on Windows OS. Windows OS removed the localhost/host (computer) name information from the hosts file in the later versions and such hostname cannot be resolved from hosts file. See https://github.com/netty/netty/issues/5386 See https://github.com/netty/netty/issues/11142

resolve

public final Future<InetAddress> resolve(String inetHost,
 Iterable<DnsRecord> additionals)

Resolves the specified name into an address.

Parameters:

inetHost - the name to resolve

additionals - additional records (OPT)

Returns:

the address as the result of the resolution

resolve

public final Future<InetAddress> resolve(String inetHost,
 Iterable<DnsRecord> additionals,
 Promise<InetAddress> promise)

Resolves the specified name into an address.

Parameters:

inetHost - the name to resolve

additionals - additional records (OPT)

promise - the Promise which will be fulfilled when the name resolution is finished

Returns:

the address as the result of the resolution

resolveAll

public final Future<List<InetAddress>> resolveAll(String inetHost,
 Iterable<DnsRecord> additionals)

Resolves the specified host name and port into a list of address.

Parameters:

inetHost - the name to resolve

additionals - additional records (OPT)

Returns:

the list of the address as the result of the resolution

resolveAll

public final Future<List<InetAddress>> resolveAll(String inetHost,
 Iterable<DnsRecord> additionals,
 Promise<List<InetAddress>> promise)

Resolves the specified host name and port into a list of address.

Parameters:

inetHost - the name to resolve

additionals - additional records (OPT)

promise - the Promise which will be fulfilled when the name resolution is finished

Returns:

the list of the address as the result of the resolution

doResolve

protected void doResolve(String inetHost,
 Promise<InetAddress> promise)
                  throws Exception

Description copied from class: SimpleNameResolver

Invoked by SimpleNameResolver.resolve(String) to perform the actual name resolution.

Specified by:

doResolve in class SimpleNameResolver<InetAddress>

Throws:

Exception

resolveAll

public final Future<List<DnsRecord>> resolveAll(DnsQuestion question)

Resolves the DnsRecords that are matched by the specified DnsQuestion. Unlike query(DnsQuestion), this method handles redirection, CNAMEs and multiple name servers. If the specified DnsQuestion is A or AAAA, this method looks up the configured HostsFileEntries before sending a query to the name servers. If a match is found in the HostsFileEntries, a synthetic A or AAAA record will be returned.

Parameters:

question - the question

Returns:

the list of the DnsRecords as the result of the resolution

resolveAll

public final Future<List<DnsRecord>> resolveAll(DnsQuestion question,
 Iterable<DnsRecord> additionals)

Resolves the DnsRecords that are matched by the specified DnsQuestion. Unlike query(DnsQuestion), this method handles redirection, CNAMEs and multiple name servers. If the specified DnsQuestion is A or AAAA, this method looks up the configured HostsFileEntries before sending a query to the name servers. If a match is found in the HostsFileEntries, a synthetic A or AAAA record will be returned.

Parameters:

question - the question

additionals - additional records (OPT)

Returns:

the list of the DnsRecords as the result of the resolution

resolveAll

public final Future<List<DnsRecord>> resolveAll(DnsQuestion question,
 Iterable<DnsRecord> additionals,
 Promise<List<DnsRecord>> promise)

Resolves the DnsRecords that are matched by the specified DnsQuestion. Unlike query(DnsQuestion), this method handles redirection, CNAMEs and multiple name servers. If the specified DnsQuestion is A or AAAA, this method looks up the configured HostsFileEntries before sending a query to the name servers. If a match is found in the HostsFileEntries, a synthetic A or AAAA record will be returned.

Parameters:

question - the question

additionals - additional records (OPT)

promise - the Promise which will be fulfilled when the resolution is finished

Returns:

the list of the DnsRecords as the result of the resolution

resolveAll

private Future<List<DnsRecord>> resolveAll(DnsQuestion question,
 DnsRecord[] additionals,
 Promise<List<DnsRecord>> promise)

resolveAllNow

private void resolveAllNow(ChannelFuture f,
 String hostname,
 DnsQuestion question,
 DnsRecord[] additionals,
 Promise<List<DnsRecord>> promise)

toException

private static UnknownHostException toException(ChannelFuture f,
 String hostname,
 DnsQuestion question,
 DnsRecord[] additionals)

toArray

private static DnsRecord[] toArray(Iterable<DnsRecord> additionals,
 boolean validateType)

validateAdditional

private static void validateAdditional(DnsRecord record,
 boolean validateType)

loopbackAddress

private InetAddress loopbackAddress()

doResolve

protected void doResolve(String inetHost,
 DnsRecord[] additionals,
 Promise<InetAddress> promise,
 DnsCache resolveCache)
                  throws Exception

Hook designed for extensibility so one can pass a different cache on each resolution attempt instead of using the global one.

Throws:

Exception

doResolveNow

private void doResolveNow(ChannelFuture f,
 String hostname,
 DnsRecord[] additionals,
 Promise<InetAddress> promise,
 DnsCache resolveCache)

doResolveCached

private boolean doResolveCached(String hostname,
 DnsRecord[] additionals,
 Promise<InetAddress> promise,
 DnsCache resolveCache)

trySuccess

static <T> boolean trySuccess(Promise<T> promise,
 T result)

tryFailure

private static void tryFailure(Promise<?> promise,
 Throwable cause)

doResolveUncached

private void doResolveUncached(Channel channel,
 String hostname,
 DnsRecord[] additionals,
 Promise<InetAddress> promise,
 DnsCache resolveCache,
 boolean completeEarlyIfPossible)

doResolveAll

protected void doResolveAll(String inetHost,
 Promise<List<InetAddress>> promise)
                     throws Exception

Description copied from class: SimpleNameResolver

Invoked by SimpleNameResolver.resolveAll(String) to perform the actual name resolution.

Specified by:

doResolveAll in class SimpleNameResolver<InetAddress>

Throws:

Exception

doResolveAll

protected void doResolveAll(String inetHost,
 DnsRecord[] additionals,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache)
                     throws Exception

Hook designed for extensibility so one can pass a different cache on each resolution attempt instead of using the global one.

Throws:

Exception

doResolveAllNow

private void doResolveAllNow(ChannelFuture f,
 String hostname,
 DnsRecord[] additionals,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache)

hasEntries

private static boolean hasEntries(List<? extends DnsCacheEntry> cachedEntries)

doResolveAllCached

static boolean doResolveAllCached(String hostname,
 DnsRecord[] additionals,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache,
 String[] searchDomains,
 int ndots,
 InternetProtocolFamily[] resolvedInternetProtocolFamilies)

doResolveAllUncached

private void doResolveAllUncached(Channel channel,
 String hostname,
 DnsRecord[] additionals,
 Promise<?> originalPromise,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache,
 boolean completeEarlyIfPossible)

doResolveAllUncached0

private void doResolveAllUncached0(Channel channel,
 String hostname,
 DnsRecord[] additionals,
 Promise<?> originalPromise,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache,
 boolean completeEarlyIfPossible)

resolveNow

private void resolveNow(Channel channel,
 String hostname,
 DnsRecord[] additionals,
 Promise<?> originalPromise,
 Promise<List<InetAddress>> promise,
 DnsCache resolveCache,
 boolean completeEarlyIfPossible)

hostname

private static String hostname(String inetHost)

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(DnsQuestion question)

Sends a DNS query with the specified question.

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(DnsQuestion question,
 Iterable<DnsRecord> additionals)

Sends a DNS query with the specified question with additional records.

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(DnsQuestion question,
 Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)

Sends a DNS query with the specified question.

nextNameServerAddress

private InetSocketAddress nextNameServerAddress()

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(InetSocketAddress nameServerAddr,
 DnsQuestion question)

Sends a DNS query with the specified question using the specified name server list.

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(InetSocketAddress nameServerAddr,
 DnsQuestion question,
 Iterable<DnsRecord> additionals)

Sends a DNS query with the specified question with additional records using the specified name server list.

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(InetSocketAddress nameServerAddr,
 DnsQuestion question,
 Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)

Sends a DNS query with the specified question using the specified name server list.

query

public Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> query(InetSocketAddress nameServerAddr,
 DnsQuestion question,
 Iterable<DnsRecord> additionals,
 Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)

Sends a DNS query with the specified question with additional records using the specified name server list.

isTransportOrTimeoutError

public static boolean isTransportOrTimeoutError(Throwable cause)

Returns true if the Throwable was caused by an timeout or transport error. These methods can be used on the Future.cause() that is returned by the various methods exposed by this DnsNameResolver.

isTimeoutError

public static boolean isTimeoutError(Throwable cause)

Returns true if the Throwable was caused by an timeout. These methods can be used on the Future.cause() that is returned by the various methods exposed by this DnsNameResolver.

doQuery

final Future<AddressedEnvelope<DnsResponse,InetSocketAddress>> doQuery(Channel channel,
 InetSocketAddress nameServerAddr,
 DnsQuestion question,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 DnsRecord[] additionals,
 boolean flush,
 Promise<AddressedEnvelope<? extends DnsResponse,InetSocketAddress>> promise)

cast

private static Promise<AddressedEnvelope<DnsResponse,InetSocketAddress>> cast(Promise<?> promise)

newNameServerAddressStream

final DnsServerAddressStream newNameServerAddressStream(String hostname)

registerOrBind

private static ChannelFuture registerOrBind(Bootstrap bootstrap,
 SocketAddress localAddress)