Package io.netty.resolver.dns

Class DnsResolveContext<T>

java.lang.Object

io.netty.resolver.dns.DnsResolveContext<T>

Direct Known Subclasses:

DnsAddressResolveContext, DnsRecordResolveContext

abstract class DnsResolveContext<T>
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static final class	DnsResolveContext.AuthoritativeNameServer
private static final class	DnsResolveContext.AuthoritativeNameServerList	Holds the closed DNS Servers for a domain.
private final class	DnsResolveContext.CombinedDnsServerAddressStream
private static final class	DnsResolveContext.DnsAddressStreamList
(package private) static final class	DnsResolveContext.DnsResolveContextException
private static final class	DnsResolveContext.RedirectAuthoritativeDnsServerCache
private static final class	DnsResolveContext.SearchDomainUnknownHostException

Field Summary

Fields

Modifier and Type	Field	Description
(package private) final DnsRecord[]	additionals
private int	allowedQueries
private final Channel	channel
private static final RuntimeException	CNAME_NOT_FOUND_QUERY_FAILED_EXCEPTION
private boolean	completeEarly
private final int	dnsClass
private final DnsRecordType[]	expectedTypes
private List<T>	finalResult
private final String	hostname
private static final InternalLogger	logger
private static final RuntimeException	NAME_SERVERS_EXHAUSTED_EXCEPTION
private final DnsServerAddressStream	nameServerAddrs
private static final RuntimeException	NO_MATCHING_RECORD_QUERY_FAILED_EXCEPTION
private static final RuntimeException	NXDOMAIN_CAUSE_QUERY_FAILED_EXCEPTION
private static final RuntimeException	NXDOMAIN_QUERY_FAILED_EXCEPTION
private final Promise<?>	originalPromise
(package private) final DnsNameResolver	parent
private static final String	PROP_TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS
private final Set<Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>>	queriesInProgress
private static final RuntimeException	SERVFAIL_QUERY_FAILED_EXCEPTION
private boolean	triedCNAME
(package private) static boolean	TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS
private static final RuntimeException	UNRECOGNIZED_TYPE_QUERY_FAILED_EXCEPTION

Constructor Summary

Constructors

Constructor	Description
DnsResolveContext(DnsNameResolver parent, Channel channel, Promise<?> originalPromise, String hostname, int dnsClass, DnsRecordType[] expectedTypes, DnsRecord[] additionals, DnsServerAddressStream nameServerAddrs, int allowedQueries)

Method Summary

Modifier and Type	Method	Description
(package private) AuthoritativeDnsServerCache	authoritativeDnsServerCache()	The AuthoritativeDnsServerCache to use while resolving.
private static Map<String,String>	buildAliasMap(DnsResponse response, DnsCnameCache cache, EventLoop loop)
(package private) abstract void	cache(String hostname, DnsRecord[] additionals, DnsRecord result, T convertedResult)	Caches a successful resolution.
(package private) abstract void	cache(String hostname, DnsRecord[] additionals, UnknownHostException cause)	Caches a failed resolution.
private static Throwable	cause(DnsResponseCode code)
(package private) Channel	channel()	The Channel used.
private static void	checkCnameLoop(String hostname, String first, String second)
(package private) DnsCnameCache	cnameCache()	The DnsCnameCache that is used for resolving.
(package private) static String	cnameResolveFromCache(DnsCnameCache cnameCache, String name)
private static String	cnameResolveFromCacheLoop(DnsCnameCache cnameCache, String hostname, String first, String mapping)
(package private) abstract T	convertRecord(DnsRecord record, String hostname, DnsRecord[] additionals, EventLoop eventLoop)	Converts the given DnsRecord into T.
(package private) static String	decodeDomainName(ByteBuf in)
(package private) void	doSearchDomainQuery(String hostname, Promise<List<T>> nextPromise)
private static DnsResolveContext.AuthoritativeNameServerList	extractAuthoritativeNameServers(String questionName, DnsResponse res)	Returns the invalid input: '{@code {@link AuthoritativeNameServerList} which were included in {@link DnsSection#AUTHORITY} or {@code null} if non are found.'
(package private) abstract List<T>	filterResults(List<T> unfiltered)	Returns a filtered list of results which should be the final result of DNS resolution.
private void	finishResolve(Promise<List<T>> promise, Throwable cause)
private void	followCname(DnsQuestion question, String cname, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise)
private DnsServerAddressStream	getNameServers(String name)
private DnsServerAddressStream	getNameServersFromCache(String hostname)	Returns the DnsServerAddressStream that was cached for the given hostname or null if non could be found.
private boolean	handleRedirect(DnsQuestion question, AddressedEnvelope<DnsResponse,InetSocketAddress> envelope, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise)	Handles a redirect answer if needed and returns true if a redirect query has been made.
private boolean	hasNDots()
private static String	hostnameWithDot(String name)
private void	internalResolve(String name, Promise<List<T>> promise)
(package private) abstract boolean	isCompleteEarly(T resolved)
(package private) abstract boolean	isDuplicateAllowed()	Returns true if we should allow duplicates in the result or false if no duplicates should be included.
private DnsQueryLifecycleObserver	newDnsQueryLifecycleObserver(DnsQuestion question)
(package private) abstract DnsResolveContext<T>	newResolverContext(DnsNameResolver parent, Channel channel, Promise<?> originalPromise, String hostname, int dnsClass, DnsRecordType[] expectedTypes, DnsRecord[] additionals, DnsServerAddressStream nameServerAddrs, int allowedQueries)	Creates a new context with the given parameters.
private void	onExpectedResponse(DnsQuestion question, AddressedEnvelope<DnsResponse,InetSocketAddress> envelope, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise)
private void	onResponse(DnsServerAddressStream nameServerAddrStream, int nameServerAddrStreamIndex, DnsQuestion question, AddressedEnvelope<DnsResponse,InetSocketAddress> envelope, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise)
private void	onResponseCNAME(DnsQuestion question, Map<String,String> cnames, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise)
private void	query(DnsServerAddressStream nameServerAddrStream, int nameServerAddrStreamIndex, DnsQuestion question, DnsQueryLifecycleObserver queryLifecycleObserver, boolean flush, Promise<List<T>> promise, Throwable cause)
private boolean	query(String hostname, DnsRecordType type, DnsServerAddressStream dnsServerAddressStream, boolean flush, Promise<List<T>> promise)
private void	queryUnresolvedNameServer(InetSocketAddress nameServerAddr, DnsServerAddressStream nameServerAddrStream, int nameServerAddrStreamIndex, DnsQuestion question, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise, Throwable cause)
private static AuthoritativeDnsServerCache	redirectAuthoritativeDnsServerCache(AuthoritativeDnsServerCache authoritativeDnsServerCache)
(package private) void	resolve(Promise<List<T>> promise)
(package private) DnsCache	resolveCache()	The DnsCache to use while resolving.
private void	tryToFinishResolve(DnsServerAddressStream nameServerAddrStream, int nameServerAddrStreamIndex, DnsQuestion question, DnsQueryLifecycleObserver queryLifecycleObserver, Promise<List<T>> promise, Throwable cause)

Methods inherited from class java.lang.Object

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

Field Details

logger

private static final InternalLogger logger

PROP_TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS

private static final String PROP_TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS

See Also:

• Constant Field Values

TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS

static boolean TRY_FINAL_CNAME_ON_ADDRESS_LOOKUPS

NXDOMAIN_QUERY_FAILED_EXCEPTION

private static final RuntimeException NXDOMAIN_QUERY_FAILED_EXCEPTION

CNAME_NOT_FOUND_QUERY_FAILED_EXCEPTION

private static final RuntimeException CNAME_NOT_FOUND_QUERY_FAILED_EXCEPTION

NO_MATCHING_RECORD_QUERY_FAILED_EXCEPTION

private static final RuntimeException NO_MATCHING_RECORD_QUERY_FAILED_EXCEPTION

UNRECOGNIZED_TYPE_QUERY_FAILED_EXCEPTION

private static final RuntimeException UNRECOGNIZED_TYPE_QUERY_FAILED_EXCEPTION

NAME_SERVERS_EXHAUSTED_EXCEPTION

private static final RuntimeException NAME_SERVERS_EXHAUSTED_EXCEPTION

SERVFAIL_QUERY_FAILED_EXCEPTION

private static final RuntimeException SERVFAIL_QUERY_FAILED_EXCEPTION

NXDOMAIN_CAUSE_QUERY_FAILED_EXCEPTION

private static final RuntimeException NXDOMAIN_CAUSE_QUERY_FAILED_EXCEPTION

parent

final DnsNameResolver parent

channel

private final Channel channel

originalPromise

private final Promise<?> originalPromise

nameServerAddrs

private final DnsServerAddressStream nameServerAddrs

hostname

private final String hostname

dnsClass

private final int dnsClass

expectedTypes

private final DnsRecordType[] expectedTypes

additionals

final DnsRecord[] additionals

queriesInProgress

private final Set<Future<AddressedEnvelope<DnsResponse,InetSocketAddress>>> queriesInProgress

finalResult

private List<T> finalResult

allowedQueries

private int allowedQueries

triedCNAME

private boolean triedCNAME

completeEarly

private boolean completeEarly

Constructor Details

DnsResolveContext

DnsResolveContext(DnsNameResolver parent,
 Channel channel,
 Promise<?> originalPromise,
 String hostname,
 int dnsClass,
 DnsRecordType[] expectedTypes,
 DnsRecord[] additionals,
 DnsServerAddressStream nameServerAddrs,
 int allowedQueries)

Method Details

channel

Channel channel()

The Channel used.

resolveCache

DnsCache resolveCache()

The DnsCache to use while resolving.

cnameCache

DnsCnameCache cnameCache()

The DnsCnameCache that is used for resolving.

authoritativeDnsServerCache

AuthoritativeDnsServerCache authoritativeDnsServerCache()

The AuthoritativeDnsServerCache to use while resolving.

newResolverContext

abstract DnsResolveContext<T> newResolverContext(DnsNameResolver parent,
 Channel channel,
 Promise<?> originalPromise,
 String hostname,
 int dnsClass,
 DnsRecordType[] expectedTypes,
 DnsRecord[] additionals,
 DnsServerAddressStream nameServerAddrs,
 int allowedQueries)

Creates a new context with the given parameters.

convertRecord

abstract T convertRecord(DnsRecord record,
 String hostname,
 DnsRecord[] additionals,
 EventLoop eventLoop)

Converts the given DnsRecord into T.

filterResults

abstract List<T> filterResults(List<T> unfiltered)

Returns a filtered list of results which should be the final result of DNS resolution. This must take into account JDK semantics such as NetUtil.isIpV6AddressesPreferred().

isCompleteEarly

abstract boolean isCompleteEarly(T resolved)

isDuplicateAllowed

abstract boolean isDuplicateAllowed()

Returns true if we should allow duplicates in the result or false if no duplicates should be included.

cache

abstract void cache(String hostname,
 DnsRecord[] additionals,
 DnsRecord result,
 T convertedResult)

Caches a successful resolution.

cache

abstract void cache(String hostname,
 DnsRecord[] additionals,
 UnknownHostException cause)

Caches a failed resolution.

resolve

void resolve(Promise<List<T>> promise)

hasNDots

private boolean hasNDots()

doSearchDomainQuery

void doSearchDomainQuery(String hostname,
 Promise<List<T>> nextPromise)

hostnameWithDot

private static String hostnameWithDot(String name)

cnameResolveFromCache

static String cnameResolveFromCache(DnsCnameCache cnameCache,
 String name)
                             throws UnknownHostException

Throws:

UnknownHostException

cnameResolveFromCacheLoop

private static String cnameResolveFromCacheLoop(DnsCnameCache cnameCache,
 String hostname,
 String first,
 String mapping)
                                         throws UnknownHostException

Throws:

UnknownHostException

checkCnameLoop

private static void checkCnameLoop(String hostname,
 String first,
 String second)
                            throws UnknownHostException

Throws:

UnknownHostException

internalResolve

private void internalResolve(String name,
 Promise<List<T>> promise)

getNameServersFromCache

private DnsServerAddressStream getNameServersFromCache(String hostname)

Returns the DnsServerAddressStream that was cached for the given hostname or null if non could be found.

query

private void query(DnsServerAddressStream nameServerAddrStream,
 int nameServerAddrStreamIndex,
 DnsQuestion question,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 boolean flush,
 Promise<List<T>> promise,
 Throwable cause)

queryUnresolvedNameServer

private void queryUnresolvedNameServer(InetSocketAddress nameServerAddr,
 DnsServerAddressStream nameServerAddrStream,
 int nameServerAddrStreamIndex,
 DnsQuestion question,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise,
 Throwable cause)

redirectAuthoritativeDnsServerCache

private static AuthoritativeDnsServerCache redirectAuthoritativeDnsServerCache(AuthoritativeDnsServerCache authoritativeDnsServerCache)

onResponse

private void onResponse(DnsServerAddressStream nameServerAddrStream,
 int nameServerAddrStreamIndex,
 DnsQuestion question,
 AddressedEnvelope<DnsResponse,InetSocketAddress> envelope,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise)

handleRedirect

private boolean handleRedirect(DnsQuestion question,
 AddressedEnvelope<DnsResponse,InetSocketAddress> envelope,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise)

Handles a redirect answer if needed and returns true if a redirect query has been made.

cause

private static Throwable cause(DnsResponseCode code)

extractAuthoritativeNameServers

private static DnsResolveContext.AuthoritativeNameServerList extractAuthoritativeNameServers(String questionName,
 DnsResponse res)

Returns the invalid input: '{@code {@link AuthoritativeNameServerList} which were included in {@link DnsSection#AUTHORITY} or {@code null} if non are found.'

onExpectedResponse

private void onExpectedResponse(DnsQuestion question,
 AddressedEnvelope<DnsResponse,InetSocketAddress> envelope,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise)

onResponseCNAME

private void onResponseCNAME(DnsQuestion question,
 Map<String,String> cnames,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise)

buildAliasMap

private static Map<String,String> buildAliasMap(DnsResponse response,
 DnsCnameCache cache,
 EventLoop loop)

tryToFinishResolve

private void tryToFinishResolve(DnsServerAddressStream nameServerAddrStream,
 int nameServerAddrStreamIndex,
 DnsQuestion question,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise,
 Throwable cause)

finishResolve

private void finishResolve(Promise<List<T>> promise,
 Throwable cause)

decodeDomainName

static String decodeDomainName(ByteBuf in)

getNameServers

private DnsServerAddressStream getNameServers(String name)

followCname

private void followCname(DnsQuestion question,
 String cname,
 DnsQueryLifecycleObserver queryLifecycleObserver,
 Promise<List<T>> promise)

query

private boolean query(String hostname,
 DnsRecordType type,
 DnsServerAddressStream dnsServerAddressStream,
 boolean flush,
 Promise<List<T>> promise)

newDnsQueryLifecycleObserver

private DnsQueryLifecycleObserver newDnsQueryLifecycleObserver(DnsQuestion question)