io.netty.handler.codec.dns

Class DnsResponseHeader

java.lang.Object

io.netty.handler.codec.dns.DnsHeader

io.netty.handler.codec.dns.DnsResponseHeader

public final class DnsResponseHeader
extends DnsHeader

The DNS response header class which is used when receiving data from a DNS server. Contains information contained in a DNS response header, such as recursion availability, and response codes.

Field Summary

Fields inherited from class io.netty.handler.codec.dns.DnsHeader

OPCODE_IQUERY, OPCODE_QUERY, TYPE_QUERY, TYPE_RESPONSE

Constructor Summary

Constructors

Constructor and Description
DnsResponseHeader(DnsMessage parent, int id) Constructor for a DNS packet response header.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isAuthoritativeAnswer() Returns true if responding server is authoritative for the domain name in the query message.
boolean	isRecursionAvailable() Returns true if DNS server can handle recursive queries.
boolean	isTruncated() Returns true if response has been truncated, usually if it is over 512 bytes.
DnsResponseCode	responseCode() Returns the 4 bit return code.
DnsResponseHeader	setAuthoritativeAnswer(boolean authoritativeAnswer) Set to true if responding server is authoritative for the domain name in the query message.
DnsResponseHeader	setId(int id) Sets the id for this DnsMessage.
DnsResponseHeader	setOpcode(int opcode) Sets the opcode for this DnsMessage.
DnsResponseHeader	setRecursionAvailable(boolean recursionAvailable) Set to true if DNS server can handle recursive queries.
DnsHeader	setRecursionDesired(boolean recursionDesired) Sets whether a name server is directed to pursue a query recursively or not.
DnsResponseHeader	setResponseCode(DnsResponseCode responseCode) Sets the response code for this message.
DnsResponseHeader	setTruncated(boolean truncated) Set to true if response has been truncated (usually happens for responses over 512 bytes).
DnsResponseHeader	setType(int type) Sets the DnsHeader type.
DnsResponseHeader	setZ(int z) Sets the field Z.
int	type() Returns the DnsMessage type.

Methods inherited from class io.netty.handler.codec.dns.DnsHeader

additionalResourceCount, answerCount, authorityResourceCount, id, isRecursionDesired, opcode, questionCount, z

Methods inherited from class java.lang.Object

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

Constructor Detail

DnsResponseHeader

public DnsResponseHeader(DnsMessage parent,
                 int id)

Constructor for a DNS packet response header. The id is received by reading a DnsQuery and is sent back to the client.

Parameters:

parent - the DnsMessage this header belongs to

id - a 2 bit unsigned identification number received from client

Method Detail

isAuthoritativeAnswer

public boolean isAuthoritativeAnswer()

Returns true if responding server is authoritative for the domain name in the query message.

isTruncated

public boolean isTruncated()

Returns true if response has been truncated, usually if it is over 512 bytes.

isRecursionAvailable

public boolean isRecursionAvailable()

Returns true if DNS server can handle recursive queries.

responseCode

public DnsResponseCode responseCode()

Returns the 4 bit return code.

type

public int type()

Returns the DnsMessage type. This will always return TYPE_RESPONSE.

Overrides:

type in class DnsHeader

See Also:

DnsHeader.TYPE_QUERY

setAuthoritativeAnswer

public DnsResponseHeader setAuthoritativeAnswer(boolean authoritativeAnswer)

Set to true if responding server is authoritative for the domain name in the query message.

Parameters:

authoritativeAnswer - flag for authoritative answer

setTruncated

public DnsResponseHeader setTruncated(boolean truncated)

Set to true if response has been truncated (usually happens for responses over 512 bytes).

Parameters:

truncated - flag for truncation

setRecursionAvailable

public DnsResponseHeader setRecursionAvailable(boolean recursionAvailable)

Set to true if DNS server can handle recursive queries.

Parameters:

recursionAvailable - flag for recursion availability

setResponseCode

public DnsResponseHeader setResponseCode(DnsResponseCode responseCode)

Sets the response code for this message.

Parameters:

responseCode - the response code

setType

public DnsResponseHeader setType(int type)

Sets the DnsHeader type. Must be TYPE_RESPONSE.

Overrides:

setType in class DnsHeader

Parameters:

type - message type

Returns:

the header to allow method chaining

setId

public DnsResponseHeader setId(int id)

Description copied from class: DnsHeader

Sets the id for this DnsMessage.

Overrides:

setId in class DnsHeader

Parameters:

id - a unique 2 byte unsigned identifier

Returns:

the header to allow method chaining

setRecursionDesired

public DnsHeader setRecursionDesired(boolean recursionDesired)

Description copied from class: DnsHeader

Sets whether a name server is directed to pursue a query recursively or not.

Overrides:

setRecursionDesired in class DnsHeader

Parameters:

recursionDesired - if set to true, pursues query recursively

Returns:

the header to allow method chaining

setOpcode

public DnsResponseHeader setOpcode(int opcode)

Description copied from class: DnsHeader

Sets the opcode for this DnsMessage.

Overrides:

setOpcode in class DnsHeader

Parameters:

opcode - opcode to set

Returns:

the header to allow method chaining

setZ

public DnsResponseHeader setZ(int z)

Description copied from class: DnsHeader

Sets the field Z. This field is reserved and should remain as 0 if the DNS server does not make usage of this field.

Overrides:

setZ in class DnsHeader

Parameters:

z - the value for the reserved field Z