Package org.minidns.dnsmessage
Class DnsMessage
- java.lang.Object
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- org.minidns.dnsmessage.DnsMessage
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public class DnsMessage extends Object
A DNS message as defined by RFC 1035. The message consists of a header and 4 sections: question, answer, nameserver and addition resource record section. A message can either be parsed (DnsMessage(byte[])
) or serialized (toArray()
).- See Also:
- RFC 1035
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Nested Class Summary
Nested Classes Modifier and Type Class Description static class
DnsMessage.Builder
static class
DnsMessage.OPCODE
Symbolic DNS Opcode values.static class
DnsMessage.RESPONSE_CODE
Possible DNS response codes.
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Field Summary
Fields Modifier and Type Field Description List<Record<? extends Data>>
additionalSection
The additional section.List<Record<? extends Data>>
answerSection
The answers section records.boolean
authenticData
True if the server regarded the response as authentic.boolean
authoritativeAnswer
True if this is a authorative response.List<Record<? extends Data>>
authoritySection
The Authority Section.boolean
checkingDisabled
True if the server should not perform DNSSEC validation before returning the result.int
id
The DNS message id.DnsMessage.OPCODE
opcode
The DNS message opcode.int
optRrPosition
boolean
qr
The QR flag of the DNS message header.List<Question>
questions
The question section content.long
receiveTimestamp
The receive timestamp.boolean
recursionAvailable
True if recursion is possible.boolean
recursionDesired
True if the server should recurse.DnsMessage.RESPONSE_CODE
responseCode
The response code of this dns message.boolean
truncated
True if message is truncated.
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Constructor Summary
Constructors Modifier Constructor Description DnsMessage(byte[] data)
Build a DNS Message based on a binary DNS message.protected
DnsMessage(DnsMessage.Builder builder)
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description DnsMessage.Builder
asBuilder()
DatagramPacket
asDatagram(InetAddress address, int port)
DnsMessage
asNormalizedVersion()
String
asTerminalOutput()
Format the DnsMessage object in a way suitable for terminal output.static DnsMessage.Builder
builder()
List<Record<? extends Data>>
copyAnswers()
Copy the records found in the answer section into a new list.List<Record<? extends Data>>
copyAuthority()
Copy the records found in the authority section into a new list.List<Question>
copyQuestions()
Copy the questions found in the question section.boolean
equals(Object other)
<D extends Data>
List<Record<D>>filterAdditionalSectionBy(Class<D> type)
<D extends Data>
List<Record<D>>filterAnswerSectionBy(Class<D> type)
<D extends Data>
List<Record<D>>filterAuthoritySectionBy(Class<D> type)
<D extends Data>
Set<D>getAnswersFor(Question q)
long
getAnswersMinTtl()
Get the minimum TTL from all answers in seconds.Edns
getEdns()
<D extends Data>
Record<D>getFirstOfTypeFromAdditionalSection(Class<D> type)
<D extends Data>
Record<D>getFirstOfTypeFromAnswerSection(Class<D> type)
<D extends Data>
Record<D>getFirstOfTypeFromAuthoritySection(Class<D> type)
ByteBuffer
getInByteBuffer()
Record<OPT>
getOptPseudoRecord()
Question
getQuestion()
DnsMessage.Builder
getResponseBuilder(DnsMessage.RESPONSE_CODE responseCode)
int
hashCode()
boolean
isDnssecOk()
Check if the EDNS DO (DNSSEC OK) flag is set.byte[]
toArray()
Generate a binary dns packet out of this message.String
toString()
void
writeTo(OutputStream outputStream)
void
writeTo(OutputStream outputStream, boolean writeLength)
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Field Detail
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id
public final int id
The DNS message id.
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opcode
public final DnsMessage.OPCODE opcode
The DNS message opcode.
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responseCode
public final DnsMessage.RESPONSE_CODE responseCode
The response code of this dns message.
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qr
public final boolean qr
The QR flag of the DNS message header. Note that this will betrue
if the message is a response andfalse
if it is a query.- See Also:
- RFC 1035 § 4.1.1
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authoritativeAnswer
public final boolean authoritativeAnswer
True if this is a authorative response. If set, the responding nameserver is an authority for the domain name in the question section. Note that the answer section may have multiple owner names because of aliases. This flag corresponds to the name which matches the query name, or the first owner name in the query section.- See Also:
- RFC 1035 § 4.1.1. Header section format
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truncated
public final boolean truncated
True if message is truncated. Then TCP should be used.
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recursionDesired
public final boolean recursionDesired
True if the server should recurse.
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recursionAvailable
public final boolean recursionAvailable
True if recursion is possible.
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authenticData
public final boolean authenticData
True if the server regarded the response as authentic.
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checkingDisabled
public final boolean checkingDisabled
True if the server should not perform DNSSEC validation before returning the result.
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questions
public final List<Question> questions
The question section content. Usually there will be only one question.This list is unmodifiable.
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answerSection
public final List<Record<? extends Data>> answerSection
The answers section records. Note that it is not guaranteed that all records found in this section will be direct answers to the question in the query. If DNSSEC is used, then this section also contains the RRSIG record.This list is unmodifiable.
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authoritySection
public final List<Record<? extends Data>> authoritySection
The Authority Section. Note that it is not guaranteed that this section only contains nameserver records. If DNSSEC is used, then this section could also contain a NSEC(3) record.This list is unmodifiable.
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additionalSection
public final List<Record<? extends Data>> additionalSection
The additional section. It eventually contains RRs which relate to the query.This list is unmodifiable.
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optRrPosition
public final int optRrPosition
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receiveTimestamp
public final long receiveTimestamp
The receive timestamp. Set only if this message was created via parse. This should be used to evaluate TTLs.
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Constructor Detail
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DnsMessage
protected DnsMessage(DnsMessage.Builder builder)
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DnsMessage
public DnsMessage(byte[] data) throws IOException
Build a DNS Message based on a binary DNS message.- Parameters:
data
- The DNS message data.- Throws:
IOException
- On read errors.
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Method Detail
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toArray
public byte[] toArray()
Generate a binary dns packet out of this message.- Returns:
- byte[] the binary representation.
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asDatagram
public DatagramPacket asDatagram(InetAddress address, int port)
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writeTo
public void writeTo(OutputStream outputStream) throws IOException
- Throws:
IOException
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writeTo
public void writeTo(OutputStream outputStream, boolean writeLength) throws IOException
- Throws:
IOException
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getInByteBuffer
public ByteBuffer getInByteBuffer()
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getQuestion
public Question getQuestion()
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copyQuestions
public List<Question> copyQuestions()
Copy the questions found in the question section.- Returns:
- a copy of the question section questions.
- See Also:
questions
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copyAnswers
public List<Record<? extends Data>> copyAnswers()
Copy the records found in the answer section into a new list.- Returns:
- a copy of the answer section records.
- See Also:
answerSection
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copyAuthority
public List<Record<? extends Data>> copyAuthority()
Copy the records found in the authority section into a new list.- Returns:
- a copy of the authority section records.
- See Also:
authoritySection
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getOptPseudoRecord
public Record<OPT> getOptPseudoRecord()
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isDnssecOk
public boolean isDnssecOk()
Check if the EDNS DO (DNSSEC OK) flag is set.- Returns:
- true if the DO flag is set.
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asTerminalOutput
public String asTerminalOutput()
Format the DnsMessage object in a way suitable for terminal output. The format is loosely based on the output provided bydig
.- Returns:
- This message as a String suitable for terminal output.
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getAnswersFor
public <D extends Data> Set<D> getAnswersFor(Question q)
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getAnswersMinTtl
public long getAnswersMinTtl()
Get the minimum TTL from all answers in seconds.- Returns:
- the minimum TTL from all answers in seconds.
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asBuilder
public DnsMessage.Builder asBuilder()
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asNormalizedVersion
public DnsMessage asNormalizedVersion()
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getResponseBuilder
public DnsMessage.Builder getResponseBuilder(DnsMessage.RESPONSE_CODE responseCode)
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filterAnswerSectionBy
public <D extends Data> List<Record<D>> filterAnswerSectionBy(Class<D> type)
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filterAuthoritySectionBy
public <D extends Data> List<Record<D>> filterAuthoritySectionBy(Class<D> type)
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filterAdditionalSectionBy
public <D extends Data> List<Record<D>> filterAdditionalSectionBy(Class<D> type)
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getFirstOfTypeFromAnswerSection
public <D extends Data> Record<D> getFirstOfTypeFromAnswerSection(Class<D> type)
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getFirstOfTypeFromAuthoritySection
public <D extends Data> Record<D> getFirstOfTypeFromAuthoritySection(Class<D> type)
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getFirstOfTypeFromAdditionalSection
public <D extends Data> Record<D> getFirstOfTypeFromAdditionalSection(Class<D> type)
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builder
public static DnsMessage.Builder builder()
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