Struct trust_dns_proto::xfer::dns_response::DnsResponse

pub struct DnsResponse(_);

A DNS response object

For Most DNS requests, only one response is expected, the exception is a multicast request.

Implementations

impl DnsResponse

pub fn soa(&self) -> Option<SOA>

Retrieves the SOA from the response. This will only exist if it was an authoritative response.

pub fn negative_ttl(&self) -> Option<u32>

Looks in the authority section for an SOA record from the response, and returns the negative_ttl, None if not available.

[RFC 2308](https://tools.ietf.org/html/rfc2308#section-5) DNS NCACHE March 1998

5 - Caching Negative Answers

  Like normal answers negative answers have a time to live (TTL).  As
  there is no record in the answer section to which this TTL can be
  applied, the TTL must be carried by another method.  This is done by
  including the SOA record from the zone in the authority section of
  the reply.  When the authoritative server creates this record its TTL
  is taken from the minimum of the SOA.MINIMUM field and SOA's TTL.
  This TTL decrements in a similar manner to a normal cached answer and
  upon reaching zero (0) indicates the cached negative answer MUST NOT
  be used again.

  A negative answer that resulted from a name error (NXDOMAIN) should
  be cached such that it can be retrieved and returned in response to
  another query for the same <QNAME, QCLASS> that resulted in the
  cached negative response.

  A negative answer that resulted from a no data error (NODATA) should
  be cached such that it can be retrieved and returned in response to
  another query for the same <QNAME, QTYPE, QCLASS> that resulted in
  the cached negative response.

  The NXT record, if it exists in the authority section of a negative
  answer received, MUST be stored such that it can be be located and
  returned with SOA record in the authority section, as should any SIG
  records in the authority section.  For NXDOMAIN answers there is no
  "necessary" obvious relationship between the NXT records and the
  QNAME.  The NXT record MUST have the same owner name as the query
  name for NODATA responses.

  Negative responses without SOA records SHOULD NOT be cached as there
  is no way to prevent the negative responses looping forever between a
  pair of servers even with a short TTL.

  Despite the DNS forming a tree of servers, with various mis-
  configurations it is possible to form a loop in the query graph, e.g.
  two servers listing each other as forwarders, various lame server
  configurations.  Without a TTL count down a cache negative response
  when received by the next server would have its TTL reset.  This
  negative indication could then live forever circulating between the
  servers involved.

  As with caching positive responses it is sensible for a resolver to
  limit for how long it will cache a negative response as the protocol
  supports caching for up to 68 years.  Such a limit should not be
  greater than that applied to positive answers and preferably be
  tunable.  Values of one to three hours have been found to work well
  and would make sensible a default.  Values exceeding one day have
  been found to be problematic.

pub fn contains_answer(&self) -> bool

Does the response contain any records matching the query name and type?

pub fn negative_type(&self) -> Option<NegativeType>

Retrieve the type of the negative response. The Various types should be handled when caching or otherwise differently.

See NegativeType

Methods from Deref<Target = Message>

pub fn truncate(&self) -> Self

Truncates a Message, this blindly removes all response fields and sets truncated to true

pub fn set_id(&mut self, id: u16) -> &mut Self

see Header::set_id

pub fn set_message_type(&mut self, message_type: MessageType) -> &mut Self

see Header::set_message_type

pub fn set_op_code(&mut self, op_code: OpCode) -> &mut Self

see Header::set_op_code

pub fn set_authoritative(&mut self, authoritative: bool) -> &mut Self

see Header::set_authoritative

pub fn set_truncated(&mut self, truncated: bool) -> &mut Self

see Header::set_truncated

pub fn set_recursion_desired(&mut self, recursion_desired: bool) -> &mut Self

see Header::set_recursion_desired

pub fn set_recursion_available(
    &mut self,
    recursion_available: bool
) -> &mut Self

see Header::set_recursion_available

pub fn set_authentic_data(&mut self, authentic_data: bool) -> &mut Self

see Header::set_authentic_data

pub fn set_checking_disabled(&mut self, checking_disabled: bool) -> &mut Self

see Header::set_checking_disabled

pub fn set_response_code(&mut self, response_code: ResponseCode) -> &mut Self

see Header::set_response_code

pub fn add_query(&mut self, query: Query) -> &mut Self

Add a query to the Message, either the query response from the server, or the request Query.

pub fn add_queries<Q, I>(&mut self, queries: Q) -> &mut Self where
    Q: IntoIterator<Item = Query, IntoIter = I>,
    I: Iterator<Item = Query>, 

Adds an iterator over a set of Queries to be added to the message

pub fn add_answer(&mut self, record: Record) -> &mut Self

Add an answer to the Message

pub fn add_answers<R, I>(&mut self, records: R) -> &mut Self where
    R: IntoIterator<Item = Record, IntoIter = I>,
    I: Iterator<Item = Record>, 

Add all the records from the iterator to the answers section of the Message

pub fn insert_answers(&mut self, records: Vec<Record>)

Sets the answers to the specified set of Records.

Panics

Will panic if answer records are already associated to the message.

pub fn add_name_server(&mut self, record: Record) -> &mut Self

Add a name server record to the Message

pub fn add_name_servers<R, I>(&mut self, records: R) -> &mut Self where
    R: IntoIterator<Item = Record, IntoIter = I>,
    I: Iterator<Item = Record>, 

Add all the records in the Iterator to the name server section of the message

pub fn insert_name_servers(&mut self, records: Vec<Record>)

Sets the name_servers to the specified set of Records.

Panics

Will panic if name_servers records are already associated to the message.

pub fn add_additional(&mut self, record: Record) -> &mut Self

Add an additional Record to the message

pub fn insert_additionals(&mut self, records: Vec<Record>)

Sets the additional to the specified set of Records.

Panics

Will panic if additional records are already associated to the message.

pub fn set_edns(&mut self, edns: Edns) -> &mut Self

Add the EDNS section to the Message

pub fn add_sig0(&mut self, record: Record) -> &mut Self

This is supported on crate feature dnssec only.

Add a SIG0 record, i.e. sign this message

This must be used only after all records have been associated. Generally this will be handled by the client and not need to be used directly

pub fn add_tsig(&mut self, record: Record) -> &mut Self

This is supported on crate feature dnssec only.

Add a TSIG record, i.e. authenticate this message

This must be used only after all records have been associated. Generally this will be handled by the client and not need to be used directly

pub fn header(&self) -> &Header

Gets the header of the Message

pub fn id(&self) -> u16

see Header::id()

pub fn message_type(&self) -> MessageType

see Header::message_type()

pub fn op_code(&self) -> OpCode

see Header::op_code()

pub fn authoritative(&self) -> bool

see Header::authoritative()

pub fn truncated(&self) -> bool

see Header::truncated()

pub fn recursion_desired(&self) -> bool

see Header::recursion_desired()

pub fn recursion_available(&self) -> bool

see Header::recursion_available()

pub fn authentic_data(&self) -> bool

see Header::authentic_data()

pub fn checking_disabled(&self) -> bool

see Header::checking_disabled()

pub fn response_code(&self) -> ResponseCode

Return value

The ResponseCode, if this is an EDNS message then this will join the section from the OPT record to create the EDNS ResponseCode

pub fn queries(&self) -> &[Query]

Question        Carries the query name and other query parameters.

pub fn queries_mut(&mut self) -> &mut Vec<Query>

Provides mutable access to queries

pub fn take_queries(&mut self) -> Vec<Query>

Removes all the answers from the Message

pub fn answers(&self) -> &[Record]

Answer          Carries RRs which directly answer the query.

pub fn answers_mut(&mut self) -> &mut Vec<Record>

Provides mutable access to answers

pub fn take_answers(&mut self) -> Vec<Record>

Removes all the answers from the Message

pub fn name_servers(&self) -> &[Record]

Authority       Carries RRs which describe other authoritative servers.
                May optionally carry the SOA RR for the authoritative
                data in the answer section.

pub fn name_servers_mut(&mut self) -> &mut Vec<Record>

Provides mutable access to name_servers

pub fn take_name_servers(&mut self) -> Vec<Record>

Remove the name servers from the Message

pub fn additionals(&self) -> &[Record]

Additional      Carries RRs which may be helpful in using the RRs in the
                other sections.

pub fn additionals_mut(&mut self) -> &mut Vec<Record>

Provides mutable access to additionals

pub fn take_additionals(&mut self) -> Vec<Record>

Remove the additional Records from the Message

pub fn all_sections(&self) -> impl Iterator<Item = &Record>

All sections chained

pub fn edns(&self) -> Option<&Edns>

RFC 6891, EDNS(0) Extensions, April 2013

6.1.1.  Basic Elements

 An OPT pseudo-RR (sometimes called a meta-RR) MAY be added to the
 additional data section of a request.

 The OPT RR has RR type 41.

 If an OPT record is present in a received request, compliant
 responders MUST include an OPT record in their respective responses.

 An OPT record does not carry any DNS data.  It is used only to
 contain control information pertaining to the question-and-answer
 sequence of a specific transaction.  OPT RRs MUST NOT be cached,
 forwarded, or stored in or loaded from Zone Files.

 The OPT RR MAY be placed anywhere within the additional data section.
 When an OPT RR is included within any DNS message, it MUST be the
 only OPT RR in that message.  If a query message with more than one
 OPT RR is received, a FORMERR (RCODE=1) MUST be returned.  The
 placement flexibility for the OPT RR does not override the need for
 the TSIG or SIG(0) RRs to be the last in the additional section
 whenever they are present.

Return value

Returns the EDNS record if it was found in the additional section.

pub fn edns_mut(&mut self) -> &mut Edns

If edns is_none, this will create a new default Edns.

pub fn max_payload(&self) -> u16

Return value

the max payload value as it’s defined in the EDNS section.

pub fn version(&self) -> u8

Return value

the version as defined in the EDNS record

pub fn sig0(&self) -> &[Record]

RFC 2535, Domain Name System Security Extensions, March 1999

A DNS request may be optionally signed by including one or more SIGs
 at the end of the query. Such SIGs are identified by having a "type
 covered" field of zero. They sign the preceding DNS request message
 including DNS header but not including the IP header or any request
 SIGs at the end and before the request RR counts have been adjusted
 for the inclusions of any request SIG(s).

Return value

The sig0 and tsig, i.e. signed record, for verifying the sending and package integrity

pub fn signature(&self) -> &[Record]

RFC 2535, Domain Name System Security Extensions, March 1999

A DNS request may be optionally signed by including one or more SIGs
 at the end of the query. Such SIGs are identified by having a "type
 covered" field of zero. They sign the preceding DNS request message
 including DNS header but not including the IP header or any request
 SIGs at the end and before the request RR counts have been adjusted
 for the inclusions of any request SIG(s).

Return value

The sig0 and tsig, i.e. signed record, for verifying the sending and package integrity

pub fn take_signature(&mut self) -> Vec<Record>

Remove signatures from the Message

pub fn to_vec(&self) -> Result<Vec<u8>, ProtoError>

Encodes the Message into a buffer

pub fn finalize<MF: MessageFinalizer>(
    &mut self,
    finalizer: &MF,
    inception_time: u32
) -> ProtoResult<Option<MessageVerifier>>

Finalize the message prior to sending.

Subsequent to calling this, the Message should not change.

Trait Implementations

impl Clone for DnsResponse

fn clone(&self) -> DnsResponse

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DnsResponse

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for DnsResponse

type Target = Message

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for DnsResponse

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl From<DnsResponse> for Message

fn from(response: DnsResponse) -> Message

Performs the conversion.

impl From<Message> for DnsResponse

fn from(message: Message) -> DnsResponse

Performs the conversion.