Struct DnsMessageHeader 

pub struct DnsMessageHeader {
    pub id: u16,
    pub is_response: bool,
    pub op_code: DnsOpCode,
    pub authoritative_answer: bool,
    pub truncated: bool,
    pub recursion_desired: bool,
    pub recursion_available: bool,
    pub response_code: DnsResponseCode,
    pub question_count: u16,
    pub answer_count: u16,
    pub name_server_count: u16,
    pub additional_count: u16,
}

4.1.1. Header section format

The header contains the following fields:

                                1  1  1  1  1  1
  0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                      ID                       |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    QDCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ANCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    NSCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
|                    ARCOUNT                    |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

Fields

id: u16

ID A 16 bit identifier assigned by the program that generates any kind of query. This identifier is copied the corresponding reply and can be used by the requester to match up replies to outstanding queries.

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

is_response: bool

QR A one bit field that specifies whether this message is a query (0), or a response (1).

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

op_code: DnsOpCode

OPCODE A four bit field that specifies kind of query in this message. This value is set by the originator of a query and copied into the response. The values are:

• 0 a standard query (QUERY)
• 1 an inverse query (IQUERY)
• 2 a server status request (STATUS)
• 3-15 reserved for future use

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

authoritative_answer: bool

AA Authoritative Answer - this bit is valid in responses, and specifies that the responding name server is an authority for the domain name in question section.

Note that the contents of the answer section may have multiple owner names because of aliases. The AA bit corresponds to the name which matches the query name, or the first owner name in the answer section.

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

truncated: bool

TC TrunCation - specifies that this message was truncated due to length greater than that permitted on the transmission channel.

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

recursion_desired: bool

RD Recursion Desired - this bit may be set in a query and is copied into the response. If RD is set, it directs the name server to pursue the query recursively. Recursive query support is optional.

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

recursion_available: bool

RA Recursion Available - this be is set or cleared in a response, and denotes whether recursive query support is available in the name server.

https://datatracker.ietf.org/doc/html/rfc1035#section-4.1.1

response_code: DnsResponseCode

question_count: u16

answer_count: u16

name_server_count: u16

additional_count: u16

Implementations

impl DnsMessageHeader

pub fn read<const N: usize>(buf: &mut FixedBuf<N>) -> Result<Self, DnsError>

Errors

Returns an error when buf does not contain a valid message header.

pub fn write<const N: usize>( &self, out: &mut FixedBuf<N>, ) -> Result<(), DnsError>

Errors

Returns an error when buf fills up.

Trait Implementations

impl Clone for DnsMessageHeader

fn clone(&self) -> DnsMessageHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DnsMessageHeader

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

Formats the value using the given formatter.

impl Hash for DnsMessageHeader

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for DnsMessageHeader

fn eq(&self, other: &DnsMessageHeader) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for DnsMessageHeader

impl StructuralPartialEq for DnsMessageHeader