Struct MessageHeader 

pub struct MessageHeader { /* private fields */ }

Available on crate features dns and std only.

The fixed twelve-octet header of a DNS message.

RFC 1035 Section 4.1.1 defines the identifier, the flag word, and the four section counts. The counts describe the message as sent; they are not a promise that every counted record is present or well formed.

Implementations

impl MessageHeader

pub const WIRE_LEN: usize = 12

Wire length of a DNS message header in octets.

pub fn parse(message: &[u8]) -> Result<MessageHeader, MessageParseError>

Parse the fixed header at the start of a DNS message.

Octets beyond the header are ignored, so this also inspects a message whose sections are unparsed, truncated, or not yet received.

pub const fn id(&self) -> u16

Return the message identifier that pairs a response with its query.

pub const fn flags(&self) -> u16

Return the raw flag word, including the reserved Z bit.

pub const fn is_response(&self) -> bool

Return whether the QR bit marks this message as a response.

pub const fn opcode(&self) -> u8

Return the four-bit OPCODE, where zero is a standard query.

pub const fn is_authoritative(&self) -> bool

Return whether the answering server is authoritative for the name.

pub const fn is_truncated(&self) -> bool

Return whether the message was truncated by its transport.

pub const fn is_recursion_desired(&self) -> bool

Return whether the query asked the server to recurse.

pub const fn is_recursion_available(&self) -> bool

Return whether the server offers recursion.

pub const fn is_authentic_data(&self) -> bool

Return the RFC 4035 authentic-data bit.

pub const fn is_checking_disabled(&self) -> bool

Return the RFC 4035 checking-disabled bit.

pub fn response_code(&self) -> ResponseCode

Return the response code held by the header’s low four bits.

EDNS(0) and TSIG extend this field with upper bits carried elsewhere in the message; those extensions are not read here.

pub const fn question_count(&self) -> u16

Return the declared question count (QDCOUNT).

pub const fn answer_count(&self) -> u16

Return the declared answer count (ANCOUNT).

pub const fn authority_count(&self) -> u16

Return the declared authority count (NSCOUNT).

Message never parses that section; this reports what it skipped.

pub const fn additional_count(&self) -> u16

Return the declared additional count (ARCOUNT).

Message never parses that section; this reports what it skipped.

Trait Implementations

impl Clone for MessageHeader

fn clone(&self) -> MessageHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for MessageHeader

impl Debug for MessageHeader

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

Formats the value using the given formatter.

impl Eq for MessageHeader

impl Hash for MessageHeader

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

where __H: Hasher,

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 MessageHeader

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MessageHeader