Struct Flags

pub struct Flags {
    pub qr: bool,
    pub aa: bool,
    pub tc: bool,
    pub rd: bool,
    pub ra: bool,
    pub ad: bool,
    pub cd: bool,
}

The flags contained in the DNS message header.

This is a utility type that makes it easier to work with flags. It contains only standard DNS message flags that are part of the Header, i.e., EDNS flags are not included.

This type has a text notation and can be created from it as well. Each flags that is set is represented by a two-letter token, which is the uppercase version of the flag name. If mutliple flags are set, the tokens are separated by space.

use core::str::FromStr;
use domain::base::header::Flags;

let flags = Flags::from_str("QR AA").unwrap();
assert!(flags.qr && flags.aa);
assert_eq!(format!("{}", flags), "QR AA");

Fields

qr: bool

The QR bit specifies whether a message is a query (false) or a response (true). In other words, this bit is actually stating whether the message is not a query. So, perhaps it might be good to read ‘QR’ as ‘query response.’

aa: bool

Using the AA bit, a name server generating a response states whether it is authoritative for the requested domain name, ie., whether this response is an authoritative answer. The field has no meaning in a query.

tc: bool

The truncation (TC) bit is set if there was more data available then fit into the message. This is typically used when employing datagram transports such as UDP to signal that the answer didn’t fit into a response and the query should be tried again using a stream transport such as TCP.

rd: bool

The recursion desired (RD) bit may be set in a query to ask the name server to try and recursively gather a response if it doesn’t have the data available locally. The bit’s value is copied into the response.

ra: bool

In a response, the recursion available (RA) bit denotes whether the responding name server supports recursion. It has no meaning in a query.

ad: bool

The authentic data (AD) bit is used by security-aware recursive name servers to indicate that it considers all RRsets in its response are authentic, i.e., have successfully passed DNSSEC validation.

cd: bool

The checking disabled (CD) bit is used by a security-aware resolver to indicate that it does not want upstream name servers to perform verification but rather would like to verify everything itself.

Implementations

impl Flags

Creation and Conversion

pub fn new() -> Self

Creates new flags.

All flags will be unset.

Trait Implementations

impl Clone for Flags

fn clone(&self) -> Flags

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Flags

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

Formats the value using the given formatter.

impl Default for Flags

fn default() -> Flags

Returns the “default value” for a type.

impl Display for Flags

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

Formats the value using the given formatter.

impl FromStr for Flags

type Err = FlagsFromStrError

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for Flags

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 Flags

fn eq(&self, other: &Flags) -> 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 Copy for Flags

impl Eq for Flags

impl StructuralPartialEq for Flags