Struct OptRcode

pub struct OptRcode(/* private fields */);

Extended DNS Response Codes for OPT records.

Originally, the response code embedded in the header of each DNS message was four bits long. This code, defined in [RFC 1035], is represented by the Rcode type. The extension mechanism for DNS initially defined in RFC 2671 and updated by RFC 6891 added eight more bits to be stored in the OPT pseudo-resource record. This type represents the complete 12 bit extended response code.

There is a third, 16 bit wide response code for transaction authentication (TSIG) defined in RFC 2845 and represented by the TsigRcode type. The code mostly shares the same name space except for an unfortunate collision in between the BADVERS and BADSIG values. Because of this, we decided to have separate types.

The values for all three response code types are defined in the IANA DNS RCODEs registry. This type is complete as of 2019-01-28.

The 12-bit extended RCODE defined by RFC 6891 stores the lowest 4-bits of the extended RCODE in the main DNS header RCODE field and stores the remaining 8-bits (right shifted by 4-bits) in the OPT record header RCODE field, like so:

NoError:    0 = 0b0000_0000_0000
                            ^^^^ Stored in DNS header RCODE field
                  ^^^^_^^^^      Stored in OPT header RCODE field

FormErr:    1 = 0b0000_0000_0001
                            ^^^^ Stored in DNS header RCODE field
                  ^^^^_^^^^      Stored in OPT header RCODE field

BadVers:   16 = 0b0000_0001_0000
                            ^^^^ Stored in DNS header RCODE field
                  ^^^^_^^^^      Stored in OPT header RCODE field

BadCookie: 23 = 0b0000_0001_0111
                            ^^^^ Stored in DNS header RCODE field
                  ^^^^_^^^^      Stored in OPT header RCODE field

This type offers several functions to ease working with the separate parts and the combined value of an extended RCODE:

• OptRcode::rcode: the RFC 1035 header RCODE part.
• OptRcode::ext`: the RFC 6891 ENDS OPT extended RCODE part.
• OptRcode::to_parts`: to access both parts at once.
• OptRcode::to_int`: the IANA number for the RCODE combining both parts.

Implementations

impl OptRcode

pub const NOERROR: Self = _

No error condition.

(Otherwise known as success.)

Defined in RFC 1035.

pub const FORMERR: Self = _

Format error.

The name server was unable to interpret the query.

Defined in RFC 1035.

pub const SERVFAIL: Self = _

Server failure.

The name server was unable to process this query due to a problem with the name server.

Defined in RFC 1035.

pub const NXDOMAIN: Self = _

Name error.

The domain name given in the query does not exist at the name server.

Defined in RFC 1035.

pub const NOTIMP: Self = _

Not implemented.

The name server does not support the requested kind of query.

Defined in RFC 1035.

pub const REFUSED: Self = _

Query refused.

The name server refused to perform the operation requested by the query for policy reasons.

Defined in RFC 1035.

pub const YXDOMAIN: Self = _

Name exists when it should not.

Returned for an UPDATE query when a domain requested to not exist does in fact exist.

Returned when resolving a DNAME redirection when the resulting name exceeds the length of 255 octets.

Defined in RFC 2136 for the UPDATE query and RFC 6672 for DNAME redirection.

pub const YXRRSET: Self = _

RR set exists when it should not.

Returned for an UPDATE query when an RRset requested to not exist does in fact exist.

Defined in RFC 2136.

pub const NXRRSET: Self = _

RR set that should exist does not.

Returned for an UPDATE query when an RRset requested to exist does not.

Defined in RFC 2136.

pub const NOTAUTH: Self = _

Server not authoritative for zone or client not authorized.

Returned for an UPDATE query when the server is not an authoritative name server for the requested domain.

Returned for queries using TSIG when authorisation failed.

Defined in RFC 2136 for UPDATE and RFC 2845 for TSIG.

pub const NOTZONE: Self = _

Name not contained in zone.

A name used in the prerequisite or update section is not within the zone given in the zone section.

Defined in RFC 2136.

pub const BADVERS: Self = _

Bad OPT version.

A name server does not implement the EDNS version requested in the OPT record.

Defined in RFC 6891.

pub const BADCOOKIE: Self = _

Bad or missing server cookie.

The request contained a COOKIE option either without a server cookie or with a server cookie that did not validate.

Defined in RFC 7873.

impl OptRcode

pub const fn checked_from_int(value: u16) -> Option<OptRcode>

Creates an rcode from an integer, returning None if invalid.

The rcode is valid if the upper four bits of value are all zero.

pub const fn masked_from_int(value: u16) -> OptRcode

Creates an rcode from an integer, only considering the lower four bits.

This function will ignore the upper four bit of value.

pub const fn from_rcode(rcode: Rcode) -> Self

Creates an OPT rcode from a plain rcode.

pub const fn to_int(self) -> u16

Returns the integer value for this rcode.

Only the lower 12 bits of the returned octet are used by the rcode. The upper four bits are always zero.

pub fn from_parts(rcode: Rcode, ext: u8) -> OptRcode

Creates an extended rcode value from its parts.

pub fn to_parts(self) -> (Rcode, u8)

Returns the two parts of an extended rcode value.

pub fn rcode(self) -> Rcode

Returns the rcode part of the extended rcode.

pub fn ext(self) -> u8

Returns the extended octet of the extended rcode.

pub fn is_ext(&self) -> bool

Returns true if the RCODE is extended, false otherwise.

pub const fn to_mnemonic(self) -> Option<&'static [u8]>

Returns the mnemonic for this value if there is one.

Trait Implementations

impl Clone for OptRcode

fn clone(&self) -> OptRcode

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for OptRcode

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

Formats the value using the given formatter.

impl Display for OptRcode

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

Formats the value using the given formatter.

impl From<OptRcode> for TsigRcode

fn from(value: OptRcode) -> TsigRcode

Converts to this type from the input type.

impl From<OptRcode> for u16

fn from(value: OptRcode) -> u16

Converts to this type from the input type.

impl From<Rcode> for OptRcode

fn from(value: Rcode) -> OptRcode

Converts to this type from the input type.

impl FromStr for OptRcode

type Err = ()

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 OptRcode

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 Ord for OptRcode

fn cmp(&self, other: &OptRcode) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for OptRcode

fn eq(&self, other: &OptRcode) -> 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 PartialOrd for OptRcode

fn partial_cmp(&self, other: &OptRcode) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

Tests less than (for self and other) and is used by the < operator.

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

Tests less than or equal to (for self and other) and is used by the <= operator.

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

Tests greater than (for self and other) and is used by the > operator.

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

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<u16> for OptRcode

type Error = InvalidRcode

The type returned in the event of a conversion error.

fn try_from(value: u16) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for OptRcode

impl Eq for OptRcode

impl StructuralPartialEq for OptRcode