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//! Extended DNS Error
//------------ Extended Error Code ---------------------------------------------------------
int_enum! {
/// Extended DNS error codes.
///
/// A complementary data can be put in EDNS opt, providing
/// additional information about the cause of DNS errors. Defined
/// in [RFC 8914]. Current registered values can be found in [IANA
/// registry].
///
/// [RFC 8914]: https://tools.ietf.org/html/rfc8914
/// [IANA registry]: https://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml#extended-dns-error-codes
=>
ExtendedErrorCode, u16;
/// The error in question falls into a category that does not
/// match known extended error codes. Implementations SHOULD
/// include an EXTRA-TEXT value to augment this error code with
/// additional information.
(Other => 0, b"Other Error")
/// The resolver attempted to perform DNSSEC validation, but a DNSKEY
/// RRset contained only unsupported DNSSEC algorithms.
(UnsupportedDnskeyAlgorithm => 1, b"Unsupported DNSKEY Algorithm")
/// The resolver attempted to perform DNSSEC validation, but a DS
/// RRset contained only unsupported Digest Types.
(UnsupportedDsDigestType => 2, b"Unsupported DS Digest Type")
/// The resolver was unable to resolve the answer within its time
/// limits and decided to answer with previously cached data
/// instead of answering with an error. This is typically caused
/// by problems communicating with an authoritative server,
/// possibly as result of a denial of service (DoS) attack against
/// another network. (See also Code 19.)
(StaleAnswer => 3, b"Stale Answer")
/// For policy reasons (legal obligation or malware filtering, for
/// instance), an answer was forged. Note that this should be
/// used when an answer is still provided, not when failure
/// codes are returned instead. See Blocked (15), Censored
/// (16), and Filtered (17) for use when returning other
/// response codes.
(ForgedAnswer => 4, b"Forged Answer")
/// The resolver attempted to perform DNSSEC validation, but
/// validation ended in the Indeterminate state [RFC 4035].
///
/// [RFC 4035]: https://tools.ietf.org/html/rfc4035
(DnssecIndeterminate => 5, b"DNSSEC Indeterminate")
/// The resolver attempted to perform DNSSEC validation, but
/// validation ended in the Bogus state.
(DnssecBogus => 6, b"DNSSEC Bogus")
/// The resolver attempted to perform DNSSEC validation, but no
/// signatures are presently valid and some (often all) are
/// expired.
(SignatureExpired => 7, b"Signature Expired")
/// The resolver attempted to perform DNSSEC validation, but no
/// signatures are presently valid and at least some are not yet
/// valid.
(SignatureNotYetValid => 8, b"Signature Not Yet Valid")
/// A DS record existed at a parent, but no supported matching
/// DNSKEY record could be found for the child.
(DnskeyMissing => 9, b"DNSKEY Missing")
/// The resolver attempted to perform DNSSEC validation, but no
/// RRSIGs could be found for at least one RRset where RRSIGs were
/// expected.
(RrsigsMissing => 10, b"RRSIGs Missing")
/// The resolver attempted to perform DNSSEC validation, but no
/// Zone Key Bit was set in a DNSKEY.
(NoZoneKeyBitSet => 11, b"No Zone Key Bit Set")
/// The resolver attempted to perform DNSSEC validation, but the
/// requested data was missing and a covering NSEC or NSEC3 was
/// not provided.
(NsecMissing => 12, b"NSEC Missing")
/// The resolver is returning the SERVFAIL RCODE from its cache.
(CachedError => 13, b"Cached Error")
/// The server is unable to answer the query, as it was not fully
/// functional when the query was received.
(NotReady => 14, b"Not Ready")
/// The server is unable to respond to the request because the
/// domain is on a blocklist due to an internal security policy
/// imposed by the operator of the server resolving or forwarding
/// the query.
(Blocked => 15, b"Blocked")
/// The server is unable to respond to the request because the
/// domain is on a blocklist due to an external requirement
/// imposed by an entity other than the operator of the server
/// resolving or forwarding the query. Note that how the imposed
/// policy is applied is irrelevant (in-band DNS filtering, court
/// order, etc.).
(Censored => 16, b"Censored")
/// The server is unable to respond to the request because the
/// domain is on a blocklist as requested by the client.
/// Functionally, this amounts to "you requested that we filter
/// domains like this one."
(Filtered => 17, b"Filtered")
/// An authoritative server or recursive resolver that receives a
/// query from an "unauthorized" client can annotate its REFUSED
/// message with this code. Examples of "unauthorized" clients are
/// recursive queries from IP addresses outside the network,
/// blocklisted IP addresses, local policy, etc.
(Prohibited => 18, b"Prohibited")
/// The resolver was unable to resolve an answer within its
/// configured time limits and decided to answer with a previously
/// cached NXDOMAIN answer instead of answering with an error.
/// This may be caused, for example, by problems communicating
/// with an authoritative server, possibly as result of a denial
/// of service (DoS) attack against another network. (See also
/// Code 3.)
(StaleNxdomainAnswer => 19, b"Stale NXDomain Answer")
/// An authoritative server that receives a query with the
/// Recursion Desired (RD) bit clear, or when it is not configured
/// for recursion for a domain for which it is not authoritative,
/// SHOULD include this EDE code in the REFUSED response. A
/// resolver that receives a query with the RD bit clear SHOULD
/// include this EDE code in the REFUSED response.
(NotAuthoritative => 20, b"Not Authoritative")
/// The requested operation or query is not supported.
(NotSupported => 21, b"Not Supported")
/// The resolver could not reach any of the authoritative name
/// servers (or they potentially refused to reply).
(NoReachableAuthority => 22, b"No Reachable Authority")
/// An unrecoverable error occurred while communicating with
/// another server.
(NetworkError => 23, b"Network Error")
/// The authoritative server cannot answer with data for a zone it
/// is otherwise configured to support. Examples of this include
/// its most recent zone being too old or having expired.
(InvalidData => 24, b"Invalid Data")
}
/// Start of the private range for EDE codes.
///
/// ```text
/// Registration Procedures:
/// o 0 - 49151: First come, first served.
/// o 49152 - 65535: Private use.
/// ```
pub const EDE_PRIVATE_RANGE_BEGIN: u16 = 49152;
// Only implement `Display` for `ExtendedErrorCode`, as the `FromStr`
// bundled by the `int_enum_*` macros is not very useful.
impl core::fmt::Display for ExtendedErrorCode {
fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
use core::fmt::Write;
match self.to_mnemonic() {
Some(m) => {
for ch in m {
f.write_char(*ch as char)?
}
Ok(())
}
None => write!(f, "EDE{}", self.to_int()),
}
}
}