Enum DnsParseError 

pub enum DnsParseError {
    TooShort,
    QdcountZero,
    QdcountUnsupported(u16),
    LabelOverflow,
    NameOverflow,
    CompressionRejected,
    UnsupportedClass(u16),
    InvalidLabelByte(u8),
}

Errors the parser can surface. Each maps to a reasonCode on the emitted dns_query event:

• DnsParseError::TooShort, DnsParseError::QdcountZero, DnsParseError::QdcountUnsupported, DnsParseError::LabelOverflow, DnsParseError::NameOverflow, DnsParseError::CompressionRejected, DnsParseError::UnsupportedClass, DnsParseError::InvalidLabelByte → malformed_query (proxy drops the packet — no response — matching common resolver behaviour against malformed input).

Variants

TooShort

Packet smaller than the 12-byte header or truncated mid-question.

QdcountZero

Header QDCOUNT field was 0. A query with no questions is malformed — there is nothing to evaluate against the allowlist. The T2.B multi-question expansion accepts QDCOUNT >= 1; only the degenerate zero case is now refused at the parser layer.

QdcountUnsupported(u16)

Header QDCOUNT was greater than 1 on the hot-path single-question API. HIGH-D1 closed the policy-bypass / log-evasion gap that arose from “parse FIRST question, forward all bytes verbatim”: a hostile guest could craft a [allowed.example.com, attacker.tld] packet, pass the allowlist on Q1, and have Q2 silently resolved by the upstream resolver. The supervisor’s contract is one allow-listed query in, one logged event out — so the parser now refuses any QDCOUNT != 1 on the proxy path. Tools that need multi-question inspection should use parse_query_multi.

LabelOverflow

A QNAME label exceeded the RFC 1035 63-octet maximum.

NameOverflow

Total QNAME length exceeded the RFC 1035 253-octet maximum.

CompressionRejected

Encountered a pointer-compressed label in a query QNAME — the parser rejects these as a defense against adversarial inputs.

UnsupportedClass(u16)

qclass was not IN (1). The parser only forwards Internet-class queries.

InvalidLabelByte(u8)

Label byte fell outside RFC 1035’s preferred ASCII set.

Trait Implementations

impl Debug for DnsParseError

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

Formats the value using the given formatter.

impl Display for DnsParseError

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

Formats the value using the given formatter.

impl Error for DnsParseError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for DnsParseError

fn eq(&self, other: &DnsParseError) -> 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 DnsParseError

impl StructuralPartialEq for DnsParseError