Struct HickoryResolver 

pub struct HickoryResolver { /* private fields */ }

The production resolver, reading /etc/resolv.conf at startup.

Implementations

impl HickoryResolver

pub fn from_system() -> Result<Self>

Builds a resolver from the system configuration, with hickory’s default cache.

pub fn from_system_uncached() -> Result<Self>

Same, with caching disabled.

dns-01 asks about a record the client has just published, so a cached negative answer would fail a challenge that is in fact satisfied — for the whole negative TTL, which the client does not control. Answering from the authoritative servers every time is the point of the lookup.

pub fn from_address(addr: SocketAddr) -> Result<Self>

Builds a resolver querying only addr (config.dns.resolver), instead of the system configuration. Used by reverse_dns, which wants caching.

pub fn from_address_uncached(addr: SocketAddr) -> Result<Self>

Same, with caching disabled — the dns-01 counterpart of Self::from_address, for the same reason Self::from_system_uncached disables it.

Trait Implementations

impl Resolver for HickoryResolver

fn reverse<'life0, 'async_trait>( &'life0 self, ip: IpAddr, ) -> Pin<Box<dyn Future<Output = Result<Vec<String>, String>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

hickory’s *_lookup methods (used here and in Self::forward and Self::txt) surface both NXDOMAIN and an empty NOERROR answer as Err(NetError), not Ok with no records — so without distinguishing is_no_records_found() in each of the three, “the client just doesn’t have this record” (the ordinary shape of “no PTR record for this address”, or a dns-01 TXT record not published yet) is indistinguishable from the resolver genuinely failing (SERVFAIL, timeout). filter::reverse_dns depends on telling those apart: the former denies the request, the latter is a 500 the client can retry. (dns_01 happens not to care — both cases map to the same ChallengeError::Dns there — which is why this went uncaught until reverse_dns was first exercised against a real resolver, in the podman-compose lab’s filters/reverse_dns.)

fn forward<'life0, 'life1, 'async_trait>( &'life0 self, name: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Vec<IpAddr>, String>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

A/AAAA addresses for name.

fn txt<'life0, 'life1, 'async_trait>( &'life0 self, name: &'life1 str, ) -> Pin<Box<dyn Future<Output = Result<Vec<String>, String>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait,

TXT records for name.