Struct trust_dns_resolver::Resolver

pub struct Resolver { /* fields omitted */ }

The Resolver is used for performing DNS queries.

For forward (A) lookups, hostname -> IP address, see: Resolver::lookup_ip

Special note about resource consumption. The Resolver and all Trust-DNS software is built around the Tokio async-io library. This synchronous Resolver is intended to be a simpler wrapper for of the [trust_dns_resolver::ResolverFuture]. To allow the Resolver to be Send + Sync, the construction of the ResolverFuture is lazy, this means some of the features of the ResolverFuture, like performance based resolution via the most efficient NameServer will be lost (the lookup cache is shared across invocations of the Resolver). If these other features of the Trust-DNS Resolver are desired, please use the tokio based ResolverFuture.

Note: Threaded/Sync usage: In multithreaded scenarios, the internal Tokio Runtime will block on an internal Mutex for the tokio Runtime in use. For higher performance, it's recommended to use the AsyncResolver.

Methods

impl Resolver

pub fn new(config: ResolverConfig, options: ResolverOpts) -> Result<Self>

Constructs a new Resolver with the specified configuration.

Arguments

• config - configuration for the resolver
• options - resolver options for performing lookups
• client_connection - ClientConnection for establishing the connection to the DNS server

Returns

A new Resolver or an error if there was an error with the configuration.

pub fn default() -> Result<Self>

Constructs a new Resolver with default config and default options.

See [ResolverConfig::default] and [ResolverOpts::default] for more information.

Returns

A new Resolver or an error if there was an error with the configuration.

pub fn from_system_conf() -> Result<Self>

Constructs a new Resolver with the system configuration.

This will use /etc/resolv.conf on Unix OSes and the registry on Windows.

pub fn lookup(
    &self,
    name: &str,
    record_type: RecordType
) -> ResolveResult<Lookup>

Generic lookup for any RecordType

WARNING This interface may change in the future, please use [Self::lookup_ip] or another variant for more stable interfaces.

Arguments

• name - name of the record to lookup, if name is not a valid domain name, an error will be returned
• record_type - type of record to lookup

pub fn lookup_ip(&self, host: &str) -> ResolveResult<LookupIp>

Performs a dual-stack DNS lookup for the IP for the given hostname.

See the configuration and options parameters for controlling the way in which A(Ipv4) and AAAA(Ipv6) lookups will be performed. For the least expensive query a fully-qualified-domain-name, FQDN, which ends in a final ., e.g. www.example.com., will only issue one query. Anything else will always incur the cost of querying the ResolverConfig::domain and ResolverConfig::search.

Arguments

• host - string hostname, if this is an invalid hostname, an error will be returned.

pub fn lookup_service(
    &self,
    service: &str,
    protocol: &str,
    name: &str
) -> ResolveResult<SrvLookup>

Deprecated:

use lookup_srv instead, this interface is none ideal

Performs a DNS lookup for an SRV record for the specified service type and protocol at the given name.

This is a convenience method over lookup_srv, it combines the service, protocol and name into a single name: _service._protocol.name.

Arguments

• service - service to lookup, e.g. ldap or http
• protocol - wire protocol, e.g. udp or tcp
• name - zone or other name at which the service is located.

pub fn lookup_srv(&self, name: &str) -> ResolveResult<SrvLookup>

Lookup an SRV record.

pub fn reverse_lookup(&self, query: IpAddr) -> ResolveResult<ReverseLookup>

Performs a lookup for the associated type.

Arguments

• query - a type which can be converted to Name via From.

pub fn ipv4_lookup(&self, query: &str) -> ResolveResult<Ipv4Lookup>

Performs a lookup for the associated type.

hint queries that end with a '.' are fully qualified names and are cheaper lookups

Arguments

• query - a str which parses to a domain name, failure to parse will return an error

pub fn ipv6_lookup(&self, query: &str) -> ResolveResult<Ipv6Lookup>

Performs a lookup for the associated type.

hint queries that end with a '.' are fully qualified names and are cheaper lookups

Arguments

• query - a str which parses to a domain name, failure to parse will return an error

pub fn mx_lookup(&self, query: &str) -> ResolveResult<MxLookup>

Performs a lookup for the associated type.

hint queries that end with a '.' are fully qualified names and are cheaper lookups

Arguments

• query - a str which parses to a domain name, failure to parse will return an error

pub fn srv_lookup(&self, query: &str) -> ResolveResult<SrvLookup>

Performs a lookup for the associated type.

hint queries that end with a '.' are fully qualified names and are cheaper lookups

Arguments

• query - a str which parses to a domain name, failure to parse will return an error

pub fn txt_lookup(&self, query: &str) -> ResolveResult<TxtLookup>

Performs a lookup for the associated type.

hint queries that end with a '.' are fully qualified names and are cheaper lookups

Arguments

• query - a str which parses to a domain name, failure to parse will return an error