Struct async_std_resolver::config::ResolverOpts

#[non_exhaustive]
pub struct ResolverOpts {

    pub ndots: usize,
    pub timeout: Duration,
    pub attempts: usize,
    pub rotate: bool,
    pub check_names: bool,
    pub edns0: bool,
    pub validate: bool,
    pub ip_strategy: LookupIpStrategy,
    pub cache_size: usize,
    pub use_hosts_file: bool,
    pub positive_min_ttl: Option<Duration>,
    pub negative_min_ttl: Option<Duration>,
    pub positive_max_ttl: Option<Duration>,
    pub negative_max_ttl: Option<Duration>,
    pub num_concurrent_reqs: usize,
    pub preserve_intermediates: bool,
    pub try_tcp_on_error: bool,
    pub server_ordering_strategy: ServerOrderingStrategy,
    pub recursion_desired: bool,
    pub authentic_data: bool,
    pub shuffle_dns_servers: bool,
}

Configuration for the Resolver

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

ndots: usize

Sets the number of dots that must appear (unless it’s a final dot representing the root) before a query is assumed to include the TLD. The default is one, which means that www would never be assumed to be a TLD, and would always be appended to either the search

timeout: Duration

Specify the timeout for a request. Defaults to 5 seconds

attempts: usize

Number of retries after lookup failure before giving up. Defaults to 2

rotate: bool

Rotate through the resource records in the response (if there is more than one for a given name)

check_names: bool

Validate the names in the response, not implemented don’t really see the point unless you need to support badly configured DNS

edns0: bool

Enable edns, for larger records

validate: bool

Use DNSSEC to validate the request

ip_strategy: LookupIpStrategy

The ip_strategy for the Resolver to use when lookup Ipv4 or Ipv6 addresses

cache_size: usize

Cache size is in number of records (some records can be large)

use_hosts_file: bool

Check /ect/hosts file before dns requery (only works for unix like OS)

positive_min_ttl: Option<Duration>

Optional minimum TTL for positive responses.

If this is set, any positive responses with a TTL lower than this value will have a TTL of positive_min_ttl instead. Otherwise, this will default to 0 seconds.

negative_min_ttl: Option<Duration>

Optional minimum TTL for negative (NXDOMAIN) responses.

If this is set, any negative responses with a TTL lower than this value will have a TTL of negative_min_ttl instead. Otherwise, this will default to 0 seconds.

positive_max_ttl: Option<Duration>

Optional maximum TTL for positive responses.

If this is set, any positive responses with a TTL higher than this value will have a TTL of positive_max_ttl instead. Otherwise, this will default to MAX_TTL seconds.

negative_max_ttl: Option<Duration>

Optional maximum TTL for negative (NXDOMAIN) responses.

If this is set, any negative responses with a TTL higher than this value will have a TTL of negative_max_ttl instead. Otherwise, this will default to MAX_TTL seconds.

num_concurrent_reqs: usize

Number of concurrent requests per query

Where more than one nameserver is configured, this configures the resolver to send queries to a number of servers in parallel. Defaults to 2; 0 or 1 will execute requests serially.

preserve_intermediates: bool

Preserve all intermediate records in the lookup response, such as CNAME records

try_tcp_on_error: bool

Try queries over TCP if they fail over UDP.

server_ordering_strategy: ServerOrderingStrategy

The server ordering strategy that the resolver should use.

recursion_desired: bool

Request upstream recursive resolvers to not perform any recursion.

This is true by default, disabling this is useful for requesting single records, but may prevent successful resolution.

authentic_data: bool

This is true by default, disabling this is useful for requesting single records, but may prevent successful resolution.

shuffle_dns_servers: bool

Shuffle DNS servers before each query.

Trait Implementations

impl Clone for ResolverOpts

fn clone(&self) -> ResolverOpts

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ResolverOpts

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

Formats the value using the given formatter.

impl Default for ResolverOpts

fn default() -> ResolverOpts

Default values for the Resolver configuration.

This follows the resolv.conf defaults as defined in the Linux man pages

impl PartialEq for ResolverOpts

fn eq(&self, other: &ResolverOpts) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ResolverOpts

impl Eq for ResolverOpts

impl StructuralEq for ResolverOpts

impl StructuralPartialEq for ResolverOpts