dns

Documentation

Index

• Variables
• func LookupIP4(host string) (ips []net.IP, err error)
• func LookupIP6(host string) (ips []net.IP, err error)
• type LocalDNS
  • func NewLocalDNS(opts Options) *LocalDNS
  • func (s *LocalDNS) LookupIP(host string, ...) (ips []net.IP, err error)
  • func (s *LocalDNS) ReverseLookup(ip string) (hosts []string, err error)
  • func (s *LocalDNS) Run()
• type Options
• type Resolver
  • func (r *Resolver) LookupIP(host string, t uint16) (ips []net.IP, err error)

Variables

var (
	ErrLocalDNSDisabled = errors.New("local dns is disabled")
)

Functions

func LookupIP4

func LookupIP4(host string) (ips []net.IP, err error)

func LookupIP6

func LookupIP6(host string) (ips []net.IP, err error)

Types

type LocalDNS

type LocalDNS struct {
	// contains filtered or unexported fields
}

LocalDNS local dns server it has a simple dns cache, and can customize dns message exchange function

func NewLocalDNS

func NewLocalDNS(opts Options) *LocalDNS

func (*LocalDNS) LookupIP

func (s *LocalDNS) LookupIP(host string,
	exchange func(dnServer string, query *dns.Msg) (resp *dns.Msg, err error)) (ips []net.IP, err error)

LookupIP lookup ip address for a host use custom exchange function

func (*LocalDNS) ReverseLookup

func (s *LocalDNS) ReverseLookup(ip string) (hosts []string, err error)

ReverseLookup reverse lookup hostnames for an ip address

func (*LocalDNS) Run

func (s *LocalDNS) Run()

Run run the local dns server

type Options

type Options struct {
	Listen   string                                                                              // listen address
	Upstream string                                                                              // upstream dns server
	Evict    time.Duration                                                                       // cache evict duration
	Exchange func(upstream string, clientAddr string, query *dns.Msg) (resp *dns.Msg, err error) // dns message exchange function
}

Options local dns server options

type Resolver

type Resolver struct {
	IPv4Servers []string
	IPv6Servers []string
	Exchange    func(dnServer string, r *dns.Msg) (*dns.Msg, error)
}

var DefaultResolver Resolver = Resolver{
	IPv4Servers: []string{"8.8.8.8:53", "223.5.5.5:53"},
	IPv6Servers: []string{"[2001:4860:4860::8888]:53", "[2400:3200::1]:53"},
	Exchange: func(dnServer string, r *dns.Msg) (resp *dns.Msg, err error) {
		dnsLookupCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		resp, _, err = dnsClient.ExchangeContext(dnsLookupCtx, r, dnServer)
		return
	},
}

func (*Resolver) LookupIP

func (r *Resolver) LookupIP(host string, t uint16) (ips []net.IP, err error)