46 lines
813 B
Go
46 lines
813 B
Go
package dnsresolver
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import (
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"errors"
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"net"
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"github.com/miekg/dns"
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)
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type dnsResolver struct {
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resolver dns.Client
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}
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// New creates new DomainNameResolver.
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func New() DomainNameResolver {
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return &dnsResolver{
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resolver: dns.Client{},
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}
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}
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// ResolveA implements DomainNameResolver.
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func (r *dnsResolver) ResolveA(domain, nameserver string) ([]net.IP, error) {
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msg := &dns.Msg{}
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msg.SetQuestion(domain+".", dns.TypeA)
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answer, _, err := r.resolver.Exchange(msg, nameserver+":53")
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if err != nil {
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return nil, err
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}
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if len(answer.Answer) == 0 {
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return nil, errors.New("empty answer")
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}
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result := make([]net.IP, len(answer.Answer))
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for idx, rr := range answer.Answer {
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record := rr.(*dns.A)
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result[idx] = record.A
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}
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return result, nil
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}
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var (
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_ DomainNameResolver = &dnsResolver{}
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)
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