66 lines
1.2 KiB
Go
66 lines
1.2 KiB
Go
package resolvers
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import (
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"bytes"
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"fmt"
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"io/ioutil"
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"net/http"
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"time"
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"github.com/miekg/dns"
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)
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// DOHResolver represents the config options for setting up a DOH based resolver.
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type DOHResolver struct {
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client *http.Client
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servers []string
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}
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// NewDOHResolver accepts a list of nameservers and configures a DOH based resolver.
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func NewDOHResolver(servers []string) (Resolver, error) {
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httpClient := &http.Client{
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Timeout: 10 * time.Second,
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}
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return &DOHResolver{
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client: httpClient,
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servers: servers,
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}, nil
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}
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func (r *DOHResolver) Lookup(questions []dns.Question) error {
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messages := prepareMessages(questions)
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for _, m := range messages {
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b, err := m.Pack()
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if err != nil {
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return err
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}
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for _, srv := range r.servers {
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resp, err := r.client.Post(srv, "application/dns-message", bytes.NewBuffer(b))
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if err != nil {
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return err
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}
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if resp.StatusCode != http.StatusOK {
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return err
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}
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body, err := ioutil.ReadAll(resp.Body)
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if err != nil {
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return err
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}
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r := &dns.Msg{}
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err = r.Unpack(body)
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if err != nil {
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return err
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}
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for _, ans := range r.Answer {
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if t, ok := ans.(*dns.A); ok {
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fmt.Println(t.String())
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}
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}
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}
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}
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return nil
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}
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