101 lines
2.3 KiB
Go
101 lines
2.3 KiB
Go
// SPDX-License-Identifier: BSD-3-Clause
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package resolvers
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import (
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"bytes"
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"crypto/tls"
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"fmt"
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"io"
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"net/http"
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"time"
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"git.froth.zone/sam/awl/pkg/util"
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"github.com/miekg/dns"
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)
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// HTTPSResolver is for DNS-over-HTTPS queries.
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type HTTPSResolver struct {
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opts util.Options
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}
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var _ Resolver = (*HTTPSResolver)(nil)
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// LookUp performs a DNS query.
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func (resolver *HTTPSResolver) LookUp(msg *dns.Msg) (util.Response, error) {
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var resp util.Response
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httpR := &http.Client{
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Timeout: resolver.opts.Request.Timeout,
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Transport: &http.Transport{
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MaxConnsPerHost: 1,
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MaxIdleConns: 1,
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MaxIdleConnsPerHost: 1,
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Proxy: http.ProxyFromEnvironment,
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TLSClientConfig: &tls.Config{
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//nolint:gosec // This is intentional if the user requests it
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InsecureSkipVerify: resolver.opts.TLSNoVerify,
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ServerName: resolver.opts.TLSHost,
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},
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},
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}
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buf, err := msg.Pack()
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: packing: %w", err)
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}
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resolver.opts.Logger.Debug("https: sending HTTPS request")
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req, err := http.NewRequest("POST", resolver.opts.Request.Server, bytes.NewBuffer(buf))
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: request creation: %w", err)
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}
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req.Header.Set("Content-Type", "application/dns-message")
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req.Header.Set("Accept", "application/dns-message")
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now := time.Now()
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res, err := httpR.Do(req)
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resp.RTT = time.Since(now)
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: HTTP request: %w", err)
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}
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if res.StatusCode != http.StatusOK {
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return util.Response{}, &ErrHTTPStatus{res.StatusCode}
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}
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resolver.opts.Logger.Debug("https: reading response")
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fullRes, err := io.ReadAll(res.Body)
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: body read: %w", err)
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}
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err = res.Body.Close()
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: body close: %w", err)
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}
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resolver.opts.Logger.Debug("https: unpacking response")
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resp.DNS = &dns.Msg{}
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err = resp.DNS.Unpack(fullRes)
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if err != nil {
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return util.Response{}, fmt.Errorf("doh: dns message unpack: %w", err)
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}
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return resp, nil
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}
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// ErrHTTPStatus is returned when DoH returns a bad status code.
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type ErrHTTPStatus struct {
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code int
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}
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func (e *ErrHTTPStatus) Error() string {
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return fmt.Sprintf("doh server responded with HTTP %d", e.code)
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}
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