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b0b317fdd6
When the plugin chain returns an error rcode without writing a response (it falls off the end, or returns SERVFAIL/REFUSED/FORMERR/NOTIMP), the server generates and sends the error to the client after dnstap's ServeDNS returns, so ResponseWriter.WriteMsg is never called and no CLIENT_RESPONSE dnstap message is emitted. dnstap consumers then see a CLIENT_QUERY with no matching CLIENT_RESPONSE. Synthesize the deferred response and tap it as a CLIENT_RESPONSE, mirroring the deferred-response handling already added to plugin/log. Fixes #6532 Signed-off-by: Saleh <root@lr0.org>
52 lines
1.3 KiB
Go
52 lines
1.3 KiB
Go
package dnstap
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import (
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"context"
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"time"
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"github.com/coredns/coredns/plugin/dnstap/msg"
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"github.com/coredns/coredns/request"
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tap "github.com/dnstap/golang-dnstap"
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"github.com/miekg/dns"
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)
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// ResponseWriter captures the client response and logs the query to dnstap.
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type ResponseWriter struct {
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queryTime time.Time
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query *dns.Msg
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ctx context.Context
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written bool // whether WriteMsg was called, i.e. a response was written to the client
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dns.ResponseWriter
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*Dnstap
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}
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// WriteMsg writes back the response to the client and THEN works on logging the request and response to dnstap.
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func (w *ResponseWriter) WriteMsg(resp *dns.Msg) error {
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err := w.ResponseWriter.WriteMsg(resp)
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if err != nil {
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return err
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}
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w.written = true
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w.tapResponse(resp)
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return nil
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}
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// tapResponse sends a CLIENT_RESPONSE dnstap message for resp. It does not
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// write anything back to the client; the caller is responsible for that.
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func (w *ResponseWriter) tapResponse(resp *dns.Msg) {
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r := new(tap.Message)
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msg.SetQueryTime(r, w.queryTime)
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msg.SetResponseTime(r, time.Now())
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msg.SetQueryAddress(r, w.RemoteAddr())
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if w.IncludeRawMessage {
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buf, _ := resp.Pack()
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r.ResponseMessage = buf
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}
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msg.SetType(r, tap.Message_CLIENT_RESPONSE)
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state := request.Request{W: w.ResponseWriter, Req: w.query}
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w.TapMessageWithMetadata(w.ctx, r, state)
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}
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