daf8ef0da8
* adds the dnstap I/O thread and should fix a lot of mistakes * docs * -race test * oops * docs
84 lines
1.9 KiB
Go
84 lines
1.9 KiB
Go
package dnstap
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import (
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"fmt"
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"io"
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"github.com/coredns/coredns/plugin"
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"github.com/coredns/coredns/plugin/dnstap/msg"
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"github.com/coredns/coredns/plugin/dnstap/taprw"
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tap "github.com/dnstap/golang-dnstap"
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"github.com/miekg/dns"
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"golang.org/x/net/context"
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)
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// Dnstap is the dnstap handler.
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type Dnstap struct {
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Next plugin.Handler
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IO IORoutine
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Pack bool
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}
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type (
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// IORoutine is the dnstap I/O thread as defined by: <http://dnstap.info/Architecture>.
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IORoutine interface {
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Dnstap(tap.Dnstap)
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}
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// Tapper is implemented by the Context passed by the dnstap handler.
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Tapper interface {
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TapMessage(*tap.Message) error
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TapBuilder() msg.Builder
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}
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tapContext struct {
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context.Context
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Dnstap
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}
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)
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// TapperFromContext will return a Tapper if the dnstap plugin is enabled.
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func TapperFromContext(ctx context.Context) (t Tapper) {
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t, _ = ctx.(Tapper)
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return
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}
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func tapMessageTo(w io.Writer, m *tap.Message) error {
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frame, err := msg.Marshal(m)
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if err != nil {
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return fmt.Errorf("marshal: %s", err)
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}
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_, err = w.Write(frame)
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return err
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}
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// TapMessage implements Tapper.
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func (h Dnstap) TapMessage(m *tap.Message) error {
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h.IO.Dnstap(msg.Wrap(m))
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return nil
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}
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// TapBuilder implements Tapper.
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func (h Dnstap) TapBuilder() msg.Builder {
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return msg.Builder{Full: h.Pack}
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}
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// ServeDNS logs the client query and response to dnstap and passes the dnstap Context.
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func (h Dnstap) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
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rw := &taprw.ResponseWriter{ResponseWriter: w, Tapper: &h, Query: r}
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rw.QueryEpoch()
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code, err := plugin.NextOrFailure(h.Name(), h.Next, tapContext{ctx, h}, rw, r)
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if err != nil {
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// ignore dnstap errors
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return code, err
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}
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if err := rw.DnstapError(); err != nil {
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return code, plugin.Error("dnstap", err)
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}
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return code, nil
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}
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// Name returns dnstap.
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func (h Dnstap) Name() string { return "dnstap" }
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