auto make -f Makefile.doc

man/coredns-dnstap.7

@@ -1,5 +1,5 @@
 .\" Generated by Mmark Markdown Processer - mmark.miek.nl
-.TH "COREDNS-DNSTAP" 7 "September 2020" "CoreDNS" "CoreDNS Plugins"
+.TH "COREDNS-DNSTAP" 7 "October 2020" "CoreDNS" "CoreDNS Plugins"
 
 .SH "NAME"
 .PP
@@ -111,27 +111,44 @@ $ dnstap \-l 127.0.0.1:6000
 .RE
 
 .SH "USING DNSTAP IN YOUR PLUGIN"
+.PP
+In your setup function, check to see if the \fIdnstap\fP plugin is loaded:
+
 .PP
 .RS
 
 .nf
-import (
-    "github.com/coredns/coredns/plugin/dnstap"
-    "github.com/coredns/coredns/plugin/dnstap/msg"
-)
-
-func (h Dnstap) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
-    // log client query to Dnstap
-    if t := dnstap.TapperFromContext(ctx); t != nil {
-        b := msg.New().Time(time.Now()).Addr(w.RemoteAddr())
-        if t.Pack() {
-            b.Msg(r)
-        }
-        if m, err := b.ToClientQuery(); err == nil {
-            t.TapMessage(m)
+c.OnStartup(func() error {
+    if taph := dnsserver.GetConfig(c).Handler("dnstap"); taph != nil {
+        if tapPlugin, ok := taph.(dnstap.Dnstap); ok {
+            f.tapPlugin = \&tapPlugin
         }
     }
+    return nil
+})
 
+.fi
+.RE
+
+.PP
+And then in your plugin:
+
+.PP
+.RS
+
+.nf
+func (x RandomPlugin) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
+    if tapPlugin != nil {
+        q := new(msg.Msg)
+        msg.SetQueryTime(q, time.Now())
+        msg.SetQueryAddress(q, w.RemoteAddr())
+        if tapPlugin.IncludeRawMessage {
+            buf, \_ := r.Pack() // r has been seen packed/unpacked before, this should not fail
+            q.QueryMessage = buf
+        }
+        msg.SetType(q, tap.Message\_CLIENT\_QUERY)
+        tapPlugin.TapMessage(q)
+    }
     // ...
 }
 
@@ -140,6 +157,7 @@ func (h Dnstap) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
 
 .SH "SEE ALSO"
 .PP
-dnstap.info
-\[la]https://dnstap.info\[ra].
+The website dnstap.info
+\[la]https://dnstap.info\[ra] has info on the dnstap protocol.
+The \fIforward\fP plugin's \fB\fCdnstap.go\fR uses dnstap to tap messages sent to an upstream.