core: block CH queries earlier (#973)

block chaos queries, unless the chaos or proxy middleware is loaded. We
respond with REFUSED.

This removes the need for each middleware to do this class != ClassINET
if-then.

Also make config.Registry non-public.

5 files changed, 1 insertions, 22 deletions

diff --git a/middleware/auto/auto.go b/middleware/auto/auto.go
index 019613a0f..31fe53e23 100644
--- a/middleware/auto/auto.go
+++ b/middleware/auto/auto.go
@@ -2,7 +2,6 @@
 package auto
 
 import (
-	"errors"
 	"regexp"
 	"time"
 
@@ -43,9 +42,6 @@ type (
 // ServeDNS implements the middleware.Handle interface.
 func (a Auto) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(a.Name(), errors.New("can only deal with ClassINET"))
-	}
 	qname := state.Name()
 
 	// TODO(miek): match the qname better in the map
diff --git a/middleware/etcd/handler.go b/middleware/etcd/handler.go
index a5e5f1b80..2de6fb629 100644
--- a/middleware/etcd/handler.go
+++ b/middleware/etcd/handler.go
@@ -1,8 +1,6 @@
 package etcd
 
 import (
-	"errors"
-
 	"github.com/coredns/coredns/middleware"
 	"github.com/coredns/coredns/middleware/etcd/msg"
 	"github.com/coredns/coredns/middleware/pkg/debug"
@@ -17,9 +15,7 @@ import (
 func (e *Etcd) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	opt := middleware.Options{}
 	state := request.Request{W: w, Req: r}
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(e.Name(), errors.New("can only deal with ClassINET"))
-	}
+
 	name := state.Name()
 	if e.Debugging {
 		if bug := debug.IsDebug(name); bug != "" {
diff --git a/middleware/file/file.go b/middleware/file/file.go
index 8a4cd27e2..27ab0cd1b 100644
--- a/middleware/file/file.go
+++ b/middleware/file/file.go
@@ -2,7 +2,6 @@
 package file
 
 import (
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -32,9 +31,6 @@ type (
 func (f File) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
 
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(f.Name(), errors.New("can only deal with ClassINET"))
-	}
 	qname := state.Name()
 	// TODO(miek): match the qname better in the map
 	zone := middleware.Zones(f.Zones.Names).Matches(qname)
diff --git a/middleware/hosts/hosts.go b/middleware/hosts/hosts.go
index 68bd41b34..28efc47ec 100644
--- a/middleware/hosts/hosts.go
+++ b/middleware/hosts/hosts.go
@@ -1,7 +1,6 @@
 package hosts
 
 import (
-	"errors"
 	"net"
 
 	"golang.org/x/net/context"
@@ -23,9 +22,6 @@ type Hosts struct {
 // ServeDNS implements the middleware.Handle interface.
 func (h Hosts) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(h.Name(), errors.New("can only deal with ClassINET"))
-	}
 	qname := state.Name()
 
 	answers := []dns.RR{}
diff --git a/middleware/kubernetes/handler.go b/middleware/kubernetes/handler.go
index 871605ef9..b6cc703b7 100644
--- a/middleware/kubernetes/handler.go
+++ b/middleware/kubernetes/handler.go
@@ -1,8 +1,6 @@
 package kubernetes
 
 import (
-	"errors"
-
 	"github.com/coredns/coredns/middleware"
 	"github.com/coredns/coredns/middleware/pkg/dnsutil"
 	"github.com/coredns/coredns/request"
@@ -14,9 +12,6 @@ import (
 // ServeDNS implements the middleware.Handler interface.
 func (k Kubernetes) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
 	state := request.Request{W: w, Req: r}
-	if state.QClass() != dns.ClassINET {
-		return dns.RcodeServerFailure, middleware.Error(k.Name(), errors.New("can only deal with ClassINET"))
-	}
 
 	m := new(dns.Msg)
 	m.SetReply(r)