coredns/middleware/etcd/handler.go
Miek Gieben 55dafe6f59 core: block CH queries earlier ()
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.
2017-08-25 08:55:53 +01:00

119 lines
3.4 KiB
Go

package etcd
import (
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/etcd/msg"
"github.com/coredns/coredns/middleware/pkg/debug"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// ServeDNS implements the middleware.Handler interface.
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}
name := state.Name()
if e.Debugging {
if bug := debug.IsDebug(name); bug != "" {
opt.Debug = r.Question[0].Name
state.Clear()
state.Req.Question[0].Name = bug
}
}
// We need to check stubzones first, because we may get a request for a zone we
// are not auth. for *but* do have a stubzone forward for. If we do the stubzone
// handler will handle the request.
if e.Stubmap != nil && len(*e.Stubmap) > 0 {
for zone := range *e.Stubmap {
if middleware.Name(zone).Matches(name) {
stub := Stub{Etcd: e, Zone: zone}
return stub.ServeDNS(ctx, w, r)
}
}
}
zone := middleware.Zones(e.Zones).Matches(state.Name())
if zone == "" {
if opt.Debug != "" {
r.Question[0].Name = opt.Debug
}
if e.Fallthrough {
return middleware.NextOrFailure(e.Name(), e.Next, ctx, w, r)
}
return dns.RcodeServerFailure, nil
}
var (
records, extra []dns.RR
debug []msg.Service
err error
)
switch state.Type() {
case "A":
records, debug, err = middleware.A(e, zone, state, nil, opt)
case "AAAA":
records, debug, err = middleware.AAAA(e, zone, state, nil, opt)
case "TXT":
records, debug, err = middleware.TXT(e, zone, state, opt)
case "CNAME":
records, debug, err = middleware.CNAME(e, zone, state, opt)
case "PTR":
records, debug, err = middleware.PTR(e, zone, state, opt)
case "MX":
records, extra, debug, err = middleware.MX(e, zone, state, opt)
case "SRV":
records, extra, debug, err = middleware.SRV(e, zone, state, opt)
case "SOA":
records, debug, err = middleware.SOA(e, zone, state, opt)
case "NS":
if state.Name() == zone {
records, extra, debug, err = middleware.NS(e, zone, state, opt)
break
}
fallthrough
default:
// Do a fake A lookup, so we can distinguish between NODATA and NXDOMAIN
_, debug, err = middleware.A(e, zone, state, nil, opt)
}
if opt.Debug != "" {
// Substitute this name with the original when we return the request.
state.Clear()
state.Req.Question[0].Name = opt.Debug
}
if e.IsNameError(err) {
// Make err nil when returning here, so we don't log spam for NXDOMAIN.
return middleware.BackendError(e, zone, dns.RcodeNameError, state, debug, nil /* err */, opt)
}
if err != nil {
return middleware.BackendError(e, zone, dns.RcodeServerFailure, state, debug, err, opt)
}
if len(records) == 0 {
return middleware.BackendError(e, zone, dns.RcodeSuccess, state, debug, err, opt)
}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
m.Answer = append(m.Answer, records...)
m.Extra = append(m.Extra, extra...)
if opt.Debug != "" {
m.Extra = append(m.Extra, middleware.ServicesToTxt(debug)...)
}
m = dnsutil.Dedup(m)
state.SizeAndDo(m)
m, _ = state.Scrub(m)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
// Name implements the Handler interface.
func (e *Etcd) Name() string { return "etcd" }