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package etcd
import (
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/dnsutil"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// ServeDNS implements the plugin.Handler interface.
func (e *Etcd) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
opt := plugin.Options{}
state := request.Request{W: w, Req: r, Context: ctx}
name := state.Name()
// 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 plugin.Name(zone).Matches(name) {
stub := Stub{Etcd: e, Zone: zone}
return stub.ServeDNS(ctx, w, r)
}
}
}
zone := plugin.Zones(e.Zones).Matches(state.Name())
if zone == "" {
return plugin.NextOrFailure(e.Name(), e.Next, ctx, w, r)
}
var (
records, extra []dns.RR
err error
)
switch state.QType() {
case dns.TypeA:
records, err = plugin.A(e, zone, state, nil, opt)
case dns.TypeAAAA:
records, err = plugin.AAAA(e, zone, state, nil, opt)
case dns.TypeTXT:
records, err = plugin.TXT(e, zone, state, opt)
case dns.TypeCNAME:
records, err = plugin.CNAME(e, zone, state, opt)
case dns.TypePTR:
records, err = plugin.PTR(e, zone, state, opt)
case dns.TypeMX:
records, extra, err = plugin.MX(e, zone, state, opt)
case dns.TypeSRV:
records, extra, err = plugin.SRV(e, zone, state, opt)
case dns.TypeSOA:
records, err = plugin.SOA(e, zone, state, opt)
case dns.TypeNS:
if state.Name() == zone {
records, extra, err = plugin.NS(e, zone, state, opt)
break
}
fallthrough
default:
// Do a fake A lookup, so we can distinguish between NODATA and NXDOMAIN
_, err = plugin.A(e, zone, state, nil, opt)
}
if e.IsNameError(err) {
if e.Fall.Through(state.Name()) {
return plugin.NextOrFailure(e.Name(), e.Next, ctx, w, r)
}
// Make err nil when returning here, so we don't log spam for NXDOMAIN.
return plugin.BackendError(e, zone, dns.RcodeNameError, state, nil /* err */, opt)
}
if err != nil {
return plugin.BackendError(e, zone, dns.RcodeServerFailure, state, err, opt)
}
if len(records) == 0 {
return plugin.BackendError(e, zone, dns.RcodeSuccess, state, 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...)
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" }
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