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middleware/reverse: random updates (#516)

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* middleware/reverse: random updates

Make the documentation somewhat shorter (and hopefully clearer in the
process). Also to be on-par with the *auto* middleware, start counting
the referenced zones from 1 (instead of 0).
Some variable cleanups and use the NextOrFailure in the ServeDNS
function.

* More TODOs
This commit is contained in:
Miek Gieben 2017-02-10 12:48:51 +00:00 • committed by GitHub
parent 87a39a6353
commit 3e196a6d57
5 changed files with 123 additions and 154 deletions
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47
middleware/reverse/reverse.go
View file

@ -3,31 +3,33 @@ package reverse
import (
"net"
"github.com/miekg/coredns/request"
"github.com/miekg/coredns/middleware"
"github.com/miekg/coredns/middleware/pkg/dnsutil"
"github.com/miekg/coredns/request"
"github.com/miekg/dns"
"golang.org/x/net/context"
)
// Reverse provides dynamic reverse dns and the related forward rr
// Reverse provides dynamic reverse DNS and the related forward RR.
type Reverse struct {
Next middleware.Handler
Networks networks
}
// ServeDNS implements the middleware.Handler interface.
func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
var rr dns.RR
nextHandler := true
func (re Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
var (
rr dns.RR
fallThrough bool
)
state := request.Request{W: w, Req: r}
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
switch state.QType(){
switch state.QType() {
case dns.TypePTR:
address := dnsutil.ExtractAddressFromReverse(state.Name())
@ -38,11 +40,11 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
ip := net.ParseIP(address)
// loop through the configured networks
for _, n := range reverse.Networks {
if (n.IPnet.Contains(ip)) {
nextHandler = n.Fallthrough
for _, n := range re.Networks {
if n.IPnet.Contains(ip) {
fallThrough = n.Fallthrough
rr = &dns.PTR{
Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: n.TTL},
Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypePTR, Class: dns.ClassINET, Ttl: n.TTL},
Ptr: n.ipToHostname(ip),
}
break
@ -50,9 +52,9 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
}
case dns.TypeA:
for _, n := range reverse.Networks {
for _, n := range re.Networks {
if dns.IsSubDomain(n.Zone, state.Name()) {
nextHandler = n.Fallthrough
fallThrough = n.Fallthrough
// skip if requesting an v4 address and network is not v4
if n.IPnet.IP.To4() == nil {
@ -62,8 +64,8 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
result := n.hostnameToIP(state.Name())
if result != nil {
rr = &dns.A{
Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: n.TTL},
A: result,
Hdr: dns.RR_Header{Name: state.QName(), Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: n.TTL},
A: result,
}
break
}
@ -71,9 +73,9 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
}
case dns.TypeAAAA:
for _, n := range reverse.Networks {
for _, n := range re.Networks {
if dns.IsSubDomain(n.Zone, state.Name()) {
nextHandler = n.Fallthrough
fallThrough = n.Fallthrough
// Do not use To16 which tries to make v4 in v6
if n.IPnet.IP.To4() != nil {
@ -93,13 +95,8 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
}
if rr == nil {
if reverse.Next == nil || !nextHandler {
// could not resolv
w.WriteMsg(m)
return dns.RcodeNameError, nil
}
return reverse.Next.ServeDNS(ctx, w, r)
if rr == nil && !fallThrough {
return middleware.NextOrFailure(re.Name(), re.Next, ctx, w, r)
}
m.Answer = append(m.Answer, rr)
@ -109,6 +106,4 @@ func (reverse Reverse) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dn
}
// Name implements the Handler interface.
func (reverse Reverse) Name() string {
return "reverse"
}
func (re Reverse) Name() string { return "reverse" }