coredns/middleware/file/closest.go
Miek Gieben 2adbdf34d9 Use qname/qtype for lookups
Drop the use of dns.RR when in fact the only thing we use is the name

and type of the RR. Cleans up a bunch of stuff and also stops the weird

making of dns.RRs just for a lookup. Should safe some memory as well.



Fixes: #66
2016-04-02 17:49:13 +01:00

62 lines
1.6 KiB
Go

package file
import "github.com/miekg/dns"
// ClosestEncloser returns the closest encloser for rr.
func (z *Zone) ClosestEncloser(qname string, qtype uint16) string {
// tree/tree.go does not store a parent *Node pointer, so we can't
// just follow up the tree. TODO(miek): fix.
offset, end := dns.NextLabel(qname, 0)
for !end {
elem, _ := z.Tree.Search(qname, qtype)
if elem != nil {
return elem.Name()
}
qname = qname[offset:]
offset, end = dns.NextLabel(qname, offset)
}
return z.SOA.Header().Name
}
// nameErrorProof finds the closest encloser and return an NSEC that proofs
// the wildcard does not exist and an NSEC that proofs the name does no exist.
func (z *Zone) nameErrorProof(qname string, qtype uint16) []dns.RR {
elem := z.Tree.Prev(qname)
if elem == nil {
return nil
}
nsec := z.lookupNSEC(elem, true)
nsecIndex := 0
for i := 0; i < len(nsec); i++ {
if nsec[i].Header().Rrtype == dns.TypeNSEC {
nsecIndex = i
break
}
}
// We do this lookup twice, once for wildcard and once for the name proof. TODO(miek): fix
ce := z.ClosestEncloser(qname, qtype)
elem = z.Tree.Prev("*." + ce)
if elem == nil {
// Root?
return nil
}
nsec1 := z.lookupNSEC(elem, true)
nsec1Index := 0
for i := 0; i < len(nsec1); i++ {
if nsec1[i].Header().Rrtype == dns.TypeNSEC {
nsec1Index = i
break
}
}
// Check for duplicate NSEC.
if nsec[nsecIndex].Header().Name == nsec1[nsec1Index].Header().Name &&
nsec[nsecIndex].(*dns.NSEC).NextDomain == nsec1[nsec1Index].(*dns.NSEC).NextDomain {
return nsec
}
return append(nsec, nsec1...)
}