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
This commit is contained in:
Miek Gieben
2016-04-02 17:49:13 +01:00
parent 9b21646954
commit 2adbdf34d9
5 changed files with 58 additions and 92 deletions

View File

@@ -19,33 +19,21 @@ const (
// Lookup looks up qname and qtype in the zone. When do is true DNSSEC records are included.
// Three sets of records are returned, one for the answer, one for authority and one for the additional section.
func (z *Zone) Lookup(qname string, qtype uint16, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
var rr dns.RR
mk, known := dns.TypeToRR[qtype]
if !known {
return nil, nil, nil, ServerFailure
} else {
rr = mk()
}
if qtype == dns.TypeSOA {
return z.lookupSOA(do)
}
// Misuse rr to be a question.
rr.Header().Rrtype = qtype
rr.Header().Name = qname
elem, res := z.Tree.Get(rr)
elem, res := z.Tree.Search(qname, qtype)
if elem == nil {
if res == tree.EmptyNonTerminal {
return z.emptyNonTerminal(rr, do)
return z.emptyNonTerminal(qname, do)
}
return z.nameError(rr, do)
return z.nameError(qname, qtype, do)
}
rrs := elem.Types(dns.TypeCNAME)
if len(rrs) > 0 { // should only ever be 1 actually; TODO(miek) check for this?
rr.Header().Name = rrs[0].(*dns.CNAME).Target
return z.lookupCNAME(rrs, rr, do)
return z.lookupCNAME(rrs, qtype, do)
}
rrs = elem.Types(qtype)
@@ -67,33 +55,29 @@ func (z *Zone) noData(elem *tree.Elem, do bool) ([]dns.RR, []dns.RR, []dns.RR, R
return nil, append(soa, nsec...), nil, Success
}
func (z *Zone) emptyNonTerminal(rr dns.RR, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
func (z *Zone) emptyNonTerminal(qname string, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
soa, _, _, _ := z.lookupSOA(do)
elem := z.Tree.Prev(rr)
elem := z.Tree.Prev(qname)
nsec := z.lookupNSEC(elem, do)
return nil, append(soa, nsec...), nil, Success
}
func (z *Zone) nameError(rr dns.RR, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
func (z *Zone) nameError(qname string, qtype uint16, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
// Is there a wildcard?
rr1 := dns.Copy(rr)
rr1.Header().Name = rr.Header().Name
rr1.Header().Rrtype = rr.Header().Rrtype
ce := z.ClosestEncloser(rr1)
rr1.Header().Name = "*." + ce
elem, _ := z.Tree.Get(rr1) // use result here?
ce := z.ClosestEncloser(qname, qtype)
elem, _ := z.Tree.Search("*."+ce, qtype) // use result here?
if elem != nil {
ret := elem.Types(rr1.Header().Rrtype) // there can only be one of these (or zero)
ret := elem.Types(qtype) // there can only be one of these (or zero)
switch {
case ret != nil:
if do {
sigs := elem.Types(dns.TypeRRSIG)
sigs = signatureForSubType(sigs, rr.Header().Rrtype)
sigs = signatureForSubType(sigs, qtype)
ret = append(ret, sigs...)
}
ret = wildcardReplace(rr, ce, ret)
ret = wildcardReplace(qname, ce, ret)
return ret, nil, nil, Success
case ret == nil:
// nodata, nsec from the wildcard - type does not exist
@@ -106,7 +90,7 @@ func (z *Zone) nameError(rr dns.RR, do bool) ([]dns.RR, []dns.RR, []dns.RR, Resu
ret := []dns.RR{z.SOA}
if do {
ret = append(ret, z.SIG...)
ret = append(ret, z.nameErrorProof(rr)...)
ret = append(ret, z.nameErrorProof(qname, qtype)...)
}
return nil, ret, nil, NameError
}
@@ -135,15 +119,15 @@ func (z *Zone) lookupNSEC(elem *tree.Elem, do bool) []dns.RR {
return nsec
}
func (z *Zone) lookupCNAME(rrs []dns.RR, rr dns.RR, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
elem, _ := z.Tree.Get(rr)
func (z *Zone) lookupCNAME(rrs []dns.RR, qtype uint16, do bool) ([]dns.RR, []dns.RR, []dns.RR, Result) {
elem, _ := z.Tree.Search(rrs[0].(*dns.CNAME).Target, qtype)
if elem == nil {
return rrs, nil, nil, Success
}
extra := cnameForType(elem.All(), rr.Header().Rrtype)
extra := cnameForType(elem.All(), qtype)
if do {
sigs := elem.Types(dns.TypeRRSIG)
sigs = signatureForSubType(sigs, rr.Header().Rrtype)
sigs = signatureForSubType(sigs, qtype)
if len(sigs) > 0 {
extra = append(extra, sigs...)
}
@@ -175,25 +159,13 @@ func signatureForSubType(rrs []dns.RR, subtype uint16) []dns.RR {
return sigs
}
// wildcardReplace replaces the first wildcard with label.
func wildcardReplace(rr dns.RR, ce string, rrs []dns.RR) []dns.RR {
// Get how many labels the ce is off from the fullname, this is how much of the
// original rr's '*' we must replace.
labels := dns.CountLabel(rr.Header().Name) - dns.CountLabel(ce) // can not be 0, TODO(miek): check
indexes := dns.Split(rr.Header().Name)
if labels >= len(indexes) {
// TODO(miek): yes then what?
// Is the == right here?
return nil
}
replacement := rr.Header().Name[:indexes[labels]]
// wildcardReplace replaces the ownername with the original query name.
func wildcardReplace(qname, ce string, rrs []dns.RR) []dns.RR {
// need to copy here, otherwise we change in zone stuff
ret := make([]dns.RR, len(rrs))
for i, r := range rrs {
ret[i] = dns.Copy(r)
ret[i].Header().Name = replacement + r.Header().Name[2:]
ret[i].Header().Name = qname
}
return ret
}