// ServeDNS implements the middleware.Handler interface.
func (d Dnssec) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := middleware.State{W: w, Req: r}
do := state.Do()
qname := state.Name()
qtype := state.QType()
zone := middleware.Zones(d.zones).Matches(qname)
if zone == "" {
return d.Next.ServeDNS(ctx, w, r)
}
// Intercept queries for DNSKEY, but only if one of the zones matches the qname, otherwise we let
// the query through.
if qtype == dns.TypeDNSKEY {
for _, z := range d.zones {
if qname == z {
resp := d.getDNSKEY(state, z, do)
state.SizeAndDo(resp)
w.WriteMsg(resp)
return dns.RcodeSuccess, nil
}
}
}
drr := NewDnssecResponseWriter(w, d)
return d.Next.ServeDNS(ctx, drr, r)
}
// ServeDNS implements the middleware.Handler interface.
func (c Cache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := middleware.State{W: w, Req: r}
qname := state.Name()
qtype := state.QType()
zone := middleware.Zones(c.Zones).Matches(qname)
if zone == "" {
return c.Next.ServeDNS(ctx, w, r)
}
do := state.Do() // might need more from OPT record?
if i, ok := c.get(qname, qtype, do); ok {
resp := i.toMsg(r)
state.SizeAndDo(resp)
w.WriteMsg(resp)
cacheHitCount.WithLabelValues(zone).Inc()
return dns.RcodeSuccess, nil
}
cacheMissCount.WithLabelValues(zone).Inc()
crr := NewCachingResponseWriter(w, c.cache, c.cap)
return c.Next.ServeDNS(ctx, crr, r)
}
func (d *DnssecResponseWriter) WriteMsg(res *dns.Msg) error {
// By definition we should sign anything that comes back, we should still figure out for
// which zone it should be.
state := middleware.State{W: d.ResponseWriter, Req: res}
qname := state.Name()
zone := middleware.Zones(d.d.zones).Matches(qname)
if zone == "" {
return d.ResponseWriter.WriteMsg(res)
}
if state.Do() {
res = d.d.Sign(state, zone, time.Now().UTC())
}
state.SizeAndDo(res)
return d.ResponseWriter.WriteMsg(res)
}
// Report is a plain reporting function that the server can use for REFUSED and other
// queries that are turned down because they don't match any middleware.
func Report(state middleware.State, zone, rcode string, size int, start time.Time) {
if requestCount == nil {
// no metrics are enabled
return
}
// Proto and Family
net := state.Proto()
fam := "1"
if state.Family() == 2 {
fam = "2"
}
typ := state.QType()
requestCount.WithLabelValues(zone, net, fam).Inc()
requestDuration.WithLabelValues(zone).Observe(float64(time.Since(start) / time.Millisecond))
if state.Do() {
requestDo.WithLabelValues(zone).Inc()
}
if _, known := monitorType[typ]; known {
requestType.WithLabelValues(zone, dns.Type(typ).String()).Inc()
} else {
requestType.WithLabelValues(zone, other).Inc()
}
if typ == dns.TypeIXFR || typ == dns.TypeAXFR {
responseTransferSize.WithLabelValues(zone, net).Observe(float64(size))
requestTransferSize.WithLabelValues(zone, net).Observe(float64(state.Size()))
} else {
responseSize.WithLabelValues(zone, net).Observe(float64(size))
requestSize.WithLabelValues(zone, net).Observe(float64(state.Size()))
}
responseRcode.WithLabelValues(zone, rcode).Inc()
}
func (f File) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := middleware.State{W: w, Req: r}
if state.QClass() != dns.ClassINET {
return dns.RcodeServerFailure, errors.New("can only deal with ClassINET")
}
qname := state.Name()
zone := middleware.Zones(f.Zones.Names).Matches(qname)
if zone == "" {
if f.Next != nil {
return f.Next.ServeDNS(ctx, w, r)
}
return dns.RcodeServerFailure, errors.New("no next middleware found")
}
z, ok := f.Zones.Z[zone]
if !ok {
return f.Next.ServeDNS(ctx, w, r)
}
if z == nil {
return dns.RcodeServerFailure, nil
}
if r.Opcode == dns.OpcodeNotify {
if z.isNotify(state) {
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
state.SizeAndDo(m)
w.WriteMsg(m)
log.Printf("[INFO] Notify from %s for %s: checking transfer", state.IP(), zone)
ok, err := z.shouldTransfer()
if ok {
z.TransferIn()
} else {
log.Printf("[INFO] Notify from %s for %s: no serial increase seen", state.IP(), zone)
}
if err != nil {
log.Printf("[WARNING] Notify from %s for %s: failed primary check: %s", state.IP(), zone, err)
}
return dns.RcodeSuccess, nil
}
log.Printf("[INFO] Dropping notify from %s for %s", state.IP(), zone)
return dns.RcodeSuccess, nil
}
if z.Expired != nil && *z.Expired {
log.Printf("[ERROR] Zone %s is expired", zone)
return dns.RcodeServerFailure, nil
}
if state.QType() == dns.TypeAXFR || state.QType() == dns.TypeIXFR {
xfr := Xfr{z}
return xfr.ServeDNS(ctx, w, r)
}
answer, ns, extra, result := z.Lookup(qname, state.QType(), state.Do())
m := new(dns.Msg)
m.SetReply(r)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
m.Answer, m.Ns, m.Extra = answer, ns, extra
switch result {
case Success:
case NoData:
case NameError:
m.Rcode = dns.RcodeNameError
case Delegation:
m.Authoritative = false
case ServerFailure:
return dns.RcodeServerFailure, nil
}
state.SizeAndDo(m)
m, _ = state.Scrub(m)
w.WriteMsg(m)
return dns.RcodeSuccess, nil
}
