func (e Etcd) NS(zone string, state middleware.State) (records, extra []dns.RR, debug []msg.Service, err error) {
// NS record for this zone live in a special place, ns.dns.<zone>. Fake our lookup.
// only a tad bit fishy...
old := state.QName()
state.Clear()
state.Req.Question[0].Name = "ns.dns." + zone
services, debug, err := e.records(state, false)
if err != nil {
return nil, nil, debug, err
}
// ... and reset
state.Req.Question[0].Name = old
for _, serv := range services {
ip := net.ParseIP(serv.Host)
switch {
case ip == nil:
return nil, nil, debug, fmt.Errorf("NS record must be an IP address: %s", serv.Host)
case ip.To4() != nil:
serv.Host = msg.Domain(serv.Key)
records = append(records, serv.NewNS(state.QName()))
extra = append(extra, serv.NewA(serv.Host, ip.To4()))
case ip.To4() == nil:
serv.Host = msg.Domain(serv.Key)
records = append(records, serv.NewNS(state.QName()))
extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
}
}
return records, extra, debug, nil
}
// MX returns MX records from etcd.
// If the Target is not a name but an IP address, a name is created on the fly.
func (e Etcd) MX(zone string, state middleware.State) (records, extra []dns.RR, debug []msg.Service, err error) {
services, debug, err := e.records(state, false)
if err != nil {
return nil, nil, debug, err
}
lookup := make(map[string]bool)
for _, serv := range services {
if !serv.Mail {
continue
}
ip := net.ParseIP(serv.Host)
switch {
case ip == nil:
mx := serv.NewMX(state.QName())
records = append(records, mx)
if _, ok := lookup[mx.Mx]; ok {
break
}
lookup[mx.Mx] = true
if !dns.IsSubDomain(zone, mx.Mx) {
m1, e1 := e.Proxy.Lookup(state, mx.Mx, dns.TypeA)
if e1 == nil {
extra = append(extra, m1.Answer...)
}
m1, e1 = e.Proxy.Lookup(state, mx.Mx, dns.TypeAAAA)
if e1 == nil {
// If we have seen CNAME's we *assume* that they are already added.
for _, a := range m1.Answer {
if _, ok := a.(*dns.CNAME); !ok {
extra = append(extra, a)
}
}
}
break
}
// Internal name
state1 := copyState(state, mx.Mx, dns.TypeA)
addr, debugAddr, e1 := e.A(zone, state1, nil)
if e1 == nil {
extra = append(extra, addr...)
debug = append(debug, debugAddr...)
}
// e.AAAA as well
case ip.To4() != nil:
serv.Host = msg.Domain(serv.Key)
records = append(records, serv.NewMX(state.QName()))
extra = append(extra, serv.NewA(serv.Host, ip.To4()))
case ip.To4() == nil:
serv.Host = msg.Domain(serv.Key)
records = append(records, serv.NewMX(state.QName()))
extra = append(extra, serv.NewAAAA(serv.Host, ip.To16()))
}
}
return records, extra, debug, nil
}
// Look in .../dns/stub/<zone>/xx for msg.Services. Loop through them
// extract <zone> and add them as forwarders (ip:port-combos) for
// the stub zones. Only numeric (i.e. IP address) hosts are used.
// Only the first zone configured on e is used for the lookup.
func (e *Etcd) updateStubZones() {
zone := e.Zones[0]
services, err := e.Records(stubDomain+"."+zone, false)
if err != nil {
return
}
stubmap := make(map[string]proxy.Proxy)
// track the nameservers on a per domain basis, but allow a list on the domain.
nameservers := map[string][]string{}
for _, serv := range services {
if serv.Port == 0 {
serv.Port = 53
}
ip := net.ParseIP(serv.Host)
if ip == nil {
log.Printf("[WARNING] Non IP address stub nameserver: %s", serv.Host)
continue
}
domain := msg.Domain(serv.Key)
labels := dns.SplitDomainName(domain)
// If the remaining name equals any of the zones we have, we ignore it.
for _, z := range e.Zones {
// Chop of left most label, because that is used as the nameserver place holder
// and drop the right most labels that belong to zone.
// We must *also* chop of dns.stub. which means cutting two more labels.
domain = dns.Fqdn(strings.Join(labels[1:len(labels)-dns.CountLabel(z)-2], "."))
if domain == z {
log.Printf("[WARNING] Skipping nameserver for domain we are authoritative for: %s", domain)
continue
}
nameservers[domain] = append(nameservers[domain], net.JoinHostPort(serv.Host, strconv.Itoa(serv.Port)))
}
}
for domain, nss := range nameservers {
stubmap[domain] = proxy.New(nss)
}
// atomic swap (at least that's what we hope it is)
if len(stubmap) > 0 {
e.Stubmap = &stubmap
}
return
}
// SRV returns SRV records from etcd.
// If the Target is not a name but an IP address, a name is created on the fly.
func (e Etcd) SRV(zone string, state middleware.State) (records, extra []dns.RR, debug []msg.Service, err error) {
services, debug, err := e.records(state, false)
if err != nil {
return nil, nil, nil, err
}
// Looping twice to get the right weight vs priority
w := make(map[int]int)
for _, serv := range services {
weight := 100
if serv.Weight != 0 {
weight = serv.Weight
}
if _, ok := w[serv.Priority]; !ok {
w[serv.Priority] = weight
continue
}
w[serv.Priority] += weight
}
lookup := make(map[string]bool)
for _, serv := range services {
w1 := 100.0 / float64(w[serv.Priority])
if serv.Weight == 0 {
w1 *= 100
} else {
w1 *= float64(serv.Weight)
}
weight := uint16(math.Floor(w1))
ip := net.ParseIP(serv.Host)
switch {
case ip == nil:
srv := serv.NewSRV(state.QName(), weight)
records = append(records, srv)
if _, ok := lookup[srv.Target]; ok {
break
}
lookup[srv.Target] = true
if !dns.IsSubDomain(zone, srv.Target) {
m1, e1 := e.Proxy.Lookup(state, srv.Target, dns.TypeA)
if e1 == nil {
extra = append(extra, m1.Answer...)
}
m1, e1 = e.Proxy.Lookup(state, srv.Target, dns.TypeAAAA)
if e1 == nil {
// If we have seen CNAME's we *assume* that they are already added.
for _, a := range m1.Answer {
if _, ok := a.(*dns.CNAME); !ok {
extra = append(extra, a)
}
}
}
break
}
// Internal name, we should have some info on them, either v4 or v6
// Clients expect a complete answer, because we are a recursor in their view.
state1 := copyState(state, srv.Target, dns.TypeA)
addr, debugAddr, e1 := e.A(zone, state1, nil)
if e1 == nil {
extra = append(extra, addr...)
debug = append(debug, debugAddr...)
}
// e.AAA(zone, state1, nil) as well...?
case ip.To4() != nil:
serv.Host = msg.Domain(serv.Key)
srv := serv.NewSRV(state.QName(), weight)
records = append(records, srv)
extra = append(extra, serv.NewA(srv.Target, ip.To4()))
case ip.To4() == nil:
serv.Host = msg.Domain(serv.Key)
srv := serv.NewSRV(state.QName(), weight)
records = append(records, srv)
extra = append(extra, serv.NewAAAA(srv.Target, ip.To16()))
}
}
return records, extra, debug, nil
}
