func findApex(m *dns.Msg, z *dns.Zone) {
apex, exact := z.Find(z.Origin)
if exact {
// What if we don't have this? TODO(mg)
m.Ns = apex.RR[dns.TypeSOA]
}
return
}
func serve(w dns.ResponseWriter, req *dns.Msg, z *dns.Zone) {
if z == nil {
panic("fksd: no zone")
}
m := new(dns.Msg)
// Just NACK ANYs
if req.Question[0].Qtype == dns.TypeANY {
m.SetRcode(req, dns.RcodeServerFailure)
ednsFromRequest(req, m)
w.WriteMsg(m)
return
}
logPrintf("[zone %s] incoming %s %s %d from %s\n", z.Origin, req.Question[0].Name, dns.TypeToString[req.Question[0].Qtype], req.MsgHdr.Id, w.RemoteAddr())
node, exact, ref := z.FindFunc(req.Question[0].Name, func(n interface{}) bool {
return n.(*dns.ZoneData).NonAuth
})
if ref {
logPrintf("[zone %s] referral due\n", z.Origin)
m.SetReply(req)
m.Ns = node.RR[dns.TypeNS]
for _, n := range m.Ns {
if dns.IsSubDomain(n.(*dns.NS).Ns, n.Header().Name) {
findGlue(m, z, n.(*dns.NS).Ns)
}
}
ednsFromRequest(req, m)
w.WriteMsg(m)
return
}
if exact {
exactMatch(w, req, m, z, node)
return
}
// Not an exact match nor an referral
if z.Wildcard > 0 {
lx := dns.SplitLabels(req.Question[0].Name)
wc := "*." + strings.Join(lx[1:], ".")
node, exact = z.Find(wc)
if exact {
logPrintf("[zone %s] wildcard answer\n", z.Origin)
// as exact,but not complete -- only the last part
}
}
nameerror(w, m, req)
return
}
func findGlue(m *dns.Msg, z *dns.Zone, nameserver string) {
glue := z.Find(nameserver)
if glue != nil {
if a4, ok := glue.RR[dns.TypeAAAA]; ok {
m.Extra = append(m.Extra, a4...)
return
}
if a, ok := glue.RR[dns.TypeA]; ok {
m.Extra = append(m.Extra, a...)
return
}
}
// length or the returned packet! TODO(mg)
return
}