func handleDnsRequest(w dns.ResponseWriter, r *dns.Msg) {
m := new(dns.Msg)
m.SetReply(r)
m.Compress = false
switch r.Opcode {
case dns.OpcodeQuery:
parseQuery(m)
case dns.OpcodeUpdate:
for _, question := range r.Question {
for _, rr := range r.Ns {
updateRecord(rr, &question)
}
}
}
if r.IsTsig() != nil {
if w.TsigStatus() == nil {
m.SetTsig(r.Extra[len(r.Extra)-1].(*dns.TSIG).Hdr.Name,
dns.HmacMD5, 300, time.Now().Unix())
} else {
log.Println("Status", w.TsigStatus().Error())
}
}
w.WriteMsg(m)
}
func parseQuery(m *dns.Msg) {
var rr dns.RR
for _, q := range m.Question {
if read_rr, e := getRecord(q.Name, q.Qtype); e == nil {
rr = read_rr.(dns.RR)
if rr.Header().Name == q.Name {
m.Answer = append(m.Answer, rr)
}
} else {
m2 := new(dns.Msg)
if q.Qtype == dns.TypeA {
m2.SetQuestion(q.Name, dns.TypeA)
} else {
m2.Question = make([]dns.Question, 1)
m2.Question[0] = q
}
ret := queryUpStream(m2)
if ret != nil {
if q.Qtype == dns.TypeA {
for _, r := range ret.Answer {
// fmt.Printf("%s\n", r)
if *cache {
storeRecord(r) //FIXME: only be able to save one record
}
tmp := strings.Split(r.String(), " ")
if len(tmp) > 2 && tmp[len(tmp)-2] == "A" {
fmt.Printf("%s\n", tmp[len(tmp)-1])
}
}
}
m.Answer = append(m.Answer, ret.Answer...)
}
}
}
}