// Perform probing & announcement
//TODO: implement a proper probing & conflict resolution
func (s *server) probe() {
q := new(dns.Msg)
q.SetQuestion(s.service.ServiceInstanceName(), dns.TypePTR)
q.RecursionDesired = false
srv := &dns.SRV{
Hdr: dns.RR_Header{
Name: s.service.ServiceInstanceName(),
Rrtype: dns.TypeSRV,
Class: dns.ClassINET,
Ttl: 3200,
},
Priority: 0,
Weight: 0,
Port: uint16(s.service.Port),
Target: s.service.HostName,
}
txt := &dns.TXT{
Hdr: dns.RR_Header{
Name: s.service.ServiceInstanceName(),
Rrtype: dns.TypeTXT,
Class: dns.ClassINET,
Ttl: 3200,
},
Txt: s.service.Text,
}
q.Ns = []dns.RR{srv, txt}
randomizer := rand.New(rand.NewSource(time.Now().UnixNano()))
for i := 0; i < 3; i++ {
if err := s.multicastResponse(q); err != nil {
log.Println("[ERR] bonjour: failed to send probe:", err.Error())
}
time.Sleep(time.Duration(randomizer.Intn(250)) * time.Millisecond)
}
resp := new(dns.Msg)
resp.Answer = []dns.RR{}
resp.Extra = []dns.RR{}
s.composeLookupAnswers(resp, 3200)
for i := 0; i < 3; i++ {
if err := s.multicastResponse(resp); err != nil {
log.Println("[ERR] bonjour: failed to send announcement:", err.Error())
}
time.Sleep(2 * time.Second)
}
}
// addSOA is used to add an SOA record to a message for the given domain
func (d *DNSServer) addSOA(domain string, msg *dns.Msg) {
soa := &dns.SOA{
Hdr: dns.RR_Header{
Name: domain,
Rrtype: dns.TypeSOA,
Class: dns.ClassINET,
Ttl: 0,
},
Ns: "ns." + domain,
Mbox: "postmaster." + domain,
Serial: uint32(time.Now().Unix()),
Refresh: 3600,
Retry: 600,
Expire: 86400,
Minttl: 0,
}
msg.Ns = append(msg.Ns, soa)
}