func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.Msg, error) {
addr, ipv6Miss := r.sb.ResolveName(name, ipType)
if addr == nil && ipv6Miss {
// Send a reply without any Answer sections
log.Debugf("Lookup name %s present without IPv6 address", name)
resp := createRespMsg(query)
return resp, nil
}
if addr == nil {
return nil, nil
}
log.Debugf("Lookup for %s: IP %v", name, addr)
resp := createRespMsg(query)
if len(addr) > 1 {
addr = shuffleAddr(addr)
}
if ipType == types.IPv4 {
for _, ip := range addr {
rr := new(dns.A)
rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: respTTL}
rr.A = ip
resp.Answer = append(resp.Answer, rr)
}
} else {
for _, ip := range addr {
rr := new(dns.AAAA)
rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: respTTL}
rr.AAAA = ip
resp.Answer = append(resp.Answer, rr)
}
}
return resp, nil
}
func (r *resolver) handleIPQuery(name string, query *dns.Msg, ipType int) (*dns.Msg, error) {
addr := r.sb.ResolveName(name, ipType)
if addr == nil {
return nil, nil
}
log.Debugf("Lookup for %s: IP %v", name, addr)
resp := new(dns.Msg)
resp.SetReply(query)
setCommonFlags(resp)
if len(addr) > 1 {
addr = shuffleAddr(addr)
}
if ipType == netutils.IPv4 {
for _, ip := range addr {
rr := new(dns.A)
rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: respTTL}
rr.A = ip
resp.Answer = append(resp.Answer, rr)
}
} else {
for _, ip := range addr {
rr := new(dns.AAAA)
rr.Hdr = dns.RR_Header{Name: name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: respTTL}
rr.AAAA = ip
resp.Answer = append(resp.Answer, rr)
}
}
return resp, nil
}
func route(w dns.ResponseWriter, req *dns.Msg) {
if len(req.Question) != 1 {
failWithRcode(w, req, dns.RcodeRefused)
return
}
question := req.Question[0]
qtype := question.Qtype
if question.Qclass != dns.ClassINET {
failWithRcode(w, req, dns.RcodeRefused)
return
}
remoteIP := w.RemoteAddr().(*net.UDPAddr).IP
m := new(dns.Msg)
m.Id = req.Id
switch qtype {
case dns.TypeA:
if remoteIP4 := remoteIP.To4(); remoteIP4 != nil {
rr := new(dns.A)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.A = remoteIP4
m.Answer = []dns.RR{rr}
}
case dns.TypeAAAA:
if remoteIP16 := remoteIP.To16(); remoteIP16 != nil {
rr := new(dns.AAAA)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.AAAA = remoteIP16
m.Answer = []dns.RR{rr}
}
case dns.TypeTXT:
rr := new(dns.TXT)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: question.Qtype,
Class: dns.ClassINET, Ttl: 10}
rr.Txt = []string{fmt.Sprintf("Resolver IP: %v", remoteIP.String())}
m.Answer = []dns.RR{rr}
}
m.Question = req.Question
m.Response = true
m.Authoritative = true
w.WriteMsg(m)
}
func parseValue(t uint16, value string, h dns.RR_Header) dns.RR {
switch t {
case dns.TypeA:
a := new(dns.A)
a.Hdr = h
a.A, _ = parseA(value)
return a
case dns.TypeAAAA:
aaaa := new(dns.AAAA)
aaaa.Hdr = h
aaaa.AAAA, _ = parseAAAA(value)
return aaaa
case dns.TypeSRV:
srv := new(dns.SRV)
srv.Hdr = h
srv.Priority, srv.Weight, srv.Port, srv.Target, _ = parseSRV(value)
return srv
}
return nil
}
func answerAAAA(q *dns.Question, v *DNSValue) dns.RR {
answer := new(dns.AAAA)
answer.Header().Name = q.Name
answer.Header().Rrtype = dns.TypeAAAA
answer.Header().Class = dns.ClassINET
answer.AAAA = net.ParseIP(v.Value)
return answer
}
func (s *server) AddressRecords(q dns.Question) (records []dns.RR, err error) {
name := strings.ToLower(q.Name)
if name == "master."+s.config.Domain || name == s.config.Domain {
for _, m := range s.client.GetCluster() {
u, e := url.Parse(m)
if e != nil {
continue
}
h, _, e := net.SplitHostPort(u.Host)
if e != nil {
continue
}
ip := net.ParseIP(h)
switch {
case ip.To4() != nil && q.Qtype == dns.TypeA:
records = append(records, &dns.A{Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.Ttl}, A: ip.To4()})
case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
records = append(records, &dns.AAAA{Hdr: dns.RR_Header{Name: q.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.Ttl}, AAAA: ip.To16()})
}
}
return
}
r, err := s.client.Get(path(name), false, true)
if err != nil {
println(err.Error())
return nil, err
}
var serv *Service
if !r.Node.Dir { // single element
if err := json.Unmarshal([]byte(r.Node.Value), &serv); err != nil {
log.Printf("error: Failure to parse value: %q", err)
return nil, err
}
ip := net.ParseIP(serv.Host)
ttl := uint32(r.Node.TTL)
if ttl == 0 {
ttl = s.Ttl
}
switch {
case ip == nil:
case ip.To4() != nil && q.Qtype == dns.TypeA:
a := new(dns.A)
a.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: ttl}
a.A = ip.To4()
records = append(records, a)
case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
aaaa := new(dns.AAAA)
aaaa.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: ttl}
aaaa.AAAA = ip.To16()
records = append(records, aaaa)
}
return records, nil
}
for _, serv := range s.loopNodes(&r.Node.Nodes) {
ip := net.ParseIP(serv.Host)
switch {
case ip == nil:
case ip.To4() != nil && q.Qtype == dns.TypeA:
a := new(dns.A)
a.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: uint32(r.Node.TTL)}
a.A = ip.To4()
records = append(records, a)
case ip.To4() == nil && q.Qtype == dns.TypeAAAA:
aaaa := new(dns.AAAA)
aaaa.Hdr = dns.RR_Header{Name: q.Name, Rrtype: q.Qtype, Class: dns.ClassINET, Ttl: uint32(r.Node.TTL)}
aaaa.AAAA = ip.To16()
records = append(records, aaaa)
}
}
if s.config.RoundRobin {
switch l := len(records); l {
case 2:
if dns.Id()%2 == 0 {
records[0], records[1] = records[1], records[0]
}
default:
// Do a minimum of l swap, maximum of 4l swaps
for j := 0; j < l*(int(dns.Id())%4+1); j++ {
q := int(dns.Id()) % l
p := int(dns.Id()) % l
if q == p {
p = (p + 1) % l
}
records[q], records[p] = records[p], records[q]
}
}
}
return records, nil
}
// updateDNS updates the current slices of dns.RR so incoming requests get a
// fast answer
func updateDNS(s *dnsseeder) {
var rr4std, rr4non, rr6std, rr6non []dns.RR
s.mtx.RLock()
// loop over each dns recprd type we need
for t := range []int{dnsV4Std, dnsV4Non, dnsV6Std, dnsV6Non} {
// FIXME above needs to be convertwd into one scan of theList if possible
numRR := 0
for _, nd := range s.theList {
// when we reach max exit
if numRR >= 25 {
break
}
if nd.status != statusCG {
continue
}
if t == dnsV4Std || t == dnsV4Non {
if t == dnsV4Std && nd.dnsType == dnsV4Std {
r := new(dns.A)
r.Hdr = dns.RR_Header{Name: s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
r.A = nd.na.IP
rr4std = append(rr4std, r)
numRR++
}
// if the node is using a non standard port then add the encoded port info to DNS
if t == dnsV4Non && nd.dnsType == dnsV4Non {
r := new(dns.A)
r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
r.A = nd.na.IP
rr4non = append(rr4non, r)
numRR++
r = new(dns.A)
r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: s.ttl}
r.A = nd.nonstdIP
rr4non = append(rr4non, r)
numRR++
}
}
if t == dnsV6Std || t == dnsV6Non {
if t == dnsV6Std && nd.dnsType == dnsV6Std {
r := new(dns.AAAA)
r.Hdr = dns.RR_Header{Name: s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
r.AAAA = nd.na.IP
rr6std = append(rr6std, r)
numRR++
}
// if the node is using a non standard port then add the encoded port info to DNS
if t == dnsV6Non && nd.dnsType == dnsV6Non {
r := new(dns.AAAA)
r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
r.AAAA = nd.na.IP
rr6non = append(rr6non, r)
numRR++
r = new(dns.AAAA)
r.Hdr = dns.RR_Header{Name: "nonstd." + s.dnsHost + ".", Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: s.ttl}
r.AAAA = nd.nonstdIP
rr6non = append(rr6non, r)
numRR++
}
}
}
}
s.mtx.RUnlock()
config.dnsmtx.Lock()
// update the map holding the details for this seeder
for t := range []int{dnsV4Std, dnsV4Non, dnsV6Std, dnsV6Non} {
switch t {
case dnsV4Std:
config.dns[s.dnsHost+".A"] = rr4std
case dnsV4Non:
config.dns["nonstd."+s.dnsHost+".A"] = rr4non
case dnsV6Std:
config.dns[s.dnsHost+".AAAA"] = rr6std
case dnsV6Non:
config.dns["nonstd."+s.dnsHost+".AAAA"] = rr6non
}
}
config.dnsmtx.Unlock()
if config.stats {
s.counts.mtx.RLock()
log.Printf("%s - DNS available: v4std: %v v4non: %v v6std: %v v6non: %v\n", s.name, len(rr4std), len(rr4non), len(rr6std), len(rr6non))
log.Printf("%s - DNS counts: v4std: %v v4non: %v v6std: %v v6non: %v total: %v\n",
s.name,
s.counts.DNSCounts[dnsV4Std],
s.counts.DNSCounts[dnsV4Non],
s.counts.DNSCounts[dnsV6Std],
s.counts.DNSCounts[dnsV6Non],
s.counts.DNSCounts[dnsV4Std]+s.counts.DNSCounts[dnsV4Non]+s.counts.DNSCounts[dnsV6Std]+s.counts.DNSCounts[dnsV6Non])
s.counts.mtx.RUnlock()
}
}
