netbird/client/internal/dns/local.go
Maycon Santos 20a73e3e14
Sync peers FQDN (#584)
Use stdout and stderr log path only if on Linux and attempt to create the path

Update status system with FQDN fields and 
status command to display the domain names of remote and local peers

Set some DNS logs to tracing

update readme file
2022-11-26 13:29:50 +01:00

67 lines
1.5 KiB
Go

package dns
import (
"fmt"
"github.com/miekg/dns"
nbdns "github.com/netbirdio/netbird/dns"
log "github.com/sirupsen/logrus"
"sync"
)
type localResolver struct {
registeredMap registrationMap
records sync.Map
}
// ServeDNS handles a DNS request
func (d *localResolver) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
log.Tracef("received question: %#v\n", r.Question[0])
replyMessage := &dns.Msg{}
replyMessage.SetReply(r)
replyMessage.RecursionAvailable = true
replyMessage.Rcode = dns.RcodeSuccess
response := d.lookupRecord(r)
if response != nil {
replyMessage.Answer = append(replyMessage.Answer, response)
}
err := w.WriteMsg(replyMessage)
if err != nil {
log.Debugf("got an error while writing the local resolver response, error: %v", err)
}
}
func (d *localResolver) lookupRecord(r *dns.Msg) dns.RR {
question := r.Question[0]
record, found := d.records.Load(buildRecordKey(question.Name, question.Qclass, question.Qtype))
if !found {
return nil
}
return record.(dns.RR)
}
func (d *localResolver) registerRecord(record nbdns.SimpleRecord) error {
fullRecord, err := dns.NewRR(record.String())
if err != nil {
return err
}
fullRecord.Header().Rdlength = record.Len()
header := fullRecord.Header()
d.records.Store(buildRecordKey(header.Name, header.Class, header.Rrtype), fullRecord)
return nil
}
func (d *localResolver) deleteRecord(recordKey string) {
d.records.Delete(dns.Fqdn(recordKey))
}
func buildRecordKey(name string, class, qType uint16) string {
key := fmt.Sprintf("%s_%d_%d", name, class, qType)
return key
}