Tidy example package

Signed-off-by: Jake Sanders <i@am.so-aweso.me>
This commit is contained in:
Jake Sanders
2021-02-22 16:02:41 +00:00
parent 4f51af7d86
commit 1f895be0fe
3 changed files with 63 additions and 47 deletions

View File

@@ -2,6 +2,7 @@ package example
import (
"fmt"
"github.com/miekg/dns"
)
@@ -11,45 +12,7 @@ func (e *exampleSolver) handleDNSRequest(w dns.ResponseWriter, req *dns.Msg) {
switch req.Opcode {
case dns.OpcodeQuery:
for _, q := range msg.Question {
switch q.Qtype {
case dns.TypeA:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN A 127.0.0.1", q.Name))
if err != nil {
msg.SetRcode(req, dns.RcodeNameError)
} else {
msg.Answer = append(msg.Answer, rr)
}
case dns.TypeTXT:
// get record
e.RLock()
record, found := e.txtRecords[q.Name]
e.RUnlock()
if !found {
msg.SetRcode(req, dns.RcodeNameError)
} else {
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN TXT %s", q.Name, record))
if err != nil {
msg.SetRcode(req, dns.RcodeServerFailure)
break
}
msg.Answer = append(msg.Answer, rr)
}
case dns.TypeNS:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN NS ns.example-acme-webook.invalid.", q.Name))
if err != nil {
msg.SetRcode(req, dns.RcodeServerFailure)
break
} else {
msg.Answer = append(msg.Answer, rr)
}
case dns.TypeSOA:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN SOA %s 20 5 5 5 5", "ns.example-acme-webook.invalid.", "ns.example-acme-webook.invalid."))
if err != nil {
msg.SetRcode(req, dns.RcodeServerFailure)
break
}
msg.Answer = append(msg.Answer, rr)
default:
if err := e.addDNSAnswer(q, msg, req); err != nil {
msg.SetRcode(req, dns.RcodeServerFailure)
break
}
@@ -57,3 +20,50 @@ func (e *exampleSolver) handleDNSRequest(w dns.ResponseWriter, req *dns.Msg) {
}
w.WriteMsg(msg)
}
func (e *exampleSolver) addDNSAnswer(q dns.Question, msg *dns.Msg, req *dns.Msg) error {
switch q.Qtype {
// Always return loopback for any A query
case dns.TypeA:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN A 127.0.0.1", q.Name))
if err != nil {
return err
}
msg.Answer = append(msg.Answer, rr)
return nil
// TXT records are the only important record for ACME dns-01 challenges
case dns.TypeTXT:
e.RLock()
record, found := e.txtRecords[q.Name]
e.RUnlock()
if !found {
msg.SetRcode(req, dns.RcodeNameError)
return nil
}
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN TXT %s", q.Name, record))
if err != nil {
return err
}
msg.Answer = append(msg.Answer, rr)
return nil
// NS and SOA are for authoritative lookups, return obviously invalid data
case dns.TypeNS:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN NS ns.example-acme-webook.invalid.", q.Name))
if err != nil {
return err
}
msg.Answer = append(msg.Answer, rr)
return nil
case dns.TypeSOA:
rr, err := dns.NewRR(fmt.Sprintf("%s 5 IN SOA %s 20 5 5 5 5", "ns.example-acme-webook.invalid.", "ns.example-acme-webook.invalid."))
if err != nil {
return err
}
msg.Answer = append(msg.Answer, rr)
return nil
default:
return fmt.Errorf("unimplemented record type %v", q.Qtype)
}
}