StackExchange/dnscontrol
1
1
Fork 0
mirror of https://github.com/StackExchange/dnscontrol.git synced 2025-09-04 20:24:23 +08:00
Code Issues Projects Releases Packages Wiki Activity

AXFRDDNS: Chunk large changes in multiple packets (#3732)

Browse source 
Co-authored-by: Mynacol <Mynacol@users.noreply.github.com>
Co-authored-by: Tom Limoncelli <6293917+tlimoncelli@users.noreply.github.com>
This commit is contained in:
Mynacol 2025-08-28 18:27:18 +02:00 • committed by GitHub
parent 89ac03faca
commit c858e8fa57
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 49 additions and 23 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

72
providers/axfrddns/axfrddnsProvider.go
View file

@ -366,8 +366,8 @@ func (c *axfrddnsProvider) GetZoneRecords(domain string, meta map[string]string)
}
// BuildCorrection return a Correction for a given set of DDNS update and the corresponding message.
func (c *axfrddnsProvider) BuildCorrection(dc *models.DomainConfig, msgs []string, update *dns.Msg) *models.Correction {
if update == nil {
func (c *axfrddnsProvider) BuildCorrection(dc *models.DomainConfig, msgs []string, updates []*dns.Msg) *models.Correction {
if updates == nil {
return &models.Correction{
Msg: fmt.Sprintf("DDNS UPDATES to '%s' (primary master: '%s'). Changes:\n%s", dc.Name, c.master, strings.Join(msgs, "\n")),
}
@ -375,26 +375,28 @@ func (c *axfrddnsProvider) BuildCorrection(dc *models.DomainConfig, msgs []strin
return &models.Correction{
Msg: fmt.Sprintf("DDNS UPDATES to '%s' (primary master: '%s'). Changes:\n%s", dc.Name, c.master, strings.Join(msgs, "\n")),
F: func() error {
update.Compress = true
client := new(dns.Client)
client.Net = c.updateMode
client.Timeout = dnsTimeout
if c.updateKey != nil {
client.TsigSecret = map[string]string{c.updateKey.id: c.updateKey.secret}
update.SetTsig(c.updateKey.id, c.updateKey.algo, 300, time.Now().Unix())
if c.updateKey.algo == dns.HmacMD5 {
client.TsigProvider = md5Provider(c.updateKey.secret)
for _, update := range updates {
update.Compress = true
client := new(dns.Client)
client.Net = c.updateMode
client.Timeout = dnsTimeout
if c.updateKey != nil {
client.TsigSecret = map[string]string{c.updateKey.id: c.updateKey.secret}
update.SetTsig(c.updateKey.id, c.updateKey.algo, 300, time.Now().Unix())
if c.updateKey.algo == dns.HmacMD5 {
client.TsigProvider = md5Provider(c.updateKey.secret)
}
}
}
msg, _, err := client.Exchange(update, c.master)
if err != nil {
return err
}
if msg.MsgHdr.Rcode != 0 {
return fmt.Errorf("[Error] AXFRDDNS: nameserver refused to update the zone: %s (%d)",
dns.RcodeToString[msg.MsgHdr.Rcode],
msg.MsgHdr.Rcode)
msg, _, err := client.Exchange(update, c.master)
if err != nil {
return err
}
if msg.MsgHdr.Rcode != 0 {
return fmt.Errorf("[Error] AXFRDDNS: nameserver refused to update the zone: %s (%d)",
dns.RcodeToString[msg.MsgHdr.Rcode],
msg.MsgHdr.Rcode)
}
}
return nil
@ -453,8 +455,7 @@ func (c *axfrddnsProvider) GetZoneRecordsCorrections(dc *models.DomainConfig, fo
var msgs []string
var reports []string
update := new(dns.Msg)
update.SetUpdate(dc.Name + ".")
updates := []*dns.Msg{}
dummyNs1, err := dns.NewRR(dc.Name + ". IN NS dnscontrol.invalid.")
if err != nil {
@ -473,6 +474,9 @@ func (c *axfrddnsProvider) GetZoneRecordsCorrections(dc *models.DomainConfig, fo
return nil, 0, nil
}
update := new(dns.Msg)
update.SetUpdate(dc.Name + ".")
// A DNS server should silently ignore a DDNS update that removes
// the last NS record of a zone. Since modifying a record is
// implemented by successively a deletion of the old record and an
@ -491,6 +495,9 @@ func (c *axfrddnsProvider) GetZoneRecordsCorrections(dc *models.DomainConfig, fo
update.Insert([]dns.RR{dummyNs1})
}
i := 1
appendFinalUpdate := true
for _, change := range changes {
switch change.Type {
case diff2.DELETE:
@ -523,16 +530,35 @@ func (c *axfrddnsProvider) GetZoneRecordsCorrections(dc *models.DomainConfig, fo
case diff2.REPORT:
reports = append(reports, change.Msgs...)
}
// Chunk packets that exceed 2^14 = 16 KiB.
// A single DNS RR can theoretically reach 64 KiB, the total packet limit.
// This is a compromise, succeeding whenever RRs are not bigger than about 64 KiB - 16 KiB = 48 KiB.
if update.Len() >= 2<<13 {
updates = append(updates, update)
update = new(dns.Msg)
update.SetUpdate(dc.Name + ".")
appendFinalUpdate = false
i = 1
} else {
appendFinalUpdate = true
i++
}
}
if hasNSDeletion {
update.Remove([]dns.RR{dummyNs2})
appendFinalUpdate = true
}
if appendFinalUpdate {
updates = append(updates, update)
}
returnValue := []*models.Correction{}
if len(msgs) > 0 {
returnValue = append(returnValue, c.BuildCorrection(dc, msgs, update))
returnValue = append(returnValue, c.BuildCorrection(dc, msgs, updates))
}
if len(reports) > 0 {
returnValue = append(returnValue, c.BuildCorrection(dc, reports, nil))