chore: DNS cache policy follow upstream

This commit is contained in:
Larvan2 2023-09-17 17:18:35 +08:00
parent 33d41338ef
commit 6a5a94f48f

View file

@ -30,9 +30,13 @@ const (
)
func minimalTTL(records []D.RR) uint32 {
return lo.MinBy(records, func(r1 D.RR, r2 D.RR) bool {
minObj := lo.MinBy(records, func(r1 D.RR, r2 D.RR) bool {
return r1.Header().Ttl < r2.Header().Ttl
}).Header().Ttl
})
if minObj != nil {
return minObj.Header().Ttl
}
return 0
}
func updateTTL(records []D.RR, ttl uint32) {
@ -46,27 +50,25 @@ func updateTTL(records []D.RR, ttl uint32) {
}
func putMsgToCache(c *cache.LruCache[string, *D.Msg], key string, msg *D.Msg) {
// skip dns cache for acme challenge
if len(msg.Question) != 0 {
if q := msg.Question[0]; q.Qtype == D.TypeTXT && strings.HasPrefix(q.Name, "_acme-challenge") {
log.Debugln("[DNS] dns cache ignored because of acme challenge for: %s", q.Name)
return
putMsgToCacheWithExpire(c, key, msg, 0)
}
func putMsgToCacheWithExpire(c *cache.LruCache[string, *D.Msg], key string, msg *D.Msg, sec uint32) {
if sec == 0 {
if sec = minimalTTL(msg.Answer); sec == 0 {
if sec = minimalTTL(msg.Ns); sec == 0 {
sec = minimalTTL(msg.Extra)
}
}
var ttl uint32
switch {
case len(msg.Answer) != 0:
ttl = minimalTTL(msg.Answer)
case len(msg.Ns) != 0:
ttl = minimalTTL(msg.Ns)
case len(msg.Extra) != 0:
ttl = minimalTTL(msg.Extra)
default:
log.Debugln("[DNS] response msg empty: %#v", msg)
if sec == 0 {
return
}
c.SetWithExpire(key, msg.Copy(), time.Now().Add(time.Second*time.Duration(ttl)))
sec = max(sec, 120) // at least 2 minutes to cache
}
c.SetWithExpire(key, msg.Copy(), time.Now().Add(time.Duration(sec)*time.Second))
}
func setMsgTTL(msg *D.Msg, ttl uint32) {