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-rw-r--r--plugin/cache/cache.go8
-rw-r--r--plugin/cache/item.go56
-rw-r--r--plugin/pkg/dnsutil/ttl.go72
-rw-r--r--plugin/pkg/dnsutil/ttl_test.go (renamed from plugin/cache/minttl_test.go)14
4 files changed, 83 insertions, 67 deletions
diff --git a/plugin/cache/cache.go b/plugin/cache/cache.go
index ed39fee86..c46267658 100644
--- a/plugin/cache/cache.go
+++ b/plugin/cache/cache.go
@@ -9,6 +9,7 @@ import (
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/cache"
+ "github.com/coredns/coredns/plugin/pkg/dnsutil"
"github.com/coredns/coredns/plugin/pkg/response"
"github.com/coredns/coredns/request"
@@ -158,7 +159,7 @@ func (w *ResponseWriter) WriteMsg(res *dns.Msg) error {
duration = w.nttl
}
- msgTTL := minMsgTTL(res, mt)
+ msgTTL := dnsutil.MinimalTTL(res, mt)
if msgTTL < duration {
duration = msgTTL
}
@@ -226,9 +227,8 @@ func (w *ResponseWriter) Write(buf []byte) (int, error) {
}
const (
- maxTTL = 1 * time.Hour
- maxNTTL = 30 * time.Minute
- failSafeTTL = 5 * time.Second
+ maxTTL = dnsutil.MaximumDefaulTTL
+ maxNTTL = dnsutil.MaximumDefaulTTL / 2
defaultCap = 10000 // default capacity of the cache.
diff --git a/plugin/cache/item.go b/plugin/cache/item.go
index 5761cdf87..f4858c3b1 100644
--- a/plugin/cache/item.go
+++ b/plugin/cache/item.go
@@ -4,7 +4,6 @@ import (
"time"
"github.com/coredns/coredns/plugin/cache/freq"
- "github.com/coredns/coredns/plugin/pkg/response"
"github.com/miekg/dns"
)
@@ -87,58 +86,3 @@ func (i *item) ttl(now time.Time) int {
ttl := int(i.origTTL) - int(now.UTC().Sub(i.stored).Seconds())
return ttl
}
-
-func minMsgTTL(m *dns.Msg, mt response.Type) time.Duration {
- if mt != response.NoError && mt != response.NameError && mt != response.NoData {
- return 0
- }
-
- // No data to examine, return a short ttl as a fail safe.
- if len(m.Answer)+len(m.Ns)+len(m.Extra) == 0 {
- return failSafeTTL
- }
-
- minTTL := maxTTL
- for _, r := range m.Answer {
- switch mt {
- case response.NameError, response.NoData:
- if r.Header().Rrtype == dns.TypeSOA {
- minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
- }
- case response.NoError, response.Delegation:
- if r.Header().Ttl < uint32(minTTL.Seconds()) {
- minTTL = time.Duration(r.Header().Ttl) * time.Second
- }
- }
- }
- for _, r := range m.Ns {
- switch mt {
- case response.NameError, response.NoData:
- if r.Header().Rrtype == dns.TypeSOA {
- minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
- }
- case response.NoError, response.Delegation:
- if r.Header().Ttl < uint32(minTTL.Seconds()) {
- minTTL = time.Duration(r.Header().Ttl) * time.Second
- }
- }
- }
-
- for _, r := range m.Extra {
- if r.Header().Rrtype == dns.TypeOPT {
- // OPT records use TTL field for extended rcode and flags
- continue
- }
- switch mt {
- case response.NameError, response.NoData:
- if r.Header().Rrtype == dns.TypeSOA {
- minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
- }
- case response.NoError, response.Delegation:
- if r.Header().Ttl < uint32(minTTL.Seconds()) {
- minTTL = time.Duration(r.Header().Ttl) * time.Second
- }
- }
- }
- return minTTL
-}
diff --git a/plugin/pkg/dnsutil/ttl.go b/plugin/pkg/dnsutil/ttl.go
new file mode 100644
index 000000000..e969fa8a6
--- /dev/null
+++ b/plugin/pkg/dnsutil/ttl.go
@@ -0,0 +1,72 @@
+package dnsutil
+
+import (
+ "time"
+
+ "github.com/coredns/coredns/plugin/pkg/response"
+
+ "github.com/miekg/dns"
+)
+
+// MinimalTTL scans the message returns the lowest TTL found taking into the response.Type of the message.
+func MinimalTTL(m *dns.Msg, mt response.Type) time.Duration {
+ if mt != response.NoError && mt != response.NameError && mt != response.NoData {
+ return MinimalDefaultTTL
+ }
+
+ // No data to examine, return a short ttl as a fail safe.
+ if len(m.Answer)+len(m.Ns)+len(m.Extra) == 0 {
+ return MinimalDefaultTTL
+ }
+
+ minTTL := MaximumDefaulTTL
+ for _, r := range m.Answer {
+ switch mt {
+ case response.NameError, response.NoData:
+ if r.Header().Rrtype == dns.TypeSOA {
+ minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
+ }
+ case response.NoError, response.Delegation:
+ if r.Header().Ttl < uint32(minTTL.Seconds()) {
+ minTTL = time.Duration(r.Header().Ttl) * time.Second
+ }
+ }
+ }
+ for _, r := range m.Ns {
+ switch mt {
+ case response.NameError, response.NoData:
+ if r.Header().Rrtype == dns.TypeSOA {
+ minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
+ }
+ case response.NoError, response.Delegation:
+ if r.Header().Ttl < uint32(minTTL.Seconds()) {
+ minTTL = time.Duration(r.Header().Ttl) * time.Second
+ }
+ }
+ }
+
+ for _, r := range m.Extra {
+ if r.Header().Rrtype == dns.TypeOPT {
+ // OPT records use TTL field for extended rcode and flags
+ continue
+ }
+ switch mt {
+ case response.NameError, response.NoData:
+ if r.Header().Rrtype == dns.TypeSOA {
+ minTTL = time.Duration(r.(*dns.SOA).Minttl) * time.Second
+ }
+ case response.NoError, response.Delegation:
+ if r.Header().Ttl < uint32(minTTL.Seconds()) {
+ minTTL = time.Duration(r.Header().Ttl) * time.Second
+ }
+ }
+ }
+ return minTTL
+}
+
+const (
+ // MinimalDefaultTTL is the absolute lowest TTL we use in CoreDNS.
+ MinimalDefaultTTL = 5 * time.Second
+ // MaximumDefaulTTL is the maximum TTL was use on RRsets in CoreDNS.
+ MaximumDefaulTTL = 1 * time.Hour
+)
diff --git a/plugin/cache/minttl_test.go b/plugin/pkg/dnsutil/ttl_test.go
index 376c638a1..ee11d06f3 100644
--- a/plugin/cache/minttl_test.go
+++ b/plugin/pkg/dnsutil/ttl_test.go
@@ -1,4 +1,4 @@
-package cache
+package dnsutil
import (
"testing"
@@ -12,7 +12,7 @@ import (
// See https://github.com/kubernetes/dns/issues/121, add some specific tests for those use cases.
-func TestMinMsgTTL(t *testing.T) {
+func TestMinimalTTL(t *testing.T) {
m := new(dns.Msg)
m.SetQuestion("z.alm.im.", dns.TypeA)
m.Ns = []dns.RR{
@@ -25,7 +25,7 @@ func TestMinMsgTTL(t *testing.T) {
if mt != response.NoData {
t.Fatalf("Expected type to be response.NoData, got %s", mt)
}
- dur := minMsgTTL(m, mt) // minTTL on msg is 3600 (neg. ttl on SOA)
+ dur := MinimalTTL(m, mt) // minTTL on msg is 3600 (neg. ttl on SOA)
if dur != time.Duration(3600*time.Second) {
t.Fatalf("Expected minttl duration to be %d, got %d", 3600, dur)
}
@@ -35,13 +35,13 @@ func TestMinMsgTTL(t *testing.T) {
if mt != response.NameError {
t.Fatalf("Expected type to be response.NameError, got %s", mt)
}
- dur = minMsgTTL(m, mt) // minTTL on msg is 3600 (neg. ttl on SOA)
+ dur = MinimalTTL(m, mt) // minTTL on msg is 3600 (neg. ttl on SOA)
if dur != time.Duration(3600*time.Second) {
t.Fatalf("Expected minttl duration to be %d, got %d", 3600, dur)
}
}
-func BenchmarkMinMsgTTL(b *testing.B) {
+func BenchmarkMinimalTTL(b *testing.B) {
m := new(dns.Msg)
m.SetQuestion("example.org.", dns.TypeA)
m.Ns = []dns.RR{
@@ -64,9 +64,9 @@ func BenchmarkMinMsgTTL(b *testing.B) {
b.ResetTimer()
for i := 0; i < b.N; i++ {
- dur := minMsgTTL(m, mt)
+ dur := MinimalTTL(m, mt)
if dur != 1000*time.Second {
- b.Fatalf("Wrong minMsgTTL %d, expected %d", dur, 1000*time.Second)
+ b.Fatalf("Wrong MinimalTTL %d, expected %d", dur, 1000*time.Second)
}
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-30 21:37:26 +0000