From b5334b1517440c15ae0dcc85ece4c03adfd17e49 Mon Sep 17 00:00:00 2001
From: Jen <furry13@gmail.com>
Date: Tue, 8 Oct 2024 23:34:17 +1100
Subject: [PATCH] RDNSS/RDNSSL lifetimes shall be 3 times MaxRtrAdvInterval
 (#48)

* RDNSS/RDNSSL lifetimes shall me 3 times MaxRtrAdvInterval

See RFC8106 (which obsoletes RFC6106)
---
 internal/config/config_test.go |  6 +++---
 internal/config/plugin.go      |  8 ++++++--
 internal/config/plugin_test.go | 14 +++++++-------
 3 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index d4ff693..4982b58 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -238,11 +238,11 @@ func TestParse(t *testing.T) {
 								Lifetime:   24 * time.Hour,
 							},
 							&plugin.RDNSS{
-								Lifetime: 20 * time.Minute,
+								Lifetime: 30 * time.Minute,
 								Servers:  []netip.Addr{netip.MustParseAddr("2001:db8::1")},
 							},
 							&plugin.DNSSL{
-								Lifetime:    20 * time.Minute,
+								Lifetime:    30 * time.Minute,
 								DomainNames: []string{"lan.example.com"},
 							},
 							plugin.NewMTU(1500),
@@ -265,7 +265,7 @@ func TestParse(t *testing.T) {
 						Plugins: []plugin.Plugin{
 							&plugin.RDNSS{
 								Auto:     true,
-								Lifetime: 8 * time.Second,
+								Lifetime: 12 * time.Second,
 							},
 							&plugin.LLA{},
 						},
diff --git a/internal/config/plugin.go b/internal/config/plugin.go
index c6673a6..bbbcdb2 100644
--- a/internal/config/plugin.go
+++ b/internal/config/plugin.go
@@ -153,7 +153,9 @@ func parsePlugins(ifi rawInterface, maxInterval time.Duration, epoch time.Time)
 // parseDNSSL parses a DNSSL plugin.
 func parseDNSSL(d rawDNSSL, maxInterval time.Duration) (*plugin.DNSSL, error) {
 	// By default, compute lifetime as recommended by radvd.
-	lifetime, err := parseDuration(d.Lifetime, 2*maxInterval)
+	// As per RFC8106, the default lifetime SHOULD be at least
+	// 3 * MaxRtrAdvInterval.
+	lifetime, err := parseDuration(d.Lifetime, 3*maxInterval)
 	if err != nil {
 		return nil, fmt.Errorf("invalid lifetime: %v", err)
 	}
@@ -319,7 +321,9 @@ func parseRoute(r rawRoute, epoch time.Time) (*plugin.Route, error) {
 // parseRDNSS parses a RDNSS plugin.
 func parseRDNSS(d rawRDNSS, maxInterval time.Duration) (*plugin.RDNSS, error) {
 	// If auto, compute lifetime as recommended by radvd.
-	lifetime, err := parseDuration(d.Lifetime, 2*maxInterval)
+	// As per RFC8106, the default lifetime SHOULD be at least
+	// 3 * MaxRtrAdvInterval.
+	lifetime, err := parseDuration(d.Lifetime, 3*maxInterval)
 	if err != nil {
 		return nil, fmt.Errorf("invalid lifetime: %v", err)
 	}
diff --git a/internal/config/plugin_test.go b/internal/config/plugin_test.go
index 3ccd048..539069c 100644
--- a/internal/config/plugin_test.go
+++ b/internal/config/plugin_test.go
@@ -83,7 +83,7 @@ func Test_parseDNSSL(t *testing.T) {
 			  domain_names = ["foo.example.com"]
 			`,
 			d: &plugin.DNSSL{
-				Lifetime:    20 * time.Minute,
+				Lifetime:    30 * time.Minute,
 				DomainNames: []string{"foo.example.com"},
 			},
 			ok: true,
@@ -97,7 +97,7 @@ func Test_parseDNSSL(t *testing.T) {
 			  lifetime = "auto"
 			`,
 			d: &plugin.DNSSL{
-				Lifetime:    20 * time.Minute,
+				Lifetime:    30 * time.Minute,
 				DomainNames: []string{"foo.example.com"},
 			},
 			ok: true,
@@ -669,7 +669,7 @@ func Test_parseRDNSS(t *testing.T) {
 			  servers = ["2001:db8::1"]
 			`,
 			r: &plugin.RDNSS{
-				Lifetime: 20 * time.Minute,
+				Lifetime: 30 * time.Minute,
 				Servers:  []netip.Addr{netip.MustParseAddr("2001:db8::1")},
 			},
 			ok: true,
@@ -683,7 +683,7 @@ func Test_parseRDNSS(t *testing.T) {
 			  lifetime = "auto"
 			`,
 			r: &plugin.RDNSS{
-				Lifetime: 20 * time.Minute,
+				Lifetime: 30 * time.Minute,
 				Servers:  []netip.Addr{netip.MustParseAddr("2001:db8::1")},
 			},
 			ok: true,
@@ -696,7 +696,7 @@ func Test_parseRDNSS(t *testing.T) {
 			`,
 			r: &plugin.RDNSS{
 				Auto:     true,
-				Lifetime: 20 * time.Minute,
+				Lifetime: 30 * time.Minute,
 			},
 			ok: true,
 		},
@@ -709,7 +709,7 @@ func Test_parseRDNSS(t *testing.T) {
 			`,
 			r: &plugin.RDNSS{
 				Auto:     true,
-				Lifetime: 20 * time.Minute,
+				Lifetime: 30 * time.Minute,
 			},
 			ok: true,
 		},
@@ -722,7 +722,7 @@ func Test_parseRDNSS(t *testing.T) {
 			`,
 			r: &plugin.RDNSS{
 				Auto:     true,
-				Lifetime: 20 * time.Minute,
+				Lifetime: 30 * time.Minute,
 				Servers:  []netip.Addr{netip.MustParseAddr("2001:db8::1")},
 			},
 			ok: true,