From c5782406154850aceda876453688349299bff2b2 Mon Sep 17 00:00:00 2001
From: Lionel Jouin <lionel.jouin@est.tech>
Date: Fri, 30 Aug 2024 15:51:32 +0200
Subject: [PATCH] Use of Scope for routes in IPAM

Add Scope for routes for cni spec v1.1

Signed-off-by: Lionel Jouin <lionel.jouin@est.tech>
---
 pkg/ipam/ipam_linux.go      |  6 +++++-
 pkg/ipam/ipam_linux_test.go | 18 +++++++++++++++---
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/pkg/ipam/ipam_linux.go b/pkg/ipam/ipam_linux.go
index 6c2bfe72f..d9b81ebf5 100644
--- a/pkg/ipam/ipam_linux.go
+++ b/pkg/ipam/ipam_linux.go
@@ -119,8 +119,12 @@ func ConfigureIface(ifName string, res *current.Result) error {
 			Gw:        gw,
 		}
 
+		if r.Scope != nil {
+			route.Scope = netlink.Scope(*r.Scope)
+		}
+
 		if err = netlink.RouteAddEcmp(&route); err != nil {
-			return fmt.Errorf("failed to add route '%v via %v dev %v': %v", r.Dst, gw, ifName, err)
+			return fmt.Errorf("failed to add route '%v via %v dev %v (Scope: %v)': %v", r.Dst, gw, ifName, route.Scope, err)
 		}
 	}
 
diff --git a/pkg/ipam/ipam_linux_test.go b/pkg/ipam/ipam_linux_test.go
index 6d4ec4a47..a2feb4f74 100644
--- a/pkg/ipam/ipam_linux_test.go
+++ b/pkg/ipam/ipam_linux_test.go
@@ -41,8 +41,9 @@ func ipNetEqual(a, b *net.IPNet) bool {
 
 var _ = Describe("ConfigureIface", func() {
 	var originalNS ns.NetNS
-	var ipv4, ipv6, routev4, routev6 *net.IPNet
+	var ipv4, ipv6, routev4, routev6, routev4Scope *net.IPNet
 	var ipgw4, ipgw6, routegwv4, routegwv6 net.IP
+	var routeScope int
 	var result *current.Result
 
 	BeforeEach(func() {
@@ -77,6 +78,10 @@ var _ = Describe("ConfigureIface", func() {
 		routegwv4 = net.ParseIP("1.2.3.5")
 		Expect(routegwv4).NotTo(BeNil())
 
+		_, routev4Scope, err = net.ParseCIDR("1.2.3.4/32")
+		Expect(err).NotTo(HaveOccurred())
+		Expect(routev4Scope).NotTo(BeNil())
+
 		ipgw4 = net.ParseIP("1.2.3.1")
 		Expect(ipgw4).NotTo(BeNil())
 
@@ -93,6 +98,8 @@ var _ = Describe("ConfigureIface", func() {
 		ipgw6 = net.ParseIP("abcd:1234:ffff::1")
 		Expect(ipgw6).NotTo(BeNil())
 
+		routeScope = 200
+
 		result = &current.Result{
 			Interfaces: []*current.Interface{
 				{
@@ -121,6 +128,7 @@ var _ = Describe("ConfigureIface", func() {
 			Routes: []*types.Route{
 				{Dst: *routev4, GW: routegwv4},
 				{Dst: *routev6, GW: routegwv6},
+				{Dst: *routev4Scope, Scope: &routeScope},
 			},
 		}
 	})
@@ -162,7 +170,7 @@ var _ = Describe("ConfigureIface", func() {
 			routes, err := netlink.RouteList(link, 0)
 			Expect(err).NotTo(HaveOccurred())
 
-			var v4found, v6found bool
+			var v4found, v6found, v4Scopefound bool
 			for _, route := range routes {
 				isv4 := route.Dst.IP.To4() != nil
 				if isv4 && ipNetEqual(route.Dst, routev4) && route.Gw.Equal(routegwv4) {
@@ -171,13 +179,17 @@ var _ = Describe("ConfigureIface", func() {
 				if !isv4 && ipNetEqual(route.Dst, routev6) && route.Gw.Equal(routegwv6) {
 					v6found = true
 				}
+				if isv4 && ipNetEqual(route.Dst, routev4Scope) && int(route.Scope) == routeScope {
+					v4Scopefound = true
+				}
 
-				if v4found && v6found {
+				if v4found && v6found && v4Scopefound {
 					break
 				}
 			}
 			Expect(v4found).To(BeTrue())
 			Expect(v6found).To(BeTrue())
+			Expect(v4Scopefound).To(BeTrue())
 
 			return nil
 		})