add support for bridge port neighbor suppression

this PR adds support for setting neigh_suppress attribute to a member port of a bridge

link_linux.go

@@ -2461,6 +2461,14 @@ func (h *Handle) LinkSetBrProxyArpWiFi(link Link, mode bool) error {
 	return h.setProtinfoAttr(link, mode, nl.IFLA_BRPORT_PROXYARP_WIFI)
 }
 
+func LinkSetBrNeighSuppress(link Link, mode bool) error {
+	return pkgHandle.LinkSetBrNeighSuppress(link, mode)
+}
+
+func (h *Handle) LinkSetBrNeighSuppress(link Link, mode bool) error {
+	return h.setProtinfoAttr(link, mode, nl.IFLA_BRPORT_NEIGH_SUPPRESS)
+}
+
 func (h *Handle) setProtinfoAttr(link Link, mode bool, attr int) error {
 	base := link.Attrs()
 	h.ensureIndex(base)

protinfo.go

@@ -15,6 +15,7 @@ type Protinfo struct {
 	ProxyArp      bool
 	ProxyArpWiFi  bool
 	Isolated      bool
+	NeighSuppress bool
 }
 
 // String returns a list of enabled flags
@@ -51,6 +52,9 @@ func (prot *Protinfo) String() string {
 	if prot.Isolated {
 		boolStrings = append(boolStrings, "Isolated")
 	}
+	if prot.NeighSuppress {
+		boolStrings = append(boolStrings, "NeighSuppress")
+	}
 	return strings.Join(boolStrings, " ")
 }
 

protinfo_linux.go

@@ -70,6 +70,8 @@ func parseProtinfo(infos []syscall.NetlinkRouteAttr) (pi Protinfo) {
 			pi.ProxyArpWiFi = byteToBool(info.Value[0])
 		case nl.IFLA_BRPORT_ISOLATED:
 			pi.Isolated = byteToBool(info.Value[0])
+		case nl.IFLA_BRPORT_NEIGH_SUPPRESS:
+			pi.NeighSuppress = byteToBool(info.Value[0])
 		}
 	}
 	return

protinfo_test.go

@@ -1,3 +1,4 @@
+//go:build linux
 // +build linux
 
 package netlink
@@ -83,6 +84,9 @@ func TestProtinfo(t *testing.T) {
 	if pi1.Flood != oldpi1.Flood {
 		t.Fatalf("Flood field was changed for %s but shouldn't", iface1.Name)
 	}
+	if pi1.NeighSuppress != oldpi1.NeighSuppress {
+		t.Fatalf("NeighSuppress field was changed for %s but shouldn't", iface1.Name)
+	}
 
 	if err := LinkSetGuard(iface2, true); err != nil {
 		t.Fatal(err)
@@ -118,6 +122,9 @@ func TestProtinfo(t *testing.T) {
 	if pi2.Flood != oldpi2.Flood {
 		t.Fatalf("Flood field was changed for %s but shouldn't", iface2.Name)
 	}
+	if pi2.NeighSuppress != oldpi2.NeighSuppress {
+		t.Fatalf("NeighSuppress field was changed for %s but shouldn't", iface2.Name)
+	}
 
 	if err := LinkSetHairpin(iface3, true); err == nil || err.Error() != "operation not supported" {
 		t.Fatalf("Set protinfo attrs for link without master is not supported, but err: %s", err)
@@ -162,6 +169,20 @@ func TestProtinfo(t *testing.T) {
 		t.Fatalf("Flood field was changed for %s but shouldn't", iface4.Name)
 	}
 
+	// BR_NEIGH_SUPPRESS added on 4.15
+	minKernelRequired(t, 4, 15)
+
+	if err := LinkSetBrNeighSuppress(iface1, true); err != nil {
+		t.Fatal(err)
+	}
+	pi1, err = LinkGetProtinfo(iface1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !pi1.NeighSuppress {
+		t.Fatalf("NeighSuppress is not enabled for %s but should", iface1.Name)
+	}
+
 	// Setting kernel requirement for next tests which require BRPORT_ISOLATED
 	minKernelRequired(t, 4, 18)