Implement static routing support

api/v1alpha1/vrfrouteconfiguration_types.go

@@ -64,6 +64,8 @@ type VRFRouteConfigurationSpec struct {
 	// Aggregate Routes that should be announced
 	Aggregate []string `json:"aggregate,omitempty"`
 
+	StaticRoutes []string `json:"staticRoutes,omitempty"`
+
 	// +kubebuilder:validation:Required
 	// +kubebuilder:validation:Minimum=1
 	// +kubebuilder:validation:Maximum=65534

config/crd/bases/network.schiff.telekom.de_vrfrouteconfigurations.yaml

@@ -113,6 +113,10 @@ spec:
                 maximum: 65534
                 minimum: 1
                 type: integer
+              staticRoutes:
+                items:
+                  type: string
+                type: array
               vrf:
                 description: VRF this configuration refers to
                 maxLength: 12

pkg/frr/manager.go

@@ -46,6 +46,11 @@ type VRFConfiguration struct {
 	AggregateIPv6 []string
 	Import        []PrefixList
 	Export        []PrefixList
+
+	StaticRoutesIPv4       []string
+	StaticRoutesIPv6       []string
+	StaticRouteInterface   string
+	StaticRouteIPv6NextHop string
 }
 
 type FRRConfiguration struct {

pkg/frr/tpl/vrf.tpl

@@ -4,4 +4,10 @@ vrf vr.{{$vrf.Name}}
  vni {{$vrf.VNI}}
 exit-vrf
 {{end}}
+{{range $item := $vrf.StaticRoutesIPv4}}
+ip route {{$item}} 169.254.0.1 {{$vrf.StaticRouteInterface}}
+{{- end }}
+{{range $item := $vrf.StaticRoutesIPv6}}
+ipv6 route {{$item}} {{$vrf.StaticRouteIPv6NextHop}} {{$vrf.StaticRouteInterface}}
+{{- end }}
 {{- end -}}

pkg/nl/layer3.go

@@ -2,9 +2,12 @@ package nl
 
 import (
 	"fmt"
+	"net"
 	"sort"
+	"strings"
 
 	"github.com/telekom/das-schiff-network-operator/pkg/bpf"
+	"github.com/vishvananda/netlink"
 )
 
 type VRFInformation struct {
@@ -139,3 +142,51 @@ func (n *NetlinkManager) GetL3ByName(name string) (*VRFInformation, error) {
 	}
 	return nil, fmt.Errorf("no VRF with name %s", name)
 }
+
+func (n *NetlinkManager) getVethFromVRF(links []netlink.Link, vrf *netlink.Vrf) (*netlink.Veth, error) {
+	for _, link := range links {
+		if link.Attrs().MasterIndex == vrf.Attrs().Index && link.Type() == "veth" && strings.HasPrefix(link.Attrs().Name, VRF_TO_DEFAULT_PREFIX) {
+			return link.(*netlink.Veth), nil
+		}
+	}
+	return nil, fmt.Errorf("no veth in vrf %s found", vrf.Attrs().Name)
+}
+
+func (n *NetlinkManager) GetInterfaceAndNexthop(vrf string) (string, net.IP, error) {
+	links, err := netlink.LinkList()
+	if err != nil {
+		return "", nil, err
+	}
+	for _, link := range links {
+		if link.Type() != "vrf" {
+			continue
+		}
+		if link.Attrs().Name != fmt.Sprintf("Vrf_%s", vrf) && link.Attrs().Name != fmt.Sprintf("%s%s", VRF_PREFIX, vrf) {
+			continue
+		}
+		veth, err := n.getVethFromVRF(links, link.(*netlink.Vrf))
+		if err != nil {
+			return "", nil, err
+		}
+
+		vethPeerIdx, err := netlink.VethPeerIndex(veth)
+		if err != nil {
+			return "", nil, err
+		}
+
+		vethPeer, err := netlink.LinkByIndex(vethPeerIdx)
+		if err != nil {
+			return "", nil, err
+		}
+
+		addresses, err := netlink.AddrList(veth, netlink.FAMILY_V4)
+		if err != nil {
+			return "", nil, err
+		}
+		if len(addresses) != 1 {
+			return "", nil, fmt.Errorf("veth in vrf %s has more than one IPv6 address", vrf)
+		}
+		return vethPeer.Attrs().Name, addresses[0].IP, nil
+	}
+	return "", nil, fmt.Errorf("no vrf with name %s found", vrf)
+}

pkg/reconciler/layer3.go

@@ -84,6 +84,17 @@ func (r *reconcile) reconcileLayer3(l3vnis []networkv1alpha1.VRFRouteConfigurati
 				config.AggregateIPv4 = append(config.AggregateIPv4, aggregate)
 			}
 		}
+		for _, staticRoute := range spec.StaticRoutes {
+			_, network, err := net.ParseCIDR(staticRoute)
+			if err != nil {
+				return err
+			}
+			if network.IP.To4() == nil {
+				config.StaticRoutesIPv6 = append(config.StaticRoutesIPv6, staticRoute)
+			} else {
+				config.StaticRoutesIPv4 = append(config.StaticRoutesIPv4, staticRoute)
+			}
+		}
 		vrfConfigMap[spec.VRF] = config
 	}
 
@@ -105,6 +116,15 @@ func (r *reconcile) reconcileLayer3(l3vnis []networkv1alpha1.VRFRouteConfigurati
 	// We wait here for two seconds to let FRR settle after updating netlink devices
 	time.Sleep(2 * time.Second)
 
+	for _, vrf := range vrfConfigs {
+		routeInterface, routeNextHop, err := r.netlinkManager.GetInterfaceAndNexthop(vrf.Name)
+		if err != nil {
+			return err
+		}
+		vrf.StaticRouteInterface = routeInterface
+		vrf.StaticRouteIPv6NextHop = routeNextHop.String()
+	}
+
 	changed, err := r.frrManager.Configure(frr.FRRConfiguration{
 		VRFs: vrfConfigs,
 		ASN:  r.config.ServerASN,