datapath: Move IPsec logic to get local IPs

Those helper functions to retrieve the local IPs are all IPsec specific
so let's move them to the ipsec.go file. No functional changes in this
commit.

Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>

pkg/datapath/linux/ipsec.go

@@ -22,6 +22,40 @@ import (
 	"github.com/cilium/cilium/pkg/option"
 )
 
+// getDefaultEncryptionInterface() is needed to find the interface used when
+// populating neighbor table and doing arpRequest. For most configurations
+// there is only a single interface so choosing [0] works by choosing the only
+// interface. However EKS, uses multiple interfaces, but fortunately for us
+// in EKS any interface would work so pick the [0] index here as well.
+func getDefaultEncryptionInterface() string {
+	iface := ""
+	if len(option.Config.EncryptInterface) > 0 {
+		iface = option.Config.EncryptInterface[0]
+	}
+	return iface
+}
+
+func getLinkLocalIP(family int) (net.IP, error) {
+	iface := getDefaultEncryptionInterface()
+	link, err := netlink.LinkByName(iface)
+	if err != nil {
+		return nil, err
+	}
+	addr, err := netlink.AddrList(link, family)
+	if err != nil {
+		return nil, err
+	}
+	return addr[0].IPNet.IP, nil
+}
+
+func getV4LinkLocalIP() (net.IP, error) {
+	return getLinkLocalIP(netlink.FAMILY_V4)
+}
+
+func getV6LinkLocalIP() (net.IP, error) {
+	return getLinkLocalIP(netlink.FAMILY_V6)
+}
+
 func upsertIPsecLog(err error, spec string, loc, rem *net.IPNet, spi uint8, nodeID uint16) error {
 	scopedLog := log.WithFields(logrus.Fields{
 		logfields.Reason:   spec,

pkg/datapath/linux/node.go

@@ -926,40 +926,6 @@ func (n *linuxNodeHandler) DeleteMiscNeighbor(oldNode *nodeTypes.Node) {
 	n.deleteNeighbor(oldNode)
 }
 
-// getDefaultEncryptionInterface() is needed to find the interface used when
-// populating neighbor table and doing arpRequest. For most configurations
-// there is only a single interface so choosing [0] works by choosing the only
-// interface. However EKS, uses multiple interfaces, but fortunately for us
-// in EKS any interface would work so pick the [0] index here as well.
-func getDefaultEncryptionInterface() string {
-	iface := ""
-	if len(option.Config.EncryptInterface) > 0 {
-		iface = option.Config.EncryptInterface[0]
-	}
-	return iface
-}
-
-func getLinkLocalIP(family int) (net.IP, error) {
-	iface := getDefaultEncryptionInterface()
-	link, err := netlink.LinkByName(iface)
-	if err != nil {
-		return nil, err
-	}
-	addr, err := netlink.AddrList(link, family)
-	if err != nil {
-		return nil, err
-	}
-	return addr[0].IPNet.IP, nil
-}
-
-func getV4LinkLocalIP() (net.IP, error) {
-	return getLinkLocalIP(netlink.FAMILY_V4)
-}
-
-func getV6LinkLocalIP() (net.IP, error) {
-	return getLinkLocalIP(netlink.FAMILY_V6)
-}
-
 // Must be called with linuxNodeHandler.mutex held.
 func (n *linuxNodeHandler) nodeUpdate(oldNode, newNode *nodeTypes.Node, firstAddition bool) error {
 	var (