IPAddress validation

Validate IPAddress name is in canonical format
Validate ParentRef is required, and Resource and Name.
Validate IPAddress is inmutable on update.

pkg/apis/networking/validation/validation.go

@@ -18,6 +18,7 @@ package validation
 
 import (
 	"fmt"
+	"net/netip"
 	"strings"
 
 	v1 "k8s.io/api/core/v1"
@@ -741,3 +742,77 @@ func validateClusterCIDRUpdateSpec(update, old *networking.ClusterCIDRSpec, fldP
 
 	return allErrs
 }
+
+// ValidateIPAddressName validates that the name is the decimal representation of an IP address.
+// IPAddress does not support generating names, prefix is not considered.
+func ValidateIPAddressName(name string, prefix bool) []string {
+	var errs []string
+	ip, err := netip.ParseAddr(name)
+	if err != nil {
+		errs = append(errs, err.Error())
+	} else if ip.String() != name {
+		errs = append(errs, "not a valid ip in canonical format")
+
+	}
+	return errs
+}
+
+func ValidateIPAddress(ipAddress *networking.IPAddress) field.ErrorList {
+	allErrs := apivalidation.ValidateObjectMeta(&ipAddress.ObjectMeta, false, ValidateIPAddressName, field.NewPath("metadata"))
+	errs := validateIPAddressParentReference(ipAddress.Spec.ParentRef, field.NewPath("spec"))
+	allErrs = append(allErrs, errs...)
+	return allErrs
+
+}
+
+// validateIPAddressParentReference ensures that the IPAddress ParenteReference exists and is valid.
+func validateIPAddressParentReference(params *networking.ParentReference, fldPath *field.Path) field.ErrorList {
+	allErrs := field.ErrorList{}
+
+	if params == nil {
+		allErrs = append(allErrs, field.Required(fldPath.Child("parentRef"), ""))
+		return allErrs
+	}
+
+	fldPath = fldPath.Child("parentRef")
+	// group is required but the Core group used by Services is the empty value, so it can not be enforced
+	if params.Group != "" {
+		for _, msg := range validation.IsDNS1123Subdomain(params.Group) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("group"), params.Group, msg))
+		}
+	}
+
+	// resource is required
+	if params.Resource == "" {
+		allErrs = append(allErrs, field.Required(fldPath.Child("resource"), ""))
+	} else {
+		for _, msg := range pathvalidation.IsValidPathSegmentName(params.Resource) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("resource"), params.Resource, msg))
+		}
+	}
+
+	// name is required
+	if params.Name == "" {
+		allErrs = append(allErrs, field.Required(fldPath.Child("name"), ""))
+	} else {
+		for _, msg := range pathvalidation.IsValidPathSegmentName(params.Name) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("name"), params.Name, msg))
+		}
+	}
+
+	// namespace is optional
+	if params.Namespace != "" {
+		for _, msg := range pathvalidation.IsValidPathSegmentName(params.Namespace) {
+			allErrs = append(allErrs, field.Invalid(fldPath.Child("namespace"), params.Namespace, msg))
+		}
+	}
+	return allErrs
+}
+
+// ValidateIPAddressUpdate tests if an update to an IPAddress is valid.
+func ValidateIPAddressUpdate(update, old *networking.IPAddress) field.ErrorList {
+	var allErrs field.ErrorList
+	allErrs = append(allErrs, apivalidation.ValidateObjectMetaUpdate(&update.ObjectMeta, &old.ObjectMeta, field.NewPath("metadata"))...)
+	allErrs = append(allErrs, apivalidation.ValidateImmutableField(update.Spec.ParentRef, old.Spec.ParentRef, field.NewPath("spec").Child("parentRef"))...)
+	return allErrs
+}