Add special IP validations to IP CEL type

staging/src/k8s.io/apiserver/pkg/cel/library/ip.go

@@ -78,16 +78,51 @@ import (
 //	ip.isCanonical('2001:DB8::ABCD') // returns false
 //	ip.isCanonical('2001:db8::0:0:0:abcd') // returns false
 //
-// family
+// family / isUnspecified / isLoopback / isLinkLocalMulticast / isLinkLocalUnicast / isGlobalUnicast
 //
 // - family: returns the IP addresses' family (IPv4 or IPv6) as an integer, either '4' or '6'.
 //
+// - isUnspecified: returns true if the IP address is the unspecified address.
+// Either the IPv4 address "0.0.0.0" or the IPv6 address "::".
+//
+// - isLoopback: returns true if the IP address is the loopback address.
+// Either an IPv4 address with a value of 127.x.x.x or an IPv6 address with a value of ::1.
+//
+// - isLinkLocalMulticast: returns true if the IP address is a link-local multicast address.
+// Either an IPv4 address with a value of 224.0.0.x or an IPv6 address in the network ff00::/8.
+//
+// - isLinkLocalUnicast: returns true if the IP address is a link-local unicast address.
+// Either an IPv4 address with a value of 169.254.x.x or an IPv6 address in the network fe80::/10.
+//
+// - isGlobalUnicast: returns true if the IP address is a global unicast address.
+// Either an IPv4 address that is not zero or 255.255.255.255 or an IPv6 address that is not a link-local unicast, loopback or multicast address.
+//
 // Examples:
 //
 // ip('127.0.0.1').family() // returns '4”
 // ip('::1').family() // returns '6'
 // ip('127.0.0.1').family() == 4 // returns true
 // ip('::1').family() == 6 // returns true
+// ip('0.0.0.0').isUnspecified() // returns true
+// ip('127.0.0.1').isUnspecified() // returns false
+// ip('::').isUnspecified() // returns true
+// ip('::1').isUnspecified() // returns false
+// ip('127.0.0.1').isLoopback() // returns true
+// ip('192.168.0.1').isLoopback() // returns false
+// ip('::1').isLoopback() // returns true
+// ip('2001:db8::abcd').isLoopback() // returns false
+// ip('224.0.0.1').isLinkLocalMulticast() // returns true
+// ip('224.0.1.1').isLinkLocalMulticast() // returns false
+// ip('ff02::1').isLinkLocalMulticast() // returns true
+// ip('fd00::1').isLinkLocalMulticast() // returns false
+// ip('169.254.169.254').isLinkLocalUnicast() // returns true
+// ip('192.168.0.1').isLinkLocalUnicast() // returns false
+// ip('fe80::1').isLinkLocalUnicast() // returns true
+// ip('fd80::1').isLinkLocalUnicast() // returns false
+// ip('192.168.0.1').isGlobalUnicast() // returns true
+// ip('255.255.255.255').isGlobalUnicast() // returns false
+// ip('2001:db8::abcd').isGlobalUnicast() // returns true
+// ip('ff00::1').isGlobalUnicast() // returns false
 func IP() cel.EnvOption {
 	return cel.Lib(ipLib)
 }
@@ -113,6 +148,26 @@ var ipLibraryDecls = map[string][]cel.FunctionOpt{
 		cel.Overload("ip_is_canonical", []*cel.Type{cel.StringType}, cel.BoolType,
 			cel.UnaryBinding(ipIsCanonical)),
 	},
+	"isUnspecified": {
+		cel.MemberOverload("ip_is_unspecified", []*cel.Type{apiservercel.IPType}, cel.BoolType,
+			cel.UnaryBinding(isUnspecified)),
+	},
+	"isLoopback": {
+		cel.MemberOverload("ip_is_loopback", []*cel.Type{apiservercel.IPType}, cel.BoolType,
+			cel.UnaryBinding(isLoopback)),
+	},
+	"isLinkLocalMulticast": {
+		cel.MemberOverload("ip_is_link_local_multicast", []*cel.Type{apiservercel.IPType}, cel.BoolType,
+			cel.UnaryBinding(isLinkLocalMulticast)),
+	},
+	"isLinkLocalUnicast": {
+		cel.MemberOverload("ip_is_link_local_unicast", []*cel.Type{apiservercel.IPType}, cel.BoolType,
+			cel.UnaryBinding(isLinkLocalUnicast)),
+	},
+	"isGlobalUnicast": {
+		cel.MemberOverload("ip_is_global_unicast", []*cel.Type{apiservercel.IPType}, cel.BoolType,
+			cel.UnaryBinding(isGlobalUnicast)),
+	},
 	"isIP": {
 		cel.Overload("is_ip", []*cel.Type{cel.StringType}, cel.BoolType,
 			cel.UnaryBinding(isIP)),
@@ -207,6 +262,51 @@ func isIP(arg ref.Val) ref.Val {
 	return types.Bool(err == nil)
 }
 
+func isUnspecified(arg ref.Val) ref.Val {
+	ip, ok := arg.(apiservercel.IP)
+	if !ok {
+		return types.MaybeNoSuchOverloadErr(arg)
+	}
+
+	return types.Bool(ip.Addr.IsUnspecified())
+}
+
+func isLoopback(arg ref.Val) ref.Val {
+	ip, ok := arg.(apiservercel.IP)
+	if !ok {
+		return types.MaybeNoSuchOverloadErr(arg)
+	}
+
+	return types.Bool(ip.Addr.IsLoopback())
+}
+
+func isLinkLocalMulticast(arg ref.Val) ref.Val {
+	ip, ok := arg.(apiservercel.IP)
+	if !ok {
+		return types.MaybeNoSuchOverloadErr(arg)
+	}
+
+	return types.Bool(ip.Addr.IsLinkLocalMulticast())
+}
+
+func isLinkLocalUnicast(arg ref.Val) ref.Val {
+	ip, ok := arg.(apiservercel.IP)
+	if !ok {
+		return types.MaybeNoSuchOverloadErr(arg)
+	}
+
+	return types.Bool(ip.Addr.IsLinkLocalUnicast())
+}
+
+func isGlobalUnicast(arg ref.Val) ref.Val {
+	ip, ok := arg.(apiservercel.IP)
+	if !ok {
+		return types.MaybeNoSuchOverloadErr(arg)
+	}
+
+	return types.Bool(ip.Addr.IsGlobalUnicast())
+}
+
 // parseIPAddr parses a string into an IP address.
 // We use this function to parse IP addresses in the CEL library
 // so that we can share the common logic of rejecting IP addresses

staging/src/k8s.io/apiserver/pkg/cel/library/library_compatibility_test.go

@@ -48,7 +48,7 @@ func TestLibraryCompatibility(t *testing.T) {
 		// Kubernetes <1.29>:
 		"add", "asApproximateFloat", "asInteger", "compareTo", "isGreaterThan", "isInteger", "isLessThan", "isQuantity", "quantity", "sign", "sub",
 		// Kubernetes <1.30>:
-		"ip", "family", "ip.isCanonical", "isIP", "string",
+		"ip", "family", "isUnspecified", "isLoopback", "isLinkLocalMulticast", "isLinkLocalUnicast", "isGlobalUnicast", "ip.isCanonical", "isIP", "string",
 		// Kubernetes <1.??>:
 	)