Add support for netip.Addr and netip.Prefix to IPFamily functions.

All the functions that previously took a net.IP or string now also
take a netip.Addr. All the functions that previously took a *net.IPNet
or string now also take a netip.Prefix.

Author: danwinship

net/v2/ipfamily.go

@@ -18,6 +18,7 @@ package net
 
 import (
 	"net"
+	"net/netip"
 )
 
 // IPFamily refers to the IP family of an address or CIDR value. Its values are
@@ -36,16 +37,16 @@ const (
 )
 
 type ipOrString interface {
-	net.IP | string
+	net.IP | netip.Addr | string
 }
 
 type cidrOrString interface {
-	*net.IPNet | string
+	*net.IPNet | netip.Prefix | string
 }
 
 // IPFamilyOf returns the IP family of val (or IPFamilyUnknown if val is nil or invalid).
 // IPv6-encoded IPv4 addresses (e.g., "::ffff:1.2.3.4") are considered IPv4. val can be a
-// net.IP or a string containing a single IP address.
+// net.IP, a netip.Addr, or a string containing a single IP address.
 //
 // Note that "k8s.io/utils/net/v2".IPFamily intentionally has identical values to
 // "k8s.io/api/core/v1".IPFamily and "k8s.io/discovery/v1".AddressType, so you can cast
@@ -59,6 +60,13 @@ func IPFamilyOf[T ipOrString](val T) IPFamily {
 		case typedVal.To16() != nil:
 			return IPv6
 		}
+	case netip.Addr:
+		switch {
+		case typedVal.Is4(), typedVal.Is4In6():
+			return IPv4
+		case typedVal.Is6():
+			return IPv6
+		}
 	case string:
 		return IPFamilyOf(ParseIPSloppy(typedVal))
 	}
@@ -103,7 +111,7 @@ func IsDualStackPair[T ipOrString](vals []T) bool {
 
 // IPFamilyOfCIDR returns the IP family of val (or IPFamilyUnknown if val is nil or
 // invalid). IPv6-encoded IPv4 addresses (e.g., "::ffff:1.2.3.0/120") are considered IPv4.
-// val can be a *net.IPNet or a string containing a single CIDR value.
+// val can be a *net.IPNet, a netip.Prefix, or a string containing a single CIDR value.
 //
 // Note that "k8s.io/utils/net/v2".IPFamily intentionally has identical values to
 // "k8s.io/api/core/v1".IPFamily and "k8s.io/discovery/v1".AddressType, so you can cast
@@ -120,6 +128,11 @@ func IPFamilyOfCIDR[T cidrOrString](val T) IPFamily {
 				return family
 			}
 		}
+	case netip.Prefix:
+		if !typedVal.IsValid() {
+			return IPFamilyUnknown
+		}
+		return IPFamilyOf(typedVal.Addr())
 	case string:
 		parsedIP, _, _ := ParseCIDRSloppy(typedVal)
 		return IPFamilyOf(parsedIP)

net/v2/ipfamily_test.go

@@ -19,6 +19,7 @@ package net
 import (
 	"fmt"
 	"net"
+	"net/netip"
 	"testing"
 )
 
@@ -87,8 +88,10 @@ func TestIsDualStack(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.desc, func(t *testing.T) {
 			netips := make([]net.IP, len(tc.ips))
+			addrs := make([]netip.Addr, len(tc.ips))
 			for i := range tc.ips {
 				netips[i] = ParseIPSloppy(tc.ips[i])
+				addrs[i], _ = netip.ParseAddr(tc.ips[i])
 			}
 
 			dualStack := IsDualStack(tc.ips)
@@ -106,6 +109,14 @@ func TestIsDualStack(t *testing.T) {
 			if IsDualStackPair(netips) != (dualStack && len(tc.ips) == 2) {
 				t.Errorf("IsDualStackIPPair gave wrong result for []net.IP")
 			}
+
+			dualStack = IsDualStack(addrs)
+			if dualStack != tc.expectedResult {
+				t.Errorf("expected %v []netip.Addr got %v", tc.expectedResult, dualStack)
+			}
+			if IsDualStackPair(addrs) != (dualStack && len(tc.ips) == 2) {
+				t.Errorf("IsDualStackIPPair gave wrong result for []netip.Addr")
+			}
 		})
 	}
 }
@@ -166,8 +177,10 @@ func TestIsDualStackCIDRs(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.desc, func(t *testing.T) {
 			ipnets := make([]*net.IPNet, len(tc.cidrs))
+			prefixes := make([]netip.Prefix, len(tc.cidrs))
 			for i := range tc.cidrs {
 				_, ipnets[i], _ = ParseCIDRSloppy(tc.cidrs[i])
+				prefixes[i], _ = netip.ParsePrefix(tc.cidrs[i])
 			}
 
 			dualStack := IsDualStackCIDRs(tc.cidrs)
@@ -185,6 +198,14 @@ func TestIsDualStackCIDRs(t *testing.T) {
 			if IsDualStackCIDRPair(ipnets) != (dualStack && len(tc.cidrs) == 2) {
 				t.Errorf("IsDualStackCIDRPair gave wrong result for []*net.IPNet")
 			}
+
+			dualStack = IsDualStackCIDRs(prefixes)
+			if dualStack != tc.expectedResult {
+				t.Errorf("expected %v []netip.Prefix got %v", tc.expectedResult, dualStack)
+			}
+			if IsDualStackCIDRPair(prefixes) != (dualStack && len(tc.cidrs) == 2) {
+				t.Errorf("IsDualStackCIDRPair gave wrong result for []netip.Prefix")
+			}
 		})
 	}
 }
@@ -221,6 +242,12 @@ func TestIPFamilyOf(t *testing.T) {
 				isIPv6 := IsIPv6(ip)
 				checkOneIPFamily(t, ip.String(), tc.family, family, isIPv4, isIPv6)
 			}
+			for _, addr := range tc.addrs {
+				family := IPFamilyOf(addr)
+				isIPv4 := IsIPv4(addr)
+				isIPv6 := IsIPv6(addr)
+				checkOneIPFamily(t, addr.String(), tc.family, family, isIPv4, isIPv6)
+			}
 		})
 	}
 
@@ -236,6 +263,12 @@ func TestIPFamilyOf(t *testing.T) {
 				isIPv6 := IsIPv6(ip)
 				checkOneIPFamily(t, fmt.Sprintf("%#v", ip), IPFamilyUnknown, family, isIPv4, isIPv6)
 			}
+			for _, addr := range tc.addrs {
+				family := IPFamilyOf(addr)
+				isIPv4 := IsIPv4(addr)
+				isIPv6 := IsIPv6(addr)
+				checkOneIPFamily(t, fmt.Sprintf("%#v", addr), IPFamilyUnknown, family, isIPv4, isIPv6)
+			}
 			for _, str := range tc.strings {
 				family := IPFamilyOf(str)
 				isIPv4 := IsIPv4(str)
@@ -265,6 +298,12 @@ func TestIPFamilyOfCIDR(t *testing.T) {
 				isIPv6 := IsIPv6CIDR(ipnet)
 				checkOneIPFamily(t, ipnet.String(), tc.family, family, isIPv4, isIPv6)
 			}
+			for _, prefix := range tc.prefixes {
+				family := IPFamilyOfCIDR(prefix)
+				isIPv4 := IsIPv4CIDR(prefix)
+				isIPv6 := IsIPv6CIDR(prefix)
+				checkOneIPFamily(t, prefix.String(), tc.family, family, isIPv4, isIPv6)
+			}
 		})
 	}
 
@@ -284,6 +323,12 @@ func TestIPFamilyOfCIDR(t *testing.T) {
 				}
 				checkOneIPFamily(t, str, IPFamilyUnknown, family, isIPv4, isIPv6)
 			}
+			for _, prefix := range tc.prefixes {
+				family := IPFamilyOfCIDR(prefix)
+				isIPv4 := IsIPv4CIDR(prefix)
+				isIPv6 := IsIPv6CIDR(prefix)
+				checkOneIPFamily(t, fmt.Sprintf("%#v", prefix), IPFamilyUnknown, family, isIPv4, isIPv6)
+			}
 			for _, str := range tc.strings {
 				family := IPFamilyOfCIDR(str)
 				isIPv4 := IsIPv4CIDR(str)

net/v2/ips_test.go

@@ -45,6 +45,7 @@ type testIP struct {
 // IPFamily tests (unless `skipFamily: true`):
 //   - Each element of .strings should be identified as .family.
 //   - Each element of .ips should be identified as .family.
+//   - Each element of .addrs should be identified as .family.
 //
 // Parsing tests (unless `skipParse: true`):
 //   - Each element of .strings should parse to a value equal to .ips[0].
@@ -233,6 +234,7 @@ var goodTestIPs = []testIP{
 // IPFamily tests (unless `skipFamily: true`):
 //   - Each element of .strings should be identified as IPFamilyUnknown.
 //   - Each element of .ips should be identified as IPFamilyUnknown.
+//   - Each element of .addrs should be identified as IPFamilyUnknown.
 //
 // Parsing tests (unless `skipParse: true`):
 //   - Each element of .strings should fail to parse.
@@ -354,6 +356,7 @@ type testCIDR struct {
 // IPFamily tests (unless `skipFamily: true`):
 //   - Each element of .strings should be identified as .family.
 //   - Each element of .ipnets should be identified as .family.
+//   - Each element of .prefixes should be identified as .family.
 //
 // Parsing tests (unless `skipParse: true`):
 //   - Each element of .strings should parse to a value "equal" to .ipnets[0].
@@ -597,6 +600,7 @@ var goodTestCIDRs = []testCIDR{
 // IPFamily tests (unless `skipFamily: true`):
 //   - Each element of .strings should be identified as IPFamilyUnknown.
 //   - Each element of .ipnets should be identified as IPFamilyUnknown.
+//   - Each element of .prefixes should be identified as IPFamilyUnknown.
 //
 // Parsing tests (unless `skipParse: true`):
 //   - Each element of .strings should fail to parse.