Add conversion from CIDR to IPNet

net/address/address.go

@@ -160,6 +160,11 @@ func (cidr CIDR) String() string {
 	return fmt.Sprintf("%s/%d", cidr.Addr.String(), cidr.PrefixLen)
 }
 
+func (cidr CIDR) IPNet() (r *net.IPNet) {
+	mask := net.CIDRMask(cidr.PrefixLen, 8*net.IPv4len)
+	return &net.IPNet{IP: cidr.Addr.IP4(), Mask: mask}
+}
+
 // FromIP4 converts an ipv4 address to our integer address type
 func FromIP4(ip4 net.IP) (r Address) {
 	for _, b := range ip4.To4() {

net/address/address_test.go

@@ -1,6 +1,7 @@
 package address
 
 import (
+	"net"
 	"testing"
 	"testing/quick"
 
@@ -67,3 +68,15 @@ func TestCIDRStartAndEnd(t *testing.T) {
 	require.Equal(t, ip("10.0.0.0"), cidr.Start(), "")
 	require.Equal(t, ip("10.0.1.0"), cidr.End(), "")
 }
+
+func TestConversions(t *testing.T) {
+	addrStr := "10.2.3.0"
+	cidrStr := addrStr + "/24"
+	addr := ip(addrStr)
+	require.Equal(t, addr.String(), addrStr)
+	require.Equal(t, addr.IP4(), net.ParseIP(addrStr).To4())
+	cidr, _ := ParseCIDR(cidrStr)
+	require.Equal(t, cidr.String(), cidrStr)
+	_, ipnet, _ := net.ParseCIDR(cidrStr)
+	require.Equal(t, cidr.IPNet(), ipnet)
+}