Remove FlagsMask from Addr struct

addr.go

@@ -10,10 +10,9 @@ import (
 // include a mask, so it stores the address as a net.IPNet.
 type Addr struct {
 	*net.IPNet
-	Label     string
-	Flags     int
-	Scope     int
-	FlagsMask int
+	Label string
+	Flags int
+	Scope int
 }
 
 // String returns $ip/$netmask $label

addr_linux.go

@@ -56,7 +56,7 @@ func addrHandle(link Link, addr *Addr, req *nl.NetlinkRequest) error {
 	addressData := nl.NewRtAttr(syscall.IFA_ADDRESS, addrData)
 	req.AddData(addressData)
 
-	if addr.FlagsMask != 0 {
+	if addr.Flags != 0 {
 		b := make([]byte, 4)
 		native.PutUint32(b, uint32(addr.Flags))
 		flagsData := nl.NewRtAttr(IFA_FLAGS, b)

addr_test.go

@@ -106,8 +106,7 @@ func TestAddrAddDelFlags(t *testing.T) {
 			IP:   net.IPv4(127, 1, 1, 1),
 			Mask: net.CIDRMask(24, 32),
 		},
-		Flags:     syscall.IFA_F_PERMANENT,
-		FlagsMask: syscall.IFA_F_PERMANENT,
+		Flags: syscall.IFA_F_PERMANENT,
 	}
 	if err = AddrAdd(link, addr); err != nil {
 		t.Fatal(err)