--- /dev/null
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package unix
+
+// Round the length of a raw sockaddr up to align it properly.
+func cmsgAlignOf(salen int) int {
+ salign := SizeofPtr
+ if SizeofPtr == 8 && !supportsABI(_dragonflyABIChangeVersion) {
+ // 64-bit Dragonfly before the September 2019 ABI changes still requires
+ // 32-bit aligned access to network subsystem.
+ salign = 4
+ }
+ return (salen + salign - 1) & ^(salign - 1)
+}