aboutsummaryrefslogtreecommitdiff
path: root/src/syscall/sockcmsg_unix_other.go
blob: 3aaf7c3616c6331aa936b155754f41447c8360d0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
// 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.

// +build aix darwin freebsd linux netbsd openbsd solaris

package syscall

import (
	"runtime"
)

// Round the length of a raw sockaddr up to align it properly.
func cmsgAlignOf(salen int) int {
	salign := sizeofPtr

	// dragonfly needs to check ABI version at runtime, see cmsgAlignOf in
	// sockcmsg_dragonfly.go
	switch runtime.GOOS {
	case "aix":
		// There is no alignment on AIX.
		salign = 1
	case "darwin", "ios", "illumos", "solaris":
		// NOTE: It seems like 64-bit Darwin, Illumos and Solaris
		// kernels still require 32-bit aligned access to network
		// subsystem.
		if sizeofPtr == 8 {
			salign = 4
		}
	case "netbsd", "openbsd":
		// NetBSD and OpenBSD armv7 require 64-bit alignment.
		if runtime.GOARCH == "arm" {
			salign = 8
		}
	}

	return (salen + salign - 1) & ^(salign - 1)
}