sockcmsg_unix_other.mx raw

   1  // Copyright 2019 The Go Authors. All rights reserved.
   2  // Use of this source code is governed by a BSD-style
   3  // license that can be found in the LICENSE file.
   4  
   5  //go:build aix || darwin || freebsd || linux || netbsd || openbsd || solaris
   6  
   7  package syscall
   8  
   9  import (
  10  	"runtime"
  11  )
  12  
  13  // Round the length of a raw sockaddr up to align it properly.
  14  func cmsgAlignOf(salen int) int {
  15  	salign := sizeofPtr
  16  
  17  	// dragonfly needs to check ABI version at runtime, see cmsgAlignOf in
  18  	// sockcmsg_dragonfly.go
  19  	switch runtime.GOOS {
  20  	case "aix":
  21  		// There is no alignment on AIX.
  22  		salign = 1
  23  	case "darwin", "ios", "illumos", "solaris":
  24  		// NOTE: It seems like 64-bit Darwin, Illumos and Solaris
  25  		// kernels still require 32-bit aligned access to network
  26  		// subsystem.
  27  		if sizeofPtr == 8 {
  28  			salign = 4
  29  		}
  30  	case "netbsd", "openbsd":
  31  		// NetBSD and OpenBSD armv7 require 64-bit alignment.
  32  		if runtime.GOARCH == "arm" {
  33  			salign = 8
  34  		}
  35  		// NetBSD aarch64 requires 128-bit alignment.
  36  		if runtime.GOOS == "netbsd" && runtime.GOARCH == "arm64" {
  37  			salign = 16
  38  		}
  39  	}
  40  
  41  	return (salen + salign - 1) & ^(salign - 1)
  42  }
  43