1// Copyright 2012 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 || dragonfly || freebsd || netbsd || openbsd
6// +build aix darwin dragonfly freebsd netbsd openbsd
7
8package ipv4
9
10import (
11	"net"
12	"syscall"
13	"unsafe"
14
15	"golang.org/x/net/internal/iana"
16	"golang.org/x/net/internal/socket"
17
18	"golang.org/x/sys/unix"
19)
20
21func marshalDst(b []byte, cm *ControlMessage) []byte {
22	m := socket.ControlMessage(b)
23	m.MarshalHeader(iana.ProtocolIP, unix.IP_RECVDSTADDR, net.IPv4len)
24	return m.Next(net.IPv4len)
25}
26
27func parseDst(cm *ControlMessage, b []byte) {
28	if len(cm.Dst) < net.IPv4len {
29		cm.Dst = make(net.IP, net.IPv4len)
30	}
31	copy(cm.Dst, b[:net.IPv4len])
32}
33
34func marshalInterface(b []byte, cm *ControlMessage) []byte {
35	m := socket.ControlMessage(b)
36	m.MarshalHeader(iana.ProtocolIP, sockoptReceiveInterface, syscall.SizeofSockaddrDatalink)
37	return m.Next(syscall.SizeofSockaddrDatalink)
38}
39
40func parseInterface(cm *ControlMessage, b []byte) {
41	var sadl syscall.SockaddrDatalink
42	copy((*[unsafe.Sizeof(sadl)]byte)(unsafe.Pointer(&sadl))[:], b)
43	cm.IfIndex = int(sadl.Index)
44}
45