control_bsd.go raw

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