golang.org/x/net@v0.25.1-0.20240516223405-c87a5b62e243/ipv4/control_bsd.go (about)

     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  }