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// Copyright 2014 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 darwin linux solaris
package ipv4
import (
"syscall"
"unsafe"
"golang.org/x/net/internal/iana"
)
func marshalPacketInfo(b []byte, cm *ControlMessage) []byte {
m := (*syscall.Cmsghdr)(unsafe.Pointer(&b[0]))
m.Level = iana.ProtocolIP
m.Type = sysIP_PKTINFO
m.SetLen(syscall.CmsgLen(sizeofInetPktinfo))
if cm != nil {
pi := (*inetPktinfo)(unsafe.Pointer(&b[syscall.CmsgLen(0)]))
if ip := cm.Src.To4(); ip != nil {
copy(pi.Spec_dst[:], ip)
}
if cm.IfIndex > 0 {
pi.setIfindex(cm.IfIndex)
}
}
return b[syscall.CmsgSpace(sizeofInetPktinfo):]
}
func parsePacketInfo(cm *ControlMessage, b []byte) {
pi := (*inetPktinfo)(unsafe.Pointer(&b[0]))
cm.IfIndex = int(pi.Ifindex)
cm.Dst = pi.Addr[:]
}
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