github.com/google/netstack@v0.0.0-20191123085552-55fcc16cd0eb/tcpip/link/fdbased/endpoint_unsafe.go (about)

     1  // Copyright 2019 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // +build linux
    16  
    17  package fdbased
    18  
    19  import (
    20  	"reflect"
    21  	"unsafe"
    22  )
    23  
    24  const virtioNetHdrSize = int(unsafe.Sizeof(virtioNetHdr{}))
    25  
    26  func vnetHdrToByteSlice(hdr *virtioNetHdr) (slice []byte) {
    27  	sh := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
    28  	sh.Data = uintptr(unsafe.Pointer(hdr))
    29  	sh.Len = virtioNetHdrSize
    30  	sh.Cap = virtioNetHdrSize
    31  	return
    32  }