libgo/go/golang_org/x/net/route/sys.go

   1 // Copyright 2016 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 // +build darwin dragonfly freebsd netbsd openbsd
   6
   7 package route
   8
   9 import "unsafe"
  10
  11 var (
  12         nativeEndian binaryByteOrder
  13         kernelAlign  int
  14         wireFormats  map[int]*wireFormat
  15 )
  16
  17 func init() {
  18         i := uint32(1)
  19         b := (*[4]byte)(unsafe.Pointer(&i))
  20         if b[0] == 1 {
  21                 nativeEndian = littleEndian
  22         } else {
  23                 nativeEndian = bigEndian
  24         }
  25         kernelAlign, wireFormats = probeRoutingStack()
  26 }
  27
  28 func roundup(l int) int {
  29         if l == 0 {
  30                 return kernelAlign
  31         }
  32         return (l + kernelAlign - 1) & ^(kernelAlign - 1)
  33 }
  34
  35 type wireFormat struct {
  36         extOff  int // offset of header extension
  37         bodyOff int // offset of message body
  38         parse   func(RIBType, []byte) (Message, error)
  39 }