helper.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  package ipv4
   6  
   7  import (
   8  	"errors"
   9  	"net"
  10  	"runtime"
  11  
  12  	"golang.org/x/net/internal/socket"
  13  )
  14  
  15  var (
  16  	errInvalidConn       = errors.New("invalid connection")
  17  	errMissingAddress    = errors.New("missing address")
  18  	errNilHeader         = errors.New("nil header")
  19  	errHeaderTooShort    = errors.New("header too short")
  20  	errExtHeaderTooShort = errors.New("extension header too short")
  21  	errInvalidConnType   = errors.New("invalid conn type")
  22  	errNotImplemented    = errors.New("not implemented on " + runtime.GOOS + "/" + runtime.GOARCH)
  23  
  24  	// See https://www.freebsd.org/doc/en/books/porters-handbook/versions.html.
  25  	freebsdVersion  uint32
  26  	compatFreeBSD32 bool // 386 emulation on amd64
  27  )
  28  
  29  // See golang.org/issue/30899.
  30  func adjustFreeBSD32(m *socket.Message) {
  31  	// FreeBSD 12.0-RELEASE is affected by https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=236737
  32  	if 1200086 <= freebsdVersion && freebsdVersion < 1201000 {
  33  		l := (m.NN + 4 - 1) &^ (4 - 1)
  34  		if m.NN < l && l <= len(m.OOB) {
  35  			m.NN = l
  36  		}
  37  	}
  38  }
  39  
  40  func boolint(b bool) int {
  41  	if b {
  42  		return 1
  43  	}
  44  	return 0
  45  }
  46  
  47  func netAddrToIP4(a net.Addr) net.IP {
  48  	switch v := a.(type) {
  49  	case *net.UDPAddr:
  50  		if ip := v.IP.To4(); ip != nil {
  51  			return ip
  52  		}
  53  	case *net.IPAddr:
  54  		if ip := v.IP.To4(); ip != nil {
  55  			return ip
  56  		}
  57  	}
  58  	return nil
  59  }
  60  
  61  func opAddr(a net.Addr) net.Addr {
  62  	switch a.(type) {
  63  	case *net.TCPAddr:
  64  		if a == nil {
  65  			return nil
  66  		}
  67  	case *net.UDPAddr:
  68  		if a == nil {
  69  			return nil
  70  		}
  71  	case *net.IPAddr:
  72  		if a == nil {
  73  			return nil
  74  		}
  75  	}
  76  	return a
  77  }
  78