vendor/github.com/miekg/dns/vendor/golang.org/x/net/internal/nettest/stack.go

   1 // Copyright 2014 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 nettest provides utilities for network testing.
   6 package nettest // import "golang.org/x/net/internal/nettest"
   7
   8 import (
   9         "fmt"
  10         "io/ioutil"
  11         "net"
  12         "os"
  13         "runtime"
  14 )
  15
  16 var (
  17         supportsIPv4 bool
  18         supportsIPv6 bool
  19 )
  20
  21 func init() {
  22         if ln, err := net.Listen("tcp4", "127.0.0.1:0"); err == nil {
  23                 ln.Close()
  24                 supportsIPv4 = true
  25         }
  26         if ln, err := net.Listen("tcp6", "[::1]:0"); err == nil {
  27                 ln.Close()
  28                 supportsIPv6 = true
  29         }
  30 }
  31
  32 // SupportsIPv4 reports whether the platform supports IPv4 networking
  33 // functionality.
  34 func SupportsIPv4() bool { return supportsIPv4 }
  35
  36 // SupportsIPv6 reports whether the platform supports IPv6 networking
  37 // functionality.
  38 func SupportsIPv6() bool { return supportsIPv6 }
  39
  40 // SupportsRawIPSocket reports whether the platform supports raw IP
  41 // sockets.
  42 func SupportsRawIPSocket() (string, bool) {
  43         return supportsRawIPSocket()
  44 }
  45
  46 // SupportsIPv6MulticastDeliveryOnLoopback reports whether the
  47 // platform supports IPv6 multicast packet delivery on software
  48 // loopback interface.
  49 func SupportsIPv6MulticastDeliveryOnLoopback() bool {
  50         return supportsIPv6MulticastDeliveryOnLoopback()
  51 }
  52
  53 // ProtocolNotSupported reports whether err is a protocol not
  54 // supported error.
  55 func ProtocolNotSupported(err error) bool {
  56         return protocolNotSupported(err)
  57 }
  58
  59 // TestableNetwork reports whether network is testable on the current
  60 // platform configuration.
  61 func TestableNetwork(network string) bool {
  62         // This is based on logic from standard library's
  63         // net/platform_test.go.
  64         switch network {
  65         case "unix", "unixgram":
  66                 switch runtime.GOOS {
  67                 case "android", "js", "nacl", "plan9", "windows":
  68                         return false
  69                 }
  70                 if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
  71                         return false
  72                 }
  73         case "unixpacket":
  74                 switch runtime.GOOS {
  75                 case "android", "darwin", "freebsd", "js", "nacl", "plan9", "windows":
  76                         return false
  77                 case "netbsd":
  78                         // It passes on amd64 at least. 386 fails (Issue 22927). arm is unknown.
  79                         if runtime.GOARCH == "386" {
  80                                 return false
  81                         }
  82                 }
  83         }
  84         return true
  85 }
  86
  87 // NewLocalListener returns a listener which listens to a loopback IP
  88 // address or local file system path.
  89 // Network must be "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
  90 func NewLocalListener(network string) (net.Listener, error) {
  91         switch network {
  92         case "tcp":
  93                 if supportsIPv4 {
  94                         if ln, err := net.Listen("tcp4", "127.0.0.1:0"); err == nil {
  95                                 return ln, nil
  96                         }
  97                 }
  98                 if supportsIPv6 {
  99                         return net.Listen("tcp6", "[::1]:0")
 100                 }
 101         case "tcp4":
 102                 if supportsIPv4 {
 103                         return net.Listen("tcp4", "127.0.0.1:0")
 104                 }
 105         case "tcp6":
 106                 if supportsIPv6 {
 107                         return net.Listen("tcp6", "[::1]:0")
 108                 }
 109         case "unix", "unixpacket":
 110                 return net.Listen(network, localPath())
 111         }
 112         return nil, fmt.Errorf("%s is not supported", network)
 113 }
 114
 115 // NewLocalPacketListener returns a packet listener which listens to a
 116 // loopback IP address or local file system path.
 117 // Network must be "udp", "udp4", "udp6" or "unixgram".
 118 func NewLocalPacketListener(network string) (net.PacketConn, error) {
 119         switch network {
 120         case "udp":
 121                 if supportsIPv4 {
 122                         if c, err := net.ListenPacket("udp4", "127.0.0.1:0"); err == nil {
 123                                 return c, nil
 124                         }
 125                 }
 126                 if supportsIPv6 {
 127                         return net.ListenPacket("udp6", "[::1]:0")
 128                 }
 129         case "udp4":
 130                 if supportsIPv4 {
 131                         return net.ListenPacket("udp4", "127.0.0.1:0")
 132                 }
 133         case "udp6":
 134                 if supportsIPv6 {
 135                         return net.ListenPacket("udp6", "[::1]:0")
 136                 }
 137         case "unixgram":
 138                 return net.ListenPacket(network, localPath())
 139         }
 140         return nil, fmt.Errorf("%s is not supported", network)
 141 }
 142
 143 func localPath() string {
 144         f, err := ioutil.TempFile("", "nettest")
 145         if err != nil {
 146                 panic(err)
 147         }
 148         path := f.Name()
 149         f.Close()
 150         os.Remove(path)
 151         return path
 152 }