text: // Copyright 2012 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.
  
  package ipv4_test
  
  import (
  	"net"
  	"runtime"
  	"testing"
  
  	"golang.org/x/net/internal/iana"
  	"golang.org/x/net/internal/nettest"
  	"golang.org/x/net/ipv4"
  )
  
  func TestConnUnicastSocketOptions(t *testing.T) {
  	switch runtime.GOOS {
  	case "nacl", "plan9":
  		t.Skipf("not supported on %s", runtime.GOOS)
  	}
  	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
  	if ifi == nil {
  		t.Skipf("not available on %s", runtime.GOOS)
  	}
  
  	ln, err := net.Listen("tcp4", "127.0.0.1:0")
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer ln.Close()
  
  	done := make(chan bool)
  	go acceptor(t, ln, done)
  
  	c, err := net.Dial("tcp4", ln.Addr().String())
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer c.Close()
  
  	testUnicastSocketOptions(t, ipv4.NewConn(c))
  
  	<-done
  }
  
  var packetConnUnicastSocketOptionTests = []struct {
  	net, proto, addr string
  }{
  	{"udp4", "", "127.0.0.1:0"},
  	{"ip4", ":icmp", "127.0.0.1"},
  }
  
  func TestPacketConnUnicastSocketOptions(t *testing.T) {
  	switch runtime.GOOS {
  	case "nacl", "plan9":
  		t.Skipf("not supported on %s", runtime.GOOS)
  	}
  	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
  	if ifi == nil {
  		t.Skipf("not available on %s", runtime.GOOS)
  	}
  
  	m, ok := nettest.SupportsRawIPSocket()
  	for _, tt := range packetConnUnicastSocketOptionTests {
  		if tt.net == "ip4" && !ok {
  			t.Log(m)
  			continue
  		}
  		c, err := net.ListenPacket(tt.net+tt.proto, tt.addr)
  		if err != nil {
  			t.Fatal(err)
  		}
  		defer c.Close()
  
  		testUnicastSocketOptions(t, ipv4.NewPacketConn(c))
  	}
  }
  
  func TestRawConnUnicastSocketOptions(t *testing.T) {
  	switch runtime.GOOS {
  	case "nacl", "plan9":
  		t.Skipf("not supported on %s", runtime.GOOS)
  	}
  	if m, ok := nettest.SupportsRawIPSocket(); !ok {
  		t.Skip(m)
  	}
  	ifi := nettest.RoutedInterface("ip4", net.FlagUp|net.FlagLoopback)
  	if ifi == nil {
  		t.Skipf("not available on %s", runtime.GOOS)
  	}
  
  	c, err := net.ListenPacket("ip4:icmp", "127.0.0.1")
  	if err != nil {
  		t.Fatal(err)
  	}
  	defer c.Close()
  
  	r, err := ipv4.NewRawConn(c)
  	if err != nil {
  		t.Fatal(err)
  	}
  
  	testUnicastSocketOptions(t, r)
  }
  
  type testIPv4UnicastConn interface {
  	TOS() (int, error)
  	SetTOS(int) error
  	TTL() (int, error)
  	SetTTL(int) error
  }
  
  func testUnicastSocketOptions(t *testing.T, c testIPv4UnicastConn) {
  	tos := iana.DiffServCS0 | iana.NotECNTransport
  	switch runtime.GOOS {
  	case "windows":
  		// IP_TOS option is supported on Windows 8 and beyond.
  		t.Skipf("not supported on %s", runtime.GOOS)
  	}
  
  	if err := c.SetTOS(tos); err != nil {
  		t.Fatal(err)
  	}
  	if v, err := c.TOS(); err != nil {
  		t.Fatal(err)
  	} else if v != tos {
  		t.Fatalf("got %v; want %v", v, tos)
  	}
  	const ttl = 255
  	if err := c.SetTTL(ttl); err != nil {
  		t.Fatal(err)
  	}
  	if v, err := c.TTL(); err != nil {
  		t.Fatal(err)
  	} else if v != ttl {
  		t.Fatalf("got %v; want %v", v, ttl)
  	}
  }
  