diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_bsd.go b/src/vendor/golang_org/x/net/internal/nettest/helper_bsd.go
new file mode 100644
index 0000000..a6e433b
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_bsd.go
@@ -0,0 +1,53 @@
+// Copyright 2016 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.
+
+// +build darwin dragonfly freebsd netbsd openbsd
+
+package nettest
+
+import (
+	"runtime"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+var darwinVersion int
+
+func init() {
+	if runtime.GOOS == "darwin" {
+		// See http://support.apple.com/kb/HT1633.
+		s, err := syscall.Sysctl("kern.osrelease")
+		if err != nil {
+			return
+		}
+		ss := strings.Split(s, ".")
+		if len(ss) == 0 {
+			return
+		}
+		darwinVersion, _ = strconv.Atoi(ss[0])
+	}
+}
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	switch runtime.GOOS {
+	case "freebsd":
+		// See http://www.freebsd.org/cgi/query-pr.cgi?pr=180065.
+		// Even after the fix, it looks like the latest
+		// kernels don't deliver link-local scoped multicast
+		// packets correctly.
+		return false
+	case "darwin":
+		return !causesIPv6Crash()
+	default:
+		return true
+	}
+}
+
+func causesIPv6Crash() bool {
+	// We see some kernel crash when running IPv6 with IP-level
+	// options on Darwin kernel version 12 or below.
+	// See golang.org/issues/17015.
+	return darwinVersion < 13
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_nobsd.go b/src/vendor/golang_org/x/net/internal/nettest/helper_nobsd.go
new file mode 100644
index 0000000..bc7da5e
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_nobsd.go
@@ -0,0 +1,15 @@
+// Copyright 2016 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.
+
+// +build linux solaris
+
+package nettest
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	return true
+}
+
+func causesIPv6Crash() bool {
+	return false
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_posix.go b/src/vendor/golang_org/x/net/internal/nettest/helper_posix.go
new file mode 100644
index 0000000..963ed99
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_posix.go
@@ -0,0 +1,31 @@
+// Copyright 2014 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.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris windows
+
+package nettest
+
+import (
+	"os"
+	"syscall"
+)
+
+func protocolNotSupported(err error) bool {
+	switch err := err.(type) {
+	case syscall.Errno:
+		switch err {
+		case syscall.EPROTONOSUPPORT, syscall.ENOPROTOOPT:
+			return true
+		}
+	case *os.SyscallError:
+		switch err := err.Err.(type) {
+		case syscall.Errno:
+			switch err {
+			case syscall.EPROTONOSUPPORT, syscall.ENOPROTOOPT:
+				return true
+			}
+		}
+	}
+	return false
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_stub.go b/src/vendor/golang_org/x/net/internal/nettest/helper_stub.go
new file mode 100644
index 0000000..ea61b6f
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_stub.go
@@ -0,0 +1,32 @@
+// Copyright 2014 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.
+
+// +build nacl plan9
+
+package nettest
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func maxOpenFiles() int {
+	return defaultMaxOpenFiles
+}
+
+func supportsRawIPSocket() (string, bool) {
+	return fmt.Sprintf("not supported on %s", runtime.GOOS), false
+}
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	return false
+}
+
+func causesIPv6Crash() bool {
+	return false
+}
+
+func protocolNotSupported(err error) bool {
+	return false
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_unix.go b/src/vendor/golang_org/x/net/internal/nettest/helper_unix.go
new file mode 100644
index 0000000..ed13e44
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_unix.go
@@ -0,0 +1,29 @@
+// Copyright 2015 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.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package nettest
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"syscall"
+)
+
+func maxOpenFiles() int {
+	var rlim syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlim); err != nil {
+		return defaultMaxOpenFiles
+	}
+	return int(rlim.Cur)
+}
+
+func supportsRawIPSocket() (string, bool) {
+	if os.Getuid() != 0 {
+		return fmt.Sprintf("must be root on %s", runtime.GOOS), false
+	}
+	return "", true
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/helper_windows.go b/src/vendor/golang_org/x/net/internal/nettest/helper_windows.go
new file mode 100644
index 0000000..3dcb727
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/helper_windows.go
@@ -0,0 +1,42 @@
+// Copyright 2015 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 nettest
+
+import (
+	"fmt"
+	"runtime"
+	"syscall"
+)
+
+func maxOpenFiles() int {
+	return 4 * defaultMaxOpenFiles /* actually it's 16581375 */
+}
+
+func supportsRawIPSocket() (string, bool) {
+	// From http://msdn.microsoft.com/en-us/library/windows/desktop/ms740548.aspx:
+	// Note: To use a socket of type SOCK_RAW requires administrative privileges.
+	// Users running Winsock applications that use raw sockets must be a member of
+	// the Administrators group on the local computer, otherwise raw socket calls
+	// will fail with an error code of WSAEACCES. On Windows Vista and later, access
+	// for raw sockets is enforced at socket creation. In earlier versions of Windows,
+	// access for raw sockets is enforced during other socket operations.
+	s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, 0)
+	if err == syscall.WSAEACCES {
+		return fmt.Sprintf("no access to raw socket allowed on %s", runtime.GOOS), false
+	}
+	if err != nil {
+		return err.Error(), false
+	}
+	syscall.Closesocket(s)
+	return "", true
+}
+
+func supportsIPv6MulticastDeliveryOnLoopback() bool {
+	return true
+}
+
+func causesIPv6Crash() bool {
+	return false
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/interface.go b/src/vendor/golang_org/x/net/internal/nettest/interface.go
new file mode 100644
index 0000000..8e6333a
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/interface.go
@@ -0,0 +1,94 @@
+// 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 nettest
+
+import "net"
+
+// IsMulticastCapable reports whether ifi is an IP multicast-capable
+// network interface. Network must be "ip", "ip4" or "ip6".
+func IsMulticastCapable(network string, ifi *net.Interface) (net.IP, bool) {
+	switch network {
+	case "ip", "ip4", "ip6":
+	default:
+		return nil, false
+	}
+	if ifi == nil || ifi.Flags&net.FlagUp == 0 || ifi.Flags&net.FlagMulticast == 0 {
+		return nil, false
+	}
+	return hasRoutableIP(network, ifi)
+}
+
+// RoutedInterface returns a network interface that can route IP
+// traffic and satisfies flags. It returns nil when an appropriate
+// network interface is not found. Network must be "ip", "ip4" or
+// "ip6".
+func RoutedInterface(network string, flags net.Flags) *net.Interface {
+	switch network {
+	case "ip", "ip4", "ip6":
+	default:
+		return nil
+	}
+	ift, err := net.Interfaces()
+	if err != nil {
+		return nil
+	}
+	for _, ifi := range ift {
+		if ifi.Flags&flags != flags {
+			continue
+		}
+		if _, ok := hasRoutableIP(network, &ifi); !ok {
+			continue
+		}
+		return &ifi
+	}
+	return nil
+}
+
+func hasRoutableIP(network string, ifi *net.Interface) (net.IP, bool) {
+	ifat, err := ifi.Addrs()
+	if err != nil {
+		return nil, false
+	}
+	for _, ifa := range ifat {
+		switch ifa := ifa.(type) {
+		case *net.IPAddr:
+			if ip := routableIP(network, ifa.IP); ip != nil {
+				return ip, true
+			}
+		case *net.IPNet:
+			if ip := routableIP(network, ifa.IP); ip != nil {
+				return ip, true
+			}
+		}
+	}
+	return nil, false
+}
+
+func routableIP(network string, ip net.IP) net.IP {
+	if !ip.IsLoopback() && !ip.IsLinkLocalUnicast() && !ip.IsGlobalUnicast() {
+		return nil
+	}
+	switch network {
+	case "ip4":
+		if ip := ip.To4(); ip != nil {
+			return ip
+		}
+	case "ip6":
+		if ip.IsLoopback() { // addressing scope of the loopback address depends on each implementation
+			return nil
+		}
+		if ip := ip.To16(); ip != nil && ip.To4() == nil {
+			return ip
+		}
+	default:
+		if ip := ip.To4(); ip != nil {
+			return ip
+		}
+		if ip := ip.To16(); ip != nil {
+			return ip
+		}
+	}
+	return nil
+}
diff --git a/src/vendor/golang_org/x/net/internal/nettest/rlimit.go b/src/vendor/golang_org/x/net/internal/nettest/rlimit.go
new file mode 100644
index 0000000..bb34aec
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/rlimit.go
@@ -0,0 +1,11 @@
+// Copyright 2015 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 nettest
+
+const defaultMaxOpenFiles = 256
+
+// MaxOpenFiles returns the maximum number of open files for the
+// caller's process.
+func MaxOpenFiles() int { return maxOpenFiles() }
diff --git a/src/vendor/golang_org/x/net/internal/nettest/stack.go b/src/vendor/golang_org/x/net/internal/nettest/stack.go
new file mode 100644
index 0000000..06f4e09
--- /dev/null
+++ b/src/vendor/golang_org/x/net/internal/nettest/stack.go
@@ -0,0 +1,152 @@
+// Copyright 2014 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 nettest provides utilities for network testing.
+package nettest // import "golang.org/x/net/internal/nettest"
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os"
+	"runtime"
+)
+
+var (
+	supportsIPv4 bool
+	supportsIPv6 bool
+)
+
+func init() {
+	if ln, err := net.Listen("tcp4", "127.0.0.1:0"); err == nil {
+		ln.Close()
+		supportsIPv4 = true
+	}
+	if ln, err := net.Listen("tcp6", "[::1]:0"); err == nil {
+		ln.Close()
+		supportsIPv6 = true
+	}
+}
+
+// SupportsIPv4 reports whether the platform supports IPv4 networking
+// functionality.
+func SupportsIPv4() bool { return supportsIPv4 }
+
+// SupportsIPv6 reports whether the platform supports IPv6 networking
+// functionality.
+func SupportsIPv6() bool { return supportsIPv6 }
+
+// SupportsRawIPSocket reports whether the platform supports raw IP
+// sockets.
+func SupportsRawIPSocket() (string, bool) {
+	return supportsRawIPSocket()
+}
+
+// SupportsIPv6MulticastDeliveryOnLoopback reports whether the
+// platform supports IPv6 multicast packet delivery on software
+// loopback interface.
+func SupportsIPv6MulticastDeliveryOnLoopback() bool {
+	return supportsIPv6MulticastDeliveryOnLoopback()
+}
+
+// ProtocolNotSupported reports whether err is a protocol not
+// supported error.
+func ProtocolNotSupported(err error) bool {
+	return protocolNotSupported(err)
+}
+
+// TestableNetwork reports whether network is testable on the current
+// platform configuration.
+func TestableNetwork(network string) bool {
+	// This is based on logic from standard library's
+	// net/platform_test.go.
+	switch network {
+	case "unix", "unixgram":
+		switch runtime.GOOS {
+		case "android", "nacl", "plan9", "windows":
+			return false
+		}
+		if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+			return false
+		}
+	case "unixpacket":
+		switch runtime.GOOS {
+		case "android", "darwin", "freebsd", "nacl", "plan9", "windows":
+			return false
+		case "netbsd":
+			// It passes on amd64 at least. 386 fails (Issue 22927). arm is unknown.
+			if runtime.GOARCH == "386" {
+				return false
+			}
+		}
+	}
+	return true
+}
+
+// NewLocalListener returns a listener which listens to a loopback IP
+// address or local file system path.
+// Network must be "tcp", "tcp4", "tcp6", "unix" or "unixpacket".
+func NewLocalListener(network string) (net.Listener, error) {
+	switch network {
+	case "tcp":
+		if supportsIPv4 {
+			if ln, err := net.Listen("tcp4", "127.0.0.1:0"); err == nil {
+				return ln, nil
+			}
+		}
+		if supportsIPv6 {
+			return net.Listen("tcp6", "[::1]:0")
+		}
+	case "tcp4":
+		if supportsIPv4 {
+			return net.Listen("tcp4", "127.0.0.1:0")
+		}
+	case "tcp6":
+		if supportsIPv6 {
+			return net.Listen("tcp6", "[::1]:0")
+		}
+	case "unix", "unixpacket":
+		return net.Listen(network, localPath())
+	}
+	return nil, fmt.Errorf("%s is not supported", network)
+}
+
+// NewLocalPacketListener returns a packet listener which listens to a
+// loopback IP address or local file system path.
+// Network must be "udp", "udp4", "udp6" or "unixgram".
+func NewLocalPacketListener(network string) (net.PacketConn, error) {
+	switch network {
+	case "udp":
+		if supportsIPv4 {
+			if c, err := net.ListenPacket("udp4", "127.0.0.1:0"); err == nil {
+				return c, nil
+			}
+		}
+		if supportsIPv6 {
+			return net.ListenPacket("udp6", "[::1]:0")
+		}
+	case "udp4":
+		if supportsIPv4 {
+			return net.ListenPacket("udp4", "127.0.0.1:0")
+		}
+	case "udp6":
+		if supportsIPv6 {
+			return net.ListenPacket("udp6", "[::1]:0")
+		}
+	case "unixgram":
+		return net.ListenPacket(network, localPath())
+	}
+	return nil, fmt.Errorf("%s is not supported", network)
+}
+
+func localPath() string {
+	f, err := ioutil.TempFile("", "nettest")
+	if err != nil {
+		panic(err)
+	}
+	path := f.Name()
+	f.Close()
+	os.Remove(path)
+	return path
+}
diff --git a/src/vendor/golang_org/x/net/nettest/conntest_test.go b/src/vendor/golang_org/x/net/nettest/conntest_test.go
index 23bd69f..ae8426a 100644
--- a/src/vendor/golang_org/x/net/nettest/conntest_test.go
+++ b/src/vendor/golang_org/x/net/nettest/conntest_test.go
@@ -7,64 +7,14 @@
 package nettest
 
 import (
-	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"runtime"
 	"testing"
+
+	"golang_org/x/net/internal/nettest"
 )
 
-// testUnixAddr uses ioutil.TempFile to get a name that is unique.
-// It also uses /tmp directory in case it is prohibited to create UNIX
-// sockets in TMPDIR.
-func testUnixAddr() string {
-	f, err := ioutil.TempFile("", "go-nettest")
-	if err != nil {
-		panic(err)
-	}
-	addr := f.Name()
-	f.Close()
-	os.Remove(addr)
-	return addr
-}
-
-// testableNetwork reports whether network is testable on the current
-// platform configuration.
-// This is based on logic from standard library's net/platform_test.go.
-func testableNetwork(network string) bool {
-	switch network {
-	case "unix":
-		switch runtime.GOOS {
-		case "android", "nacl", "plan9", "windows":
-			return false
-		}
-		if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
-			return false
-		}
-	case "unixpacket":
-		switch runtime.GOOS {
-		case "android", "darwin", "nacl", "plan9", "windows", "freebsd":
-			return false
-		}
-	}
-	return true
-}
-
-func newLocalListener(network string) (net.Listener, error) {
-	switch network {
-	case "tcp":
-		ln, err := net.Listen("tcp", "127.0.0.1:0")
-		if err != nil {
-			ln, err = net.Listen("tcp6", "[::1]:0")
-		}
-		return ln, err
-	case "unix", "unixpacket":
-		return net.Listen(network, testUnixAddr())
-	}
-	return nil, fmt.Errorf("%s is not supported", network)
-}
-
 func TestTestConn(t *testing.T) {
 	tests := []struct{ name, network string }{
 		{"TCP", "tcp"},
@@ -74,12 +24,12 @@
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if !testableNetwork(tt.network) {
+			if !nettest.TestableNetwork(tt.network) {
 				t.Skipf("not supported on %s", runtime.GOOS)
 			}
 
 			mp := func() (c1, c2 net.Conn, stop func(), err error) {
-				ln, err := newLocalListener(tt.network)
+				ln, err := nettest.NewLocalListener(tt.network)
 				if err != nil {
 					return nil, nil, nil, err
 				}