net: disable SIO_UDP_CONNRESET behavior on windows.

Fixes #5834.

LGTM=alex.brainman
R=golang-codereviews, bradfitz, alex.brainman, mikioh.mikioh, in60jp, iant
CC=golang-codereviews
https://golang.org/cl/149510043

src/net/fd_windows.go

@@ -294,6 +294,18 @@ func (fd *netFD) init() error {
 			fd.skipSyncNotif = true
 		}
 	}
+	// Disable SIO_UDP_CONNRESET behavior.
+	// http://support.microsoft.com/kb/263823
+	switch fd.net {
+	case "udp", "udp4", "udp6":
+		ret := uint32(0)
+		flag := uint32(0)
+		size := uint32(unsafe.Sizeof(flag))
+		err := syscall.WSAIoctl(fd.sysfd, syscall.SIO_UDP_CONNRESET, (*byte)(unsafe.Pointer(&flag)), size, nil, 0, &ret, nil, 0)
+		if err != nil {
+			return os.NewSyscallError("WSAIoctl", err)
+		}
+	}
 	fd.rop.mode = 'r'
 	fd.wop.mode = 'w'
 	fd.rop.fd = fd

src/net/udp_test.go

@@ -9,6 +9,7 @@ import (
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 )
 
 func TestResolveUDPAddr(t *testing.T) {
@@ -34,6 +35,41 @@ func TestResolveUDPAddr(t *testing.T) {
 	}
 }
 
+func TestReadFromUDP(t *testing.T) {
+	ra, err := ResolveUDPAddr("udp", "127.0.0.1:7")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	la, err := ResolveUDPAddr("udp", "127.0.0.1:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	c, err := ListenUDP("udp", la)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	_, err = c.WriteToUDP([]byte("a"), ra)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = c.SetDeadline(time.Now().Add(100 * time.Millisecond))
+	if err != nil {
+		t.Fatal(err)
+	}
+	b := make([]byte, 1)
+	_, _, err = c.ReadFromUDP(b)
+	if err == nil {
+		t.Fatal("ReadFromUDP should fail")
+	} else if !isTimeout(err) {
+		t.Fatal(err)
+	}
+}
+
 func TestWriteToUDP(t *testing.T) {
 	switch runtime.GOOS {
 	case "plan9":

src/syscall/ztypes_windows.go

@@ -547,6 +547,7 @@ const (
 	IOC_WS2                            = 0x08000000
 	SIO_GET_EXTENSION_FUNCTION_POINTER = IOC_INOUT | IOC_WS2 | 6
 	SIO_KEEPALIVE_VALS                 = IOC_IN | IOC_VENDOR | 4
+	SIO_UDP_CONNRESET                  = IOC_IN | IOC_VENDOR | 12
 
 	// cf. http://support.microsoft.com/default.aspx?scid=kb;en-us;257460