internal/poll: disable SIO_UDP_NETRESET on Windows

Disable the reception of NET_UNREACHABLE (TTL expired) message reporting
on UDP sockets to match the default behavior of sockets on other
plaforms.

See https://learn.microsoft.com/en-us/windows/win32/winsock/winsock-ioctls#sio_udp_netreset

This is similar to, but a different case from the prior change 3114bd6 /
https://golang.org/issue/5834 that disabled one of the two flags
influencing behavior in response to the reception of related ICMP.

Updates #5834
Updates #68614

Change-Id: I39bc77ab68f5edfc14514d78870ff4a24c0f645e
GitHub-Last-Rev: 78f073bac226aeca438b64acc2c66f76c25f29f8
GitHub-Pull-Request: golang/go#68615
Reviewed-on: https://go-review.googlesource.com/c/go/+/601397
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Michael Pratt <mpratt@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>

diff --git a/src/internal/syscall/windows/types_windows.go b/src/internal/syscall/windows/types_windows.go
index adc8b00bd8993532ba3480d595254c2c4fe92696..6c81754e1a9a887b5a3a65c81ddf90b7d134aada 100644 (file)
--- a/src/internal/syscall/windows/types_windows.go
+++ b/src/internal/syscall/windows/types_windows.go
@@ -14,6 +14,8 @@ const (
        TCP_KEEPIDLE  = 0x03
        TCP_KEEPCNT   = 0x10
        TCP_KEEPINTVL = 0x11
+
+       SIO_UDP_NETRESET = syscall.IOC_IN | syscall.IOC_VENDOR | 15
 )
 
 const (

diff --git a/src/net/fd_windows.go b/src/net/fd_windows.go
index f7609a7cfe8c2879a41725c8101bbb92ed55b2ca..4ad8e0204fde402f9fb424ea25b7280d642889f4 100644 (file)
--- a/src/net/fd_windows.go
+++ b/src/net/fd_windows.go
@@ -67,6 +67,15 @@ func (fd *netFD) init() error {
                if err != nil {
                        return wrapSyscallError("wsaioctl", err)
                }
+               // Disable reporting of NET_UNREACHABLE errors.
+               // See https://go.dev/issue/68614.
+               ret = 0
+               flag = 0
+               size = uint32(unsafe.Sizeof(flag))
+               err = syscall.WSAIoctl(fd.pfd.Sysfd, windows.SIO_UDP_NETRESET, (*byte)(unsafe.Pointer(&flag)), size, nil, 0, &ret, nil, 0)
+               if err != nil {
+                       return wrapSyscallError("wsaioctl", err)
+               }
        }
        return nil
 }