tun: windows: Retry R/W on ERROR_OPERATION_ABORTED

Signed-off-by: Simon Rozman <simon@rozman.si>

tun/tun_windows.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"os"
 	"sync"
+	"syscall"
 	"time"
 	"unsafe"
 
@@ -119,7 +120,7 @@ func (tun *NativeTun) openTUN() error {
 	for tun.tunFileWrite == nil {
 		tun.tunFileWrite, err = os.OpenFile(name, os.O_WRONLY, 0)
 		if err != nil {
-			if retries > 0 {
+			if retries > 0 && !tun.close {
 				time.Sleep(time.Second / retryRate)
 				retries--
 				continue
@@ -258,18 +259,31 @@ func (tun *NativeTun) Read(buff []byte, offset int) (int, error) {
 		}
 
 		// Fill queue.
+		retries := retryTimeout * retryRate
+		for {
 			n, err := file.Read(tun.rdBuff.data[:])
 			if err != nil {
 				tun.rdBuff.offset = 0
 				tun.rdBuff.avail = 0
+				pe, ok := err.(*os.PathError)
 				if tun.close {
-				return 0, err
+					return 0, os.ErrClosed
 				}
-			tun.closeTUN()
+				if retries > 0 && ok && pe.Err == windows.ERROR_OPERATION_ABORTED {
+					time.Sleep(time.Second / retryRate)
+					retries--
 					continue
 				}
+				if ok && pe.Err == syscall.Errno(6) /*windows.ERROR_INVALID_HANDLE*/ {
+					tun.closeTUN()
+					break
+				}
+				return 0, err
+			}
 			tun.rdBuff.offset = 0
 			tun.rdBuff.avail = uint32(n)
+			break
+		}
 	}
 }
 
@@ -288,19 +302,31 @@ func (tun *NativeTun) Flush() error {
 		}
 
 		// Flush write buffer.
+		retries := retryTimeout * retryRate
+		for {
 			_, err = file.Write(tun.wrBuff.data[:tun.wrBuff.offset])
 			tun.wrBuff.packetNum = 0
 			tun.wrBuff.offset = 0
 			if err != nil {
+				pe, ok := err.(*os.PathError)
 				if tun.close {
-				return err
+					return os.ErrClosed
 				}
-			tun.closeTUN()
+				if retries > 0 && ok && pe.Err == windows.ERROR_OPERATION_ABORTED {
+					time.Sleep(time.Second / retryRate)
+					retries--
 					continue
 				}
+				if ok && pe.Err == syscall.Errno(6) /*windows.ERROR_INVALID_HANDLE*/ {
+					tun.closeTUN()
+					break
+				}
+				return err
+			}
 			return nil
 		}
 	}
+}
 
 func (tun *NativeTun) putTunPacket(buff []byte) error {
 	size := uint32(len(buff))