diff options
Diffstat (limited to 'tun/tun_windows.go')
| -rw-r--r-- | tun/tun_windows.go | 104 |
1 files changed, 64 insertions, 40 deletions
diff --git a/tun/tun_windows.go b/tun/tun_windows.go index d2bcd01..5a4103d 100644 --- a/tun/tun_windows.go +++ b/tun/tun_windows.go @@ -8,6 +8,7 @@ package tun import ( "errors" "os" + "sync" "unsafe" "golang.org/x/sys/windows" @@ -22,13 +23,6 @@ const ( packetExchangeSizeWrite uint32 = 0x10000 // Write exchange buffer size (defaults to 64kiB) ) -const ( - signalClose = iota - signalDataAvail - - signalMax -) - type exchgBufRead struct { data [packetExchangeSizeRead]byte offset uint32 @@ -42,15 +36,17 @@ type exchgBufWrite struct { } type nativeTun struct { - wt *wintun.Wintun - tunName string - signalName *uint16 - tunFile *os.File - rdBuff *exchgBufRead - wrBuff *exchgBufWrite - signals [signalMax]windows.Handle - events chan TUNEvent - errors chan error + wt *wintun.Wintun + tunName string + signalName *uint16 + tunFile *os.File + tunLock sync.Mutex + rdBuff *exchgBufRead + wrBuff *exchgBufWrite + tunDataAvail windows.Handle + userClose windows.Handle + events chan TUNEvent + errors chan error } func packetAlign(size uint32) uint32 { @@ -104,7 +100,7 @@ func CreateTUN(ifname string) (TUNDevice, error) { } // Create close event. - tun.signals[signalClose], err = windows.CreateEvent(nil, 1 /*TRUE*/, 0 /*FALSE*/, nil) + tun.userClose, err = windows.CreateEvent(nil, 1 /*TRUE*/, 0 /*FALSE*/, nil) if err != nil { wt.DeleteInterface(0) return nil, err @@ -121,7 +117,7 @@ func (tun *nativeTun) openTUN() error { if err != nil { // After examining possible error conditions, many arose that were only temporary: windows.ERROR_FILE_NOT_FOUND, "read <filename> closed", etc. // To simplify, we will enter a retry-loop on _any_ error until session is closed by user. - switch evt, e := windows.WaitForSingleObject(tun.signals[signalClose], 1000); evt { + switch evt, e := windows.WaitForSingleObject(tun.userClose, 1000); evt { case windows.WAIT_OBJECT_0, windows.WAIT_ABANDONED: return errors.New("TUN closed") case windows.WAIT_TIMEOUT: @@ -139,21 +135,24 @@ func (tun *nativeTun) openTUN() error { } tun.tunFile = file - tun.signals[signalDataAvail] = event + tun.tunDataAvail = event return nil } } func (tun *nativeTun) closeTUN() (err error) { - if tun.signals[signalDataAvail] != 0 { + tun.tunLock.Lock() + defer tun.tunLock.Unlock() + + if tun.tunDataAvail != 0 { // Close interface data ready event. - e := windows.CloseHandle(tun.signals[signalDataAvail]) + e := windows.CloseHandle(tun.tunDataAvail) if err != nil { err = e } - tun.signals[signalDataAvail] = 0 + tun.tunDataAvail = 0 } if tun.tunFile != nil { @@ -169,6 +168,21 @@ func (tun *nativeTun) closeTUN() (err error) { return } +func (tun *nativeTun) getTUN() (*os.File, windows.Handle, error) { + tun.tunLock.Lock() + defer tun.tunLock.Unlock() + + if tun.tunFile == nil || tun.tunDataAvail == 0 { + // TUN device is not open (yet). + err := tun.openTUN() + if err != nil { + return nil, 0, err + } + } + + return tun.tunFile, tun.tunDataAvail, nil +} + func (tun *nativeTun) Name() (string, error) { return tun.wt.GetInterfaceName() } @@ -182,8 +196,8 @@ func (tun *nativeTun) Events() chan TUNEvent { } func (tun *nativeTun) Close() error { - windows.SetEvent(tun.signals[signalClose]) - err := windows.CloseHandle(tun.signals[signalClose]) + windows.SetEvent(tun.userClose) + err := windows.CloseHandle(tun.userClose) e := tun.closeTUN() if err == nil { @@ -230,28 +244,25 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { return int(size), nil } - if tun.signals[signalDataAvail] == 0 { - // Data pipe and interface data available event are not open (yet). - err := tun.openTUN() - if err != nil { - return 0, err - } + // Get TUN data ready event. + _, tunDataAvail, err := tun.getTUN() + if err != nil { + return 0, err } // Wait for user close or interface data. - r, err := windows.WaitForMultipleObjects(tun.signals[:], false, windows.INFINITE) + r, err := windows.WaitForMultipleObjects([]windows.Handle{tun.userClose, tunDataAvail}, false, windows.INFINITE) if err != nil { return 0, errors.New("Waiting for data failed: " + err.Error()) } switch r { - case windows.WAIT_OBJECT_0 + signalClose, windows.WAIT_ABANDONED + signalClose: + case windows.WAIT_OBJECT_0 + 0, windows.WAIT_ABANDONED + 0: return 0, errors.New("TUN closed") - case windows.WAIT_OBJECT_0 + signalDataAvail: + case windows.WAIT_OBJECT_0 + 1: // Data is available. - case windows.WAIT_ABANDONED + signalDataAvail: - // TUN stopped. Reopen it. + case windows.WAIT_ABANDONED + 1: + // TUN stopped. tun.closeTUN() - continue case windows.WAIT_TIMEOUT: // Congratulations, we reached infinity. Let's do it again! :) continue @@ -259,11 +270,16 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { return 0, errors.New("unexpected result from WaitForMultipleObjects") } + // Get TUN data pipe. + file, _, err := tun.getTUN() + if err != nil { + return 0, err + } + // Fill queue. - n, err := tun.tunFile.Read(tun.rdBuff.data[:]) + n, err := file.Read(tun.rdBuff.data[:]) if err != nil { - // TUN interface stopped, returned incomplete data, etc. - // Retry. + // TUN interface stopped, failed, etc. Retry. tun.rdBuff.avail = 0 tun.closeTUN() continue @@ -276,11 +292,19 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { // Note: flush() and putTunPacket() assume the caller comes only from a single thread; there's no locking. func (tun *nativeTun) flush() error { + // Get TUN data pipe. + file, _, err := tun.getTUN() + if err != nil { + return err + } + // Flush write buffer. - _, err := tun.tunFile.Write(tun.wrBuff.data[:tun.wrBuff.offset]) + _, err = file.Write(tun.wrBuff.data[:tun.wrBuff.offset]) tun.wrBuff.packetNum = 0 tun.wrBuff.offset = 0 if err != nil { + // TUN interface stopped, failed, etc. Drop. + tun.closeTUN() return err } |