diff options
| -rw-r--r-- | tun/tun_windows.go | 77 |
1 files changed, 44 insertions, 33 deletions
diff --git a/tun/tun_windows.go b/tun/tun_windows.go index 3c990c4..d2bcd01 100644 --- a/tun/tun_windows.go +++ b/tun/tun_windows.go @@ -18,7 +18,8 @@ const ( packetSizeMax uint32 = 0xeffc // Maximum packet size: 4 + packetSizeMax == 0xf000 packetExchangeMax uint32 = 256 // Number of packets that may be written at a time packetExchangeAlignment uint32 = 16 // Number of bytes packets are aligned to in exchange buffers - packetExchangeSize uint32 = 0x100000 // Exchange buffer size (defaults to 1MiB) + packetExchangeSizeRead uint32 = 0x100000 // Read exchange buffer size (defaults to 1MiB) + packetExchangeSizeWrite uint32 = 0x10000 // Write exchange buffer size (defaults to 64kiB) ) const ( @@ -28,20 +29,28 @@ const ( signalMax ) +type exchgBufRead struct { + data [packetExchangeSizeRead]byte + offset uint32 + avail uint32 +} + +type exchgBufWrite struct { + data [packetExchangeSizeWrite]byte + offset uint32 + packetNum uint32 +} + type nativeTun struct { - wt *wintun.Wintun - tunName string - signalName *uint16 - tunFile *os.File - wrBuff [packetExchangeSize]byte - rdBuff [packetExchangeSize]byte - signals [signalMax]windows.Handle - wrOffset uint32 - wrPacketNum uint32 - rdOffset uint32 - rdAvailabe uint32 - events chan TUNEvent - errors chan error + wt *wintun.Wintun + tunName string + signalName *uint16 + tunFile *os.File + rdBuff *exchgBufRead + wrBuff *exchgBufWrite + signals [signalMax]windows.Handle + events chan TUNEvent + errors chan error } func packetAlign(size uint32) uint32 { @@ -88,6 +97,8 @@ func CreateTUN(ifname string) (TUNDevice, error) { wt: wt, tunName: wt.DataFileName(), signalName: signalNameUTF16, + rdBuff: &exchgBufRead{}, + wrBuff: &exchgBufWrite{}, events: make(chan TUNEvent, 10), errors: make(chan error, 1), } @@ -203,19 +214,19 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { } for { - if tun.rdOffset+4 <= tun.rdAvailabe { - // Get packet from the queue. - size := *(*uint32)(unsafe.Pointer(&tun.rdBuff[tun.rdOffset])) + if tun.rdBuff.offset+4 <= tun.rdBuff.avail { + // Get packet from the exchange buffer. + size := *(*uint32)(unsafe.Pointer(&tun.rdBuff.data[tun.rdBuff.offset])) pSize := packetAlign(4 + size) - if packetSizeMax < size || tun.rdAvailabe < tun.rdOffset+pSize { + if packetSizeMax < size || tun.rdBuff.avail < tun.rdBuff.offset+pSize { // Invalid packet size. - tun.rdAvailabe = 0 + tun.rdBuff.avail = 0 continue } // Copy data. - copy(buff[offset:], (*(*[packetSizeMax]byte)(unsafe.Pointer(&tun.rdBuff[tun.rdOffset+4])))[:size]) - tun.rdOffset += pSize + copy(buff[offset:], (*(*[packetSizeMax]byte)(unsafe.Pointer(&tun.rdBuff.data[tun.rdBuff.offset+4])))[:size]) + tun.rdBuff.offset += pSize return int(size), nil } @@ -249,16 +260,16 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { } // Fill queue. - n, err := tun.tunFile.Read(tun.rdBuff[:]) + n, err := tun.tunFile.Read(tun.rdBuff.data[:]) if err != nil { // TUN interface stopped, returned incomplete data, etc. // Retry. - tun.rdAvailabe = 0 + tun.rdBuff.avail = 0 tun.closeTUN() continue } - tun.rdOffset = 0 - tun.rdAvailabe = uint32(n) + tun.rdBuff.offset = 0 + tun.rdBuff.avail = uint32(n) } } @@ -266,9 +277,9 @@ func (tun *nativeTun) Read(buff []byte, offset int) (int, error) { func (tun *nativeTun) flush() error { // Flush write buffer. - _, err := tun.tunFile.Write(tun.wrBuff[:tun.wrOffset]) - tun.wrPacketNum = 0 - tun.wrOffset = 0 + _, err := tun.tunFile.Write(tun.wrBuff.data[:tun.wrBuff.offset]) + tun.wrBuff.packetNum = 0 + tun.wrBuff.offset = 0 if err != nil { return err } @@ -286,7 +297,7 @@ func (tun *nativeTun) putTunPacket(buff []byte) error { } pSize := packetAlign(4 + size) - if tun.wrPacketNum >= packetExchangeMax || tun.wrOffset+pSize >= packetExchangeSize { + if tun.wrBuff.packetNum >= packetExchangeMax || tun.wrBuff.offset+pSize >= packetExchangeSizeWrite { // Exchange buffer is full -> flush first. err := tun.flush() if err != nil { @@ -295,11 +306,11 @@ func (tun *nativeTun) putTunPacket(buff []byte) error { } // Write packet to the exchange buffer. - *(*uint32)(unsafe.Pointer(&tun.wrBuff[tun.wrOffset])) = size - copy((*(*[packetSizeMax]byte)(unsafe.Pointer(&tun.wrBuff[tun.wrOffset+4])))[:size], buff) + *(*uint32)(unsafe.Pointer(&tun.wrBuff.data[tun.wrBuff.offset])) = size + copy((*(*[packetSizeMax]byte)(unsafe.Pointer(&tun.wrBuff.data[tun.wrBuff.offset+4])))[:size], buff) - tun.wrPacketNum++ - tun.wrOffset += pSize + tun.wrBuff.packetNum++ + tun.wrBuff.offset += pSize return nil } |