From a1a97d1e4120fa1c137e0cc647b3c657019780fb Mon Sep 17 00:00:00 2001 From: Simon Rozman Date: Mon, 10 Jun 2019 08:47:16 +0200 Subject: setupapi: unify ERROR_INSUFFICIENT_BUFFER handling Signed-off-by: Simon Rozman --- tun/wintun/setupapi/setupapi_windows.go | 90 ++++++++++++--------------------- 1 file changed, 32 insertions(+), 58 deletions(-) (limited to 'tun') diff --git a/tun/wintun/setupapi/setupapi_windows.go b/tun/wintun/setupapi/setupapi_windows.go index 6757743..2ee836a 100644 --- a/tun/wintun/setupapi/setupapi_windows.go +++ b/tun/wintun/setupapi/setupapi_windows.go @@ -150,34 +150,21 @@ func (deviceInfoSet DevInfo) SetSelectedDriver(deviceInfoData *DevInfoData, driv // SetupDiGetDriverInfoDetail function retrieves driver information detail for a device information set or a particular device information element in the device information set. func SetupDiGetDriverInfoDetail(deviceInfoSet DevInfo, deviceInfoData *DevInfoData, driverInfoData *DrvInfoData) (*DrvInfoDetailData, error) { - const bufCapacity = 0x800 - buf := [bufCapacity]byte{} - var bufLen uint32 - - data := (*DrvInfoDetailData)(unsafe.Pointer(&buf[0])) - data.size = sizeofDrvInfoDetailData - - err := setupDiGetDriverInfoDetail(deviceInfoSet, deviceInfoData, driverInfoData, data, bufCapacity, &bufLen) - if err == nil { - // The buffer was was sufficiently big. - data.size = bufLen - return data, nil - } - - if errWin, ok := err.(windows.Errno); ok && errWin == windows.ERROR_INSUFFICIENT_BUFFER { - // The buffer was too small. Now that we got the required size, create another one big enough and retry. - buf := make([]byte, bufLen) + reqSize := uint32(2048) + for { + buf := make([]byte, reqSize) data := (*DrvInfoDetailData)(unsafe.Pointer(&buf[0])) data.size = sizeofDrvInfoDetailData - - err = setupDiGetDriverInfoDetail(deviceInfoSet, deviceInfoData, driverInfoData, data, bufLen, &bufLen) - if err == nil { - data.size = bufLen - return data, nil + err := setupDiGetDriverInfoDetail(deviceInfoSet, deviceInfoData, driverInfoData, data, uint32(len(buf)), &reqSize) + if err == windows.ERROR_INSUFFICIENT_BUFFER { + continue } + if err != nil { + return nil, err + } + data.size = reqSize + return data, nil } - - return nil, err } // DriverInfoDetail method retrieves driver information detail for a device information set or a particular device information element in the device information set. @@ -238,24 +225,19 @@ func (deviceInfoSet DevInfo) OpenDevRegKey(DeviceInfoData *DevInfoData, Scope DI // SetupDiGetDeviceRegistryProperty function retrieves a specified Plug and Play device property. func SetupDiGetDeviceRegistryProperty(deviceInfoSet DevInfo, deviceInfoData *DevInfoData, property SPDRP) (value interface{}, err error) { - buf := make([]byte, 0x100) - var dataType, bufLen uint32 - err = setupDiGetDeviceRegistryProperty(deviceInfoSet, deviceInfoData, property, &dataType, &buf[0], uint32(cap(buf)), &bufLen) - if err == nil { - // The buffer was sufficiently big. - return getRegistryValue(buf[:bufLen], dataType) - } - - if errWin, ok := err.(windows.Errno); ok && errWin == windows.ERROR_INSUFFICIENT_BUFFER { - // The buffer was too small. Now that we got the required size, create another one big enough and retry. - buf = make([]byte, bufLen) - err = setupDiGetDeviceRegistryProperty(deviceInfoSet, deviceInfoData, property, &dataType, &buf[0], uint32(cap(buf)), &bufLen) - if err == nil { - return getRegistryValue(buf[:bufLen], dataType) + reqSize := uint32(256) + for { + var dataType uint32 + buf := make([]byte, reqSize) + err = setupDiGetDeviceRegistryProperty(deviceInfoSet, deviceInfoData, property, &dataType, &buf[0], uint32(len(buf)), &reqSize) + if err == windows.ERROR_INSUFFICIENT_BUFFER { + continue + } + if err != nil { + return } + return getRegistryValue(buf[:reqSize], dataType) } - - return } func getRegistryValue(buf []byte, dataType uint32) (interface{}, error) { @@ -442,10 +424,6 @@ func SetupDiClassGuidsFromNameEx(className string, machineName string) ([]window return nil, err } - const bufCapacity = 4 - var buf [bufCapacity]windows.GUID - var bufLen uint32 - var machineNameUTF16 *uint16 if machineName != "" { machineNameUTF16, err = windows.UTF16PtrFromString(machineName) @@ -454,22 +432,18 @@ func SetupDiClassGuidsFromNameEx(className string, machineName string) ([]window } } - err = setupDiClassGuidsFromNameEx(classNameUTF16, &buf[0], bufCapacity, &bufLen, machineNameUTF16, 0) - if err == nil { - // The GUID array was sufficiently big. Return its slice. - return buf[:bufLen], nil - } - - if errWin, ok := err.(windows.Errno); ok && errWin == windows.ERROR_INSUFFICIENT_BUFFER { - // The GUID array was too small. Now that we got the required size, create another one big enough and retry. - buf := make([]windows.GUID, bufLen) - err = setupDiClassGuidsFromNameEx(classNameUTF16, &buf[0], bufLen, &bufLen, machineNameUTF16, 0) - if err == nil { - return buf[:bufLen], nil + reqSize := uint32(4) + for { + buf := make([]windows.GUID, reqSize) + err = setupDiClassGuidsFromNameEx(classNameUTF16, &buf[0], uint32(len(buf)), &reqSize, machineNameUTF16, 0) + if err == windows.ERROR_INSUFFICIENT_BUFFER { + continue } + if err != nil { + return nil, err + } + return buf[:reqSize], nil } - - return nil, err } //sys setupDiGetSelectedDevice(deviceInfoSet DevInfo, deviceInfoData *DevInfoData) (err error) = setupapi.SetupDiGetSelectedDevice -- cgit v1.2.3