调用IoCallDriver如何获得返回字节数？

toy720

调用IoCallDriver如何获得返回字节数？ [复制链接]

我自己构造了个IOCTL类型的IRP发送给别的驱动处理，处理以后会有数据返回，怎么知道返回数据的长度呢？是用这个pNewIrp->IoStatus.Information吗？我用这个获得的字节数和被调用驱动实际返回数目相差甚远（比实际的大）。

ppz2005

是的 因为ddk上就是这样说的
Information
This is set to a request-dependent value. For example, on successful completion of a transfer request, this is set to the number of bytes transferred. If a transfer request is completed with another STATUS_XXX, this member is set to zero.

mef575

应该用构造该IRP的函数IoBuildDeviceIoControlRequest的最后个参数返回。