Symbolic Link name in Filter driver question

NTDEV
1

Hi,
I’ve recently written an Upper Filter driver which loads after my main WDM driver. The installation and the loading is successful however, I’ve run into a problem concerning accessing my main WDM driver now.

This Upper Filter driver has additional IO controls which I added. In order to do this I created a symbolic link so that I can make calls into these IOCTLS from my application. Unfortunately now that I can access my Filter driver with this symbolic name, I can’t access my main WDM driver using the other symbolic link name I created in the WDM driver. If I comment out the code that creates the symbolic link name in my Filter driver I can then use the WDM symbolic link name to access the WDM driver. I need to be able to do both.

Is there a way to have separate symbolic link names for your Upper Filter driver and the WDM driver I am filtering? I would imagine there is but how to do this escapes me. Also, if there is an article concerning doing this I’d appreciate it. The only article I found was how to send IOCTL’s to a Filter driver.

Thanks

2

Are you creating your filter device object as exclusive? Is the stack marked as exclusive (what device class are you installed under)? If either are true, then there can only be one handle to the stack and we have to talk about alternative solutions.

Are you passing the IRP_MJ_CREATE down the stack to the FDO?

d