attach multiple programs to tun/tap interface

Hi,

I have a basic query on tun/tap driver design. Is it possible to attach multiple user-space programs to the same tun/tap interface. I have not set the interface as EXCLUSIVE, but still on trying to do ioctl with cmd as “TUNSETIFF” from the second user space program, I get “Device busy”.

Seeing through the driver code, it looks like it does not allow multiple user-programs to attach to the same interface, but is this valid, and please let me know why this requirement was taken.

Will you please help me in understanding this?

Thanks,
Prashant