Network buffers.

Hi All,

I have a unique requirement for a ethernet device. We need to DMA
packets from the device which has a header associated along with the
ethernet frame. I need a efficient mechanism to pass this packet to the
user-space. The user-space process will process the header and provide
the ifindex of the interface.

I was thinking of a circular buffer between the kernel and user space.
But the issue is that after the user-space provides the map from the
header to the ifindex, I need that information back in the
kernel(preferably using the same buffer). I currently have the
mapping(header->ifindex) only in user space and don't want to replicate
the mapping in the kernel space.

Is there a better mechanism to solve this?

Thanks,

Shobha.