Mods to acking procedure

Folks,

  Thanks for the help in my attempts earlier in getting the driver to run 
on a linksys compact flash card.

  My end goal is this. I want to modify the broadcast mechanism to include 
some acknowledge mechanism. Additionally, I also want to create an API to 
control that mechanism on the fly. That, I suppose will involve creating 
some ioctls.

  Where in the driver are data packets handled and passed on to the higher 
layers ? Is it there where the mods for acknowledgement have to take place 
?

  Can someone point in the right direction ?

regards..
Vikram