Bypassing RX_MMAP when it is full

I would like to enable the following functionality. I do not know whether it already exists or needs to be implemented. I would like to enable/disable logic to egress an incoming frame through some specified port in cases where RX_MMAP is full and would drop. Can this be done through bpf filters or kernel modules? Does it require any changes in the kernel itself? Thank you for your time. -- Sincerely, David Illescas