Packet filter statistics question

Hi! I'm making a test on linux packet filtering (using BPF). I set the
filter with setsockopt(..., SO_ATTACH_FILTER, ...). The problem I have
is how can I get the number of packets that don't pass the filter to
make some statistics. I searched the groups but didn't find a hint on
this. I tried with the tpacket_stats structure but it doesn't help me
since tp_drops is the number of packets that were big enough to
overcome the packet receive buffer *AFTER* passing the filter.
Is there any solution on this?
Thanks. Chukie.