I have a system containing 2 ndis intermediate drivers. The first driver
determines "additional data" about a packet and then sends the packet and
"additional data" to the second driver. I intend on using the out-of-bound
data struct in the packet descriptor to send the "additional data".

Is this a good/correct way to do this? Are my two drivers free to use the
OOB struct in a packet descriptor or is it reserved for exclusive use by
tcp/ip and nic drivers? Also, if a some other intermediate driver is
inserted in between my two drivers, is there a chance the new driver will not
copy the OOB data of packets that it receives?

I have also considered using the protocol reserved and miniport reserved
sections of packet descriptors to do this but I'm concerned this may break if
another intermediate is inserted between my drivers.

Is there anyone who has attempted this type of thing before and/or has some
good ideas?

mirage