[vortex] Where to timestamp packets in 3c59x.c ?

Marcus Ramos marcus@ansp.br
Wed, 07 Mar 2001 16:22:17 -0300


I am developing an application to measure packet delay (and further
loss) in an IP network. In order to achieve more precise results, all
measured sites with be equipped with GPS receivers, which will provide a
common time reference system for the network.

In order to exclude as much as possible the processing time spent in the
main application, I intend to timestamp the packets from inside the
driver, right before they are sent to the wire. On the reverse side,
they will be timestamped again as soon as the driver detects the arrival
of a new packet, before passing them over to the higher network protocol

I am using RH7 with kernel 2.2.16. The NIC is a 3C905C-TX PCI and I am
using 3c59x.o to drive it.

I've been through the driver's source code plus Linux Device Writing
from ORA. But still I don't find it easy to locate the correct points
where to insert my timestamping code on the just leaving and the just
arriving packets. Does anybody know of any doc or info source that could
help me in doing so ? Or maybe someone can simply point me directly to
the line numbers of 3c59x.c ?

I apologize if the subject is not adequate for this list, for this is my
first posting to it.

Thanks in advance,