Re: [PATCH net-next] em_canid: Ematch rule to match CAN frames according to their identifiers

Hello Oliver;

On Fri, 2012-06-29 at 17:44 +0200, Oliver Hartkopp wrote: 

What about a zero length check here?

	if (!len)
		return -EINVAL;

The length could alternatively be checked here too

http://lxr.linux.no/#linux+v3.4.4/net/sched/ematch.c#L235

if em->ops->datalen is set.

But here's no

	.datalen = sizeof(struct can_filter),

defined, right?

The main reason I didn't define the tcf_ematch_ops.datalen field is
because the documentation says it is "length of expected configuration
data" (not "minimal").
For the sake of possible future changes of the built-in length checking,
I will do the check by myself -- I will add the zero-length check (at
least all checks will be at the same place).

Regards;
Rostislav