On Sat. 19 Aug. 2023 at 22:10, Vincent Mailhol <vincent.mailhol@xxxxxxxxx> wrote: > On Sat. 19 Aug. 2023, 01:19, Jakub Kicinski <kuba@xxxxxxxxxx> wrote: > > > > On Thu, 17 Aug 2023 12:10:13 +0200 Martin Hundebøll wrote: > > > + int len = nla_len(data[IFLA_CAN_HW_FILTER]); > > > + int num_filter = len / sizeof(struct can_filter); > > > + struct can_filter *filter = nla_data(data[IFLA_CAN_HW_FILTER]); > > > > This will prevent you from ever extending struct can_filter in > > a backward-compatible fashion, right? I obviously know very little > > about CAN but are you confident a more bespoke API to manipulate > > filters individually and allow extensibility is not warranted? > > I follow Jakub's point of view. > > The current struct can_filter is not sound. Some devices such as the > ES582.1 supports filtering of the CAN frame based on the flags (i.e. > SFF/EFF, RTR, FDF). I wrote too fast. The EFF and RTR flags are contained in the canid_t, so the current struct can_filter is able to handle these two flags. But it remains true that the CAN-FD flags (FDF and BRS) are currently not handled. Not to mention that more flags will come with the upcoming CAN XL. > I think that each of the fields of the filter should have its own NLA > declaration with the whole thing wrapped within a NLA_NESTED_ARRAY. > > I also think that there should then be a method to report the precise > filtering capabilities of the hardware. > > > Yours sincerely, > Vincent Mailhol
