Hi, On Mon, Oct 11, 2010 at 11:01:56AM +0200, [email protected] wrote: > > Hello all, > I would like to bring up the self-reception theme again. > > In the discussion few weeks ago following ideas has been worked > out: > > 1) Add per-message self reception flag to can_frame > 2) Use SO_MARK > 3) sk_buff->sk may be used to see the message origin, but it is > not available in user space ... > Didn't Oliver make a patch to export (3) to userspace (via candump)? > > I personally like the first option a bit better, because the > self-reception flag is available "automatically" in the can_frame > itself without making any additional operations (like in case > of SO_MARK). Would the "can_get_echo_skb" be the right place to > set that flag? I think not.
The idea behind socketCAN is that the CAN bus is virtually extended through the linux system. (1) would deny this nature, since _not_ all CAN chips/socketCAN apps are treated equal. IMO, to support a 'self-reception' flag, you need a combination of (1) & (3): * a flag to userspace to indicate a received message was 'self-reception' * set the above flag (in raw.c or elsewhere) to indicate the sk_buff->sk matches the receiving socket. To userspace, this differs not compared to (1), but I think it respects the nature of socketCAN at kernel level. Not sure if I expressed my idea clear :-) How this would cooperate with the SO_RECV_OWN_MSGS option is unclear to me. > > Regards, > Vladislav > Regards, Kurt _______________________________________________ Socketcan-core mailing list [email protected] https://lists.berlios.de/mailman/listinfo/socketcan-core
