commit 156c2bb9f88065c8da78814f98fde665a5cbb527
author Oliver Hartkopp <socketcan@hartkopp.net> Thu Jan 17 18:43:39 2013 +0100
committer Marc Kleine-Budde <mkl@pengutronix.de> Sat Jan 26 16:59:01 2013 +0100
tree ecd77a89c19ed0e1d420568f85769d7289ac3a37
parent e2d5f2c7d66224c1a401ed1f797e467c02c025b8

can: add private data space for CAN sk_buffs

The struct can_skb_priv is used to transport additional information along
with the stored struct can(fd)_frame that can not be contained in existing
struct sk_buff elements.

can_skb_priv is located in the skb headroom, which does not touch the existing
CAN sk_buff usage with skb->data and skb->len, so that even out-of-tree
CAN drivers can be used without changes.

Btw. out-of-tree CAN drivers without can_skb_priv in the sk_buff headroom
would not support features based on can_skb_priv.

The can_skb_priv->ifindex contains the first interface where the CAN frame
appeared on the local host. Unfortunately skb->skb_iif can not be used as this
value is overwritten in every netif_receive_skb() call.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>