From 96ea3a1e2d317e7ecb6b65dc65c9dd917905a6a8 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Sun, 1 Feb 2026 15:33:17 +0100 Subject: can: add CAN skb extension infrastructure To remove the private CAN bus skb headroom infrastructure 8 bytes need to be stored in the skb. The skb extensions are a common pattern and an easy and efficient way to hold private data travelling along with the skb. We only need the skb_ext_add() and skb_ext_find() functions to allocate and access CAN specific content as the skb helpers to copy/clone/free skbs automatically take care of skb extensions and their final removal. This patch introduces the complete CAN skb extensions infrastructure: - add struct can_skb_ext in new file include/net/can.h - add include/net/can.h in MAINTAINERS - add SKB_EXT_CAN to skbuff.c and skbuff.h - select SKB_EXTENSIONS in Kconfig when CONFIG_CAN is enabled - check for existing CAN skb extensions in can_rcv() in af_can.c - add CAN skb extensions allocation at every skb_alloc() location - duplicate the skb extensions if cloning outgoing skbs (framelen/gw_hops) - introduce can_skb_ext_add() and can_skb_ext_find() helpers The patch also corrects an indention issue in the original code from 2018: Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202602010426.PnGrYAk3-lkp@intel.com/ Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-2-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni --- include/linux/skbuff.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 8b399ddf1b9b..ef56dc6318d3 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4989,6 +4989,9 @@ enum skb_ext_id { #endif #if IS_ENABLED(CONFIG_INET_PSP) SKB_EXT_PSP, +#endif +#if IS_ENABLED(CONFIG_CAN) + SKB_EXT_CAN, #endif SKB_EXT_NUM, /* must be last */ }; -- cgit v1.2.3