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Those CAN skbs do not have network/mac/transport headers nor other such references for encapsulated protocols like ethernet/IP protocols. To store data for CAN specific use-cases all CAN bus related skbuffs are created with a 16 byte private skb headroom (struct can_skb_priv). Using the skb headroom and accessing skb->head for this private data led to several problems in the past likely due to "The struct can_skb_priv business is highly unconventional for the networking stack." [1] This patch set aims to remove the unconventional skb headroom usage for CAN bus related skbuffs and use the common skb extensions instead. [1] https://lore.kernel.org/linux-can/20260104074222.29e660ac@kernel.org/ Oliver Hartkopp (6): can: use skb hash instead of private variable in headroom can: add CAN skb extension infrastructure can: move ifindex to CAN skb extensions can: move frame_len to CAN skb extensions can: remove private CAN skb headroom infrastructure can: gw: use can_gw_hops instead of sk_buff::csum_start MAINTAINERS | 1 + drivers/net/can/dev/skb.c | 123 ++++++++++++++++++++++++-------------- include/linux/can/core.h | 1 + include/linux/can/skb.h | 32 ++-------- include/linux/skbuff.h | 3 + include/net/can.h | 28 +++++++++ net/can/Kconfig | 1 + net/can/af_can.c | 23 +++++-- net/can/bcm.c | 26 +++++--- net/can/gw.c | 38 ++++++------ net/can/isotp.c | 45 +++++++++----- net/can/j1939/socket.c | 15 +++-- net/can/j1939/transport.c | 28 ++++++--- net/can/raw.c | 21 ++++--- net/core/skbuff.c | 4 ++ 15 files changed, 248 insertions(+), 141 deletions(-) create mode 100644 include/net/can.h -- 2.47.3