kernel/linux.git/drivers/net/can/dev/skb.c, branch v7.0.10

can: remove private CAN skb headroom infrastructure

2026-02-05T10:58:40+00:00

This patch removes struct can_skb_priv which was stored at skb->head and the can_skb_reserve() helper which was used to shift skb->head. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-5-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: move frame_len to CAN skb extensions

2026-02-05T10:58:40+00:00

The can_skb_priv::frame_len variable is used to cache a previous calculated CAN frame length to be passed to BQL queueing disciplines. Move the can_skb_priv::frame_len content to can_skb_ext::can_framelen. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-4-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: move ifindex to CAN skb extensions

2026-02-05T10:58:40+00:00

When routing CAN frames over different CAN interfaces the interface index skb->iif is overwritten with every single hop. To prevent sending a CAN frame back to its originating (first) incoming CAN interface another ifindex variable is needed, which was stored in can_skb_priv::ifindex. Move the can_skb_priv::ifindex content to can_skb_ext::can_iif. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-3-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: add CAN skb extension infrastructure

2026-02-05T10:58:39+00:00

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

can: use skb hash instead of private variable in headroom

2026-02-05T10:58:39+00:00

The can_skb_priv::skbcnt variable is used to identify CAN skbs in the RX path analogue to the skb->hash. As the skb hash is not filled in CAN skbs move the private skbcnt value to skb->hash and set skb->sw_hash accordingly. The skb->hash is a value used for RPS to identify skbs. Use it as intended. Signed-off-by: Marc Kleine-Budde Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260201-can_skb_ext-v8-1-3635d790fe8b@hartkopp.net Signed-off-by: Paolo Abeni

can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds

2023-10-05T19:34:13+00:00

If the "struct can_priv::echoo_skb" is accessed out of bounds, this would cause a kernel crash. Instead, issue a meaningful warning message and return with an error. Fixes: a6e4bc530403 ("can: make the number of echo skb's configurable") Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-5-91b5c1fd922c@pengutronix.de Reviewed-by: Vincent Mailhol Signed-off-by: Marc Kleine-Budde

can: dev: fix missing CAN XL support in can_put_echo_skb()

2023-05-15T20:24:46+00:00

can_put_echo_skb() checks for the enabled IFF_ECHO flag and the correct ETH_P type of the given skbuff. When implementing the CAN XL support the new check for ETH_P_CANXL has been forgotten. Fixes: fb08cba12b52 ("can: canxl: update CAN infrastructure for CAN XL frames") Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20230506184515.39241-1-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: dev: fix skb drop check

2022-11-07T13:00:27+00:00

In commit a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") the priv->ctrlmode element is read even on virtual CAN interfaces that do not create the struct can_priv at startup. This out-of-bounds read may lead to CAN frame drops for virtual CAN interfaces like vcan and vxcan. This patch mainly reverts the original commit and adds a new helper for CAN interface drivers that provide the required information in struct can_priv. Fixes: a6d190f8c767 ("can: skb: drop tx skb if in listen only mode") Reported-by: Dariusz Stojaczyk Cc: Vincent Mailhol Cc: Max Staudt Signed-off-by: Oliver Hartkopp Acked-by: Vincent Mailhol Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net Cc: stable@vger.kernel.org # 6.0.x [mkl: patch pch_can, too] Signed-off-by: Marc Kleine-Budde

can: canxl: update CAN infrastructure for CAN XL frames

2022-09-15T07:08:09+00:00

- add new ETH_P_CANXL ethernet protocol type - update skb checks for CAN XL - add alloc_canxl_skb() which now needs a data length parameter - introduce init_can_skb_reserve() to reduce code duplication Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-6-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: set CANFD_FDF flag in all CAN FD frame structures

2022-09-15T07:08:08+00:00

To simplify the testing in user space all struct canfd_frame's provided by the CAN subsystem of the Linux kernel now have the CANFD_FDF flag set in canfd_frame::flags. NB: Handcrafted ETH_P_CANFD frames introduced via PF_PACKET socket might not set this bit correctly. During the check for sufficient headroom in PF_PACKET sk_buffs the uninitialized CAN sk_buff data structures are filled. In the case of a CAN FD frame the CANFD_FDF flag is set accordingly. As the CAN frame content is already zero initialized in alloc_canfd_skb() the obsolete initialization of cf->flags in the CTU CAN FD driver has been removed as it would overwrite the already set CANFD_FDF flag. Acked-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://lore.kernel.org/all/20220912170725.120748-4-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde