kernel/linux.git/drivers/net/can/dev, branch v6.18.21

can: netlink: can_changelink(): add missing error handling to call can_ctrlmode_changelink()

2026-04-02T11:23:18+00:00

commit cadf6019231b614ebbd9ec2a16e5997ecbd8d016 upstream. In commit e1a5cd9d6665 ("can: netlink: add can_ctrlmode_changelink()") the CAN Control Mode (IFLA_CAN_CTRLMODE) handling was factored out into the can_ctrlmode_changelink() function. But the call to can_ctrlmode_changelink() is missing the error handling. Add the missing error handling and propagation to the call can_ctrlmode_changelink(). Cc: stable@vger.kernel.org Fixes: e1a5cd9d6665 ("can: netlink: add can_ctrlmode_changelink()") Link: https://patch.msgid.link/20260310-can_ctrlmode_changelink-add-error-handling-v1-1-0daf63d85922@pengutronix.de Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

can: netlink: can_changelink(): allow disabling of automatic restart

2025-10-20T15:20:12+00:00

Since the commit c1f3f9797c1f ("can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode"), the automatic restart delay can only be set for devices that implement the restart handler struct can_priv::do_set_mode. As it makes no sense to configure a automatic restart for devices that doesn't support it. However, since systemd commit 13ce5d4632e3 ("network/can: properly handle CAN.RestartSec=0") [1], systemd-networkd correctly handles a restart delay of "0" (i.e. the restart is disabled). Which means that a disabled restart is always configured in the kernel. On systems with both changes active this causes that CAN interfaces that don't implement a restart handler cannot be brought up by systemd-networkd. Solve this problem by allowing a delay of "0" to be configured, even if the device does not implement a restart handler. [1] https://github.com/systemd/systemd/commit/13ce5d4632e395521e6205c954493c7fc1c4c6e0 Cc: stable@vger.kernel.org Cc: Andrei Lalaev Reported-by: Marc Kleine-Budde Closes: https://lore.kernel.org/all/20251020-certain-arrogant-vole-of-sunshine-141841-mkl@pengutronix.de Fixes: c1f3f9797c1f ("can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode") Link: https://patch.msgid.link/20251020-netlink-fix-restart-v1-1-3f53c7f8520b@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add userland error messages

2025-09-24T15:09:47+00:00

Use NL_SET_ERR_MSG() and NL_SET_ERR_MSG_FMT() to return meaningful error messages to the userland whenever a -EOPNOTSUPP error is returned due to a failed validation of the CAN netlink arguments. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-20-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: dev: add can_get_ctrlmode_str()

2025-09-24T15:09:47+00:00

In an effort to give more human readable messages when errors occur because of conflicting options, it can be useful to convert the CAN control mode flags into text. Add a function which converts the first set CAN control mode into a human readable string. The reason to only convert the first one is to simplify edge cases: imagine that there are several invalid control modes, we would just return the first invalid one to the user, thus not having to handle complex string concatenation. The user can then solve the first problem, call the netlink interface again and see the next issue. People who wish to enumerate all the control modes can still do so by, for example, using this new function in a for_each_set_bit() loop. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-19-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: calc_bittiming: make can_calc_tdco() FD agnostic

2025-09-24T15:09:46+00:00

can_calc_tdco() uses the CAN_CTRLMODE_FD_TDC_MASK and CAN_CTRLMODE_TDC_AUTO macros making it specific to CAN FD. Add the tdc mask to the function parameter list. The value of the tdc auto flag can then be derived from that mask and stored in a local variable. This way, the function becomes CAN FD agnostic and can be reused later on for the CAN XL TDC. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-18-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: netlink: make can_tdc_fill_info() FD agnostic

2025-09-24T15:09:46+00:00

can_tdc_fill_info() depends on some variables which are specific to CAN FD. Move these to the function parameters list so that, later on, this function can be reused for the CAN XL TDC. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-17-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: netlink: add can_bitrate_const_fill_info()

2025-09-24T15:09:46+00:00

Add can_bitrate_const_fill_info() to factorise the logic when filling the bitrate constant information for Classical CAN and CAN FD. This function will be reused later on for CAN XL. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-16-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: netlink: add can_bittiming_const_fill_info()

2025-09-24T15:09:46+00:00

Add function can_bittiming_const_fill_info() to factorise the logic when filling the bittiming constant information for Classical CAN and CAN FD. This function will be reused later on for CAN XL. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-15-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: netlink: add can_bittiming_fill_info()

2025-09-24T15:09:46+00:00

Add can_bittiming_fill_info() to factorise the logic when filling the bittiming information for Classical CAN and CAN FD. This function will be reused later on for CAN XL. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-14-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde

can: netlink: add can_data_bittiming_get_size()

2025-09-24T15:09:46+00:00

Add the can_data_bittiming_get_size() function to factorise the logic to retrieve the size of below data bittiming parameters: - data_bittiming - data_bittiming_const - data_bitrate_const - tdc parameters This function will be reused later on for CAN XL. Signed-off-by: Vincent Mailhol Link: https://patch.msgid.link/20250923-canxl-netlink-prep-v4-13-e720d28f66fe@kernel.org Signed-off-by: Marc Kleine-Budde