kernel/linux.git/drivers/net/can/dev/netlink.c, branch v6.19.11

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

2026-04-02T11:25:40+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: propagate CAN device capabilities via ml_priv

2026-01-15T08:52:04+00:00

Commit 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") caused a sequence of dependency and linker fixes. Instead of accessing CAN device internal data structures which caused the dependency problems this patch introduces capability information into the CAN specific ml_priv data which is accessible from both sides. With this change the CAN network layer can check the required features and the decoupling of the driver layer and network layer is restored. Fixes: 1a620a723853 ("can: raw: instantly reject unsupported CAN frames") Cc: Marc Kleine-Budde Cc: Arnd Bergmann Cc: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20260109144135.8495-3-socketcan@hartkopp.net Signed-off-by: Marc Kleine-Budde

can: netlink: add PWM netlink interface

2025-11-26T10:20:43+00:00

When the TMS is switched on, the node uses PWM (Pulse Width Modulation) during the data phase instead of the classic NRZ (Non Return to Zero) encoding. PWM is configured by three parameters: - PWMS: Pulse Width Modulation Short phase - PWML: Pulse Width Modulation Long phase - PWMO: Pulse Width Modulation Offset time For each of these parameters, define three IFLA symbols: - IFLA_CAN_PWM_PWM*_MIN: the minimum allowed value. - IFLA_CAN_PWM_PWM*_MAX: the maximum allowed value. - IFLA_CAN_PWM_PWM*: the runtime value. This results in a total of nine IFLA symbols which are all nested in a parent IFLA_CAN_XL_PWM symbol. IFLA_CAN_PWM_PWM*_MIN and IFLA_CAN_PWM_PWM*_MAX define the range of allowed values and will match the value statically configured by the device in struct can_pwm_const. IFLA_CAN_PWM_PWM* match the runtime values stored in struct can_pwm. Those parameters may only be configured when the tms mode is on. If the PWMS, PWML and PWMO parameters are provided, check that all the needed parameters are present using can_validate_pwm(), then check their value using can_validate_pwm_bittiming(). PWMO defaults to zero if omitted. Otherwise, if CAN_CTRLMODE_XL_TMS is true but none of the PWM parameters are provided, calculate them using can_calc_pwm(). Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-11-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add CAN_CTRLMODE_XL_TMS flag

2025-11-26T10:20:43+00:00

The Transceiver Mode Switching (TMS) indicates whether the CAN XL controller shall use the PWM or NRZ encoding during the data phase. The term "transceiver mode switching" is used in both ISO 11898-1 and CiA 612-2 (although only the latter one uses the abbreviation TMS). We adopt the same naming convention here for consistency. Add the CAN_CTRLMODE_XL_TMS flag to the list of the CAN control modes. Add can_validate_xl_flags() to check the coherency of the TMS flag. That function will be reused in upcoming changes to validate the other CAN XL flags. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-6-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add initial CAN XL support

2025-11-26T10:20:43+00:00

CAN XL uses bittiming parameters different from Classical CAN and CAN FD. Thus, all the data bittiming parameters, including TDC, need to be duplicated for CAN XL. Add the CAN XL netlink interface for all the features which are common with CAN FD. Any new CAN XL specific features are added later on. The first time CAN XL is activated, the MTU is set by default to CANXL_MAX_MTU. The user may then configure a custom MTU within the CANXL_MIN_MTU to CANXL_MAX_MTU range, in which case, the custom MTU value will be kept as long as CAN XL remains active. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-5-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

can: netlink: add CAN_CTRLMODE_RESTRICTED

2025-11-26T10:20:43+00:00

ISO 11898-1:2024 adds a new restricted operation mode. This mode is added as a mandatory feature for nodes which support CAN XL and is retrofitted as optional for legacy nodes (i.e. the ones which only support Classical CAN and CAN FD). The restricted operation mode is nearly the same as the listen only mode: the node can not send data frames or remote frames and can not send dominant bits if an error occurs. The only exception is that the node shall still send the acknowledgment bit. A second niche exception is that the node may still send a data frame containing a time reference message if the node is a primary time provider, but because the time provider feature is not yet implemented in the kernel, this second exception is not relevant to us at the moment. Add the CAN_CTRLMODE_RESTRICTED control mode flag and update the can_dev_dropped_skb() helper function accordingly. Finally, bail out if both CAN_CTRLMODE_LISTENONLY and CAN_CTRLMODE_RESTRICTED are provided. Signed-off-by: Vincent Mailhol Signed-off-by: Oliver Hartkopp Link: https://patch.msgid.link/20251126-canxl-v8-4-e7e3eb74f889@pengutronix.de Signed-off-by: Marc Kleine-Budde

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: 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