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can: raw: instantly reject unsupported CAN frames 

For real CAN interfaces the CAN_CTRLMODE_FD and CAN_CTRLMODE_XL control
modes indicate whether an interface can handle those CAN FD/XL frames.

In the case a CAN XL interface is configured in CANXL-only mode with
disabled error-signalling neither CAN CC nor CAN FD frames can be sent.

The checks are performed on CAN_RAW sockets to give an instant feedback
to the user when writing unsupported CAN frames to the interface.

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20251126-canxl-v8-16-e7e3eb74f889@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Oliver Hartkopp 2025-11-26 11:16:17 +01:00 committed by Marc Kleine-Budde
parent 816cf430e8
commit 1a620a7238
1 changed files with 46 additions and 8 deletions
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54
net/can/raw.c
View File

@ -892,20 +892,58 @@ static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb)
}
}
static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu)
static inline bool raw_dev_cc_enabled(struct net_device *dev,
struct can_priv *priv)
{
/* Classical CAN -> no checks for flags and device capabilities */
if (can_is_can_skb(skb))
/* The CANXL-only mode disables error-signalling on the CAN bus
* which is needed to send CAN CC/FD frames
*/
if (priv)
return !can_dev_in_xl_only_mode(priv);
/* virtual CAN interfaces always support CAN CC */
return true;
}
static inline bool raw_dev_fd_enabled(struct net_device *dev,
struct can_priv *priv)
{
/* check FD ctrlmode on real CAN interfaces */
if (priv)
return (priv->ctrlmode & CAN_CTRLMODE_FD);
/* check MTU for virtual CAN FD interfaces */
return (READ_ONCE(dev->mtu) >= CANFD_MTU);
}
static inline bool raw_dev_xl_enabled(struct net_device *dev,
struct can_priv *priv)
{
/* check XL ctrlmode on real CAN interfaces */
if (priv)
return (priv->ctrlmode & CAN_CTRLMODE_XL);
/* check MTU for virtual CAN XL interfaces */
return can_is_canxl_dev_mtu(READ_ONCE(dev->mtu));
}
static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb,
struct net_device *dev)
{
struct can_priv *priv = safe_candev_priv(dev);
/* Classical CAN */
if (can_is_can_skb(skb) && raw_dev_cc_enabled(dev, priv))
return CAN_MTU;
/* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */
/* CAN FD */
if (ro->fd_frames && can_is_canfd_skb(skb) &&
(mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu)))
raw_dev_fd_enabled(dev, priv))
return CANFD_MTU;
/* CAN XL -> needs to be enabled and a CAN XL device */
/* CAN XL */
if (ro->xl_frames && can_is_canxl_skb(skb) &&
can_is_canxl_dev_mtu(mtu))
raw_dev_xl_enabled(dev, priv))
return CANXL_MTU;
return 0;
@ -961,7 +999,7 @@ static int raw_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
err = -EINVAL;
/* check for valid CAN (CC/FD/XL) frame content */
txmtu = raw_check_txframe(ro, skb, READ_ONCE(dev->mtu));
txmtu = raw_check_txframe(ro, skb, dev);
if (!txmtu)
goto free_skb;