Commit 4650ff58 authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by Marc Kleine-Budde
Browse files

Revert "can: raw: instantly reject unsupported CAN frames" 



This reverts commit 1a620a72

and its follow-up fixes for the introduced dependency issues.

commit 1a620a72 ("can: raw: instantly reject unsupported CAN frames")
commit cb2dc6d2 ("can: Kconfig: select CAN driver infrastructure by default")
commit 6abd4577 ("can: fix build dependency")
commit 5a5aff63 ("can: fix build dependency")

The entire problem was caused by the requirement that a new network layer
feature needed to know about the protocol capabilities of the CAN devices.
Instead of accessing CAN device internal data structures which caused the
dependency problems a better approach has been developed which makes use of
CAN specific ml_priv data which is accessible from both sides.

Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vincent Mailhol <mailhol@kernel.org>
Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260109144135.8495-2-socketcan@hartkopp.net


Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 3879cffd

drivers/net/can/Kconfig

+5 −2
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only



menuconfig CAN_DEV

	bool "CAN Device Drivers"

	tristate "CAN Device Drivers"

	default y

	depends on CAN

	help
@@ -17,7 +17,10 @@ menuconfig CAN_DEV 
	  virtual ones. If you own such devices or plan to use the virtual CAN

	  interfaces to develop applications, say Y here.



if CAN_DEV && CAN

	  To compile as a module, choose M here: the module will be called

	  can-dev.



if CAN_DEV



config CAN_VCAN

	tristate "Virtual Local CAN Interface (vcan)"

drivers/net/can/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -7,7 +7,7 @@ obj-$(CONFIG_CAN_VCAN) += vcan.o 
obj-$(CONFIG_CAN_VXCAN)		+= vxcan.o

obj-$(CONFIG_CAN_SLCAN)		+= slcan/



obj-$(CONFIG_CAN_DEV)		+= dev/

obj-y				+= dev/

obj-y				+= esd/

obj-y				+= rcar/

obj-y				+= rockchip/

drivers/net/can/dev/Makefile

+3 −2
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



obj-$(CONFIG_CAN) += can-dev.o

obj-$(CONFIG_CAN_DEV) += can-dev.o



can-dev-y += skb.o



can-dev-$(CONFIG_CAN_DEV) += skb.o

can-dev-$(CONFIG_CAN_CALC_BITTIMING) += calc_bittiming.o

can-dev-$(CONFIG_CAN_NETLINK) += bittiming.o

can-dev-$(CONFIG_CAN_NETLINK) += dev.o

include/linux/can/dev.h

+0 −7
Original line number Diff line number Diff line
@@ -111,14 +111,7 @@ struct net_device *alloc_candev_mqs(int sizeof_priv, unsigned int echo_skb_max, 
void free_candev(struct net_device *dev);



/* a candev safe wrapper around netdev_priv */

#if IS_ENABLED(CONFIG_CAN_NETLINK)

struct can_priv *safe_candev_priv(struct net_device *dev);

#else

static inline struct can_priv *safe_candev_priv(struct net_device *dev)

{

	return NULL;

}

#endif



int open_candev(struct net_device *dev);

void close_candev(struct net_device *dev);

net/can/raw.c

+8 −46
Original line number Diff line number Diff line
@@ -892,58 +892,20 @@ static void raw_put_canxl_vcid(struct raw_sock *ro, struct sk_buff *skb) 
	}

}



static inline bool raw_dev_cc_enabled(struct net_device *dev,

				      struct can_priv *priv)

static unsigned int raw_check_txframe(struct raw_sock *ro, struct sk_buff *skb, int mtu)

{

	/* 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))

	/* Classical CAN -> no checks for flags and device capabilities */

	if (can_is_can_skb(skb))

		return CAN_MTU;



	/* CAN FD */

	/* CAN FD -> needs to be enabled and a CAN FD or CAN XL device */

	if (ro->fd_frames && can_is_canfd_skb(skb) &&

	    raw_dev_fd_enabled(dev, priv))

	    (mtu == CANFD_MTU || can_is_canxl_dev_mtu(mtu)))

		return CANFD_MTU;



	/* CAN XL */

	/* CAN XL -> needs to be enabled and a CAN XL device */

	if (ro->xl_frames && can_is_canxl_skb(skb) &&

	    raw_dev_xl_enabled(dev, priv))

	    can_is_canxl_dev_mtu(mtu))

		return CANXL_MTU;



	return 0;
@@ -999,7 +961,7 @@ 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, dev);

	txmtu = raw_check_txframe(ro, skb, READ_ONCE(dev->mtu));

	if (!txmtu)

		goto free_skb;