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

This reverts commit 1a620a723853a0f49703c317d52dc6b9602cbaa8

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

commit 1a620a723853 ("can: raw: instantly reject unsupported CAN frames")
commit cb2dc6d2869a ("can: Kconfig: select CAN driver infrastructure by default")
commit 6abd4577bccc ("can: fix build dependency")
commit 5a5aff6338c0 ("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: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://patch.msgid.link/20260109144135.8495-2-socketcan@hartkopp.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index cfaea6178a71969d714206e7a647682bf4be33a3..e15e320db476362255ad6ad05f3e192e55cd4706 100644 (file)
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -1,7 +1,7 @@
 # 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)"

diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index 37e2f1a2faecd741a044982567460bfb492e8c8e..d7bc10a6b8eae273aa203cf2bc1f8ea92d1187f5 100644 (file)
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -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/

diff --git a/drivers/net/can/dev/Makefile b/drivers/net/can/dev/Makefile
index 64226acf0f3d40b443eb7596a7bef191d062672b..633687d6b6c0c07ece0815337d667e70ab2239f2 100644 (file)
--- a/drivers/net/can/dev/Makefile
+++ b/drivers/net/can/dev/Makefile
@@ -1,8 +1,9 @@
 # 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

diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index f6416a56e95d51cb590441ace861ad92a746bf0b..52c8be5c160e47796c1e0d7a77f8dc17aaee810d 100644 (file)
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -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);

diff --git a/net/can/raw.c b/net/can/raw.c
index be1ef7cf4204ecdc7aa0a943a3aab644e7e2c1dc..f36a83d3447cfd6d70364dbd49534507f059660e 100644 (file)
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -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;