Merge tag 'linux-can-fixes-for-6.19-20260115' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2026-01-15

this is a pull request of 4 patches for net/main, it super-seeds the
"can 2026-01-14" pull request. The dev refcount leak in patch #3 is
fixed.

The first 3 patches are by Oliver Hartkopp and revert the approach to
instantly reject unsupported CAN frames introduced in
net-next-for-v6.19 and replace it by placing the needed data into the
CAN specific ml_priv.

The last patch is by Tetsuo Handa and fixes a J1939 refcount leak for
j1939_session in session deactivation upon receiving the second RTS.

linux-can-fixes-for-6.19-20260115

* tag 'linux-can-fixes-for-6.19-20260115' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
  net: can: j1939: j1939_xtp_rx_rts_session_active(): deactivate session upon receiving the second rts
  can: raw: instantly reject disabled CAN frames
  can: propagate CAN device capabilities via ml_priv
  Revert "can: raw: instantly reject unsupported CAN frames"
====================

Link: https://patch.msgid.link/20260115090603.1124860-1-mkl@pengutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 25 insertions, 7 deletions

diff --git a/include/linux/can/can-ml.h b/include/linux/can/can-ml.h
index 8afa92d15a66..1e99fda2b380 100644
--- a/include/linux/can/can-ml.h
+++ b/include/linux/can/can-ml.h
@@ -46,6 +46,12 @@
 #include <linux/list.h>
 #include <linux/netdevice.h>
 
+/* exposed CAN device capabilities for network layer */
+#define CAN_CAP_CC BIT(0) /* CAN CC aka Classical CAN */
+#define CAN_CAP_FD BIT(1) /* CAN FD */
+#define CAN_CAP_XL BIT(2) /* CAN XL */
+#define CAN_CAP_RO BIT(3) /* read-only mode (LISTEN/RESTRICTED) */
+
 #define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
 #define CAN_EFF_RCV_HASH_BITS 10
 #define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)
@@ -64,6 +70,7 @@ struct can_ml_priv {
 #ifdef CAN_J1939
 	struct j1939_priv *j1939_priv;
 #endif
+	u32 can_cap;
 };
 
 static inline struct can_ml_priv *can_get_ml_priv(struct net_device *dev)
@@ -77,4 +84,21 @@ static inline void can_set_ml_priv(struct net_device *dev,
 	netdev_set_ml_priv(dev, ml_priv, ML_PRIV_CAN);
 }
 
+static inline bool can_cap_enabled(struct net_device *dev, u32 cap)
+{
+	struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+	if (!can_ml)
+		return false;
+
+	return (can_ml->can_cap & cap);
+}
+
+static inline void can_set_cap(struct net_device *dev, u32 cap)
+{
+	struct can_ml_priv *can_ml = can_get_ml_priv(dev);
+
+	can_ml->can_cap = cap;
+}
+
 #endif /* CAN_ML_H */
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index f6416a56e95d..6d0710d6f571 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -111,18 +111,12 @@ 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);
 void can_set_default_mtu(struct net_device *dev);
+void can_set_cap_info(struct net_device *dev);
 int __must_check can_set_static_ctrlmode(struct net_device *dev,
 					 u32 static_mode);
 int can_hwtstamp_get(struct net_device *netdev,