[PATCH net-next 6/7] can: add drop reasons in the receive path of AF_CAN
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2025-06-10 09:49:40
Also in:
linux-can
Subsystem:
can network layer, networking [general], the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Davide Caratti <redacted>
Besides the existing pr_warn_once(), use skb drop reasons in case AF_CAN
layer drops non-conformant CAN{,FD,XL} frames, or conformant frames
received by "wrong" devices, so that it's possible to debug (and count)
such events using existing tracepoints:
| # perf record -e skb:kfree_skb -aR -- ./drv/canfdtest -v -g -l 1 vcan0
| # perf script
| [...]
| canfdtest 1123 [000] 3893.271264: skb:kfree_skb: skbaddr=0xffff975703c9f700 rx_sk=(nil) protocol=12 location=can_rcv+0x4b reason: CAN_RX_INVALID_FRAME
Signed-off-by: Davide Caratti <redacted>
Link: https://patch.msgid.link/20250604160605.1005704-2-dcaratti@redhat.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
include/net/dropreason-core.h | 18 ++++++++++++++++++
net/can/af_can.c | 6 +++---
2 files changed, 21 insertions(+), 3 deletions(-)
diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index bcf9d7467e1a..b9e78290269e 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h@@ -121,6 +121,9 @@ FN(ARP_PVLAN_DISABLE) \ FN(MAC_IEEE_MAC_CONTROL) \ FN(BRIDGE_INGRESS_STP_STATE) \ + FN(CAN_RX_INVALID_FRAME) \ + FN(CANFD_RX_INVALID_FRAME) \ + FN(CANXL_RX_INVALID_FRAME) \ FNe(MAX) /**
@@ -573,6 +576,21 @@ enum skb_drop_reason { * ingress bridge port does not allow frames to be forwarded. */ SKB_DROP_REASON_BRIDGE_INGRESS_STP_STATE, + /** + * @SKB_DROP_REASON_CAN_RX_INVALID_FRAME: received + * non conform CAN frame (or device is unable to receive CAN frames) + */ + SKB_DROP_REASON_CAN_RX_INVALID_FRAME, + /** + * @SKB_DROP_REASON_CANFD_RX_INVALID_FRAME: received + * non conform CAN-FD frame (or device is unable to receive CAN frames) + */ + SKB_DROP_REASON_CANFD_RX_INVALID_FRAME, + /** + * @SKB_DROP_REASON_CANXL_RX_INVALID_FRAME: received + * non conform CAN-XL frame (or device is unable to receive CAN frames) + */ + SKB_DROP_REASON_CANXL_RX_INVALID_FRAME, /** * @SKB_DROP_REASON_MAX: the maximum of core drop reasons, which * shouldn't be used as a real 'reason' - only for tracing code gen
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 4aab7033c933..b2387a46794a 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c@@ -683,7 +683,7 @@ static int can_rcv(struct sk_buff *skb, struct net_device *dev, pr_warn_once("PF_CAN: dropped non conform CAN skbuff: dev type %d, len %d\n", dev->type, skb->len); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_CAN_RX_INVALID_FRAME); return NET_RX_DROP; }
@@ -698,7 +698,7 @@ static int canfd_rcv(struct sk_buff *skb, struct net_device *dev, pr_warn_once("PF_CAN: dropped non conform CAN FD skbuff: dev type %d, len %d\n", dev->type, skb->len); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_CANFD_RX_INVALID_FRAME); return NET_RX_DROP; }
@@ -713,7 +713,7 @@ static int canxl_rcv(struct sk_buff *skb, struct net_device *dev, pr_warn_once("PF_CAN: dropped non conform CAN XL skbuff: dev type %d, len %d\n", dev->type, skb->len); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_CANXL_RX_INVALID_FRAME); return NET_RX_DROP; }
--
2.47.2