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can-isotp: enable RX timeout handling in listen-only mode

PATCH Applied Oliver Hartkopp 2 participants 2 messages Oct 19, 2020 – Oct 20, 2020

Subsystems (2)
CAN network drivers CAN network layer
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Oliver Hartkopp

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#0 lore raw

PATCH 1/1 can-isotp: enable RX timeout handling in listen-only mode

As reported by Thomas Wagner here
https://github.com/hartkopp/can-isotp/issues/34
the timeout handling for data frames is not enabled when the isotp socket is used in listen-only mode (sockopt CAN_ISOTP_LISTEN_MODE). This mode is enabled by the isotpsniffer application which therefore became inconsistend with the strict rx timeout rules when running the isotp protocol in the operational mode.

This patch fixes this inconsistency by moving the return condition for the listen-only mode behind the timeout handling code.

Reported-by Thomas Wagner <[email protected]>
Signed-off-by Oliver Hartkopp <[email protected]>
---
 net/can/isotp.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
net/can/isotp.c +4 -4
index 4c2062875893..a79287ef86da 100644
@@ -567,22 +567,22 @@ static int isotp_rcv_cf(struct sock *sk, struct canfd_frame *cf, int ae,
 		nskb->dev = skb->dev;
 		isotp_rcv_skb(nskb, sk);
 		return 0;
 	}
 
-	/* no creation of flow control frames */
-	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
-		return 0;
-
 	/* perform blocksize handling, if enabled */
 	if (!so->rxfc.bs || ++so->rx.bs < so->rxfc.bs) {
 		/* start rx timeout watchdog */
 		hrtimer_start(&so->rxtimer, ktime_set(1, 0),
 			      HRTIMER_MODE_REL_SOFT);
 		return 0;
 	}
 
+	/* no creation of flow control frames */
+	if (so->opt.flags & CAN_ISOTP_LISTEN_MODE)
+		return 0;
+
 	/* we reached the specified blocksize so->rxfc.bs */
 	isotp_send_fc(sk, ae, ISOTP_FC_CTS);
 	return 0;
 }
Signature · 1 line
2.28.0
maintainer Applied
#1 lore raw
Quoted 8 lines · Oliver Hartkopp

As reported by Thomas Wagner here
https://github.com/hartkopp/can-isotp/issues/34
the timeout handling for data frames is not enabled when the isotp socket is used in listen-only mode (sockopt CAN_ISOTP_LISTEN_MODE). This mode is enabled by the isotpsniffer application which therefore became inconsistend with the strict rx timeout rules when running the isotp protocol in the operational mode.

Quoted 5 lines

This patch fixes this inconsistency by moving the return condition for the listen-only mode behind the timeout handling code.

Reported-by Thomas Wagner <[email protected]>
Signed-off-by Oliver Hartkopp <[email protected]>

Applied to linux-can.

tnx,
Marc

Signature · 4 lines
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