[PATCH] can: fix loss of CAN frames in raw_rcv

[PATCH] can: fix loss of CAN frames in raw_rcv

[Marc Kleine-Budde]

From: Oliver Hartkopp <socketcan@hartkopp.net>

As reported by Manfred Schlaegl here

   http://marc.info/?l=linux-netdev&m=143482089824232&w=2

commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for
overlapping CAN filters" requires the skb->tstamp to be set to check for
identical CAN skbs.

As net timestamping is influenced by several players (netstamp_needed and
netdev_tstamp_prequeue) Manfred missed a proper timestamp which leads to
CAN frame loss.

As skb timestamping became now mandatory for CAN related skbs this patch
makes sure that received CAN skbs always have a proper timestamp set.
Maybe there's a better solution in the future but this patch fixes the
CAN frame loss so far.

Reported-by: Manfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev.c   | 5 +++++
 drivers/net/can/slcan.c | 1 +
 drivers/net/can/vcan.c  | 3 +++
 net/can/af_can.c        | 6 +++++-
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index b0f69248cb71..e9b1810d319f 100644
--- a/drivers/net/can/dev.c
+++ b/drivers/net/can/dev.c
@@ -440,6 +440,9 @@ unsigned int can_get_echo_skb(struct net_device *dev, unsigned int idx)
 		struct can_frame *cf = (struct can_frame *)skb->data;
 		u8 dlc = cf->can_dlc;
 
+		if (!(skb->tstamp.tv64))
+			__net_timestamp(skb);
+
 		netif_rx(priv->echo_skb[idx]);
 		priv->echo_skb[idx] = NULL;
 
@@ -575,6 +578,7 @@ struct sk_buff *alloc_can_skb(struct net_device *dev, struct can_frame **cf)
 	if (unlikely(!skb))
 		return NULL;
 
+	__net_timestamp(skb);
 	skb->protocol = htons(ETH_P_CAN);
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -603,6 +607,7 @@ struct sk_buff *alloc_canfd_skb(struct net_device *dev,
 	if (unlikely(!skb))
 		return NULL;
 
+	__net_timestamp(skb);
 	skb->protocol = htons(ETH_P_CANFD);
 	skb->pkt_type = PACKET_BROADCAST;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
diff --git a/drivers/net/can/slcan.c b/drivers/net/can/slcan.c
index c837eb91d43e..f64f5290d6f8 100644
--- a/drivers/net/can/slcan.c
+++ b/drivers/net/can/slcan.c
@@ -207,6 +207,7 @@ static void slc_bump(struct slcan *sl)
 	if (!skb)
 		return;
 
+	__net_timestamp(skb);
 	skb->dev = sl->dev;
 	skb->protocol = htons(ETH_P_CAN);
 	skb->pkt_type = PACKET_BROADCAST;
diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
index 674f367087c5..0ce868de855d 100644
--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -78,6 +78,9 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 	skb->dev       = dev;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;
 
+	if (!(skb->tstamp.tv64))
+		__net_timestamp(skb);
+
 	netif_rx_ni(skb);
 }
 
diff --git a/net/can/af_can.c b/net/can/af_can.c
index 32d710eaf1fc..689c818ed007 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -310,8 +310,12 @@ int can_send(struct sk_buff *skb, int loop)
 		return err;
 	}
 
-	if (newskb)
+	if (newskb) {
+		if (!(newskb->tstamp.tv64))
+			__net_timestamp(newskb);
+
 		netif_rx_ni(newskb);
+	}
 
 	/* update statistics */
 	can_stats.tx_frames++;
-- 
2.1.4

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missing in stable 4.1.1 - was Re: pull-request: can 2015-06-21

[Oliver Hartkopp]

Hello Greg,

On 23.06.2015 15:43, David Miller wrote:
> From: Marc Kleine-Budde <mkl@pengutronix.de>
> Date: Sun, 21 Jun 2015 19:04:58 +0200
>
>> this is a, probably too late, pull request for v4.1.
>>
>> Oliver Hartkopp fixed a bug in the generic CAN frame handling code, which may
>> lead to loss of CAN frames. It was introduced during v4.1 development.
>>
>> Please queue via net/master if possible, net-next/master otherwise. I've added
>> stable on Cc, just in case.
>
> Pulled, thanks.

the patch "can: fix loss of CAN frames in raw_rcv" was sent to stable on 
2015-06-21 but unfortunately did not find its way into 4.1.1 :-(

The upstream commit is:

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36c01245eb8046c16eee6431e7dbfbb302635fa8

which slipped into 4.2 at merge window opening time.

So it just got lost in the stable queue somehow.

Best regards,
Oliver

Re: missing in stable 4.1.1 - was Re: pull-request: can 2015-06-21

[Greg KH]

On Tue, Jun 30, 2015 at 09:31:36PM +0200, Oliver Hartkopp wrote:
> Hello Greg,
> 
> On 23.06.2015 15:43, David Miller wrote:
> >From: Marc Kleine-Budde <mkl@pengutronix.de>
> >Date: Sun, 21 Jun 2015 19:04:58 +0200
> >
> >>this is a, probably too late, pull request for v4.1.
> >>
> >>Oliver Hartkopp fixed a bug in the generic CAN frame handling code, which may
> >>lead to loss of CAN frames. It was introduced during v4.1 development.
> >>
> >>Please queue via net/master if possible, net-next/master otherwise. I've added
> >>stable on Cc, just in case.
> >
> >Pulled, thanks.
> 
> the patch "can: fix loss of CAN frames in raw_rcv" was sent to stable on
> 2015-06-21 but unfortunately did not find its way into 4.1.1 :-(
> 
> The upstream commit is:
> 
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36c01245eb8046c16eee6431e7dbfbb302635fa8
> 
> which slipped into 4.2 at merge window opening time.
> 
> So it just got lost in the stable queue somehow.

No, it's still there.  I don't queue up patches for a stable release
until they have shown up in a public release from Linus.  So in this
case, it will be elgible to be in a stable kernel after 4.2-rc1 is out.

Unless you tell me otherwise, so if you want this in the next 4.1-stable
release, I can queue it up now.

thanks,

greg k-h

Re: missing in stable 4.1.1 - was Re: pull-request: can 2015-06-21

[Oliver Hartkopp]

On 30.06.2015 22:07, Greg KH wrote:
> On Tue, Jun 30, 2015 at 09:31:36PM +0200, Oliver Hartkopp wrote:

>> The upstream commit is:
>>
>> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36c01245eb8046c16eee6431e7dbfbb302635fa8
>>
>> which slipped into 4.2 at merge window opening time.
>>
>> So it just got lost in the stable queue somehow.
>
> No, it's still there.  I don't queue up patches for a stable release
> until they have shown up in a public release from Linus.  So in this
> case, it will be elgible to be in a stable kernel after 4.2-rc1 is out.
>
> Unless you tell me otherwise, so if you want this in the next 4.1-stable
> release, I can queue it up now.

I would really appreciate it if you can queue it up now.

We already had a bug report for 4.1.0 which is fixed by this patch.

Thanks & best regards,
Oliver

Re: missing in stable 4.1.1 - was Re: pull-request: can 2015-06-21

[Greg KH]

On Tue, Jun 30, 2015 at 10:28:08PM +0200, Oliver Hartkopp wrote:
> On 30.06.2015 22:07, Greg KH wrote:
> >On Tue, Jun 30, 2015 at 09:31:36PM +0200, Oliver Hartkopp wrote:
> 
> >>The upstream commit is:
> >>
> >>http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36c01245eb8046c16eee6431e7dbfbb302635fa8
> >>
> >>which slipped into 4.2 at merge window opening time.
> >>
> >>So it just got lost in the stable queue somehow.
> >
> >No, it's still there.  I don't queue up patches for a stable release
> >until they have shown up in a public release from Linus.  So in this
> >case, it will be elgible to be in a stable kernel after 4.2-rc1 is out.
> >
> >Unless you tell me otherwise, so if you want this in the next 4.1-stable
> >release, I can queue it up now.
> 
> I would really appreciate it if you can queue it up now.
> 
> We already had a bug report for 4.1.0 which is fixed by this patch.

Ok, now queued up, thanks.

greg k-h

Re: missing in stable 4.1.1 - was Re: pull-request: can 2015-06-21

[David Miller]

From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Tue, 30 Jun 2015 21:31:36 +0200

> Hello Greg,
> 
> On 23.06.2015 15:43, David Miller wrote:
>> From: Marc Kleine-Budde <mkl@pengutronix.de>
>> Date: Sun, 21 Jun 2015 19:04:58 +0200
>>
>>> this is a, probably too late, pull request for v4.1.
>>>
>>> Oliver Hartkopp fixed a bug in the generic CAN frame handling code,
>>> which may
>>> lead to loss of CAN frames. It was introduced during v4.1 development.
>>>
>>> Please queue via net/master if possible, net-next/master
>>> otherwise. I've added
>>> stable on Cc, just in case.
>>
>> Pulled, thanks.
> 
> the patch "can: fix loss of CAN frames in raw_rcv" was sent to stable
> on 2015-06-21 but unfortunately did not find its way into 4.1.1 :-(
> 
> The upstream commit is:
> 
> http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=36c01245eb8046c16eee6431e7dbfbb302635fa8
> 
> which slipped into 4.2 at merge window opening time.
> 
> So it just got lost in the stable queue somehow.

Please take care of CAN -stable submissions yourself, thanks.