can: fix loss of CAN frames in raw_rcv

commit 36c01245eb8046c16eee6431e7dbfbb302635fa8 upstream.

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>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 1 deletions

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++;