vxcan: enable local echo for sent CAN frames

stable inclusion
from stable-v5.10.110
commit 71f311b1238009c070af21c80c6e34ce85d9e7e9
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=71f311b1238009c070af21c80c6e34ce85d9e7e9

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[ Upstream commit 259bdba2 ]

The vxcan driver provides a pair of virtual CAN interfaces to exchange
CAN traffic between different namespaces - analogue to veth.

In opposite to the vcan driver the local sent CAN traffic on this interface
is not echo'ed back but only sent to the remote peer. This is unusual and
can be easily fixed by removing IFF_ECHO from the netdevice flags that
are set for vxcan interfaces by default at startup.

Without IFF_ECHO set on driver level, the local sent CAN frames are echo'ed
in af_can.c in can_send(). This patch makes vxcan interfaces adopt the
same local echo behavior and procedures as known from the vcan interfaces.

Fixes: a8f820a3 ("can: add Virtual CAN Tunnel driver (vxcan)")
Link: https://lore.kernel.org/all/20220309120416.83514-5-socketcan@hartkopp.net


Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>