[PATCH 4.4 112/115] macvlan: Only deliver one copy of the frame to the macvlan interface

From: Greg Kroah-Hartman
Date: Mon Dec 18 2017 - 12:50:46 EST

4.4-stable review patch. If anyone has any objections, please let me know.


From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>

[ Upstream commit dd6b9c2c332b40f142740d1b11fb77c653ff98ea ]

This patch intoduces a slight adjustment for macvlan to address the fact
that in source mode I was seeing two copies of any packet addressed to the
macvlan interface being delivered where there should have been only one.

The issue appears to be that one copy was delivered based on the source MAC
address and then the second copy was being delivered based on the
destination MAC address. To fix it I am just treating a unicast address
match as though it is not a match since source based macvlan isn't supposed
to be matching based on the destination MAC anyway.

Fixes: 79cf79abce71 ("macvlan: add source mode")
Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/macvlan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -441,7 +441,7 @@ static rx_handler_result_t macvlan_handl
struct macvlan_dev, list);
vlan = macvlan_hash_lookup(port, eth->h_dest);
- if (vlan == NULL)
+ if (!vlan || vlan->mode == MACVLAN_MODE_SOURCE)

dev = vlan->dev;