[PATCH AUTOSEL 4.19 46/73] macvlan: return correct error value

Sasha Levin
2018-12-13T04:48:13Z

From: Matteo Croce <mcroce@redhat.com>

[ Upstream commit 59f997b088d26a774958cb7b17b0763cd82de7ec ]

A MAC address must be unique among all the macvlan devices with the same
lower device. The only exception is the passthru [sic] mode,
which shares the lower device address.

When duplicate addresses are detected, EBUSY is returned when bringing
the interface up:

# ip link add macvlan0 link eth0 type macvlan
# read addr </sys/class/net/eth0/address
# ip link set macvlan0 address $addr
# ip link set macvlan0 up
RTNETLINK answers: Device or resource busy

Use correct error code which is EADDRINUSE, and do the check also
earlier, on address change:

# ip link set macvlan0 address $addr
RTNETLINK answers: Address already in use

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/macvlan.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index cfda146f3b3b..6372cdc4a510 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -608,7 +608,7 @@ static int macvlan_open(struct net_device *dev)
goto hash_add;
}

- err = -EBUSY;
+ err = -EADDRINUSE;
if (macvlan_addr_busy(vlan->port, dev->dev_addr))
goto out;

@@ -706,7 +706,7 @@ static int macvlan_sync_address(struct net_device *dev, unsigned char *addr)
} else {
/* Rehash and update the device filters */
if (macvlan_addr_busy(vlan->port, addr))
- return -EBUSY;
+ return -EADDRINUSE;

if (!macvlan_passthru(port)) {
err = dev_uc_add(lowerdev, addr);
@@ -747,6 +747,9 @@ static int macvlan_set_mac_address(struct net_device *dev, void *p)
return dev_set_mac_address(vlan->lowerdev, addr);
}

+ if (macvlan_addr_busy(vlan->port, addr->sa_data))
+ return -EADDRINUSE;
+
return macvlan_sync_address(dev, addr->sa_data);
}

--
2.19.1