From: Mahesh Bandewar <maheshb@google.com>
Date: Sat, 6 Dec 2014 23:53:19 +0000 (-0800)
Subject: ipvlan: play well with macvlan device
X-Git-Tag: v3.19-rc1~118^2~42
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=764e433b3c43d47e2d19e4bd32fec093421b9cff

ipvlan: play well with macvlan device

If a device is already a macvlan port then refuse to use it as
an ipvlan port in the early stage of port creation.

	thost1:~# ip link add link eth0 mvl0 type macvlan
	thost1:~# echo $?
	0
	thost1:~# ip link add link eth0 ipvl0 type ipvlan
	RTNETLINK answers: Device or resource busy
	thost1:~# echo $?
	2
	thost1:~#

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index feb185389a87..a66ff8197008 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -38,6 +38,12 @@ static int ipvlan_port_create(struct net_device *dev)
 		netdev_err(dev, "Master is either lo or non-ether device\n");
 		return -EINVAL;
 	}
+
+	if (netif_is_macvlan_port(dev)) {
+		netdev_err(dev, "Master is a macvlan port.\n");
+		return -EBUSY;
+	}
+
 	port = kzalloc(sizeof(struct ipvl_port), GFP_KERNEL);
 	if (!port)
 		return -ENOMEM;