From: Jiri Wiesner jwiesner@suse.com
[ Upstream commit 63aae7b17344d4b08a7d05cb07044de4c0f9dcc6 ]
There is a problem when ipvlan slaves are created on a master device that is a vmxnet3 device (ipvlan in VMware guests). The vmxnet3 driver does not support unicast address filtering. When an ipvlan device is brought up in ipvlan_open(), the ipvlan driver calls dev_uc_add() to add the hardware address of the vmxnet3 master device to the unicast address list of the master device, phy_dev->uc. This inevitably leads to the vmxnet3 master device being forced into promiscuous mode by __dev_set_rx_mode().
Promiscuous mode is switched on the master despite the fact that there is still only one hardware address that the master device should use for filtering in order for the ipvlan device to be able to receive packets. The comment above struct net_device describes the uc_promisc member as a "counter, that indicates, that promiscuous mode has been enabled due to the need to listen to additional unicast addresses in a device that does not implement ndo_set_rx_mode()". Moreover, the design of ipvlan guarantees that only the hardware address of a master device, phy_dev->dev_addr, will be used to transmit and receive all packets from its ipvlan slaves. Thus, the unicast address list of the master device should not be modified by ipvlan_open() and ipvlan_stop() in order to make ipvlan a workable option on masters that do not support unicast address filtering.
Fixes: 2ad7bf3638411 ("ipvlan: Initial check-in of the IPVLAN driver") Reported-by: Per Sundstrom per.sundstrom@redqube.se Signed-off-by: Jiri Wiesner jwiesner@suse.com Reviewed-by: Eric Dumazet edumazet@google.com Acked-by: Mahesh Bandewar maheshb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ipvlan/ipvlan_main.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index 0115a2868933c..87f605a33c37a 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -236,7 +236,6 @@ static void ipvlan_uninit(struct net_device *dev) static int ipvlan_open(struct net_device *dev) { struct ipvl_dev *ipvlan = netdev_priv(dev); - struct net_device *phy_dev = ipvlan->phy_dev; struct ipvl_addr *addr;
if (ipvlan->port->mode == IPVLAN_MODE_L3 || @@ -250,7 +249,7 @@ static int ipvlan_open(struct net_device *dev) ipvlan_ht_addr_add(ipvlan, addr); rcu_read_unlock();
- return dev_uc_add(phy_dev, phy_dev->dev_addr); + return 0; }
static int ipvlan_stop(struct net_device *dev) @@ -262,8 +261,6 @@ static int ipvlan_stop(struct net_device *dev) dev_uc_unsync(phy_dev, dev); dev_mc_unsync(phy_dev, dev);
- dev_uc_del(phy_dev, phy_dev->dev_addr); - rcu_read_lock(); list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) ipvlan_ht_addr_del(addr);