ipvlan: implement VEPA mode

This is very similar to the Macvlan VEPA mode, however, there is some
difference. IPvlan uses the mac-address of the lower device, so the VEPA
mode has implications of ICMP-redirects for packets destined for its
immediate neighbors sharing same master since the packets will have same
source and dest mac. The external switch/router will send redirect msg.

Having said that, this will be useful tool in terms of debugging
since IPvlan will not switch packets within its slaves and rely completely
on the external entity as intended in 802.1Qbg.

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

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
index 4368afb1934c..a266aa435d4d 100644
--- a/drivers/net/ipvlan/ipvlan_main.c
+++ b/drivers/net/ipvlan/ipvlan_main.c
@@ -478,6 +478,11 @@ static int ipvlan_nl_changelink(struct net_device *dev,
                         ipvlan_mark_private(port);
                 else
                         ipvlan_clear_private(port);
+
+                if (flags & IPVLAN_F_VEPA)
+                        ipvlan_mark_vepa(port);
+                else
+                        ipvlan_clear_vepa(port);
         }
 
         return err;
@@ -506,8 +511,12 @@ static int ipvlan_nl_validate(struct nlattr *tb[], struct nlattr *data[],
         if (data[IFLA_IPVLAN_FLAGS]) {
                 u16 flags = nla_get_u16(data[IFLA_IPVLAN_FLAGS]);
 
-                /* Only one bit is used at this moment. */
-                if (flags & ~IPVLAN_F_PRIVATE)
+                /* Only two bits are used at this moment. */
+                if (flags & ~(IPVLAN_F_PRIVATE | IPVLAN_F_VEPA))
+                        return -EINVAL;
+                /* Also both flags can't be active at the same time. */
+                if ((flags & (IPVLAN_F_PRIVATE | IPVLAN_F_VEPA)) ==
+                    (IPVLAN_F_PRIVATE | IPVLAN_F_VEPA))
                         return -EINVAL;
         }