vxlan: advertise netns of vxlan dev in fdb msg

Netlink FDB messages are sent in the link netns. The header of these messages
contains the ifindex (ndm_ifindex) of the netdevice, but this ifindex is
unusable in case of x-netns vxlan.
I named the new attribute NDA_NDM_IFINDEX_NETNSID, to avoid confusion with
NDA_IFINDEX.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0346eaa6d236..19d3664ab9dd 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -339,6 +339,11 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
         ndm->ndm_flags = fdb->flags;
         ndm->ndm_type = RTN_UNICAST;
 
+        if (!net_eq(dev_net(vxlan->dev), vxlan->net) &&
+            nla_put_s32(skb, NDA_NDM_IFINDEX_NETNSID,
+                        peernet2id(vxlan->net, dev_net(vxlan->dev))))
+                goto nla_put_failure;
+
         if (send_eth && nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->eth_addr))
                 goto nla_put_failure;