net/mlx5e: Use hint to resolve route when in HW multipath mode

As part of creating the tunnel headers while offloading TC encap rules,
we resolve the route and neighbour in order to get the source /
destination mac.

Since the way we offload multipath route is by having two HW rules,
one per uplink port, doing naive route lookup might get us a "wrong"
routing path which goes through the peer uplink and this will get us
eventually to create a wrong L2 header for the tunnel.

To avoid that, we use a device hint to get the correct route.

Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
index 03e5d0d8fd8f79f620d6a57ced2d0a0005cf0eb0..fa2a3c444cdc604c308999f140a3125becd9c8d3 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.c
@@ -54,12 +54,24 @@ static int mlx5e_route_lookup_ipv4(struct mlx5e_priv *priv,
        struct neighbour *n = NULL;
 
 #if IS_ENABLED(CONFIG_INET)
+       struct mlx5_core_dev *mdev = priv->mdev;
+       struct net_device *uplink_dev;
        int ret;
 
+       if (mlx5_lag_is_multipath(mdev)) {
+               struct mlx5_eswitch *esw = mdev->priv.eswitch;
+
+               uplink_dev = mlx5_eswitch_uplink_get_proto_dev(esw, REP_ETH);
+               fl4->flowi4_oif = uplink_dev->ifindex;
+       }
+
        rt = ip_route_output_key(dev_net(mirred_dev), fl4);
        ret = PTR_ERR_OR_ZERO(rt);
        if (ret)
                return ret;
+
+       if (mlx5_lag_is_multipath(mdev) && !rt->rt_gateway)
+               return -ENETUNREACH;
 #else
        return -EOPNOTSUPP;
 #endif