[PATCH ipsec-next 1/2] xfrm interface: avoid xi lookup in xfrmi_decode_session()

[Eyal Birger]

The xfrmi context exists in the netdevice priv context.
Avoid looking for it in a separate list.

Signed-off-by: Eyal Birger <eyal.bir...@gmail.com>
---
 net/xfrm/xfrm_interface.c | 23 +++++++++++++----------
 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index c407ecbc5d46..069dafeba873 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -47,6 +47,7 @@ static int xfrmi_dev_init(struct net_device *dev);
 static void xfrmi_dev_setup(struct net_device *dev);
 static struct rtnl_link_ops xfrmi_link_ops __read_mostly;
 static unsigned int xfrmi_net_id __read_mostly;
+static const struct net_device_ops xfrmi_netdev_ops;
 
 struct xfrmi_net {
        /* lists for storing interfaces in use */
@@ -73,8 +74,7 @@ static struct xfrm_if *xfrmi_lookup(struct net *net, struct 
xfrm_state *x)
 static struct xfrm_if *xfrmi_decode_session(struct sk_buff *skb,
                                            unsigned short family)
 {
-       struct xfrmi_net *xfrmn;
-       struct xfrm_if *xi;
+       struct net_device *dev;
        int ifindex = 0;
 
        if (!secpath_exists(skb) || !skb->dev)
@@ -88,18 +88,21 @@ static struct xfrm_if *xfrmi_decode_session(struct sk_buff 
*skb,
                ifindex = inet_sdif(skb);
                break;
        }
-       if (!ifindex)
-               ifindex = skb->dev->ifindex;
 
-       xfrmn = net_generic(xs_net(xfrm_input_state(skb)), xfrmi_net_id);
+       if (ifindex) {
+               struct net *net = xs_net(xfrm_input_state(skb));
 
-       for_each_xfrmi_rcu(xfrmn->xfrmi[0], xi) {
-               if (ifindex == xi->dev->ifindex &&
-                       (xi->dev->flags & IFF_UP))
-                               return xi;
+               dev = dev_get_by_index_rcu(net, ifindex);
+       } else {
+               dev = skb->dev;
        }
 
-       return NULL;
+       if (!dev || !(dev->flags & IFF_UP))
+               return NULL;
+       if (dev->netdev_ops != &xfrmi_netdev_ops)
+               return NULL;
+
+       return netdev_priv(dev);
 }
 
 static void xfrmi_link(struct xfrmi_net *xfrmn, struct xfrm_if *xi)
-- 
2.25.1