xfrm: cache bundles instead of policies for outgoing flows

__xfrm_lookup() is called for each packet transmitted out of
system. The xfrm_find_bundle() does a linear search which can
kill system performance depending on how many bundles are
required per policy.

This modifies __xfrm_lookup() to store bundles directly in
the flow cache. If we did not get a hit, we just create a new
bundle instead of doing slow search. This means that we can now
get multiple xfrm_dst's for same flow (on per-cpu basis).

Signed-off-by: Timo Teras <timo.teras@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 3 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 35396e2dd1d..625dd61ccbb 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -267,7 +267,6 @@ struct xfrm_policy_afinfo {
                                                xfrm_address_t *saddr,
                                                xfrm_address_t *daddr);
         int                     (*get_saddr)(struct net *net, xfrm_address_t *saddr, xfrm_address_t *daddr);
-        struct dst_entry        *(*find_bundle)(struct flowi *fl, struct xfrm_policy *policy);
         void                    (*decode_session)(struct sk_buff *skb,
                                                   struct flowi *fl,
                                                   int reverse);
@@ -483,13 +482,13 @@ struct xfrm_policy {
         struct timer_list       timer;
 
         struct flow_cache_object flo;
+        atomic_t                genid;
         u32                     priority;
         u32                     index;
         struct xfrm_mark        mark;
         struct xfrm_selector    selector;
         struct xfrm_lifetime_cfg lft;
         struct xfrm_lifetime_cur curlft;
-        struct dst_entry       *bundles;
         struct xfrm_policy_walk_entry walk;
         u8                      type;
         u8                      action;
@@ -879,11 +878,15 @@ struct xfrm_dst {
                 struct rt6_info         rt6;
         } u;
         struct dst_entry *route;
+        struct flow_cache_object flo;
+        struct xfrm_policy *pols[XFRM_POLICY_TYPE_MAX];
+        int num_pols, num_xfrms;
 #ifdef CONFIG_XFRM_SUB_POLICY
         struct flowi *origin;
         struct xfrm_selector *partner;
 #endif
-        u32 genid;
+        u32 xfrm_genid;
+        u32 policy_genid;
         u32 route_mtu_cached;
         u32 child_mtu_cached;
         u32 route_cookie;
@@ -893,6 +896,7 @@ struct xfrm_dst {
 #ifdef CONFIG_XFRM
 static inline void xfrm_dst_destroy(struct xfrm_dst *xdst)
 {
+        xfrm_pols_put(xdst->pols, xdst->num_pols);
         dst_release(xdst->route);
         if (likely(xdst->u.dst.xfrm))
                 xfrm_state_put(xdst->u.dst.xfrm);