[XFRM]: Export SAD info.

On a system with a lot of SAs, counting SAD entries chews useful
CPU time since you need to dump the whole SAD to user space;
i.e something like ip xfrm state ls | grep -i src | wc -l
I have seen taking literally minutes on a 40K SAs when the system
is swapping.
With this patch, some of the SAD info (that was already being tracked)
is exposed to user space. i.e you do:
ip xfrm state count
And you get the count; you can also pass -s to the command line and
get the hash info.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index e144a25814bd..8287081d77f2 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -416,6 +416,13 @@ struct xfrm_audit
         u32     secid;
 };
 
+/* SAD metadata, add more later */
+struct xfrm_sadinfo
+{
+        u32 sadhcnt; /* current hash bkts */
+        u32 sadhmcnt; /* max allowed hash bkts */
+        u32 sadcnt; /* current running count */
+};
 #ifdef CONFIG_AUDITSYSCALL
 extern void xfrm_audit_log(uid_t auid, u32 secid, int type, int result,
                     struct xfrm_policy *xp, struct xfrm_state *x);
@@ -938,6 +945,7 @@ static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **s
 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
 extern int xfrm_state_delete(struct xfrm_state *x);
 extern void xfrm_state_flush(u8 proto, struct xfrm_audit *audit_info);
+extern void xfrm_sad_getinfo(struct xfrm_sadinfo *si);
 extern int xfrm_replay_check(struct xfrm_state *x, __be32 seq);
 extern void xfrm_replay_advance(struct xfrm_state *x, __be32 seq);
 extern void xfrm_replay_notify(struct xfrm_state *x, int event);