[IPSEC] Add complete xfrm event notification

Heres the final patch.
What this patch provides

- netlink xfrm events
- ability to have events generated by netlink propagated to pfkey
  and vice versa.
- fixes the acquire lets-be-happy-with-one-success issue

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/linux/xfrm.h

@@ -257,5 +257,7 @@ struct xfrm_usersa_flush {
 
 #define XFRMGRP_ACQUIRE		1
 #define XFRMGRP_EXPIRE		2
+#define XFRMGRP_SA		4
+#define XFRMGRP_POLICY		8
 
 #endif /* _LINUX_XFRM_H */

include/net/xfrm.h

@@ -158,6 +158,27 @@ enum {
 	XFRM_STATE_DEAD
 };
 
+/* events that could be sent by kernel */
+enum {
+	XFRM_SAP_INVALID,
+	XFRM_SAP_EXPIRED,
+	XFRM_SAP_ADDED,
+	XFRM_SAP_UPDATED,
+	XFRM_SAP_DELETED,
+	XFRM_SAP_FLUSHED,
+	__XFRM_SAP_MAX
+};
+#define XFRM_SAP_MAX (__XFRM_SAP_MAX - 1)
+
+/* callback structure passed from either netlink or pfkey */
+struct km_event
+{
+	u32	data;
+	u32	seq;
+	u32	pid;
+	u32	event;
+};
+
 struct xfrm_type;
 struct xfrm_dst;
 struct xfrm_policy_afinfo {
@@ -179,6 +200,8 @@ struct xfrm_policy_afinfo {
 
 extern int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo);
 extern int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo);
+extern void km_policy_notify(struct xfrm_policy *xp, int dir, struct km_event *c);
+extern void km_state_notify(struct xfrm_state *x, struct km_event *c);
 
 #define XFRM_ACQ_EXPIRES	30
 
@@ -290,11 +313,11 @@ struct xfrm_mgr
 {
 	struct list_head	list;
 	char			*id;
-	int			(*notify)(struct xfrm_state *x, int event);
+	int			(*notify)(struct xfrm_state *x, struct km_event *c);
 	int			(*acquire)(struct xfrm_state *x, struct xfrm_tmpl *, struct xfrm_policy *xp, int dir);
 	struct xfrm_policy	*(*compile_policy)(u16 family, int opt, u8 *data, int len, int *dir);
 	int			(*new_mapping)(struct xfrm_state *x, xfrm_address_t *ipaddr, u16 sport);
-	int			(*notify_policy)(struct xfrm_policy *x, int dir, int event);
+	int			(*notify_policy)(struct xfrm_policy *x, int dir, struct km_event *c);
 };
 
 extern int xfrm_register_km(struct xfrm_mgr *km);
@@ -817,7 +840,7 @@ extern int xfrm_state_add(struct xfrm_state *x);
 extern int xfrm_state_update(struct xfrm_state *x);
 extern struct xfrm_state *xfrm_state_lookup(xfrm_address_t *daddr, u32 spi, u8 proto, unsigned short family);
 extern struct xfrm_state *xfrm_find_acq_byseq(u32 seq);
-extern void xfrm_state_delete(struct xfrm_state *x);
+extern int xfrm_state_delete(struct xfrm_state *x);
 extern void xfrm_state_flush(u8 proto);
 extern int xfrm_replay_check(struct xfrm_state *x, u32 seq);
 extern void xfrm_replay_advance(struct xfrm_state *x, u32 seq);