[XFRM]: Add sorting interface for state and template.

Under two transformation policies it is required to merge them.
This is a platform to sort state for outbound and templates
for inbound respectively.
It will be used when Mobile IPv6 and IPsec are used at the same time.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 4655ca2..d341603 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -254,6 +254,8 @@
 	struct xfrm_state	*(*find_acq)(u8 mode, u32 reqid, u8 proto, 
 					     xfrm_address_t *daddr, xfrm_address_t *saddr, 
 					     int create);
+	int			(*tmpl_sort)(struct xfrm_tmpl **dst, struct xfrm_tmpl **src, int n);
+	int			(*state_sort)(struct xfrm_state **dst, struct xfrm_state **src, int n);
 };
 
 extern int xfrm_state_register_afinfo(struct xfrm_state_afinfo *afinfo);
@@ -1002,6 +1004,24 @@
 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_state_lookup_byaddr(xfrm_address_t *daddr, xfrm_address_t *saddr, u8 proto, unsigned short family);
+#ifdef CONFIG_XFRM_SUB_POLICY
+extern int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
+			  int n, unsigned short family);
+extern int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
+			   int n, unsigned short family);
+#else
+static inline int xfrm_tmpl_sort(struct xfrm_tmpl **dst, struct xfrm_tmpl **src,
+				 int n, unsigned short family)
+{
+	return -ENOSYS;
+}
+
+static inline int xfrm_state_sort(struct xfrm_state **dst, struct xfrm_state **src,
+				  int n, unsigned short family)
+{
+	return -ENOSYS;
+}
+#endif
 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);