xfrm: MIGRATE enhancements (draft-ebalard-mext-pfkey-enhanced-migrate)

Provides implementation of the enhancements of XFRM/PF_KEY MIGRATE mechanism
specified in draft-ebalard-mext-pfkey-enhanced-migrate-00. Defines associated
PF_KEY SADB_X_EXT_KMADDRESS extension and XFRM/netlink XFRMA_KMADDRESS
attribute.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/xfrm.h b/include/linux/xfrm.h
index fb0c215..4bc1e6b 100644
--- a/include/linux/xfrm.h
+++ b/include/linux/xfrm.h
@@ -279,6 +279,7 @@
 	XFRMA_POLICY_TYPE,	/* struct xfrm_userpolicy_type */
 	XFRMA_MIGRATE,
 	XFRMA_ALG_AEAD,		/* struct xfrm_algo_aead */
+	XFRMA_KMADDRESS,        /* struct xfrm_user_kmaddress */
 	__XFRMA_MAX
 
 #define XFRMA_MAX (__XFRMA_MAX - 1)
@@ -415,6 +416,15 @@
 	struct xfrm_selector		sel;
 };
 
+/* Used by MIGRATE to pass addresses IKE should use to perform
+ * SA negotiation with the peer */
+struct xfrm_user_kmaddress {
+	xfrm_address_t                  local;
+	xfrm_address_t                  remote;
+	__u32				reserved;
+	__u16				family;
+};
+
 struct xfrm_user_migrate {
 	xfrm_address_t			old_daddr;
 	xfrm_address_t			old_saddr;