--- openflow-2013-01-22.h	2015-07-23 09:54:17.308479369 -0700
+++ openflow-2013-05-24.h	2015-07-23 09:54:17.312479369 -0700
@@ -1085,6 +1085,15 @@
 };
 OFP_ASSERT(sizeof(struct ofp_action_output) == 16);
 
+/* Action structure for OFPAT_COPY_TTL_OUT, OFPAT_COPY_TTL_IN,
+ * OFPAT_DEC_MPLS_TTL, OFPAT_DEC_NW_TTL, OFPAT_POP_VLAN and OFPAT_POP_PBB. */
+struct ofp_action_generic {
+    uint16_t type;                  /* OFPAT_SET_MPLS_TTL. */
+    uint16_t len;                   /* Length is 8. */
+    uint8_t pad[4];                 /* Pad to 64 bits. */
+};
+OFP_ASSERT(sizeof(struct ofp_action_empty) == 8);
+
 /* Action structure for OFPAT_SET_MPLS_TTL. */
 struct ofp_action_mpls_ttl {
     uint16_t type;                  /* OFPAT_SET_MPLS_TTL. */