diff --git a/sys/netpfil/ipfw/ip_fw_private.h b/sys/netpfil/ipfw/ip_fw_private.h
index 1440b1a40ee..bd4cefb7fed 100644
--- a/sys/netpfil/ipfw/ip_fw_private.h
+++ b/sys/netpfil/ipfw/ip_fw_private.h
@@ -251,6 +251,40 @@ VNET_DECLARE(unsigned int, fw_tables_sets);
 
 struct tables_config;
 
+#ifndef V_hook_state
+typedef int (*ipfw_hook_t)(const void *arg, const void *extdata);
+/* callback hooks for notify on update of internal states and aliases */
+VNET_DECLARE(ipfw_hook_t, hook_state);
+#define V_hook_state		VNET(hook_state)
+VNET_DECLARE(ipfw_hook_t, hook_alias);
+#define V_hook_alias		VNET(hook_alias)
+VNET_DECLARE(ipfw_hook_t, sync_state);
+#define V_sync_state		VNET(sync_state)
+VNET_DECLARE(ipfw_hook_t, sync_alias);
+#define V_sync_alias		VNET(sync_alias)
+#endif
+
+struct ipfw_dyn_hook_extdata {
+	unsigned int	ruleid;
+	unsigned short	rulenum;
+	unsigned short	fibnum;
+	unsigned short	kidx;
+	unsigned char	cmdtype;
+};
+
+int ipfw_dyn_install_sync_state(const struct ipfw_flow_id *pkt, void *rule, 
+		uint32_t ruleid, uint16_t rulenum, uint16_t kidx, uint8_t cmdtype);
+
+#define ipfw_unregister_state_hook()	V_hook_state = NULL
+#define ipfw_unregister_alias_hook()	V_hook_alias = NULL
+#define ipfw_register_state_hook(_hcb)	V_hook_state = (_hcb)
+#define ipfw_register_alias_hook(_hcb)	V_hook_alias = (_hcb)
+
+#define ipfw_unregister_state_sync()	V_sync_state = NULL
+#define ipfw_unregister_alias_sync()	V_sync_alias = NULL
+#define ipfw_register_state_sync(_hcb)	V_sync_state = (_hcb)
+#define ipfw_register_alias_sync(_hcb)	V_sync_alias = (_hcb)
+
 #ifdef _KERNEL
 /*
  * Here we have the structure representing an ipfw rule.
@@ -295,6 +329,22 @@ struct ip_fw {
 
 #endif
 
+/* Nat configuration data struct. */
+struct cfg_nat {
+	/* chain of nat instances */
+	LIST_ENTRY(cfg_nat)	_next;
+	int			id;		/* nat id  */
+	struct in_addr		ip;		/* nat ip address */
+	struct libalias		*lib;		/* libalias instance */
+	int			mode;		/* aliasing mode */
+	int			redir_cnt; /* number of entry in spool chain */
+	/* chain of redir instances */
+	LIST_HEAD(redir_chain, cfg_redir) redir_chain;  
+	char			if_name[IF_NAMESIZE];	/* interface name */
+	u_short			alias_port_lo;	/* low range for port aliasing */
+	u_short			alias_port_hi;	/* high range for port aliasing */
+};
+
 struct ip_fw_chain {
 	struct ip_fw	**map;		/* array of rule ptrs to ease lookup */
 	uint32_t	id;		/* ruleset id */