-int spf_init(uschar *,uschar *);
-int spf_process(uschar **, uschar *);
+BOOL spf_init(uschar *,uschar *);
+int spf_process(const uschar **, uschar *, int);
+
+#define SPF_PROCESS_NORMAL 0
+#define SPF_PROCESS_GUESS 1
+#define SPF_PROCESS_FALLBACK 2