ospf6d: add SPF logs, statistics, and display of SPF parameters

Signed-off-by: Pradosh Mohapatra <pmohapat at cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma at cumulusnetworks.com>
[DL: adapted to rebase / readded randomly lost line]
[DL: killed timeval_subtract]
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/ospf6d/ospf6_top.h b/ospf6d/ospf6_top.h
index 9d7cfd9..866f92f 100644
--- a/ospf6d/ospf6_top.h
+++ b/ospf6d/ospf6_top.h
@@ -70,9 +70,11 @@
   unsigned int spf_holdtime;		/* SPF hold time. */
   unsigned int spf_max_holdtime;	/* SPF maximum-holdtime */
   unsigned int spf_hold_multiplier;	/* Adaptive multiplier for hold time */
+  unsigned int spf_reason;              /* reason bits while scheduling SPF */
 
   struct timeval ts_spf;		/* SPF calculation time stamp. */
   struct timeval ts_spf_duration;	/* Execution time of last SPF */
+  unsigned int last_spf_reason;         /* Last SPF reason */
 
   /* Threads */
   struct thread *t_spf_calc;	        /* SPF calculation timer. */