Changes in this contiki:

project.conf
/* inside rpl-mrhof.c you can enable printing details (rank) of chosen parent 
 * Good for monitoring malicious node "destructive force".
 * Remember, RPL can detect loops and avoid them, so eventually there will be
 * one at least connection tot he sink, even if the malicious advertises low rank
 */
#define PRINT_CHOOSING_PARENT_DETAILS 0

/* Enable STATISTICS: it will give you UDP and ICMP per node */
#define UIP_CONF_STATISTICS 1  

rpl-icmp6.c
Declarations
/* George they will be sent to app layer for extra info to the sink*/ 
static  rpl_parent_t *dao_preffered_parent;
static  uip_ipaddr_t *dao_preffered_parent_ip;
static  uip_ipaddr_t dao_prefix_own_ip;

l504 PRINTF->printf("RPL: LEAF ONLY DIO rank set to INFINITE_RANK\n");

l1135: You can use those variables on application layer 
(contiki/examples/ipv6/rpl-udp-controller-data/udp-client.c)

/* George they will be external to app layer for extra info to the sink*/ 
dao_preffered_parent = parent;
dao_preffered_parent_ip = rpl_get_parent_ipaddr(dao_preffered_parent->dag->preferred_parent);
dao_prefix_own_ip = prefix; //node's current own IP address

rpl-mrhof.c
l228: Kept the same logic of returing the best parent, just printing details
about the two parents been currently compared. You can monitor the behavior
of mobile ndoes

/* George : printing all avaliable parents. 
 * Good for monitoring malicious nodes succesful behavior 
 */
	if (p1_cost < p2_cost){
#ifdef PRINT_CHOOSING_PARENT_DETAILS 
		printf("MRHOF activ.p %u--%5u",rpl_get_parent_ipaddr(p1)->u8[15],p1_cost);
		printf(". Alt p: %u--%5u",rpl_get_parent_ipaddr(p2)->u8[15],p2_cost);
		printf(", my rank %u\n",dag->rank);
#endif /* PRINT_CHOOSING_PARENT_DETAILS */			
		return p1;
	}
	else{// they cannot be equal, since it would never come here...
#ifdef PRINT_CHOOSING_PARENT_DETAILS		
		printf("MRHOF-2 activ.p %u--%5u",rpl_get_parent_ipaddr(p2)->u8[15],p2_cost);
		printf(". Alt p: %u--%5u",rpl_get_parent_ipaddr(p1)->u8[15],p1_cost);
		printf(", my rank %u\n",dag->rank);
#endif /* PRINT_CHOOSING_PARENT_DETAILS */			
		return p2;	
	}
		
	/* Original return */	
  //return p1_cost < p2_cost ? p1 : p2;