extern int gbp_contract_delete (epg_id_t src_epg, epg_id_t dst_epg);
extern index_t gbp_rule_alloc (gbp_rule_action_t action,
extern int gbp_contract_delete (epg_id_t src_epg, epg_id_t dst_epg);
extern index_t gbp_rule_alloc (gbp_rule_action_t action,