224 lines
7.4 KiB
C
224 lines
7.4 KiB
C
/*
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* Copyright (c) 2014-2015, Yanzi Networks AB.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the copyright holders nor the
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* names of its contributors may be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
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* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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/**
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* \addtogroup uip6
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* @{
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*/
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/**
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* \file
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*
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* Default RPL NBR policy
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* decides when to add a new discovered node to the nbr table from RPL.
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*
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* \author Joakim Eriksson <joakime@sics.se>
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* Contributors: Niclas Finne <nfi@sics.se>, Oriol Piñol <oriol@yanzi.se>,
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*
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*/
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#include "net/rpl-lite/rpl.h"
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#include "net/nbr-table.h"
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/* Log configuration */
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#include "sys/log.h"
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#define LOG_MODULE "RPL"
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#define LOG_LEVEL RPL_LOG_LEVEL
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/*
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* Policy for neighbor adds
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* - one node is locked (default route)
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* - max X children (nexthops)
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* - max Y "best parents"
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* => at least MAX_NBRS - (Y + X + 1) free slots for other.
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*
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* NOTE: this policy assumes that all neighbors end up being IPv6
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* neighbors and are not only MAC neighbors.
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*/
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#define MAX_CHILDREN (NBR_TABLE_MAX_NEIGHBORS - 2)
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#define UIP_IP_BUF ((struct uip_ip_hdr *)&uip_buf[UIP_LLH_LEN])
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static int num_parents; /* all nodes that are possible parents */
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static int num_children; /* all children that we have as nexthop */
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static int num_free;
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static linkaddr_t *worst_rank_nbr; /* the neighbor with the worst rank */
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static rpl_rank_t worst_rank;
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/*---------------------------------------------------------------------------*/
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#if DEBUG == DEBUG_FULL
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/*
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* This create a periodic call of the update_nbr function that will print
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* useful debugging information when in DEBUG_FULL mode
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*/
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static void update_nbr(void);
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static struct ctimer periodic_timer;
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static int timer_init = 0;
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static void
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handle_periodic_timer(void *ptr)
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{
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update_nbr();
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ctimer_restart(&periodic_timer);
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}
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#endif /* DEBUG == DEBUG_FULL */
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/*---------------------------------------------------------------------------*/
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static int
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node_is_child(uip_ipaddr_t *addr) {
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/* in storing mode this was possible to figure out with uip_ds6_route_is_nexthop.
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* Need some replacement mechanism in non-storing context */
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return 0;
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}
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/*---------------------------------------------------------------------------*/
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static void
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update_nbr(void)
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{
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uip_ds6_nbr_t *ds6_nbr;
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rpl_nbr_t *rpl_nbr;
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int num_used;
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int is_used;
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rpl_rank_t rank;
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#if DEBUG == DEBUG_FULL
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if(!timer_init) {
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timer_init = 1;
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ctimer_set(&periodic_timer, 60 * CLOCK_SECOND,
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&handle_periodic_timer, NULL);
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}
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#endif /* DEBUG == DEBUG_FULL */
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worst_rank = 0;
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worst_rank_nbr = NULL;
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num_used = 0;
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num_parents = 0;
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num_children = 0;
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ds6_nbr = nbr_table_head(ds6_neighbors);
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while(ds6_nbr != NULL) {
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linkaddr_t *lladdr = nbr_table_get_lladdr(ds6_neighbors, ds6_nbr);
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is_used = 0;
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/*
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* Check if this neighbor is used as nexthop and therefore being a
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* RPL child.
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*/
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if(node_is_child(&ds6_nbr->ipaddr) != 0) {
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is_used++;
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num_children++;
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}
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rpl_nbr = rpl_neighbor_get_from_lladdr((uip_lladdr_t *)lladdr);
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if(rpl_nbr != NULL && rpl_neighbor_is_parent(rpl_nbr)) {
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num_parents++;
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if(curr_instance.dag.preferred_parent == rpl_nbr) {
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/*
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* This is the preferred parent for the DAG and must not be removed
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* Note: this assumes that only RPL adds default routes.
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*/
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} else if(is_used == 0 && worst_rank < RPL_INFINITE_RANK &&
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rpl_nbr->rank > 0 &&
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(rank = curr_instance.of->rank_via_nbr(rpl_nbr)) > worst_rank) {
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/* This is the worst-rank neighbor - this is a good candidate for removal */
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worst_rank = rank;
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worst_rank_nbr = lladdr;
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}
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/* add to is_used after evaluation of is_used above */
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is_used++;
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}
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if(is_used == 0) {
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/* This neighbor is neither parent or child and can be safely removed */
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worst_rank_nbr = lladdr;
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worst_rank = RPL_INFINITE_RANK;
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}
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ds6_nbr = nbr_table_next(ds6_neighbors, ds6_nbr);
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num_used++;
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}
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/* how many more IP neighbors can be have? */
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num_free = NBR_TABLE_MAX_NEIGHBORS - num_used;
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LOG_INFO("nbr-policy: free: %d, children: %d, parents: %d routes: %d\n",
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num_free, num_children, num_parents, uip_ds6_route_num_routes());
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}
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/*---------------------------------------------------------------------------*/
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/* Called whenever we get a unicast DIS - e.g. someone that already
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have this node in its table - since it is a unicast */
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static const linkaddr_t *
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find_removable_dis(uip_ipaddr_t *from)
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{
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update_nbr();
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if(num_children < MAX_CHILDREN) {
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return worst_rank_nbr;
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}
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return NULL;
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}
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/*---------------------------------------------------------------------------*/
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static const linkaddr_t *
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find_removable_dio(uip_ipaddr_t *from, rpl_dio_t *dio)
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{
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update_nbr();
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if(!curr_instance.used || curr_instance.instance_id != dio->instance_id) {
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LOG_WARN("nbr-policy: did not find instance id: %d\n", dio->instance_id);
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return NULL;
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}
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/* Add the new neighbor only if it is better than the current worst. */
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if(dio->rank + curr_instance.min_hoprankinc < worst_rank - curr_instance.min_hoprankinc / 2) {
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/* Found *great* neighbor - add! */
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LOG_INFO("nbr-policy: DIO rank %u, worse_rank %u -- add to cache\n",
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dio->rank, worst_rank);
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return worst_rank_nbr;
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}
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LOG_INFO("nbr-policy: DIO rank %u, worse_rank %u -- do not add to cache\n",
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dio->rank, worst_rank);
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return NULL;
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}
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/*---------------------------------------------------------------------------*/
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const linkaddr_t *
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rpl_nbr_policy_find_removable(nbr_table_reason_t reason, void *data)
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{
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/* When we get the DIO/DAO/DIS we know that UIP contains the
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incoming packet */
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switch(reason) {
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case NBR_TABLE_REASON_RPL_DIO:
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return find_removable_dio(&UIP_IP_BUF->srcipaddr, data);
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case NBR_TABLE_REASON_RPL_DAO:
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return NULL; /* DAOs are end-to-end in non-storing, this
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nbr-policy reason is unused */
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case NBR_TABLE_REASON_RPL_DIS:
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return find_removable_dis(&UIP_IP_BUF->srcipaddr);
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default:
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return NULL;
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}
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}
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/*---------------------------------------------------------------------------*/
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/** @}*/
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