contiki/core/net/rpl/rpl-ns.c

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/*
* Copyright (c) 2016, Inria.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This file is part of the Contiki operating system.
*/
/**
* \file
* RPL non-storing mode specific functions. Includes support for
* source routing.
*
* \author Simon Duquennoy <simon.duquennoy@inria.fr>
*/
#include "net/rpl/rpl-conf.h"
#include "net/ip/uip.h"
#include "net/ip/tcpip.h"
#include "net/ipv6/uip-ds6.h"
#include "net/ipv6/uip-icmp6.h"
#include "net/rpl/rpl-private.h"
#include "net/rpl/rpl-ns.h"
#include "lib/list.h"
#include "lib/memb.h"
#if RPL_WITH_NON_STORING
#define DEBUG DEBUG_NONE
#include "net/ip/uip-debug.h"
#include <limits.h>
#include <string.h>
/* Total number of nodes */
static int num_nodes;
/* Every known node in the network */
LIST(nodelist);
MEMB(nodememb, rpl_ns_node_t, RPL_NS_LINK_NUM);
/*---------------------------------------------------------------------------*/
int
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rpl_ns_num_nodes(void)
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{
return num_nodes;
}
/*---------------------------------------------------------------------------*/
static int
node_matches_address(const rpl_dag_t *dag, const rpl_ns_node_t *node, const uip_ipaddr_t *addr)
{
return addr != NULL
&& node != NULL
&& dag != NULL
&& dag == node->dag
&& !memcmp(addr, &node->dag->dag_id, 8)
&& !memcmp(((const unsigned char *)addr) + 8, node->link_identifier, 8);
}
/*---------------------------------------------------------------------------*/
rpl_ns_node_t *
rpl_ns_get_node(const rpl_dag_t *dag, const uip_ipaddr_t *addr)
{
rpl_ns_node_t *l;
for(l = list_head(nodelist); l != NULL; l = list_item_next(l)) {
/* Compare prefix and node identifier */
if(node_matches_address(dag, l, addr)) {
return l;
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
int
rpl_ns_is_node_reachable(const rpl_dag_t *dag, const uip_ipaddr_t *addr)
{
int max_depth = RPL_NS_LINK_NUM;
rpl_ns_node_t *node = rpl_ns_get_node(dag, addr);
rpl_ns_node_t *root_node = rpl_ns_get_node(dag, dag != NULL ? &dag->dag_id : NULL);
while(node != NULL && node != root_node && max_depth > 0) {
node = node->parent;
max_depth--;
}
return node != NULL && node == root_node;
}
/*---------------------------------------------------------------------------*/
void
rpl_ns_expire_parent(rpl_dag_t *dag, const uip_ipaddr_t *child, const uip_ipaddr_t *parent)
{
rpl_ns_node_t *l = rpl_ns_get_node(dag, child);
/* Check if parent matches */
if(l != NULL && node_matches_address(dag, l->parent, parent)) {
l->lifetime = RPL_NOPATH_REMOVAL_DELAY;
}
}
/*---------------------------------------------------------------------------*/
rpl_ns_node_t *
rpl_ns_update_node(rpl_dag_t *dag, const uip_ipaddr_t *child, const uip_ipaddr_t *parent, uint32_t lifetime)
{
rpl_ns_node_t *child_node = rpl_ns_get_node(dag, child);
rpl_ns_node_t *parent_node = rpl_ns_get_node(dag, parent);
rpl_ns_node_t *old_parent_node;
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if(parent != NULL) {
/* No node for the parent, add one with infinite lifetime */
if(parent_node == NULL) {
parent_node = rpl_ns_update_node(dag, parent, NULL, 0xffffffff);
if(parent_node == NULL) {
return NULL;
}
}
}
/* No node for this child, add one */
if(child_node == NULL) {
child_node = memb_alloc(&nodememb);
/* No space left, abort */
if(child_node == NULL) {
return NULL;
}
child_node->parent = NULL;
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list_add(nodelist, child_node);
num_nodes++;
}
/* Initialize node */
child_node->dag = dag;
child_node->lifetime = lifetime;
memcpy(child_node->link_identifier, ((const unsigned char *)child) + 8, 8);
/* Is the node reachable before the update? */
if(rpl_ns_is_node_reachable(dag, child)) {
old_parent_node = child_node->parent;
/* Update node */
child_node->parent = parent_node;
/* Has the node become unreachable? May happen if we create a loop. */
if(!rpl_ns_is_node_reachable(dag, child)) {
/* The new parent makes the node unreachable, restore old parent.
* We will take the update next time, with chances we know more of
* the topology and the loop is gone. */
child_node->parent = old_parent_node;
}
} else {
child_node->parent = parent_node;
}
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return child_node;
}
/*---------------------------------------------------------------------------*/
void
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rpl_ns_init(void)
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{
num_nodes = 0;
memb_init(&nodememb);
list_init(nodelist);
}
/*---------------------------------------------------------------------------*/
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rpl_ns_node_t *
rpl_ns_node_head(void)
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{
return list_head(nodelist);
}
/*---------------------------------------------------------------------------*/
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rpl_ns_node_t *
rpl_ns_node_next(rpl_ns_node_t *item)
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{
return list_item_next(item);
}
/*---------------------------------------------------------------------------*/
void
rpl_ns_get_node_global_addr(uip_ipaddr_t *addr, rpl_ns_node_t *node)
{
if(addr != NULL && node != NULL && node->dag != NULL) {
memcpy(addr, &node->dag->dag_id, 8);
memcpy(((unsigned char *)addr) + 8, &node->link_identifier, 8);
}
}
/*---------------------------------------------------------------------------*/
void
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rpl_ns_periodic(void)
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{
rpl_ns_node_t *l;
/* First pass, decrement lifetime for all nodes with non-infinite lifetime */
for(l = list_head(nodelist); l != NULL; l = list_item_next(l)) {
/* Don't touch infinite lifetime nodes */
if(l->lifetime != 0xffffffff && l->lifetime > 0) {
l->lifetime--;
}
}
/* Second pass, for all expire nodes, deallocate them iff no child points to them */
for(l = list_head(nodelist); l != NULL; l = list_item_next(l)) {
if(l->lifetime == 0) {
rpl_ns_node_t *l2;
for(l2 = list_head(nodelist); l2 != NULL; l2 = list_item_next(l2)) {
if(l2->parent == l) {
break;
}
}
/* No child found, deallocate node */
list_remove(nodelist, l);
memb_free(&nodememb, l);
num_nodes--;
}
}
}
#endif /* RPL_WITH_NON_STORING */