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nes-proj/os/net/ipv6/uip-ds6-nbr.c

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/*
* Copyright (c) 2013, Swedish Institute of Computer Science.
* 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.
*
*
*/
/**
* \addtogroup uip
* @{
*/
/**
* \file
* IPv6 Neighbor cache (link-layer/IPv6 address mapping)
* \author Mathilde Durvy <mdurvy@cisco.com>
* \author Julien Abeille <jabeille@cisco.com>
* \author Simon Duquennoy <simonduq@sics.se>
*
*/
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include "lib/list.h"
#include "net/link-stats.h"
#include "net/linkaddr.h"
#include "net/packetbuf.h"
#include "net/ipv6/uip-ds6.h"
#include "net/ipv6/uip-ds6-nbr.h"
#include "net/ipv6/uip-nd6.h"
#include "net/routing/routing.h"
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
#include "lib/memb.h"
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "IPv6 Nbr"
#define LOG_LEVEL LOG_LEVEL_IPV6
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
/**
* Add nbr to the list in nbr_entry. In other words, this function associates an
* IPv6 address in nbr with a link-layer address in nbr_entry.
* \param nbr the neighbor cache entry for an IPv6 address
* \param nbr_entry the nbr_table entry for an link-layer address
*/
static void add_uip_ds6_nbr_to_nbr_entry(uip_ds6_nbr_t *nbr,
uip_ds6_nbr_entry_t *nbr_entry);
/**
* Remove nbr from the list of the corresponding nbr_entry
* \param nbr a neighbor cache entry (nbr) to be removed
*/
static void remove_uip_ds6_nbr_from_nbr_entry(uip_ds6_nbr_t *nbr);
/**
* Remove nbr_etnry from nbr_table
* \param nbr_entry a nbr_table entry (nbr_entry) to be removed
*/
static void remove_nbr_entry(uip_ds6_nbr_entry_t *nbr_entry);
/**
* Free memory for a specified neighbor cache entry
* \param nbr a neighbor cache entry to be freed
*/
static void free_uip_ds6_nbr(uip_ds6_nbr_t *nbr);
/**
* Callback function called when a nbr_table entry is removed
* \param nbr_entry a nbr_entry to be removed
*/
static void callback_nbr_entry_removal(uip_ds6_nbr_entry_t *nbr_entry);
NBR_TABLE(uip_ds6_nbr_entry_t, uip_ds6_nbr_entries);
MEMB(uip_ds6_nbr_memb, uip_ds6_nbr_t, UIP_DS6_NBR_MAX_NEIGHBOR_CACHES);
#else
NBR_TABLE(uip_ds6_nbr_t, ds6_neighbors);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
/*---------------------------------------------------------------------------*/
void
uip_ds6_neighbors_init(void)
{
link_stats_init();
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
memb_init(&uip_ds6_nbr_memb);
nbr_table_register(uip_ds6_nbr_entries,
(nbr_table_callback *)callback_nbr_entry_removal);
#else
nbr_table_register(ds6_neighbors, (nbr_table_callback *)uip_ds6_nbr_rm);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_nbr_add(const uip_ipaddr_t *ipaddr, const uip_lladdr_t *lladdr,
uint8_t isrouter, uint8_t state, nbr_table_reason_t reason,
void *data)
{
uip_ds6_nbr_t *nbr;
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
assert(uip_ds6_nbr_lookup(ipaddr) == NULL);
if(uip_ds6_nbr_lookup(ipaddr)) {
LOG_ERR("%s: uip_ds6_nbr for ", __func__);
LOG_ERR_6ADDR(ipaddr);
LOG_ERR_("has already existed\n");
return NULL;
}
nbr_entry = nbr_table_get_from_lladdr(uip_ds6_nbr_entries,
(const linkaddr_t *)lladdr);
if(nbr_entry == NULL) {
if((nbr_entry =
nbr_table_add_lladdr(uip_ds6_nbr_entries,
(linkaddr_t*)lladdr, reason, data)) == NULL) {
LOG_ERR("%s: cannot allocate a new uip_ds6_nbr_entry\n", __func__);
return NULL;
} else {
LIST_STRUCT_INIT(nbr_entry, uip_ds6_nbrs);
}
}
if(list_length(nbr_entry->uip_ds6_nbrs) < UIP_DS6_NBR_MAX_6ADDRS_PER_NBR) {
/* it has room to add another IPv6 address */
} else {
/*
* it's already had the maximum number of IPv6 addresses; cannot
* add another.
*/
LOG_ERR("%s: no room in nbr_entry for ", __func__);
LOG_ERR_LLADDR((const linkaddr_t *)lladdr);
LOG_ERR_("\n");
return NULL;
}
if((nbr = (uip_ds6_nbr_t *)memb_alloc(&uip_ds6_nbr_memb)) == NULL) {
LOG_ERR("%s: cannot allocate a new uip_ds6_nbr\n", __func__);
if(list_length(nbr_entry->uip_ds6_nbrs) == 0) {
nbr_table_remove(uip_ds6_nbr_entries, nbr_entry);
}
} else {
add_uip_ds6_nbr_to_nbr_entry(nbr, nbr_entry);
}
#else
nbr = nbr_table_add_lladdr(ds6_neighbors, (linkaddr_t*)lladdr, reason, data);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
if(nbr) {
uip_ipaddr_copy(&nbr->ipaddr, ipaddr);
#if UIP_ND6_SEND_RA || !UIP_CONF_ROUTER
nbr->isrouter = isrouter;
#endif /* UIP_ND6_SEND_RA || !UIP_CONF_ROUTER */
nbr->state = state;
#if UIP_CONF_IPV6_QUEUE_PKT
uip_packetqueue_new(&nbr->packethandle);
#endif /* UIP_CONF_IPV6_QUEUE_PKT */
#if UIP_ND6_SEND_NS
if(nbr->state == NBR_REACHABLE) {
stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
} else {
/* We set the timer in expired state */
stimer_set(&nbr->reachable, 0);
}
stimer_set(&nbr->sendns, 0);
nbr->nscount = 0;
#endif /* UIP_ND6_SEND_NS */
LOG_INFO("Adding neighbor with ip addr ");
LOG_INFO_6ADDR(ipaddr);
LOG_INFO_(" link addr ");
LOG_INFO_LLADDR((linkaddr_t*)lladdr);
LOG_INFO_(" state %u\n", state);
NETSTACK_ROUTING.neighbor_state_changed(nbr);
return nbr;
} else {
LOG_INFO("Add drop ip addr ");
LOG_INFO_6ADDR(ipaddr);
LOG_INFO_(" link addr (%p) ", lladdr);
LOG_INFO_LLADDR((linkaddr_t*)lladdr);
LOG_INFO_(" state %u\n", state);
return NULL;
}
}
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
/*---------------------------------------------------------------------------*/
static void
add_uip_ds6_nbr_to_nbr_entry(uip_ds6_nbr_t *nbr,
uip_ds6_nbr_entry_t *nbr_entry)
{
LOG_DBG("%s: add nbr(%p) to nbr_entry (%p)\n",
__func__, nbr, nbr_entry);
nbr->nbr_entry = nbr_entry;
list_add(nbr_entry->uip_ds6_nbrs, nbr);
}
/*---------------------------------------------------------------------------*/
static void
remove_uip_ds6_nbr_from_nbr_entry(uip_ds6_nbr_t *nbr)
{
if(nbr == NULL) {
return;
}
LOG_DBG("%s: remove nbr(%p) from nbr_entry (%p)\n",
__func__, nbr, nbr->nbr_entry);
list_remove(nbr->nbr_entry->uip_ds6_nbrs, nbr);
}
/*---------------------------------------------------------------------------*/
static void
remove_nbr_entry(uip_ds6_nbr_entry_t *nbr_entry)
{
if(nbr_entry == NULL) {
return;
}
LOG_DBG("%s: remove nbr_entry (%p) from nbr_table\n",
__func__, nbr_entry);
(void)nbr_table_remove(uip_ds6_nbr_entries, nbr_entry);
}
/*---------------------------------------------------------------------------*/
static void
free_uip_ds6_nbr(uip_ds6_nbr_t *nbr)
{
if(nbr == NULL) {
return;
}
#if UIP_CONF_IPV6_QUEUE_PKT
uip_packetqueue_free(&nbr->packethandle);
#endif /* UIP_CONF_IPV6_QUEUE_PKT */
NETSTACK_ROUTING.neighbor_state_changed(nbr);
assert(nbr->nbr_entry != NULL);
if(nbr->nbr_entry == NULL) {
LOG_ERR("%s: unexpected error nbr->nbr_entry is NULL\n", __func__);
} else {
remove_uip_ds6_nbr_from_nbr_entry(nbr);
if(list_length(nbr->nbr_entry->uip_ds6_nbrs) == 0) {
remove_nbr_entry(nbr->nbr_entry);
}
}
LOG_DBG("%s: free memory for nbr(%p)\n", __func__, nbr);
memb_free(&uip_ds6_nbr_memb, nbr);
}
/*---------------------------------------------------------------------------*/
static void
callback_nbr_entry_removal(uip_ds6_nbr_entry_t *nbr_entry)
{
uip_ds6_nbr_t *nbr;
uip_ds6_nbr_t *next_nbr;
if(nbr_entry == NULL) {
return;
}
for(nbr = (uip_ds6_nbr_t *)list_head(nbr_entry->uip_ds6_nbrs);
nbr != NULL;
nbr = next_nbr) {
next_nbr = (uip_ds6_nbr_t *)list_item_next(nbr);
free_uip_ds6_nbr(nbr);
}
}
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
/*---------------------------------------------------------------------------*/
int
uip_ds6_nbr_rm(uip_ds6_nbr_t *nbr)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
if(nbr == NULL) {
return 0;
} else {
free_uip_ds6_nbr(nbr);
return 1;
}
#else /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
if(nbr != NULL) {
#if UIP_CONF_IPV6_QUEUE_PKT
uip_packetqueue_free(&nbr->packethandle);
#endif /* UIP_CONF_IPV6_QUEUE_PKT */
NETSTACK_ROUTING.neighbor_state_changed(nbr);
return nbr_table_remove(ds6_neighbors, nbr);
}
return 0;
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
int
uip_ds6_nbr_update_ll(uip_ds6_nbr_t **nbr_pp, const uip_lladdr_t *new_ll_addr)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
uip_ds6_nbr_t *nbr;
#else
uip_ds6_nbr_t nbr_backup;
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
if(nbr_pp == NULL || new_ll_addr == NULL) {
LOG_ERR("%s: invalid argument\n", __func__);
return -1;
}
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
if((nbr_entry =
nbr_table_get_from_lladdr(uip_ds6_nbr_entries,
(const linkaddr_t *)new_ll_addr)) == NULL) {
if((nbr_entry =
nbr_table_add_lladdr(uip_ds6_nbr_entries,
(const linkaddr_t*)new_ll_addr,
NBR_TABLE_REASON_IPV6_ND, NULL)) == NULL) {
LOG_ERR("%s: cannot allocate a nbr_entry for", __func__);
LOG_ERR_LLADDR((const linkaddr_t *)new_ll_addr);
return -1;
} else {
LIST_STRUCT_INIT(nbr_entry, uip_ds6_nbrs);
}
}
nbr = *nbr_pp;
remove_uip_ds6_nbr_from_nbr_entry(nbr);
if(list_length(nbr->nbr_entry->uip_ds6_nbrs) == 0) {
remove_nbr_entry(nbr->nbr_entry);
}
add_uip_ds6_nbr_to_nbr_entry(nbr, nbr_entry);
#else /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
/* make sure new_ll_addr is not used in some other nbr */
if(uip_ds6_nbr_ll_lookup(new_ll_addr) != NULL) {
LOG_ERR("%s: new_ll_addr, ", __func__);
LOG_ERR_LLADDR((const linkaddr_t *)new_ll_addr);
LOG_ERR_(", is already used in another nbr\n");
return -1;
}
memcpy(&nbr_backup, *nbr_pp, sizeof(uip_ds6_nbr_t));
if(uip_ds6_nbr_rm(*nbr_pp) == 0) {
LOG_ERR("%s: input nbr cannot be removed\n", __func__);
return -1;
}
if((*nbr_pp = uip_ds6_nbr_add(&nbr_backup.ipaddr, new_ll_addr,
nbr_backup.isrouter, nbr_backup.state,
NBR_TABLE_REASON_IPV6_ND, NULL)) == NULL) {
LOG_ERR("%s: cannot allocate a new nbr for new_ll_addr\n", __func__);
return -1;
}
memcpy(*nbr_pp, &nbr_backup, sizeof(uip_ds6_nbr_t));
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
return 0;
}
/*---------------------------------------------------------------------------*/
const uip_ipaddr_t *
uip_ds6_nbr_get_ipaddr(const uip_ds6_nbr_t *nbr)
{
return (nbr != NULL) ? &nbr->ipaddr : NULL;
}
/*---------------------------------------------------------------------------*/
const uip_lladdr_t *
uip_ds6_nbr_get_ll(const uip_ds6_nbr_t *nbr)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
if(nbr == NULL) {
return NULL;
}
return (const uip_lladdr_t *)nbr_table_get_lladdr(uip_ds6_nbr_entries,
nbr->nbr_entry);
#else
return (const uip_lladdr_t *)nbr_table_get_lladdr(ds6_neighbors, nbr);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
int
uip_ds6_nbr_num(void)
{
int num = 0;
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
for(nbr_entry = nbr_table_head(uip_ds6_nbr_entries);
nbr_entry != NULL;
nbr_entry = nbr_table_next(uip_ds6_nbr_entries, nbr_entry)) {
num += list_length(nbr_entry->uip_ds6_nbrs);
}
#else
uip_ds6_nbr_t *nbr;
for(nbr = nbr_table_head(ds6_neighbors);
nbr != NULL;
nbr = nbr_table_next(ds6_neighbors, nbr)) {
num++;
}
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
return num;
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_nbr_head(void)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
if((nbr_entry = nbr_table_head(uip_ds6_nbr_entries)) == NULL) {
return NULL;
}
assert(list_head(nbr_entry->uip_ds6_nbrs) != NULL);
return (uip_ds6_nbr_t *)list_head(nbr_entry->uip_ds6_nbrs);
#else
return nbr_table_head(ds6_neighbors);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_nbr_next(uip_ds6_nbr_t *nbr)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
if(nbr == NULL) {
return NULL;
}
if(list_item_next(nbr) != NULL) {
return list_item_next(nbr);
}
nbr_entry = nbr_table_next(uip_ds6_nbr_entries, nbr->nbr_entry);
if(nbr_entry == NULL) {
return NULL;
} else {
assert(list_head(nbr_entry->uip_ds6_nbrs) != NULL);
return (uip_ds6_nbr_t *)list_head(nbr_entry->uip_ds6_nbrs);
}
#else
return nbr_table_next(ds6_neighbors, nbr);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_nbr_lookup(const uip_ipaddr_t *ipaddr)
{
uip_ds6_nbr_t *nbr;
if(ipaddr == NULL) {
return NULL;
}
for(nbr = uip_ds6_nbr_head(); nbr != NULL; nbr = uip_ds6_nbr_next(nbr)) {
if(uip_ipaddr_cmp(&nbr->ipaddr, ipaddr)) {
return nbr;
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_nbr_ll_lookup(const uip_lladdr_t *lladdr)
{
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
/*
* we cannot determine which entry should return by lladdr alone;
* return the first entry associated with lladdr.
*/
nbr_entry =
(uip_ds6_nbr_entry_t *)nbr_table_get_from_lladdr(uip_ds6_nbr_entries,
(linkaddr_t*)lladdr);
if(nbr_entry == NULL) {
return NULL;
}
assert(list_head(nbr_entry->uip_ds6_nbrs) != NULL);
return (uip_ds6_nbr_t *)list_head(nbr_entry->uip_ds6_nbrs);
#else
return nbr_table_get_from_lladdr(ds6_neighbors, (linkaddr_t*)lladdr);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
/*---------------------------------------------------------------------------*/
uip_ipaddr_t *
uip_ds6_nbr_ipaddr_from_lladdr(const uip_lladdr_t *lladdr)
{
uip_ds6_nbr_t *nbr = uip_ds6_nbr_ll_lookup(lladdr);
return nbr ? &nbr->ipaddr : NULL;
}
/*---------------------------------------------------------------------------*/
const uip_lladdr_t *
uip_ds6_nbr_lladdr_from_ipaddr(const uip_ipaddr_t *ipaddr)
{
uip_ds6_nbr_t *nbr = uip_ds6_nbr_lookup(ipaddr);
return nbr ? uip_ds6_nbr_get_ll(nbr) : NULL;
}
#if UIP_DS6_LL_NUD
/*---------------------------------------------------------------------------*/
static void
update_nbr_reachable_state_by_ack(uip_ds6_nbr_t *nbr, const linkaddr_t *lladdr)
{
if(nbr != NULL && nbr->state != NBR_INCOMPLETE) {
nbr->state = NBR_REACHABLE;
stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
LOG_INFO("received a link layer ACK : ");
LOG_INFO_LLADDR(lladdr);
LOG_INFO_(" is reachable.\n");
}
}
#endif /* UIP_DS6_LL_NUD */
/*---------------------------------------------------------------------------*/
void
uip_ds6_link_callback(int status, int numtx)
{
#if UIP_DS6_LL_NUD
const linkaddr_t *dest = packetbuf_addr(PACKETBUF_ADDR_RECEIVER);
if(linkaddr_cmp(dest, &linkaddr_null)) {
return;
}
/* From RFC4861, page 72, last paragraph of section 7.3.3:
*
* "In some cases, link-specific information may indicate that a path to
* a neighbor has failed (e.g., the resetting of a virtual circuit). In
* such cases, link-specific information may be used to purge Neighbor
* Cache entries before the Neighbor Unreachability Detection would do
* so. However, link-specific information MUST NOT be used to confirm
* the reachability of a neighbor; such information does not provide
* end-to-end confirmation between neighboring IP layers."
*
* However, we assume that receiving a link layer ack ensures the delivery
* of the transmitted packed to the IP stack of the neighbour. This is a
* fair assumption and allows battery powered nodes save some battery by
* not re-testing the state of a neighbour periodically if it
* acknowledges link packets. */
if(status == MAC_TX_OK) {
uip_ds6_nbr_t *nbr;
#if UIP_DS6_NBR_MULTI_IPV6_ADDRS
uip_ds6_nbr_entry_t *nbr_entry;
if((nbr_entry =
(uip_ds6_nbr_entry_t *)nbr_table_get_from_lladdr(uip_ds6_nbr_entries,
dest)) == NULL) {
return;
}
for(nbr = (uip_ds6_nbr_t *)list_head(nbr_entry->uip_ds6_nbrs);
nbr != NULL;
nbr = (uip_ds6_nbr_t *)list_item_next(nbr)) {
update_nbr_reachable_state_by_ack(nbr, dest);
}
#else /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
nbr = uip_ds6_nbr_ll_lookup((uip_lladdr_t *)dest);
update_nbr_reachable_state_by_ack(nbr, dest);
#endif /* UIP_DS6_NBR_MULTI_IPV6_ADDRS */
}
#endif /* UIP_DS6_LL_NUD */
}
#if UIP_ND6_SEND_NS
/*---------------------------------------------------------------------------*/
/** Periodic processing on neighbors */
void
uip_ds6_neighbor_periodic(void)
{
uip_ds6_nbr_t *nbr = uip_ds6_nbr_head();
while(nbr != NULL) {
switch(nbr->state) {
case NBR_REACHABLE:
if(stimer_expired(&nbr->reachable)) {
#if UIP_CONF_ROUTER
/* when a neighbor leave its REACHABLE state and is a default router,
instead of going to STALE state it enters DELAY state in order to
force a NUD on it. Otherwise, if there is no upward traffic, the
node never knows if the default router is still reachable. This
mimics the 6LoWPAN-ND behavior.
*/
if(uip_ds6_defrt_lookup(&nbr->ipaddr) != NULL) {
LOG_INFO("REACHABLE: defrt moving to DELAY (");
LOG_INFO_6ADDR(&nbr->ipaddr);
LOG_INFO_(")\n");
nbr->state = NBR_DELAY;
stimer_set(&nbr->reachable, UIP_ND6_DELAY_FIRST_PROBE_TIME);
nbr->nscount = 0;
} else {
LOG_INFO("REACHABLE: moving to STALE (");
LOG_INFO_6ADDR(&nbr->ipaddr);
LOG_INFO_(")\n");
nbr->state = NBR_STALE;
}
#else /* UIP_CONF_ROUTER */
LOG_INFO("REACHABLE: moving to STALE (");
LOG_INFO_6ADDR(&nbr->ipaddr);
LOG_INFO_(")\n");
nbr->state = NBR_STALE;
#endif /* UIP_CONF_ROUTER */
}
break;
case NBR_INCOMPLETE:
if(nbr->nscount >= UIP_ND6_MAX_MULTICAST_SOLICIT) {
uip_ds6_nbr_rm(nbr);
} else if(stimer_expired(&nbr->sendns) && (uip_len == 0)) {
nbr->nscount++;
LOG_INFO("NBR_INCOMPLETE: NS %u\n", nbr->nscount);
uip_nd6_ns_output(NULL, NULL, &nbr->ipaddr);
stimer_set(&nbr->sendns, uip_ds6_if.retrans_timer / 1000);
}
break;
case NBR_DELAY:
if(stimer_expired(&nbr->reachable)) {
nbr->state = NBR_PROBE;
nbr->nscount = 0;
LOG_INFO("DELAY: moving to PROBE\n");
stimer_set(&nbr->sendns, 0);
}
break;
case NBR_PROBE:
if(nbr->nscount >= UIP_ND6_MAX_UNICAST_SOLICIT) {
uip_ds6_defrt_t *locdefrt;
LOG_INFO("PROBE END\n");
if((locdefrt = uip_ds6_defrt_lookup(&nbr->ipaddr)) != NULL) {
if (!locdefrt->isinfinite) {
uip_ds6_defrt_rm(locdefrt);
}
}
uip_ds6_nbr_rm(nbr);
} else if(stimer_expired(&nbr->sendns) && (uip_len == 0)) {
nbr->nscount++;
LOG_INFO("PROBE: NS %u\n", nbr->nscount);
uip_nd6_ns_output(NULL, &nbr->ipaddr, &nbr->ipaddr);
stimer_set(&nbr->sendns, uip_ds6_if.retrans_timer / 1000);
}
break;
default:
break;
}
nbr = uip_ds6_nbr_next(nbr);
}
}
/*---------------------------------------------------------------------------*/
void
uip_ds6_nbr_refresh_reachable_state(const uip_ipaddr_t *ipaddr)
{
uip_ds6_nbr_t *nbr;
nbr = uip_ds6_nbr_lookup(ipaddr);
if(nbr != NULL) {
nbr->state = NBR_REACHABLE;
nbr->nscount = 0;
stimer_set(&nbr->reachable, UIP_ND6_REACHABLE_TIME / 1000);
}
}
/*---------------------------------------------------------------------------*/
uip_ds6_nbr_t *
uip_ds6_get_least_lifetime_neighbor(void)
{
uip_ds6_nbr_t *nbr = uip_ds6_nbr_head();
uip_ds6_nbr_t *nbr_expiring = NULL;
while(nbr != NULL) {
if(nbr_expiring != NULL) {
clock_time_t curr = stimer_remaining(&nbr->reachable);
if(curr < stimer_remaining(&nbr->reachable)) {
nbr_expiring = nbr;
}
} else {
nbr_expiring = nbr;
}
nbr = uip_ds6_nbr_next(nbr);
}
return nbr_expiring;
}
#endif /* UIP_ND6_SEND_NS */
/*---------------------------------------------------------------------------*/
/** @} */
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