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RIOT/sys/net/gnrc/network_layer/ndp/gnrc_ndp.c

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/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for
* more details.
*/
/**
* @ingroup net_gnrc_ndp
* @{
*
* @file
*
* @author Martine Lenders <mlenders@inf.fu-berlin.de>
*/
#include <errno.h>
#include <string.h>
#include "byteorder.h"
#include "net/fib.h"
#include "net/ieee802154.h"
#include "net/ipv6/ext/rh.h"
#include "net/gnrc/icmpv6.h"
#include "net/gnrc/ipv6.h"
#include "net/gnrc/sixlowpan/nd.h"
#include "net/gnrc.h"
#include "net/sixlowpan/nd.h"
#include "random.h"
#include "utlist.h"
#include "thread.h"
#include "xtimer.h"
#include "net/gnrc/ndp/internal.h"
#include "net/gnrc/ndp.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#if ENABLE_DEBUG
/* For PRIu8 etc. */
#include <inttypes.h>
static char addr_str[IPV6_ADDR_MAX_STR_LEN];
#endif
/* sets an entry to stale if its l2addr differs from the given one or creates it stale if it
* does not exist */
static void _stale_nc(kernel_pid_t iface, ipv6_addr_t *ipaddr, uint8_t *l2addr,
int l2addr_len)
{
if (l2addr_len != -ENOTSUP) {
gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, ipaddr);
if (nc_entry == NULL) {
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
/* tentative type see https://tools.ietf.org/html/rfc6775#section-6.3 */
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
if ((ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) &&
(ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER)) {
if ((nc_entry = gnrc_ipv6_nc_add(iface, ipaddr, l2addr,
(uint16_t)l2addr_len,
GNRC_IPV6_NC_STATE_STALE |
GNRC_IPV6_NC_TYPE_TENTATIVE)) != NULL) {
xtimer_set_msg(&nc_entry->type_timeout,
(GNRC_SIXLOWPAN_ND_TENTATIVE_NCE_LIFETIME * US_PER_SEC),
&nc_entry->type_timeout_msg,
gnrc_ipv6_pid);
}
return;
}
#endif
gnrc_ipv6_nc_add(iface, ipaddr, l2addr, (uint16_t)l2addr_len,
GNRC_IPV6_NC_STATE_STALE);
}
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
/* unreachable set in gnrc_ndp_retrans_nbr_sol() will just be staled */
else if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_UNREACHABLE) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
#endif
else if (((uint16_t)l2addr_len != nc_entry->l2_addr_len) ||
(memcmp(l2addr, nc_entry->l2_addr, l2addr_len) != 0)) {
/* if entry exists but l2 address differs: set */
nc_entry->l2_addr_len = (uint16_t)l2addr_len;
memcpy(nc_entry->l2_addr, l2addr, l2addr_len);
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
}
}
void gnrc_ndp_nbr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_nbr_sol_t *nbr_sol,
size_t icmpv6_size)
{
uint16_t opt_offset = 0;
uint8_t l2src[GNRC_IPV6_NC_L2_ADDR_MAX];
uint8_t *buf = ((uint8_t *)nbr_sol) + sizeof(ndp_nbr_sol_t);
ipv6_addr_t *tgt, nbr_adv_dst;
gnrc_pktsnip_t *nbr_adv_opts = NULL;
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
ndp_opt_t *sl2a_opt = NULL;
sixlowpan_nd_opt_ar_t *ar_opt = NULL;
#endif
int sicmpv6_size = (int)icmpv6_size, l2src_len = 0;
DEBUG("ndp: received neighbor solicitation (src: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG("dst: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG("tgt: %s)\n",
ipv6_addr_to_str(addr_str, &nbr_sol->tgt, sizeof(addr_str)));
/* check validity */
if ((ipv6->hl != 255) || (nbr_sol->code != 0) ||
(icmpv6_size < sizeof(ndp_nbr_sol_t)) ||
ipv6_addr_is_multicast(&nbr_sol->tgt) ||
(ipv6_addr_is_unspecified(&ipv6->src) &&
ipv6_addr_is_solicited_node(&ipv6->dst))) {
DEBUG("ndp: neighbor solicitation was invalid.\n");
/* icmpv6 releases */
return;
}
if ((tgt = gnrc_ipv6_netif_find_addr(iface, &nbr_sol->tgt)) == NULL) {
DEBUG("ndp: Target address is not to interface %" PRIkernel_pid "\n",
iface);
/* icmpv6 releases */
return;
}
sicmpv6_size -= sizeof(ndp_nbr_sol_t);
while (sicmpv6_size > 0) {
ndp_opt_t *opt = (ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NDP_OPT_SL2A:
if ((l2src_len = gnrc_ndp_internal_sl2a_opt_handle(pkt, ipv6, nbr_sol->type, opt,
l2src)) < 0) {
/* -ENOTSUP can not happen, since the function only returns this for invalid
* message types containing the SL2A. Neighbor solicitations are not an
* invalid message type for SL2A. According to that, we don't need to watch
* out for that here, but regardless, the source link-layer address option
* is invalid. */
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
sl2a_opt = opt;
break;
case NDP_OPT_AR:
/* actually handling at the end of the function (see below) */
ar_opt = (sixlowpan_nd_opt_ar_t *)opt;
#endif
break;
default:
/* silently discard all other options */
break;
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
#if ENABLE_DEBUG
if (sicmpv6_size < 0) {
DEBUG("ndp: Option parsing out of sync.\n");
}
#endif
}
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
assert(ipv6_iface != NULL);
if ((sl2a_opt != NULL) && (ar_opt != NULL) &&
(ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) &&
(ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER)) {
uint8_t status = gnrc_sixlowpan_nd_opt_ar_handle(iface, ipv6,
nbr_sol->type,
&ipv6->src, ar_opt,
l2src, l2src_len);
/* check for multihop DAD return */
nbr_adv_opts = gnrc_sixlowpan_nd_opt_ar_build(status, GNRC_SIXLOWPAN_ND_AR_LTIME,
&ar_opt->eui64, NULL);
if (status == 0) {
memcpy(&nbr_adv_dst, &ipv6->src, sizeof(ipv6_addr_t));
}
else {
/* see https://tools.ietf.org/html/rfc6775#section-6.5.2 */
eui64_t iid;
ieee802154_get_iid(&iid, ar_opt->eui64.uint8, sizeof(eui64_t));
ipv6_addr_set_aiid(&nbr_adv_dst, iid.uint8);
ipv6_addr_set_link_local_prefix(&nbr_adv_dst);
}
}
else { /* gnrc_sixlowpan_nd_opt_ar_handle updates neighbor cache */
_stale_nc(iface, &ipv6->src, l2src, l2src_len);
memcpy(&nbr_adv_dst, &ipv6->src, sizeof(ipv6_addr_t));
}
#else
_stale_nc(iface, &ipv6->src, l2src, l2src_len);
memcpy(&nbr_adv_dst, &ipv6->src, sizeof(ipv6_addr_t));
#endif
gnrc_ndp_internal_send_nbr_adv(iface, tgt, &nbr_adv_dst, ipv6_addr_is_multicast(&ipv6->dst),
nbr_adv_opts);
}
static inline bool _pkt_has_l2addr(gnrc_netif_hdr_t *netif_hdr)
{
return (netif_hdr != NULL) && (netif_hdr->src_l2addr_len != 0) &&
(netif_hdr->dst_l2addr_len != 0);
}
void gnrc_ndp_nbr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_nbr_adv_t *nbr_adv,
size_t icmpv6_size)
{
uint16_t opt_offset = 0;
uint8_t *buf = ((uint8_t *)nbr_adv) + sizeof(ndp_nbr_adv_t);
int l2tgt_len = 0;
uint8_t l2tgt[GNRC_IPV6_NC_L2_ADDR_MAX];
int sicmpv6_size = (int)icmpv6_size;
gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, &nbr_adv->tgt);
gnrc_pktsnip_t *netif;
gnrc_netif_hdr_t *netif_hdr = NULL;
DEBUG("ndp: received neighbor advertisement (src: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG("dst: %s, ",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG("tgt: %s)\n",
ipv6_addr_to_str(addr_str, &nbr_adv->tgt, sizeof(addr_str)));
/* check validity */
if ((ipv6->hl != 255) || (nbr_adv->code != 0) ||
(icmpv6_size < sizeof(ndp_nbr_adv_t)) ||
ipv6_addr_is_multicast(&nbr_adv->tgt)) {
DEBUG("ndp: neighbor advertisement was invalid.\n");
/* icmpv6 releases */
return;
}
if (nc_entry == NULL) {
/* see https://tools.ietf.org/html/rfc4861#section-7.2.5 */
DEBUG("ndp: no neighbor cache entry found for advertisement's target\n");
/* icmpv6 releases */
return;
}
sicmpv6_size -= sizeof(ndp_nbr_adv_t);
while (sicmpv6_size > 0) {
ndp_opt_t *opt = (ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NDP_OPT_TL2A:
if ((l2tgt_len = gnrc_ndp_internal_tl2a_opt_handle(pkt, ipv6, nbr_adv->type, opt, l2tgt)) < 0) {
/* invalid target link-layer address option */
return;
}
break;
#ifdef MODULE_GNRC_SIXLOWPAN_ND
case NDP_OPT_AR:
/* address registration option is always ignored when invalid */
gnrc_sixlowpan_nd_opt_ar_handle(iface, ipv6, nbr_adv->type,
&nbr_adv->tgt,
(sixlowpan_nd_opt_ar_t *)opt,
NULL, 0);
break;
#endif
default:
/* silently discard all other options */
break;
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
#if ENABLE_DEBUG
if (sicmpv6_size < 0) {
DEBUG("ndp: Option parsing out of sync.\n");
}
#endif
}
netif = gnrc_pktsnip_search_type(pkt, GNRC_NETTYPE_NETIF);
if (netif != NULL) {
netif_hdr = netif->data;
}
if (l2tgt_len != -ENOTSUP) {
#ifdef MODULE_GNRC_SIXLOWPAN_ND
/* check if entry wasn't removed by ARO, ideally there should not be any TL2A in here */
nc_entry = gnrc_ipv6_nc_get(iface, &nbr_adv->tgt);
if (nc_entry == NULL) {
return;
}
#endif
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_INCOMPLETE) {
if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len == 0)) {
/* link-layer has addresses, but no TLLAO supplied: discard silently
* (see https://tools.ietf.org/html/rfc4861#section-7.2.5) */
return;
}
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_REACHABLE);
}
else {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= GNRC_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
/* TODO: update state of neighbor as router in FIB? */
}
#ifdef MODULE_GNRC_NDP_NODE
gnrc_pktqueue_t *queued_pkt;
while ((queued_pkt = gnrc_pktqueue_remove_head(&nc_entry->pkts)) != NULL) {
if (gnrc_netapi_send(gnrc_ipv6_pid, queued_pkt->pkt) < 1) {
DEBUG("ndp: unable to send queued packet\n");
gnrc_pktbuf_release(queued_pkt->pkt);
}
queued_pkt->pkt = NULL;
}
#endif
}
else {
/* first or-term: no link-layer, but nc_entry has l2addr,
* second or-term: different l2addr cached */
bool l2tgt_changed = false;
if ((!_pkt_has_l2addr(netif_hdr)) && (l2tgt_len == 0)) {
/* there was previously a L2 address registered */
l2tgt_changed = (nc_entry->l2_addr_len != 0);
}
/* link-layer has addresses and TLLAO with different address */
else if (_pkt_has_l2addr(netif_hdr) && (l2tgt_len != 0)) {
l2tgt_changed = (!(l2tgt_len == nc_entry->l2_addr_len)) &&
(memcmp(nc_entry->l2_addr, l2tgt, l2tgt_len) == 0);
}
if ((nbr_adv->flags & NDP_NBR_ADV_FLAGS_O) || !l2tgt_changed ||
(l2tgt_len == 0)) {
if (l2tgt_len != 0) {
nc_entry->iface = iface;
nc_entry->l2_addr_len = l2tgt_len;
memcpy(nc_entry->l2_addr, l2tgt, l2tgt_len);
}
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_REACHABLE);
}
else if (l2tgt_changed) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
if (nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= GNRC_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
/* TODO: update state of neighbor as router in FIB? */
}
}
else if (l2tgt_changed &&
gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_REACHABLE) {
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
}
}
}
return;
}
#if (defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_ROUTER))
void gnrc_ndp_rtr_sol_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt,
ipv6_hdr_t *ipv6, ndp_rtr_sol_t *rtr_sol,
size_t icmpv6_size)
{
gnrc_ipv6_netif_t *if_entry = gnrc_ipv6_netif_get(iface);
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER) {
gnrc_ipv6_nc_t *nc_entry;
int sicmpv6_size = (int)icmpv6_size, l2src_len = 0;
uint8_t l2src[GNRC_IPV6_NC_L2_ADDR_MAX];
uint16_t opt_offset = 0;
uint8_t *buf = (uint8_t *)(rtr_sol + 1);
/* check validity */
if ((ipv6->hl != 255) || (rtr_sol->code != 0) ||
(icmpv6_size < sizeof(ndp_rtr_sol_t))) {
DEBUG("ndp: router solicitation was invalid\n");
return;
}
sicmpv6_size -= sizeof(ndp_rtr_sol_t);
while (sicmpv6_size > 0) {
ndp_opt_t *opt = (ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NDP_OPT_SL2A:
l2src_len = gnrc_ndp_internal_sl2a_opt_handle(pkt, ipv6,
rtr_sol->type,
opt, l2src);
if (l2src_len < 0) {
/* -ENOTSUP can not happen */
/* invalid source link-layer address option */
return;
}
_stale_nc(iface, &ipv6->src, l2src, l2src_len);
break;
default:
/* silently discard all other options */
break;
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
#if ENABLE_DEBUG
if (sicmpv6_size < 0) {
DEBUG("ndp: Option parsing out of sync.\n");
}
#endif
}
/* send delayed */
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_RTR_ADV) {
uint32_t delay;
uint32_t ms = GNRC_NDP_MAX_RTR_ADV_DELAY;
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) {
ms = GNRC_SIXLOWPAN_ND_MAX_RTR_ADV_DELAY;
}
#endif
delay = random_uint32_range(0, ms);
xtimer_remove(&if_entry->rtr_adv_timer);
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
/* in case of a 6LBR we have to check if the interface is actually
* the 6lo interface */
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) {
gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
if (nc_entry != NULL) {
if_entry->rtr_adv_msg.type = GNRC_NDP_MSG_RTR_ADV_SIXLOWPAN_DELAY;
if_entry->rtr_adv_msg.content.ptr = nc_entry;
xtimer_set_msg(&if_entry->rtr_adv_timer, delay, &if_entry->rtr_adv_msg,
gnrc_ipv6_pid);
}
}
#elif defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_BORDER_ROUTER)
if (ipv6_addr_is_unspecified(&ipv6->src)) {
/* either multicast, if source unspecified */
if_entry->rtr_adv_msg.type = GNRC_NDP_MSG_RTR_ADV_RETRANS;
if_entry->rtr_adv_msg.content.ptr = if_entry;
xtimer_set_msg(&if_entry->rtr_adv_timer, delay, &if_entry->rtr_adv_msg,
gnrc_ipv6_pid);
}
else {
/* or unicast, if source is known */
/* XXX: can't just use GNRC_NETAPI_MSG_TYPE_SND, since the next retransmission
* must also be set. */
nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
if (nc_entry) {
xtimer_set_msg(&nc_entry->rtr_adv_timer, delay, &nc_entry->rtr_adv_msg,
gnrc_ipv6_pid);
}
}
#endif
}
nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
if (nc_entry != NULL) {
/* unset isRouter flag
* (https://tools.ietf.org/html/rfc4861#section-6.2.6) */
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
}
}
/* otherwise ignore silently */
}
#endif
static inline void _set_reach_time(gnrc_ipv6_netif_t *if_entry, uint32_t mean)
{
uint32_t reach_time = random_uint32_range(GNRC_NDP_MIN_RAND, GNRC_NDP_MAX_RAND);
if_entry->reach_time_base = mean;
/* to avoid floating point number computation and have higher value entropy, the
* boundaries for the random value are multiplied by 10 and we need to account for that */
reach_time = (reach_time * if_entry->reach_time_base) / 10;
if_entry->reach_time = reach_time;
}
void gnrc_ndp_rtr_adv_handle(kernel_pid_t iface, gnrc_pktsnip_t *pkt, ipv6_hdr_t *ipv6,
ndp_rtr_adv_t *rtr_adv, size_t icmpv6_size)
{
uint8_t *buf = (uint8_t *)(rtr_adv + 1);
gnrc_ipv6_nc_t *nc_entry = NULL;
gnrc_ipv6_netif_t *if_entry = gnrc_ipv6_netif_get(iface);
uint8_t l2src[GNRC_IPV6_NC_L2_ADDR_MAX];
#ifdef MODULE_GNRC_SIXLOWPAN_ND
uint32_t next_rtr_sol = 0;
#endif
int sicmpv6_size = (int)icmpv6_size, l2src_len = 0;
uint16_t opt_offset = 0;
if (!ipv6_addr_is_link_local(&ipv6->src) ||
ipv6_addr_is_multicast(&ipv6->src) ||
(ipv6->hl != 255) || (rtr_adv->code != 0) ||
(icmpv6_size < sizeof(ndp_rtr_adv_t))) {
DEBUG("ndp: router advertisement was invalid\n");
/* icmpv6 releases */
return;
}
/* get source from default router list */
nc_entry = gnrc_ipv6_nc_get(iface, &ipv6->src);
if (nc_entry == NULL) { /* not in default router list */
/* create default router list entry */
nc_entry = gnrc_ipv6_nc_add(iface, &ipv6->src, NULL, 0,
GNRC_IPV6_NC_STATE_STALE | GNRC_IPV6_NC_IS_ROUTER);
if (nc_entry == NULL) {
DEBUG("ndp: error on default router list entry creation\n");
return;
}
}
else if ((nc_entry->flags & GNRC_IPV6_NC_IS_ROUTER) && (byteorder_ntohs(rtr_adv->ltime) == 0)) {
nc_entry->flags &= ~GNRC_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags |= GNRC_IPV6_NC_IS_ROUTER;
}
/* set router life timer */
if (rtr_adv->ltime.u16 != 0) {
uint16_t ltime = byteorder_ntohs(rtr_adv->ltime);
#ifdef MODULE_GNRC_SIXLOWPAN_ND
next_rtr_sol = ltime;
#endif
xtimer_set_msg(&nc_entry->rtr_timeout, (ltime * US_PER_SEC),
&nc_entry->rtr_timeout_msg, thread_getpid());
}
/* set current hop limit from message if available */
if (rtr_adv->cur_hl != 0) {
if_entry->cur_hl = rtr_adv->cur_hl;
}
/* set flags from message */
if_entry->flags &= ~GNRC_IPV6_NETIF_FLAGS_RTR_ADV_MASK;
if_entry->flags |= (rtr_adv->flags << GNRC_IPV6_NETIF_FLAGS_RTR_ADV_POS) &
GNRC_IPV6_NETIF_FLAGS_RTR_ADV_MASK;
/* set reachable time from message if it is not the same as the random base
* value */
if ((rtr_adv->reach_time.u32 != 0) &&
(if_entry->reach_time_base != byteorder_ntohl(rtr_adv->reach_time))) {
_set_reach_time(if_entry, byteorder_ntohl(rtr_adv->reach_time));
}
/* set retransmission timer from message */
if (rtr_adv->retrans_timer.u32 != 0) {
if_entry->retrans_timer = byteorder_ntohl(rtr_adv->retrans_timer);
}
mutex_unlock(&if_entry->mutex);
sicmpv6_size -= sizeof(ndp_rtr_adv_t);
/* parse options */
while (sicmpv6_size > 0) {
ndp_opt_t *opt = (ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NDP_OPT_SL2A:
if ((l2src_len = gnrc_ndp_internal_sl2a_opt_handle(pkt, ipv6, rtr_adv->type, opt,
l2src)) < 0) {
/* -ENOTSUP can not happen */
/* invalid source link-layer address option */
return;
}
break;
case NDP_OPT_MTU:
if (!gnrc_ndp_internal_mtu_opt_handle(iface, rtr_adv->type, (ndp_opt_mtu_t *)opt)) {
/* invalid MTU option */
return;
}
break;
case NDP_OPT_PI:
if (!gnrc_ndp_internal_pi_opt_handle(iface, rtr_adv->type, (ndp_opt_pi_t *)opt)) {
/* invalid prefix information option */
return;
}
#ifdef MODULE_GNRC_SIXLOWPAN_ND
uint32_t valid_ltime = byteorder_ntohl(((ndp_opt_pi_t *)opt)->valid_ltime);
if ((valid_ltime != 0) && (valid_ltime < next_rtr_sol)) {
next_rtr_sol = valid_ltime;
}
#endif
break;
#ifdef MODULE_GNRC_SIXLOWPAN_ND
case NDP_OPT_6CTX:
if (!gnrc_sixlowpan_nd_opt_6ctx_handle(rtr_adv->type,
(sixlowpan_nd_opt_6ctx_t *)opt)) {
/* invalid 6LoWPAN context option */
return;
}
uint16_t ltime = byteorder_ntohs(((sixlowpan_nd_opt_6ctx_t *)opt)->ltime);
if ((ltime != 0) && (ltime < (next_rtr_sol / 60))) {
next_rtr_sol = ltime * 60;
}
break;
#endif
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
case NDP_OPT_ABR:
gnrc_sixlowpan_nd_opt_abr_handle(iface, rtr_adv, icmpv6_size,
(sixlowpan_nd_opt_abr_t *)opt);
break;
#endif
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
#if ENABLE_DEBUG
if (sicmpv6_size < 0) {
DEBUG("ndp: Option parsing out of sync.\n");
}
#endif
}
#if ENABLE_DEBUG && defined(MODULE_GNRC_SIXLOWPAN_ND)
if ((if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) && (l2src_len <= 0)) {
DEBUG("ndp: Router advertisement did not contain any source address information\n");
}
#endif
_stale_nc(iface, &ipv6->src, l2src, l2src_len);
/* stop multicast router solicitation retransmission timer */
xtimer_remove(&if_entry->rtr_sol_timer);
#ifdef MODULE_GNRC_SIXLOWPAN_ND
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) {
/* 3/4 of the time should be "well before" enough the respective timeout
* not to run out; see https://tools.ietf.org/html/rfc6775#section-5.4.3 */
next_rtr_sol *= 3;
next_rtr_sol = (next_rtr_sol > 4) ? (next_rtr_sol >> 2) : 1;
/* according to https://tools.ietf.org/html/rfc6775#section-5.3:
* "In all cases, the RS retransmissions are terminated when an RA is
* received."
* Hence, reset router solicitation counter and reset timer. */
if_entry->rtr_sol_count = 0;
gnrc_sixlowpan_nd_rtr_sol_reschedule(nc_entry, next_rtr_sol);
gnrc_ndp_internal_send_nbr_sol(nc_entry->iface, NULL, &nc_entry->ipv6_addr,
&nc_entry->ipv6_addr);
if (if_entry->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER) {
gnrc_ipv6_netif_set_rtr_adv(if_entry, true);
}
}
#endif
}
void gnrc_ndp_retrans_nbr_sol(gnrc_ipv6_nc_t *nc_entry)
{
if ((gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_INCOMPLETE) ||
(gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_PROBE)) {
if (nc_entry->probes_remaining > 1) {
ipv6_addr_t dst;
DEBUG("ndp: Retransmit neighbor solicitation for %s\n",
ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)));
/* retransmit neighbor solicatation */
if (gnrc_ipv6_nc_get_state(nc_entry) == GNRC_IPV6_NC_STATE_INCOMPLETE) {
ipv6_addr_set_solicited_nodes(&dst, &nc_entry->ipv6_addr);
}
else {
dst.u64[0] = nc_entry->ipv6_addr.u64[0];
dst.u64[1] = nc_entry->ipv6_addr.u64[1];
}
nc_entry->probes_remaining--;
if (nc_entry->iface == KERNEL_PID_UNDEF) {
kernel_pid_t ifs[GNRC_NETIF_NUMOF];
size_t ifnum = gnrc_netif_get(ifs);
for (size_t i = 0; i < ifnum; i++) {
gnrc_ndp_internal_send_nbr_sol(ifs[i], NULL, &nc_entry->ipv6_addr, &dst);
}
gnrc_ndp_internal_reset_nbr_sol_timer(nc_entry, GNRC_NDP_RETRANS_TIMER,
GNRC_NDP_MSG_NBR_SOL_RETRANS, gnrc_ipv6_pid);
}
else {
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(nc_entry->iface);
gnrc_ndp_internal_send_nbr_sol(nc_entry->iface, NULL, &nc_entry->ipv6_addr, &dst);
mutex_lock(&ipv6_iface->mutex);
gnrc_ndp_internal_reset_nbr_sol_timer(nc_entry, ipv6_iface->retrans_timer,
GNRC_NDP_MSG_NBR_SOL_RETRANS, gnrc_ipv6_pid);
mutex_unlock(&ipv6_iface->mutex);
}
}
else if (nc_entry->probes_remaining <= 1) {
/* For a 6LoWPAN router entries may be set to UNREACHABLE instead
* of removing them, since RFC6775, section 6
* (https://tools.ietf.org/html/rfc6775#section-6) says: "if NUD on
* the router determines that the host is UNREACHABLE (based on the
* logic in [RFC4861]), the NCE SHOULD NOT be deleted but rather
* retained until the Registration Lifetime expires." However, this
* "SHOULD NOT" is not implemented to circumvent NCEs going into
* UNREACHABLE forever and in order to save some memory in the
* neighbor cache. */
DEBUG("ndp: Remove nc entry %s for interface %" PRIkernel_pid "\n",
ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)),
nc_entry->iface);
gnrc_ipv6_nc_remove(nc_entry->iface, &nc_entry->ipv6_addr);
}
}
}
void gnrc_ndp_state_timeout(gnrc_ipv6_nc_t *nc_entry)
{
switch (gnrc_ipv6_nc_get_state(nc_entry)) {
case GNRC_IPV6_NC_STATE_REACHABLE:
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_STALE);
break;
case GNRC_IPV6_NC_STATE_DELAY:
gnrc_ndp_internal_set_state(nc_entry, GNRC_IPV6_NC_STATE_PROBE);
break;
default:
break;
}
}
void gnrc_ndp_netif_add(gnrc_ipv6_netif_t *iface)
{
/* set default values */
mutex_lock(&iface->mutex);
_set_reach_time(iface, GNRC_NDP_REACH_TIME);
iface->retrans_timer = GNRC_NDP_RETRANS_TIMER;
mutex_unlock(&iface->mutex);
}
void gnrc_ndp_netif_remove(gnrc_ipv6_netif_t *iface)
{
/* TODO */
(void) iface;
}
gnrc_pktsnip_t *gnrc_ndp_nbr_sol_build(ipv6_addr_t *tgt, gnrc_pktsnip_t *options)
{
gnrc_pktsnip_t *pkt;
DEBUG("ndp: building neighbor solicitation message\n");
if (ipv6_addr_is_multicast(tgt)) {
DEBUG("ndp: tgt must not be multicast\n");
return NULL;
}
pkt = gnrc_icmpv6_build(options, ICMPV6_NBR_SOL, 0, sizeof(ndp_nbr_sol_t));
if (pkt != NULL) {
ndp_nbr_sol_t *nbr_sol = pkt->data;
nbr_sol->resv.u32 = 0;
nbr_sol->tgt.u64[0].u64 = tgt->u64[0].u64;
nbr_sol->tgt.u64[1].u64 = tgt->u64[1].u64;
}
return pkt;
}
gnrc_pktsnip_t *gnrc_ndp_nbr_adv_build(uint8_t flags, ipv6_addr_t *tgt,
gnrc_pktsnip_t *options)
{
gnrc_pktsnip_t *pkt;
DEBUG("ndp: building neighbor advertisement message\n");
if (ipv6_addr_is_multicast(tgt)) {
DEBUG("ndp: tgt must not be multicast\n");
return NULL;
}
pkt = gnrc_icmpv6_build(options, ICMPV6_NBR_ADV, 0, sizeof(ndp_nbr_adv_t));
if (pkt != NULL) {
ndp_nbr_adv_t *nbr_adv = pkt->data;
nbr_adv->flags = (flags & NDP_NBR_ADV_FLAGS_MASK);
nbr_adv->resv[0] = nbr_adv->resv[1] = nbr_adv->resv[2] = 0;
nbr_adv->tgt.u64[0].u64 = tgt->u64[0].u64;
nbr_adv->tgt.u64[1].u64 = tgt->u64[1].u64;
}
return pkt;
}
gnrc_pktsnip_t *gnrc_ndp_rtr_sol_build(gnrc_pktsnip_t *options)
{
gnrc_pktsnip_t *pkt;
DEBUG("ndp: building router solicitation message\n");
pkt = gnrc_icmpv6_build(options, ICMPV6_RTR_SOL, 0, sizeof(ndp_rtr_sol_t));
if (pkt != NULL) {
ndp_rtr_sol_t *rtr_sol = pkt->data;
rtr_sol->resv.u32 = 0;
}
return pkt;
}
static inline size_t _ceil8(uint8_t length)
{
/* NDP options use units of 8 byte for there length field, so round up */
return (length + 7U) & 0xf8U;
}
gnrc_pktsnip_t *gnrc_ndp_opt_build(uint8_t type, size_t size, gnrc_pktsnip_t *next)
{
ndp_opt_t *opt;
gnrc_pktsnip_t *pkt = gnrc_pktbuf_add(next, NULL, _ceil8(size), GNRC_NETTYPE_UNDEF);
if (pkt == NULL) {
DEBUG("ndp: no space left in packet buffer\n");
return NULL;
}
opt = pkt->data;
opt->type = type;
opt->len = (uint8_t)(pkt->size / 8);
return pkt;
}
static inline gnrc_pktsnip_t *_opt_l2a_build(uint8_t type, const uint8_t *l2addr,
uint8_t l2addr_len, gnrc_pktsnip_t *next)
{
gnrc_pktsnip_t *pkt = gnrc_ndp_opt_build(type, sizeof(ndp_opt_t) + l2addr_len, next);
if (pkt != NULL) {
ndp_opt_t *l2a_opt = pkt->data;
memset(l2a_opt + 1, 0, pkt->size - sizeof(ndp_opt_t));
memcpy(l2a_opt + 1, l2addr, l2addr_len);
}
return pkt;
}
gnrc_pktsnip_t *gnrc_ndp_opt_sl2a_build(const uint8_t *l2addr, uint8_t l2addr_len,
gnrc_pktsnip_t *next)
{
DEBUG("ndp: building source link-layer address option (l2addr: %s)\n",
gnrc_netif_addr_to_str(addr_str, sizeof(addr_str), l2addr, l2addr_len));
return _opt_l2a_build(NDP_OPT_SL2A, l2addr, l2addr_len, next);
}
gnrc_pktsnip_t *gnrc_ndp_opt_tl2a_build(const uint8_t *l2addr, uint8_t l2addr_len,
gnrc_pktsnip_t *next)
{
DEBUG("ndp: building target link-layer address option (l2addr: %s)\n",
gnrc_netif_addr_to_str(addr_str, sizeof(addr_str), l2addr, l2addr_len));
return _opt_l2a_build(NDP_OPT_TL2A, l2addr, l2addr_len, next);
}
#if (defined(MODULE_GNRC_NDP_ROUTER) || defined(MODULE_GNRC_SIXLOWPAN_ND_ROUTER))
gnrc_pktsnip_t *gnrc_ndp_rtr_adv_build(uint8_t cur_hl, uint8_t flags,
uint16_t ltime, uint32_t reach_time,
uint32_t retrans_timer, gnrc_pktsnip_t *options)
{
gnrc_pktsnip_t *pkt;
DEBUG("ndp rtr: building router advertisement message\n");
pkt = gnrc_icmpv6_build(options, ICMPV6_RTR_ADV, 0, sizeof(ndp_rtr_adv_t));
if (pkt != NULL) {
ndp_rtr_adv_t *rtr_adv = pkt->data;
rtr_adv->cur_hl = cur_hl;
rtr_adv->flags = (flags & NDP_RTR_ADV_FLAGS_MASK);
rtr_adv->ltime = byteorder_htons(ltime);
rtr_adv->reach_time = byteorder_htonl(reach_time);
rtr_adv->retrans_timer = byteorder_htonl(retrans_timer);
}
return pkt;
}
gnrc_pktsnip_t *gnrc_ndp_opt_pi_build(uint8_t prefix_len, uint8_t flags,
uint32_t valid_ltime, uint32_t pref_ltime,
ipv6_addr_t *prefix, gnrc_pktsnip_t *next)
{
gnrc_pktsnip_t *pkt = gnrc_ndp_opt_build(NDP_OPT_PI, sizeof(ndp_opt_pi_t),
next);
if (pkt != NULL) {
ndp_opt_pi_t *pi_opt = pkt->data;
pi_opt->prefix_len = prefix_len;
pi_opt->flags = (flags & NDP_OPT_PI_FLAGS_MASK);
pi_opt->valid_ltime = byteorder_htonl(valid_ltime);
pi_opt->pref_ltime = byteorder_htonl(pref_ltime);
pi_opt->resv.u32 = 0;
/* Bits beyond prefix_len MUST be 0 */
ipv6_addr_set_unspecified(&pi_opt->prefix);
ipv6_addr_init_prefix(&pi_opt->prefix, prefix, prefix_len);
}
return pkt;
}
gnrc_pktsnip_t *gnrc_ndp_opt_mtu_build(uint32_t mtu, gnrc_pktsnip_t *next)
{
gnrc_pktsnip_t *pkt = gnrc_ndp_opt_build(NDP_OPT_MTU, sizeof(ndp_opt_mtu_t),
next);
if (pkt != NULL) {
ndp_opt_mtu_t *mtu_opt = pkt->data;
mtu_opt->resv.u16 = 0;
mtu_opt->mtu = byteorder_htonl(mtu);
}
return pkt;
}
#endif
/**
* @}
*/