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RIOT/sys/net/gnrc/network_layer/ipv6/nib/nib.c
Martine Lenders b970d00064 gnrc_ipv6_nib: check if pkt is NULL on error 
According to the documentation of `gnrc_ipv6_nib_get_next_hop_l2addr()`
`pkt` may be `NULL`. However, whenever that function sends an error
message (the methods for that require `orig_pkt` not to be NULL) `pkt`
is not checked, which may lead to failed assertions.
2019-03-14 14:29:13 +01:00

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/*
* Copyright (C) 2017 Freie Universität Berlin
*
* 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.
*/
/**
* @{
*
* @file
* @author Martine Lenders <m.lenders@fu-berlin.de>
*/
#include <errno.h>
#include <stdbool.h>
#include "log.h"
#include "net/ipv6/addr.h"
#include "net/gnrc/icmpv6/error.h"
#include "net/gnrc/nettype.h"
#include "net/gnrc/netif/internal.h"
#include "net/gnrc/ipv6/nib.h"
#include "net/gnrc/ndp.h"
#include "net/gnrc/pktqueue.h"
#include "net/gnrc/sixlowpan/nd.h"
#include "net/ndp.h"
#include "net/sixlowpan/nd.h"
#if GNRC_IPV6_NIB_CONF_DNS
#include "net/sock/dns.h"
#endif
#include "_nib-internal.h"
#include "_nib-arsm.h"
#include "_nib-router.h"
#include "_nib-6ln.h"
#include "_nib-6lr.h"
#include "_nib-slaac.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#if ENABLE_DEBUG
#include "xtimer.h"
#endif
static char addr_str[IPV6_ADDR_MAX_STR_LEN];
#if GNRC_IPV6_NIB_CONF_QUEUE_PKT
static gnrc_pktqueue_t _queue_pool[GNRC_IPV6_NIB_NUMOF];
#endif /* GNRC_IPV6_NIB_CONF_QUEUE_PKT */
#if GNRC_IPV6_NIB_CONF_DNS
static evtimer_msg_event_t _rdnss_timeout;
#endif
/**
* @internal
* @{
*/
#if GNRC_IPV6_NIB_CONF_ROUTER
static void _handle_rtr_sol(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_rtr_sol_t *rtr_sol, size_t icmpv6_len);
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
static void _handle_rtr_adv(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_rtr_adv_t *rtr_adv, size_t icmpv6_len);
static void _handle_nbr_sol(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_nbr_sol_t *nbr_sol, size_t icmpv6_len);
static void _handle_nbr_adv(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_nbr_adv_t *nbr_adv, size_t icmpv6_len);
static bool _resolve_addr(const ipv6_addr_t *dst, gnrc_netif_t *netif,
gnrc_pktsnip_t *pkt, gnrc_ipv6_nib_nc_t *nce,
_nib_onl_entry_t *entry);
static void _handle_pfx_timeout(_nib_offl_entry_t *pfx);
static void _handle_rtr_timeout(_nib_dr_entry_t *router);
static void _handle_snd_na(gnrc_pktsnip_t *pkt);
/* needs to be exported for 6LN's ARO handling */
void _handle_search_rtr(gnrc_netif_t *netif);
#if GNRC_IPV6_NIB_CONF_DNS
static void _handle_rdnss_timeout(sock_udp_ep_t *dns_server);
#endif
/** @} */
void gnrc_ipv6_nib_init(void)
{
evtimer_event_t *tmp;
mutex_lock(&_nib_mutex);
for (evtimer_event_t *ptr = _nib_evtimer.events;
(ptr != NULL) && (tmp = (ptr->next), 1);
ptr = tmp) {
evtimer_del((evtimer_t *)(&_nib_evtimer), ptr);
}
_nib_init();
mutex_unlock(&_nib_mutex);
}
void gnrc_ipv6_nib_init_iface(gnrc_netif_t *netif)
{
assert(netif != NULL);
DEBUG("nib: Initialize interface %u\n", netif->pid);
gnrc_netif_acquire(netif);
_init_iface_arsm(netif);
netif->ipv6.retrans_time = NDP_RETRANS_TIMER_MS;
#if GNRC_IPV6_NIB_CONF_SLAAC || GNRC_IPV6_NIB_CONF_6LN
/* TODO: set differently dependent on GNRC_IPV6_NIB_CONF_SLAAC if
* alternatives exist */
netif->ipv6.aac_mode = GNRC_NETIF_AAC_AUTO;
#endif /* GNRC_IPV6_NIB_CONF_SLAAC || GNRC_IPV6_NIB_CONF_6LN */
_init_iface_router(netif);
#if GNRC_IPV6_NIB_CONF_6LN
netif->ipv6.rs_sent = 0;
#endif /* GNRC_IPV6_NIB_CONF_6LN */
if (netif->device_type == NETDEV_TYPE_IEEE802154) {
/* see https://tools.ietf.org/html/rfc6775#section-5.2 */
uint16_t src_len = IEEE802154_LONG_ADDRESS_LEN;
gnrc_netapi_opt_t opt = { .opt = NETOPT_SRC_LEN,
.data = &src_len,
.data_len = sizeof(src_len) };
/* XXX we are supposed to be in interface context here, so use driver
* directly everything else would deadlock anyway */
netif->ops->set(netif, &opt);
}
netif->ipv6.na_sent = 0;
if (gnrc_netif_ipv6_group_join_internal(netif,
&ipv6_addr_all_nodes_link_local) < 0) {
DEBUG("nib: Can't join link-local all-nodes on interface %u\n",
netif->pid);
gnrc_netif_release(netif);
return;
}
_auto_configure_addr(netif, &ipv6_addr_link_local_prefix, 64U);
if (!(gnrc_netif_is_rtr_adv(netif)) ||
(gnrc_netif_is_6ln(netif) && !gnrc_netif_is_6lbr(netif))) {
uint32_t next_rs_time = random_uint32_range(0, NDP_MAX_RS_MS_DELAY);
_evtimer_add(netif, GNRC_IPV6_NIB_SEARCH_RTR, &netif->ipv6.search_rtr,
next_rs_time);
}
#if GNRC_IPV6_NIB_CONF_ROUTER
else {
_handle_snd_mc_ra(netif);
}
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
gnrc_netif_release(netif);
}
static bool _on_link(const ipv6_addr_t *dst, unsigned *iface)
{
_nib_offl_entry_t *entry = NULL;
#if GNRC_IPV6_NIB_CONF_6LN
if (*iface != 0) {
if (gnrc_netif_is_6ln(gnrc_netif_get_by_pid(*iface))) {
return ipv6_addr_is_link_local(dst);
}
}
#endif /* GNRC_IPV6_NIB_CONF_6LN */
while ((entry = _nib_offl_iter(entry))) {
if ((entry->mode & _PL) && (entry->flags & _PFX_ON_LINK) &&
(ipv6_addr_match_prefix(dst, &entry->pfx) >= entry->pfx_len)) {
*iface = _nib_onl_get_if(entry->next_hop);
return true;
}
}
return ipv6_addr_is_link_local(dst);
}
int gnrc_ipv6_nib_get_next_hop_l2addr(const ipv6_addr_t *dst,
gnrc_netif_t *netif, gnrc_pktsnip_t *pkt,
gnrc_ipv6_nib_nc_t *nce)
{
int res = 0;
DEBUG("nib: get next hop link-layer address of %s%%%u\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)),
(netif != NULL) ? (unsigned)netif->pid : 0U);
gnrc_netif_acquire(netif);
mutex_lock(&_nib_mutex);
do { /* XXX: hidden goto ;-) */
_nib_onl_entry_t *node = _nib_onl_get(dst,
(netif == NULL) ? 0 : netif->pid);
/* consider neighbor cache entries first */
unsigned iface = (node == NULL) ? 0 : _nib_onl_get_if(node);
if ((node != NULL) || _on_link(dst, &iface)) {
DEBUG("nib: %s is on-link or in NC, start address resolution\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
/* on-link prefixes return their interface */
if (!ipv6_addr_is_link_local(dst) && (iface != 0)) {
/* release preassumed interface */
gnrc_netif_release(netif);
netif = gnrc_netif_get_by_pid(iface);
gnrc_netif_acquire(netif);
}
if ((netif == NULL) ||
!_resolve_addr(dst, netif, pkt, nce, node)) {
DEBUG("nib: host unreachable\n");
/* _resolve_addr releases pkt only if not queued (in which case
* we also shouldn't release), but if netif is not defined we
* should release in any case. */
if ((netif == NULL) && (pkt != NULL)) {
gnrc_icmpv6_error_dst_unr_send(ICMPV6_ERROR_DST_UNR_ADDR,
pkt);
gnrc_pktbuf_release_error(pkt, EHOSTUNREACH);
}
res = -EHOSTUNREACH;
break;
}
}
else {
gnrc_ipv6_nib_ft_t route;
DEBUG("nib: %s is off-link, resolve route\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
res = _nib_get_route(dst, pkt, &route);
if ((res < 0) || ipv6_addr_is_unspecified(&route.next_hop)) {
DEBUG("nib: no route to %s found or is prefix list entry, "
"search neighbor cache\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
if (res == 0) {
DEBUG("nib: prefix list entry => taking dst as next hop\n");
memcpy(&route.next_hop, dst, sizeof(route.next_hop));
}
else {
res = -ENETUNREACH;
if (pkt != NULL) {
gnrc_icmpv6_error_dst_unr_send(
ICMPV6_ERROR_DST_UNR_NO_ROUTE,
pkt
);
gnrc_pktbuf_release_error(pkt, ENETUNREACH);
}
break;
}
}
if ((netif != NULL) && (netif->pid != (int)route.iface)) {
/* drop pre-assumed netif */
gnrc_netif_release(netif);
}
if ((netif == NULL) || (netif->pid != (int)route.iface)) {
/* get actual netif */
netif = gnrc_netif_get_by_pid(route.iface);
gnrc_netif_acquire(netif);
}
node = _nib_onl_get(&route.next_hop,
(netif != NULL) ? netif->pid : 0);
if (_resolve_addr(&route.next_hop, netif, pkt, nce, node)) {
_call_route_info_cb(netif,
GNRC_IPV6_NIB_ROUTE_INFO_TYPE_RN,
&route.dst,
(void *)((intptr_t)route.dst_len));
#if GNRC_IPV6_NIB_CONF_DC
_nib_dc_add(&route.next_hop, netif->pid, dst);
#endif /* GNRC_IPV6_NIB_CONF_DC */
}
else {
/* _resolve_addr releases pkt if not queued (in which case
* we also shouldn't release */
res = -EHOSTUNREACH;
}
}
} while (0);
mutex_unlock(&_nib_mutex);
gnrc_netif_release(netif);
return res;
}
void gnrc_ipv6_nib_handle_pkt(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const icmpv6_hdr_t *icmpv6, size_t icmpv6_len)
{
DEBUG("nib: Handle packet (icmpv6->type = %u)\n", icmpv6->type);
assert(netif != NULL);
gnrc_netif_acquire(netif);
mutex_lock(&_nib_mutex);
switch (icmpv6->type) {
#if GNRC_IPV6_NIB_CONF_ROUTER
case ICMPV6_RTR_SOL:
_handle_rtr_sol(netif, ipv6, (ndp_rtr_sol_t *)icmpv6, icmpv6_len);
break;
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
case ICMPV6_RTR_ADV:
_handle_rtr_adv(netif, ipv6, (ndp_rtr_adv_t *)icmpv6, icmpv6_len);
break;
case ICMPV6_NBR_SOL:
_handle_nbr_sol(netif, ipv6, (ndp_nbr_sol_t *)icmpv6, icmpv6_len);
break;
case ICMPV6_NBR_ADV:
_handle_nbr_adv(netif, ipv6, (ndp_nbr_adv_t *)icmpv6, icmpv6_len);
break;
#if GNRC_IPV6_NIB_CONF_REDIRECT
case ICMPV6_REDIRECT:
/* TODO */
break;
#endif /* GNRC_IPV6_NIB_CONF_REDIRECT */
#if GNRC_IPV6_NIB_CONF_MULTIHOP_DAD
case ICMPV6_DAR:
/* TODO */
break;
case ICMPV6_DAC:
/* TODO */
break;
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_DAD */
}
mutex_unlock(&_nib_mutex);
gnrc_netif_release(netif);
}
void gnrc_ipv6_nib_handle_timer_event(void *ctx, uint16_t type)
{
DEBUG("nib: Handle timer event (ctx = %p, type = 0x%04x, now = %ums)\n",
ctx, type, (unsigned)xtimer_now_usec() / 1000);
mutex_lock(&_nib_mutex);
switch (type) {
#if GNRC_IPV6_NIB_CONF_ARSM
case GNRC_IPV6_NIB_SND_UC_NS:
case GNRC_IPV6_NIB_SND_MC_NS:
_handle_snd_ns(ctx);
break;
case GNRC_IPV6_NIB_REACH_TIMEOUT:
case GNRC_IPV6_NIB_DELAY_TIMEOUT:
_handle_state_timeout(ctx);
break;
case GNRC_IPV6_NIB_RECALC_REACH_TIME:
_recalc_reach_time(ctx);
break;
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
case GNRC_IPV6_NIB_SND_NA:
_handle_snd_na(ctx);
break;
case GNRC_IPV6_NIB_SEARCH_RTR:
_handle_search_rtr(ctx);
break;
#if GNRC_IPV6_NIB_CONF_ROUTER
case GNRC_IPV6_NIB_REPLY_RS:
_handle_reply_rs(ctx);
break;
case GNRC_IPV6_NIB_SND_MC_RA:
_handle_snd_mc_ra(ctx);
break;
case GNRC_IPV6_NIB_ROUTE_TIMEOUT:
_nib_ft_remove(ctx);
break;
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
#if GNRC_IPV6_NIB_CONF_6LR
case GNRC_IPV6_NIB_ADDR_REG_TIMEOUT:
_nib_nc_remove(ctx);
break;
#endif /* GNRC_IPV6_NIB_CONF_6LR */
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
case GNRC_IPV6_NIB_ABR_TIMEOUT:
_nib_abr_remove(&((_nib_abr_entry_t *)ctx)->addr);
break;
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
case GNRC_IPV6_NIB_PFX_TIMEOUT:
_handle_pfx_timeout(ctx);
break;
case GNRC_IPV6_NIB_RTR_TIMEOUT:
_handle_rtr_timeout(ctx);
break;
#if GNRC_IPV6_NIB_CONF_6LN
case GNRC_IPV6_NIB_REREG_ADDRESS:
_handle_rereg_address(ctx);
break;
#endif /* GNRC_IPV6_NIB_CONF_6LN */
case GNRC_IPV6_NIB_DAD:
_handle_dad(ctx);
break;
case GNRC_IPV6_NIB_VALID_ADDR:
_handle_valid_addr(ctx);
break;
#if GNRC_IPV6_NIB_CONF_DNS
case GNRC_IPV6_NIB_RDNSS_TIMEOUT:
_handle_rdnss_timeout(ctx);
#endif
default:
break;
}
mutex_unlock(&_nib_mutex);
}
#if GNRC_IPV6_NIB_CONF_ROUTER
void gnrc_ipv6_nib_change_rtr_adv_iface(gnrc_netif_t *netif, bool enable)
{
gnrc_netif_acquire(netif);
if (enable) {
_set_rtr_adv(netif);
}
else {
uint32_t next_rs_time = random_uint32_range(0, NDP_MAX_RS_MS_DELAY);
netif->ipv6.ra_sent = (UINT8_MAX - NDP_MAX_FIN_RA_NUMOF) + 1;
netif->flags &= ~GNRC_NETIF_FLAGS_IPV6_RTR_ADV;
/* send final router advertisements */
_handle_snd_mc_ra(netif);
_evtimer_add(netif, GNRC_IPV6_NIB_SEARCH_RTR, &netif->ipv6.search_rtr,
next_rs_time);
}
gnrc_netif_release(netif);
}
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
/*
* @internal
* @{
*/
static void _handle_mtuo(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_mtu_t *mtuo);
#if GNRC_IPV6_NIB_CONF_DNS
static uint32_t _handle_rdnsso(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_rdnss_t *rdnsso);
#endif
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
static uint32_t _handle_pio(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_pi_t *pio,
_nib_abr_entry_t *abr);
#else /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
static uint32_t _handle_pio(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_pi_t *pio);
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
/** @} */
/* Iterator for NDP options in a packet */
#define FOREACH_OPT(ndp_pkt, opt, icmpv6_len) \
for (opt = (ndp_opt_t *)(ndp_pkt + 1); \
icmpv6_len > 0; \
icmpv6_len -= (opt->len << 3), \
opt = (ndp_opt_t *)(((uint8_t *)opt) + (opt->len << 3)))
#if GNRC_IPV6_NIB_CONF_ROUTER
static void _handle_rtr_sol(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_rtr_sol_t *rtr_sol, size_t icmpv6_len)
{
size_t tmp_len = icmpv6_len - sizeof(ndp_rtr_sol_t);
_nib_onl_entry_t *nce = NULL;
ndp_opt_t *opt;
uint32_t next_ra_delay = random_uint32_range(0, NDP_MAX_RA_DELAY);
assert(netif != NULL);
/* check validity, see: https://tools.ietf.org/html/rfc4861#section-6.1.1 */
/* checksum is checked by GNRC's ICMPv6 module */
if (!(gnrc_netif_is_rtr(netif)) || (ipv6->hl != 255U) ||
(rtr_sol->code != 0U) || (icmpv6_len < sizeof(ndp_rtr_sol_t))) {
DEBUG("nib: Received router solicitation is invalid (or interface %i "
"is not a forwarding interface). Discarding silently\n",
netif->pid);
DEBUG(" - IP Hop Limit: %u (should be 255)\n", ipv6->hl);
DEBUG(" - ICMP code: %u (should be 0)\n", rtr_sol->code);
DEBUG(" - ICMP length: %u (should > %u)\n", (unsigned)icmpv6_len,
(unsigned)sizeof(ndp_rtr_sol_t));
return;
}
/* pre-check option length */
FOREACH_OPT(rtr_sol, opt, tmp_len) {
if (tmp_len > icmpv6_len) {
DEBUG("nib: Payload length (%u) of RS doesn't align with options\n",
(unsigned)icmpv6_len);
return;
}
if (opt->len == 0U) {
DEBUG("nib: Option of length 0 detected. "
"Discarding router solicitation silently\n");
return;
}
if ((opt->type == NDP_OPT_SL2A) &&
ipv6_addr_is_unspecified(&ipv6->src)) {
DEBUG("nib: RS contains SLLAO, but source was unspecfied. "
"Discarding router solicitation silently\n");
return;
}
}
DEBUG("nib: Received valid router solicitation:\n");
DEBUG(" - Source address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Destination address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
if (!ipv6_addr_is_unspecified(&ipv6->src)) {
tmp_len = icmpv6_len - sizeof(ndp_rtr_sol_t);
FOREACH_OPT(rtr_sol, opt, tmp_len) {
switch (opt->type) {
case NDP_OPT_SL2A:
if (!gnrc_netif_is_6ln(netif)) {
_handle_sl2ao(netif, ipv6, (const icmpv6_hdr_t *)rtr_sol,
opt);
}
break;
default:
break;
}
}
nce = _nib_onl_get(&ipv6->src, netif->pid);
}
if (!gnrc_netif_is_6ln(netif)) {
uint32_t next_ra_scheduled = _evtimer_lookup(netif,
GNRC_IPV6_NIB_SND_MC_RA);
if (next_ra_scheduled < next_ra_delay) {
DEBUG("nib: There is a MC RA scheduled within the next %" PRIu32 "ms. "
"Using that to advertise router\n", next_ra_scheduled);
return;
}
else if (nce != NULL) {
/* we send unicast RAs so we do not need to rate-limit as
* https://tools.ietf.org/html/rfc4861#section-6.2.6 asks for */
_evtimer_add(nce, GNRC_IPV6_NIB_REPLY_RS, &nce->reply_rs,
next_ra_delay);
}
else {
uint32_t now = (xtimer_now_usec64() / MS_PER_SEC) & UINT32_MAX;
/* check for integer overflows and initial value of last_ra */
if (((netif->ipv6.last_ra > (UINT32_MAX - NDP_MIN_MS_DELAY_BETWEEN_RAS) &&
(now < NDP_MIN_MS_DELAY_BETWEEN_RAS))) ||
((now - NDP_MIN_MS_DELAY_BETWEEN_RAS) > netif->ipv6.last_ra)) {
next_ra_delay += NDP_MIN_MS_DELAY_BETWEEN_RAS;
}
_evtimer_add(netif, GNRC_IPV6_NIB_SND_MC_RA, &netif->ipv6.snd_mc_ra,
next_ra_delay);
}
}
#if GNRC_IPV6_NIB_CONF_6LR
else if (gnrc_netif_is_rtr(netif) && gnrc_netif_is_rtr_adv(netif)) {
_snd_rtr_advs(netif, &ipv6->src, false);
}
#endif /* GNRC_IPV6_NIB_CONF_6LR */
}
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
static inline uint32_t _min(uint32_t a, uint32_t b)
{
return (a < b) ? a : b;
}
static void _handle_rtr_adv(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_rtr_adv_t *rtr_adv, size_t icmpv6_len)
{
size_t tmp_len = icmpv6_len - sizeof(ndp_rtr_adv_t);
_nib_dr_entry_t *dr = NULL;
ndp_opt_t *opt;
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
sixlowpan_nd_opt_abr_t *abro = NULL;
_nib_abr_entry_t *abr = NULL;
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
uint32_t next_timeout = UINT32_MAX;
assert(netif != NULL);
/* check validity, see: https://tools.ietf.org/html/rfc4861#section-6.1.1 */
/* checksum is checked by GNRC's ICMPv6 module */
if (!(ipv6_addr_is_link_local(&ipv6->src)) ||
(ipv6->hl != 255U) || (rtr_adv->code != 0U) ||
(icmpv6_len < sizeof(ndp_rtr_adv_t)) ||
(!gnrc_netif_is_6ln(netif) &&
(byteorder_ntohs(rtr_adv->ltime) > NDP_RTR_ADV_LTIME_SEC_MAX))) {
DEBUG("nib: Received router advertisement is invalid. "
"Discarding silently\n");
DEBUG(" - IP Hop Limit: %u (should be 255)\n", ipv6->hl);
DEBUG(" - ICMP code: %u (should be 0)\n", rtr_adv->code);
DEBUG(" - ICMP length: %u (should > %u)\n", (unsigned)icmpv6_len,
(unsigned)sizeof(ndp_rtr_adv_t));
DEBUG(" - Source address: %s (should be link-local)\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Router lifetime: %u (should be <= 9000 on non-6LN)\n",
byteorder_ntohs(rtr_adv->ltime));
return;
}
/* pre-check option length */
FOREACH_OPT(rtr_adv, opt, tmp_len) {
if (tmp_len > icmpv6_len) {
DEBUG("nib: Payload length (%u) of RA doesn't align with options\n",
(unsigned)icmpv6_len);
return;
}
if (opt->len == 0U) {
DEBUG("nib: Option of length 0 detected. "
"Discarding router advertisement silently\n");
return;
}
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
if (opt->type == NDP_OPT_ABR) {
if (abro != NULL) {
DEBUG("nib: More than one ABRO. "
"Discarding router advertisement silently\n");
return;
}
abro = (sixlowpan_nd_opt_abr_t *)opt;
}
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
}
DEBUG("nib: Received valid router advertisement:\n");
DEBUG(" - Source address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Destination address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG(" - Cur Hop Limit: %u\n", rtr_adv->cur_hl);
DEBUG(" - Flags: %c%c\n",
(rtr_adv->flags & NDP_RTR_ADV_FLAGS_M) ? 'M' : '-',
(rtr_adv->flags & NDP_RTR_ADV_FLAGS_O) ? 'O' : '-');
DEBUG(" - Router Lifetime: %us\n", byteorder_ntohs(rtr_adv->ltime));
DEBUG(" - Reachable Time: %" PRIu32 "ms\n",
byteorder_ntohl(rtr_adv->reach_time));
DEBUG(" - Retrans Timer: %" PRIu32 "ms\n",
byteorder_ntohl(rtr_adv->retrans_timer));
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
if (abro != NULL) {
if ((abr = _handle_abro(abro)) == NULL) {
DEBUG("nib: could not allocate space for new border router or "
"there is no new information in the RA. "
"Discarding silently\n");
return;
}
/* UINT16_MAX * 60 * 1000 < UINT32_MAX so there are no overflows */
next_timeout = _min(next_timeout,
byteorder_ntohs(abro->ltime) * SEC_PER_MIN *
MS_PER_SEC);
}
#if !GNRC_IPV6_NIB_CONF_6LBR
else if (gnrc_netif_is_6lr(netif)) {
DEBUG("nib: multihop prefix and context dissemination on router activated,\n"
" but no ABRO found. Discarding router advertisement silently\n");
return;
}
#endif /* !GNRC_IPV6_NIB_CONF_6LBR */
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
if (rtr_adv->ltime.u16 != 0) {
uint16_t rtr_ltime = byteorder_ntohs(rtr_adv->ltime);
dr = _nib_drl_add(&ipv6->src, netif->pid);
if (dr != NULL) {
_evtimer_add(dr, GNRC_IPV6_NIB_RTR_TIMEOUT, &dr->rtr_timeout,
rtr_ltime * MS_PER_SEC);
}
else {
DEBUG("nib: default router list is full. Ignoring RA from %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
return;
}
/* UINT16_MAX * 1000 < UINT32_MAX so there are no overflows */
next_timeout = _min(next_timeout, rtr_ltime * MS_PER_SEC);
}
else {
dr = _nib_drl_get(&ipv6->src, netif->pid);
DEBUG("nib: router lifetime was 0. Removing router and routes via it.");
if (dr != NULL) {
_handle_rtr_timeout(dr);
}
dr = NULL;
}
if (rtr_adv->cur_hl != 0) {
netif->cur_hl = rtr_adv->cur_hl;
}
#if GNRC_IPV6_NIB_CONF_ARSM
if (rtr_adv->reach_time.u32 != 0) {
uint32_t reach_time = byteorder_ntohl(rtr_adv->reach_time);
if (reach_time != netif->ipv6.reach_time_base) {
_evtimer_add(netif, GNRC_IPV6_NIB_RECALC_REACH_TIME,
&netif->ipv6.recalc_reach_time,
GNRC_IPV6_NIB_CONF_REACH_TIME_RESET);
netif->ipv6.reach_time_base = reach_time;
_recalc_reach_time(&netif->ipv6);
}
}
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
if (rtr_adv->retrans_timer.u32 != 0) {
netif->ipv6.retrans_time = byteorder_ntohl(rtr_adv->retrans_timer);
}
#if GNRC_IPV6_NIB_CONF_6LN
if ((dr != NULL) && gnrc_netif_is_6ln(netif) &&
!gnrc_netif_is_6lbr(netif)) {
/* (register addresses already assigned but not valid yet)*/
for (int i = 0; i < GNRC_NETIF_IPV6_ADDRS_NUMOF; i++) {
if ((netif->ipv6.addrs_flags[i] != 0) &&
(netif->ipv6.addrs_flags[i] != GNRC_NETIF_IPV6_ADDRS_FLAGS_STATE_VALID)) {
_handle_rereg_address(&netif->ipv6.addrs[i]);
}
}
}
#endif /* GNRC_IPV6_NIB_CONF_6LN */
tmp_len = icmpv6_len - sizeof(ndp_rtr_adv_t);
FOREACH_OPT(rtr_adv, opt, tmp_len) {
switch (opt->type) {
case NDP_OPT_SL2A:
_handle_sl2ao(netif, ipv6, (const icmpv6_hdr_t *)rtr_adv,
opt);
break;
case NDP_OPT_MTU:
_handle_mtuo(netif, (const icmpv6_hdr_t *)rtr_adv,
(ndp_opt_mtu_t *)opt);
break;
case NDP_OPT_PI: {
uint32_t min_pfx_timeout;
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
min_pfx_timeout = _handle_pio(netif,
(const icmpv6_hdr_t *)rtr_adv,
(ndp_opt_pi_t *)opt, abr);
#else /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
min_pfx_timeout = _handle_pio(netif,
(const icmpv6_hdr_t *)rtr_adv,
(ndp_opt_pi_t *)opt);
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
next_timeout = _min(next_timeout, min_pfx_timeout);
break;
}
/* ABRO was already secured in the option check above */
#if GNRC_IPV6_NIB_CONF_6LN
case NDP_OPT_6CTX:
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
next_timeout = _min(_handle_6co((icmpv6_hdr_t *)rtr_adv,
(sixlowpan_nd_opt_6ctx_t *)opt,
abr), next_timeout);
#else /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
next_timeout = _min(_handle_6co((icmpv6_hdr_t *)rtr_adv,
(sixlowpan_nd_opt_6ctx_t *)opt),
next_timeout);
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
break;
#endif /* GNRC_IPV6_NIB_CONF_6LN */
#if GNRC_IPV6_NIB_CONF_DNS
case NDP_OPT_RDNSS:
next_timeout = _min(_handle_rdnsso(netif,
(icmpv6_hdr_t *)rtr_adv,
(ndp_opt_rdnss_t *)opt),
next_timeout);
break;
#endif
default:
break;
}
}
/* stop sending router solicitations
* see https://tools.ietf.org/html/rfc4861#section-6.3.7 */
evtimer_del(&_nib_evtimer, &netif->ipv6.search_rtr.event);
#if GNRC_IPV6_NIB_CONF_6LN
if (gnrc_netif_is_6ln(netif) && !gnrc_netif_is_6lbr(netif)) {
_set_rtr_adv(netif);
/* but re-fetch information from router in time */
_evtimer_add(netif, GNRC_IPV6_NIB_SEARCH_RTR,
&netif->ipv6.search_rtr, (next_timeout >> 2) * 3);
/* i.e. 3/4 of the time before the earliest expires */
}
#endif /* GNRC_IPV6_NIB_CONF_6LN */
}
static inline size_t _get_l2src(const gnrc_netif_t *netif, uint8_t *l2src)
{
#if GNRC_NETIF_L2ADDR_MAXLEN > 0
memcpy(l2src, netif->l2addr, netif->l2addr_len);
return netif->l2addr_len;
#else /* GNRC_NETIF_L2ADDR_MAXLEN > 0 */
(void)netif;
(void)l2src;
return 0;
#endif /* GNRC_NETIF_L2ADDR_MAXLEN > 0 */
}
static gnrc_pktsnip_t *_check_release_pkt(gnrc_pktsnip_t *pkt,
gnrc_pktsnip_t *payload)
{
if (pkt == NULL) {
DEBUG("nib: No space left in packet buffer. Not replying NS");
gnrc_pktbuf_release(payload);
}
return pkt;
}
static void _send_delayed_nbr_adv(const gnrc_netif_t *netif,
const ipv6_addr_t *tgt,
const ipv6_hdr_t *ipv6_hdr,
gnrc_pktsnip_t *payload)
{
gnrc_pktsnip_t *pkt;
_nib_onl_entry_t *nce;
uint8_t reply_flags = NDP_NBR_ADV_FLAGS_S;
nce = _nib_onl_get(tgt, netif->pid);
if ((nce == NULL) || !(nce->mode & _NC)) {
/* usually this should be the case, but when NCE is full, just
* ignore the sending. Other nodes in this anycast group are
* then preferred */
gnrc_pktbuf_release(payload);
return;
}
#if GNRC_IPV6_NIB_CONF_ROUTER
if (gnrc_netif_is_rtr(netif)) {
reply_flags |= NDP_NBR_ADV_FLAGS_R;
}
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
#if GNRC_NETIF_L2ADDR_MAXLEN > 0
if (ipv6_addr_is_multicast(&ipv6_hdr->dst)) {
uint8_t l2addr[GNRC_NETIF_L2ADDR_MAXLEN];
size_t l2addr_len = _get_l2src(netif, l2addr);
if (l2addr_len > 0) {
pkt = gnrc_ndp_opt_tl2a_build(l2addr, l2addr_len, payload);
if ((payload = _check_release_pkt(pkt, payload)) == NULL) {
return;
}
}
else {
reply_flags |= NDP_NBR_ADV_FLAGS_O;
}
}
else {
reply_flags |= NDP_NBR_ADV_FLAGS_O;
}
#else /* GNRC_NETIF_L2ADDR_MAXLEN > 0 */
reply_flags |= NDP_NBR_ADV_FLAGS_O;
#endif /* GNRC_NETIF_L2ADDR_MAXLEN > 0 */
/* discard const qualifier */
pkt = gnrc_ndp_nbr_adv_build(tgt, reply_flags, payload);
if ((payload = _check_release_pkt(pkt, payload)) == NULL) {
return;
}
pkt = gnrc_ipv6_hdr_build(payload, NULL, &ipv6_hdr->src);
if ((payload = _check_release_pkt(pkt, payload)) == NULL) {
return;
}
((ipv6_hdr_t *)payload->data)->hl = 255;
pkt = gnrc_netif_hdr_build(NULL, 0, NULL, 0);
if ((pkt = _check_release_pkt(pkt, payload)) == NULL) {
return;
}
((gnrc_netif_hdr_t *)pkt->data)->if_pid = netif->pid;
LL_PREPEND(payload, pkt);
_evtimer_add(pkt, GNRC_IPV6_NIB_SND_NA, &nce->snd_na,
random_uint32_range(0, NDP_MAX_ANYCAST_MS_DELAY));
}
static void _handle_nbr_sol(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_nbr_sol_t *nbr_sol, size_t icmpv6_len)
{
size_t tmp_len = icmpv6_len - sizeof(ndp_nbr_sol_t);
int tgt_idx;
ndp_opt_t *opt;
/* check validity, see: https://tools.ietf.org/html/rfc4861#section-7.1.1 */
/* checksum is checked by GNRC's ICMPv6 module */
if ((ipv6->hl != 255U) || (nbr_sol->code != 0U) ||
(icmpv6_len < 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("nib: Received neighbor solicitation is invalid. Discarding silently\n");
DEBUG(" - IP Hop Limit: %u (should be 255)\n", ipv6->hl);
DEBUG(" - ICMP code: %u (should be 0)\n", nbr_sol->code);
DEBUG(" - ICMP length: %u (should > %u)\n", (unsigned)icmpv6_len,
(unsigned)sizeof(ndp_nbr_sol_t));
DEBUG(" - Target address: %s (should not be multicast)\n",
ipv6_addr_to_str(addr_str, &nbr_sol->tgt, sizeof(addr_str)));
DEBUG(" - Source address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Destination address: %s (should be of format "
"ff02::1:ffxx:xxxx if source address is ::)\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
return;
}
/* check if target is assigned only now in case the length was wrong */
tgt_idx = gnrc_netif_ipv6_addr_idx(netif, &nbr_sol->tgt);
if (tgt_idx < 0) {
DEBUG("nib: Target address %s is not assigned to the local interface\n",
ipv6_addr_to_str(addr_str, &nbr_sol->tgt, sizeof(addr_str)));
return;
}
/* pre-check option length */
FOREACH_OPT(nbr_sol, opt, tmp_len) {
if (tmp_len > icmpv6_len) {
DEBUG("nib: Payload length (%u) of NS doesn't align with options\n",
(unsigned)icmpv6_len);
return;
}
if (opt->len == 0U) {
DEBUG("nib: Option of length 0 detected. "
"Discarding neighbor solicitation silently\n");
return;
}
}
DEBUG("nib: Received valid neighbor solicitation:\n");
DEBUG(" - Target address: %s\n",
ipv6_addr_to_str(addr_str, &nbr_sol->tgt, sizeof(addr_str)));
DEBUG(" - Source address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Destination address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
#if GNRC_IPV6_NIB_CONF_SLAAC
gnrc_netif_t *tgt_netif = gnrc_netif_get_by_ipv6_addr(&nbr_sol->tgt);
if (tgt_netif != NULL) {
int idx = gnrc_netif_ipv6_addr_idx(tgt_netif, &nbr_sol->tgt);
if (gnrc_netif_ipv6_addr_dad_trans(tgt_netif, idx)) {
if (!ipv6_addr_is_unspecified(&ipv6->src)) {
/* (see https://tools.ietf.org/html/rfc4862#section-5.4.3) */
DEBUG("nib: Neighbor is performing AR, but target address is "
"still TENTATIVE for us => Ignoring NS\n");
return;
}
/* cancel validation timer */
evtimer_del(&_nib_evtimer,
&tgt_netif->ipv6.addrs_timers[idx].event);
_remove_tentative_addr(tgt_netif, &nbr_sol->tgt);
return;
}
}
#endif /* GNRC_IPV6_NIB_CONF_SLAAC */
if (ipv6_addr_is_unspecified(&ipv6->src)) {
gnrc_ndp_nbr_adv_send(&nbr_sol->tgt, netif, &ipv6->src, false, NULL);
}
else {
gnrc_pktsnip_t *reply_aro = NULL;
#if GNRC_IPV6_NIB_CONF_6LR
ndp_opt_t *sl2ao = NULL;
sixlowpan_nd_opt_ar_t *aro = NULL;
#else /* GNRC_IPV6_NIB_CONF_6LR */
#define sl2ao (NULL)
#define aro (NULL)
#endif /* GNRC_IPV6_NIB_CONF_6LR */
tmp_len = icmpv6_len - sizeof(ndp_nbr_sol_t);
if (!(netif->flags & GNRC_NETIF_FLAGS_HAS_L2ADDR)) {
/* Set STALE NCE if link-layer has no addresses */
_nib_nc_add(&ipv6->src, netif->pid,
GNRC_IPV6_NIB_NC_INFO_NUD_STATE_STALE);
}
FOREACH_OPT(nbr_sol, opt, tmp_len) {
switch (opt->type) {
case NDP_OPT_SL2A:
#if GNRC_IPV6_NIB_CONF_6LR
if (gnrc_netif_is_6lr(netif)) {
DEBUG("nib: Storing SL2AO for later handling\n");
sl2ao = opt;
break;
}
#endif /* GNRC_IPV6_NIB_CONF_6LR */
_handle_sl2ao(netif, ipv6, (const icmpv6_hdr_t *)nbr_sol,
opt);
break;
#if GNRC_IPV6_NIB_CONF_6LR
case NDP_OPT_AR:
DEBUG("nib: Storing ARO for later handling\n");
aro = (sixlowpan_nd_opt_ar_t *)opt;
break;
#endif /* GNRC_IPV6_NIB_CONF_6LR */
default:
DEBUG("nib: Ignoring unrecognized option type %u for NS\n",
opt->type);
break;
}
}
reply_aro = _copy_and_handle_aro(netif, ipv6, nbr_sol, aro, sl2ao);
/* check if target address is anycast */
if (netif->ipv6.addrs_flags[tgt_idx] & GNRC_NETIF_IPV6_ADDRS_FLAGS_ANYCAST) {
_send_delayed_nbr_adv(netif, &nbr_sol->tgt, ipv6, reply_aro);
}
else {
gnrc_ndp_nbr_adv_send(&nbr_sol->tgt, netif, &ipv6->src,
ipv6_addr_is_multicast(&ipv6->dst),
reply_aro);
}
}
}
static void _handle_nbr_adv(gnrc_netif_t *netif, const ipv6_hdr_t *ipv6,
const ndp_nbr_adv_t *nbr_adv, size_t icmpv6_len)
{
size_t tmp_len = icmpv6_len - sizeof(ndp_nbr_adv_t);
ndp_opt_t *opt;
_nib_onl_entry_t *nce;
/* check validity, see: https://tools.ietf.org/html/rfc4861#section-7.1.2 */
/* checksum is checked by GNRC's ICMPv6 module */
if ((ipv6->hl != 255U) || (nbr_adv->code != 0U) ||
(icmpv6_len < sizeof(ndp_nbr_adv_t)) ||
ipv6_addr_is_multicast(&nbr_adv->tgt) ||
(ipv6_addr_is_multicast(&ipv6->dst) &&
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_S))) {
DEBUG("nib: Received neighbor advertisement is invalid. Discarding silently\n");
DEBUG(" - IP Hop Limit: %u (should be 255)\n", ipv6->hl);
DEBUG(" - ICMP code: %u (should be 0)\n", nbr_adv->code);
DEBUG(" - ICMP length: %u (should > %u)\n", (unsigned)icmpv6_len,
(unsigned)sizeof(ndp_nbr_adv_t));
DEBUG(" - Target address: %s (should not be multicast)\n",
ipv6_addr_to_str(addr_str, &nbr_adv->tgt, sizeof(addr_str)));
DEBUG(" - Destination address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG(" - Flags: %c%c%c (S must not be set if destination is multicast)\n",
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) ? 'R' : '-',
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) ? 'S' : '-',
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_O) ? 'O' : '-');
return;
}
/* pre-check option length */
FOREACH_OPT(nbr_adv, opt, tmp_len) {
if (tmp_len > icmpv6_len) {
DEBUG("nib: Payload length (%u) of NA doesn't align with options\n",
(unsigned)icmpv6_len);
return;
}
if (opt->len == 0U) {
DEBUG("nib: Option of length 0 detected. "
"Discarding neighbor advertisement silently\n");
return;
}
}
DEBUG("nib: Received valid neighbor advertisement:\n");
DEBUG(" - Target address: %s\n",
ipv6_addr_to_str(addr_str, &nbr_adv->tgt, sizeof(addr_str)));
DEBUG(" - Source address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG(" - Destination address: %s\n",
ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG(" - Flags: %c%c%c\n",
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_R) ? 'R' : '-',
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) ? 'S' : '-',
(nbr_adv->flags & NDP_NBR_ADV_FLAGS_O) ? 'O' : '-');
#if GNRC_IPV6_NIB_CONF_SLAAC
gnrc_netif_t *tgt_netif = gnrc_netif_get_by_ipv6_addr(&nbr_adv->tgt);
if (tgt_netif != NULL) {
int idx = gnrc_netif_ipv6_addr_idx(tgt_netif, &nbr_adv->tgt);
if (gnrc_netif_ipv6_addr_dad_trans(tgt_netif, idx)) {
/* cancel validation timer */
evtimer_del(&_nib_evtimer,
&tgt_netif->ipv6.addrs_timers[idx].event);
_remove_tentative_addr(tgt_netif, &nbr_adv->tgt);
return;
}
/* else case beyond scope of RFC4862:
* https://tools.ietf.org/html/rfc4862#section-5.4.4 */
}
#endif /* GNRC_IPV6_NIB_CONF_SLAAC */
if (((nce = _nib_onl_get(&nbr_adv->tgt, netif->pid)) != NULL) &&
(nce->mode & _NC)) {
#if GNRC_IPV6_NIB_CONF_ARSM
bool tl2ao_avail = false;
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
#if GNRC_IPV6_NIB_CONF_6LN
uint8_t aro_status = _ADDR_REG_STATUS_UNAVAIL;
#endif
tmp_len = icmpv6_len - sizeof(ndp_nbr_adv_t);
FOREACH_OPT(nbr_adv, opt, tmp_len) {
switch (opt->type) {
#if GNRC_IPV6_NIB_CONF_ARSM
case NDP_OPT_TL2A:
_handle_adv_l2(netif, nce, (icmpv6_hdr_t *)nbr_adv, opt);
tl2ao_avail = true;
break;
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
#if GNRC_IPV6_NIB_CONF_6LN
case NDP_OPT_AR:
aro_status = _handle_aro(netif, ipv6,
(const icmpv6_hdr_t *)nbr_adv,
(const sixlowpan_nd_opt_ar_t *)opt,
opt, nce);
break;
#endif /* GNRC_IPV6_NIB_CONF_6LN */
default:
DEBUG("nib: Ignoring unrecognized option type %u for NA\n",
opt->type);
}
}
#if GNRC_IPV6_NIB_CONF_ARSM
if (!tl2ao_avail && (nbr_adv->flags & NDP_NBR_ADV_FLAGS_S) &&
(_get_nud_state(nce) != GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE)) {
/* reachability confirmed without TL2AO */
_set_reachable(netif, nce);
}
if (!(netif->flags & GNRC_NETIF_FLAGS_HAS_L2ADDR)) {
_handle_adv_l2(netif, nce, (icmpv6_hdr_t *)nbr_adv, NULL);
}
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
#if GNRC_IPV6_NIB_CONF_SLAAC && GNRC_IPV6_NIB_CONF_6LN
/* 6Lo-ND duplicate address detection (DAD) was ignored by neighbor, try
* traditional DAD */
if ((aro_status == _ADDR_REG_STATUS_UNAVAIL) &&
gnrc_netif_is_6ln(netif)) {
_handle_dad(&ipv6->dst);
}
#elif GNRC_IPV6_NIB_CONF_6LN
(void)aro_status;
#endif
}
}
#if GNRC_IPV6_NIB_CONF_QUEUE_PKT
static gnrc_pktqueue_t *_alloc_queue_entry(gnrc_pktsnip_t *pkt)
{
for (int i = 0; i < GNRC_IPV6_NIB_NUMOF; i++) {
if (_queue_pool[i].pkt == NULL) {
_queue_pool[i].pkt = pkt;
return &_queue_pool[i];
}
}
return NULL;
}
#endif /* GNRC_IPV6_NIB_CONF_QUEUE_PKT */
static bool _resolve_addr(const ipv6_addr_t *dst, gnrc_netif_t *netif,
gnrc_pktsnip_t *pkt, gnrc_ipv6_nib_nc_t *nce,
_nib_onl_entry_t *entry)
{
bool res = false;
if ((netif != NULL) && (netif->device_type == NETDEV_TYPE_SLIP)) {
/* XXX: Linux doesn't do neighbor discovery for SLIP so no use sending
* NS and since SLIP doesn't have link-layer addresses anyway, we can
* just return the interface without any link-layer addresses */
memcpy(&nce->ipv6, dst, sizeof(nce->ipv6));
nce->info = (netif->pid << _NIB_IF_POS);
nce->l2addr_len = 0;
return true;
}
#if GNRC_IPV6_NIB_CONF_ARSM
if ((entry != NULL) && (entry->mode & _NC) && _is_reachable(entry)) {
if (_get_nud_state(entry) == GNRC_IPV6_NIB_NC_INFO_NUD_STATE_STALE) {
_set_nud_state(netif, entry, GNRC_IPV6_NIB_NC_INFO_NUD_STATE_DELAY);
_evtimer_add(entry, GNRC_IPV6_NIB_DELAY_TIMEOUT,
&entry->nud_timeout, NDP_DELAY_FIRST_PROBE_MS);
}
DEBUG("nib: resolve address %s%%%u from neighbor cache\n",
ipv6_addr_to_str(addr_str, &entry->ipv6, sizeof(addr_str)),
_nib_onl_get_if(entry));
_nib_nc_get(entry, nce);
res = true;
}
#else /* GNRC_IPV6_NIB_CONF_ARSM */
if (entry != NULL) {
DEBUG("nib: resolve address %s%%%u from neighbor cache\n",
ipv6_addr_to_str(addr_str, &entry->ipv6, sizeof(addr_str)),
_nib_onl_get_if(entry));
_nib_nc_get(entry, nce);
res = true;
}
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
else if (!(res = _resolve_addr_from_ipv6(dst, netif, nce))) {
#if GNRC_IPV6_NIB_CONF_ARSM
bool reset = false;
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
DEBUG("nib: resolve address %s by probing neighbors\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
if ((entry == NULL) || !(entry->mode & _NC)) {
entry = _nib_nc_add(dst, (netif != NULL) ? netif->pid : 0,
GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE);
if (entry == NULL) {
gnrc_pktbuf_release(pkt);
return false;
}
#if GNRC_IPV6_NIB_CONF_ROUTER
if (netif != NULL) {
_call_route_info_cb(netif,
GNRC_IPV6_NIB_ROUTE_INFO_TYPE_NSC,
dst,
(void *)GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE);
}
#endif /* GNRC_IPV6_NIB_CONF_ROUTER */
#if GNRC_IPV6_NIB_CONF_ARSM
reset = true;
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
}
#if GNRC_IPV6_NIB_CONF_ARSM
else if (_get_nud_state(entry) == GNRC_IPV6_NIB_NC_INFO_NUD_STATE_UNREACHABLE) {
/* reduce back-off to possibly resolve neighbor sooner again */
entry->ns_sent = 3;
}
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
if (pkt != NULL) {
#if GNRC_IPV6_NIB_CONF_QUEUE_PKT
if (_get_nud_state(entry) == GNRC_IPV6_NIB_NC_INFO_NUD_STATE_INCOMPLETE) {
gnrc_pktqueue_t *queue_entry = _alloc_queue_entry(pkt);
if (queue_entry != NULL) {
if (netif != NULL) {
gnrc_pktsnip_t *netif_hdr = gnrc_netif_hdr_build(
NULL, 0, NULL, 0
);
if (netif_hdr == NULL) {
DEBUG("nib: can't allocate netif header for queue\n");
gnrc_pktbuf_release(pkt);
queue_entry->pkt = NULL;
return false;
}
((gnrc_netif_hdr_t *)netif_hdr->data)->if_pid = netif->pid;
LL_PREPEND(queue_entry->pkt, netif_hdr);
}
gnrc_pktqueue_add(&entry->pktqueue, queue_entry);
}
else {
DEBUG("nib: can't allocate entry for packet queue "
"dropping packet\n");
gnrc_pktbuf_release(pkt);
return false;
}
}
/* pkt != NULL already checked above */
else {
gnrc_icmpv6_error_dst_unr_send(ICMPV6_ERROR_DST_UNR_ADDR,
pkt);
gnrc_pktbuf_release_error(pkt, EHOSTUNREACH);
}
#else /* GNRC_IPV6_NIB_CONF_QUEUE_PKT */
gnrc_icmpv6_error_dst_unr_send(ICMPV6_ERROR_DST_UNR_ADDR,
pkt);
gnrc_pktbuf_release_error(pkt, EHOSTUNREACH);
#endif /* GNRC_IPV6_NIB_CONF_QUEUE_PKT */
}
#if GNRC_IPV6_NIB_CONF_ARSM
_probe_nbr(entry, reset);
#endif /* GNRC_IPV6_NIB_CONF_ARSM */
}
return res;
}
static void _handle_snd_na(gnrc_pktsnip_t *pkt)
{
#ifdef MODULE_GNRC_IPV6
DEBUG("nib: Send delayed neighbor advertisement\n");
if (!gnrc_netapi_dispatch_send(GNRC_NETTYPE_IPV6, GNRC_NETREG_DEMUX_CTX_ALL,
pkt)) {
DEBUG("nib: No receivers for neighbor advertisement\n");
gnrc_pktbuf_release_error(pkt, EBADF);
}
#else /* MODULE_GNRC_IPV6 */
(void)pkt;
DEBUG("nib: No IPv6 module to send delayed neighbor advertisement\n");
#endif /* MODULE_GNRC_IPV6 */
}
static void _handle_pfx_timeout(_nib_offl_entry_t *pfx)
{
gnrc_netif_t *netif = gnrc_netif_get_by_pid(_nib_onl_get_if(pfx->next_hop));
uint32_t now = (xtimer_now_usec64() / US_PER_MS) & UINT32_MAX;
gnrc_netif_acquire(netif);
if (now >= pfx->valid_until) {
evtimer_del(&_nib_evtimer, &pfx->pfx_timeout.event);
for (int i = 0; i < GNRC_NETIF_IPV6_ADDRS_NUMOF; i++) {
if (ipv6_addr_match_prefix(&netif->ipv6.addrs[i],
&pfx->pfx) >= pfx->pfx_len) {
gnrc_netif_ipv6_addr_remove_internal(netif,
&netif->ipv6.addrs[i]);
}
}
pfx->mode &= ~_PL;
_nib_offl_clear(pfx);
}
else if (now >= pfx->pref_until) {
for (int i = 0; i < GNRC_NETIF_IPV6_ADDRS_NUMOF; i++) {
if (ipv6_addr_match_prefix(&netif->ipv6.addrs[i],
&pfx->pfx) >= pfx->pfx_len) {
netif->ipv6.addrs_flags[i] &= ~GNRC_NETIF_IPV6_ADDRS_FLAGS_STATE_MASK;
netif->ipv6.addrs_flags[i] |= GNRC_NETIF_IPV6_ADDRS_FLAGS_STATE_DEPRECATED;
}
}
_evtimer_add(pfx, GNRC_IPV6_NIB_PFX_TIMEOUT, &pfx->pfx_timeout,
pfx->valid_until - now);
}
gnrc_netif_release(netif);
}
static void _handle_rtr_timeout(_nib_dr_entry_t *router)
{
if ((router->next_hop != NULL) && (router->next_hop->mode & _DRL)) {
_nib_offl_entry_t *route = NULL;
unsigned iface = _nib_onl_get_if(router->next_hop);
ipv6_addr_t addr;
memcpy(&addr, &router->next_hop, sizeof(addr));
_nib_drl_remove(router);
/* also remove all routes to that router */
while ((route = _nib_offl_iter(route))) {
if ((route->next_hop != NULL) &&
(_nib_onl_get_if(route->next_hop) == iface) &&
(ipv6_addr_equal(&route->next_hop->ipv6, &addr))) {
route->mode = _EMPTY;
route->next_hop->mode &= ~_DST;
_nib_offl_clear(route);
/* XXX routing protocol get's informed in case NUD
* determines ipv6->src (still in neighbor cache) to be
* unreachable */
}
}
}
}
void _handle_search_rtr(gnrc_netif_t *netif)
{
#if !GNRC_IPV6_NIB_CONF_NO_RTR_SOL
gnrc_netif_acquire(netif);
if (!(gnrc_netif_is_rtr_adv(netif)) || gnrc_netif_is_6ln(netif)) {
uint32_t next_rs = _evtimer_lookup(netif, GNRC_IPV6_NIB_SEARCH_RTR);
uint32_t interval = _get_next_rs_interval(netif);
if (next_rs > interval) {
gnrc_ndp_rtr_sol_send(netif, &ipv6_addr_all_routers_link_local);
if (netif->ipv6.rs_sent < 10U) {
/* with more the backoff (required in RFC 6775) is truncated
* anyway and this way we prevent overflows. 10 is arbitrary, so
* we do not need a define here */
netif->ipv6.rs_sent++;
}
if ((netif->ipv6.rs_sent < NDP_MAX_RS_NUMOF) ||
gnrc_netif_is_6ln(netif)) {
/* 6LN will solicitate indefinitely */
_evtimer_add(netif, GNRC_IPV6_NIB_SEARCH_RTR,
&netif->ipv6.search_rtr, interval);
}
}
}
gnrc_netif_release(netif);
#else
(void)netif;
#endif /* !GNRC_IPV6_NIB_CONF_NO_RTR_SOL */
}
#if GNRC_IPV6_NIB_CONF_DNS
static void _handle_rdnss_timeout(sock_udp_ep_t *dns_server)
{
memset(dns_server, 0, sizeof(sock_udp_ep_t));
}
#endif
static void _handle_mtuo(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_mtu_t *mtuo)
{
if ((mtuo->len != NDP_OPT_MTU_LEN) || (icmpv6->type != ICMPV6_RTR_ADV)) {
return;
}
if (byteorder_ntohl(mtuo->mtu) >= IPV6_MIN_MTU) {
netif->ipv6.mtu = byteorder_ntohl(mtuo->mtu);
}
}
#if GNRC_IPV6_NIB_CONF_DNS
static uint32_t _handle_rdnsso(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_rdnss_t *rdnsso)
{
uint32_t ltime = UINT32_MAX;
const ipv6_addr_t *addr;
if ((rdnsso->len < NDP_OPT_RDNSS_MIN_LEN) ||
(icmpv6->type != ICMPV6_RTR_ADV)) {
return ltime;
}
/* select first if unassigned, search possible address otherwise */
addr = (sock_dns_server.port == 0) ? &rdnsso->addrs[0] : NULL;
if (addr == NULL) {
unsigned addrs_num = (rdnsso->len - 1) / 2;
for (unsigned i = 0; i < addrs_num; i++) {
if (memcmp(sock_dns_server.addr.ipv6,
&rdnsso->addrs[i],
sizeof(rdnsso->addrs[i])) == 0) {
addr = &rdnsso->addrs[i];
break;
}
}
}
#if SOCK_HAS_IPV6
ltime = byteorder_ntohl(rdnsso->ltime);
if (addr != NULL) {
if (ltime > 0) {
sock_dns_server.port = SOCK_DNS_PORT;
sock_dns_server.family = AF_INET6;
sock_dns_server.netif = netif->pid;
memcpy(sock_dns_server.addr.ipv6, rdnsso->addrs,
sizeof(sock_dns_server.addr.ipv6));
if (ltime < UINT32_MAX) {
/* the valid lifetime is given in seconds, but our timers work
* in milliseconds, so we have to scale down to the smallest
* possible value (UINT32_MAX - 1). This is however alright
* since we ask for a new router advertisement before this
* timeout expires */
ltime = (ltime > (UINT32_MAX / MS_PER_SEC)) ?
(UINT32_MAX - 1) : ltime * MS_PER_SEC;
_evtimer_add(&sock_dns_server, GNRC_IPV6_NIB_RDNSS_TIMEOUT,
&_rdnss_timeout, ltime);
}
}
else {
evtimer_del(&_nib_evtimer, &_rdnss_timeout.event);
_handle_rdnss_timeout(&sock_dns_server);
}
}
#else
(void)addr;
#endif
return ltime;
}
#endif
static void _remove_prefix(const ipv6_addr_t *pfx, unsigned pfx_len)
{
_nib_offl_entry_t *offl = NULL;
while ((offl = _nib_offl_iter(offl))) {
if ((offl->mode & _PL) &&
(offl->pfx_len == pfx_len) &&
(ipv6_addr_match_prefix(&offl->pfx, pfx) >= pfx_len)) {
_nib_pl_remove(offl);
}
}
return;
}
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
static inline bool _multihop_p6c(gnrc_netif_t *netif, _nib_abr_entry_t *abr)
{
(void)netif; /* gnrc_netif_is_6lr() might resolve to a NOP */
return (gnrc_netif_is_6lr(netif) && (abr != NULL));
}
#else /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
#define _multihop_p6c(netif, abr) (false)
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
static uint32_t _handle_pio(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_pi_t *pio, _nib_abr_entry_t *abr)
#else /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
static uint32_t _handle_pio(gnrc_netif_t *netif, const icmpv6_hdr_t *icmpv6,
const ndp_opt_pi_t *pio)
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
{
uint32_t valid_ltime;
uint32_t pref_ltime;
valid_ltime = byteorder_ntohl(pio->valid_ltime);
pref_ltime = byteorder_ntohl(pio->pref_ltime);
if ((pio->len != NDP_OPT_PI_LEN) || (icmpv6->type != ICMPV6_RTR_ADV) ||
ipv6_addr_is_link_local(&pio->prefix) || (valid_ltime < pref_ltime)) {
DEBUG("nib: ignoring PIO with invalid data\n");
return UINT32_MAX;
}
DEBUG("nib: received valid Prefix Information option:\n");
DEBUG(" - Prefix: %s/%u\n",
ipv6_addr_to_str(addr_str, &pio->prefix, sizeof(addr_str)),
pio->prefix_len);
DEBUG(" - Flags: %c%c\n",
(pio->flags & NDP_OPT_PI_FLAGS_L) ? 'L' : '-',
(pio->flags & NDP_OPT_PI_FLAGS_A) ? 'A' : '-');
DEBUG(" - Valid lifetime: %" PRIu32 "\n",
byteorder_ntohl(pio->valid_ltime));
DEBUG(" - Preferred lifetime: %" PRIu32 "\n",
byteorder_ntohl(pio->pref_ltime));
if (pio->flags & NDP_OPT_PI_FLAGS_A) {
_auto_configure_addr(netif, &pio->prefix, pio->prefix_len);
}
if ((pio->flags & NDP_OPT_PI_FLAGS_L) || _multihop_p6c(netif, abr)) {
_nib_offl_entry_t *pfx;
if (pio->valid_ltime.u32 == 0) {
DEBUG("nib: PIO for %s/%u with lifetime 0. Removing prefix.\n",
ipv6_addr_to_str(addr_str, &pio->prefix, sizeof(addr_str)),
pio->prefix_len);
_remove_prefix(&pio->prefix, pio->prefix_len);
return UINT32_MAX;
}
if (valid_ltime < UINT32_MAX) { /* UINT32_MAX means infinite lifetime */
/* the valid lifetime is given in seconds, but our timers work in
* microseconds, so we have to scale down to the smallest possible
* value (UINT32_MAX - 1). This is however alright since we ask for
* a new router advertisement before this timeout expires */
valid_ltime = (valid_ltime > (UINT32_MAX / MS_PER_SEC)) ?
(UINT32_MAX - 1) : valid_ltime * MS_PER_SEC;
}
if (pref_ltime < UINT32_MAX) { /* UINT32_MAX means infinite lifetime */
/* same treatment for pref_ltime */
pref_ltime = (pref_ltime > (UINT32_MAX / MS_PER_SEC)) ?
(UINT32_MAX - 1) : pref_ltime * MS_PER_SEC;
}
if ((pfx = _nib_pl_add(netif->pid, &pio->prefix, pio->prefix_len,
valid_ltime, pref_ltime))) {
#if GNRC_IPV6_NIB_CONF_MULTIHOP_P6C
if (abr != NULL) {
_nib_abr_add_pfx(abr, pfx);
}
#endif /* GNRC_IPV6_NIB_CONF_MULTIHOP_P6C */
if (pio->flags & NDP_OPT_PI_FLAGS_L) {
pfx->flags |= _PFX_ON_LINK;
}
if (pio->flags & NDP_OPT_PI_FLAGS_A) {
pfx->flags |= _PFX_SLAAC;
}
return _min(pref_ltime, valid_ltime);
}
}
return UINT32_MAX;
}
/** @} */
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