static ng_ipv6_addr_t *_default_router(void)
{
ng_ipv6_nc_t *router = ng_ipv6_nc_get_next_router(NULL);
/* first look if there is any reachable router */
while (router != NULL) {
if ((ng_ipv6_nc_get_state(router) != NG_IPV6_NC_STATE_INCOMPLETE) &&
(ng_ipv6_nc_get_state(router) != NG_IPV6_NC_STATE_UNREACHABLE)) {
_last_router = NULL;
return &router->ipv6_addr;
}
router = ng_ipv6_nc_get_next_router(router);
}
/* else take the first one, but keep round-robin in further selections */
router = ng_ipv6_nc_get_next_router(_last_router);
if (router == NULL) { /* end of router list or there is none => wrap around */
router = ng_ipv6_nc_get_next_router(router);
if (router == NULL) { /* still nothing found => no router in list */
return NULL;
}
}
_last_router = router;
return &router->ipv6_addr;
}
void ng_ndp_retrans_nbr_sol(ng_ipv6_nc_t *nc_entry)
{
if ((ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_INCOMPLETE) ||
(ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_PROBE)) {
if (nc_entry->probes_remaining > 1) {
ng_ipv6_addr_t dst;
DEBUG("ndp: Retransmit neighbor solicitation for %s\n",
ng_ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)));
/* retransmit neighbor solicatation */
if (ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_INCOMPLETE) {
ng_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) {
timex_t t = { 0, NG_NDP_RETRANS_TIMER };
kernel_pid_t ifs[NG_NETIF_NUMOF];
size_t ifnum = ng_netif_get(ifs);
for (size_t i = 0; i < ifnum; i++) {
_send_nbr_sol(ifs[i], &nc_entry->ipv6_addr, &dst);
}
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer, t, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
}
else {
ng_ipv6_netif_t *ipv6_iface = ng_ipv6_netif_get(nc_entry->iface);
_send_nbr_sol(nc_entry->iface, &nc_entry->ipv6_addr, &dst);
mutex_lock(&ipv6_iface->mutex);
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer,
ipv6_iface->retrans_timer, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
mutex_unlock(&ipv6_iface->mutex);
}
}
else if (nc_entry->probes_remaining <= 1) {
DEBUG("ndp: Remove nc entry %s for interface %" PRIkernel_pid "\n",
ng_ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)),
nc_entry->iface);
#ifdef MODULE_FIB
fib_remove_entry((uint8_t *) & (nc_entry->ipv6_addr), sizeof(ng_ipv6_addr_t));
#endif
ng_ipv6_nc_remove(nc_entry->iface, &nc_entry->ipv6_addr);
}
}
}
void ng_ndp_state_timeout(ng_ipv6_nc_t *nc_entry)
{
switch (ng_ipv6_nc_get_state(nc_entry)) {
case NG_IPV6_NC_STATE_REACHABLE:
_set_state(nc_entry, NG_IPV6_NC_STATE_STALE);
break;
case NG_IPV6_NC_STATE_DELAY:
_set_state(nc_entry, NG_IPV6_NC_STATE_PROBE);
break;
default:
break;
}
}
kernel_pid_t ng_ndp_next_hop_l2addr(uint8_t *l2addr, uint8_t *l2addr_len,
kernel_pid_t iface, ng_ipv6_addr_t *dst,
ng_pktsnip_t *pkt)
{
ng_ipv6_addr_t *next_hop_ip = NULL, *prefix = NULL;
#ifdef MODULE_NG_IPV6_EXT_RH
next_hop_ip = ng_ipv6_ext_rh_next_hop(hdr);
#endif
#ifdef MODULE_FIB
size_t next_hop_size = sizeof(ng_ipv6_addr_t);
uint32_t next_hop_flags = 0;
ng_ipv6_addr_t next_hop_actual; /* FIB copies address into this variable */
if ((next_hop_ip == NULL) &&
(fib_get_next_hop(&iface, next_hop_actual.u8, &next_hop_size,
&next_hop_flags, (uint8_t *)dst,
sizeof(ng_ipv6_addr_t), 0) >= 0) &&
(next_hop_size == sizeof(ng_ipv6_addr_t))) {
next_hop_ip = &next_hop_actual;
}
#endif
if (next_hop_ip == NULL) { /* no route to host */
if (iface == KERNEL_PID_UNDEF) {
/* ng_ipv6_netif_t doubles as prefix list */
iface = ng_ipv6_netif_find_by_prefix(&prefix, dst);
}
else {
/* ng_ipv6_netif_t doubles as prefix list */
prefix = ng_ipv6_netif_match_prefix(iface, dst);
}
if ((prefix != NULL) && /* prefix is on-link */
(ng_ipv6_netif_addr_get(prefix)->flags &
NG_IPV6_NETIF_ADDR_FLAGS_NDP_ON_LINK)) {
next_hop_ip = dst;
#ifdef MODULE_FIB
/* We don't care if FIB is full, this is just for efficiency
* for later sends */
fib_add_entry(iface, (uint8_t *)dst, sizeof(ng_ipv6_addr_t), 0,
(uint8_t *)next_hop_ip, sizeof(ng_ipv6_addr_t), 0,
FIB_LIFETIME_NO_EXPIRE);
#endif
}
}
if (next_hop_ip == NULL) {
next_hop_ip = _default_router();
#ifdef MODULE_FIB
/* We don't care if FIB is full, this is just for efficiency for later
* sends */
fib_add_entry(iface, (uint8_t *)dst, sizeof(ng_ipv6_addr_t), 0,
(uint8_t *)next_hop_ip, sizeof(ng_ipv6_addr_t), 0,
FIB_LIFETIME_NO_EXPIRE);
#endif
}
if (next_hop_ip != NULL) {
ng_ipv6_nc_t *nc_entry = ng_ipv6_nc_get(iface, next_hop_ip);
if ((nc_entry != NULL) && ng_ipv6_nc_is_reachable(nc_entry)) {
DEBUG("ndp: found reachable neighbor (%s => ",
ng_ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)));
DEBUG("%s)\n",
ng_netif_addr_to_str(addr_str, sizeof(addr_str),
nc_entry->l2_addr, nc_entry->l2_addr_len));
if (ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_STALE) {
_set_state(nc_entry, NG_IPV6_NC_STATE_DELAY);
}
memcpy(l2addr, nc_entry->l2_addr, nc_entry->l2_addr_len);
*l2addr_len = nc_entry->l2_addr_len;
/* TODO: unreachability check */
return nc_entry->iface;
}
else if (nc_entry == NULL) {
ng_pktqueue_t *pkt_node;
ng_ipv6_addr_t dst_sol;
nc_entry = ng_ipv6_nc_add(iface, next_hop_ip, NULL, 0,
NG_IPV6_NC_STATE_INCOMPLETE << NG_IPV6_NC_STATE_POS);
if (nc_entry == NULL) {
DEBUG("ndp: could not create neighbor cache entry\n");
return KERNEL_PID_UNDEF;
}
pkt_node = _alloc_pkt_node(pkt);
if (pkt_node == NULL) {
DEBUG("ndp: could not add packet to packet queue\n");
}
else {
/* prevent packet from being released by IPv6 */
ng_pktbuf_hold(pkt_node->pkt, 1);
ng_pktqueue_add(&nc_entry->pkts, pkt_node);
}
/* address resolution */
ng_ipv6_addr_set_solicited_nodes(&dst_sol, next_hop_ip);
if (iface == KERNEL_PID_UNDEF) {
timex_t t = { 0, NG_NDP_RETRANS_TIMER };
kernel_pid_t ifs[NG_NETIF_NUMOF];
size_t ifnum = ng_netif_get(ifs);
for (size_t i = 0; i < ifnum; i++) {
_send_nbr_sol(ifs[i], next_hop_ip, &dst_sol);
}
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer, t, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
}
else {
ng_ipv6_netif_t *ipv6_iface = ng_ipv6_netif_get(iface);
_send_nbr_sol(iface, next_hop_ip, &dst_sol);
mutex_lock(&ipv6_iface->mutex);
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer,
ipv6_iface->retrans_timer, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
mutex_unlock(&ipv6_iface->mutex);
}
}
}
return KERNEL_PID_UNDEF;
}
void ng_ndp_nbr_adv_handle(kernel_pid_t iface, ng_pktsnip_t *pkt,
ng_ipv6_hdr_t *ipv6, ng_ndp_nbr_adv_t *nbr_adv,
size_t icmpv6_size)
{
uint16_t opt_offset = 0;
uint8_t *buf = ((uint8_t *)nbr_adv) + sizeof(ng_ndp_nbr_adv_t);
int l2tgt_len = 0;
uint8_t l2tgt[NG_IPV6_NC_L2_ADDR_MAX];
int sicmpv6_size = (int)icmpv6_size;
ng_ipv6_nc_t *nc_entry = ng_ipv6_nc_get(iface, &nbr_adv->tgt);
ng_pktsnip_t *netif;
ng_netif_hdr_t *netif_hdr = NULL;
DEBUG("ndp: received neighbor advertisement (src: %s, ",
ng_ipv6_addr_to_str(addr_str, &ipv6->src, sizeof(addr_str)));
DEBUG("dst: %s, ",
ng_ipv6_addr_to_str(addr_str, &ipv6->dst, sizeof(addr_str)));
DEBUG("tgt: %s)\n",
ng_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(ng_ndp_nbr_adv_t)) ||
ng_ipv6_addr_is_multicast(&nbr_adv->tgt)) {
DEBUG("ndp: neighbor advertisement was invalid.\n");
/* ipv6 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");
/* ipv6 releases */
return;
}
sicmpv6_size -= sizeof(ng_ndp_nbr_adv_t);
while (sicmpv6_size > 0) {
ng_ndp_opt_t *opt = (ng_ndp_opt_t *)(buf + opt_offset);
switch (opt->type) {
case NG_NDP_OPT_TL2A:
if ((l2tgt_len = _handle_tl2a_opt(pkt, ipv6, nbr_adv->type, opt,
l2tgt)) < 0) {
/* invalid target link-layer address option */
return;
}
break;
default:
/* silently discard all other options */
break;
}
opt_offset += (opt->len * 8);
sicmpv6_size -= (opt->len * 8);
}
LL_SEARCH_SCALAR(pkt, netif, type, NG_NETTYPE_NETIF);
if (netif != NULL) {
netif_hdr = netif->data;
}
if (ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_INCOMPLETE) {
ng_pktqueue_t *queued_pkt;
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 & NG_NDP_NBR_ADV_FLAGS_S) {
_set_state(nc_entry, NG_IPV6_NC_STATE_REACHABLE);
}
else {
_set_state(nc_entry, NG_IPV6_NC_STATE_STALE);
}
if (nbr_adv->flags & NG_NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= NG_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~NG_IPV6_NC_IS_ROUTER;
/* TODO: update FIB */
}
while ((queued_pkt = ng_pktqueue_remove_head(&nc_entry->pkts)) != NULL) {
ng_netapi_send(ng_ipv6_pid, queued_pkt->pkt);
queued_pkt->pkt = NULL;
}
}
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 & NG_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 & NG_NDP_NBR_ADV_FLAGS_S) {
_set_state(nc_entry, NG_IPV6_NC_STATE_REACHABLE);
}
else if (l2tgt_changed && (l2tgt_len != 0)) {
_set_state(nc_entry, NG_IPV6_NC_STATE_STALE);
}
if (nbr_adv->flags & NG_NDP_NBR_ADV_FLAGS_R) {
nc_entry->flags |= NG_IPV6_NC_IS_ROUTER;
}
else {
nc_entry->flags &= ~NG_IPV6_NC_IS_ROUTER;
/* TODO: update FIB */
}
}
else if (l2tgt_changed) {
if (ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_REACHABLE) {
_set_state(nc_entry, NG_IPV6_NC_STATE_STALE);
}
}
}
return;
}
void ng_ndp_retrans_nbr_sol(ng_ipv6_nc_t *nc_entry)
{
if ((nc_entry->probes_remaining > 1) &&
((ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_INCOMPLETE) ||
(ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_PROBE))) {
ng_ipv6_addr_t dst;
DEBUG("ndp: Retransmit neighbor solicitation for %s\n",
ng_ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)));
/* retransmit neighbor solicatation */
if (ng_ipv6_nc_get_state(nc_entry) == NG_IPV6_NC_STATE_INCOMPLETE) {
ng_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) {
timex_t t = { 0, NG_NDP_RETRANS_TIMER };
kernel_pid_t ifs[NG_NETIF_NUMOF];
size_t ifnum = ng_netif_get(ifs);
for (size_t i = 0; i < ifnum; i++) {
_send_nbr_sol(ifs[i], &nc_entry->ipv6_addr, &dst);
}
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer, t, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
}
else {
ng_ipv6_netif_t *ipv6_iface = ng_ipv6_netif_get(nc_entry->iface);
_send_nbr_sol(nc_entry->iface, &nc_entry->ipv6_addr, &dst);
mutex_lock(&ipv6_iface->mutex);
vtimer_remove(&nc_entry->nbr_sol_timer);
vtimer_set_msg(&nc_entry->nbr_sol_timer,
ipv6_iface->retrans_timer, ng_ipv6_pid,
NG_NDP_MSG_NBR_SOL_RETRANS, nc_entry);
mutex_unlock(&ipv6_iface->mutex);
}
}
else if (nc_entry->probes_remaining <= 1) {
ng_pktqueue_node_t *queue_node;
/* No need to call ng_ipv6_nc_remove() we know already were the
* entry is */
DEBUG("ndp: Remove nc entry %s for interface %" PRIkernel_pid "\n",
ng_ipv6_addr_to_str(addr_str, &nc_entry->ipv6_addr, sizeof(addr_str)),
nc_entry->iface);
while ((queue_node = ng_pktqueue_remove_head(&nc_entry->pkts))) {
ng_pktbuf_release(queue_node->data);
queue_node->data = NULL;
}
ng_ipv6_addr_set_unspecified(&(nc_entry->ipv6_addr));
nc_entry->iface = KERNEL_PID_UNDEF;
nc_entry->flags = 0;
nc_entry->probes_remaining = 0;
}
}
