void gnrc_ndp_internal_send_nbr_sol(kernel_pid_t iface, ipv6_addr_t *tgt,
ipv6_addr_t *dst)
{
gnrc_pktsnip_t *hdr, *pkt = NULL;
ipv6_addr_t *src = NULL;
DEBUG("ndp internal: send neighbor solicitation (iface: %" PRIkernel_pid ", tgt: %s, ",
iface, ipv6_addr_to_str(addr_str, tgt, sizeof(addr_str)));
DEBUG("dst: %s)\n", ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
/* check if there is a fitting source address to target */
if ((src = gnrc_ipv6_netif_find_best_src_addr(iface, tgt)) != NULL) {
uint8_t l2src[8];
size_t l2src_len;
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add source address link-layer address option */
pkt = gnrc_ndp_opt_sl2a_build(l2src, l2src_len, NULL);
if (pkt == NULL) {
DEBUG("ndp internal: error allocating Source Link-layer address option.\n");
gnrc_pktbuf_release(pkt);
return;
}
}
}
hdr = gnrc_ndp_nbr_sol_build(tgt, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating Neighbor solicitation.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, src);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
gnrc_netapi_send(gnrc_ipv6_pid, hdr);
}
void gnrc_ndp_internal_send_rtr_sol(kernel_pid_t iface, ipv6_addr_t *dst)
{
gnrc_pktsnip_t *hdr, *pkt = NULL;
ipv6_addr_t *src = NULL, all_routers = IPV6_ADDR_ALL_ROUTERS_LINK_LOCAL;
DEBUG("ndp internal: send router solicitation (iface: %" PRIkernel_pid ", dst: ff02::2)\n",
iface);
if (dst == NULL) {
dst = &all_routers;
}
/* check if there is a fitting source address to target */
if ((src = gnrc_ipv6_netif_find_best_src_addr(iface, dst)) != NULL) {
uint8_t l2src[8];
size_t l2src_len;
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add source address link-layer address option */
pkt = gnrc_ndp_opt_sl2a_build(l2src, l2src_len, NULL);
if (pkt == NULL) {
DEBUG("ndp internal: error allocating Source Link-layer address option.\n");
gnrc_pktbuf_release(pkt);
return;
}
}
}
hdr = gnrc_ndp_rtr_sol_build(pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating router solicitation.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, src);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
else if (gnrc_netapi_send(gnrc_ipv6_pid, hdr) < 1) {
DEBUG("ndp internal: unable to send router solicitation\n");
gnrc_pktbuf_release(hdr);
}
}
void gnrc_ndp_internal_send_rtr_adv(kernel_pid_t iface, ipv6_addr_t *src, ipv6_addr_t *dst,
bool fin)
{
gnrc_pktsnip_t *hdr, *pkt = NULL;
ipv6_addr_t all_nodes = IPV6_ADDR_ALL_NODES_LINK_LOCAL;
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
uint32_t reach_time = 0, retrans_timer = 0;
uint16_t adv_ltime = 0;
uint8_t cur_hl = 0;
if (dst == NULL) {
dst = &all_nodes;
}
DEBUG("ndp internal: send router advertisement (iface: %" PRIkernel_pid ", dst: %s%s\n",
iface, ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)), fin ? ", final" : "");
mutex_lock(&ipv6_iface->mutex);
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
if (!(ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN)) {
#endif
hdr = _add_pios(ipv6_iface, pkt);
if (hdr == NULL) {
/* pkt already released in _add_pios */
mutex_unlock(&ipv6_iface->mutex);
return;
}
pkt = hdr;
#ifdef MODULE_GNRC_SIXLOWPAN_ND_ROUTER
}
else {
gnrc_sixlowpan_nd_router_abr_t *abr = gnrc_sixlowpan_nd_router_abr_get();
if (abr != NULL) {
gnrc_sixlowpan_nd_router_prf_t *prf = abr->prfs;
/* add prefixes from border router */
while (prf) {
bool processed_before = false;
/* skip if prefix does not belong to iface */
if (prf->iface != ipv6_iface) {
prf = prf->next;
continue;
}
/* skip if prefix has been processed already */
for (gnrc_sixlowpan_nd_router_prf_t *tmp = abr->prfs; tmp != prf; tmp = tmp->next) {
if ((processed_before =
_check_prefixes(prf->prefix, tmp->prefix))) {
break;
}
}
if (processed_before) {
prf = prf->next;
continue;
}
if (_pio_from_iface_addr(&hdr, prf->prefix, pkt)) {
if (hdr != NULL) {
pkt = hdr;
}
else {
DEBUG("ndp rtr: error allocating PIO\n");
gnrc_pktbuf_release(pkt);
return;
}
}
prf = prf->next;
}
for (unsigned int i = 0; i < GNRC_SIXLOWPAN_CTX_SIZE; i++) {
gnrc_sixlowpan_ctx_t *ctx;
if (!bf_isset(abr->ctxs, i)) {
continue;
}
ctx = gnrc_sixlowpan_ctx_lookup_id(i);
hdr = gnrc_sixlowpan_nd_opt_6ctx_build(ctx->prefix_len, ctx->flags_id, ctx->ltime,
&ctx->prefix, pkt);
if (hdr == NULL) {
DEBUG("ndp rtr: error allocating 6CO\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
hdr = gnrc_sixlowpan_nd_opt_abr_build(abr->version, abr->ltime, &abr->addr, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating ABRO.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
}
#endif /* MODULE_GNRC_SIXLOWPAN_ND_ROUTER */
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_MTU) {
if ((hdr = gnrc_ndp_opt_mtu_build(ipv6_iface->mtu, pkt)) == NULL) {
DEBUG("ndp rtr: no space left in packet buffer\n");
mutex_unlock(&ipv6_iface->mutex);
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
if (src == NULL) {
mutex_unlock(&ipv6_iface->mutex);
/* get address from source selection algorithm */
src = gnrc_ipv6_netif_find_best_src_addr(iface, dst);
mutex_lock(&ipv6_iface->mutex);
}
/* add SL2A for source address */
if (src != NULL) {
DEBUG(" - SL2A\n");
uint8_t l2src[8];
size_t l2src_len;
/* optimization note: MAY also be omitted to facilitate in-bound load balancing over
* replicated interfaces.
* source: https://tools.ietf.org/html/rfc4861#section-6.2.3 */
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add source address link-layer address option */
hdr = gnrc_ndp_opt_sl2a_build(l2src, l2src_len, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating Source Link-layer address option.\n");
mutex_unlock(&ipv6_iface->mutex);
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_CUR_HL) {
cur_hl = ipv6_iface->cur_hl;
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_REACH_TIME) {
if (ipv6_iface->reach_time > (3600 * SEC_IN_USEC)) { /* reach_time > 1 hour */
reach_time = (3600 * SEC_IN_MS);
}
else {
reach_time = ipv6_iface->reach_time / MS_IN_USEC;
}
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_RETRANS_TIMER) {
retrans_timer = ipv6_iface->retrans_timer / MS_IN_USEC;
}
if (!fin) {
adv_ltime = ipv6_iface->adv_ltime;
}
mutex_unlock(&ipv6_iface->mutex);
hdr = gnrc_ndp_rtr_adv_build(cur_hl,
(ipv6_iface->flags & (GNRC_IPV6_NETIF_FLAGS_OTHER_CONF |
GNRC_IPV6_NETIF_FLAGS_MANAGED)) >> 8,
adv_ltime, reach_time, retrans_timer, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating router advertisement.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, src);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
else if (gnrc_netapi_send(gnrc_ipv6_pid, hdr) < 1) {
DEBUG("ndp internal: unable to send router advertisement\n");
gnrc_pktbuf_release(hdr);
}
}
void gnrc_ndp_internal_send_nbr_sol(kernel_pid_t iface, ipv6_addr_t *src, ipv6_addr_t *tgt,
ipv6_addr_t *dst)
{
#ifdef MODULE_GNRC_SIXLOWPAN_ND
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
assert(ipv6_iface != NULL);
#endif
gnrc_pktsnip_t *hdr, *pkt = NULL;
/* both suppressions, since they are needed in the MODULE_GNRC_SIXLOWPAN_ND branch */
/* cppcheck-suppress variableScope */
uint8_t l2src[8];
/* cppcheck-suppress variableScope */
size_t l2src_len = 0;
DEBUG("ndp internal: send neighbor solicitation (iface: %" PRIkernel_pid ", src: %s, ",
iface, ipv6_addr_to_str(addr_str, src, sizeof(addr_str)));
DEBUG(" tgt: %s, ", ipv6_addr_to_str(addr_str, tgt, sizeof(addr_str)));
DEBUG("dst: %s)\n", ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
/* check if there is a fitting source address to target */
if (src == NULL) {
src = gnrc_ipv6_netif_find_best_src_addr(iface, tgt);
}
if (src != NULL) {
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add source address link-layer address option */
pkt = gnrc_ndp_opt_sl2a_build(l2src, l2src_len, NULL);
if (pkt == NULL) {
DEBUG("ndp internal: error allocating Source Link-layer address option.\n");
gnrc_pktbuf_release(pkt);
return;
}
}
}
#ifdef MODULE_GNRC_SIXLOWPAN_ND
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_SIXLOWPAN) {
if (l2src_len != sizeof(eui64_t)) {
l2src_len = (uint16_t)gnrc_netapi_get(iface, NETOPT_ADDRESS_LONG, 0, l2src,
sizeof(l2src));
if (l2src_len != sizeof(eui64_t)) {
DEBUG("ndp internal: can't get EUI-64 of the interface\n");
gnrc_pktbuf_release(pkt);
return;
}
}
hdr = gnrc_sixlowpan_nd_opt_ar_build(0, GNRC_SIXLOWPAN_ND_AR_LTIME, (eui64_t *)l2src, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocatin Address Registration option.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
#endif
hdr = gnrc_ndp_nbr_sol_build(tgt, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating Neighbor solicitation.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, src);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
else if (gnrc_netapi_send(gnrc_ipv6_pid, hdr) < 1) {
DEBUG("ndp internal: unable to send neighbor solicitation\n");
gnrc_pktbuf_release(hdr);
}
}
void gnrc_ndp_internal_send_nbr_adv(kernel_pid_t iface, ipv6_addr_t *tgt, ipv6_addr_t *dst,
bool supply_tl2a, gnrc_pktsnip_t *ext_opts)
{
gnrc_pktsnip_t *hdr, *pkt = ext_opts;
uint8_t adv_flags = 0;
DEBUG("ndp internal: send neighbor advertisement (iface: %" PRIkernel_pid ", tgt: %s, ",
iface, ipv6_addr_to_str(addr_str, tgt, sizeof(addr_str)));
DEBUG("dst: %s, supply_tl2a: %d)\n",
ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)), supply_tl2a);
if ((gnrc_ipv6_netif_get(iface)->flags & GNRC_IPV6_NETIF_FLAGS_ROUTER) &&
(gnrc_ipv6_netif_get(iface)->flags & GNRC_IPV6_NETIF_FLAGS_RTR_ADV)) {
adv_flags |= NDP_NBR_ADV_FLAGS_R;
}
if (ipv6_addr_is_unspecified(dst)) {
ipv6_addr_set_all_nodes_multicast(dst, IPV6_ADDR_MCAST_SCP_LINK_LOCAL);
}
else {
adv_flags |= NDP_NBR_ADV_FLAGS_S;
}
if (supply_tl2a) {
uint8_t l2src[8];
size_t l2src_len;
/* we previously checked if we are the target, so we can take our L2src */
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add target address link-layer address option */
pkt = gnrc_ndp_opt_tl2a_build(l2src, l2src_len, pkt);
if (pkt == NULL) {
DEBUG("ndp internal: error allocating Target Link-layer address option.\n");
gnrc_pktbuf_release(ext_opts);
return;
}
}
}
/* TODO: also check if the node provides proxy servies for tgt */
if ((pkt != NULL) && !gnrc_ipv6_netif_addr_is_non_unicast(tgt)) {
/* TL2A is not supplied and tgt is not anycast */
adv_flags |= NDP_NBR_ADV_FLAGS_O;
}
hdr = gnrc_ndp_nbr_adv_build(adv_flags, tgt, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating Neighbor advertisement.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, NULL);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
if (gnrc_ipv6_netif_addr_is_non_unicast(tgt)) {
/* avoid collision for anycast addresses
* (see https://tools.ietf.org/html/rfc4861#section-7.2.7) */
uint32_t delay = genrand_uint32_range(0, GNRC_NDP_MAX_AC_TGT_DELAY * SEC_IN_USEC);
gnrc_ipv6_nc_t *nc_entry = gnrc_ipv6_nc_get(iface, dst);
DEBUG("ndp internal: delay neighbor advertisement for %" PRIu32 " sec.",
(delay / SEC_IN_USEC));
/* nc_entry must be set so no need to check it */
assert(nc_entry);
_send_delayed(&nc_entry->nbr_adv_timer, &nc_entry->nbr_adv_msg, delay, hdr);
}
else if (gnrc_netapi_send(gnrc_ipv6_pid, hdr) < 1) {
DEBUG("ndp internal: unable to send neighbor advertisement\n");
gnrc_pktbuf_release(hdr);
}
}
static void _send_nbr_adv(kernel_pid_t iface, ng_ipv6_addr_t *tgt,
ng_ipv6_addr_t *dst, bool supply_tl2a)
{
ng_pktsnip_t *hdr, *pkt = NULL;
uint8_t adv_flags = 0;
DEBUG("ndp: send neighbor advertisement (iface: %" PRIkernel_pid ", tgt: %s, ",
iface, ng_ipv6_addr_to_str(addr_str, tgt, sizeof(addr_str)));
DEBUG("dst: %s, supply_tl2a: %d)\n",
ng_ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)), supply_tl2a);
if (ng_ipv6_netif_get(iface)->flags & NG_IPV6_NETIF_FLAGS_ROUTER) {
adv_flags |= NG_NDP_NBR_ADV_FLAGS_R;
}
if (ng_ipv6_addr_is_unspecified(dst)) {
ng_ipv6_addr_set_all_nodes_multicast(dst,
NG_IPV6_ADDR_MCAST_SCP_LINK_LOCAL);
}
else {
adv_flags |= NG_NDP_NBR_ADV_FLAGS_S;
}
if (supply_tl2a) {
uint8_t l2src[8];
uint16_t l2src_len;
/* we previously checked if we are the target, so we can take our L2src */
l2src_len = _get_l2src(l2src, sizeof(l2src), iface);
if (l2src_len > 0) {
/* add target address link-layer address option */
pkt = ng_ndp_opt_tl2a_build(l2src, l2src_len, NULL);
if (pkt == NULL) {
DEBUG("ndp: error allocating Target Link-layer address option.\n");
ng_pktbuf_release(pkt);
return;
}
}
}
/* TODO: also check if the node provides proxy servies for tgt */
if ((pkt != NULL) && !ng_ipv6_netif_addr_is_non_unicast(tgt)) {
/* TL2A is not supplied and tgt is not anycast */
adv_flags |= NG_NDP_NBR_ADV_FLAGS_O;
}
hdr = ng_ndp_nbr_adv_build(adv_flags, tgt, pkt);
if (hdr == NULL) {
DEBUG("ndp: error allocating Neighbor advertisement.\n");
ng_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = ng_ipv6_hdr_build(pkt, NULL, 0, (uint8_t *)dst,
sizeof(ng_ipv6_addr_t));
if (hdr == NULL) {
DEBUG("ndp: error allocating IPv6 header.\n");
ng_pktbuf_release(pkt);
return;
}
((ng_ipv6_hdr_t *)hdr->data)->hl = 255;
pkt = hdr;
/* add netif header for send interface specification */
hdr = ng_netif_hdr_build(NULL, 0, NULL, 0);
if (hdr == NULL) {
DEBUG("ndp: error allocating netif header.\n");
return;
}
((ng_netif_hdr_t *)hdr->data)->if_pid = iface;
LL_PREPEND(pkt, hdr);
if (ng_ipv6_netif_addr_is_non_unicast(tgt)) {
/* avoid collision for anycast addresses
* (see https://tools.ietf.org/html/rfc4861#section-7.2.7) */
timex_t delay = { _rand(0, NG_NDP_MAX_AC_TGT_DELAY), 0 };
ng_ipv6_nc_t *nc_entry = ng_ipv6_nc_get(iface, tgt);
DEBUG("ndp: delay neighbor advertisement for %" PRIu32 " sec.",
delay.seconds);
/* nc_entry must be set so no need to check it */
_send_delayed(&nc_entry->nbr_adv_timer, delay, pkt);
}
else {
ng_netapi_send(ng_ipv6_pid, pkt);
}
}
static void _send_nbr_sol(kernel_pid_t iface, ng_ipv6_addr_t *tgt,
ng_ipv6_addr_t *dst)
{
ng_pktsnip_t *hdr, *pkt = NULL;
ng_ipv6_addr_t *src = NULL;
size_t src_len = 0;
DEBUG("ndp: send neighbor solicitation (iface: %" PRIkernel_pid ", tgt: %s, ",
iface, ng_ipv6_addr_to_str(addr_str, tgt, sizeof(addr_str)));
DEBUG("dst: %s)\n", ng_ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)));
/* check if there is a fitting source address to target */
if ((src = ng_ipv6_netif_find_best_src_addr(iface, tgt)) != NULL) {
uint8_t l2src[8];
uint16_t l2src_len;
src_len = sizeof(ng_ipv6_addr_t);
l2src_len = _get_l2src(l2src, sizeof(l2src), iface);
if (l2src_len > 0) {
/* add source address link-layer address option */
pkt = ng_ndp_opt_sl2a_build(l2src, l2src_len, NULL);
if (pkt == NULL) {
DEBUG("ndp: error allocating Source Link-layer address option.\n");
ng_pktbuf_release(pkt);
return;
}
}
}
hdr = ng_ndp_nbr_sol_build(tgt, pkt);
if (hdr == NULL) {
DEBUG("ndp: error allocating Neighbor solicitation.\n");
ng_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = ng_ipv6_hdr_build(pkt, (uint8_t *)src, src_len, (uint8_t *)dst,
sizeof(ng_ipv6_addr_t));
if (hdr == NULL) {
DEBUG("ndp: error allocating IPv6 header.\n");
ng_pktbuf_release(pkt);
return;
}
((ng_ipv6_hdr_t *)hdr->data)->hl = 255;
pkt = hdr;
/* add netif header for send interface specification */
hdr = ng_netif_hdr_build(NULL, 0, NULL, 0);
if (hdr == NULL) {
DEBUG("ndp: error allocating netif header.\n");
return;
}
((ng_netif_hdr_t *)hdr->data)->if_pid = iface;
LL_PREPEND(pkt, hdr);
ng_netapi_send(ng_ipv6_pid, pkt);
}
void gnrc_ndp_internal_send_rtr_adv(kernel_pid_t iface, ipv6_addr_t *src, ipv6_addr_t *dst,
bool fin)
{
gnrc_pktsnip_t *hdr, *pkt = NULL;
ipv6_addr_t all_nodes = IPV6_ADDR_ALL_NODES_LINK_LOCAL;
gnrc_ipv6_netif_t *ipv6_iface = gnrc_ipv6_netif_get(iface);
uint32_t reach_time = 0, retrans_timer = 0;
uint16_t adv_ltime = 0;
uint8_t cur_hl = 0;
if (dst == NULL) {
dst = &all_nodes;
}
DEBUG("ndp internal: send router advertisement (iface: %" PRIkernel_pid ", dst: %s%s\n",
iface, ipv6_addr_to_str(addr_str, dst, sizeof(addr_str)), fin ? ", final" : "");
mutex_lock(&ipv6_iface->mutex);
hdr = _add_pios(ipv6_iface, pkt);
if (hdr == NULL) {
/* pkt already released in _add_pios */
mutex_unlock(&ipv6_iface->mutex);
return;
}
pkt = hdr;
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_MTU) {
if ((hdr = gnrc_ndp_opt_mtu_build(ipv6_iface->mtu, pkt)) == NULL) {
DEBUG("ndp rtr: no space left in packet buffer\n");
mutex_unlock(&ipv6_iface->mutex);
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
if (src == NULL) {
/* get address from source selection algorithm */
src = gnrc_ipv6_netif_find_best_src_addr(iface, dst);
}
/* add SL2A for source address */
if (src != NULL) {
DEBUG(" - SL2A\n");
uint8_t l2src[8];
size_t l2src_len;
/* optimization note: MAY also be omitted to facilitate in-bound load balancing over
* replicated interfaces.
* source: https://tools.ietf.org/html/rfc4861#section-6.2.3 */
l2src_len = _get_l2src(iface, l2src, sizeof(l2src));
if (l2src_len > 0) {
/* add source address link-layer address option */
hdr = gnrc_ndp_opt_sl2a_build(l2src, l2src_len, NULL);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating Source Link-layer address option.\n");
mutex_unlock(&ipv6_iface->mutex);
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
}
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_CUR_HL) {
cur_hl = ipv6_iface->cur_hl;
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_REACH_TIME) {
uint64_t tmp = timex_uint64(ipv6_iface->reach_time) / MS_IN_USEC;
if (tmp > (3600 * SEC_IN_MS)) { /* tmp > 1 hour */
tmp = (3600 * SEC_IN_MS);
}
reach_time = (uint32_t)tmp;
}
if (ipv6_iface->flags & GNRC_IPV6_NETIF_FLAGS_ADV_RETRANS_TIMER) {
uint64_t tmp = timex_uint64(ipv6_iface->retrans_timer) / MS_IN_USEC;
if (tmp > UINT32_MAX) {
tmp = UINT32_MAX;
}
retrans_timer = (uint32_t)tmp;
}
if (!fin) {
adv_ltime = ipv6_iface->adv_ltime;
}
mutex_unlock(&ipv6_iface->mutex);
hdr = gnrc_ndp_rtr_adv_build(cur_hl,
(ipv6_iface->flags & (GNRC_IPV6_NETIF_FLAGS_OTHER_CONF |
GNRC_IPV6_NETIF_FLAGS_MANAGED)) >> 8,
adv_ltime, reach_time, retrans_timer, pkt);
if (hdr == NULL) {
DEBUG("ndp internal: error allocating router advertisement.\n");
gnrc_pktbuf_release(pkt);
return;
}
pkt = hdr;
hdr = _build_headers(iface, pkt, dst, src);
if (hdr == NULL) {
DEBUG("ndp internal: error adding lower-layer headers.\n");
gnrc_pktbuf_release(pkt);
return;
}
gnrc_netapi_send(gnrc_ipv6_pid, hdr);
}