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);
}
}
