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; } }