ra_input(void)
{
  uip_lladdr_t lladdr_aligned;

  LOG_INFO("Received RA from ");
  LOG_INFO_6ADDR(&UIP_IP_BUF->srcipaddr);
  LOG_INFO_(" to ");
  LOG_INFO_6ADDR(&UIP_IP_BUF->destipaddr);
  LOG_INFO_("\n");
  UIP_STAT(++uip_stat.nd6.recv);

#if UIP_CONF_IPV6_CHECKS
  if((UIP_IP_BUF->ttl != UIP_ND6_HOP_LIMIT) ||
     (!uip_is_addr_linklocal(&UIP_IP_BUF->srcipaddr)) ||
     (UIP_ICMP_BUF->icode != 0)) {
    LOG_ERR("RA received is bad");
    goto discard;
  }
#endif /*UIP_CONF_IPV6_CHECKS */

  if(UIP_ND6_RA_BUF->cur_ttl != 0) {
    uip_ds6_if.cur_hop_limit = UIP_ND6_RA_BUF->cur_ttl;
    LOG_INFO("uip_ds6_if.cur_hop_limit %u\n", uip_ds6_if.cur_hop_limit);
  }

  if(UIP_ND6_RA_BUF->reachable_time != 0) {
    if(uip_ds6_if.base_reachable_time !=
       uip_ntohl(UIP_ND6_RA_BUF->reachable_time)) {
      uip_ds6_if.base_reachable_time = uip_ntohl(UIP_ND6_RA_BUF->reachable_time);
      uip_ds6_if.reachable_time = uip_ds6_compute_reachable_time();
    }
  }
  if(UIP_ND6_RA_BUF->retrans_timer != 0) {
    uip_ds6_if.retrans_timer = uip_ntohl(UIP_ND6_RA_BUF->retrans_timer);
  }

  /* Options processing */
  nd6_opt_offset = UIP_ND6_RA_LEN;
  while(uip_l3_icmp_hdr_len + nd6_opt_offset < uip_len) {
    if(ND6_OPT_HDR_BUF(nd6_opt_offset)->len == 0) {
      LOG_ERR("RA received is bad");
      goto discard;
    }
    switch (ND6_OPT_HDR_BUF(nd6_opt_offset)->type) {
    case UIP_ND6_OPT_SLLAO:
      LOG_DBG("Processing SLLAO option in RA\n");
      nd6_opt_llao = (uint8_t *) ND6_OPT_HDR_BUF(nd6_opt_offset);
      nbr = uip_ds6_nbr_lookup(&UIP_IP_BUF->srcipaddr);
      if(!extract_lladdr_from_llao_aligned(&lladdr_aligned)) {
        /* failed to extract llao - discard packet */
        goto discard;
      }
      if(nbr == NULL) {
        nbr = uip_ds6_nbr_add(&UIP_IP_BUF->srcipaddr, &lladdr_aligned,
                              1, NBR_STALE, NBR_TABLE_REASON_IPV6_ND, NULL);
      } else {
        const uip_lladdr_t *lladdr = uip_ds6_nbr_get_ll(nbr);
        if(lladdr == NULL) {
          goto discard;
        }
        if(nbr->state == NBR_INCOMPLETE) {
          nbr->state = NBR_STALE;
        }
        if(memcmp(&nd6_opt_llao[UIP_ND6_OPT_DATA_OFFSET],
                  lladdr, UIP_LLADDR_LEN) != 0) {
          /* change of link layer address */
          if(uip_ds6_nbr_update_ll(&nbr,
                                   (const uip_lladdr_t *)&lladdr_aligned) < 0) {
            /* failed to update the lladdr */
            goto discard;
          }
          nbr->state = NBR_STALE;
        }
        nbr->isrouter = 1;
      }
      break;
    case UIP_ND6_OPT_MTU:
      LOG_DBG("Processing MTU option in RA\n");
      uip_ds6_if.link_mtu =
        uip_ntohl(((uip_nd6_opt_mtu *) ND6_OPT_HDR_BUF(nd6_opt_offset))->mtu);
      break;
    case UIP_ND6_OPT_PREFIX_INFO:
      LOG_DBG("Processing PREFIX option in RA\n");
      nd6_opt_prefix_info = (uip_nd6_opt_prefix_info *) ND6_OPT_HDR_BUF(nd6_opt_offset);
      if((uip_ntohl(nd6_opt_prefix_info->validlt) >=
          uip_ntohl(nd6_opt_prefix_info->preferredlt))
         && (!uip_is_addr_linklocal(&nd6_opt_prefix_info->prefix))) {
        /* on-link flag related processing */
        if(nd6_opt_prefix_info->flagsreserved1 & UIP_ND6_RA_FLAG_ONLINK) {
          prefix =
            uip_ds6_prefix_lookup(&nd6_opt_prefix_info->prefix,
                                  nd6_opt_prefix_info->preflen);
          if(prefix == NULL) {
            if(nd6_opt_prefix_info->validlt != 0) {
              if(nd6_opt_prefix_info->validlt != UIP_ND6_INFINITE_LIFETIME) {
                prefix = uip_ds6_prefix_add(&nd6_opt_prefix_info->prefix,
                                            nd6_opt_prefix_info->preflen,
                                            uip_ntohl(nd6_opt_prefix_info->
                                                  validlt));
              } else {
                prefix = uip_ds6_prefix_add(&nd6_opt_prefix_info->prefix,
                                            nd6_opt_prefix_info->preflen, 0);
              }
            }
          } else {
            switch (nd6_opt_prefix_info->validlt) {
            case 0:
              uip_ds6_prefix_rm(prefix);
              break;
            case UIP_ND6_INFINITE_LIFETIME:
              prefix->isinfinite = 1;
              break;
            default:
              LOG_DBG("Updating timer of prefix ");
              LOG_DBG_6ADDR(&prefix->ipaddr);
              LOG_DBG_(" new value %"PRIu32"\n", uip_ntohl(nd6_opt_prefix_info->validlt));
              stimer_set(&prefix->vlifetime,
                         uip_ntohl(nd6_opt_prefix_info->validlt));
              prefix->isinfinite = 0;
              break;
            }
          }
        }
        /* End of on-link flag related processing */
        /* autonomous flag related processing */
        if((nd6_opt_prefix_info->flagsreserved1 & UIP_ND6_RA_FLAG_AUTONOMOUS)
           && (nd6_opt_prefix_info->validlt != 0)
           && (nd6_opt_prefix_info->preflen == UIP_DEFAULT_PREFIX_LEN)) {

          uip_ipaddr_copy(&ipaddr, &nd6_opt_prefix_info->prefix);
          uip_ds6_set_addr_iid(&ipaddr, &uip_lladdr);
          addr = uip_ds6_addr_lookup(&ipaddr);
          if((addr != NULL) && (addr->type == ADDR_AUTOCONF)) {
            if(nd6_opt_prefix_info->validlt != UIP_ND6_INFINITE_LIFETIME) {
              /* The processing below is defined in RFC4862 section 5.5.3 e */
              if((uip_ntohl(nd6_opt_prefix_info->validlt) > 2 * 60 * 60) ||
                 (uip_ntohl(nd6_opt_prefix_info->validlt) >
                  stimer_remaining(&addr->vlifetime))) {
                LOG_DBG("Updating timer of address ");
                LOG_DBG_6ADDR(&addr->ipaddr);
                LOG_DBG_(" new value %lu\n",
                       (unsigned long)uip_ntohl(nd6_opt_prefix_info->validlt));
                stimer_set(&addr->vlifetime,
                           uip_ntohl(nd6_opt_prefix_info->validlt));
              } else {
                stimer_set(&addr->vlifetime, 2 * 60 * 60);
                LOG_DBG("Updating timer of address ");
                LOG_DBG_6ADDR(&addr->ipaddr);
                LOG_DBG_(" new value %lu\n", (unsigned long)(2 * 60 * 60));
              }
              addr->isinfinite = 0;
            } else {
              addr->isinfinite = 1;
            }
          } else {
            if(uip_ntohl(nd6_opt_prefix_info->validlt) ==
               UIP_ND6_INFINITE_LIFETIME) {
              uip_ds6_addr_add(&ipaddr, 0, ADDR_AUTOCONF);
            } else {
              uip_ds6_addr_add(&ipaddr, uip_ntohl(nd6_opt_prefix_info->validlt),
                               ADDR_AUTOCONF);
            }
          }
        }
        /* End of autonomous flag related processing */
      }
      break;
#if UIP_ND6_RA_RDNSS
    case UIP_ND6_OPT_RDNSS:
      LOG_DBG("Processing RDNSS option\n");
      uint8_t naddr = (ND6_OPT_RDNSS_BUF(nd6_opt_offset)->len - 1) / 2;
      uip_ipaddr_t *ip = (uip_ipaddr_t *)(&ND6_OPT_RDNSS_BUF(nd6_opt_offset)->ip);
      LOG_DBG("got %d nameservers\n", naddr);
      while(naddr-- > 0) {
        LOG_DBG("nameserver: ");
        LOG_DBG_6ADDR(ip);
        LOG_DBG_(" lifetime: %"PRIx32"\n", uip_ntohl(ND6_OPT_RDNSS_BUF(nd6_opt_offset)->lifetime));
        uip_nameserver_update(ip, uip_ntohl(ND6_OPT_RDNSS_BUF(nd6_opt_offset)->lifetime));
        ip++;
      }
      break;
#endif /* UIP_ND6_RA_RDNSS */
    default:
      LOG_ERR("ND option not supported in RA\n");
      break;
    }
    nd6_opt_offset += (ND6_OPT_HDR_BUF(nd6_opt_offset)->len << 3);
  }

  defrt = uip_ds6_defrt_lookup(&UIP_IP_BUF->srcipaddr);
  if(UIP_ND6_RA_BUF->router_lifetime != 0) {
    if(nbr != NULL) {
      nbr->isrouter = 1;
    }
    if(defrt == NULL) {
      uip_ds6_defrt_add(&UIP_IP_BUF->srcipaddr,
                        (unsigned
                         long)(uip_ntohs(UIP_ND6_RA_BUF->router_lifetime)));
    } else {
      stimer_set(&(defrt->lifetime),
                 (unsigned long)(uip_ntohs(UIP_ND6_RA_BUF->router_lifetime)));
    }
  } else {
    if(defrt != NULL) {
      uip_ds6_defrt_rm(defrt);
    }
  }

#if UIP_CONF_IPV6_QUEUE_PKT
  /* If the nbr just became reachable (e.g. it was in NBR_INCOMPLETE state
   * and we got a SLLAO), check if we had buffered a pkt for it */
  /*  if((nbr != NULL) && (nbr->queue_buf_len != 0)) {
    uip_len = nbr->queue_buf_len;
    memcpy(UIP_IP_BUF, nbr->queue_buf, uip_len);
    nbr->queue_buf_len = 0;
    return;
    }*/
  if(nbr != NULL && uip_packetqueue_buflen(&nbr->packethandle) != 0) {
    uip_len = uip_packetqueue_buflen(&nbr->packethandle);
    memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
    uip_packetqueue_free(&nbr->packethandle);
    return;
  }

#endif /*UIP_CONF_IPV6_QUEUE_PKT */

discard:
  uipbuf_clear();
  return;
}