ospf_lsa.c

router source code for the ospdf.

      link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, oi->output_cost);
    }
  else
    {
       /* Option 2:  We need to include link to a stub
	 network regardless of the state of the neighbor */
      masklen2ip (oi->address->prefixlen, &mask);
      id.s_addr = oi->address->u.prefix4.s_addr & mask.s_addr;
      link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, oi->output_cost);
    }
  links++;

  return links;
}

/* Describe Broadcast Link. */
int
lsa_link_broadcast_set (struct stream *s, struct ospf_interface *oi)
{
  struct ospf_neighbor *dr;
  struct in_addr id, mask;

  /* Describe Type 3 Link. */
  if (oi->state == ISM_Waiting)
    {
      masklen2ip (oi->address->prefixlen, &mask);
      id.s_addr = oi->address->u.prefix4.s_addr & mask.s_addr;
      link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, oi->output_cost);
      return 1;
    }

  dr = ospf_nbr_lookup_by_addr (oi->nbrs, &DR (oi));
  /* Describe Type 2 link. */
  if (dr && (dr->state == NSM_Full ||
	     IPV4_ADDR_SAME (&oi->address->u.prefix4, &DR (oi))) &&
      ospf_nbr_count (oi, NSM_Full) > 0)
    {
      link_info_set (s, DR (oi), oi->address->u.prefix4,
		     LSA_LINK_TYPE_TRANSIT, 0, oi->output_cost);
    }
  /* Describe type 3 link. */
  else
    {
      masklen2ip (oi->address->prefixlen, &mask);
      id.s_addr = oi->address->u.prefix4.s_addr & mask.s_addr;
      link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, oi->output_cost);
    }
  return 1;
}

int
lsa_link_loopback_set (struct stream *s, struct ospf_interface *oi)
{
  struct in_addr id, mask;

  /* Describe Type 3 Link. */
  if (oi->state != ISM_Loopback)
    return 0;

  mask.s_addr = 0xffffffff;
  id.s_addr = oi->address->u.prefix4.s_addr;
  link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, oi->output_cost);
  return 1;
}

/* Describe Virtual Link. */
int
lsa_link_virtuallink_set (struct stream *s, struct ospf_interface *oi)
{
  struct ospf_neighbor *nbr;

  if (oi->state == ISM_PointToPoint)
    if ((nbr = ospf_nbr_lookup_ptop (oi)))
      if (nbr->state == NSM_Full)
	{
	  link_info_set (s, nbr->router_id, oi->address->u.prefix4,
			 LSA_LINK_TYPE_VIRTUALLINK, 0, oi->output_cost);
	  return 1;
	}

  return 0;
}

#define lsa_link_nbma_set(S,O)  lsa_link_broadcast_set (S, O)

/* This function add for support point-to-multipoint ,see RFC2328
   12.4.1.4.*/
int
lsa_link_ptomp_set (struct stream *s, struct ospf_interface *oi)
{
  int links = 0;
  struct route_node *rn;
  struct ospf_neighbor *nbr = NULL;
  struct in_addr id, mask;

  mask.s_addr = 0xffffffff;
  id.s_addr = oi->address->u.prefix4.s_addr;
  link_info_set (s, id, mask, LSA_LINK_TYPE_STUB, 0, 0);
  links++;

  zlog_info ("PointToMultipoint: running ptomultip_set");

  /* Search neighbor, */
  for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
    if ((nbr = rn->info) != NULL)
      /* Ignore myself. */
      if (!IPV4_ADDR_SAME (&nbr->router_id, &oi->ospf->router_id))
	if (nbr->state == NSM_Full)

	  {
	    link_info_set (s, nbr->router_id, oi->address->u.prefix4,
			   LSA_LINK_TYPE_POINTOPOINT, 0, oi->output_cost);
	    links++;
	    zlog_info ("PointToMultipoint: set link to %s",
		       inet_ntoa(oi->address->u.prefix4));
	  }
  
  return links;
}

/* Set router-LSA link information. */
int
router_lsa_link_set (struct stream *s, struct ospf_area *area)
{
  listnode node;
  int links = 0;

  for (node = listhead (area->oiflist); node; node = nextnode (node))
    {
      struct ospf_interface *oi = node->data;
      struct interface *ifp = oi->ifp;

      /* Check interface is up, OSPF is enable. */
      if (if_is_up (ifp))
	{
	  if (oi->state != ISM_Down)
	    {
	      /* Describe each link. */
	      switch (oi->type)
		{
		case OSPF_IFTYPE_POINTOPOINT:
		  links += lsa_link_ptop_set (s, oi);
		  break;
		case OSPF_IFTYPE_BROADCAST:
		  links += lsa_link_broadcast_set (s, oi);
		  break;
		case OSPF_IFTYPE_NBMA:
		  links += lsa_link_nbma_set (s, oi);
		  break;
		case OSPF_IFTYPE_POINTOMULTIPOINT:
		  links += lsa_link_ptomp_set (s, oi);
		  break;
		case OSPF_IFTYPE_VIRTUALLINK:
		  links += lsa_link_virtuallink_set (s, oi);
		  break;
		case OSPF_IFTYPE_LOOPBACK:
		  links += lsa_link_loopback_set (s, oi); 
		}
	    }
	}
    }

  return links;
}

/* Set router-LSA body. */
void
ospf_router_lsa_body_set (struct stream *s, struct ospf_area *area)
{
  unsigned long putp;
  u_int16_t cnt;

  /* Set flags. */
  stream_putc (s, router_lsa_flags (area));

  /* Set Zero fields. */
  stream_putc (s, 0);

  /* Keep pointer to # links. */
  putp = s->putp;

  /* Forward word */
  stream_putw(s, 0);

  /* Set all link information. */
  cnt = router_lsa_link_set (s, area);

  /* Set # of links here. */
  stream_putw_at (s, putp, cnt);
}

/* Create new router-LSA. */
struct ospf_lsa *
ospf_router_lsa_new (struct ospf_area *area)
{
  struct ospf *ospf = area->ospf;
  struct stream *s;
  struct lsa_header *lsah;
  struct ospf_lsa *new;
  int length;

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("LSA[Type1]: Create router-LSA instance");

  /* Create a stream for LSA. */
  s = stream_new (OSPF_MAX_LSA_SIZE);
  lsah = (struct lsa_header *) STREAM_DATA (s);

#ifdef HAVE_NSSA
  /* Set LSA common header fields. */
  lsa_header_set (s, LSA_OPTIONS_GET (area) | LSA_NSSA_GET (area),
		  OSPF_ROUTER_LSA, ospf->router_id, ospf->router_id);
#else /* ! HAVE_NSSA */
  /* Set LSA common header fields. */
  lsa_header_set (s, LSA_OPTIONS_GET (area),
		  OSPF_ROUTER_LSA, ospf->router_id, ospf->router_id);
#endif /* HAVE_NSSA */

  /* Set router-LSA body fields. */
  ospf_router_lsa_body_set (s, area);

  /* Set length. */
  length = stream_get_endp (s);
  lsah->length = htons (length);

  /* Now, create OSPF LSA instance. */
  new = ospf_lsa_new ();
  new->area = area;
  SET_FLAG (new->flags, OSPF_LSA_SELF);

  /* Copy LSA data to store, discard stream. */
  new->data = ospf_lsa_data_new (length);
  memcpy (new->data, lsah, length);
  stream_free (s);

  return new;
}

/* Originate Router-LSA. */
struct ospf_lsa *
ospf_router_lsa_originate (struct ospf_area *area)
{
  struct ospf_lsa *new;

  /* Create new router-LSA instance. */
  new = ospf_router_lsa_new (area);

  /* Sanity check. */
  if (new->data->adv_router.s_addr == 0)
    {
      if (IS_DEBUG_OSPF_EVENT)
	zlog_info ("LSA[Type1]: AdvRouter is 0, discard");
      ospf_lsa_discard (new);
      return NULL;
    }

  /* Install LSA to LSDB. */
  new = ospf_lsa_install (area->ospf, NULL, new);

  /* Update LSA origination count. */
  area->ospf->lsa_originate_count++;

  /* Flooding new LSA through area. */
  ospf_flood_through_area (area, NULL, new);

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    {
      zlog_info ("LSA[Type%d:%s]: Originate router-LSA %p",
		 new->data->type, inet_ntoa (new->data->id), new);
      ospf_lsa_header_dump (new->data);
    }

  return new;
}

/* Refresh router-LSA. */
struct ospf_lsa *
ospf_router_lsa_refresh (struct ospf_lsa *lsa)
{
  struct ospf_area *area = lsa->area;
  struct ospf_lsa *new;

  /* Sanity check. */
  assert (lsa->data);

  /* Delete LSA from neighbor retransmit-list. */
  ospf_ls_retransmit_delete_nbr_area (area, lsa);

  /* Create new router-LSA instance. */
  new = ospf_router_lsa_new (area);
  new->data->ls_seqnum = lsa_seqnum_increment (lsa);

  ospf_lsa_install (area->ospf, NULL, new);

  /* Flood LSA through area. */
  ospf_flood_through_area (area, NULL, new);

  /* Debug logging. */
  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    {
      zlog_info ("LSA[Type%d:%s]: router-LSA refresh",
		 new->data->type, inet_ntoa (new->data->id));
      ospf_lsa_header_dump (new->data);
    }

  return NULL;
}

int
ospf_router_lsa_timer (struct thread *t)
{
  struct ospf_area *area;

  if (IS_DEBUG_OSPF_EVENT)
    zlog_info ("Timer[router-LSA]: (router-LSA Refresh expire)");

  area = THREAD_ARG (t);
  area->t_router_lsa_self = NULL;

  /* Now refresh router-LSA. */
  if (area->router_lsa_self)
    ospf_router_lsa_refresh (area->router_lsa_self);
  /* Newly originate router-LSA. */
  else
    ospf_router_lsa_originate (area);

  return 0;
}

void
ospf_router_lsa_timer_add (struct ospf_area *area)
{
  /* Keep area's self-originated router-LSA. */
  struct ospf_lsa *lsa = area->router_lsa_self;

  /* Cancel previously scheduled router-LSA timer. */
  if (area->t_router_lsa_self)
    if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
      zlog_info ("LSA[Type1]: Cancel previous router-LSA timer");

  OSPF_TIMER_OFF (area->t_router_lsa_self);

  /* If router-LSA is originated previously, check the interval time. */
  if (lsa)
    {
      int delay;
      if ((delay = ospf_lsa_refresh_delay (lsa)) > 0)
        {
	  OSPF_AREA_TIMER_ON (area->t_router_lsa_self,
			      ospf_router_lsa_timer, delay);
	  return;
        }
    }

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("LSA[Type1]: Scheduling router-LSA origination right away");

  /* Immediately refresh router-LSA. */
  OSPF_AREA_TIMER_ON (area->t_router_lsa_self, ospf_router_lsa_timer, 0);
}

int
ospf_router_lsa_update_timer (struct thread *thread)
{
  struct ospf *ospf = THREAD_ARG (thread);
  listnode node;

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("Timer[router-LSA Update]: (timer expire)");

  ospf->t_router_lsa_update = NULL;

  for (node = listhead (ospf->areas); node; nextnode (node))
    {
      struct ospf_area *area = getdata (node);
      struct ospf_lsa *lsa = area->router_lsa_self;
      struct router_lsa *rl;
      char *area_str;

      /* Keep Area ID string. */
      area_str = AREA_NAME (area);

      /* If LSA not exist in this Area, originate new. */
      if (lsa == NULL)
        {
	  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
	    zlog_info("LSA[Type1]: Create router-LSA for Area %s", area_str);

	  ospf_router_lsa_originate (area);
        }
      /* If router-ID is changed, Link ID must change.
	 First flush old LSA, then originate new. */
      else if (!IPV4_ADDR_SAME (&lsa->data->id, &ospf->router_id))
	{
	  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
	    zlog_info("LSA[Type%d:%s]: Refresh router-LSA for Area %s",
		      lsa->data->type, inet_ntoa (lsa->data->id), area_str);
	  ospf_lsa_flush_area (lsa, area);
	  ospf_lsa_unlock (area->router_lsa_self);
	  area->router_lsa_self = NULL;

	  /* Refresh router-LSA, (not install) and flood through area. */
	  ospf_router_lsa_timer_add (area);
	}
      else
	{
	  rl = (struct router_lsa *) lsa->data;
	  /* Refresh router-LSA, (not install) and flood through area. */
	  if (rl->flags != ospf->flags)
	    ospf_router_lsa_timer_add (area);
	}
    }

  return 0;
}


/* network-LSA related functions. */
/* Originate Network-LSA. */
void
ospf_network_lsa_body_set (struct stream *s, struct ospf_interface *oi)
{
  struct in_addr mask;
  struct route_node *rn;
  struct ospf_neighbor *nbr;

  masklen2ip (oi->address->prefixlen, &mask);
  stream_put_ipv4 (s, mask.s_addr);

  /* The network-LSA lists those routers that are fully adjacent to
    the Designated Router; each fully adjacent router is identified by
    its OSPF Router ID.  The Designated Router includes itself in this
    list. RFC2328, Section 12.4.2 */

  for (rn = route_top (oi->nbrs); rn; rn = route_next (rn))
    if ((nbr = rn->info) != NULL)
      if (nbr->state == NSM_Full || nbr == oi->nbr_self)
	stream_put_ipv4 (s, nbr->router_id.s_addr);
}

struct ospf_lsa *
ospf_network_lsa_new (struct ospf_interface *oi)
{
  struct stream *s;
  struct ospf_lsa *new;
  struct lsa_header *lsah;
  int length;

  /* If there are no neighbours on this network (the net is stub),
     the router does not originate network-LSA (see RFC 12.4.2) */
  if (oi->full_nbrs == 0)
    return NULL;
  
  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("LSA[Type2]: Create network-LSA instance");

  /* Create new stream for LSA. */
  s = stream_new (OSPF_MAX_LSA_SIZE);
  lsah = (struct lsa_header *) STREAM_DATA (s);

  lsa_header_set (s, (OPTIONS (oi) | LSA_OPTIONS_GET (oi->area)),
		  OSPF_NETWORK_LSA, DR (oi), oi->ospf->router_id);

  /* Set network-LSA body fields. */
  ospf_network_lsa_body_set (s, oi);

  /* Set length. */
  length = stream_get_endp (s);
  lsah->length = htons (length);

  /* Create OSPF LSA instance. */
  new = ospf_lsa_new ();
  new->area = oi->area;
  SET_FLAG (new->flags, OSPF_LSA_SELF);

  /* Copy LSA to store. */
  new->data = ospf_lsa_data_new (length);
  memcpy (new->data, lsah, length);
  stream_free (s);

  return new;
}

/* Originate network-LSA. */
struct ospf_lsa *
ospf_network_lsa_originate (struct ospf_interface *oi)
{
  struct ospf_lsa *new;

  /* Create new network-LSA instance. */
  new = ospf_network_lsa_new (oi);
  if (new == NULL)
    return NULL;

  /* Install LSA to LSDB. */
  new = ospf_lsa_install (oi->ospf, oi, new);

  /* Update LSA origination count. */
  oi->ospf->lsa_originate_count++;

  /* Flooding new LSA through area. */
  ospf_flood_through_area (oi->area, NULL, new);

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    {
      zlog_info ("LSA[Type%d:%s]: Originate network-LSA %p",
		 new->data->type, inet_ntoa (new->data->id), new);
      ospf_lsa_header_dump (new->data);
    }

  return new;
}

int
ospf_network_lsa_refresh (struct ospf_lsa *lsa, struct ospf_interface *oi)