ospf_lsa.c

router source code for the ospdf.

{
  struct ospf_area *area = lsa->area;
  struct ospf_lsa *new;

  assert (lsa->data);

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

  /* Create new network-LSA instance. */
  new = ospf_network_lsa_new (oi);
  if (new == NULL)
    return -1;
  new->data->ls_seqnum = lsa_seqnum_increment (lsa);

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

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

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

  return 0;
}

int
ospf_network_lsa_refresh_timer (struct thread *t)
{
  struct ospf_interface *oi;

  oi = THREAD_ARG (t);
  oi->t_network_lsa_self = NULL;

  if (oi->network_lsa_self)
    /* Now refresh network-LSA. */
    ospf_network_lsa_refresh (oi->network_lsa_self, oi);
  else
    /* Newly create network-LSA. */
    ospf_network_lsa_originate (oi);

  return 0;
}

void
ospf_network_lsa_timer_add (struct ospf_interface *oi)
{
  /* Keep interface's self-originated network-LSA. */
  struct ospf_lsa *lsa = oi->network_lsa_self;

  /* Cancel previously schedules network-LSA timer. */
  if (oi->t_network_lsa_self)
    if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
      zlog_info ("LSA[Type2]: Cancel previous network-LSA timer");
  OSPF_TIMER_OFF (oi->t_network_lsa_self);

  /* If network-LSA is originated previously, check the interval time. */
  if (lsa)
    {
      int delay;
      if ((delay = ospf_lsa_refresh_delay (lsa)) > 0)
        {
          oi->t_network_lsa_self =
            thread_add_timer (master, ospf_network_lsa_refresh_timer,
			      oi, delay);
          return;
        }
    }

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("Scheduling network-LSA origination right away");

  /* Immediately refresh network-LSA. */
  oi->t_network_lsa_self =
    thread_add_event (master, ospf_network_lsa_refresh_timer, oi, 0);
}


void
stream_put_ospf_metric (struct stream *s, u_int32_t metric_value)
{
  u_int32_t metric;
  char *mp;

  /* Put 0 metric. TOS metric is not supported. */
  metric = htonl (metric_value);
  mp = (char *) &metric;
  mp++;
  stream_put (s, mp, 3);
}

/* summary-LSA related functions. */
void
ospf_summary_lsa_body_set (struct stream *s, struct prefix *p,
			   u_int32_t metric)
{
  struct in_addr mask;

  masklen2ip (p->prefixlen, &mask);

  /* Put Network Mask. */
  stream_put_ipv4 (s, mask.s_addr);

  /* Set # TOS. */
  stream_putc (s, (u_char) 0);

  /* Set metric. */
  stream_put_ospf_metric (s, metric);
}

struct ospf_lsa *
ospf_summary_lsa_new (struct ospf_area *area, struct prefix *p,
		      u_int32_t metric, struct in_addr id)
{
  struct stream *s;
  struct ospf_lsa *new;
  struct lsa_header *lsah;
  int length;

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("LSA[Type3]: Create summary-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, LSA_OPTIONS_GET (area), OSPF_SUMMARY_LSA,
		  id, area->ospf->router_id);

  /* Set summary-LSA body fields. */
  ospf_summary_lsa_body_set (s, p, metric);

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

  /* Create OSPF LSA instance. */
  new = ospf_lsa_new ();
  new->area = 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 Summary-LSA. */
struct ospf_lsa *
ospf_summary_lsa_originate (struct prefix_ipv4 *p, u_int32_t metric, 
			    struct ospf_area *area)
{
  struct ospf_lsa *new;
  struct in_addr id;
  
  id = ospf_lsa_unique_id (area->ospf, area->lsdb, OSPF_SUMMARY_LSA, p);

  /* Create new summary-LSA instance. */
  new = ospf_summary_lsa_new (area, (struct prefix *) p, metric, id);

  /* Instlal 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 summary-LSA %p",
		 new->data->type, inet_ntoa (new->data->id), new);
      ospf_lsa_header_dump (new->data);
    }

  return new;
}

struct ospf_lsa*
ospf_summary_lsa_refresh (struct ospf *ospf, struct ospf_lsa *lsa)
{
  struct ospf_lsa *new;
  struct summary_lsa *sl;
  struct prefix p;
  
  /* Sanity check. */
  assert (lsa->data);

  sl = (struct summary_lsa *)lsa->data;
  p.prefixlen = ip_masklen (sl->mask);
  new = ospf_summary_lsa_new (lsa->area, &p, GET_METRIC (sl->metric),
			      sl->header.id);

  new->data->ls_seqnum = lsa_seqnum_increment (lsa);
  
  /* Re-calculate checksum. */
  ospf_lsa_checksum (new->data);

  ospf_lsa_install (ospf, NULL, new);
  
  /* Flood LSA through AS. */
  ospf_flood_through_area (new->area, NULL, new);

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


/* summary-ASBR-LSA related functions. */
void
ospf_summary_asbr_lsa_body_set (struct stream *s, struct prefix *p,
				u_int32_t metric)
{
  struct in_addr mask;

  masklen2ip (p->prefixlen, &mask);

  /* Put Network Mask. */
  stream_put_ipv4 (s, mask.s_addr);

  /* Set # TOS. */
  stream_putc (s, (u_char) 0);

  /* Set metric. */
  stream_put_ospf_metric (s, metric);
}

struct ospf_lsa *
ospf_summary_asbr_lsa_new (struct ospf_area *area, struct prefix *p,
			   u_int32_t metric, struct in_addr id)
{
  struct stream *s;
  struct ospf_lsa *new;
  struct lsa_header *lsah;
  int length;

  if (IS_DEBUG_OSPF (lsa, LSA_GENERATE))
    zlog_info ("LSA[Type3]: Create summary-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, LSA_OPTIONS_GET (area), OSPF_ASBR_SUMMARY_LSA,
		  id, area->ospf->router_id);

  /* Set summary-LSA body fields. */
  ospf_summary_asbr_lsa_body_set (s, p, metric);

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

  /* Create OSPF LSA instance. */
  new = ospf_lsa_new ();
  new->area = 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 summary-ASBR-LSA. */
struct ospf_lsa *
ospf_summary_asbr_lsa_originate (struct prefix_ipv4 *p, u_int32_t metric, 
				 struct ospf_area *area)
{
  struct ospf_lsa *new;
  struct in_addr id;
  
  id = ospf_lsa_unique_id (area->ospf, area->lsdb, OSPF_ASBR_SUMMARY_LSA, p);

  /* Create new summary-LSA instance. */
  new = ospf_summary_asbr_lsa_new (area, (struct prefix *) p, metric, id);

  /* 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 summary-ASBR-LSA %p",
		 new->data->type, inet_ntoa (new->data->id), new);
      ospf_lsa_header_dump (new->data);
    }

  return new;
}

struct ospf_lsa*
ospf_summary_asbr_lsa_refresh (struct ospf *ospf, struct ospf_lsa *lsa)
{
  struct ospf_lsa *new;
  struct summary_lsa *sl;
  struct prefix p;

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

  sl = (struct summary_lsa *)lsa->data;
  p.prefixlen = ip_masklen (sl->mask);
  new = ospf_summary_asbr_lsa_new (lsa->area, &p, GET_METRIC (sl->metric),
				   sl->header.id);
  
  new->data->ls_seqnum = lsa_seqnum_increment (lsa);
  
  /* Re-calculate checksum. */
  ospf_lsa_checksum (new->data);

  ospf_lsa_install (ospf, NULL, new);
  
  /* Flood LSA through area. */
  ospf_flood_through_area (new->area, NULL, new);

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

  return new;
}

/* AS-external-LSA related functions. */

/* Get nexthop for AS-external-LSAs.  Return nexthop if its interface
   is connected, else 0*/
struct in_addr
ospf_external_lsa_nexthop_get (struct ospf *ospf, struct in_addr nexthop)
{
  struct in_addr fwd;
  struct prefix nh;
  listnode n1;

  fwd.s_addr = 0;

  if (!nexthop.s_addr)
    return fwd;

  /* Check whether nexthop is covered by OSPF network. */
  nh.family = AF_INET;
  nh.u.prefix4 = nexthop;
  nh.prefixlen = IPV4_MAX_BITLEN;

  for (n1 = listhead (ospf->oiflist); n1; nextnode (n1))
    {
      struct ospf_interface *oi = getdata (n1);

      if (if_is_up (oi->ifp))
	if (oi->address->family == AF_INET)
	  if (prefix_match (oi->address, &nh))
	    return nexthop;
    }

  return fwd;
}

#ifdef HAVE_NSSA
/* NSSA-external-LSA related functions. */

/* Get 1st IP connection for Forward Addr */
          
struct in_addr
ospf_get_ip_from_ifp (struct ospf_interface *oi)
{
  struct in_addr fwd;

  fwd.s_addr = 0;

  if (if_is_up (oi->ifp))
    return oi->address->u.prefix4;
  
  return fwd;
}

/* Get 1st IP connection for Forward Addr */
struct in_addr
ospf_get_nssa_ip (struct ospf_area *area)
{
  struct in_addr fwd;
  struct in_addr best_default;
  listnode n1;

  fwd.s_addr = 0;
  best_default.s_addr = 0;

  for (n1 = listhead (area->ospf->oiflist); n1; nextnode (n1))
    {
      struct ospf_interface *oi = getdata (n1);

      if (if_is_up (oi->ifp))
	if (oi->area->external_routing == OSPF_AREA_NSSA)
	  if (oi->address && oi->address->family == AF_INET)
	    {
	      if (best_default.s_addr == 0)
		best_default = oi->address->u.prefix4;
	      if (oi->area == area)
		return oi->address->u.prefix4;
	    }
    }

  if (best_default.s_addr != 0)
    return best_default;

  return fwd;
}
#endif /* HAVE_NSSA */

#define DEFAULT_DEFAULT_METRIC	             20
#define DEFAULT_DEFAULT_ORIGINATE_METRIC     10
#define DEFAULT_DEFAULT_ALWAYS_METRIC	      1

#define DEFAULT_METRIC_TYPE		     EXTERNAL_METRIC_TYPE_2

int
metric_type (struct ospf *ospf, u_char src)
{
  return (ospf->dmetric[src].type < 0 ?
	  DEFAULT_METRIC_TYPE : ospf->dmetric[src].type);
}

int
metric_value (struct ospf *ospf, u_char src)
{
  if (ospf->dmetric[src].value < 0)
    {
      if (src == DEFAULT_ROUTE)
	{
	  if (ospf->default_originate == DEFAULT_ORIGINATE_ZEBRA)
	    return DEFAULT_DEFAULT_ORIGINATE_METRIC;
	  else
	    return DEFAULT_DEFAULT_ALWAYS_METRIC;
	}
      else if (ospf->default_metric < 0)
	return DEFAULT_DEFAULT_METRIC;
      else
	return ospf->default_metric;
    }

  return ospf->dmetric[src].value;
}

/* Set AS-external-LSA body. */
void
ospf_external_lsa_body_set (struct stream *s, struct external_info *ei,
			    struct ospf *ospf)
{
  struct prefix_ipv4 *p = &ei->p;
  struct in_addr mask, fwd_addr;
  u_int32_t mvalue;
  int mtype;
  int type;

  /* Put Network Mask. */
  masklen2ip (p->prefixlen, &mask);
  stream_put_ipv4 (s, mask.s_addr);

  /* If prefix is default, specify DEFAULT_ROUTE. */
  type = is_prefix_default (&ei->p) ? DEFAULT_ROUTE : ei->type;
  
  mtype = (ROUTEMAP_METRIC_TYPE (ei) != -1) ?
    ROUTEMAP_METRIC_TYPE (ei) : metric_type (ospf, type);

  mvalue = (ROUTEMAP_METRIC (ei) != -1) ?
    ROUTEMAP_METRIC (ei) : metric_value (ospf, type);

  /* Put type of external metric. */
  stream_putc (s, (mtype == EXTERNAL_METRIC_TYPE_2 ? 0x80 : 0));

  /* Put 0 metric. TOS metric is not supported. */
  stream_put_ospf_metric (s, mvalue);
  
  /* Get forwarding address to nexthop if on the Connection List, else 0. */
  fwd_addr = ospf_external_lsa_nexthop_get (ospf, ei->nexthop);

  /* Put forwarding address. */
  stream_put_ipv4 (s, fwd_addr.s_addr);
  
  /* Put route tag -- This value should be introduced from configuration. */
  stream_putl (s, 0);
}

/* Create new external-LSA. */
struct ospf_lsa *
ospf_external_lsa_new (struct ospf *ospf,
		       struct external_info *ei, struct in_addr *old_id)
{
  struct stream *s;
  struct lsa_header *lsah;
  struct ospf_lsa *new;
  struct in_addr id;