frr/isisd/isis_lsp.c

/*
 * IS-IS Rout(e)ing protocol - isis_lsp.c
 *                             LSP processing
 *
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology      
 *                           Institute of Communications Engineering
 * Copyright (C) 2013-2015   Christian Franke <chris@opensourcerouting.org>
 *
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU General Public License as published by the Free 
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,but WITHOUT 
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for 
 * more details.

 * You should have received a copy of the GNU General Public License along 
 * with this program; if not, write to the Free Software Foundation, Inc., 
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#include <zebra.h>

#include "linklist.h"
#include "thread.h"
#include "vty.h"
#include "stream.h"
#include "memory.h"
#include "log.h"
#include "prefix.h"
#include "command.h"
#include "hash.h"
#include "if.h"
#include "checksum.h"
#include "md5.h"
#include "table.h"

#include "isisd/dict.h"
#include "isisd/isis_constants.h"
#include "isisd/isis_common.h"
#include "isisd/isis_flags.h"
#include "isisd/isis_circuit.h"
#include "isisd/isisd.h"
#include "isisd/isis_tlv.h"
#include "isisd/isis_lsp.h"
#include "isisd/isis_pdu.h"
#include "isisd/isis_dynhn.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_csm.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_spf.h"
#include "isisd/isis_te.h"

/* staticly assigned vars for printing purposes */
char lsp_bits_string[200];     /* FIXME: enough ? */

static int lsp_l1_refresh (struct thread *thread);
static int lsp_l2_refresh (struct thread *thread);
static int lsp_l1_refresh_pseudo (struct thread *thread);
static int lsp_l2_refresh_pseudo (struct thread *thread);

int
lsp_id_cmp (u_char * id1, u_char * id2)
{
  return memcmp (id1, id2, ISIS_SYS_ID_LEN + 2);
}

dict_t *
lsp_db_init (void)
{
  dict_t *dict;

  dict = dict_create (DICTCOUNT_T_MAX, (dict_comp_t) lsp_id_cmp);

  return dict;
}

struct isis_lsp *
lsp_search (u_char * id, dict_t * lspdb)
{
  dnode_t *node;

#ifdef EXTREME_DEBUG
  dnode_t *dn;

  zlog_debug ("searching db");
  for (dn = dict_first (lspdb); dn; dn = dict_next (lspdb, dn))
    {
      zlog_debug ("%s\t%pX", rawlspid_print ((u_char *) dnode_getkey (dn)),
		  dnode_get (dn));
    }
#endif /* EXTREME DEBUG */

  node = dict_lookup (lspdb, id);

  if (node)
    return (struct isis_lsp *) dnode_get (node);

  return NULL;
}

static void
lsp_clear_data (struct isis_lsp *lsp)
{
  if (!lsp)
    return;

  if (lsp->tlv_data.hostname)
    isis_dynhn_remove (lsp->lsp_header->lsp_id);

  if (lsp->own_lsp)
    {
      if (lsp->tlv_data.nlpids)
        XFREE (MTYPE_ISIS_TLV, lsp->tlv_data.nlpids);
      if (lsp->tlv_data.hostname)
        XFREE (MTYPE_ISIS_TLV, lsp->tlv_data.hostname);
      if (lsp->tlv_data.router_id)
        XFREE (MTYPE_ISIS_TLV, lsp->tlv_data.router_id);
    }

  free_tlvs (&lsp->tlv_data);
}

static void
lsp_destroy (struct isis_lsp *lsp)
{
  struct listnode *cnode, *lnode, *lnnode;
  struct isis_lsp *lsp_in_list;
  struct isis_circuit *circuit;

  if (!lsp)
    return;

  if (lsp->area->circuit_list) {
    for (ALL_LIST_ELEMENTS_RO (lsp->area->circuit_list, cnode, circuit))
      {
        if (circuit->lsp_queue == NULL)
          continue;
        for (ALL_LIST_ELEMENTS (circuit->lsp_queue, lnode, lnnode, lsp_in_list))
          if (lsp_in_list == lsp)
            list_delete_node(circuit->lsp_queue, lnode);
      }
  }
  ISIS_FLAGS_CLEAR_ALL (lsp->SSNflags);
  ISIS_FLAGS_CLEAR_ALL (lsp->SRMflags);

  lsp_clear_data (lsp);

  if (LSP_FRAGMENT (lsp->lsp_header->lsp_id) == 0 && lsp->lspu.frags)
    {
      list_delete (lsp->lspu.frags);
      lsp->lspu.frags = NULL;
    }

  isis_spf_schedule (lsp->area, lsp->level);
#ifdef HAVE_IPV6
  isis_spf_schedule6 (lsp->area, lsp->level);
#endif

  if (lsp->pdu)
    stream_free (lsp->pdu);
  XFREE (MTYPE_ISIS_LSP, lsp);
}

void
lsp_db_destroy (dict_t * lspdb)
{
  dnode_t *dnode, *next;
  struct isis_lsp *lsp;

  dnode = dict_first (lspdb);
  while (dnode)
    {
      next = dict_next (lspdb, dnode);
      lsp = dnode_get (dnode);
      lsp_destroy (lsp);
      dict_delete_free (lspdb, dnode);
      dnode = next;
    }

  dict_free (lspdb);

  return;
}

/*
 * Remove all the frags belonging to the given lsp
 */
static void
lsp_remove_frags (struct list *frags, dict_t * lspdb)
{
  dnode_t *dnode;
  struct listnode *lnode, *lnnode;
  struct isis_lsp *lsp;

  for (ALL_LIST_ELEMENTS (frags, lnode, lnnode, lsp))
    {
      dnode = dict_lookup (lspdb, lsp->lsp_header->lsp_id);
      lsp_destroy (lsp);
      dnode_destroy (dict_delete (lspdb, dnode));
    }

  list_delete_all_node (frags);

  return;
}

void
lsp_search_and_destroy (u_char * id, dict_t * lspdb)
{
  dnode_t *node;
  struct isis_lsp *lsp;

  node = dict_lookup (lspdb, id);
  if (node)
    {
      node = dict_delete (lspdb, node);
      lsp = dnode_get (node);
      /*
       * If this is a zero lsp, remove all the frags now 
       */
      if (LSP_FRAGMENT (lsp->lsp_header->lsp_id) == 0)
	{
	  if (lsp->lspu.frags)
	    lsp_remove_frags (lsp->lspu.frags, lspdb);
	}
      else
	{
	  /* 
	   * else just remove this frag, from the zero lsps' frag list
	   */
	  if (lsp->lspu.zero_lsp && lsp->lspu.zero_lsp->lspu.frags)
	    listnode_delete (lsp->lspu.zero_lsp->lspu.frags, lsp);
	}
      lsp_destroy (lsp);
      dnode_destroy (node);
    }
}

/*
 * Compares a LSP to given values
 * Params are given in net order
 */
int
lsp_compare (char *areatag, struct isis_lsp *lsp, u_int32_t seq_num,
	     u_int16_t checksum, u_int16_t rem_lifetime)
{
  /* no point in double ntohl on seqnum */
  if (lsp->lsp_header->seq_num == seq_num &&
      lsp->lsp_header->checksum == checksum &&
      /*comparing with 0, no need to do ntohl */
      ((lsp->lsp_header->rem_lifetime == 0 && rem_lifetime == 0) ||
       (lsp->lsp_header->rem_lifetime != 0 && rem_lifetime != 0)))
    {
      if (isis->debugs & DEBUG_SNP_PACKETS)
	{
	  zlog_debug ("ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04x,"
		      " lifetime %us",
		      areatag,
		      rawlspid_print (lsp->lsp_header->lsp_id),
		      ntohl (lsp->lsp_header->seq_num),
		      ntohs (lsp->lsp_header->checksum),
		      ntohs (lsp->lsp_header->rem_lifetime));
	  zlog_debug ("ISIS-Snp (%s):         is equal to ours seq 0x%08x,"
		      " cksum 0x%04x, lifetime %us",
		      areatag,
		      ntohl (seq_num), ntohs (checksum), ntohs (rem_lifetime));
	}
      return LSP_EQUAL;
    }

  /*
   * LSPs with identical checksums should only be treated as newer if:
   * a) The current LSP has a remaining lifetime != 0 and the other LSP has a
   *    remaining lifetime == 0. In this case, we should participate in the purge
   *    and should not treat the current LSP with remaining lifetime == 0 as older.
   * b) The LSP has an incorrect checksum. In this case, we need to react as given
   *    in 7.3.16.2.
   */
   if (ntohl (seq_num) > ntohl (lsp->lsp_header->seq_num)
      || (ntohl(seq_num) == ntohl(lsp->lsp_header->seq_num)
          && (  (lsp->lsp_header->rem_lifetime != 0
                 && rem_lifetime == 0)
              || lsp->lsp_header->checksum != checksum)))
    {
      if (isis->debugs & DEBUG_SNP_PACKETS)
	{
	  zlog_debug ("ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04x,"
		      " lifetime %us",
		      areatag,
		      rawlspid_print (lsp->lsp_header->lsp_id),
		      ntohl (seq_num), ntohs (checksum), ntohs (rem_lifetime));
	  zlog_debug ("ISIS-Snp (%s):       is newer than ours seq 0x%08x, "
		      "cksum 0x%04x, lifetime %us",
		      areatag,
		      ntohl (lsp->lsp_header->seq_num),
		      ntohs (lsp->lsp_header->checksum),
		      ntohs (lsp->lsp_header->rem_lifetime));
	}
      return LSP_NEWER;
    }
  if (isis->debugs & DEBUG_SNP_PACKETS)
    {
      zlog_debug
	("ISIS-Snp (%s): Compare LSP %s seq 0x%08x, cksum 0x%04x, lifetime %us",
	 areatag, rawlspid_print (lsp->lsp_header->lsp_id), ntohl (seq_num),
	 ntohs (checksum), ntohs (rem_lifetime));
      zlog_debug ("ISIS-Snp (%s):       is older than ours seq 0x%08x,"
		  " cksum 0x%04x, lifetime %us", areatag,
		  ntohl (lsp->lsp_header->seq_num),
		  ntohs (lsp->lsp_header->checksum),
		  ntohs (lsp->lsp_header->rem_lifetime));
    }

  return LSP_OLDER;
}

static void
lsp_auth_add (struct isis_lsp *lsp)
{
  struct isis_passwd *passwd;
  unsigned char hmac_md5_hash[ISIS_AUTH_MD5_SIZE];

  /*
   * Add the authentication info if its present
   */
  (lsp->level == IS_LEVEL_1) ? (passwd = &lsp->area->area_passwd) :
                               (passwd = &lsp->area->domain_passwd);
  switch (passwd->type)
    {
      /* Cleartext */
      case ISIS_PASSWD_TYPE_CLEARTXT:
        memcpy (&lsp->tlv_data.auth_info, passwd, sizeof (struct isis_passwd));
        tlv_add_authinfo (passwd->type, passwd->len, passwd->passwd, lsp->pdu);
        break;

      /* HMAC MD5 */
      case ISIS_PASSWD_TYPE_HMAC_MD5:
        /* Remember where TLV is written so we can later
         * overwrite the MD5 hash */
        lsp->auth_tlv_offset = stream_get_endp (lsp->pdu);
        memset(&hmac_md5_hash, 0, ISIS_AUTH_MD5_SIZE);
        lsp->tlv_data.auth_info.type = ISIS_PASSWD_TYPE_HMAC_MD5;
        lsp->tlv_data.auth_info.len = ISIS_AUTH_MD5_SIZE;
        memcpy (&lsp->tlv_data.auth_info.passwd, hmac_md5_hash,
                ISIS_AUTH_MD5_SIZE);
        tlv_add_authinfo (passwd->type, ISIS_AUTH_MD5_SIZE, hmac_md5_hash,
                          lsp->pdu);
        break;

      default:
        break;
    }
}

static void
lsp_auth_update (struct isis_lsp *lsp)
{
  struct isis_passwd *passwd;
  unsigned char hmac_md5_hash[ISIS_AUTH_MD5_SIZE];
  uint16_t checksum, rem_lifetime;

  /* For HMAC MD5 we need to recompute the md5 hash and store it */
  (lsp->level == IS_LEVEL_1) ? (passwd = &lsp->area->area_passwd) :
                               (passwd = &lsp->area->domain_passwd);
  if (passwd->type != ISIS_PASSWD_TYPE_HMAC_MD5)
    return;

  /*
   * In transient conditions (when net is configured where authentication
   * config and lsp regenerate schedule is not yet run), there could be
   * an own_lsp with auth_tlv_offset set to 0. In such a case, simply
   * return, when lsp_regenerate is run, lsp will have auth tlv.
   */
  if (lsp->auth_tlv_offset == 0)
    return;

  /*
   * RFC 5304 set auth value, checksum and remaining lifetime to zero
   * before computation and reset to old values after computation.
   */
  checksum = lsp->lsp_header->checksum;
  rem_lifetime = lsp->lsp_header->rem_lifetime;
  lsp->lsp_header->checksum = 0;
  lsp->lsp_header->rem_lifetime = 0;
  /* Set the authentication value as well to zero */
  memset (STREAM_DATA (lsp->pdu) + lsp->auth_tlv_offset + 3,
          0, ISIS_AUTH_MD5_SIZE);
  /* Compute autentication value */
  hmac_md5 (STREAM_DATA (lsp->pdu), stream_get_endp(lsp->pdu),
            (unsigned char *) &passwd->passwd, passwd->len,
            (unsigned char *) &hmac_md5_hash);
  /* Copy the hash into the stream */
  memcpy (STREAM_DATA (lsp->pdu) + lsp->auth_tlv_offset + 3,
          hmac_md5_hash, ISIS_AUTH_MD5_SIZE);
  memcpy (&lsp->tlv_data.auth_info.passwd, hmac_md5_hash,
          ISIS_AUTH_MD5_SIZE);
  /* Copy back the checksum and remaining lifetime */
  lsp->lsp_header->checksum = checksum;
  lsp->lsp_header->rem_lifetime = rem_lifetime;
}

void
lsp_inc_seqnum (struct isis_lsp *lsp, u_int32_t seq_num)
{
  u_int32_t newseq;

  if (seq_num == 0 || ntohl (lsp->lsp_header->seq_num) > seq_num)
    newseq = ntohl (lsp->lsp_header->seq_num) + 1;
  else
    newseq = seq_num + 1;

  lsp->lsp_header->seq_num = htonl (newseq);

  /* Recompute authentication and checksum information */
  lsp_auth_update (lsp);
  /* ISO 10589 - 7.3.11 Generation of the checksum
   * The checksum shall be computed over all fields in the LSP which appear
   * after the Remaining Lifetime field. This field (and those appearing
   * before it) are excluded so that the LSP may be aged by systems without
   * requiring recomputation.
   */
  fletcher_checksum(STREAM_DATA (lsp->pdu) + 12,
                    ntohs (lsp->lsp_header->pdu_len) - 12, 12);

  isis_spf_schedule (lsp->area, lsp->level);
#ifdef HAVE_IPV6
  isis_spf_schedule6 (lsp->area, lsp->level);
#endif

  return;
}

/*
 * Genetates checksum for LSP and its frags
 */
static void
lsp_seqnum_update (struct isis_lsp *lsp0)
{
  struct isis_lsp *lsp;
  struct listnode *node;

  lsp_inc_seqnum (lsp0, 0);

  if (!lsp0->lspu.frags)
    return;

  for (ALL_LIST_ELEMENTS_RO (lsp0->lspu.frags, node, lsp))
    lsp_inc_seqnum (lsp, 0);

  return;
}

static u_int8_t
lsp_bits_generate (int level, int overload_bit, int attached_bit)
{
  u_int8_t lsp_bits = 0;
  if (level == IS_LEVEL_1)
    lsp_bits = IS_LEVEL_1;
  else
    lsp_bits = IS_LEVEL_1_AND_2;
  if (overload_bit)
    lsp_bits |= overload_bit;
  if (attached_bit)
    lsp_bits |= attached_bit;
  return lsp_bits;
}

static void
lsp_update_data (struct isis_lsp *lsp, struct stream *stream,
                 struct isis_area *area, int level)
{
  uint32_t expected = 0, found;
  int retval;

  /* free the old lsp data */
  lsp_clear_data (lsp);

  /* copying only the relevant part of our stream */
  if (lsp->pdu != NULL)
    stream_free (lsp->pdu);
  lsp->pdu = stream_dup (stream);

  /* setting pointers to the correct place */
  lsp->isis_header = (struct isis_fixed_hdr *) (STREAM_DATA (lsp->pdu));
  lsp->lsp_header = (struct isis_link_state_hdr *) (STREAM_DATA (lsp->pdu) +
						    ISIS_FIXED_HDR_LEN);
  lsp->area = area;
  lsp->level = level;
  lsp->age_out = ZERO_AGE_LIFETIME;
  lsp->installed = time (NULL);
  /*
   * Get LSP data i.e. TLVs
   */
  expected |= TLVFLAG_AUTH_INFO;
  expected |= TLVFLAG_AREA_ADDRS;
  expected |= TLVFLAG_IS_NEIGHS;
  expected |= TLVFLAG_NLPID;
  if (area->dynhostname)
    expected |= TLVFLAG_DYN_HOSTNAME;
  if (area->newmetric)
    {
      expected |= TLVFLAG_TE_IS_NEIGHS;
      expected |= TLVFLAG_TE_IPV4_REACHABILITY;
      expected |= TLVFLAG_TE_ROUTER_ID;
    }
  expected |= TLVFLAG_IPV4_ADDR;
  expected |= TLVFLAG_IPV4_INT_REACHABILITY;
  expected |= TLVFLAG_IPV4_EXT_REACHABILITY;
#ifdef HAVE_IPV6
  expected |= TLVFLAG_IPV6_ADDR;
  expected |= TLVFLAG_IPV6_REACHABILITY;
#endif /* HAVE_IPV6 */

  retval = parse_tlvs (area->area_tag, STREAM_DATA (lsp->pdu) +
                       ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN,
                       ntohs (lsp->lsp_header->pdu_len) -
                       ISIS_FIXED_HDR_LEN - ISIS_LSP_HDR_LEN,
                       &expected, &found, &lsp->tlv_data,
                       NULL);
  if (retval != ISIS_OK)
    {
      zlog_warn ("Could not parse LSP");
      return;
    }

  if ((found & TLVFLAG_DYN_HOSTNAME) && (area->dynhostname))
    {
      isis_dynhn_insert (lsp->lsp_header->lsp_id, lsp->tlv_data.hostname,
                         (lsp->lsp_header->lsp_bits & LSPBIT_IST) ==
                          IS_LEVEL_1_AND_2 ? IS_LEVEL_2 : IS_LEVEL_1);
    }

  return;
}

void
lsp_update (struct isis_lsp *lsp, struct stream *stream,
            struct isis_area *area, int level)
{
  dnode_t *dnode = NULL;

  /* Remove old LSP from database. This is required since the
   * lsp_update_data will free the lsp->pdu (which has the key, lsp_id)
   * and will update it with the new data in the stream. */
  dnode = dict_lookup (area->lspdb[level - 1], lsp->lsp_header->lsp_id);
  if (dnode)
    dnode_destroy (dict_delete (area->lspdb[level - 1], dnode));

  /* rebuild the lsp data */
  lsp_update_data (lsp, stream, area, level);

  /* insert the lsp back into the database */
  lsp_insert (lsp, area->lspdb[level - 1]);
}

/* creation of LSP directly from what we received */
struct isis_lsp *
lsp_new_from_stream_ptr (struct stream *stream,
			 u_int16_t pdu_len, struct isis_lsp *lsp0,
			 struct isis_area *area, int level)
{
  struct isis_lsp *lsp;

  lsp = XCALLOC (MTYPE_ISIS_LSP, sizeof (struct isis_lsp));
  lsp_update_data (lsp, stream, area, level);

  if (lsp0 == NULL)
    {
      /*
       * zero lsp -> create the list for fragments
       */
      lsp->lspu.frags = list_new ();
    }
  else
    {
      /*
       * a fragment -> set the backpointer and add this to zero lsps frag list
       */
      lsp->lspu.zero_lsp = lsp0;
      listnode_add (lsp0->lspu.frags, lsp);
    }

  return lsp;
}

struct isis_lsp *
lsp_new(struct isis_area *area, u_char * lsp_id,
	u_int16_t rem_lifetime, u_int32_t seq_num,
	u_int8_t lsp_bits, u_int16_t checksum, int level)
{
  struct isis_lsp *lsp;

  lsp = XCALLOC (MTYPE_ISIS_LSP, sizeof (struct isis_lsp));
  lsp->area = area;

  lsp->pdu = stream_new(LLC_LEN + area->lsp_mtu);
  if (LSP_FRAGMENT (lsp_id) == 0)
    lsp->lspu.frags = list_new ();
  lsp->isis_header = (struct isis_fixed_hdr *) (STREAM_DATA (lsp->pdu));
  lsp->lsp_header = (struct isis_link_state_hdr *)
    (STREAM_DATA (lsp->pdu) + ISIS_FIXED_HDR_LEN);

  /* at first we fill the FIXED HEADER */
  (level == IS_LEVEL_1) ? fill_fixed_hdr (lsp->isis_header, L1_LINK_STATE) :
    fill_fixed_hdr (lsp->isis_header, L2_LINK_STATE);

  /* now for the LSP HEADER */
  /* Minimal LSP PDU size */
  lsp->lsp_header->pdu_len = htons (ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);
  memcpy (lsp->lsp_header->lsp_id, lsp_id, ISIS_SYS_ID_LEN + 2);
  lsp->lsp_header->checksum = checksum;	/* Provided in network order */
  lsp->lsp_header->seq_num = htonl (seq_num);
  lsp->lsp_header->rem_lifetime = htons (rem_lifetime);
  lsp->lsp_header->lsp_bits = lsp_bits;
  lsp->level = level;
  lsp->age_out = ZERO_AGE_LIFETIME;

  stream_forward_endp (lsp->pdu, ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);

  if (isis->debugs & DEBUG_EVENTS)
    zlog_debug ("New LSP with ID %s-%02x-%02x len %d seqnum %08x",
		sysid_print (lsp_id), LSP_PSEUDO_ID (lsp->lsp_header->lsp_id),
		LSP_FRAGMENT (lsp->lsp_header->lsp_id),
		ntohl (lsp->lsp_header->pdu_len),
		ntohl (lsp->lsp_header->seq_num));

  return lsp;
}

void
lsp_insert (struct isis_lsp *lsp, dict_t * lspdb)
{
  dict_alloc_insert (lspdb, lsp->lsp_header->lsp_id, lsp);
  if (lsp->lsp_header->seq_num != 0)
    {
      isis_spf_schedule (lsp->area, lsp->level);
#ifdef HAVE_IPV6
      isis_spf_schedule6 (lsp->area, lsp->level);
#endif
    }
}

/*
 * Build a list of LSPs with non-zero ht bounded by start and stop ids
 */
void
lsp_build_list_nonzero_ht (u_char * start_id, u_char * stop_id,
			   struct list *list, dict_t * lspdb)
{
  dnode_t *first, *last, *curr;

  first = dict_lower_bound (lspdb, start_id);
  if (!first)
    return;

  last = dict_upper_bound (lspdb, stop_id);

  curr = first;

  if (((struct isis_lsp *) (curr->dict_data))->lsp_header->rem_lifetime)
    listnode_add (list, first->dict_data);

  while (curr)
    {
      curr = dict_next (lspdb, curr);
      if (curr &&
	  ((struct isis_lsp *) (curr->dict_data))->lsp_header->rem_lifetime)
	listnode_add (list, curr->dict_data);
      if (curr == last)
	break;
    }

  return;
}

/*
 * Build a list of num_lsps LSPs bounded by start_id and stop_id.
 */
void
lsp_build_list (u_char * start_id, u_char * stop_id, u_char num_lsps,
		struct list *list, dict_t * lspdb)
{
  u_char count;
  dnode_t *first, *last, *curr;

  first = dict_lower_bound (lspdb, start_id);
  if (!first)
    return;

  last = dict_upper_bound (lspdb, stop_id);

  curr = first;

  listnode_add (list, first->dict_data);
  count = 1;

  while (curr)
    {
      curr = dict_next (lspdb, curr);
      if (curr)
        {
          listnode_add (list, curr->dict_data);
          count++;
        }
      if (count == num_lsps || curr == last)
        break;
    }

  return;
}

/*
 * Build a list of LSPs with SSN flag set for the given circuit
 */
void
lsp_build_list_ssn (struct isis_circuit *circuit, u_char num_lsps,
                    struct list *list, dict_t * lspdb)
{
  dnode_t *dnode, *next;
  struct isis_lsp *lsp;
  u_char count = 0;

  dnode = dict_first (lspdb);
  while (dnode != NULL)
    {
      next = dict_next (lspdb, dnode);
      lsp = dnode_get (dnode);
      if (ISIS_CHECK_FLAG (lsp->SSNflags, circuit))
        {
          listnode_add (list, lsp);
          ++count;
        }
      if (count == num_lsps)
        break;
      dnode = next;
    }

  return;
}

static void
lsp_set_time (struct isis_lsp *lsp)
{
  assert (lsp);

  if (lsp->lsp_header->rem_lifetime == 0)
    {
      if (lsp->age_out > 0)
        lsp->age_out--;
      return;
    }

  lsp->lsp_header->rem_lifetime =
    htons (ntohs (lsp->lsp_header->rem_lifetime) - 1);
}

static void
lspid_print (u_char * lsp_id, u_char * trg, char dynhost, char frag)
{
  struct isis_dynhn *dyn = NULL;
  u_char id[SYSID_STRLEN];

  if (dynhost)
    dyn = dynhn_find_by_id (lsp_id);
  else
    dyn = NULL;

  if (dyn)
      sprintf ((char *)id, "%.14s", dyn->name.name);
  else if (!memcmp (isis->sysid, lsp_id, ISIS_SYS_ID_LEN) && dynhost)
      sprintf ((char *)id, "%.14s", unix_hostname ());
  else
      memcpy (id, sysid_print (lsp_id), 15);
  if (frag)
    sprintf ((char *)trg, "%s.%02x-%02x", id, LSP_PSEUDO_ID (lsp_id),
	     LSP_FRAGMENT (lsp_id));
  else
    sprintf ((char *)trg, "%s.%02x", id, LSP_PSEUDO_ID (lsp_id));
}

/* Convert the lsp attribute bits to attribute string */
const char *
lsp_bits2string (u_char * lsp_bits)
{
  char *pos = lsp_bits_string;

  if (!*lsp_bits)
    return " none";

  /* we only focus on the default metric */
  pos += sprintf (pos, "%d/",
		  ISIS_MASK_LSP_ATT_DEFAULT_BIT (*lsp_bits) ? 1 : 0);

  pos += sprintf (pos, "%d/",
		  ISIS_MASK_LSP_PARTITION_BIT (*lsp_bits) ? 1 : 0);

  pos += sprintf (pos, "%d", ISIS_MASK_LSP_OL_BIT (*lsp_bits) ? 1 : 0);

  *(pos) = '\0';

  return lsp_bits_string;
}

/* this function prints the lsp on show isis database */
void
lsp_print (struct isis_lsp *lsp, struct vty *vty, char dynhost)
{
  u_char LSPid[255];
  char age_out[8];

  lspid_print (lsp->lsp_header->lsp_id, LSPid, dynhost, 1);
  vty_out (vty, "%-21s%c  ", LSPid, lsp->own_lsp ? '*' : ' ');
  vty_out (vty, "%5u   ", ntohs (lsp->lsp_header->pdu_len));
  vty_out (vty, "0x%08x  ", ntohl (lsp->lsp_header->seq_num));
  vty_out (vty, "0x%04x  ", ntohs (lsp->lsp_header->checksum));
  if (ntohs (lsp->lsp_header->rem_lifetime) == 0)
    {
      snprintf (age_out, 8, "(%u)", lsp->age_out);
      age_out[7] = '\0';
      vty_out (vty, "%7s   ", age_out);
    }
  else
    vty_out (vty, " %5u    ", ntohs (lsp->lsp_header->rem_lifetime));
  vty_out (vty, "%s%s",
           lsp_bits2string (&lsp->lsp_header->lsp_bits), VTY_NEWLINE);
}

void
lsp_print_detail (struct isis_lsp *lsp, struct vty *vty, char dynhost)
{
  struct area_addr *area_addr;
  int i;
  struct listnode *lnode;
  struct is_neigh *is_neigh;
  struct te_is_neigh *te_is_neigh;
  struct ipv4_reachability *ipv4_reach;
  struct in_addr *ipv4_addr;
  struct te_ipv4_reachability *te_ipv4_reach;
#ifdef HAVE_IPV6
  struct ipv6_reachability *ipv6_reach;
  struct in6_addr in6;
  u_char buff[BUFSIZ];
#endif
  u_char LSPid[255];
  u_char hostname[255];
  u_char ipv4_reach_prefix[20];
  u_char ipv4_reach_mask[20];
  u_char ipv4_address[20];

  lspid_print (lsp->lsp_header->lsp_id, LSPid, dynhost, 1);
  lsp_print (lsp, vty, dynhost);

  /* for all area address */
  if (lsp->tlv_data.area_addrs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.area_addrs, lnode, area_addr))
      {
	vty_out (vty, "  Area Address: %s%s",
		 isonet_print (area_addr->area_addr, area_addr->addr_len),
		 VTY_NEWLINE);
      }
  
  /* for the nlpid tlv */
  if (lsp->tlv_data.nlpids)
    {
      for (i = 0; i < lsp->tlv_data.nlpids->count; i++)
	{
	  switch (lsp->tlv_data.nlpids->nlpids[i])
	    {
	    case NLPID_IP:
	    case NLPID_IPV6:
	      vty_out (vty, "  NLPID       : 0x%X%s",
		       lsp->tlv_data.nlpids->nlpids[i], VTY_NEWLINE);
	      break;
	    default:
	      vty_out (vty, "  NLPID       : %s%s", "unknown", VTY_NEWLINE);
	      break;
	    }
	}
    }

  /* for the hostname tlv */
  if (lsp->tlv_data.hostname)
    {
      bzero (hostname, sizeof (hostname));
      memcpy (hostname, lsp->tlv_data.hostname->name,
	      lsp->tlv_data.hostname->namelen);
      vty_out (vty, "  Hostname    : %s%s", hostname, VTY_NEWLINE);
    }

  /* authentication tlv */
  if (lsp->tlv_data.auth_info.type != ISIS_PASSWD_TYPE_UNUSED)
    {
      if (lsp->tlv_data.auth_info.type == ISIS_PASSWD_TYPE_HMAC_MD5)
        vty_out (vty, "  Auth type   : md5%s", VTY_NEWLINE);
      else if (lsp->tlv_data.auth_info.type == ISIS_PASSWD_TYPE_CLEARTXT)
        vty_out (vty, "  Auth type   : clear text%s", VTY_NEWLINE);
    }

  /* TE router id */
  if (lsp->tlv_data.router_id)
    {
      memcpy (ipv4_address, inet_ntoa (lsp->tlv_data.router_id->id),
	      sizeof (ipv4_address));
      vty_out (vty, "  Router ID   : %s%s", ipv4_address, VTY_NEWLINE);
    }

  if (lsp->tlv_data.ipv4_addrs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.ipv4_addrs, lnode, ipv4_addr))
      {
        memcpy (ipv4_address, inet_ntoa (*ipv4_addr), sizeof (ipv4_address));
        vty_out (vty, "  IPv4 Address: %s%s", ipv4_address, VTY_NEWLINE);
      }

  /* for the IS neighbor tlv */
  if (lsp->tlv_data.is_neighs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.is_neighs, lnode, is_neigh))
      {
	lspid_print (is_neigh->neigh_id, LSPid, dynhost, 0);
	vty_out (vty, "  Metric      : %-8d IS            : %s%s",
		 is_neigh->metrics.metric_default, LSPid, VTY_NEWLINE);
      }
  
  /* for the internal reachable tlv */
  if (lsp->tlv_data.ipv4_int_reachs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.ipv4_int_reachs, lnode,
			       ipv4_reach))
    {
      memcpy (ipv4_reach_prefix, inet_ntoa (ipv4_reach->prefix),
	      sizeof (ipv4_reach_prefix));
      memcpy (ipv4_reach_mask, inet_ntoa (ipv4_reach->mask),
	      sizeof (ipv4_reach_mask));
      vty_out (vty, "  Metric      : %-8d IPv4-Internal : %s %s%s",
	       ipv4_reach->metrics.metric_default, ipv4_reach_prefix,
	       ipv4_reach_mask, VTY_NEWLINE);
    }

  /* for the external reachable tlv */
  if (lsp->tlv_data.ipv4_ext_reachs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.ipv4_ext_reachs, lnode, 
			       ipv4_reach))
    {
      memcpy (ipv4_reach_prefix, inet_ntoa (ipv4_reach->prefix),
	      sizeof (ipv4_reach_prefix));
      memcpy (ipv4_reach_mask, inet_ntoa (ipv4_reach->mask),
	      sizeof (ipv4_reach_mask));
      vty_out (vty, "  Metric      : %-8d IPv4-External : %s %s%s",
	       ipv4_reach->metrics.metric_default, ipv4_reach_prefix,
	       ipv4_reach_mask, VTY_NEWLINE);
    }
  
  /* IPv6 tlv */
#ifdef HAVE_IPV6
  if (lsp->tlv_data.ipv6_reachs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.ipv6_reachs, lnode, ipv6_reach))
    {
      memset (&in6, 0, sizeof (in6));
      memcpy (in6.s6_addr, ipv6_reach->prefix,
	      PSIZE (ipv6_reach->prefix_len));
      inet_ntop (AF_INET6, &in6, (char *)buff, BUFSIZ);
      if ((ipv6_reach->control_info &
	   CTRL_INFO_DISTRIBUTION) == DISTRIBUTION_INTERNAL)
	vty_out (vty, "  Metric      : %-8d IPv6-Internal : %s/%d%s",
		 ntohl (ipv6_reach->metric),
		 buff, ipv6_reach->prefix_len, VTY_NEWLINE);
      else
	vty_out (vty, "  Metric      : %-8d IPv6-External : %s/%d%s",
		 ntohl (ipv6_reach->metric),
		 buff, ipv6_reach->prefix_len, VTY_NEWLINE);
    }
#endif

  /* TE IS neighbor tlv */
  if (lsp->tlv_data.te_is_neighs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.te_is_neighs, lnode, te_is_neigh))
    {
      lspid_print (te_is_neigh->neigh_id, LSPid, dynhost, 0);
      vty_out (vty, "  Metric      : %-8d IS-Extended   : %s%s",
	       GET_TE_METRIC(te_is_neigh), LSPid, VTY_NEWLINE);
      if (IS_MPLS_TE(isisMplsTE))
        mpls_te_print_detail(vty, te_is_neigh);
    }

  /* TE IPv4 tlv */
  if (lsp->tlv_data.te_ipv4_reachs)
    for (ALL_LIST_ELEMENTS_RO (lsp->tlv_data.te_ipv4_reachs, lnode,
			       te_ipv4_reach))
    {
      /* FIXME: There should be better way to output this stuff. */
      vty_out (vty, "  Metric      : %-8d IPv4-Extended : %s/%d%s",
	       ntohl (te_ipv4_reach->te_metric),
	       inet_ntoa (newprefix2inaddr (&te_ipv4_reach->prefix_start,
					    te_ipv4_reach->control)),
	       te_ipv4_reach->control & 0x3F, VTY_NEWLINE);
    }
  vty_out (vty, "%s", VTY_NEWLINE);

  return;
}

/* print all the lsps info in the local lspdb */
int
lsp_print_all (struct vty *vty, dict_t * lspdb, char detail, char dynhost)
{

  dnode_t *node = dict_first (lspdb), *next;
  int lsp_count = 0;

  if (detail == ISIS_UI_LEVEL_BRIEF)
    {
      while (node != NULL)
	{
	  /* I think it is unnecessary, so I comment it out */
	  /* dict_contains (lspdb, node); */
	  next = dict_next (lspdb, node);
	  lsp_print (dnode_get (node), vty, dynhost);
	  node = next;
	  lsp_count++;
	}
    }
  else if (detail == ISIS_UI_LEVEL_DETAIL)
    {
      while (node != NULL)
	{
	  next = dict_next (lspdb, node);
	  lsp_print_detail (dnode_get (node), vty, dynhost);
	  node = next;
	  lsp_count++;
	}
    }

  return lsp_count;
}

#define FRAG_THOLD(S,T) \
  ((STREAM_SIZE(S)*T)/100)

/* stream*, area->lsp_frag_threshold, increment */
#define FRAG_NEEDED(S,T,I) \
  (STREAM_SIZE(S)-STREAM_REMAIN(S)+(I) > FRAG_THOLD(S,T))

/* FIXME: It shouldn't be necessary to pass tlvsize here, TLVs can have
 * variable length (TE TLVs, sub TLVs). */
static void
lsp_tlv_fit (struct isis_lsp *lsp, struct list **from, struct list **to,
	     int tlvsize, int frag_thold,
	     int tlv_build_func (struct list *, struct stream *))
{
  int count, i;

  /* can we fit all ? */
  if (!FRAG_NEEDED (lsp->pdu, frag_thold, listcount (*from) * tlvsize + 2))
    {
      tlv_build_func (*from, lsp->pdu);
      if (listcount (*to) != 0)
	{
	  struct listnode *node, *nextnode;
	  void *elem;

	  for (ALL_LIST_ELEMENTS (*from, node, nextnode, elem))
	    {
	      listnode_add (*to, elem);
	      list_delete_node (*from, node);
	    }
	}
      else
	{
	  list_free (*to);
	  *to = *from;
	  *from = NULL;
	}
    }
  else if (!FRAG_NEEDED (lsp->pdu, frag_thold, tlvsize + 2))
    {
      /* fit all we can */
      count = FRAG_THOLD (lsp->pdu, frag_thold) - 2 -
	(STREAM_SIZE (lsp->pdu) - STREAM_REMAIN (lsp->pdu));
      count = count / tlvsize;
      if (count > (int)listcount (*from))
	count = listcount (*from);
      for (i = 0; i < count; i++)
	{
	  listnode_add (*to, listgetdata (listhead (*from)));
	  listnode_delete (*from, listgetdata (listhead (*from)));
	}
      tlv_build_func (*to, lsp->pdu);
    }
  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));
  return;
}

/* Process IS_NEIGHBOURS TLV with TE subTLVs */
void
lsp_te_tlv_fit (struct isis_lsp *lsp, struct list **from, struct list **to, int frag_thold)
{
  int count, size = 0;
  struct listnode *node, *nextnode;
  struct te_is_neigh *elem;

  /* Start computing real size of TLVs */
  for (ALL_LIST_ELEMENTS (*from, node, nextnode, elem))
    size = size + elem->sub_tlvs_length + IS_NEIGHBOURS_LEN;

  /* can we fit all ? */
  if (!FRAG_NEEDED (lsp->pdu, frag_thold, size))
    {
      tlv_add_te_is_neighs (*from, lsp->pdu);
      if (listcount (*to) != 0)
        {
          for (ALL_LIST_ELEMENTS (*from, node, nextnode, elem))
            {
              listnode_add (*to, elem);
              list_delete_node (*from, node);
            }
        }
      else
        {
          list_free (*to);
          *to = *from;
          *from = NULL;
        }
    }
  else
    {
      /* fit all we can */
      /* Compute remaining place in LSP PDU */
      count = FRAG_THOLD (lsp->pdu, frag_thold) - 2 -
        (STREAM_SIZE (lsp->pdu) - STREAM_REMAIN (lsp->pdu));
      /* Determine size of TE SubTLVs */
      elem = (struct te_is_neigh *)listgetdata ((struct listnode *)listhead (*from));
      count = count - elem->sub_tlvs_length - IS_NEIGHBOURS_LEN;
      if (count > 0)
        {
          while (count > 0)
            {
              listnode_add (*to, listgetdata ((struct listnode *)listhead (*from)));
              listnode_delete (*from, listgetdata ((struct listnode *)listhead (*from)));

              elem = (struct te_is_neigh *)listgetdata ((struct listnode *)listhead (*from));
              count = count - elem->sub_tlvs_length - IS_NEIGHBOURS_LEN;
            }

          tlv_add_te_is_neighs (*to, lsp->pdu);
        }
    }
  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));
  return;
}

static u_int16_t
lsp_rem_lifetime (struct isis_area *area, int level)
{
  u_int16_t rem_lifetime;

  /* Add jitter to configured LSP lifetime */
  rem_lifetime = isis_jitter (area->max_lsp_lifetime[level - 1],
                              MAX_AGE_JITTER);

  /* No jitter if the max refresh will be less than configure gen interval */
  /* N.B. this calucation is acceptable since rem_lifetime is in [332,65535] at
   * this point */
  if (area->lsp_gen_interval[level - 1] > (rem_lifetime - 300))
    rem_lifetime = area->max_lsp_lifetime[level - 1];

  return rem_lifetime;
}

static u_int16_t
lsp_refresh_time (struct isis_lsp *lsp, u_int16_t rem_lifetime)
{
  struct isis_area *area = lsp->area;
  int level = lsp->level;
  u_int16_t refresh_time;

  /* Add jitter to LSP refresh time */
  refresh_time = isis_jitter (area->lsp_refresh[level - 1],
                              MAX_LSP_GEN_JITTER);

  /* RFC 4444 : make sure the refresh time is at least less than 300
   * of the remaining lifetime and more than gen interval */
  if (refresh_time <= area->lsp_gen_interval[level - 1] ||
      refresh_time > (rem_lifetime - 300))
    refresh_time = rem_lifetime - 300;

  /* In cornercases, refresh_time might be <= lsp_gen_interval, however
   * we accept this violation to satisfy refresh_time <= rem_lifetime - 300 */

  return refresh_time;
}

static struct isis_lsp *
lsp_next_frag (u_char frag_num, struct isis_lsp *lsp0, struct isis_area *area,
	       int level)
{
  struct isis_lsp *lsp;
  u_char frag_id[ISIS_SYS_ID_LEN + 2];

  memcpy (frag_id, lsp0->lsp_header->lsp_id, ISIS_SYS_ID_LEN + 1);
  LSP_FRAGMENT (frag_id) = frag_num;
  /* FIXME add authentication TLV for fragment LSPs */
  lsp = lsp_search (frag_id, area->lspdb[level - 1]);
  if (lsp)
    {
      /* Clear the TLVs */
      lsp_clear_data (lsp);
      return lsp;
    }
  lsp = lsp_new (area, frag_id, ntohs(lsp0->lsp_header->rem_lifetime), 0,
                 lsp_bits_generate (level, area->overload_bit,
                 area->attached_bit), 0, level);
  lsp->area = area;
  lsp->own_lsp = 1;
  lsp_insert (lsp, area->lspdb[level - 1]);
  listnode_add (lsp0->lspu.frags, lsp);
  lsp->lspu.zero_lsp = lsp0;
  return lsp;
}

static void
lsp_build_ext_reach_ipv4(struct isis_lsp *lsp, struct isis_area *area,
                         struct tlvs *tlv_data)
{
  struct route_table *er_table;
  struct route_node *rn;
  struct prefix_ipv4 *ipv4;
  struct isis_ext_info *info;
  struct ipv4_reachability *ipreach;
  struct te_ipv4_reachability *te_ipreach;

  er_table = get_ext_reach(area, AF_INET, lsp->level);
  if (!er_table)
    return;

  for (rn = route_top(er_table); rn; rn = route_next(rn))
    {
      if (!rn->info)
        continue;

      ipv4 = (struct prefix_ipv4*)&rn->p;
      info = rn->info;
      if (area->oldmetric)
        {
          if (tlv_data->ipv4_ext_reachs == NULL)
            {
              tlv_data->ipv4_ext_reachs = list_new();
              tlv_data->ipv4_ext_reachs->del = free_tlv;
            }
          ipreach = XMALLOC(MTYPE_ISIS_TLV, sizeof(*ipreach));

          ipreach->prefix.s_addr = ipv4->prefix.s_addr;
          masklen2ip(ipv4->prefixlen, &ipreach->mask);
          ipreach->prefix.s_addr &= ipreach->mask.s_addr;

          if ((info->metric & 0x3f) != info->metric)
            ipreach->metrics.metric_default = 0x3f;
          else
            ipreach->metrics.metric_default = info->metric;
          ipreach->metrics.metric_expense = METRICS_UNSUPPORTED;
          ipreach->metrics.metric_error = METRICS_UNSUPPORTED;
          ipreach->metrics.metric_delay = METRICS_UNSUPPORTED;
          listnode_add(tlv_data->ipv4_ext_reachs, ipreach);
        }
      if (area->newmetric)
        {
          if (tlv_data->te_ipv4_reachs == NULL)
            {
              tlv_data->te_ipv4_reachs = list_new();
              tlv_data->te_ipv4_reachs->del = free_tlv;
            }
          te_ipreach =
              XCALLOC(MTYPE_ISIS_TLV,
                      sizeof(*te_ipreach) - 1 + PSIZE(ipv4->prefixlen));
          if (info->metric > MAX_WIDE_PATH_METRIC)
            te_ipreach->te_metric = htonl(MAX_WIDE_PATH_METRIC);
          else
            te_ipreach->te_metric = htonl(info->metric);
          te_ipreach->control = ipv4->prefixlen & 0x3f;
          memcpy(&te_ipreach->prefix_start, &ipv4->prefix.s_addr,
                 PSIZE(ipv4->prefixlen));
          listnode_add(tlv_data->te_ipv4_reachs, te_ipreach);
        }
    }
}

static void
lsp_build_ext_reach_ipv6(struct isis_lsp *lsp, struct isis_area *area,
                         struct tlvs *tlv_data)
{
  struct route_table *er_table;
  struct route_node *rn;
  struct prefix_ipv6 *ipv6;
  struct isis_ext_info *info;
  struct ipv6_reachability *ip6reach;

  er_table = get_ext_reach(area, AF_INET6, lsp->level);
  if (!er_table)
    return;

  for (rn = route_top(er_table); rn; rn = route_next(rn))
    {
      if (!rn->info)
        continue;

      ipv6 = (struct prefix_ipv6*)&rn->p;
      info = rn->info;

      if (tlv_data->ipv6_reachs == NULL)
        {
          tlv_data->ipv6_reachs = list_new();
          tlv_data->ipv6_reachs->del = free_tlv;
        }
      ip6reach = XCALLOC(MTYPE_ISIS_TLV, sizeof(*ip6reach));
      if (info->metric > MAX_WIDE_PATH_METRIC)
        ip6reach->metric = htonl(MAX_WIDE_PATH_METRIC);
      else
        ip6reach->metric = htonl(info->metric);
      ip6reach->control_info = DISTRIBUTION_EXTERNAL;
      ip6reach->prefix_len = ipv6->prefixlen;
      memcpy(ip6reach->prefix, ipv6->prefix.s6_addr, sizeof(ip6reach->prefix));
      listnode_add(tlv_data->ipv6_reachs, ip6reach);
    }
}

static void
lsp_build_ext_reach (struct isis_lsp *lsp, struct isis_area *area,
                     struct tlvs *tlv_data)
{
  lsp_build_ext_reach_ipv4(lsp, area, tlv_data);
  lsp_build_ext_reach_ipv6(lsp, area, tlv_data);
}

/*
 * Builds the LSP data part. This func creates a new frag whenever 
 * area->lsp_frag_threshold is exceeded.
 */
static void
lsp_build (struct isis_lsp *lsp, struct isis_area *area)
{
  struct is_neigh *is_neigh;
  struct te_is_neigh *te_is_neigh;
  struct listnode *node, *ipnode;
  int level = lsp->level;
  struct isis_circuit *circuit;
  struct prefix_ipv4 *ipv4;
  struct ipv4_reachability *ipreach;
  struct te_ipv4_reachability *te_ipreach;
  struct isis_adjacency *nei;
#ifdef HAVE_IPV6
  struct prefix_ipv6 *ipv6, ip6prefix;
  struct ipv6_reachability *ip6reach;
#endif /* HAVE_IPV6 */
  struct tlvs tlv_data;
  struct isis_lsp *lsp0 = lsp;
  struct in_addr *routerid;
  uint32_t expected = 0, found = 0;
  uint32_t metric;
  u_char zero_id[ISIS_SYS_ID_LEN + 1];
  int retval = ISIS_OK;
  char buf[BUFSIZ];

  lsp_debug("ISIS (%s): Constructing local system LSP for level %d", area->area_tag, level);

  /*
   * Building the zero lsp
   */
  memset (zero_id, 0, ISIS_SYS_ID_LEN + 1);

  /* Reset stream endp. Stream is always there and on every LSP refresh only
   * TLV part of it is overwritten. So we must seek past header we will not
   * touch. */
  stream_reset (lsp->pdu);
  stream_forward_endp (lsp->pdu, ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);

  /*
   * Add the authentication info if its present
   */
  lsp_auth_add (lsp);

  /*
   * First add the tlvs related to area
   */

  /* Area addresses */
  if (lsp->tlv_data.area_addrs == NULL)
    lsp->tlv_data.area_addrs = list_new ();
  list_add_list (lsp->tlv_data.area_addrs, area->area_addrs);
  if (listcount (lsp->tlv_data.area_addrs) > 0)
    tlv_add_area_addrs (lsp->tlv_data.area_addrs, lsp->pdu);

  /* Protocols Supported */
  if (area->ip_circuits > 0
#ifdef HAVE_IPV6
      || area->ipv6_circuits > 0
#endif /* HAVE_IPV6 */
    )
    {
      lsp->tlv_data.nlpids = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct nlpids));
      lsp->tlv_data.nlpids->count = 0;
      if (area->ip_circuits > 0)
	{
	  lsp_debug("ISIS (%s): Found IPv4 circuit, adding IPv4 to NLPIDs", area->area_tag);
	  lsp->tlv_data.nlpids->count++;
	  lsp->tlv_data.nlpids->nlpids[0] = NLPID_IP;
	}
#ifdef HAVE_IPV6
      if (area->ipv6_circuits > 0)
	{
	  lsp_debug("ISIS (%s): Found IPv6 circuit, adding IPv6 to NLPIDs", area->area_tag);
	  lsp->tlv_data.nlpids->count++;
	  lsp->tlv_data.nlpids->nlpids[lsp->tlv_data.nlpids->count - 1] =
	    NLPID_IPV6;
	}
#endif /* HAVE_IPV6 */
      tlv_add_nlpid (lsp->tlv_data.nlpids, lsp->pdu);
    }

  /* Dynamic Hostname */
  if (area->dynhostname)
    {
      const char *hostname = unix_hostname();
      size_t hostname_len = strlen(hostname);

      lsp->tlv_data.hostname = XMALLOC (MTYPE_ISIS_TLV,
					sizeof (struct hostname));

      strncpy((char *)lsp->tlv_data.hostname->name, hostname,
              sizeof(lsp->tlv_data.hostname->name));
      if (hostname_len <= MAX_TLV_LEN)
        lsp->tlv_data.hostname->namelen = hostname_len;
      else
        lsp->tlv_data.hostname->namelen = MAX_TLV_LEN;

      lsp_debug("ISIS (%s): Adding dynamic hostname '%.*s'", area->area_tag,
                lsp->tlv_data.hostname->namelen, lsp->tlv_data.hostname->name);
      tlv_add_dynamic_hostname (lsp->tlv_data.hostname, lsp->pdu);
    }
  else
    {
      lsp_debug("ISIS (%s): Not adding dynamic hostname (disabled)", area->area_tag);
    }

  /* IPv4 address and TE router ID TLVs. In case of the first one we don't
   * follow "C" vendor, but "J" vendor behavior - one IPv4 address is put into
   * LSP and this address is same as router id. */
  if (isis->router_id != 0)
    {
      inet_ntop(AF_INET, &isis->router_id, buf, sizeof(buf));
      lsp_debug("ISIS (%s): Adding router ID %s as IPv4 tlv.", area->area_tag, buf);
      if (lsp->tlv_data.ipv4_addrs == NULL)
	{
	  lsp->tlv_data.ipv4_addrs = list_new ();
	  lsp->tlv_data.ipv4_addrs->del = free_tlv;
	}

      routerid = XMALLOC (MTYPE_ISIS_TLV, sizeof (struct in_addr));
      routerid->s_addr = isis->router_id;
      listnode_add (lsp->tlv_data.ipv4_addrs, routerid);
      tlv_add_in_addr (routerid, lsp->pdu, IPV4_ADDR);

      /* Exactly same data is put into TE router ID TLV, but only if new style
       * TLV's are in use. */
      if (area->newmetric)
	{
          lsp_debug("ISIS (%s): Adding router ID also as TE router ID tlv.", area->area_tag);
	  lsp->tlv_data.router_id = XMALLOC (MTYPE_ISIS_TLV,
					     sizeof (struct in_addr));
	  lsp->tlv_data.router_id->id.s_addr = isis->router_id;
	  tlv_add_in_addr (&lsp->tlv_data.router_id->id, lsp->pdu,
                           TE_ROUTER_ID);
	}
    }
  else
    {
      lsp_debug("ISIS (%s): Router ID is unset. Not adding tlv.", area->area_tag);
    }

  memset (&tlv_data, 0, sizeof (struct tlvs));

  lsp_debug("ISIS (%s): Adding circuit specific information.", area->area_tag);

  /*
   * Then build lists of tlvs related to circuits
   */
  for (ALL_LIST_ELEMENTS_RO (area->circuit_list, node, circuit))
    {
      if (!circuit->interface)
        lsp_debug("ISIS (%s): Processing %s circuit %p with unknown interface",
                  area->area_tag, circuit_type2string(circuit->circ_type), circuit);
      else
        lsp_debug("ISIS (%s): Processing %s circuit %s",
                  area->area_tag, circuit_type2string(circuit->circ_type), circuit->interface->name);

      if (circuit->state != C_STATE_UP)
        {
          lsp_debug("ISIS (%s): Circuit is not up, ignoring.", area->area_tag);
          continue;
        }

      /*
       * Add IPv4 internal reachability of this circuit
       */
      if (circuit->ip_router && circuit->ip_addrs &&
	  circuit->ip_addrs->count > 0)
	{
	  lsp_debug("ISIS (%s): Circuit has IPv4 active, adding respective TLVs.", area->area_tag);
	  if (area->oldmetric)
	    {
	      if (tlv_data.ipv4_int_reachs == NULL)
		{
		  tlv_data.ipv4_int_reachs = list_new ();
		  tlv_data.ipv4_int_reachs->del = free_tlv;
		}
	      for (ALL_LIST_ELEMENTS_RO (circuit->ip_addrs, ipnode, ipv4))
		{
		  ipreach =
		    XMALLOC (MTYPE_ISIS_TLV, sizeof (struct ipv4_reachability));
		  ipreach->metrics.metric_default = circuit->metric[level - 1];
		  ipreach->metrics.metric_expense = METRICS_UNSUPPORTED;
		  ipreach->metrics.metric_error = METRICS_UNSUPPORTED;
		  ipreach->metrics.metric_delay = METRICS_UNSUPPORTED;
		  masklen2ip (ipv4->prefixlen, &ipreach->mask);
		  ipreach->prefix.s_addr = ((ipreach->mask.s_addr) &
					    (ipv4->prefix.s_addr));
		  inet_ntop(AF_INET, &ipreach->prefix.s_addr, buf, sizeof(buf));
		  lsp_debug("ISIS (%s): Adding old-style IP reachability for %s/%d",
		            area->area_tag, buf, ipv4->prefixlen);
		  listnode_add (tlv_data.ipv4_int_reachs, ipreach);
		}
	    }
	  if (area->newmetric)
	    {
	      if (tlv_data.te_ipv4_reachs == NULL)
		{
		  tlv_data.te_ipv4_reachs = list_new ();
		  tlv_data.te_ipv4_reachs->del = free_tlv;
		}
	      for (ALL_LIST_ELEMENTS_RO (circuit->ip_addrs, ipnode, ipv4))
		{
		  /* FIXME All this assumes that we have no sub TLVs. */
		  te_ipreach = XCALLOC (MTYPE_ISIS_TLV,
					sizeof (struct te_ipv4_reachability) +
					((ipv4->prefixlen + 7)/8) - 1);

		  if (area->oldmetric)
		    te_ipreach->te_metric = htonl (circuit->metric[level - 1]);
		  else
		    te_ipreach->te_metric = htonl (circuit->te_metric[level - 1]);

		  te_ipreach->control = (ipv4->prefixlen & 0x3F);
		  memcpy (&te_ipreach->prefix_start, &ipv4->prefix.s_addr,
			  (ipv4->prefixlen + 7)/8);
		  inet_ntop(AF_INET, &ipv4->prefix.s_addr, buf, sizeof(buf));
		  lsp_debug("ISIS (%s): Adding te-style IP reachability for %s/%d",
		            area->area_tag, buf, ipv4->prefixlen);
		  listnode_add (tlv_data.te_ipv4_reachs, te_ipreach);
		}
	    }
	}

#ifdef HAVE_IPV6
      /*
       * Add IPv6 reachability of this circuit
       */
      if (circuit->ipv6_router && circuit->ipv6_non_link &&
	  circuit->ipv6_non_link->count > 0)
	{

	  if (tlv_data.ipv6_reachs == NULL)
	    {
	      tlv_data.ipv6_reachs = list_new ();
	      tlv_data.ipv6_reachs->del = free_tlv;
	    }
          for (ALL_LIST_ELEMENTS_RO (circuit->ipv6_non_link, ipnode, ipv6))
	    {
	      ip6reach =
		XCALLOC (MTYPE_ISIS_TLV, sizeof (struct ipv6_reachability));

	      if (area->oldmetric)
		ip6reach->metric =
			  htonl (circuit->metric[level - 1]);
	      else
		  ip6reach->metric = htonl (circuit->te_metric[level - 1]);

	      ip6reach->control_info = 0;
	      ip6reach->prefix_len = ipv6->prefixlen;
	      memcpy(&ip6prefix, ipv6, sizeof(ip6prefix));
	      apply_mask_ipv6(&ip6prefix);

	      inet_ntop(AF_INET6, &ip6prefix.prefix.s6_addr, buf, sizeof(buf));
	      lsp_debug("ISIS (%s): Adding IPv6 reachability for %s/%d",
	                area->area_tag, buf, ipv6->prefixlen);

	      memcpy (ip6reach->prefix, ip6prefix.prefix.s6_addr,
		      sizeof (ip6reach->prefix));
	      listnode_add (tlv_data.ipv6_reachs, ip6reach);
	    }
	}
#endif /* HAVE_IPV6 */

      switch (circuit->circ_type)
	{
	case CIRCUIT_T_BROADCAST:
	  if (level & circuit->is_type)
	    {
	      if (area->oldmetric)
		{
		  if (tlv_data.is_neighs == NULL)
		    {
		      tlv_data.is_neighs = list_new ();
		      tlv_data.is_neighs->del = free_tlv;
		    }
		  is_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct is_neigh));
		  if (level == IS_LEVEL_1)
		    memcpy (is_neigh->neigh_id,
			    circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1);
		  else
		    memcpy (is_neigh->neigh_id,
			    circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1);
		  is_neigh->metrics.metric_default = circuit->metric[level - 1];
		  is_neigh->metrics.metric_expense = METRICS_UNSUPPORTED;
		  is_neigh->metrics.metric_error = METRICS_UNSUPPORTED;
		  is_neigh->metrics.metric_delay = METRICS_UNSUPPORTED;
                  if (!memcmp (is_neigh->neigh_id, zero_id,
                               ISIS_SYS_ID_LEN + 1))
                    {
                      XFREE (MTYPE_ISIS_TLV, is_neigh);
                      lsp_debug("ISIS (%s): No DIS for circuit, not adding old-style IS neighbor.",
                                area->area_tag);
                    }
                  else
                    {
                      listnode_add (tlv_data.is_neighs, is_neigh);
                      lsp_debug("ISIS (%s): Adding DIS %s.%02x as old-style neighbor",
                                area->area_tag, sysid_print(is_neigh->neigh_id),
                                LSP_PSEUDO_ID(is_neigh->neigh_id));
                    }
		}
	      if (area->newmetric)
		{
		  if (tlv_data.te_is_neighs == NULL)
		    {
		      tlv_data.te_is_neighs = list_new ();
		      tlv_data.te_is_neighs->del = free_tlv;
		    }
		  te_is_neigh = XCALLOC (MTYPE_ISIS_TLV,
					 sizeof (struct te_is_neigh));
		  if (level == IS_LEVEL_1)
		    memcpy (te_is_neigh->neigh_id,
			    circuit->u.bc.l1_desig_is, ISIS_SYS_ID_LEN + 1);
		  else
		    memcpy (te_is_neigh->neigh_id,
			    circuit->u.bc.l2_desig_is, ISIS_SYS_ID_LEN + 1);
		  if (area->oldmetric)
		    metric = circuit->metric[level - 1];
		  else
		    metric = circuit->te_metric[level - 1];
		  SET_TE_METRIC(te_is_neigh, metric);
                  if (!memcmp (te_is_neigh->neigh_id, zero_id,
                               ISIS_SYS_ID_LEN + 1))
                    {
                      XFREE (MTYPE_ISIS_TLV, te_is_neigh);
                      lsp_debug("ISIS (%s): No DIS for circuit, not adding te-style IS neighbor.",
                                area->area_tag);
                    }
                  else
                    {
                      /* Check if MPLS_TE is activate */
                      if (IS_MPLS_TE(isisMplsTE) && HAS_LINK_PARAMS(circuit->interface))
                        /* Add SubTLVs & Adjust real size of SubTLVs */
                        te_is_neigh->sub_tlvs_length = add_te_subtlvs(te_is_neigh->sub_tlvs, circuit->mtc);
                      else
                        /* Or keep only TE metric with no SubTLVs if MPLS_TE is off */
                        te_is_neigh->sub_tlvs_length = 0;

                      listnode_add (tlv_data.te_is_neighs, te_is_neigh);
                      lsp_debug("ISIS (%s): Adding DIS %s.%02x as te-style neighbor",
                                area->area_tag, sysid_print(te_is_neigh->neigh_id),
                                LSP_PSEUDO_ID(te_is_neigh->neigh_id));
                    }
		}
	    }
	  else
	    {
	      lsp_debug("ISIS (%s): Circuit is not active for current level. Not adding IS neighbors",
	                area->area_tag);
	    }
	  break;
	case CIRCUIT_T_P2P:
	  nei = circuit->u.p2p.neighbor;
	  if (nei && (level & nei->circuit_t))
	    {
	      if (area->oldmetric)
		{
		  if (tlv_data.is_neighs == NULL)
		    {
		      tlv_data.is_neighs = list_new ();
		      tlv_data.is_neighs->del = free_tlv;
		    }
		  is_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct is_neigh));
		  memcpy (is_neigh->neigh_id, nei->sysid, ISIS_SYS_ID_LEN);
		  is_neigh->metrics.metric_default = circuit->metric[level - 1];
		  is_neigh->metrics.metric_expense = METRICS_UNSUPPORTED;
		  is_neigh->metrics.metric_error = METRICS_UNSUPPORTED;
		  is_neigh->metrics.metric_delay = METRICS_UNSUPPORTED;
		  listnode_add (tlv_data.is_neighs, is_neigh);
		  lsp_debug("ISIS (%s): Adding old-style is reach for %s", area->area_tag,
                            sysid_print(is_neigh->neigh_id));
		}
	      if (area->newmetric)
		{
		  uint32_t metric;

		  if (tlv_data.te_is_neighs == NULL)
		    {
		      tlv_data.te_is_neighs = list_new ();
		      tlv_data.te_is_neighs->del = free_tlv;
		    }
		  te_is_neigh = XCALLOC (MTYPE_ISIS_TLV,
					 sizeof (struct te_is_neigh));
		  memcpy (te_is_neigh->neigh_id, nei->sysid, ISIS_SYS_ID_LEN);
		  metric = circuit->te_metric[level - 1];
		  SET_TE_METRIC(te_is_neigh, metric);
		  /* Check if MPLS_TE is activate */
                  if (IS_MPLS_TE(isisMplsTE) && HAS_LINK_PARAMS(circuit->interface))
                    /* Update Local and Remote IP address for MPLS TE circuit parameters */
                    /* NOTE sure that it is the pertinent place for that updates */
                    /* Local IP address could be updated in isis_circuit.c - isis_circuit_add_addr() */
                    /* But, where update remote IP address ? in isis_pdu.c - process_p2p_hello() ? */

                    /* Add SubTLVs & Adjust real size of SubTLVs */
                    te_is_neigh->sub_tlvs_length = add_te_subtlvs(te_is_neigh->sub_tlvs, circuit->mtc);
                  else
                    /* Or keep only TE metric with no SubTLVs if MPLS_TE is off */
                    te_is_neigh->sub_tlvs_length = 0;
		  listnode_add (tlv_data.te_is_neighs, te_is_neigh);
		  lsp_debug("ISIS (%s): Adding te-style is reach for %s", area->area_tag,
                            sysid_print(te_is_neigh->neigh_id));
		}
	    }
          else
            {
              lsp_debug("ISIS (%s): No adjacency for given level on this circuit. Not adding IS neighbors",
              area->area_tag);
            }
	  break;
	case CIRCUIT_T_LOOPBACK:
          break;
	default:
	  zlog_warn ("lsp_area_create: unknown circuit type");
	}
    }

  lsp_build_ext_reach(lsp, area, &tlv_data);

  lsp_debug("ISIS (%s): LSP construction is complete. Serializing...", area->area_tag);

  while (tlv_data.ipv4_int_reachs && listcount (tlv_data.ipv4_int_reachs))
    {
      if (lsp->tlv_data.ipv4_int_reachs == NULL)
	lsp->tlv_data.ipv4_int_reachs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.ipv4_int_reachs,
		   &lsp->tlv_data.ipv4_int_reachs,
		   IPV4_REACH_LEN, area->lsp_frag_threshold,
		   tlv_add_ipv4_int_reachs);
      if (tlv_data.ipv4_int_reachs && listcount (tlv_data.ipv4_int_reachs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }

  while (tlv_data.ipv4_ext_reachs && listcount (tlv_data.ipv4_ext_reachs))
    {
      if (lsp->tlv_data.ipv4_ext_reachs == NULL)
	lsp->tlv_data.ipv4_ext_reachs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.ipv4_ext_reachs,
		   &lsp->tlv_data.ipv4_ext_reachs,
		   IPV4_REACH_LEN, area->lsp_frag_threshold,
		   tlv_add_ipv4_ext_reachs);
      if (tlv_data.ipv4_ext_reachs && listcount (tlv_data.ipv4_ext_reachs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }

  /* FIXME: We pass maximum te_ipv4_reachability length to the lsp_tlv_fit()
   * for now. lsp_tlv_fit() needs to be fixed to deal with variable length
   * TLVs (sub TLVs!). */
  while (tlv_data.te_ipv4_reachs && listcount (tlv_data.te_ipv4_reachs))
    {
      if (lsp->tlv_data.te_ipv4_reachs == NULL)
	lsp->tlv_data.te_ipv4_reachs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.te_ipv4_reachs,
		   &lsp->tlv_data.te_ipv4_reachs,
		   TE_IPV4_REACH_LEN, area->lsp_frag_threshold,
		   tlv_add_te_ipv4_reachs);
      if (tlv_data.te_ipv4_reachs && listcount (tlv_data.te_ipv4_reachs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }

#ifdef  HAVE_IPV6
  while (tlv_data.ipv6_reachs && listcount (tlv_data.ipv6_reachs))
    {
      if (lsp->tlv_data.ipv6_reachs == NULL)
	lsp->tlv_data.ipv6_reachs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.ipv6_reachs,
		   &lsp->tlv_data.ipv6_reachs,
		   IPV6_REACH_LEN, area->lsp_frag_threshold,
		   tlv_add_ipv6_reachs);
      if (tlv_data.ipv6_reachs && listcount (tlv_data.ipv6_reachs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }
#endif /* HAVE_IPV6 */

  while (tlv_data.is_neighs && listcount (tlv_data.is_neighs))
    {
      if (lsp->tlv_data.is_neighs == NULL)
	lsp->tlv_data.is_neighs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.is_neighs,
		   &lsp->tlv_data.is_neighs,
		   IS_NEIGHBOURS_LEN, area->lsp_frag_threshold,
		   tlv_add_is_neighs);
      if (tlv_data.is_neighs && listcount (tlv_data.is_neighs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }

  while (tlv_data.te_is_neighs && listcount (tlv_data.te_is_neighs))
    {
      if (lsp->tlv_data.te_is_neighs == NULL)
	lsp->tlv_data.te_is_neighs = list_new ();
      lsp_tlv_fit (lsp, &tlv_data.te_is_neighs, &lsp->tlv_data.te_is_neighs,
		   IS_NEIGHBOURS_LEN, area->lsp_frag_threshold,
		   tlv_add_te_is_neighs);
      if (tlv_data.te_is_neighs && listcount (tlv_data.te_is_neighs))
	lsp = lsp_next_frag (LSP_FRAGMENT (lsp->lsp_header->lsp_id) + 1,
			     lsp0, area, level);
    }
  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));

  free_tlvs (&tlv_data);

  /* Validate the LSP */
  retval = parse_tlvs (area->area_tag, STREAM_DATA (lsp->pdu) +
                       ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN,
                       stream_get_endp (lsp->pdu) -
                       ISIS_FIXED_HDR_LEN - ISIS_LSP_HDR_LEN,
                       &expected, &found, &tlv_data, NULL);
  assert (retval == ISIS_OK);

  return;
}

/*
 * 7.3.7 and 7.3.9 Generation on non-pseudonode LSPs
 */
int
lsp_generate (struct isis_area *area, int level)
{
  struct isis_lsp *oldlsp, *newlsp;
  u_int32_t seq_num = 0;
  u_char lspid[ISIS_SYS_ID_LEN + 2];
  u_int16_t rem_lifetime, refresh_time;

  if ((area == NULL) || (area->is_type & level) != level)
    return ISIS_ERROR;

  memset (&lspid, 0, ISIS_SYS_ID_LEN + 2);
  memcpy (&lspid, isis->sysid, ISIS_SYS_ID_LEN);

  /* only builds the lsp if the area shares the level */
  oldlsp = lsp_search (lspid, area->lspdb[level - 1]);
  if (oldlsp)
    {
      /* FIXME: we should actually initiate a purge */
      seq_num = ntohl (oldlsp->lsp_header->seq_num);
      lsp_search_and_destroy (oldlsp->lsp_header->lsp_id,
                              area->lspdb[level - 1]);
    }
  rem_lifetime = lsp_rem_lifetime (area, level);
  newlsp = lsp_new (area, lspid, rem_lifetime, seq_num,
                    area->is_type | area->overload_bit | area->attached_bit,
                    0, level);
  newlsp->area = area;
  newlsp->own_lsp = 1;

  lsp_insert (newlsp, area->lspdb[level - 1]);
  /* build_lsp_data (newlsp, area); */
  lsp_build (newlsp, area);
  /* time to calculate our checksum */
  lsp_seqnum_update (newlsp);
  newlsp->last_generated = time(NULL);
  lsp_set_all_srmflags (newlsp);

  refresh_time = lsp_refresh_time (newlsp, rem_lifetime);

  THREAD_TIMER_OFF (area->t_lsp_refresh[level - 1]);
  area->lsp_regenerate_pending[level - 1] = 0;
  if (level == IS_LEVEL_1)
    THREAD_TIMER_ON (master, area->t_lsp_refresh[level - 1],
                     lsp_l1_refresh, area, refresh_time);
  else if (level == IS_LEVEL_2)
    THREAD_TIMER_ON (master, area->t_lsp_refresh[level - 1],
                     lsp_l2_refresh, area, refresh_time);

  if (isis->debugs & DEBUG_UPDATE_PACKETS)
    {
      zlog_debug ("ISIS-Upd (%s): Building L%d LSP %s, len %d, "
                  "seq 0x%08x, cksum 0x%04x, lifetime %us refresh %us",
                  area->area_tag, level,
                  rawlspid_print (newlsp->lsp_header->lsp_id),
                  ntohl (newlsp->lsp_header->pdu_len),
                  ntohl (newlsp->lsp_header->seq_num),
                  ntohs (newlsp->lsp_header->checksum),
                  ntohs (newlsp->lsp_header->rem_lifetime),
                  refresh_time);
    }
  sched_debug("ISIS (%s): Built L%d LSP. Set triggered regenerate to non-pending.",
              area->area_tag, level);

  return ISIS_OK;
}

/*
 * Search own LSPs, update holding time and set SRM
 */
static int
lsp_regenerate (struct isis_area *area, int level)
{
  dict_t *lspdb;
  struct isis_lsp *lsp, *frag;
  struct listnode *node;
  u_char lspid[ISIS_SYS_ID_LEN + 2];
  u_int16_t rem_lifetime, refresh_time;

  if ((area == NULL) || (area->is_type & level) != level)
    return ISIS_ERROR;

  lspdb = area->lspdb[level - 1];

  memset (lspid, 0, ISIS_SYS_ID_LEN + 2);
  memcpy (lspid, isis->sysid, ISIS_SYS_ID_LEN);

  lsp = lsp_search (lspid, lspdb);

  if (!lsp)
    {
      zlog_err ("ISIS-Upd (%s): lsp_regenerate: no L%d LSP found!",
                area->area_tag, level);
      return ISIS_ERROR;
    }

  lsp_clear_data (lsp);
  lsp_build (lsp, area);
  lsp->lsp_header->lsp_bits = lsp_bits_generate (level, area->overload_bit,
                                                 area->attached_bit);
  rem_lifetime = lsp_rem_lifetime (area, level);
  lsp->lsp_header->rem_lifetime = htons (rem_lifetime);
  lsp_seqnum_update (lsp);

  lsp->last_generated = time (NULL);
  lsp_set_all_srmflags (lsp);
  for (ALL_LIST_ELEMENTS_RO (lsp->lspu.frags, node, frag))
    {
      frag->lsp_header->lsp_bits = lsp_bits_generate (level,
                                                      area->overload_bit,
                                                      area->attached_bit);
      /* Set the lifetime values of all the fragments to the same value,
       * so that no fragment expires before the lsp is refreshed.
       */
      frag->lsp_header->rem_lifetime = htons (rem_lifetime);
      lsp_set_all_srmflags (frag);
    }

  refresh_time = lsp_refresh_time (lsp, rem_lifetime);
  if (level == IS_LEVEL_1)
    THREAD_TIMER_ON (master, area->t_lsp_refresh[level - 1],
                     lsp_l1_refresh, area, refresh_time);
  else if (level == IS_LEVEL_2)
    THREAD_TIMER_ON (master, area->t_lsp_refresh[level - 1],
                     lsp_l2_refresh, area, refresh_time);
  area->lsp_regenerate_pending[level - 1] = 0;

  if (isis->debugs & DEBUG_UPDATE_PACKETS)
    {
      zlog_debug ("ISIS-Upd (%s): Refreshing our L%d LSP %s, len %d, "
                  "seq 0x%08x, cksum 0x%04x, lifetime %us refresh %us",
                  area->area_tag, level,
                  rawlspid_print (lsp->lsp_header->lsp_id),
                  ntohl (lsp->lsp_header->pdu_len),
                  ntohl (lsp->lsp_header->seq_num),
                  ntohs (lsp->lsp_header->checksum),
                  ntohs (lsp->lsp_header->rem_lifetime),
                  refresh_time);
    }
  sched_debug("ISIS (%s): Rebuilt L%d LSP. Set triggered regenerate to non-pending.",
              area->area_tag, level);

  return ISIS_OK;
}

/*
 * Something has changed or periodic refresh -> regenerate LSP
 */
static int
lsp_l1_refresh (struct thread *thread)
{
  struct isis_area *area;

  area = THREAD_ARG (thread);
  assert (area);

  area->t_lsp_refresh[0] = NULL;
  area->lsp_regenerate_pending[0] = 0;

  if ((area->is_type & IS_LEVEL_1) == 0)
    return ISIS_ERROR;

  sched_debug("ISIS (%s): LSP L1 refresh timer expired. Refreshing LSP...", area->area_tag);
  return lsp_regenerate (area, IS_LEVEL_1);
}

static int
lsp_l2_refresh (struct thread *thread)
{
  struct isis_area *area;

  area = THREAD_ARG (thread);
  assert (area);

  area->t_lsp_refresh[1] = NULL;
  area->lsp_regenerate_pending[1] = 0;

  if ((area->is_type & IS_LEVEL_2) == 0)
    return ISIS_ERROR;

  sched_debug("ISIS (%s): LSP L2 refresh timer expired. Refreshing LSP...", area->area_tag);
  return lsp_regenerate (area, IS_LEVEL_2);
}

int
lsp_regenerate_schedule (struct isis_area *area, int level, int all_pseudo)
{
  struct isis_lsp *lsp;
  u_char id[ISIS_SYS_ID_LEN + 2];
  time_t now, diff;
  long timeout;
  struct listnode *cnode;
  struct isis_circuit *circuit;
  int lvl;

  if (area == NULL)
    return ISIS_ERROR;

  sched_debug("ISIS (%s): Scheduling regeneration of %s LSPs, %sincluding PSNs",
            area->area_tag, circuit_t2string(level), all_pseudo ? "" : "not ");

  memcpy (id, isis->sysid, ISIS_SYS_ID_LEN);
  LSP_PSEUDO_ID (id) = LSP_FRAGMENT (id) = 0;
  now = time (NULL);

  for (lvl = IS_LEVEL_1; lvl <= IS_LEVEL_2; lvl++)
    {
      if (!((level & lvl) && (area->is_type & lvl)))
        continue;

      sched_debug("ISIS (%s): Checking whether L%d needs to be scheduled",
                  area->area_tag, lvl);

      if (area->lsp_regenerate_pending[lvl - 1])
        {
          struct timeval remain = thread_timer_remain(area->t_lsp_refresh[lvl - 1]);
          sched_debug("ISIS (%s): Regeneration is already pending, nothing todo."
                      " (Due in %lld.%03lld seconds)", area->area_tag,
                      (long long)remain.tv_sec, (long long)remain.tv_usec / 1000);
          continue;
        }

      lsp = lsp_search (id, area->lspdb[lvl - 1]);
      if (!lsp)
        {
          sched_debug("ISIS (%s): We do not have any LSPs to regenerate, nothing todo.",
                      area->area_tag);
          continue;
        }

      /*
       * Throttle avoidance
       */
      sched_debug("ISIS (%s): Will schedule regen timer. Last run was: %lld, Now is: %lld",
                  area->area_tag, (long long)lsp->last_generated, (long long)now);
      THREAD_TIMER_OFF (area->t_lsp_refresh[lvl - 1]);
      diff = now - lsp->last_generated;
      if (diff < area->lsp_gen_interval[lvl - 1])
        {
          timeout = 1000 * (area->lsp_gen_interval[lvl - 1] - diff);
          sched_debug("ISIS (%s): Scheduling in %ld ms to match configured lsp_gen_interval",
                      area->area_tag, timeout);
        }
      else
        {
          /*
           * lsps are not regenerated if lsp_regenerate function is called
           * directly. However if the lsp_regenerate call is queued for
           * later execution it works.
           */
          timeout = 100;
          sched_debug("ISIS (%s): Last generation was more than lsp_gen_interval ago."
                      " Scheduling for execution in %ld ms.", area->area_tag, timeout);
        }

      area->lsp_regenerate_pending[lvl - 1] = 1;
      if (lvl == IS_LEVEL_1)
        {
          THREAD_TIMER_MSEC_ON(master, area->t_lsp_refresh[lvl - 1],
                               lsp_l1_refresh, area, timeout);
        }
      else if (lvl == IS_LEVEL_2)
        {
          THREAD_TIMER_MSEC_ON(master, area->t_lsp_refresh[lvl - 1],
                               lsp_l2_refresh, area, timeout);
        }
    }

  if (all_pseudo)
    {
      for (ALL_LIST_ELEMENTS_RO (area->circuit_list, cnode, circuit))
        lsp_regenerate_schedule_pseudo (circuit, level);
    }

  return ISIS_OK;
}

/*
 * Funcs for pseudonode LSPs
 */

/*
 * 7.3.8 and 7.3.10 Generation of level 1 and 2 pseudonode LSPs 
 */
static void
lsp_build_pseudo (struct isis_lsp *lsp, struct isis_circuit *circuit,
		  int level)
{
  struct isis_adjacency *adj;
  struct is_neigh *is_neigh;
  struct te_is_neigh *te_is_neigh;
  struct es_neigh *es_neigh;
  struct list *adj_list;
  struct listnode *node;
  struct isis_area *area = circuit->area;

  lsp_debug("ISIS (%s): Constructing pseudo LSP %s for interface %s level %d",
            area->area_tag, rawlspid_print(lsp->lsp_header->lsp_id),
            circuit->interface->name, level);

  lsp->level = level;
  /* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
  lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0,
                                                 circuit->area->attached_bit);

  /*
   * add self to IS neighbours 
   */
  if (circuit->area->oldmetric)
    {
      if (lsp->tlv_data.is_neighs == NULL)
	{
	  lsp->tlv_data.is_neighs = list_new ();
	  lsp->tlv_data.is_neighs->del = free_tlv;
	}
      is_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct is_neigh));

      memcpy (&is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN);
      listnode_add (lsp->tlv_data.is_neighs, is_neigh);
      lsp_debug("ISIS (%s): Adding %s.%02x as old-style neighbor (self)",
                area->area_tag, sysid_print(is_neigh->neigh_id),
                LSP_PSEUDO_ID(is_neigh->neigh_id));
    }
  if (circuit->area->newmetric)
    {
      if (lsp->tlv_data.te_is_neighs == NULL)
	{
	  lsp->tlv_data.te_is_neighs = list_new ();
	  lsp->tlv_data.te_is_neighs->del = free_tlv;
	}
      te_is_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct te_is_neigh));

      memcpy (&te_is_neigh->neigh_id, isis->sysid, ISIS_SYS_ID_LEN);
      listnode_add (lsp->tlv_data.te_is_neighs, te_is_neigh);
      lsp_debug("ISIS (%s): Adding %s.%02x as te-style neighbor (self)",
                area->area_tag, sysid_print(te_is_neigh->neigh_id),
                LSP_PSEUDO_ID(te_is_neigh->neigh_id));
    }

  adj_list = list_new ();
  isis_adj_build_up_list (circuit->u.bc.adjdb[level - 1], adj_list);

  for (ALL_LIST_ELEMENTS_RO (adj_list, node, adj))
    {
      if (adj->level & level)
	{
	  if ((level == IS_LEVEL_1 && adj->sys_type == ISIS_SYSTYPE_L1_IS) ||
	      (level == IS_LEVEL_1 && adj->sys_type == ISIS_SYSTYPE_L2_IS &&
	      adj->adj_usage == ISIS_ADJ_LEVEL1AND2) ||
	      (level == IS_LEVEL_2 && adj->sys_type == ISIS_SYSTYPE_L2_IS))
	    {
	      /* an IS neighbour -> add it */
	      if (circuit->area->oldmetric)
		{
		  is_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct is_neigh));

		  memcpy (&is_neigh->neigh_id, adj->sysid, ISIS_SYS_ID_LEN);
		  listnode_add (lsp->tlv_data.is_neighs, is_neigh);
		  lsp_debug("ISIS (%s): Adding %s.%02x as old-style neighbor (peer)",
		            area->area_tag, sysid_print(is_neigh->neigh_id),
		            LSP_PSEUDO_ID(is_neigh->neigh_id));
		}
	      if (circuit->area->newmetric)
		{
		  te_is_neigh = XCALLOC (MTYPE_ISIS_TLV,
					 sizeof (struct te_is_neigh));
		  memcpy (&te_is_neigh->neigh_id, adj->sysid, ISIS_SYS_ID_LEN);
		  listnode_add (lsp->tlv_data.te_is_neighs, te_is_neigh);
		  lsp_debug("ISIS (%s): Adding %s.%02x as te-style neighbor (peer)",
		            area->area_tag, sysid_print(te_is_neigh->neigh_id),
		            LSP_PSEUDO_ID(te_is_neigh->neigh_id));
		}
	    }
	  else if (level == IS_LEVEL_1 && adj->sys_type == ISIS_SYSTYPE_ES)
	    {
	      /* an ES neigbour add it, if we are building level 1 LSP */
	      /* FIXME: the tlv-format is hard to use here */
	      if (lsp->tlv_data.es_neighs == NULL)
		{
		  lsp->tlv_data.es_neighs = list_new ();
		  lsp->tlv_data.es_neighs->del = free_tlv;
		}
	      es_neigh = XCALLOC (MTYPE_ISIS_TLV, sizeof (struct es_neigh));
	      
	      memcpy (&es_neigh->first_es_neigh, adj->sysid, ISIS_SYS_ID_LEN);
	      listnode_add (lsp->tlv_data.es_neighs, es_neigh);
	      lsp_debug("ISIS (%s): Adding %s as ES neighbor (peer)",
	                area->area_tag, sysid_print(es_neigh->first_es_neigh));
	    }
	  else
	    {
	      lsp_debug("ISIS (%s): Ignoring neighbor %s, level does not match",
	                area->area_tag, sysid_print(adj->sysid));
	    }
	}
      else
        {
	  lsp_debug("ISIS (%s): Ignoring neighbor %s, level does not intersect",
	            area->area_tag, sysid_print(adj->sysid));
	}
    }
  list_delete (adj_list);

  lsp_debug("ISIS (%s): Pseudo LSP construction is complete.", area->area_tag);

  /* Reset endp of stream to overwrite only TLV part of it. */
  stream_reset (lsp->pdu);
  stream_forward_endp (lsp->pdu, ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);

  /*
   * Add the authentication info if it's present
   */
  lsp_auth_add (lsp);

  if (lsp->tlv_data.is_neighs && listcount (lsp->tlv_data.is_neighs) > 0)
    tlv_add_is_neighs (lsp->tlv_data.is_neighs, lsp->pdu);

  if (lsp->tlv_data.te_is_neighs && listcount (lsp->tlv_data.te_is_neighs) > 0)
    tlv_add_te_is_neighs (lsp->tlv_data.te_is_neighs, lsp->pdu);

  if (lsp->tlv_data.es_neighs && listcount (lsp->tlv_data.es_neighs) > 0)
    tlv_add_is_neighs (lsp->tlv_data.es_neighs, lsp->pdu);

  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));

  /* Recompute authentication and checksum information */
  lsp_auth_update (lsp);
  fletcher_checksum(STREAM_DATA (lsp->pdu) + 12,
                    ntohs (lsp->lsp_header->pdu_len) - 12, 12);

  return;
}

int
lsp_generate_pseudo (struct isis_circuit *circuit, int level)
{
  dict_t *lspdb = circuit->area->lspdb[level - 1];
  struct isis_lsp *lsp;
  u_char lsp_id[ISIS_SYS_ID_LEN + 2];
  u_int16_t rem_lifetime, refresh_time;

  if ((circuit->is_type & level) != level ||
      (circuit->state != C_STATE_UP) ||
      (circuit->circ_type != CIRCUIT_T_BROADCAST) ||
      (circuit->u.bc.is_dr[level - 1] == 0))
    return ISIS_ERROR;

  memcpy (lsp_id, isis->sysid, ISIS_SYS_ID_LEN);
  LSP_FRAGMENT (lsp_id) = 0;
  LSP_PSEUDO_ID (lsp_id) = circuit->circuit_id;

  /*
   * If for some reason have a pseudo LSP in the db already -> regenerate
   */
  if (lsp_search (lsp_id, lspdb))
    return lsp_regenerate_schedule_pseudo (circuit, level);

  rem_lifetime = lsp_rem_lifetime (circuit->area, level);
  /* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
  lsp = lsp_new (circuit->area, lsp_id, rem_lifetime, 1,
                 circuit->area->is_type | circuit->area->attached_bit,
                 0, level);
  lsp->area = circuit->area;

  lsp_build_pseudo (lsp, circuit, level);

  lsp->own_lsp = 1;
  lsp_insert (lsp, lspdb);
  lsp_set_all_srmflags (lsp);

  refresh_time = lsp_refresh_time (lsp, rem_lifetime);
  THREAD_TIMER_OFF (circuit->u.bc.t_refresh_pseudo_lsp[level - 1]);
  circuit->lsp_regenerate_pending[level - 1] = 0;
  if (level == IS_LEVEL_1)
    THREAD_TIMER_ON (master, circuit->u.bc.t_refresh_pseudo_lsp[level - 1],
                     lsp_l1_refresh_pseudo, circuit, refresh_time);
  else if (level == IS_LEVEL_2)
    THREAD_TIMER_ON (master, circuit->u.bc.t_refresh_pseudo_lsp[level - 1],
                     lsp_l2_refresh_pseudo, circuit, refresh_time);

  if (isis->debugs & DEBUG_UPDATE_PACKETS)
    {
      zlog_debug ("ISIS-Upd (%s): Building L%d Pseudo LSP %s, len %d, "
                  "seq 0x%08x, cksum 0x%04x, lifetime %us, refresh %us",
                  circuit->area->area_tag, level,
                  rawlspid_print (lsp->lsp_header->lsp_id),
                  ntohl (lsp->lsp_header->pdu_len),
                  ntohl (lsp->lsp_header->seq_num),
                  ntohs (lsp->lsp_header->checksum),
                  ntohs (lsp->lsp_header->rem_lifetime),
                  refresh_time);
    }

  return ISIS_OK;
}

static int
lsp_regenerate_pseudo (struct isis_circuit *circuit, int level)
{
  dict_t *lspdb = circuit->area->lspdb[level - 1];
  struct isis_lsp *lsp;
  u_char lsp_id[ISIS_SYS_ID_LEN + 2];
  u_int16_t rem_lifetime, refresh_time;

  if ((circuit->is_type & level) != level ||
      (circuit->state != C_STATE_UP) ||
      (circuit->circ_type != CIRCUIT_T_BROADCAST) ||
      (circuit->u.bc.is_dr[level - 1] == 0))
    return ISIS_ERROR;

  memcpy (lsp_id, isis->sysid, ISIS_SYS_ID_LEN);
  LSP_PSEUDO_ID (lsp_id) = circuit->circuit_id;
  LSP_FRAGMENT (lsp_id) = 0;

  lsp = lsp_search (lsp_id, lspdb);

  if (!lsp)
    {
      zlog_err ("lsp_regenerate_pseudo: no l%d LSP %s found!",
                level, rawlspid_print (lsp_id));
      return ISIS_ERROR;
    }
  lsp_clear_data (lsp);

  lsp_build_pseudo (lsp, circuit, level);

  /* RFC3787  section 4 SHOULD not set overload bit in pseudo LSPs */
  lsp->lsp_header->lsp_bits = lsp_bits_generate (level, 0,
                                                 circuit->area->attached_bit);
  rem_lifetime = lsp_rem_lifetime (circuit->area, level);
  lsp->lsp_header->rem_lifetime = htons (rem_lifetime);
  lsp_inc_seqnum (lsp, 0);
  lsp->last_generated = time (NULL);
  lsp_set_all_srmflags (lsp);

  refresh_time = lsp_refresh_time (lsp, rem_lifetime);
  if (level == IS_LEVEL_1)
    THREAD_TIMER_ON (master, circuit->u.bc.t_refresh_pseudo_lsp[level - 1],
                     lsp_l1_refresh_pseudo, circuit, refresh_time);
  else if (level == IS_LEVEL_2)
    THREAD_TIMER_ON (master, circuit->u.bc.t_refresh_pseudo_lsp[level - 1],
                     lsp_l2_refresh_pseudo, circuit, refresh_time);

  if (isis->debugs & DEBUG_UPDATE_PACKETS)
    {
      zlog_debug ("ISIS-Upd (%s): Refreshing L%d Pseudo LSP %s, len %d, "
                  "seq 0x%08x, cksum 0x%04x, lifetime %us, refresh %us",
                  circuit->area->area_tag, level,
                  rawlspid_print (lsp->lsp_header->lsp_id),
                  ntohl (lsp->lsp_header->pdu_len),
                  ntohl (lsp->lsp_header->seq_num),
                  ntohs (lsp->lsp_header->checksum),
                  ntohs (lsp->lsp_header->rem_lifetime),
                  refresh_time);
    }

  return ISIS_OK;
}

/*
 * Something has changed or periodic refresh -> regenerate pseudo LSP
 */
static int
lsp_l1_refresh_pseudo (struct thread *thread)
{
  struct isis_circuit *circuit;
  u_char id[ISIS_SYS_ID_LEN + 2];

  circuit = THREAD_ARG (thread);

  circuit->u.bc.t_refresh_pseudo_lsp[0] = NULL;
  circuit->lsp_regenerate_pending[0] = 0;

  if ((circuit->u.bc.is_dr[0] == 0) ||
      (circuit->is_type & IS_LEVEL_1) == 0)
    {
      memcpy (id, isis->sysid, ISIS_SYS_ID_LEN);
      LSP_PSEUDO_ID (id) = circuit->circuit_id;
      LSP_FRAGMENT (id) = 0;
      lsp_purge_pseudo (id, circuit, IS_LEVEL_1);
      return ISIS_ERROR;
    }

  return lsp_regenerate_pseudo (circuit, IS_LEVEL_1);
}

static int
lsp_l2_refresh_pseudo (struct thread *thread)
{
  struct isis_circuit *circuit;
  u_char id[ISIS_SYS_ID_LEN + 2];

  circuit = THREAD_ARG (thread);

  circuit->u.bc.t_refresh_pseudo_lsp[1] = NULL;
  circuit->lsp_regenerate_pending[1] = 0;

  if ((circuit->u.bc.is_dr[1] == 0) ||
      (circuit->is_type & IS_LEVEL_2) == 0)
    {
      memcpy (id, isis->sysid, ISIS_SYS_ID_LEN);
      LSP_PSEUDO_ID (id) = circuit->circuit_id;
      LSP_FRAGMENT (id) = 0;
      lsp_purge_pseudo (id, circuit, IS_LEVEL_2);
      return ISIS_ERROR;
    }

  return lsp_regenerate_pseudo (circuit, IS_LEVEL_2);
}

int
lsp_regenerate_schedule_pseudo (struct isis_circuit *circuit, int level)
{
  struct isis_lsp *lsp;
  u_char lsp_id[ISIS_SYS_ID_LEN + 2];
  time_t now, diff;
  long timeout;
  int lvl;
  struct isis_area *area = circuit->area;

  if (circuit == NULL ||
      circuit->circ_type != CIRCUIT_T_BROADCAST ||
      circuit->state != C_STATE_UP)
    return ISIS_OK;

  sched_debug("ISIS (%s): Scheduling regeneration of %s pseudo LSP for interface %s",
              area->area_tag, circuit_t2string(level), circuit->interface->name);

  memcpy (lsp_id, isis->sysid, ISIS_SYS_ID_LEN);
  LSP_PSEUDO_ID (lsp_id) = circuit->circuit_id;
  LSP_FRAGMENT (lsp_id) = 0;
  now = time (NULL);

  for (lvl = IS_LEVEL_1; lvl <= IS_LEVEL_2; lvl++)
    {
      sched_debug("ISIS (%s): Checking whether L%d pseudo LSP needs to be scheduled",
                  area->area_tag, lvl);

      if (!((level & lvl) && (circuit->is_type & lvl)))
        {
          sched_debug("ISIS (%s): Level is not active on circuit",
                      area->area_tag);
          continue;
        }

      if (circuit->u.bc.is_dr[lvl - 1] == 0)
        {
          sched_debug("ISIS (%s): This IS is not DR, nothing to do.",
                      area->area_tag);
          continue;
        }

      if (circuit->lsp_regenerate_pending[lvl - 1])
        {
          struct timeval remain =
                  thread_timer_remain(circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
          sched_debug("ISIS (%s): Regenerate is already pending, nothing todo."
                      " (Due in %lld.%03lld seconds)", area->area_tag,
                      (long long)remain.tv_sec, (long long)remain.tv_usec/1000);
          continue;
        }

      lsp = lsp_search (lsp_id, circuit->area->lspdb[lvl - 1]);
      if (!lsp)
        {
          sched_debug("ISIS (%s): Pseudonode LSP does not exist yet, nothing to regenerate.",
                      area->area_tag);
          continue;
        }

      /*
       * Throttle avoidance
       */
      sched_debug("ISIS (%s): Will schedule PSN regen timer. Last run was: %lld, Now is: %lld",
                  area->area_tag, (long long)lsp->last_generated, (long long) now);
      THREAD_TIMER_OFF (circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1]);
      diff = now - lsp->last_generated;
      if (diff < circuit->area->lsp_gen_interval[lvl - 1])
        {
          timeout = 1000 * (circuit->area->lsp_gen_interval[lvl - 1] - diff);
          sched_debug("ISIS (%s): Sechduling in %ld ms to match configured lsp_gen_interval",
                      area->area_tag, timeout);
        }
      else
        {
          timeout = 100;
          sched_debug("ISIS (%s): Last generation was more than lsp_gen_interval ago."
                      " Scheduling for execution in %ld ms.", area->area_tag, timeout);
        }

      circuit->lsp_regenerate_pending[lvl - 1] = 1;

      if (lvl == IS_LEVEL_1)
        {
          THREAD_TIMER_MSEC_ON(master,
                               circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1],
                               lsp_l1_refresh_pseudo, circuit, timeout);
        }
      else if (lvl == IS_LEVEL_2)
        {
          THREAD_TIMER_MSEC_ON(master,
                               circuit->u.bc.t_refresh_pseudo_lsp[lvl - 1],
                               lsp_l2_refresh_pseudo, circuit, timeout);
        }
    }

  return ISIS_OK;
}

/*
 * Walk through LSPs for an area
 *  - set remaining lifetime
 *  - set LSPs with SRMflag set for sending
 */
int
lsp_tick (struct thread *thread)
{
  struct isis_area *area;
  struct isis_circuit *circuit;
  struct isis_lsp *lsp;
  struct list *lsp_list;
  struct listnode *lspnode, *cnode;
  dnode_t *dnode, *dnode_next;
  int level;
  u_int16_t rem_lifetime;

  lsp_list = list_new ();

  area = THREAD_ARG (thread);
  assert (area);
  area->t_tick = NULL;
  THREAD_TIMER_ON (master, area->t_tick, lsp_tick, area, 1);

  /*
   * Build a list of LSPs with (any) SRMflag set
   * and removed the ones that have aged out
   */
  for (level = 0; level < ISIS_LEVELS; level++)
    {
      if (area->lspdb[level] && dict_count (area->lspdb[level]) > 0)
        {
          for (dnode = dict_first (area->lspdb[level]);
               dnode != NULL; dnode = dnode_next)
            {
              dnode_next = dict_next (area->lspdb[level], dnode);
              lsp = dnode_get (dnode);

              /*
               * The lsp rem_lifetime is kept at 0 for MaxAge or
               * ZeroAgeLifetime depending on explicit purge or
               * natural age out. So schedule spf only once when
               * the first time rem_lifetime becomes 0.
               */
              rem_lifetime = ntohs(lsp->lsp_header->rem_lifetime);
              lsp_set_time (lsp);

              /*
               * Schedule may run spf which should be done only after
               * the lsp rem_lifetime becomes 0 for the first time.
               * ISO 10589 - 7.3.16.4 first paragraph.
               */
              if (rem_lifetime == 1 && lsp->lsp_header->seq_num != 0)
                {
                  /* 7.3.16.4 a) set SRM flags on all */
                  lsp_set_all_srmflags (lsp);
                  /* 7.3.16.4 b) retain only the header FIXME  */
                  /* 7.3.16.4 c) record the time to purge FIXME */
                  /* run/schedule spf */
                  /* isis_spf_schedule is called inside lsp_destroy() below;
                   * so it is not needed here. */
                  /* isis_spf_schedule (lsp->area, lsp->level); */
                }

              if (lsp->age_out == 0)
                {
                  zlog_debug ("ISIS-Upd (%s): L%u LSP %s seq 0x%08x aged out",
                              area->area_tag,
                              lsp->level,
                              rawlspid_print (lsp->lsp_header->lsp_id),
                              ntohl (lsp->lsp_header->seq_num));
                  lsp_destroy (lsp);
                  lsp = NULL;
                  dict_delete_free (area->lspdb[level], dnode);
                }
              else if (flags_any_set (lsp->SRMflags))
                listnode_add (lsp_list, lsp);
            }

          /*
           * Send LSPs on circuits indicated by the SRMflags
           */
          if (listcount (lsp_list) > 0)
            {
              for (ALL_LIST_ELEMENTS_RO (area->circuit_list, cnode, circuit))
                {
                  int diff = time (NULL) - circuit->lsp_queue_last_cleared;
                  if (circuit->lsp_queue == NULL ||
                      diff < MIN_LSP_TRANS_INTERVAL)
                    continue;
                  for (ALL_LIST_ELEMENTS_RO (lsp_list, lspnode, lsp))
                    {
                      if (circuit->upadjcount[lsp->level - 1] &&
                          ISIS_CHECK_FLAG (lsp->SRMflags, circuit))
                        {
                          /* Add the lsp only if it is not already in lsp
                           * queue */
                          if (! listnode_lookup (circuit->lsp_queue, lsp))
                            {
                              listnode_add (circuit->lsp_queue, lsp);
                              thread_add_event (master, send_lsp, circuit, 0);
                            }
                        }
                    }
                }
              list_delete_all_node (lsp_list);
            }
        }
    }

  list_delete (lsp_list);

  return ISIS_OK;
}

void
lsp_purge_pseudo (u_char * id, struct isis_circuit *circuit, int level)
{
  struct isis_lsp *lsp;
  u_int16_t seq_num;
  u_int8_t lsp_bits;

  lsp = lsp_search (id, circuit->area->lspdb[level - 1]);
  if (!lsp)
    return;

  /* store old values */
  seq_num = lsp->lsp_header->seq_num;
  lsp_bits = lsp->lsp_header->lsp_bits;

  /* reset stream */
  lsp_clear_data (lsp);
  stream_reset (lsp->pdu);

  /* update header */
  lsp->lsp_header->pdu_len = htons (ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);
  memcpy (lsp->lsp_header->lsp_id, id, ISIS_SYS_ID_LEN + 2);
  lsp->lsp_header->checksum = 0;
  lsp->lsp_header->seq_num = seq_num;
  lsp->lsp_header->rem_lifetime = 0;
  lsp->lsp_header->lsp_bits = lsp_bits;
  lsp->level = level;
  lsp->age_out = lsp->area->max_lsp_lifetime[level-1];
  stream_forward_endp (lsp->pdu, ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);

  /*
   * Add and update the authentication info if its present
   */
  lsp_auth_add (lsp);
  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));
  lsp_auth_update (lsp);
  fletcher_checksum(STREAM_DATA (lsp->pdu) + 12,
                    ntohs (lsp->lsp_header->pdu_len) - 12, 12);

  lsp_set_all_srmflags (lsp);

  return;
}

/*
 * Purge own LSP that is received and we don't have. 
 * -> Do as in 7.3.16.4
 */
void
lsp_purge_non_exist (int level,
		     struct isis_link_state_hdr *lsp_hdr,
		     struct isis_area *area)
{
  struct isis_lsp *lsp;

  /*
   * We need to create the LSP to be purged 
   */
  lsp = XCALLOC (MTYPE_ISIS_LSP, sizeof (struct isis_lsp));
  lsp->area = area;
  lsp->level = level;
  lsp->pdu = stream_new(LLC_LEN + area->lsp_mtu);
  lsp->isis_header = (struct isis_fixed_hdr *) STREAM_DATA (lsp->pdu);
  fill_fixed_hdr (lsp->isis_header, (lsp->level == IS_LEVEL_1) ? L1_LINK_STATE
		  : L2_LINK_STATE);
  lsp->lsp_header = (struct isis_link_state_hdr *) (STREAM_DATA (lsp->pdu) +
						    ISIS_FIXED_HDR_LEN);
  memcpy (lsp->lsp_header, lsp_hdr, ISIS_LSP_HDR_LEN);
  stream_forward_endp (lsp->pdu, ISIS_FIXED_HDR_LEN + ISIS_LSP_HDR_LEN);

  /*
   * Set the remaining lifetime to 0
   */
  lsp->lsp_header->rem_lifetime = 0;

  /*
   * Add and update the authentication info if its present
   */
  lsp_auth_add (lsp);
  lsp_auth_update (lsp);

  /*
   * Update the PDU length to header plus any authentication TLV.
   */
  lsp->lsp_header->pdu_len = htons (stream_get_endp (lsp->pdu));

  /*
   * Put the lsp into LSPdb
   */
  lsp_insert (lsp, area->lspdb[lsp->level - 1]);

  /*
   * Send in to whole area
   */
  lsp_set_all_srmflags (lsp);

  return;
}

void lsp_set_all_srmflags (struct isis_lsp *lsp)
{
  struct listnode *node;
  struct isis_circuit *circuit;

  assert (lsp);

  ISIS_FLAGS_CLEAR_ALL(lsp->SRMflags);

  if (lsp->area)
    {
      struct list *circuit_list = lsp->area->circuit_list;
      for (ALL_LIST_ELEMENTS_RO (circuit_list, node, circuit))
        {
          ISIS_SET_FLAG(lsp->SRMflags, circuit);
        }
    }
}