File: isis_route.c

package info (click to toggle)
quagga 0.99.5-5etch3
  • links: PTS
  • area: main
  • in suites: etch
  • size: 12,140 kB
  • ctags: 12,172
  • sloc: ansic: 170,694; sh: 10,447; perl: 639; makefile: 547; awk: 129; lisp: 62
file content (739 lines) | stat: -rw-r--r-- 18,792 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
/*
 * IS-IS Rout(e)ing protocol               - isis_route.c
 * Copyright (C) 2001,2002   Sampo Saaristo
 *                           Tampere University of Technology      
 *                           Institute of Communications Engineering
 *
 *                                         based on ../ospf6d/ospf6_route.[ch]
 *                                         by Yasuhiro Ohara
 *
 * This program is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU General Public Licenseas 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 "thread.h"
#include "linklist.h"
#include "vty.h"
#include "log.h"
#include "memory.h"
#include "prefix.h"
#include "hash.h"
#include "if.h"
#include "table.h"

#include "isis_constants.h"
#include "isis_common.h"
#include "dict.h"
#include "isisd.h"
#include "isis_misc.h"
#include "isis_adjacency.h"
#include "isis_circuit.h"
#include "isis_tlv.h"
#include "isis_pdu.h"
#include "isis_lsp.h"
#include "isis_spf.h"
#include "isis_route.h"
#include "isis_zebra.h"

extern struct isis *isis;
extern struct thread_master *master;

static struct isis_nexthop *
isis_nexthop_create (struct in_addr *ip, unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop *nexthop;

  for (ALL_LIST_ELEMENTS_RO (isis->nexthops, node, nexthop))
    {
      if (nexthop->ifindex != ifindex)
	continue;
      if (ip && memcmp (&nexthop->ip, ip, sizeof (struct in_addr)) != 0)
	continue;

      nexthop->lock++;
      return nexthop;
    }

  nexthop = XCALLOC (MTYPE_ISIS_NEXTHOP, sizeof (struct isis_nexthop));
  if (!nexthop)
    {
      zlog_err ("ISIS-Rte: isis_nexthop_create: out of memory!");
    }

  nexthop->ifindex = ifindex;
  memcpy (&nexthop->ip, ip, sizeof (struct in_addr));
  listnode_add (isis->nexthops, nexthop);
  nexthop->lock++;

  return nexthop;
}

static void
isis_nexthop_delete (struct isis_nexthop *nexthop)
{
  nexthop->lock--;
  if (nexthop->lock == 0)
    {
      listnode_delete (isis->nexthops, nexthop);
      XFREE (MTYPE_ISIS_NEXTHOP, nexthop);
    }

  return;
}

static int
nexthoplookup (struct list *nexthops, struct in_addr *ip,
	       unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop *nh;

  for (ALL_LIST_ELEMENTS_RO (nexthops, node, nh))
    {
      if (!(memcmp (ip, &nh->ip, sizeof (struct in_addr))) &&
	  ifindex == nh->ifindex)
	return 1;
    }

  return 0;
}

#ifdef EXTREME_DEBUG
static void
nexthop_print (struct isis_nexthop *nh)
{
  u_char buf[BUFSIZ];

  inet_ntop (AF_INET, &nh->ip, (char *) buf, BUFSIZ);

  zlog_debug ("      %s %u", buf, nh->ifindex);
}

static void
nexthops_print (struct list *nhs)
{
  struct listnode *node;
  struct isis_nexthop *nh;

  for (ALL_LIST_ELEMENTS_RO (nhs, node, nh))
    nexthop_print (nh);
}
#endif /* EXTREME_DEBUG */

#ifdef HAVE_IPV6
static struct isis_nexthop6 *
isis_nexthop6_new (struct in6_addr *ip6, unsigned int ifindex)
{
  struct isis_nexthop6 *nexthop6;

  nexthop6 = XCALLOC (MTYPE_ISIS_NEXTHOP6, sizeof (struct isis_nexthop6));
  if (!nexthop6)
    {
      zlog_err ("ISIS-Rte: isis_nexthop_create6: out of memory!");
    }

  nexthop6->ifindex = ifindex;
  memcpy (&nexthop6->ip6, ip6, sizeof (struct in6_addr));
  nexthop6->lock++;

  return nexthop6;
}

static struct isis_nexthop6 *
isis_nexthop6_create (struct in6_addr *ip6, unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop6 *nexthop6;

  for (ALL_LIST_ELEMENTS_RO (isis->nexthops6, node, nexthop6))
    {
      if (nexthop6->ifindex != ifindex)
	continue;
      if (ip6 && memcmp (&nexthop6->ip6, ip6, sizeof (struct in6_addr)) != 0)
	continue;

      nexthop6->lock++;
      return nexthop6;
    }

  nexthop6 = isis_nexthop6_new (ip6, ifindex);

  return nexthop6;
}

static void
isis_nexthop6_delete (struct isis_nexthop6 *nexthop6)
{

  nexthop6->lock--;
  if (nexthop6->lock == 0)
    {
      listnode_delete (isis->nexthops6, nexthop6);
      XFREE (MTYPE_ISIS_NEXTHOP6, nexthop6);
    }

  return;
}

static int
nexthop6lookup (struct list *nexthops6, struct in6_addr *ip6,
		unsigned int ifindex)
{
  struct listnode *node;
  struct isis_nexthop6 *nh6;

  for (ALL_LIST_ELEMENTS_RO (nexthops6, node, nh6))
    {
      if (!(memcmp (ip6, &nh6->ip6, sizeof (struct in6_addr))) &&
	  ifindex == nh6->ifindex)
	return 1;
    }

  return 0;
}

#ifdef EXTREME_DEBUG
static void
nexthop6_print (struct isis_nexthop6 *nh6)
{
  u_char buf[BUFSIZ];

  inet_ntop (AF_INET6, &nh6->ip6, (char *) buf, BUFSIZ);

  zlog_debug ("      %s %u", buf, nh6->ifindex);
}

static void
nexthops6_print (struct list *nhs6)
{
  struct listnode *node;
  struct isis_nexthop6 *nh6;

  for (ALL_LIST_ELEMENTS_RO (nhs6, node, nh6))
    nexthop6_print (nh6);
}
#endif /* EXTREME_DEBUG */
#endif /* HAVE_IPV6 */

static void
adjinfo2nexthop (struct list *nexthops, struct isis_adjacency *adj)
{
  struct isis_nexthop *nh;
  struct listnode *node;
  struct in_addr *ipv4_addr;

  if (adj->ipv4_addrs == NULL)
    return;

  for (ALL_LIST_ELEMENTS_RO (adj->ipv4_addrs, node, ipv4_addr))
    {
      if (!nexthoplookup (nexthops, ipv4_addr,
			  adj->circuit->interface->ifindex))
	{
	  nh = isis_nexthop_create (ipv4_addr,
				    adj->circuit->interface->ifindex);
	  listnode_add (nexthops, nh);
	}
    }
}

#ifdef HAVE_IPV6
static void
adjinfo2nexthop6 (struct list *nexthops6, struct isis_adjacency *adj)
{
  struct listnode *node;
  struct in6_addr *ipv6_addr;
  struct isis_nexthop6 *nh6;

  if (!adj->ipv6_addrs)
    return;

  for (ALL_LIST_ELEMENTS_RO (adj->ipv6_addrs, node, ipv6_addr))
    {
      if (!nexthop6lookup (nexthops6, ipv6_addr,
			   adj->circuit->interface->ifindex))
	{
	  nh6 = isis_nexthop6_create (ipv6_addr,
				      adj->circuit->interface->ifindex);
	  listnode_add (nexthops6, nh6);
	}
    }
}
#endif /* HAVE_IPV6 */

static struct isis_route_info *
isis_route_info_new (uint32_t cost, uint32_t depth, u_char family,
		     struct list *adjacencies)
{
  struct isis_route_info *rinfo;
  struct isis_adjacency *adj;
  struct listnode *node;

  rinfo = XCALLOC (MTYPE_ISIS_ROUTE_INFO, sizeof (struct isis_route_info));
  if (!rinfo)
    {
      zlog_err ("ISIS-Rte: isis_route_info_new: out of memory!");
      return NULL;
    }

  if (family == AF_INET)
    {
      rinfo->nexthops = list_new ();
      for (ALL_LIST_ELEMENTS_RO (adjacencies, node, adj))
        adjinfo2nexthop (rinfo->nexthops, adj);
    }
#ifdef HAVE_IPV6
  if (family == AF_INET6)
    {
      rinfo->nexthops6 = list_new ();
      for (ALL_LIST_ELEMENTS_RO (adjacencies, node, adj))
        adjinfo2nexthop6 (rinfo->nexthops6, adj);
    }

#endif /* HAVE_IPV6 */

  rinfo->cost = cost;
  rinfo->depth = depth;

  return rinfo;
}

static void
isis_route_info_delete (struct isis_route_info *route_info)
{
  if (route_info->nexthops)
    {
      route_info->nexthops->del = (void (*)(void *)) isis_nexthop_delete;
      list_delete (route_info->nexthops);
    }

#ifdef HAVE_IPV6
  if (route_info->nexthops6)
    {
      route_info->nexthops6->del = (void (*)(void *)) isis_nexthop6_delete;
      list_delete (route_info->nexthops6);
    }
#endif /* HAVE_IPV6 */

  XFREE (MTYPE_ISIS_ROUTE_INFO, route_info);
}

static int
isis_route_info_same_attrib (struct isis_route_info *new,
			     struct isis_route_info *old)
{
  if (new->cost != old->cost)
    return 0;
  if (new->depth != old->depth)
    return 0;

  return 1;
}

static int
isis_route_info_same (struct isis_route_info *new,
		      struct isis_route_info *old, u_char family)
{
  struct listnode *node;
  struct isis_nexthop *nexthop;
#ifdef HAVE_IPV6
  struct isis_nexthop6 *nexthop6;
#endif /* HAVE_IPV6 */
  if (!isis_route_info_same_attrib (new, old))
    return 0;

  if (family == AF_INET)
    {
      for (ALL_LIST_ELEMENTS_RO (new->nexthops, node, nexthop))
        if (nexthoplookup (old->nexthops, &nexthop->ip, nexthop->ifindex) 
              == 0)
          return 0;

      for (ALL_LIST_ELEMENTS_RO (old->nexthops, node, nexthop))
        if (nexthoplookup (new->nexthops, &nexthop->ip, nexthop->ifindex) 
             == 0)
          return 0;
    }
#ifdef HAVE_IPV6
  else if (family == AF_INET6)
    {
      for (ALL_LIST_ELEMENTS_RO (new->nexthops6, node, nexthop6))
        if (nexthop6lookup (old->nexthops6, &nexthop6->ip6,
                            nexthop6->ifindex) == 0)
          return 0;

      for (ALL_LIST_ELEMENTS_RO (old->nexthops6, node, nexthop6))
        if (nexthop6lookup (new->nexthops6, &nexthop6->ip6,
                            nexthop6->ifindex) == 0)
          return 0;
    }
#endif /* HAVE_IPV6 */

  return 1;
}

static void
isis_nexthops_merge (struct list *new, struct list *old)
{
  struct listnode *node;
  struct isis_nexthop *nexthop;

  for (ALL_LIST_ELEMENTS_RO (new, node, nexthop))
    {
      if (nexthoplookup (old, &nexthop->ip, nexthop->ifindex))
	continue;
      listnode_add (old, nexthop);
      nexthop->lock++;
    }
}

#ifdef HAVE_IPV6
static void
isis_nexthops6_merge (struct list *new, struct list *old)
{
  struct listnode *node;
  struct isis_nexthop6 *nexthop6;

  for (ALL_LIST_ELEMENTS_RO (new, node, nexthop6))
    {
      if (nexthop6lookup (old, &nexthop6->ip6, nexthop6->ifindex))
	continue;
      listnode_add (old, nexthop6);
      nexthop6->lock++;
    }
}
#endif /* HAVE_IPV6 */

static void
isis_route_info_merge (struct isis_route_info *new,
		       struct isis_route_info *old, u_char family)
{
  if (family == AF_INET)
    isis_nexthops_merge (new->nexthops, old->nexthops);
#ifdef HAVE_IPV6
  else if (family == AF_INET6)
    isis_nexthops6_merge (new->nexthops6, old->nexthops6);
#endif /* HAVE_IPV6 */

  return;
}

static int
isis_route_info_prefer_new (struct isis_route_info *new,
			    struct isis_route_info *old)
{
  if (!CHECK_FLAG (old->flag, ISIS_ROUTE_FLAG_ACTIVE))
    return 1;

  if (new->cost < old->cost)
    return 1;

  return 0;
}

struct isis_route_info *
isis_route_create (struct prefix *prefix, u_int32_t cost, u_int32_t depth,
		   struct list *adjacencies, struct isis_area *area,
		   int level)
{
  struct route_node *route_node;
  struct isis_route_info *rinfo_new, *rinfo_old, *route_info = NULL;
  u_char buff[BUFSIZ];
  u_char family;

  family = prefix->family;
  /* for debugs */
  prefix2str (prefix, (char *) buff, BUFSIZ);

  rinfo_new = isis_route_info_new (cost, depth, family, adjacencies);
  if (!rinfo_new)
    {
      zlog_err ("ISIS-Rte (%s): isis_route_create: out of memory!",
		area->area_tag);
      return NULL;
    }

  if (family == AF_INET)
    route_node = route_node_get (area->route_table[level - 1], prefix);
#ifdef HAVE_IPV6
  else if (family == AF_INET6)
    route_node = route_node_get (area->route_table6[level - 1], prefix);
#endif /* HAVE_IPV6 */
  else
    return NULL;
  rinfo_old = route_node->info;
  if (!rinfo_old)
    {
      if (isis->debugs & DEBUG_RTE_EVENTS)
	zlog_debug ("ISIS-Rte (%s) route created: %s", area->area_tag, buff);
      SET_FLAG (rinfo_new->flag, ISIS_ROUTE_FLAG_ACTIVE);
      route_node->info = rinfo_new;
      return rinfo_new;
    }

  if (isis->debugs & DEBUG_RTE_EVENTS)
    zlog_debug ("ISIS-Rte (%s) route already exists: %s", area->area_tag,
	       buff);

  if (isis_route_info_same (rinfo_new, rinfo_old, family))
    {
      if (isis->debugs & DEBUG_RTE_EVENTS)
	zlog_debug ("ISIS-Rte (%s) route unchanged: %s", area->area_tag, buff);
      isis_route_info_delete (rinfo_new);
      route_info = rinfo_old;
    }
  else if (isis_route_info_same_attrib (rinfo_new, rinfo_old))
    {
      /* merge the nexthop lists */
      if (isis->debugs & DEBUG_RTE_EVENTS)
	zlog_debug ("ISIS-Rte (%s) route changed (same attribs): %s",
		   area->area_tag, buff);
#ifdef EXTREME_DEBUG
      if (family == AF_INET)
	{
	  zlog_debug ("Old nexthops");
	  nexthops_print (rinfo_old->nexthops);
	  zlog_debug ("New nexthops");
	  nexthops_print (rinfo_new->nexthops);
	}
      else if (family == AF_INET6)
	{
	  zlog_debug ("Old nexthops");
	  nexthops6_print (rinfo_old->nexthops6);
	  zlog_debug ("New nexthops");
	  nexthops6_print (rinfo_new->nexthops6);
	}
#endif /* EXTREME_DEBUG */
      isis_route_info_merge (rinfo_new, rinfo_old, family);
      isis_route_info_delete (rinfo_new);
      route_info = rinfo_old;
      UNSET_FLAG (route_info->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNC);
    }
  else
    {
      if (isis_route_info_prefer_new (rinfo_new, rinfo_old))
	{
	  if (isis->debugs & DEBUG_RTE_EVENTS)
	    zlog_debug ("ISIS-Rte (%s) route changed: %s", area->area_tag,
			buff);
	  isis_route_info_delete (rinfo_old);
	  route_info = rinfo_new;
	}
      else
	{
	  if (isis->debugs & DEBUG_RTE_EVENTS)
	    zlog_debug ("ISIS-Rte (%s) route rejected: %s", area->area_tag,
			buff);
	  isis_route_info_delete (rinfo_new);
	  route_info = rinfo_old;
	}
    }

  SET_FLAG (route_info->flag, ISIS_ROUTE_FLAG_ACTIVE);
  route_node->info = route_info;

  return route_info;
}

static void
isis_route_delete (struct prefix *prefix, struct route_table *table)
{
  struct route_node *rode;
  struct isis_route_info *rinfo;
  char buff[BUFSIZ];

  /* for log */
  prefix2str (prefix, buff, BUFSIZ);


  rode = route_node_get (table, prefix);
  rinfo = rode->info;

  if (rinfo == NULL)
    {
      if (isis->debugs & DEBUG_RTE_EVENTS)
	zlog_debug ("ISIS-Rte: tried to delete non-existant route %s", buff);
      return;
    }

  if (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNC))
    {
      UNSET_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE);
      if (isis->debugs & DEBUG_RTE_EVENTS)
	zlog_debug ("ISIS-Rte: route delete  %s", buff);
      isis_zebra_route_update (prefix, rinfo);
    }
  isis_route_info_delete (rinfo);
  rode->info = NULL;

  return;
}

/* Validating routes in particular table. */
static void
isis_route_validate_table (struct isis_area *area, struct route_table *table)
{
  struct route_node *rnode, *drnode;
  struct isis_route_info *rinfo;
  u_char buff[BUFSIZ];

  for (rnode = route_top (table); rnode; rnode = route_next (rnode))
    {
      if (rnode->info == NULL)
	continue;
      rinfo = rnode->info;

      if (isis->debugs & DEBUG_RTE_EVENTS)
	{
	  prefix2str (&rnode->p, (char *) buff, BUFSIZ);
	  zlog_debug ("ISIS-Rte (%s): route validate: %s %s %s",
		      area->area_tag,
		      (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ZEBRA_SYNC) ?
		      "sync'ed" : "nosync"),
		      (CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE) ?
		      "active" : "inactive"), buff);
	}

      isis_zebra_route_update (&rnode->p, rinfo);
      if (!CHECK_FLAG (rinfo->flag, ISIS_ROUTE_FLAG_ACTIVE))
	{
	  /* Area is either L1 or L2 => we use level route tables directly for
	   * validating => no problems with deleting routes. */
	  if (area->is_type != IS_LEVEL_1_AND_2)
	    {
	      isis_route_delete (&rnode->p, table);
	      continue;
	    }
	  /* If area is L1L2, we work with merge table and therefore must
	   * delete node from level tables as well before deleting route info.
	   * FIXME: Is it performance problem? There has to be the better way.
	   * Like not to deal with it here at all (see the next comment)? */
	  if (rnode->p.family == AF_INET)
	    {
	      drnode = route_node_get (area->route_table[0], &rnode->p);
	      if (drnode->info == rnode->info)
		drnode->info = NULL;
	      drnode = route_node_get (area->route_table[1], &rnode->p);
	      if (drnode->info == rnode->info)
		drnode->info = NULL;
	    }
	  if (rnode->p.family == AF_INET6)
	    {
	      drnode = route_node_get (area->route_table6[0], &rnode->p);
	      if (drnode->info == rnode->info)
		drnode->info = NULL;
	      drnode = route_node_get (area->route_table6[1], &rnode->p);
	      if (drnode->info == rnode->info)
		drnode->info = NULL;
	    }
	      
	  isis_route_delete (&rnode->p, table);
	}
    }
}

/* Function to validate route tables for L1L2 areas. In this case we can't use
 * level route tables directly, we have to merge them at first. L1 routes are
 * preferred over the L2 ones.
 *
 * Merge algorithm is trivial (at least for now). All L1 paths are copied into
 * merge table at first, then L2 paths are added if L1 path for same prefix
 * doesn't already exists there.
 *
 * FIXME: Is it right place to do it at all? Maybe we should push both levels
 * to the RIB with different zebra route types and let RIB handle this? */
static void
isis_route_validate_merge (struct isis_area *area, int family)
{
  struct route_table *table = NULL;
  struct route_table *merge;
  struct route_node *rnode, *mrnode;

  merge = route_table_init ();

  if (family == AF_INET)
    table = area->route_table[0];
  else if (family == AF_INET6)
    table = area->route_table6[0];

  for (rnode = route_top (table); rnode; rnode = route_next (rnode))
    {
      if (rnode->info == NULL)
        continue;
      mrnode = route_node_get (merge, &rnode->p);
      mrnode->info = rnode->info;
    }

  if (family == AF_INET)
    table = area->route_table[1];
  else if (family == AF_INET6)
    table = area->route_table6[1];

  for (rnode = route_top (table); rnode; rnode = route_next (rnode))
    {
      if (rnode->info == NULL)
        continue;
      mrnode = route_node_get (merge, &rnode->p);
      if (mrnode->info != NULL)
        continue;
      mrnode->info = rnode->info;
    }

  isis_route_validate_table (area, merge);
  route_table_finish (merge);
}

/* Walk through route tables and propagate necessary changes into RIB. In case
 * of L1L2 area, level tables have to be merged at first. */
int
isis_route_validate (struct thread *thread)
{
  struct isis_area *area;

  area = THREAD_ARG (thread);

  if (area->is_type == IS_LEVEL_1)
    { 
      isis_route_validate_table (area, area->route_table[0]);
      goto validate_ipv6;
    }
  if (area->is_type == IS_LEVEL_2)
    {
      isis_route_validate_table (area, area->route_table[1]);
      goto validate_ipv6;
    }

  isis_route_validate_merge (area, AF_INET);

#ifdef HAVE_IPV6
validate_ipv6:
  if (area->is_type == IS_LEVEL_1)
    {
      isis_route_validate_table (area, area->route_table6[0]);
      return ISIS_OK;
    }
  if (area->is_type == IS_LEVEL_2)
    {
      isis_route_validate_table (area, area->route_table6[1]);
      return ISIS_OK;
    }

  isis_route_validate_merge (area, AF_INET6);
#endif

  return ISIS_OK;
}