-
Notifications
You must be signed in to change notification settings - Fork 1.3k
/
Copy pathisis_sr.c
1288 lines (1107 loc) · 34.3 KB
/
isis_sr.c
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
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* This is an implementation of Segment Routing for IS-IS as per RFC 8667
*
* Copyright (C) 2019 Orange http://www.orange.com
*
* Author: Olivier Dugeon <olivier.dugeon@orange.com>
* Contributor: Renato Westphal <renato@opensourcerouting.org> for NetDEF
*
* 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; see the file COPYING; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <zebra.h>
#include "if.h"
#include "linklist.h"
#include "log.h"
#include "command.h"
#include "termtable.h"
#include "memory.h"
#include "prefix.h"
#include "table.h"
#include "srcdest_table.h"
#include "vty.h"
#include "zclient.h"
#include "lib/lib_errors.h"
#include "isisd/isisd.h"
#include "isisd/isis_spf.h"
#include "isisd/isis_spf_private.h"
#include "isisd/isis_adjacency.h"
#include "isisd/isis_route.h"
#include "isisd/isis_mt.h"
#include "isisd/isis_sr.h"
#include "isisd/isis_tlvs.h"
#include "isisd/isis_misc.h"
#include "isisd/isis_zebra.h"
#include "isisd/isis_errors.h"
/* Local variables and functions */
DEFINE_MTYPE_STATIC(ISISD, ISIS_SR_INFO, "ISIS segment routing information");
static void sr_local_block_delete(struct isis_area *area);
static int sr_local_block_init(struct isis_area *area);
static void sr_adj_sid_update(struct sr_adjacency *sra,
struct sr_local_block *srlb);
static void sr_adj_sid_del(struct sr_adjacency *sra);
/* --- RB-Tree Management functions ----------------------------------------- */
/**
* Configured SR Prefix comparison for RB-Tree.
*
* @param a First SR prefix
* @param b Second SR prefix
*
* @return -1 (a < b), 0 (a == b) or +1 (a > b)
*/
static inline int sr_prefix_sid_cfg_compare(const struct sr_prefix_cfg *a,
const struct sr_prefix_cfg *b)
{
return prefix_cmp(&a->prefix, &b->prefix);
}
DECLARE_RBTREE_UNIQ(srdb_prefix_cfg, struct sr_prefix_cfg, entry,
sr_prefix_sid_cfg_compare);
/**
* Find SRGB associated to a System ID.
*
* @param area IS-IS LSP database
* @param sysid System ID to lookup
*
* @return Pointer to SRGB if found, NULL otherwise
*/
struct isis_sr_block *isis_sr_find_srgb(struct lspdb_head *lspdb,
const uint8_t *sysid)
{
struct isis_lsp *lsp;
lsp = isis_root_system_lsp(lspdb, sysid);
if (!lsp)
return NULL;
if (!lsp->tlvs->router_cap
|| lsp->tlvs->router_cap->srgb.range_size == 0)
return NULL;
return &lsp->tlvs->router_cap->srgb;
}
/**
* Compute input label for the given Prefix-SID.
*
* @param area IS-IS area
* @param psid IS-IS Prefix-SID Sub-TLV
* @param local Indicates whether the Prefix-SID is local or not
*
* @return MPLS label or MPLS_INVALID_LABEL in case of SRGB overflow
*/
mpls_label_t sr_prefix_in_label(struct isis_area *area,
struct isis_prefix_sid *psid, bool local)
{
/*
* No need to assign a label for local Prefix-SIDs unless the no-PHP
* flag is set.
*/
if (local
&& (!CHECK_FLAG(psid->flags, ISIS_PREFIX_SID_NO_PHP)
|| CHECK_FLAG(psid->flags, ISIS_PREFIX_SID_EXPLICIT_NULL)))
return MPLS_INVALID_LABEL;
/* Return SID value as MPLS label if it is an Absolute SID */
if (CHECK_FLAG(psid->flags,
ISIS_PREFIX_SID_VALUE | ISIS_PREFIX_SID_LOCAL))
return psid->value;
/* Check that SID index falls inside the SRGB */
if (psid->value >= (area->srdb.config.srgb_upper_bound
- area->srdb.config.srgb_lower_bound + 1)) {
flog_warn(EC_ISIS_SID_OVERFLOW,
"%s: SID index %u falls outside local SRGB range",
__func__, psid->value);
return MPLS_INVALID_LABEL;
}
/* Return MPLS label as SID index + SRGB_lower_bound as per RFC 8667 */
return (area->srdb.config.srgb_lower_bound + psid->value);
}
/**
* Compute output label for the given Prefix-SID.
*
* @param lspdb IS-IS LSP database
* @param family Prefix-SID address family
* @param psid Prefix-SID Sub-TLV
* @param nh_sysid System ID of the nexthop node
* @param last_hop Indicates whether the nexthop node is the last hop
*
* @return MPLS label or MPLS_INVALID_LABEL in case of error
*/
mpls_label_t sr_prefix_out_label(struct lspdb_head *lspdb, int family,
struct isis_prefix_sid *psid,
const uint8_t *nh_sysid, bool last_hop)
{
struct isis_sr_block *nh_srgb;
if (last_hop) {
if (!CHECK_FLAG(psid->flags, ISIS_PREFIX_SID_NO_PHP))
return MPLS_LABEL_IMPLICIT_NULL;
if (CHECK_FLAG(psid->flags, ISIS_PREFIX_SID_EXPLICIT_NULL)) {
if (family == AF_INET)
return MPLS_LABEL_IPV4_EXPLICIT_NULL;
else
return MPLS_LABEL_IPV6_EXPLICIT_NULL;
}
/* Fallthrough */
}
/* Return SID value as MPLS label if it is an Absolute SID */
if (CHECK_FLAG(psid->flags,
ISIS_PREFIX_SID_VALUE | ISIS_PREFIX_SID_LOCAL)) {
/*
* V/L SIDs have local significance, so only adjacent routers
* can use them (RFC8667 section #2.1.1.1)
*/
if (!last_hop)
return MPLS_INVALID_LABEL;
return psid->value;
}
/* Check that SID index falls inside the SRGB */
nh_srgb = isis_sr_find_srgb(lspdb, nh_sysid);
if (!nh_srgb)
return MPLS_INVALID_LABEL;
/*
* Check if the nexthop can handle SR-MPLS encapsulated IPv4 or
* IPv6 packets.
*/
if ((family == AF_INET && !IS_SR_IPV4(nh_srgb))
|| (family == AF_INET6 && !IS_SR_IPV6(nh_srgb)))
return MPLS_INVALID_LABEL;
if (psid->value >= nh_srgb->range_size) {
flog_warn(EC_ISIS_SID_OVERFLOW,
"%s: SID index %u falls outside remote SRGB range",
__func__, psid->value);
return MPLS_INVALID_LABEL;
}
/* Return MPLS label as SID index + SRGB_lower_bound as per RFC 8667 */
return (nh_srgb->lower_bound + psid->value);
}
/* --- Functions used for Yang model and CLI to configure Segment Routing --- */
/**
* Check if prefix correspond to a Node SID.
*
* @param ifp Interface
* @param prefix Prefix to be checked
*
* @return True if the interface/address pair corresponds to a Node-SID
*/
static bool sr_prefix_is_node_sid(const struct interface *ifp,
const struct prefix *prefix)
{
return (if_is_loopback(ifp) && is_host_route(prefix));
}
/**
* Update local SRGB configuration. SRGB is reserved though Label Manager.
* This function trigger the update of local Prefix-SID installation.
*
* @param area IS-IS area
* @param lower_bound Lower bound of SRGB
* @param upper_bound Upper bound of SRGB
*
* @return 0 on success, -1 otherwise
*/
int isis_sr_cfg_srgb_update(struct isis_area *area, uint32_t lower_bound,
uint32_t upper_bound)
{
struct isis_sr_db *srdb = &area->srdb;
sr_debug("ISIS-Sr (%s): Update SRGB with new range [%u/%u]",
area->area_tag, lower_bound, upper_bound);
/* Just store new SRGB values if Label Manager is not available.
* SRGB will be configured later when SR start */
if (!isis_zebra_label_manager_ready()) {
srdb->config.srgb_lower_bound = lower_bound;
srdb->config.srgb_upper_bound = upper_bound;
return 0;
}
/* Label Manager is ready, start by releasing the old SRGB. */
if (srdb->srgb_active) {
isis_zebra_release_label_range(srdb->config.srgb_lower_bound,
srdb->config.srgb_upper_bound);
srdb->srgb_active = false;
}
srdb->config.srgb_lower_bound = lower_bound;
srdb->config.srgb_upper_bound = upper_bound;
if (srdb->enabled) {
/* then request new SRGB if SR is enabled. */
if (isis_zebra_request_label_range(
srdb->config.srgb_lower_bound,
srdb->config.srgb_upper_bound
- srdb->config.srgb_lower_bound + 1) < 0) {
srdb->srgb_active = false;
return -1;
} else
srdb->srgb_active = true;
sr_debug(" |- Got new SRGB [%u/%u]",
srdb->config.srgb_lower_bound,
srdb->config.srgb_upper_bound);
lsp_regenerate_schedule(area, area->is_type, 0);
} else if (srdb->config.enabled) {
/* Try to enable SR again using the new SRGB. */
isis_sr_start(area);
}
return 0;
}
/**
* Update Segment Routing Local Block range which is reserved though the
* Label Manager. This function trigger the update of local Adjacency-SID
* installation.
*
* @param area IS-IS area
* @param lower_bound Lower bound of SRLB
* @param upper_bound Upper bound of SRLB
*
* @return 0 on success, -1 otherwise
*/
int isis_sr_cfg_srlb_update(struct isis_area *area, uint32_t lower_bound,
uint32_t upper_bound)
{
struct isis_sr_db *srdb = &area->srdb;
struct listnode *node;
struct sr_adjacency *sra;
sr_debug("ISIS-Sr (%s): Update SRLB with new range [%u/%u]",
area->area_tag, lower_bound, upper_bound);
/* Just store new SRLB values if Label Manager is not available.
* SRLB will be configured later when SR start */
if (!isis_zebra_label_manager_ready()) {
srdb->config.srlb_lower_bound = lower_bound;
srdb->config.srlb_upper_bound = upper_bound;
return 0;
}
/* LM is ready, start by deleting the old SRLB */
sr_local_block_delete(area);
srdb->config.srlb_lower_bound = lower_bound;
srdb->config.srlb_upper_bound = upper_bound;
if (srdb->enabled) {
/* Initialize new SRLB */
if (sr_local_block_init(area) != 0)
return -1;
/* Reinstall local Adjacency-SIDs with new labels. */
for (ALL_LIST_ELEMENTS_RO(area->srdb.adj_sids, node, sra))
sr_adj_sid_update(sra, &srdb->srlb);
/* Update and Flood LSP */
lsp_regenerate_schedule(area, area->is_type, 0);
} else if (srdb->config.enabled) {
/* Try to enable SR again using the new SRLB. */
isis_sr_start(area);
}
return 0;
}
/**
* Add new Prefix-SID configuration to the SRDB.
*
* @param area IS-IS area
* @param prefix Prefix to be added
*
* @return Newly added Prefix-SID configuration structure
*/
struct sr_prefix_cfg *isis_sr_cfg_prefix_add(struct isis_area *area,
const struct prefix *prefix)
{
struct sr_prefix_cfg *pcfg;
struct interface *ifp;
sr_debug("ISIS-Sr (%s): Add local prefix %pFX", area->area_tag, prefix);
pcfg = XCALLOC(MTYPE_ISIS_SR_INFO, sizeof(*pcfg));
pcfg->prefix = *prefix;
pcfg->area = area;
/* Pull defaults from the YANG module. */
pcfg->sid_type = yang_get_default_enum(
"%s/prefix-sid-map/prefix-sid/sid-value-type", ISIS_SR);
pcfg->last_hop_behavior = yang_get_default_enum(
"%s/prefix-sid-map/prefix-sid/last-hop-behavior", ISIS_SR);
/* Mark as node Sid if the prefix is host and configured in loopback */
ifp = if_lookup_prefix(prefix, VRF_DEFAULT);
if (ifp && sr_prefix_is_node_sid(ifp, prefix))
pcfg->node_sid = true;
/* Save prefix-sid configuration. */
srdb_prefix_cfg_add(&area->srdb.config.prefix_sids, pcfg);
return pcfg;
}
/**
* Removal of locally configured Prefix-SID.
*
* @param pcfg Configured Prefix-SID
*/
void isis_sr_cfg_prefix_del(struct sr_prefix_cfg *pcfg)
{
struct isis_area *area = pcfg->area;
sr_debug("ISIS-Sr (%s): Delete local Prefix-SID %pFX %s %u",
area->area_tag, &pcfg->prefix,
pcfg->sid_type == SR_SID_VALUE_TYPE_INDEX ? "index" : "label",
pcfg->sid);
srdb_prefix_cfg_del(&area->srdb.config.prefix_sids, pcfg);
XFREE(MTYPE_ISIS_SR_INFO, pcfg);
}
/**
* Lookup for Prefix-SID in the local configuration.
*
* @param area IS-IS area
* @param prefix Prefix to lookup
*
* @return Configured Prefix-SID structure if found, NULL otherwise
*/
struct sr_prefix_cfg *isis_sr_cfg_prefix_find(struct isis_area *area,
union prefixconstptr prefix)
{
struct sr_prefix_cfg pcfg = {};
prefix_copy(&pcfg.prefix, prefix.p);
return srdb_prefix_cfg_find(&area->srdb.config.prefix_sids, &pcfg);
}
/**
* Fill in Prefix-SID Sub-TLV according to the corresponding configuration.
*
* @param pcfg Prefix-SID configuration
* @param external False if prefix is locally configured, true otherwise
* @param psid Prefix-SID sub-TLV to be updated
*/
void isis_sr_prefix_cfg2subtlv(const struct sr_prefix_cfg *pcfg, bool external,
struct isis_prefix_sid *psid)
{
/* Set SID algorithm. */
psid->algorithm = SR_ALGORITHM_SPF;
/* Set SID flags. */
psid->flags = 0;
switch (pcfg->last_hop_behavior) {
case SR_LAST_HOP_BEHAVIOR_EXP_NULL:
SET_FLAG(psid->flags, ISIS_PREFIX_SID_NO_PHP);
SET_FLAG(psid->flags, ISIS_PREFIX_SID_EXPLICIT_NULL);
break;
case SR_LAST_HOP_BEHAVIOR_NO_PHP:
SET_FLAG(psid->flags, ISIS_PREFIX_SID_NO_PHP);
UNSET_FLAG(psid->flags, ISIS_PREFIX_SID_EXPLICIT_NULL);
break;
case SR_LAST_HOP_BEHAVIOR_PHP:
UNSET_FLAG(psid->flags, ISIS_PREFIX_SID_NO_PHP);
UNSET_FLAG(psid->flags, ISIS_PREFIX_SID_EXPLICIT_NULL);
break;
}
if (external)
SET_FLAG(psid->flags, ISIS_PREFIX_SID_READVERTISED);
if (pcfg->node_sid && !pcfg->n_flag_clear)
SET_FLAG(psid->flags, ISIS_PREFIX_SID_NODE);
/* Set SID value. */
psid->value = pcfg->sid;
if (pcfg->sid_type == SR_SID_VALUE_TYPE_ABSOLUTE) {
SET_FLAG(psid->flags, ISIS_PREFIX_SID_VALUE);
SET_FLAG(psid->flags, ISIS_PREFIX_SID_LOCAL);
}
}
/**
* Delete all backup Adj-SIDs.
*
* @param area IS-IS area
* @param level IS-IS level
*/
void isis_area_delete_backup_adj_sids(struct isis_area *area, int level)
{
struct sr_adjacency *sra;
struct listnode *node, *nnode;
for (ALL_LIST_ELEMENTS(area->srdb.adj_sids, node, nnode, sra))
if (sra->type == ISIS_SR_LAN_BACKUP
&& (sra->adj->level & level))
sr_adj_sid_del(sra);
}
/* --- Segment Routing Local Block management functions --------------------- */
/**
* Initialize Segment Routing Local Block from SRDB configuration and reserve
* block of bits to manage label allocation.
*
* @param area IS-IS area
*/
static int sr_local_block_init(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
struct sr_local_block *srlb = &srdb->srlb;
/* Check if SRLB is not already configured */
if (srlb->active)
return 0;
/*
* Request SRLB to the label manager. If the allocation fails, return
* an error to disable SR until a new SRLB is successfully allocated.
*/
if (isis_zebra_request_label_range(
srdb->config.srlb_lower_bound,
srdb->config.srlb_upper_bound
- srdb->config.srlb_lower_bound + 1)) {
srlb->active = false;
return -1;
}
sr_debug("ISIS-Sr (%s): Got new SRLB [%u/%u]", area->area_tag,
srdb->config.srlb_lower_bound, srdb->config.srlb_upper_bound);
/* Initialize the SRLB */
srlb->start = srdb->config.srlb_lower_bound;
srlb->end = srdb->config.srlb_upper_bound;
srlb->current = 0;
/* Compute the needed Used Mark number and allocate them */
srlb->max_block = (srlb->end - srlb->start + 1) / SRLB_BLOCK_SIZE;
if (((srlb->end - srlb->start + 1) % SRLB_BLOCK_SIZE) != 0)
srlb->max_block++;
srlb->used_mark = XCALLOC(MTYPE_ISIS_SR_INFO,
srlb->max_block * SRLB_BLOCK_SIZE);
srlb->active = true;
return 0;
}
/**
* Remove Segment Routing Local Block.
*
* @param area IS-IS area
*/
static void sr_local_block_delete(struct isis_area *area)
{
struct isis_sr_db *srdb = &area->srdb;
struct sr_local_block *srlb = &srdb->srlb;
/* Check if SRLB is not already delete */
if (!srlb->active)
return;
sr_debug("ISIS-Sr (%s): Remove SRLB [%u/%u]", area->area_tag,
srlb->start, srlb->end);
/* First release the label block */
isis_zebra_release_label_range(srdb->config.srlb_lower_bound,
srdb->config.srlb_upper_bound);
/* Then reset SRLB structure */
if (srlb->used_mark != NULL)
XFREE(MTYPE_ISIS_SR_INFO, srlb->used_mark);
srlb->active = false;
}
/**
* Request a label from the Segment Routing Local Block.
*
* @param srlb Segment Routing Local Block
*
* @return First available label on success or MPLS_INVALID_LABEL if the
* block of labels is full
*/
static mpls_label_t sr_local_block_request_label(struct sr_local_block *srlb)
{
mpls_label_t label;
uint32_t index;
uint32_t pos;
uint32_t size = srlb->end - srlb->start + 1;
/* Check if we ran out of available labels */
if (srlb->current >= size)
return MPLS_INVALID_LABEL;
/* Get first available label and mark it used */
label = srlb->current + srlb->start;
index = srlb->current / SRLB_BLOCK_SIZE;
pos = 1ULL << (srlb->current % SRLB_BLOCK_SIZE);
srlb->used_mark[index] |= pos;
/* Jump to the next free position */
srlb->current++;
pos = srlb->current % SRLB_BLOCK_SIZE;
while (srlb->current < size) {
if (pos == 0)
index++;
if (!((1ULL << pos) & srlb->used_mark[index]))
break;
else {
srlb->current++;
pos = srlb->current % SRLB_BLOCK_SIZE;
}
}
if (srlb->current == size)
zlog_warn(
"SR: Warning, SRLB is depleted and next label request will fail");
return label;
}
/**
* Release label in the Segment Routing Local Block.
*
* @param srlb Segment Routing Local Block
* @param label Label to be release
*
* @return 0 on success or -1 if label falls outside SRLB
*/
static int sr_local_block_release_label(struct sr_local_block *srlb,
mpls_label_t label)
{
uint32_t index;
uint32_t pos;
/* Check that label falls inside the SRLB */
if ((label < srlb->start) || (label > srlb->end)) {
flog_warn(EC_ISIS_SID_OVERFLOW,
"%s: Returning label %u is outside SRLB [%u/%u]",
__func__, label, srlb->start, srlb->end);
return -1;
}
index = (label - srlb->start) / SRLB_BLOCK_SIZE;
pos = 1ULL << ((label - srlb->start) % SRLB_BLOCK_SIZE);
srlb->used_mark[index] &= ~pos;
/* Reset current to the first available position */
for (index = 0; index < srlb->max_block; index++) {
if (srlb->used_mark[index] != 0xFFFFFFFFFFFFFFFF) {
for (pos = 0; pos < SRLB_BLOCK_SIZE; pos++)
if (!((1ULL << pos) & srlb->used_mark[index])) {
srlb->current =
index * SRLB_BLOCK_SIZE + pos;
break;
}
break;
}
}
return 0;
}
/* --- Segment Routing Adjacency-SID management functions ------------------- */
/**
* Add new local Adjacency-SID.
*
* @param adj IS-IS Adjacency
* @param family Inet Family (IPv4 or IPv6)
* @param backup True to initialize backup Adjacency SID
* @param nexthops List of backup nexthops (for backup Adj-SIDs only)
*/
void sr_adj_sid_add_single(struct isis_adjacency *adj, int family, bool backup,
struct list *nexthops)
{
struct isis_circuit *circuit = adj->circuit;
struct isis_area *area = circuit->area;
struct sr_adjacency *sra;
struct isis_adj_sid *adj_sid;
struct isis_lan_adj_sid *ladj_sid;
union g_addr nexthop = {};
uint8_t flags;
mpls_label_t input_label;
sr_debug("ISIS-Sr (%s): Add %s Adjacency SID", area->area_tag,
backup ? "Backup" : "Primary");
/* Determine nexthop IP address */
switch (family) {
case AF_INET:
if (!circuit->ip_router || !adj->ipv4_address_count)
return;
nexthop.ipv4 = adj->ipv4_addresses[0];
break;
case AF_INET6:
if (!circuit->ipv6_router || !adj->ll_ipv6_count)
return;
nexthop.ipv6 = adj->ll_ipv6_addrs[0];
break;
default:
flog_err(EC_LIB_DEVELOPMENT,
"%s: unexpected address-family: %u", __func__, family);
exit(1);
}
/* Prepare Segment Routing Adjacency as per RFC8667 section #2.2 */
flags = EXT_SUBTLV_LINK_ADJ_SID_VFLG | EXT_SUBTLV_LINK_ADJ_SID_LFLG;
if (family == AF_INET6)
SET_FLAG(flags, EXT_SUBTLV_LINK_ADJ_SID_FFLG);
if (backup)
SET_FLAG(flags, EXT_SUBTLV_LINK_ADJ_SID_BFLG);
/* Get a label from the SRLB for this Adjacency */
input_label = sr_local_block_request_label(&area->srdb.srlb);
if (input_label == MPLS_INVALID_LABEL)
return;
if (circuit->ext == NULL)
circuit->ext = isis_alloc_ext_subtlvs();
sra = XCALLOC(MTYPE_ISIS_SR_INFO, sizeof(*sra));
sra->type = backup ? ISIS_SR_LAN_BACKUP : ISIS_SR_ADJ_NORMAL;
sra->input_label = input_label;
sra->nexthop.family = family;
sra->nexthop.address = nexthop;
if (backup && nexthops) {
struct isis_vertex_adj *vadj;
struct listnode *node;
sra->backup_nexthops = list_new();
for (ALL_LIST_ELEMENTS_RO(nexthops, node, vadj)) {
struct isis_adjacency *adj = vadj->sadj->adj;
struct mpls_label_stack *label_stack;
label_stack = vadj->label_stack;
adjinfo2nexthop(family, sra->backup_nexthops, adj, NULL,
label_stack);
}
}
switch (circuit->circ_type) {
/* LAN Adjacency-SID for Broadcast interface section #2.2.2 */
case CIRCUIT_T_BROADCAST:
ladj_sid = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*ladj_sid));
ladj_sid->family = family;
ladj_sid->flags = flags;
ladj_sid->weight = 0;
memcpy(ladj_sid->neighbor_id, adj->sysid,
sizeof(ladj_sid->neighbor_id));
ladj_sid->sid = input_label;
isis_tlvs_add_lan_adj_sid(circuit->ext, ladj_sid);
sra->u.ladj_sid = ladj_sid;
break;
/* Adjacency-SID for Point to Point interface section #2.2.1 */
case CIRCUIT_T_P2P:
adj_sid = XCALLOC(MTYPE_ISIS_SUBTLV, sizeof(*adj_sid));
adj_sid->family = family;
adj_sid->flags = flags;
adj_sid->weight = 0;
adj_sid->sid = input_label;
isis_tlvs_add_adj_sid(circuit->ext, adj_sid);
sra->u.adj_sid = adj_sid;
break;
default:
flog_err(EC_LIB_DEVELOPMENT, "%s: unexpected circuit type: %u",
__func__, circuit->circ_type);
exit(1);
}
/* Add Adjacency-SID in SRDB */
sra->adj = adj;
listnode_add(area->srdb.adj_sids, sra);
listnode_add(adj->adj_sids, sra);
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_ADD, sra);
}
/**
* Add Primary and Backup local Adjacency SID.
*
* @param adj IS-IS Adjacency
* @param family Inet Family (IPv4 or IPv6)
*/
static void sr_adj_sid_add(struct isis_adjacency *adj, int family)
{
sr_adj_sid_add_single(adj, family, false, NULL);
}
static void sr_adj_sid_update(struct sr_adjacency *sra,
struct sr_local_block *srlb)
{
struct isis_circuit *circuit = sra->adj->circuit;
/* First remove the old MPLS Label */
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_DELETE, sra);
/* Got new label in the new SRLB */
sra->input_label = sr_local_block_request_label(srlb);
if (sra->input_label == MPLS_INVALID_LABEL)
return;
switch (circuit->circ_type) {
case CIRCUIT_T_BROADCAST:
sra->u.ladj_sid->sid = sra->input_label;
break;
case CIRCUIT_T_P2P:
sra->u.adj_sid->sid = sra->input_label;
break;
default:
flog_warn(EC_LIB_DEVELOPMENT, "%s: unexpected circuit type: %u",
__func__, circuit->circ_type);
break;
}
/* Finally configure the new MPLS Label */
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_ADD, sra);
}
/**
* Delete local Adj-SID.
*
* @param sra Segment Routing Adjacency
*/
static void sr_adj_sid_del(struct sr_adjacency *sra)
{
struct isis_circuit *circuit = sra->adj->circuit;
struct isis_area *area = circuit->area;
sr_debug("ISIS-Sr (%s): Delete Adjacency SID", area->area_tag);
isis_zebra_send_adjacency_sid(ZEBRA_MPLS_LABELS_DELETE, sra);
/* Release dynamic label and remove subTLVs */
switch (circuit->circ_type) {
case CIRCUIT_T_BROADCAST:
sr_local_block_release_label(&area->srdb.srlb,
sra->u.ladj_sid->sid);
isis_tlvs_del_lan_adj_sid(circuit->ext, sra->u.ladj_sid);
break;
case CIRCUIT_T_P2P:
sr_local_block_release_label(&area->srdb.srlb,
sra->u.adj_sid->sid);
isis_tlvs_del_adj_sid(circuit->ext, sra->u.adj_sid);
break;
default:
flog_err(EC_LIB_DEVELOPMENT, "%s: unexpected circuit type: %u",
__func__, circuit->circ_type);
exit(1);
}
if (sra->type == ISIS_SR_LAN_BACKUP && sra->backup_nexthops) {
sra->backup_nexthops->del =
(void (*)(void *))isis_nexthop_delete;
list_delete(&sra->backup_nexthops);
}
/* Remove Adjacency-SID from the SRDB */
listnode_delete(area->srdb.adj_sids, sra);
listnode_delete(sra->adj->adj_sids, sra);
XFREE(MTYPE_ISIS_SR_INFO, sra);
}
/**
* Lookup Segment Routing Adj-SID by family and type.
*
* @param adj IS-IS Adjacency
* @param family Inet Family (IPv4 or IPv6)
* @param type Adjacency SID type
*/
struct sr_adjacency *isis_sr_adj_sid_find(struct isis_adjacency *adj,
int family, enum sr_adj_type type)
{
struct sr_adjacency *sra;
struct listnode *node;
for (ALL_LIST_ELEMENTS_RO(adj->adj_sids, node, sra))
if (sra->nexthop.family == family && sra->type == type)
return sra;
return NULL;
}
/**
* Remove all Adjacency-SIDs associated to an adjacency that is going down.
*
* @param adj IS-IS Adjacency
*
* @return 0
*/
static int sr_adj_state_change(struct isis_adjacency *adj)
{
struct sr_adjacency *sra;
struct listnode *node, *nnode;
if (!adj->circuit->area->srdb.enabled)
return 0;
if (adj->adj_state == ISIS_ADJ_UP)
return 0;
for (ALL_LIST_ELEMENTS(adj->adj_sids, node, nnode, sra))
sr_adj_sid_del(sra);
return 0;
}
/**
* When IS-IS Adjacency got one or more IPv4/IPv6 addresses, add new IPv4 or
* IPv6 address to corresponding Adjacency-SID accordingly.
*
* @param adj IS-IS Adjacency
* @param family Inet Family (IPv4 or IPv6)
* @param global Indicate if it concerns the Local or Global IPv6 addresses
*
* @return 0
*/
static int sr_adj_ip_enabled(struct isis_adjacency *adj, int family,
bool global)
{
if (!adj->circuit->area->srdb.enabled || global)
return 0;
sr_adj_sid_add(adj, family);
return 0;
}
/**
* When IS-IS Adjacency doesn't have any IPv4 or IPv6 addresses anymore,
* delete the corresponding Adjacency-SID(s) accordingly.
*
* @param adj IS-IS Adjacency
* @param family Inet Family (IPv4 or IPv6)
* @param global Indicate if it concerns the Local or Global IPv6 addresses
*
* @return 0
*/
static int sr_adj_ip_disabled(struct isis_adjacency *adj, int family,
bool global)
{
struct sr_adjacency *sra;
struct listnode *node, *nnode;
if (!adj->circuit->area->srdb.enabled || global)
return 0;
for (ALL_LIST_ELEMENTS(adj->adj_sids, node, nnode, sra))
if (sra->nexthop.family == family)
sr_adj_sid_del(sra);
return 0;
}
/**
* Activate local Prefix-SID when loopback interface goes up for IS-IS.
*
* @param ifp Loopback Interface
*
* @return 0
*/
static int sr_if_new_hook(struct interface *ifp)
{
struct isis_circuit *circuit;
struct isis_area *area;
struct connected *connected;
struct listnode *node;
/* Get corresponding circuit */
circuit = circuit_scan_by_ifp(ifp);
if (!circuit)
return 0;
area = circuit->area;
if (!area)
return 0;
/*
* Update the Node-SID flag of the configured Prefix-SID mappings if
* necessary. This needs to be done here since isisd reads the startup
* configuration before receiving interface information from zebra.
*/
FOR_ALL_INTERFACES_ADDRESSES (ifp, connected, node) {
struct sr_prefix_cfg *pcfg;
pcfg = isis_sr_cfg_prefix_find(area, connected->address);
if (!pcfg)
continue;
if (sr_prefix_is_node_sid(ifp, &pcfg->prefix)) {
pcfg->node_sid = true;
lsp_regenerate_schedule(area, area->is_type, 0);
}
}
return 0;
}
/**
* Show LFIB operation in human readable format.
*
* @param buf Buffer to store string output. Must be pre-allocate
* @param size Size of the buffer
* @param label_in Input Label
* @param label_out Output Label
*
* @return String containing LFIB operation in human readable format
*/
char *sr_op2str(char *buf, size_t size, mpls_label_t label_in,
mpls_label_t label_out)
{
if (size < 24)
return NULL;
if (label_in == MPLS_INVALID_LABEL) {
snprintf(buf, size, "no-op.");
return buf;
}
switch (label_out) {
case MPLS_LABEL_IMPLICIT_NULL:
snprintf(buf, size, "Pop(%u)", label_in);
break;
case MPLS_LABEL_IPV4_EXPLICIT_NULL:
case MPLS_LABEL_IPV6_EXPLICIT_NULL:
snprintf(buf, size, "Swap(%u, null)", label_in);
break;
case MPLS_INVALID_LABEL:
snprintf(buf, size, "no-op.");
break;
default: