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Merge pull request #8850 from opensourcerouting/ospf6-checksum-json
[mirror_frr.git] / bgpd / bgp_nht.c
1 /* BGP Nexthop tracking
2 * Copyright (C) 2013 Cumulus Networks, Inc.
3 *
4 * This file is part of GNU Zebra.
5 *
6 * GNU Zebra is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2, or (at your option) any
9 * later version.
10 *
11 * GNU Zebra is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; see the file COPYING; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <zebra.h>
22
23 #include "command.h"
24 #include "thread.h"
25 #include "prefix.h"
26 #include "zclient.h"
27 #include "stream.h"
28 #include "network.h"
29 #include "log.h"
30 #include "memory.h"
31 #include "nexthop.h"
32 #include "vrf.h"
33 #include "filter.h"
34 #include "nexthop_group.h"
35
36 #include "bgpd/bgpd.h"
37 #include "bgpd/bgp_table.h"
38 #include "bgpd/bgp_route.h"
39 #include "bgpd/bgp_attr.h"
40 #include "bgpd/bgp_nexthop.h"
41 #include "bgpd/bgp_debug.h"
42 #include "bgpd/bgp_errors.h"
43 #include "bgpd/bgp_nht.h"
44 #include "bgpd/bgp_fsm.h"
45 #include "bgpd/bgp_zebra.h"
46 #include "bgpd/bgp_flowspec_util.h"
47 #include "bgpd/bgp_evpn.h"
48 #include "bgpd/bgp_rd.h"
49
50 extern struct zclient *zclient;
51
52 static void register_zebra_rnh(struct bgp_nexthop_cache *bnc,
53 int is_bgp_static_route);
54 static void unregister_zebra_rnh(struct bgp_nexthop_cache *bnc,
55 int is_bgp_static_route);
56 static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p);
57 static int bgp_nht_ifp_initial(struct thread *thread);
58
59 static int bgp_isvalid_nexthop(struct bgp_nexthop_cache *bnc)
60 {
61 return (bgp_zebra_num_connects() == 0
62 || (bnc && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID)
63 && bnc->nexthop_num > 0));
64 }
65
66 static int bgp_isvalid_labeled_nexthop(struct bgp_nexthop_cache *bnc)
67 {
68 /*
69 * In the case of MPLS-VPN, the label is learned from LDP or other
70 * protocols, and nexthop tracking is enabled for the label.
71 * The value is recorded as BGP_NEXTHOP_LABELED_VALID.
72 * In the case of SRv6-VPN, we need to track the reachability to the
73 * SID (in other words, IPv6 address). As in MPLS, we need to record
74 * the value as BGP_NEXTHOP_SID_VALID. However, this function is
75 * currently not implemented, and this function assumes that all
76 * Transit routes for SRv6-VPN are valid.
77 */
78 return (bgp_zebra_num_connects() == 0
79 || (bnc && bnc->nexthop_num > 0
80 && (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_LABELED_VALID)
81 || bnc->bgp->srv6_enabled)));
82 }
83
84 static void bgp_unlink_nexthop_check(struct bgp_nexthop_cache *bnc)
85 {
86 if (LIST_EMPTY(&(bnc->paths)) && !bnc->nht_info) {
87 if (BGP_DEBUG(nht, NHT)) {
88 char buf[PREFIX2STR_BUFFER];
89 zlog_debug("%s: freeing bnc %s(%u)(%s)", __func__,
90 bnc_str(bnc, buf, PREFIX2STR_BUFFER),
91 bnc->srte_color, bnc->bgp->name_pretty);
92 }
93 /* only unregister if this is the last nh for this prefix*/
94 if (!bnc_existing_for_prefix(bnc))
95 unregister_zebra_rnh(
96 bnc, CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE));
97 bnc_free(bnc);
98 }
99 }
100
101 void bgp_unlink_nexthop(struct bgp_path_info *path)
102 {
103 struct bgp_nexthop_cache *bnc = path->nexthop;
104
105 if (!bnc)
106 return;
107
108 path_nh_map(path, NULL, false);
109
110 bgp_unlink_nexthop_check(bnc);
111 }
112
113 void bgp_replace_nexthop_by_peer(struct peer *from, struct peer *to)
114 {
115 struct prefix pp;
116 struct prefix pt;
117 struct bgp_nexthop_cache *bncp, *bnct;
118 afi_t afi;
119
120 if (!sockunion2hostprefix(&from->su, &pp))
121 return;
122
123 afi = family2afi(pp.family);
124 bncp = bnc_find(&from->bgp->nexthop_cache_table[afi], &pp, 0);
125
126 if (!sockunion2hostprefix(&to->su, &pt))
127 return;
128
129 bnct = bnc_find(&to->bgp->nexthop_cache_table[afi], &pt, 0);
130
131 if (bnct != bncp)
132 return;
133
134 if (bnct)
135 bnct->nht_info = to;
136 }
137
138 void bgp_unlink_nexthop_by_peer(struct peer *peer)
139 {
140 struct prefix p;
141 struct bgp_nexthop_cache *bnc;
142 afi_t afi = family2afi(peer->su.sa.sa_family);
143
144 if (!sockunion2hostprefix(&peer->su, &p))
145 return;
146
147 bnc = bnc_find(&peer->bgp->nexthop_cache_table[afi], &p, 0);
148 if (!bnc)
149 return;
150
151 /* cleanup the peer reference */
152 bnc->nht_info = NULL;
153
154 bgp_unlink_nexthop_check(bnc);
155 }
156
157 /*
158 * A route and its nexthop might belong to different VRFs. Therefore,
159 * we need both the bgp_route and bgp_nexthop pointers.
160 */
161 int bgp_find_or_add_nexthop(struct bgp *bgp_route, struct bgp *bgp_nexthop,
162 afi_t afi, safi_t safi, struct bgp_path_info *pi,
163 struct peer *peer, int connected)
164 {
165 struct bgp_nexthop_cache_head *tree = NULL;
166 struct bgp_nexthop_cache *bnc;
167 struct prefix p;
168 uint32_t srte_color = 0;
169 int is_bgp_static_route = 0;
170 ifindex_t ifindex = 0;
171
172 if (pi) {
173 is_bgp_static_route = ((pi->type == ZEBRA_ROUTE_BGP)
174 && (pi->sub_type == BGP_ROUTE_STATIC))
175 ? 1
176 : 0;
177
178 /* Since Extended Next-hop Encoding (RFC5549) support, we want
179 to derive
180 address-family from the next-hop. */
181 if (!is_bgp_static_route)
182 afi = BGP_ATTR_NEXTHOP_AFI_IP6(pi->attr) ? AFI_IP6
183 : AFI_IP;
184
185 /* Validation for the ipv4 mapped ipv6 nexthop. */
186 if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) {
187 afi = AFI_IP;
188 }
189
190 /* This will return true if the global IPv6 NH is a link local
191 * addr */
192 if (make_prefix(afi, pi, &p) < 0)
193 return 1;
194
195 srte_color = pi->attr->srte_color;
196 } else if (peer) {
197 /*
198 * Gather the ifindex for if up/down events to be
199 * tagged into this fun
200 */
201 if (afi == AFI_IP6
202 && IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr))
203 ifindex = peer->su.sin6.sin6_scope_id;
204
205 if (!sockunion2hostprefix(&peer->su, &p)) {
206 if (BGP_DEBUG(nht, NHT)) {
207 zlog_debug(
208 "%s: Attempting to register with unknown AFI %d (not %d or %d)",
209 __func__, afi, AFI_IP, AFI_IP6);
210 }
211 return 0;
212 }
213 } else
214 return 0;
215
216 if (is_bgp_static_route)
217 tree = &bgp_nexthop->import_check_table[afi];
218 else
219 tree = &bgp_nexthop->nexthop_cache_table[afi];
220
221 bnc = bnc_find(tree, &p, srte_color);
222 if (!bnc) {
223 bnc = bnc_new(tree, &p, srte_color);
224 bnc->bgp = bgp_nexthop;
225 bnc->ifindex = ifindex;
226 if (BGP_DEBUG(nht, NHT)) {
227 char buf[PREFIX2STR_BUFFER];
228
229 zlog_debug("Allocated bnc %s(%u)(%s) peer %p",
230 bnc_str(bnc, buf, PREFIX2STR_BUFFER),
231 bnc->srte_color, bnc->bgp->name_pretty,
232 peer);
233 }
234 } else {
235 if (BGP_DEBUG(nht, NHT)) {
236 char buf[PREFIX2STR_BUFFER];
237
238 zlog_debug(
239 "Found existing bnc %s(%s) flags 0x%x ifindex %d #paths %d peer %p",
240 bnc_str(bnc, buf, PREFIX2STR_BUFFER),
241 bnc->bgp->name_pretty, bnc->flags, bnc->ifindex,
242 bnc->path_count, bnc->nht_info);
243 }
244 }
245
246 if (pi && is_route_parent_evpn(pi))
247 bnc->is_evpn_gwip_nexthop = true;
248
249 if (is_bgp_static_route) {
250 SET_FLAG(bnc->flags, BGP_STATIC_ROUTE);
251
252 /* If we're toggling the type, re-register */
253 if ((CHECK_FLAG(bgp_route->flags, BGP_FLAG_IMPORT_CHECK))
254 && !CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH)) {
255 SET_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH);
256 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
257 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
258 } else if ((!CHECK_FLAG(bgp_route->flags,
259 BGP_FLAG_IMPORT_CHECK))
260 && CHECK_FLAG(bnc->flags,
261 BGP_STATIC_ROUTE_EXACT_MATCH)) {
262 UNSET_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH);
263 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
264 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
265 }
266 }
267 /* When nexthop is already known, but now requires 'connected'
268 * resolution,
269 * re-register it. The reverse scenario where the nexthop currently
270 * requires
271 * 'connected' resolution does not need a re-register (i.e., we treat
272 * 'connected-required' as an override) except in the scenario where
273 * this
274 * is actually a case of tracking a peer for connectivity (e.g., after
275 * disable connected-check).
276 * NOTE: We don't track the number of paths separately for 'connected-
277 * required' vs 'connected-not-required' as this change is not a common
278 * scenario.
279 */
280 else if (connected && !CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED)) {
281 SET_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED);
282 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
283 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
284 } else if (peer && !connected
285 && CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED)) {
286 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED);
287 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
288 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
289 }
290 if (peer && (bnc->ifindex != ifindex)) {
291 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
292 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
293 bnc->ifindex = ifindex;
294 }
295 if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW) {
296 SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
297 SET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
298 } else if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED)
299 && !is_default_host_route(&bnc->prefix))
300 register_zebra_rnh(bnc, is_bgp_static_route);
301
302 if (pi && pi->nexthop != bnc) {
303 /* Unlink from existing nexthop cache, if any. This will also
304 * free
305 * the nexthop cache entry, if appropriate.
306 */
307 bgp_unlink_nexthop(pi);
308
309 /* updates NHT pi list reference */
310 path_nh_map(pi, bnc, true);
311
312 if (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_VALID) && bnc->metric)
313 (bgp_path_info_extra_get(pi))->igpmetric = bnc->metric;
314 else if (pi->extra)
315 pi->extra->igpmetric = 0;
316 } else if (peer) {
317 /*
318 * Let's not accidently save the peer data for a peer
319 * we are going to throw away in a second or so.
320 * When we come back around we'll fix up this
321 * data properly in replace_nexthop_by_peer
322 */
323 if (CHECK_FLAG(peer->flags, PEER_FLAG_CONFIG_NODE))
324 bnc->nht_info = (void *)peer; /* NHT peer reference */
325 }
326
327 /*
328 * We are cheating here. Views have no associated underlying
329 * ability to detect nexthops. So when we have a view
330 * just tell everyone the nexthop is valid
331 */
332 if (bgp_route->inst_type == BGP_INSTANCE_TYPE_VIEW)
333 return 1;
334 else if (safi == SAFI_UNICAST && pi
335 && pi->sub_type == BGP_ROUTE_IMPORTED && pi->extra
336 && pi->extra->num_labels && !bnc->is_evpn_gwip_nexthop) {
337 return bgp_isvalid_labeled_nexthop(bnc);
338 } else
339 return (bgp_isvalid_nexthop(bnc));
340 }
341
342 void bgp_delete_connected_nexthop(afi_t afi, struct peer *peer)
343 {
344 struct bgp_nexthop_cache *bnc;
345 struct prefix p;
346
347 if (!peer)
348 return;
349
350 if (!sockunion2hostprefix(&peer->su, &p))
351 return;
352
353 bnc = bnc_find(&peer->bgp->nexthop_cache_table[family2afi(p.family)],
354 &p, 0);
355 if (!bnc) {
356 if (BGP_DEBUG(nht, NHT))
357 zlog_debug(
358 "Cannot find connected NHT node for peer %s(%s)",
359 peer->host, peer->bgp->name_pretty);
360 return;
361 }
362
363 if (bnc->nht_info != peer) {
364 if (BGP_DEBUG(nht, NHT))
365 zlog_debug(
366 "Connected NHT %p node for peer %s(%s) points to %p",
367 bnc, peer->host, bnc->bgp->name_pretty,
368 bnc->nht_info);
369 return;
370 }
371
372 bnc->nht_info = NULL;
373
374 if (LIST_EMPTY(&(bnc->paths))) {
375 if (BGP_DEBUG(nht, NHT))
376 zlog_debug(
377 "Freeing connected NHT node %p for peer %s(%s)",
378 bnc, peer->host, bnc->bgp->name_pretty);
379 unregister_zebra_rnh(bnc, 0);
380 bnc_free(bnc);
381 }
382 }
383
384 static void bgp_process_nexthop_update(struct bgp_nexthop_cache *bnc,
385 struct zapi_route *nhr)
386 {
387 struct nexthop *nexthop;
388 struct nexthop *oldnh;
389 struct nexthop *nhlist_head = NULL;
390 struct nexthop *nhlist_tail = NULL;
391 int i;
392 bool evpn_resolved = false;
393
394 bnc->last_update = bgp_clock();
395 bnc->change_flags = 0;
396
397 /* debug print the input */
398 if (BGP_DEBUG(nht, NHT)) {
399 char bnc_buf[BNC_FLAG_DUMP_SIZE];
400
401 zlog_debug(
402 "%s(%u): Rcvd NH update %pFX(%u) - metric %d/%d #nhops %d/%d flags %s",
403 bnc->bgp->name_pretty, bnc->bgp->vrf_id, &nhr->prefix,
404 bnc->srte_color, nhr->metric, bnc->metric,
405 nhr->nexthop_num, bnc->nexthop_num,
406 bgp_nexthop_dump_bnc_flags(bnc, bnc_buf,
407 sizeof(bnc_buf)));
408 }
409
410 if (nhr->metric != bnc->metric)
411 bnc->change_flags |= BGP_NEXTHOP_METRIC_CHANGED;
412
413 if (nhr->nexthop_num != bnc->nexthop_num)
414 bnc->change_flags |= BGP_NEXTHOP_CHANGED;
415
416 if (nhr->nexthop_num) {
417 struct peer *peer = bnc->nht_info;
418
419 /* notify bgp fsm if nbr ip goes from invalid->valid */
420 if (!bnc->nexthop_num)
421 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
422
423 if (!bnc->is_evpn_gwip_nexthop)
424 bnc->flags |= BGP_NEXTHOP_VALID;
425 bnc->metric = nhr->metric;
426 bnc->nexthop_num = nhr->nexthop_num;
427
428 bnc->flags &= ~BGP_NEXTHOP_LABELED_VALID; /* check below */
429
430 for (i = 0; i < nhr->nexthop_num; i++) {
431 int num_labels = 0;
432
433 nexthop = nexthop_from_zapi_nexthop(&nhr->nexthops[i]);
434
435 /*
436 * Turn on RA for the v6 nexthops
437 * we receive from bgp. This is to allow us
438 * to work with v4 routing over v6 nexthops
439 */
440 if (peer && !peer->ifp
441 && CHECK_FLAG(peer->flags,
442 PEER_FLAG_CAPABILITY_ENHE)
443 && nhr->prefix.family == AF_INET6
444 && nexthop->type != NEXTHOP_TYPE_BLACKHOLE) {
445 struct interface *ifp;
446
447 ifp = if_lookup_by_index(nexthop->ifindex,
448 nexthop->vrf_id);
449 if (ifp)
450 zclient_send_interface_radv_req(
451 zclient, nexthop->vrf_id, ifp,
452 true,
453 BGP_UNNUM_DEFAULT_RA_INTERVAL);
454 }
455 /* There is at least one label-switched path */
456 if (nexthop->nh_label &&
457 nexthop->nh_label->num_labels) {
458
459 bnc->flags |= BGP_NEXTHOP_LABELED_VALID;
460 num_labels = nexthop->nh_label->num_labels;
461 }
462
463 if (BGP_DEBUG(nht, NHT)) {
464 char buf[NEXTHOP_STRLEN];
465 zlog_debug(
466 " nhop via %s (%d labels)",
467 nexthop2str(nexthop, buf, sizeof(buf)),
468 num_labels);
469 }
470
471 if (nhlist_tail) {
472 nhlist_tail->next = nexthop;
473 nhlist_tail = nexthop;
474 } else {
475 nhlist_tail = nexthop;
476 nhlist_head = nexthop;
477 }
478
479 /* No need to evaluate the nexthop if we have already
480 * determined
481 * that there has been a change.
482 */
483 if (bnc->change_flags & BGP_NEXTHOP_CHANGED)
484 continue;
485
486 for (oldnh = bnc->nexthop; oldnh; oldnh = oldnh->next)
487 if (nexthop_same(oldnh, nexthop))
488 break;
489
490 if (!oldnh)
491 bnc->change_flags |= BGP_NEXTHOP_CHANGED;
492 }
493 bnc_nexthop_free(bnc);
494 bnc->nexthop = nhlist_head;
495
496 /*
497 * Gateway IP nexthop is L3 reachable. Mark it as
498 * BGP_NEXTHOP_VALID only if it is recursively resolved with a
499 * remote EVPN RT-2.
500 * Else, mark it as BGP_NEXTHOP_EVPN_INCOMPLETE.
501 * When its mapping with EVPN RT-2 is established, unset
502 * BGP_NEXTHOP_EVPN_INCOMPLETE and set BGP_NEXTHOP_VALID.
503 */
504 if (bnc->is_evpn_gwip_nexthop) {
505 evpn_resolved = bgp_evpn_is_gateway_ip_resolved(bnc);
506
507 if (BGP_DEBUG(nht, NHT)) {
508 char buf2[PREFIX2STR_BUFFER];
509
510 prefix2str(&bnc->prefix, buf2, sizeof(buf2));
511 zlog_debug(
512 "EVPN gateway IP %s recursive MAC/IP lookup %s",
513 buf2,
514 (evpn_resolved ? "successful"
515 : "failed"));
516 }
517
518 if (evpn_resolved) {
519 bnc->flags |= BGP_NEXTHOP_VALID;
520 bnc->flags &= ~BGP_NEXTHOP_EVPN_INCOMPLETE;
521 bnc->change_flags |= BGP_NEXTHOP_MACIP_CHANGED;
522 } else {
523 bnc->flags |= BGP_NEXTHOP_EVPN_INCOMPLETE;
524 bnc->flags &= ~BGP_NEXTHOP_VALID;
525 }
526 }
527 } else {
528 bnc->flags &= ~BGP_NEXTHOP_EVPN_INCOMPLETE;
529 bnc->flags &= ~BGP_NEXTHOP_VALID;
530 bnc->flags &= ~BGP_NEXTHOP_LABELED_VALID;
531 bnc->nexthop_num = nhr->nexthop_num;
532
533 /* notify bgp fsm if nbr ip goes from valid->invalid */
534 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
535
536 bnc_nexthop_free(bnc);
537 bnc->nexthop = NULL;
538 }
539
540 evaluate_paths(bnc);
541 }
542
543 static void bgp_nht_ifp_table_handle(struct bgp *bgp,
544 struct bgp_nexthop_cache_head *table,
545 struct interface *ifp, bool up)
546 {
547 struct bgp_nexthop_cache *bnc;
548
549 frr_each (bgp_nexthop_cache, table, bnc) {
550 if (bnc->ifindex != ifp->ifindex)
551 continue;
552
553 bnc->last_update = bgp_clock();
554 bnc->change_flags = 0;
555
556 /*
557 * For interface based routes ( ala the v6 LL routes
558 * that this was written for ) the metric received
559 * for the connected route is 0 not 1.
560 */
561 bnc->metric = 0;
562 if (up) {
563 SET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
564 SET_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED);
565 bnc->nexthop_num = 1;
566 } else {
567 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
568 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
569 SET_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED);
570 bnc->nexthop_num = 0;
571 }
572
573 evaluate_paths(bnc);
574 }
575 }
576 static void bgp_nht_ifp_handle(struct interface *ifp, bool up)
577 {
578 struct bgp *bgp;
579
580 bgp = bgp_lookup_by_vrf_id(ifp->vrf_id);
581 if (!bgp)
582 return;
583
584 bgp_nht_ifp_table_handle(bgp, &bgp->nexthop_cache_table[AFI_IP6], ifp,
585 up);
586 bgp_nht_ifp_table_handle(bgp, &bgp->import_check_table[AFI_IP6], ifp,
587 up);
588 }
589
590 void bgp_nht_ifp_up(struct interface *ifp)
591 {
592 bgp_nht_ifp_handle(ifp, true);
593 }
594
595 void bgp_nht_ifp_down(struct interface *ifp)
596 {
597 bgp_nht_ifp_handle(ifp, false);
598 }
599
600 static int bgp_nht_ifp_initial(struct thread *thread)
601 {
602 ifindex_t ifindex = THREAD_VAL(thread);
603 struct interface *ifp = if_lookup_by_index_all_vrf(ifindex);
604
605 if (!ifp)
606 return 0;
607
608 if (BGP_DEBUG(nht, NHT))
609 zlog_debug(
610 "Handle NHT initial update for Intf %s(%d) status %s",
611 ifp->name, ifp->ifindex, if_is_up(ifp) ? "up" : "down");
612
613 if (if_is_up(ifp))
614 bgp_nht_ifp_up(ifp);
615 else
616 bgp_nht_ifp_down(ifp);
617
618 return 0;
619 }
620
621 /*
622 * So the bnc code has the ability to handle interface up/down
623 * events to properly handle v6 LL peering.
624 * What is happening here:
625 * The event system for peering expects the nht code to
626 * report on the tracking events after we move to active
627 * So let's give the system a chance to report on that event
628 * in a manner that is expected.
629 */
630 void bgp_nht_interface_events(struct peer *peer)
631 {
632 struct bgp *bgp = peer->bgp;
633 struct bgp_nexthop_cache_head *table;
634 struct bgp_nexthop_cache *bnc;
635 struct prefix p;
636
637 if (!IN6_IS_ADDR_LINKLOCAL(&peer->su.sin6.sin6_addr))
638 return;
639
640 if (!sockunion2hostprefix(&peer->su, &p))
641 return;
642
643 table = &bgp->nexthop_cache_table[AFI_IP6];
644 bnc = bnc_find(table, &p, 0);
645 if (!bnc)
646 return;
647
648 if (bnc->ifindex)
649 thread_add_event(bm->master, bgp_nht_ifp_initial, NULL,
650 bnc->ifindex, NULL);
651 }
652
653 void bgp_parse_nexthop_update(int command, vrf_id_t vrf_id)
654 {
655 struct bgp_nexthop_cache_head *tree = NULL;
656 struct bgp_nexthop_cache *bnc;
657 struct bgp *bgp;
658 struct zapi_route nhr;
659 afi_t afi;
660
661 bgp = bgp_lookup_by_vrf_id(vrf_id);
662 if (!bgp) {
663 flog_err(
664 EC_BGP_NH_UPD,
665 "parse nexthop update: instance not found for vrf_id %u",
666 vrf_id);
667 return;
668 }
669
670 if (!zapi_nexthop_update_decode(zclient->ibuf, &nhr)) {
671 zlog_err("%s[%s]: Failure to decode nexthop update", __func__,
672 bgp->name_pretty);
673 return;
674 }
675
676 afi = family2afi(nhr.prefix.family);
677 if (command == ZEBRA_NEXTHOP_UPDATE)
678 tree = &bgp->nexthop_cache_table[afi];
679 else if (command == ZEBRA_IMPORT_CHECK_UPDATE)
680 tree = &bgp->import_check_table[afi];
681
682 bnc = bnc_find(tree, &nhr.prefix, nhr.srte_color);
683 if (!bnc) {
684 if (BGP_DEBUG(nht, NHT))
685 zlog_debug(
686 "parse nexthop update(%pFX(%u)(%s)): bnc info not found",
687 &nhr.prefix, nhr.srte_color, bgp->name_pretty);
688 return;
689 }
690
691 bgp_process_nexthop_update(bnc, &nhr);
692
693 /*
694 * HACK: if any BGP route is dependant on an SR-policy that doesn't
695 * exist, zebra will never send NH updates relative to that policy. In
696 * that case, whenever we receive an update about a colorless NH, update
697 * the corresponding colorful NHs that share the same endpoint but that
698 * are inactive. This ugly hack should work around the problem at the
699 * cost of a performance pernalty. Long term, what should be done is to
700 * make zebra's RNH subsystem aware of SR-TE colors (like bgpd is),
701 * which should provide a better infrastructure to solve this issue in
702 * a more efficient and elegant way.
703 */
704 if (nhr.srte_color == 0) {
705 struct bgp_nexthop_cache *bnc_iter;
706
707 frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi],
708 bnc_iter) {
709 if (!prefix_same(&bnc->prefix, &bnc_iter->prefix)
710 || bnc_iter->srte_color == 0
711 || CHECK_FLAG(bnc_iter->flags, BGP_NEXTHOP_VALID))
712 continue;
713
714 bgp_process_nexthop_update(bnc_iter, &nhr);
715 }
716 }
717 }
718
719 /*
720 * Cleanup nexthop registration and status information for BGP nexthops
721 * pertaining to this VRF. This is invoked upon VRF deletion.
722 */
723 void bgp_cleanup_nexthops(struct bgp *bgp)
724 {
725 for (afi_t afi = AFI_IP; afi < AFI_MAX; afi++) {
726 struct bgp_nexthop_cache *bnc;
727
728 frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi],
729 bnc) {
730 /* Clear relevant flags. */
731 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_VALID);
732 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
733 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
734 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_EVPN_INCOMPLETE);
735 }
736 }
737 }
738
739 /**
740 * make_prefix - make a prefix structure from the path (essentially
741 * path's node.
742 */
743 static int make_prefix(int afi, struct bgp_path_info *pi, struct prefix *p)
744 {
745
746 int is_bgp_static = ((pi->type == ZEBRA_ROUTE_BGP)
747 && (pi->sub_type == BGP_ROUTE_STATIC))
748 ? 1
749 : 0;
750 struct bgp_dest *net = pi->net;
751 const struct prefix *p_orig = bgp_dest_get_prefix(net);
752 struct in_addr ipv4;
753
754 if (p_orig->family == AF_FLOWSPEC) {
755 if (!pi->peer)
756 return -1;
757 return bgp_flowspec_get_first_nh(pi->peer->bgp,
758 pi, p, afi);
759 }
760 memset(p, 0, sizeof(struct prefix));
761 switch (afi) {
762 case AFI_IP:
763 p->family = AF_INET;
764 if (is_bgp_static) {
765 p->u.prefix4 = p_orig->u.prefix4;
766 p->prefixlen = p_orig->prefixlen;
767 } else {
768 if (IS_MAPPED_IPV6(&pi->attr->mp_nexthop_global)) {
769 ipv4_mapped_ipv6_to_ipv4(
770 &pi->attr->mp_nexthop_global, &ipv4);
771 p->u.prefix4 = ipv4;
772 p->prefixlen = IPV4_MAX_BITLEN;
773 } else {
774 p->u.prefix4 = pi->attr->nexthop;
775 p->prefixlen = IPV4_MAX_BITLEN;
776 }
777 }
778 break;
779 case AFI_IP6:
780 p->family = AF_INET6;
781
782 if (is_bgp_static) {
783 p->u.prefix6 = p_orig->u.prefix6;
784 p->prefixlen = p_orig->prefixlen;
785 } else {
786 /* If we receive MP_REACH nexthop with ::(LL)
787 * or LL(LL), use LL address as nexthop cache.
788 */
789 if (pi->attr->mp_nexthop_len
790 == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL
791 && (IN6_IS_ADDR_UNSPECIFIED(
792 &pi->attr->mp_nexthop_global)
793 || IN6_IS_ADDR_LINKLOCAL(
794 &pi->attr->mp_nexthop_global)))
795 p->u.prefix6 = pi->attr->mp_nexthop_local;
796 else
797 p->u.prefix6 = pi->attr->mp_nexthop_global;
798 p->prefixlen = IPV6_MAX_BITLEN;
799 }
800 break;
801 default:
802 if (BGP_DEBUG(nht, NHT)) {
803 zlog_debug(
804 "%s: Attempting to make prefix with unknown AFI %d (not %d or %d)",
805 __func__, afi, AFI_IP, AFI_IP6);
806 }
807 break;
808 }
809 return 0;
810 }
811
812 /**
813 * sendmsg_zebra_rnh -- Format and send a nexthop register/Unregister
814 * command to Zebra.
815 * ARGUMENTS:
816 * struct bgp_nexthop_cache *bnc -- the nexthop structure.
817 * int command -- command to send to zebra
818 * RETURNS:
819 * void.
820 */
821 static void sendmsg_zebra_rnh(struct bgp_nexthop_cache *bnc, int command)
822 {
823 bool exact_match = false;
824 int ret;
825
826 if (!zclient)
827 return;
828
829 /* Don't try to register if Zebra doesn't know of this instance. */
830 if (!IS_BGP_INST_KNOWN_TO_ZEBRA(bnc->bgp)) {
831 if (BGP_DEBUG(zebra, ZEBRA))
832 zlog_debug(
833 "%s: No zebra instance to talk to, not installing NHT entry",
834 __func__);
835 return;
836 }
837
838 if (!bgp_zebra_num_connects()) {
839 if (BGP_DEBUG(zebra, ZEBRA))
840 zlog_debug(
841 "%s: We have not connected yet, cannot send nexthops",
842 __func__);
843 }
844 if ((command == ZEBRA_NEXTHOP_REGISTER
845 || command == ZEBRA_IMPORT_ROUTE_REGISTER)
846 && (CHECK_FLAG(bnc->flags, BGP_NEXTHOP_CONNECTED)
847 || CHECK_FLAG(bnc->flags, BGP_STATIC_ROUTE_EXACT_MATCH)))
848 exact_match = true;
849
850 if (BGP_DEBUG(zebra, ZEBRA))
851 zlog_debug("%s: sending cmd %s for %pFX (vrf %s)", __func__,
852 zserv_command_string(command), &bnc->prefix,
853 bnc->bgp->name_pretty);
854
855 ret = zclient_send_rnh(zclient, command, &bnc->prefix, exact_match,
856 bnc->bgp->vrf_id);
857 /* TBD: handle the failure */
858 if (ret == ZCLIENT_SEND_FAILURE)
859 flog_warn(EC_BGP_ZEBRA_SEND,
860 "sendmsg_nexthop: zclient_send_message() failed");
861
862 if ((command == ZEBRA_NEXTHOP_REGISTER)
863 || (command == ZEBRA_IMPORT_ROUTE_REGISTER))
864 SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
865 else if ((command == ZEBRA_NEXTHOP_UNREGISTER)
866 || (command == ZEBRA_IMPORT_ROUTE_UNREGISTER))
867 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
868 return;
869 }
870
871 /**
872 * register_zebra_rnh - register a NH/route with Zebra for notification
873 * when the route or the route to the nexthop changes.
874 * ARGUMENTS:
875 * struct bgp_nexthop_cache *bnc
876 * RETURNS:
877 * void.
878 */
879 static void register_zebra_rnh(struct bgp_nexthop_cache *bnc,
880 int is_bgp_import_route)
881 {
882 /* Check if we have already registered */
883 if (bnc->flags & BGP_NEXTHOP_REGISTERED)
884 return;
885
886 if (bnc->ifindex) {
887 SET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
888 return;
889 }
890
891 if (is_bgp_import_route)
892 sendmsg_zebra_rnh(bnc, ZEBRA_IMPORT_ROUTE_REGISTER);
893 else
894 sendmsg_zebra_rnh(bnc, ZEBRA_NEXTHOP_REGISTER);
895 }
896
897 /**
898 * unregister_zebra_rnh -- Unregister the route/nexthop from Zebra.
899 * ARGUMENTS:
900 * struct bgp_nexthop_cache *bnc
901 * RETURNS:
902 * void.
903 */
904 static void unregister_zebra_rnh(struct bgp_nexthop_cache *bnc,
905 int is_bgp_import_route)
906 {
907 /* Check if we have already registered */
908 if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED))
909 return;
910
911 if (bnc->ifindex) {
912 UNSET_FLAG(bnc->flags, BGP_NEXTHOP_REGISTERED);
913 return;
914 }
915
916 if (is_bgp_import_route)
917 sendmsg_zebra_rnh(bnc, ZEBRA_IMPORT_ROUTE_UNREGISTER);
918 else
919 sendmsg_zebra_rnh(bnc, ZEBRA_NEXTHOP_UNREGISTER);
920 }
921
922 /**
923 * evaluate_paths - Evaluate the paths/nets associated with a nexthop.
924 * ARGUMENTS:
925 * struct bgp_nexthop_cache *bnc -- the nexthop structure.
926 * RETURNS:
927 * void.
928 */
929 void evaluate_paths(struct bgp_nexthop_cache *bnc)
930 {
931 struct bgp_dest *dest;
932 struct bgp_path_info *path;
933 int afi;
934 struct peer *peer = (struct peer *)bnc->nht_info;
935 struct bgp_table *table;
936 safi_t safi;
937 struct bgp *bgp_path;
938 const struct prefix *p;
939
940 if (BGP_DEBUG(nht, NHT)) {
941 char buf[PREFIX2STR_BUFFER];
942 char bnc_buf[BNC_FLAG_DUMP_SIZE];
943 char chg_buf[BNC_FLAG_DUMP_SIZE];
944
945 bnc_str(bnc, buf, PREFIX2STR_BUFFER);
946 zlog_debug(
947 "NH update for %s(%u)(%s) - flags %s chgflags %s- evaluate paths",
948 buf, bnc->srte_color, bnc->bgp->name_pretty,
949 bgp_nexthop_dump_bnc_flags(bnc, bnc_buf,
950 sizeof(bnc_buf)),
951 bgp_nexthop_dump_bnc_change_flags(bnc, chg_buf,
952 sizeof(bnc_buf)));
953 }
954
955 LIST_FOREACH (path, &(bnc->paths), nh_thread) {
956 if (!(path->type == ZEBRA_ROUTE_BGP
957 && ((path->sub_type == BGP_ROUTE_NORMAL)
958 || (path->sub_type == BGP_ROUTE_STATIC)
959 || (path->sub_type == BGP_ROUTE_IMPORTED))))
960 continue;
961
962 dest = path->net;
963 assert(dest && bgp_dest_table(dest));
964 p = bgp_dest_get_prefix(dest);
965 afi = family2afi(p->family);
966 table = bgp_dest_table(dest);
967 safi = table->safi;
968
969 /*
970 * handle routes from other VRFs (they can have a
971 * nexthop in THIS VRF). bgp_path is the bgp instance
972 * that owns the route referencing this nexthop.
973 */
974 bgp_path = table->bgp;
975
976 /*
977 * Path becomes valid/invalid depending on whether the nexthop
978 * reachable/unreachable.
979 *
980 * In case of unicast routes that were imported from vpn
981 * and that have labels, they are valid only if there are
982 * nexthops with labels
983 *
984 * If the nexthop is EVPN gateway-IP,
985 * do not check for a valid label.
986 */
987
988 bool bnc_is_valid_nexthop = false;
989 bool path_valid = false;
990
991 if (safi == SAFI_UNICAST && path->sub_type == BGP_ROUTE_IMPORTED
992 && path->extra && path->extra->num_labels
993 && (path->attr->evpn_overlay.type
994 != OVERLAY_INDEX_GATEWAY_IP)) {
995 bnc_is_valid_nexthop =
996 bgp_isvalid_labeled_nexthop(bnc) ? true : false;
997 } else {
998 if (bgp_update_martian_nexthop(
999 bnc->bgp, afi, safi, path->type,
1000 path->sub_type, path->attr, dest)) {
1001 if (BGP_DEBUG(nht, NHT))
1002 zlog_debug(
1003 "%s: prefix %pBD (vrf %s), ignoring path due to martian or self-next-hop",
1004 __func__, dest, bgp_path->name);
1005 } else
1006 bnc_is_valid_nexthop =
1007 bgp_isvalid_nexthop(bnc) ? true : false;
1008 }
1009
1010 if (BGP_DEBUG(nht, NHT)) {
1011 char buf1[RD_ADDRSTRLEN];
1012
1013 if (dest->pdest) {
1014 prefix_rd2str((struct prefix_rd *)bgp_dest_get_prefix(dest->pdest),
1015 buf1, sizeof(buf1));
1016 zlog_debug(
1017 "... eval path %d/%d %pBD RD %s %s flags 0x%x",
1018 afi, safi, dest, buf1,
1019 bgp_path->name_pretty, path->flags);
1020 } else
1021 zlog_debug(
1022 "... eval path %d/%d %pBD %s flags 0x%x",
1023 afi, safi, dest, bgp_path->name_pretty,
1024 path->flags);
1025 }
1026
1027 /* Skip paths marked for removal or as history. */
1028 if (CHECK_FLAG(path->flags, BGP_PATH_REMOVED)
1029 || CHECK_FLAG(path->flags, BGP_PATH_HISTORY))
1030 continue;
1031
1032 /* Copy the metric to the path. Will be used for bestpath
1033 * computation */
1034 if (bgp_isvalid_nexthop(bnc) && bnc->metric)
1035 (bgp_path_info_extra_get(path))->igpmetric =
1036 bnc->metric;
1037 else if (path->extra)
1038 path->extra->igpmetric = 0;
1039
1040 if (CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_METRIC_CHANGED)
1041 || CHECK_FLAG(bnc->change_flags, BGP_NEXTHOP_CHANGED)
1042 || path->attr->srte_color != 0)
1043 SET_FLAG(path->flags, BGP_PATH_IGP_CHANGED);
1044
1045 path_valid = !!CHECK_FLAG(path->flags, BGP_PATH_VALID);
1046 if (path_valid != bnc_is_valid_nexthop) {
1047 if (path_valid) {
1048 /* No longer valid, clear flag; also for EVPN
1049 * routes, unimport from VRFs if needed.
1050 */
1051 bgp_aggregate_decrement(bgp_path, p, path, afi,
1052 safi);
1053 bgp_path_info_unset_flag(dest, path,
1054 BGP_PATH_VALID);
1055 if (safi == SAFI_EVPN &&
1056 bgp_evpn_is_prefix_nht_supported(bgp_dest_get_prefix(dest)))
1057 bgp_evpn_unimport_route(bgp_path,
1058 afi, safi, bgp_dest_get_prefix(dest), path);
1059 } else {
1060 /* Path becomes valid, set flag; also for EVPN
1061 * routes, import from VRFs if needed.
1062 */
1063 bgp_path_info_set_flag(dest, path,
1064 BGP_PATH_VALID);
1065 bgp_aggregate_increment(bgp_path, p, path, afi,
1066 safi);
1067 if (safi == SAFI_EVPN &&
1068 bgp_evpn_is_prefix_nht_supported(bgp_dest_get_prefix(dest)))
1069 bgp_evpn_import_route(bgp_path,
1070 afi, safi, bgp_dest_get_prefix(dest), path);
1071 }
1072 }
1073
1074 bgp_process(bgp_path, dest, afi, safi);
1075 }
1076
1077 if (peer) {
1078 int valid_nexthops = bgp_isvalid_nexthop(bnc);
1079
1080 if (valid_nexthops) {
1081 /*
1082 * Peering cannot occur across a blackhole nexthop
1083 */
1084 if (bnc->nexthop_num == 1 && bnc->nexthop
1085 && bnc->nexthop->type == NEXTHOP_TYPE_BLACKHOLE) {
1086 peer->last_reset = PEER_DOWN_WAITING_NHT;
1087 valid_nexthops = 0;
1088 } else
1089 peer->last_reset = PEER_DOWN_WAITING_OPEN;
1090 } else
1091 peer->last_reset = PEER_DOWN_WAITING_NHT;
1092
1093 if (!CHECK_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED)) {
1094 if (BGP_DEBUG(nht, NHT))
1095 zlog_debug(
1096 "%s: Updating peer (%s(%s)) status with NHT nexthops %d",
1097 __func__, peer->host,
1098 peer->bgp->name_pretty,
1099 !!valid_nexthops);
1100 bgp_fsm_nht_update(peer, !!valid_nexthops);
1101 SET_FLAG(bnc->flags, BGP_NEXTHOP_PEER_NOTIFIED);
1102 }
1103 }
1104
1105 RESET_FLAG(bnc->change_flags);
1106 }
1107
1108 /**
1109 * path_nh_map - make or break path-to-nexthop association.
1110 * ARGUMENTS:
1111 * path - pointer to the path structure
1112 * bnc - pointer to the nexthop structure
1113 * make - if set, make the association. if unset, just break the existing
1114 * association.
1115 */
1116 void path_nh_map(struct bgp_path_info *path, struct bgp_nexthop_cache *bnc,
1117 bool make)
1118 {
1119 if (path->nexthop) {
1120 LIST_REMOVE(path, nh_thread);
1121 path->nexthop->path_count--;
1122 path->nexthop = NULL;
1123 }
1124 if (make) {
1125 LIST_INSERT_HEAD(&(bnc->paths), path, nh_thread);
1126 path->nexthop = bnc;
1127 path->nexthop->path_count++;
1128 }
1129 }
1130
1131 /*
1132 * This function is called to register nexthops to zebra
1133 * as that we may have tried to install the nexthops
1134 * before we actually have a zebra connection
1135 */
1136 void bgp_nht_register_nexthops(struct bgp *bgp)
1137 {
1138 for (afi_t afi = AFI_IP; afi < AFI_MAX; afi++) {
1139 struct bgp_nexthop_cache *bnc;
1140
1141 frr_each (bgp_nexthop_cache, &bgp->nexthop_cache_table[afi],
1142 bnc) {
1143 register_zebra_rnh(bnc, 0);
1144 }
1145 }
1146 }
1147
1148 void bgp_nht_reg_enhe_cap_intfs(struct peer *peer)
1149 {
1150 struct bgp *bgp;
1151 struct bgp_nexthop_cache *bnc;
1152 struct nexthop *nhop;
1153 struct interface *ifp;
1154 struct prefix p;
1155
1156 if (peer->ifp)
1157 return;
1158
1159 bgp = peer->bgp;
1160 if (!sockunion2hostprefix(&peer->su, &p)) {
1161 zlog_warn("%s: Unable to convert sockunion to prefix for %s",
1162 __func__, peer->host);
1163 return;
1164 }
1165
1166 if (p.family != AF_INET6)
1167 return;
1168
1169 bnc = bnc_find(&bgp->nexthop_cache_table[AFI_IP6], &p, 0);
1170 if (!bnc)
1171 return;
1172
1173 if (peer != bnc->nht_info)
1174 return;
1175
1176 for (nhop = bnc->nexthop; nhop; nhop = nhop->next) {
1177 ifp = if_lookup_by_index(nhop->ifindex, nhop->vrf_id);
1178
1179 if (!ifp)
1180 continue;
1181
1182 zclient_send_interface_radv_req(zclient,
1183 nhop->vrf_id,
1184 ifp, true,
1185 BGP_UNNUM_DEFAULT_RA_INTERVAL);
1186 }
1187 }
1188
1189 void bgp_nht_dereg_enhe_cap_intfs(struct peer *peer)
1190 {
1191 struct bgp *bgp;
1192 struct bgp_nexthop_cache *bnc;
1193 struct nexthop *nhop;
1194 struct interface *ifp;
1195 struct prefix p;
1196
1197 if (peer->ifp)
1198 return;
1199
1200 bgp = peer->bgp;
1201
1202 if (!sockunion2hostprefix(&peer->su, &p)) {
1203 zlog_warn("%s: Unable to convert sockunion to prefix for %s",
1204 __func__, peer->host);
1205 return;
1206 }
1207
1208 if (p.family != AF_INET6)
1209 return;
1210
1211 bnc = bnc_find(&bgp->nexthop_cache_table[AFI_IP6], &p, 0);
1212 if (!bnc)
1213 return;
1214
1215 if (peer != bnc->nht_info)
1216 return;
1217
1218 for (nhop = bnc->nexthop; nhop; nhop = nhop->next) {
1219 ifp = if_lookup_by_index(nhop->ifindex, nhop->vrf_id);
1220
1221 if (!ifp)
1222 continue;
1223
1224 zclient_send_interface_radv_req(zclient, nhop->vrf_id, ifp, 0,
1225 0);
1226 }
1227 }
1228
1229 /****************************************************************************
1230 * L3 NHGs are used for fast failover of nexthops in the dplane. These are
1231 * the APIs for allocating L3 NHG ids. Management of the L3 NHG itself is
1232 * left to the application using it.
1233 * PS: Currently EVPN host routes is the only app using L3 NHG for fast
1234 * failover of remote ES links.
1235 ***************************************************************************/
1236 static bitfield_t bgp_nh_id_bitmap;
1237 static uint32_t bgp_l3nhg_start;
1238
1239 /* XXX - currently we do nothing on the callbacks */
1240 static void bgp_l3nhg_add_cb(const char *name)
1241 {
1242 }
1243 static void bgp_l3nhg_add_nexthop_cb(const struct nexthop_group_cmd *nhgc,
1244 const struct nexthop *nhop)
1245 {
1246 }
1247 static void bgp_l3nhg_del_nexthop_cb(const struct nexthop_group_cmd *nhgc,
1248 const struct nexthop *nhop)
1249 {
1250 }
1251 static void bgp_l3nhg_del_cb(const char *name)
1252 {
1253 }
1254
1255 static void bgp_l3nhg_zebra_init(void)
1256 {
1257 static bool bgp_l3nhg_zebra_inited;
1258 if (bgp_l3nhg_zebra_inited)
1259 return;
1260
1261 bgp_l3nhg_zebra_inited = true;
1262 bgp_l3nhg_start = zclient_get_nhg_start(ZEBRA_ROUTE_BGP);
1263 nexthop_group_init(bgp_l3nhg_add_cb, bgp_l3nhg_add_nexthop_cb,
1264 bgp_l3nhg_del_nexthop_cb, bgp_l3nhg_del_cb);
1265 }
1266
1267
1268 #define min(A, B) ((A) < (B) ? (A) : (B))
1269 void bgp_l3nhg_init(void)
1270 {
1271 uint32_t id_max;
1272
1273 id_max = min(ZEBRA_NHG_PROTO_SPACING - 1, 16 * 1024);
1274 bf_init(bgp_nh_id_bitmap, id_max);
1275 bf_assign_zero_index(bgp_nh_id_bitmap);
1276
1277 if (BGP_DEBUG(nht, NHT) || BGP_DEBUG(evpn_mh, EVPN_MH_ES))
1278 zlog_debug("bgp l3_nhg range %u - %u", bgp_l3nhg_start + 1,
1279 bgp_l3nhg_start + id_max);
1280 }
1281
1282 void bgp_l3nhg_finish(void)
1283 {
1284 bf_free(bgp_nh_id_bitmap);
1285 }
1286
1287 uint32_t bgp_l3nhg_id_alloc(void)
1288 {
1289 uint32_t nhg_id = 0;
1290
1291 bgp_l3nhg_zebra_init();
1292 bf_assign_index(bgp_nh_id_bitmap, nhg_id);
1293 if (nhg_id)
1294 nhg_id += bgp_l3nhg_start;
1295
1296 return nhg_id;
1297 }
1298
1299 void bgp_l3nhg_id_free(uint32_t nhg_id)
1300 {
1301 if (!nhg_id || (nhg_id <= bgp_l3nhg_start))
1302 return;
1303
1304 nhg_id -= bgp_l3nhg_start;
1305
1306 bf_release_index(bgp_nh_id_bitmap, nhg_id);
1307 }
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