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bgpd: IPv6 session flapping with MP_REACH_NLRI and 0.0.0.0 in NEXT_HOP attribute
[mirror_frr.git] / bgpd / bgp_attr.c
1 /* BGP attributes management routines.
2 * Copyright (C) 1996, 97, 98, 1999 Kunihiro Ishiguro
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 "linklist.h"
24 #include "prefix.h"
25 #include "memory.h"
26 #include "vector.h"
27 #include "stream.h"
28 #include "log.h"
29 #include "hash.h"
30 #include "jhash.h"
31 #include "queue.h"
32 #include "table.h"
33 #include "filter.h"
34 #include "command.h"
35
36 #include "bgpd/bgpd.h"
37 #include "bgpd/bgp_attr.h"
38 #include "bgpd/bgp_route.h"
39 #include "bgpd/bgp_aspath.h"
40 #include "bgpd/bgp_community.h"
41 #include "bgpd/bgp_debug.h"
42 #include "bgpd/bgp_errors.h"
43 #include "bgpd/bgp_label.h"
44 #include "bgpd/bgp_packet.h"
45 #include "bgpd/bgp_ecommunity.h"
46 #include "bgpd/bgp_lcommunity.h"
47 #include "bgpd/bgp_updgrp.h"
48 #include "bgpd/bgp_encap_types.h"
49 #if ENABLE_BGP_VNC
50 #include "bgpd/rfapi/bgp_rfapi_cfg.h"
51 #include "bgp_encap_types.h"
52 #include "bgp_vnc_types.h"
53 #endif
54 #include "bgp_encap_types.h"
55 #include "bgp_evpn.h"
56 #include "bgp_flowspec_private.h"
57 #include "bgp_mac.h"
58
59 /* Attribute strings for logging. */
60 static const struct message attr_str[] = {
61 {BGP_ATTR_ORIGIN, "ORIGIN"},
62 {BGP_ATTR_AS_PATH, "AS_PATH"},
63 {BGP_ATTR_NEXT_HOP, "NEXT_HOP"},
64 {BGP_ATTR_MULTI_EXIT_DISC, "MULTI_EXIT_DISC"},
65 {BGP_ATTR_LOCAL_PREF, "LOCAL_PREF"},
66 {BGP_ATTR_ATOMIC_AGGREGATE, "ATOMIC_AGGREGATE"},
67 {BGP_ATTR_AGGREGATOR, "AGGREGATOR"},
68 {BGP_ATTR_COMMUNITIES, "COMMUNITY"},
69 {BGP_ATTR_ORIGINATOR_ID, "ORIGINATOR_ID"},
70 {BGP_ATTR_CLUSTER_LIST, "CLUSTER_LIST"},
71 {BGP_ATTR_DPA, "DPA"},
72 {BGP_ATTR_ADVERTISER, "ADVERTISER"},
73 {BGP_ATTR_RCID_PATH, "RCID_PATH"},
74 {BGP_ATTR_MP_REACH_NLRI, "MP_REACH_NLRI"},
75 {BGP_ATTR_MP_UNREACH_NLRI, "MP_UNREACH_NLRI"},
76 {BGP_ATTR_EXT_COMMUNITIES, "EXT_COMMUNITIES"},
77 {BGP_ATTR_AS4_PATH, "AS4_PATH"},
78 {BGP_ATTR_AS4_AGGREGATOR, "AS4_AGGREGATOR"},
79 {BGP_ATTR_AS_PATHLIMIT, "AS_PATHLIMIT"},
80 {BGP_ATTR_PMSI_TUNNEL, "PMSI_TUNNEL_ATTRIBUTE"},
81 {BGP_ATTR_ENCAP, "ENCAP"},
82 #if ENABLE_BGP_VNC_ATTR
83 {BGP_ATTR_VNC, "VNC"},
84 #endif
85 {BGP_ATTR_LARGE_COMMUNITIES, "LARGE_COMMUNITY"},
86 {BGP_ATTR_PREFIX_SID, "PREFIX_SID"},
87 {0}};
88
89 static const struct message attr_flag_str[] = {
90 {BGP_ATTR_FLAG_OPTIONAL, "Optional"},
91 {BGP_ATTR_FLAG_TRANS, "Transitive"},
92 {BGP_ATTR_FLAG_PARTIAL, "Partial"},
93 /* bgp_attr_flags_diagnose() relies on this bit being last in
94 this list */
95 {BGP_ATTR_FLAG_EXTLEN, "Extended Length"},
96 {0}};
97
98 static struct hash *cluster_hash;
99
100 static void *cluster_hash_alloc(void *p)
101 {
102 const struct cluster_list *val = (const struct cluster_list *)p;
103 struct cluster_list *cluster;
104
105 cluster = XMALLOC(MTYPE_CLUSTER, sizeof(struct cluster_list));
106 cluster->length = val->length;
107
108 if (cluster->length) {
109 cluster->list = XMALLOC(MTYPE_CLUSTER_VAL, val->length);
110 memcpy(cluster->list, val->list, val->length);
111 } else
112 cluster->list = NULL;
113
114 cluster->refcnt = 0;
115
116 return cluster;
117 }
118
119 /* Cluster list related functions. */
120 static struct cluster_list *cluster_parse(struct in_addr *pnt, int length)
121 {
122 struct cluster_list tmp;
123 struct cluster_list *cluster;
124
125 tmp.length = length;
126 tmp.list = pnt;
127
128 cluster = hash_get(cluster_hash, &tmp, cluster_hash_alloc);
129 cluster->refcnt++;
130 return cluster;
131 }
132
133 int cluster_loop_check(struct cluster_list *cluster, struct in_addr originator)
134 {
135 int i;
136
137 for (i = 0; i < cluster->length / 4; i++)
138 if (cluster->list[i].s_addr == originator.s_addr)
139 return 1;
140 return 0;
141 }
142
143 static unsigned int cluster_hash_key_make(void *p)
144 {
145 const struct cluster_list *cluster = p;
146
147 return jhash(cluster->list, cluster->length, 0);
148 }
149
150 static bool cluster_hash_cmp(const void *p1, const void *p2)
151 {
152 const struct cluster_list *cluster1 = p1;
153 const struct cluster_list *cluster2 = p2;
154
155 return (cluster1->length == cluster2->length
156 && memcmp(cluster1->list, cluster2->list, cluster1->length)
157 == 0);
158 }
159
160 static void cluster_free(struct cluster_list *cluster)
161 {
162 XFREE(MTYPE_CLUSTER_VAL, cluster->list);
163 XFREE(MTYPE_CLUSTER, cluster);
164 }
165
166 static struct cluster_list *cluster_intern(struct cluster_list *cluster)
167 {
168 struct cluster_list *find;
169
170 find = hash_get(cluster_hash, cluster, cluster_hash_alloc);
171 find->refcnt++;
172
173 return find;
174 }
175
176 void cluster_unintern(struct cluster_list *cluster)
177 {
178 if (cluster->refcnt)
179 cluster->refcnt--;
180
181 if (cluster->refcnt == 0) {
182 hash_release(cluster_hash, cluster);
183 cluster_free(cluster);
184 }
185 }
186
187 static void cluster_init(void)
188 {
189 cluster_hash = hash_create(cluster_hash_key_make, cluster_hash_cmp,
190 "BGP Cluster");
191 }
192
193 static void cluster_finish(void)
194 {
195 hash_clean(cluster_hash, (void (*)(void *))cluster_free);
196 hash_free(cluster_hash);
197 cluster_hash = NULL;
198 }
199
200 static struct hash *encap_hash = NULL;
201 #if ENABLE_BGP_VNC
202 static struct hash *vnc_hash = NULL;
203 #endif
204
205 struct bgp_attr_encap_subtlv *encap_tlv_dup(struct bgp_attr_encap_subtlv *orig)
206 {
207 struct bgp_attr_encap_subtlv *new;
208 struct bgp_attr_encap_subtlv *tail;
209 struct bgp_attr_encap_subtlv *p;
210
211 for (p = orig, tail = new = NULL; p; p = p->next) {
212 int size = sizeof(struct bgp_attr_encap_subtlv) + p->length;
213 if (tail) {
214 tail->next = XCALLOC(MTYPE_ENCAP_TLV, size);
215 tail = tail->next;
216 } else {
217 tail = new = XCALLOC(MTYPE_ENCAP_TLV, size);
218 }
219 assert(tail);
220 memcpy(tail, p, size);
221 tail->next = NULL;
222 }
223
224 return new;
225 }
226
227 static void encap_free(struct bgp_attr_encap_subtlv *p)
228 {
229 struct bgp_attr_encap_subtlv *next;
230 while (p) {
231 next = p->next;
232 p->next = NULL;
233 XFREE(MTYPE_ENCAP_TLV, p);
234 p = next;
235 }
236 }
237
238 void bgp_attr_flush_encap(struct attr *attr)
239 {
240 if (!attr)
241 return;
242
243 if (attr->encap_subtlvs) {
244 encap_free(attr->encap_subtlvs);
245 attr->encap_subtlvs = NULL;
246 }
247 #if ENABLE_BGP_VNC
248 if (attr->vnc_subtlvs) {
249 encap_free(attr->vnc_subtlvs);
250 attr->vnc_subtlvs = NULL;
251 }
252 #endif
253 }
254
255 /*
256 * Compare encap sub-tlv chains
257 *
258 * 1 = equivalent
259 * 0 = not equivalent
260 *
261 * This algorithm could be made faster if needed
262 */
263 static int encap_same(const struct bgp_attr_encap_subtlv *h1,
264 const struct bgp_attr_encap_subtlv *h2)
265 {
266 const struct bgp_attr_encap_subtlv *p;
267 const struct bgp_attr_encap_subtlv *q;
268
269 if (h1 == h2)
270 return 1;
271 if (h1 == NULL || h2 == NULL)
272 return 0;
273
274 for (p = h1; p; p = p->next) {
275 for (q = h2; q; q = q->next) {
276 if ((p->type == q->type) && (p->length == q->length)
277 && !memcmp(p->value, q->value, p->length)) {
278
279 break;
280 }
281 }
282 if (!q)
283 return 0;
284 }
285
286 for (p = h2; p; p = p->next) {
287 for (q = h1; q; q = q->next) {
288 if ((p->type == q->type) && (p->length == q->length)
289 && !memcmp(p->value, q->value, p->length)) {
290
291 break;
292 }
293 }
294 if (!q)
295 return 0;
296 }
297
298 return 1;
299 }
300
301 static void *encap_hash_alloc(void *p)
302 {
303 /* Encap structure is already allocated. */
304 return p;
305 }
306
307 typedef enum {
308 ENCAP_SUBTLV_TYPE,
309 #if ENABLE_BGP_VNC
310 VNC_SUBTLV_TYPE
311 #endif
312 } encap_subtlv_type;
313
314 static struct bgp_attr_encap_subtlv *
315 encap_intern(struct bgp_attr_encap_subtlv *encap, encap_subtlv_type type)
316 {
317 struct bgp_attr_encap_subtlv *find;
318 struct hash *hash = encap_hash;
319 #if ENABLE_BGP_VNC
320 if (type == VNC_SUBTLV_TYPE)
321 hash = vnc_hash;
322 #endif
323
324 find = hash_get(hash, encap, encap_hash_alloc);
325 if (find != encap)
326 encap_free(encap);
327 find->refcnt++;
328
329 return find;
330 }
331
332 static void encap_unintern(struct bgp_attr_encap_subtlv **encapp,
333 encap_subtlv_type type)
334 {
335 struct bgp_attr_encap_subtlv *encap = *encapp;
336 if (encap->refcnt)
337 encap->refcnt--;
338
339 if (encap->refcnt == 0) {
340 struct hash *hash = encap_hash;
341 #if ENABLE_BGP_VNC
342 if (type == VNC_SUBTLV_TYPE)
343 hash = vnc_hash;
344 #endif
345 hash_release(hash, encap);
346 encap_free(encap);
347 *encapp = NULL;
348 }
349 }
350
351 static unsigned int encap_hash_key_make(void *p)
352 {
353 const struct bgp_attr_encap_subtlv *encap = p;
354
355 return jhash(encap->value, encap->length, 0);
356 }
357
358 static bool encap_hash_cmp(const void *p1, const void *p2)
359 {
360 return encap_same((const struct bgp_attr_encap_subtlv *)p1,
361 (const struct bgp_attr_encap_subtlv *)p2);
362 }
363
364 static void encap_init(void)
365 {
366 encap_hash = hash_create(encap_hash_key_make, encap_hash_cmp,
367 "BGP Encap Hash");
368 #if ENABLE_BGP_VNC
369 vnc_hash = hash_create(encap_hash_key_make, encap_hash_cmp,
370 "BGP VNC Hash");
371 #endif
372 }
373
374 static void encap_finish(void)
375 {
376 hash_clean(encap_hash, (void (*)(void *))encap_free);
377 hash_free(encap_hash);
378 encap_hash = NULL;
379 #if ENABLE_BGP_VNC
380 hash_clean(vnc_hash, (void (*)(void *))encap_free);
381 hash_free(vnc_hash);
382 vnc_hash = NULL;
383 #endif
384 }
385
386 static bool overlay_index_same(const struct attr *a1, const struct attr *a2)
387 {
388 if (!a1 && a2)
389 return false;
390 if (!a2 && a1)
391 return false;
392 if (!a1 && !a2)
393 return true;
394 return !memcmp(&(a1->evpn_overlay), &(a2->evpn_overlay),
395 sizeof(struct bgp_route_evpn));
396 }
397
398 /* Unknown transit attribute. */
399 static struct hash *transit_hash;
400
401 static void transit_free(struct transit *transit)
402 {
403 XFREE(MTYPE_TRANSIT_VAL, transit->val);
404 XFREE(MTYPE_TRANSIT, transit);
405 }
406
407 static void *transit_hash_alloc(void *p)
408 {
409 /* Transit structure is already allocated. */
410 return p;
411 }
412
413 static struct transit *transit_intern(struct transit *transit)
414 {
415 struct transit *find;
416
417 find = hash_get(transit_hash, transit, transit_hash_alloc);
418 if (find != transit)
419 transit_free(transit);
420 find->refcnt++;
421
422 return find;
423 }
424
425 void transit_unintern(struct transit *transit)
426 {
427 if (transit->refcnt)
428 transit->refcnt--;
429
430 if (transit->refcnt == 0) {
431 hash_release(transit_hash, transit);
432 transit_free(transit);
433 }
434 }
435
436 static unsigned int transit_hash_key_make(void *p)
437 {
438 const struct transit *transit = p;
439
440 return jhash(transit->val, transit->length, 0);
441 }
442
443 static bool transit_hash_cmp(const void *p1, const void *p2)
444 {
445 const struct transit *transit1 = p1;
446 const struct transit *transit2 = p2;
447
448 return (transit1->length == transit2->length
449 && memcmp(transit1->val, transit2->val, transit1->length) == 0);
450 }
451
452 static void transit_init(void)
453 {
454 transit_hash = hash_create(transit_hash_key_make, transit_hash_cmp,
455 "BGP Transit Hash");
456 }
457
458 static void transit_finish(void)
459 {
460 hash_clean(transit_hash, (void (*)(void *))transit_free);
461 hash_free(transit_hash);
462 transit_hash = NULL;
463 }
464
465 /* Attribute hash routines. */
466 static struct hash *attrhash;
467
468 /* Shallow copy of an attribute
469 * Though, not so shallow that it doesn't copy the contents
470 * of the attr_extra pointed to by 'extra'
471 */
472 void bgp_attr_dup(struct attr *new, struct attr *orig)
473 {
474 *new = *orig;
475 }
476
477 unsigned long int attr_count(void)
478 {
479 return attrhash->count;
480 }
481
482 unsigned long int attr_unknown_count(void)
483 {
484 return transit_hash->count;
485 }
486
487 unsigned int attrhash_key_make(void *p)
488 {
489 const struct attr *attr = (struct attr *)p;
490 uint32_t key = 0;
491 #define MIX(val) key = jhash_1word(val, key)
492 #define MIX3(a, b, c) key = jhash_3words((a), (b), (c), key)
493
494 MIX3(attr->origin, attr->nexthop.s_addr, attr->med);
495 MIX3(attr->local_pref, attr->aggregator_as,
496 attr->aggregator_addr.s_addr);
497 MIX3(attr->weight, attr->mp_nexthop_global_in.s_addr,
498 attr->originator_id.s_addr);
499 MIX3(attr->tag, attr->label, attr->label_index);
500
501 if (attr->aspath)
502 MIX(aspath_key_make(attr->aspath));
503 if (attr->community)
504 MIX(community_hash_make(attr->community));
505
506 if (attr->lcommunity)
507 MIX(lcommunity_hash_make(attr->lcommunity));
508 if (attr->ecommunity)
509 MIX(ecommunity_hash_make(attr->ecommunity));
510 if (attr->cluster)
511 MIX(cluster_hash_key_make(attr->cluster));
512 if (attr->transit)
513 MIX(transit_hash_key_make(attr->transit));
514 if (attr->encap_subtlvs)
515 MIX(encap_hash_key_make(attr->encap_subtlvs));
516 #if ENABLE_BGP_VNC
517 if (attr->vnc_subtlvs)
518 MIX(encap_hash_key_make(attr->vnc_subtlvs));
519 #endif
520 MIX(attr->mp_nexthop_len);
521 key = jhash(attr->mp_nexthop_global.s6_addr, IPV6_MAX_BYTELEN, key);
522 key = jhash(attr->mp_nexthop_local.s6_addr, IPV6_MAX_BYTELEN, key);
523 MIX(attr->nh_ifindex);
524 MIX(attr->nh_lla_ifindex);
525
526 return key;
527 }
528
529 bool attrhash_cmp(const void *p1, const void *p2)
530 {
531 const struct attr *attr1 = p1;
532 const struct attr *attr2 = p2;
533
534 if (attr1->flag == attr2->flag && attr1->origin == attr2->origin
535 && attr1->nexthop.s_addr == attr2->nexthop.s_addr
536 && attr1->aspath == attr2->aspath
537 && attr1->community == attr2->community && attr1->med == attr2->med
538 && attr1->local_pref == attr2->local_pref
539 && attr1->rmap_change_flags == attr2->rmap_change_flags) {
540 if (attr1->aggregator_as == attr2->aggregator_as
541 && attr1->aggregator_addr.s_addr
542 == attr2->aggregator_addr.s_addr
543 && attr1->weight == attr2->weight
544 && attr1->tag == attr2->tag
545 && attr1->label_index == attr2->label_index
546 && attr1->mp_nexthop_len == attr2->mp_nexthop_len
547 && attr1->ecommunity == attr2->ecommunity
548 && attr1->lcommunity == attr2->lcommunity
549 && attr1->cluster == attr2->cluster
550 && attr1->transit == attr2->transit
551 && (attr1->encap_tunneltype == attr2->encap_tunneltype)
552 && encap_same(attr1->encap_subtlvs, attr2->encap_subtlvs)
553 #if ENABLE_BGP_VNC
554 && encap_same(attr1->vnc_subtlvs, attr2->vnc_subtlvs)
555 #endif
556 && IPV6_ADDR_SAME(&attr1->mp_nexthop_global,
557 &attr2->mp_nexthop_global)
558 && IPV6_ADDR_SAME(&attr1->mp_nexthop_local,
559 &attr2->mp_nexthop_local)
560 && IPV4_ADDR_SAME(&attr1->mp_nexthop_global_in,
561 &attr2->mp_nexthop_global_in)
562 && IPV4_ADDR_SAME(&attr1->originator_id,
563 &attr2->originator_id)
564 && overlay_index_same(attr1, attr2)
565 && attr1->nh_ifindex == attr2->nh_ifindex
566 && attr1->nh_lla_ifindex == attr2->nh_lla_ifindex)
567 return true;
568 }
569
570 return false;
571 }
572
573 static void attrhash_init(void)
574 {
575 attrhash =
576 hash_create(attrhash_key_make, attrhash_cmp, "BGP Attributes");
577 }
578
579 /*
580 * special for hash_clean below
581 */
582 static void attr_vfree(void *attr)
583 {
584 XFREE(MTYPE_ATTR, attr);
585 }
586
587 static void attrhash_finish(void)
588 {
589 hash_clean(attrhash, attr_vfree);
590 hash_free(attrhash);
591 attrhash = NULL;
592 }
593
594 static void attr_show_all_iterator(struct hash_bucket *bucket, struct vty *vty)
595 {
596 struct attr *attr = bucket->data;
597
598 vty_out(vty, "attr[%ld] nexthop %s\n", attr->refcnt,
599 inet_ntoa(attr->nexthop));
600 vty_out(vty, "\tflags: %" PRIu64 " med: %u local_pref: %u origin: %u weight: %u label: %u\n",
601 attr->flag, attr->med, attr->local_pref, attr->origin,
602 attr->weight, attr->label);
603 }
604
605 void attr_show_all(struct vty *vty)
606 {
607 hash_iterate(attrhash, (void (*)(struct hash_bucket *,
608 void *))attr_show_all_iterator,
609 vty);
610 }
611
612 static void *bgp_attr_hash_alloc(void *p)
613 {
614 struct attr *val = (struct attr *)p;
615 struct attr *attr;
616
617 attr = XMALLOC(MTYPE_ATTR, sizeof(struct attr));
618 *attr = *val;
619 if (val->encap_subtlvs) {
620 val->encap_subtlvs = NULL;
621 }
622 #if ENABLE_BGP_VNC
623 if (val->vnc_subtlvs) {
624 val->vnc_subtlvs = NULL;
625 }
626 #endif
627 attr->refcnt = 0;
628 return attr;
629 }
630
631 /* Internet argument attribute. */
632 struct attr *bgp_attr_intern(struct attr *attr)
633 {
634 struct attr *find;
635
636 /* Intern referenced strucutre. */
637 if (attr->aspath) {
638 if (!attr->aspath->refcnt)
639 attr->aspath = aspath_intern(attr->aspath);
640 else
641 attr->aspath->refcnt++;
642 }
643 if (attr->community) {
644 if (!attr->community->refcnt)
645 attr->community = community_intern(attr->community);
646 else
647 attr->community->refcnt++;
648 }
649
650 if (attr->ecommunity) {
651 if (!attr->ecommunity->refcnt)
652 attr->ecommunity = ecommunity_intern(attr->ecommunity);
653 else
654 attr->ecommunity->refcnt++;
655 }
656 if (attr->lcommunity) {
657 if (!attr->lcommunity->refcnt)
658 attr->lcommunity = lcommunity_intern(attr->lcommunity);
659 else
660 attr->lcommunity->refcnt++;
661 }
662 if (attr->cluster) {
663 if (!attr->cluster->refcnt)
664 attr->cluster = cluster_intern(attr->cluster);
665 else
666 attr->cluster->refcnt++;
667 }
668 if (attr->transit) {
669 if (!attr->transit->refcnt)
670 attr->transit = transit_intern(attr->transit);
671 else
672 attr->transit->refcnt++;
673 }
674 if (attr->encap_subtlvs) {
675 if (!attr->encap_subtlvs->refcnt)
676 attr->encap_subtlvs = encap_intern(attr->encap_subtlvs,
677 ENCAP_SUBTLV_TYPE);
678 else
679 attr->encap_subtlvs->refcnt++;
680 }
681 #if ENABLE_BGP_VNC
682 if (attr->vnc_subtlvs) {
683 if (!attr->vnc_subtlvs->refcnt)
684 attr->vnc_subtlvs = encap_intern(attr->vnc_subtlvs,
685 VNC_SUBTLV_TYPE);
686 else
687 attr->vnc_subtlvs->refcnt++;
688 }
689 #endif
690
691 /* At this point, attr only contains intern'd pointers. that means
692 * if we find it in attrhash, it has all the same pointers and we
693 * correctly updated the refcounts on these.
694 * If we don't find it, we need to allocate a one because in all
695 * cases this returns a new reference to a hashed attr, but the input
696 * wasn't on hash. */
697 find = (struct attr *)hash_get(attrhash, attr, bgp_attr_hash_alloc);
698 find->refcnt++;
699
700 return find;
701 }
702
703 /* Make network statement's attribute. */
704 struct attr *bgp_attr_default_set(struct attr *attr, uint8_t origin)
705 {
706 memset(attr, 0, sizeof(struct attr));
707
708 attr->origin = origin;
709 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
710 attr->aspath = aspath_empty();
711 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
712 attr->weight = BGP_ATTR_DEFAULT_WEIGHT;
713 attr->tag = 0;
714 attr->label_index = BGP_INVALID_LABEL_INDEX;
715 attr->label = MPLS_INVALID_LABEL;
716 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
717 attr->mp_nexthop_len = IPV6_MAX_BYTELEN;
718
719 return attr;
720 }
721
722 /* Create the attributes for an aggregate */
723 struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
724 struct aspath *aspath,
725 struct community *community,
726 struct ecommunity *ecommunity,
727 struct lcommunity *lcommunity,
728 int as_set, uint8_t atomic_aggregate)
729 {
730 struct attr attr;
731 struct attr *new;
732
733 memset(&attr, 0, sizeof(struct attr));
734
735 /* Origin attribute. */
736 attr.origin = origin;
737 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
738
739 /* AS path attribute. */
740 if (aspath)
741 attr.aspath = aspath_intern(aspath);
742 else
743 attr.aspath = aspath_empty();
744 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
745
746 /* Next hop attribute. */
747 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
748
749 if (community) {
750 uint32_t gshut = COMMUNITY_GSHUT;
751
752 /* If we are not shutting down ourselves and we are
753 * aggregating a route that contains the GSHUT community we
754 * need to remove that community when creating the aggregate */
755 if (!bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)
756 && community_include(community, gshut)) {
757 community_del_val(community, &gshut);
758 }
759
760 attr.community = community;
761 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
762 }
763
764 if (ecommunity) {
765 attr.ecommunity = ecommunity;
766 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES);
767 }
768
769 if (lcommunity) {
770 attr.lcommunity = lcommunity;
771 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES);
772 }
773
774 if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
775 bgp_attr_add_gshut_community(&attr);
776 }
777
778 attr.label_index = BGP_INVALID_LABEL_INDEX;
779 attr.label = MPLS_INVALID_LABEL;
780 attr.weight = BGP_ATTR_DEFAULT_WEIGHT;
781 attr.mp_nexthop_len = IPV6_MAX_BYTELEN;
782 if (!as_set || atomic_aggregate)
783 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE);
784 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR);
785 if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION))
786 attr.aggregator_as = bgp->confed_id;
787 else
788 attr.aggregator_as = bgp->as;
789 attr.aggregator_addr = bgp->router_id;
790 attr.label_index = BGP_INVALID_LABEL_INDEX;
791 attr.label = MPLS_INVALID_LABEL;
792
793 new = bgp_attr_intern(&attr);
794
795 aspath_unintern(&new->aspath);
796 return new;
797 }
798
799 /* Unintern just the sub-components of the attr, but not the attr */
800 void bgp_attr_unintern_sub(struct attr *attr)
801 {
802 /* aspath refcount shoud be decrement. */
803 if (attr->aspath)
804 aspath_unintern(&attr->aspath);
805 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH));
806
807 if (attr->community)
808 community_unintern(&attr->community);
809 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES));
810
811 if (attr->ecommunity)
812 ecommunity_unintern(&attr->ecommunity);
813 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES));
814
815 if (attr->lcommunity)
816 lcommunity_unintern(&attr->lcommunity);
817 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES));
818
819 if (attr->cluster)
820 cluster_unintern(attr->cluster);
821 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST));
822
823 if (attr->transit)
824 transit_unintern(attr->transit);
825
826 if (attr->encap_subtlvs)
827 encap_unintern(&attr->encap_subtlvs, ENCAP_SUBTLV_TYPE);
828
829 #if ENABLE_BGP_VNC
830 if (attr->vnc_subtlvs)
831 encap_unintern(&attr->vnc_subtlvs, VNC_SUBTLV_TYPE);
832 #endif
833 }
834
835 /*
836 * We have some show commands that let you experimentally
837 * apply a route-map. When we apply the route-map
838 * we are reseting values but not saving them for
839 * posterity via intern'ing( because route-maps don't
840 * do that) but at this point in time we need
841 * to compare the new attr to the old and if the
842 * routemap has changed it we need to, as Snoop Dog says,
843 * Drop it like it's hot
844 */
845 void bgp_attr_undup(struct attr *new, struct attr *old)
846 {
847 if (new->aspath != old->aspath)
848 aspath_free(new->aspath);
849
850 if (new->community != old->community)
851 community_free(&new->community);
852
853 if (new->ecommunity != old->ecommunity)
854 ecommunity_free(&new->ecommunity);
855
856 if (new->lcommunity != old->lcommunity)
857 lcommunity_free(&new->lcommunity);
858 }
859
860 /* Free bgp attribute and aspath. */
861 void bgp_attr_unintern(struct attr **pattr)
862 {
863 struct attr *attr = *pattr;
864 struct attr *ret;
865 struct attr tmp;
866
867 /* Decrement attribute reference. */
868 attr->refcnt--;
869
870 tmp = *attr;
871
872 /* If reference becomes zero then free attribute object. */
873 if (attr->refcnt == 0) {
874 ret = hash_release(attrhash, attr);
875 assert(ret != NULL);
876 XFREE(MTYPE_ATTR, attr);
877 *pattr = NULL;
878 }
879
880 bgp_attr_unintern_sub(&tmp);
881 }
882
883 void bgp_attr_flush(struct attr *attr)
884 {
885 if (attr->aspath && !attr->aspath->refcnt) {
886 aspath_free(attr->aspath);
887 attr->aspath = NULL;
888 }
889 if (attr->community && !attr->community->refcnt)
890 community_free(&attr->community);
891 if (attr->ecommunity && !attr->ecommunity->refcnt)
892 ecommunity_free(&attr->ecommunity);
893 if (attr->lcommunity && !attr->lcommunity->refcnt)
894 lcommunity_free(&attr->lcommunity);
895 if (attr->cluster && !attr->cluster->refcnt) {
896 cluster_free(attr->cluster);
897 attr->cluster = NULL;
898 }
899 if (attr->transit && !attr->transit->refcnt) {
900 transit_free(attr->transit);
901 attr->transit = NULL;
902 }
903 if (attr->encap_subtlvs && !attr->encap_subtlvs->refcnt) {
904 encap_free(attr->encap_subtlvs);
905 attr->encap_subtlvs = NULL;
906 }
907 #if ENABLE_BGP_VNC
908 if (attr->vnc_subtlvs && !attr->vnc_subtlvs->refcnt) {
909 encap_free(attr->vnc_subtlvs);
910 attr->vnc_subtlvs = NULL;
911 }
912 #endif
913 }
914
915 /* Implement draft-scudder-idr-optional-transitive behaviour and
916 * avoid resetting sessions for malformed attributes which are
917 * are partial/optional and hence where the error likely was not
918 * introduced by the sending neighbour.
919 */
920 static bgp_attr_parse_ret_t
921 bgp_attr_malformed(struct bgp_attr_parser_args *args, uint8_t subcode,
922 bgp_size_t length)
923 {
924 struct peer *const peer = args->peer;
925 const uint8_t flags = args->flags;
926 /* startp and length must be special-cased, as whether or not to
927 * send the attribute data with the NOTIFY depends on the error,
928 * the caller therefore signals this with the seperate length argument
929 */
930 uint8_t *notify_datap = (length > 0 ? args->startp : NULL);
931
932 /* Only relax error handling for eBGP peers */
933 if (peer->sort != BGP_PEER_EBGP) {
934 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
935 notify_datap, length);
936 return BGP_ATTR_PARSE_ERROR;
937 }
938
939 /* Adjust the stream getp to the end of the attribute, in case we can
940 * still proceed but the caller hasn't read all the attribute.
941 */
942 stream_set_getp(BGP_INPUT(peer),
943 (args->startp - STREAM_DATA(BGP_INPUT(peer)))
944 + args->total);
945
946 switch (args->type) {
947 /* where an attribute is relatively inconsequential, e.g. it does not
948 * affect route selection, and can be safely ignored, then any such
949 * attributes which are malformed should just be ignored and the route
950 * processed as normal.
951 */
952 case BGP_ATTR_AS4_AGGREGATOR:
953 case BGP_ATTR_AGGREGATOR:
954 case BGP_ATTR_ATOMIC_AGGREGATE:
955 return BGP_ATTR_PARSE_PROCEED;
956
957 /* Core attributes, particularly ones which may influence route
958 * selection, should always cause session resets
959 */
960 case BGP_ATTR_ORIGIN:
961 case BGP_ATTR_AS_PATH:
962 case BGP_ATTR_NEXT_HOP:
963 case BGP_ATTR_MULTI_EXIT_DISC:
964 case BGP_ATTR_LOCAL_PREF:
965 case BGP_ATTR_COMMUNITIES:
966 case BGP_ATTR_ORIGINATOR_ID:
967 case BGP_ATTR_CLUSTER_LIST:
968 case BGP_ATTR_MP_REACH_NLRI:
969 case BGP_ATTR_MP_UNREACH_NLRI:
970 case BGP_ATTR_EXT_COMMUNITIES:
971 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
972 notify_datap, length);
973 return BGP_ATTR_PARSE_ERROR;
974 }
975
976 /* Partial optional attributes that are malformed should not cause
977 * the whole session to be reset. Instead treat it as a withdrawal
978 * of the routes, if possible.
979 */
980 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS)
981 && CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
982 && CHECK_FLAG(flags, BGP_ATTR_FLAG_PARTIAL))
983 return BGP_ATTR_PARSE_WITHDRAW;
984
985 /* default to reset */
986 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
987 }
988
989 /* Find out what is wrong with the path attribute flag bits and log the error.
990 "Flag bits" here stand for Optional, Transitive and Partial, but not for
991 Extended Length. Checking O/T/P bits at once implies, that the attribute
992 being diagnosed is defined by RFC as either a "well-known" or an "optional,
993 non-transitive" attribute. */
994 static void
995 bgp_attr_flags_diagnose(struct bgp_attr_parser_args *args,
996 uint8_t desired_flags /* how RFC says it must be */
997 )
998 {
999 uint8_t seen = 0, i;
1000 uint8_t real_flags = args->flags;
1001 const uint8_t attr_code = args->type;
1002
1003 desired_flags &= ~BGP_ATTR_FLAG_EXTLEN;
1004 real_flags &= ~BGP_ATTR_FLAG_EXTLEN;
1005 for (i = 0; i <= 2; i++) /* O,T,P, but not E */
1006 if (CHECK_FLAG(desired_flags, attr_flag_str[i].key)
1007 != CHECK_FLAG(real_flags, attr_flag_str[i].key)) {
1008 flog_err(EC_BGP_ATTR_FLAG,
1009 "%s attribute must%s be flagged as \"%s\"",
1010 lookup_msg(attr_str, attr_code, NULL),
1011 CHECK_FLAG(desired_flags, attr_flag_str[i].key)
1012 ? ""
1013 : " not",
1014 attr_flag_str[i].str);
1015 seen = 1;
1016 }
1017 if (!seen) {
1018 zlog_debug(
1019 "Strange, %s called for attr %s, but no problem found with flags"
1020 " (real flags 0x%x, desired 0x%x)",
1021 __func__, lookup_msg(attr_str, attr_code, NULL),
1022 real_flags, desired_flags);
1023 }
1024 }
1025
1026 /* Required flags for attributes. EXTLEN will be masked off when testing,
1027 * as will PARTIAL for optional+transitive attributes.
1028 */
1029 const uint8_t attr_flags_values[] = {
1030 [BGP_ATTR_ORIGIN] = BGP_ATTR_FLAG_TRANS,
1031 [BGP_ATTR_AS_PATH] = BGP_ATTR_FLAG_TRANS,
1032 [BGP_ATTR_NEXT_HOP] = BGP_ATTR_FLAG_TRANS,
1033 [BGP_ATTR_MULTI_EXIT_DISC] = BGP_ATTR_FLAG_OPTIONAL,
1034 [BGP_ATTR_LOCAL_PREF] = BGP_ATTR_FLAG_TRANS,
1035 [BGP_ATTR_ATOMIC_AGGREGATE] = BGP_ATTR_FLAG_TRANS,
1036 [BGP_ATTR_AGGREGATOR] = BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,
1037 [BGP_ATTR_COMMUNITIES] = BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,
1038 [BGP_ATTR_ORIGINATOR_ID] = BGP_ATTR_FLAG_OPTIONAL,
1039 [BGP_ATTR_CLUSTER_LIST] = BGP_ATTR_FLAG_OPTIONAL,
1040 [BGP_ATTR_MP_REACH_NLRI] = BGP_ATTR_FLAG_OPTIONAL,
1041 [BGP_ATTR_MP_UNREACH_NLRI] = BGP_ATTR_FLAG_OPTIONAL,
1042 [BGP_ATTR_EXT_COMMUNITIES] =
1043 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1044 [BGP_ATTR_AS4_PATH] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1045 [BGP_ATTR_AS4_AGGREGATOR] =
1046 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1047 [BGP_ATTR_PMSI_TUNNEL] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1048 [BGP_ATTR_LARGE_COMMUNITIES] =
1049 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1050 [BGP_ATTR_PREFIX_SID] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1051 };
1052 static const size_t attr_flags_values_max = array_size(attr_flags_values) - 1;
1053
1054 static int bgp_attr_flag_invalid(struct bgp_attr_parser_args *args)
1055 {
1056 uint8_t mask = BGP_ATTR_FLAG_EXTLEN;
1057 const uint8_t flags = args->flags;
1058 const uint8_t attr_code = args->type;
1059
1060 /* there may be attributes we don't know about */
1061 if (attr_code > attr_flags_values_max)
1062 return 0;
1063 if (attr_flags_values[attr_code] == 0)
1064 return 0;
1065
1066 /* RFC4271, "For well-known attributes, the Transitive bit MUST be set
1067 * to
1068 * 1."
1069 */
1070 if (!CHECK_FLAG(BGP_ATTR_FLAG_OPTIONAL, flags)
1071 && !CHECK_FLAG(BGP_ATTR_FLAG_TRANS, flags)) {
1072 flog_err(
1073 EC_BGP_ATTR_FLAG,
1074 "%s well-known attributes must have transitive flag set (%x)",
1075 lookup_msg(attr_str, attr_code, NULL), flags);
1076 return 1;
1077 }
1078
1079 /* "For well-known attributes and for optional non-transitive
1080 * attributes,
1081 * the Partial bit MUST be set to 0."
1082 */
1083 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_PARTIAL)) {
1084 if (!CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)) {
1085 flog_err(EC_BGP_ATTR_FLAG,
1086 "%s well-known attribute "
1087 "must NOT have the partial flag set (%x)",
1088 lookup_msg(attr_str, attr_code, NULL), flags);
1089 return 1;
1090 }
1091 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
1092 && !CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS)) {
1093 flog_err(EC_BGP_ATTR_FLAG,
1094 "%s optional + transitive attribute "
1095 "must NOT have the partial flag set (%x)",
1096 lookup_msg(attr_str, attr_code, NULL), flags);
1097 return 1;
1098 }
1099 }
1100
1101 /* Optional transitive attributes may go through speakers that don't
1102 * reocgnise them and set the Partial bit.
1103 */
1104 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
1105 && CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS))
1106 SET_FLAG(mask, BGP_ATTR_FLAG_PARTIAL);
1107
1108 if ((flags & ~mask) == attr_flags_values[attr_code])
1109 return 0;
1110
1111 bgp_attr_flags_diagnose(args, attr_flags_values[attr_code]);
1112 return 1;
1113 }
1114
1115 /* Get origin attribute of the update message. */
1116 static bgp_attr_parse_ret_t bgp_attr_origin(struct bgp_attr_parser_args *args)
1117 {
1118 struct peer *const peer = args->peer;
1119 struct attr *const attr = args->attr;
1120 const bgp_size_t length = args->length;
1121
1122 /* If any recognized attribute has Attribute Length that conflicts
1123 with the expected length (based on the attribute type code), then
1124 the Error Subcode is set to Attribute Length Error. The Data
1125 field contains the erroneous attribute (type, length and
1126 value). */
1127 if (length != 1) {
1128 flog_err(EC_BGP_ATTR_LEN,
1129 "Origin attribute length is not one %d", length);
1130 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1131 args->total);
1132 }
1133
1134 /* Fetch origin attribute. */
1135 attr->origin = stream_getc(BGP_INPUT(peer));
1136
1137 /* If the ORIGIN attribute has an undefined value, then the Error
1138 Subcode is set to Invalid Origin Attribute. The Data field
1139 contains the unrecognized attribute (type, length and value). */
1140 if ((attr->origin != BGP_ORIGIN_IGP) && (attr->origin != BGP_ORIGIN_EGP)
1141 && (attr->origin != BGP_ORIGIN_INCOMPLETE)) {
1142 flog_err(EC_BGP_ATTR_ORIGIN,
1143 "Origin attribute value is invalid %d", attr->origin);
1144 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_INVAL_ORIGIN,
1145 args->total);
1146 }
1147
1148 /* Set oring attribute flag. */
1149 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
1150
1151 return 0;
1152 }
1153
1154 /* Parse AS path information. This function is wrapper of
1155 aspath_parse. */
1156 static int bgp_attr_aspath(struct bgp_attr_parser_args *args)
1157 {
1158 struct attr *const attr = args->attr;
1159 struct peer *const peer = args->peer;
1160 const bgp_size_t length = args->length;
1161
1162 /*
1163 * peer with AS4 => will get 4Byte ASnums
1164 * otherwise, will get 16 Bit
1165 */
1166 attr->aspath = aspath_parse(peer->curr, length,
1167 CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV));
1168
1169 /* In case of IBGP, length will be zero. */
1170 if (!attr->aspath) {
1171 flog_err(EC_BGP_ATTR_MAL_AS_PATH,
1172 "Malformed AS path from %s, length is %d", peer->host,
1173 length);
1174 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
1175 0);
1176 }
1177
1178 /* Set aspath attribute flag. */
1179 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
1180
1181 return BGP_ATTR_PARSE_PROCEED;
1182 }
1183
1184 static bgp_attr_parse_ret_t bgp_attr_aspath_check(struct peer *const peer,
1185 struct attr *const attr)
1186 {
1187 /* These checks were part of bgp_attr_aspath, but with
1188 * as4 we should to check aspath things when
1189 * aspath synthesizing with as4_path has already taken place.
1190 * Otherwise we check ASPATH and use the synthesized thing, and that is
1191 * not right.
1192 * So do the checks later, i.e. here
1193 */
1194 struct aspath *aspath;
1195
1196 /* Confederation sanity check. */
1197 if ((peer->sort == BGP_PEER_CONFED
1198 && !aspath_left_confed_check(attr->aspath))
1199 || (peer->sort == BGP_PEER_EBGP
1200 && aspath_confed_check(attr->aspath))) {
1201 flog_err(EC_BGP_ATTR_MAL_AS_PATH, "Malformed AS path from %s",
1202 peer->host);
1203 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
1204 BGP_NOTIFY_UPDATE_MAL_AS_PATH);
1205 return BGP_ATTR_PARSE_ERROR;
1206 }
1207
1208 /* First AS check for EBGP. */
1209 if (CHECK_FLAG(peer->flags, PEER_FLAG_ENFORCE_FIRST_AS)) {
1210 if (peer->sort == BGP_PEER_EBGP
1211 && !aspath_firstas_check(attr->aspath, peer->as)) {
1212 flog_err(EC_BGP_ATTR_FIRST_AS,
1213 "%s incorrect first AS (must be %u)",
1214 peer->host, peer->as);
1215 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
1216 BGP_NOTIFY_UPDATE_MAL_AS_PATH);
1217 return BGP_ATTR_PARSE_ERROR;
1218 }
1219 }
1220
1221 /* local-as prepend */
1222 if (peer->change_local_as
1223 && !CHECK_FLAG(peer->flags, PEER_FLAG_LOCAL_AS_NO_PREPEND)) {
1224 aspath = aspath_dup(attr->aspath);
1225 aspath = aspath_add_seq(aspath, peer->change_local_as);
1226 aspath_unintern(&attr->aspath);
1227 attr->aspath = aspath_intern(aspath);
1228 }
1229
1230 return BGP_ATTR_PARSE_PROCEED;
1231 }
1232
1233 /* Parse AS4 path information. This function is another wrapper of
1234 aspath_parse. */
1235 static int bgp_attr_as4_path(struct bgp_attr_parser_args *args,
1236 struct aspath **as4_path)
1237 {
1238 struct peer *const peer = args->peer;
1239 struct attr *const attr = args->attr;
1240 const bgp_size_t length = args->length;
1241
1242 *as4_path = aspath_parse(peer->curr, length, 1);
1243
1244 /* In case of IBGP, length will be zero. */
1245 if (!*as4_path) {
1246 flog_err(EC_BGP_ATTR_MAL_AS_PATH,
1247 "Malformed AS4 path from %s, length is %d", peer->host,
1248 length);
1249 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
1250 0);
1251 }
1252
1253 /* Set aspath attribute flag. */
1254 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH);
1255
1256 return BGP_ATTR_PARSE_PROCEED;
1257 }
1258
1259 /*
1260 * Check that the nexthop attribute is valid.
1261 */
1262 bgp_attr_parse_ret_t
1263 bgp_attr_nexthop_valid(struct peer *peer, struct attr *attr)
1264 {
1265 in_addr_t nexthop_h;
1266
1267 nexthop_h = ntohl(attr->nexthop.s_addr);
1268 if ((IPV4_NET0(nexthop_h) || IPV4_NET127(nexthop_h)
1269 || IPV4_CLASS_DE(nexthop_h))
1270 && !BGP_DEBUG(allow_martians, ALLOW_MARTIANS)) {
1271 char buf[INET_ADDRSTRLEN];
1272
1273 inet_ntop(AF_INET, &attr->nexthop.s_addr, buf,
1274 INET_ADDRSTRLEN);
1275 flog_err(EC_BGP_ATTR_MARTIAN_NH, "Martian nexthop %s",
1276 buf);
1277 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
1278 BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP);
1279 return BGP_ATTR_PARSE_ERROR;
1280 }
1281
1282 return BGP_ATTR_PARSE_PROCEED;
1283 }
1284
1285 /* Nexthop attribute. */
1286 static bgp_attr_parse_ret_t bgp_attr_nexthop(struct bgp_attr_parser_args *args)
1287 {
1288 struct peer *const peer = args->peer;
1289 struct attr *const attr = args->attr;
1290 const bgp_size_t length = args->length;
1291
1292 /* Check nexthop attribute length. */
1293 if (length != 4) {
1294 flog_err(EC_BGP_ATTR_LEN,
1295 "Nexthop attribute length isn't four [%d]", length);
1296
1297 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1298 args->total);
1299 }
1300
1301 attr->nexthop.s_addr = stream_get_ipv4(peer->curr);
1302 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
1303
1304 return BGP_ATTR_PARSE_PROCEED;
1305 }
1306
1307 /* MED atrribute. */
1308 static bgp_attr_parse_ret_t bgp_attr_med(struct bgp_attr_parser_args *args)
1309 {
1310 struct peer *const peer = args->peer;
1311 struct attr *const attr = args->attr;
1312 const bgp_size_t length = args->length;
1313
1314 /* Length check. */
1315 if (length != 4) {
1316 flog_err(EC_BGP_ATTR_LEN,
1317 "MED attribute length isn't four [%d]", length);
1318
1319 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1320 args->total);
1321 }
1322
1323 attr->med = stream_getl(peer->curr);
1324
1325 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
1326
1327 return BGP_ATTR_PARSE_PROCEED;
1328 }
1329
1330 /* Local preference attribute. */
1331 static bgp_attr_parse_ret_t
1332 bgp_attr_local_pref(struct bgp_attr_parser_args *args)
1333 {
1334 struct peer *const peer = args->peer;
1335 struct attr *const attr = args->attr;
1336 const bgp_size_t length = args->length;
1337
1338 /* Length check. */
1339 if (length != 4) {
1340 flog_err(EC_BGP_ATTR_LEN,
1341 "LOCAL_PREF attribute length isn't 4 [%u]", length);
1342 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1343 args->total);
1344 }
1345
1346 /* If it is contained in an UPDATE message that is received from an
1347 external peer, then this attribute MUST be ignored by the
1348 receiving speaker. */
1349 if (peer->sort == BGP_PEER_EBGP) {
1350 stream_forward_getp(peer->curr, length);
1351 return BGP_ATTR_PARSE_PROCEED;
1352 }
1353
1354 attr->local_pref = stream_getl(peer->curr);
1355
1356 /* Set the local-pref flag. */
1357 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
1358
1359 return BGP_ATTR_PARSE_PROCEED;
1360 }
1361
1362 /* Atomic aggregate. */
1363 static int bgp_attr_atomic(struct bgp_attr_parser_args *args)
1364 {
1365 struct attr *const attr = args->attr;
1366 const bgp_size_t length = args->length;
1367
1368 /* Length check. */
1369 if (length != 0) {
1370 flog_err(EC_BGP_ATTR_LEN,
1371 "ATOMIC_AGGREGATE attribute length isn't 0 [%u]",
1372 length);
1373 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1374 args->total);
1375 }
1376
1377 /* Set atomic aggregate flag. */
1378 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE);
1379
1380 return BGP_ATTR_PARSE_PROCEED;
1381 }
1382
1383 /* Aggregator attribute */
1384 static int bgp_attr_aggregator(struct bgp_attr_parser_args *args)
1385 {
1386 struct peer *const peer = args->peer;
1387 struct attr *const attr = args->attr;
1388 const bgp_size_t length = args->length;
1389
1390 int wantedlen = 6;
1391
1392 /* peer with AS4 will send 4 Byte AS, peer without will send 2 Byte */
1393 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV))
1394 wantedlen = 8;
1395
1396 if (length != wantedlen) {
1397 flog_err(EC_BGP_ATTR_LEN,
1398 "AGGREGATOR attribute length isn't %u [%u]", wantedlen,
1399 length);
1400 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1401 args->total);
1402 }
1403
1404 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV))
1405 attr->aggregator_as = stream_getl(peer->curr);
1406 else
1407 attr->aggregator_as = stream_getw(peer->curr);
1408 attr->aggregator_addr.s_addr = stream_get_ipv4(peer->curr);
1409
1410 /* Set atomic aggregate flag. */
1411 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR);
1412
1413 return BGP_ATTR_PARSE_PROCEED;
1414 }
1415
1416 /* New Aggregator attribute */
1417 static bgp_attr_parse_ret_t
1418 bgp_attr_as4_aggregator(struct bgp_attr_parser_args *args,
1419 as_t *as4_aggregator_as,
1420 struct in_addr *as4_aggregator_addr)
1421 {
1422 struct peer *const peer = args->peer;
1423 struct attr *const attr = args->attr;
1424 const bgp_size_t length = args->length;
1425
1426 if (length != 8) {
1427 flog_err(EC_BGP_ATTR_LEN, "New Aggregator length is not 8 [%d]",
1428 length);
1429 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1430 0);
1431 }
1432
1433 *as4_aggregator_as = stream_getl(peer->curr);
1434 as4_aggregator_addr->s_addr = stream_get_ipv4(peer->curr);
1435
1436 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR);
1437
1438 return BGP_ATTR_PARSE_PROCEED;
1439 }
1440
1441 /* Munge Aggregator and New-Aggregator, AS_PATH and NEW_AS_PATH.
1442 */
1443 static bgp_attr_parse_ret_t
1444 bgp_attr_munge_as4_attrs(struct peer *const peer, struct attr *const attr,
1445 struct aspath *as4_path, as_t as4_aggregator,
1446 struct in_addr *as4_aggregator_addr)
1447 {
1448 int ignore_as4_path = 0;
1449 struct aspath *newpath;
1450
1451 if (!attr->aspath) {
1452 /* NULL aspath shouldn't be possible as bgp_attr_parse should
1453 * have
1454 * checked that all well-known, mandatory attributes were
1455 * present.
1456 *
1457 * Can only be a problem with peer itself - hard error
1458 */
1459 return BGP_ATTR_PARSE_ERROR;
1460 }
1461
1462 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)) {
1463 /* peer can do AS4, so we ignore AS4_PATH and AS4_AGGREGATOR
1464 * if given.
1465 * It is worth a warning though, because the peer really
1466 * should not send them
1467 */
1468 if (BGP_DEBUG(as4, AS4)) {
1469 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH)))
1470 zlog_debug("[AS4] %s %s AS4_PATH", peer->host,
1471 "AS4 capable peer, yet it sent");
1472
1473 if (attr->flag
1474 & (ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR)))
1475 zlog_debug("[AS4] %s %s AS4_AGGREGATOR",
1476 peer->host,
1477 "AS4 capable peer, yet it sent");
1478 }
1479
1480 return BGP_ATTR_PARSE_PROCEED;
1481 }
1482
1483 /* We have a asn16 peer. First, look for AS4_AGGREGATOR
1484 * because that may override AS4_PATH
1485 */
1486 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR))) {
1487 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR))) {
1488 /* received both.
1489 * if the as_number in aggregator is not AS_TRANS,
1490 * then AS4_AGGREGATOR and AS4_PATH shall be ignored
1491 * and the Aggregator shall be taken as
1492 * info on the aggregating node, and the AS_PATH
1493 * shall be taken as the AS_PATH
1494 * otherwise
1495 * the Aggregator shall be ignored and the
1496 * AS4_AGGREGATOR shall be taken as the
1497 * Aggregating node and the AS_PATH is to be
1498 * constructed "as in all other cases"
1499 */
1500 if (attr->aggregator_as != BGP_AS_TRANS) {
1501 /* ignore */
1502 if (BGP_DEBUG(as4, AS4))
1503 zlog_debug(
1504 "[AS4] %s BGP not AS4 capable peer"
1505 " send AGGREGATOR != AS_TRANS and"
1506 " AS4_AGGREGATOR, so ignore"
1507 " AS4_AGGREGATOR and AS4_PATH",
1508 peer->host);
1509 ignore_as4_path = 1;
1510 } else {
1511 /* "New_aggregator shall be taken as aggregator"
1512 */
1513 attr->aggregator_as = as4_aggregator;
1514 attr->aggregator_addr.s_addr =
1515 as4_aggregator_addr->s_addr;
1516 }
1517 } else {
1518 /* We received a AS4_AGGREGATOR but no AGGREGATOR.
1519 * That is bogus - but reading the conditions
1520 * we have to handle AS4_AGGREGATOR as if it were
1521 * AGGREGATOR in that case
1522 */
1523 if (BGP_DEBUG(as4, AS4))
1524 zlog_debug(
1525 "[AS4] %s BGP not AS4 capable peer send"
1526 " AS4_AGGREGATOR but no AGGREGATOR, will take"
1527 " it as if AGGREGATOR with AS_TRANS had been there",
1528 peer->host);
1529 attr->aggregator_as = as4_aggregator;
1530 /* sweep it under the carpet and simulate a "good"
1531 * AGGREGATOR */
1532 attr->flag |= (ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR));
1533 }
1534 }
1535
1536 /* need to reconcile NEW_AS_PATH and AS_PATH */
1537 if (!ignore_as4_path
1538 && (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH)))) {
1539 newpath = aspath_reconcile_as4(attr->aspath, as4_path);
1540 if (!newpath)
1541 return BGP_ATTR_PARSE_ERROR;
1542
1543 aspath_unintern(&attr->aspath);
1544 attr->aspath = aspath_intern(newpath);
1545 }
1546 return BGP_ATTR_PARSE_PROCEED;
1547 }
1548
1549 /* Community attribute. */
1550 static bgp_attr_parse_ret_t
1551 bgp_attr_community(struct bgp_attr_parser_args *args)
1552 {
1553 struct peer *const peer = args->peer;
1554 struct attr *const attr = args->attr;
1555 const bgp_size_t length = args->length;
1556
1557 if (length == 0) {
1558 attr->community = NULL;
1559 return BGP_ATTR_PARSE_PROCEED;
1560 }
1561
1562 attr->community =
1563 community_parse((uint32_t *)stream_pnt(peer->curr), length);
1564
1565 /* XXX: fix community_parse to use stream API and remove this */
1566 stream_forward_getp(peer->curr, length);
1567
1568 if (!attr->community)
1569 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1570 args->total);
1571
1572 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
1573
1574 return BGP_ATTR_PARSE_PROCEED;
1575 }
1576
1577 /* Originator ID attribute. */
1578 static bgp_attr_parse_ret_t
1579 bgp_attr_originator_id(struct bgp_attr_parser_args *args)
1580 {
1581 struct peer *const peer = args->peer;
1582 struct attr *const attr = args->attr;
1583 const bgp_size_t length = args->length;
1584
1585 /* Length check. */
1586 if (length != 4) {
1587 flog_err(EC_BGP_ATTR_LEN, "Bad originator ID length %d",
1588 length);
1589
1590 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1591 args->total);
1592 }
1593
1594 attr->originator_id.s_addr = stream_get_ipv4(peer->curr);
1595
1596 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID);
1597
1598 return BGP_ATTR_PARSE_PROCEED;
1599 }
1600
1601 /* Cluster list attribute. */
1602 static bgp_attr_parse_ret_t
1603 bgp_attr_cluster_list(struct bgp_attr_parser_args *args)
1604 {
1605 struct peer *const peer = args->peer;
1606 struct attr *const attr = args->attr;
1607 const bgp_size_t length = args->length;
1608
1609 /* Check length. */
1610 if (length % 4) {
1611 flog_err(EC_BGP_ATTR_LEN, "Bad cluster list length %d", length);
1612
1613 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1614 args->total);
1615 }
1616
1617 attr->cluster =
1618 cluster_parse((struct in_addr *)stream_pnt(peer->curr), length);
1619
1620 /* XXX: Fix cluster_parse to use stream API and then remove this */
1621 stream_forward_getp(peer->curr, length);
1622
1623 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST);
1624
1625 return BGP_ATTR_PARSE_PROCEED;
1626 }
1627
1628 /* Multiprotocol reachability information parse. */
1629 int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
1630 struct bgp_nlri *mp_update)
1631 {
1632 iana_afi_t pkt_afi;
1633 afi_t afi;
1634 iana_safi_t pkt_safi;
1635 safi_t safi;
1636 bgp_size_t nlri_len;
1637 size_t start;
1638 struct stream *s;
1639 struct peer *const peer = args->peer;
1640 struct attr *const attr = args->attr;
1641 const bgp_size_t length = args->length;
1642
1643 /* Set end of packet. */
1644 s = BGP_INPUT(peer);
1645 start = stream_get_getp(s);
1646
1647 /* safe to read statically sized header? */
1648 #define BGP_MP_REACH_MIN_SIZE 5
1649 #define LEN_LEFT (length - (stream_get_getp(s) - start))
1650 if ((length > STREAM_READABLE(s)) || (length < BGP_MP_REACH_MIN_SIZE)) {
1651 zlog_info("%s: %s sent invalid length, %lu", __func__,
1652 peer->host, (unsigned long)length);
1653 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1654 }
1655
1656 /* Load AFI, SAFI. */
1657 pkt_afi = stream_getw(s);
1658 pkt_safi = stream_getc(s);
1659
1660 /* Convert AFI, SAFI to internal values, check. */
1661 if (bgp_map_afi_safi_iana2int(pkt_afi, pkt_safi, &afi, &safi)) {
1662 /* Log if AFI or SAFI is unrecognized. This is not an error
1663 * unless
1664 * the attribute is otherwise malformed.
1665 */
1666 if (bgp_debug_update(peer, NULL, NULL, 0))
1667 zlog_debug(
1668 "%s: MP_REACH received AFI %u or SAFI %u is unrecognized",
1669 peer->host, pkt_afi, pkt_safi);
1670 return BGP_ATTR_PARSE_ERROR;
1671 }
1672
1673 /* Get nexthop length. */
1674 attr->mp_nexthop_len = stream_getc(s);
1675
1676 if (LEN_LEFT < attr->mp_nexthop_len) {
1677 zlog_info(
1678 "%s: %s, MP nexthop length, %u, goes past end of attribute",
1679 __func__, peer->host, attr->mp_nexthop_len);
1680 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1681 }
1682
1683 /* Nexthop length check. */
1684 switch (attr->mp_nexthop_len) {
1685 case 0:
1686 if (safi != SAFI_FLOWSPEC) {
1687 zlog_info("%s: (%s) Wrong multiprotocol next hop length: %d",
1688 __func__, peer->host, attr->mp_nexthop_len);
1689 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1690 }
1691 break;
1692 case BGP_ATTR_NHLEN_VPNV4:
1693 stream_getl(s); /* RD high */
1694 stream_getl(s); /* RD low */
1695 /*
1696 * NOTE: intentional fall through
1697 * - for consistency in rx processing
1698 *
1699 * The following comment is to signal GCC this intention
1700 * and suppress the warning
1701 */
1702 /* FALLTHRU */
1703 case BGP_ATTR_NHLEN_IPV4:
1704 stream_get(&attr->mp_nexthop_global_in, s, IPV4_MAX_BYTELEN);
1705 /* Probably needed for RFC 2283 */
1706 if (attr->nexthop.s_addr == 0)
1707 memcpy(&attr->nexthop.s_addr,
1708 &attr->mp_nexthop_global_in, IPV4_MAX_BYTELEN);
1709 break;
1710 case BGP_ATTR_NHLEN_IPV6_GLOBAL:
1711 case BGP_ATTR_NHLEN_VPNV6_GLOBAL:
1712 if (attr->mp_nexthop_len == BGP_ATTR_NHLEN_VPNV6_GLOBAL) {
1713 stream_getl(s); /* RD high */
1714 stream_getl(s); /* RD low */
1715 }
1716 stream_get(&attr->mp_nexthop_global, s, IPV6_MAX_BYTELEN);
1717 if (IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_global)) {
1718 if (!peer->nexthop.ifp) {
1719 zlog_warn("%s: Received a V6/VPNV6 Global attribute but address is a V6 LL and we have no peer interface information, withdrawing",
1720 peer->host);
1721 return BGP_ATTR_PARSE_WITHDRAW;
1722 }
1723 attr->nh_ifindex = peer->nexthop.ifp->ifindex;
1724 }
1725 break;
1726 case BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL:
1727 case BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL:
1728 if (attr->mp_nexthop_len
1729 == BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL) {
1730 stream_getl(s); /* RD high */
1731 stream_getl(s); /* RD low */
1732 }
1733 stream_get(&attr->mp_nexthop_global, s, IPV6_MAX_BYTELEN);
1734 if (IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_global)) {
1735 if (!peer->nexthop.ifp) {
1736 zlog_warn("%s: Received V6/VPNV6 Global and LL attribute but global address is a V6 LL and we have no peer interface information, withdrawing",
1737 peer->host);
1738 return BGP_ATTR_PARSE_WITHDRAW;
1739 }
1740 attr->nh_ifindex = peer->nexthop.ifp->ifindex;
1741 }
1742 if (attr->mp_nexthop_len
1743 == BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL) {
1744 stream_getl(s); /* RD high */
1745 stream_getl(s); /* RD low */
1746 }
1747 stream_get(&attr->mp_nexthop_local, s, IPV6_MAX_BYTELEN);
1748 if (!IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local)) {
1749 char buf1[INET6_ADDRSTRLEN];
1750 char buf2[INET6_ADDRSTRLEN];
1751
1752 if (bgp_debug_update(peer, NULL, NULL, 1))
1753 zlog_debug(
1754 "%s rcvd nexthops %s, %s -- ignoring non-LL value",
1755 peer->host,
1756 inet_ntop(AF_INET6,
1757 &attr->mp_nexthop_global,
1758 buf1, INET6_ADDRSTRLEN),
1759 inet_ntop(AF_INET6,
1760 &attr->mp_nexthop_local, buf2,
1761 INET6_ADDRSTRLEN));
1762
1763 attr->mp_nexthop_len = IPV6_MAX_BYTELEN;
1764 }
1765 if (!peer->nexthop.ifp) {
1766 zlog_warn("%s: Received a V6 LL nexthop and we have no peer interface information, withdrawing",
1767 peer->host);
1768 return BGP_ATTR_PARSE_WITHDRAW;
1769 }
1770 attr->nh_lla_ifindex = peer->nexthop.ifp->ifindex;
1771 break;
1772 default:
1773 zlog_info("%s: (%s) Wrong multiprotocol next hop length: %d",
1774 __func__, peer->host, attr->mp_nexthop_len);
1775 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1776 }
1777
1778 if (!LEN_LEFT) {
1779 zlog_info("%s: (%s) Failed to read SNPA and NLRI(s)", __func__,
1780 peer->host);
1781 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1782 }
1783
1784 {
1785 uint8_t val;
1786 if ((val = stream_getc(s)))
1787 flog_warn(
1788 EC_BGP_DEFUNCT_SNPA_LEN,
1789 "%s sent non-zero value, %u, for defunct SNPA-length field",
1790 peer->host, val);
1791 }
1792
1793 /* must have nrli_len, what is left of the attribute */
1794 nlri_len = LEN_LEFT;
1795 if (nlri_len > STREAM_READABLE(s)) {
1796 zlog_info("%s: (%s) Failed to read NLRI", __func__, peer->host);
1797 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1798 }
1799
1800 if (!nlri_len) {
1801 zlog_info("%s: (%s) No Reachability, Treating as a EOR marker",
1802 __func__, peer->host);
1803
1804 mp_update->afi = afi;
1805 mp_update->safi = safi;
1806 return BGP_ATTR_PARSE_EOR;
1807 }
1808
1809 mp_update->afi = afi;
1810 mp_update->safi = safi;
1811 mp_update->nlri = stream_pnt(s);
1812 mp_update->length = nlri_len;
1813
1814 stream_forward_getp(s, nlri_len);
1815
1816 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI);
1817
1818 return BGP_ATTR_PARSE_PROCEED;
1819 #undef LEN_LEFT
1820 }
1821
1822 /* Multiprotocol unreachable parse */
1823 int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
1824 struct bgp_nlri *mp_withdraw)
1825 {
1826 struct stream *s;
1827 iana_afi_t pkt_afi;
1828 afi_t afi;
1829 iana_safi_t pkt_safi;
1830 safi_t safi;
1831 uint16_t withdraw_len;
1832 struct peer *const peer = args->peer;
1833 struct attr *const attr = args->attr;
1834 const bgp_size_t length = args->length;
1835
1836 s = peer->curr;
1837
1838 #define BGP_MP_UNREACH_MIN_SIZE 3
1839 if ((length > STREAM_READABLE(s)) || (length < BGP_MP_UNREACH_MIN_SIZE))
1840 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1841
1842 pkt_afi = stream_getw(s);
1843 pkt_safi = stream_getc(s);
1844
1845 /* Convert AFI, SAFI to internal values, check. */
1846 if (bgp_map_afi_safi_iana2int(pkt_afi, pkt_safi, &afi, &safi)) {
1847 /* Log if AFI or SAFI is unrecognized. This is not an error
1848 * unless
1849 * the attribute is otherwise malformed.
1850 */
1851 if (bgp_debug_update(peer, NULL, NULL, 0))
1852 zlog_debug(
1853 "%s: MP_UNREACH received AFI %u or SAFI %u is unrecognized",
1854 peer->host, pkt_afi, pkt_safi);
1855 return BGP_ATTR_PARSE_ERROR;
1856 }
1857
1858 withdraw_len = length - BGP_MP_UNREACH_MIN_SIZE;
1859
1860 mp_withdraw->afi = afi;
1861 mp_withdraw->safi = safi;
1862 mp_withdraw->nlri = stream_pnt(s);
1863 mp_withdraw->length = withdraw_len;
1864
1865 stream_forward_getp(s, withdraw_len);
1866
1867 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI);
1868
1869 return BGP_ATTR_PARSE_PROCEED;
1870 }
1871
1872 /* Large Community attribute. */
1873 static bgp_attr_parse_ret_t
1874 bgp_attr_large_community(struct bgp_attr_parser_args *args)
1875 {
1876 struct peer *const peer = args->peer;
1877 struct attr *const attr = args->attr;
1878 const bgp_size_t length = args->length;
1879
1880 /*
1881 * Large community follows new attribute format.
1882 */
1883 if (length == 0) {
1884 attr->lcommunity = NULL;
1885 /* Empty extcomm doesn't seem to be invalid per se */
1886 return BGP_ATTR_PARSE_PROCEED;
1887 }
1888
1889 attr->lcommunity =
1890 lcommunity_parse((uint8_t *)stream_pnt(peer->curr), length);
1891 /* XXX: fix ecommunity_parse to use stream API */
1892 stream_forward_getp(peer->curr, length);
1893
1894 if (!attr->lcommunity)
1895 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1896 args->total);
1897
1898 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES);
1899
1900 return BGP_ATTR_PARSE_PROCEED;
1901 }
1902
1903 /* Extended Community attribute. */
1904 static bgp_attr_parse_ret_t
1905 bgp_attr_ext_communities(struct bgp_attr_parser_args *args)
1906 {
1907 struct peer *const peer = args->peer;
1908 struct attr *const attr = args->attr;
1909 const bgp_size_t length = args->length;
1910 uint8_t sticky = 0;
1911
1912 if (length == 0) {
1913 attr->ecommunity = NULL;
1914 /* Empty extcomm doesn't seem to be invalid per se */
1915 return BGP_ATTR_PARSE_PROCEED;
1916 }
1917
1918 attr->ecommunity =
1919 ecommunity_parse((uint8_t *)stream_pnt(peer->curr), length);
1920 /* XXX: fix ecommunity_parse to use stream API */
1921 stream_forward_getp(peer->curr, length);
1922
1923 if (!attr->ecommunity)
1924 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1925 args->total);
1926
1927 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES);
1928
1929 /* Extract MAC mobility sequence number, if any. */
1930 attr->mm_seqnum = bgp_attr_mac_mobility_seqnum(attr, &sticky);
1931 attr->sticky = sticky;
1932
1933 /* Check if this is a Gateway MAC-IP advertisement */
1934 attr->default_gw = bgp_attr_default_gw(attr);
1935
1936 /* Handle scenario where router flag ecommunity is not
1937 * set but default gw ext community is present.
1938 * Use default gateway, set and propogate R-bit.
1939 */
1940 if (attr->default_gw)
1941 attr->router_flag = 1;
1942
1943 /* Check EVPN Neighbor advertisement flags, R-bit */
1944 bgp_attr_evpn_na_flag(attr, &attr->router_flag);
1945
1946 /* Extract the Rmac, if any */
1947 if (bgp_attr_rmac(attr, &attr->rmac)) {
1948 if (bgp_debug_update(peer, NULL, NULL, 1) &&
1949 bgp_mac_exist(&attr->rmac)) {
1950 char buf1[ETHER_ADDR_STRLEN];
1951
1952 zlog_debug("%s: router mac %s is self mac",
1953 __func__,
1954 prefix_mac2str(&attr->rmac, buf1,
1955 sizeof(buf1)));
1956 }
1957
1958 }
1959
1960 return BGP_ATTR_PARSE_PROCEED;
1961 }
1962
1963 /* Parse Tunnel Encap attribute in an UPDATE */
1964 static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
1965 bgp_size_t length, /* IN: attr's length field */
1966 struct attr *attr, /* IN: caller already allocated */
1967 uint8_t flag, /* IN: attr's flags field */
1968 uint8_t *startp)
1969 {
1970 bgp_size_t total;
1971 uint16_t tunneltype = 0;
1972
1973 total = length + (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
1974
1975 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS)
1976 || !CHECK_FLAG(flag, BGP_ATTR_FLAG_OPTIONAL)) {
1977 zlog_info(
1978 "Tunnel Encap attribute flag isn't optional and transitive %d",
1979 flag);
1980 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
1981 BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
1982 startp, total);
1983 return -1;
1984 }
1985
1986 if (BGP_ATTR_ENCAP == type) {
1987 /* read outer TLV type and length */
1988 uint16_t tlv_length;
1989
1990 if (length < 4) {
1991 zlog_info(
1992 "Tunnel Encap attribute not long enough to contain outer T,L");
1993 bgp_notify_send_with_data(
1994 peer, BGP_NOTIFY_UPDATE_ERR,
1995 BGP_NOTIFY_UPDATE_OPT_ATTR_ERR, startp, total);
1996 return -1;
1997 }
1998 tunneltype = stream_getw(BGP_INPUT(peer));
1999 tlv_length = stream_getw(BGP_INPUT(peer));
2000 length -= 4;
2001
2002 if (tlv_length != length) {
2003 zlog_info("%s: tlv_length(%d) != length(%d)", __func__,
2004 tlv_length, length);
2005 }
2006 }
2007
2008 while (length >= 4) {
2009 uint16_t subtype = 0;
2010 uint16_t sublength = 0;
2011 struct bgp_attr_encap_subtlv *tlv;
2012
2013 if (BGP_ATTR_ENCAP == type) {
2014 subtype = stream_getc(BGP_INPUT(peer));
2015 sublength = stream_getc(BGP_INPUT(peer));
2016 length -= 2;
2017 #if ENABLE_BGP_VNC
2018 } else {
2019 subtype = stream_getw(BGP_INPUT(peer));
2020 sublength = stream_getw(BGP_INPUT(peer));
2021 length -= 4;
2022 #endif
2023 }
2024
2025 if (sublength > length) {
2026 zlog_info(
2027 "Tunnel Encap attribute sub-tlv length %d exceeds remaining length %d",
2028 sublength, length);
2029 bgp_notify_send_with_data(
2030 peer, BGP_NOTIFY_UPDATE_ERR,
2031 BGP_NOTIFY_UPDATE_OPT_ATTR_ERR, startp, total);
2032 return -1;
2033 }
2034
2035 /* alloc and copy sub-tlv */
2036 /* TBD make sure these are freed when attributes are released */
2037 tlv = XCALLOC(MTYPE_ENCAP_TLV,
2038 sizeof(struct bgp_attr_encap_subtlv) + sublength);
2039 tlv->type = subtype;
2040 tlv->length = sublength;
2041 stream_get(tlv->value, peer->curr, sublength);
2042 length -= sublength;
2043
2044 /* attach tlv to encap chain */
2045 if (BGP_ATTR_ENCAP == type) {
2046 struct bgp_attr_encap_subtlv *stlv_last;
2047 for (stlv_last = attr->encap_subtlvs;
2048 stlv_last && stlv_last->next;
2049 stlv_last = stlv_last->next)
2050 ;
2051 if (stlv_last) {
2052 stlv_last->next = tlv;
2053 } else {
2054 attr->encap_subtlvs = tlv;
2055 }
2056 #if ENABLE_BGP_VNC
2057 } else {
2058 struct bgp_attr_encap_subtlv *stlv_last;
2059 for (stlv_last = attr->vnc_subtlvs;
2060 stlv_last && stlv_last->next;
2061 stlv_last = stlv_last->next)
2062 ;
2063 if (stlv_last) {
2064 stlv_last->next = tlv;
2065 } else {
2066 attr->vnc_subtlvs = tlv;
2067 }
2068 #endif
2069 }
2070 }
2071
2072 if (BGP_ATTR_ENCAP == type) {
2073 attr->encap_tunneltype = tunneltype;
2074 }
2075
2076 if (length) {
2077 /* spurious leftover data */
2078 zlog_info(
2079 "Tunnel Encap attribute length is bad: %d leftover octets",
2080 length);
2081 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
2082 BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2083 startp, total);
2084 return -1;
2085 }
2086
2087 return 0;
2088 }
2089
2090 /*
2091 * Read an individual SID value returning how much data we have read
2092 * Returns 0 if there was an error that needs to be passed up the stack
2093 */
2094 static bgp_attr_parse_ret_t bgp_attr_psid_sub(int32_t type,
2095 int32_t length,
2096 struct bgp_attr_parser_args *args,
2097 struct bgp_nlri *mp_update)
2098 {
2099 struct peer *const peer = args->peer;
2100 struct attr *const attr = args->attr;
2101 uint32_t label_index;
2102 struct in6_addr ipv6_sid;
2103 uint32_t srgb_base;
2104 uint32_t srgb_range;
2105 int srgb_count;
2106
2107 if (type == BGP_PREFIX_SID_LABEL_INDEX) {
2108 if (length != BGP_PREFIX_SID_LABEL_INDEX_LENGTH) {
2109 flog_err(
2110 EC_BGP_ATTR_LEN,
2111 "Prefix SID label index length is %d instead of %d",
2112 length, BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
2113 return bgp_attr_malformed(args,
2114 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2115 args->total);
2116 }
2117
2118 /* Ignore flags and reserved */
2119 stream_getc(peer->curr);
2120 stream_getw(peer->curr);
2121
2122 /* Fetch the label index and see if it is valid. */
2123 label_index = stream_getl(peer->curr);
2124 if (label_index == BGP_INVALID_LABEL_INDEX)
2125 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2126 args->total);
2127
2128 /* Store label index; subsequently, we'll check on
2129 * address-family */
2130 attr->label_index = label_index;
2131
2132 /*
2133 * Ignore the Label index attribute unless received for
2134 * labeled-unicast
2135 * SAFI.
2136 */
2137 if (!mp_update->length
2138 || mp_update->safi != SAFI_LABELED_UNICAST)
2139 attr->label_index = BGP_INVALID_LABEL_INDEX;
2140 }
2141
2142 /* Placeholder code for the IPv6 SID type */
2143 else if (type == BGP_PREFIX_SID_IPV6) {
2144 if (length != BGP_PREFIX_SID_IPV6_LENGTH) {
2145 flog_err(EC_BGP_ATTR_LEN,
2146 "Prefix SID IPv6 length is %d instead of %d",
2147 length, BGP_PREFIX_SID_IPV6_LENGTH);
2148 return bgp_attr_malformed(args,
2149 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2150 args->total);
2151 }
2152
2153 /* Ignore reserved */
2154 stream_getc(peer->curr);
2155 stream_getw(peer->curr);
2156
2157 stream_get(&ipv6_sid, peer->curr, 16);
2158 }
2159
2160 /* Placeholder code for the Originator SRGB type */
2161 else if (type == BGP_PREFIX_SID_ORIGINATOR_SRGB) {
2162 /* Ignore flags */
2163 stream_getw(peer->curr);
2164
2165 length -= 2;
2166
2167 if (length % BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH) {
2168 flog_err(
2169 EC_BGP_ATTR_LEN,
2170 "Prefix SID Originator SRGB length is %d, it must be a multiple of %d ",
2171 length, BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH);
2172 return bgp_attr_malformed(
2173 args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2174 args->total);
2175 }
2176
2177 srgb_count = length / BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH;
2178
2179 for (int i = 0; i < srgb_count; i++) {
2180 stream_get(&srgb_base, peer->curr, 3);
2181 stream_get(&srgb_range, peer->curr, 3);
2182 }
2183 }
2184
2185 return BGP_ATTR_PARSE_PROCEED;
2186 }
2187
2188 /* Prefix SID attribute
2189 * draft-ietf-idr-bgp-prefix-sid-05
2190 */
2191 bgp_attr_parse_ret_t
2192 bgp_attr_prefix_sid(int32_t tlength, struct bgp_attr_parser_args *args,
2193 struct bgp_nlri *mp_update)
2194 {
2195 struct peer *const peer = args->peer;
2196 struct attr *const attr = args->attr;
2197 bgp_attr_parse_ret_t ret;
2198
2199 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID);
2200
2201 while (tlength) {
2202 int32_t type, length;
2203
2204 type = stream_getc(peer->curr);
2205 length = stream_getw(peer->curr);
2206
2207 ret = bgp_attr_psid_sub(type, length, args, mp_update);
2208
2209 if (ret != BGP_ATTR_PARSE_PROCEED)
2210 return ret;
2211 /*
2212 * Subtract length + the T and the L
2213 * since length is the Vector portion
2214 */
2215 tlength -= length + 3;
2216
2217 if (tlength < 0) {
2218 flog_err(
2219 EC_BGP_ATTR_LEN,
2220 "Prefix SID internal length %d causes us to read beyond the total Prefix SID length",
2221 length);
2222 return bgp_attr_malformed(args,
2223 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2224 args->total);
2225 }
2226 }
2227
2228 return BGP_ATTR_PARSE_PROCEED;
2229 }
2230
2231 /* PMSI tunnel attribute (RFC 6514)
2232 * Basic validation checks done here.
2233 */
2234 static bgp_attr_parse_ret_t
2235 bgp_attr_pmsi_tunnel(struct bgp_attr_parser_args *args)
2236 {
2237 struct peer *const peer = args->peer;
2238 struct attr *const attr = args->attr;
2239 const bgp_size_t length = args->length;
2240 uint8_t tnl_type;
2241 int attr_parse_len = 2 + BGP_LABEL_BYTES;
2242
2243 /* Verify that the receiver is expecting "ingress replication" as we
2244 * can only support that.
2245 */
2246 if (length < attr_parse_len) {
2247 flog_err(EC_BGP_ATTR_LEN, "Bad PMSI tunnel attribute length %d",
2248 length);
2249 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2250 args->total);
2251 }
2252 stream_getc(peer->curr); /* Flags */
2253 tnl_type = stream_getc(peer->curr);
2254 if (tnl_type > PMSI_TNLTYPE_MAX) {
2255 flog_err(EC_BGP_ATTR_PMSI_TYPE,
2256 "Invalid PMSI tunnel attribute type %d", tnl_type);
2257 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2258 args->total);
2259 }
2260 if (tnl_type == PMSI_TNLTYPE_INGR_REPL) {
2261 if (length != 9) {
2262 flog_err(EC_BGP_ATTR_PMSI_LEN,
2263 "Bad PMSI tunnel attribute length %d for IR",
2264 length);
2265 return bgp_attr_malformed(
2266 args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2267 args->total);
2268 }
2269 }
2270
2271 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL);
2272 attr->pmsi_tnl_type = tnl_type;
2273 stream_get(&attr->label, peer->curr, BGP_LABEL_BYTES);
2274
2275 /* Forward read pointer of input stream. */
2276 stream_forward_getp(peer->curr, length - attr_parse_len);
2277
2278 return BGP_ATTR_PARSE_PROCEED;
2279 }
2280
2281 /* BGP unknown attribute treatment. */
2282 static bgp_attr_parse_ret_t bgp_attr_unknown(struct bgp_attr_parser_args *args)
2283 {
2284 bgp_size_t total = args->total;
2285 struct transit *transit;
2286 struct peer *const peer = args->peer;
2287 struct attr *const attr = args->attr;
2288 uint8_t *const startp = args->startp;
2289 const uint8_t type = args->type;
2290 const uint8_t flag = args->flags;
2291 const bgp_size_t length = args->length;
2292
2293 if (bgp_debug_update(peer, NULL, NULL, 1))
2294 zlog_debug(
2295 "%s Unknown attribute is received (type %d, length %d)",
2296 peer->host, type, length);
2297
2298 /* Forward read pointer of input stream. */
2299 stream_forward_getp(peer->curr, length);
2300
2301 /* If any of the mandatory well-known attributes are not recognized,
2302 then the Error Subcode is set to Unrecognized Well-known
2303 Attribute. The Data field contains the unrecognized attribute
2304 (type, length and value). */
2305 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_OPTIONAL)) {
2306 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_UNREC_ATTR,
2307 args->total);
2308 }
2309
2310 /* Unrecognized non-transitive optional attributes must be quietly
2311 ignored and not passed along to other BGP peers. */
2312 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS))
2313 return BGP_ATTR_PARSE_PROCEED;
2314
2315 /* If a path with recognized transitive optional attribute is
2316 accepted and passed along to other BGP peers and the Partial bit
2317 in the Attribute Flags octet is set to 1 by some previous AS, it
2318 is not set back to 0 by the current AS. */
2319 SET_FLAG(*startp, BGP_ATTR_FLAG_PARTIAL);
2320
2321 /* Store transitive attribute to the end of attr->transit. */
2322 if (!attr->transit)
2323 attr->transit = XCALLOC(MTYPE_TRANSIT, sizeof(struct transit));
2324
2325 transit = attr->transit;
2326
2327 if (transit->val)
2328 transit->val = XREALLOC(MTYPE_TRANSIT_VAL, transit->val,
2329 transit->length + total);
2330 else
2331 transit->val = XMALLOC(MTYPE_TRANSIT_VAL, total);
2332
2333 memcpy(transit->val + transit->length, startp, total);
2334 transit->length += total;
2335
2336 return BGP_ATTR_PARSE_PROCEED;
2337 }
2338
2339 /* Well-known attribute check. */
2340 static int bgp_attr_check(struct peer *peer, struct attr *attr)
2341 {
2342 uint8_t type = 0;
2343
2344 /* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an
2345 * empty UPDATE. */
2346 if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag)
2347 return BGP_ATTR_PARSE_PROCEED;
2348
2349 /* "An UPDATE message that contains the MP_UNREACH_NLRI is not required
2350 to carry any other path attributes.", though if MP_REACH_NLRI or NLRI
2351 are present, it should. Check for any other attribute being present
2352 instead.
2353 */
2354 if ((!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) &&
2355 CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI))))
2356 return BGP_ATTR_PARSE_PROCEED;
2357
2358 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN)))
2359 type = BGP_ATTR_ORIGIN;
2360
2361 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH)))
2362 type = BGP_ATTR_AS_PATH;
2363
2364 /* RFC 2858 makes Next-Hop optional/ignored, if MP_REACH_NLRI is present
2365 * and
2366 * NLRI is empty. We can't easily check NLRI empty here though.
2367 */
2368 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP))
2369 && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)))
2370 type = BGP_ATTR_NEXT_HOP;
2371
2372 if (peer->sort == BGP_PEER_IBGP
2373 && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF)))
2374 type = BGP_ATTR_LOCAL_PREF;
2375
2376 if (type) {
2377 flog_warn(EC_BGP_MISSING_ATTRIBUTE,
2378 "%s Missing well-known attribute %s.", peer->host,
2379 lookup_msg(attr_str, type, NULL));
2380 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
2381 BGP_NOTIFY_UPDATE_MISS_ATTR, &type,
2382 1);
2383 return BGP_ATTR_PARSE_ERROR;
2384 }
2385 return BGP_ATTR_PARSE_PROCEED;
2386 }
2387
2388 /* Read attribute of update packet. This function is called from
2389 bgp_update_receive() in bgp_packet.c. */
2390 bgp_attr_parse_ret_t bgp_attr_parse(struct peer *peer, struct attr *attr,
2391 bgp_size_t size, struct bgp_nlri *mp_update,
2392 struct bgp_nlri *mp_withdraw)
2393 {
2394 bgp_attr_parse_ret_t ret;
2395 uint8_t flag = 0;
2396 uint8_t type = 0;
2397 bgp_size_t length;
2398 uint8_t *startp, *endp;
2399 uint8_t *attr_endp;
2400 uint8_t seen[BGP_ATTR_BITMAP_SIZE];
2401 /* we need the as4_path only until we have synthesized the as_path with
2402 * it */
2403 /* same goes for as4_aggregator */
2404 struct aspath *as4_path = NULL;
2405 as_t as4_aggregator = 0;
2406 struct in_addr as4_aggregator_addr = {.s_addr = 0};
2407
2408 /* Initialize bitmap. */
2409 memset(seen, 0, BGP_ATTR_BITMAP_SIZE);
2410
2411 /* End pointer of BGP attribute. */
2412 endp = BGP_INPUT_PNT(peer) + size;
2413
2414 /* Get attributes to the end of attribute length. */
2415 while (BGP_INPUT_PNT(peer) < endp) {
2416 /* Check remaining length check.*/
2417 if (endp - BGP_INPUT_PNT(peer) < BGP_ATTR_MIN_LEN) {
2418 /* XXX warning: long int format, int arg (arg 5) */
2419 flog_warn(
2420 EC_BGP_ATTRIBUTE_TOO_SMALL,
2421 "%s: error BGP attribute length %lu is smaller than min len",
2422 peer->host,
2423 (unsigned long)(endp
2424 - stream_pnt(BGP_INPUT(peer))));
2425
2426 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2427 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2428 return BGP_ATTR_PARSE_ERROR;
2429 }
2430
2431 /* Fetch attribute flag and type. */
2432 startp = BGP_INPUT_PNT(peer);
2433 /* "The lower-order four bits of the Attribute Flags octet are
2434 unused. They MUST be zero when sent and MUST be ignored when
2435 received." */
2436 flag = 0xF0 & stream_getc(BGP_INPUT(peer));
2437 type = stream_getc(BGP_INPUT(peer));
2438
2439 /* Check whether Extended-Length applies and is in bounds */
2440 if (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN)
2441 && ((endp - startp) < (BGP_ATTR_MIN_LEN + 1))) {
2442 flog_warn(
2443 EC_BGP_EXT_ATTRIBUTE_TOO_SMALL,
2444 "%s: Extended length set, but just %lu bytes of attr header",
2445 peer->host,
2446 (unsigned long)(endp
2447 - stream_pnt(BGP_INPUT(peer))));
2448
2449 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2450 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2451 return BGP_ATTR_PARSE_ERROR;
2452 }
2453
2454 /* Check extended attribue length bit. */
2455 if (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN))
2456 length = stream_getw(BGP_INPUT(peer));
2457 else
2458 length = stream_getc(BGP_INPUT(peer));
2459
2460 /* If any attribute appears more than once in the UPDATE
2461 message, then the Error Subcode is set to Malformed Attribute
2462 List. */
2463
2464 if (CHECK_BITMAP(seen, type)) {
2465 flog_warn(
2466 EC_BGP_ATTRIBUTE_REPEATED,
2467 "%s: error BGP attribute type %d appears twice in a message",
2468 peer->host, type);
2469
2470 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2471 BGP_NOTIFY_UPDATE_MAL_ATTR);
2472 return BGP_ATTR_PARSE_ERROR;
2473 }
2474
2475 /* Set type to bitmap to check duplicate attribute. `type' is
2476 unsigned char so it never overflow bitmap range. */
2477
2478 SET_BITMAP(seen, type);
2479
2480 /* Overflow check. */
2481 attr_endp = BGP_INPUT_PNT(peer) + length;
2482
2483 if (attr_endp > endp) {
2484 flog_warn(
2485 EC_BGP_ATTRIBUTE_TOO_LARGE,
2486 "%s: BGP type %d length %d is too large, attribute total length is %d. attr_endp is %p. endp is %p",
2487 peer->host, type, length, size, attr_endp,
2488 endp);
2489 /*
2490 * RFC 4271 6.3
2491 * If any recognized attribute has an Attribute
2492 * Length that conflicts with the expected length
2493 * (based on the attribute type code), then the
2494 * Error Subcode MUST be set to Attribute Length
2495 * Error. The Data field MUST contain the erroneous
2496 * attribute (type, length, and value).
2497 * ----------
2498 * We do not currently have a good way to determine the
2499 * length of the attribute independent of the length
2500 * received in the message. Instead we send the
2501 * minimum between the amount of data we have and the
2502 * amount specified by the attribute length field.
2503 *
2504 * Instead of directly passing in the packet buffer and
2505 * offset we use the stream_get* functions to read into
2506 * a stack buffer, since they perform bounds checking
2507 * and we are working with untrusted data.
2508 */
2509 unsigned char ndata[BGP_MAX_PACKET_SIZE];
2510 memset(ndata, 0x00, sizeof(ndata));
2511 size_t lfl =
2512 CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN) ? 2 : 1;
2513 /* Rewind to end of flag field */
2514 stream_forward_getp(BGP_INPUT(peer), -(1 + lfl));
2515 /* Type */
2516 stream_get(&ndata[0], BGP_INPUT(peer), 1);
2517 /* Length */
2518 stream_get(&ndata[1], BGP_INPUT(peer), lfl);
2519 /* Value */
2520 size_t atl = attr_endp - startp;
2521 size_t ndl = MIN(atl, STREAM_READABLE(BGP_INPUT(peer)));
2522 stream_get(&ndata[lfl + 1], BGP_INPUT(peer), ndl);
2523
2524 bgp_notify_send_with_data(
2525 peer, BGP_NOTIFY_UPDATE_ERR,
2526 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR, ndata,
2527 ndl + lfl + 1);
2528
2529 return BGP_ATTR_PARSE_ERROR;
2530 }
2531
2532 struct bgp_attr_parser_args attr_args = {
2533 .peer = peer,
2534 .length = length,
2535 .attr = attr,
2536 .type = type,
2537 .flags = flag,
2538 .startp = startp,
2539 .total = attr_endp - startp,
2540 };
2541
2542
2543 /* If any recognized attribute has Attribute Flags that conflict
2544 with the Attribute Type Code, then the Error Subcode is set
2545 to
2546 Attribute Flags Error. The Data field contains the erroneous
2547 attribute (type, length and value). */
2548 if (bgp_attr_flag_invalid(&attr_args)) {
2549 ret = bgp_attr_malformed(
2550 &attr_args, BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
2551 attr_args.total);
2552 if (ret == BGP_ATTR_PARSE_PROCEED)
2553 continue;
2554 return ret;
2555 }
2556
2557 /* OK check attribute and store it's value. */
2558 switch (type) {
2559 case BGP_ATTR_ORIGIN:
2560 ret = bgp_attr_origin(&attr_args);
2561 break;
2562 case BGP_ATTR_AS_PATH:
2563 ret = bgp_attr_aspath(&attr_args);
2564 break;
2565 case BGP_ATTR_AS4_PATH:
2566 ret = bgp_attr_as4_path(&attr_args, &as4_path);
2567 break;
2568 case BGP_ATTR_NEXT_HOP:
2569 ret = bgp_attr_nexthop(&attr_args);
2570 break;
2571 case BGP_ATTR_MULTI_EXIT_DISC:
2572 ret = bgp_attr_med(&attr_args);
2573 break;
2574 case BGP_ATTR_LOCAL_PREF:
2575 ret = bgp_attr_local_pref(&attr_args);
2576 break;
2577 case BGP_ATTR_ATOMIC_AGGREGATE:
2578 ret = bgp_attr_atomic(&attr_args);
2579 break;
2580 case BGP_ATTR_AGGREGATOR:
2581 ret = bgp_attr_aggregator(&attr_args);
2582 break;
2583 case BGP_ATTR_AS4_AGGREGATOR:
2584 ret = bgp_attr_as4_aggregator(&attr_args,
2585 &as4_aggregator,
2586 &as4_aggregator_addr);
2587 break;
2588 case BGP_ATTR_COMMUNITIES:
2589 ret = bgp_attr_community(&attr_args);
2590 break;
2591 case BGP_ATTR_LARGE_COMMUNITIES:
2592 ret = bgp_attr_large_community(&attr_args);
2593 break;
2594 case BGP_ATTR_ORIGINATOR_ID:
2595 ret = bgp_attr_originator_id(&attr_args);
2596 break;
2597 case BGP_ATTR_CLUSTER_LIST:
2598 ret = bgp_attr_cluster_list(&attr_args);
2599 break;
2600 case BGP_ATTR_MP_REACH_NLRI:
2601 ret = bgp_mp_reach_parse(&attr_args, mp_update);
2602 break;
2603 case BGP_ATTR_MP_UNREACH_NLRI:
2604 ret = bgp_mp_unreach_parse(&attr_args, mp_withdraw);
2605 break;
2606 case BGP_ATTR_EXT_COMMUNITIES:
2607 ret = bgp_attr_ext_communities(&attr_args);
2608 break;
2609 #if ENABLE_BGP_VNC_ATTR
2610 case BGP_ATTR_VNC:
2611 #endif
2612 case BGP_ATTR_ENCAP:
2613 ret = bgp_attr_encap(type, peer, length, attr, flag,
2614 startp);
2615 break;
2616 case BGP_ATTR_PREFIX_SID:
2617 ret = bgp_attr_prefix_sid(length,
2618 &attr_args, mp_update);
2619 break;
2620 case BGP_ATTR_PMSI_TUNNEL:
2621 ret = bgp_attr_pmsi_tunnel(&attr_args);
2622 break;
2623 default:
2624 ret = bgp_attr_unknown(&attr_args);
2625 break;
2626 }
2627
2628 if (ret == BGP_ATTR_PARSE_ERROR_NOTIFYPLS) {
2629 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2630 BGP_NOTIFY_UPDATE_MAL_ATTR);
2631 ret = BGP_ATTR_PARSE_ERROR;
2632 }
2633
2634 if (ret == BGP_ATTR_PARSE_EOR) {
2635 if (as4_path)
2636 aspath_unintern(&as4_path);
2637 return ret;
2638 }
2639
2640 /* If hard error occurred immediately return to the caller. */
2641 if (ret == BGP_ATTR_PARSE_ERROR) {
2642 flog_warn(EC_BGP_ATTRIBUTE_PARSE_ERROR,
2643 "%s: Attribute %s, parse error", peer->host,
2644 lookup_msg(attr_str, type, NULL));
2645 if (as4_path)
2646 aspath_unintern(&as4_path);
2647 return ret;
2648 }
2649 if (ret == BGP_ATTR_PARSE_WITHDRAW) {
2650
2651 flog_warn(
2652 EC_BGP_ATTRIBUTE_PARSE_WITHDRAW,
2653 "%s: Attribute %s, parse error - treating as withdrawal",
2654 peer->host, lookup_msg(attr_str, type, NULL));
2655 if (as4_path)
2656 aspath_unintern(&as4_path);
2657 return ret;
2658 }
2659
2660 /* Check the fetched length. */
2661 if (BGP_INPUT_PNT(peer) != attr_endp) {
2662 flog_warn(EC_BGP_ATTRIBUTE_FETCH_ERROR,
2663 "%s: BGP attribute %s, fetch error",
2664 peer->host, lookup_msg(attr_str, type, NULL));
2665 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2666 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2667 if (as4_path)
2668 aspath_unintern(&as4_path);
2669 return BGP_ATTR_PARSE_ERROR;
2670 }
2671 }
2672
2673 /* Check final read pointer is same as end pointer. */
2674 if (BGP_INPUT_PNT(peer) != endp) {
2675 flog_warn(EC_BGP_ATTRIBUTES_MISMATCH,
2676 "%s: BGP attribute %s, length mismatch", peer->host,
2677 lookup_msg(attr_str, type, NULL));
2678 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2679 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2680 if (as4_path)
2681 aspath_unintern(&as4_path);
2682 return BGP_ATTR_PARSE_ERROR;
2683 }
2684
2685 /*
2686 * RFC4271: If the NEXT_HOP attribute field is syntactically incorrect,
2687 * then the Error Subcode MUST be set to Invalid NEXT_HOP Attribute.
2688 * This is implemented below and will result in a NOTIFICATION. If the
2689 * NEXT_HOP attribute is semantically incorrect, the error SHOULD be
2690 * logged, and the route SHOULD be ignored. In this case, a NOTIFICATION
2691 * message SHOULD NOT be sent. This is implemented elsewhere.
2692 *
2693 * RFC4760: An UPDATE message that carries no NLRI, other than the one
2694 * encoded in the MP_REACH_NLRI attribute, SHOULD NOT carry the NEXT_HOP
2695 * attribute. If such a message contains the NEXT_HOP attribute, the BGP
2696 * speaker that receives the message SHOULD ignore this attribute.
2697 */
2698 if (CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP))
2699 && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI))) {
2700 if (bgp_attr_nexthop_valid(peer, attr) < 0) {
2701 return BGP_ATTR_PARSE_ERROR;
2702 }
2703 }
2704
2705 /* Check all mandatory well-known attributes are present */
2706 if ((ret = bgp_attr_check(peer, attr)) < 0) {
2707 if (as4_path)
2708 aspath_unintern(&as4_path);
2709 return ret;
2710 }
2711
2712 /*
2713 * At this place we can see whether we got AS4_PATH and/or
2714 * AS4_AGGREGATOR from a 16Bit peer and act accordingly.
2715 * We can not do this before we've read all attributes because
2716 * the as4 handling does not say whether AS4_PATH has to be sent
2717 * after AS_PATH or not - and when AS4_AGGREGATOR will be send
2718 * in relationship to AGGREGATOR.
2719 * So, to be defensive, we are not relying on any order and read
2720 * all attributes first, including these 32bit ones, and now,
2721 * afterwards, we look what and if something is to be done for as4.
2722 *
2723 * It is possible to not have AS_PATH, e.g. GR EoR and sole
2724 * MP_UNREACH_NLRI.
2725 */
2726 /* actually... this doesn't ever return failure currently, but
2727 * better safe than sorry */
2728 if (CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH))
2729 && bgp_attr_munge_as4_attrs(peer, attr, as4_path, as4_aggregator,
2730 &as4_aggregator_addr)) {
2731 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2732 BGP_NOTIFY_UPDATE_MAL_ATTR);
2733 if (as4_path)
2734 aspath_unintern(&as4_path);
2735 return BGP_ATTR_PARSE_ERROR;
2736 }
2737
2738 /* At this stage, we have done all fiddling with as4, and the
2739 * resulting info is in attr->aggregator resp. attr->aspath
2740 * so we can chuck as4_aggregator and as4_path alltogether in
2741 * order to save memory
2742 */
2743 if (as4_path) {
2744 aspath_unintern(&as4_path); /* unintern - it is in the hash */
2745 /* The flag that we got this is still there, but that does not
2746 * do any trouble
2747 */
2748 }
2749 /*
2750 * The "rest" of the code does nothing with as4_aggregator.
2751 * there is no memory attached specifically which is not part
2752 * of the attr.
2753 * so ignoring just means do nothing.
2754 */
2755 /*
2756 * Finally do the checks on the aspath we did not do yet
2757 * because we waited for a potentially synthesized aspath.
2758 */
2759 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS_PATH))) {
2760 ret = bgp_attr_aspath_check(peer, attr);
2761 if (ret != BGP_ATTR_PARSE_PROCEED)
2762 return ret;
2763 }
2764 /* Finally intern unknown attribute. */
2765 if (attr->transit)
2766 attr->transit = transit_intern(attr->transit);
2767 if (attr->encap_subtlvs)
2768 attr->encap_subtlvs =
2769 encap_intern(attr->encap_subtlvs, ENCAP_SUBTLV_TYPE);
2770 #if ENABLE_BGP_VNC
2771 if (attr->vnc_subtlvs)
2772 attr->vnc_subtlvs =
2773 encap_intern(attr->vnc_subtlvs, VNC_SUBTLV_TYPE);
2774 #endif
2775
2776 return BGP_ATTR_PARSE_PROCEED;
2777 }
2778
2779 size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer, afi_t afi,
2780 safi_t safi, struct bpacket_attr_vec_arr *vecarr,
2781 struct attr *attr)
2782 {
2783 size_t sizep;
2784 iana_afi_t pkt_afi;
2785 iana_safi_t pkt_safi;
2786 afi_t nh_afi;
2787
2788 /* Set extended bit always to encode the attribute length as 2 bytes */
2789 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_EXTLEN);
2790 stream_putc(s, BGP_ATTR_MP_REACH_NLRI);
2791 sizep = stream_get_endp(s);
2792 stream_putw(s, 0); /* Marker: Attribute length. */
2793
2794
2795 /* Convert AFI, SAFI to values for packet. */
2796 bgp_map_afi_safi_int2iana(afi, safi, &pkt_afi, &pkt_safi);
2797
2798 stream_putw(s, pkt_afi); /* AFI */
2799 stream_putc(s, pkt_safi); /* SAFI */
2800
2801 /* Nexthop AFI */
2802 if (afi == AFI_IP
2803 && (safi == SAFI_UNICAST || safi == SAFI_LABELED_UNICAST))
2804 nh_afi = peer_cap_enhe(peer, afi, safi) ? AFI_IP6 : AFI_IP;
2805 else
2806 nh_afi = BGP_NEXTHOP_AFI_FROM_NHLEN(attr->mp_nexthop_len);
2807
2808 /* Nexthop */
2809 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s, attr);
2810 switch (nh_afi) {
2811 case AFI_IP:
2812 switch (safi) {
2813 case SAFI_UNICAST:
2814 case SAFI_MULTICAST:
2815 case SAFI_LABELED_UNICAST:
2816 stream_putc(s, 4);
2817 stream_put_ipv4(s, attr->nexthop.s_addr);
2818 break;
2819 case SAFI_MPLS_VPN:
2820 stream_putc(s, 12);
2821 stream_putl(s, 0); /* RD = 0, per RFC */
2822 stream_putl(s, 0);
2823 stream_put(s, &attr->mp_nexthop_global_in, 4);
2824 break;
2825 case SAFI_ENCAP:
2826 case SAFI_EVPN:
2827 stream_putc(s, 4);
2828 stream_put(s, &attr->mp_nexthop_global_in, 4);
2829 break;
2830 case SAFI_FLOWSPEC:
2831 stream_putc(s, 0); /* no nexthop for flowspec */
2832 default:
2833 break;
2834 }
2835 break;
2836 case AFI_IP6:
2837 switch (safi) {
2838 case SAFI_UNICAST:
2839 case SAFI_MULTICAST:
2840 case SAFI_LABELED_UNICAST:
2841 case SAFI_EVPN: {
2842 if (attr->mp_nexthop_len
2843 == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) {
2844 stream_putc(s,
2845 BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL);
2846 stream_put(s, &attr->mp_nexthop_global,
2847 IPV6_MAX_BYTELEN);
2848 stream_put(s, &attr->mp_nexthop_local,
2849 IPV6_MAX_BYTELEN);
2850 } else {
2851 stream_putc(s, IPV6_MAX_BYTELEN);
2852 stream_put(s, &attr->mp_nexthop_global,
2853 IPV6_MAX_BYTELEN);
2854 }
2855 } break;
2856 case SAFI_MPLS_VPN: {
2857 if (attr->mp_nexthop_len
2858 == BGP_ATTR_NHLEN_IPV6_GLOBAL) {
2859 stream_putc(s, 24);
2860 stream_putl(s, 0); /* RD = 0, per RFC */
2861 stream_putl(s, 0);
2862 stream_put(s, &attr->mp_nexthop_global,
2863 IPV6_MAX_BYTELEN);
2864 } else if (attr->mp_nexthop_len
2865 == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) {
2866 stream_putc(s, 48);
2867 stream_putl(s, 0); /* RD = 0, per RFC */
2868 stream_putl(s, 0);
2869 stream_put(s, &attr->mp_nexthop_global,
2870 IPV6_MAX_BYTELEN);
2871 stream_putl(s, 0); /* RD = 0, per RFC */
2872 stream_putl(s, 0);
2873 stream_put(s, &attr->mp_nexthop_local,
2874 IPV6_MAX_BYTELEN);
2875 }
2876 } break;
2877 case SAFI_ENCAP:
2878 stream_putc(s, IPV6_MAX_BYTELEN);
2879 stream_put(s, &attr->mp_nexthop_global,
2880 IPV6_MAX_BYTELEN);
2881 break;
2882 case SAFI_FLOWSPEC:
2883 stream_putc(s, 0); /* no nexthop for flowspec */
2884 default:
2885 break;
2886 }
2887 break;
2888 default:
2889 if (safi != SAFI_FLOWSPEC)
2890 flog_err(
2891 EC_BGP_ATTR_NH_SEND_LEN,
2892 "Bad nexthop when sending to %s, AFI %u SAFI %u nhlen %d",
2893 peer->host, afi, safi, attr->mp_nexthop_len);
2894 break;
2895 }
2896
2897 /* SNPA */
2898 stream_putc(s, 0);
2899 return sizep;
2900 }
2901
2902 void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
2903 struct prefix *p, struct prefix_rd *prd,
2904 mpls_label_t *label, uint32_t num_labels,
2905 int addpath_encode, uint32_t addpath_tx_id,
2906 struct attr *attr)
2907 {
2908 if (safi == SAFI_MPLS_VPN) {
2909 if (addpath_encode)
2910 stream_putl(s, addpath_tx_id);
2911 /* Label, RD, Prefix write. */
2912 stream_putc(s, p->prefixlen + 88);
2913 stream_put(s, label, BGP_LABEL_BYTES);
2914 stream_put(s, prd->val, 8);
2915 stream_put(s, &p->u.prefix, PSIZE(p->prefixlen));
2916 } else if (afi == AFI_L2VPN && safi == SAFI_EVPN) {
2917 /* EVPN prefix - contents depend on type */
2918 bgp_evpn_encode_prefix(s, p, prd, label, num_labels, attr,
2919 addpath_encode, addpath_tx_id);
2920 } else if (safi == SAFI_LABELED_UNICAST) {
2921 /* Prefix write with label. */
2922 stream_put_labeled_prefix(s, p, label);
2923 } else if (safi == SAFI_FLOWSPEC) {
2924 if (PSIZE (p->prefixlen)+2 < FLOWSPEC_NLRI_SIZELIMIT)
2925 stream_putc(s, PSIZE (p->prefixlen)+2);
2926 else
2927 stream_putw(s, (PSIZE (p->prefixlen)+2)|(0xf<<12));
2928 stream_putc(s, 2);/* Filter type */
2929 stream_putc(s, p->prefixlen);/* Prefix length */
2930 stream_put(s, &p->u.prefix, PSIZE (p->prefixlen));
2931 } else
2932 stream_put_prefix_addpath(s, p, addpath_encode, addpath_tx_id);
2933 }
2934
2935 size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi, struct prefix *p)
2936 {
2937 int size = PSIZE(p->prefixlen);
2938 if (safi == SAFI_MPLS_VPN)
2939 size += 88;
2940 else if (afi == AFI_L2VPN && safi == SAFI_EVPN)
2941 size += 232; // TODO: Maximum possible for type-2, type-3 and
2942 // type-5
2943 return size;
2944 }
2945
2946 /*
2947 * Encodes the tunnel encapsulation attribute,
2948 * and with ENABLE_BGP_VNC the VNC attribute which uses
2949 * almost the same TLV format
2950 */
2951 static void bgp_packet_mpattr_tea(struct bgp *bgp, struct peer *peer,
2952 struct stream *s, struct attr *attr,
2953 uint8_t attrtype)
2954 {
2955 unsigned int attrlenfield = 0;
2956 unsigned int attrhdrlen = 0;
2957 struct bgp_attr_encap_subtlv *subtlvs;
2958 struct bgp_attr_encap_subtlv *st;
2959 const char *attrname;
2960
2961 if (!attr || (attrtype == BGP_ATTR_ENCAP
2962 && (!attr->encap_tunneltype
2963 || attr->encap_tunneltype == BGP_ENCAP_TYPE_MPLS)))
2964 return;
2965
2966 switch (attrtype) {
2967 case BGP_ATTR_ENCAP:
2968 attrname = "Tunnel Encap";
2969 subtlvs = attr->encap_subtlvs;
2970 if (subtlvs == NULL) /* nothing to do */
2971 return;
2972 /*
2973 * The tunnel encap attr has an "outer" tlv.
2974 * T = tunneltype,
2975 * L = total length of subtlvs,
2976 * V = concatenated subtlvs.
2977 */
2978 attrlenfield = 2 + 2; /* T + L */
2979 attrhdrlen = 1 + 1; /* subTLV T + L */
2980 break;
2981
2982 #if ENABLE_BGP_VNC_ATTR
2983 case BGP_ATTR_VNC:
2984 attrname = "VNC";
2985 subtlvs = attr->vnc_subtlvs;
2986 if (subtlvs == NULL) /* nothing to do */
2987 return;
2988 attrlenfield = 0; /* no outer T + L */
2989 attrhdrlen = 2 + 2; /* subTLV T + L */
2990 break;
2991 #endif
2992
2993 default:
2994 assert(0);
2995 }
2996
2997 /* compute attr length */
2998 for (st = subtlvs; st; st = st->next) {
2999 attrlenfield += (attrhdrlen + st->length);
3000 }
3001
3002 if (attrlenfield > 0xffff) {
3003 zlog_info("%s attribute is too long (length=%d), can't send it",
3004 attrname, attrlenfield);
3005 return;
3006 }
3007
3008 if (attrlenfield > 0xff) {
3009 /* 2-octet length field */
3010 stream_putc(s,
3011 BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL
3012 | BGP_ATTR_FLAG_EXTLEN);
3013 stream_putc(s, attrtype);
3014 stream_putw(s, attrlenfield & 0xffff);
3015 } else {
3016 /* 1-octet length field */
3017 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL);
3018 stream_putc(s, attrtype);
3019 stream_putc(s, attrlenfield & 0xff);
3020 }
3021
3022 if (attrtype == BGP_ATTR_ENCAP) {
3023 /* write outer T+L */
3024 stream_putw(s, attr->encap_tunneltype);
3025 stream_putw(s, attrlenfield - 4);
3026 }
3027
3028 /* write each sub-tlv */
3029 for (st = subtlvs; st; st = st->next) {
3030 if (attrtype == BGP_ATTR_ENCAP) {
3031 stream_putc(s, st->type);
3032 stream_putc(s, st->length);
3033 #if ENABLE_BGP_VNC
3034 } else {
3035 stream_putw(s, st->type);
3036 stream_putw(s, st->length);
3037 #endif
3038 }
3039 stream_put(s, st->value, st->length);
3040 }
3041 }
3042
3043 void bgp_packet_mpattr_end(struct stream *s, size_t sizep)
3044 {
3045 /* Set MP attribute length. Don't count the (2) bytes used to encode
3046 the attr length */
3047 stream_putw_at(s, sizep, (stream_get_endp(s) - sizep) - 2);
3048 }
3049
3050 static int bgp_append_local_as(struct peer *peer, afi_t afi, safi_t safi)
3051 {
3052 if (!BGP_AS_IS_PRIVATE(peer->local_as)
3053 || (BGP_AS_IS_PRIVATE(peer->local_as)
3054 && !CHECK_FLAG(peer->af_flags[afi][safi],
3055 PEER_FLAG_REMOVE_PRIVATE_AS)
3056 && !CHECK_FLAG(peer->af_flags[afi][safi],
3057 PEER_FLAG_REMOVE_PRIVATE_AS_ALL)
3058 && !CHECK_FLAG(peer->af_flags[afi][safi],
3059 PEER_FLAG_REMOVE_PRIVATE_AS_REPLACE)
3060 && !CHECK_FLAG(peer->af_flags[afi][safi],
3061 PEER_FLAG_REMOVE_PRIVATE_AS_ALL_REPLACE)))
3062 return 1;
3063 return 0;
3064 }
3065
3066 /* Make attribute packet. */
3067 bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
3068 struct stream *s, struct attr *attr,
3069 struct bpacket_attr_vec_arr *vecarr,
3070 struct prefix *p, afi_t afi, safi_t safi,
3071 struct peer *from, struct prefix_rd *prd,
3072 mpls_label_t *label, uint32_t num_labels,
3073 int addpath_encode, uint32_t addpath_tx_id)
3074 {
3075 size_t cp;
3076 size_t aspath_sizep;
3077 struct aspath *aspath;
3078 int send_as4_path = 0;
3079 int send_as4_aggregator = 0;
3080 int use32bit = (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)) ? 1 : 0;
3081
3082 if (!bgp)
3083 bgp = peer->bgp;
3084
3085 /* Remember current pointer. */
3086 cp = stream_get_endp(s);
3087
3088 if (p
3089 && !((afi == AFI_IP && safi == SAFI_UNICAST)
3090 && !peer_cap_enhe(peer, afi, safi))) {
3091 size_t mpattrlen_pos = 0;
3092
3093 mpattrlen_pos = bgp_packet_mpattr_start(s, peer, afi, safi,
3094 vecarr, attr);
3095 bgp_packet_mpattr_prefix(s, afi, safi, p, prd, label,
3096 num_labels, addpath_encode,
3097 addpath_tx_id, attr);
3098 bgp_packet_mpattr_end(s, mpattrlen_pos);
3099 }
3100
3101 /* Origin attribute. */
3102 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3103 stream_putc(s, BGP_ATTR_ORIGIN);
3104 stream_putc(s, 1);
3105 stream_putc(s, attr->origin);
3106
3107 /* AS path attribute. */
3108
3109 /* If remote-peer is EBGP */
3110 if (peer->sort == BGP_PEER_EBGP
3111 && (!CHECK_FLAG(peer->af_flags[afi][safi],
3112 PEER_FLAG_AS_PATH_UNCHANGED)
3113 || attr->aspath->segments == NULL)
3114 && (!CHECK_FLAG(peer->af_flags[afi][safi],
3115 PEER_FLAG_RSERVER_CLIENT))) {
3116 aspath = aspath_dup(attr->aspath);
3117
3118 /* Even though we may not be configured for confederations we
3119 * may have
3120 * RXed an AS_PATH with AS_CONFED_SEQUENCE or AS_CONFED_SET */
3121 aspath = aspath_delete_confed_seq(aspath);
3122
3123 if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION)) {
3124 /* Stuff our path CONFED_ID on the front */
3125 aspath = aspath_add_seq(aspath, bgp->confed_id);
3126 } else {
3127 if (peer->change_local_as) {
3128 /* If replace-as is specified, we only use the
3129 change_local_as when
3130 advertising routes. */
3131 if (!CHECK_FLAG(peer->flags,
3132 PEER_FLAG_LOCAL_AS_REPLACE_AS))
3133 if (bgp_append_local_as(peer, afi,
3134 safi))
3135 aspath = aspath_add_seq(
3136 aspath, peer->local_as);
3137 aspath = aspath_add_seq(aspath,
3138 peer->change_local_as);
3139 } else {
3140 aspath = aspath_add_seq(aspath, peer->local_as);
3141 }
3142 }
3143 } else if (peer->sort == BGP_PEER_CONFED) {
3144 /* A confed member, so we need to do the AS_CONFED_SEQUENCE
3145 * thing */
3146 aspath = aspath_dup(attr->aspath);
3147 aspath = aspath_add_confed_seq(aspath, peer->local_as);
3148 } else
3149 aspath = attr->aspath;
3150
3151 /* If peer is not AS4 capable, then:
3152 * - send the created AS_PATH out as AS4_PATH (optional, transitive),
3153 * but ensure that no AS_CONFED_SEQUENCE and AS_CONFED_SET path
3154 * segment
3155 * types are in it (i.e. exclude them if they are there)
3156 * AND do this only if there is at least one asnum > 65535 in the
3157 * path!
3158 * - send an AS_PATH out, but put 16Bit ASnums in it, not 32bit, and
3159 * change
3160 * all ASnums > 65535 to BGP_AS_TRANS
3161 */
3162
3163 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_EXTLEN);
3164 stream_putc(s, BGP_ATTR_AS_PATH);
3165 aspath_sizep = stream_get_endp(s);
3166 stream_putw(s, 0);
3167 stream_putw_at(s, aspath_sizep, aspath_put(s, aspath, use32bit));
3168
3169 /* OLD session may need NEW_AS_PATH sent, if there are 4-byte ASNs
3170 * in the path
3171 */
3172 if (!use32bit && aspath_has_as4(aspath))
3173 send_as4_path =
3174 1; /* we'll do this later, at the correct place */
3175
3176 /* Nexthop attribute. */
3177 if (afi == AFI_IP && safi == SAFI_UNICAST
3178 && !peer_cap_enhe(peer, afi, safi)) {
3179 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP)) {
3180 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3181 stream_putc(s, BGP_ATTR_NEXT_HOP);
3182 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s,
3183 attr);
3184 stream_putc(s, 4);
3185 stream_put_ipv4(s, attr->nexthop.s_addr);
3186 } else if (peer_cap_enhe(from, afi, safi)) {
3187 /*
3188 * Likely this is the case when an IPv4 prefix was
3189 * received with
3190 * Extended Next-hop capability and now being advertised
3191 * to
3192 * non-ENHE peers.
3193 * Setting the mandatory (ipv4) next-hop attribute here
3194 * to enable
3195 * implicit next-hop self with correct (ipv4 address
3196 * family).
3197 */
3198 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3199 stream_putc(s, BGP_ATTR_NEXT_HOP);
3200 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s,
3201 NULL);
3202 stream_putc(s, 4);
3203 stream_put_ipv4(s, 0);
3204 }
3205 }
3206
3207 /* MED attribute. */
3208 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC)
3209 || bgp->maxmed_active) {
3210 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3211 stream_putc(s, BGP_ATTR_MULTI_EXIT_DISC);
3212 stream_putc(s, 4);
3213 stream_putl(s, (bgp->maxmed_active ? bgp->maxmed_value
3214 : attr->med));
3215 }
3216
3217 /* Local preference. */
3218 if (peer->sort == BGP_PEER_IBGP || peer->sort == BGP_PEER_CONFED) {
3219 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3220 stream_putc(s, BGP_ATTR_LOCAL_PREF);
3221 stream_putc(s, 4);
3222 stream_putl(s, attr->local_pref);
3223 }
3224
3225 /* Atomic aggregate. */
3226 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE)) {
3227 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3228 stream_putc(s, BGP_ATTR_ATOMIC_AGGREGATE);
3229 stream_putc(s, 0);
3230 }
3231
3232 /* Aggregator. */
3233 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR)) {
3234 /* Common to BGP_ATTR_AGGREGATOR, regardless of ASN size */
3235 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3236 stream_putc(s, BGP_ATTR_AGGREGATOR);
3237
3238 if (use32bit) {
3239 /* AS4 capable peer */
3240 stream_putc(s, 8);
3241 stream_putl(s, attr->aggregator_as);
3242 } else {
3243 /* 2-byte AS peer */
3244 stream_putc(s, 6);
3245
3246 /* Is ASN representable in 2-bytes? Or must AS_TRANS be
3247 * used? */
3248 if (attr->aggregator_as > 65535) {
3249 stream_putw(s, BGP_AS_TRANS);
3250
3251 /* we have to send AS4_AGGREGATOR, too.
3252 * we'll do that later in order to send
3253 * attributes in ascending
3254 * order.
3255 */
3256 send_as4_aggregator = 1;
3257 } else
3258 stream_putw(s, (uint16_t)attr->aggregator_as);
3259 }
3260 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3261 }
3262
3263 /* Community attribute. */
3264 if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_SEND_COMMUNITY)
3265 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES))) {
3266 if (attr->community->size * 4 > 255) {
3267 stream_putc(s,
3268 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3269 | BGP_ATTR_FLAG_EXTLEN);
3270 stream_putc(s, BGP_ATTR_COMMUNITIES);
3271 stream_putw(s, attr->community->size * 4);
3272 } else {
3273 stream_putc(s,
3274 BGP_ATTR_FLAG_OPTIONAL
3275 | BGP_ATTR_FLAG_TRANS);
3276 stream_putc(s, BGP_ATTR_COMMUNITIES);
3277 stream_putc(s, attr->community->size * 4);
3278 }
3279 stream_put(s, attr->community->val, attr->community->size * 4);
3280 }
3281
3282 /*
3283 * Large Community attribute.
3284 */
3285 if (CHECK_FLAG(peer->af_flags[afi][safi],
3286 PEER_FLAG_SEND_LARGE_COMMUNITY)
3287 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES))) {
3288 if (lcom_length(attr->lcommunity) > 255) {
3289 stream_putc(s,
3290 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3291 | BGP_ATTR_FLAG_EXTLEN);
3292 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3293 stream_putw(s, lcom_length(attr->lcommunity));
3294 } else {
3295 stream_putc(s,
3296 BGP_ATTR_FLAG_OPTIONAL
3297 | BGP_ATTR_FLAG_TRANS);
3298 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3299 stream_putc(s, lcom_length(attr->lcommunity));
3300 }
3301 stream_put(s, attr->lcommunity->val,
3302 lcom_length(attr->lcommunity));
3303 }
3304
3305 /* Route Reflector. */
3306 if (peer->sort == BGP_PEER_IBGP && from
3307 && from->sort == BGP_PEER_IBGP) {
3308 /* Originator ID. */
3309 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3310 stream_putc(s, BGP_ATTR_ORIGINATOR_ID);
3311 stream_putc(s, 4);
3312
3313 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID))
3314 stream_put_in_addr(s, &attr->originator_id);
3315 else
3316 stream_put_in_addr(s, &from->remote_id);
3317
3318 /* Cluster list. */
3319 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3320 stream_putc(s, BGP_ATTR_CLUSTER_LIST);
3321
3322 if (attr->cluster) {
3323 stream_putc(s, attr->cluster->length + 4);
3324 /* If this peer configuration's parent BGP has
3325 * cluster_id. */
3326 if (bgp->config & BGP_CONFIG_CLUSTER_ID)
3327 stream_put_in_addr(s, &bgp->cluster_id);
3328 else
3329 stream_put_in_addr(s, &bgp->router_id);
3330 stream_put(s, attr->cluster->list,
3331 attr->cluster->length);
3332 } else {
3333 stream_putc(s, 4);
3334 /* If this peer configuration's parent BGP has
3335 * cluster_id. */
3336 if (bgp->config & BGP_CONFIG_CLUSTER_ID)
3337 stream_put_in_addr(s, &bgp->cluster_id);
3338 else
3339 stream_put_in_addr(s, &bgp->router_id);
3340 }
3341 }
3342
3343 /* Extended Communities attribute. */
3344 if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_SEND_EXT_COMMUNITY)
3345 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES))) {
3346 if (peer->sort == BGP_PEER_IBGP
3347 || peer->sort == BGP_PEER_CONFED) {
3348 if (attr->ecommunity->size * 8 > 255) {
3349 stream_putc(s,
3350 BGP_ATTR_FLAG_OPTIONAL
3351 | BGP_ATTR_FLAG_TRANS
3352 | BGP_ATTR_FLAG_EXTLEN);
3353 stream_putc(s, BGP_ATTR_EXT_COMMUNITIES);
3354 stream_putw(s, attr->ecommunity->size * 8);
3355 } else {
3356 stream_putc(s,
3357 BGP_ATTR_FLAG_OPTIONAL
3358 | BGP_ATTR_FLAG_TRANS);
3359 stream_putc(s, BGP_ATTR_EXT_COMMUNITIES);
3360 stream_putc(s, attr->ecommunity->size * 8);
3361 }
3362 stream_put(s, attr->ecommunity->val,
3363 attr->ecommunity->size * 8);
3364 } else {
3365 uint8_t *pnt;
3366 int tbit;
3367 int ecom_tr_size = 0;
3368 int i;
3369
3370 for (i = 0; i < attr->ecommunity->size; i++) {
3371 pnt = attr->ecommunity->val + (i * 8);
3372 tbit = *pnt;
3373
3374 if (CHECK_FLAG(tbit,
3375 ECOMMUNITY_FLAG_NON_TRANSITIVE))
3376 continue;
3377
3378 ecom_tr_size++;
3379 }
3380
3381 if (ecom_tr_size) {
3382 if (ecom_tr_size * 8 > 255) {
3383 stream_putc(
3384 s,
3385 BGP_ATTR_FLAG_OPTIONAL
3386 | BGP_ATTR_FLAG_TRANS
3387 | BGP_ATTR_FLAG_EXTLEN);
3388 stream_putc(s,
3389 BGP_ATTR_EXT_COMMUNITIES);
3390 stream_putw(s, ecom_tr_size * 8);
3391 } else {
3392 stream_putc(
3393 s,
3394 BGP_ATTR_FLAG_OPTIONAL
3395 | BGP_ATTR_FLAG_TRANS);
3396 stream_putc(s,
3397 BGP_ATTR_EXT_COMMUNITIES);
3398 stream_putc(s, ecom_tr_size * 8);
3399 }
3400
3401 for (i = 0; i < attr->ecommunity->size; i++) {
3402 pnt = attr->ecommunity->val + (i * 8);
3403 tbit = *pnt;
3404
3405 if (CHECK_FLAG(
3406 tbit,
3407 ECOMMUNITY_FLAG_NON_TRANSITIVE))
3408 continue;
3409
3410 stream_put(s, pnt, 8);
3411 }
3412 }
3413 }
3414 }
3415
3416 /* Label index attribute. */
3417 if (safi == SAFI_LABELED_UNICAST) {
3418 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID)) {
3419 uint32_t label_index;
3420
3421 label_index = attr->label_index;
3422
3423 if (label_index != BGP_INVALID_LABEL_INDEX) {
3424 stream_putc(s,
3425 BGP_ATTR_FLAG_OPTIONAL
3426 | BGP_ATTR_FLAG_TRANS);
3427 stream_putc(s, BGP_ATTR_PREFIX_SID);
3428 stream_putc(s, 10);
3429 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX);
3430 stream_putw(s,
3431 BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
3432 stream_putc(s, 0); // reserved
3433 stream_putw(s, 0); // flags
3434 stream_putl(s, label_index);
3435 }
3436 }
3437 }
3438
3439 if (send_as4_path) {
3440 /* If the peer is NOT As4 capable, AND */
3441 /* there are ASnums > 65535 in path THEN
3442 * give out AS4_PATH */
3443
3444 /* Get rid of all AS_CONFED_SEQUENCE and AS_CONFED_SET
3445 * path segments!
3446 * Hm, I wonder... confederation things *should* only be at
3447 * the beginning of an aspath, right? Then we should use
3448 * aspath_delete_confed_seq for this, because it is already
3449 * there! (JK)
3450 * Folks, talk to me: what is reasonable here!?
3451 */
3452 aspath = aspath_delete_confed_seq(aspath);
3453
3454 stream_putc(s,
3455 BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL
3456 | BGP_ATTR_FLAG_EXTLEN);
3457 stream_putc(s, BGP_ATTR_AS4_PATH);
3458 aspath_sizep = stream_get_endp(s);
3459 stream_putw(s, 0);
3460 stream_putw_at(s, aspath_sizep, aspath_put(s, aspath, 1));
3461 }
3462
3463 if (aspath != attr->aspath)
3464 aspath_free(aspath);
3465
3466 if (send_as4_aggregator) {
3467 /* send AS4_AGGREGATOR, at this place */
3468 /* this section of code moved here in order to ensure the
3469 * correct
3470 * *ascending* order of attributes
3471 */
3472 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3473 stream_putc(s, BGP_ATTR_AS4_AGGREGATOR);
3474 stream_putc(s, 8);
3475 stream_putl(s, attr->aggregator_as);
3476 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3477 }
3478
3479 if (((afi == AFI_IP || afi == AFI_IP6)
3480 && (safi == SAFI_ENCAP || safi == SAFI_MPLS_VPN))
3481 || (afi == AFI_L2VPN && safi == SAFI_EVPN)) {
3482 /* Tunnel Encap attribute */
3483 bgp_packet_mpattr_tea(bgp, peer, s, attr, BGP_ATTR_ENCAP);
3484
3485 #if ENABLE_BGP_VNC_ATTR
3486 /* VNC attribute */
3487 bgp_packet_mpattr_tea(bgp, peer, s, attr, BGP_ATTR_VNC);
3488 #endif
3489 }
3490
3491 /* PMSI Tunnel */
3492 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL)) {
3493 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3494 stream_putc(s, BGP_ATTR_PMSI_TUNNEL);
3495 stream_putc(s, 9); // Length
3496 stream_putc(s, 0); // Flags
3497 stream_putc(s, attr->pmsi_tnl_type);
3498 stream_put(s, &(attr->label),
3499 BGP_LABEL_BYTES); // MPLS Label / VXLAN VNI
3500 stream_put_ipv4(s, attr->nexthop.s_addr);
3501 // Unicast tunnel endpoint IP address
3502 }
3503
3504 /* Unknown transit attribute. */
3505 if (attr->transit)
3506 stream_put(s, attr->transit->val, attr->transit->length);
3507
3508 /* Return total size of attribute. */
3509 return stream_get_endp(s) - cp;
3510 }
3511
3512 size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi, safi_t safi)
3513 {
3514 unsigned long attrlen_pnt;
3515 iana_afi_t pkt_afi;
3516 iana_safi_t pkt_safi;
3517
3518 /* Set extended bit always to encode the attribute length as 2 bytes */
3519 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_EXTLEN);
3520 stream_putc(s, BGP_ATTR_MP_UNREACH_NLRI);
3521
3522 attrlen_pnt = stream_get_endp(s);
3523 stream_putw(s, 0); /* Length of this attribute. */
3524
3525 /* Convert AFI, SAFI to values for packet. */
3526 bgp_map_afi_safi_int2iana(afi, safi, &pkt_afi, &pkt_safi);
3527
3528 stream_putw(s, pkt_afi);
3529 stream_putc(s, pkt_safi);
3530
3531 return attrlen_pnt;
3532 }
3533
3534 void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p, afi_t afi,
3535 safi_t safi, struct prefix_rd *prd,
3536 mpls_label_t *label, uint32_t num_labels,
3537 int addpath_encode, uint32_t addpath_tx_id,
3538 struct attr *attr)
3539 {
3540 uint8_t wlabel[3] = {0x80, 0x00, 0x00};
3541
3542 if (safi == SAFI_LABELED_UNICAST) {
3543 label = (mpls_label_t *)wlabel;
3544 num_labels = 1;
3545 }
3546
3547 bgp_packet_mpattr_prefix(s, afi, safi, p, prd, label, num_labels,
3548 addpath_encode, addpath_tx_id, attr);
3549 }
3550
3551 void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt)
3552 {
3553 bgp_packet_mpattr_end(s, attrlen_pnt);
3554 }
3555
3556 /* Initialization of attribute. */
3557 void bgp_attr_init(void)
3558 {
3559 aspath_init();
3560 attrhash_init();
3561 community_init();
3562 ecommunity_init();
3563 lcommunity_init();
3564 cluster_init();
3565 transit_init();
3566 encap_init();
3567 }
3568
3569 void bgp_attr_finish(void)
3570 {
3571 aspath_finish();
3572 attrhash_finish();
3573 community_finish();
3574 ecommunity_finish();
3575 lcommunity_finish();
3576 cluster_finish();
3577 transit_finish();
3578 encap_finish();
3579 }
3580
3581 /* Make attribute packet. */
3582 void bgp_dump_routes_attr(struct stream *s, struct attr *attr,
3583 struct prefix *prefix)
3584 {
3585 unsigned long cp;
3586 unsigned long len;
3587 size_t aspath_lenp;
3588 struct aspath *aspath;
3589 int addpath_encode = 0;
3590 uint32_t addpath_tx_id = 0;
3591
3592 /* Remember current pointer. */
3593 cp = stream_get_endp(s);
3594
3595 /* Place holder of length. */
3596 stream_putw(s, 0);
3597
3598 /* Origin attribute. */
3599 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3600 stream_putc(s, BGP_ATTR_ORIGIN);
3601 stream_putc(s, 1);
3602 stream_putc(s, attr->origin);
3603
3604 aspath = attr->aspath;
3605
3606 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_EXTLEN);
3607 stream_putc(s, BGP_ATTR_AS_PATH);
3608 aspath_lenp = stream_get_endp(s);
3609 stream_putw(s, 0);
3610
3611 stream_putw_at(s, aspath_lenp, aspath_put(s, aspath, 1));
3612
3613 /* Nexthop attribute. */
3614 /* If it's an IPv6 prefix, don't dump the IPv4 nexthop to save space */
3615 if (prefix != NULL && prefix->family != AF_INET6) {
3616 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3617 stream_putc(s, BGP_ATTR_NEXT_HOP);
3618 stream_putc(s, 4);
3619 stream_put_ipv4(s, attr->nexthop.s_addr);
3620 }
3621
3622 /* MED attribute. */
3623 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC)) {
3624 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3625 stream_putc(s, BGP_ATTR_MULTI_EXIT_DISC);
3626 stream_putc(s, 4);
3627 stream_putl(s, attr->med);
3628 }
3629
3630 /* Local preference. */
3631 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF)) {
3632 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3633 stream_putc(s, BGP_ATTR_LOCAL_PREF);
3634 stream_putc(s, 4);
3635 stream_putl(s, attr->local_pref);
3636 }
3637
3638 /* Atomic aggregate. */
3639 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE)) {
3640 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3641 stream_putc(s, BGP_ATTR_ATOMIC_AGGREGATE);
3642 stream_putc(s, 0);
3643 }
3644
3645 /* Aggregator. */
3646 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR)) {
3647 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3648 stream_putc(s, BGP_ATTR_AGGREGATOR);
3649 stream_putc(s, 8);
3650 stream_putl(s, attr->aggregator_as);
3651 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3652 }
3653
3654 /* Community attribute. */
3655 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES)) {
3656 if (attr->community->size * 4 > 255) {
3657 stream_putc(s,
3658 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3659 | BGP_ATTR_FLAG_EXTLEN);
3660 stream_putc(s, BGP_ATTR_COMMUNITIES);
3661 stream_putw(s, attr->community->size * 4);
3662 } else {
3663 stream_putc(s,
3664 BGP_ATTR_FLAG_OPTIONAL
3665 | BGP_ATTR_FLAG_TRANS);
3666 stream_putc(s, BGP_ATTR_COMMUNITIES);
3667 stream_putc(s, attr->community->size * 4);
3668 }
3669 stream_put(s, attr->community->val, attr->community->size * 4);
3670 }
3671
3672 /* Large Community attribute. */
3673 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES)) {
3674 if (lcom_length(attr->lcommunity) > 255) {
3675 stream_putc(s,
3676 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3677 | BGP_ATTR_FLAG_EXTLEN);
3678 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3679 stream_putw(s, lcom_length(attr->lcommunity));
3680 } else {
3681 stream_putc(s,
3682 BGP_ATTR_FLAG_OPTIONAL
3683 | BGP_ATTR_FLAG_TRANS);
3684 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3685 stream_putc(s, lcom_length(attr->lcommunity));
3686 }
3687
3688 stream_put(s, attr->lcommunity->val,
3689 lcom_length(attr->lcommunity));
3690 }
3691
3692 /* Add a MP_NLRI attribute to dump the IPv6 next hop */
3693 if (prefix != NULL && prefix->family == AF_INET6
3694 && (attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL
3695 || attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)) {
3696 int sizep;
3697
3698 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3699 stream_putc(s, BGP_ATTR_MP_REACH_NLRI);
3700 sizep = stream_get_endp(s);
3701
3702 /* MP header */
3703 stream_putc(s, 0); /* Marker: Attribute length. */
3704 stream_putw(s, AFI_IP6); /* AFI */
3705 stream_putc(s, SAFI_UNICAST); /* SAFI */
3706
3707 /* Next hop */
3708 stream_putc(s, attr->mp_nexthop_len);
3709 stream_put(s, &attr->mp_nexthop_global, IPV6_MAX_BYTELEN);
3710 if (attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)
3711 stream_put(s, &attr->mp_nexthop_local,
3712 IPV6_MAX_BYTELEN);
3713
3714 /* SNPA */
3715 stream_putc(s, 0);
3716
3717 /* Prefix */
3718 stream_put_prefix_addpath(s, prefix, addpath_encode,
3719 addpath_tx_id);
3720
3721 /* Set MP attribute length. */
3722 stream_putc_at(s, sizep, (stream_get_endp(s) - sizep) - 1);
3723 }
3724
3725 /* Prefix SID */
3726 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID)) {
3727 if (attr->label_index != BGP_INVALID_LABEL_INDEX) {
3728 stream_putc(s,
3729 BGP_ATTR_FLAG_OPTIONAL
3730 | BGP_ATTR_FLAG_TRANS);
3731 stream_putc(s, BGP_ATTR_PREFIX_SID);
3732 stream_putc(s, 10);
3733 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX);
3734 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
3735 stream_putc(s, 0); // reserved
3736 stream_putw(s, 0); // flags
3737 stream_putl(s, attr->label_index);
3738 }
3739 }
3740
3741 /* Return total size of attribute. */
3742 len = stream_get_endp(s) - cp - 2;
3743 stream_putw_at(s, cp, len);
3744 }
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