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Merge pull request #2814 from qlyoung/fix-ospf6d-lsa-uaf-test
[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
58 /* Attribute strings for logging. */
59 static const struct message attr_str[] = {
60 {BGP_ATTR_ORIGIN, "ORIGIN"},
61 {BGP_ATTR_AS_PATH, "AS_PATH"},
62 {BGP_ATTR_NEXT_HOP, "NEXT_HOP"},
63 {BGP_ATTR_MULTI_EXIT_DISC, "MULTI_EXIT_DISC"},
64 {BGP_ATTR_LOCAL_PREF, "LOCAL_PREF"},
65 {BGP_ATTR_ATOMIC_AGGREGATE, "ATOMIC_AGGREGATE"},
66 {BGP_ATTR_AGGREGATOR, "AGGREGATOR"},
67 {BGP_ATTR_COMMUNITIES, "COMMUNITY"},
68 {BGP_ATTR_ORIGINATOR_ID, "ORIGINATOR_ID"},
69 {BGP_ATTR_CLUSTER_LIST, "CLUSTER_LIST"},
70 {BGP_ATTR_DPA, "DPA"},
71 {BGP_ATTR_ADVERTISER, "ADVERTISER"},
72 {BGP_ATTR_RCID_PATH, "RCID_PATH"},
73 {BGP_ATTR_MP_REACH_NLRI, "MP_REACH_NLRI"},
74 {BGP_ATTR_MP_UNREACH_NLRI, "MP_UNREACH_NLRI"},
75 {BGP_ATTR_EXT_COMMUNITIES, "EXT_COMMUNITIES"},
76 {BGP_ATTR_AS4_PATH, "AS4_PATH"},
77 {BGP_ATTR_AS4_AGGREGATOR, "AS4_AGGREGATOR"},
78 {BGP_ATTR_AS_PATHLIMIT, "AS_PATHLIMIT"},
79 {BGP_ATTR_PMSI_TUNNEL, "PMSI_TUNNEL_ATTRIBUTE"},
80 {BGP_ATTR_ENCAP, "ENCAP"},
81 #if ENABLE_BGP_VNC
82 {BGP_ATTR_VNC, "VNC"},
83 #endif
84 {BGP_ATTR_LARGE_COMMUNITIES, "LARGE_COMMUNITY"},
85 {BGP_ATTR_PREFIX_SID, "PREFIX_SID"},
86 {0}};
87
88 static const struct message attr_flag_str[] = {
89 {BGP_ATTR_FLAG_OPTIONAL, "Optional"},
90 {BGP_ATTR_FLAG_TRANS, "Transitive"},
91 {BGP_ATTR_FLAG_PARTIAL, "Partial"},
92 /* bgp_attr_flags_diagnose() relies on this bit being last in
93 this list */
94 {BGP_ATTR_FLAG_EXTLEN, "Extended Length"},
95 {0}};
96
97 static struct hash *cluster_hash;
98
99 static void *cluster_hash_alloc(void *p)
100 {
101 const struct cluster_list *val = (const struct cluster_list *)p;
102 struct cluster_list *cluster;
103
104 cluster = XMALLOC(MTYPE_CLUSTER, sizeof(struct cluster_list));
105 cluster->length = val->length;
106
107 if (cluster->length) {
108 cluster->list = XMALLOC(MTYPE_CLUSTER_VAL, val->length);
109 memcpy(cluster->list, val->list, val->length);
110 } else
111 cluster->list = NULL;
112
113 cluster->refcnt = 0;
114
115 return cluster;
116 }
117
118 /* Cluster list related functions. */
119 static struct cluster_list *cluster_parse(struct in_addr *pnt, int length)
120 {
121 struct cluster_list tmp;
122 struct cluster_list *cluster;
123
124 tmp.length = length;
125 tmp.list = pnt;
126
127 cluster = hash_get(cluster_hash, &tmp, cluster_hash_alloc);
128 cluster->refcnt++;
129 return cluster;
130 }
131
132 int cluster_loop_check(struct cluster_list *cluster, struct in_addr originator)
133 {
134 int i;
135
136 for (i = 0; i < cluster->length / 4; i++)
137 if (cluster->list[i].s_addr == originator.s_addr)
138 return 1;
139 return 0;
140 }
141
142 static unsigned int cluster_hash_key_make(void *p)
143 {
144 const struct cluster_list *cluster = p;
145
146 return jhash(cluster->list, cluster->length, 0);
147 }
148
149 static int cluster_hash_cmp(const void *p1, const void *p2)
150 {
151 const struct cluster_list *cluster1 = p1;
152 const struct cluster_list *cluster2 = p2;
153
154 return (cluster1->length == cluster2->length
155 && memcmp(cluster1->list, cluster2->list, cluster1->length)
156 == 0);
157 }
158
159 static void cluster_free(struct cluster_list *cluster)
160 {
161 if (cluster->list)
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(struct bgp_attr_encap_subtlv *h1,
264 struct bgp_attr_encap_subtlv *h2)
265 {
266 struct bgp_attr_encap_subtlv *p;
267 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 int encap_hash_cmp(const void *p1, const void *p2)
359 {
360 return encap_same((struct bgp_attr_encap_subtlv *)p1,
361 (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 overlay_index));
396 }
397
398 /* Unknown transit attribute. */
399 static struct hash *transit_hash;
400
401 static void transit_free(struct transit *transit)
402 {
403 if (transit->val)
404 XFREE(MTYPE_TRANSIT_VAL, transit->val);
405 XFREE(MTYPE_TRANSIT, transit);
406 }
407
408 static void *transit_hash_alloc(void *p)
409 {
410 /* Transit structure is already allocated. */
411 return p;
412 }
413
414 static struct transit *transit_intern(struct transit *transit)
415 {
416 struct transit *find;
417
418 find = hash_get(transit_hash, transit, transit_hash_alloc);
419 if (find != transit)
420 transit_free(transit);
421 find->refcnt++;
422
423 return find;
424 }
425
426 void transit_unintern(struct transit *transit)
427 {
428 if (transit->refcnt)
429 transit->refcnt--;
430
431 if (transit->refcnt == 0) {
432 hash_release(transit_hash, transit);
433 transit_free(transit);
434 }
435 }
436
437 static unsigned int transit_hash_key_make(void *p)
438 {
439 const struct transit *transit = p;
440
441 return jhash(transit->val, transit->length, 0);
442 }
443
444 static int transit_hash_cmp(const void *p1, const void *p2)
445 {
446 const struct transit *transit1 = p1;
447 const struct transit *transit2 = p2;
448
449 return (transit1->length == transit2->length
450 && memcmp(transit1->val, transit2->val, transit1->length) == 0);
451 }
452
453 static void transit_init(void)
454 {
455 transit_hash = hash_create(transit_hash_key_make, transit_hash_cmp,
456 "BGP Transit Hash");
457 }
458
459 static void transit_finish(void)
460 {
461 hash_clean(transit_hash, (void (*)(void *))transit_free);
462 hash_free(transit_hash);
463 transit_hash = NULL;
464 }
465
466 /* Attribute hash routines. */
467 static struct hash *attrhash;
468
469 /* Shallow copy of an attribute
470 * Though, not so shallow that it doesn't copy the contents
471 * of the attr_extra pointed to by 'extra'
472 */
473 void bgp_attr_dup(struct attr *new, struct attr *orig)
474 {
475 *new = *orig;
476 }
477
478 unsigned long int attr_count(void)
479 {
480 return attrhash->count;
481 }
482
483 unsigned long int attr_unknown_count(void)
484 {
485 return transit_hash->count;
486 }
487
488 unsigned int attrhash_key_make(void *p)
489 {
490 const struct attr *attr = (struct attr *)p;
491 uint32_t key = 0;
492 #define MIX(val) key = jhash_1word(val, key)
493 #define MIX3(a, b, c) key = jhash_3words((a), (b), (c), key)
494
495 MIX3(attr->origin, attr->nexthop.s_addr, attr->med);
496 MIX3(attr->local_pref, attr->aggregator_as,
497 attr->aggregator_addr.s_addr);
498 MIX3(attr->weight, attr->mp_nexthop_global_in.s_addr,
499 attr->originator_id.s_addr);
500 MIX3(attr->tag, attr->label, attr->label_index);
501
502 if (attr->aspath)
503 MIX(aspath_key_make(attr->aspath));
504 if (attr->community)
505 MIX(community_hash_make(attr->community));
506
507 if (attr->lcommunity)
508 MIX(lcommunity_hash_make(attr->lcommunity));
509 if (attr->ecommunity)
510 MIX(ecommunity_hash_make(attr->ecommunity));
511 if (attr->cluster)
512 MIX(cluster_hash_key_make(attr->cluster));
513 if (attr->transit)
514 MIX(transit_hash_key_make(attr->transit));
515 if (attr->encap_subtlvs)
516 MIX(encap_hash_key_make(attr->encap_subtlvs));
517 #if ENABLE_BGP_VNC
518 if (attr->vnc_subtlvs)
519 MIX(encap_hash_key_make(attr->vnc_subtlvs));
520 #endif
521 MIX(attr->mp_nexthop_len);
522 key = jhash(attr->mp_nexthop_global.s6_addr, IPV6_MAX_BYTELEN, key);
523 key = jhash(attr->mp_nexthop_local.s6_addr, IPV6_MAX_BYTELEN, key);
524 MIX(attr->nh_ifindex);
525 MIX(attr->nh_lla_ifindex);
526
527 return key;
528 }
529
530 int attrhash_cmp(const void *p1, const void *p2)
531 {
532 const struct attr *attr1 = p1;
533 const struct attr *attr2 = p2;
534
535 if (attr1->flag == attr2->flag && attr1->origin == attr2->origin
536 && attr1->nexthop.s_addr == attr2->nexthop.s_addr
537 && attr1->aspath == attr2->aspath
538 && attr1->community == attr2->community && attr1->med == attr2->med
539 && attr1->local_pref == attr2->local_pref
540 && attr1->rmap_change_flags == attr2->rmap_change_flags) {
541 if (attr1->aggregator_as == attr2->aggregator_as
542 && attr1->aggregator_addr.s_addr
543 == attr2->aggregator_addr.s_addr
544 && attr1->weight == attr2->weight
545 && attr1->tag == attr2->tag
546 && attr1->label_index == attr2->label_index
547 && attr1->mp_nexthop_len == attr2->mp_nexthop_len
548 && attr1->ecommunity == attr2->ecommunity
549 && attr1->lcommunity == attr2->lcommunity
550 && attr1->cluster == attr2->cluster
551 && attr1->transit == attr2->transit
552 && (attr1->encap_tunneltype == attr2->encap_tunneltype)
553 && encap_same(attr1->encap_subtlvs, attr2->encap_subtlvs)
554 #if ENABLE_BGP_VNC
555 && encap_same(attr1->vnc_subtlvs, attr2->vnc_subtlvs)
556 #endif
557 && IPV6_ADDR_SAME(&attr1->mp_nexthop_global,
558 &attr2->mp_nexthop_global)
559 && IPV6_ADDR_SAME(&attr1->mp_nexthop_local,
560 &attr2->mp_nexthop_local)
561 && IPV4_ADDR_SAME(&attr1->mp_nexthop_global_in,
562 &attr2->mp_nexthop_global_in)
563 && IPV4_ADDR_SAME(&attr1->originator_id,
564 &attr2->originator_id)
565 && overlay_index_same(attr1, attr2)
566 && attr1->nh_ifindex == attr2->nh_ifindex
567 && attr1->nh_lla_ifindex == attr2->nh_lla_ifindex)
568 return 1;
569 }
570
571 return 0;
572 }
573
574 static void attrhash_init(void)
575 {
576 attrhash =
577 hash_create(attrhash_key_make, attrhash_cmp, "BGP Attributes");
578 }
579
580 /*
581 * special for hash_clean below
582 */
583 static void attr_vfree(void *attr)
584 {
585 XFREE(MTYPE_ATTR, attr);
586 }
587
588 static void attrhash_finish(void)
589 {
590 hash_clean(attrhash, attr_vfree);
591 hash_free(attrhash);
592 attrhash = NULL;
593 }
594
595 static void attr_show_all_iterator(struct hash_backet *backet, struct vty *vty)
596 {
597 struct attr *attr = backet->data;
598
599 vty_out(vty, "attr[%ld] nexthop %s\n", attr->refcnt,
600 inet_ntoa(attr->nexthop));
601 vty_out(vty, "\tflags: %" PRIu64 " med: %u local_pref: %u origin: %u weight: %u label: %u\n",
602 attr->flag, attr->med, attr->local_pref, attr->origin,
603 attr->weight, attr->label);
604 }
605
606 void attr_show_all(struct vty *vty)
607 {
608 hash_iterate(attrhash, (void (*)(struct hash_backet *,
609 void *))attr_show_all_iterator,
610 vty);
611 }
612
613 static void *bgp_attr_hash_alloc(void *p)
614 {
615 struct attr *val = (struct attr *)p;
616 struct attr *attr;
617
618 attr = XMALLOC(MTYPE_ATTR, sizeof(struct attr));
619 *attr = *val;
620 if (val->encap_subtlvs) {
621 val->encap_subtlvs = NULL;
622 }
623 #if ENABLE_BGP_VNC
624 if (val->vnc_subtlvs) {
625 val->vnc_subtlvs = NULL;
626 }
627 #endif
628 attr->refcnt = 0;
629 return attr;
630 }
631
632 /* Internet argument attribute. */
633 struct attr *bgp_attr_intern(struct attr *attr)
634 {
635 struct attr *find;
636
637 /* Intern referenced strucutre. */
638 if (attr->aspath) {
639 if (!attr->aspath->refcnt)
640 attr->aspath = aspath_intern(attr->aspath);
641 else
642 attr->aspath->refcnt++;
643 }
644 if (attr->community) {
645 if (!attr->community->refcnt)
646 attr->community = community_intern(attr->community);
647 else
648 attr->community->refcnt++;
649 }
650
651 if (attr->ecommunity) {
652 if (!attr->ecommunity->refcnt)
653 attr->ecommunity = ecommunity_intern(attr->ecommunity);
654 else
655 attr->ecommunity->refcnt++;
656 }
657 if (attr->lcommunity) {
658 if (!attr->lcommunity->refcnt)
659 attr->lcommunity = lcommunity_intern(attr->lcommunity);
660 else
661 attr->lcommunity->refcnt++;
662 }
663 if (attr->cluster) {
664 if (!attr->cluster->refcnt)
665 attr->cluster = cluster_intern(attr->cluster);
666 else
667 attr->cluster->refcnt++;
668 }
669 if (attr->transit) {
670 if (!attr->transit->refcnt)
671 attr->transit = transit_intern(attr->transit);
672 else
673 attr->transit->refcnt++;
674 }
675 if (attr->encap_subtlvs) {
676 if (!attr->encap_subtlvs->refcnt)
677 attr->encap_subtlvs = encap_intern(attr->encap_subtlvs,
678 ENCAP_SUBTLV_TYPE);
679 else
680 attr->encap_subtlvs->refcnt++;
681 }
682 #if ENABLE_BGP_VNC
683 if (attr->vnc_subtlvs) {
684 if (!attr->vnc_subtlvs->refcnt)
685 attr->vnc_subtlvs = encap_intern(attr->vnc_subtlvs,
686 VNC_SUBTLV_TYPE);
687 else
688 attr->vnc_subtlvs->refcnt++;
689 }
690 #endif
691
692 /* At this point, attr only contains intern'd pointers. that means
693 * if we find it in attrhash, it has all the same pointers and we
694 * correctly updated the refcounts on these.
695 * If we don't find it, we need to allocate a one because in all
696 * cases this returns a new reference to a hashed attr, but the input
697 * wasn't on hash. */
698 find = (struct attr *)hash_get(attrhash, attr, bgp_attr_hash_alloc);
699 find->refcnt++;
700
701 return find;
702 }
703
704 /* Make network statement's attribute. */
705 struct attr *bgp_attr_default_set(struct attr *attr, uint8_t origin)
706 {
707 memset(attr, 0, sizeof(struct attr));
708
709 attr->origin = origin;
710 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
711 attr->aspath = aspath_empty();
712 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
713 attr->weight = BGP_ATTR_DEFAULT_WEIGHT;
714 attr->tag = 0;
715 attr->label_index = BGP_INVALID_LABEL_INDEX;
716 attr->label = MPLS_INVALID_LABEL;
717 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
718 attr->mp_nexthop_len = IPV6_MAX_BYTELEN;
719
720 return attr;
721 }
722
723 /* Create the attributes for an aggregate */
724 struct attr *bgp_attr_aggregate_intern(struct bgp *bgp, uint8_t origin,
725 struct aspath *aspath,
726 struct community *community, int as_set,
727 uint8_t atomic_aggregate)
728 {
729 struct attr attr;
730 struct attr *new;
731
732 memset(&attr, 0, sizeof(struct attr));
733
734 /* Origin attribute. */
735 attr.origin = origin;
736 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
737
738 /* AS path attribute. */
739 if (aspath)
740 attr.aspath = aspath_intern(aspath);
741 else
742 attr.aspath = aspath_empty();
743 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
744
745 /* Next hop attribute. */
746 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
747
748 if (community) {
749 uint32_t gshut = COMMUNITY_GSHUT;
750
751 /* If we are not shutting down ourselves and we are
752 * aggregating a route that contains the GSHUT community we
753 * need to remove that community when creating the aggregate */
754 if (!bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)
755 && community_include(community, gshut)) {
756 community_del_val(community, &gshut);
757 }
758
759 attr.community = community;
760 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
761 }
762
763 if (bgp_flag_check(bgp, BGP_FLAG_GRACEFUL_SHUTDOWN)) {
764 bgp_attr_add_gshut_community(&attr);
765 }
766
767 attr.label_index = BGP_INVALID_LABEL_INDEX;
768 attr.label = MPLS_INVALID_LABEL;
769 attr.weight = BGP_ATTR_DEFAULT_WEIGHT;
770 attr.mp_nexthop_len = IPV6_MAX_BYTELEN;
771 if (!as_set || atomic_aggregate)
772 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE);
773 attr.flag |= ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR);
774 if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION))
775 attr.aggregator_as = bgp->confed_id;
776 else
777 attr.aggregator_as = bgp->as;
778 attr.aggregator_addr = bgp->router_id;
779 attr.label_index = BGP_INVALID_LABEL_INDEX;
780 attr.label = MPLS_INVALID_LABEL;
781
782 new = bgp_attr_intern(&attr);
783
784 aspath_unintern(&new->aspath);
785 return new;
786 }
787
788 /* Unintern just the sub-components of the attr, but not the attr */
789 void bgp_attr_unintern_sub(struct attr *attr)
790 {
791 /* aspath refcount shoud be decrement. */
792 if (attr->aspath)
793 aspath_unintern(&attr->aspath);
794 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH));
795
796 if (attr->community)
797 community_unintern(&attr->community);
798 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES));
799
800 if (attr->ecommunity)
801 ecommunity_unintern(&attr->ecommunity);
802 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES));
803
804 if (attr->lcommunity)
805 lcommunity_unintern(&attr->lcommunity);
806 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES));
807
808 if (attr->cluster)
809 cluster_unintern(attr->cluster);
810 UNSET_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST));
811
812 if (attr->transit)
813 transit_unintern(attr->transit);
814
815 if (attr->encap_subtlvs)
816 encap_unintern(&attr->encap_subtlvs, ENCAP_SUBTLV_TYPE);
817
818 #if ENABLE_BGP_VNC
819 if (attr->vnc_subtlvs)
820 encap_unintern(&attr->vnc_subtlvs, VNC_SUBTLV_TYPE);
821 #endif
822 }
823
824 /*
825 * We have some show commands that let you experimentally
826 * apply a route-map. When we apply the route-map
827 * we are reseting values but not saving them for
828 * posterity via intern'ing( because route-maps don't
829 * do that) but at this point in time we need
830 * to compare the new attr to the old and if the
831 * routemap has changed it we need to, as Snoop Dog says,
832 * Drop it like it's hot
833 */
834 void bgp_attr_undup(struct attr *new, struct attr *old)
835 {
836 if (new->aspath != old->aspath)
837 aspath_free(new->aspath);
838
839 if (new->community != old->community)
840 community_free(new->community);
841
842 if (new->ecommunity != old->ecommunity)
843 ecommunity_free(&new->ecommunity);
844
845 if (new->lcommunity != old->lcommunity)
846 lcommunity_free(&new->lcommunity);
847 }
848
849 /* Free bgp attribute and aspath. */
850 void bgp_attr_unintern(struct attr **pattr)
851 {
852 struct attr *attr = *pattr;
853 struct attr *ret;
854 struct attr tmp;
855
856 /* Decrement attribute reference. */
857 attr->refcnt--;
858
859 tmp = *attr;
860
861 /* If reference becomes zero then free attribute object. */
862 if (attr->refcnt == 0) {
863 ret = hash_release(attrhash, attr);
864 assert(ret != NULL);
865 XFREE(MTYPE_ATTR, attr);
866 *pattr = NULL;
867 }
868
869 bgp_attr_unintern_sub(&tmp);
870 }
871
872 void bgp_attr_flush(struct attr *attr)
873 {
874 if (attr->aspath && !attr->aspath->refcnt) {
875 aspath_free(attr->aspath);
876 attr->aspath = NULL;
877 }
878 if (attr->community && !attr->community->refcnt) {
879 community_free(attr->community);
880 attr->community = NULL;
881 }
882
883 if (attr->ecommunity && !attr->ecommunity->refcnt)
884 ecommunity_free(&attr->ecommunity);
885 if (attr->lcommunity && !attr->lcommunity->refcnt)
886 lcommunity_free(&attr->lcommunity);
887 if (attr->cluster && !attr->cluster->refcnt) {
888 cluster_free(attr->cluster);
889 attr->cluster = NULL;
890 }
891 if (attr->transit && !attr->transit->refcnt) {
892 transit_free(attr->transit);
893 attr->transit = NULL;
894 }
895 if (attr->encap_subtlvs && !attr->encap_subtlvs->refcnt) {
896 encap_free(attr->encap_subtlvs);
897 attr->encap_subtlvs = NULL;
898 }
899 #if ENABLE_BGP_VNC
900 if (attr->vnc_subtlvs && !attr->vnc_subtlvs->refcnt) {
901 encap_free(attr->vnc_subtlvs);
902 attr->vnc_subtlvs = NULL;
903 }
904 #endif
905 }
906
907 /* Implement draft-scudder-idr-optional-transitive behaviour and
908 * avoid resetting sessions for malformed attributes which are
909 * are partial/optional and hence where the error likely was not
910 * introduced by the sending neighbour.
911 */
912 static bgp_attr_parse_ret_t
913 bgp_attr_malformed(struct bgp_attr_parser_args *args, uint8_t subcode,
914 bgp_size_t length)
915 {
916 struct peer *const peer = args->peer;
917 const uint8_t flags = args->flags;
918 /* startp and length must be special-cased, as whether or not to
919 * send the attribute data with the NOTIFY depends on the error,
920 * the caller therefore signals this with the seperate length argument
921 */
922 uint8_t *notify_datap = (length > 0 ? args->startp : NULL);
923
924 /* Only relax error handling for eBGP peers */
925 if (peer->sort != BGP_PEER_EBGP) {
926 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
927 notify_datap, length);
928 return BGP_ATTR_PARSE_ERROR;
929 }
930
931 /* Adjust the stream getp to the end of the attribute, in case we can
932 * still proceed but the caller hasn't read all the attribute.
933 */
934 stream_set_getp(BGP_INPUT(peer),
935 (args->startp - STREAM_DATA(BGP_INPUT(peer)))
936 + args->total);
937
938 switch (args->type) {
939 /* where an attribute is relatively inconsequential, e.g. it does not
940 * affect route selection, and can be safely ignored, then any such
941 * attributes which are malformed should just be ignored and the route
942 * processed as normal.
943 */
944 case BGP_ATTR_AS4_AGGREGATOR:
945 case BGP_ATTR_AGGREGATOR:
946 case BGP_ATTR_ATOMIC_AGGREGATE:
947 return BGP_ATTR_PARSE_PROCEED;
948
949 /* Core attributes, particularly ones which may influence route
950 * selection, should always cause session resets
951 */
952 case BGP_ATTR_ORIGIN:
953 case BGP_ATTR_AS_PATH:
954 case BGP_ATTR_NEXT_HOP:
955 case BGP_ATTR_MULTI_EXIT_DISC:
956 case BGP_ATTR_LOCAL_PREF:
957 case BGP_ATTR_COMMUNITIES:
958 case BGP_ATTR_ORIGINATOR_ID:
959 case BGP_ATTR_CLUSTER_LIST:
960 case BGP_ATTR_MP_REACH_NLRI:
961 case BGP_ATTR_MP_UNREACH_NLRI:
962 case BGP_ATTR_EXT_COMMUNITIES:
963 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR, subcode,
964 notify_datap, length);
965 return BGP_ATTR_PARSE_ERROR;
966 }
967
968 /* Partial optional attributes that are malformed should not cause
969 * the whole session to be reset. Instead treat it as a withdrawal
970 * of the routes, if possible.
971 */
972 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS)
973 && CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
974 && CHECK_FLAG(flags, BGP_ATTR_FLAG_PARTIAL))
975 return BGP_ATTR_PARSE_WITHDRAW;
976
977 /* default to reset */
978 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
979 }
980
981 /* Find out what is wrong with the path attribute flag bits and log the error.
982 "Flag bits" here stand for Optional, Transitive and Partial, but not for
983 Extended Length. Checking O/T/P bits at once implies, that the attribute
984 being diagnosed is defined by RFC as either a "well-known" or an "optional,
985 non-transitive" attribute. */
986 static void
987 bgp_attr_flags_diagnose(struct bgp_attr_parser_args *args,
988 uint8_t desired_flags /* how RFC says it must be */
989 )
990 {
991 uint8_t seen = 0, i;
992 uint8_t real_flags = args->flags;
993 const uint8_t attr_code = args->type;
994
995 desired_flags &= ~BGP_ATTR_FLAG_EXTLEN;
996 real_flags &= ~BGP_ATTR_FLAG_EXTLEN;
997 for (i = 0; i <= 2; i++) /* O,T,P, but not E */
998 if (CHECK_FLAG(desired_flags, attr_flag_str[i].key)
999 != CHECK_FLAG(real_flags, attr_flag_str[i].key)) {
1000 flog_err(
1001 BGP_ERR_ATTR_FLAG,
1002 "%s attribute must%s be flagged as \"%s\"",
1003 lookup_msg(attr_str, attr_code, NULL),
1004 CHECK_FLAG(desired_flags, attr_flag_str[i].key)
1005 ? ""
1006 : " not",
1007 attr_flag_str[i].str);
1008 seen = 1;
1009 }
1010 if (!seen) {
1011 zlog_debug(
1012 "Strange, %s called for attr %s, but no problem found with flags"
1013 " (real flags 0x%x, desired 0x%x)",
1014 __func__, lookup_msg(attr_str, attr_code, NULL),
1015 real_flags, desired_flags);
1016 }
1017 }
1018
1019 /* Required flags for attributes. EXTLEN will be masked off when testing,
1020 * as will PARTIAL for optional+transitive attributes.
1021 */
1022 const uint8_t attr_flags_values[] = {
1023 [BGP_ATTR_ORIGIN] = BGP_ATTR_FLAG_TRANS,
1024 [BGP_ATTR_AS_PATH] = BGP_ATTR_FLAG_TRANS,
1025 [BGP_ATTR_NEXT_HOP] = BGP_ATTR_FLAG_TRANS,
1026 [BGP_ATTR_MULTI_EXIT_DISC] = BGP_ATTR_FLAG_OPTIONAL,
1027 [BGP_ATTR_LOCAL_PREF] = BGP_ATTR_FLAG_TRANS,
1028 [BGP_ATTR_ATOMIC_AGGREGATE] = BGP_ATTR_FLAG_TRANS,
1029 [BGP_ATTR_AGGREGATOR] = BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,
1030 [BGP_ATTR_COMMUNITIES] = BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL,
1031 [BGP_ATTR_ORIGINATOR_ID] = BGP_ATTR_FLAG_OPTIONAL,
1032 [BGP_ATTR_CLUSTER_LIST] = BGP_ATTR_FLAG_OPTIONAL,
1033 [BGP_ATTR_MP_REACH_NLRI] = BGP_ATTR_FLAG_OPTIONAL,
1034 [BGP_ATTR_MP_UNREACH_NLRI] = BGP_ATTR_FLAG_OPTIONAL,
1035 [BGP_ATTR_EXT_COMMUNITIES] =
1036 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1037 [BGP_ATTR_AS4_PATH] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1038 [BGP_ATTR_AS4_AGGREGATOR] =
1039 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1040 [BGP_ATTR_PMSI_TUNNEL] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1041 [BGP_ATTR_LARGE_COMMUNITIES] =
1042 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1043 [BGP_ATTR_PREFIX_SID] = BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS,
1044 };
1045 static const size_t attr_flags_values_max = array_size(attr_flags_values) - 1;
1046
1047 static int bgp_attr_flag_invalid(struct bgp_attr_parser_args *args)
1048 {
1049 uint8_t mask = BGP_ATTR_FLAG_EXTLEN;
1050 const uint8_t flags = args->flags;
1051 const uint8_t attr_code = args->type;
1052
1053 /* there may be attributes we don't know about */
1054 if (attr_code > attr_flags_values_max)
1055 return 0;
1056 if (attr_flags_values[attr_code] == 0)
1057 return 0;
1058
1059 /* RFC4271, "For well-known attributes, the Transitive bit MUST be set
1060 * to
1061 * 1."
1062 */
1063 if (!CHECK_FLAG(BGP_ATTR_FLAG_OPTIONAL, flags)
1064 && !CHECK_FLAG(BGP_ATTR_FLAG_TRANS, flags)) {
1065 flog_err(
1066 BGP_ERR_ATTR_FLAG,
1067 "%s well-known attributes must have transitive flag set (%x)",
1068 lookup_msg(attr_str, attr_code, NULL), flags);
1069 return 1;
1070 }
1071
1072 /* "For well-known attributes and for optional non-transitive
1073 * attributes,
1074 * the Partial bit MUST be set to 0."
1075 */
1076 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_PARTIAL)) {
1077 if (!CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)) {
1078 flog_err(BGP_ERR_ATTR_FLAG,
1079 "%s well-known attribute "
1080 "must NOT have the partial flag set (%x)",
1081 lookup_msg(attr_str, attr_code, NULL), flags);
1082 return 1;
1083 }
1084 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
1085 && !CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS)) {
1086 flog_err(BGP_ERR_ATTR_FLAG,
1087 "%s optional + transitive attribute "
1088 "must NOT have the partial flag set (%x)",
1089 lookup_msg(attr_str, attr_code, NULL), flags);
1090 return 1;
1091 }
1092 }
1093
1094 /* Optional transitive attributes may go through speakers that don't
1095 * reocgnise them and set the Partial bit.
1096 */
1097 if (CHECK_FLAG(flags, BGP_ATTR_FLAG_OPTIONAL)
1098 && CHECK_FLAG(flags, BGP_ATTR_FLAG_TRANS))
1099 SET_FLAG(mask, BGP_ATTR_FLAG_PARTIAL);
1100
1101 if ((flags & ~mask) == attr_flags_values[attr_code])
1102 return 0;
1103
1104 bgp_attr_flags_diagnose(args, attr_flags_values[attr_code]);
1105 return 1;
1106 }
1107
1108 /* Get origin attribute of the update message. */
1109 static bgp_attr_parse_ret_t bgp_attr_origin(struct bgp_attr_parser_args *args)
1110 {
1111 struct peer *const peer = args->peer;
1112 struct attr *const attr = args->attr;
1113 const bgp_size_t length = args->length;
1114
1115 /* If any recognized attribute has Attribute Length that conflicts
1116 with the expected length (based on the attribute type code), then
1117 the Error Subcode is set to Attribute Length Error. The Data
1118 field contains the erroneous attribute (type, length and
1119 value). */
1120 if (length != 1) {
1121 flog_err(BGP_ERR_ATTR_LEN,
1122 "Origin attribute length is not one %d", length);
1123 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1124 args->total);
1125 }
1126
1127 /* Fetch origin attribute. */
1128 attr->origin = stream_getc(BGP_INPUT(peer));
1129
1130 /* If the ORIGIN attribute has an undefined value, then the Error
1131 Subcode is set to Invalid Origin Attribute. The Data field
1132 contains the unrecognized attribute (type, length and value). */
1133 if ((attr->origin != BGP_ORIGIN_IGP) && (attr->origin != BGP_ORIGIN_EGP)
1134 && (attr->origin != BGP_ORIGIN_INCOMPLETE)) {
1135 flog_err(BGP_ERR_ATTR_ORIGIN,
1136 "Origin attribute value is invalid %d", attr->origin);
1137 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_INVAL_ORIGIN,
1138 args->total);
1139 }
1140
1141 /* Set oring attribute flag. */
1142 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGIN);
1143
1144 return 0;
1145 }
1146
1147 /* Parse AS path information. This function is wrapper of
1148 aspath_parse. */
1149 static int bgp_attr_aspath(struct bgp_attr_parser_args *args)
1150 {
1151 struct attr *const attr = args->attr;
1152 struct peer *const peer = args->peer;
1153 const bgp_size_t length = args->length;
1154
1155 /*
1156 * peer with AS4 => will get 4Byte ASnums
1157 * otherwise, will get 16 Bit
1158 */
1159 attr->aspath = aspath_parse(peer->curr, length,
1160 CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV));
1161
1162 /* In case of IBGP, length will be zero. */
1163 if (!attr->aspath) {
1164 flog_err(BGP_ERR_ATTR_MAL_AS_PATH,
1165 "Malformed AS path from %s, length is %d", peer->host,
1166 length);
1167 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
1168 0);
1169 }
1170
1171 /* Set aspath attribute flag. */
1172 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS_PATH);
1173
1174 return BGP_ATTR_PARSE_PROCEED;
1175 }
1176
1177 static bgp_attr_parse_ret_t bgp_attr_aspath_check(struct peer *const peer,
1178 struct attr *const attr)
1179 {
1180 /* These checks were part of bgp_attr_aspath, but with
1181 * as4 we should to check aspath things when
1182 * aspath synthesizing with as4_path has already taken place.
1183 * Otherwise we check ASPATH and use the synthesized thing, and that is
1184 * not right.
1185 * So do the checks later, i.e. here
1186 */
1187 struct aspath *aspath;
1188
1189 /* Confederation sanity check. */
1190 if ((peer->sort == BGP_PEER_CONFED
1191 && !aspath_left_confed_check(attr->aspath))
1192 || (peer->sort == BGP_PEER_EBGP
1193 && aspath_confed_check(attr->aspath))) {
1194 flog_err(BGP_ERR_ATTR_MAL_AS_PATH, "Malformed AS path from %s",
1195 peer->host);
1196 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
1197 BGP_NOTIFY_UPDATE_MAL_AS_PATH);
1198 return BGP_ATTR_PARSE_ERROR;
1199 }
1200
1201 /* First AS check for EBGP. */
1202 if (CHECK_FLAG(peer->flags, PEER_FLAG_ENFORCE_FIRST_AS)) {
1203 if (peer->sort == BGP_PEER_EBGP
1204 && !aspath_firstas_check(attr->aspath, peer->as)) {
1205 flog_err(BGP_ERR_ATTR_FIRST_AS,
1206 "%s incorrect first AS (must be %u)",
1207 peer->host, peer->as);
1208 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
1209 BGP_NOTIFY_UPDATE_MAL_AS_PATH);
1210 return BGP_ATTR_PARSE_ERROR;
1211 }
1212 }
1213
1214 /* local-as prepend */
1215 if (peer->change_local_as
1216 && !CHECK_FLAG(peer->flags, PEER_FLAG_LOCAL_AS_NO_PREPEND)) {
1217 aspath = aspath_dup(attr->aspath);
1218 aspath = aspath_add_seq(aspath, peer->change_local_as);
1219 aspath_unintern(&attr->aspath);
1220 attr->aspath = aspath_intern(aspath);
1221 }
1222
1223 return BGP_ATTR_PARSE_PROCEED;
1224 }
1225
1226 /* Parse AS4 path information. This function is another wrapper of
1227 aspath_parse. */
1228 static int bgp_attr_as4_path(struct bgp_attr_parser_args *args,
1229 struct aspath **as4_path)
1230 {
1231 struct peer *const peer = args->peer;
1232 struct attr *const attr = args->attr;
1233 const bgp_size_t length = args->length;
1234
1235 *as4_path = aspath_parse(peer->curr, length, 1);
1236
1237 /* In case of IBGP, length will be zero. */
1238 if (!*as4_path) {
1239 flog_err(BGP_ERR_ATTR_MAL_AS_PATH,
1240 "Malformed AS4 path from %s, length is %d",
1241 peer->host, length);
1242 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_MAL_AS_PATH,
1243 0);
1244 }
1245
1246 /* Set aspath attribute flag. */
1247 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH);
1248
1249 return BGP_ATTR_PARSE_PROCEED;
1250 }
1251
1252 /* Nexthop attribute. */
1253 static bgp_attr_parse_ret_t bgp_attr_nexthop(struct bgp_attr_parser_args *args)
1254 {
1255 struct peer *const peer = args->peer;
1256 struct attr *const attr = args->attr;
1257 const bgp_size_t length = args->length;
1258
1259 in_addr_t nexthop_h, nexthop_n;
1260
1261 /* Check nexthop attribute length. */
1262 if (length != 4) {
1263 flog_err(BGP_ERR_ATTR_LEN,
1264 "Nexthop attribute length isn't four [%d]", length);
1265
1266 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1267 args->total);
1268 }
1269
1270 /* According to section 6.3 of RFC4271, syntactically incorrect NEXT_HOP
1271 attribute must result in a NOTIFICATION message (this is implemented
1272 below).
1273 At the same time, semantically incorrect NEXT_HOP is more likely to
1274 be just
1275 logged locally (this is implemented somewhere else). The UPDATE
1276 message
1277 gets ignored in any of these cases. */
1278 nexthop_n = stream_get_ipv4(peer->curr);
1279 nexthop_h = ntohl(nexthop_n);
1280 if ((IPV4_NET0(nexthop_h) || IPV4_NET127(nexthop_h)
1281 || IPV4_CLASS_DE(nexthop_h))
1282 && !BGP_DEBUG(
1283 allow_martians,
1284 ALLOW_MARTIANS)) /* loopbacks may be used in testing */
1285 {
1286 char buf[INET_ADDRSTRLEN];
1287 inet_ntop(AF_INET, &nexthop_n, buf, INET_ADDRSTRLEN);
1288 flog_err(BGP_ERR_ATTR_MARTIAN_NH, "Martian nexthop %s", buf);
1289 return bgp_attr_malformed(
1290 args, BGP_NOTIFY_UPDATE_INVAL_NEXT_HOP, args->total);
1291 }
1292
1293 attr->nexthop.s_addr = nexthop_n;
1294 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP);
1295
1296 return BGP_ATTR_PARSE_PROCEED;
1297 }
1298
1299 /* MED atrribute. */
1300 static bgp_attr_parse_ret_t bgp_attr_med(struct bgp_attr_parser_args *args)
1301 {
1302 struct peer *const peer = args->peer;
1303 struct attr *const attr = args->attr;
1304 const bgp_size_t length = args->length;
1305
1306 /* Length check. */
1307 if (length != 4) {
1308 flog_err(BGP_ERR_ATTR_LEN,
1309 "MED attribute length isn't four [%d]", length);
1310
1311 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1312 args->total);
1313 }
1314
1315 attr->med = stream_getl(peer->curr);
1316
1317 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC);
1318
1319 return BGP_ATTR_PARSE_PROCEED;
1320 }
1321
1322 /* Local preference attribute. */
1323 static bgp_attr_parse_ret_t
1324 bgp_attr_local_pref(struct bgp_attr_parser_args *args)
1325 {
1326 struct peer *const peer = args->peer;
1327 struct attr *const attr = args->attr;
1328 const bgp_size_t length = args->length;
1329
1330 /* Length check. */
1331 if (length != 4) {
1332 flog_err(BGP_ERR_ATTR_LEN,
1333 "LOCAL_PREF attribute length isn't 4 [%u]", length);
1334 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1335 args->total);
1336 }
1337
1338 /* If it is contained in an UPDATE message that is received from an
1339 external peer, then this attribute MUST be ignored by the
1340 receiving speaker. */
1341 if (peer->sort == BGP_PEER_EBGP) {
1342 stream_forward_getp(peer->curr, length);
1343 return BGP_ATTR_PARSE_PROCEED;
1344 }
1345
1346 attr->local_pref = stream_getl(peer->curr);
1347
1348 /* Set the local-pref flag. */
1349 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF);
1350
1351 return BGP_ATTR_PARSE_PROCEED;
1352 }
1353
1354 /* Atomic aggregate. */
1355 static int bgp_attr_atomic(struct bgp_attr_parser_args *args)
1356 {
1357 struct attr *const attr = args->attr;
1358 const bgp_size_t length = args->length;
1359
1360 /* Length check. */
1361 if (length != 0) {
1362 flog_err(BGP_ERR_ATTR_LEN,
1363 "ATOMIC_AGGREGATE attribute length isn't 0 [%u]",
1364 length);
1365 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1366 args->total);
1367 }
1368
1369 /* Set atomic aggregate flag. */
1370 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE);
1371
1372 return BGP_ATTR_PARSE_PROCEED;
1373 }
1374
1375 /* Aggregator attribute */
1376 static int bgp_attr_aggregator(struct bgp_attr_parser_args *args)
1377 {
1378 struct peer *const peer = args->peer;
1379 struct attr *const attr = args->attr;
1380 const bgp_size_t length = args->length;
1381
1382 int wantedlen = 6;
1383
1384 /* peer with AS4 will send 4 Byte AS, peer without will send 2 Byte */
1385 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV))
1386 wantedlen = 8;
1387
1388 if (length != wantedlen) {
1389 flog_err(BGP_ERR_ATTR_LEN,
1390 "AGGREGATOR attribute length isn't %u [%u]",
1391 wantedlen, length);
1392 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1393 args->total);
1394 }
1395
1396 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV))
1397 attr->aggregator_as = stream_getl(peer->curr);
1398 else
1399 attr->aggregator_as = stream_getw(peer->curr);
1400 attr->aggregator_addr.s_addr = stream_get_ipv4(peer->curr);
1401
1402 /* Set atomic aggregate flag. */
1403 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR);
1404
1405 return BGP_ATTR_PARSE_PROCEED;
1406 }
1407
1408 /* New Aggregator attribute */
1409 static bgp_attr_parse_ret_t
1410 bgp_attr_as4_aggregator(struct bgp_attr_parser_args *args,
1411 as_t *as4_aggregator_as,
1412 struct in_addr *as4_aggregator_addr)
1413 {
1414 struct peer *const peer = args->peer;
1415 struct attr *const attr = args->attr;
1416 const bgp_size_t length = args->length;
1417
1418 if (length != 8) {
1419 flog_err(BGP_ERR_ATTR_LEN,
1420 "New Aggregator length is not 8 [%d]", length);
1421 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1422 0);
1423 }
1424
1425 *as4_aggregator_as = stream_getl(peer->curr);
1426 as4_aggregator_addr->s_addr = stream_get_ipv4(peer->curr);
1427
1428 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR);
1429
1430 return BGP_ATTR_PARSE_PROCEED;
1431 }
1432
1433 /* Munge Aggregator and New-Aggregator, AS_PATH and NEW_AS_PATH.
1434 */
1435 static bgp_attr_parse_ret_t
1436 bgp_attr_munge_as4_attrs(struct peer *const peer, struct attr *const attr,
1437 struct aspath *as4_path, as_t as4_aggregator,
1438 struct in_addr *as4_aggregator_addr)
1439 {
1440 int ignore_as4_path = 0;
1441 struct aspath *newpath;
1442
1443 if (!attr->aspath) {
1444 /* NULL aspath shouldn't be possible as bgp_attr_parse should
1445 * have
1446 * checked that all well-known, mandatory attributes were
1447 * present.
1448 *
1449 * Can only be a problem with peer itself - hard error
1450 */
1451 return BGP_ATTR_PARSE_ERROR;
1452 }
1453
1454 if (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)) {
1455 /* peer can do AS4, so we ignore AS4_PATH and AS4_AGGREGATOR
1456 * if given.
1457 * It is worth a warning though, because the peer really
1458 * should not send them
1459 */
1460 if (BGP_DEBUG(as4, AS4)) {
1461 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH)))
1462 zlog_debug("[AS4] %s %s AS4_PATH", peer->host,
1463 "AS4 capable peer, yet it sent");
1464
1465 if (attr->flag
1466 & (ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR)))
1467 zlog_debug("[AS4] %s %s AS4_AGGREGATOR",
1468 peer->host,
1469 "AS4 capable peer, yet it sent");
1470 }
1471
1472 return BGP_ATTR_PARSE_PROCEED;
1473 }
1474
1475 /* We have a asn16 peer. First, look for AS4_AGGREGATOR
1476 * because that may override AS4_PATH
1477 */
1478 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_AGGREGATOR))) {
1479 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR))) {
1480 /* received both.
1481 * if the as_number in aggregator is not AS_TRANS,
1482 * then AS4_AGGREGATOR and AS4_PATH shall be ignored
1483 * and the Aggregator shall be taken as
1484 * info on the aggregating node, and the AS_PATH
1485 * shall be taken as the AS_PATH
1486 * otherwise
1487 * the Aggregator shall be ignored and the
1488 * AS4_AGGREGATOR shall be taken as the
1489 * Aggregating node and the AS_PATH is to be
1490 * constructed "as in all other cases"
1491 */
1492 if (attr->aggregator_as != BGP_AS_TRANS) {
1493 /* ignore */
1494 if (BGP_DEBUG(as4, AS4))
1495 zlog_debug(
1496 "[AS4] %s BGP not AS4 capable peer"
1497 " send AGGREGATOR != AS_TRANS and"
1498 " AS4_AGGREGATOR, so ignore"
1499 " AS4_AGGREGATOR and AS4_PATH",
1500 peer->host);
1501 ignore_as4_path = 1;
1502 } else {
1503 /* "New_aggregator shall be taken as aggregator"
1504 */
1505 attr->aggregator_as = as4_aggregator;
1506 attr->aggregator_addr.s_addr =
1507 as4_aggregator_addr->s_addr;
1508 }
1509 } else {
1510 /* We received a AS4_AGGREGATOR but no AGGREGATOR.
1511 * That is bogus - but reading the conditions
1512 * we have to handle AS4_AGGREGATOR as if it were
1513 * AGGREGATOR in that case
1514 */
1515 if (BGP_DEBUG(as4, AS4))
1516 zlog_debug(
1517 "[AS4] %s BGP not AS4 capable peer send"
1518 " AS4_AGGREGATOR but no AGGREGATOR, will take"
1519 " it as if AGGREGATOR with AS_TRANS had been there",
1520 peer->host);
1521 attr->aggregator_as = as4_aggregator;
1522 /* sweep it under the carpet and simulate a "good"
1523 * AGGREGATOR */
1524 attr->flag |= (ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR));
1525 }
1526 }
1527
1528 /* need to reconcile NEW_AS_PATH and AS_PATH */
1529 if (!ignore_as4_path
1530 && (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS4_PATH)))) {
1531 newpath = aspath_reconcile_as4(attr->aspath, as4_path);
1532 if (!newpath)
1533 return BGP_ATTR_PARSE_ERROR;
1534
1535 aspath_unintern(&attr->aspath);
1536 attr->aspath = aspath_intern(newpath);
1537 }
1538 return BGP_ATTR_PARSE_PROCEED;
1539 }
1540
1541 /* Community attribute. */
1542 static bgp_attr_parse_ret_t
1543 bgp_attr_community(struct bgp_attr_parser_args *args)
1544 {
1545 struct peer *const peer = args->peer;
1546 struct attr *const attr = args->attr;
1547 const bgp_size_t length = args->length;
1548
1549 if (length == 0) {
1550 attr->community = NULL;
1551 return BGP_ATTR_PARSE_PROCEED;
1552 }
1553
1554 attr->community =
1555 community_parse((uint32_t *)stream_pnt(peer->curr), length);
1556
1557 /* XXX: fix community_parse to use stream API and remove this */
1558 stream_forward_getp(peer->curr, length);
1559
1560 if (!attr->community)
1561 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1562 args->total);
1563
1564 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES);
1565
1566 return BGP_ATTR_PARSE_PROCEED;
1567 }
1568
1569 /* Originator ID attribute. */
1570 static bgp_attr_parse_ret_t
1571 bgp_attr_originator_id(struct bgp_attr_parser_args *args)
1572 {
1573 struct peer *const peer = args->peer;
1574 struct attr *const attr = args->attr;
1575 const bgp_size_t length = args->length;
1576
1577 /* Length check. */
1578 if (length != 4) {
1579 flog_err(BGP_ERR_ATTR_LEN, "Bad originator ID length %d",
1580 length);
1581
1582 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1583 args->total);
1584 }
1585
1586 attr->originator_id.s_addr = stream_get_ipv4(peer->curr);
1587
1588 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID);
1589
1590 return BGP_ATTR_PARSE_PROCEED;
1591 }
1592
1593 /* Cluster list attribute. */
1594 static bgp_attr_parse_ret_t
1595 bgp_attr_cluster_list(struct bgp_attr_parser_args *args)
1596 {
1597 struct peer *const peer = args->peer;
1598 struct attr *const attr = args->attr;
1599 const bgp_size_t length = args->length;
1600
1601 /* Check length. */
1602 if (length % 4) {
1603 flog_err(BGP_ERR_ATTR_LEN, "Bad cluster list length %d",
1604 length);
1605
1606 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
1607 args->total);
1608 }
1609
1610 attr->cluster =
1611 cluster_parse((struct in_addr *)stream_pnt(peer->curr), length);
1612
1613 /* XXX: Fix cluster_parse to use stream API and then remove this */
1614 stream_forward_getp(peer->curr, length);
1615
1616 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_CLUSTER_LIST);
1617
1618 return BGP_ATTR_PARSE_PROCEED;
1619 }
1620
1621 /* Multiprotocol reachability information parse. */
1622 int bgp_mp_reach_parse(struct bgp_attr_parser_args *args,
1623 struct bgp_nlri *mp_update)
1624 {
1625 iana_afi_t pkt_afi;
1626 afi_t afi;
1627 iana_safi_t pkt_safi;
1628 safi_t safi;
1629 bgp_size_t nlri_len;
1630 size_t start;
1631 struct stream *s;
1632 struct peer *const peer = args->peer;
1633 struct attr *const attr = args->attr;
1634 const bgp_size_t length = args->length;
1635
1636 /* Set end of packet. */
1637 s = BGP_INPUT(peer);
1638 start = stream_get_getp(s);
1639
1640 /* safe to read statically sized header? */
1641 #define BGP_MP_REACH_MIN_SIZE 5
1642 #define LEN_LEFT (length - (stream_get_getp(s) - start))
1643 if ((length > STREAM_READABLE(s)) || (length < BGP_MP_REACH_MIN_SIZE)) {
1644 zlog_info("%s: %s sent invalid length, %lu", __func__,
1645 peer->host, (unsigned long)length);
1646 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1647 }
1648
1649 /* Load AFI, SAFI. */
1650 pkt_afi = stream_getw(s);
1651 pkt_safi = stream_getc(s);
1652
1653 /* Convert AFI, SAFI to internal values, check. */
1654 if (bgp_map_afi_safi_iana2int(pkt_afi, pkt_safi, &afi, &safi)) {
1655 /* Log if AFI or SAFI is unrecognized. This is not an error
1656 * unless
1657 * the attribute is otherwise malformed.
1658 */
1659 if (bgp_debug_update(peer, NULL, NULL, 0))
1660 zlog_debug(
1661 "%s: MP_REACH received AFI %u or SAFI %u is unrecognized",
1662 peer->host, pkt_afi, pkt_safi);
1663 return BGP_ATTR_PARSE_ERROR;
1664 }
1665
1666 /* Get nexthop length. */
1667 attr->mp_nexthop_len = stream_getc(s);
1668
1669 if (LEN_LEFT < attr->mp_nexthop_len) {
1670 zlog_info(
1671 "%s: %s, MP nexthop length, %u, goes past end of attribute",
1672 __func__, peer->host, attr->mp_nexthop_len);
1673 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1674 }
1675
1676 /* Nexthop length check. */
1677 switch (attr->mp_nexthop_len) {
1678 case 0:
1679 if (safi != SAFI_FLOWSPEC) {
1680 zlog_info("%s: (%s) Wrong multiprotocol next hop length: %d",
1681 __func__, peer->host, attr->mp_nexthop_len);
1682 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1683 }
1684 break;
1685 case BGP_ATTR_NHLEN_VPNV4:
1686 stream_getl(s); /* RD high */
1687 stream_getl(s); /* RD low */
1688 /*
1689 * NOTE: intentional fall through
1690 * - for consistency in rx processing
1691 *
1692 * The following comment is to signal GCC this intention
1693 * and supress the warning
1694 */
1695 /* FALLTHRU */
1696 case BGP_ATTR_NHLEN_IPV4:
1697 stream_get(&attr->mp_nexthop_global_in, s, IPV4_MAX_BYTELEN);
1698 /* Probably needed for RFC 2283 */
1699 if (attr->nexthop.s_addr == 0)
1700 memcpy(&attr->nexthop.s_addr,
1701 &attr->mp_nexthop_global_in, IPV4_MAX_BYTELEN);
1702 break;
1703 case BGP_ATTR_NHLEN_IPV6_GLOBAL:
1704 case BGP_ATTR_NHLEN_VPNV6_GLOBAL:
1705 if (attr->mp_nexthop_len == BGP_ATTR_NHLEN_VPNV6_GLOBAL) {
1706 stream_getl(s); /* RD high */
1707 stream_getl(s); /* RD low */
1708 }
1709 stream_get(&attr->mp_nexthop_global, s, IPV6_MAX_BYTELEN);
1710 if (IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_global))
1711 attr->nh_ifindex = peer->nexthop.ifp->ifindex;
1712 break;
1713 case BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL:
1714 case BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL:
1715 if (attr->mp_nexthop_len
1716 == BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL) {
1717 stream_getl(s); /* RD high */
1718 stream_getl(s); /* RD low */
1719 }
1720 stream_get(&attr->mp_nexthop_global, s, IPV6_MAX_BYTELEN);
1721 if (IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_global))
1722 attr->nh_ifindex = peer->nexthop.ifp->ifindex;
1723 if (attr->mp_nexthop_len
1724 == BGP_ATTR_NHLEN_VPNV6_GLOBAL_AND_LL) {
1725 stream_getl(s); /* RD high */
1726 stream_getl(s); /* RD low */
1727 }
1728 stream_get(&attr->mp_nexthop_local, s, IPV6_MAX_BYTELEN);
1729 if (!IN6_IS_ADDR_LINKLOCAL(&attr->mp_nexthop_local)) {
1730 char buf1[INET6_ADDRSTRLEN];
1731 char buf2[INET6_ADDRSTRLEN];
1732
1733 if (bgp_debug_update(peer, NULL, NULL, 1))
1734 zlog_debug(
1735 "%s rcvd nexthops %s, %s -- ignoring non-LL value",
1736 peer->host,
1737 inet_ntop(AF_INET6,
1738 &attr->mp_nexthop_global,
1739 buf1, INET6_ADDRSTRLEN),
1740 inet_ntop(AF_INET6,
1741 &attr->mp_nexthop_local, buf2,
1742 INET6_ADDRSTRLEN));
1743
1744 attr->mp_nexthop_len = IPV6_MAX_BYTELEN;
1745 }
1746 attr->nh_lla_ifindex = peer->nexthop.ifp->ifindex;
1747 break;
1748 default:
1749 zlog_info("%s: (%s) Wrong multiprotocol next hop length: %d",
1750 __func__, peer->host, attr->mp_nexthop_len);
1751 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1752 }
1753
1754 if (!LEN_LEFT) {
1755 zlog_info("%s: (%s) Failed to read SNPA and NLRI(s)", __func__,
1756 peer->host);
1757 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1758 }
1759
1760 {
1761 uint8_t val;
1762 if ((val = stream_getc(s)))
1763 zlog_warn(
1764 "%s sent non-zero value, %u, for defunct SNPA-length field",
1765 peer->host, val);
1766 }
1767
1768 /* must have nrli_len, what is left of the attribute */
1769 nlri_len = LEN_LEFT;
1770 if (nlri_len > STREAM_READABLE(s)) {
1771 zlog_info("%s: (%s) Failed to read NLRI", __func__, peer->host);
1772 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1773 }
1774
1775 if (!nlri_len) {
1776 zlog_info("%s: (%s) No Reachability, Treating as a EOR marker",
1777 __func__, peer->host);
1778
1779 mp_update->afi = afi;
1780 mp_update->safi = safi;
1781 return BGP_ATTR_PARSE_EOR;
1782 }
1783
1784 mp_update->afi = afi;
1785 mp_update->safi = safi;
1786 mp_update->nlri = stream_pnt(s);
1787 mp_update->length = nlri_len;
1788
1789 stream_forward_getp(s, nlri_len);
1790
1791 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI);
1792
1793 return BGP_ATTR_PARSE_PROCEED;
1794 #undef LEN_LEFT
1795 }
1796
1797 /* Multiprotocol unreachable parse */
1798 int bgp_mp_unreach_parse(struct bgp_attr_parser_args *args,
1799 struct bgp_nlri *mp_withdraw)
1800 {
1801 struct stream *s;
1802 iana_afi_t pkt_afi;
1803 afi_t afi;
1804 iana_safi_t pkt_safi;
1805 safi_t safi;
1806 uint16_t withdraw_len;
1807 struct peer *const peer = args->peer;
1808 struct attr *const attr = args->attr;
1809 const bgp_size_t length = args->length;
1810
1811 s = peer->curr;
1812
1813 #define BGP_MP_UNREACH_MIN_SIZE 3
1814 if ((length > STREAM_READABLE(s)) || (length < BGP_MP_UNREACH_MIN_SIZE))
1815 return BGP_ATTR_PARSE_ERROR_NOTIFYPLS;
1816
1817 pkt_afi = stream_getw(s);
1818 pkt_safi = stream_getc(s);
1819
1820 /* Convert AFI, SAFI to internal values, check. */
1821 if (bgp_map_afi_safi_iana2int(pkt_afi, pkt_safi, &afi, &safi)) {
1822 /* Log if AFI or SAFI is unrecognized. This is not an error
1823 * unless
1824 * the attribute is otherwise malformed.
1825 */
1826 if (bgp_debug_update(peer, NULL, NULL, 0))
1827 zlog_debug(
1828 "%s: MP_UNREACH received AFI %u or SAFI %u is unrecognized",
1829 peer->host, pkt_afi, pkt_safi);
1830 return BGP_ATTR_PARSE_ERROR;
1831 }
1832
1833 withdraw_len = length - BGP_MP_UNREACH_MIN_SIZE;
1834
1835 mp_withdraw->afi = afi;
1836 mp_withdraw->safi = safi;
1837 mp_withdraw->nlri = stream_pnt(s);
1838 mp_withdraw->length = withdraw_len;
1839
1840 stream_forward_getp(s, withdraw_len);
1841
1842 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI);
1843
1844 return BGP_ATTR_PARSE_PROCEED;
1845 }
1846
1847 /* Large Community attribute. */
1848 static bgp_attr_parse_ret_t
1849 bgp_attr_large_community(struct bgp_attr_parser_args *args)
1850 {
1851 struct peer *const peer = args->peer;
1852 struct attr *const attr = args->attr;
1853 const bgp_size_t length = args->length;
1854
1855 /*
1856 * Large community follows new attribute format.
1857 */
1858 if (length == 0) {
1859 attr->lcommunity = NULL;
1860 /* Empty extcomm doesn't seem to be invalid per se */
1861 return BGP_ATTR_PARSE_PROCEED;
1862 }
1863
1864 attr->lcommunity =
1865 lcommunity_parse((uint8_t *)stream_pnt(peer->curr), length);
1866 /* XXX: fix ecommunity_parse to use stream API */
1867 stream_forward_getp(peer->curr, length);
1868
1869 if (!attr->lcommunity)
1870 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1871 args->total);
1872
1873 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES);
1874
1875 return BGP_ATTR_PARSE_PROCEED;
1876 }
1877
1878 /* Extended Community attribute. */
1879 static bgp_attr_parse_ret_t
1880 bgp_attr_ext_communities(struct bgp_attr_parser_args *args)
1881 {
1882 struct peer *const peer = args->peer;
1883 struct attr *const attr = args->attr;
1884 const bgp_size_t length = args->length;
1885 uint8_t sticky = 0;
1886
1887 if (length == 0) {
1888 attr->ecommunity = NULL;
1889 /* Empty extcomm doesn't seem to be invalid per se */
1890 return BGP_ATTR_PARSE_PROCEED;
1891 }
1892
1893 attr->ecommunity =
1894 ecommunity_parse((uint8_t *)stream_pnt(peer->curr), length);
1895 /* XXX: fix ecommunity_parse to use stream API */
1896 stream_forward_getp(peer->curr, length);
1897
1898 if (!attr->ecommunity)
1899 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
1900 args->total);
1901
1902 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES);
1903
1904 /* Extract MAC mobility sequence number, if any. */
1905 attr->mm_seqnum = bgp_attr_mac_mobility_seqnum(attr, &sticky);
1906 attr->sticky = sticky;
1907
1908 /* Check if this is a Gateway MAC-IP advertisement */
1909 attr->default_gw = bgp_attr_default_gw(attr);
1910
1911 /* Handle scenario where router flag ecommunity is not
1912 * set but default gw ext community is present.
1913 * Use default gateway, set and propogate R-bit.
1914 */
1915 if (attr->default_gw)
1916 attr->router_flag = 1;
1917
1918 /* Check EVPN Neighbor advertisement flags, R-bit */
1919 bgp_attr_evpn_na_flag(attr, &attr->router_flag);
1920
1921 /* Extract the Rmac, if any */
1922 bgp_attr_rmac(attr, &attr->rmac);
1923
1924 return BGP_ATTR_PARSE_PROCEED;
1925 }
1926
1927 /* Parse Tunnel Encap attribute in an UPDATE */
1928 static int bgp_attr_encap(uint8_t type, struct peer *peer, /* IN */
1929 bgp_size_t length, /* IN: attr's length field */
1930 struct attr *attr, /* IN: caller already allocated */
1931 uint8_t flag, /* IN: attr's flags field */
1932 uint8_t *startp)
1933 {
1934 bgp_size_t total;
1935 uint16_t tunneltype = 0;
1936
1937 total = length + (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN) ? 4 : 3);
1938
1939 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS)
1940 || !CHECK_FLAG(flag, BGP_ATTR_FLAG_OPTIONAL)) {
1941 zlog_info(
1942 "Tunnel Encap attribute flag isn't optional and transitive %d",
1943 flag);
1944 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
1945 BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
1946 startp, total);
1947 return -1;
1948 }
1949
1950 if (BGP_ATTR_ENCAP == type) {
1951 /* read outer TLV type and length */
1952 uint16_t tlv_length;
1953
1954 if (length < 4) {
1955 zlog_info(
1956 "Tunnel Encap attribute not long enough to contain outer T,L");
1957 bgp_notify_send_with_data(
1958 peer, BGP_NOTIFY_UPDATE_ERR,
1959 BGP_NOTIFY_UPDATE_OPT_ATTR_ERR, startp, total);
1960 return -1;
1961 }
1962 tunneltype = stream_getw(BGP_INPUT(peer));
1963 tlv_length = stream_getw(BGP_INPUT(peer));
1964 length -= 4;
1965
1966 if (tlv_length != length) {
1967 zlog_info("%s: tlv_length(%d) != length(%d)", __func__,
1968 tlv_length, length);
1969 }
1970 }
1971
1972 while (length >= 4) {
1973 uint16_t subtype = 0;
1974 uint16_t sublength = 0;
1975 struct bgp_attr_encap_subtlv *tlv;
1976
1977 if (BGP_ATTR_ENCAP == type) {
1978 subtype = stream_getc(BGP_INPUT(peer));
1979 sublength = stream_getc(BGP_INPUT(peer));
1980 length -= 2;
1981 #if ENABLE_BGP_VNC
1982 } else {
1983 subtype = stream_getw(BGP_INPUT(peer));
1984 sublength = stream_getw(BGP_INPUT(peer));
1985 length -= 4;
1986 #endif
1987 }
1988
1989 if (sublength > length) {
1990 zlog_info(
1991 "Tunnel Encap attribute sub-tlv length %d exceeds remaining length %d",
1992 sublength, length);
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
1999 /* alloc and copy sub-tlv */
2000 /* TBD make sure these are freed when attributes are released */
2001 tlv = XCALLOC(MTYPE_ENCAP_TLV,
2002 sizeof(struct bgp_attr_encap_subtlv) + sublength);
2003 tlv->type = subtype;
2004 tlv->length = sublength;
2005 stream_get(tlv->value, peer->curr, sublength);
2006 length -= sublength;
2007
2008 /* attach tlv to encap chain */
2009 if (BGP_ATTR_ENCAP == type) {
2010 struct bgp_attr_encap_subtlv *stlv_last;
2011 for (stlv_last = attr->encap_subtlvs;
2012 stlv_last && stlv_last->next;
2013 stlv_last = stlv_last->next)
2014 ;
2015 if (stlv_last) {
2016 stlv_last->next = tlv;
2017 } else {
2018 attr->encap_subtlvs = tlv;
2019 }
2020 #if ENABLE_BGP_VNC
2021 } else {
2022 struct bgp_attr_encap_subtlv *stlv_last;
2023 for (stlv_last = attr->vnc_subtlvs;
2024 stlv_last && stlv_last->next;
2025 stlv_last = stlv_last->next)
2026 ;
2027 if (stlv_last) {
2028 stlv_last->next = tlv;
2029 } else {
2030 attr->vnc_subtlvs = tlv;
2031 }
2032 #endif
2033 }
2034 }
2035
2036 if (BGP_ATTR_ENCAP == type) {
2037 attr->encap_tunneltype = tunneltype;
2038 }
2039
2040 if (length) {
2041 /* spurious leftover data */
2042 zlog_info(
2043 "Tunnel Encap attribute length is bad: %d leftover octets",
2044 length);
2045 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
2046 BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2047 startp, total);
2048 return -1;
2049 }
2050
2051 return 0;
2052 }
2053
2054 /*
2055 * Read an individual SID value returning how much data we have read
2056 * Returns 0 if there was an error that needs to be passed up the stack
2057 */
2058 static bgp_attr_parse_ret_t bgp_attr_psid_sub(int32_t type,
2059 int32_t length,
2060 struct bgp_attr_parser_args *args,
2061 struct bgp_nlri *mp_update)
2062 {
2063 struct peer *const peer = args->peer;
2064 struct attr *const attr = args->attr;
2065 uint32_t label_index;
2066 struct in6_addr ipv6_sid;
2067 uint32_t srgb_base;
2068 uint32_t srgb_range;
2069 int srgb_count;
2070
2071 if (type == BGP_PREFIX_SID_LABEL_INDEX) {
2072 if (length != BGP_PREFIX_SID_LABEL_INDEX_LENGTH) {
2073 flog_err(
2074 BGP_ERR_ATTR_LEN,
2075 "Prefix SID label index length is %d instead of %d",
2076 length, BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
2077 return bgp_attr_malformed(args,
2078 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2079 args->total);
2080 }
2081
2082 /* Ignore flags and reserved */
2083 stream_getc(peer->curr);
2084 stream_getw(peer->curr);
2085
2086 /* Fetch the label index and see if it is valid. */
2087 label_index = stream_getl(peer->curr);
2088 if (label_index == BGP_INVALID_LABEL_INDEX)
2089 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2090 args->total);
2091
2092 /* Store label index; subsequently, we'll check on
2093 * address-family */
2094 attr->label_index = label_index;
2095
2096 /*
2097 * Ignore the Label index attribute unless received for
2098 * labeled-unicast
2099 * SAFI.
2100 */
2101 if (!mp_update->length
2102 || mp_update->safi != SAFI_LABELED_UNICAST)
2103 attr->label_index = BGP_INVALID_LABEL_INDEX;
2104 }
2105
2106 /* Placeholder code for the IPv6 SID type */
2107 else if (type == BGP_PREFIX_SID_IPV6) {
2108 if (length != BGP_PREFIX_SID_IPV6_LENGTH) {
2109 flog_err(BGP_ERR_ATTR_LEN,
2110 "Prefix SID IPv6 length is %d instead of %d",
2111 length, BGP_PREFIX_SID_IPV6_LENGTH);
2112 return bgp_attr_malformed(args,
2113 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2114 args->total);
2115 }
2116
2117 /* Ignore reserved */
2118 stream_getc(peer->curr);
2119 stream_getw(peer->curr);
2120
2121 stream_get(&ipv6_sid, peer->curr, 16);
2122 }
2123
2124 /* Placeholder code for the Originator SRGB type */
2125 else if (type == BGP_PREFIX_SID_ORIGINATOR_SRGB) {
2126 /* Ignore flags */
2127 stream_getw(peer->curr);
2128
2129 length -= 2;
2130
2131 if (length % BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH) {
2132 flog_err(
2133 BGP_ERR_ATTR_LEN,
2134 "Prefix SID Originator SRGB length is %d, it must be a multiple of %d ",
2135 length, BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH);
2136 return bgp_attr_malformed(
2137 args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2138 args->total);
2139 }
2140
2141 srgb_count = length / BGP_PREFIX_SID_ORIGINATOR_SRGB_LENGTH;
2142
2143 for (int i = 0; i < srgb_count; i++) {
2144 stream_get(&srgb_base, peer->curr, 3);
2145 stream_get(&srgb_range, peer->curr, 3);
2146 }
2147 }
2148
2149 return BGP_ATTR_PARSE_PROCEED;
2150 }
2151
2152 /* Prefix SID attribute
2153 * draft-ietf-idr-bgp-prefix-sid-05
2154 */
2155 bgp_attr_parse_ret_t
2156 bgp_attr_prefix_sid(int32_t tlength, struct bgp_attr_parser_args *args,
2157 struct bgp_nlri *mp_update)
2158 {
2159 struct peer *const peer = args->peer;
2160 struct attr *const attr = args->attr;
2161 bgp_attr_parse_ret_t ret;
2162
2163 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID);
2164
2165 while (tlength) {
2166 int32_t type, length;
2167
2168 type = stream_getc(peer->curr);
2169 length = stream_getw(peer->curr);
2170
2171 ret = bgp_attr_psid_sub(type, length, args, mp_update);
2172
2173 if (ret != BGP_ATTR_PARSE_PROCEED)
2174 return ret;
2175 /*
2176 * Subtract length + the T and the L
2177 * since length is the Vector portion
2178 */
2179 tlength -= length + 3;
2180
2181 if (tlength < 0) {
2182 flog_err(
2183 BGP_ERR_ATTR_LEN,
2184 "Prefix SID internal length %d causes us to read beyond the total Prefix SID length",
2185 length);
2186 return bgp_attr_malformed(args,
2187 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2188 args->total);
2189 }
2190 }
2191
2192 return BGP_ATTR_PARSE_PROCEED;
2193 }
2194
2195 /* PMSI tunnel attribute (RFC 6514)
2196 * Basic validation checks done here.
2197 */
2198 static bgp_attr_parse_ret_t
2199 bgp_attr_pmsi_tunnel(struct bgp_attr_parser_args *args)
2200 {
2201 struct peer *const peer = args->peer;
2202 struct attr *const attr = args->attr;
2203 const bgp_size_t length = args->length;
2204 uint8_t tnl_type;
2205
2206 /* Verify that the receiver is expecting "ingress replication" as we
2207 * can only support that.
2208 */
2209 if (length < 2) {
2210 flog_err(BGP_ERR_ATTR_LEN,
2211 "Bad PMSI tunnel attribute length %d", length);
2212 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2213 args->total);
2214 }
2215 stream_getc(peer->curr); /* Flags */
2216 tnl_type = stream_getc(peer->curr);
2217 if (tnl_type > PMSI_TNLTYPE_MAX) {
2218 flog_err(BGP_ERR_ATTR_PMSI_TYPE,
2219 "Invalid PMSI tunnel attribute type %d", tnl_type);
2220 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_OPT_ATTR_ERR,
2221 args->total);
2222 }
2223 if (tnl_type == PMSI_TNLTYPE_INGR_REPL) {
2224 if (length != 9) {
2225 flog_err(BGP_ERR_ATTR_PMSI_LEN,
2226 "Bad PMSI tunnel attribute length %d for IR",
2227 length);
2228 return bgp_attr_malformed(
2229 args, BGP_NOTIFY_UPDATE_ATTR_LENG_ERR,
2230 args->total);
2231 }
2232 }
2233
2234 attr->flag |= ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL);
2235 attr->pmsi_tnl_type = tnl_type;
2236
2237 /* Forward read pointer of input stream. */
2238 stream_forward_getp(peer->curr, length - 2);
2239
2240 return BGP_ATTR_PARSE_PROCEED;
2241 }
2242
2243 /* BGP unknown attribute treatment. */
2244 static bgp_attr_parse_ret_t bgp_attr_unknown(struct bgp_attr_parser_args *args)
2245 {
2246 bgp_size_t total = args->total;
2247 struct transit *transit;
2248 struct peer *const peer = args->peer;
2249 struct attr *const attr = args->attr;
2250 uint8_t *const startp = args->startp;
2251 const uint8_t type = args->type;
2252 const uint8_t flag = args->flags;
2253 const bgp_size_t length = args->length;
2254
2255 if (bgp_debug_update(peer, NULL, NULL, 1))
2256 zlog_debug(
2257 "%s Unknown attribute is received (type %d, length %d)",
2258 peer->host, type, length);
2259
2260 /* Forward read pointer of input stream. */
2261 stream_forward_getp(peer->curr, length);
2262
2263 /* If any of the mandatory well-known attributes are not recognized,
2264 then the Error Subcode is set to Unrecognized Well-known
2265 Attribute. The Data field contains the unrecognized attribute
2266 (type, length and value). */
2267 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_OPTIONAL)) {
2268 return bgp_attr_malformed(args, BGP_NOTIFY_UPDATE_UNREC_ATTR,
2269 args->total);
2270 }
2271
2272 /* Unrecognized non-transitive optional attributes must be quietly
2273 ignored and not passed along to other BGP peers. */
2274 if (!CHECK_FLAG(flag, BGP_ATTR_FLAG_TRANS))
2275 return BGP_ATTR_PARSE_PROCEED;
2276
2277 /* If a path with recognized transitive optional attribute is
2278 accepted and passed along to other BGP peers and the Partial bit
2279 in the Attribute Flags octet is set to 1 by some previous AS, it
2280 is not set back to 0 by the current AS. */
2281 SET_FLAG(*startp, BGP_ATTR_FLAG_PARTIAL);
2282
2283 /* Store transitive attribute to the end of attr->transit. */
2284 if (!attr->transit)
2285 attr->transit = XCALLOC(MTYPE_TRANSIT, sizeof(struct transit));
2286
2287 transit = attr->transit;
2288
2289 if (transit->val)
2290 transit->val = XREALLOC(MTYPE_TRANSIT_VAL, transit->val,
2291 transit->length + total);
2292 else
2293 transit->val = XMALLOC(MTYPE_TRANSIT_VAL, total);
2294
2295 memcpy(transit->val + transit->length, startp, total);
2296 transit->length += total;
2297
2298 return BGP_ATTR_PARSE_PROCEED;
2299 }
2300
2301 /* Well-known attribute check. */
2302 static int bgp_attr_check(struct peer *peer, struct attr *attr)
2303 {
2304 uint8_t type = 0;
2305
2306 /* BGP Graceful-Restart End-of-RIB for IPv4 unicast is signaled as an
2307 * empty UPDATE. */
2308 if (CHECK_FLAG(peer->cap, PEER_CAP_RESTART_RCV) && !attr->flag)
2309 return BGP_ATTR_PARSE_PROCEED;
2310
2311 /* "An UPDATE message that contains the MP_UNREACH_NLRI is not required
2312 to carry any other path attributes.", though if MP_REACH_NLRI or NLRI
2313 are present, it should. Check for any other attribute being present
2314 instead.
2315 */
2316 if ((!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)) &&
2317 CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_UNREACH_NLRI))))
2318 return BGP_ATTR_PARSE_PROCEED;
2319
2320 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_ORIGIN)))
2321 type = BGP_ATTR_ORIGIN;
2322
2323 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH)))
2324 type = BGP_ATTR_AS_PATH;
2325
2326 /* RFC 2858 makes Next-Hop optional/ignored, if MP_REACH_NLRI is present
2327 * and
2328 * NLRI is empty. We can't easily check NLRI empty here though.
2329 */
2330 if (!CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP))
2331 && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_MP_REACH_NLRI)))
2332 type = BGP_ATTR_NEXT_HOP;
2333
2334 if (peer->sort == BGP_PEER_IBGP
2335 && !CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF)))
2336 type = BGP_ATTR_LOCAL_PREF;
2337
2338 if (type) {
2339 zlog_warn("%s Missing well-known attribute %s.", peer->host,
2340 lookup_msg(attr_str, type, NULL));
2341 bgp_notify_send_with_data(peer, BGP_NOTIFY_UPDATE_ERR,
2342 BGP_NOTIFY_UPDATE_MISS_ATTR, &type,
2343 1);
2344 return BGP_ATTR_PARSE_ERROR;
2345 }
2346 return BGP_ATTR_PARSE_PROCEED;
2347 }
2348
2349 /* Read attribute of update packet. This function is called from
2350 bgp_update_receive() in bgp_packet.c. */
2351 bgp_attr_parse_ret_t bgp_attr_parse(struct peer *peer, struct attr *attr,
2352 bgp_size_t size, struct bgp_nlri *mp_update,
2353 struct bgp_nlri *mp_withdraw)
2354 {
2355 int ret;
2356 uint8_t flag = 0;
2357 uint8_t type = 0;
2358 bgp_size_t length;
2359 uint8_t *startp, *endp;
2360 uint8_t *attr_endp;
2361 uint8_t seen[BGP_ATTR_BITMAP_SIZE];
2362 /* we need the as4_path only until we have synthesized the as_path with
2363 * it */
2364 /* same goes for as4_aggregator */
2365 struct aspath *as4_path = NULL;
2366 as_t as4_aggregator = 0;
2367 struct in_addr as4_aggregator_addr = {.s_addr = 0};
2368
2369 /* Initialize bitmap. */
2370 memset(seen, 0, BGP_ATTR_BITMAP_SIZE);
2371
2372 /* End pointer of BGP attribute. */
2373 endp = BGP_INPUT_PNT(peer) + size;
2374
2375 /* Get attributes to the end of attribute length. */
2376 while (BGP_INPUT_PNT(peer) < endp) {
2377 /* Check remaining length check.*/
2378 if (endp - BGP_INPUT_PNT(peer) < BGP_ATTR_MIN_LEN) {
2379 /* XXX warning: long int format, int arg (arg 5) */
2380 zlog_warn(
2381 "%s: error BGP attribute length %lu is smaller than min len",
2382 peer->host,
2383 (unsigned long)(endp
2384 - stream_pnt(BGP_INPUT(peer))));
2385
2386 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2387 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2388 return BGP_ATTR_PARSE_ERROR;
2389 }
2390
2391 /* Fetch attribute flag and type. */
2392 startp = BGP_INPUT_PNT(peer);
2393 /* "The lower-order four bits of the Attribute Flags octet are
2394 unused. They MUST be zero when sent and MUST be ignored when
2395 received." */
2396 flag = 0xF0 & stream_getc(BGP_INPUT(peer));
2397 type = stream_getc(BGP_INPUT(peer));
2398
2399 /* Check whether Extended-Length applies and is in bounds */
2400 if (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN)
2401 && ((endp - startp) < (BGP_ATTR_MIN_LEN + 1))) {
2402 zlog_warn(
2403 "%s: Extended length set, but just %lu bytes of attr header",
2404 peer->host,
2405 (unsigned long)(endp
2406 - stream_pnt(BGP_INPUT(peer))));
2407
2408 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2409 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2410 return BGP_ATTR_PARSE_ERROR;
2411 }
2412
2413 /* Check extended attribue length bit. */
2414 if (CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN))
2415 length = stream_getw(BGP_INPUT(peer));
2416 else
2417 length = stream_getc(BGP_INPUT(peer));
2418
2419 /* If any attribute appears more than once in the UPDATE
2420 message, then the Error Subcode is set to Malformed Attribute
2421 List. */
2422
2423 if (CHECK_BITMAP(seen, type)) {
2424 zlog_warn(
2425 "%s: error BGP attribute type %d appears twice in a message",
2426 peer->host, type);
2427
2428 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2429 BGP_NOTIFY_UPDATE_MAL_ATTR);
2430 return BGP_ATTR_PARSE_ERROR;
2431 }
2432
2433 /* Set type to bitmap to check duplicate attribute. `type' is
2434 unsigned char so it never overflow bitmap range. */
2435
2436 SET_BITMAP(seen, type);
2437
2438 /* Overflow check. */
2439 attr_endp = BGP_INPUT_PNT(peer) + length;
2440
2441 if (attr_endp > endp) {
2442 zlog_warn(
2443 "%s: BGP type %d length %d is too large, attribute total length is %d. attr_endp is %p. endp is %p",
2444 peer->host, type, length, size, attr_endp,
2445 endp);
2446 /*
2447 * RFC 4271 6.3
2448 * If any recognized attribute has an Attribute
2449 * Length that conflicts with the expected length
2450 * (based on the attribute type code), then the
2451 * Error Subcode MUST be set to Attribute Length
2452 * Error. The Data field MUST contain the erroneous
2453 * attribute (type, length, and value).
2454 * ----------
2455 * We do not currently have a good way to determine the
2456 * length of the attribute independent of the length
2457 * received in the message. Instead we send the
2458 * minimum between the amount of data we have and the
2459 * amount specified by the attribute length field.
2460 *
2461 * Instead of directly passing in the packet buffer and
2462 * offset we use the stream_get* functions to read into
2463 * a stack buffer, since they perform bounds checking
2464 * and we are working with untrusted data.
2465 */
2466 unsigned char ndata[BGP_MAX_PACKET_SIZE];
2467 memset(ndata, 0x00, sizeof(ndata));
2468 size_t lfl =
2469 CHECK_FLAG(flag, BGP_ATTR_FLAG_EXTLEN) ? 2 : 1;
2470 /* Rewind to end of flag field */
2471 stream_forward_getp(BGP_INPUT(peer), -(1 + lfl));
2472 /* Type */
2473 stream_get(&ndata[0], BGP_INPUT(peer), 1);
2474 /* Length */
2475 stream_get(&ndata[1], BGP_INPUT(peer), lfl);
2476 /* Value */
2477 size_t atl = attr_endp - startp;
2478 size_t ndl = MIN(atl, STREAM_READABLE(BGP_INPUT(peer)));
2479 stream_get(&ndata[lfl + 1], BGP_INPUT(peer), ndl);
2480
2481 bgp_notify_send_with_data(
2482 peer, BGP_NOTIFY_UPDATE_ERR,
2483 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR, ndata,
2484 ndl + lfl + 1);
2485
2486 return BGP_ATTR_PARSE_ERROR;
2487 }
2488
2489 struct bgp_attr_parser_args attr_args = {
2490 .peer = peer,
2491 .length = length,
2492 .attr = attr,
2493 .type = type,
2494 .flags = flag,
2495 .startp = startp,
2496 .total = attr_endp - startp,
2497 };
2498
2499
2500 /* If any recognized attribute has Attribute Flags that conflict
2501 with the Attribute Type Code, then the Error Subcode is set
2502 to
2503 Attribute Flags Error. The Data field contains the erroneous
2504 attribute (type, length and value). */
2505 if (bgp_attr_flag_invalid(&attr_args)) {
2506 bgp_attr_parse_ret_t ret;
2507 ret = bgp_attr_malformed(
2508 &attr_args, BGP_NOTIFY_UPDATE_ATTR_FLAG_ERR,
2509 attr_args.total);
2510 if (ret == BGP_ATTR_PARSE_PROCEED)
2511 continue;
2512 return ret;
2513 }
2514
2515 /* OK check attribute and store it's value. */
2516 switch (type) {
2517 case BGP_ATTR_ORIGIN:
2518 ret = bgp_attr_origin(&attr_args);
2519 break;
2520 case BGP_ATTR_AS_PATH:
2521 ret = bgp_attr_aspath(&attr_args);
2522 break;
2523 case BGP_ATTR_AS4_PATH:
2524 ret = bgp_attr_as4_path(&attr_args, &as4_path);
2525 break;
2526 case BGP_ATTR_NEXT_HOP:
2527 ret = bgp_attr_nexthop(&attr_args);
2528 break;
2529 case BGP_ATTR_MULTI_EXIT_DISC:
2530 ret = bgp_attr_med(&attr_args);
2531 break;
2532 case BGP_ATTR_LOCAL_PREF:
2533 ret = bgp_attr_local_pref(&attr_args);
2534 break;
2535 case BGP_ATTR_ATOMIC_AGGREGATE:
2536 ret = bgp_attr_atomic(&attr_args);
2537 break;
2538 case BGP_ATTR_AGGREGATOR:
2539 ret = bgp_attr_aggregator(&attr_args);
2540 break;
2541 case BGP_ATTR_AS4_AGGREGATOR:
2542 ret = bgp_attr_as4_aggregator(&attr_args,
2543 &as4_aggregator,
2544 &as4_aggregator_addr);
2545 break;
2546 case BGP_ATTR_COMMUNITIES:
2547 ret = bgp_attr_community(&attr_args);
2548 break;
2549 case BGP_ATTR_LARGE_COMMUNITIES:
2550 ret = bgp_attr_large_community(&attr_args);
2551 break;
2552 case BGP_ATTR_ORIGINATOR_ID:
2553 ret = bgp_attr_originator_id(&attr_args);
2554 break;
2555 case BGP_ATTR_CLUSTER_LIST:
2556 ret = bgp_attr_cluster_list(&attr_args);
2557 break;
2558 case BGP_ATTR_MP_REACH_NLRI:
2559 ret = bgp_mp_reach_parse(&attr_args, mp_update);
2560 break;
2561 case BGP_ATTR_MP_UNREACH_NLRI:
2562 ret = bgp_mp_unreach_parse(&attr_args, mp_withdraw);
2563 break;
2564 case BGP_ATTR_EXT_COMMUNITIES:
2565 ret = bgp_attr_ext_communities(&attr_args);
2566 break;
2567 #if ENABLE_BGP_VNC
2568 case BGP_ATTR_VNC:
2569 #endif
2570 case BGP_ATTR_ENCAP:
2571 ret = bgp_attr_encap(type, peer, length, attr, flag,
2572 startp);
2573 break;
2574 case BGP_ATTR_PREFIX_SID:
2575 ret = bgp_attr_prefix_sid(length,
2576 &attr_args, mp_update);
2577 break;
2578 case BGP_ATTR_PMSI_TUNNEL:
2579 ret = bgp_attr_pmsi_tunnel(&attr_args);
2580 break;
2581 default:
2582 ret = bgp_attr_unknown(&attr_args);
2583 break;
2584 }
2585
2586 if (ret == BGP_ATTR_PARSE_ERROR_NOTIFYPLS) {
2587 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2588 BGP_NOTIFY_UPDATE_MAL_ATTR);
2589 ret = BGP_ATTR_PARSE_ERROR;
2590 }
2591
2592 if (ret == BGP_ATTR_PARSE_EOR) {
2593 if (as4_path)
2594 aspath_unintern(&as4_path);
2595 return ret;
2596 }
2597
2598 /* If hard error occured immediately return to the caller. */
2599 if (ret == BGP_ATTR_PARSE_ERROR) {
2600 zlog_warn("%s: Attribute %s, parse error", peer->host,
2601 lookup_msg(attr_str, type, NULL));
2602 if (as4_path)
2603 aspath_unintern(&as4_path);
2604 return ret;
2605 }
2606 if (ret == BGP_ATTR_PARSE_WITHDRAW) {
2607
2608 zlog_warn(
2609 "%s: Attribute %s, parse error - treating as withdrawal",
2610 peer->host, lookup_msg(attr_str, type, NULL));
2611 if (as4_path)
2612 aspath_unintern(&as4_path);
2613 return ret;
2614 }
2615
2616 /* Check the fetched length. */
2617 if (BGP_INPUT_PNT(peer) != attr_endp) {
2618 zlog_warn("%s: BGP attribute %s, fetch error",
2619 peer->host, lookup_msg(attr_str, type, NULL));
2620 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2621 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2622 if (as4_path)
2623 aspath_unintern(&as4_path);
2624 return BGP_ATTR_PARSE_ERROR;
2625 }
2626 }
2627
2628 /* Check final read pointer is same as end pointer. */
2629 if (BGP_INPUT_PNT(peer) != endp) {
2630 zlog_warn("%s: BGP attribute %s, length mismatch", peer->host,
2631 lookup_msg(attr_str, type, NULL));
2632 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2633 BGP_NOTIFY_UPDATE_ATTR_LENG_ERR);
2634 if (as4_path)
2635 aspath_unintern(&as4_path);
2636 return BGP_ATTR_PARSE_ERROR;
2637 }
2638
2639 /* Check all mandatory well-known attributes are present */
2640 {
2641 bgp_attr_parse_ret_t ret;
2642 if ((ret = bgp_attr_check(peer, attr)) < 0) {
2643 if (as4_path)
2644 aspath_unintern(&as4_path);
2645 return ret;
2646 }
2647 }
2648
2649 /*
2650 * At this place we can see whether we got AS4_PATH and/or
2651 * AS4_AGGREGATOR from a 16Bit peer and act accordingly.
2652 * We can not do this before we've read all attributes because
2653 * the as4 handling does not say whether AS4_PATH has to be sent
2654 * after AS_PATH or not - and when AS4_AGGREGATOR will be send
2655 * in relationship to AGGREGATOR.
2656 * So, to be defensive, we are not relying on any order and read
2657 * all attributes first, including these 32bit ones, and now,
2658 * afterwards, we look what and if something is to be done for as4.
2659 *
2660 * It is possible to not have AS_PATH, e.g. GR EoR and sole
2661 * MP_UNREACH_NLRI.
2662 */
2663 /* actually... this doesn't ever return failure currently, but
2664 * better safe than sorry */
2665 if (CHECK_FLAG(attr->flag, ATTR_FLAG_BIT(BGP_ATTR_AS_PATH))
2666 && bgp_attr_munge_as4_attrs(peer, attr, as4_path, as4_aggregator,
2667 &as4_aggregator_addr)) {
2668 bgp_notify_send(peer, BGP_NOTIFY_UPDATE_ERR,
2669 BGP_NOTIFY_UPDATE_MAL_ATTR);
2670 if (as4_path)
2671 aspath_unintern(&as4_path);
2672 return BGP_ATTR_PARSE_ERROR;
2673 }
2674
2675 /* At this stage, we have done all fiddling with as4, and the
2676 * resulting info is in attr->aggregator resp. attr->aspath
2677 * so we can chuck as4_aggregator and as4_path alltogether in
2678 * order to save memory
2679 */
2680 if (as4_path) {
2681 aspath_unintern(&as4_path); /* unintern - it is in the hash */
2682 /* The flag that we got this is still there, but that does not
2683 * do any trouble
2684 */
2685 }
2686 /*
2687 * The "rest" of the code does nothing with as4_aggregator.
2688 * there is no memory attached specifically which is not part
2689 * of the attr.
2690 * so ignoring just means do nothing.
2691 */
2692 /*
2693 * Finally do the checks on the aspath we did not do yet
2694 * because we waited for a potentially synthesized aspath.
2695 */
2696 if (attr->flag & (ATTR_FLAG_BIT(BGP_ATTR_AS_PATH))) {
2697 ret = bgp_attr_aspath_check(peer, attr);
2698 if (ret != BGP_ATTR_PARSE_PROCEED)
2699 return ret;
2700 }
2701 /* Finally intern unknown attribute. */
2702 if (attr->transit)
2703 attr->transit = transit_intern(attr->transit);
2704 if (attr->encap_subtlvs)
2705 attr->encap_subtlvs =
2706 encap_intern(attr->encap_subtlvs, ENCAP_SUBTLV_TYPE);
2707 #if ENABLE_BGP_VNC
2708 if (attr->vnc_subtlvs)
2709 attr->vnc_subtlvs =
2710 encap_intern(attr->vnc_subtlvs, VNC_SUBTLV_TYPE);
2711 #endif
2712
2713 return BGP_ATTR_PARSE_PROCEED;
2714 }
2715
2716 size_t bgp_packet_mpattr_start(struct stream *s, struct peer *peer, afi_t afi,
2717 safi_t safi, struct bpacket_attr_vec_arr *vecarr,
2718 struct attr *attr)
2719 {
2720 size_t sizep;
2721 iana_afi_t pkt_afi;
2722 iana_safi_t pkt_safi;
2723 afi_t nh_afi;
2724
2725 /* Set extended bit always to encode the attribute length as 2 bytes */
2726 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_EXTLEN);
2727 stream_putc(s, BGP_ATTR_MP_REACH_NLRI);
2728 sizep = stream_get_endp(s);
2729 stream_putw(s, 0); /* Marker: Attribute length. */
2730
2731
2732 /* Convert AFI, SAFI to values for packet. */
2733 bgp_map_afi_safi_int2iana(afi, safi, &pkt_afi, &pkt_safi);
2734
2735 stream_putw(s, pkt_afi); /* AFI */
2736 stream_putc(s, pkt_safi); /* SAFI */
2737
2738 /* Nexthop AFI */
2739 if (afi == AFI_IP
2740 && (safi == SAFI_UNICAST || safi == SAFI_LABELED_UNICAST))
2741 nh_afi = peer_cap_enhe(peer, afi, safi) ? AFI_IP6 : AFI_IP;
2742 else
2743 nh_afi = BGP_NEXTHOP_AFI_FROM_NHLEN(attr->mp_nexthop_len);
2744
2745 /* Nexthop */
2746 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s, attr);
2747 switch (nh_afi) {
2748 case AFI_IP:
2749 switch (safi) {
2750 case SAFI_UNICAST:
2751 case SAFI_MULTICAST:
2752 case SAFI_LABELED_UNICAST:
2753 stream_putc(s, 4);
2754 stream_put_ipv4(s, attr->nexthop.s_addr);
2755 break;
2756 case SAFI_MPLS_VPN:
2757 stream_putc(s, 12);
2758 stream_putl(s, 0); /* RD = 0, per RFC */
2759 stream_putl(s, 0);
2760 stream_put(s, &attr->mp_nexthop_global_in, 4);
2761 break;
2762 case SAFI_ENCAP:
2763 case SAFI_EVPN:
2764 stream_putc(s, 4);
2765 stream_put(s, &attr->mp_nexthop_global_in, 4);
2766 break;
2767 case SAFI_FLOWSPEC:
2768 stream_putc(s, 0); /* no nexthop for flowspec */
2769 default:
2770 break;
2771 }
2772 break;
2773 case AFI_IP6:
2774 switch (safi) {
2775 case SAFI_UNICAST:
2776 case SAFI_MULTICAST:
2777 case SAFI_LABELED_UNICAST:
2778 case SAFI_EVPN: {
2779 if (attr->mp_nexthop_len
2780 == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) {
2781 stream_putc(s,
2782 BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL);
2783 stream_put(s, &attr->mp_nexthop_global,
2784 IPV6_MAX_BYTELEN);
2785 stream_put(s, &attr->mp_nexthop_local,
2786 IPV6_MAX_BYTELEN);
2787 } else {
2788 stream_putc(s, IPV6_MAX_BYTELEN);
2789 stream_put(s, &attr->mp_nexthop_global,
2790 IPV6_MAX_BYTELEN);
2791 }
2792 } break;
2793 case SAFI_MPLS_VPN: {
2794 if (attr->mp_nexthop_len
2795 == BGP_ATTR_NHLEN_IPV6_GLOBAL) {
2796 stream_putc(s, 24);
2797 stream_putl(s, 0); /* RD = 0, per RFC */
2798 stream_putl(s, 0);
2799 stream_put(s, &attr->mp_nexthop_global,
2800 IPV6_MAX_BYTELEN);
2801 } else if (attr->mp_nexthop_len
2802 == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL) {
2803 stream_putc(s, 48);
2804 stream_putl(s, 0); /* RD = 0, per RFC */
2805 stream_putl(s, 0);
2806 stream_put(s, &attr->mp_nexthop_global,
2807 IPV6_MAX_BYTELEN);
2808 stream_putl(s, 0); /* RD = 0, per RFC */
2809 stream_putl(s, 0);
2810 stream_put(s, &attr->mp_nexthop_local,
2811 IPV6_MAX_BYTELEN);
2812 }
2813 } break;
2814 case SAFI_ENCAP:
2815 stream_putc(s, IPV6_MAX_BYTELEN);
2816 stream_put(s, &attr->mp_nexthop_global,
2817 IPV6_MAX_BYTELEN);
2818 break;
2819 case SAFI_FLOWSPEC:
2820 stream_putc(s, 0); /* no nexthop for flowspec */
2821 default:
2822 break;
2823 }
2824 break;
2825 default:
2826 if (safi != SAFI_FLOWSPEC)
2827 flog_err(
2828 BGP_ERR_ATTR_NH_SEND_LEN,
2829 "Bad nexthop when sending to %s, AFI %u SAFI %u nhlen %d",
2830 peer->host, afi, safi, attr->mp_nexthop_len);
2831 break;
2832 }
2833
2834 /* SNPA */
2835 stream_putc(s, 0);
2836 return sizep;
2837 }
2838
2839 void bgp_packet_mpattr_prefix(struct stream *s, afi_t afi, safi_t safi,
2840 struct prefix *p, struct prefix_rd *prd,
2841 mpls_label_t *label, uint32_t num_labels,
2842 int addpath_encode, uint32_t addpath_tx_id,
2843 struct attr *attr)
2844 {
2845 if (safi == SAFI_MPLS_VPN) {
2846 if (addpath_encode)
2847 stream_putl(s, addpath_tx_id);
2848 /* Label, RD, Prefix write. */
2849 stream_putc(s, p->prefixlen + 88);
2850 stream_put(s, label, BGP_LABEL_BYTES);
2851 stream_put(s, prd->val, 8);
2852 stream_put(s, &p->u.prefix, PSIZE(p->prefixlen));
2853 } else if (afi == AFI_L2VPN && safi == SAFI_EVPN) {
2854 /* EVPN prefix - contents depend on type */
2855 bgp_evpn_encode_prefix(s, p, prd, label, num_labels, attr,
2856 addpath_encode, addpath_tx_id);
2857 } else if (safi == SAFI_LABELED_UNICAST) {
2858 /* Prefix write with label. */
2859 stream_put_labeled_prefix(s, p, label);
2860 } else if (safi == SAFI_FLOWSPEC) {
2861 if (PSIZE (p->prefixlen)+2 < FLOWSPEC_NLRI_SIZELIMIT)
2862 stream_putc(s, PSIZE (p->prefixlen)+2);
2863 else
2864 stream_putw(s, (PSIZE (p->prefixlen)+2)|(0xf<<12));
2865 stream_putc(s, 2);/* Filter type */
2866 stream_putc(s, p->prefixlen);/* Prefix length */
2867 stream_put(s, &p->u.prefix, PSIZE (p->prefixlen));
2868 } else
2869 stream_put_prefix_addpath(s, p, addpath_encode, addpath_tx_id);
2870 }
2871
2872 size_t bgp_packet_mpattr_prefix_size(afi_t afi, safi_t safi, struct prefix *p)
2873 {
2874 int size = PSIZE(p->prefixlen);
2875 if (safi == SAFI_MPLS_VPN)
2876 size += 88;
2877 else if (afi == AFI_L2VPN && safi == SAFI_EVPN)
2878 size += 232; // TODO: Maximum possible for type-2, type-3 and
2879 // type-5
2880 return size;
2881 }
2882
2883 /*
2884 * Encodes the tunnel encapsulation attribute,
2885 * and with ENABLE_BGP_VNC the VNC attribute which uses
2886 * almost the same TLV format
2887 */
2888 static void bgp_packet_mpattr_tea(struct bgp *bgp, struct peer *peer,
2889 struct stream *s, struct attr *attr,
2890 uint8_t attrtype)
2891 {
2892 unsigned int attrlenfield = 0;
2893 unsigned int attrhdrlen = 0;
2894 struct bgp_attr_encap_subtlv *subtlvs;
2895 struct bgp_attr_encap_subtlv *st;
2896 const char *attrname;
2897
2898 if (!attr || (attrtype == BGP_ATTR_ENCAP
2899 && (!attr->encap_tunneltype
2900 || attr->encap_tunneltype == BGP_ENCAP_TYPE_MPLS)))
2901 return;
2902
2903 switch (attrtype) {
2904 case BGP_ATTR_ENCAP:
2905 attrname = "Tunnel Encap";
2906 subtlvs = attr->encap_subtlvs;
2907 if (subtlvs == NULL) /* nothing to do */
2908 return;
2909 /*
2910 * The tunnel encap attr has an "outer" tlv.
2911 * T = tunneltype,
2912 * L = total length of subtlvs,
2913 * V = concatenated subtlvs.
2914 */
2915 attrlenfield = 2 + 2; /* T + L */
2916 attrhdrlen = 1 + 1; /* subTLV T + L */
2917 break;
2918
2919 #if ENABLE_BGP_VNC
2920 case BGP_ATTR_VNC:
2921 attrname = "VNC";
2922 subtlvs = attr->vnc_subtlvs;
2923 if (subtlvs == NULL) /* nothing to do */
2924 return;
2925 attrlenfield = 0; /* no outer T + L */
2926 attrhdrlen = 2 + 2; /* subTLV T + L */
2927 break;
2928 #endif
2929
2930 default:
2931 assert(0);
2932 }
2933
2934 /* compute attr length */
2935 for (st = subtlvs; st; st = st->next) {
2936 attrlenfield += (attrhdrlen + st->length);
2937 }
2938
2939 if (attrlenfield > 0xffff) {
2940 zlog_info("%s attribute is too long (length=%d), can't send it",
2941 attrname, attrlenfield);
2942 return;
2943 }
2944
2945 if (attrlenfield > 0xff) {
2946 /* 2-octet length field */
2947 stream_putc(s,
2948 BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL
2949 | BGP_ATTR_FLAG_EXTLEN);
2950 stream_putc(s, attrtype);
2951 stream_putw(s, attrlenfield & 0xffff);
2952 } else {
2953 /* 1-octet length field */
2954 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL);
2955 stream_putc(s, attrtype);
2956 stream_putc(s, attrlenfield & 0xff);
2957 }
2958
2959 if (attrtype == BGP_ATTR_ENCAP) {
2960 /* write outer T+L */
2961 stream_putw(s, attr->encap_tunneltype);
2962 stream_putw(s, attrlenfield - 4);
2963 }
2964
2965 /* write each sub-tlv */
2966 for (st = subtlvs; st; st = st->next) {
2967 if (attrtype == BGP_ATTR_ENCAP) {
2968 stream_putc(s, st->type);
2969 stream_putc(s, st->length);
2970 #if ENABLE_BGP_VNC
2971 } else {
2972 stream_putw(s, st->type);
2973 stream_putw(s, st->length);
2974 #endif
2975 }
2976 stream_put(s, st->value, st->length);
2977 }
2978 }
2979
2980 void bgp_packet_mpattr_end(struct stream *s, size_t sizep)
2981 {
2982 /* Set MP attribute length. Don't count the (2) bytes used to encode
2983 the attr length */
2984 stream_putw_at(s, sizep, (stream_get_endp(s) - sizep) - 2);
2985 }
2986
2987 /* Make attribute packet. */
2988 bgp_size_t bgp_packet_attribute(struct bgp *bgp, struct peer *peer,
2989 struct stream *s, struct attr *attr,
2990 struct bpacket_attr_vec_arr *vecarr,
2991 struct prefix *p, afi_t afi, safi_t safi,
2992 struct peer *from, struct prefix_rd *prd,
2993 mpls_label_t *label, uint32_t num_labels,
2994 int addpath_encode, uint32_t addpath_tx_id)
2995 {
2996 size_t cp;
2997 size_t aspath_sizep;
2998 struct aspath *aspath;
2999 int send_as4_path = 0;
3000 int send_as4_aggregator = 0;
3001 int use32bit = (CHECK_FLAG(peer->cap, PEER_CAP_AS4_RCV)) ? 1 : 0;
3002
3003 if (!bgp)
3004 bgp = peer->bgp;
3005
3006 /* Remember current pointer. */
3007 cp = stream_get_endp(s);
3008
3009 if (p
3010 && !((afi == AFI_IP && safi == SAFI_UNICAST)
3011 && !peer_cap_enhe(peer, afi, safi))) {
3012 size_t mpattrlen_pos = 0;
3013
3014 mpattrlen_pos = bgp_packet_mpattr_start(s, peer, afi, safi,
3015 vecarr, attr);
3016 bgp_packet_mpattr_prefix(s, afi, safi, p, prd, label,
3017 num_labels, addpath_encode,
3018 addpath_tx_id, attr);
3019 bgp_packet_mpattr_end(s, mpattrlen_pos);
3020 }
3021
3022 /* Origin attribute. */
3023 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3024 stream_putc(s, BGP_ATTR_ORIGIN);
3025 stream_putc(s, 1);
3026 stream_putc(s, attr->origin);
3027
3028 /* AS path attribute. */
3029
3030 /* If remote-peer is EBGP */
3031 if (peer->sort == BGP_PEER_EBGP
3032 && (!CHECK_FLAG(peer->af_flags[afi][safi],
3033 PEER_FLAG_AS_PATH_UNCHANGED)
3034 || attr->aspath->segments == NULL)
3035 && (!CHECK_FLAG(peer->af_flags[afi][safi],
3036 PEER_FLAG_RSERVER_CLIENT))) {
3037 aspath = aspath_dup(attr->aspath);
3038
3039 /* Even though we may not be configured for confederations we
3040 * may have
3041 * RXed an AS_PATH with AS_CONFED_SEQUENCE or AS_CONFED_SET */
3042 aspath = aspath_delete_confed_seq(aspath);
3043
3044 if (CHECK_FLAG(bgp->config, BGP_CONFIG_CONFEDERATION)) {
3045 /* Stuff our path CONFED_ID on the front */
3046 aspath = aspath_add_seq(aspath, bgp->confed_id);
3047 } else {
3048 if (peer->change_local_as) {
3049 /* If replace-as is specified, we only use the
3050 change_local_as when
3051 advertising routes. */
3052 if (!CHECK_FLAG(
3053 peer->flags,
3054 PEER_FLAG_LOCAL_AS_REPLACE_AS)) {
3055 aspath = aspath_add_seq(aspath,
3056 peer->local_as);
3057 }
3058 aspath = aspath_add_seq(aspath,
3059 peer->change_local_as);
3060 } else {
3061 aspath = aspath_add_seq(aspath, peer->local_as);
3062 }
3063 }
3064 } else if (peer->sort == BGP_PEER_CONFED) {
3065 /* A confed member, so we need to do the AS_CONFED_SEQUENCE
3066 * thing */
3067 aspath = aspath_dup(attr->aspath);
3068 aspath = aspath_add_confed_seq(aspath, peer->local_as);
3069 } else
3070 aspath = attr->aspath;
3071
3072 /* If peer is not AS4 capable, then:
3073 * - send the created AS_PATH out as AS4_PATH (optional, transitive),
3074 * but ensure that no AS_CONFED_SEQUENCE and AS_CONFED_SET path
3075 * segment
3076 * types are in it (i.e. exclude them if they are there)
3077 * AND do this only if there is at least one asnum > 65535 in the
3078 * path!
3079 * - send an AS_PATH out, but put 16Bit ASnums in it, not 32bit, and
3080 * change
3081 * all ASnums > 65535 to BGP_AS_TRANS
3082 */
3083
3084 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_EXTLEN);
3085 stream_putc(s, BGP_ATTR_AS_PATH);
3086 aspath_sizep = stream_get_endp(s);
3087 stream_putw(s, 0);
3088 stream_putw_at(s, aspath_sizep, aspath_put(s, aspath, use32bit));
3089
3090 /* OLD session may need NEW_AS_PATH sent, if there are 4-byte ASNs
3091 * in the path
3092 */
3093 if (!use32bit && aspath_has_as4(aspath))
3094 send_as4_path =
3095 1; /* we'll do this later, at the correct place */
3096
3097 /* Nexthop attribute. */
3098 if (afi == AFI_IP && safi == SAFI_UNICAST
3099 && !peer_cap_enhe(peer, afi, safi)) {
3100 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_NEXT_HOP)) {
3101 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3102 stream_putc(s, BGP_ATTR_NEXT_HOP);
3103 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s,
3104 attr);
3105 stream_putc(s, 4);
3106 stream_put_ipv4(s, attr->nexthop.s_addr);
3107 } else if (peer_cap_enhe(from, afi, safi)) {
3108 /*
3109 * Likely this is the case when an IPv4 prefix was
3110 * received with
3111 * Extended Next-hop capability and now being advertised
3112 * to
3113 * non-ENHE peers.
3114 * Setting the mandatory (ipv4) next-hop attribute here
3115 * to enable
3116 * implicit next-hop self with correct (ipv4 address
3117 * family).
3118 */
3119 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3120 stream_putc(s, BGP_ATTR_NEXT_HOP);
3121 bpacket_attr_vec_arr_set_vec(vecarr, BGP_ATTR_VEC_NH, s,
3122 NULL);
3123 stream_putc(s, 4);
3124 stream_put_ipv4(s, 0);
3125 }
3126 }
3127
3128 /* MED attribute. */
3129 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC)
3130 || bgp->maxmed_active) {
3131 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3132 stream_putc(s, BGP_ATTR_MULTI_EXIT_DISC);
3133 stream_putc(s, 4);
3134 stream_putl(s, (bgp->maxmed_active ? bgp->maxmed_value
3135 : attr->med));
3136 }
3137
3138 /* Local preference. */
3139 if (peer->sort == BGP_PEER_IBGP || peer->sort == BGP_PEER_CONFED) {
3140 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3141 stream_putc(s, BGP_ATTR_LOCAL_PREF);
3142 stream_putc(s, 4);
3143 stream_putl(s, attr->local_pref);
3144 }
3145
3146 /* Atomic aggregate. */
3147 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE)) {
3148 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3149 stream_putc(s, BGP_ATTR_ATOMIC_AGGREGATE);
3150 stream_putc(s, 0);
3151 }
3152
3153 /* Aggregator. */
3154 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR)) {
3155 /* Common to BGP_ATTR_AGGREGATOR, regardless of ASN size */
3156 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3157 stream_putc(s, BGP_ATTR_AGGREGATOR);
3158
3159 if (use32bit) {
3160 /* AS4 capable peer */
3161 stream_putc(s, 8);
3162 stream_putl(s, attr->aggregator_as);
3163 } else {
3164 /* 2-byte AS peer */
3165 stream_putc(s, 6);
3166
3167 /* Is ASN representable in 2-bytes? Or must AS_TRANS be
3168 * used? */
3169 if (attr->aggregator_as > 65535) {
3170 stream_putw(s, BGP_AS_TRANS);
3171
3172 /* we have to send AS4_AGGREGATOR, too.
3173 * we'll do that later in order to send
3174 * attributes in ascending
3175 * order.
3176 */
3177 send_as4_aggregator = 1;
3178 } else
3179 stream_putw(s, (uint16_t)attr->aggregator_as);
3180 }
3181 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3182 }
3183
3184 /* Community attribute. */
3185 if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_SEND_COMMUNITY)
3186 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES))) {
3187 if (attr->community->size * 4 > 255) {
3188 stream_putc(s,
3189 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3190 | BGP_ATTR_FLAG_EXTLEN);
3191 stream_putc(s, BGP_ATTR_COMMUNITIES);
3192 stream_putw(s, attr->community->size * 4);
3193 } else {
3194 stream_putc(s,
3195 BGP_ATTR_FLAG_OPTIONAL
3196 | BGP_ATTR_FLAG_TRANS);
3197 stream_putc(s, BGP_ATTR_COMMUNITIES);
3198 stream_putc(s, attr->community->size * 4);
3199 }
3200 stream_put(s, attr->community->val, attr->community->size * 4);
3201 }
3202
3203 /*
3204 * Large Community attribute.
3205 */
3206 if (CHECK_FLAG(peer->af_flags[afi][safi],
3207 PEER_FLAG_SEND_LARGE_COMMUNITY)
3208 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES))) {
3209 if (lcom_length(attr->lcommunity) > 255) {
3210 stream_putc(s,
3211 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3212 | BGP_ATTR_FLAG_EXTLEN);
3213 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3214 stream_putw(s, lcom_length(attr->lcommunity));
3215 } else {
3216 stream_putc(s,
3217 BGP_ATTR_FLAG_OPTIONAL
3218 | BGP_ATTR_FLAG_TRANS);
3219 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3220 stream_putc(s, lcom_length(attr->lcommunity));
3221 }
3222 stream_put(s, attr->lcommunity->val,
3223 lcom_length(attr->lcommunity));
3224 }
3225
3226 /* Route Reflector. */
3227 if (peer->sort == BGP_PEER_IBGP && from
3228 && from->sort == BGP_PEER_IBGP) {
3229 /* Originator ID. */
3230 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3231 stream_putc(s, BGP_ATTR_ORIGINATOR_ID);
3232 stream_putc(s, 4);
3233
3234 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID))
3235 stream_put_in_addr(s, &attr->originator_id);
3236 else
3237 stream_put_in_addr(s, &from->remote_id);
3238
3239 /* Cluster list. */
3240 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3241 stream_putc(s, BGP_ATTR_CLUSTER_LIST);
3242
3243 if (attr->cluster) {
3244 stream_putc(s, attr->cluster->length + 4);
3245 /* If this peer configuration's parent BGP has
3246 * cluster_id. */
3247 if (bgp->config & BGP_CONFIG_CLUSTER_ID)
3248 stream_put_in_addr(s, &bgp->cluster_id);
3249 else
3250 stream_put_in_addr(s, &bgp->router_id);
3251 stream_put(s, attr->cluster->list,
3252 attr->cluster->length);
3253 } else {
3254 stream_putc(s, 4);
3255 /* If this peer configuration's parent BGP has
3256 * cluster_id. */
3257 if (bgp->config & BGP_CONFIG_CLUSTER_ID)
3258 stream_put_in_addr(s, &bgp->cluster_id);
3259 else
3260 stream_put_in_addr(s, &bgp->router_id);
3261 }
3262 }
3263
3264 /* Extended Communities attribute. */
3265 if (CHECK_FLAG(peer->af_flags[afi][safi], PEER_FLAG_SEND_EXT_COMMUNITY)
3266 && (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_EXT_COMMUNITIES))) {
3267 if (peer->sort == BGP_PEER_IBGP
3268 || peer->sort == BGP_PEER_CONFED) {
3269 if (attr->ecommunity->size * 8 > 255) {
3270 stream_putc(s,
3271 BGP_ATTR_FLAG_OPTIONAL
3272 | BGP_ATTR_FLAG_TRANS
3273 | BGP_ATTR_FLAG_EXTLEN);
3274 stream_putc(s, BGP_ATTR_EXT_COMMUNITIES);
3275 stream_putw(s, attr->ecommunity->size * 8);
3276 } else {
3277 stream_putc(s,
3278 BGP_ATTR_FLAG_OPTIONAL
3279 | BGP_ATTR_FLAG_TRANS);
3280 stream_putc(s, BGP_ATTR_EXT_COMMUNITIES);
3281 stream_putc(s, attr->ecommunity->size * 8);
3282 }
3283 stream_put(s, attr->ecommunity->val,
3284 attr->ecommunity->size * 8);
3285 } else {
3286 uint8_t *pnt;
3287 int tbit;
3288 int ecom_tr_size = 0;
3289 int i;
3290
3291 for (i = 0; i < attr->ecommunity->size; i++) {
3292 pnt = attr->ecommunity->val + (i * 8);
3293 tbit = *pnt;
3294
3295 if (CHECK_FLAG(tbit,
3296 ECOMMUNITY_FLAG_NON_TRANSITIVE))
3297 continue;
3298
3299 ecom_tr_size++;
3300 }
3301
3302 if (ecom_tr_size) {
3303 if (ecom_tr_size * 8 > 255) {
3304 stream_putc(
3305 s,
3306 BGP_ATTR_FLAG_OPTIONAL
3307 | BGP_ATTR_FLAG_TRANS
3308 | BGP_ATTR_FLAG_EXTLEN);
3309 stream_putc(s,
3310 BGP_ATTR_EXT_COMMUNITIES);
3311 stream_putw(s, ecom_tr_size * 8);
3312 } else {
3313 stream_putc(
3314 s,
3315 BGP_ATTR_FLAG_OPTIONAL
3316 | BGP_ATTR_FLAG_TRANS);
3317 stream_putc(s,
3318 BGP_ATTR_EXT_COMMUNITIES);
3319 stream_putc(s, ecom_tr_size * 8);
3320 }
3321
3322 for (i = 0; i < attr->ecommunity->size; i++) {
3323 pnt = attr->ecommunity->val + (i * 8);
3324 tbit = *pnt;
3325
3326 if (CHECK_FLAG(
3327 tbit,
3328 ECOMMUNITY_FLAG_NON_TRANSITIVE))
3329 continue;
3330
3331 stream_put(s, pnt, 8);
3332 }
3333 }
3334 }
3335 }
3336
3337 /* Label index attribute. */
3338 if (safi == SAFI_LABELED_UNICAST) {
3339 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID)) {
3340 uint32_t label_index;
3341
3342 label_index = attr->label_index;
3343
3344 if (label_index != BGP_INVALID_LABEL_INDEX) {
3345 stream_putc(s,
3346 BGP_ATTR_FLAG_OPTIONAL
3347 | BGP_ATTR_FLAG_TRANS);
3348 stream_putc(s, BGP_ATTR_PREFIX_SID);
3349 stream_putc(s, 10);
3350 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX);
3351 stream_putw(s,
3352 BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
3353 stream_putc(s, 0); // reserved
3354 stream_putw(s, 0); // flags
3355 stream_putl(s, label_index);
3356 }
3357 }
3358 }
3359
3360 if (send_as4_path) {
3361 /* If the peer is NOT As4 capable, AND */
3362 /* there are ASnums > 65535 in path THEN
3363 * give out AS4_PATH */
3364
3365 /* Get rid of all AS_CONFED_SEQUENCE and AS_CONFED_SET
3366 * path segments!
3367 * Hm, I wonder... confederation things *should* only be at
3368 * the beginning of an aspath, right? Then we should use
3369 * aspath_delete_confed_seq for this, because it is already
3370 * there! (JK)
3371 * Folks, talk to me: what is reasonable here!?
3372 */
3373 aspath = aspath_delete_confed_seq(aspath);
3374
3375 stream_putc(s,
3376 BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_OPTIONAL
3377 | BGP_ATTR_FLAG_EXTLEN);
3378 stream_putc(s, BGP_ATTR_AS4_PATH);
3379 aspath_sizep = stream_get_endp(s);
3380 stream_putw(s, 0);
3381 stream_putw_at(s, aspath_sizep, aspath_put(s, aspath, 1));
3382 }
3383
3384 if (aspath != attr->aspath)
3385 aspath_free(aspath);
3386
3387 if (send_as4_aggregator) {
3388 /* send AS4_AGGREGATOR, at this place */
3389 /* this section of code moved here in order to ensure the
3390 * correct
3391 * *ascending* order of attributes
3392 */
3393 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3394 stream_putc(s, BGP_ATTR_AS4_AGGREGATOR);
3395 stream_putc(s, 8);
3396 stream_putl(s, attr->aggregator_as);
3397 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3398 }
3399
3400 if (((afi == AFI_IP || afi == AFI_IP6)
3401 && (safi == SAFI_ENCAP || safi == SAFI_MPLS_VPN))
3402 || (afi == AFI_L2VPN && safi == SAFI_EVPN)) {
3403 /* Tunnel Encap attribute */
3404 bgp_packet_mpattr_tea(bgp, peer, s, attr, BGP_ATTR_ENCAP);
3405
3406 #if ENABLE_BGP_VNC
3407 /* VNC attribute */
3408 bgp_packet_mpattr_tea(bgp, peer, s, attr, BGP_ATTR_VNC);
3409 #endif
3410 }
3411
3412 /* PMSI Tunnel */
3413 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PMSI_TUNNEL)) {
3414 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3415 stream_putc(s, BGP_ATTR_PMSI_TUNNEL);
3416 stream_putc(s, 9); // Length
3417 stream_putc(s, 0); // Flags
3418 stream_putc(s, PMSI_TNLTYPE_INGR_REPL); // IR (6)
3419 stream_put(s, &(attr->label),
3420 BGP_LABEL_BYTES); // MPLS Label / VXLAN VNI
3421 stream_put_ipv4(s, attr->nexthop.s_addr);
3422 // Unicast tunnel endpoint IP address
3423 }
3424
3425 /* Unknown transit attribute. */
3426 if (attr->transit)
3427 stream_put(s, attr->transit->val, attr->transit->length);
3428
3429 /* Return total size of attribute. */
3430 return stream_get_endp(s) - cp;
3431 }
3432
3433 size_t bgp_packet_mpunreach_start(struct stream *s, afi_t afi, safi_t safi)
3434 {
3435 unsigned long attrlen_pnt;
3436 iana_afi_t pkt_afi;
3437 iana_safi_t pkt_safi;
3438
3439 /* Set extended bit always to encode the attribute length as 2 bytes */
3440 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_EXTLEN);
3441 stream_putc(s, BGP_ATTR_MP_UNREACH_NLRI);
3442
3443 attrlen_pnt = stream_get_endp(s);
3444 stream_putw(s, 0); /* Length of this attribute. */
3445
3446 /* Convert AFI, SAFI to values for packet. */
3447 bgp_map_afi_safi_int2iana(afi, safi, &pkt_afi, &pkt_safi);
3448
3449 stream_putw(s, pkt_afi);
3450 stream_putc(s, pkt_safi);
3451
3452 return attrlen_pnt;
3453 }
3454
3455 void bgp_packet_mpunreach_prefix(struct stream *s, struct prefix *p, afi_t afi,
3456 safi_t safi, struct prefix_rd *prd,
3457 mpls_label_t *label, uint32_t num_labels,
3458 int addpath_encode, uint32_t addpath_tx_id,
3459 struct attr *attr)
3460 {
3461 uint8_t wlabel[3] = {0x80, 0x00, 0x00};
3462
3463 if (safi == SAFI_LABELED_UNICAST) {
3464 label = (mpls_label_t *)wlabel;
3465 num_labels = 1;
3466 }
3467
3468 return bgp_packet_mpattr_prefix(s, afi, safi, p, prd, label, num_labels,
3469 addpath_encode, addpath_tx_id, attr);
3470 }
3471
3472 void bgp_packet_mpunreach_end(struct stream *s, size_t attrlen_pnt)
3473 {
3474 bgp_packet_mpattr_end(s, attrlen_pnt);
3475 }
3476
3477 /* Initialization of attribute. */
3478 void bgp_attr_init(void)
3479 {
3480 aspath_init();
3481 attrhash_init();
3482 community_init();
3483 ecommunity_init();
3484 lcommunity_init();
3485 cluster_init();
3486 transit_init();
3487 encap_init();
3488 }
3489
3490 void bgp_attr_finish(void)
3491 {
3492 aspath_finish();
3493 attrhash_finish();
3494 community_finish();
3495 ecommunity_finish();
3496 lcommunity_finish();
3497 cluster_finish();
3498 transit_finish();
3499 encap_finish();
3500 }
3501
3502 /* Make attribute packet. */
3503 void bgp_dump_routes_attr(struct stream *s, struct attr *attr,
3504 struct prefix *prefix)
3505 {
3506 unsigned long cp;
3507 unsigned long len;
3508 size_t aspath_lenp;
3509 struct aspath *aspath;
3510 int addpath_encode = 0;
3511 uint32_t addpath_tx_id = 0;
3512
3513 /* Remember current pointer. */
3514 cp = stream_get_endp(s);
3515
3516 /* Place holder of length. */
3517 stream_putw(s, 0);
3518
3519 /* Origin attribute. */
3520 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3521 stream_putc(s, BGP_ATTR_ORIGIN);
3522 stream_putc(s, 1);
3523 stream_putc(s, attr->origin);
3524
3525 aspath = attr->aspath;
3526
3527 stream_putc(s, BGP_ATTR_FLAG_TRANS | BGP_ATTR_FLAG_EXTLEN);
3528 stream_putc(s, BGP_ATTR_AS_PATH);
3529 aspath_lenp = stream_get_endp(s);
3530 stream_putw(s, 0);
3531
3532 stream_putw_at(s, aspath_lenp, aspath_put(s, aspath, 1));
3533
3534 /* Nexthop attribute. */
3535 /* If it's an IPv6 prefix, don't dump the IPv4 nexthop to save space */
3536 if (prefix != NULL && prefix->family != AF_INET6) {
3537 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3538 stream_putc(s, BGP_ATTR_NEXT_HOP);
3539 stream_putc(s, 4);
3540 stream_put_ipv4(s, attr->nexthop.s_addr);
3541 }
3542
3543 /* MED attribute. */
3544 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_MULTI_EXIT_DISC)) {
3545 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3546 stream_putc(s, BGP_ATTR_MULTI_EXIT_DISC);
3547 stream_putc(s, 4);
3548 stream_putl(s, attr->med);
3549 }
3550
3551 /* Local preference. */
3552 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LOCAL_PREF)) {
3553 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3554 stream_putc(s, BGP_ATTR_LOCAL_PREF);
3555 stream_putc(s, 4);
3556 stream_putl(s, attr->local_pref);
3557 }
3558
3559 /* Atomic aggregate. */
3560 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ATOMIC_AGGREGATE)) {
3561 stream_putc(s, BGP_ATTR_FLAG_TRANS);
3562 stream_putc(s, BGP_ATTR_ATOMIC_AGGREGATE);
3563 stream_putc(s, 0);
3564 }
3565
3566 /* Aggregator. */
3567 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_AGGREGATOR)) {
3568 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS);
3569 stream_putc(s, BGP_ATTR_AGGREGATOR);
3570 stream_putc(s, 8);
3571 stream_putl(s, attr->aggregator_as);
3572 stream_put_ipv4(s, attr->aggregator_addr.s_addr);
3573 }
3574
3575 /* Community attribute. */
3576 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_COMMUNITIES)) {
3577 if (attr->community->size * 4 > 255) {
3578 stream_putc(s,
3579 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3580 | BGP_ATTR_FLAG_EXTLEN);
3581 stream_putc(s, BGP_ATTR_COMMUNITIES);
3582 stream_putw(s, attr->community->size * 4);
3583 } else {
3584 stream_putc(s,
3585 BGP_ATTR_FLAG_OPTIONAL
3586 | BGP_ATTR_FLAG_TRANS);
3587 stream_putc(s, BGP_ATTR_COMMUNITIES);
3588 stream_putc(s, attr->community->size * 4);
3589 }
3590 stream_put(s, attr->community->val, attr->community->size * 4);
3591 }
3592
3593 /* Large Community attribute. */
3594 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_LARGE_COMMUNITIES)) {
3595 if (lcom_length(attr->lcommunity) > 255) {
3596 stream_putc(s,
3597 BGP_ATTR_FLAG_OPTIONAL | BGP_ATTR_FLAG_TRANS
3598 | BGP_ATTR_FLAG_EXTLEN);
3599 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3600 stream_putw(s, lcom_length(attr->lcommunity));
3601 } else {
3602 stream_putc(s,
3603 BGP_ATTR_FLAG_OPTIONAL
3604 | BGP_ATTR_FLAG_TRANS);
3605 stream_putc(s, BGP_ATTR_LARGE_COMMUNITIES);
3606 stream_putc(s, lcom_length(attr->lcommunity));
3607 }
3608
3609 stream_put(s, attr->lcommunity->val,
3610 lcom_length(attr->lcommunity));
3611 }
3612
3613 /* Add a MP_NLRI attribute to dump the IPv6 next hop */
3614 if (prefix != NULL && prefix->family == AF_INET6
3615 && (attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL
3616 || attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)) {
3617 int sizep;
3618
3619 stream_putc(s, BGP_ATTR_FLAG_OPTIONAL);
3620 stream_putc(s, BGP_ATTR_MP_REACH_NLRI);
3621 sizep = stream_get_endp(s);
3622
3623 /* MP header */
3624 stream_putc(s, 0); /* Marker: Attribute length. */
3625 stream_putw(s, AFI_IP6); /* AFI */
3626 stream_putc(s, SAFI_UNICAST); /* SAFI */
3627
3628 /* Next hop */
3629 stream_putc(s, attr->mp_nexthop_len);
3630 stream_put(s, &attr->mp_nexthop_global, IPV6_MAX_BYTELEN);
3631 if (attr->mp_nexthop_len == BGP_ATTR_NHLEN_IPV6_GLOBAL_AND_LL)
3632 stream_put(s, &attr->mp_nexthop_local,
3633 IPV6_MAX_BYTELEN);
3634
3635 /* SNPA */
3636 stream_putc(s, 0);
3637
3638 /* Prefix */
3639 stream_put_prefix_addpath(s, prefix, addpath_encode,
3640 addpath_tx_id);
3641
3642 /* Set MP attribute length. */
3643 stream_putc_at(s, sizep, (stream_get_endp(s) - sizep) - 1);
3644 }
3645
3646 /* Prefix SID */
3647 if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_PREFIX_SID)) {
3648 if (attr->label_index != BGP_INVALID_LABEL_INDEX) {
3649 stream_putc(s,
3650 BGP_ATTR_FLAG_OPTIONAL
3651 | BGP_ATTR_FLAG_TRANS);
3652 stream_putc(s, BGP_ATTR_PREFIX_SID);
3653 stream_putc(s, 10);
3654 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX);
3655 stream_putc(s, BGP_PREFIX_SID_LABEL_INDEX_LENGTH);
3656 stream_putc(s, 0); // reserved
3657 stream_putw(s, 0); // flags
3658 stream_putl(s, attr->label_index);
3659 }
3660 }
3661
3662 /* Return total size of attribute. */
3663 len = stream_get_endp(s) - cp - 2;
3664 stream_putw_at(s, cp, len);
3665 }
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