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718e3744 | 1 | /* AS path management routines. |
896014f4 DL |
2 | * Copyright (C) 1996, 97, 98, 99 Kunihiro Ishiguro |
3 | * Copyright (C) 2005 Sun Microsystems, Inc. | |
4 | * | |
5 | * This file is part of GNU Zebra. | |
6 | * | |
7 | * GNU Zebra is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2, or (at your option) any | |
10 | * later version. | |
11 | * | |
12 | * GNU Zebra is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along | |
18 | * with this program; see the file COPYING; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
718e3744 | 21 | |
22 | #include <zebra.h> | |
23 | ||
24 | #include "hash.h" | |
25 | #include "memory.h" | |
26 | #include "vector.h" | |
718e3744 | 27 | #include "log.h" |
fe69a505 | 28 | #include "stream.h" |
4dcadbef | 29 | #include "command.h" |
0b2aa3a0 | 30 | #include "jhash.h" |
3f9c7369 | 31 | #include "queue.h" |
039f3a34 | 32 | #include "filter.h" |
718e3744 | 33 | |
34 | #include "bgpd/bgpd.h" | |
35 | #include "bgpd/bgp_aspath.h" | |
0b2aa3a0 PJ |
36 | #include "bgpd/bgp_debug.h" |
37 | #include "bgpd/bgp_attr.h" | |
559aaa30 | 38 | #include "bgpd/bgp_errors.h" |
6b0655a2 | 39 | |
718e3744 | 40 | /* Attr. Flags and Attr. Type Code. */ |
ade6974d | 41 | #define AS_HEADER_SIZE 2 |
718e3744 | 42 | |
0b2aa3a0 | 43 | /* Now FOUR octets are used for AS value. */ |
718e3744 | 44 | #define AS_VALUE_SIZE sizeof (as_t) |
0b2aa3a0 PJ |
45 | /* This is the old one */ |
46 | #define AS16_VALUE_SIZE sizeof (as16_t) | |
718e3744 | 47 | |
fe69a505 | 48 | /* Maximum protocol segment length value */ |
49 | #define AS_SEGMENT_MAX 255 | |
50 | ||
51 | /* The following length and size macros relate specifically to Quagga's | |
52 | * internal representation of AS-Segments, not per se to the on-wire | |
53 | * sizes and lengths. At present (200508) they sort of match, however | |
54 | * the ONLY functions which should now about the on-wire syntax are | |
55 | * aspath_put, assegment_put and assegment_parse. | |
0b2aa3a0 PJ |
56 | * |
57 | * aspath_put returns bytes written, the only definitive record of | |
58 | * size of wire-format attribute.. | |
fe69a505 | 59 | */ |
60 | ||
61 | /* Calculated size in bytes of ASN segment data to hold N ASN's */ | |
d62a17ae | 62 | #define ASSEGMENT_DATA_SIZE(N, S) \ |
63 | ((N) * ((S) ? AS_VALUE_SIZE : AS16_VALUE_SIZE)) | |
718e3744 | 64 | |
fe69a505 | 65 | /* Calculated size of segment struct to hold N ASN's */ |
0b2aa3a0 | 66 | #define ASSEGMENT_SIZE(N,S) (AS_HEADER_SIZE + ASSEGMENT_DATA_SIZE (N,S)) |
fe69a505 | 67 | |
68 | /* AS segment octet length. */ | |
0b2aa3a0 | 69 | #define ASSEGMENT_LEN(X,S) ASSEGMENT_SIZE((X)->length,S) |
fe69a505 | 70 | |
71 | /* AS_SEQUENCE segments can be packed together */ | |
72 | /* Can the types of X and Y be considered for packing? */ | |
d62a17ae | 73 | #define ASSEGMENT_TYPES_PACKABLE(X, Y) \ |
74 | (((X)->type == (Y)->type) && ((X)->type == AS_SEQUENCE)) | |
fe69a505 | 75 | /* Types and length of X,Y suitable for packing? */ |
d62a17ae | 76 | #define ASSEGMENTS_PACKABLE(X, Y) \ |
77 | (ASSEGMENT_TYPES_PACKABLE((X), (Y)) \ | |
78 | && (((X)->length + (Y)->length) <= AS_SEGMENT_MAX)) | |
fe69a505 | 79 | |
d62a17ae | 80 | /* As segment header - the on-wire representation |
fe69a505 | 81 | * NOT the internal representation! |
82 | */ | |
d62a17ae | 83 | struct assegment_header { |
d7c0a89a QY |
84 | uint8_t type; |
85 | uint8_t length; | |
718e3744 | 86 | }; |
87 | ||
88 | /* Hash for aspath. This is the top level structure of AS path. */ | |
da88ea82 | 89 | static struct hash *ashash; |
8fdc32ab | 90 | |
91 | /* Stream for SNMP. See aspath_snmp_pathseg */ | |
92 | static struct stream *snmp_stream; | |
6b0655a2 | 93 | |
f669f7d2 | 94 | /* Callers are required to initialize the memory */ |
d62a17ae | 95 | static as_t *assegment_data_new(int num) |
fe69a505 | 96 | { |
d62a17ae | 97 | return (XMALLOC(MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE(num, 1))); |
fe69a505 | 98 | } |
99 | ||
d62a17ae | 100 | static void assegment_data_free(as_t *asdata) |
289d2501 | 101 | { |
d62a17ae | 102 | XFREE(MTYPE_AS_SEG_DATA, asdata); |
289d2501 LB |
103 | } |
104 | ||
d62a17ae | 105 | const char *aspath_segment_type_str[] = {"as-invalid", "as-set", "as-sequence", |
106 | "as-confed-sequence", "as-confed-set"}; | |
f1aa5d8a | 107 | |
fe69a505 | 108 | /* Get a new segment. Note that 0 is an allowed length, |
109 | * and will result in a segment with no allocated data segment. | |
110 | * the caller should immediately assign data to the segment, as the segment | |
111 | * otherwise is not generally valid | |
112 | */ | |
d7c0a89a | 113 | static struct assegment *assegment_new(uint8_t type, unsigned short length) |
d62a17ae | 114 | { |
115 | struct assegment *new; | |
116 | ||
117 | new = XCALLOC(MTYPE_AS_SEG, sizeof(struct assegment)); | |
118 | ||
119 | if (length) | |
120 | new->as = assegment_data_new(length); | |
121 | ||
122 | new->length = length; | |
123 | new->type = type; | |
124 | ||
125 | return new; | |
126 | } | |
127 | ||
128 | static void assegment_free(struct assegment *seg) | |
129 | { | |
130 | if (!seg) | |
131 | return; | |
132 | ||
133 | if (seg->as) | |
134 | assegment_data_free(seg->as); | |
135 | memset(seg, 0xfe, sizeof(struct assegment)); | |
136 | XFREE(MTYPE_AS_SEG, seg); | |
137 | ||
138 | return; | |
fe69a505 | 139 | } |
140 | ||
141 | /* free entire chain of segments */ | |
d62a17ae | 142 | static void assegment_free_all(struct assegment *seg) |
fe69a505 | 143 | { |
d62a17ae | 144 | struct assegment *prev; |
145 | ||
146 | while (seg) { | |
147 | prev = seg; | |
148 | seg = seg->next; | |
149 | assegment_free(prev); | |
150 | } | |
fe69a505 | 151 | } |
152 | ||
153 | /* Duplicate just the given assegment and its data */ | |
d62a17ae | 154 | static struct assegment *assegment_dup(struct assegment *seg) |
fe69a505 | 155 | { |
d62a17ae | 156 | struct assegment *new; |
157 | ||
158 | new = assegment_new(seg->type, seg->length); | |
159 | memcpy(new->as, seg->as, ASSEGMENT_DATA_SIZE(new->length, 1)); | |
160 | ||
161 | return new; | |
fe69a505 | 162 | } |
163 | ||
164 | /* Duplicate entire chain of assegments, return the head */ | |
d62a17ae | 165 | static struct assegment *assegment_dup_all(struct assegment *seg) |
166 | { | |
167 | struct assegment *new = NULL; | |
168 | struct assegment *head = NULL; | |
169 | ||
170 | while (seg) { | |
171 | if (head) { | |
172 | new->next = assegment_dup(seg); | |
173 | new = new->next; | |
174 | } else | |
175 | head = new = assegment_dup(seg); | |
176 | ||
177 | seg = seg->next; | |
178 | } | |
179 | return head; | |
fe69a505 | 180 | } |
181 | ||
182 | /* prepend the as number to given segment, given num of times */ | |
d62a17ae | 183 | static struct assegment *assegment_prepend_asns(struct assegment *seg, |
184 | as_t asnum, int num) | |
fe69a505 | 185 | { |
d62a17ae | 186 | as_t *newas; |
187 | int i; | |
fe69a505 | 188 | |
d62a17ae | 189 | if (!num) |
190 | return seg; | |
f669f7d2 | 191 | |
d62a17ae | 192 | if (num >= AS_SEGMENT_MAX) |
193 | return seg; /* we don't do huge prepends */ | |
f669f7d2 | 194 | |
d62a17ae | 195 | if ((newas = assegment_data_new(seg->length + num)) == NULL) |
196 | return seg; | |
197 | ||
198 | for (i = 0; i < num; i++) | |
199 | newas[i] = asnum; | |
200 | ||
201 | memcpy(newas + num, seg->as, ASSEGMENT_DATA_SIZE(seg->length, 1)); | |
202 | assegment_data_free(seg->as); | |
203 | seg->as = newas; | |
204 | seg->length += num; | |
205 | ||
206 | return seg; | |
fe69a505 | 207 | } |
208 | ||
209 | /* append given array of as numbers to the segment */ | |
d62a17ae | 210 | static struct assegment *assegment_append_asns(struct assegment *seg, |
211 | as_t *asnos, int num) | |
fe69a505 | 212 | { |
d62a17ae | 213 | as_t *newas; |
fe69a505 | 214 | |
e00d8008 NT |
215 | if (!seg) |
216 | return seg; | |
217 | ||
d62a17ae | 218 | newas = XREALLOC(MTYPE_AS_SEG_DATA, seg->as, |
219 | ASSEGMENT_DATA_SIZE(seg->length + num, 1)); | |
220 | ||
0ce1ca80 DS |
221 | seg->as = newas; |
222 | memcpy(seg->as + seg->length, asnos, | |
223 | ASSEGMENT_DATA_SIZE(num, 1)); | |
224 | seg->length += num; | |
225 | return seg; | |
fe69a505 | 226 | } |
227 | ||
d62a17ae | 228 | static int int_cmp(const void *p1, const void *p2) |
fe69a505 | 229 | { |
d62a17ae | 230 | const as_t *as1 = p1; |
231 | const as_t *as2 = p2; | |
232 | ||
233 | return (*as1 == *as2) ? 0 : ((*as1 > *as2) ? 1 : -1); | |
fe69a505 | 234 | } |
235 | ||
236 | /* normalise the segment. | |
237 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
238 | * Internally, we do not care about the wire segment length limit, and | |
239 | * we want each distinct AS_PATHs to have the exact same internal | |
240 | * representation - eg, so that our hashing actually works.. | |
241 | */ | |
d62a17ae | 242 | static struct assegment *assegment_normalise(struct assegment *head) |
243 | { | |
244 | struct assegment *seg = head, *pin; | |
245 | struct assegment *tmp; | |
246 | ||
247 | if (!head) | |
248 | return head; | |
249 | ||
250 | while (seg) { | |
251 | pin = seg; | |
252 | ||
253 | /* Sort values SET segments, for determinism in paths to aid | |
254 | * creation of hash values / path comparisons | |
255 | * and because it helps other lesser implementations ;) | |
256 | */ | |
257 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) { | |
258 | int tail = 0; | |
259 | int i; | |
260 | ||
261 | qsort(seg->as, seg->length, sizeof(as_t), int_cmp); | |
262 | ||
263 | /* weed out dupes */ | |
264 | for (i = 1; i < seg->length; i++) { | |
265 | if (seg->as[tail] == seg->as[i]) | |
266 | continue; | |
267 | ||
268 | tail++; | |
269 | if (tail < i) | |
270 | seg->as[tail] = seg->as[i]; | |
271 | } | |
272 | /* seg->length can be 0.. */ | |
273 | if (seg->length) | |
274 | seg->length = tail + 1; | |
275 | } | |
276 | ||
277 | /* read ahead from the current, pinned segment while the | |
278 | * segments | |
279 | * are packable/mergeable. Append all following packable | |
280 | * segments | |
281 | * to the segment we have pinned and remove these appended | |
282 | * segments. | |
283 | */ | |
284 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) { | |
285 | tmp = pin->next; | |
286 | seg = pin->next; | |
287 | ||
288 | /* append the next sequence to the pinned sequence */ | |
289 | pin = assegment_append_asns(pin, seg->as, seg->length); | |
290 | ||
291 | /* bypass the next sequence */ | |
292 | pin->next = seg->next; | |
293 | ||
294 | /* get rid of the now referenceless segment */ | |
295 | assegment_free(tmp); | |
296 | } | |
297 | ||
298 | seg = pin->next; | |
0b2aa3a0 | 299 | } |
d62a17ae | 300 | return head; |
718e3744 | 301 | } |
302 | ||
d62a17ae | 303 | static struct aspath *aspath_new(void) |
718e3744 | 304 | { |
d62a17ae | 305 | return XCALLOC(MTYPE_AS_PATH, sizeof(struct aspath)); |
306 | } | |
f1aa5d8a | 307 | |
d62a17ae | 308 | /* Free AS path structure. */ |
309 | void aspath_free(struct aspath *aspath) | |
310 | { | |
311 | if (!aspath) | |
312 | return; | |
313 | if (aspath->segments) | |
314 | assegment_free_all(aspath->segments); | |
0a22ddfb | 315 | XFREE(MTYPE_AS_STR, aspath->str); |
d62a17ae | 316 | |
317 | if (aspath->json) { | |
318 | json_object_free(aspath->json); | |
319 | aspath->json = NULL; | |
320 | } | |
f1aa5d8a | 321 | |
d62a17ae | 322 | XFREE(MTYPE_AS_PATH, aspath); |
718e3744 | 323 | } |
324 | ||
325 | /* Unintern aspath from AS path bucket. */ | |
d62a17ae | 326 | void aspath_unintern(struct aspath **aspath) |
718e3744 | 327 | { |
d62a17ae | 328 | struct aspath *ret; |
329 | struct aspath *asp = *aspath; | |
330 | ||
331 | if (asp->refcnt) | |
332 | asp->refcnt--; | |
718e3744 | 333 | |
d62a17ae | 334 | if (asp->refcnt == 0) { |
335 | /* This aspath must exist in aspath hash table. */ | |
336 | ret = hash_release(ashash, asp); | |
337 | assert(ret != NULL); | |
338 | aspath_free(asp); | |
339 | *aspath = NULL; | |
340 | } | |
718e3744 | 341 | } |
342 | ||
343 | /* Return the start or end delimiters for a particular Segment type */ | |
344 | #define AS_SEG_START 0 | |
345 | #define AS_SEG_END 1 | |
d7c0a89a | 346 | static char aspath_delimiter_char(uint8_t type, uint8_t which) |
d62a17ae | 347 | { |
348 | int i; | |
349 | struct { | |
350 | int type; | |
351 | char start; | |
352 | char end; | |
353 | } aspath_delim_char[] = {{AS_SET, '{', '}'}, | |
354 | {AS_CONFED_SET, '[', ']'}, | |
355 | {AS_CONFED_SEQUENCE, '(', ')'}, | |
356 | {0}}; | |
357 | ||
358 | for (i = 0; aspath_delim_char[i].type != 0; i++) { | |
359 | if (aspath_delim_char[i].type == type) { | |
360 | if (which == AS_SEG_START) | |
361 | return aspath_delim_char[i].start; | |
362 | else if (which == AS_SEG_END) | |
363 | return aspath_delim_char[i].end; | |
364 | } | |
718e3744 | 365 | } |
d62a17ae | 366 | return ' '; |
718e3744 | 367 | } |
368 | ||
014b670e | 369 | /* countup asns from this segment and index onward */ |
d62a17ae | 370 | static int assegment_count_asns(struct assegment *seg, int from) |
371 | { | |
372 | int count = 0; | |
373 | while (seg) { | |
374 | if (!from) | |
375 | count += seg->length; | |
376 | else { | |
377 | count += (seg->length - from); | |
378 | from = 0; | |
379 | } | |
380 | seg = seg->next; | |
381 | } | |
382 | return count; | |
383 | } | |
384 | ||
385 | unsigned int aspath_count_confeds(struct aspath *aspath) | |
386 | { | |
387 | int count = 0; | |
388 | struct assegment *seg = aspath->segments; | |
389 | ||
390 | while (seg) { | |
391 | if (seg->type == AS_CONFED_SEQUENCE) | |
392 | count += seg->length; | |
393 | else if (seg->type == AS_CONFED_SET) | |
394 | count++; | |
395 | ||
396 | seg = seg->next; | |
397 | } | |
398 | return count; | |
399 | } | |
400 | ||
401 | unsigned int aspath_count_hops(const struct aspath *aspath) | |
402 | { | |
403 | int count = 0; | |
404 | struct assegment *seg = aspath->segments; | |
405 | ||
406 | while (seg) { | |
407 | if (seg->type == AS_SEQUENCE) | |
408 | count += seg->length; | |
409 | else if (seg->type == AS_SET) | |
410 | count++; | |
411 | ||
412 | seg = seg->next; | |
413 | } | |
414 | return count; | |
fe69a505 | 415 | } |
416 | ||
0b2aa3a0 PJ |
417 | /* Estimate size aspath /might/ take if encoded into an |
418 | * ASPATH attribute. | |
419 | * | |
420 | * This is a quick estimate, not definitive! aspath_put() | |
421 | * may return a different number!! | |
422 | */ | |
d62a17ae | 423 | unsigned int aspath_size(struct aspath *aspath) |
fe69a505 | 424 | { |
d62a17ae | 425 | int size = 0; |
426 | struct assegment *seg = aspath->segments; | |
427 | ||
428 | while (seg) { | |
429 | size += ASSEGMENT_SIZE(seg->length, 1); | |
430 | seg = seg->next; | |
431 | } | |
432 | return size; | |
fe69a505 | 433 | } |
434 | ||
2815e61f | 435 | /* Return highest public ASN in path */ |
d62a17ae | 436 | as_t aspath_highest(struct aspath *aspath) |
437 | { | |
438 | struct assegment *seg = aspath->segments; | |
439 | as_t highest = 0; | |
440 | unsigned int i; | |
441 | ||
442 | while (seg) { | |
443 | for (i = 0; i < seg->length; i++) | |
444 | if (seg->as[i] > highest | |
445 | && !BGP_AS_IS_PRIVATE(seg->as[i])) | |
446 | highest = seg->as[i]; | |
447 | seg = seg->next; | |
448 | } | |
449 | return highest; | |
2815e61f PJ |
450 | } |
451 | ||
bc3dd427 | 452 | /* Return the left-most ASN in path */ |
d62a17ae | 453 | as_t aspath_leftmost(struct aspath *aspath) |
bc3dd427 | 454 | { |
d62a17ae | 455 | struct assegment *seg = aspath->segments; |
456 | as_t leftmost = 0; | |
bc3dd427 | 457 | |
d62a17ae | 458 | if (seg && seg->length && seg->type == AS_SEQUENCE) |
459 | leftmost = seg->as[0]; | |
bc3dd427 | 460 | |
d62a17ae | 461 | return leftmost; |
bc3dd427 DW |
462 | } |
463 | ||
0b2aa3a0 | 464 | /* Return 1 if there are any 4-byte ASes in the path */ |
d62a17ae | 465 | unsigned int aspath_has_as4(struct aspath *aspath) |
466 | { | |
467 | struct assegment *seg = aspath->segments; | |
468 | unsigned int i; | |
469 | ||
470 | while (seg) { | |
471 | for (i = 0; i < seg->length; i++) | |
472 | if (seg->as[i] > BGP_AS_MAX) | |
473 | return 1; | |
474 | seg = seg->next; | |
475 | } | |
476 | return 0; | |
0b2aa3a0 PJ |
477 | } |
478 | ||
718e3744 | 479 | /* Convert aspath structure to string expression. */ |
68e1a55b | 480 | static void aspath_make_str_count(struct aspath *as, bool make_json) |
d62a17ae | 481 | { |
482 | struct assegment *seg; | |
483 | int str_size; | |
484 | int len = 0; | |
485 | char *str_buf; | |
486 | json_object *jaspath_segments = NULL; | |
487 | json_object *jseg = NULL; | |
488 | json_object *jseg_list = NULL; | |
489 | ||
68e1a55b DS |
490 | if (make_json) { |
491 | as->json = json_object_new_object(); | |
492 | jaspath_segments = json_object_new_array(); | |
493 | } | |
d62a17ae | 494 | |
495 | /* Empty aspath. */ | |
496 | if (!as->segments) { | |
68e1a55b DS |
497 | if (make_json) { |
498 | json_object_string_add(as->json, "string", "Local"); | |
996c9314 LB |
499 | json_object_object_add(as->json, "segments", |
500 | jaspath_segments); | |
68e1a55b DS |
501 | json_object_int_add(as->json, "length", 0); |
502 | } | |
d62a17ae | 503 | as->str = XMALLOC(MTYPE_AS_STR, 1); |
504 | as->str[0] = '\0'; | |
505 | as->str_len = 0; | |
506 | return; | |
507 | } | |
508 | ||
509 | seg = as->segments; | |
510 | ||
511 | /* ASN takes 5 to 10 chars plus seperator, see below. | |
512 | * If there is one differing segment type, we need an additional | |
513 | * 2 chars for segment delimiters, and the final '\0'. | |
514 | * Hopefully this is large enough to avoid hitting the realloc | |
515 | * code below for most common sequences. | |
516 | * | |
517 | * This was changed to 10 after the well-known BGP assertion, which | |
518 | * had hit some parts of the Internet in May of 2009. | |
519 | */ | |
014b670e | 520 | #define ASN_STR_LEN (10 + 1) |
d62a17ae | 521 | str_size = MAX(assegment_count_asns(seg, 0) * ASN_STR_LEN + 2 + 1, |
522 | ASPATH_STR_DEFAULT_LEN); | |
523 | str_buf = XMALLOC(MTYPE_AS_STR, str_size); | |
524 | ||
525 | while (seg) { | |
526 | int i; | |
527 | char seperator; | |
528 | ||
529 | /* Check AS type validity. Set seperator for segment */ | |
530 | switch (seg->type) { | |
531 | case AS_SET: | |
532 | case AS_CONFED_SET: | |
533 | seperator = ','; | |
534 | break; | |
535 | case AS_SEQUENCE: | |
536 | case AS_CONFED_SEQUENCE: | |
537 | seperator = ' '; | |
538 | break; | |
539 | default: | |
540 | XFREE(MTYPE_AS_STR, str_buf); | |
541 | as->str = NULL; | |
542 | as->str_len = 0; | |
543 | json_object_free(as->json); | |
544 | as->json = NULL; | |
68e1a55b | 545 | |
d62a17ae | 546 | return; |
547 | } | |
548 | ||
549 | /* We might need to increase str_buf, particularly if path has | |
550 | * differing segments types, our initial guesstimate above will | |
551 | * have been wrong. Need 10 chars for ASN, a seperator each and | |
552 | * potentially two segment delimiters, plus a space between each | |
553 | * segment and trailing zero. | |
554 | * | |
555 | * This definitely didn't work with the value of 5 bytes and | |
556 | * 32-bit ASNs. | |
557 | */ | |
014b670e | 558 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) |
d62a17ae | 559 | if ((len + SEGMENT_STR_LEN(seg)) > str_size) { |
560 | str_size = len + SEGMENT_STR_LEN(seg); | |
561 | str_buf = XREALLOC(MTYPE_AS_STR, str_buf, str_size); | |
562 | } | |
014b670e DO |
563 | #undef ASN_STR_LEN |
564 | #undef SEGMENT_STR_LEN | |
d62a17ae | 565 | |
566 | if (seg->type != AS_SEQUENCE) | |
567 | len += snprintf( | |
568 | str_buf + len, str_size - len, "%c", | |
569 | aspath_delimiter_char(seg->type, AS_SEG_START)); | |
570 | ||
68e1a55b DS |
571 | if (make_json) |
572 | jseg_list = json_object_new_array(); | |
d62a17ae | 573 | |
574 | /* write out the ASNs, with their seperators, bar the last one*/ | |
575 | for (i = 0; i < seg->length; i++) { | |
68e1a55b | 576 | if (make_json) |
996c9314 LB |
577 | json_object_array_add( |
578 | jseg_list, | |
579 | json_object_new_int(seg->as[i])); | |
d62a17ae | 580 | |
581 | len += snprintf(str_buf + len, str_size - len, "%u", | |
582 | seg->as[i]); | |
583 | ||
584 | if (i < (seg->length - 1)) | |
585 | len += snprintf(str_buf + len, str_size - len, | |
586 | "%c", seperator); | |
587 | } | |
588 | ||
68e1a55b DS |
589 | if (make_json) { |
590 | jseg = json_object_new_object(); | |
996c9314 LB |
591 | json_object_string_add( |
592 | jseg, "type", | |
593 | aspath_segment_type_str[seg->type]); | |
68e1a55b DS |
594 | json_object_object_add(jseg, "list", jseg_list); |
595 | json_object_array_add(jaspath_segments, jseg); | |
596 | } | |
d62a17ae | 597 | |
598 | if (seg->type != AS_SEQUENCE) | |
599 | len += snprintf( | |
600 | str_buf + len, str_size - len, "%c", | |
601 | aspath_delimiter_char(seg->type, AS_SEG_END)); | |
602 | if (seg->next) | |
603 | len += snprintf(str_buf + len, str_size - len, " "); | |
604 | ||
605 | seg = seg->next; | |
606 | } | |
607 | ||
608 | assert(len < str_size); | |
609 | ||
610 | str_buf[len] = '\0'; | |
611 | as->str = str_buf; | |
612 | as->str_len = len; | |
613 | ||
68e1a55b DS |
614 | if (make_json) { |
615 | json_object_string_add(as->json, "string", str_buf); | |
616 | json_object_object_add(as->json, "segments", jaspath_segments); | |
617 | json_object_int_add(as->json, "length", aspath_count_hops(as)); | |
618 | } | |
619 | ||
d62a17ae | 620 | return; |
621 | } | |
622 | ||
68e1a55b | 623 | void aspath_str_update(struct aspath *as, bool make_json) |
d62a17ae | 624 | { |
0a22ddfb | 625 | XFREE(MTYPE_AS_STR, as->str); |
d62a17ae | 626 | |
627 | if (as->json) { | |
628 | json_object_free(as->json); | |
629 | as->json = NULL; | |
630 | } | |
631 | ||
68e1a55b | 632 | aspath_make_str_count(as, make_json); |
fe69a505 | 633 | } |
634 | ||
718e3744 | 635 | /* Intern allocated AS path. */ |
d62a17ae | 636 | struct aspath *aspath_intern(struct aspath *aspath) |
718e3744 | 637 | { |
d62a17ae | 638 | struct aspath *find; |
f669f7d2 | 639 | |
d62a17ae | 640 | /* Assert this AS path structure is not interned and has the string |
641 | representation built. */ | |
642 | assert(aspath->refcnt == 0); | |
643 | assert(aspath->str); | |
718e3744 | 644 | |
d62a17ae | 645 | /* Check AS path hash. */ |
646 | find = hash_get(ashash, aspath, hash_alloc_intern); | |
647 | if (find != aspath) | |
648 | aspath_free(aspath); | |
718e3744 | 649 | |
d62a17ae | 650 | find->refcnt++; |
718e3744 | 651 | |
d62a17ae | 652 | return find; |
718e3744 | 653 | } |
654 | ||
655 | /* Duplicate aspath structure. Created same aspath structure but | |
656 | reference count and AS path string is cleared. */ | |
d62a17ae | 657 | struct aspath *aspath_dup(struct aspath *aspath) |
718e3744 | 658 | { |
d62a17ae | 659 | unsigned short buflen = aspath->str_len + 1; |
660 | struct aspath *new; | |
718e3744 | 661 | |
d62a17ae | 662 | new = XCALLOC(MTYPE_AS_PATH, sizeof(struct aspath)); |
663 | new->json = NULL; | |
718e3744 | 664 | |
d62a17ae | 665 | if (aspath->segments) |
666 | new->segments = assegment_dup_all(aspath->segments); | |
718e3744 | 667 | |
d62a17ae | 668 | if (!aspath->str) |
669 | return new; | |
f669f7d2 | 670 | |
d62a17ae | 671 | new->str = XMALLOC(MTYPE_AS_STR, buflen); |
672 | new->str_len = aspath->str_len; | |
f669f7d2 | 673 | |
d62a17ae | 674 | /* copy the string data */ |
675 | if (aspath->str_len > 0) | |
676 | memcpy(new->str, aspath->str, buflen); | |
677 | else | |
678 | new->str[0] = '\0'; | |
718e3744 | 679 | |
d62a17ae | 680 | return new; |
718e3744 | 681 | } |
682 | ||
d62a17ae | 683 | static void *aspath_hash_alloc(void *arg) |
718e3744 | 684 | { |
d62a17ae | 685 | const struct aspath *aspath = arg; |
686 | struct aspath *new; | |
718e3744 | 687 | |
d62a17ae | 688 | /* Malformed AS path value. */ |
689 | assert(aspath->str); | |
718e3744 | 690 | |
d62a17ae | 691 | /* New aspath structure is needed. */ |
692 | new = XMALLOC(MTYPE_AS_PATH, sizeof(struct aspath)); | |
f669f7d2 | 693 | |
d62a17ae | 694 | /* Reuse segments and string representation */ |
695 | new->refcnt = 0; | |
696 | new->segments = aspath->segments; | |
697 | new->str = aspath->str; | |
698 | new->str_len = aspath->str_len; | |
699 | new->json = aspath->json; | |
f669f7d2 | 700 | |
d62a17ae | 701 | return new; |
718e3744 | 702 | } |
703 | ||
ab005298 | 704 | /* parse as-segment byte stream in struct assegment */ |
d62a17ae | 705 | static int assegments_parse(struct stream *s, size_t length, |
706 | struct assegment **result, int use32bit) | |
707 | { | |
708 | struct assegment_header segh; | |
709 | struct assegment *seg, *prev = NULL, *head = NULL; | |
710 | size_t bytes = 0; | |
711 | ||
712 | /* empty aspath (ie iBGP or somesuch) */ | |
713 | if (length == 0) | |
714 | return 0; | |
715 | ||
716 | if (BGP_DEBUG(as4, AS4_SEGMENT)) | |
717 | zlog_debug( | |
718 | "[AS4SEG] Parse aspath segment: got total byte length %lu", | |
719 | (unsigned long)length); | |
720 | /* basic checks */ | |
721 | if ((STREAM_READABLE(s) < length) | |
722 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
723 | || (length % AS16_VALUE_SIZE)) | |
724 | return -1; | |
725 | ||
726 | while (bytes < length) { | |
727 | int i; | |
728 | size_t seg_size; | |
729 | ||
730 | if ((length - bytes) <= AS_HEADER_SIZE) { | |
731 | if (head) | |
732 | assegment_free_all(head); | |
733 | return -1; | |
734 | } | |
735 | ||
736 | /* softly softly, get the header first on its own */ | |
737 | segh.type = stream_getc(s); | |
738 | segh.length = stream_getc(s); | |
739 | ||
740 | seg_size = ASSEGMENT_SIZE(segh.length, use32bit); | |
741 | ||
742 | if (BGP_DEBUG(as4, AS4_SEGMENT)) | |
743 | zlog_debug( | |
744 | "[AS4SEG] Parse aspath segment: got type %d, length %d", | |
745 | segh.type, segh.length); | |
746 | ||
747 | /* check it.. */ | |
748 | if (((bytes + seg_size) > length) | |
749 | /* 1771bis 4.3b: seg length contains one or more */ | |
750 | || (segh.length == 0) | |
751 | /* Paranoia in case someone changes type of segment length. | |
752 | * Shift both values by 0x10 to make the comparison operate | |
753 | * on more, than 8 bits (otherwise it's a warning, bug | |
754 | * #564). | |
755 | */ | |
756 | || ((sizeof segh.length > 1) | |
757 | && (0x10 + segh.length > 0x10 + AS_SEGMENT_MAX))) { | |
758 | if (head) | |
759 | assegment_free_all(head); | |
760 | return -1; | |
761 | } | |
762 | ||
763 | switch (segh.type) { | |
764 | case AS_SEQUENCE: | |
765 | case AS_SET: | |
766 | case AS_CONFED_SEQUENCE: | |
767 | case AS_CONFED_SET: | |
768 | break; | |
769 | default: | |
770 | if (head) | |
771 | assegment_free_all(head); | |
772 | return -1; | |
773 | } | |
774 | ||
775 | /* now its safe to trust lengths */ | |
776 | seg = assegment_new(segh.type, segh.length); | |
777 | ||
778 | if (head) | |
779 | prev->next = seg; | |
780 | else /* it's the first segment */ | |
781 | head = prev = seg; | |
782 | ||
783 | for (i = 0; i < segh.length; i++) | |
784 | seg->as[i] = | |
785 | (use32bit) ? stream_getl(s) : stream_getw(s); | |
786 | ||
787 | bytes += seg_size; | |
788 | ||
789 | if (BGP_DEBUG(as4, AS4_SEGMENT)) | |
790 | zlog_debug( | |
791 | "[AS4SEG] Parse aspath segment: Bytes now: %lu", | |
792 | (unsigned long)bytes); | |
793 | ||
794 | prev = seg; | |
795 | } | |
796 | ||
797 | *result = assegment_normalise(head); | |
798 | return 0; | |
fe69a505 | 799 | } |
800 | ||
ab005298 PJ |
801 | /* AS path parse function. pnt is a pointer to byte stream and length |
802 | is length of byte stream. If there is same AS path in the the AS | |
d62a17ae | 803 | path hash then return it else make new AS path structure. |
804 | ||
b881c707 | 805 | On error NULL is returned. |
cddb8112 | 806 | */ |
d62a17ae | 807 | struct aspath *aspath_parse(struct stream *s, size_t length, int use32bit) |
808 | { | |
809 | struct aspath as; | |
810 | struct aspath *find; | |
811 | ||
812 | /* If length is odd it's malformed AS path. */ | |
813 | /* Nit-picking: if (use32bit == 0) it is malformed if odd, | |
814 | * otherwise its malformed when length is larger than 2 and (length-2) | |
815 | * is not dividable by 4. | |
816 | * But... this time we're lazy | |
817 | */ | |
818 | if (length % AS16_VALUE_SIZE) | |
819 | return NULL; | |
820 | ||
821 | memset(&as, 0, sizeof(struct aspath)); | |
822 | if (assegments_parse(s, length, &as.segments, use32bit) < 0) | |
823 | return NULL; | |
824 | ||
825 | /* If already same aspath exist then return it. */ | |
826 | find = hash_get(ashash, &as, aspath_hash_alloc); | |
827 | ||
828 | /* bug! should not happen, let the daemon crash below */ | |
829 | assert(find); | |
830 | ||
831 | /* if the aspath was already hashed free temporary memory. */ | |
832 | if (find->refcnt) { | |
833 | assegment_free_all(as.segments); | |
834 | /* aspath_key_make() always updates the string */ | |
835 | XFREE(MTYPE_AS_STR, as.str); | |
836 | if (as.json) { | |
837 | json_object_free(as.json); | |
838 | as.json = NULL; | |
839 | } | |
4390a8ee | 840 | } |
f669f7d2 | 841 | |
d62a17ae | 842 | find->refcnt++; |
718e3744 | 843 | |
d62a17ae | 844 | return find; |
718e3744 | 845 | } |
846 | ||
d62a17ae | 847 | static void assegment_data_put(struct stream *s, as_t *as, int num, |
848 | int use32bit) | |
fe69a505 | 849 | { |
d62a17ae | 850 | int i; |
851 | assert(num <= AS_SEGMENT_MAX); | |
852 | ||
853 | for (i = 0; i < num; i++) | |
854 | if (use32bit) | |
855 | stream_putl(s, as[i]); | |
856 | else { | |
857 | if (as[i] <= BGP_AS_MAX) | |
858 | stream_putw(s, as[i]); | |
859 | else | |
860 | stream_putw(s, BGP_AS_TRANS); | |
861 | } | |
fe69a505 | 862 | } |
718e3744 | 863 | |
d7c0a89a | 864 | static size_t assegment_header_put(struct stream *s, uint8_t type, int length) |
718e3744 | 865 | { |
d62a17ae | 866 | size_t lenp; |
867 | assert(length <= AS_SEGMENT_MAX); | |
868 | stream_putc(s, type); | |
869 | lenp = stream_get_endp(s); | |
870 | stream_putc(s, length); | |
871 | return lenp; | |
fe69a505 | 872 | } |
718e3744 | 873 | |
fe69a505 | 874 | /* write aspath data to stream */ |
d62a17ae | 875 | size_t aspath_put(struct stream *s, struct aspath *as, int use32bit) |
876 | { | |
877 | struct assegment *seg = as->segments; | |
878 | size_t bytes = 0; | |
879 | ||
880 | if (!seg || seg->length == 0) | |
881 | return 0; | |
882 | ||
883 | if (seg) { | |
884 | /* | |
885 | * Hey, what do we do when we have > STREAM_WRITABLE(s) here? | |
886 | * At the moment, we would write out a partial aspath, and our | |
887 | * peer | |
888 | * will complain and drop the session :-/ | |
889 | * | |
890 | * The general assumption here is that many things tested will | |
891 | * never happen. And, in real live, up to now, they have not. | |
892 | */ | |
9d303b37 DL |
893 | while (seg && (ASSEGMENT_LEN(seg, use32bit) |
894 | <= STREAM_WRITEABLE(s))) { | |
d62a17ae | 895 | struct assegment *next = seg->next; |
896 | int written = 0; | |
897 | int asns_packed = 0; | |
898 | size_t lenp; | |
899 | ||
900 | /* Overlength segments have to be split up */ | |
901 | while ((seg->length - written) > AS_SEGMENT_MAX) { | |
902 | assegment_header_put(s, seg->type, | |
903 | AS_SEGMENT_MAX); | |
248c86da | 904 | assegment_data_put(s, (seg->as + written), AS_SEGMENT_MAX, |
d62a17ae | 905 | use32bit); |
906 | written += AS_SEGMENT_MAX; | |
996c9314 LB |
907 | bytes += ASSEGMENT_SIZE(AS_SEGMENT_MAX, |
908 | use32bit); | |
d62a17ae | 909 | } |
910 | ||
911 | /* write the final segment, probably is also the first | |
912 | */ | |
913 | lenp = assegment_header_put(s, seg->type, | |
914 | seg->length - written); | |
915 | assegment_data_put(s, (seg->as + written), | |
916 | seg->length - written, use32bit); | |
917 | ||
918 | /* Sequence-type segments can be 'packed' together | |
919 | * Case of a segment which was overlength and split up | |
920 | * will be missed here, but that doesn't matter. | |
921 | */ | |
922 | while (next && ASSEGMENTS_PACKABLE(seg, next)) { | |
923 | /* NB: We should never normally get here given | |
924 | * we | |
925 | * normalise aspath data when parse them. | |
926 | * However, better | |
927 | * safe than sorry. We potentially could call | |
928 | * assegment_normalise here instead, but it's | |
929 | * cheaper and | |
930 | * easier to do it on the fly here rather than | |
931 | * go through | |
932 | * the segment list twice every time we write | |
933 | * out | |
934 | * aspath's. | |
935 | */ | |
936 | ||
937 | /* Next segment's data can fit in this one */ | |
938 | assegment_data_put(s, next->as, next->length, | |
939 | use32bit); | |
940 | ||
941 | /* update the length of the segment header */ | |
942 | stream_putc_at(s, lenp, | |
943 | seg->length - written | |
944 | + next->length); | |
945 | asns_packed += next->length; | |
946 | ||
947 | next = next->next; | |
948 | } | |
949 | ||
950 | bytes += ASSEGMENT_SIZE( | |
951 | seg->length - written + asns_packed, use32bit); | |
952 | seg = next; | |
953 | } | |
954 | } | |
955 | return bytes; | |
fe69a505 | 956 | } |
957 | ||
958 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
959 | * We have no way to manage the storage, so we use a static stream | |
960 | * wrapper around aspath_put. | |
961 | */ | |
d7c0a89a | 962 | uint8_t *aspath_snmp_pathseg(struct aspath *as, size_t *varlen) |
fe69a505 | 963 | { |
964 | #define SNMP_PATHSEG_MAX 1024 | |
8fdc32ab | 965 | |
d62a17ae | 966 | if (!snmp_stream) |
967 | snmp_stream = stream_new(SNMP_PATHSEG_MAX); | |
968 | else | |
969 | stream_reset(snmp_stream); | |
970 | ||
971 | if (!as) { | |
972 | *varlen = 0; | |
973 | return NULL; | |
974 | } | |
975 | aspath_put(snmp_stream, as, 0); /* use 16 bit for now here */ | |
976 | ||
977 | *varlen = stream_get_endp(snmp_stream); | |
978 | return stream_pnt(snmp_stream); | |
979 | } | |
980 | ||
fe69a505 | 981 | #define min(A,B) ((A) < (B) ? (A) : (B)) |
718e3744 | 982 | |
d62a17ae | 983 | static struct assegment *aspath_aggregate_as_set_add(struct aspath *aspath, |
984 | struct assegment *asset, | |
985 | as_t as) | |
986 | { | |
987 | int i; | |
988 | ||
989 | /* If this is first AS set member, create new as-set segment. */ | |
990 | if (asset == NULL) { | |
991 | asset = assegment_new(AS_SET, 1); | |
992 | if (!aspath->segments) | |
993 | aspath->segments = asset; | |
994 | else { | |
995 | struct assegment *seg = aspath->segments; | |
996 | while (seg->next) | |
997 | seg = seg->next; | |
998 | seg->next = asset; | |
999 | } | |
1000 | asset->type = AS_SET; | |
1001 | asset->length = 1; | |
1002 | asset->as[0] = as; | |
1003 | } else { | |
1004 | /* Check this AS value already exists or not. */ | |
1005 | for (i = 0; i < asset->length; i++) | |
1006 | if (asset->as[i] == as) | |
1007 | return asset; | |
1008 | ||
1009 | asset->length++; | |
1010 | asset->as = XREALLOC(MTYPE_AS_SEG_DATA, asset->as, | |
1011 | asset->length * AS_VALUE_SIZE); | |
1012 | asset->as[asset->length - 1] = as; | |
1013 | } | |
1014 | ||
1015 | ||
1016 | return asset; | |
718e3744 | 1017 | } |
1018 | ||
1019 | /* Modify as1 using as2 for aggregation. */ | |
d62a17ae | 1020 | struct aspath *aspath_aggregate(struct aspath *as1, struct aspath *as2) |
1021 | { | |
1022 | int i; | |
1023 | int minlen = 0; | |
1024 | int match = 0; | |
1025 | int from; | |
1026 | struct assegment *seg1 = as1->segments; | |
1027 | struct assegment *seg2 = as2->segments; | |
1028 | struct aspath *aspath = NULL; | |
1029 | struct assegment *asset = NULL; | |
1030 | struct assegment *prevseg = NULL; | |
1031 | ||
1032 | /* First of all check common leading sequence. */ | |
1033 | while (seg1 && seg2) { | |
1034 | /* Check segment type. */ | |
1035 | if (seg1->type != seg2->type) | |
1036 | break; | |
1037 | ||
1038 | /* Minimum segment length. */ | |
1039 | minlen = min(seg1->length, seg2->length); | |
1040 | ||
1041 | for (match = 0; match < minlen; match++) | |
1042 | if (seg1->as[match] != seg2->as[match]) | |
1043 | break; | |
1044 | ||
1045 | if (match) { | |
1046 | struct assegment *seg = assegment_new(seg1->type, 0); | |
1047 | ||
1048 | seg = assegment_append_asns(seg, seg1->as, match); | |
1049 | ||
1050 | if (!aspath) { | |
1051 | aspath = aspath_new(); | |
1052 | aspath->segments = seg; | |
1053 | } else | |
1054 | prevseg->next = seg; | |
1055 | ||
1056 | prevseg = seg; | |
1057 | } | |
1058 | ||
1059 | if (match != minlen || match != seg1->length | |
1060 | || seg1->length != seg2->length) | |
1061 | break; | |
1062 | /* We are moving on to the next segment to reset match */ | |
1063 | else | |
1064 | match = 0; | |
1065 | ||
1066 | seg1 = seg1->next; | |
1067 | seg2 = seg2->next; | |
1068 | } | |
1069 | ||
1070 | if (!aspath) | |
1071 | aspath = aspath_new(); | |
1072 | ||
1073 | /* Make as-set using rest of all information. */ | |
1074 | from = match; | |
1075 | while (seg1) { | |
1076 | for (i = from; i < seg1->length; i++) | |
1077 | asset = aspath_aggregate_as_set_add(aspath, asset, | |
1078 | seg1->as[i]); | |
1079 | ||
1080 | from = 0; | |
1081 | seg1 = seg1->next; | |
718e3744 | 1082 | } |
1083 | ||
d62a17ae | 1084 | from = match; |
1085 | while (seg2) { | |
1086 | for (i = from; i < seg2->length; i++) | |
1087 | asset = aspath_aggregate_as_set_add(aspath, asset, | |
1088 | seg2->as[i]); | |
1089 | ||
1090 | from = 0; | |
1091 | seg2 = seg2->next; | |
1092 | } | |
1093 | ||
1094 | assegment_normalise(aspath->segments); | |
68e1a55b | 1095 | aspath_str_update(aspath, false); |
d62a17ae | 1096 | return aspath; |
718e3744 | 1097 | } |
1098 | ||
1099 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
1100 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
d62a17ae | 1101 | or not the peer's AS number. */ |
1102 | int aspath_firstas_check(struct aspath *aspath, as_t asno) | |
718e3744 | 1103 | { |
d62a17ae | 1104 | if ((aspath == NULL) || (aspath->segments == NULL)) |
1105 | return 0; | |
1106 | ||
1107 | if (aspath->segments && (aspath->segments->type == AS_SEQUENCE) | |
1108 | && (aspath->segments->as[0] == asno)) | |
1109 | return 1; | |
718e3744 | 1110 | |
d62a17ae | 1111 | return 0; |
718e3744 | 1112 | } |
1113 | ||
d62a17ae | 1114 | unsigned int aspath_get_first_as(struct aspath *aspath) |
06370dac | 1115 | { |
d62a17ae | 1116 | if (aspath == NULL || aspath->segments == NULL) |
1117 | return 0; | |
06370dac | 1118 | |
d62a17ae | 1119 | return aspath->segments->as[0]; |
06370dac DW |
1120 | } |
1121 | ||
d62a17ae | 1122 | unsigned int aspath_get_last_as(struct aspath *aspath) |
aac9ef6c | 1123 | { |
d62a17ae | 1124 | int i; |
1125 | unsigned int last_as = 0; | |
1126 | const struct assegment *seg; | |
aac9ef6c | 1127 | |
d62a17ae | 1128 | if (aspath == NULL || aspath->segments == NULL) |
1129 | return last_as; | |
aac9ef6c | 1130 | |
d62a17ae | 1131 | seg = aspath->segments; |
aac9ef6c | 1132 | |
d62a17ae | 1133 | while (seg) { |
1134 | if (seg->type == AS_SEQUENCE || seg->type == AS_CONFED_SEQUENCE) | |
1135 | for (i = 0; i < seg->length; i++) | |
1136 | last_as = seg->as[i]; | |
1137 | seg = seg->next; | |
1138 | } | |
aac9ef6c | 1139 | |
d62a17ae | 1140 | return last_as; |
aac9ef6c DW |
1141 | } |
1142 | ||
1f742f21 | 1143 | /* AS path loop check. If aspath contains asno then return >= 1. */ |
d62a17ae | 1144 | int aspath_loop_check(struct aspath *aspath, as_t asno) |
1145 | { | |
1146 | struct assegment *seg; | |
1147 | int count = 0; | |
1148 | ||
1149 | if ((aspath == NULL) || (aspath->segments == NULL)) | |
1150 | return 0; | |
1151 | ||
1152 | seg = aspath->segments; | |
1153 | ||
1154 | while (seg) { | |
1155 | int i; | |
1156 | ||
1157 | for (i = 0; i < seg->length; i++) | |
1158 | if (seg->as[i] == asno) | |
1159 | count++; | |
1160 | ||
1161 | seg = seg->next; | |
1162 | } | |
1163 | return count; | |
718e3744 | 1164 | } |
1165 | ||
1166 | /* When all of AS path is private AS return 1. */ | |
d62a17ae | 1167 | int aspath_private_as_check(struct aspath *aspath) |
718e3744 | 1168 | { |
d62a17ae | 1169 | struct assegment *seg; |
5000f21c | 1170 | |
d62a17ae | 1171 | if (!(aspath && aspath->segments)) |
1172 | return 0; | |
5000f21c | 1173 | |
d62a17ae | 1174 | seg = aspath->segments; |
718e3744 | 1175 | |
d62a17ae | 1176 | while (seg) { |
1177 | int i; | |
5000f21c | 1178 | |
d62a17ae | 1179 | for (i = 0; i < seg->length; i++) { |
1180 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) | |
1181 | return 0; | |
1182 | } | |
1183 | seg = seg->next; | |
718e3744 | 1184 | } |
d62a17ae | 1185 | return 1; |
718e3744 | 1186 | } |
1187 | ||
c7122e14 | 1188 | /* Return True if the entire ASPATH consist of the specified ASN */ |
d62a17ae | 1189 | int aspath_single_asn_check(struct aspath *aspath, as_t asn) |
c7122e14 | 1190 | { |
d62a17ae | 1191 | struct assegment *seg; |
c7122e14 | 1192 | |
d62a17ae | 1193 | if (!(aspath && aspath->segments)) |
1194 | return 0; | |
c7122e14 | 1195 | |
d62a17ae | 1196 | seg = aspath->segments; |
c7122e14 | 1197 | |
d62a17ae | 1198 | while (seg) { |
1199 | int i; | |
c7122e14 | 1200 | |
d62a17ae | 1201 | for (i = 0; i < seg->length; i++) { |
1202 | if (seg->as[i] != asn) | |
1203 | return 0; | |
1204 | } | |
1205 | seg = seg->next; | |
c7122e14 | 1206 | } |
d62a17ae | 1207 | return 1; |
c7122e14 DS |
1208 | } |
1209 | ||
1210 | /* Replace all instances of the target ASN with our own ASN */ | |
d62a17ae | 1211 | struct aspath *aspath_replace_specific_asn(struct aspath *aspath, |
1212 | as_t target_asn, as_t our_asn) | |
c7122e14 | 1213 | { |
d62a17ae | 1214 | struct aspath *new; |
1215 | struct assegment *seg; | |
c7122e14 | 1216 | |
d62a17ae | 1217 | new = aspath_dup(aspath); |
1218 | seg = new->segments; | |
c7122e14 | 1219 | |
d62a17ae | 1220 | while (seg) { |
1221 | int i; | |
c7122e14 | 1222 | |
d62a17ae | 1223 | for (i = 0; i < seg->length; i++) { |
1224 | if (seg->as[i] == target_asn) | |
1225 | seg->as[i] = our_asn; | |
1226 | } | |
1227 | seg = seg->next; | |
c7122e14 | 1228 | } |
c7122e14 | 1229 | |
68e1a55b | 1230 | aspath_str_update(new, false); |
d62a17ae | 1231 | return new; |
c7122e14 DS |
1232 | } |
1233 | ||
5000f21c | 1234 | /* Replace all private ASNs with our own ASN */ |
d62a17ae | 1235 | struct aspath *aspath_replace_private_asns(struct aspath *aspath, as_t asn) |
5000f21c | 1236 | { |
d62a17ae | 1237 | struct aspath *new; |
1238 | struct assegment *seg; | |
5000f21c | 1239 | |
d62a17ae | 1240 | new = aspath_dup(aspath); |
1241 | seg = new->segments; | |
5000f21c | 1242 | |
d62a17ae | 1243 | while (seg) { |
1244 | int i; | |
5000f21c | 1245 | |
d62a17ae | 1246 | for (i = 0; i < seg->length; i++) { |
1247 | if (BGP_AS_IS_PRIVATE(seg->as[i])) | |
1248 | seg->as[i] = asn; | |
1249 | } | |
1250 | seg = seg->next; | |
5000f21c | 1251 | } |
5000f21c | 1252 | |
68e1a55b | 1253 | aspath_str_update(new, false); |
d62a17ae | 1254 | return new; |
5000f21c DS |
1255 | } |
1256 | ||
1257 | /* Remove all private ASNs */ | |
d62a17ae | 1258 | struct aspath *aspath_remove_private_asns(struct aspath *aspath) |
1259 | { | |
1260 | struct aspath *new; | |
1261 | struct assegment *seg; | |
1262 | struct assegment *new_seg; | |
1263 | struct assegment *last_new_seg; | |
1264 | int i; | |
1265 | int j; | |
1266 | int public = 0; | |
1267 | ||
1268 | new = XCALLOC(MTYPE_AS_PATH, sizeof(struct aspath)); | |
1269 | ||
1270 | new->json = NULL; | |
1271 | new_seg = NULL; | |
1272 | last_new_seg = NULL; | |
1273 | seg = aspath->segments; | |
1274 | while (seg) { | |
1275 | public | |
1276 | = 0; | |
1277 | for (i = 0; i < seg->length; i++) { | |
1278 | // ASN is public | |
1279 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) { | |
1280 | public | |
1281 | ++; | |
1282 | } | |
1283 | } | |
1284 | ||
1285 | // The entire segment is private so skip it | |
1286 | if (!public) { | |
1287 | seg = seg->next; | |
1288 | continue; | |
1289 | } | |
1290 | ||
1291 | // The entire segment is public so copy it | |
1292 | else if (public == seg->length) { | |
1293 | new_seg = assegment_dup(seg); | |
1294 | } | |
1295 | ||
1296 | // The segment is a mix of public and private ASNs. Copy as many | |
1297 | // spots as | |
1298 | // there are public ASNs then come back and fill in only the | |
1299 | // public ASNs. | |
1300 | else { | |
1301 | new_seg = assegment_new(seg->type, public); | |
1302 | j = 0; | |
1303 | for (i = 0; i < seg->length; i++) { | |
1304 | // ASN is public | |
1305 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) { | |
1306 | new_seg->as[j] = seg->as[i]; | |
1307 | j++; | |
1308 | } | |
1309 | } | |
1310 | } | |
1311 | ||
1312 | // This is the first segment so set the aspath segments pointer | |
1313 | // to this one | |
1314 | if (!last_new_seg) | |
1315 | new->segments = new_seg; | |
1316 | else | |
1317 | last_new_seg->next = new_seg; | |
1318 | ||
1319 | last_new_seg = new_seg; | |
1320 | seg = seg->next; | |
1321 | } | |
1322 | ||
68e1a55b | 1323 | aspath_str_update(new, false); |
d62a17ae | 1324 | return new; |
1325 | } | |
1326 | ||
1327 | /* AS path confed check. If aspath contains confed set or sequence then return | |
1328 | * 1. */ | |
1329 | int aspath_confed_check(struct aspath *aspath) | |
1330 | { | |
1331 | struct assegment *seg; | |
1332 | ||
1333 | if (!(aspath && aspath->segments)) | |
1334 | return 0; | |
1335 | ||
1336 | seg = aspath->segments; | |
1337 | ||
1338 | while (seg) { | |
1339 | if (seg->type == AS_CONFED_SET | |
1340 | || seg->type == AS_CONFED_SEQUENCE) | |
1341 | return 1; | |
1342 | seg = seg->next; | |
1343 | } | |
1344 | return 0; | |
ca87e1d3 VT |
1345 | } |
1346 | ||
1347 | /* Leftmost AS path segment confed check. If leftmost AS segment is of type | |
1348 | AS_CONFED_SEQUENCE or AS_CONFED_SET then return 1. */ | |
d62a17ae | 1349 | int aspath_left_confed_check(struct aspath *aspath) |
ca87e1d3 VT |
1350 | { |
1351 | ||
d62a17ae | 1352 | if (!(aspath && aspath->segments)) |
1353 | return 0; | |
ca87e1d3 | 1354 | |
d62a17ae | 1355 | if ((aspath->segments->type == AS_CONFED_SEQUENCE) |
1356 | || (aspath->segments->type == AS_CONFED_SET)) | |
1357 | return 1; | |
ca87e1d3 | 1358 | |
d62a17ae | 1359 | return 0; |
ca87e1d3 VT |
1360 | } |
1361 | ||
718e3744 | 1362 | /* Merge as1 to as2. as2 should be uninterned aspath. */ |
d62a17ae | 1363 | static struct aspath *aspath_merge(struct aspath *as1, struct aspath *as2) |
718e3744 | 1364 | { |
d62a17ae | 1365 | struct assegment *last, *new; |
718e3744 | 1366 | |
d62a17ae | 1367 | if (!as1 || !as2) |
1368 | return NULL; | |
718e3744 | 1369 | |
d62a17ae | 1370 | last = new = assegment_dup_all(as1->segments); |
1371 | ||
1372 | /* find the last valid segment */ | |
1373 | while (last && last->next) | |
1374 | last = last->next; | |
1375 | ||
e00d8008 NT |
1376 | if (last) |
1377 | last->next = as2->segments; | |
d62a17ae | 1378 | as2->segments = new; |
68e1a55b | 1379 | aspath_str_update(as2, false); |
d62a17ae | 1380 | return as2; |
718e3744 | 1381 | } |
1382 | ||
1383 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
d62a17ae | 1384 | struct aspath *aspath_prepend(struct aspath *as1, struct aspath *as2) |
1385 | { | |
3c510881 QY |
1386 | struct assegment *as1segtail; |
1387 | struct assegment *as2segtail; | |
1388 | struct assegment *as2seghead; | |
d62a17ae | 1389 | |
1390 | if (!as1 || !as2) | |
1391 | return NULL; | |
1392 | ||
d62a17ae | 1393 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ |
3c510881 | 1394 | if (as2->segments == NULL) { |
d62a17ae | 1395 | as2->segments = assegment_dup_all(as1->segments); |
68e1a55b | 1396 | aspath_str_update(as2, false); |
d62a17ae | 1397 | return as2; |
1398 | } | |
1399 | ||
1400 | /* If as1 is empty AS, no prepending to do. */ | |
3c510881 | 1401 | if (as1->segments == NULL) |
d62a17ae | 1402 | return as2; |
1403 | ||
1404 | /* find the tail as1's segment chain. */ | |
3c510881 QY |
1405 | as1segtail = as1->segments; |
1406 | while (as1segtail && as1segtail->next) | |
1407 | as1segtail = as1segtail->next; | |
d62a17ae | 1408 | |
1409 | /* Delete any AS_CONFED_SEQUENCE segment from as2. */ | |
3c510881 QY |
1410 | if (as1segtail->type == AS_SEQUENCE |
1411 | && as2->segments->type == AS_CONFED_SEQUENCE) | |
d62a17ae | 1412 | as2 = aspath_delete_confed_seq(as2); |
1413 | ||
3c510881 QY |
1414 | if (!as2->segments) { |
1415 | as2->segments = assegment_dup_all(as1->segments); | |
1416 | aspath_str_update(as2, false); | |
1417 | return as2; | |
1418 | } | |
1419 | ||
d62a17ae | 1420 | /* Compare last segment type of as1 and first segment type of as2. */ |
3c510881 | 1421 | if (as1segtail->type != as2->segments->type) |
d62a17ae | 1422 | return aspath_merge(as1, as2); |
1423 | ||
3c510881 | 1424 | if (as1segtail->type == AS_SEQUENCE) { |
d62a17ae | 1425 | /* We have two chains of segments, as1->segments and seg2, |
1426 | * and we have to attach them together, merging the attaching | |
1427 | * segments together into one. | |
1428 | * | |
1429 | * 1. dupe as1->segments onto head of as2 | |
1430 | * 2. merge seg2's asns onto last segment of this new chain | |
1431 | * 3. attach chain after seg2 | |
1432 | */ | |
1433 | ||
3c510881 QY |
1434 | /* save as2 head */ |
1435 | as2seghead = as2->segments; | |
1436 | ||
d62a17ae | 1437 | /* dupe as1 onto as2's head */ |
3c510881 | 1438 | as2segtail = as2->segments = assegment_dup_all(as1->segments); |
d62a17ae | 1439 | |
3c510881 QY |
1440 | /* refind the tail of as2 */ |
1441 | while (as2segtail && as2segtail->next) | |
1442 | as2segtail = as2segtail->next; | |
d62a17ae | 1443 | |
1444 | /* merge the old head, seg2, into tail, seg1 */ | |
3c510881 QY |
1445 | assegment_append_asns(as2segtail, as2seghead->as, |
1446 | as2seghead->length); | |
d62a17ae | 1447 | |
3c510881 QY |
1448 | /* |
1449 | * bypass the merged seg2, and attach any chain after it | |
1450 | * to chain descending from as2's head | |
d62a17ae | 1451 | */ |
e00d8008 NT |
1452 | if (as2segtail) |
1453 | as2segtail->next = as2seghead->next; | |
d62a17ae | 1454 | |
3c510881 QY |
1455 | /* as2->segments is now referenceless and useless */ |
1456 | assegment_free(as2seghead); | |
d62a17ae | 1457 | |
1458 | /* we've now prepended as1's segment chain to as2, merging | |
1459 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1460 | */ | |
68e1a55b | 1461 | aspath_str_update(as2, false); |
d62a17ae | 1462 | return as2; |
1463 | } else { | |
1464 | /* AS_SET merge code is needed at here. */ | |
1465 | return aspath_merge(as1, as2); | |
1466 | } | |
1467 | /* XXX: Ermmm, what if as1 has multiple segments?? */ | |
1468 | ||
1469 | /* Not reached */ | |
718e3744 | 1470 | } |
1471 | ||
841f7a57 DO |
1472 | /* Iterate over AS_PATH segments and wipe all occurences of the |
1473 | * listed AS numbers. Hence some segments may lose some or even | |
1474 | * all data on the way, the operation is implemented as a smarter | |
1475 | * version of aspath_dup(), which allocates memory to hold the new | |
1476 | * data, not the original. The new AS path is returned. | |
1477 | */ | |
d62a17ae | 1478 | struct aspath *aspath_filter_exclude(struct aspath *source, |
1479 | struct aspath *exclude_list) | |
1480 | { | |
1481 | struct assegment *srcseg, *exclseg, *lastseg; | |
1482 | struct aspath *newpath; | |
1483 | ||
1484 | newpath = aspath_new(); | |
1485 | lastseg = NULL; | |
1486 | ||
1487 | for (srcseg = source->segments; srcseg; srcseg = srcseg->next) { | |
1488 | unsigned i, y, newlen = 0, done = 0, skip_as; | |
1489 | struct assegment *newseg; | |
1490 | ||
1491 | /* Find out, how much ASns are we going to pick from this | |
1492 | * segment. | |
1493 | * We can't perform filtering right inline, because the size of | |
1494 | * the new segment isn't known at the moment yet. | |
1495 | */ | |
1496 | for (i = 0; i < srcseg->length; i++) { | |
1497 | skip_as = 0; | |
1498 | for (exclseg = exclude_list->segments; | |
1499 | exclseg && !skip_as; exclseg = exclseg->next) | |
1500 | for (y = 0; y < exclseg->length; y++) | |
1501 | if (srcseg->as[i] == exclseg->as[y]) { | |
1502 | skip_as = 1; | |
1503 | // There's no sense in testing | |
1504 | // the rest of exclusion list, | |
1505 | // bail out. | |
1506 | break; | |
1507 | } | |
1508 | if (!skip_as) | |
1509 | newlen++; | |
1510 | } | |
1511 | /* newlen is now the number of ASns to copy */ | |
1512 | if (!newlen) | |
1513 | continue; | |
1514 | ||
1515 | /* Actual copying. Allocate memory and iterate once more, | |
1516 | * performing filtering. */ | |
1517 | newseg = assegment_new(srcseg->type, newlen); | |
1518 | for (i = 0; i < srcseg->length; i++) { | |
1519 | skip_as = 0; | |
1520 | for (exclseg = exclude_list->segments; | |
1521 | exclseg && !skip_as; exclseg = exclseg->next) | |
1522 | for (y = 0; y < exclseg->length; y++) | |
1523 | if (srcseg->as[i] == exclseg->as[y]) { | |
1524 | skip_as = 1; | |
1525 | break; | |
1526 | } | |
1527 | if (skip_as) | |
1528 | continue; | |
1529 | newseg->as[done++] = srcseg->as[i]; | |
1530 | } | |
1531 | /* At his point newlen must be equal to done, and both must be | |
1532 | * positive. Append | |
1533 | * the filtered segment to the gross result. */ | |
1534 | if (!lastseg) | |
1535 | newpath->segments = newseg; | |
1536 | else | |
1537 | lastseg->next = newseg; | |
1538 | lastseg = newseg; | |
1539 | } | |
68e1a55b | 1540 | aspath_str_update(newpath, false); |
d62a17ae | 1541 | /* We are happy returning even an empty AS_PATH, because the |
1542 | * administrator | |
1543 | * might expect this very behaviour. There's a mean to avoid this, if | |
1544 | * necessary, | |
1545 | * by having a match rule against certain AS_PATH regexps in the | |
1546 | * route-map index. | |
1547 | */ | |
1548 | aspath_free(source); | |
1549 | return newpath; | |
841f7a57 DO |
1550 | } |
1551 | ||
718e3744 | 1552 | /* Add specified AS to the leftmost of aspath. */ |
d62a17ae | 1553 | static struct aspath *aspath_add_asns(struct aspath *aspath, as_t asno, |
d7c0a89a | 1554 | uint8_t type, unsigned num) |
d62a17ae | 1555 | { |
1556 | struct assegment *assegment = aspath->segments; | |
1557 | unsigned i; | |
1558 | ||
1559 | if (assegment && assegment->type == type) { | |
1560 | /* extend existing segment */ | |
1561 | aspath->segments = | |
1562 | assegment_prepend_asns(aspath->segments, asno, num); | |
1563 | } else { | |
1564 | /* prepend with new segment */ | |
1565 | struct assegment *newsegment = assegment_new(type, num); | |
1566 | for (i = 0; i < num; i++) | |
1567 | newsegment->as[i] = asno; | |
1568 | ||
1569 | /* insert potentially replacing empty segment */ | |
1570 | if (assegment && assegment->length == 0) { | |
1571 | newsegment->next = assegment->next; | |
1572 | assegment_free(assegment); | |
1573 | } else | |
1574 | newsegment->next = assegment; | |
1575 | aspath->segments = newsegment; | |
bc3dd427 | 1576 | } |
718e3744 | 1577 | |
68e1a55b | 1578 | aspath_str_update(aspath, false); |
d62a17ae | 1579 | return aspath; |
718e3744 | 1580 | } |
1581 | ||
bc3dd427 | 1582 | /* Add specified AS to the leftmost of aspath num times. */ |
d62a17ae | 1583 | struct aspath *aspath_add_seq_n(struct aspath *aspath, as_t asno, unsigned num) |
bc3dd427 | 1584 | { |
d62a17ae | 1585 | return aspath_add_asns(aspath, asno, AS_SEQUENCE, num); |
bc3dd427 DW |
1586 | } |
1587 | ||
718e3744 | 1588 | /* Add specified AS to the leftmost of aspath. */ |
d62a17ae | 1589 | struct aspath *aspath_add_seq(struct aspath *aspath, as_t asno) |
718e3744 | 1590 | { |
d62a17ae | 1591 | return aspath_add_asns(aspath, asno, AS_SEQUENCE, 1); |
718e3744 | 1592 | } |
1593 | ||
1594 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1595 | as2's leftmost AS is same return 1. */ | |
d62a17ae | 1596 | int aspath_cmp_left(const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1597 | { |
d62a17ae | 1598 | const struct assegment *seg1; |
1599 | const struct assegment *seg2; | |
1600 | ||
1601 | if (!(aspath1 && aspath2)) | |
1602 | return 0; | |
718e3744 | 1603 | |
d62a17ae | 1604 | seg1 = aspath1->segments; |
1605 | seg2 = aspath2->segments; | |
718e3744 | 1606 | |
d62a17ae | 1607 | /* If both paths are originated in this AS then we do want to compare |
1608 | * MED */ | |
1609 | if (!seg1 && !seg2) | |
1610 | return 1; | |
718e3744 | 1611 | |
d62a17ae | 1612 | /* find first non-confed segments for each */ |
9d303b37 DL |
1613 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) |
1614 | || (seg1->type == AS_CONFED_SET))) | |
d62a17ae | 1615 | seg1 = seg1->next; |
2a3fa5d7 | 1616 | |
9d303b37 DL |
1617 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1618 | || (seg2->type == AS_CONFED_SET))) | |
d62a17ae | 1619 | seg2 = seg2->next; |
718e3744 | 1620 | |
d62a17ae | 1621 | /* Check as1's */ |
1622 | if (!(seg1 && seg2 && (seg1->type == AS_SEQUENCE) | |
1623 | && (seg2->type == AS_SEQUENCE))) | |
1624 | return 0; | |
718e3744 | 1625 | |
d62a17ae | 1626 | if (seg1->as[0] == seg2->as[0]) |
1627 | return 1; | |
718e3744 | 1628 | |
d62a17ae | 1629 | return 0; |
718e3744 | 1630 | } |
1631 | ||
0b2aa3a0 PJ |
1632 | /* Truncate an aspath after a number of hops, and put the hops remaining |
1633 | * at the front of another aspath. Needed for AS4 compat. | |
1634 | * | |
1635 | * Returned aspath is a /new/ aspath, which should either by free'd or | |
1636 | * interned by the caller, as desired. | |
1637 | */ | |
d62a17ae | 1638 | struct aspath *aspath_reconcile_as4(struct aspath *aspath, |
1639 | struct aspath *as4path) | |
1640 | { | |
1641 | struct assegment *seg, *newseg, *prevseg = NULL; | |
1642 | struct aspath *newpath = NULL, *mergedpath; | |
1643 | int hops, cpasns = 0; | |
1644 | ||
e8a3a0a0 | 1645 | if (!aspath || !as4path) |
d62a17ae | 1646 | return NULL; |
1647 | ||
1648 | seg = aspath->segments; | |
1649 | ||
1650 | /* CONFEDs should get reconciled too.. */ | |
1651 | hops = (aspath_count_hops(aspath) + aspath_count_confeds(aspath)) | |
1652 | - aspath_count_hops(as4path); | |
1653 | ||
1654 | if (hops < 0) { | |
1655 | if (BGP_DEBUG(as4, AS4)) | |
ade6974d | 1656 | flog_warn( |
e50f7cfd | 1657 | EC_BGP_ASPATH_FEWER_HOPS, |
ade6974d | 1658 | "[AS4] Fewer hops in AS_PATH than NEW_AS_PATH"); |
d62a17ae | 1659 | /* Something's gone wrong. The RFC says we should now ignore |
1660 | * AS4_PATH, | |
1661 | * which is daft behaviour - it contains vital loop-detection | |
1662 | * information which must have been removed from AS_PATH. | |
1663 | */ | |
1664 | hops = aspath_count_hops(aspath); | |
1665 | } | |
1666 | ||
1667 | if (!hops) { | |
1668 | newpath = aspath_dup(as4path); | |
68e1a55b | 1669 | aspath_str_update(newpath, false); |
d62a17ae | 1670 | return newpath; |
0b2aa3a0 | 1671 | } |
d62a17ae | 1672 | |
1673 | if (BGP_DEBUG(as4, AS4)) | |
1674 | zlog_debug( | |
1675 | "[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now", | |
1676 | aspath->str, as4path->str); | |
1677 | ||
1678 | while (seg && hops > 0) { | |
1679 | switch (seg->type) { | |
1680 | case AS_SET: | |
1681 | case AS_CONFED_SET: | |
1682 | hops--; | |
1683 | cpasns = seg->length; | |
1684 | break; | |
1685 | case AS_CONFED_SEQUENCE: | |
1686 | /* Should never split a confed-sequence, if hop-count | |
1687 | * suggests we must then something's gone wrong | |
1688 | * somewhere. | |
1689 | * | |
1690 | * Most important goal is to preserve AS_PATHs prime | |
1691 | * function | |
1692 | * as loop-detector, so we fudge the numbers so that the | |
1693 | * entire | |
1694 | * confed-sequence is merged in. | |
1695 | */ | |
1696 | if (hops < seg->length) { | |
1697 | if (BGP_DEBUG(as4, AS4)) | |
1698 | zlog_debug( | |
1699 | "[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls" | |
1700 | " across 2/4 ASN boundary somewhere, broken.."); | |
1701 | hops = seg->length; | |
1702 | } | |
1703 | /* fallthru */ | |
1704 | case AS_SEQUENCE: | |
1705 | cpasns = MIN(seg->length, hops); | |
1706 | hops -= seg->length; | |
1707 | } | |
1708 | ||
1709 | assert(cpasns <= seg->length); | |
1710 | ||
1711 | newseg = assegment_new(seg->type, 0); | |
1712 | newseg = assegment_append_asns(newseg, seg->as, cpasns); | |
1713 | ||
1714 | if (!newpath) { | |
1715 | newpath = aspath_new(); | |
1716 | newpath->segments = newseg; | |
1717 | } else | |
1718 | prevseg->next = newseg; | |
1719 | ||
1720 | prevseg = newseg; | |
1721 | seg = seg->next; | |
1722 | } | |
1723 | ||
1724 | /* We may be able to join some segments here, and we must | |
1725 | * do this because... we want normalised aspaths in out hash | |
1726 | * and we do not want to stumble in aspath_put. | |
1727 | */ | |
1728 | mergedpath = aspath_merge(newpath, aspath_dup(as4path)); | |
1729 | aspath_free(newpath); | |
1730 | mergedpath->segments = assegment_normalise(mergedpath->segments); | |
68e1a55b | 1731 | aspath_str_update(mergedpath, false); |
d62a17ae | 1732 | |
1733 | if (BGP_DEBUG(as4, AS4)) | |
1734 | zlog_debug("[AS4] result of synthesizing is %s", | |
1735 | mergedpath->str); | |
1736 | ||
1737 | return mergedpath; | |
0b2aa3a0 PJ |
1738 | } |
1739 | ||
718e3744 | 1740 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and |
1741 | as2's leftmost AS is same return 1. (confederation as-path | |
1742 | only). */ | |
74df8d6d DS |
1743 | bool aspath_cmp_left_confed(const struct aspath *aspath1, |
1744 | const struct aspath *aspath2) | |
718e3744 | 1745 | { |
d62a17ae | 1746 | if (!(aspath1 && aspath2)) |
74df8d6d | 1747 | return false; |
718e3744 | 1748 | |
d62a17ae | 1749 | if (!(aspath1->segments && aspath2->segments)) |
74df8d6d | 1750 | return false; |
d62a17ae | 1751 | |
1752 | if ((aspath1->segments->type != AS_CONFED_SEQUENCE) | |
1753 | || (aspath2->segments->type != AS_CONFED_SEQUENCE)) | |
74df8d6d | 1754 | return false; |
d62a17ae | 1755 | |
1756 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
74df8d6d | 1757 | return true; |
d62a17ae | 1758 | |
74df8d6d | 1759 | return false; |
718e3744 | 1760 | } |
1761 | ||
66b199b2 DS |
1762 | /* Delete all AS_CONFED_SEQUENCE/SET segments from aspath. |
1763 | * RFC 5065 section 4.1.c.1 | |
1764 | * | |
1765 | * 1) if any path segments of the AS_PATH are of the type | |
1766 | * AS_CONFED_SEQUENCE or AS_CONFED_SET, those segments MUST be | |
1767 | * removed from the AS_PATH attribute, leaving the sanitized | |
1768 | * AS_PATH attribute to be operated on by steps 2, 3 or 4. | |
1769 | */ | |
d62a17ae | 1770 | struct aspath *aspath_delete_confed_seq(struct aspath *aspath) |
718e3744 | 1771 | { |
d62a17ae | 1772 | struct assegment *seg, *prev, *next; |
1773 | char removed_confed_segment; | |
1774 | ||
1775 | if (!(aspath && aspath->segments)) | |
1776 | return aspath; | |
718e3744 | 1777 | |
d62a17ae | 1778 | seg = aspath->segments; |
1779 | removed_confed_segment = 0; | |
1780 | next = NULL; | |
1781 | prev = NULL; | |
718e3744 | 1782 | |
d62a17ae | 1783 | while (seg) { |
1784 | next = seg->next; | |
66b199b2 | 1785 | |
d62a17ae | 1786 | if (seg->type == AS_CONFED_SEQUENCE |
1787 | || seg->type == AS_CONFED_SET) { | |
1788 | /* This is the first segment in the aspath */ | |
1789 | if (aspath->segments == seg) | |
1790 | aspath->segments = seg->next; | |
1791 | else | |
1792 | prev->next = seg->next; | |
66b199b2 | 1793 | |
d62a17ae | 1794 | assegment_free(seg); |
1795 | removed_confed_segment = 1; | |
1796 | } else | |
1797 | prev = seg; | |
66b199b2 | 1798 | |
d62a17ae | 1799 | seg = next; |
1800 | } | |
66b199b2 | 1801 | |
d62a17ae | 1802 | if (removed_confed_segment) |
68e1a55b | 1803 | aspath_str_update(aspath, false); |
66b199b2 | 1804 | |
d62a17ae | 1805 | return aspath; |
718e3744 | 1806 | } |
1807 | ||
1808 | /* Add new AS number to the leftmost part of the aspath as | |
1809 | AS_CONFED_SEQUENCE. */ | |
d62a17ae | 1810 | struct aspath *aspath_add_confed_seq(struct aspath *aspath, as_t asno) |
718e3744 | 1811 | { |
d62a17ae | 1812 | return aspath_add_asns(aspath, asno, AS_CONFED_SEQUENCE, 1); |
718e3744 | 1813 | } |
1814 | ||
1815 | /* Add new as value to as path structure. */ | |
d62a17ae | 1816 | static void aspath_as_add(struct aspath *as, as_t asno) |
718e3744 | 1817 | { |
d62a17ae | 1818 | struct assegment *seg = as->segments; |
1819 | ||
1820 | if (!seg) | |
1821 | return; | |
718e3744 | 1822 | |
d62a17ae | 1823 | /* Last segment search procedure. */ |
1824 | while (seg->next) | |
1825 | seg = seg->next; | |
93c1749c | 1826 | |
d62a17ae | 1827 | assegment_append_asns(seg, &asno, 1); |
718e3744 | 1828 | } |
1829 | ||
1830 | /* Add new as segment to the as path. */ | |
d62a17ae | 1831 | static void aspath_segment_add(struct aspath *as, int type) |
718e3744 | 1832 | { |
d62a17ae | 1833 | struct assegment *seg = as->segments; |
1834 | struct assegment *new = assegment_new(type, 0); | |
718e3744 | 1835 | |
d62a17ae | 1836 | if (seg) { |
1837 | while (seg->next) | |
1838 | seg = seg->next; | |
1839 | seg->next = new; | |
1840 | } else | |
1841 | as->segments = new; | |
718e3744 | 1842 | } |
1843 | ||
d62a17ae | 1844 | struct aspath *aspath_empty(void) |
718e3744 | 1845 | { |
d62a17ae | 1846 | return aspath_parse(NULL, 0, 1); /* 32Bit ;-) */ |
718e3744 | 1847 | } |
1848 | ||
d62a17ae | 1849 | struct aspath *aspath_empty_get(void) |
718e3744 | 1850 | { |
d62a17ae | 1851 | struct aspath *aspath; |
718e3744 | 1852 | |
d62a17ae | 1853 | aspath = aspath_new(); |
68e1a55b | 1854 | aspath_make_str_count(aspath, false); |
d62a17ae | 1855 | return aspath; |
718e3744 | 1856 | } |
1857 | ||
d62a17ae | 1858 | unsigned long aspath_count(void) |
718e3744 | 1859 | { |
d62a17ae | 1860 | return ashash->count; |
1861 | } | |
6b0655a2 | 1862 | |
d62a17ae | 1863 | /* |
718e3744 | 1864 | Theoretically, one as path can have: |
1865 | ||
1866 | One BGP packet size should be less than 4096. | |
1867 | One BGP attribute size should be less than 4096 - BGP header size. | |
1868 | One BGP aspath size should be less than 4096 - BGP header size - | |
1869 | BGP mandantry attribute size. | |
1870 | */ | |
1871 | ||
1872 | /* AS path string lexical token enum. */ | |
d62a17ae | 1873 | enum as_token { |
1874 | as_token_asval, | |
1875 | as_token_set_start, | |
1876 | as_token_set_end, | |
1877 | as_token_confed_seq_start, | |
1878 | as_token_confed_seq_end, | |
1879 | as_token_confed_set_start, | |
1880 | as_token_confed_set_end, | |
1881 | as_token_unknown | |
718e3744 | 1882 | }; |
1883 | ||
1884 | /* Return next token and point for string parse. */ | |
d62a17ae | 1885 | static const char *aspath_gettoken(const char *buf, enum as_token *token, |
d7c0a89a | 1886 | unsigned long *asno) |
d62a17ae | 1887 | { |
1888 | const char *p = buf; | |
1889 | ||
1890 | /* Skip seperators (space for sequences, ',' for sets). */ | |
1891 | while (isspace((int)*p) || *p == ',') | |
1892 | p++; | |
1893 | ||
1894 | /* Check the end of the string and type specify characters | |
1895 | (e.g. {}()). */ | |
1896 | switch (*p) { | |
1897 | case '\0': | |
1898 | return NULL; | |
1899 | case '{': | |
1900 | *token = as_token_set_start; | |
1901 | p++; | |
1902 | return p; | |
1903 | case '}': | |
1904 | *token = as_token_set_end; | |
1905 | p++; | |
1906 | return p; | |
1907 | case '(': | |
1908 | *token = as_token_confed_seq_start; | |
1909 | p++; | |
1910 | return p; | |
1911 | case ')': | |
1912 | *token = as_token_confed_seq_end; | |
1913 | p++; | |
1914 | return p; | |
1915 | case '[': | |
1916 | *token = as_token_confed_set_start; | |
1917 | p++; | |
1918 | return p; | |
1919 | case ']': | |
1920 | *token = as_token_confed_set_end; | |
1921 | p++; | |
1922 | return p; | |
1923 | } | |
1924 | ||
1925 | /* Check actual AS value. */ | |
1926 | if (isdigit((int)*p)) { | |
1927 | as_t asval; | |
1928 | ||
1929 | *token = as_token_asval; | |
1930 | asval = (*p - '0'); | |
1931 | p++; | |
1932 | ||
1933 | while (isdigit((int)*p)) { | |
1934 | asval *= 10; | |
1935 | asval += (*p - '0'); | |
1936 | p++; | |
1937 | } | |
1938 | *asno = asval; | |
1939 | return p; | |
718e3744 | 1940 | } |
718e3744 | 1941 | |
d62a17ae | 1942 | /* There is no match then return unknown token. */ |
1943 | *token = as_token_unknown; | |
b42d80dd VJ |
1944 | p++; |
1945 | return p; | |
d62a17ae | 1946 | } |
1947 | ||
1948 | struct aspath *aspath_str2aspath(const char *str) | |
1949 | { | |
1950 | enum as_token token = as_token_unknown; | |
d7c0a89a QY |
1951 | unsigned short as_type; |
1952 | unsigned long asno = 0; | |
d62a17ae | 1953 | struct aspath *aspath; |
1954 | int needtype; | |
1955 | ||
1956 | aspath = aspath_new(); | |
1957 | ||
1958 | /* We start default type as AS_SEQUENCE. */ | |
1959 | as_type = AS_SEQUENCE; | |
1960 | needtype = 1; | |
1961 | ||
1962 | while ((str = aspath_gettoken(str, &token, &asno)) != NULL) { | |
1963 | switch (token) { | |
1964 | case as_token_asval: | |
1965 | if (needtype) { | |
1966 | aspath_segment_add(aspath, as_type); | |
1967 | needtype = 0; | |
1968 | } | |
1969 | aspath_as_add(aspath, asno); | |
1970 | break; | |
1971 | case as_token_set_start: | |
1972 | as_type = AS_SET; | |
1973 | aspath_segment_add(aspath, as_type); | |
1974 | needtype = 0; | |
1975 | break; | |
1976 | case as_token_set_end: | |
1977 | as_type = AS_SEQUENCE; | |
1978 | needtype = 1; | |
1979 | break; | |
1980 | case as_token_confed_seq_start: | |
1981 | as_type = AS_CONFED_SEQUENCE; | |
1982 | aspath_segment_add(aspath, as_type); | |
1983 | needtype = 0; | |
1984 | break; | |
1985 | case as_token_confed_seq_end: | |
1986 | as_type = AS_SEQUENCE; | |
1987 | needtype = 1; | |
1988 | break; | |
1989 | case as_token_confed_set_start: | |
1990 | as_type = AS_CONFED_SET; | |
1991 | aspath_segment_add(aspath, as_type); | |
1992 | needtype = 0; | |
1993 | break; | |
1994 | case as_token_confed_set_end: | |
1995 | as_type = AS_SEQUENCE; | |
1996 | needtype = 1; | |
1997 | break; | |
1998 | case as_token_unknown: | |
1999 | default: | |
2000 | aspath_free(aspath); | |
2001 | return NULL; | |
2002 | } | |
2003 | } | |
2004 | ||
68e1a55b | 2005 | aspath_make_str_count(aspath, false); |
718e3744 | 2006 | |
d62a17ae | 2007 | return aspath; |
718e3744 | 2008 | } |
6b0655a2 | 2009 | |
718e3744 | 2010 | /* Make hash value by raw aspath data. */ |
d8b87afe | 2011 | unsigned int aspath_key_make(const void *p) |
718e3744 | 2012 | { |
d8b87afe | 2013 | const struct aspath *aspath = p; |
d62a17ae | 2014 | unsigned int key = 0; |
718e3744 | 2015 | |
d62a17ae | 2016 | if (!aspath->str) |
d8b87afe | 2017 | aspath_str_update((struct aspath *)aspath, false); |
f669f7d2 | 2018 | |
d62a17ae | 2019 | key = jhash(aspath->str, aspath->str_len, 2334325); |
718e3744 | 2020 | |
d62a17ae | 2021 | return key; |
718e3744 | 2022 | } |
2023 | ||
2024 | /* If two aspath have same value then return 1 else return 0 */ | |
74df8d6d | 2025 | bool aspath_cmp(const void *arg1, const void *arg2) |
d62a17ae | 2026 | { |
2027 | const struct assegment *seg1 = ((const struct aspath *)arg1)->segments; | |
2028 | const struct assegment *seg2 = ((const struct aspath *)arg2)->segments; | |
2029 | ||
2030 | while (seg1 || seg2) { | |
2031 | int i; | |
2032 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
74df8d6d | 2033 | return false; |
d62a17ae | 2034 | if (seg1->type != seg2->type) |
74df8d6d | 2035 | return false; |
d62a17ae | 2036 | if (seg1->length != seg2->length) |
74df8d6d | 2037 | return false; |
d62a17ae | 2038 | for (i = 0; i < seg1->length; i++) |
2039 | if (seg1->as[i] != seg2->as[i]) | |
74df8d6d | 2040 | return false; |
d62a17ae | 2041 | seg1 = seg1->next; |
2042 | seg2 = seg2->next; | |
2043 | } | |
74df8d6d | 2044 | return true; |
718e3744 | 2045 | } |
2046 | ||
2047 | /* AS path hash initialize. */ | |
d62a17ae | 2048 | void aspath_init(void) |
718e3744 | 2049 | { |
996c9314 | 2050 | ashash = hash_create_size(32768, aspath_key_make, aspath_cmp, |
3f65c5b1 | 2051 | "BGP AS Path"); |
718e3744 | 2052 | } |
8fdc32ab | 2053 | |
d62a17ae | 2054 | void aspath_finish(void) |
8fdc32ab | 2055 | { |
d62a17ae | 2056 | hash_clean(ashash, (void (*)(void *))aspath_free); |
2057 | hash_free(ashash); | |
2058 | ashash = NULL; | |
2059 | ||
2060 | if (snmp_stream) | |
2061 | stream_free(snmp_stream); | |
8fdc32ab | 2062 | } |
6b0655a2 | 2063 | |
718e3744 | 2064 | /* return and as path value */ |
d62a17ae | 2065 | const char *aspath_print(struct aspath *as) |
718e3744 | 2066 | { |
d62a17ae | 2067 | return (as ? as->str : NULL); |
718e3744 | 2068 | } |
2069 | ||
2070 | /* Printing functions */ | |
841f7a57 DO |
2071 | /* Feed the AS_PATH to the vty; the suffix string follows it only in case |
2072 | * AS_PATH wasn't empty. | |
2073 | */ | |
d62a17ae | 2074 | void aspath_print_vty(struct vty *vty, const char *format, struct aspath *as, |
2075 | const char *suffix) | |
718e3744 | 2076 | { |
d62a17ae | 2077 | assert(format); |
2078 | vty_out(vty, format, as->str); | |
2079 | if (as->str_len && strlen(suffix)) | |
2080 | vty_out(vty, "%s", suffix); | |
718e3744 | 2081 | } |
2082 | ||
e3b78da8 | 2083 | static void aspath_show_all_iterator(struct hash_bucket *bucket, |
d62a17ae | 2084 | struct vty *vty) |
718e3744 | 2085 | { |
d62a17ae | 2086 | struct aspath *as; |
718e3744 | 2087 | |
e3b78da8 | 2088 | as = (struct aspath *)bucket->data; |
718e3744 | 2089 | |
e3b78da8 | 2090 | vty_out(vty, "[%p:%u] (%ld) ", (void *)bucket, bucket->key, as->refcnt); |
d62a17ae | 2091 | vty_out(vty, "%s\n", as->str); |
718e3744 | 2092 | } |
2093 | ||
2094 | /* Print all aspath and hash information. This function is used from | |
716b2d8a | 2095 | `show [ip] bgp paths' command. */ |
d62a17ae | 2096 | void aspath_print_all_vty(struct vty *vty) |
718e3744 | 2097 | { |
e3b78da8 | 2098 | hash_iterate(ashash, (void (*)(struct hash_bucket *, |
9d303b37 | 2099 | void *))aspath_show_all_iterator, |
d62a17ae | 2100 | vty); |
718e3744 | 2101 | } |
e00d8008 NT |
2102 | |
2103 | static struct aspath *bgp_aggr_aspath_lookup(struct bgp_aggregate *aggregate, | |
2104 | struct aspath *aspath) | |
2105 | { | |
2106 | return hash_lookup(aggregate->aspath_hash, aspath); | |
2107 | } | |
2108 | ||
2109 | static void *bgp_aggr_aspath_hash_alloc(void *p) | |
2110 | { | |
2111 | struct aspath *ref = (struct aspath *)p; | |
2112 | struct aspath *aspath = NULL; | |
2113 | ||
2114 | aspath = aspath_dup(ref); | |
2115 | return aspath; | |
2116 | } | |
2117 | ||
2118 | static void bgp_aggr_aspath_prepare(struct hash_backet *hb, void *arg) | |
2119 | { | |
2120 | struct aspath *asmerge = NULL; | |
2121 | struct aspath *hb_aspath = hb->data; | |
2122 | struct aspath **aggr_aspath = arg; | |
2123 | ||
2124 | if (*aggr_aspath) { | |
2125 | asmerge = aspath_aggregate(*aggr_aspath, hb_aspath); | |
2126 | aspath_free(*aggr_aspath); | |
2127 | *aggr_aspath = asmerge; | |
2128 | } else | |
2129 | *aggr_aspath = aspath_dup(hb_aspath); | |
2130 | } | |
2131 | ||
2132 | void bgp_aggr_aspath_remove(void *arg) | |
2133 | { | |
2134 | struct aspath *aspath = arg; | |
2135 | ||
2136 | aspath_free(aspath); | |
2137 | } | |
2138 | ||
2139 | void bgp_compute_aggregate_aspath(struct bgp_aggregate *aggregate, | |
2140 | struct aspath *aspath) | |
2141 | { | |
2142 | struct aspath *aggr_aspath = NULL; | |
2143 | ||
2144 | if ((aggregate == NULL) || (aspath == NULL)) | |
2145 | return; | |
2146 | ||
2147 | /* Create hash if not already created. | |
2148 | */ | |
2149 | if (aggregate->aspath_hash == NULL) | |
2150 | aggregate->aspath_hash = hash_create( | |
2151 | aspath_key_make, aspath_cmp, | |
2152 | "BGP Aggregator as-path hash"); | |
2153 | ||
2154 | aggr_aspath = bgp_aggr_aspath_lookup(aggregate, aspath); | |
2155 | if (aggr_aspath == NULL) { | |
2156 | /* Insert as-path into hash. | |
2157 | */ | |
2158 | aggr_aspath = hash_get(aggregate->aspath_hash, aspath, | |
2159 | bgp_aggr_aspath_hash_alloc); | |
2160 | ||
2161 | /* Compute aggregate's as-path. | |
2162 | */ | |
2163 | hash_iterate(aggregate->aspath_hash, | |
2164 | bgp_aggr_aspath_prepare, | |
2165 | &aggregate->aspath); | |
2166 | } | |
2167 | ||
2168 | /* Increment refernce counter. | |
2169 | */ | |
2170 | aggr_aspath->refcnt++; | |
2171 | } | |
2172 | ||
2173 | void bgp_remove_aspath_from_aggregate(struct bgp_aggregate *aggregate, | |
2174 | struct aspath *aspath) | |
2175 | { | |
2176 | struct aspath *aggr_aspath = NULL; | |
2177 | struct aspath *ret_aspath = NULL; | |
2178 | ||
2179 | if ((aggregate == NULL) || (aspath == NULL)) | |
2180 | return; | |
2181 | ||
2182 | if (aggregate->aspath_hash == NULL) | |
2183 | return; | |
2184 | ||
2185 | /* Look-up the aspath in the hash. | |
2186 | */ | |
2187 | aggr_aspath = bgp_aggr_aspath_lookup(aggregate, aspath); | |
2188 | if (aggr_aspath) { | |
2189 | aggr_aspath->refcnt--; | |
2190 | ||
2191 | if (aggr_aspath->refcnt == 0) { | |
2192 | ret_aspath = hash_release(aggregate->aspath_hash, | |
2193 | aggr_aspath); | |
2194 | aspath_free(ret_aspath); | |
2195 | ||
2196 | /* Remove aggregate's old as-path. | |
2197 | */ | |
2198 | aspath_free(aggregate->aspath); | |
2199 | aggregate->aspath = NULL; | |
2200 | ||
2201 | /* Compute aggregate's as-path. | |
2202 | */ | |
2203 | hash_iterate(aggregate->aspath_hash, | |
2204 | bgp_aggr_aspath_prepare, | |
2205 | &aggregate->aspath); | |
2206 | } | |
2207 | } | |
2208 | } |