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