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718e3744 | 1 | /* AS path management routines. |
2 | Copyright (C) 1996, 97, 98, 99 Kunihiro Ishiguro | |
fe69a505 | 3 | Copyright (C) 2005 Sun Microsystems, Inc. |
718e3744 | 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 | |
18 | along with GNU Zebra; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
22 | #include <zebra.h> | |
23 | ||
24 | #include "hash.h" | |
25 | #include "memory.h" | |
26 | #include "vector.h" | |
27 | #include "vty.h" | |
28 | #include "str.h" | |
29 | #include "log.h" | |
fe69a505 | 30 | #include "stream.h" |
0b2aa3a0 | 31 | #include "jhash.h" |
3f9c7369 | 32 | #include "queue.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" | |
6b0655a2 | 38 | |
718e3744 | 39 | /* Attr. Flags and Attr. Type Code. */ |
40 | #define AS_HEADER_SIZE 2 | |
41 | ||
0b2aa3a0 | 42 | /* Now FOUR octets are used for AS value. */ |
718e3744 | 43 | #define AS_VALUE_SIZE sizeof (as_t) |
0b2aa3a0 PJ |
44 | /* This is the old one */ |
45 | #define AS16_VALUE_SIZE sizeof (as16_t) | |
718e3744 | 46 | |
fe69a505 | 47 | /* Maximum protocol segment length value */ |
48 | #define AS_SEGMENT_MAX 255 | |
49 | ||
50 | /* The following length and size macros relate specifically to Quagga's | |
51 | * internal representation of AS-Segments, not per se to the on-wire | |
52 | * sizes and lengths. At present (200508) they sort of match, however | |
53 | * the ONLY functions which should now about the on-wire syntax are | |
54 | * aspath_put, assegment_put and assegment_parse. | |
0b2aa3a0 PJ |
55 | * |
56 | * aspath_put returns bytes written, the only definitive record of | |
57 | * size of wire-format attribute.. | |
fe69a505 | 58 | */ |
59 | ||
60 | /* Calculated size in bytes of ASN segment data to hold N ASN's */ | |
0b2aa3a0 PJ |
61 | #define ASSEGMENT_DATA_SIZE(N,S) \ |
62 | ((N) * ( (S) ? AS_VALUE_SIZE : AS16_VALUE_SIZE) ) | |
718e3744 | 63 | |
fe69a505 | 64 | /* Calculated size of segment struct to hold N ASN's */ |
0b2aa3a0 | 65 | #define ASSEGMENT_SIZE(N,S) (AS_HEADER_SIZE + ASSEGMENT_DATA_SIZE (N,S)) |
fe69a505 | 66 | |
67 | /* AS segment octet length. */ | |
0b2aa3a0 | 68 | #define ASSEGMENT_LEN(X,S) ASSEGMENT_SIZE((X)->length,S) |
fe69a505 | 69 | |
70 | /* AS_SEQUENCE segments can be packed together */ | |
71 | /* Can the types of X and Y be considered for packing? */ | |
72 | #define ASSEGMENT_TYPES_PACKABLE(X,Y) \ | |
73 | ( ((X)->type == (Y)->type) \ | |
74 | && ((X)->type == AS_SEQUENCE)) | |
75 | /* Types and length of X,Y suitable for packing? */ | |
76 | #define ASSEGMENTS_PACKABLE(X,Y) \ | |
77 | ( ASSEGMENT_TYPES_PACKABLE( (X), (Y)) \ | |
78 | && ( ((X)->length + (Y)->length) <= AS_SEGMENT_MAX ) ) | |
79 | ||
80 | /* As segment header - the on-wire representation | |
81 | * NOT the internal representation! | |
82 | */ | |
83 | struct assegment_header | |
718e3744 | 84 | { |
85 | u_char type; | |
86 | u_char length; | |
718e3744 | 87 | }; |
88 | ||
89 | /* Hash for aspath. This is the top level structure of AS path. */ | |
da88ea82 | 90 | static struct hash *ashash; |
8fdc32ab | 91 | |
92 | /* Stream for SNMP. See aspath_snmp_pathseg */ | |
93 | static struct stream *snmp_stream; | |
6b0655a2 | 94 | |
f669f7d2 | 95 | /* Callers are required to initialize the memory */ |
f63f06da | 96 | static as_t * |
fe69a505 | 97 | assegment_data_new (int num) |
98 | { | |
f669f7d2 | 99 | return (XMALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num, 1))); |
fe69a505 | 100 | } |
101 | ||
f1aa5d8a DS |
102 | const char *aspath_segment_type_str[] = { |
103 | "as-invalid", | |
104 | "as-set", | |
105 | "as-sequence", | |
106 | "as-confed-sequence", | |
107 | "as-confed-set" | |
108 | }; | |
109 | ||
fe69a505 | 110 | /* Get a new segment. Note that 0 is an allowed length, |
111 | * and will result in a segment with no allocated data segment. | |
112 | * the caller should immediately assign data to the segment, as the segment | |
113 | * otherwise is not generally valid | |
114 | */ | |
115 | static struct assegment * | |
116 | assegment_new (u_char type, u_short length) | |
117 | { | |
118 | struct assegment *new; | |
119 | ||
120 | new = XCALLOC (MTYPE_AS_SEG, sizeof (struct assegment)); | |
121 | ||
122 | if (length) | |
123 | new->as = assegment_data_new (length); | |
124 | ||
125 | new->length = length; | |
126 | new->type = type; | |
127 | ||
128 | return new; | |
129 | } | |
130 | ||
131 | static void | |
132 | assegment_free (struct assegment *seg) | |
133 | { | |
134 | if (!seg) | |
135 | return; | |
136 | ||
137 | if (seg->as) | |
138 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
139 | memset (seg, 0xfe, sizeof(struct assegment)); | |
140 | XFREE (MTYPE_AS_SEG, seg); | |
141 | ||
142 | return; | |
143 | } | |
144 | ||
145 | /* free entire chain of segments */ | |
146 | static void | |
147 | assegment_free_all (struct assegment *seg) | |
148 | { | |
149 | struct assegment *prev; | |
150 | ||
151 | while (seg) | |
152 | { | |
153 | prev = seg; | |
154 | seg = seg->next; | |
155 | assegment_free (prev); | |
156 | } | |
157 | } | |
158 | ||
159 | /* Duplicate just the given assegment and its data */ | |
160 | static struct assegment * | |
161 | assegment_dup (struct assegment *seg) | |
162 | { | |
163 | struct assegment *new; | |
164 | ||
165 | new = assegment_new (seg->type, seg->length); | |
0b2aa3a0 | 166 | memcpy (new->as, seg->as, ASSEGMENT_DATA_SIZE (new->length, 1) ); |
fe69a505 | 167 | |
168 | return new; | |
169 | } | |
170 | ||
171 | /* Duplicate entire chain of assegments, return the head */ | |
172 | static struct assegment * | |
173 | assegment_dup_all (struct assegment *seg) | |
174 | { | |
175 | struct assegment *new = NULL; | |
176 | struct assegment *head = NULL; | |
177 | ||
178 | while (seg) | |
179 | { | |
180 | if (head) | |
181 | { | |
182 | new->next = assegment_dup (seg); | |
183 | new = new->next; | |
184 | } | |
185 | else | |
186 | head = new = assegment_dup (seg); | |
187 | ||
188 | seg = seg->next; | |
189 | } | |
190 | return head; | |
191 | } | |
192 | ||
193 | /* prepend the as number to given segment, given num of times */ | |
194 | static struct assegment * | |
195 | assegment_prepend_asns (struct assegment *seg, as_t asnum, int num) | |
196 | { | |
197 | as_t *newas; | |
f669f7d2 | 198 | int i; |
fe69a505 | 199 | |
200 | if (!num) | |
201 | return seg; | |
202 | ||
203 | if (num >= AS_SEGMENT_MAX) | |
204 | return seg; /* we don't do huge prepends */ | |
205 | ||
206 | newas = assegment_data_new (seg->length + num); | |
fe69a505 | 207 | |
f669f7d2 JBD |
208 | for (i = 0; i < num; i++) |
209 | newas[i] = asnum; | |
210 | ||
211 | memcpy (newas + num, seg->as, ASSEGMENT_DATA_SIZE (seg->length, 1)); | |
212 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
213 | seg->as = newas; | |
214 | seg->length += num; | |
215 | ||
216 | return seg; | |
fe69a505 | 217 | } |
218 | ||
219 | /* append given array of as numbers to the segment */ | |
220 | static struct assegment * | |
221 | assegment_append_asns (struct assegment *seg, as_t *asnos, int num) | |
222 | { | |
02335429 | 223 | as_t *newas; |
224 | ||
225 | newas = XREALLOC (MTYPE_AS_SEG_DATA, seg->as, | |
0b2aa3a0 | 226 | ASSEGMENT_DATA_SIZE (seg->length + num, 1)); |
fe69a505 | 227 | |
02335429 | 228 | if (newas) |
fe69a505 | 229 | { |
02335429 | 230 | seg->as = newas; |
0b2aa3a0 | 231 | memcpy (seg->as + seg->length, asnos, ASSEGMENT_DATA_SIZE(num, 1)); |
fe69a505 | 232 | seg->length += num; |
233 | return seg; | |
234 | } | |
235 | ||
236 | assegment_free_all (seg); | |
237 | return NULL; | |
238 | } | |
239 | ||
240 | static int | |
241 | int_cmp (const void *p1, const void *p2) | |
242 | { | |
243 | const as_t *as1 = p1; | |
244 | const as_t *as2 = p2; | |
245 | ||
246 | return (*as1 == *as2) | |
247 | ? 0 : ( (*as1 > *as2) ? 1 : -1); | |
248 | } | |
249 | ||
250 | /* normalise the segment. | |
251 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
252 | * Internally, we do not care about the wire segment length limit, and | |
253 | * we want each distinct AS_PATHs to have the exact same internal | |
254 | * representation - eg, so that our hashing actually works.. | |
255 | */ | |
256 | static struct assegment * | |
257 | assegment_normalise (struct assegment *head) | |
258 | { | |
259 | struct assegment *seg = head, *pin; | |
260 | struct assegment *tmp; | |
261 | ||
262 | if (!head) | |
263 | return head; | |
264 | ||
265 | while (seg) | |
266 | { | |
267 | pin = seg; | |
268 | ||
269 | /* Sort values SET segments, for determinism in paths to aid | |
270 | * creation of hash values / path comparisons | |
271 | * and because it helps other lesser implementations ;) | |
272 | */ | |
273 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) | |
0b2aa3a0 PJ |
274 | { |
275 | int tail = 0; | |
276 | int i; | |
277 | ||
278 | qsort (seg->as, seg->length, sizeof(as_t), int_cmp); | |
279 | ||
280 | /* weed out dupes */ | |
281 | for (i=1; i < seg->length; i++) | |
282 | { | |
283 | if (seg->as[tail] == seg->as[i]) | |
284 | continue; | |
285 | ||
286 | tail++; | |
287 | if (tail < i) | |
288 | seg->as[tail] = seg->as[i]; | |
289 | } | |
290 | /* seg->length can be 0.. */ | |
291 | if (seg->length) | |
292 | seg->length = tail + 1; | |
293 | } | |
fe69a505 | 294 | |
295 | /* read ahead from the current, pinned segment while the segments | |
296 | * are packable/mergeable. Append all following packable segments | |
297 | * to the segment we have pinned and remove these appended | |
298 | * segments. | |
299 | */ | |
300 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) | |
301 | { | |
302 | tmp = pin->next; | |
303 | seg = pin->next; | |
304 | ||
305 | /* append the next sequence to the pinned sequence */ | |
306 | pin = assegment_append_asns (pin, seg->as, seg->length); | |
307 | ||
308 | /* bypass the next sequence */ | |
309 | pin->next = seg->next; | |
310 | ||
311 | /* get rid of the now referenceless segment */ | |
312 | assegment_free (tmp); | |
313 | ||
314 | } | |
315 | ||
316 | seg = pin->next; | |
317 | } | |
318 | return head; | |
319 | } | |
6b0655a2 | 320 | |
718e3744 | 321 | static struct aspath * |
fe69a505 | 322 | aspath_new (void) |
718e3744 | 323 | { |
393deb9b | 324 | return XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 325 | } |
326 | ||
327 | /* Free AS path structure. */ | |
328 | void | |
329 | aspath_free (struct aspath *aspath) | |
330 | { | |
331 | if (!aspath) | |
332 | return; | |
fe69a505 | 333 | if (aspath->segments) |
334 | assegment_free_all (aspath->segments); | |
718e3744 | 335 | if (aspath->str) |
336 | XFREE (MTYPE_AS_STR, aspath->str); | |
f1aa5d8a DS |
337 | |
338 | if (aspath->json) | |
339 | { | |
340 | json_object_free(aspath->json); | |
341 | aspath->json = NULL; | |
342 | } | |
343 | ||
718e3744 | 344 | XFREE (MTYPE_AS_PATH, aspath); |
345 | } | |
346 | ||
347 | /* Unintern aspath from AS path bucket. */ | |
348 | void | |
f6f434b2 | 349 | aspath_unintern (struct aspath **aspath) |
718e3744 | 350 | { |
351 | struct aspath *ret; | |
f6f434b2 PJ |
352 | struct aspath *asp = *aspath; |
353 | ||
354 | if (asp->refcnt) | |
355 | asp->refcnt--; | |
718e3744 | 356 | |
f6f434b2 | 357 | if (asp->refcnt == 0) |
718e3744 | 358 | { |
359 | /* This aspath must exist in aspath hash table. */ | |
f6f434b2 | 360 | ret = hash_release (ashash, asp); |
718e3744 | 361 | assert (ret != NULL); |
f6f434b2 PJ |
362 | aspath_free (asp); |
363 | *aspath = NULL; | |
718e3744 | 364 | } |
365 | } | |
366 | ||
367 | /* Return the start or end delimiters for a particular Segment type */ | |
368 | #define AS_SEG_START 0 | |
369 | #define AS_SEG_END 1 | |
370 | static char | |
371 | aspath_delimiter_char (u_char type, u_char which) | |
372 | { | |
373 | int i; | |
374 | struct | |
375 | { | |
376 | int type; | |
377 | char start; | |
378 | char end; | |
379 | } aspath_delim_char [] = | |
380 | { | |
381 | { AS_SET, '{', '}' }, | |
718e3744 | 382 | { AS_CONFED_SET, '[', ']' }, |
383 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
384 | { 0 } | |
385 | }; | |
386 | ||
387 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
388 | { | |
389 | if (aspath_delim_char[i].type == type) | |
390 | { | |
391 | if (which == AS_SEG_START) | |
392 | return aspath_delim_char[i].start; | |
393 | else if (which == AS_SEG_END) | |
394 | return aspath_delim_char[i].end; | |
395 | } | |
396 | } | |
397 | return ' '; | |
398 | } | |
399 | ||
014b670e DO |
400 | /* countup asns from this segment and index onward */ |
401 | static int | |
402 | assegment_count_asns (struct assegment *seg, int from) | |
403 | { | |
404 | int count = 0; | |
405 | while (seg) | |
406 | { | |
407 | if (!from) | |
408 | count += seg->length; | |
409 | else | |
410 | { | |
411 | count += (seg->length - from); | |
412 | from = 0; | |
413 | } | |
414 | seg = seg->next; | |
415 | } | |
416 | return count; | |
417 | } | |
418 | ||
fe69a505 | 419 | unsigned int |
420 | aspath_count_confeds (struct aspath *aspath) | |
421 | { | |
422 | int count = 0; | |
423 | struct assegment *seg = aspath->segments; | |
424 | ||
425 | while (seg) | |
426 | { | |
427 | if (seg->type == AS_CONFED_SEQUENCE) | |
428 | count += seg->length; | |
429 | else if (seg->type == AS_CONFED_SET) | |
430 | count++; | |
431 | ||
432 | seg = seg->next; | |
433 | } | |
434 | return count; | |
435 | } | |
436 | ||
437 | unsigned int | |
ffd0c037 | 438 | aspath_count_hops (const struct aspath *aspath) |
fe69a505 | 439 | { |
440 | int count = 0; | |
441 | struct assegment *seg = aspath->segments; | |
442 | ||
443 | while (seg) | |
444 | { | |
445 | if (seg->type == AS_SEQUENCE) | |
446 | count += seg->length; | |
447 | else if (seg->type == AS_SET) | |
448 | count++; | |
449 | ||
450 | seg = seg->next; | |
451 | } | |
452 | return count; | |
453 | } | |
454 | ||
0b2aa3a0 PJ |
455 | /* Estimate size aspath /might/ take if encoded into an |
456 | * ASPATH attribute. | |
457 | * | |
458 | * This is a quick estimate, not definitive! aspath_put() | |
459 | * may return a different number!! | |
460 | */ | |
fe69a505 | 461 | unsigned int |
462 | aspath_size (struct aspath *aspath) | |
463 | { | |
464 | int size = 0; | |
465 | struct assegment *seg = aspath->segments; | |
466 | ||
467 | while (seg) | |
468 | { | |
0b2aa3a0 | 469 | size += ASSEGMENT_SIZE(seg->length, 1); |
fe69a505 | 470 | seg = seg->next; |
471 | } | |
472 | return size; | |
473 | } | |
474 | ||
2815e61f PJ |
475 | /* Return highest public ASN in path */ |
476 | as_t | |
477 | aspath_highest (struct aspath *aspath) | |
478 | { | |
479 | struct assegment *seg = aspath->segments; | |
480 | as_t highest = 0; | |
481 | unsigned int i; | |
5000f21c | 482 | |
2815e61f PJ |
483 | while (seg) |
484 | { | |
485 | for (i = 0; i < seg->length; i++) | |
5000f21c | 486 | if (seg->as[i] > highest && !BGP_AS_IS_PRIVATE(seg->as[i])) |
2815e61f PJ |
487 | highest = seg->as[i]; |
488 | seg = seg->next; | |
489 | } | |
490 | return highest; | |
491 | } | |
492 | ||
0b2aa3a0 PJ |
493 | /* Return 1 if there are any 4-byte ASes in the path */ |
494 | unsigned int | |
495 | aspath_has_as4 (struct aspath *aspath) | |
496 | { | |
497 | struct assegment *seg = aspath->segments; | |
498 | unsigned int i; | |
499 | ||
500 | while (seg) | |
501 | { | |
502 | for (i = 0; i < seg->length; i++) | |
503 | if (seg->as[i] > BGP_AS_MAX) | |
504 | return 1; | |
505 | seg = seg->next; | |
506 | } | |
507 | return 0; | |
508 | } | |
509 | ||
718e3744 | 510 | /* Convert aspath structure to string expression. */ |
f669f7d2 | 511 | static void |
718e3744 | 512 | aspath_make_str_count (struct aspath *as) |
513 | { | |
fe69a505 | 514 | struct assegment *seg; |
515 | int str_size; | |
516 | int len = 0; | |
c9e52be3 | 517 | char *str_buf; |
f1aa5d8a DS |
518 | json_object *jaspath_segments = NULL; |
519 | json_object *jseg = NULL; | |
520 | json_object *jseg_list = NULL; | |
521 | ||
522 | as->json = json_object_new_object(); | |
523 | jaspath_segments = json_object_new_array(); | |
718e3744 | 524 | |
525 | /* Empty aspath. */ | |
fe69a505 | 526 | if (!as->segments) |
718e3744 | 527 | { |
f1aa5d8a DS |
528 | json_object_string_add(as->json, "string", "Local"); |
529 | json_object_object_add(as->json, "segments", jaspath_segments); | |
530 | json_object_int_add(as->json, "length", 0); | |
f669f7d2 JBD |
531 | as->str = XMALLOC (MTYPE_AS_STR, 1); |
532 | as->str[0] = '\0'; | |
533 | as->str_len = 0; | |
534 | return; | |
718e3744 | 535 | } |
fe69a505 | 536 | |
537 | seg = as->segments; | |
538 | ||
014b670e DO |
539 | /* ASN takes 5 to 10 chars plus seperator, see below. |
540 | * If there is one differing segment type, we need an additional | |
541 | * 2 chars for segment delimiters, and the final '\0'. | |
542 | * Hopefully this is large enough to avoid hitting the realloc | |
543 | * code below for most common sequences. | |
544 | * | |
545 | * This was changed to 10 after the well-known BGP assertion, which | |
546 | * had hit some parts of the Internet in May of 2009. | |
547 | */ | |
548 | #define ASN_STR_LEN (10 + 1) | |
549 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
550 | ASPATH_STR_DEFAULT_LEN); | |
718e3744 | 551 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); |
718e3744 | 552 | |
fe69a505 | 553 | while (seg) |
718e3744 | 554 | { |
555 | int i; | |
fe69a505 | 556 | char seperator; |
718e3744 | 557 | |
fe69a505 | 558 | /* Check AS type validity. Set seperator for segment */ |
559 | switch (seg->type) | |
560 | { | |
561 | case AS_SET: | |
562 | case AS_CONFED_SET: | |
563 | seperator = ','; | |
564 | break; | |
565 | case AS_SEQUENCE: | |
566 | case AS_CONFED_SEQUENCE: | |
567 | seperator = ' '; | |
568 | break; | |
569 | default: | |
570 | XFREE (MTYPE_AS_STR, str_buf); | |
f669f7d2 JBD |
571 | as->str = NULL; |
572 | as->str_len = 0; | |
f1aa5d8a DS |
573 | json_object_free(as->json); |
574 | as->json = NULL; | |
f669f7d2 | 575 | return; |
fe69a505 | 576 | } |
577 | ||
014b670e DO |
578 | /* We might need to increase str_buf, particularly if path has |
579 | * differing segments types, our initial guesstimate above will | |
580 | * have been wrong. Need 10 chars for ASN, a seperator each and | |
581 | * potentially two segment delimiters, plus a space between each | |
582 | * segment and trailing zero. | |
583 | * | |
584 | * This definitely didn't work with the value of 5 bytes and | |
585 | * 32-bit ASNs. | |
586 | */ | |
587 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
588 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
589 | { | |
590 | str_size = len + SEGMENT_STR_LEN(seg); | |
591 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
592 | } | |
593 | #undef ASN_STR_LEN | |
594 | #undef SEGMENT_STR_LEN | |
595 | ||
fe69a505 | 596 | if (seg->type != AS_SEQUENCE) |
014b670e DO |
597 | len += snprintf (str_buf + len, str_size - len, |
598 | "%c", | |
599 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
f1aa5d8a DS |
600 | |
601 | jseg_list = json_object_new_array(); | |
fe69a505 | 602 | |
603 | /* write out the ASNs, with their seperators, bar the last one*/ | |
604 | for (i = 0; i < seg->length; i++) | |
605 | { | |
f1aa5d8a DS |
606 | json_object_array_add(jseg_list, json_object_new_int(seg->as[i])); |
607 | ||
fe69a505 | 608 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); |
609 | ||
610 | if (i < (seg->length - 1)) | |
611 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
612 | } | |
f1aa5d8a DS |
613 | |
614 | jseg = json_object_new_object(); | |
615 | json_object_string_add(jseg, "type", aspath_segment_type_str[seg->type]); | |
616 | json_object_object_add(jseg, "list", jseg_list); | |
617 | json_object_array_add(jaspath_segments, jseg); | |
fe69a505 | 618 | |
619 | if (seg->type != AS_SEQUENCE) | |
620 | len += snprintf (str_buf + len, str_size - len, "%c", | |
621 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
622 | if (seg->next) | |
623 | len += snprintf (str_buf + len, str_size - len, " "); | |
624 | ||
625 | seg = seg->next; | |
718e3744 | 626 | } |
fe69a505 | 627 | |
628 | assert (len < str_size); | |
629 | ||
630 | str_buf[len] = '\0'; | |
f669f7d2 JBD |
631 | as->str = str_buf; |
632 | as->str_len = len; | |
718e3744 | 633 | |
f1aa5d8a DS |
634 | json_object_string_add(as->json, "string", str_buf); |
635 | json_object_object_add(as->json, "segments", jaspath_segments); | |
636 | json_object_int_add(as->json, "length", aspath_count_hops (as)); | |
f669f7d2 | 637 | return; |
718e3744 | 638 | } |
639 | ||
fe69a505 | 640 | static void |
641 | aspath_str_update (struct aspath *as) | |
642 | { | |
643 | if (as->str) | |
644 | XFREE (MTYPE_AS_STR, as->str); | |
f1aa5d8a DS |
645 | |
646 | if (as->json) | |
647 | { | |
648 | json_object_free(as->json); | |
649 | as->json = NULL; | |
650 | } | |
651 | ||
f669f7d2 | 652 | aspath_make_str_count (as); |
fe69a505 | 653 | } |
654 | ||
718e3744 | 655 | /* Intern allocated AS path. */ |
656 | struct aspath * | |
657 | aspath_intern (struct aspath *aspath) | |
658 | { | |
659 | struct aspath *find; | |
f669f7d2 JBD |
660 | |
661 | /* Assert this AS path structure is not interned and has the string | |
662 | representation built. */ | |
718e3744 | 663 | assert (aspath->refcnt == 0); |
f669f7d2 | 664 | assert (aspath->str); |
718e3744 | 665 | |
666 | /* Check AS path hash. */ | |
667 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
718e3744 | 668 | if (find != aspath) |
fe69a505 | 669 | aspath_free (aspath); |
718e3744 | 670 | |
671 | find->refcnt++; | |
672 | ||
718e3744 | 673 | return find; |
674 | } | |
675 | ||
676 | /* Duplicate aspath structure. Created same aspath structure but | |
677 | reference count and AS path string is cleared. */ | |
678 | struct aspath * | |
679 | aspath_dup (struct aspath *aspath) | |
680 | { | |
f669f7d2 | 681 | unsigned short buflen = aspath->str_len + 1; |
718e3744 | 682 | struct aspath *new; |
683 | ||
fe69a505 | 684 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
f1aa5d8a | 685 | new->json = NULL; |
718e3744 | 686 | |
fe69a505 | 687 | if (aspath->segments) |
688 | new->segments = assegment_dup_all (aspath->segments); | |
718e3744 | 689 | |
f669f7d2 JBD |
690 | if (!aspath->str) |
691 | return new; | |
692 | ||
693 | new->str = XMALLOC (MTYPE_AS_STR, buflen); | |
694 | new->str_len = aspath->str_len; | |
695 | ||
696 | /* copy the string data */ | |
697 | if (aspath->str_len > 0) | |
698 | memcpy (new->str, aspath->str, buflen); | |
699 | else | |
700 | new->str[0] = '\0'; | |
718e3744 | 701 | |
702 | return new; | |
703 | } | |
704 | ||
94f2b392 | 705 | static void * |
fe69a505 | 706 | aspath_hash_alloc (void *arg) |
718e3744 | 707 | { |
f669f7d2 JBD |
708 | const struct aspath *aspath = arg; |
709 | struct aspath *new; | |
718e3744 | 710 | |
718e3744 | 711 | /* Malformed AS path value. */ |
f669f7d2 | 712 | assert (aspath->str); |
718e3744 | 713 | |
f669f7d2 JBD |
714 | /* New aspath structure is needed. */ |
715 | new = XMALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
716 | ||
717 | /* Reuse segments and string representation */ | |
718 | new->refcnt = 0; | |
719 | new->segments = aspath->segments; | |
720 | new->str = aspath->str; | |
721 | new->str_len = aspath->str_len; | |
f1aa5d8a | 722 | new->json = aspath->json; |
f669f7d2 JBD |
723 | |
724 | return new; | |
718e3744 | 725 | } |
726 | ||
ab005298 | 727 | /* parse as-segment byte stream in struct assegment */ |
b881c707 PJ |
728 | static int |
729 | assegments_parse (struct stream *s, size_t length, | |
730 | struct assegment **result, int use32bit) | |
fe69a505 | 731 | { |
732 | struct assegment_header segh; | |
733 | struct assegment *seg, *prev = NULL, *head = NULL; | |
ab005298 | 734 | size_t bytes = 0; |
fe69a505 | 735 | |
ab005298 PJ |
736 | /* empty aspath (ie iBGP or somesuch) */ |
737 | if (length == 0) | |
b881c707 | 738 | return 0; |
fe69a505 | 739 | |
0b2aa3a0 PJ |
740 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
741 | zlog_debug ("[AS4SEG] Parse aspath segment: got total byte length %lu", | |
742 | (unsigned long) length); | |
ab005298 PJ |
743 | /* basic checks */ |
744 | if ((STREAM_READABLE(s) < length) | |
745 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
746 | || (length % AS16_VALUE_SIZE )) | |
b881c707 | 747 | return -1; |
fe69a505 | 748 | |
ab005298 | 749 | while (bytes < length) |
fe69a505 | 750 | { |
751 | int i; | |
cddb8112 | 752 | size_t seg_size; |
fe69a505 | 753 | |
ab005298 | 754 | if ((length - bytes) <= AS_HEADER_SIZE) |
cddb8112 | 755 | { |
ab005298 PJ |
756 | if (head) |
757 | assegment_free_all (head); | |
b881c707 | 758 | return -1; |
fdbc8e77 PJ |
759 | } |
760 | ||
ab005298 | 761 | /* softly softly, get the header first on its own */ |
fe69a505 | 762 | segh.type = stream_getc (s); |
763 | segh.length = stream_getc (s); | |
764 | ||
0b2aa3a0 PJ |
765 | seg_size = ASSEGMENT_SIZE(segh.length, use32bit); |
766 | ||
767 | if (BGP_DEBUG (as4, AS4_SEGMENT)) | |
768 | zlog_debug ("[AS4SEG] Parse aspath segment: got type %d, length %d", | |
769 | segh.type, segh.length); | |
770 | ||
ab005298 PJ |
771 | /* check it.. */ |
772 | if ( ((bytes + seg_size) > length) | |
773 | /* 1771bis 4.3b: seg length contains one or more */ | |
774 | || (segh.length == 0) | |
775 | /* Paranoia in case someone changes type of segment length. | |
776 | * Shift both values by 0x10 to make the comparison operate | |
777 | * on more, than 8 bits (otherwise it's a warning, bug #564). | |
2eb445e1 | 778 | */ |
ab005298 PJ |
779 | || ((sizeof segh.length > 1) |
780 | && (0x10 + segh.length > 0x10 + AS_SEGMENT_MAX))) | |
fe69a505 | 781 | { |
ab005298 | 782 | if (head) |
fe69a505 | 783 | assegment_free_all (head); |
b881c707 | 784 | return -1; |
fe69a505 | 785 | } |
786 | ||
fdbc8e77 PJ |
787 | switch (segh.type) |
788 | { | |
789 | case AS_SEQUENCE: | |
790 | case AS_SET: | |
fdbc8e77 PJ |
791 | case AS_CONFED_SEQUENCE: |
792 | case AS_CONFED_SET: | |
ab005298 PJ |
793 | break; |
794 | default: | |
795 | if (head) | |
796 | assegment_free_all (head); | |
b881c707 | 797 | return -1; |
fe69a505 | 798 | } |
799 | ||
800 | /* now its safe to trust lengths */ | |
801 | seg = assegment_new (segh.type, segh.length); | |
802 | ||
803 | if (head) | |
804 | prev->next = seg; | |
805 | else /* it's the first segment */ | |
806 | head = prev = seg; | |
807 | ||
808 | for (i = 0; i < segh.length; i++) | |
0b2aa3a0 PJ |
809 | seg->as[i] = (use32bit) ? stream_getl (s) : stream_getw (s); |
810 | ||
ab005298 PJ |
811 | bytes += seg_size; |
812 | ||
0b2aa3a0 | 813 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
ab005298 PJ |
814 | zlog_debug ("[AS4SEG] Parse aspath segment: Bytes now: %lu", |
815 | (unsigned long) bytes); | |
fe69a505 | 816 | |
817 | prev = seg; | |
818 | } | |
819 | ||
b881c707 PJ |
820 | *result = assegment_normalise (head); |
821 | return 0; | |
fe69a505 | 822 | } |
823 | ||
ab005298 PJ |
824 | /* AS path parse function. pnt is a pointer to byte stream and length |
825 | is length of byte stream. If there is same AS path in the the AS | |
b881c707 PJ |
826 | path hash then return it else make new AS path structure. |
827 | ||
828 | On error NULL is returned. | |
cddb8112 | 829 | */ |
718e3744 | 830 | struct aspath * |
ab005298 | 831 | aspath_parse (struct stream *s, size_t length, int use32bit) |
718e3744 | 832 | { |
833 | struct aspath as; | |
834 | struct aspath *find; | |
835 | ||
ab005298 PJ |
836 | /* If length is odd it's malformed AS path. */ |
837 | /* Nit-picking: if (use32bit == 0) it is malformed if odd, | |
838 | * otherwise its malformed when length is larger than 2 and (length-2) | |
839 | * is not dividable by 4. | |
840 | * But... this time we're lazy | |
841 | */ | |
842 | if (length % AS16_VALUE_SIZE ) | |
843 | return NULL; | |
cddb8112 | 844 | |
ab005298 | 845 | memset (&as, 0, sizeof (struct aspath)); |
b881c707 PJ |
846 | if (assegments_parse (s, length, &as.segments, use32bit) < 0) |
847 | return NULL; | |
f669f7d2 | 848 | |
718e3744 | 849 | /* If already same aspath exist then return it. */ |
850 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
f669f7d2 JBD |
851 | |
852 | /* bug! should not happen, let the daemon crash below */ | |
853 | assert (find); | |
854 | ||
855 | /* if the aspath was already hashed free temporary memory. */ | |
856 | if (find->refcnt) | |
857 | { | |
858 | assegment_free_all (as.segments); | |
859 | /* aspath_key_make() always updates the string */ | |
860 | XFREE (MTYPE_AS_STR, as.str); | |
4390a8ee DS |
861 | if (as.json) |
862 | { | |
863 | json_object_free(as.json); | |
864 | as.json = NULL; | |
865 | } | |
f669f7d2 JBD |
866 | } |
867 | ||
718e3744 | 868 | find->refcnt++; |
869 | ||
870 | return find; | |
871 | } | |
872 | ||
f63f06da | 873 | static void |
0b2aa3a0 | 874 | assegment_data_put (struct stream *s, as_t *as, int num, int use32bit) |
fe69a505 | 875 | { |
876 | int i; | |
877 | assert (num <= AS_SEGMENT_MAX); | |
878 | ||
879 | for (i = 0; i < num; i++) | |
0b2aa3a0 PJ |
880 | if ( use32bit ) |
881 | stream_putl (s, as[i]); | |
882 | else | |
883 | { | |
884 | if ( as[i] <= BGP_AS_MAX ) | |
885 | stream_putw(s, as[i]); | |
886 | else | |
887 | stream_putw(s, BGP_AS_TRANS); | |
888 | } | |
fe69a505 | 889 | } |
718e3744 | 890 | |
f63f06da | 891 | static size_t |
fe69a505 | 892 | assegment_header_put (struct stream *s, u_char type, int length) |
718e3744 | 893 | { |
fe69a505 | 894 | size_t lenp; |
895 | assert (length <= AS_SEGMENT_MAX); | |
896 | stream_putc (s, type); | |
897 | lenp = stream_get_endp (s); | |
898 | stream_putc (s, length); | |
899 | return lenp; | |
900 | } | |
718e3744 | 901 | |
fe69a505 | 902 | /* write aspath data to stream */ |
0b2aa3a0 PJ |
903 | size_t |
904 | aspath_put (struct stream *s, struct aspath *as, int use32bit ) | |
fe69a505 | 905 | { |
906 | struct assegment *seg = as->segments; | |
0b2aa3a0 | 907 | size_t bytes = 0; |
fe69a505 | 908 | |
909 | if (!seg || seg->length == 0) | |
0b2aa3a0 | 910 | return 0; |
fe69a505 | 911 | |
912 | if (seg) | |
718e3744 | 913 | { |
0b2aa3a0 PJ |
914 | /* |
915 | * Hey, what do we do when we have > STREAM_WRITABLE(s) here? | |
916 | * At the moment, we would write out a partial aspath, and our peer | |
917 | * will complain and drop the session :-/ | |
918 | * | |
919 | * The general assumption here is that many things tested will | |
920 | * never happen. And, in real live, up to now, they have not. | |
921 | */ | |
922 | while (seg && (ASSEGMENT_LEN(seg, use32bit) <= STREAM_WRITEABLE(s))) | |
fe69a505 | 923 | { |
0b2aa3a0 | 924 | struct assegment *next = seg->next; |
fe69a505 | 925 | int written = 0; |
0b2aa3a0 | 926 | int asns_packed = 0; |
fe69a505 | 927 | size_t lenp; |
928 | ||
929 | /* Overlength segments have to be split up */ | |
930 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
931 | { | |
932 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
0b2aa3a0 | 933 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX, use32bit); |
fe69a505 | 934 | written += AS_SEGMENT_MAX; |
0b2aa3a0 | 935 | bytes += ASSEGMENT_SIZE (written, use32bit); |
fe69a505 | 936 | } |
937 | ||
938 | /* write the final segment, probably is also the first */ | |
939 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
0b2aa3a0 PJ |
940 | assegment_data_put (s, (seg->as + written), seg->length - written, |
941 | use32bit); | |
fe69a505 | 942 | |
943 | /* Sequence-type segments can be 'packed' together | |
944 | * Case of a segment which was overlength and split up | |
945 | * will be missed here, but that doesn't matter. | |
946 | */ | |
0b2aa3a0 | 947 | while (next && ASSEGMENTS_PACKABLE (seg, next)) |
fe69a505 | 948 | { |
949 | /* NB: We should never normally get here given we | |
950 | * normalise aspath data when parse them. However, better | |
951 | * safe than sorry. We potentially could call | |
952 | * assegment_normalise here instead, but it's cheaper and | |
953 | * easier to do it on the fly here rather than go through | |
954 | * the segment list twice every time we write out | |
955 | * aspath's. | |
956 | */ | |
957 | ||
958 | /* Next segment's data can fit in this one */ | |
0b2aa3a0 | 959 | assegment_data_put (s, next->as, next->length, use32bit); |
fe69a505 | 960 | |
961 | /* update the length of the segment header */ | |
0b2aa3a0 PJ |
962 | stream_putc_at (s, lenp, seg->length - written + next->length); |
963 | asns_packed += next->length; | |
964 | ||
965 | next = next->next; | |
fe69a505 | 966 | } |
0b2aa3a0 PJ |
967 | |
968 | bytes += ASSEGMENT_SIZE (seg->length - written + asns_packed, | |
969 | use32bit); | |
970 | seg = next; | |
fe69a505 | 971 | } |
718e3744 | 972 | } |
0b2aa3a0 | 973 | return bytes; |
fe69a505 | 974 | } |
975 | ||
976 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
977 | * We have no way to manage the storage, so we use a static stream | |
978 | * wrapper around aspath_put. | |
979 | */ | |
980 | u_char * | |
981 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
982 | { | |
983 | #define SNMP_PATHSEG_MAX 1024 | |
8fdc32ab | 984 | |
985 | if (!snmp_stream) | |
986 | snmp_stream = stream_new (SNMP_PATHSEG_MAX); | |
718e3744 | 987 | else |
8fdc32ab | 988 | stream_reset (snmp_stream); |
fe69a505 | 989 | |
990 | if (!as) | |
718e3744 | 991 | { |
fe69a505 | 992 | *varlen = 0; |
993 | return NULL; | |
718e3744 | 994 | } |
0b2aa3a0 | 995 | aspath_put (snmp_stream, as, 0); /* use 16 bit for now here */ |
fe69a505 | 996 | |
8fdc32ab | 997 | *varlen = stream_get_endp (snmp_stream); |
998 | return stream_pnt(snmp_stream); | |
718e3744 | 999 | } |
fe69a505 | 1000 | |
1001 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
718e3744 | 1002 | |
94f2b392 | 1003 | static struct assegment * |
718e3744 | 1004 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, |
1005 | as_t as) | |
1006 | { | |
1007 | int i; | |
1008 | ||
1009 | /* If this is first AS set member, create new as-set segment. */ | |
1010 | if (asset == NULL) | |
1011 | { | |
fe69a505 | 1012 | asset = assegment_new (AS_SET, 1); |
1013 | if (! aspath->segments) | |
1014 | aspath->segments = asset; | |
718e3744 | 1015 | else |
fe69a505 | 1016 | { |
1017 | struct assegment *seg = aspath->segments; | |
1018 | while (seg->next) | |
1019 | seg = seg->next; | |
1020 | seg->next = asset; | |
1021 | } | |
718e3744 | 1022 | asset->type = AS_SET; |
1023 | asset->length = 1; | |
fe69a505 | 1024 | asset->as[0] = as; |
718e3744 | 1025 | } |
1026 | else | |
1027 | { | |
718e3744 | 1028 | /* Check this AS value already exists or not. */ |
1029 | for (i = 0; i < asset->length; i++) | |
fe69a505 | 1030 | if (asset->as[i] == as) |
718e3744 | 1031 | return asset; |
fe69a505 | 1032 | |
718e3744 | 1033 | asset->length++; |
fe69a505 | 1034 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, |
1035 | asset->length * AS_VALUE_SIZE); | |
1036 | asset->as[asset->length - 1] = as; | |
718e3744 | 1037 | } |
fe69a505 | 1038 | |
718e3744 | 1039 | |
1040 | return asset; | |
1041 | } | |
1042 | ||
1043 | /* Modify as1 using as2 for aggregation. */ | |
1044 | struct aspath * | |
1045 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
1046 | { | |
1047 | int i; | |
1048 | int minlen; | |
1049 | int match; | |
fe69a505 | 1050 | int from; |
1051 | struct assegment *seg1 = as1->segments; | |
1052 | struct assegment *seg2 = as2->segments; | |
0b2aa3a0 | 1053 | struct aspath *aspath = NULL; |
718e3744 | 1054 | struct assegment *asset; |
0b2aa3a0 | 1055 | struct assegment *prevseg = NULL; |
718e3744 | 1056 | |
1057 | match = 0; | |
1058 | minlen = 0; | |
1059 | aspath = NULL; | |
1060 | asset = NULL; | |
718e3744 | 1061 | |
1062 | /* First of all check common leading sequence. */ | |
fe69a505 | 1063 | while (seg1 && seg2) |
0b2aa3a0 | 1064 | { |
718e3744 | 1065 | /* Check segment type. */ |
1066 | if (seg1->type != seg2->type) | |
1067 | break; | |
1068 | ||
1069 | /* Minimum segment length. */ | |
1070 | minlen = min (seg1->length, seg2->length); | |
1071 | ||
1072 | for (match = 0; match < minlen; match++) | |
fe69a505 | 1073 | if (seg1->as[match] != seg2->as[match]) |
718e3744 | 1074 | break; |
1075 | ||
1076 | if (match) | |
1077 | { | |
0b2aa3a0 PJ |
1078 | struct assegment *seg = assegment_new (seg1->type, 0); |
1079 | ||
1080 | seg = assegment_append_asns (seg, seg1->as, match); | |
1081 | ||
718e3744 | 1082 | if (! aspath) |
0b2aa3a0 PJ |
1083 | { |
1084 | aspath = aspath_new (); | |
1085 | aspath->segments = seg; | |
1086 | } | |
1087 | else | |
1088 | prevseg->next = seg; | |
1089 | ||
1090 | prevseg = seg; | |
718e3744 | 1091 | } |
1092 | ||
1093 | if (match != minlen || match != seg1->length | |
1094 | || seg1->length != seg2->length) | |
1095 | break; | |
b5d58c32 DS |
1096 | /* We are moving on to the next segment to reset match */ |
1097 | else | |
1098 | match = 0; | |
fe69a505 | 1099 | |
1100 | seg1 = seg1->next; | |
1101 | seg2 = seg2->next; | |
718e3744 | 1102 | } |
1103 | ||
1104 | if (! aspath) | |
1105 | aspath = aspath_new(); | |
1106 | ||
1107 | /* Make as-set using rest of all information. */ | |
fe69a505 | 1108 | from = match; |
1109 | while (seg1) | |
718e3744 | 1110 | { |
fe69a505 | 1111 | for (i = from; i < seg1->length; i++) |
1112 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
1113 | ||
1114 | from = 0; | |
1115 | seg1 = seg1->next; | |
718e3744 | 1116 | } |
1117 | ||
fe69a505 | 1118 | from = match; |
1119 | while (seg2) | |
718e3744 | 1120 | { |
fe69a505 | 1121 | for (i = from; i < seg2->length; i++) |
1122 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
718e3744 | 1123 | |
fe69a505 | 1124 | from = 0; |
1125 | seg2 = seg2->next; | |
718e3744 | 1126 | } |
fe69a505 | 1127 | |
1128 | assegment_normalise (aspath->segments); | |
1129 | aspath_str_update (aspath); | |
718e3744 | 1130 | return aspath; |
1131 | } | |
1132 | ||
1133 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
1134 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
1135 | or not the peer's AS number. */ | |
1136 | int | |
1137 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
1138 | { | |
fe69a505 | 1139 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1140 | return 0; |
fe69a505 | 1141 | |
1142 | if (aspath->segments | |
1143 | && (aspath->segments->type == AS_SEQUENCE) | |
1144 | && (aspath->segments->as[0] == asno )) | |
718e3744 | 1145 | return 1; |
1146 | ||
1147 | return 0; | |
1148 | } | |
1149 | ||
1f742f21 | 1150 | /* AS path loop check. If aspath contains asno then return >= 1. */ |
718e3744 | 1151 | int |
1152 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
1153 | { | |
fe69a505 | 1154 | struct assegment *seg; |
718e3744 | 1155 | int count = 0; |
1156 | ||
1f742f21 | 1157 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1158 | return 0; |
fe69a505 | 1159 | |
1160 | seg = aspath->segments; | |
1161 | ||
1162 | while (seg) | |
718e3744 | 1163 | { |
1164 | int i; | |
718e3744 | 1165 | |
fe69a505 | 1166 | for (i = 0; i < seg->length; i++) |
1167 | if (seg->as[i] == asno) | |
718e3744 | 1168 | count++; |
fe69a505 | 1169 | |
1170 | seg = seg->next; | |
718e3744 | 1171 | } |
1172 | return count; | |
1173 | } | |
1174 | ||
1175 | /* When all of AS path is private AS return 1. */ | |
1176 | int | |
1177 | aspath_private_as_check (struct aspath *aspath) | |
1178 | { | |
fe69a505 | 1179 | struct assegment *seg; |
5000f21c | 1180 | |
fe69a505 | 1181 | if ( !(aspath && aspath->segments) ) |
718e3744 | 1182 | return 0; |
5000f21c | 1183 | |
fe69a505 | 1184 | seg = aspath->segments; |
718e3744 | 1185 | |
fe69a505 | 1186 | while (seg) |
718e3744 | 1187 | { |
1188 | int i; | |
5000f21c | 1189 | |
fe69a505 | 1190 | for (i = 0; i < seg->length; i++) |
718e3744 | 1191 | { |
5000f21c | 1192 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) |
718e3744 | 1193 | return 0; |
1194 | } | |
fe69a505 | 1195 | seg = seg->next; |
718e3744 | 1196 | } |
1197 | return 1; | |
1198 | } | |
1199 | ||
c7122e14 DS |
1200 | /* Return True if the entire ASPATH consist of the specified ASN */ |
1201 | int | |
1202 | aspath_single_asn_check (struct aspath *aspath, as_t asn) | |
1203 | { | |
1204 | struct assegment *seg; | |
1205 | ||
1206 | if ( !(aspath && aspath->segments) ) | |
1207 | return 0; | |
1208 | ||
1209 | seg = aspath->segments; | |
1210 | ||
1211 | while (seg) | |
1212 | { | |
1213 | int i; | |
1214 | ||
1215 | for (i = 0; i < seg->length; i++) | |
1216 | { | |
1217 | if (seg->as[i] != asn) | |
1218 | return 0; | |
1219 | } | |
1220 | seg = seg->next; | |
1221 | } | |
1222 | return 1; | |
1223 | } | |
1224 | ||
1225 | /* Replace all instances of the target ASN with our own ASN */ | |
1226 | struct aspath * | |
1227 | aspath_replace_specific_asn (struct aspath *aspath, as_t target_asn, | |
1228 | as_t our_asn) | |
1229 | { | |
1230 | struct aspath *new; | |
1231 | struct assegment *seg; | |
1232 | ||
1233 | new = aspath_dup(aspath); | |
1234 | seg = new->segments; | |
1235 | ||
1236 | while (seg) | |
1237 | { | |
1238 | int i; | |
1239 | ||
1240 | for (i = 0; i < seg->length; i++) | |
1241 | { | |
1242 | if (seg->as[i] == target_asn) | |
1243 | seg->as[i] = our_asn; | |
1244 | } | |
1245 | seg = seg->next; | |
1246 | } | |
1247 | ||
1248 | aspath_str_update(new); | |
1249 | return new; | |
1250 | } | |
1251 | ||
5000f21c DS |
1252 | /* Replace all private ASNs with our own ASN */ |
1253 | struct aspath * | |
1254 | aspath_replace_private_asns (struct aspath *aspath, as_t asn) | |
1255 | { | |
1256 | struct aspath *new; | |
1257 | struct assegment *seg; | |
1258 | ||
1259 | new = aspath_dup(aspath); | |
1260 | seg = new->segments; | |
1261 | ||
1262 | while (seg) | |
1263 | { | |
1264 | int i; | |
1265 | ||
1266 | for (i = 0; i < seg->length; i++) | |
1267 | { | |
1268 | if (BGP_AS_IS_PRIVATE(seg->as[i])) | |
1269 | seg->as[i] = asn; | |
1270 | } | |
1271 | seg = seg->next; | |
1272 | } | |
1273 | ||
1274 | aspath_str_update(new); | |
1275 | return new; | |
1276 | } | |
1277 | ||
1278 | /* Remove all private ASNs */ | |
1279 | struct aspath * | |
1280 | aspath_remove_private_asns (struct aspath *aspath) | |
1281 | { | |
1282 | struct aspath *new; | |
1283 | struct assegment *seg; | |
1284 | struct assegment *new_seg; | |
1285 | struct assegment *last_new_seg; | |
1286 | int i; | |
1287 | int j; | |
1288 | int public = 0; | |
1289 | ||
1290 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
1291 | ||
f1aa5d8a | 1292 | new->json = NULL; |
5000f21c DS |
1293 | new_seg = NULL; |
1294 | last_new_seg = NULL; | |
1295 | seg = aspath->segments; | |
1296 | while (seg) | |
1297 | { | |
1298 | public = 0; | |
1299 | for (i = 0; i < seg->length; i++) | |
1300 | { | |
1301 | // ASN is public | |
1302 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) | |
1303 | { | |
1304 | public++; | |
1305 | } | |
1306 | } | |
1307 | ||
1308 | // The entire segment is private so skip it | |
1309 | if (!public) | |
1310 | { | |
1311 | seg = seg->next; | |
1312 | continue; | |
1313 | } | |
1314 | ||
1315 | // The entire segment is public so copy it | |
1316 | else if (public == seg->length) | |
1317 | { | |
1318 | new_seg = assegment_dup (seg); | |
1319 | } | |
1320 | ||
1321 | // The segment is a mix of public and private ASNs. Copy as many spots as | |
1322 | // there are public ASNs then come back and fill in only the public ASNs. | |
1323 | else | |
1324 | { | |
1325 | new_seg = assegment_new (seg->type, public); | |
1326 | j = 0; | |
1327 | for (i = 0; i < seg->length; i++) | |
1328 | { | |
1329 | // ASN is public | |
1330 | if (!BGP_AS_IS_PRIVATE(seg->as[i])) | |
1331 | { | |
1332 | new_seg->as[j] = seg->as[i]; | |
1333 | j++; | |
1334 | } | |
1335 | } | |
1336 | } | |
1337 | ||
1338 | // This is the first segment so set the aspath segments pointer to this one | |
1339 | if (!last_new_seg) | |
1340 | new->segments = new_seg; | |
1341 | else | |
1342 | last_new_seg->next = new_seg; | |
1343 | ||
1344 | last_new_seg = new_seg; | |
1345 | seg = seg->next; | |
1346 | } | |
1347 | ||
1348 | aspath_str_update(new); | |
1349 | return new; | |
1350 | } | |
1351 | ||
ca87e1d3 VT |
1352 | /* AS path confed check. If aspath contains confed set or sequence then return 1. */ |
1353 | int | |
1354 | aspath_confed_check (struct aspath *aspath) | |
1355 | { | |
1356 | struct assegment *seg; | |
1357 | ||
1358 | if ( !(aspath && aspath->segments) ) | |
1359 | return 0; | |
1360 | ||
1361 | seg = aspath->segments; | |
1362 | ||
1363 | while (seg) | |
1364 | { | |
1365 | if (seg->type == AS_CONFED_SET || seg->type == AS_CONFED_SEQUENCE) | |
1366 | return 1; | |
1367 | seg = seg->next; | |
1368 | } | |
1369 | return 0; | |
1370 | } | |
1371 | ||
1372 | /* Leftmost AS path segment confed check. If leftmost AS segment is of type | |
1373 | AS_CONFED_SEQUENCE or AS_CONFED_SET then return 1. */ | |
1374 | int | |
1375 | aspath_left_confed_check (struct aspath *aspath) | |
1376 | { | |
1377 | ||
1378 | if ( !(aspath && aspath->segments) ) | |
1379 | return 0; | |
1380 | ||
1381 | if ( (aspath->segments->type == AS_CONFED_SEQUENCE) | |
1382 | || (aspath->segments->type == AS_CONFED_SET) ) | |
1383 | return 1; | |
1384 | ||
1385 | return 0; | |
1386 | } | |
1387 | ||
718e3744 | 1388 | /* Merge as1 to as2. as2 should be uninterned aspath. */ |
94f2b392 | 1389 | static struct aspath * |
718e3744 | 1390 | aspath_merge (struct aspath *as1, struct aspath *as2) |
1391 | { | |
fe69a505 | 1392 | struct assegment *last, *new; |
718e3744 | 1393 | |
1394 | if (! as1 || ! as2) | |
1395 | return NULL; | |
1396 | ||
fe69a505 | 1397 | last = new = assegment_dup_all (as1->segments); |
1398 | ||
1399 | /* find the last valid segment */ | |
1400 | while (last && last->next) | |
1401 | last = last->next; | |
1402 | ||
1403 | last->next = as2->segments; | |
1404 | as2->segments = new; | |
1405 | aspath_str_update (as2); | |
718e3744 | 1406 | return as2; |
1407 | } | |
1408 | ||
1409 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1410 | struct aspath * | |
1411 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1412 | { | |
fe69a505 | 1413 | struct assegment *seg1; |
1414 | struct assegment *seg2; | |
718e3744 | 1415 | |
1416 | if (! as1 || ! as2) | |
1417 | return NULL; | |
fe69a505 | 1418 | |
1419 | seg1 = as1->segments; | |
1420 | seg2 = as2->segments; | |
1421 | ||
1422 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
718e3744 | 1423 | if (seg2 == NULL) |
1424 | { | |
fe69a505 | 1425 | as2->segments = assegment_dup_all (as1->segments); |
1426 | aspath_str_update (as2); | |
718e3744 | 1427 | return as2; |
1428 | } | |
fe69a505 | 1429 | |
1430 | /* If as1 is empty AS, no prepending to do. */ | |
718e3744 | 1431 | if (seg1 == NULL) |
1432 | return as2; | |
fe69a505 | 1433 | |
1434 | /* find the tail as1's segment chain. */ | |
1435 | while (seg1 && seg1->next) | |
1436 | seg1 = seg1->next; | |
718e3744 | 1437 | |
736d4408 VT |
1438 | /* Delete any AS_CONFED_SEQUENCE segment from as2. */ |
1439 | if (seg1->type == AS_SEQUENCE && seg2->type == AS_CONFED_SEQUENCE) | |
1440 | as2 = aspath_delete_confed_seq (as2); | |
1441 | ||
718e3744 | 1442 | /* Compare last segment type of as1 and first segment type of as2. */ |
1443 | if (seg1->type != seg2->type) | |
1444 | return aspath_merge (as1, as2); | |
1445 | ||
1446 | if (seg1->type == AS_SEQUENCE) | |
1447 | { | |
fe69a505 | 1448 | /* We have two chains of segments, as1->segments and seg2, |
1449 | * and we have to attach them together, merging the attaching | |
1450 | * segments together into one. | |
1451 | * | |
1452 | * 1. dupe as1->segments onto head of as2 | |
1453 | * 2. merge seg2's asns onto last segment of this new chain | |
1454 | * 3. attach chain after seg2 | |
1455 | */ | |
718e3744 | 1456 | |
fe69a505 | 1457 | /* dupe as1 onto as2's head */ |
1458 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1459 | ||
1460 | /* refind the tail of as2, reusing seg1 */ | |
1461 | while (seg1 && seg1->next) | |
1462 | seg1 = seg1->next; | |
1463 | ||
1464 | /* merge the old head, seg2, into tail, seg1 */ | |
1465 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1466 | ||
1467 | /* bypass the merged seg2, and attach any chain after it to | |
1468 | * chain descending from as2's head | |
1469 | */ | |
1470 | seg1->next = seg2->next; | |
1471 | ||
1472 | /* seg2 is now referenceless and useless*/ | |
1473 | assegment_free (seg2); | |
1474 | ||
1475 | /* we've now prepended as1's segment chain to as2, merging | |
1476 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1477 | */ | |
1478 | aspath_str_update (as2); | |
718e3744 | 1479 | return as2; |
1480 | } | |
1481 | else | |
1482 | { | |
1483 | /* AS_SET merge code is needed at here. */ | |
1484 | return aspath_merge (as1, as2); | |
1485 | } | |
fe69a505 | 1486 | /* XXX: Ermmm, what if as1 has multiple segments?? */ |
1487 | ||
718e3744 | 1488 | /* Not reached */ |
1489 | } | |
1490 | ||
841f7a57 DO |
1491 | /* Iterate over AS_PATH segments and wipe all occurences of the |
1492 | * listed AS numbers. Hence some segments may lose some or even | |
1493 | * all data on the way, the operation is implemented as a smarter | |
1494 | * version of aspath_dup(), which allocates memory to hold the new | |
1495 | * data, not the original. The new AS path is returned. | |
1496 | */ | |
1497 | struct aspath * | |
1498 | aspath_filter_exclude (struct aspath * source, struct aspath * exclude_list) | |
1499 | { | |
1500 | struct assegment * srcseg, * exclseg, * lastseg; | |
1501 | struct aspath * newpath; | |
1502 | ||
1503 | newpath = aspath_new(); | |
1504 | lastseg = NULL; | |
1505 | ||
1506 | for (srcseg = source->segments; srcseg; srcseg = srcseg->next) | |
1507 | { | |
1508 | unsigned i, y, newlen = 0, done = 0, skip_as; | |
1509 | struct assegment * newseg; | |
1510 | ||
1511 | /* Find out, how much ASns are we going to pick from this segment. | |
1512 | * We can't perform filtering right inline, because the size of | |
1513 | * the new segment isn't known at the moment yet. | |
1514 | */ | |
1515 | for (i = 0; i < srcseg->length; i++) | |
1516 | { | |
1517 | skip_as = 0; | |
1518 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1519 | for (y = 0; y < exclseg->length; y++) | |
1520 | if (srcseg->as[i] == exclseg->as[y]) | |
1521 | { | |
1522 | skip_as = 1; | |
1523 | // There's no sense in testing the rest of exclusion list, bail out. | |
1524 | break; | |
1525 | } | |
1526 | if (!skip_as) | |
1527 | newlen++; | |
1528 | } | |
1529 | /* newlen is now the number of ASns to copy */ | |
1530 | if (!newlen) | |
1531 | continue; | |
1532 | ||
1533 | /* Actual copying. Allocate memory and iterate once more, performing filtering. */ | |
1534 | newseg = assegment_new (srcseg->type, newlen); | |
1535 | for (i = 0; i < srcseg->length; i++) | |
1536 | { | |
1537 | skip_as = 0; | |
1538 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1539 | for (y = 0; y < exclseg->length; y++) | |
1540 | if (srcseg->as[i] == exclseg->as[y]) | |
1541 | { | |
1542 | skip_as = 1; | |
1543 | break; | |
1544 | } | |
1545 | if (skip_as) | |
1546 | continue; | |
1547 | newseg->as[done++] = srcseg->as[i]; | |
1548 | } | |
1549 | /* At his point newlen must be equal to done, and both must be positive. Append | |
1550 | * the filtered segment to the gross result. */ | |
1551 | if (!lastseg) | |
1552 | newpath->segments = newseg; | |
1553 | else | |
1554 | lastseg->next = newseg; | |
1555 | lastseg = newseg; | |
1556 | } | |
1557 | aspath_str_update (newpath); | |
1558 | /* We are happy returning even an empty AS_PATH, because the administrator | |
1559 | * might expect this very behaviour. There's a mean to avoid this, if necessary, | |
1560 | * by having a match rule against certain AS_PATH regexps in the route-map index. | |
1561 | */ | |
1562 | aspath_free (source); | |
1563 | return newpath; | |
1564 | } | |
1565 | ||
718e3744 | 1566 | /* Add specified AS to the leftmost of aspath. */ |
1567 | static struct aspath * | |
1568 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1569 | { | |
fe69a505 | 1570 | struct assegment *assegment = aspath->segments; |
718e3744 | 1571 | |
1572 | /* In case of empty aspath. */ | |
1573 | if (assegment == NULL || assegment->length == 0) | |
1574 | { | |
fe69a505 | 1575 | aspath->segments = assegment_new (type, 1); |
1576 | aspath->segments->as[0] = asno; | |
1577 | ||
718e3744 | 1578 | if (assegment) |
fe69a505 | 1579 | assegment_free (assegment); |
718e3744 | 1580 | |
1581 | return aspath; | |
1582 | } | |
1583 | ||
1584 | if (assegment->type == type) | |
fe69a505 | 1585 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); |
1586 | else | |
718e3744 | 1587 | { |
fe69a505 | 1588 | /* create new segment |
1589 | * push it onto head of aspath's segment chain | |
1590 | */ | |
718e3744 | 1591 | struct assegment *newsegment; |
fe69a505 | 1592 | |
1593 | newsegment = assegment_new (type, 1); | |
1594 | newsegment->as[0] = asno; | |
1595 | ||
1596 | newsegment->next = assegment; | |
1597 | aspath->segments = newsegment; | |
718e3744 | 1598 | } |
1599 | ||
1600 | return aspath; | |
1601 | } | |
1602 | ||
1603 | /* Add specified AS to the leftmost of aspath. */ | |
1604 | struct aspath * | |
1605 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1606 | { | |
1607 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1608 | } | |
1609 | ||
1610 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1611 | as2's leftmost AS is same return 1. */ | |
1612 | int | |
ffe11cfb | 1613 | aspath_cmp_left (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1614 | { |
f669f7d2 JBD |
1615 | const struct assegment *seg1; |
1616 | const struct assegment *seg2; | |
718e3744 | 1617 | |
fe69a505 | 1618 | if (!(aspath1 && aspath2)) |
1619 | return 0; | |
718e3744 | 1620 | |
fe69a505 | 1621 | seg1 = aspath1->segments; |
1622 | seg2 = aspath2->segments; | |
718e3744 | 1623 | |
2a3fa5d7 DS |
1624 | /* If both paths are originated in this AS then we do want to compare MED */ |
1625 | if (!seg1 && !seg2) | |
1626 | return 1; | |
1627 | ||
fe69a505 | 1628 | /* find first non-confed segments for each */ |
1629 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1630 | || (seg1->type == AS_CONFED_SET))) | |
1631 | seg1 = seg1->next; | |
718e3744 | 1632 | |
fe69a505 | 1633 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1634 | || (seg2->type == AS_CONFED_SET))) | |
1635 | seg2 = seg2->next; | |
718e3744 | 1636 | |
fe69a505 | 1637 | /* Check as1's */ |
1638 | if (!(seg1 && seg2 | |
1639 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1640 | return 0; | |
1641 | ||
1642 | if (seg1->as[0] == seg2->as[0]) | |
718e3744 | 1643 | return 1; |
1644 | ||
1645 | return 0; | |
1646 | } | |
1647 | ||
0b2aa3a0 PJ |
1648 | /* Truncate an aspath after a number of hops, and put the hops remaining |
1649 | * at the front of another aspath. Needed for AS4 compat. | |
1650 | * | |
1651 | * Returned aspath is a /new/ aspath, which should either by free'd or | |
1652 | * interned by the caller, as desired. | |
1653 | */ | |
1654 | struct aspath * | |
1655 | aspath_reconcile_as4 ( struct aspath *aspath, struct aspath *as4path) | |
1656 | { | |
1657 | struct assegment *seg, *newseg, *prevseg = NULL; | |
1658 | struct aspath *newpath = NULL, *mergedpath; | |
1659 | int hops, cpasns = 0; | |
1660 | ||
1661 | if (!aspath) | |
1662 | return NULL; | |
1663 | ||
1664 | seg = aspath->segments; | |
1665 | ||
1666 | /* CONFEDs should get reconciled too.. */ | |
1667 | hops = (aspath_count_hops (aspath) + aspath_count_confeds (aspath)) | |
1668 | - aspath_count_hops (as4path); | |
1669 | ||
1670 | if (hops < 0) | |
1671 | { | |
1672 | if (BGP_DEBUG (as4, AS4)) | |
1673 | zlog_warn ("[AS4] Fewer hops in AS_PATH than NEW_AS_PATH"); | |
1674 | /* Something's gone wrong. The RFC says we should now ignore AS4_PATH, | |
1675 | * which is daft behaviour - it contains vital loop-detection | |
1676 | * information which must have been removed from AS_PATH. | |
1677 | */ | |
1678 | hops = aspath_count_hops (aspath); | |
1679 | } | |
1680 | ||
1681 | if (!hops) | |
f1aa5d8a DS |
1682 | { |
1683 | newpath = aspath_dup (as4path); | |
1684 | aspath_str_update(newpath); | |
1685 | return newpath; | |
1686 | } | |
0b2aa3a0 PJ |
1687 | |
1688 | if ( BGP_DEBUG(as4, AS4)) | |
1689 | zlog_debug("[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now", | |
1690 | aspath->str, as4path->str); | |
1691 | ||
1692 | while (seg && hops > 0) | |
1693 | { | |
1694 | switch (seg->type) | |
1695 | { | |
1696 | case AS_SET: | |
1697 | case AS_CONFED_SET: | |
1698 | hops--; | |
1699 | cpasns = seg->length; | |
1700 | break; | |
1701 | case AS_CONFED_SEQUENCE: | |
1702 | /* Should never split a confed-sequence, if hop-count | |
1703 | * suggests we must then something's gone wrong somewhere. | |
1704 | * | |
1705 | * Most important goal is to preserve AS_PATHs prime function | |
1706 | * as loop-detector, so we fudge the numbers so that the entire | |
1707 | * confed-sequence is merged in. | |
1708 | */ | |
1709 | if (hops < seg->length) | |
1710 | { | |
1711 | if (BGP_DEBUG (as4, AS4)) | |
1712 | zlog_debug ("[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls" | |
1713 | " across 2/4 ASN boundary somewhere, broken.."); | |
1714 | hops = seg->length; | |
1715 | } | |
1716 | case AS_SEQUENCE: | |
1717 | cpasns = MIN(seg->length, hops); | |
1718 | hops -= seg->length; | |
1719 | } | |
1720 | ||
1721 | assert (cpasns <= seg->length); | |
1722 | ||
1723 | newseg = assegment_new (seg->type, 0); | |
1724 | newseg = assegment_append_asns (newseg, seg->as, cpasns); | |
1725 | ||
1726 | if (!newpath) | |
1727 | { | |
1728 | newpath = aspath_new (); | |
1729 | newpath->segments = newseg; | |
1730 | } | |
1731 | else | |
1732 | prevseg->next = newseg; | |
1733 | ||
1734 | prevseg = newseg; | |
1735 | seg = seg->next; | |
1736 | } | |
1737 | ||
1738 | /* We may be able to join some segments here, and we must | |
1739 | * do this because... we want normalised aspaths in out hash | |
1740 | * and we do not want to stumble in aspath_put. | |
1741 | */ | |
1742 | mergedpath = aspath_merge (newpath, aspath_dup(as4path)); | |
1743 | aspath_free (newpath); | |
1744 | mergedpath->segments = assegment_normalise (mergedpath->segments); | |
1745 | aspath_str_update (mergedpath); | |
1746 | ||
1747 | if ( BGP_DEBUG(as4, AS4)) | |
1748 | zlog_debug ("[AS4] result of synthesizing is %s", | |
1749 | mergedpath->str); | |
1750 | ||
1751 | return mergedpath; | |
1752 | } | |
1753 | ||
718e3744 | 1754 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and |
1755 | as2's leftmost AS is same return 1. (confederation as-path | |
1756 | only). */ | |
1757 | int | |
ffe11cfb | 1758 | aspath_cmp_left_confed (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1759 | { |
fe69a505 | 1760 | if (! (aspath1 && aspath2) ) |
718e3744 | 1761 | return 0; |
fe69a505 | 1762 | |
ad72740e | 1763 | if ( !(aspath1->segments && aspath2->segments) ) |
1764 | return 0; | |
1765 | ||
fe69a505 | 1766 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) |
1767 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
718e3744 | 1768 | return 0; |
fe69a505 | 1769 | |
1770 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
718e3744 | 1771 | return 1; |
1772 | ||
1773 | return 0; | |
1774 | } | |
1775 | ||
66b199b2 DS |
1776 | /* Delete all AS_CONFED_SEQUENCE/SET segments from aspath. |
1777 | * RFC 5065 section 4.1.c.1 | |
1778 | * | |
1779 | * 1) if any path segments of the AS_PATH are of the type | |
1780 | * AS_CONFED_SEQUENCE or AS_CONFED_SET, those segments MUST be | |
1781 | * removed from the AS_PATH attribute, leaving the sanitized | |
1782 | * AS_PATH attribute to be operated on by steps 2, 3 or 4. | |
1783 | */ | |
718e3744 | 1784 | struct aspath * |
1785 | aspath_delete_confed_seq (struct aspath *aspath) | |
1786 | { | |
66b199b2 DS |
1787 | struct assegment *seg, *prev, *next; |
1788 | char removed_confed_segment; | |
718e3744 | 1789 | |
fe69a505 | 1790 | if (!(aspath && aspath->segments)) |
718e3744 | 1791 | return aspath; |
1792 | ||
fe69a505 | 1793 | seg = aspath->segments; |
66b199b2 DS |
1794 | removed_confed_segment = 0; |
1795 | next = NULL; | |
1796 | prev = NULL; | |
fe69a505 | 1797 | |
66b199b2 | 1798 | while (seg) |
718e3744 | 1799 | { |
66b199b2 DS |
1800 | next = seg->next; |
1801 | ||
1802 | if (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET) | |
1803 | { | |
1804 | /* This is the first segment in the aspath */ | |
1805 | if (aspath->segments == seg) | |
1806 | aspath->segments = seg->next; | |
1807 | else | |
1808 | prev->next = seg->next; | |
1809 | ||
1810 | assegment_free (seg); | |
1811 | removed_confed_segment = 1; | |
1812 | } | |
1813 | else | |
1814 | prev = seg; | |
1815 | ||
1816 | seg = next; | |
718e3744 | 1817 | } |
66b199b2 DS |
1818 | |
1819 | if (removed_confed_segment) | |
1820 | aspath_str_update (aspath); | |
1821 | ||
718e3744 | 1822 | return aspath; |
1823 | } | |
1824 | ||
1825 | /* Add new AS number to the leftmost part of the aspath as | |
1826 | AS_CONFED_SEQUENCE. */ | |
1827 | struct aspath* | |
1828 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1829 | { | |
1830 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1831 | } | |
1832 | ||
1833 | /* Add new as value to as path structure. */ | |
94f2b392 | 1834 | static void |
718e3744 | 1835 | aspath_as_add (struct aspath *as, as_t asno) |
1836 | { | |
fe69a505 | 1837 | struct assegment *seg = as->segments; |
718e3744 | 1838 | |
fe69a505 | 1839 | if (!seg) |
1840 | return; | |
1841 | ||
93c1749c AS |
1842 | /* Last segment search procedure. */ |
1843 | while (seg->next) | |
1844 | seg = seg->next; | |
1845 | ||
fe69a505 | 1846 | assegment_append_asns (seg, &asno, 1); |
718e3744 | 1847 | } |
1848 | ||
1849 | /* Add new as segment to the as path. */ | |
94f2b392 | 1850 | static void |
718e3744 | 1851 | aspath_segment_add (struct aspath *as, int type) |
1852 | { | |
fe69a505 | 1853 | struct assegment *seg = as->segments; |
1854 | struct assegment *new = assegment_new (type, 0); | |
718e3744 | 1855 | |
93c1749c AS |
1856 | if (seg) |
1857 | { | |
1858 | while (seg->next) | |
1859 | seg = seg->next; | |
1860 | seg->next = new; | |
1861 | } | |
718e3744 | 1862 | else |
93c1749c | 1863 | as->segments = new; |
718e3744 | 1864 | } |
1865 | ||
1866 | struct aspath * | |
94f2b392 | 1867 | aspath_empty (void) |
718e3744 | 1868 | { |
ab005298 | 1869 | return aspath_parse (NULL, 0, 1); /* 32Bit ;-) */ |
718e3744 | 1870 | } |
1871 | ||
1872 | struct aspath * | |
94f2b392 | 1873 | aspath_empty_get (void) |
718e3744 | 1874 | { |
1875 | struct aspath *aspath; | |
1876 | ||
1877 | aspath = aspath_new (); | |
f669f7d2 | 1878 | aspath_make_str_count (aspath); |
718e3744 | 1879 | return aspath; |
1880 | } | |
1881 | ||
1882 | unsigned long | |
fe69a505 | 1883 | aspath_count (void) |
718e3744 | 1884 | { |
1885 | return ashash->count; | |
1886 | } | |
6b0655a2 | 1887 | |
718e3744 | 1888 | /* |
1889 | Theoretically, one as path can have: | |
1890 | ||
1891 | One BGP packet size should be less than 4096. | |
1892 | One BGP attribute size should be less than 4096 - BGP header size. | |
1893 | One BGP aspath size should be less than 4096 - BGP header size - | |
1894 | BGP mandantry attribute size. | |
1895 | */ | |
1896 | ||
1897 | /* AS path string lexical token enum. */ | |
1898 | enum as_token | |
1899 | { | |
1900 | as_token_asval, | |
1901 | as_token_set_start, | |
1902 | as_token_set_end, | |
fe69a505 | 1903 | as_token_confed_seq_start, |
1904 | as_token_confed_seq_end, | |
1905 | as_token_confed_set_start, | |
1906 | as_token_confed_set_end, | |
718e3744 | 1907 | as_token_unknown |
1908 | }; | |
1909 | ||
1910 | /* Return next token and point for string parse. */ | |
94f2b392 | 1911 | static const char * |
0b2aa3a0 | 1912 | aspath_gettoken (const char *buf, enum as_token *token, u_long *asno) |
718e3744 | 1913 | { |
fd79ac91 | 1914 | const char *p = buf; |
718e3744 | 1915 | |
fe69a505 | 1916 | /* Skip seperators (space for sequences, ',' for sets). */ |
1917 | while (isspace ((int) *p) || *p == ',') | |
718e3744 | 1918 | p++; |
1919 | ||
1920 | /* Check the end of the string and type specify characters | |
1921 | (e.g. {}()). */ | |
1922 | switch (*p) | |
1923 | { | |
1924 | case '\0': | |
1925 | return NULL; | |
718e3744 | 1926 | case '{': |
1927 | *token = as_token_set_start; | |
1928 | p++; | |
1929 | return p; | |
718e3744 | 1930 | case '}': |
1931 | *token = as_token_set_end; | |
1932 | p++; | |
1933 | return p; | |
718e3744 | 1934 | case '(': |
fe69a505 | 1935 | *token = as_token_confed_seq_start; |
718e3744 | 1936 | p++; |
1937 | return p; | |
718e3744 | 1938 | case ')': |
fe69a505 | 1939 | *token = as_token_confed_seq_end; |
1940 | p++; | |
1941 | return p; | |
fe69a505 | 1942 | case '[': |
1943 | *token = as_token_confed_set_start; | |
1944 | p++; | |
1945 | return p; | |
fe69a505 | 1946 | case ']': |
1947 | *token = as_token_confed_set_end; | |
718e3744 | 1948 | p++; |
1949 | return p; | |
718e3744 | 1950 | } |
1951 | ||
1952 | /* Check actual AS value. */ | |
1953 | if (isdigit ((int) *p)) | |
1954 | { | |
10819ece | 1955 | as_t asval; |
0b2aa3a0 | 1956 | |
718e3744 | 1957 | *token = as_token_asval; |
1958 | asval = (*p - '0'); | |
1959 | p++; | |
0b2aa3a0 | 1960 | |
718e3744 | 1961 | while (isdigit ((int) *p)) |
0b2aa3a0 PJ |
1962 | { |
1963 | asval *= 10; | |
1964 | asval += (*p - '0'); | |
1965 | p++; | |
1966 | } | |
718e3744 | 1967 | *asno = asval; |
1968 | return p; | |
1969 | } | |
1970 | ||
1971 | /* There is no match then return unknown token. */ | |
1972 | *token = as_token_unknown; | |
1973 | return p++; | |
1974 | } | |
1975 | ||
1976 | struct aspath * | |
fd79ac91 | 1977 | aspath_str2aspath (const char *str) |
718e3744 | 1978 | { |
3fff6ffc | 1979 | enum as_token token = as_token_unknown; |
718e3744 | 1980 | u_short as_type; |
0b2aa3a0 | 1981 | u_long asno = 0; |
718e3744 | 1982 | struct aspath *aspath; |
1983 | int needtype; | |
1984 | ||
1985 | aspath = aspath_new (); | |
1986 | ||
1987 | /* We start default type as AS_SEQUENCE. */ | |
1988 | as_type = AS_SEQUENCE; | |
1989 | needtype = 1; | |
1990 | ||
1991 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1992 | { | |
1993 | switch (token) | |
1994 | { | |
1995 | case as_token_asval: | |
1996 | if (needtype) | |
1997 | { | |
1998 | aspath_segment_add (aspath, as_type); | |
1999 | needtype = 0; | |
2000 | } | |
2001 | aspath_as_add (aspath, asno); | |
2002 | break; | |
2003 | case as_token_set_start: | |
2004 | as_type = AS_SET; | |
2005 | aspath_segment_add (aspath, as_type); | |
2006 | needtype = 0; | |
2007 | break; | |
2008 | case as_token_set_end: | |
2009 | as_type = AS_SEQUENCE; | |
2010 | needtype = 1; | |
2011 | break; | |
fe69a505 | 2012 | case as_token_confed_seq_start: |
718e3744 | 2013 | as_type = AS_CONFED_SEQUENCE; |
2014 | aspath_segment_add (aspath, as_type); | |
2015 | needtype = 0; | |
2016 | break; | |
fe69a505 | 2017 | case as_token_confed_seq_end: |
2018 | as_type = AS_SEQUENCE; | |
2019 | needtype = 1; | |
2020 | break; | |
2021 | case as_token_confed_set_start: | |
2022 | as_type = AS_CONFED_SET; | |
2023 | aspath_segment_add (aspath, as_type); | |
2024 | needtype = 0; | |
2025 | break; | |
2026 | case as_token_confed_set_end: | |
718e3744 | 2027 | as_type = AS_SEQUENCE; |
2028 | needtype = 1; | |
2029 | break; | |
2030 | case as_token_unknown: | |
2031 | default: | |
fe69a505 | 2032 | aspath_free (aspath); |
718e3744 | 2033 | return NULL; |
718e3744 | 2034 | } |
2035 | } | |
2036 | ||
f669f7d2 | 2037 | aspath_make_str_count (aspath); |
718e3744 | 2038 | |
2039 | return aspath; | |
2040 | } | |
6b0655a2 | 2041 | |
718e3744 | 2042 | /* Make hash value by raw aspath data. */ |
2043 | unsigned int | |
923de654 | 2044 | aspath_key_make (void *p) |
718e3744 | 2045 | { |
f669f7d2 | 2046 | struct aspath *aspath = (struct aspath *) p; |
718e3744 | 2047 | unsigned int key = 0; |
718e3744 | 2048 | |
0b2aa3a0 PJ |
2049 | if (!aspath->str) |
2050 | aspath_str_update (aspath); | |
f669f7d2 JBD |
2051 | |
2052 | key = jhash (aspath->str, aspath->str_len, 2334325); | |
718e3744 | 2053 | |
2054 | return key; | |
2055 | } | |
2056 | ||
2057 | /* If two aspath have same value then return 1 else return 0 */ | |
96450faf | 2058 | int |
ffe11cfb | 2059 | aspath_cmp (const void *arg1, const void *arg2) |
718e3744 | 2060 | { |
aea339f7 DO |
2061 | const struct assegment *seg1 = ((const struct aspath *)arg1)->segments; |
2062 | const struct assegment *seg2 = ((const struct aspath *)arg2)->segments; | |
fe69a505 | 2063 | |
2064 | while (seg1 || seg2) | |
2065 | { | |
2066 | int i; | |
2067 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
2068 | return 0; | |
2069 | if (seg1->type != seg2->type) | |
2070 | return 0; | |
2071 | if (seg1->length != seg2->length) | |
2072 | return 0; | |
2073 | for (i = 0; i < seg1->length; i++) | |
2074 | if (seg1->as[i] != seg2->as[i]) | |
2075 | return 0; | |
2076 | seg1 = seg1->next; | |
2077 | seg2 = seg2->next; | |
2078 | } | |
2079 | return 1; | |
718e3744 | 2080 | } |
2081 | ||
2082 | /* AS path hash initialize. */ | |
2083 | void | |
94f2b392 | 2084 | aspath_init (void) |
718e3744 | 2085 | { |
90645f55 | 2086 | ashash = hash_create_size (32768, aspath_key_make, aspath_cmp); |
718e3744 | 2087 | } |
8fdc32ab | 2088 | |
2089 | void | |
2090 | aspath_finish (void) | |
2091 | { | |
2092 | hash_free (ashash); | |
228da428 | 2093 | ashash = NULL; |
8fdc32ab | 2094 | |
2095 | if (snmp_stream) | |
2096 | stream_free (snmp_stream); | |
2097 | } | |
6b0655a2 | 2098 | |
718e3744 | 2099 | /* return and as path value */ |
2100 | const char * | |
2101 | aspath_print (struct aspath *as) | |
2102 | { | |
fe69a505 | 2103 | return (as ? as->str : NULL); |
718e3744 | 2104 | } |
2105 | ||
2106 | /* Printing functions */ | |
841f7a57 DO |
2107 | /* Feed the AS_PATH to the vty; the suffix string follows it only in case |
2108 | * AS_PATH wasn't empty. | |
2109 | */ | |
718e3744 | 2110 | void |
841f7a57 | 2111 | aspath_print_vty (struct vty *vty, const char *format, struct aspath *as, const char * suffix) |
718e3744 | 2112 | { |
b2518c1e PJ |
2113 | assert (format); |
2114 | vty_out (vty, format, as->str); | |
f669f7d2 | 2115 | if (as->str_len && strlen (suffix)) |
841f7a57 | 2116 | vty_out (vty, "%s", suffix); |
718e3744 | 2117 | } |
2118 | ||
94f2b392 | 2119 | static void |
718e3744 | 2120 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) |
2121 | { | |
2122 | struct aspath *as; | |
2123 | ||
2124 | as = (struct aspath *) backet->data; | |
2125 | ||
efa9f830 | 2126 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); |
718e3744 | 2127 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); |
2128 | } | |
2129 | ||
2130 | /* Print all aspath and hash information. This function is used from | |
2131 | `show ip bgp paths' command. */ | |
2132 | void | |
2133 | aspath_print_all_vty (struct vty *vty) | |
2134 | { | |
2135 | hash_iterate (ashash, | |
2136 | (void (*) (struct hash_backet *, void *)) | |
2137 | aspath_show_all_iterator, | |
2138 | vty); | |
2139 | } |