]>
Commit | Line | Data |
---|---|---|
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" |
718e3744 | 31 | |
32 | #include "bgpd/bgpd.h" | |
33 | #include "bgpd/bgp_aspath.h" | |
34 | \f | |
35 | /* Attr. Flags and Attr. Type Code. */ | |
36 | #define AS_HEADER_SIZE 2 | |
37 | ||
38 | /* Two octet is used for AS value. */ | |
39 | #define AS_VALUE_SIZE sizeof (as_t) | |
40 | ||
fe69a505 | 41 | /* Maximum protocol segment length value */ |
42 | #define AS_SEGMENT_MAX 255 | |
43 | ||
44 | /* The following length and size macros relate specifically to Quagga's | |
45 | * internal representation of AS-Segments, not per se to the on-wire | |
46 | * sizes and lengths. At present (200508) they sort of match, however | |
47 | * the ONLY functions which should now about the on-wire syntax are | |
48 | * aspath_put, assegment_put and assegment_parse. | |
49 | */ | |
50 | ||
51 | /* Calculated size in bytes of ASN segment data to hold N ASN's */ | |
52 | #define ASSEGMENT_DATA_SIZE(N) ((N) * AS_VALUE_SIZE) | |
718e3744 | 53 | |
fe69a505 | 54 | /* Calculated size of segment struct to hold N ASN's */ |
55 | #define ASSEGMENT_SIZE(N) (AS_HEADER_SIZE + ASSEGMENT_DATA_SIZE (N)) | |
56 | ||
57 | /* AS segment octet length. */ | |
58 | #define ASSEGMENT_LEN(X) ASSEGMENT_SIZE((X)->length) | |
59 | ||
60 | /* AS_SEQUENCE segments can be packed together */ | |
61 | /* Can the types of X and Y be considered for packing? */ | |
62 | #define ASSEGMENT_TYPES_PACKABLE(X,Y) \ | |
63 | ( ((X)->type == (Y)->type) \ | |
64 | && ((X)->type == AS_SEQUENCE)) | |
65 | /* Types and length of X,Y suitable for packing? */ | |
66 | #define ASSEGMENTS_PACKABLE(X,Y) \ | |
67 | ( ASSEGMENT_TYPES_PACKABLE( (X), (Y)) \ | |
68 | && ( ((X)->length + (Y)->length) <= AS_SEGMENT_MAX ) ) | |
69 | ||
70 | /* As segment header - the on-wire representation | |
71 | * NOT the internal representation! | |
72 | */ | |
73 | struct assegment_header | |
718e3744 | 74 | { |
75 | u_char type; | |
76 | u_char length; | |
718e3744 | 77 | }; |
78 | ||
79 | /* Hash for aspath. This is the top level structure of AS path. */ | |
80 | struct hash *ashash; | |
81 | \f | |
fe69a505 | 82 | static inline as_t * |
83 | assegment_data_new (int num) | |
84 | { | |
85 | return (XCALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num))); | |
86 | } | |
87 | ||
88 | static inline void | |
89 | assegment_data_free (as_t *asdata) | |
90 | { | |
91 | XFREE (MTYPE_AS_SEG_DATA,asdata); | |
92 | } | |
93 | ||
94 | /* Get a new segment. Note that 0 is an allowed length, | |
95 | * and will result in a segment with no allocated data segment. | |
96 | * the caller should immediately assign data to the segment, as the segment | |
97 | * otherwise is not generally valid | |
98 | */ | |
99 | static struct assegment * | |
100 | assegment_new (u_char type, u_short length) | |
101 | { | |
102 | struct assegment *new; | |
103 | ||
104 | new = XCALLOC (MTYPE_AS_SEG, sizeof (struct assegment)); | |
105 | ||
106 | if (length) | |
107 | new->as = assegment_data_new (length); | |
108 | ||
109 | new->length = length; | |
110 | new->type = type; | |
111 | ||
112 | return new; | |
113 | } | |
114 | ||
115 | static void | |
116 | assegment_free (struct assegment *seg) | |
117 | { | |
118 | if (!seg) | |
119 | return; | |
120 | ||
121 | if (seg->as) | |
122 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
123 | memset (seg, 0xfe, sizeof(struct assegment)); | |
124 | XFREE (MTYPE_AS_SEG, seg); | |
125 | ||
126 | return; | |
127 | } | |
128 | ||
129 | /* free entire chain of segments */ | |
130 | static void | |
131 | assegment_free_all (struct assegment *seg) | |
132 | { | |
133 | struct assegment *prev; | |
134 | ||
135 | while (seg) | |
136 | { | |
137 | prev = seg; | |
138 | seg = seg->next; | |
139 | assegment_free (prev); | |
140 | } | |
141 | } | |
142 | ||
143 | /* Duplicate just the given assegment and its data */ | |
144 | static struct assegment * | |
145 | assegment_dup (struct assegment *seg) | |
146 | { | |
147 | struct assegment *new; | |
148 | ||
149 | new = assegment_new (seg->type, seg->length); | |
150 | memcpy (new->as, seg->as, ASSEGMENT_DATA_SIZE (new->length) ); | |
151 | ||
152 | return new; | |
153 | } | |
154 | ||
155 | /* Duplicate entire chain of assegments, return the head */ | |
156 | static struct assegment * | |
157 | assegment_dup_all (struct assegment *seg) | |
158 | { | |
159 | struct assegment *new = NULL; | |
160 | struct assegment *head = NULL; | |
161 | ||
162 | while (seg) | |
163 | { | |
164 | if (head) | |
165 | { | |
166 | new->next = assegment_dup (seg); | |
167 | new = new->next; | |
168 | } | |
169 | else | |
170 | head = new = assegment_dup (seg); | |
171 | ||
172 | seg = seg->next; | |
173 | } | |
174 | return head; | |
175 | } | |
176 | ||
177 | /* prepend the as number to given segment, given num of times */ | |
178 | static struct assegment * | |
179 | assegment_prepend_asns (struct assegment *seg, as_t asnum, int num) | |
180 | { | |
181 | as_t *newas; | |
182 | ||
183 | if (!num) | |
184 | return seg; | |
185 | ||
186 | if (num >= AS_SEGMENT_MAX) | |
187 | return seg; /* we don't do huge prepends */ | |
188 | ||
189 | newas = assegment_data_new (seg->length + num); | |
190 | ||
191 | if (newas) | |
192 | { | |
193 | int i; | |
194 | for (i = 0; i < num; i++) | |
195 | newas[i] = asnum; | |
196 | ||
197 | memcpy (newas + num, seg->as, ASSEGMENT_DATA_SIZE (seg->length)); | |
198 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
199 | seg->as = newas; | |
200 | seg->length += num; | |
201 | return seg; | |
202 | } | |
203 | ||
204 | assegment_free_all (seg); | |
205 | return NULL; | |
206 | } | |
207 | ||
208 | /* append given array of as numbers to the segment */ | |
209 | static struct assegment * | |
210 | assegment_append_asns (struct assegment *seg, as_t *asnos, int num) | |
211 | { | |
02335429 | 212 | as_t *newas; |
213 | ||
214 | newas = XREALLOC (MTYPE_AS_SEG_DATA, seg->as, | |
fe69a505 | 215 | ASSEGMENT_DATA_SIZE (seg->length + num)); |
216 | ||
02335429 | 217 | if (newas) |
fe69a505 | 218 | { |
02335429 | 219 | seg->as = newas; |
fe69a505 | 220 | memcpy (seg->as + seg->length, asnos, ASSEGMENT_DATA_SIZE(num)); |
221 | seg->length += num; | |
222 | return seg; | |
223 | } | |
224 | ||
225 | assegment_free_all (seg); | |
226 | return NULL; | |
227 | } | |
228 | ||
229 | static int | |
230 | int_cmp (const void *p1, const void *p2) | |
231 | { | |
232 | const as_t *as1 = p1; | |
233 | const as_t *as2 = p2; | |
234 | ||
235 | return (*as1 == *as2) | |
236 | ? 0 : ( (*as1 > *as2) ? 1 : -1); | |
237 | } | |
238 | ||
239 | /* normalise the segment. | |
240 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
241 | * Internally, we do not care about the wire segment length limit, and | |
242 | * we want each distinct AS_PATHs to have the exact same internal | |
243 | * representation - eg, so that our hashing actually works.. | |
244 | */ | |
245 | static struct assegment * | |
246 | assegment_normalise (struct assegment *head) | |
247 | { | |
248 | struct assegment *seg = head, *pin; | |
249 | struct assegment *tmp; | |
250 | ||
251 | if (!head) | |
252 | return head; | |
253 | ||
254 | while (seg) | |
255 | { | |
256 | pin = seg; | |
257 | ||
258 | /* Sort values SET segments, for determinism in paths to aid | |
259 | * creation of hash values / path comparisons | |
260 | * and because it helps other lesser implementations ;) | |
261 | */ | |
262 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) | |
263 | qsort (seg->as, seg->length, sizeof(as_t), int_cmp); | |
264 | ||
265 | /* read ahead from the current, pinned segment while the segments | |
266 | * are packable/mergeable. Append all following packable segments | |
267 | * to the segment we have pinned and remove these appended | |
268 | * segments. | |
269 | */ | |
270 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) | |
271 | { | |
272 | tmp = pin->next; | |
273 | seg = pin->next; | |
274 | ||
275 | /* append the next sequence to the pinned sequence */ | |
276 | pin = assegment_append_asns (pin, seg->as, seg->length); | |
277 | ||
278 | /* bypass the next sequence */ | |
279 | pin->next = seg->next; | |
280 | ||
281 | /* get rid of the now referenceless segment */ | |
282 | assegment_free (tmp); | |
283 | ||
284 | } | |
285 | ||
286 | seg = pin->next; | |
287 | } | |
288 | return head; | |
289 | } | |
290 | \f | |
718e3744 | 291 | static struct aspath * |
fe69a505 | 292 | aspath_new (void) |
718e3744 | 293 | { |
294 | struct aspath *aspath; | |
295 | ||
296 | aspath = XMALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
297 | memset (aspath, 0, sizeof (struct aspath)); | |
298 | return aspath; | |
299 | } | |
300 | ||
301 | /* Free AS path structure. */ | |
302 | void | |
303 | aspath_free (struct aspath *aspath) | |
304 | { | |
305 | if (!aspath) | |
306 | return; | |
fe69a505 | 307 | if (aspath->segments) |
308 | assegment_free_all (aspath->segments); | |
718e3744 | 309 | if (aspath->str) |
310 | XFREE (MTYPE_AS_STR, aspath->str); | |
311 | XFREE (MTYPE_AS_PATH, aspath); | |
312 | } | |
313 | ||
314 | /* Unintern aspath from AS path bucket. */ | |
315 | void | |
316 | aspath_unintern (struct aspath *aspath) | |
317 | { | |
318 | struct aspath *ret; | |
319 | ||
320 | if (aspath->refcnt) | |
321 | aspath->refcnt--; | |
322 | ||
323 | if (aspath->refcnt == 0) | |
324 | { | |
325 | /* This aspath must exist in aspath hash table. */ | |
326 | ret = hash_release (ashash, aspath); | |
327 | assert (ret != NULL); | |
328 | aspath_free (aspath); | |
329 | } | |
330 | } | |
331 | ||
332 | /* Return the start or end delimiters for a particular Segment type */ | |
333 | #define AS_SEG_START 0 | |
334 | #define AS_SEG_END 1 | |
335 | static char | |
336 | aspath_delimiter_char (u_char type, u_char which) | |
337 | { | |
338 | int i; | |
339 | struct | |
340 | { | |
341 | int type; | |
342 | char start; | |
343 | char end; | |
344 | } aspath_delim_char [] = | |
345 | { | |
346 | { AS_SET, '{', '}' }, | |
718e3744 | 347 | { AS_CONFED_SET, '[', ']' }, |
348 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
349 | { 0 } | |
350 | }; | |
351 | ||
352 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
353 | { | |
354 | if (aspath_delim_char[i].type == type) | |
355 | { | |
356 | if (which == AS_SEG_START) | |
357 | return aspath_delim_char[i].start; | |
358 | else if (which == AS_SEG_END) | |
359 | return aspath_delim_char[i].end; | |
360 | } | |
361 | } | |
362 | return ' '; | |
363 | } | |
364 | ||
fe69a505 | 365 | /* countup asns from this segment and index onward */ |
366 | static int | |
367 | assegment_count_asns (struct assegment *seg, int from) | |
368 | { | |
369 | int count = 0; | |
370 | while (seg) | |
371 | { | |
372 | if (!from) | |
373 | count += seg->length; | |
374 | else | |
375 | { | |
376 | count += (seg->length - from); | |
377 | from = 0; | |
378 | } | |
379 | seg = seg->next; | |
380 | } | |
381 | return count; | |
382 | } | |
383 | ||
384 | unsigned int | |
385 | aspath_count_confeds (struct aspath *aspath) | |
386 | { | |
387 | int count = 0; | |
388 | struct assegment *seg = aspath->segments; | |
389 | ||
390 | while (seg) | |
391 | { | |
392 | if (seg->type == AS_CONFED_SEQUENCE) | |
393 | count += seg->length; | |
394 | else if (seg->type == AS_CONFED_SET) | |
395 | count++; | |
396 | ||
397 | seg = seg->next; | |
398 | } | |
399 | return count; | |
400 | } | |
401 | ||
402 | unsigned int | |
403 | aspath_count_hops (struct aspath *aspath) | |
404 | { | |
405 | int count = 0; | |
406 | struct assegment *seg = aspath->segments; | |
407 | ||
408 | while (seg) | |
409 | { | |
410 | if (seg->type == AS_SEQUENCE) | |
411 | count += seg->length; | |
412 | else if (seg->type == AS_SET) | |
413 | count++; | |
414 | ||
415 | seg = seg->next; | |
416 | } | |
417 | return count; | |
418 | } | |
419 | ||
420 | unsigned int | |
421 | aspath_size (struct aspath *aspath) | |
422 | { | |
423 | int size = 0; | |
424 | struct assegment *seg = aspath->segments; | |
425 | ||
426 | while (seg) | |
427 | { | |
428 | size += ASSEGMENT_SIZE(seg->length); | |
429 | seg = seg->next; | |
430 | } | |
431 | return size; | |
432 | } | |
433 | ||
718e3744 | 434 | /* Convert aspath structure to string expression. */ |
94f2b392 | 435 | static char * |
718e3744 | 436 | aspath_make_str_count (struct aspath *as) |
437 | { | |
fe69a505 | 438 | struct assegment *seg; |
439 | int str_size; | |
440 | int len = 0; | |
c9e52be3 | 441 | char *str_buf; |
718e3744 | 442 | |
443 | /* Empty aspath. */ | |
fe69a505 | 444 | if (!as->segments) |
718e3744 | 445 | { |
446 | str_buf = XMALLOC (MTYPE_AS_STR, 1); | |
447 | str_buf[0] = '\0'; | |
718e3744 | 448 | return str_buf; |
449 | } | |
fe69a505 | 450 | |
451 | seg = as->segments; | |
452 | ||
453 | /* ASN takes 5 chars at least, plus seperator, see below. | |
454 | * If there is one differing segment type, we need an additional | |
455 | * 2 chars for segment delimiters, and the final '\0'. | |
456 | * Hopefully this is large enough to avoid hitting the realloc | |
457 | * code below for most common sequences. | |
458 | */ | |
459 | #define ASN_STR_LEN (5 + 1) | |
460 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
461 | ASPATH_STR_DEFAULT_LEN); | |
718e3744 | 462 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); |
718e3744 | 463 | |
fe69a505 | 464 | while (seg) |
718e3744 | 465 | { |
466 | int i; | |
fe69a505 | 467 | char seperator; |
718e3744 | 468 | |
fe69a505 | 469 | /* Check AS type validity. Set seperator for segment */ |
470 | switch (seg->type) | |
471 | { | |
472 | case AS_SET: | |
473 | case AS_CONFED_SET: | |
474 | seperator = ','; | |
475 | break; | |
476 | case AS_SEQUENCE: | |
477 | case AS_CONFED_SEQUENCE: | |
478 | seperator = ' '; | |
479 | break; | |
480 | default: | |
481 | XFREE (MTYPE_AS_STR, str_buf); | |
482 | return NULL; | |
483 | } | |
484 | ||
485 | /* We might need to increase str_buf, particularly if path has | |
486 | * differing segments types, our initial guesstimate above will | |
487 | * have been wrong. need 5 chars for ASN, a seperator each and | |
488 | * potentially two segment delimiters, plus a space between each | |
489 | * segment and trailing zero. | |
490 | */ | |
491 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
492 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
493 | { | |
494 | str_size = len + SEGMENT_STR_LEN(seg); | |
495 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
496 | } | |
497 | #undef ASN_STR_LEN | |
498 | #undef SEGMENT_STR_LEN | |
499 | ||
500 | if (seg->type != AS_SEQUENCE) | |
501 | len += snprintf (str_buf + len, str_size - len, | |
502 | "%c", | |
503 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
504 | ||
505 | /* write out the ASNs, with their seperators, bar the last one*/ | |
506 | for (i = 0; i < seg->length; i++) | |
507 | { | |
508 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); | |
509 | ||
510 | if (i < (seg->length - 1)) | |
511 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
512 | } | |
513 | ||
514 | if (seg->type != AS_SEQUENCE) | |
515 | len += snprintf (str_buf + len, str_size - len, "%c", | |
516 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
517 | if (seg->next) | |
518 | len += snprintf (str_buf + len, str_size - len, " "); | |
519 | ||
520 | seg = seg->next; | |
718e3744 | 521 | } |
fe69a505 | 522 | |
523 | assert (len < str_size); | |
524 | ||
525 | str_buf[len] = '\0'; | |
718e3744 | 526 | |
527 | return str_buf; | |
528 | } | |
529 | ||
fe69a505 | 530 | static void |
531 | aspath_str_update (struct aspath *as) | |
532 | { | |
533 | if (as->str) | |
534 | XFREE (MTYPE_AS_STR, as->str); | |
535 | as->str = aspath_make_str_count (as); | |
536 | } | |
537 | ||
718e3744 | 538 | /* Intern allocated AS path. */ |
539 | struct aspath * | |
540 | aspath_intern (struct aspath *aspath) | |
541 | { | |
542 | struct aspath *find; | |
543 | ||
544 | /* Assert this AS path structure is not interned. */ | |
545 | assert (aspath->refcnt == 0); | |
546 | ||
547 | /* Check AS path hash. */ | |
548 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
549 | ||
550 | if (find != aspath) | |
fe69a505 | 551 | aspath_free (aspath); |
718e3744 | 552 | |
553 | find->refcnt++; | |
554 | ||
555 | if (! find->str) | |
556 | find->str = aspath_make_str_count (find); | |
557 | ||
558 | return find; | |
559 | } | |
560 | ||
561 | /* Duplicate aspath structure. Created same aspath structure but | |
562 | reference count and AS path string is cleared. */ | |
563 | struct aspath * | |
564 | aspath_dup (struct aspath *aspath) | |
565 | { | |
566 | struct aspath *new; | |
567 | ||
fe69a505 | 568 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 569 | |
fe69a505 | 570 | if (aspath->segments) |
571 | new->segments = assegment_dup_all (aspath->segments); | |
718e3744 | 572 | else |
fe69a505 | 573 | new->segments = NULL; |
718e3744 | 574 | |
fe69a505 | 575 | new->str = aspath_make_str_count (aspath); |
718e3744 | 576 | |
577 | return new; | |
578 | } | |
579 | ||
94f2b392 | 580 | static void * |
fe69a505 | 581 | aspath_hash_alloc (void *arg) |
718e3744 | 582 | { |
583 | struct aspath *aspath; | |
584 | ||
585 | /* New aspath strucutre is needed. */ | |
fe69a505 | 586 | aspath = aspath_dup (arg); |
587 | ||
718e3744 | 588 | /* Malformed AS path value. */ |
589 | if (! aspath->str) | |
590 | { | |
591 | aspath_free (aspath); | |
592 | return NULL; | |
593 | } | |
594 | ||
595 | return aspath; | |
596 | } | |
597 | ||
fe69a505 | 598 | /* parse as-segment byte stream in struct assegment */ |
ad72740e | 599 | static struct assegment * |
fe69a505 | 600 | assegments_parse (struct stream *s, size_t length) |
601 | { | |
602 | struct assegment_header segh; | |
603 | struct assegment *seg, *prev = NULL, *head = NULL; | |
604 | size_t bytes = 0; | |
605 | ||
606 | /* empty aspath (ie iBGP or somesuch) */ | |
607 | if (length == 0) | |
608 | return NULL; | |
609 | ||
610 | /* basic checks */ | |
611 | if ( (STREAM_READABLE(s) < length) | |
612 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
613 | || (length % AS_VALUE_SIZE)) | |
614 | return NULL; | |
615 | ||
616 | while ( (STREAM_READABLE(s) > AS_HEADER_SIZE) | |
617 | && (bytes < length)) | |
618 | { | |
619 | int i; | |
620 | ||
621 | /* softly softly, get the header first on its own */ | |
622 | segh.type = stream_getc (s); | |
623 | segh.length = stream_getc (s); | |
624 | ||
625 | /* check it.. */ | |
626 | if ( ((bytes + ASSEGMENT_SIZE(segh.length)) > length) | |
627 | /* 1771bis 4.3b: seg length contains one or more */ | |
628 | || (segh.length == 0) | |
629 | /* Paranoia in case someone changes type of segment length */ | |
630 | || ((sizeof segh.length > 1) && segh.length > AS_SEGMENT_MAX)) | |
631 | { | |
632 | if (head) | |
633 | assegment_free_all (head); | |
634 | return NULL; | |
635 | } | |
636 | ||
637 | /* now its safe to trust lengths */ | |
638 | seg = assegment_new (segh.type, segh.length); | |
639 | ||
640 | if (head) | |
641 | prev->next = seg; | |
642 | else /* it's the first segment */ | |
643 | head = prev = seg; | |
644 | ||
645 | for (i = 0; i < segh.length; i++) | |
646 | seg->as[i] = stream_getw (s); | |
647 | ||
648 | bytes += ASSEGMENT_SIZE(segh.length); | |
649 | ||
650 | prev = seg; | |
651 | } | |
652 | ||
653 | return assegment_normalise (head); | |
654 | } | |
655 | ||
718e3744 | 656 | /* AS path parse function. pnt is a pointer to byte stream and length |
657 | is length of byte stream. If there is same AS path in the the AS | |
658 | path hash then return it else make new AS path structure. */ | |
659 | struct aspath * | |
fe69a505 | 660 | aspath_parse (struct stream *s, size_t length) |
718e3744 | 661 | { |
662 | struct aspath as; | |
663 | struct aspath *find; | |
664 | ||
665 | /* If length is odd it's malformed AS path. */ | |
fe69a505 | 666 | if (length % AS_VALUE_SIZE) |
718e3744 | 667 | return NULL; |
668 | ||
fe69a505 | 669 | as.segments = assegments_parse (s, length); |
670 | ||
718e3744 | 671 | /* If already same aspath exist then return it. */ |
672 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
02335429 | 673 | |
674 | /* aspath_hash_alloc dupes segments too. that probably could be | |
675 | * optimised out. | |
676 | */ | |
677 | assegment_free_all (as.segments); | |
678 | ||
718e3744 | 679 | if (! find) |
680 | return NULL; | |
681 | find->refcnt++; | |
682 | ||
683 | return find; | |
684 | } | |
685 | ||
fe69a505 | 686 | static inline void |
687 | assegment_data_put (struct stream *s, as_t *as, int num) | |
688 | { | |
689 | int i; | |
690 | assert (num <= AS_SEGMENT_MAX); | |
691 | ||
692 | for (i = 0; i < num; i++) | |
693 | stream_putw (s, as[i]); | |
694 | } | |
718e3744 | 695 | |
fe69a505 | 696 | static inline size_t |
697 | assegment_header_put (struct stream *s, u_char type, int length) | |
718e3744 | 698 | { |
fe69a505 | 699 | size_t lenp; |
700 | assert (length <= AS_SEGMENT_MAX); | |
701 | stream_putc (s, type); | |
702 | lenp = stream_get_endp (s); | |
703 | stream_putc (s, length); | |
704 | return lenp; | |
705 | } | |
718e3744 | 706 | |
fe69a505 | 707 | /* write aspath data to stream */ |
708 | void | |
709 | aspath_put (struct stream *s, struct aspath *as) | |
710 | { | |
711 | struct assegment *seg = as->segments; | |
712 | ||
713 | if (!seg || seg->length == 0) | |
714 | return; | |
715 | ||
716 | if (seg) | |
718e3744 | 717 | { |
fe69a505 | 718 | while (seg && (ASSEGMENT_LEN (seg) <= STREAM_WRITEABLE(s))) |
719 | { | |
720 | int written = 0; | |
721 | size_t lenp; | |
722 | ||
723 | /* Overlength segments have to be split up */ | |
724 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
725 | { | |
726 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
727 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX); | |
728 | written += AS_SEGMENT_MAX; | |
729 | } | |
730 | ||
731 | /* write the final segment, probably is also the first */ | |
732 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
733 | assegment_data_put (s, (seg->as + written), seg->length - written); | |
734 | ||
735 | /* Sequence-type segments can be 'packed' together | |
736 | * Case of a segment which was overlength and split up | |
737 | * will be missed here, but that doesn't matter. | |
738 | */ | |
739 | if (seg->next && ASSEGMENTS_PACKABLE (seg, seg->next)) | |
740 | { | |
741 | /* NB: We should never normally get here given we | |
742 | * normalise aspath data when parse them. However, better | |
743 | * safe than sorry. We potentially could call | |
744 | * assegment_normalise here instead, but it's cheaper and | |
745 | * easier to do it on the fly here rather than go through | |
746 | * the segment list twice every time we write out | |
747 | * aspath's. | |
748 | */ | |
749 | ||
750 | /* Next segment's data can fit in this one */ | |
751 | assegment_data_put (s, seg->next->as, seg->next->length); | |
752 | ||
753 | /* update the length of the segment header */ | |
754 | stream_putc_at (s, lenp, | |
755 | seg->length - written + seg->next->length); | |
756 | seg = seg->next->next; /* skip to past next */ | |
757 | } | |
758 | else | |
759 | seg = seg->next; | |
760 | } | |
718e3744 | 761 | } |
fe69a505 | 762 | } |
763 | ||
764 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
765 | * We have no way to manage the storage, so we use a static stream | |
766 | * wrapper around aspath_put. | |
767 | */ | |
768 | u_char * | |
769 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
770 | { | |
771 | #define SNMP_PATHSEG_MAX 1024 | |
772 | static struct stream *s = NULL; | |
773 | ||
774 | if (!s) | |
775 | s = stream_new (SNMP_PATHSEG_MAX); | |
718e3744 | 776 | else |
fe69a505 | 777 | stream_reset (s); |
778 | ||
779 | if (!as) | |
718e3744 | 780 | { |
fe69a505 | 781 | *varlen = 0; |
782 | return NULL; | |
718e3744 | 783 | } |
fe69a505 | 784 | aspath_put (s, as); |
785 | ||
786 | *varlen = stream_get_endp (s); | |
787 | return stream_pnt(s); | |
718e3744 | 788 | } |
fe69a505 | 789 | |
790 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
718e3744 | 791 | |
94f2b392 | 792 | static struct assegment * |
718e3744 | 793 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, |
794 | as_t as) | |
795 | { | |
796 | int i; | |
797 | ||
798 | /* If this is first AS set member, create new as-set segment. */ | |
799 | if (asset == NULL) | |
800 | { | |
fe69a505 | 801 | asset = assegment_new (AS_SET, 1); |
802 | if (! aspath->segments) | |
803 | aspath->segments = asset; | |
718e3744 | 804 | else |
fe69a505 | 805 | { |
806 | struct assegment *seg = aspath->segments; | |
807 | while (seg->next) | |
808 | seg = seg->next; | |
809 | seg->next = asset; | |
810 | } | |
718e3744 | 811 | asset->type = AS_SET; |
812 | asset->length = 1; | |
fe69a505 | 813 | asset->as[0] = as; |
718e3744 | 814 | } |
815 | else | |
816 | { | |
718e3744 | 817 | /* Check this AS value already exists or not. */ |
818 | for (i = 0; i < asset->length; i++) | |
fe69a505 | 819 | if (asset->as[i] == as) |
718e3744 | 820 | return asset; |
fe69a505 | 821 | |
718e3744 | 822 | asset->length++; |
fe69a505 | 823 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, |
824 | asset->length * AS_VALUE_SIZE); | |
825 | asset->as[asset->length - 1] = as; | |
718e3744 | 826 | } |
fe69a505 | 827 | |
718e3744 | 828 | |
829 | return asset; | |
830 | } | |
831 | ||
832 | /* Modify as1 using as2 for aggregation. */ | |
833 | struct aspath * | |
834 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
835 | { | |
836 | int i; | |
837 | int minlen; | |
838 | int match; | |
fe69a505 | 839 | int from; |
840 | struct assegment *seg1 = as1->segments; | |
841 | struct assegment *seg2 = as2->segments; | |
718e3744 | 842 | struct aspath *aspath; |
843 | struct assegment *asset; | |
844 | ||
845 | match = 0; | |
846 | minlen = 0; | |
847 | aspath = NULL; | |
848 | asset = NULL; | |
718e3744 | 849 | |
850 | /* First of all check common leading sequence. */ | |
fe69a505 | 851 | while (seg1 && seg2) |
718e3744 | 852 | { |
853 | /* Check segment type. */ | |
854 | if (seg1->type != seg2->type) | |
855 | break; | |
856 | ||
857 | /* Minimum segment length. */ | |
858 | minlen = min (seg1->length, seg2->length); | |
859 | ||
860 | for (match = 0; match < minlen; match++) | |
fe69a505 | 861 | if (seg1->as[match] != seg2->as[match]) |
718e3744 | 862 | break; |
863 | ||
864 | if (match) | |
865 | { | |
866 | if (! aspath) | |
fe69a505 | 867 | aspath = aspath_new (); |
868 | aspath->segments = assegment_new (seg1->type, 0); | |
869 | aspath->segments = assegment_append_asns (aspath->segments, | |
870 | seg1->as, match); | |
718e3744 | 871 | } |
872 | ||
873 | if (match != minlen || match != seg1->length | |
874 | || seg1->length != seg2->length) | |
875 | break; | |
fe69a505 | 876 | |
877 | seg1 = seg1->next; | |
878 | seg2 = seg2->next; | |
718e3744 | 879 | } |
880 | ||
881 | if (! aspath) | |
882 | aspath = aspath_new(); | |
883 | ||
884 | /* Make as-set using rest of all information. */ | |
fe69a505 | 885 | from = match; |
886 | while (seg1) | |
718e3744 | 887 | { |
fe69a505 | 888 | for (i = from; i < seg1->length; i++) |
889 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
890 | ||
891 | from = 0; | |
892 | seg1 = seg1->next; | |
718e3744 | 893 | } |
894 | ||
fe69a505 | 895 | from = match; |
896 | while (seg2) | |
718e3744 | 897 | { |
fe69a505 | 898 | for (i = from; i < seg2->length; i++) |
899 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
718e3744 | 900 | |
fe69a505 | 901 | from = 0; |
902 | seg2 = seg2->next; | |
718e3744 | 903 | } |
fe69a505 | 904 | |
905 | assegment_normalise (aspath->segments); | |
906 | aspath_str_update (aspath); | |
718e3744 | 907 | return aspath; |
908 | } | |
909 | ||
910 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
911 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
912 | or not the peer's AS number. */ | |
913 | int | |
914 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
915 | { | |
fe69a505 | 916 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 917 | return 0; |
fe69a505 | 918 | |
919 | if (aspath->segments | |
920 | && (aspath->segments->type == AS_SEQUENCE) | |
921 | && (aspath->segments->as[0] == asno )) | |
718e3744 | 922 | return 1; |
923 | ||
924 | return 0; | |
925 | } | |
926 | ||
927 | /* AS path loop check. If aspath contains asno then return 1. */ | |
928 | int | |
929 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
930 | { | |
fe69a505 | 931 | struct assegment *seg; |
718e3744 | 932 | int count = 0; |
933 | ||
fe69a505 | 934 | if ( (aspath == NULL) || (aspath->segments) ) |
718e3744 | 935 | return 0; |
fe69a505 | 936 | |
937 | seg = aspath->segments; | |
938 | ||
939 | while (seg) | |
718e3744 | 940 | { |
941 | int i; | |
718e3744 | 942 | |
fe69a505 | 943 | for (i = 0; i < seg->length; i++) |
944 | if (seg->as[i] == asno) | |
718e3744 | 945 | count++; |
fe69a505 | 946 | |
947 | seg = seg->next; | |
718e3744 | 948 | } |
949 | return count; | |
950 | } | |
951 | ||
952 | /* When all of AS path is private AS return 1. */ | |
953 | int | |
954 | aspath_private_as_check (struct aspath *aspath) | |
955 | { | |
fe69a505 | 956 | struct assegment *seg; |
957 | ||
958 | if ( !(aspath && aspath->segments) ) | |
718e3744 | 959 | return 0; |
fe69a505 | 960 | |
961 | seg = aspath->segments; | |
718e3744 | 962 | |
fe69a505 | 963 | while (seg) |
718e3744 | 964 | { |
965 | int i; | |
718e3744 | 966 | |
fe69a505 | 967 | for (i = 0; i < seg->length; i++) |
718e3744 | 968 | { |
fe69a505 | 969 | if ( (seg->as[i] < BGP_PRIVATE_AS_MIN) |
970 | || (seg->as[i] > BGP_PRIVATE_AS_MAX) ) | |
718e3744 | 971 | return 0; |
972 | } | |
fe69a505 | 973 | seg = seg->next; |
718e3744 | 974 | } |
975 | return 1; | |
976 | } | |
977 | ||
978 | /* Merge as1 to as2. as2 should be uninterned aspath. */ | |
94f2b392 | 979 | static struct aspath * |
718e3744 | 980 | aspath_merge (struct aspath *as1, struct aspath *as2) |
981 | { | |
fe69a505 | 982 | struct assegment *last, *new; |
718e3744 | 983 | |
984 | if (! as1 || ! as2) | |
985 | return NULL; | |
986 | ||
fe69a505 | 987 | last = new = assegment_dup_all (as1->segments); |
988 | ||
989 | /* find the last valid segment */ | |
990 | while (last && last->next) | |
991 | last = last->next; | |
992 | ||
993 | last->next = as2->segments; | |
994 | as2->segments = new; | |
995 | aspath_str_update (as2); | |
718e3744 | 996 | return as2; |
997 | } | |
998 | ||
999 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1000 | struct aspath * | |
1001 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1002 | { | |
fe69a505 | 1003 | struct assegment *seg1; |
1004 | struct assegment *seg2; | |
718e3744 | 1005 | |
1006 | if (! as1 || ! as2) | |
1007 | return NULL; | |
fe69a505 | 1008 | |
1009 | seg1 = as1->segments; | |
1010 | seg2 = as2->segments; | |
1011 | ||
1012 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
718e3744 | 1013 | if (seg2 == NULL) |
1014 | { | |
fe69a505 | 1015 | as2->segments = assegment_dup_all (as1->segments); |
1016 | aspath_str_update (as2); | |
718e3744 | 1017 | return as2; |
1018 | } | |
fe69a505 | 1019 | |
1020 | /* If as1 is empty AS, no prepending to do. */ | |
718e3744 | 1021 | if (seg1 == NULL) |
1022 | return as2; | |
fe69a505 | 1023 | |
1024 | /* find the tail as1's segment chain. */ | |
1025 | while (seg1 && seg1->next) | |
1026 | seg1 = seg1->next; | |
718e3744 | 1027 | |
1028 | /* Compare last segment type of as1 and first segment type of as2. */ | |
1029 | if (seg1->type != seg2->type) | |
1030 | return aspath_merge (as1, as2); | |
1031 | ||
1032 | if (seg1->type == AS_SEQUENCE) | |
1033 | { | |
fe69a505 | 1034 | /* We have two chains of segments, as1->segments and seg2, |
1035 | * and we have to attach them together, merging the attaching | |
1036 | * segments together into one. | |
1037 | * | |
1038 | * 1. dupe as1->segments onto head of as2 | |
1039 | * 2. merge seg2's asns onto last segment of this new chain | |
1040 | * 3. attach chain after seg2 | |
1041 | */ | |
718e3744 | 1042 | |
fe69a505 | 1043 | /* dupe as1 onto as2's head */ |
1044 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1045 | ||
1046 | /* refind the tail of as2, reusing seg1 */ | |
1047 | while (seg1 && seg1->next) | |
1048 | seg1 = seg1->next; | |
1049 | ||
1050 | /* merge the old head, seg2, into tail, seg1 */ | |
1051 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1052 | ||
1053 | /* bypass the merged seg2, and attach any chain after it to | |
1054 | * chain descending from as2's head | |
1055 | */ | |
1056 | seg1->next = seg2->next; | |
1057 | ||
1058 | /* seg2 is now referenceless and useless*/ | |
1059 | assegment_free (seg2); | |
1060 | ||
1061 | /* we've now prepended as1's segment chain to as2, merging | |
1062 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1063 | */ | |
1064 | aspath_str_update (as2); | |
718e3744 | 1065 | return as2; |
1066 | } | |
1067 | else | |
1068 | { | |
1069 | /* AS_SET merge code is needed at here. */ | |
1070 | return aspath_merge (as1, as2); | |
1071 | } | |
fe69a505 | 1072 | /* XXX: Ermmm, what if as1 has multiple segments?? */ |
1073 | ||
718e3744 | 1074 | /* Not reached */ |
1075 | } | |
1076 | ||
1077 | /* Add specified AS to the leftmost of aspath. */ | |
1078 | static struct aspath * | |
1079 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1080 | { | |
fe69a505 | 1081 | struct assegment *assegment = aspath->segments; |
718e3744 | 1082 | |
1083 | /* In case of empty aspath. */ | |
1084 | if (assegment == NULL || assegment->length == 0) | |
1085 | { | |
fe69a505 | 1086 | aspath->segments = assegment_new (type, 1); |
1087 | aspath->segments->as[0] = asno; | |
1088 | ||
718e3744 | 1089 | if (assegment) |
fe69a505 | 1090 | assegment_free (assegment); |
718e3744 | 1091 | |
1092 | return aspath; | |
1093 | } | |
1094 | ||
1095 | if (assegment->type == type) | |
fe69a505 | 1096 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); |
1097 | else | |
718e3744 | 1098 | { |
fe69a505 | 1099 | /* create new segment |
1100 | * push it onto head of aspath's segment chain | |
1101 | */ | |
718e3744 | 1102 | struct assegment *newsegment; |
fe69a505 | 1103 | |
1104 | newsegment = assegment_new (type, 1); | |
1105 | newsegment->as[0] = asno; | |
1106 | ||
1107 | newsegment->next = assegment; | |
1108 | aspath->segments = newsegment; | |
718e3744 | 1109 | } |
1110 | ||
1111 | return aspath; | |
1112 | } | |
1113 | ||
1114 | /* Add specified AS to the leftmost of aspath. */ | |
1115 | struct aspath * | |
1116 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1117 | { | |
1118 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1119 | } | |
1120 | ||
1121 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1122 | as2's leftmost AS is same return 1. */ | |
1123 | int | |
1124 | aspath_cmp_left (struct aspath *aspath1, struct aspath *aspath2) | |
1125 | { | |
fe69a505 | 1126 | struct assegment *seg1 = NULL; |
1127 | struct assegment *seg2 = NULL; | |
718e3744 | 1128 | |
fe69a505 | 1129 | if (!(aspath1 && aspath2)) |
1130 | return 0; | |
718e3744 | 1131 | |
fe69a505 | 1132 | seg1 = aspath1->segments; |
1133 | seg2 = aspath2->segments; | |
718e3744 | 1134 | |
fe69a505 | 1135 | /* find first non-confed segments for each */ |
1136 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1137 | || (seg1->type == AS_CONFED_SET))) | |
1138 | seg1 = seg1->next; | |
718e3744 | 1139 | |
fe69a505 | 1140 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1141 | || (seg2->type == AS_CONFED_SET))) | |
1142 | seg2 = seg2->next; | |
718e3744 | 1143 | |
fe69a505 | 1144 | /* Check as1's */ |
1145 | if (!(seg1 && seg2 | |
1146 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1147 | return 0; | |
1148 | ||
1149 | if (seg1->as[0] == seg2->as[0]) | |
718e3744 | 1150 | return 1; |
1151 | ||
1152 | return 0; | |
1153 | } | |
1154 | ||
1155 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1156 | as2's leftmost AS is same return 1. (confederation as-path | |
1157 | only). */ | |
1158 | int | |
1159 | aspath_cmp_left_confed (struct aspath *aspath1, struct aspath *aspath2) | |
1160 | { | |
fe69a505 | 1161 | if (! (aspath1 && aspath2) ) |
718e3744 | 1162 | return 0; |
fe69a505 | 1163 | |
ad72740e | 1164 | if ( !(aspath1->segments && aspath2->segments) ) |
1165 | return 0; | |
1166 | ||
fe69a505 | 1167 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) |
1168 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
718e3744 | 1169 | return 0; |
fe69a505 | 1170 | |
1171 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
718e3744 | 1172 | return 1; |
1173 | ||
1174 | return 0; | |
1175 | } | |
1176 | ||
fe69a505 | 1177 | /* Delete all leading AS_CONFED_SEQUENCE/SET segments from aspath. |
1178 | * See RFC3065, 6.1 c1 */ | |
718e3744 | 1179 | struct aspath * |
1180 | aspath_delete_confed_seq (struct aspath *aspath) | |
1181 | { | |
fe69a505 | 1182 | struct assegment *seg; |
718e3744 | 1183 | |
fe69a505 | 1184 | if (!(aspath && aspath->segments)) |
718e3744 | 1185 | return aspath; |
1186 | ||
fe69a505 | 1187 | seg = aspath->segments; |
1188 | ||
1189 | /* "if the first path segment of the AS_PATH is | |
1190 | * of type AS_CONFED_SEQUENCE," | |
1191 | */ | |
1192 | if (aspath->segments->type != AS_CONFED_SEQUENCE) | |
1193 | return aspath; | |
718e3744 | 1194 | |
fe69a505 | 1195 | /* "... that segment and any immediately following segments |
1196 | * of the type AS_CONFED_SET or AS_CONFED_SEQUENCE are removed | |
1197 | * from the AS_PATH attribute," | |
1198 | */ | |
1199 | while (seg && | |
1200 | (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET)) | |
718e3744 | 1201 | { |
fe69a505 | 1202 | aspath->segments = seg->next; |
1203 | assegment_free (seg); | |
1204 | seg = aspath->segments; | |
718e3744 | 1205 | } |
fe69a505 | 1206 | aspath_str_update (aspath); |
718e3744 | 1207 | return aspath; |
1208 | } | |
1209 | ||
1210 | /* Add new AS number to the leftmost part of the aspath as | |
1211 | AS_CONFED_SEQUENCE. */ | |
1212 | struct aspath* | |
1213 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1214 | { | |
1215 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1216 | } | |
1217 | ||
1218 | /* Add new as value to as path structure. */ | |
94f2b392 | 1219 | static void |
718e3744 | 1220 | aspath_as_add (struct aspath *as, as_t asno) |
1221 | { | |
fe69a505 | 1222 | struct assegment *seg = as->segments; |
718e3744 | 1223 | |
1224 | /* Last segment search procedure. */ | |
fe69a505 | 1225 | while (seg && seg->next) |
1226 | seg = seg->next; | |
1227 | ||
1228 | if (!seg) | |
1229 | return; | |
1230 | ||
1231 | assegment_append_asns (seg, &asno, 1); | |
718e3744 | 1232 | } |
1233 | ||
1234 | /* Add new as segment to the as path. */ | |
94f2b392 | 1235 | static void |
718e3744 | 1236 | aspath_segment_add (struct aspath *as, int type) |
1237 | { | |
fe69a505 | 1238 | struct assegment *seg = as->segments; |
1239 | struct assegment *new = assegment_new (type, 0); | |
718e3744 | 1240 | |
fe69a505 | 1241 | while (seg && seg->next) |
1242 | seg = seg->next; | |
1243 | ||
1244 | if (seg == NULL) | |
1245 | as->segments = new; | |
718e3744 | 1246 | else |
fe69a505 | 1247 | seg->next = new; |
718e3744 | 1248 | } |
1249 | ||
1250 | struct aspath * | |
94f2b392 | 1251 | aspath_empty (void) |
718e3744 | 1252 | { |
1253 | return aspath_parse (NULL, 0); | |
1254 | } | |
1255 | ||
1256 | struct aspath * | |
94f2b392 | 1257 | aspath_empty_get (void) |
718e3744 | 1258 | { |
1259 | struct aspath *aspath; | |
1260 | ||
1261 | aspath = aspath_new (); | |
1262 | aspath->str = aspath_make_str_count (aspath); | |
1263 | return aspath; | |
1264 | } | |
1265 | ||
1266 | unsigned long | |
fe69a505 | 1267 | aspath_count (void) |
718e3744 | 1268 | { |
1269 | return ashash->count; | |
1270 | } | |
1271 | \f | |
1272 | /* | |
1273 | Theoretically, one as path can have: | |
1274 | ||
1275 | One BGP packet size should be less than 4096. | |
1276 | One BGP attribute size should be less than 4096 - BGP header size. | |
1277 | One BGP aspath size should be less than 4096 - BGP header size - | |
1278 | BGP mandantry attribute size. | |
1279 | */ | |
1280 | ||
1281 | /* AS path string lexical token enum. */ | |
1282 | enum as_token | |
1283 | { | |
1284 | as_token_asval, | |
1285 | as_token_set_start, | |
1286 | as_token_set_end, | |
fe69a505 | 1287 | as_token_confed_seq_start, |
1288 | as_token_confed_seq_end, | |
1289 | as_token_confed_set_start, | |
1290 | as_token_confed_set_end, | |
718e3744 | 1291 | as_token_unknown |
1292 | }; | |
1293 | ||
1294 | /* Return next token and point for string parse. */ | |
94f2b392 | 1295 | static const char * |
fd79ac91 | 1296 | aspath_gettoken (const char *buf, enum as_token *token, u_short *asno) |
718e3744 | 1297 | { |
fd79ac91 | 1298 | const char *p = buf; |
718e3744 | 1299 | |
fe69a505 | 1300 | /* Skip seperators (space for sequences, ',' for sets). */ |
1301 | while (isspace ((int) *p) || *p == ',') | |
718e3744 | 1302 | p++; |
1303 | ||
1304 | /* Check the end of the string and type specify characters | |
1305 | (e.g. {}()). */ | |
1306 | switch (*p) | |
1307 | { | |
1308 | case '\0': | |
1309 | return NULL; | |
1310 | break; | |
1311 | case '{': | |
1312 | *token = as_token_set_start; | |
1313 | p++; | |
1314 | return p; | |
1315 | break; | |
1316 | case '}': | |
1317 | *token = as_token_set_end; | |
1318 | p++; | |
1319 | return p; | |
1320 | break; | |
1321 | case '(': | |
fe69a505 | 1322 | *token = as_token_confed_seq_start; |
718e3744 | 1323 | p++; |
1324 | return p; | |
1325 | break; | |
1326 | case ')': | |
fe69a505 | 1327 | *token = as_token_confed_seq_end; |
1328 | p++; | |
1329 | return p; | |
1330 | break; | |
1331 | case '[': | |
1332 | *token = as_token_confed_set_start; | |
1333 | p++; | |
1334 | return p; | |
1335 | break; | |
1336 | case ']': | |
1337 | *token = as_token_confed_set_end; | |
718e3744 | 1338 | p++; |
1339 | return p; | |
1340 | break; | |
1341 | } | |
1342 | ||
1343 | /* Check actual AS value. */ | |
1344 | if (isdigit ((int) *p)) | |
1345 | { | |
1346 | u_short asval; | |
1347 | ||
1348 | *token = as_token_asval; | |
1349 | asval = (*p - '0'); | |
1350 | p++; | |
1351 | while (isdigit ((int) *p)) | |
1352 | { | |
1353 | asval *= 10; | |
1354 | asval += (*p - '0'); | |
1355 | p++; | |
1356 | } | |
1357 | *asno = asval; | |
1358 | return p; | |
1359 | } | |
1360 | ||
1361 | /* There is no match then return unknown token. */ | |
1362 | *token = as_token_unknown; | |
1363 | return p++; | |
1364 | } | |
1365 | ||
1366 | struct aspath * | |
fd79ac91 | 1367 | aspath_str2aspath (const char *str) |
718e3744 | 1368 | { |
1369 | enum as_token token; | |
1370 | u_short as_type; | |
1371 | u_short asno; | |
1372 | struct aspath *aspath; | |
1373 | int needtype; | |
1374 | ||
1375 | aspath = aspath_new (); | |
1376 | ||
1377 | /* We start default type as AS_SEQUENCE. */ | |
1378 | as_type = AS_SEQUENCE; | |
1379 | needtype = 1; | |
1380 | ||
1381 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1382 | { | |
1383 | switch (token) | |
1384 | { | |
1385 | case as_token_asval: | |
1386 | if (needtype) | |
1387 | { | |
1388 | aspath_segment_add (aspath, as_type); | |
1389 | needtype = 0; | |
1390 | } | |
1391 | aspath_as_add (aspath, asno); | |
1392 | break; | |
1393 | case as_token_set_start: | |
1394 | as_type = AS_SET; | |
1395 | aspath_segment_add (aspath, as_type); | |
1396 | needtype = 0; | |
1397 | break; | |
1398 | case as_token_set_end: | |
1399 | as_type = AS_SEQUENCE; | |
1400 | needtype = 1; | |
1401 | break; | |
fe69a505 | 1402 | case as_token_confed_seq_start: |
718e3744 | 1403 | as_type = AS_CONFED_SEQUENCE; |
1404 | aspath_segment_add (aspath, as_type); | |
1405 | needtype = 0; | |
1406 | break; | |
fe69a505 | 1407 | case as_token_confed_seq_end: |
1408 | as_type = AS_SEQUENCE; | |
1409 | needtype = 1; | |
1410 | break; | |
1411 | case as_token_confed_set_start: | |
1412 | as_type = AS_CONFED_SET; | |
1413 | aspath_segment_add (aspath, as_type); | |
1414 | needtype = 0; | |
1415 | break; | |
1416 | case as_token_confed_set_end: | |
718e3744 | 1417 | as_type = AS_SEQUENCE; |
1418 | needtype = 1; | |
1419 | break; | |
1420 | case as_token_unknown: | |
1421 | default: | |
fe69a505 | 1422 | aspath_free (aspath); |
718e3744 | 1423 | return NULL; |
1424 | break; | |
1425 | } | |
1426 | } | |
1427 | ||
1428 | aspath->str = aspath_make_str_count (aspath); | |
1429 | ||
1430 | return aspath; | |
1431 | } | |
1432 | \f | |
1433 | /* Make hash value by raw aspath data. */ | |
1434 | unsigned int | |
1435 | aspath_key_make (struct aspath *aspath) | |
1436 | { | |
1437 | unsigned int key = 0; | |
fe69a505 | 1438 | unsigned int i; |
1439 | struct assegment *seg = aspath->segments; | |
1440 | struct assegment *prev = NULL; | |
718e3744 | 1441 | |
fe69a505 | 1442 | while (seg) |
718e3744 | 1443 | { |
fe69a505 | 1444 | /* segment types should be part of the hash |
1445 | * otherwise seq(1) and set(1) will hash to same value | |
1446 | */ | |
1447 | if (!(prev && seg->type == AS_SEQUENCE && seg->type == prev->type)) | |
1448 | key += seg->type; | |
1449 | ||
1450 | for (i = 0; i < seg->length; i++) | |
1451 | key += seg->as[i]; | |
1452 | ||
1453 | prev = seg; | |
1454 | seg = seg->next; | |
718e3744 | 1455 | } |
1456 | ||
1457 | return key; | |
1458 | } | |
1459 | ||
1460 | /* If two aspath have same value then return 1 else return 0 */ | |
94f2b392 | 1461 | static int |
fe69a505 | 1462 | aspath_cmp (void *arg1, void *arg2) |
718e3744 | 1463 | { |
fe69a505 | 1464 | struct assegment *seg1 = ((struct aspath *)arg1)->segments; |
1465 | struct assegment *seg2 = ((struct aspath *)arg2)->segments; | |
1466 | ||
1467 | while (seg1 || seg2) | |
1468 | { | |
1469 | int i; | |
1470 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
1471 | return 0; | |
1472 | if (seg1->type != seg2->type) | |
1473 | return 0; | |
1474 | if (seg1->length != seg2->length) | |
1475 | return 0; | |
1476 | for (i = 0; i < seg1->length; i++) | |
1477 | if (seg1->as[i] != seg2->as[i]) | |
1478 | return 0; | |
1479 | seg1 = seg1->next; | |
1480 | seg2 = seg2->next; | |
1481 | } | |
1482 | return 1; | |
718e3744 | 1483 | } |
1484 | ||
1485 | /* AS path hash initialize. */ | |
1486 | void | |
94f2b392 | 1487 | aspath_init (void) |
718e3744 | 1488 | { |
1489 | ashash = hash_create_size (32767, aspath_key_make, aspath_cmp); | |
1490 | } | |
1491 | \f | |
1492 | /* return and as path value */ | |
1493 | const char * | |
1494 | aspath_print (struct aspath *as) | |
1495 | { | |
fe69a505 | 1496 | return (as ? as->str : NULL); |
718e3744 | 1497 | } |
1498 | ||
1499 | /* Printing functions */ | |
1500 | void | |
1501 | aspath_print_vty (struct vty *vty, struct aspath *as) | |
1502 | { | |
1503 | vty_out (vty, "%s", as->str); | |
1504 | } | |
1505 | ||
94f2b392 | 1506 | static void |
718e3744 | 1507 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) |
1508 | { | |
1509 | struct aspath *as; | |
1510 | ||
1511 | as = (struct aspath *) backet->data; | |
1512 | ||
efa9f830 | 1513 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); |
718e3744 | 1514 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); |
1515 | } | |
1516 | ||
1517 | /* Print all aspath and hash information. This function is used from | |
1518 | `show ip bgp paths' command. */ | |
1519 | void | |
1520 | aspath_print_all_vty (struct vty *vty) | |
1521 | { | |
1522 | hash_iterate (ashash, | |
1523 | (void (*) (struct hash_backet *, void *)) | |
1524 | aspath_show_all_iterator, | |
1525 | vty); | |
1526 | } |