]>
Commit | Line | Data |
---|---|---|
1 | /* AS path management routines. | |
2 | Copyright (C) 1996, 97, 98, 99 Kunihiro Ishiguro | |
3 | Copyright (C) 2005 Sun Microsystems, Inc. | |
4 | ||
5 | This file is part of GNU Zebra. | |
6 | ||
7 | GNU Zebra is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 2, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GNU Zebra is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
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" | |
30 | #include "stream.h" | |
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 | ||
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) | |
53 | ||
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 | |
74 | { | |
75 | u_char type; | |
76 | u_char length; | |
77 | }; | |
78 | ||
79 | /* Hash for aspath. This is the top level structure of AS path. */ | |
80 | struct hash *ashash; | |
81 | ||
82 | /* Stream for SNMP. See aspath_snmp_pathseg */ | |
83 | static struct stream *snmp_stream; | |
84 | \f | |
85 | static inline as_t * | |
86 | assegment_data_new (int num) | |
87 | { | |
88 | return (XCALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num))); | |
89 | } | |
90 | ||
91 | static inline void | |
92 | assegment_data_free (as_t *asdata) | |
93 | { | |
94 | XFREE (MTYPE_AS_SEG_DATA,asdata); | |
95 | } | |
96 | ||
97 | /* Get a new segment. Note that 0 is an allowed length, | |
98 | * and will result in a segment with no allocated data segment. | |
99 | * the caller should immediately assign data to the segment, as the segment | |
100 | * otherwise is not generally valid | |
101 | */ | |
102 | static struct assegment * | |
103 | assegment_new (u_char type, u_short length) | |
104 | { | |
105 | struct assegment *new; | |
106 | ||
107 | new = XCALLOC (MTYPE_AS_SEG, sizeof (struct assegment)); | |
108 | ||
109 | if (length) | |
110 | new->as = assegment_data_new (length); | |
111 | ||
112 | new->length = length; | |
113 | new->type = type; | |
114 | ||
115 | return new; | |
116 | } | |
117 | ||
118 | static void | |
119 | assegment_free (struct assegment *seg) | |
120 | { | |
121 | if (!seg) | |
122 | return; | |
123 | ||
124 | if (seg->as) | |
125 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
126 | memset (seg, 0xfe, sizeof(struct assegment)); | |
127 | XFREE (MTYPE_AS_SEG, seg); | |
128 | ||
129 | return; | |
130 | } | |
131 | ||
132 | /* free entire chain of segments */ | |
133 | static void | |
134 | assegment_free_all (struct assegment *seg) | |
135 | { | |
136 | struct assegment *prev; | |
137 | ||
138 | while (seg) | |
139 | { | |
140 | prev = seg; | |
141 | seg = seg->next; | |
142 | assegment_free (prev); | |
143 | } | |
144 | } | |
145 | ||
146 | /* Duplicate just the given assegment and its data */ | |
147 | static struct assegment * | |
148 | assegment_dup (struct assegment *seg) | |
149 | { | |
150 | struct assegment *new; | |
151 | ||
152 | new = assegment_new (seg->type, seg->length); | |
153 | memcpy (new->as, seg->as, ASSEGMENT_DATA_SIZE (new->length) ); | |
154 | ||
155 | return new; | |
156 | } | |
157 | ||
158 | /* Duplicate entire chain of assegments, return the head */ | |
159 | static struct assegment * | |
160 | assegment_dup_all (struct assegment *seg) | |
161 | { | |
162 | struct assegment *new = NULL; | |
163 | struct assegment *head = NULL; | |
164 | ||
165 | while (seg) | |
166 | { | |
167 | if (head) | |
168 | { | |
169 | new->next = assegment_dup (seg); | |
170 | new = new->next; | |
171 | } | |
172 | else | |
173 | head = new = assegment_dup (seg); | |
174 | ||
175 | seg = seg->next; | |
176 | } | |
177 | return head; | |
178 | } | |
179 | ||
180 | /* prepend the as number to given segment, given num of times */ | |
181 | static struct assegment * | |
182 | assegment_prepend_asns (struct assegment *seg, as_t asnum, int num) | |
183 | { | |
184 | as_t *newas; | |
185 | ||
186 | if (!num) | |
187 | return seg; | |
188 | ||
189 | if (num >= AS_SEGMENT_MAX) | |
190 | return seg; /* we don't do huge prepends */ | |
191 | ||
192 | newas = assegment_data_new (seg->length + num); | |
193 | ||
194 | if (newas) | |
195 | { | |
196 | int i; | |
197 | for (i = 0; i < num; i++) | |
198 | newas[i] = asnum; | |
199 | ||
200 | memcpy (newas + num, seg->as, ASSEGMENT_DATA_SIZE (seg->length)); | |
201 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
202 | seg->as = newas; | |
203 | seg->length += num; | |
204 | return seg; | |
205 | } | |
206 | ||
207 | assegment_free_all (seg); | |
208 | return NULL; | |
209 | } | |
210 | ||
211 | /* append given array of as numbers to the segment */ | |
212 | static struct assegment * | |
213 | assegment_append_asns (struct assegment *seg, as_t *asnos, int num) | |
214 | { | |
215 | as_t *newas; | |
216 | ||
217 | newas = XREALLOC (MTYPE_AS_SEG_DATA, seg->as, | |
218 | ASSEGMENT_DATA_SIZE (seg->length + num)); | |
219 | ||
220 | if (newas) | |
221 | { | |
222 | seg->as = newas; | |
223 | memcpy (seg->as + seg->length, asnos, ASSEGMENT_DATA_SIZE(num)); | |
224 | seg->length += num; | |
225 | return seg; | |
226 | } | |
227 | ||
228 | assegment_free_all (seg); | |
229 | return NULL; | |
230 | } | |
231 | ||
232 | static int | |
233 | int_cmp (const void *p1, const void *p2) | |
234 | { | |
235 | const as_t *as1 = p1; | |
236 | const as_t *as2 = p2; | |
237 | ||
238 | return (*as1 == *as2) | |
239 | ? 0 : ( (*as1 > *as2) ? 1 : -1); | |
240 | } | |
241 | ||
242 | /* normalise the segment. | |
243 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
244 | * Internally, we do not care about the wire segment length limit, and | |
245 | * we want each distinct AS_PATHs to have the exact same internal | |
246 | * representation - eg, so that our hashing actually works.. | |
247 | */ | |
248 | static struct assegment * | |
249 | assegment_normalise (struct assegment *head) | |
250 | { | |
251 | struct assegment *seg = head, *pin; | |
252 | struct assegment *tmp; | |
253 | ||
254 | if (!head) | |
255 | return head; | |
256 | ||
257 | while (seg) | |
258 | { | |
259 | pin = seg; | |
260 | ||
261 | /* Sort values SET segments, for determinism in paths to aid | |
262 | * creation of hash values / path comparisons | |
263 | * and because it helps other lesser implementations ;) | |
264 | */ | |
265 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) | |
266 | qsort (seg->as, seg->length, sizeof(as_t), int_cmp); | |
267 | ||
268 | /* read ahead from the current, pinned segment while the segments | |
269 | * are packable/mergeable. Append all following packable segments | |
270 | * to the segment we have pinned and remove these appended | |
271 | * segments. | |
272 | */ | |
273 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) | |
274 | { | |
275 | tmp = pin->next; | |
276 | seg = pin->next; | |
277 | ||
278 | /* append the next sequence to the pinned sequence */ | |
279 | pin = assegment_append_asns (pin, seg->as, seg->length); | |
280 | ||
281 | /* bypass the next sequence */ | |
282 | pin->next = seg->next; | |
283 | ||
284 | /* get rid of the now referenceless segment */ | |
285 | assegment_free (tmp); | |
286 | ||
287 | } | |
288 | ||
289 | seg = pin->next; | |
290 | } | |
291 | return head; | |
292 | } | |
293 | \f | |
294 | static struct aspath * | |
295 | aspath_new (void) | |
296 | { | |
297 | struct aspath *aspath; | |
298 | ||
299 | aspath = XMALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
300 | memset (aspath, 0, sizeof (struct aspath)); | |
301 | return aspath; | |
302 | } | |
303 | ||
304 | /* Free AS path structure. */ | |
305 | void | |
306 | aspath_free (struct aspath *aspath) | |
307 | { | |
308 | if (!aspath) | |
309 | return; | |
310 | if (aspath->segments) | |
311 | assegment_free_all (aspath->segments); | |
312 | if (aspath->str) | |
313 | XFREE (MTYPE_AS_STR, aspath->str); | |
314 | XFREE (MTYPE_AS_PATH, aspath); | |
315 | } | |
316 | ||
317 | /* Unintern aspath from AS path bucket. */ | |
318 | void | |
319 | aspath_unintern (struct aspath *aspath) | |
320 | { | |
321 | struct aspath *ret; | |
322 | ||
323 | if (aspath->refcnt) | |
324 | aspath->refcnt--; | |
325 | ||
326 | if (aspath->refcnt == 0) | |
327 | { | |
328 | /* This aspath must exist in aspath hash table. */ | |
329 | ret = hash_release (ashash, aspath); | |
330 | assert (ret != NULL); | |
331 | aspath_free (aspath); | |
332 | } | |
333 | } | |
334 | ||
335 | /* Return the start or end delimiters for a particular Segment type */ | |
336 | #define AS_SEG_START 0 | |
337 | #define AS_SEG_END 1 | |
338 | static char | |
339 | aspath_delimiter_char (u_char type, u_char which) | |
340 | { | |
341 | int i; | |
342 | struct | |
343 | { | |
344 | int type; | |
345 | char start; | |
346 | char end; | |
347 | } aspath_delim_char [] = | |
348 | { | |
349 | { AS_SET, '{', '}' }, | |
350 | { AS_CONFED_SET, '[', ']' }, | |
351 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
352 | { 0 } | |
353 | }; | |
354 | ||
355 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
356 | { | |
357 | if (aspath_delim_char[i].type == type) | |
358 | { | |
359 | if (which == AS_SEG_START) | |
360 | return aspath_delim_char[i].start; | |
361 | else if (which == AS_SEG_END) | |
362 | return aspath_delim_char[i].end; | |
363 | } | |
364 | } | |
365 | return ' '; | |
366 | } | |
367 | ||
368 | /* countup asns from this segment and index onward */ | |
369 | static int | |
370 | assegment_count_asns (struct assegment *seg, int from) | |
371 | { | |
372 | int count = 0; | |
373 | while (seg) | |
374 | { | |
375 | if (!from) | |
376 | count += seg->length; | |
377 | else | |
378 | { | |
379 | count += (seg->length - from); | |
380 | from = 0; | |
381 | } | |
382 | seg = seg->next; | |
383 | } | |
384 | return count; | |
385 | } | |
386 | ||
387 | unsigned int | |
388 | aspath_count_confeds (struct aspath *aspath) | |
389 | { | |
390 | int count = 0; | |
391 | struct assegment *seg = aspath->segments; | |
392 | ||
393 | while (seg) | |
394 | { | |
395 | if (seg->type == AS_CONFED_SEQUENCE) | |
396 | count += seg->length; | |
397 | else if (seg->type == AS_CONFED_SET) | |
398 | count++; | |
399 | ||
400 | seg = seg->next; | |
401 | } | |
402 | return count; | |
403 | } | |
404 | ||
405 | unsigned int | |
406 | aspath_count_hops (struct aspath *aspath) | |
407 | { | |
408 | int count = 0; | |
409 | struct assegment *seg = aspath->segments; | |
410 | ||
411 | while (seg) | |
412 | { | |
413 | if (seg->type == AS_SEQUENCE) | |
414 | count += seg->length; | |
415 | else if (seg->type == AS_SET) | |
416 | count++; | |
417 | ||
418 | seg = seg->next; | |
419 | } | |
420 | return count; | |
421 | } | |
422 | ||
423 | unsigned int | |
424 | aspath_size (struct aspath *aspath) | |
425 | { | |
426 | int size = 0; | |
427 | struct assegment *seg = aspath->segments; | |
428 | ||
429 | while (seg) | |
430 | { | |
431 | size += ASSEGMENT_SIZE(seg->length); | |
432 | seg = seg->next; | |
433 | } | |
434 | return size; | |
435 | } | |
436 | ||
437 | /* Convert aspath structure to string expression. */ | |
438 | static char * | |
439 | aspath_make_str_count (struct aspath *as) | |
440 | { | |
441 | struct assegment *seg; | |
442 | int str_size; | |
443 | int len = 0; | |
444 | char *str_buf; | |
445 | ||
446 | /* Empty aspath. */ | |
447 | if (!as->segments) | |
448 | { | |
449 | str_buf = XMALLOC (MTYPE_AS_STR, 1); | |
450 | str_buf[0] = '\0'; | |
451 | return str_buf; | |
452 | } | |
453 | ||
454 | seg = as->segments; | |
455 | ||
456 | /* ASN takes 5 chars at least, plus seperator, see below. | |
457 | * If there is one differing segment type, we need an additional | |
458 | * 2 chars for segment delimiters, and the final '\0'. | |
459 | * Hopefully this is large enough to avoid hitting the realloc | |
460 | * code below for most common sequences. | |
461 | */ | |
462 | #define ASN_STR_LEN (5 + 1) | |
463 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
464 | ASPATH_STR_DEFAULT_LEN); | |
465 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); | |
466 | ||
467 | while (seg) | |
468 | { | |
469 | int i; | |
470 | char seperator; | |
471 | ||
472 | /* Check AS type validity. Set seperator for segment */ | |
473 | switch (seg->type) | |
474 | { | |
475 | case AS_SET: | |
476 | case AS_CONFED_SET: | |
477 | seperator = ','; | |
478 | break; | |
479 | case AS_SEQUENCE: | |
480 | case AS_CONFED_SEQUENCE: | |
481 | seperator = ' '; | |
482 | break; | |
483 | default: | |
484 | XFREE (MTYPE_AS_STR, str_buf); | |
485 | return NULL; | |
486 | } | |
487 | ||
488 | /* We might need to increase str_buf, particularly if path has | |
489 | * differing segments types, our initial guesstimate above will | |
490 | * have been wrong. need 5 chars for ASN, a seperator each and | |
491 | * potentially two segment delimiters, plus a space between each | |
492 | * segment and trailing zero. | |
493 | */ | |
494 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
495 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
496 | { | |
497 | str_size = len + SEGMENT_STR_LEN(seg); | |
498 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
499 | } | |
500 | #undef ASN_STR_LEN | |
501 | #undef SEGMENT_STR_LEN | |
502 | ||
503 | if (seg->type != AS_SEQUENCE) | |
504 | len += snprintf (str_buf + len, str_size - len, | |
505 | "%c", | |
506 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
507 | ||
508 | /* write out the ASNs, with their seperators, bar the last one*/ | |
509 | for (i = 0; i < seg->length; i++) | |
510 | { | |
511 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); | |
512 | ||
513 | if (i < (seg->length - 1)) | |
514 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
515 | } | |
516 | ||
517 | if (seg->type != AS_SEQUENCE) | |
518 | len += snprintf (str_buf + len, str_size - len, "%c", | |
519 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
520 | if (seg->next) | |
521 | len += snprintf (str_buf + len, str_size - len, " "); | |
522 | ||
523 | seg = seg->next; | |
524 | } | |
525 | ||
526 | assert (len < str_size); | |
527 | ||
528 | str_buf[len] = '\0'; | |
529 | ||
530 | return str_buf; | |
531 | } | |
532 | ||
533 | static void | |
534 | aspath_str_update (struct aspath *as) | |
535 | { | |
536 | if (as->str) | |
537 | XFREE (MTYPE_AS_STR, as->str); | |
538 | as->str = aspath_make_str_count (as); | |
539 | } | |
540 | ||
541 | /* Intern allocated AS path. */ | |
542 | struct aspath * | |
543 | aspath_intern (struct aspath *aspath) | |
544 | { | |
545 | struct aspath *find; | |
546 | ||
547 | /* Assert this AS path structure is not interned. */ | |
548 | assert (aspath->refcnt == 0); | |
549 | ||
550 | /* Check AS path hash. */ | |
551 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
552 | ||
553 | if (find != aspath) | |
554 | aspath_free (aspath); | |
555 | ||
556 | find->refcnt++; | |
557 | ||
558 | if (! find->str) | |
559 | find->str = aspath_make_str_count (find); | |
560 | ||
561 | return find; | |
562 | } | |
563 | ||
564 | /* Duplicate aspath structure. Created same aspath structure but | |
565 | reference count and AS path string is cleared. */ | |
566 | struct aspath * | |
567 | aspath_dup (struct aspath *aspath) | |
568 | { | |
569 | struct aspath *new; | |
570 | ||
571 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
572 | ||
573 | if (aspath->segments) | |
574 | new->segments = assegment_dup_all (aspath->segments); | |
575 | else | |
576 | new->segments = NULL; | |
577 | ||
578 | new->str = aspath_make_str_count (aspath); | |
579 | ||
580 | return new; | |
581 | } | |
582 | ||
583 | static void * | |
584 | aspath_hash_alloc (void *arg) | |
585 | { | |
586 | struct aspath *aspath; | |
587 | ||
588 | /* New aspath strucutre is needed. */ | |
589 | aspath = aspath_dup (arg); | |
590 | ||
591 | /* Malformed AS path value. */ | |
592 | if (! aspath->str) | |
593 | { | |
594 | aspath_free (aspath); | |
595 | return NULL; | |
596 | } | |
597 | ||
598 | return aspath; | |
599 | } | |
600 | ||
601 | /* parse as-segment byte stream in struct assegment */ | |
602 | static struct assegment * | |
603 | assegments_parse (struct stream *s, size_t length) | |
604 | { | |
605 | struct assegment_header segh; | |
606 | struct assegment *seg, *prev = NULL, *head = NULL; | |
607 | size_t bytes = 0; | |
608 | ||
609 | /* empty aspath (ie iBGP or somesuch) */ | |
610 | if (length == 0) | |
611 | return NULL; | |
612 | ||
613 | /* basic checks */ | |
614 | if ( (STREAM_READABLE(s) < length) | |
615 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
616 | || (length % AS_VALUE_SIZE)) | |
617 | return NULL; | |
618 | ||
619 | while ( (STREAM_READABLE(s) > AS_HEADER_SIZE) | |
620 | && (bytes < length)) | |
621 | { | |
622 | int i; | |
623 | ||
624 | /* softly softly, get the header first on its own */ | |
625 | segh.type = stream_getc (s); | |
626 | segh.length = stream_getc (s); | |
627 | ||
628 | /* check it.. */ | |
629 | if ( ((bytes + ASSEGMENT_SIZE(segh.length)) > length) | |
630 | /* 1771bis 4.3b: seg length contains one or more */ | |
631 | || (segh.length == 0) | |
632 | /* Paranoia in case someone changes type of segment length */ | |
633 | || ((sizeof segh.length > 1) && segh.length > AS_SEGMENT_MAX)) | |
634 | { | |
635 | if (head) | |
636 | assegment_free_all (head); | |
637 | return NULL; | |
638 | } | |
639 | ||
640 | /* now its safe to trust lengths */ | |
641 | seg = assegment_new (segh.type, segh.length); | |
642 | ||
643 | if (head) | |
644 | prev->next = seg; | |
645 | else /* it's the first segment */ | |
646 | head = prev = seg; | |
647 | ||
648 | for (i = 0; i < segh.length; i++) | |
649 | seg->as[i] = stream_getw (s); | |
650 | ||
651 | bytes += ASSEGMENT_SIZE(segh.length); | |
652 | ||
653 | prev = seg; | |
654 | } | |
655 | ||
656 | return assegment_normalise (head); | |
657 | } | |
658 | ||
659 | /* AS path parse function. pnt is a pointer to byte stream and length | |
660 | is length of byte stream. If there is same AS path in the the AS | |
661 | path hash then return it else make new AS path structure. */ | |
662 | struct aspath * | |
663 | aspath_parse (struct stream *s, size_t length) | |
664 | { | |
665 | struct aspath as; | |
666 | struct aspath *find; | |
667 | ||
668 | /* If length is odd it's malformed AS path. */ | |
669 | if (length % AS_VALUE_SIZE) | |
670 | return NULL; | |
671 | ||
672 | as.segments = assegments_parse (s, length); | |
673 | ||
674 | /* If already same aspath exist then return it. */ | |
675 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
676 | ||
677 | /* aspath_hash_alloc dupes segments too. that probably could be | |
678 | * optimised out. | |
679 | */ | |
680 | assegment_free_all (as.segments); | |
681 | ||
682 | if (! find) | |
683 | return NULL; | |
684 | find->refcnt++; | |
685 | ||
686 | return find; | |
687 | } | |
688 | ||
689 | static inline void | |
690 | assegment_data_put (struct stream *s, as_t *as, int num) | |
691 | { | |
692 | int i; | |
693 | assert (num <= AS_SEGMENT_MAX); | |
694 | ||
695 | for (i = 0; i < num; i++) | |
696 | stream_putw (s, as[i]); | |
697 | } | |
698 | ||
699 | static inline size_t | |
700 | assegment_header_put (struct stream *s, u_char type, int length) | |
701 | { | |
702 | size_t lenp; | |
703 | assert (length <= AS_SEGMENT_MAX); | |
704 | stream_putc (s, type); | |
705 | lenp = stream_get_endp (s); | |
706 | stream_putc (s, length); | |
707 | return lenp; | |
708 | } | |
709 | ||
710 | /* write aspath data to stream */ | |
711 | void | |
712 | aspath_put (struct stream *s, struct aspath *as) | |
713 | { | |
714 | struct assegment *seg = as->segments; | |
715 | ||
716 | if (!seg || seg->length == 0) | |
717 | return; | |
718 | ||
719 | if (seg) | |
720 | { | |
721 | while (seg && (ASSEGMENT_LEN (seg) <= STREAM_WRITEABLE(s))) | |
722 | { | |
723 | int written = 0; | |
724 | size_t lenp; | |
725 | ||
726 | /* Overlength segments have to be split up */ | |
727 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
728 | { | |
729 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
730 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX); | |
731 | written += AS_SEGMENT_MAX; | |
732 | } | |
733 | ||
734 | /* write the final segment, probably is also the first */ | |
735 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
736 | assegment_data_put (s, (seg->as + written), seg->length - written); | |
737 | ||
738 | /* Sequence-type segments can be 'packed' together | |
739 | * Case of a segment which was overlength and split up | |
740 | * will be missed here, but that doesn't matter. | |
741 | */ | |
742 | if (seg->next && ASSEGMENTS_PACKABLE (seg, seg->next)) | |
743 | { | |
744 | /* NB: We should never normally get here given we | |
745 | * normalise aspath data when parse them. However, better | |
746 | * safe than sorry. We potentially could call | |
747 | * assegment_normalise here instead, but it's cheaper and | |
748 | * easier to do it on the fly here rather than go through | |
749 | * the segment list twice every time we write out | |
750 | * aspath's. | |
751 | */ | |
752 | ||
753 | /* Next segment's data can fit in this one */ | |
754 | assegment_data_put (s, seg->next->as, seg->next->length); | |
755 | ||
756 | /* update the length of the segment header */ | |
757 | stream_putc_at (s, lenp, | |
758 | seg->length - written + seg->next->length); | |
759 | seg = seg->next->next; /* skip to past next */ | |
760 | } | |
761 | else | |
762 | seg = seg->next; | |
763 | } | |
764 | } | |
765 | } | |
766 | ||
767 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
768 | * We have no way to manage the storage, so we use a static stream | |
769 | * wrapper around aspath_put. | |
770 | */ | |
771 | u_char * | |
772 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
773 | { | |
774 | #define SNMP_PATHSEG_MAX 1024 | |
775 | ||
776 | if (!snmp_stream) | |
777 | snmp_stream = stream_new (SNMP_PATHSEG_MAX); | |
778 | else | |
779 | stream_reset (snmp_stream); | |
780 | ||
781 | if (!as) | |
782 | { | |
783 | *varlen = 0; | |
784 | return NULL; | |
785 | } | |
786 | aspath_put (snmp_stream, as); | |
787 | ||
788 | *varlen = stream_get_endp (snmp_stream); | |
789 | return stream_pnt(snmp_stream); | |
790 | } | |
791 | ||
792 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
793 | ||
794 | static struct assegment * | |
795 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, | |
796 | as_t as) | |
797 | { | |
798 | int i; | |
799 | ||
800 | /* If this is first AS set member, create new as-set segment. */ | |
801 | if (asset == NULL) | |
802 | { | |
803 | asset = assegment_new (AS_SET, 1); | |
804 | if (! aspath->segments) | |
805 | aspath->segments = asset; | |
806 | else | |
807 | { | |
808 | struct assegment *seg = aspath->segments; | |
809 | while (seg->next) | |
810 | seg = seg->next; | |
811 | seg->next = asset; | |
812 | } | |
813 | asset->type = AS_SET; | |
814 | asset->length = 1; | |
815 | asset->as[0] = as; | |
816 | } | |
817 | else | |
818 | { | |
819 | /* Check this AS value already exists or not. */ | |
820 | for (i = 0; i < asset->length; i++) | |
821 | if (asset->as[i] == as) | |
822 | return asset; | |
823 | ||
824 | asset->length++; | |
825 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, | |
826 | asset->length * AS_VALUE_SIZE); | |
827 | asset->as[asset->length - 1] = as; | |
828 | } | |
829 | ||
830 | ||
831 | return asset; | |
832 | } | |
833 | ||
834 | /* Modify as1 using as2 for aggregation. */ | |
835 | struct aspath * | |
836 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
837 | { | |
838 | int i; | |
839 | int minlen; | |
840 | int match; | |
841 | int from; | |
842 | struct assegment *seg1 = as1->segments; | |
843 | struct assegment *seg2 = as2->segments; | |
844 | struct aspath *aspath; | |
845 | struct assegment *asset; | |
846 | ||
847 | match = 0; | |
848 | minlen = 0; | |
849 | aspath = NULL; | |
850 | asset = NULL; | |
851 | ||
852 | /* First of all check common leading sequence. */ | |
853 | while (seg1 && seg2) | |
854 | { | |
855 | /* Check segment type. */ | |
856 | if (seg1->type != seg2->type) | |
857 | break; | |
858 | ||
859 | /* Minimum segment length. */ | |
860 | minlen = min (seg1->length, seg2->length); | |
861 | ||
862 | for (match = 0; match < minlen; match++) | |
863 | if (seg1->as[match] != seg2->as[match]) | |
864 | break; | |
865 | ||
866 | if (match) | |
867 | { | |
868 | if (! aspath) | |
869 | aspath = aspath_new (); | |
870 | aspath->segments = assegment_new (seg1->type, 0); | |
871 | aspath->segments = assegment_append_asns (aspath->segments, | |
872 | seg1->as, match); | |
873 | } | |
874 | ||
875 | if (match != minlen || match != seg1->length | |
876 | || seg1->length != seg2->length) | |
877 | break; | |
878 | ||
879 | seg1 = seg1->next; | |
880 | seg2 = seg2->next; | |
881 | } | |
882 | ||
883 | if (! aspath) | |
884 | aspath = aspath_new(); | |
885 | ||
886 | /* Make as-set using rest of all information. */ | |
887 | from = match; | |
888 | while (seg1) | |
889 | { | |
890 | for (i = from; i < seg1->length; i++) | |
891 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
892 | ||
893 | from = 0; | |
894 | seg1 = seg1->next; | |
895 | } | |
896 | ||
897 | from = match; | |
898 | while (seg2) | |
899 | { | |
900 | for (i = from; i < seg2->length; i++) | |
901 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
902 | ||
903 | from = 0; | |
904 | seg2 = seg2->next; | |
905 | } | |
906 | ||
907 | assegment_normalise (aspath->segments); | |
908 | aspath_str_update (aspath); | |
909 | return aspath; | |
910 | } | |
911 | ||
912 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
913 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
914 | or not the peer's AS number. */ | |
915 | int | |
916 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
917 | { | |
918 | if ( (aspath == NULL) || (aspath->segments == NULL) ) | |
919 | return 0; | |
920 | ||
921 | if (aspath->segments | |
922 | && (aspath->segments->type == AS_SEQUENCE) | |
923 | && (aspath->segments->as[0] == asno )) | |
924 | return 1; | |
925 | ||
926 | return 0; | |
927 | } | |
928 | ||
929 | /* AS path loop check. If aspath contains asno then return 1. */ | |
930 | int | |
931 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
932 | { | |
933 | struct assegment *seg; | |
934 | int count = 0; | |
935 | ||
936 | if ( (aspath == NULL) || (aspath->segments) ) | |
937 | return 0; | |
938 | ||
939 | seg = aspath->segments; | |
940 | ||
941 | while (seg) | |
942 | { | |
943 | int i; | |
944 | ||
945 | for (i = 0; i < seg->length; i++) | |
946 | if (seg->as[i] == asno) | |
947 | count++; | |
948 | ||
949 | seg = seg->next; | |
950 | } | |
951 | return count; | |
952 | } | |
953 | ||
954 | /* When all of AS path is private AS return 1. */ | |
955 | int | |
956 | aspath_private_as_check (struct aspath *aspath) | |
957 | { | |
958 | struct assegment *seg; | |
959 | ||
960 | if ( !(aspath && aspath->segments) ) | |
961 | return 0; | |
962 | ||
963 | seg = aspath->segments; | |
964 | ||
965 | while (seg) | |
966 | { | |
967 | int i; | |
968 | ||
969 | for (i = 0; i < seg->length; i++) | |
970 | { | |
971 | if ( (seg->as[i] < BGP_PRIVATE_AS_MIN) | |
972 | || (seg->as[i] > BGP_PRIVATE_AS_MAX) ) | |
973 | return 0; | |
974 | } | |
975 | seg = seg->next; | |
976 | } | |
977 | return 1; | |
978 | } | |
979 | ||
980 | /* Merge as1 to as2. as2 should be uninterned aspath. */ | |
981 | static struct aspath * | |
982 | aspath_merge (struct aspath *as1, struct aspath *as2) | |
983 | { | |
984 | struct assegment *last, *new; | |
985 | ||
986 | if (! as1 || ! as2) | |
987 | return NULL; | |
988 | ||
989 | last = new = assegment_dup_all (as1->segments); | |
990 | ||
991 | /* find the last valid segment */ | |
992 | while (last && last->next) | |
993 | last = last->next; | |
994 | ||
995 | last->next = as2->segments; | |
996 | as2->segments = new; | |
997 | aspath_str_update (as2); | |
998 | return as2; | |
999 | } | |
1000 | ||
1001 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1002 | struct aspath * | |
1003 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1004 | { | |
1005 | struct assegment *seg1; | |
1006 | struct assegment *seg2; | |
1007 | ||
1008 | if (! as1 || ! as2) | |
1009 | return NULL; | |
1010 | ||
1011 | seg1 = as1->segments; | |
1012 | seg2 = as2->segments; | |
1013 | ||
1014 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
1015 | if (seg2 == NULL) | |
1016 | { | |
1017 | as2->segments = assegment_dup_all (as1->segments); | |
1018 | aspath_str_update (as2); | |
1019 | return as2; | |
1020 | } | |
1021 | ||
1022 | /* If as1 is empty AS, no prepending to do. */ | |
1023 | if (seg1 == NULL) | |
1024 | return as2; | |
1025 | ||
1026 | /* find the tail as1's segment chain. */ | |
1027 | while (seg1 && seg1->next) | |
1028 | seg1 = seg1->next; | |
1029 | ||
1030 | /* Compare last segment type of as1 and first segment type of as2. */ | |
1031 | if (seg1->type != seg2->type) | |
1032 | return aspath_merge (as1, as2); | |
1033 | ||
1034 | if (seg1->type == AS_SEQUENCE) | |
1035 | { | |
1036 | /* We have two chains of segments, as1->segments and seg2, | |
1037 | * and we have to attach them together, merging the attaching | |
1038 | * segments together into one. | |
1039 | * | |
1040 | * 1. dupe as1->segments onto head of as2 | |
1041 | * 2. merge seg2's asns onto last segment of this new chain | |
1042 | * 3. attach chain after seg2 | |
1043 | */ | |
1044 | ||
1045 | /* dupe as1 onto as2's head */ | |
1046 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1047 | ||
1048 | /* refind the tail of as2, reusing seg1 */ | |
1049 | while (seg1 && seg1->next) | |
1050 | seg1 = seg1->next; | |
1051 | ||
1052 | /* merge the old head, seg2, into tail, seg1 */ | |
1053 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1054 | ||
1055 | /* bypass the merged seg2, and attach any chain after it to | |
1056 | * chain descending from as2's head | |
1057 | */ | |
1058 | seg1->next = seg2->next; | |
1059 | ||
1060 | /* seg2 is now referenceless and useless*/ | |
1061 | assegment_free (seg2); | |
1062 | ||
1063 | /* we've now prepended as1's segment chain to as2, merging | |
1064 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1065 | */ | |
1066 | aspath_str_update (as2); | |
1067 | return as2; | |
1068 | } | |
1069 | else | |
1070 | { | |
1071 | /* AS_SET merge code is needed at here. */ | |
1072 | return aspath_merge (as1, as2); | |
1073 | } | |
1074 | /* XXX: Ermmm, what if as1 has multiple segments?? */ | |
1075 | ||
1076 | /* Not reached */ | |
1077 | } | |
1078 | ||
1079 | /* Add specified AS to the leftmost of aspath. */ | |
1080 | static struct aspath * | |
1081 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1082 | { | |
1083 | struct assegment *assegment = aspath->segments; | |
1084 | ||
1085 | /* In case of empty aspath. */ | |
1086 | if (assegment == NULL || assegment->length == 0) | |
1087 | { | |
1088 | aspath->segments = assegment_new (type, 1); | |
1089 | aspath->segments->as[0] = asno; | |
1090 | ||
1091 | if (assegment) | |
1092 | assegment_free (assegment); | |
1093 | ||
1094 | return aspath; | |
1095 | } | |
1096 | ||
1097 | if (assegment->type == type) | |
1098 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); | |
1099 | else | |
1100 | { | |
1101 | /* create new segment | |
1102 | * push it onto head of aspath's segment chain | |
1103 | */ | |
1104 | struct assegment *newsegment; | |
1105 | ||
1106 | newsegment = assegment_new (type, 1); | |
1107 | newsegment->as[0] = asno; | |
1108 | ||
1109 | newsegment->next = assegment; | |
1110 | aspath->segments = newsegment; | |
1111 | } | |
1112 | ||
1113 | return aspath; | |
1114 | } | |
1115 | ||
1116 | /* Add specified AS to the leftmost of aspath. */ | |
1117 | struct aspath * | |
1118 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1119 | { | |
1120 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1121 | } | |
1122 | ||
1123 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1124 | as2's leftmost AS is same return 1. */ | |
1125 | int | |
1126 | aspath_cmp_left (struct aspath *aspath1, struct aspath *aspath2) | |
1127 | { | |
1128 | struct assegment *seg1 = NULL; | |
1129 | struct assegment *seg2 = NULL; | |
1130 | ||
1131 | if (!(aspath1 && aspath2)) | |
1132 | return 0; | |
1133 | ||
1134 | seg1 = aspath1->segments; | |
1135 | seg2 = aspath2->segments; | |
1136 | ||
1137 | /* find first non-confed segments for each */ | |
1138 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1139 | || (seg1->type == AS_CONFED_SET))) | |
1140 | seg1 = seg1->next; | |
1141 | ||
1142 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) | |
1143 | || (seg2->type == AS_CONFED_SET))) | |
1144 | seg2 = seg2->next; | |
1145 | ||
1146 | /* Check as1's */ | |
1147 | if (!(seg1 && seg2 | |
1148 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1149 | return 0; | |
1150 | ||
1151 | if (seg1->as[0] == seg2->as[0]) | |
1152 | return 1; | |
1153 | ||
1154 | return 0; | |
1155 | } | |
1156 | ||
1157 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1158 | as2's leftmost AS is same return 1. (confederation as-path | |
1159 | only). */ | |
1160 | int | |
1161 | aspath_cmp_left_confed (struct aspath *aspath1, struct aspath *aspath2) | |
1162 | { | |
1163 | if (! (aspath1 && aspath2) ) | |
1164 | return 0; | |
1165 | ||
1166 | if ( !(aspath1->segments && aspath2->segments) ) | |
1167 | return 0; | |
1168 | ||
1169 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) | |
1170 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
1171 | return 0; | |
1172 | ||
1173 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
1174 | return 1; | |
1175 | ||
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | /* Delete all leading AS_CONFED_SEQUENCE/SET segments from aspath. | |
1180 | * See RFC3065, 6.1 c1 */ | |
1181 | struct aspath * | |
1182 | aspath_delete_confed_seq (struct aspath *aspath) | |
1183 | { | |
1184 | struct assegment *seg; | |
1185 | ||
1186 | if (!(aspath && aspath->segments)) | |
1187 | return aspath; | |
1188 | ||
1189 | seg = aspath->segments; | |
1190 | ||
1191 | /* "if the first path segment of the AS_PATH is | |
1192 | * of type AS_CONFED_SEQUENCE," | |
1193 | */ | |
1194 | if (aspath->segments->type != AS_CONFED_SEQUENCE) | |
1195 | return aspath; | |
1196 | ||
1197 | /* "... that segment and any immediately following segments | |
1198 | * of the type AS_CONFED_SET or AS_CONFED_SEQUENCE are removed | |
1199 | * from the AS_PATH attribute," | |
1200 | */ | |
1201 | while (seg && | |
1202 | (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET)) | |
1203 | { | |
1204 | aspath->segments = seg->next; | |
1205 | assegment_free (seg); | |
1206 | seg = aspath->segments; | |
1207 | } | |
1208 | aspath_str_update (aspath); | |
1209 | return aspath; | |
1210 | } | |
1211 | ||
1212 | /* Add new AS number to the leftmost part of the aspath as | |
1213 | AS_CONFED_SEQUENCE. */ | |
1214 | struct aspath* | |
1215 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1216 | { | |
1217 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1218 | } | |
1219 | ||
1220 | /* Add new as value to as path structure. */ | |
1221 | static void | |
1222 | aspath_as_add (struct aspath *as, as_t asno) | |
1223 | { | |
1224 | struct assegment *seg = as->segments; | |
1225 | ||
1226 | /* Last segment search procedure. */ | |
1227 | while (seg && seg->next) | |
1228 | seg = seg->next; | |
1229 | ||
1230 | if (!seg) | |
1231 | return; | |
1232 | ||
1233 | assegment_append_asns (seg, &asno, 1); | |
1234 | } | |
1235 | ||
1236 | /* Add new as segment to the as path. */ | |
1237 | static void | |
1238 | aspath_segment_add (struct aspath *as, int type) | |
1239 | { | |
1240 | struct assegment *seg = as->segments; | |
1241 | struct assegment *new = assegment_new (type, 0); | |
1242 | ||
1243 | while (seg && seg->next) | |
1244 | seg = seg->next; | |
1245 | ||
1246 | if (seg == NULL) | |
1247 | as->segments = new; | |
1248 | else | |
1249 | seg->next = new; | |
1250 | } | |
1251 | ||
1252 | struct aspath * | |
1253 | aspath_empty (void) | |
1254 | { | |
1255 | return aspath_parse (NULL, 0); | |
1256 | } | |
1257 | ||
1258 | struct aspath * | |
1259 | aspath_empty_get (void) | |
1260 | { | |
1261 | struct aspath *aspath; | |
1262 | ||
1263 | aspath = aspath_new (); | |
1264 | aspath->str = aspath_make_str_count (aspath); | |
1265 | return aspath; | |
1266 | } | |
1267 | ||
1268 | unsigned long | |
1269 | aspath_count (void) | |
1270 | { | |
1271 | return ashash->count; | |
1272 | } | |
1273 | \f | |
1274 | /* | |
1275 | Theoretically, one as path can have: | |
1276 | ||
1277 | One BGP packet size should be less than 4096. | |
1278 | One BGP attribute size should be less than 4096 - BGP header size. | |
1279 | One BGP aspath size should be less than 4096 - BGP header size - | |
1280 | BGP mandantry attribute size. | |
1281 | */ | |
1282 | ||
1283 | /* AS path string lexical token enum. */ | |
1284 | enum as_token | |
1285 | { | |
1286 | as_token_asval, | |
1287 | as_token_set_start, | |
1288 | as_token_set_end, | |
1289 | as_token_confed_seq_start, | |
1290 | as_token_confed_seq_end, | |
1291 | as_token_confed_set_start, | |
1292 | as_token_confed_set_end, | |
1293 | as_token_unknown | |
1294 | }; | |
1295 | ||
1296 | /* Return next token and point for string parse. */ | |
1297 | static const char * | |
1298 | aspath_gettoken (const char *buf, enum as_token *token, u_short *asno) | |
1299 | { | |
1300 | const char *p = buf; | |
1301 | ||
1302 | /* Skip seperators (space for sequences, ',' for sets). */ | |
1303 | while (isspace ((int) *p) || *p == ',') | |
1304 | p++; | |
1305 | ||
1306 | /* Check the end of the string and type specify characters | |
1307 | (e.g. {}()). */ | |
1308 | switch (*p) | |
1309 | { | |
1310 | case '\0': | |
1311 | return NULL; | |
1312 | case '{': | |
1313 | *token = as_token_set_start; | |
1314 | p++; | |
1315 | return p; | |
1316 | case '}': | |
1317 | *token = as_token_set_end; | |
1318 | p++; | |
1319 | return p; | |
1320 | case '(': | |
1321 | *token = as_token_confed_seq_start; | |
1322 | p++; | |
1323 | return p; | |
1324 | case ')': | |
1325 | *token = as_token_confed_seq_end; | |
1326 | p++; | |
1327 | return p; | |
1328 | case '[': | |
1329 | *token = as_token_confed_set_start; | |
1330 | p++; | |
1331 | return p; | |
1332 | case ']': | |
1333 | *token = as_token_confed_set_end; | |
1334 | p++; | |
1335 | return p; | |
1336 | } | |
1337 | ||
1338 | /* Check actual AS value. */ | |
1339 | if (isdigit ((int) *p)) | |
1340 | { | |
1341 | u_short asval; | |
1342 | ||
1343 | *token = as_token_asval; | |
1344 | asval = (*p - '0'); | |
1345 | p++; | |
1346 | while (isdigit ((int) *p)) | |
1347 | { | |
1348 | asval *= 10; | |
1349 | asval += (*p - '0'); | |
1350 | p++; | |
1351 | } | |
1352 | *asno = asval; | |
1353 | return p; | |
1354 | } | |
1355 | ||
1356 | /* There is no match then return unknown token. */ | |
1357 | *token = as_token_unknown; | |
1358 | return p++; | |
1359 | } | |
1360 | ||
1361 | struct aspath * | |
1362 | aspath_str2aspath (const char *str) | |
1363 | { | |
1364 | enum as_token token = as_token_unknown; | |
1365 | u_short as_type; | |
1366 | u_short asno = NULL; | |
1367 | struct aspath *aspath; | |
1368 | int needtype; | |
1369 | ||
1370 | aspath = aspath_new (); | |
1371 | ||
1372 | /* We start default type as AS_SEQUENCE. */ | |
1373 | as_type = AS_SEQUENCE; | |
1374 | needtype = 1; | |
1375 | ||
1376 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1377 | { | |
1378 | switch (token) | |
1379 | { | |
1380 | case as_token_asval: | |
1381 | if (needtype) | |
1382 | { | |
1383 | aspath_segment_add (aspath, as_type); | |
1384 | needtype = 0; | |
1385 | } | |
1386 | aspath_as_add (aspath, asno); | |
1387 | break; | |
1388 | case as_token_set_start: | |
1389 | as_type = AS_SET; | |
1390 | aspath_segment_add (aspath, as_type); | |
1391 | needtype = 0; | |
1392 | break; | |
1393 | case as_token_set_end: | |
1394 | as_type = AS_SEQUENCE; | |
1395 | needtype = 1; | |
1396 | break; | |
1397 | case as_token_confed_seq_start: | |
1398 | as_type = AS_CONFED_SEQUENCE; | |
1399 | aspath_segment_add (aspath, as_type); | |
1400 | needtype = 0; | |
1401 | break; | |
1402 | case as_token_confed_seq_end: | |
1403 | as_type = AS_SEQUENCE; | |
1404 | needtype = 1; | |
1405 | break; | |
1406 | case as_token_confed_set_start: | |
1407 | as_type = AS_CONFED_SET; | |
1408 | aspath_segment_add (aspath, as_type); | |
1409 | needtype = 0; | |
1410 | break; | |
1411 | case as_token_confed_set_end: | |
1412 | as_type = AS_SEQUENCE; | |
1413 | needtype = 1; | |
1414 | break; | |
1415 | case as_token_unknown: | |
1416 | default: | |
1417 | aspath_free (aspath); | |
1418 | return NULL; | |
1419 | } | |
1420 | } | |
1421 | ||
1422 | aspath->str = aspath_make_str_count (aspath); | |
1423 | ||
1424 | return aspath; | |
1425 | } | |
1426 | \f | |
1427 | /* Make hash value by raw aspath data. */ | |
1428 | unsigned int | |
1429 | aspath_key_make (struct aspath *aspath) | |
1430 | { | |
1431 | unsigned int key = 0; | |
1432 | unsigned int i; | |
1433 | struct assegment *seg = aspath->segments; | |
1434 | struct assegment *prev = NULL; | |
1435 | ||
1436 | while (seg) | |
1437 | { | |
1438 | /* segment types should be part of the hash | |
1439 | * otherwise seq(1) and set(1) will hash to same value | |
1440 | */ | |
1441 | if (!(prev && seg->type == AS_SEQUENCE && seg->type == prev->type)) | |
1442 | key += seg->type; | |
1443 | ||
1444 | for (i = 0; i < seg->length; i++) | |
1445 | key += seg->as[i]; | |
1446 | ||
1447 | prev = seg; | |
1448 | seg = seg->next; | |
1449 | } | |
1450 | ||
1451 | return key; | |
1452 | } | |
1453 | ||
1454 | /* If two aspath have same value then return 1 else return 0 */ | |
1455 | static int | |
1456 | aspath_cmp (void *arg1, void *arg2) | |
1457 | { | |
1458 | struct assegment *seg1 = ((struct aspath *)arg1)->segments; | |
1459 | struct assegment *seg2 = ((struct aspath *)arg2)->segments; | |
1460 | ||
1461 | while (seg1 || seg2) | |
1462 | { | |
1463 | int i; | |
1464 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
1465 | return 0; | |
1466 | if (seg1->type != seg2->type) | |
1467 | return 0; | |
1468 | if (seg1->length != seg2->length) | |
1469 | return 0; | |
1470 | for (i = 0; i < seg1->length; i++) | |
1471 | if (seg1->as[i] != seg2->as[i]) | |
1472 | return 0; | |
1473 | seg1 = seg1->next; | |
1474 | seg2 = seg2->next; | |
1475 | } | |
1476 | return 1; | |
1477 | } | |
1478 | ||
1479 | /* AS path hash initialize. */ | |
1480 | void | |
1481 | aspath_init (void) | |
1482 | { | |
1483 | ashash = hash_create_size (32767, aspath_key_make, aspath_cmp); | |
1484 | } | |
1485 | ||
1486 | void | |
1487 | aspath_finish (void) | |
1488 | { | |
1489 | hash_free (ashash); | |
1490 | ||
1491 | if (snmp_stream) | |
1492 | stream_free (snmp_stream); | |
1493 | } | |
1494 | \f | |
1495 | /* return and as path value */ | |
1496 | const char * | |
1497 | aspath_print (struct aspath *as) | |
1498 | { | |
1499 | return (as ? as->str : NULL); | |
1500 | } | |
1501 | ||
1502 | /* Printing functions */ | |
1503 | void | |
1504 | aspath_print_vty (struct vty *vty, const char *format, struct aspath *as) | |
1505 | { | |
1506 | assert (format); | |
1507 | vty_out (vty, format, as->str); | |
1508 | } | |
1509 | ||
1510 | static void | |
1511 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) | |
1512 | { | |
1513 | struct aspath *as; | |
1514 | ||
1515 | as = (struct aspath *) backet->data; | |
1516 | ||
1517 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); | |
1518 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); | |
1519 | } | |
1520 | ||
1521 | /* Print all aspath and hash information. This function is used from | |
1522 | `show ip bgp paths' command. */ | |
1523 | void | |
1524 | aspath_print_all_vty (struct vty *vty) | |
1525 | { | |
1526 | hash_iterate (ashash, | |
1527 | (void (*) (struct hash_backet *, void *)) | |
1528 | aspath_show_all_iterator, | |
1529 | vty); | |
1530 | } |