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718e3744 | 1 | /* AS path management routines. |
2 | Copyright (C) 1996, 97, 98, 99 Kunihiro Ishiguro | |
fe69a505 | 3 | Copyright (C) 2005 Sun Microsystems, Inc. |
718e3744 | 4 | |
5 | This file is part of GNU Zebra. | |
6 | ||
7 | GNU Zebra is free software; you can redistribute it and/or modify it | |
8 | under the terms of the GNU General Public License as published by the | |
9 | Free Software Foundation; either version 2, or (at your option) any | |
10 | later version. | |
11 | ||
12 | GNU Zebra is distributed in the hope that it will be useful, but | |
13 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GNU Zebra; see the file COPYING. If not, write to the Free | |
19 | Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA | |
20 | 02111-1307, USA. */ | |
21 | ||
22 | #include <zebra.h> | |
23 | ||
24 | #include "hash.h" | |
25 | #include "memory.h" | |
26 | #include "vector.h" | |
27 | #include "vty.h" | |
28 | #include "str.h" | |
29 | #include "log.h" | |
fe69a505 | 30 | #include "stream.h" |
0b2aa3a0 | 31 | #include "jhash.h" |
718e3744 | 32 | |
33 | #include "bgpd/bgpd.h" | |
34 | #include "bgpd/bgp_aspath.h" | |
0b2aa3a0 PJ |
35 | #include "bgpd/bgp_debug.h" |
36 | #include "bgpd/bgp_attr.h" | |
718e3744 | 37 | \f |
38 | /* Attr. Flags and Attr. Type Code. */ | |
39 | #define AS_HEADER_SIZE 2 | |
40 | ||
0b2aa3a0 | 41 | /* Now FOUR octets are used for AS value. */ |
718e3744 | 42 | #define AS_VALUE_SIZE sizeof (as_t) |
0b2aa3a0 PJ |
43 | /* This is the old one */ |
44 | #define AS16_VALUE_SIZE sizeof (as16_t) | |
718e3744 | 45 | |
fe69a505 | 46 | /* Maximum protocol segment length value */ |
47 | #define AS_SEGMENT_MAX 255 | |
48 | ||
49 | /* The following length and size macros relate specifically to Quagga's | |
50 | * internal representation of AS-Segments, not per se to the on-wire | |
51 | * sizes and lengths. At present (200508) they sort of match, however | |
52 | * the ONLY functions which should now about the on-wire syntax are | |
53 | * aspath_put, assegment_put and assegment_parse. | |
0b2aa3a0 PJ |
54 | * |
55 | * aspath_put returns bytes written, the only definitive record of | |
56 | * size of wire-format attribute.. | |
fe69a505 | 57 | */ |
58 | ||
59 | /* Calculated size in bytes of ASN segment data to hold N ASN's */ | |
0b2aa3a0 PJ |
60 | #define ASSEGMENT_DATA_SIZE(N,S) \ |
61 | ((N) * ( (S) ? AS_VALUE_SIZE : AS16_VALUE_SIZE) ) | |
718e3744 | 62 | |
fe69a505 | 63 | /* Calculated size of segment struct to hold N ASN's */ |
0b2aa3a0 | 64 | #define ASSEGMENT_SIZE(N,S) (AS_HEADER_SIZE + ASSEGMENT_DATA_SIZE (N,S)) |
fe69a505 | 65 | |
66 | /* AS segment octet length. */ | |
0b2aa3a0 | 67 | #define ASSEGMENT_LEN(X,S) ASSEGMENT_SIZE((X)->length,S) |
fe69a505 | 68 | |
69 | /* AS_SEQUENCE segments can be packed together */ | |
70 | /* Can the types of X and Y be considered for packing? */ | |
71 | #define ASSEGMENT_TYPES_PACKABLE(X,Y) \ | |
72 | ( ((X)->type == (Y)->type) \ | |
73 | && ((X)->type == AS_SEQUENCE)) | |
74 | /* Types and length of X,Y suitable for packing? */ | |
75 | #define ASSEGMENTS_PACKABLE(X,Y) \ | |
76 | ( ASSEGMENT_TYPES_PACKABLE( (X), (Y)) \ | |
77 | && ( ((X)->length + (Y)->length) <= AS_SEGMENT_MAX ) ) | |
78 | ||
79 | /* As segment header - the on-wire representation | |
80 | * NOT the internal representation! | |
81 | */ | |
82 | struct assegment_header | |
718e3744 | 83 | { |
84 | u_char type; | |
85 | u_char length; | |
718e3744 | 86 | }; |
87 | ||
88 | /* Hash for aspath. This is the top level structure of AS path. */ | |
da88ea82 | 89 | static struct hash *ashash; |
8fdc32ab | 90 | |
91 | /* Stream for SNMP. See aspath_snmp_pathseg */ | |
92 | static struct stream *snmp_stream; | |
718e3744 | 93 | \f |
f669f7d2 | 94 | /* Callers are required to initialize the memory */ |
f63f06da | 95 | static as_t * |
fe69a505 | 96 | assegment_data_new (int num) |
97 | { | |
f669f7d2 | 98 | return (XMALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num, 1))); |
fe69a505 | 99 | } |
100 | ||
101 | /* Get a new segment. Note that 0 is an allowed length, | |
102 | * and will result in a segment with no allocated data segment. | |
103 | * the caller should immediately assign data to the segment, as the segment | |
104 | * otherwise is not generally valid | |
105 | */ | |
106 | static struct assegment * | |
107 | assegment_new (u_char type, u_short length) | |
108 | { | |
109 | struct assegment *new; | |
110 | ||
111 | new = XCALLOC (MTYPE_AS_SEG, sizeof (struct assegment)); | |
112 | ||
113 | if (length) | |
114 | new->as = assegment_data_new (length); | |
115 | ||
116 | new->length = length; | |
117 | new->type = type; | |
118 | ||
119 | return new; | |
120 | } | |
121 | ||
122 | static void | |
123 | assegment_free (struct assegment *seg) | |
124 | { | |
125 | if (!seg) | |
126 | return; | |
127 | ||
128 | if (seg->as) | |
129 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
130 | memset (seg, 0xfe, sizeof(struct assegment)); | |
131 | XFREE (MTYPE_AS_SEG, seg); | |
132 | ||
133 | return; | |
134 | } | |
135 | ||
136 | /* free entire chain of segments */ | |
137 | static void | |
138 | assegment_free_all (struct assegment *seg) | |
139 | { | |
140 | struct assegment *prev; | |
141 | ||
142 | while (seg) | |
143 | { | |
144 | prev = seg; | |
145 | seg = seg->next; | |
146 | assegment_free (prev); | |
147 | } | |
148 | } | |
149 | ||
150 | /* Duplicate just the given assegment and its data */ | |
151 | static struct assegment * | |
152 | assegment_dup (struct assegment *seg) | |
153 | { | |
154 | struct assegment *new; | |
155 | ||
156 | new = assegment_new (seg->type, seg->length); | |
0b2aa3a0 | 157 | memcpy (new->as, seg->as, ASSEGMENT_DATA_SIZE (new->length, 1) ); |
fe69a505 | 158 | |
159 | return new; | |
160 | } | |
161 | ||
162 | /* Duplicate entire chain of assegments, return the head */ | |
163 | static struct assegment * | |
164 | assegment_dup_all (struct assegment *seg) | |
165 | { | |
166 | struct assegment *new = NULL; | |
167 | struct assegment *head = NULL; | |
168 | ||
169 | while (seg) | |
170 | { | |
171 | if (head) | |
172 | { | |
173 | new->next = assegment_dup (seg); | |
174 | new = new->next; | |
175 | } | |
176 | else | |
177 | head = new = assegment_dup (seg); | |
178 | ||
179 | seg = seg->next; | |
180 | } | |
181 | return head; | |
182 | } | |
183 | ||
184 | /* prepend the as number to given segment, given num of times */ | |
185 | static struct assegment * | |
186 | assegment_prepend_asns (struct assegment *seg, as_t asnum, int num) | |
187 | { | |
188 | as_t *newas; | |
f669f7d2 | 189 | int i; |
fe69a505 | 190 | |
191 | if (!num) | |
192 | return seg; | |
193 | ||
194 | if (num >= AS_SEGMENT_MAX) | |
195 | return seg; /* we don't do huge prepends */ | |
196 | ||
197 | newas = assegment_data_new (seg->length + num); | |
fe69a505 | 198 | |
f669f7d2 JBD |
199 | for (i = 0; i < num; i++) |
200 | newas[i] = asnum; | |
201 | ||
202 | memcpy (newas + num, seg->as, ASSEGMENT_DATA_SIZE (seg->length, 1)); | |
203 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
204 | seg->as = newas; | |
205 | seg->length += num; | |
206 | ||
207 | return seg; | |
fe69a505 | 208 | } |
209 | ||
210 | /* append given array of as numbers to the segment */ | |
211 | static struct assegment * | |
212 | assegment_append_asns (struct assegment *seg, as_t *asnos, int num) | |
213 | { | |
02335429 | 214 | as_t *newas; |
215 | ||
216 | newas = XREALLOC (MTYPE_AS_SEG_DATA, seg->as, | |
0b2aa3a0 | 217 | ASSEGMENT_DATA_SIZE (seg->length + num, 1)); |
fe69a505 | 218 | |
02335429 | 219 | if (newas) |
fe69a505 | 220 | { |
02335429 | 221 | seg->as = newas; |
0b2aa3a0 | 222 | memcpy (seg->as + seg->length, asnos, ASSEGMENT_DATA_SIZE(num, 1)); |
fe69a505 | 223 | seg->length += num; |
224 | return seg; | |
225 | } | |
226 | ||
227 | assegment_free_all (seg); | |
228 | return NULL; | |
229 | } | |
230 | ||
231 | static int | |
232 | int_cmp (const void *p1, const void *p2) | |
233 | { | |
234 | const as_t *as1 = p1; | |
235 | const as_t *as2 = p2; | |
236 | ||
237 | return (*as1 == *as2) | |
238 | ? 0 : ( (*as1 > *as2) ? 1 : -1); | |
239 | } | |
240 | ||
241 | /* normalise the segment. | |
242 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
243 | * Internally, we do not care about the wire segment length limit, and | |
244 | * we want each distinct AS_PATHs to have the exact same internal | |
245 | * representation - eg, so that our hashing actually works.. | |
246 | */ | |
247 | static struct assegment * | |
248 | assegment_normalise (struct assegment *head) | |
249 | { | |
250 | struct assegment *seg = head, *pin; | |
251 | struct assegment *tmp; | |
252 | ||
253 | if (!head) | |
254 | return head; | |
255 | ||
256 | while (seg) | |
257 | { | |
258 | pin = seg; | |
259 | ||
260 | /* Sort values SET segments, for determinism in paths to aid | |
261 | * creation of hash values / path comparisons | |
262 | * and because it helps other lesser implementations ;) | |
263 | */ | |
264 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) | |
0b2aa3a0 PJ |
265 | { |
266 | int tail = 0; | |
267 | int i; | |
268 | ||
269 | qsort (seg->as, seg->length, sizeof(as_t), int_cmp); | |
270 | ||
271 | /* weed out dupes */ | |
272 | for (i=1; i < seg->length; i++) | |
273 | { | |
274 | if (seg->as[tail] == seg->as[i]) | |
275 | continue; | |
276 | ||
277 | tail++; | |
278 | if (tail < i) | |
279 | seg->as[tail] = seg->as[i]; | |
280 | } | |
281 | /* seg->length can be 0.. */ | |
282 | if (seg->length) | |
283 | seg->length = tail + 1; | |
284 | } | |
fe69a505 | 285 | |
286 | /* read ahead from the current, pinned segment while the segments | |
287 | * are packable/mergeable. Append all following packable segments | |
288 | * to the segment we have pinned and remove these appended | |
289 | * segments. | |
290 | */ | |
291 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) | |
292 | { | |
293 | tmp = pin->next; | |
294 | seg = pin->next; | |
295 | ||
296 | /* append the next sequence to the pinned sequence */ | |
297 | pin = assegment_append_asns (pin, seg->as, seg->length); | |
298 | ||
299 | /* bypass the next sequence */ | |
300 | pin->next = seg->next; | |
301 | ||
302 | /* get rid of the now referenceless segment */ | |
303 | assegment_free (tmp); | |
304 | ||
305 | } | |
306 | ||
307 | seg = pin->next; | |
308 | } | |
309 | return head; | |
310 | } | |
311 | \f | |
718e3744 | 312 | static struct aspath * |
fe69a505 | 313 | aspath_new (void) |
718e3744 | 314 | { |
393deb9b | 315 | return XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 316 | } |
317 | ||
318 | /* Free AS path structure. */ | |
319 | void | |
320 | aspath_free (struct aspath *aspath) | |
321 | { | |
322 | if (!aspath) | |
323 | return; | |
fe69a505 | 324 | if (aspath->segments) |
325 | assegment_free_all (aspath->segments); | |
718e3744 | 326 | if (aspath->str) |
327 | XFREE (MTYPE_AS_STR, aspath->str); | |
328 | XFREE (MTYPE_AS_PATH, aspath); | |
329 | } | |
330 | ||
331 | /* Unintern aspath from AS path bucket. */ | |
332 | void | |
f6f434b2 | 333 | aspath_unintern (struct aspath **aspath) |
718e3744 | 334 | { |
335 | struct aspath *ret; | |
f6f434b2 PJ |
336 | struct aspath *asp = *aspath; |
337 | ||
338 | if (asp->refcnt) | |
339 | asp->refcnt--; | |
718e3744 | 340 | |
f6f434b2 | 341 | if (asp->refcnt == 0) |
718e3744 | 342 | { |
343 | /* This aspath must exist in aspath hash table. */ | |
f6f434b2 | 344 | ret = hash_release (ashash, asp); |
718e3744 | 345 | assert (ret != NULL); |
f6f434b2 PJ |
346 | aspath_free (asp); |
347 | *aspath = NULL; | |
718e3744 | 348 | } |
349 | } | |
350 | ||
351 | /* Return the start or end delimiters for a particular Segment type */ | |
352 | #define AS_SEG_START 0 | |
353 | #define AS_SEG_END 1 | |
354 | static char | |
355 | aspath_delimiter_char (u_char type, u_char which) | |
356 | { | |
357 | int i; | |
358 | struct | |
359 | { | |
360 | int type; | |
361 | char start; | |
362 | char end; | |
363 | } aspath_delim_char [] = | |
364 | { | |
365 | { AS_SET, '{', '}' }, | |
718e3744 | 366 | { AS_CONFED_SET, '[', ']' }, |
367 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
368 | { 0 } | |
369 | }; | |
370 | ||
371 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
372 | { | |
373 | if (aspath_delim_char[i].type == type) | |
374 | { | |
375 | if (which == AS_SEG_START) | |
376 | return aspath_delim_char[i].start; | |
377 | else if (which == AS_SEG_END) | |
378 | return aspath_delim_char[i].end; | |
379 | } | |
380 | } | |
381 | return ' '; | |
382 | } | |
383 | ||
014b670e DO |
384 | /* countup asns from this segment and index onward */ |
385 | static int | |
386 | assegment_count_asns (struct assegment *seg, int from) | |
387 | { | |
388 | int count = 0; | |
389 | while (seg) | |
390 | { | |
391 | if (!from) | |
392 | count += seg->length; | |
393 | else | |
394 | { | |
395 | count += (seg->length - from); | |
396 | from = 0; | |
397 | } | |
398 | seg = seg->next; | |
399 | } | |
400 | return count; | |
401 | } | |
402 | ||
fe69a505 | 403 | unsigned int |
404 | aspath_count_confeds (struct aspath *aspath) | |
405 | { | |
406 | int count = 0; | |
407 | struct assegment *seg = aspath->segments; | |
408 | ||
409 | while (seg) | |
410 | { | |
411 | if (seg->type == AS_CONFED_SEQUENCE) | |
412 | count += seg->length; | |
413 | else if (seg->type == AS_CONFED_SET) | |
414 | count++; | |
415 | ||
416 | seg = seg->next; | |
417 | } | |
418 | return count; | |
419 | } | |
420 | ||
421 | unsigned int | |
422 | aspath_count_hops (struct aspath *aspath) | |
423 | { | |
424 | int count = 0; | |
425 | struct assegment *seg = aspath->segments; | |
426 | ||
427 | while (seg) | |
428 | { | |
429 | if (seg->type == AS_SEQUENCE) | |
430 | count += seg->length; | |
431 | else if (seg->type == AS_SET) | |
432 | count++; | |
433 | ||
434 | seg = seg->next; | |
435 | } | |
436 | return count; | |
437 | } | |
438 | ||
0b2aa3a0 PJ |
439 | /* Estimate size aspath /might/ take if encoded into an |
440 | * ASPATH attribute. | |
441 | * | |
442 | * This is a quick estimate, not definitive! aspath_put() | |
443 | * may return a different number!! | |
444 | */ | |
fe69a505 | 445 | unsigned int |
446 | aspath_size (struct aspath *aspath) | |
447 | { | |
448 | int size = 0; | |
449 | struct assegment *seg = aspath->segments; | |
450 | ||
451 | while (seg) | |
452 | { | |
0b2aa3a0 | 453 | size += ASSEGMENT_SIZE(seg->length, 1); |
fe69a505 | 454 | seg = seg->next; |
455 | } | |
456 | return size; | |
457 | } | |
458 | ||
2815e61f PJ |
459 | /* Return highest public ASN in path */ |
460 | as_t | |
461 | aspath_highest (struct aspath *aspath) | |
462 | { | |
463 | struct assegment *seg = aspath->segments; | |
464 | as_t highest = 0; | |
465 | unsigned int i; | |
466 | ||
467 | while (seg) | |
468 | { | |
469 | for (i = 0; i < seg->length; i++) | |
470 | if (seg->as[i] > highest | |
471 | && (seg->as[i] < BGP_PRIVATE_AS_MIN | |
472 | || seg->as[i] > BGP_PRIVATE_AS_MAX)) | |
473 | highest = seg->as[i]; | |
474 | seg = seg->next; | |
475 | } | |
476 | return highest; | |
477 | } | |
478 | ||
0b2aa3a0 PJ |
479 | /* Return 1 if there are any 4-byte ASes in the path */ |
480 | unsigned int | |
481 | aspath_has_as4 (struct aspath *aspath) | |
482 | { | |
483 | struct assegment *seg = aspath->segments; | |
484 | unsigned int i; | |
485 | ||
486 | while (seg) | |
487 | { | |
488 | for (i = 0; i < seg->length; i++) | |
489 | if (seg->as[i] > BGP_AS_MAX) | |
490 | return 1; | |
491 | seg = seg->next; | |
492 | } | |
493 | return 0; | |
494 | } | |
495 | ||
718e3744 | 496 | /* Convert aspath structure to string expression. */ |
f669f7d2 | 497 | static void |
718e3744 | 498 | aspath_make_str_count (struct aspath *as) |
499 | { | |
fe69a505 | 500 | struct assegment *seg; |
501 | int str_size; | |
502 | int len = 0; | |
c9e52be3 | 503 | char *str_buf; |
718e3744 | 504 | |
505 | /* Empty aspath. */ | |
fe69a505 | 506 | if (!as->segments) |
718e3744 | 507 | { |
f669f7d2 JBD |
508 | as->str = XMALLOC (MTYPE_AS_STR, 1); |
509 | as->str[0] = '\0'; | |
510 | as->str_len = 0; | |
511 | return; | |
718e3744 | 512 | } |
fe69a505 | 513 | |
514 | seg = as->segments; | |
515 | ||
014b670e DO |
516 | /* ASN takes 5 to 10 chars plus seperator, see below. |
517 | * If there is one differing segment type, we need an additional | |
518 | * 2 chars for segment delimiters, and the final '\0'. | |
519 | * Hopefully this is large enough to avoid hitting the realloc | |
520 | * code below for most common sequences. | |
521 | * | |
522 | * This was changed to 10 after the well-known BGP assertion, which | |
523 | * had hit some parts of the Internet in May of 2009. | |
524 | */ | |
525 | #define ASN_STR_LEN (10 + 1) | |
526 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
527 | ASPATH_STR_DEFAULT_LEN); | |
718e3744 | 528 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); |
718e3744 | 529 | |
fe69a505 | 530 | while (seg) |
718e3744 | 531 | { |
532 | int i; | |
fe69a505 | 533 | char seperator; |
718e3744 | 534 | |
fe69a505 | 535 | /* Check AS type validity. Set seperator for segment */ |
536 | switch (seg->type) | |
537 | { | |
538 | case AS_SET: | |
539 | case AS_CONFED_SET: | |
540 | seperator = ','; | |
541 | break; | |
542 | case AS_SEQUENCE: | |
543 | case AS_CONFED_SEQUENCE: | |
544 | seperator = ' '; | |
545 | break; | |
546 | default: | |
547 | XFREE (MTYPE_AS_STR, str_buf); | |
f669f7d2 JBD |
548 | as->str = NULL; |
549 | as->str_len = 0; | |
550 | return; | |
fe69a505 | 551 | } |
552 | ||
014b670e DO |
553 | /* We might need to increase str_buf, particularly if path has |
554 | * differing segments types, our initial guesstimate above will | |
555 | * have been wrong. Need 10 chars for ASN, a seperator each and | |
556 | * potentially two segment delimiters, plus a space between each | |
557 | * segment and trailing zero. | |
558 | * | |
559 | * This definitely didn't work with the value of 5 bytes and | |
560 | * 32-bit ASNs. | |
561 | */ | |
562 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
563 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
564 | { | |
565 | str_size = len + SEGMENT_STR_LEN(seg); | |
566 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
567 | } | |
568 | #undef ASN_STR_LEN | |
569 | #undef SEGMENT_STR_LEN | |
570 | ||
fe69a505 | 571 | if (seg->type != AS_SEQUENCE) |
014b670e DO |
572 | len += snprintf (str_buf + len, str_size - len, |
573 | "%c", | |
574 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
fe69a505 | 575 | |
576 | /* write out the ASNs, with their seperators, bar the last one*/ | |
577 | for (i = 0; i < seg->length; i++) | |
578 | { | |
579 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); | |
580 | ||
581 | if (i < (seg->length - 1)) | |
582 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
583 | } | |
584 | ||
585 | if (seg->type != AS_SEQUENCE) | |
586 | len += snprintf (str_buf + len, str_size - len, "%c", | |
587 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
588 | if (seg->next) | |
589 | len += snprintf (str_buf + len, str_size - len, " "); | |
590 | ||
591 | seg = seg->next; | |
718e3744 | 592 | } |
fe69a505 | 593 | |
594 | assert (len < str_size); | |
595 | ||
596 | str_buf[len] = '\0'; | |
f669f7d2 JBD |
597 | as->str = str_buf; |
598 | as->str_len = len; | |
718e3744 | 599 | |
f669f7d2 | 600 | return; |
718e3744 | 601 | } |
602 | ||
fe69a505 | 603 | static void |
604 | aspath_str_update (struct aspath *as) | |
605 | { | |
606 | if (as->str) | |
607 | XFREE (MTYPE_AS_STR, as->str); | |
f669f7d2 | 608 | aspath_make_str_count (as); |
fe69a505 | 609 | } |
610 | ||
718e3744 | 611 | /* Intern allocated AS path. */ |
612 | struct aspath * | |
613 | aspath_intern (struct aspath *aspath) | |
614 | { | |
615 | struct aspath *find; | |
f669f7d2 JBD |
616 | |
617 | /* Assert this AS path structure is not interned and has the string | |
618 | representation built. */ | |
718e3744 | 619 | assert (aspath->refcnt == 0); |
f669f7d2 | 620 | assert (aspath->str); |
718e3744 | 621 | |
622 | /* Check AS path hash. */ | |
623 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
718e3744 | 624 | if (find != aspath) |
fe69a505 | 625 | aspath_free (aspath); |
718e3744 | 626 | |
627 | find->refcnt++; | |
628 | ||
718e3744 | 629 | return find; |
630 | } | |
631 | ||
632 | /* Duplicate aspath structure. Created same aspath structure but | |
633 | reference count and AS path string is cleared. */ | |
634 | struct aspath * | |
635 | aspath_dup (struct aspath *aspath) | |
636 | { | |
f669f7d2 | 637 | unsigned short buflen = aspath->str_len + 1; |
718e3744 | 638 | struct aspath *new; |
639 | ||
fe69a505 | 640 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 641 | |
fe69a505 | 642 | if (aspath->segments) |
643 | new->segments = assegment_dup_all (aspath->segments); | |
718e3744 | 644 | |
f669f7d2 JBD |
645 | if (!aspath->str) |
646 | return new; | |
647 | ||
648 | new->str = XMALLOC (MTYPE_AS_STR, buflen); | |
649 | new->str_len = aspath->str_len; | |
650 | ||
651 | /* copy the string data */ | |
652 | if (aspath->str_len > 0) | |
653 | memcpy (new->str, aspath->str, buflen); | |
654 | else | |
655 | new->str[0] = '\0'; | |
718e3744 | 656 | |
657 | return new; | |
658 | } | |
659 | ||
94f2b392 | 660 | static void * |
fe69a505 | 661 | aspath_hash_alloc (void *arg) |
718e3744 | 662 | { |
f669f7d2 JBD |
663 | const struct aspath *aspath = arg; |
664 | struct aspath *new; | |
718e3744 | 665 | |
718e3744 | 666 | /* Malformed AS path value. */ |
f669f7d2 | 667 | assert (aspath->str); |
718e3744 | 668 | if (! aspath->str) |
f669f7d2 | 669 | return NULL; |
718e3744 | 670 | |
f669f7d2 JBD |
671 | /* New aspath structure is needed. */ |
672 | new = XMALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
673 | ||
674 | /* Reuse segments and string representation */ | |
675 | new->refcnt = 0; | |
676 | new->segments = aspath->segments; | |
677 | new->str = aspath->str; | |
678 | new->str_len = aspath->str_len; | |
679 | ||
680 | return new; | |
718e3744 | 681 | } |
682 | ||
ab005298 | 683 | /* parse as-segment byte stream in struct assegment */ |
b881c707 PJ |
684 | static int |
685 | assegments_parse (struct stream *s, size_t length, | |
686 | struct assegment **result, int use32bit) | |
fe69a505 | 687 | { |
688 | struct assegment_header segh; | |
689 | struct assegment *seg, *prev = NULL, *head = NULL; | |
ab005298 | 690 | size_t bytes = 0; |
fe69a505 | 691 | |
ab005298 PJ |
692 | /* empty aspath (ie iBGP or somesuch) */ |
693 | if (length == 0) | |
b881c707 | 694 | return 0; |
fe69a505 | 695 | |
0b2aa3a0 PJ |
696 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
697 | zlog_debug ("[AS4SEG] Parse aspath segment: got total byte length %lu", | |
698 | (unsigned long) length); | |
ab005298 PJ |
699 | /* basic checks */ |
700 | if ((STREAM_READABLE(s) < length) | |
701 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
702 | || (length % AS16_VALUE_SIZE )) | |
b881c707 | 703 | return -1; |
fe69a505 | 704 | |
ab005298 | 705 | while (bytes < length) |
fe69a505 | 706 | { |
707 | int i; | |
cddb8112 | 708 | size_t seg_size; |
fe69a505 | 709 | |
ab005298 | 710 | if ((length - bytes) <= AS_HEADER_SIZE) |
cddb8112 | 711 | { |
ab005298 PJ |
712 | if (head) |
713 | assegment_free_all (head); | |
b881c707 | 714 | return -1; |
fdbc8e77 PJ |
715 | } |
716 | ||
ab005298 | 717 | /* softly softly, get the header first on its own */ |
fe69a505 | 718 | segh.type = stream_getc (s); |
719 | segh.length = stream_getc (s); | |
720 | ||
0b2aa3a0 PJ |
721 | seg_size = ASSEGMENT_SIZE(segh.length, use32bit); |
722 | ||
723 | if (BGP_DEBUG (as4, AS4_SEGMENT)) | |
724 | zlog_debug ("[AS4SEG] Parse aspath segment: got type %d, length %d", | |
725 | segh.type, segh.length); | |
726 | ||
ab005298 PJ |
727 | /* check it.. */ |
728 | if ( ((bytes + seg_size) > length) | |
729 | /* 1771bis 4.3b: seg length contains one or more */ | |
730 | || (segh.length == 0) | |
731 | /* Paranoia in case someone changes type of segment length. | |
732 | * Shift both values by 0x10 to make the comparison operate | |
733 | * on more, than 8 bits (otherwise it's a warning, bug #564). | |
2eb445e1 | 734 | */ |
ab005298 PJ |
735 | || ((sizeof segh.length > 1) |
736 | && (0x10 + segh.length > 0x10 + AS_SEGMENT_MAX))) | |
fe69a505 | 737 | { |
ab005298 | 738 | if (head) |
fe69a505 | 739 | assegment_free_all (head); |
b881c707 | 740 | return -1; |
fe69a505 | 741 | } |
742 | ||
fdbc8e77 PJ |
743 | switch (segh.type) |
744 | { | |
745 | case AS_SEQUENCE: | |
746 | case AS_SET: | |
fdbc8e77 PJ |
747 | case AS_CONFED_SEQUENCE: |
748 | case AS_CONFED_SET: | |
ab005298 PJ |
749 | break; |
750 | default: | |
751 | if (head) | |
752 | assegment_free_all (head); | |
b881c707 | 753 | return -1; |
fe69a505 | 754 | } |
755 | ||
756 | /* now its safe to trust lengths */ | |
757 | seg = assegment_new (segh.type, segh.length); | |
758 | ||
759 | if (head) | |
760 | prev->next = seg; | |
761 | else /* it's the first segment */ | |
762 | head = prev = seg; | |
763 | ||
764 | for (i = 0; i < segh.length; i++) | |
0b2aa3a0 PJ |
765 | seg->as[i] = (use32bit) ? stream_getl (s) : stream_getw (s); |
766 | ||
ab005298 PJ |
767 | bytes += seg_size; |
768 | ||
0b2aa3a0 | 769 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
ab005298 PJ |
770 | zlog_debug ("[AS4SEG] Parse aspath segment: Bytes now: %lu", |
771 | (unsigned long) bytes); | |
fe69a505 | 772 | |
773 | prev = seg; | |
774 | } | |
775 | ||
b881c707 PJ |
776 | *result = assegment_normalise (head); |
777 | return 0; | |
fe69a505 | 778 | } |
779 | ||
ab005298 PJ |
780 | /* AS path parse function. pnt is a pointer to byte stream and length |
781 | is length of byte stream. If there is same AS path in the the AS | |
b881c707 PJ |
782 | path hash then return it else make new AS path structure. |
783 | ||
784 | On error NULL is returned. | |
cddb8112 | 785 | */ |
718e3744 | 786 | struct aspath * |
ab005298 | 787 | aspath_parse (struct stream *s, size_t length, int use32bit) |
718e3744 | 788 | { |
789 | struct aspath as; | |
790 | struct aspath *find; | |
791 | ||
ab005298 PJ |
792 | /* If length is odd it's malformed AS path. */ |
793 | /* Nit-picking: if (use32bit == 0) it is malformed if odd, | |
794 | * otherwise its malformed when length is larger than 2 and (length-2) | |
795 | * is not dividable by 4. | |
796 | * But... this time we're lazy | |
797 | */ | |
798 | if (length % AS16_VALUE_SIZE ) | |
799 | return NULL; | |
cddb8112 | 800 | |
ab005298 | 801 | memset (&as, 0, sizeof (struct aspath)); |
b881c707 PJ |
802 | if (assegments_parse (s, length, &as.segments, use32bit) < 0) |
803 | return NULL; | |
f669f7d2 | 804 | |
718e3744 | 805 | /* If already same aspath exist then return it. */ |
806 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
f669f7d2 JBD |
807 | |
808 | /* bug! should not happen, let the daemon crash below */ | |
809 | assert (find); | |
810 | ||
811 | /* if the aspath was already hashed free temporary memory. */ | |
812 | if (find->refcnt) | |
813 | { | |
814 | assegment_free_all (as.segments); | |
815 | /* aspath_key_make() always updates the string */ | |
816 | XFREE (MTYPE_AS_STR, as.str); | |
817 | } | |
818 | ||
718e3744 | 819 | find->refcnt++; |
820 | ||
821 | return find; | |
822 | } | |
823 | ||
f63f06da | 824 | static void |
0b2aa3a0 | 825 | assegment_data_put (struct stream *s, as_t *as, int num, int use32bit) |
fe69a505 | 826 | { |
827 | int i; | |
828 | assert (num <= AS_SEGMENT_MAX); | |
829 | ||
830 | for (i = 0; i < num; i++) | |
0b2aa3a0 PJ |
831 | if ( use32bit ) |
832 | stream_putl (s, as[i]); | |
833 | else | |
834 | { | |
835 | if ( as[i] <= BGP_AS_MAX ) | |
836 | stream_putw(s, as[i]); | |
837 | else | |
838 | stream_putw(s, BGP_AS_TRANS); | |
839 | } | |
fe69a505 | 840 | } |
718e3744 | 841 | |
f63f06da | 842 | static size_t |
fe69a505 | 843 | assegment_header_put (struct stream *s, u_char type, int length) |
718e3744 | 844 | { |
fe69a505 | 845 | size_t lenp; |
846 | assert (length <= AS_SEGMENT_MAX); | |
847 | stream_putc (s, type); | |
848 | lenp = stream_get_endp (s); | |
849 | stream_putc (s, length); | |
850 | return lenp; | |
851 | } | |
718e3744 | 852 | |
fe69a505 | 853 | /* write aspath data to stream */ |
0b2aa3a0 PJ |
854 | size_t |
855 | aspath_put (struct stream *s, struct aspath *as, int use32bit ) | |
fe69a505 | 856 | { |
857 | struct assegment *seg = as->segments; | |
0b2aa3a0 | 858 | size_t bytes = 0; |
fe69a505 | 859 | |
860 | if (!seg || seg->length == 0) | |
0b2aa3a0 | 861 | return 0; |
fe69a505 | 862 | |
863 | if (seg) | |
718e3744 | 864 | { |
0b2aa3a0 PJ |
865 | /* |
866 | * Hey, what do we do when we have > STREAM_WRITABLE(s) here? | |
867 | * At the moment, we would write out a partial aspath, and our peer | |
868 | * will complain and drop the session :-/ | |
869 | * | |
870 | * The general assumption here is that many things tested will | |
871 | * never happen. And, in real live, up to now, they have not. | |
872 | */ | |
873 | while (seg && (ASSEGMENT_LEN(seg, use32bit) <= STREAM_WRITEABLE(s))) | |
fe69a505 | 874 | { |
0b2aa3a0 | 875 | struct assegment *next = seg->next; |
fe69a505 | 876 | int written = 0; |
0b2aa3a0 | 877 | int asns_packed = 0; |
fe69a505 | 878 | size_t lenp; |
879 | ||
880 | /* Overlength segments have to be split up */ | |
881 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
882 | { | |
883 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
0b2aa3a0 | 884 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX, use32bit); |
fe69a505 | 885 | written += AS_SEGMENT_MAX; |
0b2aa3a0 | 886 | bytes += ASSEGMENT_SIZE (written, use32bit); |
fe69a505 | 887 | } |
888 | ||
889 | /* write the final segment, probably is also the first */ | |
890 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
0b2aa3a0 PJ |
891 | assegment_data_put (s, (seg->as + written), seg->length - written, |
892 | use32bit); | |
fe69a505 | 893 | |
894 | /* Sequence-type segments can be 'packed' together | |
895 | * Case of a segment which was overlength and split up | |
896 | * will be missed here, but that doesn't matter. | |
897 | */ | |
0b2aa3a0 | 898 | while (next && ASSEGMENTS_PACKABLE (seg, next)) |
fe69a505 | 899 | { |
900 | /* NB: We should never normally get here given we | |
901 | * normalise aspath data when parse them. However, better | |
902 | * safe than sorry. We potentially could call | |
903 | * assegment_normalise here instead, but it's cheaper and | |
904 | * easier to do it on the fly here rather than go through | |
905 | * the segment list twice every time we write out | |
906 | * aspath's. | |
907 | */ | |
908 | ||
909 | /* Next segment's data can fit in this one */ | |
0b2aa3a0 | 910 | assegment_data_put (s, next->as, next->length, use32bit); |
fe69a505 | 911 | |
912 | /* update the length of the segment header */ | |
0b2aa3a0 PJ |
913 | stream_putc_at (s, lenp, seg->length - written + next->length); |
914 | asns_packed += next->length; | |
915 | ||
916 | next = next->next; | |
fe69a505 | 917 | } |
0b2aa3a0 PJ |
918 | |
919 | bytes += ASSEGMENT_SIZE (seg->length - written + asns_packed, | |
920 | use32bit); | |
921 | seg = next; | |
fe69a505 | 922 | } |
718e3744 | 923 | } |
0b2aa3a0 | 924 | return bytes; |
fe69a505 | 925 | } |
926 | ||
927 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
928 | * We have no way to manage the storage, so we use a static stream | |
929 | * wrapper around aspath_put. | |
930 | */ | |
931 | u_char * | |
932 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
933 | { | |
934 | #define SNMP_PATHSEG_MAX 1024 | |
8fdc32ab | 935 | |
936 | if (!snmp_stream) | |
937 | snmp_stream = stream_new (SNMP_PATHSEG_MAX); | |
718e3744 | 938 | else |
8fdc32ab | 939 | stream_reset (snmp_stream); |
fe69a505 | 940 | |
941 | if (!as) | |
718e3744 | 942 | { |
fe69a505 | 943 | *varlen = 0; |
944 | return NULL; | |
718e3744 | 945 | } |
0b2aa3a0 | 946 | aspath_put (snmp_stream, as, 0); /* use 16 bit for now here */ |
fe69a505 | 947 | |
8fdc32ab | 948 | *varlen = stream_get_endp (snmp_stream); |
949 | return stream_pnt(snmp_stream); | |
718e3744 | 950 | } |
fe69a505 | 951 | |
952 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
718e3744 | 953 | |
94f2b392 | 954 | static struct assegment * |
718e3744 | 955 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, |
956 | as_t as) | |
957 | { | |
958 | int i; | |
959 | ||
960 | /* If this is first AS set member, create new as-set segment. */ | |
961 | if (asset == NULL) | |
962 | { | |
fe69a505 | 963 | asset = assegment_new (AS_SET, 1); |
964 | if (! aspath->segments) | |
965 | aspath->segments = asset; | |
718e3744 | 966 | else |
fe69a505 | 967 | { |
968 | struct assegment *seg = aspath->segments; | |
969 | while (seg->next) | |
970 | seg = seg->next; | |
971 | seg->next = asset; | |
972 | } | |
718e3744 | 973 | asset->type = AS_SET; |
974 | asset->length = 1; | |
fe69a505 | 975 | asset->as[0] = as; |
718e3744 | 976 | } |
977 | else | |
978 | { | |
718e3744 | 979 | /* Check this AS value already exists or not. */ |
980 | for (i = 0; i < asset->length; i++) | |
fe69a505 | 981 | if (asset->as[i] == as) |
718e3744 | 982 | return asset; |
fe69a505 | 983 | |
718e3744 | 984 | asset->length++; |
fe69a505 | 985 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, |
986 | asset->length * AS_VALUE_SIZE); | |
987 | asset->as[asset->length - 1] = as; | |
718e3744 | 988 | } |
fe69a505 | 989 | |
718e3744 | 990 | |
991 | return asset; | |
992 | } | |
993 | ||
994 | /* Modify as1 using as2 for aggregation. */ | |
995 | struct aspath * | |
996 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
997 | { | |
998 | int i; | |
999 | int minlen; | |
1000 | int match; | |
fe69a505 | 1001 | int from; |
1002 | struct assegment *seg1 = as1->segments; | |
1003 | struct assegment *seg2 = as2->segments; | |
0b2aa3a0 | 1004 | struct aspath *aspath = NULL; |
718e3744 | 1005 | struct assegment *asset; |
0b2aa3a0 | 1006 | struct assegment *prevseg = NULL; |
718e3744 | 1007 | |
1008 | match = 0; | |
1009 | minlen = 0; | |
1010 | aspath = NULL; | |
1011 | asset = NULL; | |
718e3744 | 1012 | |
1013 | /* First of all check common leading sequence. */ | |
fe69a505 | 1014 | while (seg1 && seg2) |
0b2aa3a0 | 1015 | { |
718e3744 | 1016 | /* Check segment type. */ |
1017 | if (seg1->type != seg2->type) | |
1018 | break; | |
1019 | ||
1020 | /* Minimum segment length. */ | |
1021 | minlen = min (seg1->length, seg2->length); | |
1022 | ||
1023 | for (match = 0; match < minlen; match++) | |
fe69a505 | 1024 | if (seg1->as[match] != seg2->as[match]) |
718e3744 | 1025 | break; |
1026 | ||
1027 | if (match) | |
1028 | { | |
0b2aa3a0 PJ |
1029 | struct assegment *seg = assegment_new (seg1->type, 0); |
1030 | ||
1031 | seg = assegment_append_asns (seg, seg1->as, match); | |
1032 | ||
718e3744 | 1033 | if (! aspath) |
0b2aa3a0 PJ |
1034 | { |
1035 | aspath = aspath_new (); | |
1036 | aspath->segments = seg; | |
1037 | } | |
1038 | else | |
1039 | prevseg->next = seg; | |
1040 | ||
1041 | prevseg = seg; | |
718e3744 | 1042 | } |
1043 | ||
1044 | if (match != minlen || match != seg1->length | |
1045 | || seg1->length != seg2->length) | |
1046 | break; | |
fe69a505 | 1047 | |
1048 | seg1 = seg1->next; | |
1049 | seg2 = seg2->next; | |
718e3744 | 1050 | } |
1051 | ||
1052 | if (! aspath) | |
1053 | aspath = aspath_new(); | |
1054 | ||
1055 | /* Make as-set using rest of all information. */ | |
fe69a505 | 1056 | from = match; |
1057 | while (seg1) | |
718e3744 | 1058 | { |
fe69a505 | 1059 | for (i = from; i < seg1->length; i++) |
1060 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
1061 | ||
1062 | from = 0; | |
1063 | seg1 = seg1->next; | |
718e3744 | 1064 | } |
1065 | ||
fe69a505 | 1066 | from = match; |
1067 | while (seg2) | |
718e3744 | 1068 | { |
fe69a505 | 1069 | for (i = from; i < seg2->length; i++) |
1070 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
718e3744 | 1071 | |
fe69a505 | 1072 | from = 0; |
1073 | seg2 = seg2->next; | |
718e3744 | 1074 | } |
fe69a505 | 1075 | |
1076 | assegment_normalise (aspath->segments); | |
1077 | aspath_str_update (aspath); | |
718e3744 | 1078 | return aspath; |
1079 | } | |
1080 | ||
1081 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
1082 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
1083 | or not the peer's AS number. */ | |
1084 | int | |
1085 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
1086 | { | |
fe69a505 | 1087 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1088 | return 0; |
fe69a505 | 1089 | |
1090 | if (aspath->segments | |
1091 | && (aspath->segments->type == AS_SEQUENCE) | |
1092 | && (aspath->segments->as[0] == asno )) | |
718e3744 | 1093 | return 1; |
1094 | ||
1095 | return 0; | |
1096 | } | |
1097 | ||
1f742f21 | 1098 | /* AS path loop check. If aspath contains asno then return >= 1. */ |
718e3744 | 1099 | int |
1100 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
1101 | { | |
fe69a505 | 1102 | struct assegment *seg; |
718e3744 | 1103 | int count = 0; |
1104 | ||
1f742f21 | 1105 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1106 | return 0; |
fe69a505 | 1107 | |
1108 | seg = aspath->segments; | |
1109 | ||
1110 | while (seg) | |
718e3744 | 1111 | { |
1112 | int i; | |
718e3744 | 1113 | |
fe69a505 | 1114 | for (i = 0; i < seg->length; i++) |
1115 | if (seg->as[i] == asno) | |
718e3744 | 1116 | count++; |
fe69a505 | 1117 | |
1118 | seg = seg->next; | |
718e3744 | 1119 | } |
1120 | return count; | |
1121 | } | |
1122 | ||
1123 | /* When all of AS path is private AS return 1. */ | |
1124 | int | |
1125 | aspath_private_as_check (struct aspath *aspath) | |
1126 | { | |
fe69a505 | 1127 | struct assegment *seg; |
1128 | ||
1129 | if ( !(aspath && aspath->segments) ) | |
718e3744 | 1130 | return 0; |
fe69a505 | 1131 | |
1132 | seg = aspath->segments; | |
718e3744 | 1133 | |
fe69a505 | 1134 | while (seg) |
718e3744 | 1135 | { |
1136 | int i; | |
718e3744 | 1137 | |
fe69a505 | 1138 | for (i = 0; i < seg->length; i++) |
718e3744 | 1139 | { |
fe69a505 | 1140 | if ( (seg->as[i] < BGP_PRIVATE_AS_MIN) |
1141 | || (seg->as[i] > BGP_PRIVATE_AS_MAX) ) | |
718e3744 | 1142 | return 0; |
1143 | } | |
fe69a505 | 1144 | seg = seg->next; |
718e3744 | 1145 | } |
1146 | return 1; | |
1147 | } | |
1148 | ||
ca87e1d3 VT |
1149 | /* AS path confed check. If aspath contains confed set or sequence then return 1. */ |
1150 | int | |
1151 | aspath_confed_check (struct aspath *aspath) | |
1152 | { | |
1153 | struct assegment *seg; | |
1154 | ||
1155 | if ( !(aspath && aspath->segments) ) | |
1156 | return 0; | |
1157 | ||
1158 | seg = aspath->segments; | |
1159 | ||
1160 | while (seg) | |
1161 | { | |
1162 | if (seg->type == AS_CONFED_SET || seg->type == AS_CONFED_SEQUENCE) | |
1163 | return 1; | |
1164 | seg = seg->next; | |
1165 | } | |
1166 | return 0; | |
1167 | } | |
1168 | ||
1169 | /* Leftmost AS path segment confed check. If leftmost AS segment is of type | |
1170 | AS_CONFED_SEQUENCE or AS_CONFED_SET then return 1. */ | |
1171 | int | |
1172 | aspath_left_confed_check (struct aspath *aspath) | |
1173 | { | |
1174 | ||
1175 | if ( !(aspath && aspath->segments) ) | |
1176 | return 0; | |
1177 | ||
1178 | if ( (aspath->segments->type == AS_CONFED_SEQUENCE) | |
1179 | || (aspath->segments->type == AS_CONFED_SET) ) | |
1180 | return 1; | |
1181 | ||
1182 | return 0; | |
1183 | } | |
1184 | ||
718e3744 | 1185 | /* Merge as1 to as2. as2 should be uninterned aspath. */ |
94f2b392 | 1186 | static struct aspath * |
718e3744 | 1187 | aspath_merge (struct aspath *as1, struct aspath *as2) |
1188 | { | |
fe69a505 | 1189 | struct assegment *last, *new; |
718e3744 | 1190 | |
1191 | if (! as1 || ! as2) | |
1192 | return NULL; | |
1193 | ||
fe69a505 | 1194 | last = new = assegment_dup_all (as1->segments); |
1195 | ||
1196 | /* find the last valid segment */ | |
1197 | while (last && last->next) | |
1198 | last = last->next; | |
1199 | ||
1200 | last->next = as2->segments; | |
1201 | as2->segments = new; | |
1202 | aspath_str_update (as2); | |
718e3744 | 1203 | return as2; |
1204 | } | |
1205 | ||
1206 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1207 | struct aspath * | |
1208 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1209 | { | |
fe69a505 | 1210 | struct assegment *seg1; |
1211 | struct assegment *seg2; | |
718e3744 | 1212 | |
1213 | if (! as1 || ! as2) | |
1214 | return NULL; | |
fe69a505 | 1215 | |
1216 | seg1 = as1->segments; | |
1217 | seg2 = as2->segments; | |
1218 | ||
1219 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
718e3744 | 1220 | if (seg2 == NULL) |
1221 | { | |
fe69a505 | 1222 | as2->segments = assegment_dup_all (as1->segments); |
1223 | aspath_str_update (as2); | |
718e3744 | 1224 | return as2; |
1225 | } | |
fe69a505 | 1226 | |
1227 | /* If as1 is empty AS, no prepending to do. */ | |
718e3744 | 1228 | if (seg1 == NULL) |
1229 | return as2; | |
fe69a505 | 1230 | |
1231 | /* find the tail as1's segment chain. */ | |
1232 | while (seg1 && seg1->next) | |
1233 | seg1 = seg1->next; | |
718e3744 | 1234 | |
736d4408 VT |
1235 | /* Delete any AS_CONFED_SEQUENCE segment from as2. */ |
1236 | if (seg1->type == AS_SEQUENCE && seg2->type == AS_CONFED_SEQUENCE) | |
1237 | as2 = aspath_delete_confed_seq (as2); | |
1238 | ||
718e3744 | 1239 | /* Compare last segment type of as1 and first segment type of as2. */ |
1240 | if (seg1->type != seg2->type) | |
1241 | return aspath_merge (as1, as2); | |
1242 | ||
1243 | if (seg1->type == AS_SEQUENCE) | |
1244 | { | |
fe69a505 | 1245 | /* We have two chains of segments, as1->segments and seg2, |
1246 | * and we have to attach them together, merging the attaching | |
1247 | * segments together into one. | |
1248 | * | |
1249 | * 1. dupe as1->segments onto head of as2 | |
1250 | * 2. merge seg2's asns onto last segment of this new chain | |
1251 | * 3. attach chain after seg2 | |
1252 | */ | |
718e3744 | 1253 | |
fe69a505 | 1254 | /* dupe as1 onto as2's head */ |
1255 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1256 | ||
1257 | /* refind the tail of as2, reusing seg1 */ | |
1258 | while (seg1 && seg1->next) | |
1259 | seg1 = seg1->next; | |
1260 | ||
1261 | /* merge the old head, seg2, into tail, seg1 */ | |
1262 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1263 | ||
1264 | /* bypass the merged seg2, and attach any chain after it to | |
1265 | * chain descending from as2's head | |
1266 | */ | |
1267 | seg1->next = seg2->next; | |
1268 | ||
1269 | /* seg2 is now referenceless and useless*/ | |
1270 | assegment_free (seg2); | |
1271 | ||
1272 | /* we've now prepended as1's segment chain to as2, merging | |
1273 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1274 | */ | |
1275 | aspath_str_update (as2); | |
718e3744 | 1276 | return as2; |
1277 | } | |
1278 | else | |
1279 | { | |
1280 | /* AS_SET merge code is needed at here. */ | |
1281 | return aspath_merge (as1, as2); | |
1282 | } | |
fe69a505 | 1283 | /* XXX: Ermmm, what if as1 has multiple segments?? */ |
1284 | ||
718e3744 | 1285 | /* Not reached */ |
1286 | } | |
1287 | ||
841f7a57 DO |
1288 | /* Iterate over AS_PATH segments and wipe all occurences of the |
1289 | * listed AS numbers. Hence some segments may lose some or even | |
1290 | * all data on the way, the operation is implemented as a smarter | |
1291 | * version of aspath_dup(), which allocates memory to hold the new | |
1292 | * data, not the original. The new AS path is returned. | |
1293 | */ | |
1294 | struct aspath * | |
1295 | aspath_filter_exclude (struct aspath * source, struct aspath * exclude_list) | |
1296 | { | |
1297 | struct assegment * srcseg, * exclseg, * lastseg; | |
1298 | struct aspath * newpath; | |
1299 | ||
1300 | newpath = aspath_new(); | |
1301 | lastseg = NULL; | |
1302 | ||
1303 | for (srcseg = source->segments; srcseg; srcseg = srcseg->next) | |
1304 | { | |
1305 | unsigned i, y, newlen = 0, done = 0, skip_as; | |
1306 | struct assegment * newseg; | |
1307 | ||
1308 | /* Find out, how much ASns are we going to pick from this segment. | |
1309 | * We can't perform filtering right inline, because the size of | |
1310 | * the new segment isn't known at the moment yet. | |
1311 | */ | |
1312 | for (i = 0; i < srcseg->length; i++) | |
1313 | { | |
1314 | skip_as = 0; | |
1315 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1316 | for (y = 0; y < exclseg->length; y++) | |
1317 | if (srcseg->as[i] == exclseg->as[y]) | |
1318 | { | |
1319 | skip_as = 1; | |
1320 | // There's no sense in testing the rest of exclusion list, bail out. | |
1321 | break; | |
1322 | } | |
1323 | if (!skip_as) | |
1324 | newlen++; | |
1325 | } | |
1326 | /* newlen is now the number of ASns to copy */ | |
1327 | if (!newlen) | |
1328 | continue; | |
1329 | ||
1330 | /* Actual copying. Allocate memory and iterate once more, performing filtering. */ | |
1331 | newseg = assegment_new (srcseg->type, newlen); | |
1332 | for (i = 0; i < srcseg->length; i++) | |
1333 | { | |
1334 | skip_as = 0; | |
1335 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1336 | for (y = 0; y < exclseg->length; y++) | |
1337 | if (srcseg->as[i] == exclseg->as[y]) | |
1338 | { | |
1339 | skip_as = 1; | |
1340 | break; | |
1341 | } | |
1342 | if (skip_as) | |
1343 | continue; | |
1344 | newseg->as[done++] = srcseg->as[i]; | |
1345 | } | |
1346 | /* At his point newlen must be equal to done, and both must be positive. Append | |
1347 | * the filtered segment to the gross result. */ | |
1348 | if (!lastseg) | |
1349 | newpath->segments = newseg; | |
1350 | else | |
1351 | lastseg->next = newseg; | |
1352 | lastseg = newseg; | |
1353 | } | |
1354 | aspath_str_update (newpath); | |
1355 | /* We are happy returning even an empty AS_PATH, because the administrator | |
1356 | * might expect this very behaviour. There's a mean to avoid this, if necessary, | |
1357 | * by having a match rule against certain AS_PATH regexps in the route-map index. | |
1358 | */ | |
1359 | aspath_free (source); | |
1360 | return newpath; | |
1361 | } | |
1362 | ||
718e3744 | 1363 | /* Add specified AS to the leftmost of aspath. */ |
1364 | static struct aspath * | |
1365 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1366 | { | |
fe69a505 | 1367 | struct assegment *assegment = aspath->segments; |
718e3744 | 1368 | |
1369 | /* In case of empty aspath. */ | |
1370 | if (assegment == NULL || assegment->length == 0) | |
1371 | { | |
fe69a505 | 1372 | aspath->segments = assegment_new (type, 1); |
1373 | aspath->segments->as[0] = asno; | |
1374 | ||
718e3744 | 1375 | if (assegment) |
fe69a505 | 1376 | assegment_free (assegment); |
718e3744 | 1377 | |
1378 | return aspath; | |
1379 | } | |
1380 | ||
1381 | if (assegment->type == type) | |
fe69a505 | 1382 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); |
1383 | else | |
718e3744 | 1384 | { |
fe69a505 | 1385 | /* create new segment |
1386 | * push it onto head of aspath's segment chain | |
1387 | */ | |
718e3744 | 1388 | struct assegment *newsegment; |
fe69a505 | 1389 | |
1390 | newsegment = assegment_new (type, 1); | |
1391 | newsegment->as[0] = asno; | |
1392 | ||
1393 | newsegment->next = assegment; | |
1394 | aspath->segments = newsegment; | |
718e3744 | 1395 | } |
1396 | ||
1397 | return aspath; | |
1398 | } | |
1399 | ||
1400 | /* Add specified AS to the leftmost of aspath. */ | |
1401 | struct aspath * | |
1402 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1403 | { | |
1404 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1405 | } | |
1406 | ||
1407 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1408 | as2's leftmost AS is same return 1. */ | |
1409 | int | |
ffe11cfb | 1410 | aspath_cmp_left (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1411 | { |
f669f7d2 JBD |
1412 | const struct assegment *seg1; |
1413 | const struct assegment *seg2; | |
718e3744 | 1414 | |
fe69a505 | 1415 | if (!(aspath1 && aspath2)) |
1416 | return 0; | |
718e3744 | 1417 | |
fe69a505 | 1418 | seg1 = aspath1->segments; |
1419 | seg2 = aspath2->segments; | |
718e3744 | 1420 | |
fe69a505 | 1421 | /* find first non-confed segments for each */ |
1422 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1423 | || (seg1->type == AS_CONFED_SET))) | |
1424 | seg1 = seg1->next; | |
718e3744 | 1425 | |
fe69a505 | 1426 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1427 | || (seg2->type == AS_CONFED_SET))) | |
1428 | seg2 = seg2->next; | |
718e3744 | 1429 | |
fe69a505 | 1430 | /* Check as1's */ |
1431 | if (!(seg1 && seg2 | |
1432 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1433 | return 0; | |
1434 | ||
1435 | if (seg1->as[0] == seg2->as[0]) | |
718e3744 | 1436 | return 1; |
1437 | ||
1438 | return 0; | |
1439 | } | |
1440 | ||
0b2aa3a0 PJ |
1441 | /* Truncate an aspath after a number of hops, and put the hops remaining |
1442 | * at the front of another aspath. Needed for AS4 compat. | |
1443 | * | |
1444 | * Returned aspath is a /new/ aspath, which should either by free'd or | |
1445 | * interned by the caller, as desired. | |
1446 | */ | |
1447 | struct aspath * | |
1448 | aspath_reconcile_as4 ( struct aspath *aspath, struct aspath *as4path) | |
1449 | { | |
1450 | struct assegment *seg, *newseg, *prevseg = NULL; | |
1451 | struct aspath *newpath = NULL, *mergedpath; | |
1452 | int hops, cpasns = 0; | |
1453 | ||
1454 | if (!aspath) | |
1455 | return NULL; | |
1456 | ||
1457 | seg = aspath->segments; | |
1458 | ||
1459 | /* CONFEDs should get reconciled too.. */ | |
1460 | hops = (aspath_count_hops (aspath) + aspath_count_confeds (aspath)) | |
1461 | - aspath_count_hops (as4path); | |
1462 | ||
1463 | if (hops < 0) | |
1464 | { | |
1465 | if (BGP_DEBUG (as4, AS4)) | |
1466 | zlog_warn ("[AS4] Fewer hops in AS_PATH than NEW_AS_PATH"); | |
1467 | /* Something's gone wrong. The RFC says we should now ignore AS4_PATH, | |
1468 | * which is daft behaviour - it contains vital loop-detection | |
1469 | * information which must have been removed from AS_PATH. | |
1470 | */ | |
1471 | hops = aspath_count_hops (aspath); | |
1472 | } | |
1473 | ||
1474 | if (!hops) | |
1475 | return aspath_dup (as4path); | |
1476 | ||
1477 | if ( BGP_DEBUG(as4, AS4)) | |
1478 | zlog_debug("[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now", | |
1479 | aspath->str, as4path->str); | |
1480 | ||
1481 | while (seg && hops > 0) | |
1482 | { | |
1483 | switch (seg->type) | |
1484 | { | |
1485 | case AS_SET: | |
1486 | case AS_CONFED_SET: | |
1487 | hops--; | |
1488 | cpasns = seg->length; | |
1489 | break; | |
1490 | case AS_CONFED_SEQUENCE: | |
1491 | /* Should never split a confed-sequence, if hop-count | |
1492 | * suggests we must then something's gone wrong somewhere. | |
1493 | * | |
1494 | * Most important goal is to preserve AS_PATHs prime function | |
1495 | * as loop-detector, so we fudge the numbers so that the entire | |
1496 | * confed-sequence is merged in. | |
1497 | */ | |
1498 | if (hops < seg->length) | |
1499 | { | |
1500 | if (BGP_DEBUG (as4, AS4)) | |
1501 | zlog_debug ("[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls" | |
1502 | " across 2/4 ASN boundary somewhere, broken.."); | |
1503 | hops = seg->length; | |
1504 | } | |
1505 | case AS_SEQUENCE: | |
1506 | cpasns = MIN(seg->length, hops); | |
1507 | hops -= seg->length; | |
1508 | } | |
1509 | ||
1510 | assert (cpasns <= seg->length); | |
1511 | ||
1512 | newseg = assegment_new (seg->type, 0); | |
1513 | newseg = assegment_append_asns (newseg, seg->as, cpasns); | |
1514 | ||
1515 | if (!newpath) | |
1516 | { | |
1517 | newpath = aspath_new (); | |
1518 | newpath->segments = newseg; | |
1519 | } | |
1520 | else | |
1521 | prevseg->next = newseg; | |
1522 | ||
1523 | prevseg = newseg; | |
1524 | seg = seg->next; | |
1525 | } | |
1526 | ||
1527 | /* We may be able to join some segments here, and we must | |
1528 | * do this because... we want normalised aspaths in out hash | |
1529 | * and we do not want to stumble in aspath_put. | |
1530 | */ | |
1531 | mergedpath = aspath_merge (newpath, aspath_dup(as4path)); | |
1532 | aspath_free (newpath); | |
1533 | mergedpath->segments = assegment_normalise (mergedpath->segments); | |
1534 | aspath_str_update (mergedpath); | |
1535 | ||
1536 | if ( BGP_DEBUG(as4, AS4)) | |
1537 | zlog_debug ("[AS4] result of synthesizing is %s", | |
1538 | mergedpath->str); | |
1539 | ||
1540 | return mergedpath; | |
1541 | } | |
1542 | ||
718e3744 | 1543 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and |
1544 | as2's leftmost AS is same return 1. (confederation as-path | |
1545 | only). */ | |
1546 | int | |
ffe11cfb | 1547 | aspath_cmp_left_confed (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1548 | { |
fe69a505 | 1549 | if (! (aspath1 && aspath2) ) |
718e3744 | 1550 | return 0; |
fe69a505 | 1551 | |
ad72740e | 1552 | if ( !(aspath1->segments && aspath2->segments) ) |
1553 | return 0; | |
1554 | ||
fe69a505 | 1555 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) |
1556 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
718e3744 | 1557 | return 0; |
fe69a505 | 1558 | |
1559 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
718e3744 | 1560 | return 1; |
1561 | ||
1562 | return 0; | |
1563 | } | |
1564 | ||
fe69a505 | 1565 | /* Delete all leading AS_CONFED_SEQUENCE/SET segments from aspath. |
1566 | * See RFC3065, 6.1 c1 */ | |
718e3744 | 1567 | struct aspath * |
1568 | aspath_delete_confed_seq (struct aspath *aspath) | |
1569 | { | |
fe69a505 | 1570 | struct assegment *seg; |
718e3744 | 1571 | |
fe69a505 | 1572 | if (!(aspath && aspath->segments)) |
718e3744 | 1573 | return aspath; |
1574 | ||
fe69a505 | 1575 | seg = aspath->segments; |
1576 | ||
1577 | /* "if the first path segment of the AS_PATH is | |
1578 | * of type AS_CONFED_SEQUENCE," | |
1579 | */ | |
1580 | if (aspath->segments->type != AS_CONFED_SEQUENCE) | |
1581 | return aspath; | |
718e3744 | 1582 | |
fe69a505 | 1583 | /* "... that segment and any immediately following segments |
1584 | * of the type AS_CONFED_SET or AS_CONFED_SEQUENCE are removed | |
1585 | * from the AS_PATH attribute," | |
1586 | */ | |
1587 | while (seg && | |
1588 | (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET)) | |
718e3744 | 1589 | { |
fe69a505 | 1590 | aspath->segments = seg->next; |
1591 | assegment_free (seg); | |
1592 | seg = aspath->segments; | |
718e3744 | 1593 | } |
fe69a505 | 1594 | aspath_str_update (aspath); |
718e3744 | 1595 | return aspath; |
1596 | } | |
1597 | ||
1598 | /* Add new AS number to the leftmost part of the aspath as | |
1599 | AS_CONFED_SEQUENCE. */ | |
1600 | struct aspath* | |
1601 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1602 | { | |
1603 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1604 | } | |
1605 | ||
1606 | /* Add new as value to as path structure. */ | |
94f2b392 | 1607 | static void |
718e3744 | 1608 | aspath_as_add (struct aspath *as, as_t asno) |
1609 | { | |
fe69a505 | 1610 | struct assegment *seg = as->segments; |
718e3744 | 1611 | |
fe69a505 | 1612 | if (!seg) |
1613 | return; | |
1614 | ||
93c1749c AS |
1615 | /* Last segment search procedure. */ |
1616 | while (seg->next) | |
1617 | seg = seg->next; | |
1618 | ||
fe69a505 | 1619 | assegment_append_asns (seg, &asno, 1); |
718e3744 | 1620 | } |
1621 | ||
1622 | /* Add new as segment to the as path. */ | |
94f2b392 | 1623 | static void |
718e3744 | 1624 | aspath_segment_add (struct aspath *as, int type) |
1625 | { | |
fe69a505 | 1626 | struct assegment *seg = as->segments; |
1627 | struct assegment *new = assegment_new (type, 0); | |
718e3744 | 1628 | |
93c1749c AS |
1629 | if (seg) |
1630 | { | |
1631 | while (seg->next) | |
1632 | seg = seg->next; | |
1633 | seg->next = new; | |
1634 | } | |
718e3744 | 1635 | else |
93c1749c | 1636 | as->segments = new; |
718e3744 | 1637 | } |
1638 | ||
1639 | struct aspath * | |
94f2b392 | 1640 | aspath_empty (void) |
718e3744 | 1641 | { |
ab005298 | 1642 | return aspath_parse (NULL, 0, 1); /* 32Bit ;-) */ |
718e3744 | 1643 | } |
1644 | ||
1645 | struct aspath * | |
94f2b392 | 1646 | aspath_empty_get (void) |
718e3744 | 1647 | { |
1648 | struct aspath *aspath; | |
1649 | ||
1650 | aspath = aspath_new (); | |
f669f7d2 | 1651 | aspath_make_str_count (aspath); |
718e3744 | 1652 | return aspath; |
1653 | } | |
1654 | ||
1655 | unsigned long | |
fe69a505 | 1656 | aspath_count (void) |
718e3744 | 1657 | { |
1658 | return ashash->count; | |
1659 | } | |
1660 | \f | |
1661 | /* | |
1662 | Theoretically, one as path can have: | |
1663 | ||
1664 | One BGP packet size should be less than 4096. | |
1665 | One BGP attribute size should be less than 4096 - BGP header size. | |
1666 | One BGP aspath size should be less than 4096 - BGP header size - | |
1667 | BGP mandantry attribute size. | |
1668 | */ | |
1669 | ||
1670 | /* AS path string lexical token enum. */ | |
1671 | enum as_token | |
1672 | { | |
1673 | as_token_asval, | |
1674 | as_token_set_start, | |
1675 | as_token_set_end, | |
fe69a505 | 1676 | as_token_confed_seq_start, |
1677 | as_token_confed_seq_end, | |
1678 | as_token_confed_set_start, | |
1679 | as_token_confed_set_end, | |
718e3744 | 1680 | as_token_unknown |
1681 | }; | |
1682 | ||
1683 | /* Return next token and point for string parse. */ | |
94f2b392 | 1684 | static const char * |
0b2aa3a0 | 1685 | aspath_gettoken (const char *buf, enum as_token *token, u_long *asno) |
718e3744 | 1686 | { |
fd79ac91 | 1687 | const char *p = buf; |
718e3744 | 1688 | |
fe69a505 | 1689 | /* Skip seperators (space for sequences, ',' for sets). */ |
1690 | while (isspace ((int) *p) || *p == ',') | |
718e3744 | 1691 | p++; |
1692 | ||
1693 | /* Check the end of the string and type specify characters | |
1694 | (e.g. {}()). */ | |
1695 | switch (*p) | |
1696 | { | |
1697 | case '\0': | |
1698 | return NULL; | |
718e3744 | 1699 | case '{': |
1700 | *token = as_token_set_start; | |
1701 | p++; | |
1702 | return p; | |
718e3744 | 1703 | case '}': |
1704 | *token = as_token_set_end; | |
1705 | p++; | |
1706 | return p; | |
718e3744 | 1707 | case '(': |
fe69a505 | 1708 | *token = as_token_confed_seq_start; |
718e3744 | 1709 | p++; |
1710 | return p; | |
718e3744 | 1711 | case ')': |
fe69a505 | 1712 | *token = as_token_confed_seq_end; |
1713 | p++; | |
1714 | return p; | |
fe69a505 | 1715 | case '[': |
1716 | *token = as_token_confed_set_start; | |
1717 | p++; | |
1718 | return p; | |
fe69a505 | 1719 | case ']': |
1720 | *token = as_token_confed_set_end; | |
718e3744 | 1721 | p++; |
1722 | return p; | |
718e3744 | 1723 | } |
1724 | ||
1725 | /* Check actual AS value. */ | |
1726 | if (isdigit ((int) *p)) | |
1727 | { | |
10819ece | 1728 | as_t asval; |
0b2aa3a0 | 1729 | |
718e3744 | 1730 | *token = as_token_asval; |
1731 | asval = (*p - '0'); | |
1732 | p++; | |
0b2aa3a0 | 1733 | |
718e3744 | 1734 | while (isdigit ((int) *p)) |
0b2aa3a0 PJ |
1735 | { |
1736 | asval *= 10; | |
1737 | asval += (*p - '0'); | |
1738 | p++; | |
1739 | } | |
718e3744 | 1740 | *asno = asval; |
1741 | return p; | |
1742 | } | |
1743 | ||
1744 | /* There is no match then return unknown token. */ | |
1745 | *token = as_token_unknown; | |
1746 | return p++; | |
1747 | } | |
1748 | ||
1749 | struct aspath * | |
fd79ac91 | 1750 | aspath_str2aspath (const char *str) |
718e3744 | 1751 | { |
3fff6ffc | 1752 | enum as_token token = as_token_unknown; |
718e3744 | 1753 | u_short as_type; |
0b2aa3a0 | 1754 | u_long asno = 0; |
718e3744 | 1755 | struct aspath *aspath; |
1756 | int needtype; | |
1757 | ||
1758 | aspath = aspath_new (); | |
1759 | ||
1760 | /* We start default type as AS_SEQUENCE. */ | |
1761 | as_type = AS_SEQUENCE; | |
1762 | needtype = 1; | |
1763 | ||
1764 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1765 | { | |
1766 | switch (token) | |
1767 | { | |
1768 | case as_token_asval: | |
1769 | if (needtype) | |
1770 | { | |
1771 | aspath_segment_add (aspath, as_type); | |
1772 | needtype = 0; | |
1773 | } | |
1774 | aspath_as_add (aspath, asno); | |
1775 | break; | |
1776 | case as_token_set_start: | |
1777 | as_type = AS_SET; | |
1778 | aspath_segment_add (aspath, as_type); | |
1779 | needtype = 0; | |
1780 | break; | |
1781 | case as_token_set_end: | |
1782 | as_type = AS_SEQUENCE; | |
1783 | needtype = 1; | |
1784 | break; | |
fe69a505 | 1785 | case as_token_confed_seq_start: |
718e3744 | 1786 | as_type = AS_CONFED_SEQUENCE; |
1787 | aspath_segment_add (aspath, as_type); | |
1788 | needtype = 0; | |
1789 | break; | |
fe69a505 | 1790 | case as_token_confed_seq_end: |
1791 | as_type = AS_SEQUENCE; | |
1792 | needtype = 1; | |
1793 | break; | |
1794 | case as_token_confed_set_start: | |
1795 | as_type = AS_CONFED_SET; | |
1796 | aspath_segment_add (aspath, as_type); | |
1797 | needtype = 0; | |
1798 | break; | |
1799 | case as_token_confed_set_end: | |
718e3744 | 1800 | as_type = AS_SEQUENCE; |
1801 | needtype = 1; | |
1802 | break; | |
1803 | case as_token_unknown: | |
1804 | default: | |
fe69a505 | 1805 | aspath_free (aspath); |
718e3744 | 1806 | return NULL; |
718e3744 | 1807 | } |
1808 | } | |
1809 | ||
f669f7d2 | 1810 | aspath_make_str_count (aspath); |
718e3744 | 1811 | |
1812 | return aspath; | |
1813 | } | |
1814 | \f | |
1815 | /* Make hash value by raw aspath data. */ | |
1816 | unsigned int | |
923de654 | 1817 | aspath_key_make (void *p) |
718e3744 | 1818 | { |
f669f7d2 | 1819 | struct aspath *aspath = (struct aspath *) p; |
718e3744 | 1820 | unsigned int key = 0; |
718e3744 | 1821 | |
0b2aa3a0 PJ |
1822 | if (!aspath->str) |
1823 | aspath_str_update (aspath); | |
f669f7d2 JBD |
1824 | |
1825 | key = jhash (aspath->str, aspath->str_len, 2334325); | |
718e3744 | 1826 | |
1827 | return key; | |
1828 | } | |
1829 | ||
1830 | /* If two aspath have same value then return 1 else return 0 */ | |
96450faf | 1831 | int |
ffe11cfb | 1832 | aspath_cmp (const void *arg1, const void *arg2) |
718e3744 | 1833 | { |
aea339f7 DO |
1834 | const struct assegment *seg1 = ((const struct aspath *)arg1)->segments; |
1835 | const struct assegment *seg2 = ((const struct aspath *)arg2)->segments; | |
fe69a505 | 1836 | |
1837 | while (seg1 || seg2) | |
1838 | { | |
1839 | int i; | |
1840 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
1841 | return 0; | |
1842 | if (seg1->type != seg2->type) | |
1843 | return 0; | |
1844 | if (seg1->length != seg2->length) | |
1845 | return 0; | |
1846 | for (i = 0; i < seg1->length; i++) | |
1847 | if (seg1->as[i] != seg2->as[i]) | |
1848 | return 0; | |
1849 | seg1 = seg1->next; | |
1850 | seg2 = seg2->next; | |
1851 | } | |
1852 | return 1; | |
718e3744 | 1853 | } |
1854 | ||
1855 | /* AS path hash initialize. */ | |
1856 | void | |
94f2b392 | 1857 | aspath_init (void) |
718e3744 | 1858 | { |
90645f55 | 1859 | ashash = hash_create_size (32768, aspath_key_make, aspath_cmp); |
718e3744 | 1860 | } |
8fdc32ab | 1861 | |
1862 | void | |
1863 | aspath_finish (void) | |
1864 | { | |
1865 | hash_free (ashash); | |
228da428 | 1866 | ashash = NULL; |
8fdc32ab | 1867 | |
1868 | if (snmp_stream) | |
1869 | stream_free (snmp_stream); | |
1870 | } | |
718e3744 | 1871 | \f |
1872 | /* return and as path value */ | |
1873 | const char * | |
1874 | aspath_print (struct aspath *as) | |
1875 | { | |
fe69a505 | 1876 | return (as ? as->str : NULL); |
718e3744 | 1877 | } |
1878 | ||
1879 | /* Printing functions */ | |
841f7a57 DO |
1880 | /* Feed the AS_PATH to the vty; the suffix string follows it only in case |
1881 | * AS_PATH wasn't empty. | |
1882 | */ | |
718e3744 | 1883 | void |
841f7a57 | 1884 | aspath_print_vty (struct vty *vty, const char *format, struct aspath *as, const char * suffix) |
718e3744 | 1885 | { |
b2518c1e PJ |
1886 | assert (format); |
1887 | vty_out (vty, format, as->str); | |
f669f7d2 | 1888 | if (as->str_len && strlen (suffix)) |
841f7a57 | 1889 | vty_out (vty, "%s", suffix); |
718e3744 | 1890 | } |
1891 | ||
94f2b392 | 1892 | static void |
718e3744 | 1893 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) |
1894 | { | |
1895 | struct aspath *as; | |
1896 | ||
1897 | as = (struct aspath *) backet->data; | |
1898 | ||
efa9f830 | 1899 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); |
718e3744 | 1900 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); |
1901 | } | |
1902 | ||
1903 | /* Print all aspath and hash information. This function is used from | |
1904 | `show ip bgp paths' command. */ | |
1905 | void | |
1906 | aspath_print_all_vty (struct vty *vty) | |
1907 | { | |
1908 | hash_iterate (ashash, | |
1909 | (void (*) (struct hash_backet *, void *)) | |
1910 | aspath_show_all_iterator, | |
1911 | vty); | |
1912 | } |