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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 |
fe69a505 | 94 | static inline as_t * |
95 | assegment_data_new (int num) | |
96 | { | |
0b2aa3a0 | 97 | return (XCALLOC (MTYPE_AS_SEG_DATA, ASSEGMENT_DATA_SIZE (num, 1))); |
fe69a505 | 98 | } |
99 | ||
100 | static inline void | |
101 | assegment_data_free (as_t *asdata) | |
102 | { | |
103 | XFREE (MTYPE_AS_SEG_DATA,asdata); | |
104 | } | |
105 | ||
106 | /* Get a new segment. Note that 0 is an allowed length, | |
107 | * and will result in a segment with no allocated data segment. | |
108 | * the caller should immediately assign data to the segment, as the segment | |
109 | * otherwise is not generally valid | |
110 | */ | |
111 | static struct assegment * | |
112 | assegment_new (u_char type, u_short length) | |
113 | { | |
114 | struct assegment *new; | |
115 | ||
116 | new = XCALLOC (MTYPE_AS_SEG, sizeof (struct assegment)); | |
117 | ||
118 | if (length) | |
119 | new->as = assegment_data_new (length); | |
120 | ||
121 | new->length = length; | |
122 | new->type = type; | |
123 | ||
124 | return new; | |
125 | } | |
126 | ||
127 | static void | |
128 | assegment_free (struct assegment *seg) | |
129 | { | |
130 | if (!seg) | |
131 | return; | |
132 | ||
133 | if (seg->as) | |
134 | XFREE (MTYPE_AS_SEG_DATA, seg->as); | |
135 | memset (seg, 0xfe, sizeof(struct assegment)); | |
136 | XFREE (MTYPE_AS_SEG, seg); | |
137 | ||
138 | return; | |
139 | } | |
140 | ||
141 | /* free entire chain of segments */ | |
142 | static void | |
143 | assegment_free_all (struct assegment *seg) | |
144 | { | |
145 | struct assegment *prev; | |
146 | ||
147 | while (seg) | |
148 | { | |
149 | prev = seg; | |
150 | seg = seg->next; | |
151 | assegment_free (prev); | |
152 | } | |
153 | } | |
154 | ||
155 | /* Duplicate just the given assegment and its data */ | |
156 | static struct assegment * | |
157 | assegment_dup (struct assegment *seg) | |
158 | { | |
159 | struct assegment *new; | |
160 | ||
161 | new = assegment_new (seg->type, seg->length); | |
0b2aa3a0 | 162 | memcpy (new->as, seg->as, ASSEGMENT_DATA_SIZE (new->length, 1) ); |
fe69a505 | 163 | |
164 | return new; | |
165 | } | |
166 | ||
167 | /* Duplicate entire chain of assegments, return the head */ | |
168 | static struct assegment * | |
169 | assegment_dup_all (struct assegment *seg) | |
170 | { | |
171 | struct assegment *new = NULL; | |
172 | struct assegment *head = NULL; | |
173 | ||
174 | while (seg) | |
175 | { | |
176 | if (head) | |
177 | { | |
178 | new->next = assegment_dup (seg); | |
179 | new = new->next; | |
180 | } | |
181 | else | |
182 | head = new = assegment_dup (seg); | |
183 | ||
184 | seg = seg->next; | |
185 | } | |
186 | return head; | |
187 | } | |
188 | ||
189 | /* prepend the as number to given segment, given num of times */ | |
190 | static struct assegment * | |
191 | assegment_prepend_asns (struct assegment *seg, as_t asnum, int num) | |
192 | { | |
193 | as_t *newas; | |
194 | ||
195 | if (!num) | |
196 | return seg; | |
197 | ||
198 | if (num >= AS_SEGMENT_MAX) | |
199 | return seg; /* we don't do huge prepends */ | |
200 | ||
201 | newas = assegment_data_new (seg->length + num); | |
202 | ||
203 | if (newas) | |
204 | { | |
205 | int i; | |
206 | for (i = 0; i < num; i++) | |
207 | newas[i] = asnum; | |
208 | ||
0b2aa3a0 | 209 | memcpy (newas + num, seg->as, ASSEGMENT_DATA_SIZE (seg->length, 1)); |
fe69a505 | 210 | XFREE (MTYPE_AS_SEG_DATA, seg->as); |
211 | seg->as = newas; | |
212 | seg->length += num; | |
213 | return seg; | |
214 | } | |
215 | ||
216 | assegment_free_all (seg); | |
217 | return NULL; | |
218 | } | |
219 | ||
220 | /* append given array of as numbers to the segment */ | |
221 | static struct assegment * | |
222 | assegment_append_asns (struct assegment *seg, as_t *asnos, int num) | |
223 | { | |
02335429 | 224 | as_t *newas; |
225 | ||
226 | newas = XREALLOC (MTYPE_AS_SEG_DATA, seg->as, | |
0b2aa3a0 | 227 | ASSEGMENT_DATA_SIZE (seg->length + num, 1)); |
fe69a505 | 228 | |
02335429 | 229 | if (newas) |
fe69a505 | 230 | { |
02335429 | 231 | seg->as = newas; |
0b2aa3a0 | 232 | memcpy (seg->as + seg->length, asnos, ASSEGMENT_DATA_SIZE(num, 1)); |
fe69a505 | 233 | seg->length += num; |
234 | return seg; | |
235 | } | |
236 | ||
237 | assegment_free_all (seg); | |
238 | return NULL; | |
239 | } | |
240 | ||
241 | static int | |
242 | int_cmp (const void *p1, const void *p2) | |
243 | { | |
244 | const as_t *as1 = p1; | |
245 | const as_t *as2 = p2; | |
246 | ||
247 | return (*as1 == *as2) | |
248 | ? 0 : ( (*as1 > *as2) ? 1 : -1); | |
249 | } | |
250 | ||
251 | /* normalise the segment. | |
252 | * In particular, merge runs of AS_SEQUENCEs into one segment | |
253 | * Internally, we do not care about the wire segment length limit, and | |
254 | * we want each distinct AS_PATHs to have the exact same internal | |
255 | * representation - eg, so that our hashing actually works.. | |
256 | */ | |
257 | static struct assegment * | |
258 | assegment_normalise (struct assegment *head) | |
259 | { | |
260 | struct assegment *seg = head, *pin; | |
261 | struct assegment *tmp; | |
262 | ||
263 | if (!head) | |
264 | return head; | |
265 | ||
266 | while (seg) | |
267 | { | |
268 | pin = seg; | |
269 | ||
270 | /* Sort values SET segments, for determinism in paths to aid | |
271 | * creation of hash values / path comparisons | |
272 | * and because it helps other lesser implementations ;) | |
273 | */ | |
274 | if (seg->type == AS_SET || seg->type == AS_CONFED_SET) | |
0b2aa3a0 PJ |
275 | { |
276 | int tail = 0; | |
277 | int i; | |
278 | ||
279 | qsort (seg->as, seg->length, sizeof(as_t), int_cmp); | |
280 | ||
281 | /* weed out dupes */ | |
282 | for (i=1; i < seg->length; i++) | |
283 | { | |
284 | if (seg->as[tail] == seg->as[i]) | |
285 | continue; | |
286 | ||
287 | tail++; | |
288 | if (tail < i) | |
289 | seg->as[tail] = seg->as[i]; | |
290 | } | |
291 | /* seg->length can be 0.. */ | |
292 | if (seg->length) | |
293 | seg->length = tail + 1; | |
294 | } | |
fe69a505 | 295 | |
296 | /* read ahead from the current, pinned segment while the segments | |
297 | * are packable/mergeable. Append all following packable segments | |
298 | * to the segment we have pinned and remove these appended | |
299 | * segments. | |
300 | */ | |
301 | while (pin->next && ASSEGMENT_TYPES_PACKABLE(pin, pin->next)) | |
302 | { | |
303 | tmp = pin->next; | |
304 | seg = pin->next; | |
305 | ||
306 | /* append the next sequence to the pinned sequence */ | |
307 | pin = assegment_append_asns (pin, seg->as, seg->length); | |
308 | ||
309 | /* bypass the next sequence */ | |
310 | pin->next = seg->next; | |
311 | ||
312 | /* get rid of the now referenceless segment */ | |
313 | assegment_free (tmp); | |
314 | ||
315 | } | |
316 | ||
317 | seg = pin->next; | |
318 | } | |
319 | return head; | |
320 | } | |
321 | \f | |
718e3744 | 322 | static struct aspath * |
fe69a505 | 323 | aspath_new (void) |
718e3744 | 324 | { |
393deb9b | 325 | return XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 326 | } |
327 | ||
328 | /* Free AS path structure. */ | |
329 | void | |
330 | aspath_free (struct aspath *aspath) | |
331 | { | |
332 | if (!aspath) | |
333 | return; | |
fe69a505 | 334 | if (aspath->segments) |
335 | assegment_free_all (aspath->segments); | |
718e3744 | 336 | if (aspath->str) |
337 | XFREE (MTYPE_AS_STR, aspath->str); | |
338 | XFREE (MTYPE_AS_PATH, aspath); | |
339 | } | |
340 | ||
341 | /* Unintern aspath from AS path bucket. */ | |
342 | void | |
343 | aspath_unintern (struct aspath *aspath) | |
344 | { | |
345 | struct aspath *ret; | |
346 | ||
347 | if (aspath->refcnt) | |
348 | aspath->refcnt--; | |
349 | ||
350 | if (aspath->refcnt == 0) | |
351 | { | |
352 | /* This aspath must exist in aspath hash table. */ | |
353 | ret = hash_release (ashash, aspath); | |
354 | assert (ret != NULL); | |
355 | aspath_free (aspath); | |
356 | } | |
357 | } | |
358 | ||
359 | /* Return the start or end delimiters for a particular Segment type */ | |
360 | #define AS_SEG_START 0 | |
361 | #define AS_SEG_END 1 | |
362 | static char | |
363 | aspath_delimiter_char (u_char type, u_char which) | |
364 | { | |
365 | int i; | |
366 | struct | |
367 | { | |
368 | int type; | |
369 | char start; | |
370 | char end; | |
371 | } aspath_delim_char [] = | |
372 | { | |
373 | { AS_SET, '{', '}' }, | |
718e3744 | 374 | { AS_CONFED_SET, '[', ']' }, |
375 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
376 | { 0 } | |
377 | }; | |
378 | ||
379 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
380 | { | |
381 | if (aspath_delim_char[i].type == type) | |
382 | { | |
383 | if (which == AS_SEG_START) | |
384 | return aspath_delim_char[i].start; | |
385 | else if (which == AS_SEG_END) | |
386 | return aspath_delim_char[i].end; | |
387 | } | |
388 | } | |
389 | return ' '; | |
390 | } | |
391 | ||
014b670e DO |
392 | /* countup asns from this segment and index onward */ |
393 | static int | |
394 | assegment_count_asns (struct assegment *seg, int from) | |
395 | { | |
396 | int count = 0; | |
397 | while (seg) | |
398 | { | |
399 | if (!from) | |
400 | count += seg->length; | |
401 | else | |
402 | { | |
403 | count += (seg->length - from); | |
404 | from = 0; | |
405 | } | |
406 | seg = seg->next; | |
407 | } | |
408 | return count; | |
409 | } | |
410 | ||
fe69a505 | 411 | unsigned int |
412 | aspath_count_confeds (struct aspath *aspath) | |
413 | { | |
414 | int count = 0; | |
415 | struct assegment *seg = aspath->segments; | |
416 | ||
417 | while (seg) | |
418 | { | |
419 | if (seg->type == AS_CONFED_SEQUENCE) | |
420 | count += seg->length; | |
421 | else if (seg->type == AS_CONFED_SET) | |
422 | count++; | |
423 | ||
424 | seg = seg->next; | |
425 | } | |
426 | return count; | |
427 | } | |
428 | ||
429 | unsigned int | |
430 | aspath_count_hops (struct aspath *aspath) | |
431 | { | |
432 | int count = 0; | |
433 | struct assegment *seg = aspath->segments; | |
434 | ||
435 | while (seg) | |
436 | { | |
437 | if (seg->type == AS_SEQUENCE) | |
438 | count += seg->length; | |
439 | else if (seg->type == AS_SET) | |
440 | count++; | |
441 | ||
442 | seg = seg->next; | |
443 | } | |
444 | return count; | |
445 | } | |
446 | ||
0b2aa3a0 PJ |
447 | /* Estimate size aspath /might/ take if encoded into an |
448 | * ASPATH attribute. | |
449 | * | |
450 | * This is a quick estimate, not definitive! aspath_put() | |
451 | * may return a different number!! | |
452 | */ | |
fe69a505 | 453 | unsigned int |
454 | aspath_size (struct aspath *aspath) | |
455 | { | |
456 | int size = 0; | |
457 | struct assegment *seg = aspath->segments; | |
458 | ||
459 | while (seg) | |
460 | { | |
0b2aa3a0 | 461 | size += ASSEGMENT_SIZE(seg->length, 1); |
fe69a505 | 462 | seg = seg->next; |
463 | } | |
464 | return size; | |
465 | } | |
466 | ||
2815e61f PJ |
467 | /* Return highest public ASN in path */ |
468 | as_t | |
469 | aspath_highest (struct aspath *aspath) | |
470 | { | |
471 | struct assegment *seg = aspath->segments; | |
472 | as_t highest = 0; | |
473 | unsigned int i; | |
474 | ||
475 | while (seg) | |
476 | { | |
477 | for (i = 0; i < seg->length; i++) | |
478 | if (seg->as[i] > highest | |
479 | && (seg->as[i] < BGP_PRIVATE_AS_MIN | |
480 | || seg->as[i] > BGP_PRIVATE_AS_MAX)) | |
481 | highest = seg->as[i]; | |
482 | seg = seg->next; | |
483 | } | |
484 | return highest; | |
485 | } | |
486 | ||
0b2aa3a0 PJ |
487 | /* Return 1 if there are any 4-byte ASes in the path */ |
488 | unsigned int | |
489 | aspath_has_as4 (struct aspath *aspath) | |
490 | { | |
491 | struct assegment *seg = aspath->segments; | |
492 | unsigned int i; | |
493 | ||
494 | while (seg) | |
495 | { | |
496 | for (i = 0; i < seg->length; i++) | |
497 | if (seg->as[i] > BGP_AS_MAX) | |
498 | return 1; | |
499 | seg = seg->next; | |
500 | } | |
501 | return 0; | |
502 | } | |
503 | ||
718e3744 | 504 | /* Convert aspath structure to string expression. */ |
94f2b392 | 505 | static char * |
718e3744 | 506 | aspath_make_str_count (struct aspath *as) |
507 | { | |
fe69a505 | 508 | struct assegment *seg; |
509 | int str_size; | |
510 | int len = 0; | |
c9e52be3 | 511 | char *str_buf; |
718e3744 | 512 | |
513 | /* Empty aspath. */ | |
fe69a505 | 514 | if (!as->segments) |
718e3744 | 515 | { |
516 | str_buf = XMALLOC (MTYPE_AS_STR, 1); | |
517 | str_buf[0] = '\0'; | |
718e3744 | 518 | return str_buf; |
519 | } | |
fe69a505 | 520 | |
521 | seg = as->segments; | |
522 | ||
014b670e DO |
523 | /* ASN takes 5 to 10 chars plus seperator, see below. |
524 | * If there is one differing segment type, we need an additional | |
525 | * 2 chars for segment delimiters, and the final '\0'. | |
526 | * Hopefully this is large enough to avoid hitting the realloc | |
527 | * code below for most common sequences. | |
528 | * | |
529 | * This was changed to 10 after the well-known BGP assertion, which | |
530 | * had hit some parts of the Internet in May of 2009. | |
531 | */ | |
532 | #define ASN_STR_LEN (10 + 1) | |
533 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
534 | ASPATH_STR_DEFAULT_LEN); | |
718e3744 | 535 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); |
718e3744 | 536 | |
fe69a505 | 537 | while (seg) |
718e3744 | 538 | { |
539 | int i; | |
fe69a505 | 540 | char seperator; |
718e3744 | 541 | |
fe69a505 | 542 | /* Check AS type validity. Set seperator for segment */ |
543 | switch (seg->type) | |
544 | { | |
545 | case AS_SET: | |
546 | case AS_CONFED_SET: | |
547 | seperator = ','; | |
548 | break; | |
549 | case AS_SEQUENCE: | |
550 | case AS_CONFED_SEQUENCE: | |
551 | seperator = ' '; | |
552 | break; | |
553 | default: | |
554 | XFREE (MTYPE_AS_STR, str_buf); | |
555 | return NULL; | |
556 | } | |
557 | ||
014b670e DO |
558 | /* We might need to increase str_buf, particularly if path has |
559 | * differing segments types, our initial guesstimate above will | |
560 | * have been wrong. Need 10 chars for ASN, a seperator each and | |
561 | * potentially two segment delimiters, plus a space between each | |
562 | * segment and trailing zero. | |
563 | * | |
564 | * This definitely didn't work with the value of 5 bytes and | |
565 | * 32-bit ASNs. | |
566 | */ | |
567 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
568 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
569 | { | |
570 | str_size = len + SEGMENT_STR_LEN(seg); | |
571 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
572 | } | |
573 | #undef ASN_STR_LEN | |
574 | #undef SEGMENT_STR_LEN | |
575 | ||
fe69a505 | 576 | if (seg->type != AS_SEQUENCE) |
014b670e DO |
577 | len += snprintf (str_buf + len, str_size - len, |
578 | "%c", | |
579 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
fe69a505 | 580 | |
581 | /* write out the ASNs, with their seperators, bar the last one*/ | |
582 | for (i = 0; i < seg->length; i++) | |
583 | { | |
584 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); | |
585 | ||
586 | if (i < (seg->length - 1)) | |
587 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
588 | } | |
589 | ||
590 | if (seg->type != AS_SEQUENCE) | |
591 | len += snprintf (str_buf + len, str_size - len, "%c", | |
592 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
593 | if (seg->next) | |
594 | len += snprintf (str_buf + len, str_size - len, " "); | |
595 | ||
596 | seg = seg->next; | |
718e3744 | 597 | } |
fe69a505 | 598 | |
599 | assert (len < str_size); | |
600 | ||
601 | str_buf[len] = '\0'; | |
718e3744 | 602 | |
603 | return str_buf; | |
604 | } | |
605 | ||
fe69a505 | 606 | static void |
607 | aspath_str_update (struct aspath *as) | |
608 | { | |
609 | if (as->str) | |
610 | XFREE (MTYPE_AS_STR, as->str); | |
611 | as->str = aspath_make_str_count (as); | |
612 | } | |
613 | ||
718e3744 | 614 | /* Intern allocated AS path. */ |
615 | struct aspath * | |
616 | aspath_intern (struct aspath *aspath) | |
617 | { | |
618 | struct aspath *find; | |
619 | ||
620 | /* Assert this AS path structure is not interned. */ | |
621 | assert (aspath->refcnt == 0); | |
622 | ||
623 | /* Check AS path hash. */ | |
624 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
625 | ||
626 | if (find != aspath) | |
fe69a505 | 627 | aspath_free (aspath); |
718e3744 | 628 | |
629 | find->refcnt++; | |
630 | ||
631 | if (! find->str) | |
632 | find->str = aspath_make_str_count (find); | |
633 | ||
634 | return find; | |
635 | } | |
636 | ||
637 | /* Duplicate aspath structure. Created same aspath structure but | |
638 | reference count and AS path string is cleared. */ | |
639 | struct aspath * | |
640 | aspath_dup (struct aspath *aspath) | |
641 | { | |
642 | struct aspath *new; | |
643 | ||
fe69a505 | 644 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 645 | |
fe69a505 | 646 | if (aspath->segments) |
647 | new->segments = assegment_dup_all (aspath->segments); | |
718e3744 | 648 | else |
fe69a505 | 649 | new->segments = NULL; |
718e3744 | 650 | |
fe69a505 | 651 | new->str = aspath_make_str_count (aspath); |
718e3744 | 652 | |
653 | return new; | |
654 | } | |
655 | ||
94f2b392 | 656 | static void * |
fe69a505 | 657 | aspath_hash_alloc (void *arg) |
718e3744 | 658 | { |
659 | struct aspath *aspath; | |
660 | ||
0b2aa3a0 | 661 | /* New aspath structure is needed. */ |
fe69a505 | 662 | aspath = aspath_dup (arg); |
663 | ||
718e3744 | 664 | /* Malformed AS path value. */ |
665 | if (! aspath->str) | |
666 | { | |
667 | aspath_free (aspath); | |
668 | return NULL; | |
669 | } | |
670 | ||
671 | return aspath; | |
672 | } | |
673 | ||
cddb8112 CH |
674 | /* parse as-segment byte stream in struct assegment |
675 | * | |
676 | * Returns NULL if the AS_PATH or AS4_PATH is not valid. | |
677 | */ | |
ad72740e | 678 | static struct assegment * |
cddb8112 | 679 | assegments_parse (struct stream *s, size_t length, int use32bit, int as4_path) |
fe69a505 | 680 | { |
681 | struct assegment_header segh; | |
682 | struct assegment *seg, *prev = NULL, *head = NULL; | |
fe69a505 | 683 | |
cddb8112 | 684 | assert (length > 0); /* does not expect empty AS_PATH or AS4_PATH */ |
fe69a505 | 685 | |
0b2aa3a0 PJ |
686 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
687 | zlog_debug ("[AS4SEG] Parse aspath segment: got total byte length %lu", | |
688 | (unsigned long) length); | |
cddb8112 CH |
689 | |
690 | /* double check that length does not exceed stream */ | |
691 | if (STREAM_READABLE(s) < length) | |
fe69a505 | 692 | return NULL; |
693 | ||
cddb8112 CH |
694 | /* deal with each segment in turn */ |
695 | while (length > 0) | |
fe69a505 | 696 | { |
697 | int i; | |
cddb8112 | 698 | size_t seg_size; |
fe69a505 | 699 | |
700 | /* softly softly, get the header first on its own */ | |
fdbc8e77 | 701 | if (length < AS_HEADER_SIZE) |
cddb8112 | 702 | { |
fdbc8e77 PJ |
703 | assegment_free_all (head); |
704 | return NULL; | |
705 | } | |
706 | ||
fe69a505 | 707 | segh.type = stream_getc (s); |
708 | segh.length = stream_getc (s); | |
709 | ||
0b2aa3a0 | 710 | seg_size = ASSEGMENT_SIZE(segh.length, use32bit); |
cddb8112 | 711 | /* includes the header bytes */ |
0b2aa3a0 PJ |
712 | |
713 | if (BGP_DEBUG (as4, AS4_SEGMENT)) | |
714 | zlog_debug ("[AS4SEG] Parse aspath segment: got type %d, length %d", | |
715 | segh.type, segh.length); | |
716 | ||
fdbc8e77 PJ |
717 | switch (segh.type) |
718 | { | |
719 | case AS_SEQUENCE: | |
720 | case AS_SET: | |
721 | break ; | |
cddb8112 | 722 | |
fdbc8e77 PJ |
723 | case AS_CONFED_SEQUENCE: |
724 | case AS_CONFED_SET: | |
725 | if (!as4_path) | |
726 | break ; | |
cddb8112 CH |
727 | /* RFC4893 3: "invalid for the AS4_PATH attribute" */ |
728 | /* fall through */ | |
729 | ||
fdbc8e77 PJ |
730 | default: /* reject unknown or invalid AS_PATH segment types */ |
731 | seg_size = 0 ; | |
cddb8112 | 732 | } |
fdbc8e77 | 733 | |
cddb8112 CH |
734 | /* Stop now if segment is not valid (discarding anything collected to date) |
735 | * | |
736 | * RFC4271 4.3, Path Attributes, b) AS_PATH: | |
737 | * | |
738 | * "path segment value field contains one or more AS numbers" | |
2eb445e1 | 739 | */ |
cddb8112 | 740 | if ((seg_size == 0) || (seg_size > length) || (segh.length == 0)) |
fe69a505 | 741 | { |
fdbc8e77 | 742 | assegment_free_all (head); |
fe69a505 | 743 | return NULL; |
744 | } | |
745 | ||
cddb8112 CH |
746 | length -= seg_size ; |
747 | ||
fe69a505 | 748 | /* now its safe to trust lengths */ |
749 | seg = assegment_new (segh.type, segh.length); | |
750 | ||
751 | if (head) | |
752 | prev->next = seg; | |
753 | else /* it's the first segment */ | |
754 | head = prev = seg; | |
755 | ||
756 | for (i = 0; i < segh.length; i++) | |
0b2aa3a0 PJ |
757 | seg->as[i] = (use32bit) ? stream_getl (s) : stream_getw (s); |
758 | ||
0b2aa3a0 | 759 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
cddb8112 CH |
760 | zlog_debug ("[AS4SEG] Parse aspath segment: length left: %lu", |
761 | (unsigned long) length); | |
fe69a505 | 762 | |
763 | prev = seg; | |
764 | } | |
765 | ||
766 | return assegment_normalise (head); | |
767 | } | |
768 | ||
cddb8112 CH |
769 | /* AS path parse function -- parses AS_PATH and AS4_PATH attributes |
770 | * | |
771 | * Requires: s -- stream, currently positioned before first segment | |
772 | * of AS_PATH or AS4_PATH (ie after attribute header) | |
773 | * length -- length of the value of the AS_PATH or AS4_PATH | |
774 | * use32bit -- true <=> 4Byte ASN, otherwise 2Byte ASN | |
775 | * as4_path -- true <=> AS4_PATH, otherwise AS_PATH | |
776 | * | |
777 | * Returns: if valid: address of struct aspath in the hash of known aspaths, | |
778 | * with reference count incremented. | |
779 | * else: NULL | |
780 | * | |
781 | * NB: empty AS path (length == 0) is valid. The returned struct aspath will | |
782 | * have segments == NULL and str == zero length string (unique). | |
783 | */ | |
718e3744 | 784 | struct aspath * |
cddb8112 | 785 | aspath_parse (struct stream *s, size_t length, int use32bit, int as4_path) |
718e3744 | 786 | { |
787 | struct aspath as; | |
788 | struct aspath *find; | |
789 | ||
cddb8112 | 790 | /* Parse each segment and construct normalised list of struct assegment */ |
0b2aa3a0 | 791 | memset (&as, 0, sizeof (struct aspath)); |
cddb8112 CH |
792 | if (length != 0) |
793 | { | |
794 | as.segments = assegments_parse (s, length, use32bit, as4_path); | |
795 | ||
796 | if (as.segments == NULL) | |
797 | return NULL ; /* Invalid AS_PATH or AS4_PATH */ | |
798 | } ; | |
fe69a505 | 799 | |
718e3744 | 800 | /* If already same aspath exist then return it. */ |
801 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
02335429 | 802 | |
cddb8112 CH |
803 | assert(find) ; /* valid aspath, so must find or create */ |
804 | ||
02335429 | 805 | /* aspath_hash_alloc dupes segments too. that probably could be |
806 | * optimised out. | |
807 | */ | |
808 | assegment_free_all (as.segments); | |
0b2aa3a0 PJ |
809 | if (as.str) |
810 | XFREE (MTYPE_AS_STR, as.str); | |
02335429 | 811 | |
718e3744 | 812 | find->refcnt++; |
813 | ||
814 | return find; | |
815 | } | |
816 | ||
fe69a505 | 817 | static inline void |
0b2aa3a0 | 818 | assegment_data_put (struct stream *s, as_t *as, int num, int use32bit) |
fe69a505 | 819 | { |
820 | int i; | |
821 | assert (num <= AS_SEGMENT_MAX); | |
822 | ||
823 | for (i = 0; i < num; i++) | |
0b2aa3a0 PJ |
824 | if ( use32bit ) |
825 | stream_putl (s, as[i]); | |
826 | else | |
827 | { | |
828 | if ( as[i] <= BGP_AS_MAX ) | |
829 | stream_putw(s, as[i]); | |
830 | else | |
831 | stream_putw(s, BGP_AS_TRANS); | |
832 | } | |
fe69a505 | 833 | } |
718e3744 | 834 | |
fe69a505 | 835 | static inline size_t |
836 | assegment_header_put (struct stream *s, u_char type, int length) | |
718e3744 | 837 | { |
fe69a505 | 838 | size_t lenp; |
839 | assert (length <= AS_SEGMENT_MAX); | |
840 | stream_putc (s, type); | |
841 | lenp = stream_get_endp (s); | |
842 | stream_putc (s, length); | |
843 | return lenp; | |
844 | } | |
718e3744 | 845 | |
fe69a505 | 846 | /* write aspath data to stream */ |
0b2aa3a0 PJ |
847 | size_t |
848 | aspath_put (struct stream *s, struct aspath *as, int use32bit ) | |
fe69a505 | 849 | { |
850 | struct assegment *seg = as->segments; | |
0b2aa3a0 | 851 | size_t bytes = 0; |
fe69a505 | 852 | |
853 | if (!seg || seg->length == 0) | |
0b2aa3a0 | 854 | return 0; |
fe69a505 | 855 | |
856 | if (seg) | |
718e3744 | 857 | { |
0b2aa3a0 PJ |
858 | /* |
859 | * Hey, what do we do when we have > STREAM_WRITABLE(s) here? | |
860 | * At the moment, we would write out a partial aspath, and our peer | |
861 | * will complain and drop the session :-/ | |
862 | * | |
863 | * The general assumption here is that many things tested will | |
864 | * never happen. And, in real live, up to now, they have not. | |
865 | */ | |
866 | while (seg && (ASSEGMENT_LEN(seg, use32bit) <= STREAM_WRITEABLE(s))) | |
fe69a505 | 867 | { |
0b2aa3a0 | 868 | struct assegment *next = seg->next; |
fe69a505 | 869 | int written = 0; |
0b2aa3a0 | 870 | int asns_packed = 0; |
fe69a505 | 871 | size_t lenp; |
872 | ||
873 | /* Overlength segments have to be split up */ | |
874 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
875 | { | |
876 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
0b2aa3a0 | 877 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX, use32bit); |
fe69a505 | 878 | written += AS_SEGMENT_MAX; |
0b2aa3a0 | 879 | bytes += ASSEGMENT_SIZE (written, use32bit); |
fe69a505 | 880 | } |
881 | ||
882 | /* write the final segment, probably is also the first */ | |
883 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
0b2aa3a0 PJ |
884 | assegment_data_put (s, (seg->as + written), seg->length - written, |
885 | use32bit); | |
fe69a505 | 886 | |
887 | /* Sequence-type segments can be 'packed' together | |
888 | * Case of a segment which was overlength and split up | |
889 | * will be missed here, but that doesn't matter. | |
890 | */ | |
0b2aa3a0 | 891 | while (next && ASSEGMENTS_PACKABLE (seg, next)) |
fe69a505 | 892 | { |
893 | /* NB: We should never normally get here given we | |
894 | * normalise aspath data when parse them. However, better | |
895 | * safe than sorry. We potentially could call | |
896 | * assegment_normalise here instead, but it's cheaper and | |
897 | * easier to do it on the fly here rather than go through | |
898 | * the segment list twice every time we write out | |
899 | * aspath's. | |
900 | */ | |
901 | ||
902 | /* Next segment's data can fit in this one */ | |
0b2aa3a0 | 903 | assegment_data_put (s, next->as, next->length, use32bit); |
fe69a505 | 904 | |
905 | /* update the length of the segment header */ | |
0b2aa3a0 PJ |
906 | stream_putc_at (s, lenp, seg->length - written + next->length); |
907 | asns_packed += next->length; | |
908 | ||
909 | next = next->next; | |
fe69a505 | 910 | } |
0b2aa3a0 PJ |
911 | |
912 | bytes += ASSEGMENT_SIZE (seg->length - written + asns_packed, | |
913 | use32bit); | |
914 | seg = next; | |
fe69a505 | 915 | } |
718e3744 | 916 | } |
0b2aa3a0 | 917 | return bytes; |
fe69a505 | 918 | } |
919 | ||
920 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
921 | * We have no way to manage the storage, so we use a static stream | |
922 | * wrapper around aspath_put. | |
923 | */ | |
924 | u_char * | |
925 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
926 | { | |
927 | #define SNMP_PATHSEG_MAX 1024 | |
8fdc32ab | 928 | |
929 | if (!snmp_stream) | |
930 | snmp_stream = stream_new (SNMP_PATHSEG_MAX); | |
718e3744 | 931 | else |
8fdc32ab | 932 | stream_reset (snmp_stream); |
fe69a505 | 933 | |
934 | if (!as) | |
718e3744 | 935 | { |
fe69a505 | 936 | *varlen = 0; |
937 | return NULL; | |
718e3744 | 938 | } |
0b2aa3a0 | 939 | aspath_put (snmp_stream, as, 0); /* use 16 bit for now here */ |
fe69a505 | 940 | |
8fdc32ab | 941 | *varlen = stream_get_endp (snmp_stream); |
942 | return stream_pnt(snmp_stream); | |
718e3744 | 943 | } |
fe69a505 | 944 | |
945 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
718e3744 | 946 | |
94f2b392 | 947 | static struct assegment * |
718e3744 | 948 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, |
949 | as_t as) | |
950 | { | |
951 | int i; | |
952 | ||
953 | /* If this is first AS set member, create new as-set segment. */ | |
954 | if (asset == NULL) | |
955 | { | |
fe69a505 | 956 | asset = assegment_new (AS_SET, 1); |
957 | if (! aspath->segments) | |
958 | aspath->segments = asset; | |
718e3744 | 959 | else |
fe69a505 | 960 | { |
961 | struct assegment *seg = aspath->segments; | |
962 | while (seg->next) | |
963 | seg = seg->next; | |
964 | seg->next = asset; | |
965 | } | |
718e3744 | 966 | asset->type = AS_SET; |
967 | asset->length = 1; | |
fe69a505 | 968 | asset->as[0] = as; |
718e3744 | 969 | } |
970 | else | |
971 | { | |
718e3744 | 972 | /* Check this AS value already exists or not. */ |
973 | for (i = 0; i < asset->length; i++) | |
fe69a505 | 974 | if (asset->as[i] == as) |
718e3744 | 975 | return asset; |
fe69a505 | 976 | |
718e3744 | 977 | asset->length++; |
fe69a505 | 978 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, |
979 | asset->length * AS_VALUE_SIZE); | |
980 | asset->as[asset->length - 1] = as; | |
718e3744 | 981 | } |
fe69a505 | 982 | |
718e3744 | 983 | |
984 | return asset; | |
985 | } | |
986 | ||
987 | /* Modify as1 using as2 for aggregation. */ | |
988 | struct aspath * | |
989 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
990 | { | |
991 | int i; | |
992 | int minlen; | |
993 | int match; | |
fe69a505 | 994 | int from; |
995 | struct assegment *seg1 = as1->segments; | |
996 | struct assegment *seg2 = as2->segments; | |
0b2aa3a0 | 997 | struct aspath *aspath = NULL; |
718e3744 | 998 | struct assegment *asset; |
0b2aa3a0 | 999 | struct assegment *prevseg = NULL; |
718e3744 | 1000 | |
1001 | match = 0; | |
1002 | minlen = 0; | |
1003 | aspath = NULL; | |
1004 | asset = NULL; | |
718e3744 | 1005 | |
1006 | /* First of all check common leading sequence. */ | |
fe69a505 | 1007 | while (seg1 && seg2) |
0b2aa3a0 | 1008 | { |
718e3744 | 1009 | /* Check segment type. */ |
1010 | if (seg1->type != seg2->type) | |
1011 | break; | |
1012 | ||
1013 | /* Minimum segment length. */ | |
1014 | minlen = min (seg1->length, seg2->length); | |
1015 | ||
1016 | for (match = 0; match < minlen; match++) | |
fe69a505 | 1017 | if (seg1->as[match] != seg2->as[match]) |
718e3744 | 1018 | break; |
1019 | ||
1020 | if (match) | |
1021 | { | |
0b2aa3a0 PJ |
1022 | struct assegment *seg = assegment_new (seg1->type, 0); |
1023 | ||
1024 | seg = assegment_append_asns (seg, seg1->as, match); | |
1025 | ||
718e3744 | 1026 | if (! aspath) |
0b2aa3a0 PJ |
1027 | { |
1028 | aspath = aspath_new (); | |
1029 | aspath->segments = seg; | |
1030 | } | |
1031 | else | |
1032 | prevseg->next = seg; | |
1033 | ||
1034 | prevseg = seg; | |
718e3744 | 1035 | } |
1036 | ||
1037 | if (match != minlen || match != seg1->length | |
1038 | || seg1->length != seg2->length) | |
1039 | break; | |
fe69a505 | 1040 | |
1041 | seg1 = seg1->next; | |
1042 | seg2 = seg2->next; | |
718e3744 | 1043 | } |
1044 | ||
1045 | if (! aspath) | |
1046 | aspath = aspath_new(); | |
1047 | ||
1048 | /* Make as-set using rest of all information. */ | |
fe69a505 | 1049 | from = match; |
1050 | while (seg1) | |
718e3744 | 1051 | { |
fe69a505 | 1052 | for (i = from; i < seg1->length; i++) |
1053 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
1054 | ||
1055 | from = 0; | |
1056 | seg1 = seg1->next; | |
718e3744 | 1057 | } |
1058 | ||
fe69a505 | 1059 | from = match; |
1060 | while (seg2) | |
718e3744 | 1061 | { |
fe69a505 | 1062 | for (i = from; i < seg2->length; i++) |
1063 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
718e3744 | 1064 | |
fe69a505 | 1065 | from = 0; |
1066 | seg2 = seg2->next; | |
718e3744 | 1067 | } |
fe69a505 | 1068 | |
1069 | assegment_normalise (aspath->segments); | |
1070 | aspath_str_update (aspath); | |
718e3744 | 1071 | return aspath; |
1072 | } | |
1073 | ||
1074 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
1075 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
1076 | or not the peer's AS number. */ | |
1077 | int | |
1078 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
1079 | { | |
fe69a505 | 1080 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1081 | return 0; |
fe69a505 | 1082 | |
1083 | if (aspath->segments | |
1084 | && (aspath->segments->type == AS_SEQUENCE) | |
1085 | && (aspath->segments->as[0] == asno )) | |
718e3744 | 1086 | return 1; |
1087 | ||
1088 | return 0; | |
1089 | } | |
1090 | ||
1f742f21 | 1091 | /* AS path loop check. If aspath contains asno then return >= 1. */ |
718e3744 | 1092 | int |
1093 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
1094 | { | |
fe69a505 | 1095 | struct assegment *seg; |
718e3744 | 1096 | int count = 0; |
1097 | ||
1f742f21 | 1098 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1099 | return 0; |
fe69a505 | 1100 | |
1101 | seg = aspath->segments; | |
1102 | ||
1103 | while (seg) | |
718e3744 | 1104 | { |
1105 | int i; | |
718e3744 | 1106 | |
fe69a505 | 1107 | for (i = 0; i < seg->length; i++) |
1108 | if (seg->as[i] == asno) | |
718e3744 | 1109 | count++; |
fe69a505 | 1110 | |
1111 | seg = seg->next; | |
718e3744 | 1112 | } |
1113 | return count; | |
1114 | } | |
1115 | ||
1116 | /* When all of AS path is private AS return 1. */ | |
1117 | int | |
1118 | aspath_private_as_check (struct aspath *aspath) | |
1119 | { | |
fe69a505 | 1120 | struct assegment *seg; |
1121 | ||
1122 | if ( !(aspath && aspath->segments) ) | |
718e3744 | 1123 | return 0; |
fe69a505 | 1124 | |
1125 | seg = aspath->segments; | |
718e3744 | 1126 | |
fe69a505 | 1127 | while (seg) |
718e3744 | 1128 | { |
1129 | int i; | |
718e3744 | 1130 | |
fe69a505 | 1131 | for (i = 0; i < seg->length; i++) |
718e3744 | 1132 | { |
fe69a505 | 1133 | if ( (seg->as[i] < BGP_PRIVATE_AS_MIN) |
1134 | || (seg->as[i] > BGP_PRIVATE_AS_MAX) ) | |
718e3744 | 1135 | return 0; |
1136 | } | |
fe69a505 | 1137 | seg = seg->next; |
718e3744 | 1138 | } |
1139 | return 1; | |
1140 | } | |
1141 | ||
ca87e1d3 VT |
1142 | /* AS path confed check. If aspath contains confed set or sequence then return 1. */ |
1143 | int | |
1144 | aspath_confed_check (struct aspath *aspath) | |
1145 | { | |
1146 | struct assegment *seg; | |
1147 | ||
1148 | if ( !(aspath && aspath->segments) ) | |
1149 | return 0; | |
1150 | ||
1151 | seg = aspath->segments; | |
1152 | ||
1153 | while (seg) | |
1154 | { | |
1155 | if (seg->type == AS_CONFED_SET || seg->type == AS_CONFED_SEQUENCE) | |
1156 | return 1; | |
1157 | seg = seg->next; | |
1158 | } | |
1159 | return 0; | |
1160 | } | |
1161 | ||
1162 | /* Leftmost AS path segment confed check. If leftmost AS segment is of type | |
1163 | AS_CONFED_SEQUENCE or AS_CONFED_SET then return 1. */ | |
1164 | int | |
1165 | aspath_left_confed_check (struct aspath *aspath) | |
1166 | { | |
1167 | ||
1168 | if ( !(aspath && aspath->segments) ) | |
1169 | return 0; | |
1170 | ||
1171 | if ( (aspath->segments->type == AS_CONFED_SEQUENCE) | |
1172 | || (aspath->segments->type == AS_CONFED_SET) ) | |
1173 | return 1; | |
1174 | ||
1175 | return 0; | |
1176 | } | |
1177 | ||
718e3744 | 1178 | /* Merge as1 to as2. as2 should be uninterned aspath. */ |
94f2b392 | 1179 | static struct aspath * |
718e3744 | 1180 | aspath_merge (struct aspath *as1, struct aspath *as2) |
1181 | { | |
fe69a505 | 1182 | struct assegment *last, *new; |
718e3744 | 1183 | |
1184 | if (! as1 || ! as2) | |
1185 | return NULL; | |
1186 | ||
fe69a505 | 1187 | last = new = assegment_dup_all (as1->segments); |
1188 | ||
1189 | /* find the last valid segment */ | |
1190 | while (last && last->next) | |
1191 | last = last->next; | |
1192 | ||
1193 | last->next = as2->segments; | |
1194 | as2->segments = new; | |
1195 | aspath_str_update (as2); | |
718e3744 | 1196 | return as2; |
1197 | } | |
1198 | ||
1199 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1200 | struct aspath * | |
1201 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1202 | { | |
fe69a505 | 1203 | struct assegment *seg1; |
1204 | struct assegment *seg2; | |
718e3744 | 1205 | |
1206 | if (! as1 || ! as2) | |
1207 | return NULL; | |
fe69a505 | 1208 | |
1209 | seg1 = as1->segments; | |
1210 | seg2 = as2->segments; | |
1211 | ||
1212 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
718e3744 | 1213 | if (seg2 == NULL) |
1214 | { | |
fe69a505 | 1215 | as2->segments = assegment_dup_all (as1->segments); |
1216 | aspath_str_update (as2); | |
718e3744 | 1217 | return as2; |
1218 | } | |
fe69a505 | 1219 | |
1220 | /* If as1 is empty AS, no prepending to do. */ | |
718e3744 | 1221 | if (seg1 == NULL) |
1222 | return as2; | |
fe69a505 | 1223 | |
1224 | /* find the tail as1's segment chain. */ | |
1225 | while (seg1 && seg1->next) | |
1226 | seg1 = seg1->next; | |
718e3744 | 1227 | |
736d4408 VT |
1228 | /* Delete any AS_CONFED_SEQUENCE segment from as2. */ |
1229 | if (seg1->type == AS_SEQUENCE && seg2->type == AS_CONFED_SEQUENCE) | |
1230 | as2 = aspath_delete_confed_seq (as2); | |
1231 | ||
718e3744 | 1232 | /* Compare last segment type of as1 and first segment type of as2. */ |
1233 | if (seg1->type != seg2->type) | |
1234 | return aspath_merge (as1, as2); | |
1235 | ||
1236 | if (seg1->type == AS_SEQUENCE) | |
1237 | { | |
fe69a505 | 1238 | /* We have two chains of segments, as1->segments and seg2, |
1239 | * and we have to attach them together, merging the attaching | |
1240 | * segments together into one. | |
1241 | * | |
1242 | * 1. dupe as1->segments onto head of as2 | |
1243 | * 2. merge seg2's asns onto last segment of this new chain | |
1244 | * 3. attach chain after seg2 | |
1245 | */ | |
718e3744 | 1246 | |
fe69a505 | 1247 | /* dupe as1 onto as2's head */ |
1248 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1249 | ||
1250 | /* refind the tail of as2, reusing seg1 */ | |
1251 | while (seg1 && seg1->next) | |
1252 | seg1 = seg1->next; | |
1253 | ||
1254 | /* merge the old head, seg2, into tail, seg1 */ | |
1255 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1256 | ||
1257 | /* bypass the merged seg2, and attach any chain after it to | |
1258 | * chain descending from as2's head | |
1259 | */ | |
1260 | seg1->next = seg2->next; | |
1261 | ||
1262 | /* seg2 is now referenceless and useless*/ | |
1263 | assegment_free (seg2); | |
1264 | ||
1265 | /* we've now prepended as1's segment chain to as2, merging | |
1266 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1267 | */ | |
1268 | aspath_str_update (as2); | |
718e3744 | 1269 | return as2; |
1270 | } | |
1271 | else | |
1272 | { | |
1273 | /* AS_SET merge code is needed at here. */ | |
1274 | return aspath_merge (as1, as2); | |
1275 | } | |
fe69a505 | 1276 | /* XXX: Ermmm, what if as1 has multiple segments?? */ |
1277 | ||
718e3744 | 1278 | /* Not reached */ |
1279 | } | |
1280 | ||
841f7a57 DO |
1281 | /* Iterate over AS_PATH segments and wipe all occurences of the |
1282 | * listed AS numbers. Hence some segments may lose some or even | |
1283 | * all data on the way, the operation is implemented as a smarter | |
1284 | * version of aspath_dup(), which allocates memory to hold the new | |
1285 | * data, not the original. The new AS path is returned. | |
1286 | */ | |
1287 | struct aspath * | |
1288 | aspath_filter_exclude (struct aspath * source, struct aspath * exclude_list) | |
1289 | { | |
1290 | struct assegment * srcseg, * exclseg, * lastseg; | |
1291 | struct aspath * newpath; | |
1292 | ||
1293 | newpath = aspath_new(); | |
1294 | lastseg = NULL; | |
1295 | ||
1296 | for (srcseg = source->segments; srcseg; srcseg = srcseg->next) | |
1297 | { | |
1298 | unsigned i, y, newlen = 0, done = 0, skip_as; | |
1299 | struct assegment * newseg; | |
1300 | ||
1301 | /* Find out, how much ASns are we going to pick from this segment. | |
1302 | * We can't perform filtering right inline, because the size of | |
1303 | * the new segment isn't known at the moment yet. | |
1304 | */ | |
1305 | for (i = 0; i < srcseg->length; i++) | |
1306 | { | |
1307 | skip_as = 0; | |
1308 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1309 | for (y = 0; y < exclseg->length; y++) | |
1310 | if (srcseg->as[i] == exclseg->as[y]) | |
1311 | { | |
1312 | skip_as = 1; | |
1313 | // There's no sense in testing the rest of exclusion list, bail out. | |
1314 | break; | |
1315 | } | |
1316 | if (!skip_as) | |
1317 | newlen++; | |
1318 | } | |
1319 | /* newlen is now the number of ASns to copy */ | |
1320 | if (!newlen) | |
1321 | continue; | |
1322 | ||
1323 | /* Actual copying. Allocate memory and iterate once more, performing filtering. */ | |
1324 | newseg = assegment_new (srcseg->type, newlen); | |
1325 | for (i = 0; i < srcseg->length; i++) | |
1326 | { | |
1327 | skip_as = 0; | |
1328 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1329 | for (y = 0; y < exclseg->length; y++) | |
1330 | if (srcseg->as[i] == exclseg->as[y]) | |
1331 | { | |
1332 | skip_as = 1; | |
1333 | break; | |
1334 | } | |
1335 | if (skip_as) | |
1336 | continue; | |
1337 | newseg->as[done++] = srcseg->as[i]; | |
1338 | } | |
1339 | /* At his point newlen must be equal to done, and both must be positive. Append | |
1340 | * the filtered segment to the gross result. */ | |
1341 | if (!lastseg) | |
1342 | newpath->segments = newseg; | |
1343 | else | |
1344 | lastseg->next = newseg; | |
1345 | lastseg = newseg; | |
1346 | } | |
1347 | aspath_str_update (newpath); | |
1348 | /* We are happy returning even an empty AS_PATH, because the administrator | |
1349 | * might expect this very behaviour. There's a mean to avoid this, if necessary, | |
1350 | * by having a match rule against certain AS_PATH regexps in the route-map index. | |
1351 | */ | |
1352 | aspath_free (source); | |
1353 | return newpath; | |
1354 | } | |
1355 | ||
718e3744 | 1356 | /* Add specified AS to the leftmost of aspath. */ |
1357 | static struct aspath * | |
1358 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1359 | { | |
fe69a505 | 1360 | struct assegment *assegment = aspath->segments; |
718e3744 | 1361 | |
1362 | /* In case of empty aspath. */ | |
1363 | if (assegment == NULL || assegment->length == 0) | |
1364 | { | |
fe69a505 | 1365 | aspath->segments = assegment_new (type, 1); |
1366 | aspath->segments->as[0] = asno; | |
1367 | ||
718e3744 | 1368 | if (assegment) |
fe69a505 | 1369 | assegment_free (assegment); |
718e3744 | 1370 | |
1371 | return aspath; | |
1372 | } | |
1373 | ||
1374 | if (assegment->type == type) | |
fe69a505 | 1375 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); |
1376 | else | |
718e3744 | 1377 | { |
fe69a505 | 1378 | /* create new segment |
1379 | * push it onto head of aspath's segment chain | |
1380 | */ | |
718e3744 | 1381 | struct assegment *newsegment; |
fe69a505 | 1382 | |
1383 | newsegment = assegment_new (type, 1); | |
1384 | newsegment->as[0] = asno; | |
1385 | ||
1386 | newsegment->next = assegment; | |
1387 | aspath->segments = newsegment; | |
718e3744 | 1388 | } |
1389 | ||
1390 | return aspath; | |
1391 | } | |
1392 | ||
1393 | /* Add specified AS to the leftmost of aspath. */ | |
1394 | struct aspath * | |
1395 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1396 | { | |
1397 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1398 | } | |
1399 | ||
1400 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1401 | as2's leftmost AS is same return 1. */ | |
1402 | int | |
ffe11cfb | 1403 | aspath_cmp_left (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1404 | { |
ffe11cfb SH |
1405 | const struct assegment *seg1 = NULL; |
1406 | const struct assegment *seg2 = NULL; | |
718e3744 | 1407 | |
fe69a505 | 1408 | if (!(aspath1 && aspath2)) |
1409 | return 0; | |
718e3744 | 1410 | |
fe69a505 | 1411 | seg1 = aspath1->segments; |
1412 | seg2 = aspath2->segments; | |
718e3744 | 1413 | |
fe69a505 | 1414 | /* find first non-confed segments for each */ |
1415 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1416 | || (seg1->type == AS_CONFED_SET))) | |
1417 | seg1 = seg1->next; | |
718e3744 | 1418 | |
fe69a505 | 1419 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1420 | || (seg2->type == AS_CONFED_SET))) | |
1421 | seg2 = seg2->next; | |
718e3744 | 1422 | |
fe69a505 | 1423 | /* Check as1's */ |
1424 | if (!(seg1 && seg2 | |
1425 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1426 | return 0; | |
1427 | ||
1428 | if (seg1->as[0] == seg2->as[0]) | |
718e3744 | 1429 | return 1; |
1430 | ||
1431 | return 0; | |
1432 | } | |
1433 | ||
0b2aa3a0 PJ |
1434 | /* Truncate an aspath after a number of hops, and put the hops remaining |
1435 | * at the front of another aspath. Needed for AS4 compat. | |
1436 | * | |
1437 | * Returned aspath is a /new/ aspath, which should either by free'd or | |
1438 | * interned by the caller, as desired. | |
1439 | */ | |
1440 | struct aspath * | |
1441 | aspath_reconcile_as4 ( struct aspath *aspath, struct aspath *as4path) | |
1442 | { | |
1443 | struct assegment *seg, *newseg, *prevseg = NULL; | |
1444 | struct aspath *newpath = NULL, *mergedpath; | |
1445 | int hops, cpasns = 0; | |
1446 | ||
1447 | if (!aspath) | |
1448 | return NULL; | |
1449 | ||
1450 | seg = aspath->segments; | |
1451 | ||
1452 | /* CONFEDs should get reconciled too.. */ | |
1453 | hops = (aspath_count_hops (aspath) + aspath_count_confeds (aspath)) | |
1454 | - aspath_count_hops (as4path); | |
1455 | ||
1456 | if (hops < 0) | |
1457 | { | |
1458 | if (BGP_DEBUG (as4, AS4)) | |
1459 | zlog_warn ("[AS4] Fewer hops in AS_PATH than NEW_AS_PATH"); | |
1460 | /* Something's gone wrong. The RFC says we should now ignore AS4_PATH, | |
1461 | * which is daft behaviour - it contains vital loop-detection | |
1462 | * information which must have been removed from AS_PATH. | |
1463 | */ | |
1464 | hops = aspath_count_hops (aspath); | |
1465 | } | |
1466 | ||
1467 | if (!hops) | |
1468 | return aspath_dup (as4path); | |
1469 | ||
1470 | if ( BGP_DEBUG(as4, AS4)) | |
1471 | zlog_debug("[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now", | |
1472 | aspath->str, as4path->str); | |
1473 | ||
1474 | while (seg && hops > 0) | |
1475 | { | |
1476 | switch (seg->type) | |
1477 | { | |
1478 | case AS_SET: | |
1479 | case AS_CONFED_SET: | |
1480 | hops--; | |
1481 | cpasns = seg->length; | |
1482 | break; | |
1483 | case AS_CONFED_SEQUENCE: | |
1484 | /* Should never split a confed-sequence, if hop-count | |
1485 | * suggests we must then something's gone wrong somewhere. | |
1486 | * | |
1487 | * Most important goal is to preserve AS_PATHs prime function | |
1488 | * as loop-detector, so we fudge the numbers so that the entire | |
1489 | * confed-sequence is merged in. | |
1490 | */ | |
1491 | if (hops < seg->length) | |
1492 | { | |
1493 | if (BGP_DEBUG (as4, AS4)) | |
1494 | zlog_debug ("[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls" | |
1495 | " across 2/4 ASN boundary somewhere, broken.."); | |
1496 | hops = seg->length; | |
1497 | } | |
1498 | case AS_SEQUENCE: | |
1499 | cpasns = MIN(seg->length, hops); | |
1500 | hops -= seg->length; | |
1501 | } | |
1502 | ||
1503 | assert (cpasns <= seg->length); | |
1504 | ||
1505 | newseg = assegment_new (seg->type, 0); | |
1506 | newseg = assegment_append_asns (newseg, seg->as, cpasns); | |
1507 | ||
1508 | if (!newpath) | |
1509 | { | |
1510 | newpath = aspath_new (); | |
1511 | newpath->segments = newseg; | |
1512 | } | |
1513 | else | |
1514 | prevseg->next = newseg; | |
1515 | ||
1516 | prevseg = newseg; | |
1517 | seg = seg->next; | |
1518 | } | |
1519 | ||
1520 | /* We may be able to join some segments here, and we must | |
1521 | * do this because... we want normalised aspaths in out hash | |
1522 | * and we do not want to stumble in aspath_put. | |
1523 | */ | |
1524 | mergedpath = aspath_merge (newpath, aspath_dup(as4path)); | |
1525 | aspath_free (newpath); | |
1526 | mergedpath->segments = assegment_normalise (mergedpath->segments); | |
1527 | aspath_str_update (mergedpath); | |
1528 | ||
1529 | if ( BGP_DEBUG(as4, AS4)) | |
1530 | zlog_debug ("[AS4] result of synthesizing is %s", | |
1531 | mergedpath->str); | |
1532 | ||
1533 | return mergedpath; | |
1534 | } | |
1535 | ||
718e3744 | 1536 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and |
1537 | as2's leftmost AS is same return 1. (confederation as-path | |
1538 | only). */ | |
1539 | int | |
ffe11cfb | 1540 | aspath_cmp_left_confed (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1541 | { |
fe69a505 | 1542 | if (! (aspath1 && aspath2) ) |
718e3744 | 1543 | return 0; |
fe69a505 | 1544 | |
ad72740e | 1545 | if ( !(aspath1->segments && aspath2->segments) ) |
1546 | return 0; | |
1547 | ||
fe69a505 | 1548 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) |
1549 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
718e3744 | 1550 | return 0; |
fe69a505 | 1551 | |
1552 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
718e3744 | 1553 | return 1; |
1554 | ||
1555 | return 0; | |
1556 | } | |
1557 | ||
fe69a505 | 1558 | /* Delete all leading AS_CONFED_SEQUENCE/SET segments from aspath. |
1559 | * See RFC3065, 6.1 c1 */ | |
718e3744 | 1560 | struct aspath * |
1561 | aspath_delete_confed_seq (struct aspath *aspath) | |
1562 | { | |
fe69a505 | 1563 | struct assegment *seg; |
718e3744 | 1564 | |
fe69a505 | 1565 | if (!(aspath && aspath->segments)) |
718e3744 | 1566 | return aspath; |
1567 | ||
fe69a505 | 1568 | seg = aspath->segments; |
1569 | ||
1570 | /* "if the first path segment of the AS_PATH is | |
1571 | * of type AS_CONFED_SEQUENCE," | |
1572 | */ | |
1573 | if (aspath->segments->type != AS_CONFED_SEQUENCE) | |
1574 | return aspath; | |
718e3744 | 1575 | |
fe69a505 | 1576 | /* "... that segment and any immediately following segments |
1577 | * of the type AS_CONFED_SET or AS_CONFED_SEQUENCE are removed | |
1578 | * from the AS_PATH attribute," | |
1579 | */ | |
1580 | while (seg && | |
1581 | (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET)) | |
718e3744 | 1582 | { |
fe69a505 | 1583 | aspath->segments = seg->next; |
1584 | assegment_free (seg); | |
1585 | seg = aspath->segments; | |
718e3744 | 1586 | } |
fe69a505 | 1587 | aspath_str_update (aspath); |
718e3744 | 1588 | return aspath; |
1589 | } | |
1590 | ||
1591 | /* Add new AS number to the leftmost part of the aspath as | |
1592 | AS_CONFED_SEQUENCE. */ | |
1593 | struct aspath* | |
1594 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1595 | { | |
1596 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1597 | } | |
1598 | ||
1599 | /* Add new as value to as path structure. */ | |
94f2b392 | 1600 | static void |
718e3744 | 1601 | aspath_as_add (struct aspath *as, as_t asno) |
1602 | { | |
fe69a505 | 1603 | struct assegment *seg = as->segments; |
718e3744 | 1604 | |
fe69a505 | 1605 | if (!seg) |
1606 | return; | |
1607 | ||
93c1749c AS |
1608 | /* Last segment search procedure. */ |
1609 | while (seg->next) | |
1610 | seg = seg->next; | |
1611 | ||
fe69a505 | 1612 | assegment_append_asns (seg, &asno, 1); |
718e3744 | 1613 | } |
1614 | ||
1615 | /* Add new as segment to the as path. */ | |
94f2b392 | 1616 | static void |
718e3744 | 1617 | aspath_segment_add (struct aspath *as, int type) |
1618 | { | |
fe69a505 | 1619 | struct assegment *seg = as->segments; |
1620 | struct assegment *new = assegment_new (type, 0); | |
718e3744 | 1621 | |
93c1749c AS |
1622 | if (seg) |
1623 | { | |
1624 | while (seg->next) | |
1625 | seg = seg->next; | |
1626 | seg->next = new; | |
1627 | } | |
718e3744 | 1628 | else |
93c1749c | 1629 | as->segments = new; |
718e3744 | 1630 | } |
1631 | ||
1632 | struct aspath * | |
94f2b392 | 1633 | aspath_empty (void) |
718e3744 | 1634 | { |
cddb8112 | 1635 | return aspath_parse (NULL, 0, 1, 0); /* 32Bit ;-) not AS4_PATH */ |
718e3744 | 1636 | } |
1637 | ||
1638 | struct aspath * | |
94f2b392 | 1639 | aspath_empty_get (void) |
718e3744 | 1640 | { |
1641 | struct aspath *aspath; | |
1642 | ||
1643 | aspath = aspath_new (); | |
1644 | aspath->str = aspath_make_str_count (aspath); | |
1645 | return aspath; | |
1646 | } | |
1647 | ||
1648 | unsigned long | |
fe69a505 | 1649 | aspath_count (void) |
718e3744 | 1650 | { |
1651 | return ashash->count; | |
1652 | } | |
1653 | \f | |
1654 | /* | |
1655 | Theoretically, one as path can have: | |
1656 | ||
1657 | One BGP packet size should be less than 4096. | |
1658 | One BGP attribute size should be less than 4096 - BGP header size. | |
1659 | One BGP aspath size should be less than 4096 - BGP header size - | |
1660 | BGP mandantry attribute size. | |
1661 | */ | |
1662 | ||
1663 | /* AS path string lexical token enum. */ | |
1664 | enum as_token | |
1665 | { | |
1666 | as_token_asval, | |
1667 | as_token_set_start, | |
1668 | as_token_set_end, | |
fe69a505 | 1669 | as_token_confed_seq_start, |
1670 | as_token_confed_seq_end, | |
1671 | as_token_confed_set_start, | |
1672 | as_token_confed_set_end, | |
718e3744 | 1673 | as_token_unknown |
1674 | }; | |
1675 | ||
1676 | /* Return next token and point for string parse. */ | |
94f2b392 | 1677 | static const char * |
0b2aa3a0 | 1678 | aspath_gettoken (const char *buf, enum as_token *token, u_long *asno) |
718e3744 | 1679 | { |
fd79ac91 | 1680 | const char *p = buf; |
718e3744 | 1681 | |
fe69a505 | 1682 | /* Skip seperators (space for sequences, ',' for sets). */ |
1683 | while (isspace ((int) *p) || *p == ',') | |
718e3744 | 1684 | p++; |
1685 | ||
1686 | /* Check the end of the string and type specify characters | |
1687 | (e.g. {}()). */ | |
1688 | switch (*p) | |
1689 | { | |
1690 | case '\0': | |
1691 | return NULL; | |
718e3744 | 1692 | case '{': |
1693 | *token = as_token_set_start; | |
1694 | p++; | |
1695 | return p; | |
718e3744 | 1696 | case '}': |
1697 | *token = as_token_set_end; | |
1698 | p++; | |
1699 | return p; | |
718e3744 | 1700 | case '(': |
fe69a505 | 1701 | *token = as_token_confed_seq_start; |
718e3744 | 1702 | p++; |
1703 | return p; | |
718e3744 | 1704 | case ')': |
fe69a505 | 1705 | *token = as_token_confed_seq_end; |
1706 | p++; | |
1707 | return p; | |
fe69a505 | 1708 | case '[': |
1709 | *token = as_token_confed_set_start; | |
1710 | p++; | |
1711 | return p; | |
fe69a505 | 1712 | case ']': |
1713 | *token = as_token_confed_set_end; | |
718e3744 | 1714 | p++; |
1715 | return p; | |
718e3744 | 1716 | } |
1717 | ||
1718 | /* Check actual AS value. */ | |
1719 | if (isdigit ((int) *p)) | |
1720 | { | |
10819ece | 1721 | as_t asval; |
0b2aa3a0 | 1722 | |
718e3744 | 1723 | *token = as_token_asval; |
1724 | asval = (*p - '0'); | |
1725 | p++; | |
0b2aa3a0 | 1726 | |
718e3744 | 1727 | while (isdigit ((int) *p)) |
0b2aa3a0 PJ |
1728 | { |
1729 | asval *= 10; | |
1730 | asval += (*p - '0'); | |
1731 | p++; | |
1732 | } | |
718e3744 | 1733 | *asno = asval; |
1734 | return p; | |
1735 | } | |
1736 | ||
1737 | /* There is no match then return unknown token. */ | |
1738 | *token = as_token_unknown; | |
1739 | return p++; | |
1740 | } | |
1741 | ||
1742 | struct aspath * | |
fd79ac91 | 1743 | aspath_str2aspath (const char *str) |
718e3744 | 1744 | { |
3fff6ffc | 1745 | enum as_token token = as_token_unknown; |
718e3744 | 1746 | u_short as_type; |
0b2aa3a0 | 1747 | u_long asno = 0; |
718e3744 | 1748 | struct aspath *aspath; |
1749 | int needtype; | |
1750 | ||
1751 | aspath = aspath_new (); | |
1752 | ||
1753 | /* We start default type as AS_SEQUENCE. */ | |
1754 | as_type = AS_SEQUENCE; | |
1755 | needtype = 1; | |
1756 | ||
1757 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1758 | { | |
1759 | switch (token) | |
1760 | { | |
1761 | case as_token_asval: | |
1762 | if (needtype) | |
1763 | { | |
1764 | aspath_segment_add (aspath, as_type); | |
1765 | needtype = 0; | |
1766 | } | |
1767 | aspath_as_add (aspath, asno); | |
1768 | break; | |
1769 | case as_token_set_start: | |
1770 | as_type = AS_SET; | |
1771 | aspath_segment_add (aspath, as_type); | |
1772 | needtype = 0; | |
1773 | break; | |
1774 | case as_token_set_end: | |
1775 | as_type = AS_SEQUENCE; | |
1776 | needtype = 1; | |
1777 | break; | |
fe69a505 | 1778 | case as_token_confed_seq_start: |
718e3744 | 1779 | as_type = AS_CONFED_SEQUENCE; |
1780 | aspath_segment_add (aspath, as_type); | |
1781 | needtype = 0; | |
1782 | break; | |
fe69a505 | 1783 | case as_token_confed_seq_end: |
1784 | as_type = AS_SEQUENCE; | |
1785 | needtype = 1; | |
1786 | break; | |
1787 | case as_token_confed_set_start: | |
1788 | as_type = AS_CONFED_SET; | |
1789 | aspath_segment_add (aspath, as_type); | |
1790 | needtype = 0; | |
1791 | break; | |
1792 | case as_token_confed_set_end: | |
718e3744 | 1793 | as_type = AS_SEQUENCE; |
1794 | needtype = 1; | |
1795 | break; | |
1796 | case as_token_unknown: | |
1797 | default: | |
fe69a505 | 1798 | aspath_free (aspath); |
718e3744 | 1799 | return NULL; |
718e3744 | 1800 | } |
1801 | } | |
1802 | ||
1803 | aspath->str = aspath_make_str_count (aspath); | |
1804 | ||
1805 | return aspath; | |
1806 | } | |
1807 | \f | |
1808 | /* Make hash value by raw aspath data. */ | |
1809 | unsigned int | |
923de654 | 1810 | aspath_key_make (void *p) |
718e3744 | 1811 | { |
923de654 | 1812 | struct aspath * aspath = (struct aspath *) p; |
718e3744 | 1813 | unsigned int key = 0; |
718e3744 | 1814 | |
0b2aa3a0 PJ |
1815 | if (!aspath->str) |
1816 | aspath_str_update (aspath); | |
1817 | ||
1818 | key = jhash (aspath->str, strlen(aspath->str), 2334325); | |
718e3744 | 1819 | |
1820 | return key; | |
1821 | } | |
1822 | ||
1823 | /* If two aspath have same value then return 1 else return 0 */ | |
94f2b392 | 1824 | static int |
ffe11cfb | 1825 | aspath_cmp (const void *arg1, const void *arg2) |
718e3744 | 1826 | { |
aea339f7 DO |
1827 | const struct assegment *seg1 = ((const struct aspath *)arg1)->segments; |
1828 | const struct assegment *seg2 = ((const struct aspath *)arg2)->segments; | |
fe69a505 | 1829 | |
1830 | while (seg1 || seg2) | |
1831 | { | |
1832 | int i; | |
1833 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
1834 | return 0; | |
1835 | if (seg1->type != seg2->type) | |
1836 | return 0; | |
1837 | if (seg1->length != seg2->length) | |
1838 | return 0; | |
1839 | for (i = 0; i < seg1->length; i++) | |
1840 | if (seg1->as[i] != seg2->as[i]) | |
1841 | return 0; | |
1842 | seg1 = seg1->next; | |
1843 | seg2 = seg2->next; | |
1844 | } | |
1845 | return 1; | |
718e3744 | 1846 | } |
1847 | ||
1848 | /* AS path hash initialize. */ | |
1849 | void | |
94f2b392 | 1850 | aspath_init (void) |
718e3744 | 1851 | { |
1852 | ashash = hash_create_size (32767, aspath_key_make, aspath_cmp); | |
1853 | } | |
8fdc32ab | 1854 | |
1855 | void | |
1856 | aspath_finish (void) | |
1857 | { | |
1858 | hash_free (ashash); | |
228da428 | 1859 | ashash = NULL; |
8fdc32ab | 1860 | |
1861 | if (snmp_stream) | |
1862 | stream_free (snmp_stream); | |
1863 | } | |
718e3744 | 1864 | \f |
1865 | /* return and as path value */ | |
1866 | const char * | |
1867 | aspath_print (struct aspath *as) | |
1868 | { | |
fe69a505 | 1869 | return (as ? as->str : NULL); |
718e3744 | 1870 | } |
1871 | ||
1872 | /* Printing functions */ | |
841f7a57 DO |
1873 | /* Feed the AS_PATH to the vty; the suffix string follows it only in case |
1874 | * AS_PATH wasn't empty. | |
1875 | */ | |
718e3744 | 1876 | void |
841f7a57 | 1877 | aspath_print_vty (struct vty *vty, const char *format, struct aspath *as, const char * suffix) |
718e3744 | 1878 | { |
b2518c1e PJ |
1879 | assert (format); |
1880 | vty_out (vty, format, as->str); | |
841f7a57 DO |
1881 | if (strlen (as->str) && strlen (suffix)) |
1882 | vty_out (vty, "%s", suffix); | |
718e3744 | 1883 | } |
1884 | ||
94f2b392 | 1885 | static void |
718e3744 | 1886 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) |
1887 | { | |
1888 | struct aspath *as; | |
1889 | ||
1890 | as = (struct aspath *) backet->data; | |
1891 | ||
efa9f830 | 1892 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); |
718e3744 | 1893 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); |
1894 | } | |
1895 | ||
1896 | /* Print all aspath and hash information. This function is used from | |
1897 | `show ip bgp paths' command. */ | |
1898 | void | |
1899 | aspath_print_all_vty (struct vty *vty) | |
1900 | { | |
1901 | hash_iterate (ashash, | |
1902 | (void (*) (struct hash_backet *, void *)) | |
1903 | aspath_show_all_iterator, | |
1904 | vty); | |
1905 | } |