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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. */ | |
89 | 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 | { |
325 | struct aspath *aspath; | |
326 | ||
327 | aspath = XMALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); | |
328 | memset (aspath, 0, sizeof (struct aspath)); | |
329 | return aspath; | |
330 | } | |
331 | ||
332 | /* Free AS path structure. */ | |
333 | void | |
334 | aspath_free (struct aspath *aspath) | |
335 | { | |
336 | if (!aspath) | |
337 | return; | |
fe69a505 | 338 | if (aspath->segments) |
339 | assegment_free_all (aspath->segments); | |
718e3744 | 340 | if (aspath->str) |
341 | XFREE (MTYPE_AS_STR, aspath->str); | |
342 | XFREE (MTYPE_AS_PATH, aspath); | |
343 | } | |
344 | ||
345 | /* Unintern aspath from AS path bucket. */ | |
346 | void | |
347 | aspath_unintern (struct aspath *aspath) | |
348 | { | |
349 | struct aspath *ret; | |
350 | ||
351 | if (aspath->refcnt) | |
352 | aspath->refcnt--; | |
353 | ||
354 | if (aspath->refcnt == 0) | |
355 | { | |
356 | /* This aspath must exist in aspath hash table. */ | |
357 | ret = hash_release (ashash, aspath); | |
358 | assert (ret != NULL); | |
359 | aspath_free (aspath); | |
360 | } | |
361 | } | |
362 | ||
363 | /* Return the start or end delimiters for a particular Segment type */ | |
364 | #define AS_SEG_START 0 | |
365 | #define AS_SEG_END 1 | |
366 | static char | |
367 | aspath_delimiter_char (u_char type, u_char which) | |
368 | { | |
369 | int i; | |
370 | struct | |
371 | { | |
372 | int type; | |
373 | char start; | |
374 | char end; | |
375 | } aspath_delim_char [] = | |
376 | { | |
377 | { AS_SET, '{', '}' }, | |
718e3744 | 378 | { AS_CONFED_SET, '[', ']' }, |
379 | { AS_CONFED_SEQUENCE, '(', ')' }, | |
380 | { 0 } | |
381 | }; | |
382 | ||
383 | for (i = 0; aspath_delim_char[i].type != 0; i++) | |
384 | { | |
385 | if (aspath_delim_char[i].type == type) | |
386 | { | |
387 | if (which == AS_SEG_START) | |
388 | return aspath_delim_char[i].start; | |
389 | else if (which == AS_SEG_END) | |
390 | return aspath_delim_char[i].end; | |
391 | } | |
392 | } | |
393 | return ' '; | |
394 | } | |
395 | ||
fe69a505 | 396 | /* countup asns from this segment and index onward */ |
397 | static int | |
398 | assegment_count_asns (struct assegment *seg, int from) | |
399 | { | |
400 | int count = 0; | |
401 | while (seg) | |
402 | { | |
403 | if (!from) | |
404 | count += seg->length; | |
405 | else | |
406 | { | |
407 | count += (seg->length - from); | |
408 | from = 0; | |
409 | } | |
410 | seg = seg->next; | |
411 | } | |
412 | return count; | |
413 | } | |
414 | ||
415 | unsigned int | |
416 | aspath_count_confeds (struct aspath *aspath) | |
417 | { | |
418 | int count = 0; | |
419 | struct assegment *seg = aspath->segments; | |
420 | ||
421 | while (seg) | |
422 | { | |
423 | if (seg->type == AS_CONFED_SEQUENCE) | |
424 | count += seg->length; | |
425 | else if (seg->type == AS_CONFED_SET) | |
426 | count++; | |
427 | ||
428 | seg = seg->next; | |
429 | } | |
430 | return count; | |
431 | } | |
432 | ||
433 | unsigned int | |
434 | aspath_count_hops (struct aspath *aspath) | |
435 | { | |
436 | int count = 0; | |
437 | struct assegment *seg = aspath->segments; | |
438 | ||
439 | while (seg) | |
440 | { | |
441 | if (seg->type == AS_SEQUENCE) | |
442 | count += seg->length; | |
443 | else if (seg->type == AS_SET) | |
444 | count++; | |
445 | ||
446 | seg = seg->next; | |
447 | } | |
448 | return count; | |
449 | } | |
450 | ||
0b2aa3a0 PJ |
451 | /* Estimate size aspath /might/ take if encoded into an |
452 | * ASPATH attribute. | |
453 | * | |
454 | * This is a quick estimate, not definitive! aspath_put() | |
455 | * may return a different number!! | |
456 | */ | |
fe69a505 | 457 | unsigned int |
458 | aspath_size (struct aspath *aspath) | |
459 | { | |
460 | int size = 0; | |
461 | struct assegment *seg = aspath->segments; | |
462 | ||
463 | while (seg) | |
464 | { | |
0b2aa3a0 | 465 | size += ASSEGMENT_SIZE(seg->length, 1); |
fe69a505 | 466 | seg = seg->next; |
467 | } | |
468 | return size; | |
469 | } | |
470 | ||
2815e61f PJ |
471 | /* Return highest public ASN in path */ |
472 | as_t | |
473 | aspath_highest (struct aspath *aspath) | |
474 | { | |
475 | struct assegment *seg = aspath->segments; | |
476 | as_t highest = 0; | |
477 | unsigned int i; | |
478 | ||
479 | while (seg) | |
480 | { | |
481 | for (i = 0; i < seg->length; i++) | |
482 | if (seg->as[i] > highest | |
483 | && (seg->as[i] < BGP_PRIVATE_AS_MIN | |
484 | || seg->as[i] > BGP_PRIVATE_AS_MAX)) | |
485 | highest = seg->as[i]; | |
486 | seg = seg->next; | |
487 | } | |
488 | return highest; | |
489 | } | |
490 | ||
0b2aa3a0 PJ |
491 | /* Return 1 if there are any 4-byte ASes in the path */ |
492 | unsigned int | |
493 | aspath_has_as4 (struct aspath *aspath) | |
494 | { | |
495 | struct assegment *seg = aspath->segments; | |
496 | unsigned int i; | |
497 | ||
498 | while (seg) | |
499 | { | |
500 | for (i = 0; i < seg->length; i++) | |
501 | if (seg->as[i] > BGP_AS_MAX) | |
502 | return 1; | |
503 | seg = seg->next; | |
504 | } | |
505 | return 0; | |
506 | } | |
507 | ||
508 | /* Return number of as numbers in in path */ | |
509 | unsigned int | |
510 | aspath_count_numas (struct aspath *aspath) | |
511 | { | |
512 | struct assegment *seg = aspath->segments; | |
513 | unsigned int num; | |
514 | ||
515 | num=0; | |
516 | while (seg) | |
517 | { | |
518 | num += seg->length; | |
519 | seg = seg->next; | |
520 | } | |
521 | return num; | |
522 | } | |
523 | ||
718e3744 | 524 | /* Convert aspath structure to string expression. */ |
94f2b392 | 525 | static char * |
718e3744 | 526 | aspath_make_str_count (struct aspath *as) |
527 | { | |
fe69a505 | 528 | struct assegment *seg; |
529 | int str_size; | |
530 | int len = 0; | |
c9e52be3 | 531 | char *str_buf; |
718e3744 | 532 | |
533 | /* Empty aspath. */ | |
fe69a505 | 534 | if (!as->segments) |
718e3744 | 535 | { |
536 | str_buf = XMALLOC (MTYPE_AS_STR, 1); | |
537 | str_buf[0] = '\0'; | |
718e3744 | 538 | return str_buf; |
539 | } | |
fe69a505 | 540 | |
541 | seg = as->segments; | |
542 | ||
543 | /* ASN takes 5 chars at least, plus seperator, see below. | |
544 | * If there is one differing segment type, we need an additional | |
545 | * 2 chars for segment delimiters, and the final '\0'. | |
546 | * Hopefully this is large enough to avoid hitting the realloc | |
547 | * code below for most common sequences. | |
0b2aa3a0 PJ |
548 | * |
549 | * With 32bit ASNs, this range will increase, but only worth changing | |
550 | * once there are significant numbers of ASN >= 100000 | |
fe69a505 | 551 | */ |
552 | #define ASN_STR_LEN (5 + 1) | |
553 | str_size = MAX (assegment_count_asns (seg, 0) * ASN_STR_LEN + 2 + 1, | |
554 | ASPATH_STR_DEFAULT_LEN); | |
718e3744 | 555 | str_buf = XMALLOC (MTYPE_AS_STR, str_size); |
718e3744 | 556 | |
fe69a505 | 557 | while (seg) |
718e3744 | 558 | { |
559 | int i; | |
fe69a505 | 560 | char seperator; |
718e3744 | 561 | |
fe69a505 | 562 | /* Check AS type validity. Set seperator for segment */ |
563 | switch (seg->type) | |
564 | { | |
565 | case AS_SET: | |
566 | case AS_CONFED_SET: | |
567 | seperator = ','; | |
568 | break; | |
569 | case AS_SEQUENCE: | |
570 | case AS_CONFED_SEQUENCE: | |
571 | seperator = ' '; | |
572 | break; | |
573 | default: | |
574 | XFREE (MTYPE_AS_STR, str_buf); | |
575 | return NULL; | |
576 | } | |
577 | ||
578 | /* We might need to increase str_buf, particularly if path has | |
579 | * differing segments types, our initial guesstimate above will | |
580 | * have been wrong. need 5 chars for ASN, a seperator each and | |
581 | * potentially two segment delimiters, plus a space between each | |
582 | * segment and trailing zero. | |
0b2aa3a0 PJ |
583 | * |
584 | * This may need to revised if/when significant numbers of | |
585 | * ASNs >= 100000 are assigned and in-use on the internet... | |
fe69a505 | 586 | */ |
587 | #define SEGMENT_STR_LEN(X) (((X)->length * ASN_STR_LEN) + 2 + 1 + 1) | |
588 | if ( (len + SEGMENT_STR_LEN(seg)) > str_size) | |
589 | { | |
590 | str_size = len + SEGMENT_STR_LEN(seg); | |
591 | str_buf = XREALLOC (MTYPE_AS_STR, str_buf, str_size); | |
592 | } | |
593 | #undef ASN_STR_LEN | |
594 | #undef SEGMENT_STR_LEN | |
595 | ||
596 | if (seg->type != AS_SEQUENCE) | |
597 | len += snprintf (str_buf + len, str_size - len, | |
598 | "%c", | |
599 | aspath_delimiter_char (seg->type, AS_SEG_START)); | |
600 | ||
601 | /* write out the ASNs, with their seperators, bar the last one*/ | |
602 | for (i = 0; i < seg->length; i++) | |
603 | { | |
604 | len += snprintf (str_buf + len, str_size - len, "%u", seg->as[i]); | |
605 | ||
606 | if (i < (seg->length - 1)) | |
607 | len += snprintf (str_buf + len, str_size - len, "%c", seperator); | |
608 | } | |
609 | ||
610 | if (seg->type != AS_SEQUENCE) | |
611 | len += snprintf (str_buf + len, str_size - len, "%c", | |
612 | aspath_delimiter_char (seg->type, AS_SEG_END)); | |
613 | if (seg->next) | |
614 | len += snprintf (str_buf + len, str_size - len, " "); | |
615 | ||
616 | seg = seg->next; | |
718e3744 | 617 | } |
fe69a505 | 618 | |
619 | assert (len < str_size); | |
620 | ||
621 | str_buf[len] = '\0'; | |
718e3744 | 622 | |
623 | return str_buf; | |
624 | } | |
625 | ||
fe69a505 | 626 | static void |
627 | aspath_str_update (struct aspath *as) | |
628 | { | |
629 | if (as->str) | |
630 | XFREE (MTYPE_AS_STR, as->str); | |
631 | as->str = aspath_make_str_count (as); | |
632 | } | |
633 | ||
718e3744 | 634 | /* Intern allocated AS path. */ |
635 | struct aspath * | |
636 | aspath_intern (struct aspath *aspath) | |
637 | { | |
638 | struct aspath *find; | |
639 | ||
640 | /* Assert this AS path structure is not interned. */ | |
641 | assert (aspath->refcnt == 0); | |
642 | ||
643 | /* Check AS path hash. */ | |
644 | find = hash_get (ashash, aspath, hash_alloc_intern); | |
645 | ||
646 | if (find != aspath) | |
fe69a505 | 647 | aspath_free (aspath); |
718e3744 | 648 | |
649 | find->refcnt++; | |
650 | ||
651 | if (! find->str) | |
652 | find->str = aspath_make_str_count (find); | |
653 | ||
654 | return find; | |
655 | } | |
656 | ||
657 | /* Duplicate aspath structure. Created same aspath structure but | |
658 | reference count and AS path string is cleared. */ | |
659 | struct aspath * | |
660 | aspath_dup (struct aspath *aspath) | |
661 | { | |
662 | struct aspath *new; | |
663 | ||
fe69a505 | 664 | new = XCALLOC (MTYPE_AS_PATH, sizeof (struct aspath)); |
718e3744 | 665 | |
fe69a505 | 666 | if (aspath->segments) |
667 | new->segments = assegment_dup_all (aspath->segments); | |
718e3744 | 668 | else |
fe69a505 | 669 | new->segments = NULL; |
718e3744 | 670 | |
fe69a505 | 671 | new->str = aspath_make_str_count (aspath); |
718e3744 | 672 | |
673 | return new; | |
674 | } | |
675 | ||
94f2b392 | 676 | static void * |
fe69a505 | 677 | aspath_hash_alloc (void *arg) |
718e3744 | 678 | { |
679 | struct aspath *aspath; | |
680 | ||
0b2aa3a0 | 681 | /* New aspath structure is needed. */ |
fe69a505 | 682 | aspath = aspath_dup (arg); |
683 | ||
718e3744 | 684 | /* Malformed AS path value. */ |
685 | if (! aspath->str) | |
686 | { | |
687 | aspath_free (aspath); | |
688 | return NULL; | |
689 | } | |
690 | ||
691 | return aspath; | |
692 | } | |
693 | ||
fe69a505 | 694 | /* parse as-segment byte stream in struct assegment */ |
ad72740e | 695 | static struct assegment * |
0b2aa3a0 | 696 | assegments_parse (struct stream *s, size_t length, int use32bit) |
fe69a505 | 697 | { |
698 | struct assegment_header segh; | |
699 | struct assegment *seg, *prev = NULL, *head = NULL; | |
700 | size_t bytes = 0; | |
701 | ||
702 | /* empty aspath (ie iBGP or somesuch) */ | |
703 | if (length == 0) | |
704 | return NULL; | |
705 | ||
0b2aa3a0 PJ |
706 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
707 | zlog_debug ("[AS4SEG] Parse aspath segment: got total byte length %lu", | |
708 | (unsigned long) length); | |
fe69a505 | 709 | /* basic checks */ |
710 | if ( (STREAM_READABLE(s) < length) | |
711 | || (STREAM_READABLE(s) < AS_HEADER_SIZE) | |
0b2aa3a0 | 712 | || (length % AS16_VALUE_SIZE )) |
fe69a505 | 713 | return NULL; |
714 | ||
715 | while ( (STREAM_READABLE(s) > AS_HEADER_SIZE) | |
716 | && (bytes < length)) | |
717 | { | |
718 | int i; | |
0b2aa3a0 | 719 | int seg_size; |
fe69a505 | 720 | |
721 | /* softly softly, get the header first on its own */ | |
722 | segh.type = stream_getc (s); | |
723 | segh.length = stream_getc (s); | |
724 | ||
0b2aa3a0 PJ |
725 | seg_size = ASSEGMENT_SIZE(segh.length, use32bit); |
726 | ||
727 | if (BGP_DEBUG (as4, AS4_SEGMENT)) | |
728 | zlog_debug ("[AS4SEG] Parse aspath segment: got type %d, length %d", | |
729 | segh.type, segh.length); | |
730 | ||
fe69a505 | 731 | /* check it.. */ |
0b2aa3a0 | 732 | if ( ((bytes + seg_size) > length) |
fe69a505 | 733 | /* 1771bis 4.3b: seg length contains one or more */ |
734 | || (segh.length == 0) | |
735 | /* Paranoia in case someone changes type of segment length */ | |
0b2aa3a0 | 736 | || ((sizeof segh.length > 1) && (segh.length > AS_SEGMENT_MAX)) ) |
fe69a505 | 737 | { |
738 | if (head) | |
739 | assegment_free_all (head); | |
740 | return NULL; | |
741 | } | |
742 | ||
743 | /* now its safe to trust lengths */ | |
744 | seg = assegment_new (segh.type, segh.length); | |
745 | ||
746 | if (head) | |
747 | prev->next = seg; | |
748 | else /* it's the first segment */ | |
749 | head = prev = seg; | |
750 | ||
751 | for (i = 0; i < segh.length; i++) | |
0b2aa3a0 PJ |
752 | seg->as[i] = (use32bit) ? stream_getl (s) : stream_getw (s); |
753 | ||
754 | bytes += seg_size; | |
fe69a505 | 755 | |
0b2aa3a0 PJ |
756 | if (BGP_DEBUG (as4, AS4_SEGMENT)) |
757 | zlog_debug ("[AS4SEG] Parse aspath segment: Bytes now: %lu", | |
758 | (unsigned long) bytes); | |
fe69a505 | 759 | |
760 | prev = seg; | |
761 | } | |
762 | ||
763 | return assegment_normalise (head); | |
764 | } | |
765 | ||
718e3744 | 766 | /* AS path parse function. pnt is a pointer to byte stream and length |
767 | is length of byte stream. If there is same AS path in the the AS | |
768 | path hash then return it else make new AS path structure. */ | |
769 | struct aspath * | |
0b2aa3a0 | 770 | aspath_parse (struct stream *s, size_t length, int use32bit) |
718e3744 | 771 | { |
772 | struct aspath as; | |
773 | struct aspath *find; | |
774 | ||
775 | /* If length is odd it's malformed AS path. */ | |
0b2aa3a0 PJ |
776 | /* Nit-picking: if (use32bit == 0) it is malformed if odd, |
777 | * otherwise its malformed when length is larger than 2 and (length-2) | |
778 | * is not dividable by 4. | |
779 | * But... this time we're lazy | |
780 | */ | |
781 | if (length % AS16_VALUE_SIZE ) | |
718e3744 | 782 | return NULL; |
783 | ||
0b2aa3a0 PJ |
784 | memset (&as, 0, sizeof (struct aspath)); |
785 | as.segments = assegments_parse (s, length, use32bit); | |
fe69a505 | 786 | |
718e3744 | 787 | /* If already same aspath exist then return it. */ |
788 | find = hash_get (ashash, &as, aspath_hash_alloc); | |
02335429 | 789 | |
790 | /* aspath_hash_alloc dupes segments too. that probably could be | |
791 | * optimised out. | |
792 | */ | |
793 | assegment_free_all (as.segments); | |
0b2aa3a0 PJ |
794 | if (as.str) |
795 | XFREE (MTYPE_AS_STR, as.str); | |
02335429 | 796 | |
718e3744 | 797 | if (! find) |
798 | return NULL; | |
799 | find->refcnt++; | |
800 | ||
801 | return find; | |
802 | } | |
803 | ||
fe69a505 | 804 | static inline void |
0b2aa3a0 | 805 | assegment_data_put (struct stream *s, as_t *as, int num, int use32bit) |
fe69a505 | 806 | { |
807 | int i; | |
808 | assert (num <= AS_SEGMENT_MAX); | |
809 | ||
810 | for (i = 0; i < num; i++) | |
0b2aa3a0 PJ |
811 | if ( use32bit ) |
812 | stream_putl (s, as[i]); | |
813 | else | |
814 | { | |
815 | if ( as[i] <= BGP_AS_MAX ) | |
816 | stream_putw(s, as[i]); | |
817 | else | |
818 | stream_putw(s, BGP_AS_TRANS); | |
819 | } | |
fe69a505 | 820 | } |
718e3744 | 821 | |
fe69a505 | 822 | static inline size_t |
823 | assegment_header_put (struct stream *s, u_char type, int length) | |
718e3744 | 824 | { |
fe69a505 | 825 | size_t lenp; |
826 | assert (length <= AS_SEGMENT_MAX); | |
827 | stream_putc (s, type); | |
828 | lenp = stream_get_endp (s); | |
829 | stream_putc (s, length); | |
830 | return lenp; | |
831 | } | |
718e3744 | 832 | |
fe69a505 | 833 | /* write aspath data to stream */ |
0b2aa3a0 PJ |
834 | size_t |
835 | aspath_put (struct stream *s, struct aspath *as, int use32bit ) | |
fe69a505 | 836 | { |
837 | struct assegment *seg = as->segments; | |
0b2aa3a0 | 838 | size_t bytes = 0; |
fe69a505 | 839 | |
840 | if (!seg || seg->length == 0) | |
0b2aa3a0 | 841 | return 0; |
fe69a505 | 842 | |
843 | if (seg) | |
718e3744 | 844 | { |
0b2aa3a0 PJ |
845 | /* |
846 | * Hey, what do we do when we have > STREAM_WRITABLE(s) here? | |
847 | * At the moment, we would write out a partial aspath, and our peer | |
848 | * will complain and drop the session :-/ | |
849 | * | |
850 | * The general assumption here is that many things tested will | |
851 | * never happen. And, in real live, up to now, they have not. | |
852 | */ | |
853 | while (seg && (ASSEGMENT_LEN(seg, use32bit) <= STREAM_WRITEABLE(s))) | |
fe69a505 | 854 | { |
0b2aa3a0 | 855 | struct assegment *next = seg->next; |
fe69a505 | 856 | int written = 0; |
0b2aa3a0 | 857 | int asns_packed = 0; |
fe69a505 | 858 | size_t lenp; |
859 | ||
860 | /* Overlength segments have to be split up */ | |
861 | while ( (seg->length - written) > AS_SEGMENT_MAX) | |
862 | { | |
863 | assegment_header_put (s, seg->type, AS_SEGMENT_MAX); | |
0b2aa3a0 | 864 | assegment_data_put (s, seg->as, AS_SEGMENT_MAX, use32bit); |
fe69a505 | 865 | written += AS_SEGMENT_MAX; |
0b2aa3a0 | 866 | bytes += ASSEGMENT_SIZE (written, use32bit); |
fe69a505 | 867 | } |
868 | ||
869 | /* write the final segment, probably is also the first */ | |
870 | lenp = assegment_header_put (s, seg->type, seg->length - written); | |
0b2aa3a0 PJ |
871 | assegment_data_put (s, (seg->as + written), seg->length - written, |
872 | use32bit); | |
fe69a505 | 873 | |
874 | /* Sequence-type segments can be 'packed' together | |
875 | * Case of a segment which was overlength and split up | |
876 | * will be missed here, but that doesn't matter. | |
877 | */ | |
0b2aa3a0 | 878 | while (next && ASSEGMENTS_PACKABLE (seg, next)) |
fe69a505 | 879 | { |
880 | /* NB: We should never normally get here given we | |
881 | * normalise aspath data when parse them. However, better | |
882 | * safe than sorry. We potentially could call | |
883 | * assegment_normalise here instead, but it's cheaper and | |
884 | * easier to do it on the fly here rather than go through | |
885 | * the segment list twice every time we write out | |
886 | * aspath's. | |
887 | */ | |
888 | ||
889 | /* Next segment's data can fit in this one */ | |
0b2aa3a0 | 890 | assegment_data_put (s, next->as, next->length, use32bit); |
fe69a505 | 891 | |
892 | /* update the length of the segment header */ | |
0b2aa3a0 PJ |
893 | stream_putc_at (s, lenp, seg->length - written + next->length); |
894 | asns_packed += next->length; | |
895 | ||
896 | next = next->next; | |
fe69a505 | 897 | } |
0b2aa3a0 PJ |
898 | |
899 | bytes += ASSEGMENT_SIZE (seg->length - written + asns_packed, | |
900 | use32bit); | |
901 | seg = next; | |
fe69a505 | 902 | } |
718e3744 | 903 | } |
0b2aa3a0 | 904 | return bytes; |
fe69a505 | 905 | } |
906 | ||
907 | /* This is for SNMP BGP4PATHATTRASPATHSEGMENT | |
908 | * We have no way to manage the storage, so we use a static stream | |
909 | * wrapper around aspath_put. | |
910 | */ | |
911 | u_char * | |
912 | aspath_snmp_pathseg (struct aspath *as, size_t *varlen) | |
913 | { | |
914 | #define SNMP_PATHSEG_MAX 1024 | |
8fdc32ab | 915 | |
916 | if (!snmp_stream) | |
917 | snmp_stream = stream_new (SNMP_PATHSEG_MAX); | |
718e3744 | 918 | else |
8fdc32ab | 919 | stream_reset (snmp_stream); |
fe69a505 | 920 | |
921 | if (!as) | |
718e3744 | 922 | { |
fe69a505 | 923 | *varlen = 0; |
924 | return NULL; | |
718e3744 | 925 | } |
0b2aa3a0 | 926 | aspath_put (snmp_stream, as, 0); /* use 16 bit for now here */ |
fe69a505 | 927 | |
8fdc32ab | 928 | *varlen = stream_get_endp (snmp_stream); |
929 | return stream_pnt(snmp_stream); | |
718e3744 | 930 | } |
fe69a505 | 931 | |
932 | #define min(A,B) ((A) < (B) ? (A) : (B)) | |
718e3744 | 933 | |
94f2b392 | 934 | static struct assegment * |
718e3744 | 935 | aspath_aggregate_as_set_add (struct aspath *aspath, struct assegment *asset, |
936 | as_t as) | |
937 | { | |
938 | int i; | |
939 | ||
940 | /* If this is first AS set member, create new as-set segment. */ | |
941 | if (asset == NULL) | |
942 | { | |
fe69a505 | 943 | asset = assegment_new (AS_SET, 1); |
944 | if (! aspath->segments) | |
945 | aspath->segments = asset; | |
718e3744 | 946 | else |
fe69a505 | 947 | { |
948 | struct assegment *seg = aspath->segments; | |
949 | while (seg->next) | |
950 | seg = seg->next; | |
951 | seg->next = asset; | |
952 | } | |
718e3744 | 953 | asset->type = AS_SET; |
954 | asset->length = 1; | |
fe69a505 | 955 | asset->as[0] = as; |
718e3744 | 956 | } |
957 | else | |
958 | { | |
718e3744 | 959 | /* Check this AS value already exists or not. */ |
960 | for (i = 0; i < asset->length; i++) | |
fe69a505 | 961 | if (asset->as[i] == as) |
718e3744 | 962 | return asset; |
fe69a505 | 963 | |
718e3744 | 964 | asset->length++; |
fe69a505 | 965 | asset->as = XREALLOC (MTYPE_AS_SEG_DATA, asset->as, |
966 | asset->length * AS_VALUE_SIZE); | |
967 | asset->as[asset->length - 1] = as; | |
718e3744 | 968 | } |
fe69a505 | 969 | |
718e3744 | 970 | |
971 | return asset; | |
972 | } | |
973 | ||
974 | /* Modify as1 using as2 for aggregation. */ | |
975 | struct aspath * | |
976 | aspath_aggregate (struct aspath *as1, struct aspath *as2) | |
977 | { | |
978 | int i; | |
979 | int minlen; | |
980 | int match; | |
fe69a505 | 981 | int from; |
982 | struct assegment *seg1 = as1->segments; | |
983 | struct assegment *seg2 = as2->segments; | |
0b2aa3a0 | 984 | struct aspath *aspath = NULL; |
718e3744 | 985 | struct assegment *asset; |
0b2aa3a0 | 986 | struct assegment *prevseg = NULL; |
718e3744 | 987 | |
988 | match = 0; | |
989 | minlen = 0; | |
990 | aspath = NULL; | |
991 | asset = NULL; | |
718e3744 | 992 | |
993 | /* First of all check common leading sequence. */ | |
fe69a505 | 994 | while (seg1 && seg2) |
0b2aa3a0 | 995 | { |
718e3744 | 996 | /* Check segment type. */ |
997 | if (seg1->type != seg2->type) | |
998 | break; | |
999 | ||
1000 | /* Minimum segment length. */ | |
1001 | minlen = min (seg1->length, seg2->length); | |
1002 | ||
1003 | for (match = 0; match < minlen; match++) | |
fe69a505 | 1004 | if (seg1->as[match] != seg2->as[match]) |
718e3744 | 1005 | break; |
1006 | ||
1007 | if (match) | |
1008 | { | |
0b2aa3a0 PJ |
1009 | struct assegment *seg = assegment_new (seg1->type, 0); |
1010 | ||
1011 | seg = assegment_append_asns (seg, seg1->as, match); | |
1012 | ||
718e3744 | 1013 | if (! aspath) |
0b2aa3a0 PJ |
1014 | { |
1015 | aspath = aspath_new (); | |
1016 | aspath->segments = seg; | |
1017 | } | |
1018 | else | |
1019 | prevseg->next = seg; | |
1020 | ||
1021 | prevseg = seg; | |
718e3744 | 1022 | } |
1023 | ||
1024 | if (match != minlen || match != seg1->length | |
1025 | || seg1->length != seg2->length) | |
1026 | break; | |
fe69a505 | 1027 | |
1028 | seg1 = seg1->next; | |
1029 | seg2 = seg2->next; | |
718e3744 | 1030 | } |
1031 | ||
1032 | if (! aspath) | |
1033 | aspath = aspath_new(); | |
1034 | ||
1035 | /* Make as-set using rest of all information. */ | |
fe69a505 | 1036 | from = match; |
1037 | while (seg1) | |
718e3744 | 1038 | { |
fe69a505 | 1039 | for (i = from; i < seg1->length; i++) |
1040 | asset = aspath_aggregate_as_set_add (aspath, asset, seg1->as[i]); | |
1041 | ||
1042 | from = 0; | |
1043 | seg1 = seg1->next; | |
718e3744 | 1044 | } |
1045 | ||
fe69a505 | 1046 | from = match; |
1047 | while (seg2) | |
718e3744 | 1048 | { |
fe69a505 | 1049 | for (i = from; i < seg2->length; i++) |
1050 | asset = aspath_aggregate_as_set_add (aspath, asset, seg2->as[i]); | |
718e3744 | 1051 | |
fe69a505 | 1052 | from = 0; |
1053 | seg2 = seg2->next; | |
718e3744 | 1054 | } |
fe69a505 | 1055 | |
1056 | assegment_normalise (aspath->segments); | |
1057 | aspath_str_update (aspath); | |
718e3744 | 1058 | return aspath; |
1059 | } | |
1060 | ||
1061 | /* When a BGP router receives an UPDATE with an MP_REACH_NLRI | |
1062 | attribute, check the leftmost AS number in the AS_PATH attribute is | |
1063 | or not the peer's AS number. */ | |
1064 | int | |
1065 | aspath_firstas_check (struct aspath *aspath, as_t asno) | |
1066 | { | |
fe69a505 | 1067 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1068 | return 0; |
fe69a505 | 1069 | |
1070 | if (aspath->segments | |
1071 | && (aspath->segments->type == AS_SEQUENCE) | |
1072 | && (aspath->segments->as[0] == asno )) | |
718e3744 | 1073 | return 1; |
1074 | ||
1075 | return 0; | |
1076 | } | |
1077 | ||
1f742f21 | 1078 | /* AS path loop check. If aspath contains asno then return >= 1. */ |
718e3744 | 1079 | int |
1080 | aspath_loop_check (struct aspath *aspath, as_t asno) | |
1081 | { | |
fe69a505 | 1082 | struct assegment *seg; |
718e3744 | 1083 | int count = 0; |
1084 | ||
1f742f21 | 1085 | if ( (aspath == NULL) || (aspath->segments == NULL) ) |
718e3744 | 1086 | return 0; |
fe69a505 | 1087 | |
1088 | seg = aspath->segments; | |
1089 | ||
1090 | while (seg) | |
718e3744 | 1091 | { |
1092 | int i; | |
718e3744 | 1093 | |
fe69a505 | 1094 | for (i = 0; i < seg->length; i++) |
1095 | if (seg->as[i] == asno) | |
718e3744 | 1096 | count++; |
fe69a505 | 1097 | |
1098 | seg = seg->next; | |
718e3744 | 1099 | } |
1100 | return count; | |
1101 | } | |
1102 | ||
1103 | /* When all of AS path is private AS return 1. */ | |
1104 | int | |
1105 | aspath_private_as_check (struct aspath *aspath) | |
1106 | { | |
fe69a505 | 1107 | struct assegment *seg; |
1108 | ||
1109 | if ( !(aspath && aspath->segments) ) | |
718e3744 | 1110 | return 0; |
fe69a505 | 1111 | |
1112 | seg = aspath->segments; | |
718e3744 | 1113 | |
fe69a505 | 1114 | while (seg) |
718e3744 | 1115 | { |
1116 | int i; | |
718e3744 | 1117 | |
fe69a505 | 1118 | for (i = 0; i < seg->length; i++) |
718e3744 | 1119 | { |
fe69a505 | 1120 | if ( (seg->as[i] < BGP_PRIVATE_AS_MIN) |
1121 | || (seg->as[i] > BGP_PRIVATE_AS_MAX) ) | |
718e3744 | 1122 | return 0; |
1123 | } | |
fe69a505 | 1124 | seg = seg->next; |
718e3744 | 1125 | } |
1126 | return 1; | |
1127 | } | |
1128 | ||
1129 | /* Merge as1 to as2. as2 should be uninterned aspath. */ | |
94f2b392 | 1130 | static struct aspath * |
718e3744 | 1131 | aspath_merge (struct aspath *as1, struct aspath *as2) |
1132 | { | |
fe69a505 | 1133 | struct assegment *last, *new; |
718e3744 | 1134 | |
1135 | if (! as1 || ! as2) | |
1136 | return NULL; | |
1137 | ||
fe69a505 | 1138 | last = new = assegment_dup_all (as1->segments); |
1139 | ||
1140 | /* find the last valid segment */ | |
1141 | while (last && last->next) | |
1142 | last = last->next; | |
1143 | ||
1144 | last->next = as2->segments; | |
1145 | as2->segments = new; | |
1146 | aspath_str_update (as2); | |
718e3744 | 1147 | return as2; |
1148 | } | |
1149 | ||
1150 | /* Prepend as1 to as2. as2 should be uninterned aspath. */ | |
1151 | struct aspath * | |
1152 | aspath_prepend (struct aspath *as1, struct aspath *as2) | |
1153 | { | |
fe69a505 | 1154 | struct assegment *seg1; |
1155 | struct assegment *seg2; | |
718e3744 | 1156 | |
1157 | if (! as1 || ! as2) | |
1158 | return NULL; | |
fe69a505 | 1159 | |
1160 | seg1 = as1->segments; | |
1161 | seg2 = as2->segments; | |
1162 | ||
1163 | /* If as2 is empty, only need to dupe as1's chain onto as2 */ | |
718e3744 | 1164 | if (seg2 == NULL) |
1165 | { | |
fe69a505 | 1166 | as2->segments = assegment_dup_all (as1->segments); |
1167 | aspath_str_update (as2); | |
718e3744 | 1168 | return as2; |
1169 | } | |
fe69a505 | 1170 | |
1171 | /* If as1 is empty AS, no prepending to do. */ | |
718e3744 | 1172 | if (seg1 == NULL) |
1173 | return as2; | |
fe69a505 | 1174 | |
1175 | /* find the tail as1's segment chain. */ | |
1176 | while (seg1 && seg1->next) | |
1177 | seg1 = seg1->next; | |
718e3744 | 1178 | |
1179 | /* Compare last segment type of as1 and first segment type of as2. */ | |
1180 | if (seg1->type != seg2->type) | |
1181 | return aspath_merge (as1, as2); | |
1182 | ||
1183 | if (seg1->type == AS_SEQUENCE) | |
1184 | { | |
fe69a505 | 1185 | /* We have two chains of segments, as1->segments and seg2, |
1186 | * and we have to attach them together, merging the attaching | |
1187 | * segments together into one. | |
1188 | * | |
1189 | * 1. dupe as1->segments onto head of as2 | |
1190 | * 2. merge seg2's asns onto last segment of this new chain | |
1191 | * 3. attach chain after seg2 | |
1192 | */ | |
718e3744 | 1193 | |
fe69a505 | 1194 | /* dupe as1 onto as2's head */ |
1195 | seg1 = as2->segments = assegment_dup_all (as1->segments); | |
1196 | ||
1197 | /* refind the tail of as2, reusing seg1 */ | |
1198 | while (seg1 && seg1->next) | |
1199 | seg1 = seg1->next; | |
1200 | ||
1201 | /* merge the old head, seg2, into tail, seg1 */ | |
1202 | seg1 = assegment_append_asns (seg1, seg2->as, seg2->length); | |
1203 | ||
1204 | /* bypass the merged seg2, and attach any chain after it to | |
1205 | * chain descending from as2's head | |
1206 | */ | |
1207 | seg1->next = seg2->next; | |
1208 | ||
1209 | /* seg2 is now referenceless and useless*/ | |
1210 | assegment_free (seg2); | |
1211 | ||
1212 | /* we've now prepended as1's segment chain to as2, merging | |
1213 | * the inbetween AS_SEQUENCE of seg2 in the process | |
1214 | */ | |
1215 | aspath_str_update (as2); | |
718e3744 | 1216 | return as2; |
1217 | } | |
1218 | else | |
1219 | { | |
1220 | /* AS_SET merge code is needed at here. */ | |
1221 | return aspath_merge (as1, as2); | |
1222 | } | |
fe69a505 | 1223 | /* XXX: Ermmm, what if as1 has multiple segments?? */ |
1224 | ||
718e3744 | 1225 | /* Not reached */ |
1226 | } | |
1227 | ||
841f7a57 DO |
1228 | /* Iterate over AS_PATH segments and wipe all occurences of the |
1229 | * listed AS numbers. Hence some segments may lose some or even | |
1230 | * all data on the way, the operation is implemented as a smarter | |
1231 | * version of aspath_dup(), which allocates memory to hold the new | |
1232 | * data, not the original. The new AS path is returned. | |
1233 | */ | |
1234 | struct aspath * | |
1235 | aspath_filter_exclude (struct aspath * source, struct aspath * exclude_list) | |
1236 | { | |
1237 | struct assegment * srcseg, * exclseg, * lastseg; | |
1238 | struct aspath * newpath; | |
1239 | ||
1240 | newpath = aspath_new(); | |
1241 | lastseg = NULL; | |
1242 | ||
1243 | for (srcseg = source->segments; srcseg; srcseg = srcseg->next) | |
1244 | { | |
1245 | unsigned i, y, newlen = 0, done = 0, skip_as; | |
1246 | struct assegment * newseg; | |
1247 | ||
1248 | /* Find out, how much ASns are we going to pick from this segment. | |
1249 | * We can't perform filtering right inline, because the size of | |
1250 | * the new segment isn't known at the moment yet. | |
1251 | */ | |
1252 | for (i = 0; i < srcseg->length; i++) | |
1253 | { | |
1254 | skip_as = 0; | |
1255 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1256 | for (y = 0; y < exclseg->length; y++) | |
1257 | if (srcseg->as[i] == exclseg->as[y]) | |
1258 | { | |
1259 | skip_as = 1; | |
1260 | // There's no sense in testing the rest of exclusion list, bail out. | |
1261 | break; | |
1262 | } | |
1263 | if (!skip_as) | |
1264 | newlen++; | |
1265 | } | |
1266 | /* newlen is now the number of ASns to copy */ | |
1267 | if (!newlen) | |
1268 | continue; | |
1269 | ||
1270 | /* Actual copying. Allocate memory and iterate once more, performing filtering. */ | |
1271 | newseg = assegment_new (srcseg->type, newlen); | |
1272 | for (i = 0; i < srcseg->length; i++) | |
1273 | { | |
1274 | skip_as = 0; | |
1275 | for (exclseg = exclude_list->segments; exclseg && !skip_as; exclseg = exclseg->next) | |
1276 | for (y = 0; y < exclseg->length; y++) | |
1277 | if (srcseg->as[i] == exclseg->as[y]) | |
1278 | { | |
1279 | skip_as = 1; | |
1280 | break; | |
1281 | } | |
1282 | if (skip_as) | |
1283 | continue; | |
1284 | newseg->as[done++] = srcseg->as[i]; | |
1285 | } | |
1286 | /* At his point newlen must be equal to done, and both must be positive. Append | |
1287 | * the filtered segment to the gross result. */ | |
1288 | if (!lastseg) | |
1289 | newpath->segments = newseg; | |
1290 | else | |
1291 | lastseg->next = newseg; | |
1292 | lastseg = newseg; | |
1293 | } | |
1294 | aspath_str_update (newpath); | |
1295 | /* We are happy returning even an empty AS_PATH, because the administrator | |
1296 | * might expect this very behaviour. There's a mean to avoid this, if necessary, | |
1297 | * by having a match rule against certain AS_PATH regexps in the route-map index. | |
1298 | */ | |
1299 | aspath_free (source); | |
1300 | return newpath; | |
1301 | } | |
1302 | ||
718e3744 | 1303 | /* Add specified AS to the leftmost of aspath. */ |
1304 | static struct aspath * | |
1305 | aspath_add_one_as (struct aspath *aspath, as_t asno, u_char type) | |
1306 | { | |
fe69a505 | 1307 | struct assegment *assegment = aspath->segments; |
718e3744 | 1308 | |
1309 | /* In case of empty aspath. */ | |
1310 | if (assegment == NULL || assegment->length == 0) | |
1311 | { | |
fe69a505 | 1312 | aspath->segments = assegment_new (type, 1); |
1313 | aspath->segments->as[0] = asno; | |
1314 | ||
718e3744 | 1315 | if (assegment) |
fe69a505 | 1316 | assegment_free (assegment); |
718e3744 | 1317 | |
1318 | return aspath; | |
1319 | } | |
1320 | ||
1321 | if (assegment->type == type) | |
fe69a505 | 1322 | aspath->segments = assegment_prepend_asns (aspath->segments, asno, 1); |
1323 | else | |
718e3744 | 1324 | { |
fe69a505 | 1325 | /* create new segment |
1326 | * push it onto head of aspath's segment chain | |
1327 | */ | |
718e3744 | 1328 | struct assegment *newsegment; |
fe69a505 | 1329 | |
1330 | newsegment = assegment_new (type, 1); | |
1331 | newsegment->as[0] = asno; | |
1332 | ||
1333 | newsegment->next = assegment; | |
1334 | aspath->segments = newsegment; | |
718e3744 | 1335 | } |
1336 | ||
1337 | return aspath; | |
1338 | } | |
1339 | ||
1340 | /* Add specified AS to the leftmost of aspath. */ | |
1341 | struct aspath * | |
1342 | aspath_add_seq (struct aspath *aspath, as_t asno) | |
1343 | { | |
1344 | return aspath_add_one_as (aspath, asno, AS_SEQUENCE); | |
1345 | } | |
1346 | ||
1347 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and | |
1348 | as2's leftmost AS is same return 1. */ | |
1349 | int | |
ffe11cfb | 1350 | aspath_cmp_left (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1351 | { |
ffe11cfb SH |
1352 | const struct assegment *seg1 = NULL; |
1353 | const struct assegment *seg2 = NULL; | |
718e3744 | 1354 | |
fe69a505 | 1355 | if (!(aspath1 && aspath2)) |
1356 | return 0; | |
718e3744 | 1357 | |
fe69a505 | 1358 | seg1 = aspath1->segments; |
1359 | seg2 = aspath2->segments; | |
718e3744 | 1360 | |
fe69a505 | 1361 | /* find first non-confed segments for each */ |
1362 | while (seg1 && ((seg1->type == AS_CONFED_SEQUENCE) | |
1363 | || (seg1->type == AS_CONFED_SET))) | |
1364 | seg1 = seg1->next; | |
718e3744 | 1365 | |
fe69a505 | 1366 | while (seg2 && ((seg2->type == AS_CONFED_SEQUENCE) |
1367 | || (seg2->type == AS_CONFED_SET))) | |
1368 | seg2 = seg2->next; | |
718e3744 | 1369 | |
fe69a505 | 1370 | /* Check as1's */ |
1371 | if (!(seg1 && seg2 | |
1372 | && (seg1->type == AS_SEQUENCE) && (seg2->type == AS_SEQUENCE))) | |
1373 | return 0; | |
1374 | ||
1375 | if (seg1->as[0] == seg2->as[0]) | |
718e3744 | 1376 | return 1; |
1377 | ||
1378 | return 0; | |
1379 | } | |
1380 | ||
0b2aa3a0 PJ |
1381 | /* Truncate an aspath after a number of hops, and put the hops remaining |
1382 | * at the front of another aspath. Needed for AS4 compat. | |
1383 | * | |
1384 | * Returned aspath is a /new/ aspath, which should either by free'd or | |
1385 | * interned by the caller, as desired. | |
1386 | */ | |
1387 | struct aspath * | |
1388 | aspath_reconcile_as4 ( struct aspath *aspath, struct aspath *as4path) | |
1389 | { | |
1390 | struct assegment *seg, *newseg, *prevseg = NULL; | |
1391 | struct aspath *newpath = NULL, *mergedpath; | |
1392 | int hops, cpasns = 0; | |
1393 | ||
1394 | if (!aspath) | |
1395 | return NULL; | |
1396 | ||
1397 | seg = aspath->segments; | |
1398 | ||
1399 | /* CONFEDs should get reconciled too.. */ | |
1400 | hops = (aspath_count_hops (aspath) + aspath_count_confeds (aspath)) | |
1401 | - aspath_count_hops (as4path); | |
1402 | ||
1403 | if (hops < 0) | |
1404 | { | |
1405 | if (BGP_DEBUG (as4, AS4)) | |
1406 | zlog_warn ("[AS4] Fewer hops in AS_PATH than NEW_AS_PATH"); | |
1407 | /* Something's gone wrong. The RFC says we should now ignore AS4_PATH, | |
1408 | * which is daft behaviour - it contains vital loop-detection | |
1409 | * information which must have been removed from AS_PATH. | |
1410 | */ | |
1411 | hops = aspath_count_hops (aspath); | |
1412 | } | |
1413 | ||
1414 | if (!hops) | |
1415 | return aspath_dup (as4path); | |
1416 | ||
1417 | if ( BGP_DEBUG(as4, AS4)) | |
1418 | zlog_debug("[AS4] got AS_PATH %s and AS4_PATH %s synthesizing now", | |
1419 | aspath->str, as4path->str); | |
1420 | ||
1421 | while (seg && hops > 0) | |
1422 | { | |
1423 | switch (seg->type) | |
1424 | { | |
1425 | case AS_SET: | |
1426 | case AS_CONFED_SET: | |
1427 | hops--; | |
1428 | cpasns = seg->length; | |
1429 | break; | |
1430 | case AS_CONFED_SEQUENCE: | |
1431 | /* Should never split a confed-sequence, if hop-count | |
1432 | * suggests we must then something's gone wrong somewhere. | |
1433 | * | |
1434 | * Most important goal is to preserve AS_PATHs prime function | |
1435 | * as loop-detector, so we fudge the numbers so that the entire | |
1436 | * confed-sequence is merged in. | |
1437 | */ | |
1438 | if (hops < seg->length) | |
1439 | { | |
1440 | if (BGP_DEBUG (as4, AS4)) | |
1441 | zlog_debug ("[AS4] AS4PATHmangle: AS_CONFED_SEQUENCE falls" | |
1442 | " across 2/4 ASN boundary somewhere, broken.."); | |
1443 | hops = seg->length; | |
1444 | } | |
1445 | case AS_SEQUENCE: | |
1446 | cpasns = MIN(seg->length, hops); | |
1447 | hops -= seg->length; | |
1448 | } | |
1449 | ||
1450 | assert (cpasns <= seg->length); | |
1451 | ||
1452 | newseg = assegment_new (seg->type, 0); | |
1453 | newseg = assegment_append_asns (newseg, seg->as, cpasns); | |
1454 | ||
1455 | if (!newpath) | |
1456 | { | |
1457 | newpath = aspath_new (); | |
1458 | newpath->segments = newseg; | |
1459 | } | |
1460 | else | |
1461 | prevseg->next = newseg; | |
1462 | ||
1463 | prevseg = newseg; | |
1464 | seg = seg->next; | |
1465 | } | |
1466 | ||
1467 | /* We may be able to join some segments here, and we must | |
1468 | * do this because... we want normalised aspaths in out hash | |
1469 | * and we do not want to stumble in aspath_put. | |
1470 | */ | |
1471 | mergedpath = aspath_merge (newpath, aspath_dup(as4path)); | |
1472 | aspath_free (newpath); | |
1473 | mergedpath->segments = assegment_normalise (mergedpath->segments); | |
1474 | aspath_str_update (mergedpath); | |
1475 | ||
1476 | if ( BGP_DEBUG(as4, AS4)) | |
1477 | zlog_debug ("[AS4] result of synthesizing is %s", | |
1478 | mergedpath->str); | |
1479 | ||
1480 | return mergedpath; | |
1481 | } | |
1482 | ||
718e3744 | 1483 | /* Compare leftmost AS value for MED check. If as1's leftmost AS and |
1484 | as2's leftmost AS is same return 1. (confederation as-path | |
1485 | only). */ | |
1486 | int | |
ffe11cfb | 1487 | aspath_cmp_left_confed (const struct aspath *aspath1, const struct aspath *aspath2) |
718e3744 | 1488 | { |
fe69a505 | 1489 | if (! (aspath1 && aspath2) ) |
718e3744 | 1490 | return 0; |
fe69a505 | 1491 | |
ad72740e | 1492 | if ( !(aspath1->segments && aspath2->segments) ) |
1493 | return 0; | |
1494 | ||
fe69a505 | 1495 | if ( (aspath1->segments->type != AS_CONFED_SEQUENCE) |
1496 | || (aspath2->segments->type != AS_CONFED_SEQUENCE) ) | |
718e3744 | 1497 | return 0; |
fe69a505 | 1498 | |
1499 | if (aspath1->segments->as[0] == aspath2->segments->as[0]) | |
718e3744 | 1500 | return 1; |
1501 | ||
1502 | return 0; | |
1503 | } | |
1504 | ||
fe69a505 | 1505 | /* Delete all leading AS_CONFED_SEQUENCE/SET segments from aspath. |
1506 | * See RFC3065, 6.1 c1 */ | |
718e3744 | 1507 | struct aspath * |
1508 | aspath_delete_confed_seq (struct aspath *aspath) | |
1509 | { | |
fe69a505 | 1510 | struct assegment *seg; |
718e3744 | 1511 | |
fe69a505 | 1512 | if (!(aspath && aspath->segments)) |
718e3744 | 1513 | return aspath; |
1514 | ||
fe69a505 | 1515 | seg = aspath->segments; |
1516 | ||
1517 | /* "if the first path segment of the AS_PATH is | |
1518 | * of type AS_CONFED_SEQUENCE," | |
1519 | */ | |
1520 | if (aspath->segments->type != AS_CONFED_SEQUENCE) | |
1521 | return aspath; | |
718e3744 | 1522 | |
fe69a505 | 1523 | /* "... that segment and any immediately following segments |
1524 | * of the type AS_CONFED_SET or AS_CONFED_SEQUENCE are removed | |
1525 | * from the AS_PATH attribute," | |
1526 | */ | |
1527 | while (seg && | |
1528 | (seg->type == AS_CONFED_SEQUENCE || seg->type == AS_CONFED_SET)) | |
718e3744 | 1529 | { |
fe69a505 | 1530 | aspath->segments = seg->next; |
1531 | assegment_free (seg); | |
1532 | seg = aspath->segments; | |
718e3744 | 1533 | } |
fe69a505 | 1534 | aspath_str_update (aspath); |
718e3744 | 1535 | return aspath; |
1536 | } | |
1537 | ||
1538 | /* Add new AS number to the leftmost part of the aspath as | |
1539 | AS_CONFED_SEQUENCE. */ | |
1540 | struct aspath* | |
1541 | aspath_add_confed_seq (struct aspath *aspath, as_t asno) | |
1542 | { | |
1543 | return aspath_add_one_as (aspath, asno, AS_CONFED_SEQUENCE); | |
1544 | } | |
1545 | ||
1546 | /* Add new as value to as path structure. */ | |
94f2b392 | 1547 | static void |
718e3744 | 1548 | aspath_as_add (struct aspath *as, as_t asno) |
1549 | { | |
fe69a505 | 1550 | struct assegment *seg = as->segments; |
718e3744 | 1551 | |
fe69a505 | 1552 | if (!seg) |
1553 | return; | |
1554 | ||
93c1749c AS |
1555 | /* Last segment search procedure. */ |
1556 | while (seg->next) | |
1557 | seg = seg->next; | |
1558 | ||
fe69a505 | 1559 | assegment_append_asns (seg, &asno, 1); |
718e3744 | 1560 | } |
1561 | ||
1562 | /* Add new as segment to the as path. */ | |
94f2b392 | 1563 | static void |
718e3744 | 1564 | aspath_segment_add (struct aspath *as, int type) |
1565 | { | |
fe69a505 | 1566 | struct assegment *seg = as->segments; |
1567 | struct assegment *new = assegment_new (type, 0); | |
718e3744 | 1568 | |
93c1749c AS |
1569 | if (seg) |
1570 | { | |
1571 | while (seg->next) | |
1572 | seg = seg->next; | |
1573 | seg->next = new; | |
1574 | } | |
718e3744 | 1575 | else |
93c1749c | 1576 | as->segments = new; |
718e3744 | 1577 | } |
1578 | ||
1579 | struct aspath * | |
94f2b392 | 1580 | aspath_empty (void) |
718e3744 | 1581 | { |
0b2aa3a0 | 1582 | return aspath_parse (NULL, 0, 1); /* 32Bit ;-) */ |
718e3744 | 1583 | } |
1584 | ||
1585 | struct aspath * | |
94f2b392 | 1586 | aspath_empty_get (void) |
718e3744 | 1587 | { |
1588 | struct aspath *aspath; | |
1589 | ||
1590 | aspath = aspath_new (); | |
1591 | aspath->str = aspath_make_str_count (aspath); | |
1592 | return aspath; | |
1593 | } | |
1594 | ||
1595 | unsigned long | |
fe69a505 | 1596 | aspath_count (void) |
718e3744 | 1597 | { |
1598 | return ashash->count; | |
1599 | } | |
1600 | \f | |
1601 | /* | |
1602 | Theoretically, one as path can have: | |
1603 | ||
1604 | One BGP packet size should be less than 4096. | |
1605 | One BGP attribute size should be less than 4096 - BGP header size. | |
1606 | One BGP aspath size should be less than 4096 - BGP header size - | |
1607 | BGP mandantry attribute size. | |
1608 | */ | |
1609 | ||
1610 | /* AS path string lexical token enum. */ | |
1611 | enum as_token | |
1612 | { | |
1613 | as_token_asval, | |
1614 | as_token_set_start, | |
1615 | as_token_set_end, | |
fe69a505 | 1616 | as_token_confed_seq_start, |
1617 | as_token_confed_seq_end, | |
1618 | as_token_confed_set_start, | |
1619 | as_token_confed_set_end, | |
718e3744 | 1620 | as_token_unknown |
1621 | }; | |
1622 | ||
1623 | /* Return next token and point for string parse. */ | |
94f2b392 | 1624 | static const char * |
0b2aa3a0 | 1625 | aspath_gettoken (const char *buf, enum as_token *token, u_long *asno) |
718e3744 | 1626 | { |
fd79ac91 | 1627 | const char *p = buf; |
718e3744 | 1628 | |
fe69a505 | 1629 | /* Skip seperators (space for sequences, ',' for sets). */ |
1630 | while (isspace ((int) *p) || *p == ',') | |
718e3744 | 1631 | p++; |
1632 | ||
1633 | /* Check the end of the string and type specify characters | |
1634 | (e.g. {}()). */ | |
1635 | switch (*p) | |
1636 | { | |
1637 | case '\0': | |
1638 | return NULL; | |
718e3744 | 1639 | case '{': |
1640 | *token = as_token_set_start; | |
1641 | p++; | |
1642 | return p; | |
718e3744 | 1643 | case '}': |
1644 | *token = as_token_set_end; | |
1645 | p++; | |
1646 | return p; | |
718e3744 | 1647 | case '(': |
fe69a505 | 1648 | *token = as_token_confed_seq_start; |
718e3744 | 1649 | p++; |
1650 | return p; | |
718e3744 | 1651 | case ')': |
fe69a505 | 1652 | *token = as_token_confed_seq_end; |
1653 | p++; | |
1654 | return p; | |
fe69a505 | 1655 | case '[': |
1656 | *token = as_token_confed_set_start; | |
1657 | p++; | |
1658 | return p; | |
fe69a505 | 1659 | case ']': |
1660 | *token = as_token_confed_set_end; | |
718e3744 | 1661 | p++; |
1662 | return p; | |
718e3744 | 1663 | } |
1664 | ||
1665 | /* Check actual AS value. */ | |
1666 | if (isdigit ((int) *p)) | |
1667 | { | |
1668 | u_short asval; | |
0b2aa3a0 | 1669 | |
718e3744 | 1670 | *token = as_token_asval; |
1671 | asval = (*p - '0'); | |
1672 | p++; | |
0b2aa3a0 | 1673 | |
718e3744 | 1674 | while (isdigit ((int) *p)) |
0b2aa3a0 PJ |
1675 | { |
1676 | asval *= 10; | |
1677 | asval += (*p - '0'); | |
1678 | p++; | |
1679 | } | |
718e3744 | 1680 | *asno = asval; |
1681 | return p; | |
1682 | } | |
1683 | ||
1684 | /* There is no match then return unknown token. */ | |
1685 | *token = as_token_unknown; | |
1686 | return p++; | |
1687 | } | |
1688 | ||
1689 | struct aspath * | |
fd79ac91 | 1690 | aspath_str2aspath (const char *str) |
718e3744 | 1691 | { |
3fff6ffc | 1692 | enum as_token token = as_token_unknown; |
718e3744 | 1693 | u_short as_type; |
0b2aa3a0 | 1694 | u_long asno = 0; |
718e3744 | 1695 | struct aspath *aspath; |
1696 | int needtype; | |
1697 | ||
1698 | aspath = aspath_new (); | |
1699 | ||
1700 | /* We start default type as AS_SEQUENCE. */ | |
1701 | as_type = AS_SEQUENCE; | |
1702 | needtype = 1; | |
1703 | ||
1704 | while ((str = aspath_gettoken (str, &token, &asno)) != NULL) | |
1705 | { | |
1706 | switch (token) | |
1707 | { | |
1708 | case as_token_asval: | |
1709 | if (needtype) | |
1710 | { | |
1711 | aspath_segment_add (aspath, as_type); | |
1712 | needtype = 0; | |
1713 | } | |
1714 | aspath_as_add (aspath, asno); | |
1715 | break; | |
1716 | case as_token_set_start: | |
1717 | as_type = AS_SET; | |
1718 | aspath_segment_add (aspath, as_type); | |
1719 | needtype = 0; | |
1720 | break; | |
1721 | case as_token_set_end: | |
1722 | as_type = AS_SEQUENCE; | |
1723 | needtype = 1; | |
1724 | break; | |
fe69a505 | 1725 | case as_token_confed_seq_start: |
718e3744 | 1726 | as_type = AS_CONFED_SEQUENCE; |
1727 | aspath_segment_add (aspath, as_type); | |
1728 | needtype = 0; | |
1729 | break; | |
fe69a505 | 1730 | case as_token_confed_seq_end: |
1731 | as_type = AS_SEQUENCE; | |
1732 | needtype = 1; | |
1733 | break; | |
1734 | case as_token_confed_set_start: | |
1735 | as_type = AS_CONFED_SET; | |
1736 | aspath_segment_add (aspath, as_type); | |
1737 | needtype = 0; | |
1738 | break; | |
1739 | case as_token_confed_set_end: | |
718e3744 | 1740 | as_type = AS_SEQUENCE; |
1741 | needtype = 1; | |
1742 | break; | |
1743 | case as_token_unknown: | |
1744 | default: | |
fe69a505 | 1745 | aspath_free (aspath); |
718e3744 | 1746 | return NULL; |
718e3744 | 1747 | } |
1748 | } | |
1749 | ||
1750 | aspath->str = aspath_make_str_count (aspath); | |
1751 | ||
1752 | return aspath; | |
1753 | } | |
1754 | \f | |
1755 | /* Make hash value by raw aspath data. */ | |
1756 | unsigned int | |
923de654 | 1757 | aspath_key_make (void *p) |
718e3744 | 1758 | { |
923de654 | 1759 | struct aspath * aspath = (struct aspath *) p; |
718e3744 | 1760 | unsigned int key = 0; |
718e3744 | 1761 | |
0b2aa3a0 PJ |
1762 | if (!aspath->str) |
1763 | aspath_str_update (aspath); | |
1764 | ||
1765 | key = jhash (aspath->str, strlen(aspath->str), 2334325); | |
718e3744 | 1766 | |
1767 | return key; | |
1768 | } | |
1769 | ||
1770 | /* If two aspath have same value then return 1 else return 0 */ | |
94f2b392 | 1771 | static int |
ffe11cfb | 1772 | aspath_cmp (const void *arg1, const void *arg2) |
718e3744 | 1773 | { |
ffe11cfb SH |
1774 | const struct assegment *seg1 = ((struct aspath *)arg1)->segments; |
1775 | const struct assegment *seg2 = ((struct aspath *)arg2)->segments; | |
fe69a505 | 1776 | |
1777 | while (seg1 || seg2) | |
1778 | { | |
1779 | int i; | |
1780 | if ((!seg1 && seg2) || (seg1 && !seg2)) | |
1781 | return 0; | |
1782 | if (seg1->type != seg2->type) | |
1783 | return 0; | |
1784 | if (seg1->length != seg2->length) | |
1785 | return 0; | |
1786 | for (i = 0; i < seg1->length; i++) | |
1787 | if (seg1->as[i] != seg2->as[i]) | |
1788 | return 0; | |
1789 | seg1 = seg1->next; | |
1790 | seg2 = seg2->next; | |
1791 | } | |
1792 | return 1; | |
718e3744 | 1793 | } |
1794 | ||
1795 | /* AS path hash initialize. */ | |
1796 | void | |
94f2b392 | 1797 | aspath_init (void) |
718e3744 | 1798 | { |
1799 | ashash = hash_create_size (32767, aspath_key_make, aspath_cmp); | |
1800 | } | |
8fdc32ab | 1801 | |
1802 | void | |
1803 | aspath_finish (void) | |
1804 | { | |
1805 | hash_free (ashash); | |
1806 | ||
1807 | if (snmp_stream) | |
1808 | stream_free (snmp_stream); | |
1809 | } | |
718e3744 | 1810 | \f |
1811 | /* return and as path value */ | |
1812 | const char * | |
1813 | aspath_print (struct aspath *as) | |
1814 | { | |
fe69a505 | 1815 | return (as ? as->str : NULL); |
718e3744 | 1816 | } |
1817 | ||
1818 | /* Printing functions */ | |
841f7a57 DO |
1819 | /* Feed the AS_PATH to the vty; the suffix string follows it only in case |
1820 | * AS_PATH wasn't empty. | |
1821 | */ | |
718e3744 | 1822 | void |
841f7a57 | 1823 | aspath_print_vty (struct vty *vty, const char *format, struct aspath *as, const char * suffix) |
718e3744 | 1824 | { |
b2518c1e PJ |
1825 | assert (format); |
1826 | vty_out (vty, format, as->str); | |
841f7a57 DO |
1827 | if (strlen (as->str) && strlen (suffix)) |
1828 | vty_out (vty, "%s", suffix); | |
718e3744 | 1829 | } |
1830 | ||
94f2b392 | 1831 | static void |
718e3744 | 1832 | aspath_show_all_iterator (struct hash_backet *backet, struct vty *vty) |
1833 | { | |
1834 | struct aspath *as; | |
1835 | ||
1836 | as = (struct aspath *) backet->data; | |
1837 | ||
efa9f830 | 1838 | vty_out (vty, "[%p:%u] (%ld) ", backet, backet->key, as->refcnt); |
718e3744 | 1839 | vty_out (vty, "%s%s", as->str, VTY_NEWLINE); |
1840 | } | |
1841 | ||
1842 | /* Print all aspath and hash information. This function is used from | |
1843 | `show ip bgp paths' command. */ | |
1844 | void | |
1845 | aspath_print_all_vty (struct vty *vty) | |
1846 | { | |
1847 | hash_iterate (ashash, | |
1848 | (void (*) (struct hash_backet *, void *)) | |
1849 | aspath_show_all_iterator, | |
1850 | vty); | |
1851 | } |