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1 | /* BGP Large Communities Attribute |
2 | ||
3 | Copyright (C) 2016 Keyur Patel <keyur@arrcus.com> | |
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 "prefix.h" | |
27 | #include "command.h" | |
28 | #include "filter.h" | |
29 | ||
30 | #include "bgpd/bgpd.h" | |
31 | #include "bgpd/bgp_lcommunity.h" | |
32 | #include "bgpd/bgp_aspath.h" | |
33 | ||
34 | /* Hash of community attribute. */ | |
35 | static struct hash *lcomhash; | |
36 | ||
37 | /* Allocate a new lcommunities. */ | |
38 | static struct lcommunity * | |
39 | lcommunity_new (void) | |
40 | { | |
41 | return (struct lcommunity *) XCALLOC (MTYPE_LCOMMUNITY, | |
42 | sizeof (struct lcommunity)); | |
43 | } | |
44 | ||
45 | /* Allocate lcommunities. */ | |
46 | void | |
47 | lcommunity_free (struct lcommunity **lcom) | |
48 | { | |
49 | if ((*lcom)->val) | |
50 | XFREE (MTYPE_LCOMMUNITY_VAL, (*lcom)->val); | |
51 | if ((*lcom)->str) | |
52 | XFREE (MTYPE_LCOMMUNITY_STR, (*lcom)->str); | |
53 | XFREE (MTYPE_LCOMMUNITY, *lcom); | |
54 | lcom = NULL; | |
55 | } | |
56 | ||
57 | /* Add a new Large Communities value to Large Communities | |
58 | Attribute structure. When the value is already exists in the | |
59 | structure, we don't add the value. Newly added value is sorted by | |
60 | numerical order. When the value is added to the structure return 1 | |
61 | else return 0. */ | |
62 | static int | |
63 | lcommunity_add_val (struct lcommunity *lcom, struct lcommunity_val *lval) | |
64 | { | |
65 | u_int8_t *p; | |
66 | int ret; | |
67 | int c; | |
68 | ||
69 | /* When this is fist value, just add it. */ | |
70 | if (lcom->val == NULL) | |
71 | { | |
72 | lcom->size++; | |
73 | lcom->val = XMALLOC (MTYPE_LCOMMUNITY_VAL, lcom_length (lcom)); | |
74 | memcpy (lcom->val, lval->val, LCOMMUNITY_SIZE); | |
75 | return 1; | |
76 | } | |
77 | ||
78 | /* If the value already exists in the structure return 0. */ | |
79 | c = 0; | |
80 | for (p = lcom->val; c < lcom->size; p += LCOMMUNITY_SIZE, c++) | |
81 | { | |
82 | ret = memcmp (p, lval->val, LCOMMUNITY_SIZE); | |
83 | if (ret == 0) | |
84 | return 0; | |
85 | if (ret > 0) | |
86 | break; | |
87 | } | |
88 | ||
89 | /* Add the value to the structure with numerical sorting. */ | |
90 | lcom->size++; | |
91 | lcom->val = XREALLOC (MTYPE_LCOMMUNITY_VAL, lcom->val, lcom_length (lcom)); | |
92 | ||
93 | memmove (lcom->val + (c + 1) * LCOMMUNITY_SIZE, | |
94 | lcom->val + c * LCOMMUNITY_SIZE, | |
95 | (lcom->size - 1 - c) * LCOMMUNITY_SIZE); | |
96 | memcpy (lcom->val + c * LCOMMUNITY_SIZE, lval->val, LCOMMUNITY_SIZE); | |
97 | ||
98 | return 1; | |
99 | } | |
100 | ||
101 | /* This function takes pointer to Large Communites strucutre then | |
102 | create a new Large Communities structure by uniq and sort each | |
103 | Large Communities value. */ | |
104 | struct lcommunity * | |
105 | lcommunity_uniq_sort (struct lcommunity *lcom) | |
106 | { | |
107 | int i; | |
108 | struct lcommunity *new; | |
109 | struct lcommunity_val *lval; | |
110 | ||
111 | if (! lcom) | |
112 | return NULL; | |
113 | ||
114 | new = lcommunity_new (); | |
115 | ||
116 | for (i = 0; i < lcom->size; i++) | |
117 | { | |
118 | lval = (struct lcommunity_val *) (lcom->val + (i * LCOMMUNITY_SIZE)); | |
119 | lcommunity_add_val (new, lval); | |
120 | } | |
121 | return new; | |
122 | } | |
123 | ||
124 | /* Parse Large Communites Attribute in BGP packet. */ | |
125 | struct lcommunity * | |
126 | lcommunity_parse (u_int8_t *pnt, u_short length) | |
127 | { | |
128 | struct lcommunity tmp; | |
129 | struct lcommunity *new; | |
130 | ||
131 | /* Length check. */ | |
132 | if (length % LCOMMUNITY_SIZE) | |
133 | return NULL; | |
134 | ||
135 | /* Prepare tmporary structure for making a new Large Communities | |
136 | Attribute. */ | |
137 | tmp.size = length / LCOMMUNITY_SIZE; | |
138 | tmp.val = pnt; | |
139 | ||
140 | /* Create a new Large Communities Attribute by uniq and sort each | |
141 | Large Communities value */ | |
142 | new = lcommunity_uniq_sort (&tmp); | |
143 | ||
144 | return lcommunity_intern (new); | |
145 | } | |
146 | ||
147 | /* Duplicate the Large Communities Attribute structure. */ | |
148 | struct lcommunity * | |
149 | lcommunity_dup (struct lcommunity *lcom) | |
150 | { | |
151 | struct lcommunity *new; | |
152 | ||
153 | new = XCALLOC (MTYPE_LCOMMUNITY, sizeof (struct lcommunity)); | |
154 | new->size = lcom->size; | |
155 | if (new->size) | |
156 | { | |
157 | new->val = XMALLOC (MTYPE_LCOMMUNITY_VAL, lcom->size * LCOMMUNITY_SIZE); | |
158 | memcpy (new->val, lcom->val, lcom->size * LCOMMUNITY_SIZE); | |
159 | } | |
160 | else | |
161 | new->val = NULL; | |
162 | return new; | |
163 | } | |
164 | ||
165 | /* Retrun string representation of communities attribute. */ | |
166 | char * | |
167 | lcommunity_str (struct lcommunity *lcom) | |
168 | { | |
169 | if (! lcom->str) | |
170 | lcom->str = lcommunity_lcom2str (lcom, LCOMMUNITY_FORMAT_DISPLAY); | |
171 | return lcom->str; | |
172 | } | |
173 | ||
174 | /* Merge two Large Communities Attribute structure. */ | |
175 | struct lcommunity * | |
176 | lcommunity_merge (struct lcommunity *lcom1, struct lcommunity *lcom2) | |
177 | { | |
178 | if (lcom1->val) | |
179 | lcom1->val = XREALLOC (MTYPE_LCOMMUNITY_VAL, lcom1->val, | |
180 | (lcom1->size + lcom2->size) * LCOMMUNITY_SIZE); | |
181 | else | |
182 | lcom1->val = XMALLOC (MTYPE_LCOMMUNITY_VAL, | |
183 | (lcom1->size + lcom2->size) * LCOMMUNITY_SIZE); | |
184 | ||
185 | memcpy (lcom1->val + (lcom1->size * LCOMMUNITY_SIZE), | |
186 | lcom2->val, lcom2->size * LCOMMUNITY_SIZE); | |
187 | lcom1->size += lcom2->size; | |
188 | ||
189 | return lcom1; | |
190 | } | |
191 | ||
192 | /* Intern Large Communities Attribute. */ | |
193 | struct lcommunity * | |
194 | lcommunity_intern (struct lcommunity *lcom) | |
195 | { | |
196 | struct lcommunity *find; | |
197 | ||
198 | assert (lcom->refcnt == 0); | |
199 | ||
200 | find = (struct lcommunity *) hash_get (lcomhash, lcom, hash_alloc_intern); | |
201 | ||
202 | if (find != lcom) | |
203 | lcommunity_free (&lcom); | |
204 | ||
205 | find->refcnt++; | |
206 | ||
207 | if (! find->str) | |
208 | find->str = lcommunity_lcom2str (find, LCOMMUNITY_FORMAT_DISPLAY); | |
209 | ||
210 | return find; | |
211 | } | |
212 | ||
213 | /* Unintern Large Communities Attribute. */ | |
214 | void | |
215 | lcommunity_unintern (struct lcommunity **lcom) | |
216 | { | |
217 | struct lcommunity *ret; | |
218 | ||
219 | if ((*lcom)->refcnt) | |
220 | (*lcom)->refcnt--; | |
221 | ||
222 | /* Pull off from hash. */ | |
223 | if ((*lcom)->refcnt == 0) | |
224 | { | |
225 | /* Large community must be in the hash. */ | |
226 | ret = (struct lcommunity *) hash_release (lcomhash, *lcom); | |
227 | assert (ret != NULL); | |
228 | ||
229 | lcommunity_free (lcom); | |
230 | } | |
231 | } | |
232 | ||
233 | /* Utility function to make hash key. */ | |
234 | unsigned int | |
235 | lcommunity_hash_make (void *arg) | |
236 | { | |
237 | const struct lcommunity *lcom = arg; | |
238 | int size = lcom->size * LCOMMUNITY_SIZE; | |
239 | u_int8_t *pnt = lcom->val; | |
240 | unsigned int key = 0; | |
241 | int c; | |
242 | ||
243 | for (c = 0; c < size; c += LCOMMUNITY_SIZE) | |
244 | { | |
245 | key += pnt[c]; | |
246 | key += pnt[c + 1]; | |
247 | key += pnt[c + 2]; | |
248 | key += pnt[c + 3]; | |
249 | key += pnt[c + 4]; | |
250 | key += pnt[c + 5]; | |
251 | key += pnt[c + 6]; | |
252 | key += pnt[c + 7]; | |
253 | key += pnt[c + 8]; | |
254 | key += pnt[c + 9]; | |
255 | key += pnt[c + 10]; | |
256 | key += pnt[c + 11]; | |
257 | } | |
258 | ||
259 | return key; | |
260 | } | |
261 | ||
262 | /* Compare two Large Communities Attribute structure. */ | |
263 | int | |
264 | lcommunity_cmp (const void *arg1, const void *arg2) | |
265 | { | |
266 | const struct lcommunity *lcom1 = arg1; | |
267 | const struct lcommunity *lcom2 = arg2; | |
268 | ||
269 | return (lcom1->size == lcom2->size | |
270 | && memcmp (lcom1->val, lcom2->val, lcom1->size * LCOMMUNITY_SIZE) == 0); | |
271 | } | |
272 | ||
273 | /* Return communities hash. */ | |
274 | struct hash * | |
275 | lcommunity_hash (void) | |
276 | { | |
277 | return lcomhash; | |
278 | } | |
279 | ||
280 | /* Initialize Large Comminities related hash. */ | |
281 | void | |
282 | lcommunity_init (void) | |
283 | { | |
284 | lcomhash = hash_create (lcommunity_hash_make, lcommunity_cmp); | |
285 | } | |
286 | ||
287 | void | |
288 | lcommunity_finish (void) | |
289 | { | |
290 | hash_free (lcomhash); | |
291 | lcomhash = NULL; | |
292 | } | |
293 | ||
294 | /* Large Communities token enum. */ | |
295 | enum lcommunity_token | |
296 | { | |
297 | lcommunity_token_unknown = 0, | |
298 | lcommunity_token_val, | |
299 | }; | |
300 | ||
301 | /* Get next Large Communities token from the string. */ | |
302 | static const char * | |
303 | lcommunity_gettoken (const char *str, struct lcommunity_val *lval, | |
304 | enum lcommunity_token *token) | |
305 | { | |
306 | const char *p = str; | |
307 | ||
308 | /* Skip white space. */ | |
309 | while (isspace ((int) *p)) | |
310 | { | |
311 | p++; | |
312 | str++; | |
313 | } | |
314 | ||
315 | /* Check the end of the line. */ | |
316 | if (*p == '\0') | |
317 | return NULL; | |
318 | ||
319 | /* Community value. */ | |
320 | if (isdigit ((int) *p)) | |
321 | { | |
322 | int separator = 0; | |
323 | int digit = 0; | |
324 | u_int32_t globaladmin = 0; | |
325 | u_int32_t localdata1 = 0; | |
326 | u_int32_t localdata2 = 0; | |
327 | ||
328 | while (isdigit ((int) *p) || *p == ':') | |
329 | { | |
330 | if (*p == ':') | |
331 | { | |
332 | if (separator == 2) | |
333 | { | |
334 | *token = lcommunity_token_unknown; | |
335 | return NULL; | |
336 | } | |
337 | else | |
338 | { | |
339 | separator++; | |
340 | digit = 0; | |
341 | if (separator == 1) { | |
342 | globaladmin = localdata2; | |
343 | } else { | |
344 | localdata1 = localdata2; | |
345 | } | |
346 | localdata2 = 0; | |
347 | } | |
348 | } | |
349 | else | |
350 | { | |
351 | digit = 1; | |
352 | localdata2 *= 10; | |
353 | localdata2 += (*p - '0'); | |
354 | } | |
355 | p++; | |
356 | } | |
357 | if (! digit) | |
358 | { | |
359 | *token = lcommunity_token_unknown; | |
360 | return NULL; | |
361 | } | |
362 | ||
363 | /* | |
364 | * Copy the large comm. | |
365 | */ | |
366 | lval->val[0] = (globaladmin >> 24) & 0xff; | |
367 | lval->val[1] = (globaladmin >> 16) & 0xff; | |
368 | lval->val[2] = (globaladmin >> 8) & 0xff; | |
369 | lval->val[3] = globaladmin & 0xff; | |
370 | lval->val[4] = (localdata1 >> 24) & 0xff; | |
371 | lval->val[5] = (localdata1 >> 16) & 0xff; | |
372 | lval->val[6] = (localdata1 >> 8) & 0xff; | |
373 | lval->val[7] = localdata1 & 0xff; | |
374 | lval->val[8] = (localdata2 >> 24) & 0xff; | |
375 | lval->val[9] = (localdata2 >> 16) & 0xff; | |
376 | lval->val[10] = (localdata2 >> 8) & 0xff; | |
377 | lval->val[11] = localdata2 & 0xff; | |
378 | ||
379 | *token = lcommunity_token_val; | |
380 | return p; | |
381 | } | |
382 | *token = lcommunity_token_unknown; | |
383 | return p; | |
384 | } | |
385 | ||
386 | /* | |
387 | Convert string to large community attribute. | |
388 | When type is already known, please specify both str and type. | |
389 | ||
390 | When string includes keyword for each large community value. | |
391 | Please specify keyword_included as non-zero value. | |
392 | */ | |
393 | struct lcommunity * | |
394 | lcommunity_str2com (const char *str) | |
395 | { | |
396 | struct lcommunity *lcom = NULL; | |
397 | enum lcommunity_token token = lcommunity_token_unknown; | |
398 | struct lcommunity_val lval; | |
399 | ||
400 | while ((str = lcommunity_gettoken (str, &lval, &token))) | |
401 | { | |
402 | switch (token) | |
403 | { | |
404 | case lcommunity_token_val: | |
405 | if (lcom == NULL) | |
406 | lcom = lcommunity_new (); | |
407 | lcommunity_add_val (lcom, &lval); | |
408 | break; | |
409 | case lcommunity_token_unknown: | |
410 | default: | |
411 | if (lcom) | |
412 | lcommunity_free (&lcom); | |
413 | return NULL; | |
414 | } | |
415 | } | |
416 | return lcom; | |
417 | } | |
418 | ||
419 | int | |
420 | lcommunity_include (struct lcommunity *lcom, u_char *ptr) | |
421 | { | |
422 | int i; | |
423 | u_char *lcom_ptr; | |
424 | ||
425 | lcom_ptr = lcom->val; | |
426 | for (i = 0; i < lcom->size; i++) { | |
427 | lcom_ptr += (i * LCOMMUNITY_SIZE); | |
428 | if (memcmp (ptr, lcom_ptr, LCOMMUNITY_SIZE) == 0) | |
429 | return 1; | |
430 | } | |
431 | return 0; | |
432 | } | |
433 | ||
434 | /* Convert large community attribute to string. | |
435 | The large coms will be in 65535:65531:0 format. | |
436 | */ | |
437 | char * | |
438 | lcommunity_lcom2str (struct lcommunity *lcom, int format) | |
439 | { | |
440 | int i; | |
441 | u_int8_t *pnt; | |
442 | #define LCOMMUNITY_STR_DEFAULT_LEN 40 | |
443 | int str_size; | |
444 | int str_pnt; | |
445 | char *str_buf; | |
446 | int len = 0; | |
447 | int first = 1; | |
448 | u_int32_t globaladmin, localdata1, localdata2; | |
449 | ||
450 | if (lcom->size == 0) | |
451 | { | |
452 | str_buf = XMALLOC (MTYPE_LCOMMUNITY_STR, 1); | |
453 | str_buf[0] = '\0'; | |
454 | return str_buf; | |
455 | } | |
456 | ||
457 | /* Prepare buffer. */ | |
458 | str_buf = XMALLOC (MTYPE_LCOMMUNITY_STR, LCOMMUNITY_STR_DEFAULT_LEN + 1); | |
459 | str_size = LCOMMUNITY_STR_DEFAULT_LEN + 1; | |
460 | str_pnt = 0; | |
461 | ||
462 | for (i = 0; i < lcom->size; i++) | |
463 | { | |
464 | /* Make it sure size is enough. */ | |
465 | while (str_pnt + LCOMMUNITY_STR_DEFAULT_LEN >= str_size) | |
466 | { | |
467 | str_size *= 2; | |
468 | str_buf = XREALLOC (MTYPE_LCOMMUNITY_STR, str_buf, str_size); | |
469 | } | |
470 | ||
471 | /* Space between each value. */ | |
472 | if (! first) | |
473 | str_buf[str_pnt++] = ' '; | |
474 | ||
475 | pnt = lcom->val + (i * 12); | |
476 | ||
477 | globaladmin = (*pnt++ << 24); | |
478 | globaladmin |= (*pnt++ << 16); | |
479 | globaladmin |= (*pnt++ << 8); | |
480 | globaladmin |= (*pnt++); | |
481 | ||
482 | localdata1 = (*pnt++ << 24); | |
483 | localdata1 |= (*pnt++ << 16); | |
484 | localdata1 |= (*pnt++ << 8); | |
485 | localdata1 |= (*pnt++); | |
486 | ||
487 | localdata2 = (*pnt++ << 24); | |
488 | localdata2 |= (*pnt++ << 16); | |
489 | localdata2 |= (*pnt++ << 8); | |
490 | localdata2 |= (*pnt++); | |
491 | ||
492 | len = sprintf( str_buf + str_pnt, "%u:%u:%u", globaladmin, | |
493 | localdata1, localdata2); | |
494 | str_pnt += len; | |
495 | first = 0; | |
496 | } | |
497 | return str_buf; | |
498 | } | |
499 | ||
500 | int | |
501 | lcommunity_match (const struct lcommunity *lcom1, | |
502 | const struct lcommunity *lcom2) | |
503 | { | |
504 | int i = 0; | |
505 | int j = 0; | |
506 | ||
507 | if (lcom1 == NULL && lcom2 == NULL) | |
508 | return 1; | |
509 | ||
510 | if (lcom1 == NULL || lcom2 == NULL) | |
511 | return 0; | |
512 | ||
513 | if (lcom1->size < lcom2->size) | |
514 | return 0; | |
515 | ||
516 | /* Every community on com2 needs to be on com1 for this to match */ | |
517 | while (i < lcom1->size && j < lcom2->size) | |
518 | { | |
519 | if (memcmp (lcom1->val + (i*12), lcom2->val + (j*12), LCOMMUNITY_SIZE) == 0) | |
520 | j++; | |
521 | i++; | |
522 | } | |
523 | ||
524 | if (j == lcom2->size) | |
525 | return 1; | |
526 | else | |
527 | return 0; | |
528 | } | |
529 | ||
530 | /* Delete one lcommunity. */ | |
531 | void | |
532 | lcommunity_del_val (struct lcommunity *lcom, u_char *ptr) | |
533 | { | |
534 | int i = 0; | |
535 | int c = 0; | |
536 | ||
537 | if (! lcom->val) | |
538 | return; | |
539 | ||
540 | while (i < lcom->size) | |
541 | { | |
542 | if (memcmp (lcom->val + i*LCOMMUNITY_SIZE, ptr, LCOMMUNITY_SIZE) == 0) | |
543 | { | |
544 | c = lcom->size -i -1; | |
545 | ||
546 | if (c > 0) | |
547 | memmove (lcom->val + i*LCOMMUNITY_SIZE, lcom->val + (i + 1)*LCOMMUNITY_SIZE, c * LCOMMUNITY_SIZE); | |
548 | ||
549 | lcom->size--; | |
550 | ||
551 | if (lcom->size > 0) | |
552 | lcom->val = XREALLOC (MTYPE_COMMUNITY_VAL, lcom->val, | |
553 | lcom_length (lcom)); | |
554 | else | |
555 | { | |
556 | XFREE (MTYPE_COMMUNITY_VAL, lcom->val); | |
557 | lcom->val = NULL; | |
558 | } | |
559 | return; | |
560 | } | |
561 | i++; | |
562 | } | |
563 | } |