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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 FreeRangeRouting (FRR). | |
6 | * | |
7 | * FRR is free software; you can redistribute it and/or modify it under the | |
8 | * terms of the GNU General Public License as published by the Free Software | |
9 | * Foundation; either version 2, or (at your option) any later version. | |
10 | * | |
11 | * FRR is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
13 | * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more | |
14 | * details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along | |
17 | * with this program; see the file COPYING; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | */ | |
20 | ||
21 | #include <zebra.h> | |
22 | ||
23 | #include "hash.h" | |
24 | #include "memory.h" | |
25 | #include "prefix.h" | |
26 | #include "command.h" | |
27 | #include "filter.h" | |
28 | #include "jhash.h" | |
29 | #include "stream.h" | |
30 | ||
31 | #include "bgpd/bgpd.h" | |
32 | #include "bgpd/bgp_lcommunity.h" | |
33 | #include "bgpd/bgp_aspath.h" | |
34 | ||
35 | /* Hash of community attribute. */ | |
36 | static struct hash *lcomhash; | |
37 | ||
38 | /* Allocate a new lcommunities. */ | |
39 | static struct lcommunity *lcommunity_new(void) | |
40 | { | |
41 | return (struct lcommunity *)XCALLOC(MTYPE_LCOMMUNITY, | |
42 | sizeof(struct lcommunity)); | |
43 | } | |
44 | ||
45 | /* Allocate lcommunities. */ | |
46 | void lcommunity_free(struct lcommunity **lcom) | |
47 | { | |
48 | if ((*lcom)->val) | |
49 | XFREE(MTYPE_LCOMMUNITY_VAL, (*lcom)->val); | |
50 | if ((*lcom)->str) | |
51 | XFREE(MTYPE_LCOMMUNITY_STR, (*lcom)->str); | |
52 | XFREE(MTYPE_LCOMMUNITY, *lcom); | |
53 | } | |
54 | ||
55 | static void lcommunity_hash_free(struct lcommunity *lcom) | |
56 | { | |
57 | lcommunity_free(&lcom); | |
58 | } | |
59 | ||
60 | /* Add a new Large Communities value to Large Communities | |
61 | Attribute structure. When the value is already exists in the | |
62 | structure, we don't add the value. Newly added value is sorted by | |
63 | numerical order. When the value is added to the structure return 1 | |
64 | else return 0. */ | |
65 | static int lcommunity_add_val(struct lcommunity *lcom, | |
66 | struct lcommunity_val *lval) | |
67 | { | |
68 | uint8_t *p; | |
69 | int ret; | |
70 | int c; | |
71 | ||
72 | /* When this is fist value, just add it. */ | |
73 | if (lcom->val == NULL) { | |
74 | lcom->size++; | |
75 | lcom->val = XMALLOC(MTYPE_LCOMMUNITY_VAL, lcom_length(lcom)); | |
76 | memcpy(lcom->val, lval->val, LCOMMUNITY_SIZE); | |
77 | return 1; | |
78 | } | |
79 | ||
80 | /* If the value already exists in the structure return 0. */ | |
81 | c = 0; | |
82 | for (p = lcom->val; c < lcom->size; p += LCOMMUNITY_SIZE, c++) { | |
83 | ret = memcmp(p, lval->val, LCOMMUNITY_SIZE); | |
84 | if (ret == 0) | |
85 | return 0; | |
86 | if (ret > 0) | |
87 | break; | |
88 | } | |
89 | ||
90 | /* Add the value to the structure with numerical sorting. */ | |
91 | lcom->size++; | |
92 | lcom->val = | |
93 | XREALLOC(MTYPE_LCOMMUNITY_VAL, lcom->val, lcom_length(lcom)); | |
94 | ||
95 | memmove(lcom->val + (c + 1) * LCOMMUNITY_SIZE, | |
96 | lcom->val + c * LCOMMUNITY_SIZE, | |
97 | (lcom->size - 1 - c) * LCOMMUNITY_SIZE); | |
98 | memcpy(lcom->val + c * LCOMMUNITY_SIZE, lval->val, LCOMMUNITY_SIZE); | |
99 | ||
100 | return 1; | |
101 | } | |
102 | ||
103 | /* This function takes pointer to Large Communites strucutre then | |
104 | create a new Large Communities structure by uniq and sort each | |
105 | Large Communities value. */ | |
106 | struct lcommunity *lcommunity_uniq_sort(struct lcommunity *lcom) | |
107 | { | |
108 | int i; | |
109 | struct lcommunity *new; | |
110 | struct lcommunity_val *lval; | |
111 | ||
112 | if (!lcom) | |
113 | return NULL; | |
114 | ||
115 | new = lcommunity_new(); | |
116 | ||
117 | for (i = 0; i < lcom->size; i++) { | |
118 | lval = (struct lcommunity_val *)(lcom->val | |
119 | + (i * LCOMMUNITY_SIZE)); | |
120 | lcommunity_add_val(new, lval); | |
121 | } | |
122 | return new; | |
123 | } | |
124 | ||
125 | /* Parse Large Communites Attribute in BGP packet. */ | |
126 | struct lcommunity *lcommunity_parse(uint8_t *pnt, unsigned 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 *lcommunity_dup(struct lcommunity *lcom) | |
149 | { | |
150 | struct lcommunity *new; | |
151 | ||
152 | new = lcommunity_new(); | |
153 | new->size = lcom->size; | |
154 | if (new->size) { | |
155 | new->val = XMALLOC(MTYPE_LCOMMUNITY_VAL, lcom_length(lcom)); | |
156 | memcpy(new->val, lcom->val, lcom_length(lcom)); | |
157 | } else | |
158 | new->val = NULL; | |
159 | return new; | |
160 | } | |
161 | ||
162 | /* Merge two Large Communities Attribute structure. */ | |
163 | struct lcommunity *lcommunity_merge(struct lcommunity *lcom1, | |
164 | struct lcommunity *lcom2) | |
165 | { | |
166 | if (lcom1->val) | |
167 | lcom1->val = XREALLOC(MTYPE_LCOMMUNITY_VAL, lcom1->val, | |
168 | lcom_length(lcom1) + lcom_length(lcom2)); | |
169 | else | |
170 | lcom1->val = XMALLOC(MTYPE_LCOMMUNITY_VAL, | |
171 | lcom_length(lcom1) + lcom_length(lcom2)); | |
172 | ||
173 | memcpy(lcom1->val + lcom_length(lcom1), lcom2->val, lcom_length(lcom2)); | |
174 | lcom1->size += lcom2->size; | |
175 | ||
176 | return lcom1; | |
177 | } | |
178 | ||
179 | static void set_lcommunity_string(struct lcommunity *lcom, bool make_json) | |
180 | { | |
181 | int i; | |
182 | int len; | |
183 | bool first = 1; | |
184 | char *str_buf; | |
185 | char *str_pnt; | |
186 | uint8_t *pnt; | |
187 | uint32_t global, local1, local2; | |
188 | json_object *json_lcommunity_list = NULL; | |
189 | json_object *json_string = NULL; | |
190 | ||
191 | #define LCOMMUNITY_STR_DEFAULT_LEN 32 | |
192 | ||
193 | if (!lcom) | |
194 | return; | |
195 | ||
196 | if (make_json) { | |
197 | lcom->json = json_object_new_object(); | |
198 | json_lcommunity_list = json_object_new_array(); | |
199 | } | |
200 | ||
201 | if (lcom->size == 0) { | |
202 | str_buf = XMALLOC(MTYPE_LCOMMUNITY_STR, 1); | |
203 | str_buf[0] = '\0'; | |
204 | ||
205 | if (make_json) { | |
206 | json_object_string_add(lcom->json, "string", ""); | |
207 | json_object_object_add(lcom->json, "list", | |
208 | json_lcommunity_list); | |
209 | } | |
210 | ||
211 | lcom->str = str_buf; | |
212 | return; | |
213 | } | |
214 | ||
215 | str_buf = str_pnt = | |
216 | XMALLOC(MTYPE_LCOMMUNITY_STR, | |
217 | (LCOMMUNITY_STR_DEFAULT_LEN * lcom->size) + 1); | |
218 | ||
219 | for (i = 0; i < lcom->size; i++) { | |
220 | if (first) | |
221 | first = 0; | |
222 | else | |
223 | *str_pnt++ = ' '; | |
224 | ||
225 | pnt = lcom->val + (i * LCOMMUNITY_SIZE); | |
226 | pnt = ptr_get_be32(pnt, &global); | |
227 | pnt = ptr_get_be32(pnt, &local1); | |
228 | pnt = ptr_get_be32(pnt, &local2); | |
229 | (void)pnt; | |
230 | ||
231 | len = sprintf(str_pnt, "%u:%u:%u", global, local1, local2); | |
232 | if (make_json) { | |
233 | json_string = json_object_new_string(str_pnt); | |
234 | json_object_array_add(json_lcommunity_list, | |
235 | json_string); | |
236 | } | |
237 | ||
238 | str_pnt += len; | |
239 | } | |
240 | ||
241 | str_buf = | |
242 | XREALLOC(MTYPE_LCOMMUNITY_STR, str_buf, str_pnt - str_buf + 1); | |
243 | ||
244 | if (make_json) { | |
245 | json_object_string_add(lcom->json, "string", str_buf); | |
246 | json_object_object_add(lcom->json, "list", | |
247 | json_lcommunity_list); | |
248 | } | |
249 | ||
250 | lcom->str = str_buf; | |
251 | } | |
252 | ||
253 | /* Intern Large Communities Attribute. */ | |
254 | struct lcommunity *lcommunity_intern(struct lcommunity *lcom) | |
255 | { | |
256 | struct lcommunity *find; | |
257 | ||
258 | assert(lcom->refcnt == 0); | |
259 | ||
260 | find = (struct lcommunity *)hash_get(lcomhash, lcom, hash_alloc_intern); | |
261 | ||
262 | if (find != lcom) | |
263 | lcommunity_free(&lcom); | |
264 | ||
265 | find->refcnt++; | |
266 | ||
267 | if (!find->str) | |
268 | set_lcommunity_string(find, false); | |
269 | ||
270 | return find; | |
271 | } | |
272 | ||
273 | /* Unintern Large Communities Attribute. */ | |
274 | void lcommunity_unintern(struct lcommunity **lcom) | |
275 | { | |
276 | struct lcommunity *ret; | |
277 | ||
278 | if ((*lcom)->refcnt) | |
279 | (*lcom)->refcnt--; | |
280 | ||
281 | /* Pull off from hash. */ | |
282 | if ((*lcom)->refcnt == 0) { | |
283 | /* Large community must be in the hash. */ | |
284 | ret = (struct lcommunity *)hash_release(lcomhash, *lcom); | |
285 | assert(ret != NULL); | |
286 | ||
287 | lcommunity_free(lcom); | |
288 | } | |
289 | } | |
290 | ||
291 | /* Retrun string representation of communities attribute. */ | |
292 | char *lcommunity_str(struct lcommunity *lcom, bool make_json) | |
293 | { | |
294 | if (!lcom) | |
295 | return NULL; | |
296 | ||
297 | if (make_json && !lcom->json && lcom->str) | |
298 | XFREE(MTYPE_LCOMMUNITY_STR, lcom->str); | |
299 | ||
300 | if (!lcom->str) | |
301 | set_lcommunity_string(lcom, make_json); | |
302 | ||
303 | return lcom->str; | |
304 | } | |
305 | ||
306 | /* Utility function to make hash key. */ | |
307 | unsigned int lcommunity_hash_make(void *arg) | |
308 | { | |
309 | const struct lcommunity *lcom = arg; | |
310 | int size = lcom_length(lcom); | |
311 | ||
312 | return jhash(lcom->val, size, 0xab125423); | |
313 | } | |
314 | ||
315 | /* Compare two Large Communities Attribute structure. */ | |
316 | bool lcommunity_cmp(const void *arg1, const void *arg2) | |
317 | { | |
318 | const struct lcommunity *lcom1 = arg1; | |
319 | const struct lcommunity *lcom2 = arg2; | |
320 | ||
321 | if (lcom1 == NULL && lcom2 == NULL) | |
322 | return 1; | |
323 | ||
324 | if (lcom1 == NULL || lcom2 == NULL) | |
325 | return 0; | |
326 | ||
327 | return (lcom1->size == lcom2->size | |
328 | && memcmp(lcom1->val, lcom2->val, lcom_length(lcom1)) == 0); | |
329 | } | |
330 | ||
331 | /* Return communities hash. */ | |
332 | struct hash *lcommunity_hash(void) | |
333 | { | |
334 | return lcomhash; | |
335 | } | |
336 | ||
337 | /* Initialize Large Comminities related hash. */ | |
338 | void lcommunity_init(void) | |
339 | { | |
340 | lcomhash = hash_create(lcommunity_hash_make, lcommunity_cmp, | |
341 | "BGP lcommunity hash"); | |
342 | } | |
343 | ||
344 | void lcommunity_finish(void) | |
345 | { | |
346 | hash_clean(lcomhash, (void (*)(void *))lcommunity_hash_free); | |
347 | hash_free(lcomhash); | |
348 | lcomhash = NULL; | |
349 | } | |
350 | ||
351 | /* Large Communities token enum. */ | |
352 | enum lcommunity_token { | |
353 | lcommunity_token_unknown = 0, | |
354 | lcommunity_token_val, | |
355 | }; | |
356 | ||
357 | /* Get next Large Communities token from the string. */ | |
358 | static const char *lcommunity_gettoken(const char *str, | |
359 | struct lcommunity_val *lval, | |
360 | enum lcommunity_token *token) | |
361 | { | |
362 | const char *p = str; | |
363 | ||
364 | /* Skip white space. */ | |
365 | while (isspace((int)*p)) { | |
366 | p++; | |
367 | str++; | |
368 | } | |
369 | ||
370 | /* Check the end of the line. */ | |
371 | if (*p == '\0') | |
372 | return NULL; | |
373 | ||
374 | /* Community value. */ | |
375 | if (isdigit((int)*p)) { | |
376 | int separator = 0; | |
377 | int digit = 0; | |
378 | uint32_t globaladmin = 0; | |
379 | uint32_t localdata1 = 0; | |
380 | uint32_t localdata2 = 0; | |
381 | ||
382 | while (isdigit((int)*p) || *p == ':') { | |
383 | if (*p == ':') { | |
384 | if (separator == 2) { | |
385 | *token = lcommunity_token_unknown; | |
386 | return NULL; | |
387 | } else { | |
388 | separator++; | |
389 | digit = 0; | |
390 | if (separator == 1) { | |
391 | globaladmin = localdata2; | |
392 | } else { | |
393 | localdata1 = localdata2; | |
394 | } | |
395 | localdata2 = 0; | |
396 | } | |
397 | } else { | |
398 | digit = 1; | |
399 | localdata2 *= 10; | |
400 | localdata2 += (*p - '0'); | |
401 | } | |
402 | p++; | |
403 | } | |
404 | if (!digit) { | |
405 | *token = lcommunity_token_unknown; | |
406 | return NULL; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Copy the large comm. | |
411 | */ | |
412 | lval->val[0] = (globaladmin >> 24) & 0xff; | |
413 | lval->val[1] = (globaladmin >> 16) & 0xff; | |
414 | lval->val[2] = (globaladmin >> 8) & 0xff; | |
415 | lval->val[3] = globaladmin & 0xff; | |
416 | lval->val[4] = (localdata1 >> 24) & 0xff; | |
417 | lval->val[5] = (localdata1 >> 16) & 0xff; | |
418 | lval->val[6] = (localdata1 >> 8) & 0xff; | |
419 | lval->val[7] = localdata1 & 0xff; | |
420 | lval->val[8] = (localdata2 >> 24) & 0xff; | |
421 | lval->val[9] = (localdata2 >> 16) & 0xff; | |
422 | lval->val[10] = (localdata2 >> 8) & 0xff; | |
423 | lval->val[11] = localdata2 & 0xff; | |
424 | ||
425 | *token = lcommunity_token_val; | |
426 | return p; | |
427 | } | |
428 | *token = lcommunity_token_unknown; | |
429 | return p; | |
430 | } | |
431 | ||
432 | /* | |
433 | Convert string to large community attribute. | |
434 | When type is already known, please specify both str and type. | |
435 | ||
436 | When string includes keyword for each large community value. | |
437 | Please specify keyword_included as non-zero value. | |
438 | */ | |
439 | struct lcommunity *lcommunity_str2com(const char *str) | |
440 | { | |
441 | struct lcommunity *lcom = NULL; | |
442 | enum lcommunity_token token = lcommunity_token_unknown; | |
443 | struct lcommunity_val lval; | |
444 | ||
445 | while ((str = lcommunity_gettoken(str, &lval, &token))) { | |
446 | switch (token) { | |
447 | case lcommunity_token_val: | |
448 | if (lcom == NULL) | |
449 | lcom = lcommunity_new(); | |
450 | lcommunity_add_val(lcom, &lval); | |
451 | break; | |
452 | case lcommunity_token_unknown: | |
453 | default: | |
454 | if (lcom) | |
455 | lcommunity_free(&lcom); | |
456 | return NULL; | |
457 | } | |
458 | } | |
459 | return lcom; | |
460 | } | |
461 | ||
462 | int lcommunity_include(struct lcommunity *lcom, uint8_t *ptr) | |
463 | { | |
464 | int i; | |
465 | uint8_t *lcom_ptr; | |
466 | ||
467 | for (i = 0; i < lcom->size; i++) { | |
468 | lcom_ptr = lcom->val + (i * LCOMMUNITY_SIZE); | |
469 | if (memcmp(ptr, lcom_ptr, LCOMMUNITY_SIZE) == 0) | |
470 | return 1; | |
471 | } | |
472 | return 0; | |
473 | } | |
474 | ||
475 | int lcommunity_match(const struct lcommunity *lcom1, | |
476 | const struct lcommunity *lcom2) | |
477 | { | |
478 | int i = 0; | |
479 | int j = 0; | |
480 | ||
481 | if (lcom1 == NULL && lcom2 == NULL) | |
482 | return 1; | |
483 | ||
484 | if (lcom1 == NULL || lcom2 == NULL) | |
485 | return 0; | |
486 | ||
487 | if (lcom1->size < lcom2->size) | |
488 | return 0; | |
489 | ||
490 | /* Every community on com2 needs to be on com1 for this to match */ | |
491 | while (i < lcom1->size && j < lcom2->size) { | |
492 | if (memcmp(lcom1->val + (i * LCOMMUNITY_SIZE), | |
493 | lcom2->val + (j * LCOMMUNITY_SIZE), LCOMMUNITY_SIZE) | |
494 | == 0) | |
495 | j++; | |
496 | i++; | |
497 | } | |
498 | ||
499 | if (j == lcom2->size) | |
500 | return 1; | |
501 | else | |
502 | return 0; | |
503 | } | |
504 | ||
505 | /* Delete one lcommunity. */ | |
506 | void lcommunity_del_val(struct lcommunity *lcom, uint8_t *ptr) | |
507 | { | |
508 | int i = 0; | |
509 | int c = 0; | |
510 | ||
511 | if (!lcom->val) | |
512 | return; | |
513 | ||
514 | while (i < lcom->size) { | |
515 | if (memcmp(lcom->val + i * LCOMMUNITY_SIZE, ptr, | |
516 | LCOMMUNITY_SIZE) | |
517 | == 0) { | |
518 | c = lcom->size - i - 1; | |
519 | ||
520 | if (c > 0) | |
521 | memmove(lcom->val + i * LCOMMUNITY_SIZE, | |
522 | lcom->val + (i + 1) * LCOMMUNITY_SIZE, | |
523 | c * LCOMMUNITY_SIZE); | |
524 | ||
525 | lcom->size--; | |
526 | ||
527 | if (lcom->size > 0) | |
528 | lcom->val = | |
529 | XREALLOC(MTYPE_LCOMMUNITY_VAL, | |
530 | lcom->val, lcom_length(lcom)); | |
531 | else { | |
532 | XFREE(MTYPE_LCOMMUNITY_VAL, lcom->val); | |
533 | lcom->val = NULL; | |
534 | } | |
535 | return; | |
536 | } | |
537 | i++; | |
538 | } | |
539 | } |