1 /*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.gnu.org/licenses/gpl-2.0.html
19 *
20 * GPL HEADER END
21 */
22 /*
23 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Use is subject to license terms.
25 *
26 * Copyright (c) 2012, 2015 Intel Corporation.
27 */
28 /*
29 * This file is part of Lustre, http://www.lustre.org/
30 * Lustre is a trademark of Sun Microsystems, Inc.
31 *
32 * String manipulation functions.
33 *
34 * libcfs/libcfs/libcfs_string.c
35 *
36 * Author: Nathan Rutman <nathan.rutman@sun.com>
37 */
38
39 #include "../../include/linux/libcfs/libcfs.h"
40
41 /* Convert a text string to a bitmask */
cfs_str2mask(const char * str,const char * (* bit2str)(int bit),int * oldmask,int minmask,int allmask)42 int cfs_str2mask(const char *str, const char *(*bit2str)(int bit),
43 int *oldmask, int minmask, int allmask)
44 {
45 const char *debugstr;
46 char op = '\0';
47 int newmask = minmask, i, len, found = 0;
48
49 /* <str> must be a list of tokens separated by whitespace
50 * and optionally an operator ('+' or '-'). If an operator
51 * appears first in <str>, '*oldmask' is used as the starting point
52 * (relative), otherwise minmask is used (absolute). An operator
53 * applies to all following tokens up to the next operator.
54 */
55 while (*str != '\0') {
56 while (isspace(*str))
57 str++;
58 if (*str == '\0')
59 break;
60 if (*str == '+' || *str == '-') {
61 op = *str++;
62 if (!found)
63 /* only if first token is relative */
64 newmask = *oldmask;
65 while (isspace(*str))
66 str++;
67 if (*str == '\0') /* trailing op */
68 return -EINVAL;
69 }
70
71 /* find token length */
72 len = 0;
73 while (str[len] != '\0' && !isspace(str[len]) &&
74 str[len] != '+' && str[len] != '-')
75 len++;
76
77 /* match token */
78 found = 0;
79 for (i = 0; i < 32; i++) {
80 debugstr = bit2str(i);
81 if (debugstr && strlen(debugstr) == len &&
82 strncasecmp(str, debugstr, len) == 0) {
83 if (op == '-')
84 newmask &= ~(1 << i);
85 else
86 newmask |= (1 << i);
87 found = 1;
88 break;
89 }
90 }
91 if (!found && len == 3 &&
92 (strncasecmp(str, "ALL", len) == 0)) {
93 if (op == '-')
94 newmask = minmask;
95 else
96 newmask = allmask;
97 found = 1;
98 }
99 if (!found) {
100 CWARN("unknown mask '%.*s'.\n"
101 "mask usage: [+|-]<all|type> ...\n", len, str);
102 return -EINVAL;
103 }
104 str += len;
105 }
106
107 *oldmask = newmask;
108 return 0;
109 }
110
111 /* get the first string out of @str */
cfs_firststr(char * str,size_t size)112 char *cfs_firststr(char *str, size_t size)
113 {
114 size_t i = 0;
115 char *end;
116
117 /* trim leading spaces */
118 while (i < size && *str && isspace(*str)) {
119 ++i;
120 ++str;
121 }
122
123 /* string with all spaces */
124 if (*str == '\0')
125 goto out;
126
127 end = str;
128 while (i < size && *end != '\0' && !isspace(*end)) {
129 ++i;
130 ++end;
131 }
132
133 *end = '\0';
134 out:
135 return str;
136 }
137 EXPORT_SYMBOL(cfs_firststr);
138
139 char *
cfs_trimwhite(char * str)140 cfs_trimwhite(char *str)
141 {
142 char *end;
143
144 while (isspace(*str))
145 str++;
146
147 end = str + strlen(str);
148 while (end > str) {
149 if (!isspace(end[-1]))
150 break;
151 end--;
152 }
153
154 *end = 0;
155 return str;
156 }
157 EXPORT_SYMBOL(cfs_trimwhite);
158
159 /**
160 * Extracts tokens from strings.
161 *
162 * Looks for \a delim in string \a next, sets \a res to point to
163 * substring before the delimiter, sets \a next right after the found
164 * delimiter.
165 *
166 * \retval 1 if \a res points to a string of non-whitespace characters
167 * \retval 0 otherwise
168 */
169 int
cfs_gettok(struct cfs_lstr * next,char delim,struct cfs_lstr * res)170 cfs_gettok(struct cfs_lstr *next, char delim, struct cfs_lstr *res)
171 {
172 char *end;
173
174 if (!next->ls_str)
175 return 0;
176
177 /* skip leading white spaces */
178 while (next->ls_len) {
179 if (!isspace(*next->ls_str))
180 break;
181 next->ls_str++;
182 next->ls_len--;
183 }
184
185 if (next->ls_len == 0) /* whitespaces only */
186 return 0;
187
188 if (*next->ls_str == delim) {
189 /* first non-writespace is the delimiter */
190 return 0;
191 }
192
193 res->ls_str = next->ls_str;
194 end = memchr(next->ls_str, delim, next->ls_len);
195 if (!end) {
196 /* there is no the delimeter in the string */
197 end = next->ls_str + next->ls_len;
198 next->ls_str = NULL;
199 } else {
200 next->ls_str = end + 1;
201 next->ls_len -= (end - res->ls_str + 1);
202 }
203
204 /* skip ending whitespaces */
205 while (--end != res->ls_str) {
206 if (!isspace(*end))
207 break;
208 }
209
210 res->ls_len = end - res->ls_str + 1;
211 return 1;
212 }
213 EXPORT_SYMBOL(cfs_gettok);
214
215 /**
216 * Converts string to integer.
217 *
218 * Accepts decimal and hexadecimal number recordings.
219 *
220 * \retval 1 if first \a nob chars of \a str convert to decimal or
221 * hexadecimal integer in the range [\a min, \a max]
222 * \retval 0 otherwise
223 */
224 int
cfs_str2num_check(char * str,int nob,unsigned * num,unsigned min,unsigned max)225 cfs_str2num_check(char *str, int nob, unsigned *num,
226 unsigned min, unsigned max)
227 {
228 bool all_numbers = true;
229 char *endp, cache;
230 int rc;
231
232 /**
233 * kstrouint can only handle strings composed
234 * of only numbers. We need to scan the string
235 * passed in for the first non-digit character
236 * and end the string at that location. If we
237 * don't find any non-digit character we still
238 * need to place a '\0' at position nob since
239 * we are not interested in the rest of the
240 * string which is longer than nob in size.
241 * After we are done the character at the
242 * position we placed '\0' must be restored.
243 */
244 for (endp = str; endp < str + nob; endp++) {
245 if (!isdigit(*endp)) {
246 all_numbers = false;
247 break;
248 }
249 }
250 cache = *endp;
251 *endp = '\0';
252
253 rc = kstrtouint(str, 10, num);
254 *endp = cache;
255 if (rc || !all_numbers)
256 return 0;
257
258 return (*num >= min && *num <= max);
259 }
260 EXPORT_SYMBOL(cfs_str2num_check);
261
262 /**
263 * Parses \<range_expr\> token of the syntax. If \a bracketed is false,
264 * \a src should only have a single token which can be \<number\> or \*
265 *
266 * \retval pointer to allocated range_expr and initialized
267 * range_expr::re_lo, range_expr::re_hi and range_expr:re_stride if \a
268 `* src parses to
269 * \<number\> |
270 * \<number\> '-' \<number\> |
271 * \<number\> '-' \<number\> '/' \<number\>
272 * \retval 0 will be returned if it can be parsed, otherwise -EINVAL or
273 * -ENOMEM will be returned.
274 */
275 static int
cfs_range_expr_parse(struct cfs_lstr * src,unsigned min,unsigned max,int bracketed,struct cfs_range_expr ** expr)276 cfs_range_expr_parse(struct cfs_lstr *src, unsigned min, unsigned max,
277 int bracketed, struct cfs_range_expr **expr)
278 {
279 struct cfs_range_expr *re;
280 struct cfs_lstr tok;
281
282 LIBCFS_ALLOC(re, sizeof(*re));
283 if (!re)
284 return -ENOMEM;
285
286 if (src->ls_len == 1 && src->ls_str[0] == '*') {
287 re->re_lo = min;
288 re->re_hi = max;
289 re->re_stride = 1;
290 goto out;
291 }
292
293 if (cfs_str2num_check(src->ls_str, src->ls_len,
294 &re->re_lo, min, max)) {
295 /* <number> is parsed */
296 re->re_hi = re->re_lo;
297 re->re_stride = 1;
298 goto out;
299 }
300
301 if (!bracketed || !cfs_gettok(src, '-', &tok))
302 goto failed;
303
304 if (!cfs_str2num_check(tok.ls_str, tok.ls_len,
305 &re->re_lo, min, max))
306 goto failed;
307
308 /* <number> - */
309 if (cfs_str2num_check(src->ls_str, src->ls_len,
310 &re->re_hi, min, max)) {
311 /* <number> - <number> is parsed */
312 re->re_stride = 1;
313 goto out;
314 }
315
316 /* go to check <number> '-' <number> '/' <number> */
317 if (cfs_gettok(src, '/', &tok)) {
318 if (!cfs_str2num_check(tok.ls_str, tok.ls_len,
319 &re->re_hi, min, max))
320 goto failed;
321
322 /* <number> - <number> / ... */
323 if (cfs_str2num_check(src->ls_str, src->ls_len,
324 &re->re_stride, min, max)) {
325 /* <number> - <number> / <number> is parsed */
326 goto out;
327 }
328 }
329
330 out:
331 *expr = re;
332 return 0;
333
334 failed:
335 LIBCFS_FREE(re, sizeof(*re));
336 return -EINVAL;
337 }
338
339 /**
340 * Print the range expression \a re into specified \a buffer.
341 * If \a bracketed is true, expression does not need additional
342 * brackets.
343 *
344 * \retval number of characters written
345 */
346 static int
cfs_range_expr_print(char * buffer,int count,struct cfs_range_expr * expr,bool bracketed)347 cfs_range_expr_print(char *buffer, int count, struct cfs_range_expr *expr,
348 bool bracketed)
349 {
350 int i;
351 char s[] = "[";
352 char e[] = "]";
353
354 if (bracketed) {
355 s[0] = '\0';
356 e[0] = '\0';
357 }
358
359 if (expr->re_lo == expr->re_hi)
360 i = scnprintf(buffer, count, "%u", expr->re_lo);
361 else if (expr->re_stride == 1)
362 i = scnprintf(buffer, count, "%s%u-%u%s",
363 s, expr->re_lo, expr->re_hi, e);
364 else
365 i = scnprintf(buffer, count, "%s%u-%u/%u%s",
366 s, expr->re_lo, expr->re_hi, expr->re_stride, e);
367 return i;
368 }
369
370 /**
371 * Print a list of range expressions (\a expr_list) into specified \a buffer.
372 * If the list contains several expressions, separate them with comma
373 * and surround the list with brackets.
374 *
375 * \retval number of characters written
376 */
377 int
cfs_expr_list_print(char * buffer,int count,struct cfs_expr_list * expr_list)378 cfs_expr_list_print(char *buffer, int count, struct cfs_expr_list *expr_list)
379 {
380 struct cfs_range_expr *expr;
381 int i = 0, j = 0;
382 int numexprs = 0;
383
384 if (count <= 0)
385 return 0;
386
387 list_for_each_entry(expr, &expr_list->el_exprs, re_link)
388 numexprs++;
389
390 if (numexprs > 1)
391 i += scnprintf(buffer + i, count - i, "[");
392
393 list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
394 if (j++ != 0)
395 i += scnprintf(buffer + i, count - i, ",");
396 i += cfs_range_expr_print(buffer + i, count - i, expr,
397 numexprs > 1);
398 }
399
400 if (numexprs > 1)
401 i += scnprintf(buffer + i, count - i, "]");
402
403 return i;
404 }
405 EXPORT_SYMBOL(cfs_expr_list_print);
406
407 /**
408 * Matches value (\a value) against ranges expression list \a expr_list.
409 *
410 * \retval 1 if \a value matches
411 * \retval 0 otherwise
412 */
413 int
cfs_expr_list_match(__u32 value,struct cfs_expr_list * expr_list)414 cfs_expr_list_match(__u32 value, struct cfs_expr_list *expr_list)
415 {
416 struct cfs_range_expr *expr;
417
418 list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
419 if (value >= expr->re_lo && value <= expr->re_hi &&
420 ((value - expr->re_lo) % expr->re_stride) == 0)
421 return 1;
422 }
423
424 return 0;
425 }
426 EXPORT_SYMBOL(cfs_expr_list_match);
427
428 /**
429 * Convert express list (\a expr_list) to an array of all matched values
430 *
431 * \retval N N is total number of all matched values
432 * \retval 0 if expression list is empty
433 * \retval < 0 for failure
434 */
435 int
cfs_expr_list_values(struct cfs_expr_list * expr_list,int max,__u32 ** valpp)436 cfs_expr_list_values(struct cfs_expr_list *expr_list, int max, __u32 **valpp)
437 {
438 struct cfs_range_expr *expr;
439 __u32 *val;
440 int count = 0;
441 int i;
442
443 list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
444 for (i = expr->re_lo; i <= expr->re_hi; i++) {
445 if (((i - expr->re_lo) % expr->re_stride) == 0)
446 count++;
447 }
448 }
449
450 if (count == 0) /* empty expression list */
451 return 0;
452
453 if (count > max) {
454 CERROR("Number of values %d exceeds max allowed %d\n",
455 max, count);
456 return -EINVAL;
457 }
458
459 LIBCFS_ALLOC(val, sizeof(val[0]) * count);
460 if (!val)
461 return -ENOMEM;
462
463 count = 0;
464 list_for_each_entry(expr, &expr_list->el_exprs, re_link) {
465 for (i = expr->re_lo; i <= expr->re_hi; i++) {
466 if (((i - expr->re_lo) % expr->re_stride) == 0)
467 val[count++] = i;
468 }
469 }
470
471 *valpp = val;
472 return count;
473 }
474 EXPORT_SYMBOL(cfs_expr_list_values);
475
476 /**
477 * Frees cfs_range_expr structures of \a expr_list.
478 *
479 * \retval none
480 */
481 void
cfs_expr_list_free(struct cfs_expr_list * expr_list)482 cfs_expr_list_free(struct cfs_expr_list *expr_list)
483 {
484 while (!list_empty(&expr_list->el_exprs)) {
485 struct cfs_range_expr *expr;
486
487 expr = list_entry(expr_list->el_exprs.next,
488 struct cfs_range_expr, re_link);
489 list_del(&expr->re_link);
490 LIBCFS_FREE(expr, sizeof(*expr));
491 }
492
493 LIBCFS_FREE(expr_list, sizeof(*expr_list));
494 }
495 EXPORT_SYMBOL(cfs_expr_list_free);
496
497 /**
498 * Parses \<cfs_expr_list\> token of the syntax.
499 *
500 * \retval 0 if \a str parses to \<number\> | \<expr_list\>
501 * \retval -errno otherwise
502 */
503 int
cfs_expr_list_parse(char * str,int len,unsigned min,unsigned max,struct cfs_expr_list ** elpp)504 cfs_expr_list_parse(char *str, int len, unsigned min, unsigned max,
505 struct cfs_expr_list **elpp)
506 {
507 struct cfs_expr_list *expr_list;
508 struct cfs_range_expr *expr;
509 struct cfs_lstr src;
510 int rc;
511
512 LIBCFS_ALLOC(expr_list, sizeof(*expr_list));
513 if (!expr_list)
514 return -ENOMEM;
515
516 src.ls_str = str;
517 src.ls_len = len;
518
519 INIT_LIST_HEAD(&expr_list->el_exprs);
520
521 if (src.ls_str[0] == '[' &&
522 src.ls_str[src.ls_len - 1] == ']') {
523 src.ls_str++;
524 src.ls_len -= 2;
525
526 rc = -EINVAL;
527 while (src.ls_str) {
528 struct cfs_lstr tok;
529
530 if (!cfs_gettok(&src, ',', &tok)) {
531 rc = -EINVAL;
532 break;
533 }
534
535 rc = cfs_range_expr_parse(&tok, min, max, 1, &expr);
536 if (rc != 0)
537 break;
538
539 list_add_tail(&expr->re_link, &expr_list->el_exprs);
540 }
541 } else {
542 rc = cfs_range_expr_parse(&src, min, max, 0, &expr);
543 if (rc == 0)
544 list_add_tail(&expr->re_link, &expr_list->el_exprs);
545 }
546
547 if (rc != 0)
548 cfs_expr_list_free(expr_list);
549 else
550 *elpp = expr_list;
551
552 return rc;
553 }
554 EXPORT_SYMBOL(cfs_expr_list_parse);
555
556 /**
557 * Frees cfs_expr_list structures of \a list.
558 *
559 * For each struct cfs_expr_list structure found on \a list it frees
560 * range_expr list attached to it and frees the cfs_expr_list itself.
561 *
562 * \retval none
563 */
564 void
cfs_expr_list_free_list(struct list_head * list)565 cfs_expr_list_free_list(struct list_head *list)
566 {
567 struct cfs_expr_list *el;
568
569 while (!list_empty(list)) {
570 el = list_entry(list->next, struct cfs_expr_list, el_link);
571 list_del(&el->el_link);
572 cfs_expr_list_free(el);
573 }
574 }
575 EXPORT_SYMBOL(cfs_expr_list_free_list);
576