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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
3c9f3681 JB |
2 | /* |
3 | * Helpers for formatting and printing strings | |
4 | * | |
5 | * Copyright 31 August 2008 James Bottomley | |
16c7fa05 | 6 | * Copyright (C) 2013, Intel Corporation |
3c9f3681 | 7 | */ |
b9f28d86 | 8 | #include <linux/bug.h> |
3c9f3681 JB |
9 | #include <linux/kernel.h> |
10 | #include <linux/math64.h> | |
8bc3bcc9 | 11 | #include <linux/export.h> |
16c7fa05 | 12 | #include <linux/ctype.h> |
acdb89b6 | 13 | #include <linux/device.h> |
c8250381 | 14 | #include <linux/errno.h> |
21985319 KC |
15 | #include <linux/fs.h> |
16 | #include <linux/limits.h> | |
0d044328 | 17 | #include <linux/mm.h> |
b53f27e4 | 18 | #include <linux/slab.h> |
c8250381 | 19 | #include <linux/string.h> |
3c9f3681 | 20 | #include <linux/string_helpers.h> |
4ce615e7 KC |
21 | #include <kunit/test.h> |
22 | #include <kunit/test-bug.h> | |
3c9f3681 JB |
23 | |
24 | /** | |
25 | * string_get_size - get the size in the specified units | |
b9f28d86 JB |
26 | * @size: The size to be converted in blocks |
27 | * @blk_size: Size of the block (use 1 for size in bytes) | |
f0b7f8ad | 28 | * @units: Units to use (powers of 1000 or 1024), whether to include space separator |
3c9f3681 JB |
29 | * @buf: buffer to format to |
30 | * @len: length of buffer | |
31 | * | |
32 | * This function returns a string formatted to 3 significant figures | |
d1214c65 RV |
33 | * giving the size in the required units. @buf should have room for |
34 | * at least 9 bytes and will always be zero terminated. | |
3c9f3681 | 35 | * |
83feeb19 KO |
36 | * Return value: number of characters of output that would have been written |
37 | * (which may be greater than len, if output was truncated). | |
3c9f3681 | 38 | */ |
83feeb19 KO |
39 | int string_get_size(u64 size, u64 blk_size, const enum string_size_units units, |
40 | char *buf, int len) | |
3c9f3681 | 41 | { |
f0b7f8ad | 42 | enum string_size_units units_base = units & STRING_UNITS_MASK; |
142cda5d | 43 | static const char *const units_10[] = { |
f0b7f8ad | 44 | "", "k", "M", "G", "T", "P", "E", "Z", "Y", |
142cda5d MK |
45 | }; |
46 | static const char *const units_2[] = { | |
f0b7f8ad | 47 | "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi", |
142cda5d MK |
48 | }; |
49 | static const char *const *const units_str[] = { | |
50 | [STRING_UNITS_10] = units_10, | |
3c9f3681 JB |
51 | [STRING_UNITS_2] = units_2, |
52 | }; | |
68aecfb9 | 53 | static const unsigned int divisor[] = { |
3c9f3681 JB |
54 | [STRING_UNITS_10] = 1000, |
55 | [STRING_UNITS_2] = 1024, | |
56 | }; | |
564b026f JB |
57 | static const unsigned int rounding[] = { 500, 50, 5 }; |
58 | int i = 0, j; | |
59 | u32 remainder = 0, sf_cap; | |
3c9f3681 | 60 | char tmp[8]; |
b9f28d86 | 61 | const char *unit; |
3c9f3681 JB |
62 | |
63 | tmp[0] = '\0'; | |
564b026f JB |
64 | |
65 | if (blk_size == 0) | |
66 | size = 0; | |
67 | if (size == 0) | |
b9f28d86 | 68 | goto out; |
3c9f3681 | 69 | |
564b026f JB |
70 | /* This is Napier's algorithm. Reduce the original block size to |
71 | * | |
f0b7f8ad | 72 | * coefficient * divisor[units_base]^i |
564b026f JB |
73 | * |
74 | * we do the reduction so both coefficients are just under 32 bits so | |
75 | * that multiplying them together won't overflow 64 bits and we keep | |
76 | * as much precision as possible in the numbers. | |
77 | * | |
78 | * Note: it's safe to throw away the remainders here because all the | |
79 | * precision is in the coefficients. | |
80 | */ | |
81 | while (blk_size >> 32) { | |
f0b7f8ad | 82 | do_div(blk_size, divisor[units_base]); |
b9f28d86 JB |
83 | i++; |
84 | } | |
85 | ||
564b026f | 86 | while (size >> 32) { |
f0b7f8ad | 87 | do_div(size, divisor[units_base]); |
b9f28d86 | 88 | i++; |
b9f28d86 JB |
89 | } |
90 | ||
564b026f JB |
91 | /* now perform the actual multiplication keeping i as the sum of the |
92 | * two logarithms */ | |
b9f28d86 | 93 | size *= blk_size; |
3c9f3681 | 94 | |
564b026f | 95 | /* and logarithmically reduce it until it's just under the divisor */ |
f0b7f8ad AS |
96 | while (size >= divisor[units_base]) { |
97 | remainder = do_div(size, divisor[units_base]); | |
b9f28d86 | 98 | i++; |
3c9f3681 JB |
99 | } |
100 | ||
564b026f JB |
101 | /* work out in j how many digits of precision we need from the |
102 | * remainder */ | |
b9f28d86 JB |
103 | sf_cap = size; |
104 | for (j = 0; sf_cap*10 < 1000; j++) | |
105 | sf_cap *= 10; | |
106 | ||
f0b7f8ad | 107 | if (units_base == STRING_UNITS_2) { |
564b026f JB |
108 | /* express the remainder as a decimal. It's currently the |
109 | * numerator of a fraction whose denominator is | |
f0b7f8ad | 110 | * divisor[units_base], which is 1 << 10 for STRING_UNITS_2 */ |
b9f28d86 | 111 | remainder *= 1000; |
564b026f JB |
112 | remainder >>= 10; |
113 | } | |
114 | ||
115 | /* add a 5 to the digit below what will be printed to ensure | |
116 | * an arithmetical round up and carry it through to size */ | |
117 | remainder += rounding[j]; | |
118 | if (remainder >= 1000) { | |
119 | remainder -= 1000; | |
120 | size += 1; | |
121 | } | |
122 | ||
123 | if (j) { | |
b9f28d86 JB |
124 | snprintf(tmp, sizeof(tmp), ".%03u", remainder); |
125 | tmp[j+1] = '\0'; | |
126 | } | |
127 | ||
128 | out: | |
129 | if (i >= ARRAY_SIZE(units_2)) | |
130 | unit = "UNK"; | |
131 | else | |
f0b7f8ad | 132 | unit = units_str[units_base][i]; |
b9f28d86 | 133 | |
f0b7f8ad AS |
134 | return snprintf(buf, len, "%u%s%s%s%s", (u32)size, tmp, |
135 | (units & STRING_UNITS_NO_SPACE) ? "" : " ", | |
136 | unit, | |
137 | (units & STRING_UNITS_NO_BYTES) ? "" : "B"); | |
3c9f3681 JB |
138 | } |
139 | EXPORT_SYMBOL(string_get_size); | |
16c7fa05 | 140 | |
f0b93323 CR |
141 | /** |
142 | * parse_int_array_user - Split string into a sequence of integers | |
143 | * @from: The user space buffer to read from | |
144 | * @count: The maximum number of bytes to read | |
145 | * @array: Returned pointer to sequence of integers | |
146 | * | |
147 | * On success @array is allocated and initialized with a sequence of | |
148 | * integers extracted from the @from plus an additional element that | |
149 | * begins the sequence and specifies the integers count. | |
150 | * | |
151 | * Caller takes responsibility for freeing @array when it is no longer | |
152 | * needed. | |
153 | */ | |
154 | int parse_int_array_user(const char __user *from, size_t count, int **array) | |
155 | { | |
156 | int *ints, nints; | |
157 | char *buf; | |
158 | int ret = 0; | |
159 | ||
160 | buf = memdup_user_nul(from, count); | |
161 | if (IS_ERR(buf)) | |
162 | return PTR_ERR(buf); | |
163 | ||
164 | get_options(buf, 0, &nints); | |
165 | if (!nints) { | |
166 | ret = -ENOENT; | |
167 | goto free_buf; | |
168 | } | |
169 | ||
170 | ints = kcalloc(nints + 1, sizeof(*ints), GFP_KERNEL); | |
171 | if (!ints) { | |
172 | ret = -ENOMEM; | |
173 | goto free_buf; | |
174 | } | |
175 | ||
176 | get_options(buf, nints + 1, ints); | |
177 | *array = ints; | |
178 | ||
179 | free_buf: | |
180 | kfree(buf); | |
181 | return ret; | |
182 | } | |
183 | EXPORT_SYMBOL(parse_int_array_user); | |
184 | ||
16c7fa05 AS |
185 | static bool unescape_space(char **src, char **dst) |
186 | { | |
187 | char *p = *dst, *q = *src; | |
188 | ||
189 | switch (*q) { | |
190 | case 'n': | |
191 | *p = '\n'; | |
192 | break; | |
193 | case 'r': | |
194 | *p = '\r'; | |
195 | break; | |
196 | case 't': | |
197 | *p = '\t'; | |
198 | break; | |
199 | case 'v': | |
200 | *p = '\v'; | |
201 | break; | |
202 | case 'f': | |
203 | *p = '\f'; | |
204 | break; | |
205 | default: | |
206 | return false; | |
207 | } | |
208 | *dst += 1; | |
209 | *src += 1; | |
210 | return true; | |
211 | } | |
212 | ||
213 | static bool unescape_octal(char **src, char **dst) | |
214 | { | |
215 | char *p = *dst, *q = *src; | |
216 | u8 num; | |
217 | ||
218 | if (isodigit(*q) == 0) | |
219 | return false; | |
220 | ||
221 | num = (*q++) & 7; | |
222 | while (num < 32 && isodigit(*q) && (q - *src < 3)) { | |
223 | num <<= 3; | |
224 | num += (*q++) & 7; | |
225 | } | |
226 | *p = num; | |
227 | *dst += 1; | |
228 | *src = q; | |
229 | return true; | |
230 | } | |
231 | ||
232 | static bool unescape_hex(char **src, char **dst) | |
233 | { | |
234 | char *p = *dst, *q = *src; | |
235 | int digit; | |
236 | u8 num; | |
237 | ||
238 | if (*q++ != 'x') | |
239 | return false; | |
240 | ||
241 | num = digit = hex_to_bin(*q++); | |
242 | if (digit < 0) | |
243 | return false; | |
244 | ||
245 | digit = hex_to_bin(*q); | |
246 | if (digit >= 0) { | |
247 | q++; | |
248 | num = (num << 4) | digit; | |
249 | } | |
250 | *p = num; | |
251 | *dst += 1; | |
252 | *src = q; | |
253 | return true; | |
254 | } | |
255 | ||
256 | static bool unescape_special(char **src, char **dst) | |
257 | { | |
258 | char *p = *dst, *q = *src; | |
259 | ||
260 | switch (*q) { | |
261 | case '\"': | |
262 | *p = '\"'; | |
263 | break; | |
264 | case '\\': | |
265 | *p = '\\'; | |
266 | break; | |
267 | case 'a': | |
268 | *p = '\a'; | |
269 | break; | |
270 | case 'e': | |
271 | *p = '\e'; | |
272 | break; | |
273 | default: | |
274 | return false; | |
275 | } | |
276 | *dst += 1; | |
277 | *src += 1; | |
278 | return true; | |
279 | } | |
280 | ||
d295634e AS |
281 | /** |
282 | * string_unescape - unquote characters in the given string | |
283 | * @src: source buffer (escaped) | |
284 | * @dst: destination buffer (unescaped) | |
285 | * @size: size of the destination buffer (0 to unlimit) | |
b4658cdd JC |
286 | * @flags: combination of the flags. |
287 | * | |
288 | * Description: | |
289 | * The function unquotes characters in the given string. | |
290 | * | |
291 | * Because the size of the output will be the same as or less than the size of | |
292 | * the input, the transformation may be performed in place. | |
293 | * | |
294 | * Caller must provide valid source and destination pointers. Be aware that | |
295 | * destination buffer will always be NULL-terminated. Source string must be | |
296 | * NULL-terminated as well. The supported flags are:: | |
297 | * | |
298 | * UNESCAPE_SPACE: | |
d295634e AS |
299 | * '\f' - form feed |
300 | * '\n' - new line | |
301 | * '\r' - carriage return | |
302 | * '\t' - horizontal tab | |
303 | * '\v' - vertical tab | |
b4658cdd | 304 | * UNESCAPE_OCTAL: |
d295634e | 305 | * '\NNN' - byte with octal value NNN (1 to 3 digits) |
b4658cdd | 306 | * UNESCAPE_HEX: |
d295634e | 307 | * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) |
b4658cdd | 308 | * UNESCAPE_SPECIAL: |
d295634e AS |
309 | * '\"' - double quote |
310 | * '\\' - backslash | |
311 | * '\a' - alert (BEL) | |
312 | * '\e' - escape | |
b4658cdd | 313 | * UNESCAPE_ANY: |
d295634e AS |
314 | * all previous together |
315 | * | |
d295634e AS |
316 | * Return: |
317 | * The amount of the characters processed to the destination buffer excluding | |
318 | * trailing '\0' is returned. | |
319 | */ | |
16c7fa05 AS |
320 | int string_unescape(char *src, char *dst, size_t size, unsigned int flags) |
321 | { | |
322 | char *out = dst; | |
323 | ||
324 | while (*src && --size) { | |
325 | if (src[0] == '\\' && src[1] != '\0' && size > 1) { | |
326 | src++; | |
327 | size--; | |
328 | ||
329 | if (flags & UNESCAPE_SPACE && | |
330 | unescape_space(&src, &out)) | |
331 | continue; | |
332 | ||
333 | if (flags & UNESCAPE_OCTAL && | |
334 | unescape_octal(&src, &out)) | |
335 | continue; | |
336 | ||
337 | if (flags & UNESCAPE_HEX && | |
338 | unescape_hex(&src, &out)) | |
339 | continue; | |
340 | ||
341 | if (flags & UNESCAPE_SPECIAL && | |
342 | unescape_special(&src, &out)) | |
343 | continue; | |
344 | ||
345 | *out++ = '\\'; | |
346 | } | |
347 | *out++ = *src++; | |
348 | } | |
349 | *out = '\0'; | |
350 | ||
351 | return out - dst; | |
352 | } | |
353 | EXPORT_SYMBOL(string_unescape); | |
c8250381 | 354 | |
3aeddc7d | 355 | static bool escape_passthrough(unsigned char c, char **dst, char *end) |
c8250381 AS |
356 | { |
357 | char *out = *dst; | |
358 | ||
3aeddc7d RV |
359 | if (out < end) |
360 | *out = c; | |
361 | *dst = out + 1; | |
362 | return true; | |
c8250381 AS |
363 | } |
364 | ||
3aeddc7d | 365 | static bool escape_space(unsigned char c, char **dst, char *end) |
c8250381 AS |
366 | { |
367 | char *out = *dst; | |
368 | unsigned char to; | |
369 | ||
c8250381 AS |
370 | switch (c) { |
371 | case '\n': | |
372 | to = 'n'; | |
373 | break; | |
374 | case '\r': | |
375 | to = 'r'; | |
376 | break; | |
377 | case '\t': | |
378 | to = 't'; | |
379 | break; | |
380 | case '\v': | |
381 | to = 'v'; | |
382 | break; | |
383 | case '\f': | |
384 | to = 'f'; | |
385 | break; | |
386 | default: | |
3aeddc7d | 387 | return false; |
c8250381 AS |
388 | } |
389 | ||
3aeddc7d RV |
390 | if (out < end) |
391 | *out = '\\'; | |
392 | ++out; | |
393 | if (out < end) | |
394 | *out = to; | |
395 | ++out; | |
c8250381 | 396 | |
3aeddc7d RV |
397 | *dst = out; |
398 | return true; | |
c8250381 AS |
399 | } |
400 | ||
3aeddc7d | 401 | static bool escape_special(unsigned char c, char **dst, char *end) |
c8250381 AS |
402 | { |
403 | char *out = *dst; | |
404 | unsigned char to; | |
405 | ||
c8250381 AS |
406 | switch (c) { |
407 | case '\\': | |
408 | to = '\\'; | |
409 | break; | |
410 | case '\a': | |
411 | to = 'a'; | |
412 | break; | |
413 | case '\e': | |
414 | to = 'e'; | |
415 | break; | |
91027d0a CD |
416 | case '"': |
417 | to = '"'; | |
418 | break; | |
c8250381 | 419 | default: |
3aeddc7d | 420 | return false; |
c8250381 AS |
421 | } |
422 | ||
3aeddc7d RV |
423 | if (out < end) |
424 | *out = '\\'; | |
425 | ++out; | |
426 | if (out < end) | |
427 | *out = to; | |
428 | ++out; | |
c8250381 | 429 | |
3aeddc7d RV |
430 | *dst = out; |
431 | return true; | |
c8250381 AS |
432 | } |
433 | ||
3aeddc7d | 434 | static bool escape_null(unsigned char c, char **dst, char *end) |
c8250381 AS |
435 | { |
436 | char *out = *dst; | |
437 | ||
c8250381 | 438 | if (c) |
3aeddc7d | 439 | return false; |
c8250381 | 440 | |
3aeddc7d RV |
441 | if (out < end) |
442 | *out = '\\'; | |
443 | ++out; | |
444 | if (out < end) | |
445 | *out = '0'; | |
446 | ++out; | |
c8250381 | 447 | |
3aeddc7d RV |
448 | *dst = out; |
449 | return true; | |
c8250381 AS |
450 | } |
451 | ||
3aeddc7d | 452 | static bool escape_octal(unsigned char c, char **dst, char *end) |
c8250381 AS |
453 | { |
454 | char *out = *dst; | |
455 | ||
3aeddc7d RV |
456 | if (out < end) |
457 | *out = '\\'; | |
458 | ++out; | |
459 | if (out < end) | |
460 | *out = ((c >> 6) & 0x07) + '0'; | |
461 | ++out; | |
462 | if (out < end) | |
463 | *out = ((c >> 3) & 0x07) + '0'; | |
464 | ++out; | |
465 | if (out < end) | |
466 | *out = ((c >> 0) & 0x07) + '0'; | |
467 | ++out; | |
c8250381 AS |
468 | |
469 | *dst = out; | |
3aeddc7d | 470 | return true; |
c8250381 AS |
471 | } |
472 | ||
3aeddc7d | 473 | static bool escape_hex(unsigned char c, char **dst, char *end) |
c8250381 AS |
474 | { |
475 | char *out = *dst; | |
476 | ||
3aeddc7d RV |
477 | if (out < end) |
478 | *out = '\\'; | |
479 | ++out; | |
480 | if (out < end) | |
481 | *out = 'x'; | |
482 | ++out; | |
483 | if (out < end) | |
484 | *out = hex_asc_hi(c); | |
485 | ++out; | |
486 | if (out < end) | |
487 | *out = hex_asc_lo(c); | |
488 | ++out; | |
c8250381 AS |
489 | |
490 | *dst = out; | |
3aeddc7d | 491 | return true; |
c8250381 AS |
492 | } |
493 | ||
494 | /** | |
495 | * string_escape_mem - quote characters in the given memory buffer | |
496 | * @src: source buffer (unescaped) | |
497 | * @isz: source buffer size | |
498 | * @dst: destination buffer (escaped) | |
499 | * @osz: destination buffer size | |
b4658cdd JC |
500 | * @flags: combination of the flags |
501 | * @only: NULL-terminated string containing characters used to limit | |
502 | * the selected escape class. If characters are included in @only | |
503 | * that would not normally be escaped by the classes selected | |
504 | * in @flags, they will be copied to @dst unescaped. | |
505 | * | |
506 | * Description: | |
507 | * The process of escaping byte buffer includes several parts. They are applied | |
508 | * in the following sequence. | |
509 | * | |
62519b88 | 510 | * 1. The character is not matched to the one from @only string and thus |
b4658cdd | 511 | * must go as-is to the output. |
0362c27f | 512 | * 2. The character is matched to the printable and ASCII classes, if asked, |
a0809783 | 513 | * and in case of match it passes through to the output. |
0362c27f AS |
514 | * 3. The character is matched to the printable or ASCII class, if asked, |
515 | * and in case of match it passes through to the output. | |
516 | * 4. The character is checked if it falls into the class given by @flags. | |
b4658cdd JC |
517 | * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any |
518 | * character. Note that they actually can't go together, otherwise | |
519 | * %ESCAPE_HEX will be ignored. | |
520 | * | |
521 | * Caller must provide valid source and destination pointers. Be aware that | |
522 | * destination buffer will not be NULL-terminated, thus caller have to append | |
a0809783 | 523 | * it if needs. The supported flags are:: |
b4658cdd | 524 | * |
d89a3f73 | 525 | * %ESCAPE_SPACE: (special white space, not space itself) |
c8250381 AS |
526 | * '\f' - form feed |
527 | * '\n' - new line | |
528 | * '\r' - carriage return | |
529 | * '\t' - horizontal tab | |
530 | * '\v' - vertical tab | |
531 | * %ESCAPE_SPECIAL: | |
91027d0a | 532 | * '\"' - double quote |
c8250381 AS |
533 | * '\\' - backslash |
534 | * '\a' - alert (BEL) | |
535 | * '\e' - escape | |
536 | * %ESCAPE_NULL: | |
537 | * '\0' - null | |
538 | * %ESCAPE_OCTAL: | |
539 | * '\NNN' - byte with octal value NNN (3 digits) | |
540 | * %ESCAPE_ANY: | |
541 | * all previous together | |
542 | * %ESCAPE_NP: | |
a0809783 | 543 | * escape only non-printable characters, checked by isprint() |
c8250381 AS |
544 | * %ESCAPE_ANY_NP: |
545 | * all previous together | |
546 | * %ESCAPE_HEX: | |
547 | * '\xHH' - byte with hexadecimal value HH (2 digits) | |
a0809783 AS |
548 | * %ESCAPE_NA: |
549 | * escape only non-ascii characters, checked by isascii() | |
0362c27f AS |
550 | * %ESCAPE_NAP: |
551 | * escape only non-printable or non-ascii characters | |
aec0d096 AS |
552 | * %ESCAPE_APPEND: |
553 | * append characters from @only to be escaped by the given classes | |
554 | * | |
555 | * %ESCAPE_APPEND would help to pass additional characters to the escaped, when | |
556 | * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided. | |
a0809783 | 557 | * |
0362c27f AS |
558 | * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the |
559 | * higher priority than the rest of the flags (%ESCAPE_NAP is the highest). | |
a0809783 AS |
560 | * It doesn't make much sense to use either of them without %ESCAPE_OCTAL |
561 | * or %ESCAPE_HEX, because they cover most of the other character classes. | |
0362c27f AS |
562 | * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to |
563 | * the above. | |
c8250381 AS |
564 | * |
565 | * Return: | |
41416f23 RV |
566 | * The total size of the escaped output that would be generated for |
567 | * the given input and flags. To check whether the output was | |
568 | * truncated, compare the return value to osz. There is room left in | |
569 | * dst for a '\0' terminator if and only if ret < osz. | |
c8250381 | 570 | */ |
41416f23 | 571 | int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, |
b40bdb7f | 572 | unsigned int flags, const char *only) |
c8250381 | 573 | { |
41416f23 | 574 | char *p = dst; |
3aeddc7d | 575 | char *end = p + osz; |
b40bdb7f | 576 | bool is_dict = only && *only; |
aec0d096 | 577 | bool is_append = flags & ESCAPE_APPEND; |
c8250381 AS |
578 | |
579 | while (isz--) { | |
580 | unsigned char c = *src++; | |
aec0d096 | 581 | bool in_dict = is_dict && strchr(only, c); |
c8250381 AS |
582 | |
583 | /* | |
584 | * Apply rules in the following sequence: | |
b40bdb7f | 585 | * - the @only string is supplied and does not contain a |
c8250381 | 586 | * character under question |
0362c27f AS |
587 | * - the character is printable and ASCII, when @flags has |
588 | * %ESCAPE_NAP bit set | |
62519b88 AS |
589 | * - the character is printable, when @flags has |
590 | * %ESCAPE_NP bit set | |
a0809783 AS |
591 | * - the character is ASCII, when @flags has |
592 | * %ESCAPE_NA bit set | |
c8250381 AS |
593 | * - the character doesn't fall into a class of symbols |
594 | * defined by given @flags | |
595 | * In these cases we just pass through a character to the | |
596 | * output buffer. | |
aec0d096 AS |
597 | * |
598 | * When %ESCAPE_APPEND is passed, the characters from @only | |
599 | * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and | |
600 | * %ESCAPE_NA cases. | |
c8250381 | 601 | */ |
aec0d096 | 602 | if (!(is_append || in_dict) && is_dict && |
7e5969ae AS |
603 | escape_passthrough(c, &p, end)) |
604 | continue; | |
62519b88 | 605 | |
aec0d096 | 606 | if (!(is_append && in_dict) && isascii(c) && isprint(c) && |
0362c27f AS |
607 | flags & ESCAPE_NAP && escape_passthrough(c, &p, end)) |
608 | continue; | |
609 | ||
aec0d096 | 610 | if (!(is_append && in_dict) && isprint(c) && |
7e5969ae AS |
611 | flags & ESCAPE_NP && escape_passthrough(c, &p, end)) |
612 | continue; | |
3aeddc7d | 613 | |
aec0d096 | 614 | if (!(is_append && in_dict) && isascii(c) && |
a0809783 AS |
615 | flags & ESCAPE_NA && escape_passthrough(c, &p, end)) |
616 | continue; | |
617 | ||
7e5969ae AS |
618 | if (flags & ESCAPE_SPACE && escape_space(c, &p, end)) |
619 | continue; | |
3aeddc7d | 620 | |
7e5969ae AS |
621 | if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end)) |
622 | continue; | |
c8250381 | 623 | |
7e5969ae AS |
624 | if (flags & ESCAPE_NULL && escape_null(c, &p, end)) |
625 | continue; | |
3aeddc7d | 626 | |
7e5969ae AS |
627 | /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ |
628 | if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end)) | |
629 | continue; | |
630 | ||
631 | if (flags & ESCAPE_HEX && escape_hex(c, &p, end)) | |
632 | continue; | |
c8250381 | 633 | |
3aeddc7d | 634 | escape_passthrough(c, &p, end); |
c8250381 AS |
635 | } |
636 | ||
41416f23 | 637 | return p - dst; |
c8250381 AS |
638 | } |
639 | EXPORT_SYMBOL(string_escape_mem); | |
b53f27e4 KC |
640 | |
641 | /* | |
642 | * Return an allocated string that has been escaped of special characters | |
643 | * and double quotes, making it safe to log in quotes. | |
644 | */ | |
645 | char *kstrdup_quotable(const char *src, gfp_t gfp) | |
646 | { | |
647 | size_t slen, dlen; | |
648 | char *dst; | |
649 | const int flags = ESCAPE_HEX; | |
650 | const char esc[] = "\f\n\r\t\v\a\e\\\""; | |
651 | ||
652 | if (!src) | |
653 | return NULL; | |
654 | slen = strlen(src); | |
655 | ||
656 | dlen = string_escape_mem(src, slen, NULL, 0, flags, esc); | |
657 | dst = kmalloc(dlen + 1, gfp); | |
658 | if (!dst) | |
659 | return NULL; | |
660 | ||
661 | WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen); | |
662 | dst[dlen] = '\0'; | |
663 | ||
664 | return dst; | |
665 | } | |
666 | EXPORT_SYMBOL_GPL(kstrdup_quotable); | |
0d044328 KC |
667 | |
668 | /* | |
669 | * Returns allocated NULL-terminated string containing process | |
670 | * command line, with inter-argument NULLs replaced with spaces, | |
671 | * and other special characters escaped. | |
672 | */ | |
673 | char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp) | |
674 | { | |
675 | char *buffer, *quoted; | |
676 | int i, res; | |
677 | ||
0ee931c4 | 678 | buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
0d044328 KC |
679 | if (!buffer) |
680 | return NULL; | |
681 | ||
682 | res = get_cmdline(task, buffer, PAGE_SIZE - 1); | |
683 | buffer[res] = '\0'; | |
684 | ||
685 | /* Collapse trailing NULLs, leave res pointing to last non-NULL. */ | |
686 | while (--res >= 0 && buffer[res] == '\0') | |
687 | ; | |
688 | ||
689 | /* Replace inter-argument NULLs. */ | |
690 | for (i = 0; i <= res; i++) | |
691 | if (buffer[i] == '\0') | |
692 | buffer[i] = ' '; | |
693 | ||
694 | /* Make sure result is printable. */ | |
695 | quoted = kstrdup_quotable(buffer, gfp); | |
696 | kfree(buffer); | |
697 | return quoted; | |
698 | } | |
699 | EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline); | |
21985319 KC |
700 | |
701 | /* | |
702 | * Returns allocated NULL-terminated string containing pathname, | |
703 | * with special characters escaped, able to be safely logged. If | |
704 | * there is an error, the leading character will be "<". | |
705 | */ | |
706 | char *kstrdup_quotable_file(struct file *file, gfp_t gfp) | |
707 | { | |
708 | char *temp, *pathname; | |
709 | ||
710 | if (!file) | |
711 | return kstrdup("<unknown>", gfp); | |
712 | ||
713 | /* We add 11 spaces for ' (deleted)' to be appended */ | |
0ee931c4 | 714 | temp = kmalloc(PATH_MAX + 11, GFP_KERNEL); |
21985319 KC |
715 | if (!temp) |
716 | return kstrdup("<no_memory>", gfp); | |
717 | ||
718 | pathname = file_path(file, temp, PATH_MAX + 11); | |
719 | if (IS_ERR(pathname)) | |
720 | pathname = kstrdup("<too_long>", gfp); | |
721 | else | |
722 | pathname = kstrdup_quotable(pathname, gfp); | |
723 | ||
724 | kfree(temp); | |
725 | return pathname; | |
726 | } | |
727 | EXPORT_SYMBOL_GPL(kstrdup_quotable_file); | |
0fd16012 | 728 | |
045ad464 AS |
729 | /* |
730 | * Returns duplicate string in which the @old characters are replaced by @new. | |
731 | */ | |
732 | char *kstrdup_and_replace(const char *src, char old, char new, gfp_t gfp) | |
733 | { | |
734 | char *dst; | |
735 | ||
736 | dst = kstrdup(src, gfp); | |
737 | if (!dst) | |
738 | return NULL; | |
739 | ||
740 | return strreplace(dst, old, new); | |
741 | } | |
742 | EXPORT_SYMBOL_GPL(kstrdup_and_replace); | |
743 | ||
418e0a35 AS |
744 | /** |
745 | * kasprintf_strarray - allocate and fill array of sequential strings | |
746 | * @gfp: flags for the slab allocator | |
747 | * @prefix: prefix to be used | |
748 | * @n: amount of lines to be allocated and filled | |
749 | * | |
750 | * Allocates and fills @n strings using pattern "%s-%zu", where prefix | |
751 | * is provided by caller. The caller is responsible to free them with | |
752 | * kfree_strarray() after use. | |
753 | * | |
754 | * Returns array of strings or NULL when memory can't be allocated. | |
755 | */ | |
756 | char **kasprintf_strarray(gfp_t gfp, const char *prefix, size_t n) | |
757 | { | |
758 | char **names; | |
759 | size_t i; | |
760 | ||
761 | names = kcalloc(n + 1, sizeof(char *), gfp); | |
762 | if (!names) | |
763 | return NULL; | |
764 | ||
765 | for (i = 0; i < n; i++) { | |
766 | names[i] = kasprintf(gfp, "%s-%zu", prefix, i); | |
767 | if (!names[i]) { | |
768 | kfree_strarray(names, i); | |
769 | return NULL; | |
770 | } | |
771 | } | |
772 | ||
773 | return names; | |
774 | } | |
775 | EXPORT_SYMBOL_GPL(kasprintf_strarray); | |
776 | ||
0fd16012 BG |
777 | /** |
778 | * kfree_strarray - free a number of dynamically allocated strings contained | |
779 | * in an array and the array itself | |
780 | * | |
781 | * @array: Dynamically allocated array of strings to free. | |
782 | * @n: Number of strings (starting from the beginning of the array) to free. | |
783 | * | |
784 | * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid | |
785 | * use-cases. If @array is NULL, the function does nothing. | |
786 | */ | |
787 | void kfree_strarray(char **array, size_t n) | |
788 | { | |
789 | unsigned int i; | |
790 | ||
791 | if (!array) | |
792 | return; | |
793 | ||
794 | for (i = 0; i < n; i++) | |
795 | kfree(array[i]); | |
796 | kfree(array); | |
797 | } | |
798 | EXPORT_SYMBOL_GPL(kfree_strarray); | |
cfecea6e | 799 | |
acdb89b6 AS |
800 | struct strarray { |
801 | char **array; | |
802 | size_t n; | |
803 | }; | |
804 | ||
805 | static void devm_kfree_strarray(struct device *dev, void *res) | |
806 | { | |
807 | struct strarray *array = res; | |
808 | ||
809 | kfree_strarray(array->array, array->n); | |
810 | } | |
811 | ||
812 | char **devm_kasprintf_strarray(struct device *dev, const char *prefix, size_t n) | |
813 | { | |
814 | struct strarray *ptr; | |
815 | ||
816 | ptr = devres_alloc(devm_kfree_strarray, sizeof(*ptr), GFP_KERNEL); | |
817 | if (!ptr) | |
818 | return ERR_PTR(-ENOMEM); | |
819 | ||
820 | ptr->array = kasprintf_strarray(GFP_KERNEL, prefix, n); | |
821 | if (!ptr->array) { | |
822 | devres_free(ptr); | |
823 | return ERR_PTR(-ENOMEM); | |
824 | } | |
825 | ||
cd290a98 PL |
826 | ptr->n = n; |
827 | devres_add(dev, ptr); | |
828 | ||
acdb89b6 AS |
829 | return ptr->array; |
830 | } | |
831 | EXPORT_SYMBOL_GPL(devm_kasprintf_strarray); | |
832 | ||
cfecea6e KC |
833 | /** |
834 | * skip_spaces - Removes leading whitespace from @str. | |
835 | * @str: The string to be stripped. | |
836 | * | |
837 | * Returns a pointer to the first non-whitespace character in @str. | |
838 | */ | |
839 | char *skip_spaces(const char *str) | |
840 | { | |
841 | while (isspace(*str)) | |
842 | ++str; | |
843 | return (char *)str; | |
844 | } | |
845 | EXPORT_SYMBOL(skip_spaces); | |
846 | ||
847 | /** | |
848 | * strim - Removes leading and trailing whitespace from @s. | |
849 | * @s: The string to be stripped. | |
850 | * | |
851 | * Note that the first trailing whitespace is replaced with a %NUL-terminator | |
852 | * in the given string @s. Returns a pointer to the first non-whitespace | |
853 | * character in @s. | |
854 | */ | |
855 | char *strim(char *s) | |
856 | { | |
857 | size_t size; | |
858 | char *end; | |
859 | ||
860 | size = strlen(s); | |
861 | if (!size) | |
862 | return s; | |
863 | ||
864 | end = s + size - 1; | |
865 | while (end >= s && isspace(*end)) | |
866 | end--; | |
867 | *(end + 1) = '\0'; | |
868 | ||
869 | return skip_spaces(s); | |
870 | } | |
871 | EXPORT_SYMBOL(strim); | |
872 | ||
873 | /** | |
874 | * sysfs_streq - return true if strings are equal, modulo trailing newline | |
875 | * @s1: one string | |
876 | * @s2: another string | |
877 | * | |
878 | * This routine returns true iff two strings are equal, treating both | |
879 | * NUL and newline-then-NUL as equivalent string terminations. It's | |
880 | * geared for use with sysfs input strings, which generally terminate | |
881 | * with newlines but are compared against values without newlines. | |
882 | */ | |
883 | bool sysfs_streq(const char *s1, const char *s2) | |
884 | { | |
885 | while (*s1 && *s1 == *s2) { | |
886 | s1++; | |
887 | s2++; | |
888 | } | |
889 | ||
890 | if (*s1 == *s2) | |
891 | return true; | |
892 | if (!*s1 && *s2 == '\n' && !s2[1]) | |
893 | return true; | |
894 | if (*s1 == '\n' && !s1[1] && !*s2) | |
895 | return true; | |
896 | return false; | |
897 | } | |
898 | EXPORT_SYMBOL(sysfs_streq); | |
899 | ||
900 | /** | |
901 | * match_string - matches given string in an array | |
902 | * @array: array of strings | |
903 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
904 | * @string: string to match with | |
905 | * | |
906 | * This routine will look for a string in an array of strings up to the | |
907 | * n-th element in the array or until the first NULL element. | |
908 | * | |
909 | * Historically the value of -1 for @n, was used to search in arrays that | |
910 | * are NULL terminated. However, the function does not make a distinction | |
911 | * when finishing the search: either @n elements have been compared OR | |
912 | * the first NULL element was found. | |
913 | * | |
914 | * Return: | |
915 | * index of a @string in the @array if matches, or %-EINVAL otherwise. | |
916 | */ | |
917 | int match_string(const char * const *array, size_t n, const char *string) | |
918 | { | |
919 | int index; | |
920 | const char *item; | |
921 | ||
922 | for (index = 0; index < n; index++) { | |
923 | item = array[index]; | |
924 | if (!item) | |
925 | break; | |
926 | if (!strcmp(item, string)) | |
927 | return index; | |
928 | } | |
929 | ||
930 | return -EINVAL; | |
931 | } | |
932 | EXPORT_SYMBOL(match_string); | |
933 | ||
934 | /** | |
935 | * __sysfs_match_string - matches given string in an array | |
936 | * @array: array of strings | |
937 | * @n: number of strings in the array or -1 for NULL terminated arrays | |
938 | * @str: string to match with | |
939 | * | |
940 | * Returns index of @str in the @array or -EINVAL, just like match_string(). | |
941 | * Uses sysfs_streq instead of strcmp for matching. | |
942 | * | |
943 | * This routine will look for a string in an array of strings up to the | |
944 | * n-th element in the array or until the first NULL element. | |
945 | * | |
946 | * Historically the value of -1 for @n, was used to search in arrays that | |
947 | * are NULL terminated. However, the function does not make a distinction | |
948 | * when finishing the search: either @n elements have been compared OR | |
949 | * the first NULL element was found. | |
950 | */ | |
951 | int __sysfs_match_string(const char * const *array, size_t n, const char *str) | |
952 | { | |
953 | const char *item; | |
954 | int index; | |
955 | ||
956 | for (index = 0; index < n; index++) { | |
957 | item = array[index]; | |
958 | if (!item) | |
959 | break; | |
960 | if (sysfs_streq(item, str)) | |
961 | return index; | |
962 | } | |
963 | ||
964 | return -EINVAL; | |
965 | } | |
966 | EXPORT_SYMBOL(__sysfs_match_string); | |
967 | ||
968 | /** | |
969 | * strreplace - Replace all occurrences of character in string. | |
d01a77af | 970 | * @str: The string to operate on. |
cfecea6e KC |
971 | * @old: The character being replaced. |
972 | * @new: The character @old is replaced with. | |
973 | * | |
d01a77af AS |
974 | * Replaces the each @old character with a @new one in the given string @str. |
975 | * | |
976 | * Return: pointer to the string @str itself. | |
cfecea6e | 977 | */ |
d01a77af | 978 | char *strreplace(char *str, char old, char new) |
cfecea6e | 979 | { |
d01a77af AS |
980 | char *s = str; |
981 | ||
cfecea6e KC |
982 | for (; *s; ++s) |
983 | if (*s == old) | |
984 | *s = new; | |
d01a77af | 985 | return str; |
cfecea6e KC |
986 | } |
987 | EXPORT_SYMBOL(strreplace); | |
988 | ||
5c4e0a21 GR |
989 | /** |
990 | * memcpy_and_pad - Copy one buffer to another with padding | |
991 | * @dest: Where to copy to | |
992 | * @dest_len: The destination buffer size | |
993 | * @src: Where to copy from | |
994 | * @count: The number of bytes to copy | |
995 | * @pad: Character to use for padding if space is left in destination. | |
996 | */ | |
997 | void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, | |
998 | int pad) | |
999 | { | |
1000 | if (dest_len > count) { | |
1001 | memcpy(dest, src, count); | |
1002 | memset(dest + count, pad, dest_len - count); | |
1003 | } else { | |
1004 | memcpy(dest, src, dest_len); | |
1005 | } | |
1006 | } | |
1007 | EXPORT_SYMBOL(memcpy_and_pad); | |
1008 | ||
c430f600 | 1009 | #ifdef CONFIG_FORTIFY_SOURCE |
f68f2ff9 KC |
1010 | /* These are placeholders for fortify compile-time warnings. */ |
1011 | void __read_overflow2_field(size_t avail, size_t wanted) { } | |
1012 | EXPORT_SYMBOL(__read_overflow2_field); | |
1013 | void __write_overflow_field(size_t avail, size_t wanted) { } | |
1014 | EXPORT_SYMBOL(__write_overflow_field); | |
1015 | ||
475ddf1f KC |
1016 | static const char * const fortify_func_name[] = { |
1017 | #define MAKE_FORTIFY_FUNC_NAME(func) [MAKE_FORTIFY_FUNC(func)] = #func | |
1018 | EACH_FORTIFY_FUNC(MAKE_FORTIFY_FUNC_NAME) | |
1019 | #undef MAKE_FORTIFY_FUNC_NAME | |
1020 | }; | |
1021 | ||
3d965b33 | 1022 | void __fortify_report(const u8 reason, const size_t avail, const size_t size) |
475ddf1f KC |
1023 | { |
1024 | const u8 func = FORTIFY_REASON_FUNC(reason); | |
1025 | const bool write = FORTIFY_REASON_DIR(reason); | |
1026 | const char *name; | |
1027 | ||
1028 | name = fortify_func_name[umin(func, FORTIFY_FUNC_UNKNOWN)]; | |
3d965b33 KC |
1029 | WARN(1, "%s: detected buffer overflow: %zu byte %s of buffer size %zu\n", |
1030 | name, size, str_read_write(!write), avail); | |
475ddf1f KC |
1031 | } |
1032 | EXPORT_SYMBOL(__fortify_report); | |
1033 | ||
3d965b33 | 1034 | void __fortify_panic(const u8 reason, const size_t avail, const size_t size) |
cfecea6e | 1035 | { |
3d965b33 | 1036 | __fortify_report(reason, avail, size); |
cfecea6e KC |
1037 | BUG(); |
1038 | } | |
475ddf1f | 1039 | EXPORT_SYMBOL(__fortify_panic); |
c430f600 | 1040 | #endif /* CONFIG_FORTIFY_SOURCE */ |