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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> |
c8250381 | 13 | #include <linux/errno.h> |
21985319 KC |
14 | #include <linux/fs.h> |
15 | #include <linux/limits.h> | |
0d044328 | 16 | #include <linux/mm.h> |
b53f27e4 | 17 | #include <linux/slab.h> |
c8250381 | 18 | #include <linux/string.h> |
3c9f3681 JB |
19 | #include <linux/string_helpers.h> |
20 | ||
21 | /** | |
22 | * string_get_size - get the size in the specified units | |
b9f28d86 JB |
23 | * @size: The size to be converted in blocks |
24 | * @blk_size: Size of the block (use 1 for size in bytes) | |
3c9f3681 JB |
25 | * @units: units to use (powers of 1000 or 1024) |
26 | * @buf: buffer to format to | |
27 | * @len: length of buffer | |
28 | * | |
29 | * This function returns a string formatted to 3 significant figures | |
d1214c65 RV |
30 | * giving the size in the required units. @buf should have room for |
31 | * at least 9 bytes and will always be zero terminated. | |
3c9f3681 JB |
32 | * |
33 | */ | |
b9f28d86 | 34 | void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, |
d1214c65 | 35 | char *buf, int len) |
3c9f3681 | 36 | { |
142cda5d | 37 | static const char *const units_10[] = { |
b9f28d86 | 38 | "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" |
142cda5d MK |
39 | }; |
40 | static const char *const units_2[] = { | |
b9f28d86 | 41 | "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB" |
142cda5d MK |
42 | }; |
43 | static const char *const *const units_str[] = { | |
44 | [STRING_UNITS_10] = units_10, | |
3c9f3681 JB |
45 | [STRING_UNITS_2] = units_2, |
46 | }; | |
68aecfb9 | 47 | static const unsigned int divisor[] = { |
3c9f3681 JB |
48 | [STRING_UNITS_10] = 1000, |
49 | [STRING_UNITS_2] = 1024, | |
50 | }; | |
564b026f JB |
51 | static const unsigned int rounding[] = { 500, 50, 5 }; |
52 | int i = 0, j; | |
53 | u32 remainder = 0, sf_cap; | |
3c9f3681 | 54 | char tmp[8]; |
b9f28d86 | 55 | const char *unit; |
3c9f3681 JB |
56 | |
57 | tmp[0] = '\0'; | |
564b026f JB |
58 | |
59 | if (blk_size == 0) | |
60 | size = 0; | |
61 | if (size == 0) | |
b9f28d86 | 62 | goto out; |
3c9f3681 | 63 | |
564b026f JB |
64 | /* This is Napier's algorithm. Reduce the original block size to |
65 | * | |
66 | * coefficient * divisor[units]^i | |
67 | * | |
68 | * we do the reduction so both coefficients are just under 32 bits so | |
69 | * that multiplying them together won't overflow 64 bits and we keep | |
70 | * as much precision as possible in the numbers. | |
71 | * | |
72 | * Note: it's safe to throw away the remainders here because all the | |
73 | * precision is in the coefficients. | |
74 | */ | |
75 | while (blk_size >> 32) { | |
76 | do_div(blk_size, divisor[units]); | |
b9f28d86 JB |
77 | i++; |
78 | } | |
79 | ||
564b026f JB |
80 | while (size >> 32) { |
81 | do_div(size, divisor[units]); | |
b9f28d86 | 82 | i++; |
b9f28d86 JB |
83 | } |
84 | ||
564b026f JB |
85 | /* now perform the actual multiplication keeping i as the sum of the |
86 | * two logarithms */ | |
b9f28d86 | 87 | size *= blk_size; |
3c9f3681 | 88 | |
564b026f | 89 | /* and logarithmically reduce it until it's just under the divisor */ |
b9f28d86 JB |
90 | while (size >= divisor[units]) { |
91 | remainder = do_div(size, divisor[units]); | |
92 | i++; | |
3c9f3681 JB |
93 | } |
94 | ||
564b026f JB |
95 | /* work out in j how many digits of precision we need from the |
96 | * remainder */ | |
b9f28d86 JB |
97 | sf_cap = size; |
98 | for (j = 0; sf_cap*10 < 1000; j++) | |
99 | sf_cap *= 10; | |
100 | ||
564b026f JB |
101 | if (units == STRING_UNITS_2) { |
102 | /* express the remainder as a decimal. It's currently the | |
103 | * numerator of a fraction whose denominator is | |
104 | * divisor[units], which is 1 << 10 for STRING_UNITS_2 */ | |
b9f28d86 | 105 | remainder *= 1000; |
564b026f JB |
106 | remainder >>= 10; |
107 | } | |
108 | ||
109 | /* add a 5 to the digit below what will be printed to ensure | |
110 | * an arithmetical round up and carry it through to size */ | |
111 | remainder += rounding[j]; | |
112 | if (remainder >= 1000) { | |
113 | remainder -= 1000; | |
114 | size += 1; | |
115 | } | |
116 | ||
117 | if (j) { | |
b9f28d86 JB |
118 | snprintf(tmp, sizeof(tmp), ".%03u", remainder); |
119 | tmp[j+1] = '\0'; | |
120 | } | |
121 | ||
122 | out: | |
123 | if (i >= ARRAY_SIZE(units_2)) | |
124 | unit = "UNK"; | |
125 | else | |
126 | unit = units_str[units][i]; | |
127 | ||
84b9fbed | 128 | snprintf(buf, len, "%u%s %s", (u32)size, |
b9f28d86 | 129 | tmp, unit); |
3c9f3681 JB |
130 | } |
131 | EXPORT_SYMBOL(string_get_size); | |
16c7fa05 AS |
132 | |
133 | static bool unescape_space(char **src, char **dst) | |
134 | { | |
135 | char *p = *dst, *q = *src; | |
136 | ||
137 | switch (*q) { | |
138 | case 'n': | |
139 | *p = '\n'; | |
140 | break; | |
141 | case 'r': | |
142 | *p = '\r'; | |
143 | break; | |
144 | case 't': | |
145 | *p = '\t'; | |
146 | break; | |
147 | case 'v': | |
148 | *p = '\v'; | |
149 | break; | |
150 | case 'f': | |
151 | *p = '\f'; | |
152 | break; | |
153 | default: | |
154 | return false; | |
155 | } | |
156 | *dst += 1; | |
157 | *src += 1; | |
158 | return true; | |
159 | } | |
160 | ||
161 | static bool unescape_octal(char **src, char **dst) | |
162 | { | |
163 | char *p = *dst, *q = *src; | |
164 | u8 num; | |
165 | ||
166 | if (isodigit(*q) == 0) | |
167 | return false; | |
168 | ||
169 | num = (*q++) & 7; | |
170 | while (num < 32 && isodigit(*q) && (q - *src < 3)) { | |
171 | num <<= 3; | |
172 | num += (*q++) & 7; | |
173 | } | |
174 | *p = num; | |
175 | *dst += 1; | |
176 | *src = q; | |
177 | return true; | |
178 | } | |
179 | ||
180 | static bool unescape_hex(char **src, char **dst) | |
181 | { | |
182 | char *p = *dst, *q = *src; | |
183 | int digit; | |
184 | u8 num; | |
185 | ||
186 | if (*q++ != 'x') | |
187 | return false; | |
188 | ||
189 | num = digit = hex_to_bin(*q++); | |
190 | if (digit < 0) | |
191 | return false; | |
192 | ||
193 | digit = hex_to_bin(*q); | |
194 | if (digit >= 0) { | |
195 | q++; | |
196 | num = (num << 4) | digit; | |
197 | } | |
198 | *p = num; | |
199 | *dst += 1; | |
200 | *src = q; | |
201 | return true; | |
202 | } | |
203 | ||
204 | static bool unescape_special(char **src, char **dst) | |
205 | { | |
206 | char *p = *dst, *q = *src; | |
207 | ||
208 | switch (*q) { | |
209 | case '\"': | |
210 | *p = '\"'; | |
211 | break; | |
212 | case '\\': | |
213 | *p = '\\'; | |
214 | break; | |
215 | case 'a': | |
216 | *p = '\a'; | |
217 | break; | |
218 | case 'e': | |
219 | *p = '\e'; | |
220 | break; | |
221 | default: | |
222 | return false; | |
223 | } | |
224 | *dst += 1; | |
225 | *src += 1; | |
226 | return true; | |
227 | } | |
228 | ||
d295634e AS |
229 | /** |
230 | * string_unescape - unquote characters in the given string | |
231 | * @src: source buffer (escaped) | |
232 | * @dst: destination buffer (unescaped) | |
233 | * @size: size of the destination buffer (0 to unlimit) | |
b4658cdd JC |
234 | * @flags: combination of the flags. |
235 | * | |
236 | * Description: | |
237 | * The function unquotes characters in the given string. | |
238 | * | |
239 | * Because the size of the output will be the same as or less than the size of | |
240 | * the input, the transformation may be performed in place. | |
241 | * | |
242 | * Caller must provide valid source and destination pointers. Be aware that | |
243 | * destination buffer will always be NULL-terminated. Source string must be | |
244 | * NULL-terminated as well. The supported flags are:: | |
245 | * | |
246 | * UNESCAPE_SPACE: | |
d295634e AS |
247 | * '\f' - form feed |
248 | * '\n' - new line | |
249 | * '\r' - carriage return | |
250 | * '\t' - horizontal tab | |
251 | * '\v' - vertical tab | |
b4658cdd | 252 | * UNESCAPE_OCTAL: |
d295634e | 253 | * '\NNN' - byte with octal value NNN (1 to 3 digits) |
b4658cdd | 254 | * UNESCAPE_HEX: |
d295634e | 255 | * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) |
b4658cdd | 256 | * UNESCAPE_SPECIAL: |
d295634e AS |
257 | * '\"' - double quote |
258 | * '\\' - backslash | |
259 | * '\a' - alert (BEL) | |
260 | * '\e' - escape | |
b4658cdd | 261 | * UNESCAPE_ANY: |
d295634e AS |
262 | * all previous together |
263 | * | |
d295634e AS |
264 | * Return: |
265 | * The amount of the characters processed to the destination buffer excluding | |
266 | * trailing '\0' is returned. | |
267 | */ | |
16c7fa05 AS |
268 | int string_unescape(char *src, char *dst, size_t size, unsigned int flags) |
269 | { | |
270 | char *out = dst; | |
271 | ||
272 | while (*src && --size) { | |
273 | if (src[0] == '\\' && src[1] != '\0' && size > 1) { | |
274 | src++; | |
275 | size--; | |
276 | ||
277 | if (flags & UNESCAPE_SPACE && | |
278 | unescape_space(&src, &out)) | |
279 | continue; | |
280 | ||
281 | if (flags & UNESCAPE_OCTAL && | |
282 | unescape_octal(&src, &out)) | |
283 | continue; | |
284 | ||
285 | if (flags & UNESCAPE_HEX && | |
286 | unescape_hex(&src, &out)) | |
287 | continue; | |
288 | ||
289 | if (flags & UNESCAPE_SPECIAL && | |
290 | unescape_special(&src, &out)) | |
291 | continue; | |
292 | ||
293 | *out++ = '\\'; | |
294 | } | |
295 | *out++ = *src++; | |
296 | } | |
297 | *out = '\0'; | |
298 | ||
299 | return out - dst; | |
300 | } | |
301 | EXPORT_SYMBOL(string_unescape); | |
c8250381 | 302 | |
3aeddc7d | 303 | static bool escape_passthrough(unsigned char c, char **dst, char *end) |
c8250381 AS |
304 | { |
305 | char *out = *dst; | |
306 | ||
3aeddc7d RV |
307 | if (out < end) |
308 | *out = c; | |
309 | *dst = out + 1; | |
310 | return true; | |
c8250381 AS |
311 | } |
312 | ||
3aeddc7d | 313 | static bool escape_space(unsigned char c, char **dst, char *end) |
c8250381 AS |
314 | { |
315 | char *out = *dst; | |
316 | unsigned char to; | |
317 | ||
c8250381 AS |
318 | switch (c) { |
319 | case '\n': | |
320 | to = 'n'; | |
321 | break; | |
322 | case '\r': | |
323 | to = 'r'; | |
324 | break; | |
325 | case '\t': | |
326 | to = 't'; | |
327 | break; | |
328 | case '\v': | |
329 | to = 'v'; | |
330 | break; | |
331 | case '\f': | |
332 | to = 'f'; | |
333 | break; | |
334 | default: | |
3aeddc7d | 335 | return false; |
c8250381 AS |
336 | } |
337 | ||
3aeddc7d RV |
338 | if (out < end) |
339 | *out = '\\'; | |
340 | ++out; | |
341 | if (out < end) | |
342 | *out = to; | |
343 | ++out; | |
c8250381 | 344 | |
3aeddc7d RV |
345 | *dst = out; |
346 | return true; | |
c8250381 AS |
347 | } |
348 | ||
3aeddc7d | 349 | static bool escape_special(unsigned char c, char **dst, char *end) |
c8250381 AS |
350 | { |
351 | char *out = *dst; | |
352 | unsigned char to; | |
353 | ||
c8250381 AS |
354 | switch (c) { |
355 | case '\\': | |
356 | to = '\\'; | |
357 | break; | |
358 | case '\a': | |
359 | to = 'a'; | |
360 | break; | |
361 | case '\e': | |
362 | to = 'e'; | |
363 | break; | |
91027d0a CD |
364 | case '"': |
365 | to = '"'; | |
366 | break; | |
c8250381 | 367 | default: |
3aeddc7d | 368 | return false; |
c8250381 AS |
369 | } |
370 | ||
3aeddc7d RV |
371 | if (out < end) |
372 | *out = '\\'; | |
373 | ++out; | |
374 | if (out < end) | |
375 | *out = to; | |
376 | ++out; | |
c8250381 | 377 | |
3aeddc7d RV |
378 | *dst = out; |
379 | return true; | |
c8250381 AS |
380 | } |
381 | ||
3aeddc7d | 382 | static bool escape_null(unsigned char c, char **dst, char *end) |
c8250381 AS |
383 | { |
384 | char *out = *dst; | |
385 | ||
c8250381 | 386 | if (c) |
3aeddc7d | 387 | return false; |
c8250381 | 388 | |
3aeddc7d RV |
389 | if (out < end) |
390 | *out = '\\'; | |
391 | ++out; | |
392 | if (out < end) | |
393 | *out = '0'; | |
394 | ++out; | |
c8250381 | 395 | |
3aeddc7d RV |
396 | *dst = out; |
397 | return true; | |
c8250381 AS |
398 | } |
399 | ||
3aeddc7d | 400 | static bool escape_octal(unsigned char c, char **dst, char *end) |
c8250381 AS |
401 | { |
402 | char *out = *dst; | |
403 | ||
3aeddc7d RV |
404 | if (out < end) |
405 | *out = '\\'; | |
406 | ++out; | |
407 | if (out < end) | |
408 | *out = ((c >> 6) & 0x07) + '0'; | |
409 | ++out; | |
410 | if (out < end) | |
411 | *out = ((c >> 3) & 0x07) + '0'; | |
412 | ++out; | |
413 | if (out < end) | |
414 | *out = ((c >> 0) & 0x07) + '0'; | |
415 | ++out; | |
c8250381 AS |
416 | |
417 | *dst = out; | |
3aeddc7d | 418 | return true; |
c8250381 AS |
419 | } |
420 | ||
3aeddc7d | 421 | static bool escape_hex(unsigned char c, char **dst, char *end) |
c8250381 AS |
422 | { |
423 | char *out = *dst; | |
424 | ||
3aeddc7d RV |
425 | if (out < end) |
426 | *out = '\\'; | |
427 | ++out; | |
428 | if (out < end) | |
429 | *out = 'x'; | |
430 | ++out; | |
431 | if (out < end) | |
432 | *out = hex_asc_hi(c); | |
433 | ++out; | |
434 | if (out < end) | |
435 | *out = hex_asc_lo(c); | |
436 | ++out; | |
c8250381 AS |
437 | |
438 | *dst = out; | |
3aeddc7d | 439 | return true; |
c8250381 AS |
440 | } |
441 | ||
442 | /** | |
443 | * string_escape_mem - quote characters in the given memory buffer | |
444 | * @src: source buffer (unescaped) | |
445 | * @isz: source buffer size | |
446 | * @dst: destination buffer (escaped) | |
447 | * @osz: destination buffer size | |
b4658cdd JC |
448 | * @flags: combination of the flags |
449 | * @only: NULL-terminated string containing characters used to limit | |
450 | * the selected escape class. If characters are included in @only | |
451 | * that would not normally be escaped by the classes selected | |
452 | * in @flags, they will be copied to @dst unescaped. | |
453 | * | |
454 | * Description: | |
455 | * The process of escaping byte buffer includes several parts. They are applied | |
456 | * in the following sequence. | |
457 | * | |
62519b88 | 458 | * 1. The character is not matched to the one from @only string and thus |
b4658cdd | 459 | * must go as-is to the output. |
0362c27f | 460 | * 2. The character is matched to the printable and ASCII classes, if asked, |
a0809783 | 461 | * and in case of match it passes through to the output. |
0362c27f AS |
462 | * 3. The character is matched to the printable or ASCII class, if asked, |
463 | * and in case of match it passes through to the output. | |
464 | * 4. The character is checked if it falls into the class given by @flags. | |
b4658cdd JC |
465 | * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any |
466 | * character. Note that they actually can't go together, otherwise | |
467 | * %ESCAPE_HEX will be ignored. | |
468 | * | |
469 | * Caller must provide valid source and destination pointers. Be aware that | |
470 | * destination buffer will not be NULL-terminated, thus caller have to append | |
a0809783 | 471 | * it if needs. The supported flags are:: |
b4658cdd | 472 | * |
d89a3f73 | 473 | * %ESCAPE_SPACE: (special white space, not space itself) |
c8250381 AS |
474 | * '\f' - form feed |
475 | * '\n' - new line | |
476 | * '\r' - carriage return | |
477 | * '\t' - horizontal tab | |
478 | * '\v' - vertical tab | |
479 | * %ESCAPE_SPECIAL: | |
91027d0a | 480 | * '\"' - double quote |
c8250381 AS |
481 | * '\\' - backslash |
482 | * '\a' - alert (BEL) | |
483 | * '\e' - escape | |
484 | * %ESCAPE_NULL: | |
485 | * '\0' - null | |
486 | * %ESCAPE_OCTAL: | |
487 | * '\NNN' - byte with octal value NNN (3 digits) | |
488 | * %ESCAPE_ANY: | |
489 | * all previous together | |
490 | * %ESCAPE_NP: | |
a0809783 | 491 | * escape only non-printable characters, checked by isprint() |
c8250381 AS |
492 | * %ESCAPE_ANY_NP: |
493 | * all previous together | |
494 | * %ESCAPE_HEX: | |
495 | * '\xHH' - byte with hexadecimal value HH (2 digits) | |
a0809783 AS |
496 | * %ESCAPE_NA: |
497 | * escape only non-ascii characters, checked by isascii() | |
0362c27f AS |
498 | * %ESCAPE_NAP: |
499 | * escape only non-printable or non-ascii characters | |
aec0d096 AS |
500 | * %ESCAPE_APPEND: |
501 | * append characters from @only to be escaped by the given classes | |
502 | * | |
503 | * %ESCAPE_APPEND would help to pass additional characters to the escaped, when | |
504 | * one of %ESCAPE_NP, %ESCAPE_NA, or %ESCAPE_NAP is provided. | |
a0809783 | 505 | * |
0362c27f AS |
506 | * One notable caveat, the %ESCAPE_NAP, %ESCAPE_NP and %ESCAPE_NA have the |
507 | * higher priority than the rest of the flags (%ESCAPE_NAP is the highest). | |
a0809783 AS |
508 | * It doesn't make much sense to use either of them without %ESCAPE_OCTAL |
509 | * or %ESCAPE_HEX, because they cover most of the other character classes. | |
0362c27f AS |
510 | * %ESCAPE_NAP can utilize %ESCAPE_SPACE or %ESCAPE_SPECIAL in addition to |
511 | * the above. | |
c8250381 AS |
512 | * |
513 | * Return: | |
41416f23 RV |
514 | * The total size of the escaped output that would be generated for |
515 | * the given input and flags. To check whether the output was | |
516 | * truncated, compare the return value to osz. There is room left in | |
517 | * dst for a '\0' terminator if and only if ret < osz. | |
c8250381 | 518 | */ |
41416f23 | 519 | int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, |
b40bdb7f | 520 | unsigned int flags, const char *only) |
c8250381 | 521 | { |
41416f23 | 522 | char *p = dst; |
3aeddc7d | 523 | char *end = p + osz; |
b40bdb7f | 524 | bool is_dict = only && *only; |
aec0d096 | 525 | bool is_append = flags & ESCAPE_APPEND; |
c8250381 AS |
526 | |
527 | while (isz--) { | |
528 | unsigned char c = *src++; | |
aec0d096 | 529 | bool in_dict = is_dict && strchr(only, c); |
c8250381 AS |
530 | |
531 | /* | |
532 | * Apply rules in the following sequence: | |
b40bdb7f | 533 | * - the @only string is supplied and does not contain a |
c8250381 | 534 | * character under question |
0362c27f AS |
535 | * - the character is printable and ASCII, when @flags has |
536 | * %ESCAPE_NAP bit set | |
62519b88 AS |
537 | * - the character is printable, when @flags has |
538 | * %ESCAPE_NP bit set | |
a0809783 AS |
539 | * - the character is ASCII, when @flags has |
540 | * %ESCAPE_NA bit set | |
c8250381 AS |
541 | * - the character doesn't fall into a class of symbols |
542 | * defined by given @flags | |
543 | * In these cases we just pass through a character to the | |
544 | * output buffer. | |
aec0d096 AS |
545 | * |
546 | * When %ESCAPE_APPEND is passed, the characters from @only | |
547 | * have been excluded from the %ESCAPE_NAP, %ESCAPE_NP, and | |
548 | * %ESCAPE_NA cases. | |
c8250381 | 549 | */ |
aec0d096 | 550 | if (!(is_append || in_dict) && is_dict && |
7e5969ae AS |
551 | escape_passthrough(c, &p, end)) |
552 | continue; | |
62519b88 | 553 | |
aec0d096 | 554 | if (!(is_append && in_dict) && isascii(c) && isprint(c) && |
0362c27f AS |
555 | flags & ESCAPE_NAP && escape_passthrough(c, &p, end)) |
556 | continue; | |
557 | ||
aec0d096 | 558 | if (!(is_append && in_dict) && isprint(c) && |
7e5969ae AS |
559 | flags & ESCAPE_NP && escape_passthrough(c, &p, end)) |
560 | continue; | |
3aeddc7d | 561 | |
aec0d096 | 562 | if (!(is_append && in_dict) && isascii(c) && |
a0809783 AS |
563 | flags & ESCAPE_NA && escape_passthrough(c, &p, end)) |
564 | continue; | |
565 | ||
7e5969ae AS |
566 | if (flags & ESCAPE_SPACE && escape_space(c, &p, end)) |
567 | continue; | |
3aeddc7d | 568 | |
7e5969ae AS |
569 | if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end)) |
570 | continue; | |
c8250381 | 571 | |
7e5969ae AS |
572 | if (flags & ESCAPE_NULL && escape_null(c, &p, end)) |
573 | continue; | |
3aeddc7d | 574 | |
7e5969ae AS |
575 | /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ |
576 | if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end)) | |
577 | continue; | |
578 | ||
579 | if (flags & ESCAPE_HEX && escape_hex(c, &p, end)) | |
580 | continue; | |
c8250381 | 581 | |
3aeddc7d | 582 | escape_passthrough(c, &p, end); |
c8250381 AS |
583 | } |
584 | ||
41416f23 | 585 | return p - dst; |
c8250381 AS |
586 | } |
587 | EXPORT_SYMBOL(string_escape_mem); | |
b53f27e4 KC |
588 | |
589 | /* | |
590 | * Return an allocated string that has been escaped of special characters | |
591 | * and double quotes, making it safe to log in quotes. | |
592 | */ | |
593 | char *kstrdup_quotable(const char *src, gfp_t gfp) | |
594 | { | |
595 | size_t slen, dlen; | |
596 | char *dst; | |
597 | const int flags = ESCAPE_HEX; | |
598 | const char esc[] = "\f\n\r\t\v\a\e\\\""; | |
599 | ||
600 | if (!src) | |
601 | return NULL; | |
602 | slen = strlen(src); | |
603 | ||
604 | dlen = string_escape_mem(src, slen, NULL, 0, flags, esc); | |
605 | dst = kmalloc(dlen + 1, gfp); | |
606 | if (!dst) | |
607 | return NULL; | |
608 | ||
609 | WARN_ON(string_escape_mem(src, slen, dst, dlen, flags, esc) != dlen); | |
610 | dst[dlen] = '\0'; | |
611 | ||
612 | return dst; | |
613 | } | |
614 | EXPORT_SYMBOL_GPL(kstrdup_quotable); | |
0d044328 KC |
615 | |
616 | /* | |
617 | * Returns allocated NULL-terminated string containing process | |
618 | * command line, with inter-argument NULLs replaced with spaces, | |
619 | * and other special characters escaped. | |
620 | */ | |
621 | char *kstrdup_quotable_cmdline(struct task_struct *task, gfp_t gfp) | |
622 | { | |
623 | char *buffer, *quoted; | |
624 | int i, res; | |
625 | ||
0ee931c4 | 626 | buffer = kmalloc(PAGE_SIZE, GFP_KERNEL); |
0d044328 KC |
627 | if (!buffer) |
628 | return NULL; | |
629 | ||
630 | res = get_cmdline(task, buffer, PAGE_SIZE - 1); | |
631 | buffer[res] = '\0'; | |
632 | ||
633 | /* Collapse trailing NULLs, leave res pointing to last non-NULL. */ | |
634 | while (--res >= 0 && buffer[res] == '\0') | |
635 | ; | |
636 | ||
637 | /* Replace inter-argument NULLs. */ | |
638 | for (i = 0; i <= res; i++) | |
639 | if (buffer[i] == '\0') | |
640 | buffer[i] = ' '; | |
641 | ||
642 | /* Make sure result is printable. */ | |
643 | quoted = kstrdup_quotable(buffer, gfp); | |
644 | kfree(buffer); | |
645 | return quoted; | |
646 | } | |
647 | EXPORT_SYMBOL_GPL(kstrdup_quotable_cmdline); | |
21985319 KC |
648 | |
649 | /* | |
650 | * Returns allocated NULL-terminated string containing pathname, | |
651 | * with special characters escaped, able to be safely logged. If | |
652 | * there is an error, the leading character will be "<". | |
653 | */ | |
654 | char *kstrdup_quotable_file(struct file *file, gfp_t gfp) | |
655 | { | |
656 | char *temp, *pathname; | |
657 | ||
658 | if (!file) | |
659 | return kstrdup("<unknown>", gfp); | |
660 | ||
661 | /* We add 11 spaces for ' (deleted)' to be appended */ | |
0ee931c4 | 662 | temp = kmalloc(PATH_MAX + 11, GFP_KERNEL); |
21985319 KC |
663 | if (!temp) |
664 | return kstrdup("<no_memory>", gfp); | |
665 | ||
666 | pathname = file_path(file, temp, PATH_MAX + 11); | |
667 | if (IS_ERR(pathname)) | |
668 | pathname = kstrdup("<too_long>", gfp); | |
669 | else | |
670 | pathname = kstrdup_quotable(pathname, gfp); | |
671 | ||
672 | kfree(temp); | |
673 | return pathname; | |
674 | } | |
675 | EXPORT_SYMBOL_GPL(kstrdup_quotable_file); | |
0fd16012 BG |
676 | |
677 | /** | |
678 | * kfree_strarray - free a number of dynamically allocated strings contained | |
679 | * in an array and the array itself | |
680 | * | |
681 | * @array: Dynamically allocated array of strings to free. | |
682 | * @n: Number of strings (starting from the beginning of the array) to free. | |
683 | * | |
684 | * Passing a non-NULL @array and @n == 0 as well as NULL @array are valid | |
685 | * use-cases. If @array is NULL, the function does nothing. | |
686 | */ | |
687 | void kfree_strarray(char **array, size_t n) | |
688 | { | |
689 | unsigned int i; | |
690 | ||
691 | if (!array) | |
692 | return; | |
693 | ||
694 | for (i = 0; i < n; i++) | |
695 | kfree(array[i]); | |
696 | kfree(array); | |
697 | } | |
698 | EXPORT_SYMBOL_GPL(kfree_strarray); | |
b36cd19b GR |
699 | |
700 | /** | |
701 | * memcpy_and_pad - Copy one buffer to another with padding | |
702 | * @dest: Where to copy to | |
703 | * @dest_len: The destination buffer size | |
704 | * @src: Where to copy from | |
705 | * @count: The number of bytes to copy | |
706 | * @pad: Character to use for padding if space is left in destination. | |
707 | */ | |
708 | void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count, | |
709 | int pad) | |
710 | { | |
711 | if (dest_len > count) { | |
712 | memcpy(dest, src, count); | |
713 | memset(dest + count, pad, dest_len - count); | |
714 | } else { | |
715 | memcpy(dest, src, dest_len); | |
716 | } | |
717 | } | |
718 | EXPORT_SYMBOL(memcpy_and_pad); |