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3c9f3681 JB |
1 | /* |
2 | * Helpers for formatting and printing strings | |
3 | * | |
4 | * Copyright 31 August 2008 James Bottomley | |
16c7fa05 | 5 | * Copyright (C) 2013, Intel Corporation |
3c9f3681 JB |
6 | */ |
7 | #include <linux/kernel.h> | |
8 | #include <linux/math64.h> | |
8bc3bcc9 | 9 | #include <linux/export.h> |
16c7fa05 | 10 | #include <linux/ctype.h> |
c8250381 AS |
11 | #include <linux/errno.h> |
12 | #include <linux/string.h> | |
3c9f3681 JB |
13 | #include <linux/string_helpers.h> |
14 | ||
15 | /** | |
16 | * string_get_size - get the size in the specified units | |
17 | * @size: The size to be converted | |
18 | * @units: units to use (powers of 1000 or 1024) | |
19 | * @buf: buffer to format to | |
20 | * @len: length of buffer | |
21 | * | |
22 | * This function returns a string formatted to 3 significant figures | |
23 | * giving the size in the required units. Returns 0 on success or | |
24 | * error on failure. @buf is always zero terminated. | |
25 | * | |
26 | */ | |
27 | int string_get_size(u64 size, const enum string_size_units units, | |
28 | char *buf, int len) | |
29 | { | |
142cda5d | 30 | static const char *const units_10[] = { |
7eed8fde | 31 | "B", "kB", "MB", "GB", "TB", "PB", "EB" |
142cda5d MK |
32 | }; |
33 | static const char *const units_2[] = { | |
7eed8fde | 34 | "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB" |
142cda5d MK |
35 | }; |
36 | static const char *const *const units_str[] = { | |
37 | [STRING_UNITS_10] = units_10, | |
3c9f3681 JB |
38 | [STRING_UNITS_2] = units_2, |
39 | }; | |
68aecfb9 | 40 | static const unsigned int divisor[] = { |
3c9f3681 JB |
41 | [STRING_UNITS_10] = 1000, |
42 | [STRING_UNITS_2] = 1024, | |
43 | }; | |
44 | int i, j; | |
84b9fbed | 45 | u32 remainder = 0, sf_cap; |
3c9f3681 JB |
46 | char tmp[8]; |
47 | ||
48 | tmp[0] = '\0'; | |
a8659597 PA |
49 | i = 0; |
50 | if (size >= divisor[units]) { | |
7eed8fde | 51 | while (size >= divisor[units]) { |
a8659597 PA |
52 | remainder = do_div(size, divisor[units]); |
53 | i++; | |
54 | } | |
3c9f3681 | 55 | |
a8659597 PA |
56 | sf_cap = size; |
57 | for (j = 0; sf_cap*10 < 1000; j++) | |
58 | sf_cap *= 10; | |
3c9f3681 | 59 | |
a8659597 PA |
60 | if (j) { |
61 | remainder *= 1000; | |
84b9fbed RV |
62 | remainder /= divisor[units]; |
63 | snprintf(tmp, sizeof(tmp), ".%03u", remainder); | |
a8659597 PA |
64 | tmp[j+1] = '\0'; |
65 | } | |
3c9f3681 JB |
66 | } |
67 | ||
84b9fbed | 68 | snprintf(buf, len, "%u%s %s", (u32)size, |
3c9f3681 JB |
69 | tmp, units_str[units][i]); |
70 | ||
71 | return 0; | |
72 | } | |
73 | EXPORT_SYMBOL(string_get_size); | |
16c7fa05 AS |
74 | |
75 | static bool unescape_space(char **src, char **dst) | |
76 | { | |
77 | char *p = *dst, *q = *src; | |
78 | ||
79 | switch (*q) { | |
80 | case 'n': | |
81 | *p = '\n'; | |
82 | break; | |
83 | case 'r': | |
84 | *p = '\r'; | |
85 | break; | |
86 | case 't': | |
87 | *p = '\t'; | |
88 | break; | |
89 | case 'v': | |
90 | *p = '\v'; | |
91 | break; | |
92 | case 'f': | |
93 | *p = '\f'; | |
94 | break; | |
95 | default: | |
96 | return false; | |
97 | } | |
98 | *dst += 1; | |
99 | *src += 1; | |
100 | return true; | |
101 | } | |
102 | ||
103 | static bool unescape_octal(char **src, char **dst) | |
104 | { | |
105 | char *p = *dst, *q = *src; | |
106 | u8 num; | |
107 | ||
108 | if (isodigit(*q) == 0) | |
109 | return false; | |
110 | ||
111 | num = (*q++) & 7; | |
112 | while (num < 32 && isodigit(*q) && (q - *src < 3)) { | |
113 | num <<= 3; | |
114 | num += (*q++) & 7; | |
115 | } | |
116 | *p = num; | |
117 | *dst += 1; | |
118 | *src = q; | |
119 | return true; | |
120 | } | |
121 | ||
122 | static bool unescape_hex(char **src, char **dst) | |
123 | { | |
124 | char *p = *dst, *q = *src; | |
125 | int digit; | |
126 | u8 num; | |
127 | ||
128 | if (*q++ != 'x') | |
129 | return false; | |
130 | ||
131 | num = digit = hex_to_bin(*q++); | |
132 | if (digit < 0) | |
133 | return false; | |
134 | ||
135 | digit = hex_to_bin(*q); | |
136 | if (digit >= 0) { | |
137 | q++; | |
138 | num = (num << 4) | digit; | |
139 | } | |
140 | *p = num; | |
141 | *dst += 1; | |
142 | *src = q; | |
143 | return true; | |
144 | } | |
145 | ||
146 | static bool unescape_special(char **src, char **dst) | |
147 | { | |
148 | char *p = *dst, *q = *src; | |
149 | ||
150 | switch (*q) { | |
151 | case '\"': | |
152 | *p = '\"'; | |
153 | break; | |
154 | case '\\': | |
155 | *p = '\\'; | |
156 | break; | |
157 | case 'a': | |
158 | *p = '\a'; | |
159 | break; | |
160 | case 'e': | |
161 | *p = '\e'; | |
162 | break; | |
163 | default: | |
164 | return false; | |
165 | } | |
166 | *dst += 1; | |
167 | *src += 1; | |
168 | return true; | |
169 | } | |
170 | ||
d295634e AS |
171 | /** |
172 | * string_unescape - unquote characters in the given string | |
173 | * @src: source buffer (escaped) | |
174 | * @dst: destination buffer (unescaped) | |
175 | * @size: size of the destination buffer (0 to unlimit) | |
176 | * @flags: combination of the flags (bitwise OR): | |
177 | * %UNESCAPE_SPACE: | |
178 | * '\f' - form feed | |
179 | * '\n' - new line | |
180 | * '\r' - carriage return | |
181 | * '\t' - horizontal tab | |
182 | * '\v' - vertical tab | |
183 | * %UNESCAPE_OCTAL: | |
184 | * '\NNN' - byte with octal value NNN (1 to 3 digits) | |
185 | * %UNESCAPE_HEX: | |
186 | * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) | |
187 | * %UNESCAPE_SPECIAL: | |
188 | * '\"' - double quote | |
189 | * '\\' - backslash | |
190 | * '\a' - alert (BEL) | |
191 | * '\e' - escape | |
192 | * %UNESCAPE_ANY: | |
193 | * all previous together | |
194 | * | |
195 | * Description: | |
196 | * The function unquotes characters in the given string. | |
197 | * | |
198 | * Because the size of the output will be the same as or less than the size of | |
199 | * the input, the transformation may be performed in place. | |
200 | * | |
201 | * Caller must provide valid source and destination pointers. Be aware that | |
202 | * destination buffer will always be NULL-terminated. Source string must be | |
203 | * NULL-terminated as well. | |
204 | * | |
205 | * Return: | |
206 | * The amount of the characters processed to the destination buffer excluding | |
207 | * trailing '\0' is returned. | |
208 | */ | |
16c7fa05 AS |
209 | int string_unescape(char *src, char *dst, size_t size, unsigned int flags) |
210 | { | |
211 | char *out = dst; | |
212 | ||
213 | while (*src && --size) { | |
214 | if (src[0] == '\\' && src[1] != '\0' && size > 1) { | |
215 | src++; | |
216 | size--; | |
217 | ||
218 | if (flags & UNESCAPE_SPACE && | |
219 | unescape_space(&src, &out)) | |
220 | continue; | |
221 | ||
222 | if (flags & UNESCAPE_OCTAL && | |
223 | unescape_octal(&src, &out)) | |
224 | continue; | |
225 | ||
226 | if (flags & UNESCAPE_HEX && | |
227 | unescape_hex(&src, &out)) | |
228 | continue; | |
229 | ||
230 | if (flags & UNESCAPE_SPECIAL && | |
231 | unescape_special(&src, &out)) | |
232 | continue; | |
233 | ||
234 | *out++ = '\\'; | |
235 | } | |
236 | *out++ = *src++; | |
237 | } | |
238 | *out = '\0'; | |
239 | ||
240 | return out - dst; | |
241 | } | |
242 | EXPORT_SYMBOL(string_unescape); | |
c8250381 AS |
243 | |
244 | static int escape_passthrough(unsigned char c, char **dst, size_t *osz) | |
245 | { | |
246 | char *out = *dst; | |
247 | ||
248 | if (*osz < 1) | |
249 | return -ENOMEM; | |
250 | ||
251 | *out++ = c; | |
252 | ||
253 | *dst = out; | |
254 | *osz -= 1; | |
255 | ||
256 | return 1; | |
257 | } | |
258 | ||
259 | static int escape_space(unsigned char c, char **dst, size_t *osz) | |
260 | { | |
261 | char *out = *dst; | |
262 | unsigned char to; | |
263 | ||
264 | if (*osz < 2) | |
265 | return -ENOMEM; | |
266 | ||
267 | switch (c) { | |
268 | case '\n': | |
269 | to = 'n'; | |
270 | break; | |
271 | case '\r': | |
272 | to = 'r'; | |
273 | break; | |
274 | case '\t': | |
275 | to = 't'; | |
276 | break; | |
277 | case '\v': | |
278 | to = 'v'; | |
279 | break; | |
280 | case '\f': | |
281 | to = 'f'; | |
282 | break; | |
283 | default: | |
284 | return 0; | |
285 | } | |
286 | ||
287 | *out++ = '\\'; | |
288 | *out++ = to; | |
289 | ||
290 | *dst = out; | |
291 | *osz -= 2; | |
292 | ||
293 | return 1; | |
294 | } | |
295 | ||
296 | static int escape_special(unsigned char c, char **dst, size_t *osz) | |
297 | { | |
298 | char *out = *dst; | |
299 | unsigned char to; | |
300 | ||
301 | if (*osz < 2) | |
302 | return -ENOMEM; | |
303 | ||
304 | switch (c) { | |
305 | case '\\': | |
306 | to = '\\'; | |
307 | break; | |
308 | case '\a': | |
309 | to = 'a'; | |
310 | break; | |
311 | case '\e': | |
312 | to = 'e'; | |
313 | break; | |
314 | default: | |
315 | return 0; | |
316 | } | |
317 | ||
318 | *out++ = '\\'; | |
319 | *out++ = to; | |
320 | ||
321 | *dst = out; | |
322 | *osz -= 2; | |
323 | ||
324 | return 1; | |
325 | } | |
326 | ||
327 | static int escape_null(unsigned char c, char **dst, size_t *osz) | |
328 | { | |
329 | char *out = *dst; | |
330 | ||
331 | if (*osz < 2) | |
332 | return -ENOMEM; | |
333 | ||
334 | if (c) | |
335 | return 0; | |
336 | ||
337 | *out++ = '\\'; | |
338 | *out++ = '0'; | |
339 | ||
340 | *dst = out; | |
341 | *osz -= 2; | |
342 | ||
343 | return 1; | |
344 | } | |
345 | ||
346 | static int escape_octal(unsigned char c, char **dst, size_t *osz) | |
347 | { | |
348 | char *out = *dst; | |
349 | ||
350 | if (*osz < 4) | |
351 | return -ENOMEM; | |
352 | ||
353 | *out++ = '\\'; | |
354 | *out++ = ((c >> 6) & 0x07) + '0'; | |
355 | *out++ = ((c >> 3) & 0x07) + '0'; | |
356 | *out++ = ((c >> 0) & 0x07) + '0'; | |
357 | ||
358 | *dst = out; | |
359 | *osz -= 4; | |
360 | ||
361 | return 1; | |
362 | } | |
363 | ||
364 | static int escape_hex(unsigned char c, char **dst, size_t *osz) | |
365 | { | |
366 | char *out = *dst; | |
367 | ||
368 | if (*osz < 4) | |
369 | return -ENOMEM; | |
370 | ||
371 | *out++ = '\\'; | |
372 | *out++ = 'x'; | |
373 | *out++ = hex_asc_hi(c); | |
374 | *out++ = hex_asc_lo(c); | |
375 | ||
376 | *dst = out; | |
377 | *osz -= 4; | |
378 | ||
379 | return 1; | |
380 | } | |
381 | ||
382 | /** | |
383 | * string_escape_mem - quote characters in the given memory buffer | |
384 | * @src: source buffer (unescaped) | |
385 | * @isz: source buffer size | |
386 | * @dst: destination buffer (escaped) | |
387 | * @osz: destination buffer size | |
388 | * @flags: combination of the flags (bitwise OR): | |
389 | * %ESCAPE_SPACE: | |
390 | * '\f' - form feed | |
391 | * '\n' - new line | |
392 | * '\r' - carriage return | |
393 | * '\t' - horizontal tab | |
394 | * '\v' - vertical tab | |
395 | * %ESCAPE_SPECIAL: | |
396 | * '\\' - backslash | |
397 | * '\a' - alert (BEL) | |
398 | * '\e' - escape | |
399 | * %ESCAPE_NULL: | |
400 | * '\0' - null | |
401 | * %ESCAPE_OCTAL: | |
402 | * '\NNN' - byte with octal value NNN (3 digits) | |
403 | * %ESCAPE_ANY: | |
404 | * all previous together | |
405 | * %ESCAPE_NP: | |
406 | * escape only non-printable characters (checked by isprint) | |
407 | * %ESCAPE_ANY_NP: | |
408 | * all previous together | |
409 | * %ESCAPE_HEX: | |
410 | * '\xHH' - byte with hexadecimal value HH (2 digits) | |
411 | * @esc: NULL-terminated string of characters any of which, if found in | |
412 | * the source, has to be escaped | |
413 | * | |
414 | * Description: | |
415 | * The process of escaping byte buffer includes several parts. They are applied | |
416 | * in the following sequence. | |
417 | * 1. The character is matched to the printable class, if asked, and in | |
418 | * case of match it passes through to the output. | |
419 | * 2. The character is not matched to the one from @esc string and thus | |
420 | * must go as is to the output. | |
421 | * 3. The character is checked if it falls into the class given by @flags. | |
422 | * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any | |
423 | * character. Note that they actually can't go together, otherwise | |
424 | * %ESCAPE_HEX will be ignored. | |
425 | * | |
426 | * Caller must provide valid source and destination pointers. Be aware that | |
427 | * destination buffer will not be NULL-terminated, thus caller have to append | |
428 | * it if needs. | |
429 | * | |
430 | * Return: | |
431 | * The amount of the characters processed to the destination buffer, or | |
432 | * %-ENOMEM if the size of buffer is not enough to put an escaped character is | |
433 | * returned. | |
434 | * | |
435 | * Even in the case of error @dst pointer will be updated to point to the byte | |
436 | * after the last processed character. | |
437 | */ | |
438 | int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz, | |
439 | unsigned int flags, const char *esc) | |
440 | { | |
441 | char *out = *dst, *p = out; | |
442 | bool is_dict = esc && *esc; | |
443 | int ret = 0; | |
444 | ||
445 | while (isz--) { | |
446 | unsigned char c = *src++; | |
447 | ||
448 | /* | |
449 | * Apply rules in the following sequence: | |
450 | * - the character is printable, when @flags has | |
451 | * %ESCAPE_NP bit set | |
452 | * - the @esc string is supplied and does not contain a | |
453 | * character under question | |
454 | * - the character doesn't fall into a class of symbols | |
455 | * defined by given @flags | |
456 | * In these cases we just pass through a character to the | |
457 | * output buffer. | |
458 | */ | |
459 | if ((flags & ESCAPE_NP && isprint(c)) || | |
460 | (is_dict && !strchr(esc, c))) { | |
461 | /* do nothing */ | |
462 | } else { | |
463 | if (flags & ESCAPE_SPACE) { | |
464 | ret = escape_space(c, &p, &osz); | |
465 | if (ret < 0) | |
466 | break; | |
467 | if (ret > 0) | |
468 | continue; | |
469 | } | |
470 | ||
471 | if (flags & ESCAPE_SPECIAL) { | |
472 | ret = escape_special(c, &p, &osz); | |
473 | if (ret < 0) | |
474 | break; | |
475 | if (ret > 0) | |
476 | continue; | |
477 | } | |
478 | ||
479 | if (flags & ESCAPE_NULL) { | |
480 | ret = escape_null(c, &p, &osz); | |
481 | if (ret < 0) | |
482 | break; | |
483 | if (ret > 0) | |
484 | continue; | |
485 | } | |
486 | ||
487 | /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ | |
488 | if (flags & ESCAPE_OCTAL) { | |
489 | ret = escape_octal(c, &p, &osz); | |
490 | if (ret < 0) | |
491 | break; | |
492 | continue; | |
493 | } | |
494 | if (flags & ESCAPE_HEX) { | |
495 | ret = escape_hex(c, &p, &osz); | |
496 | if (ret < 0) | |
497 | break; | |
498 | continue; | |
499 | } | |
500 | } | |
501 | ||
502 | ret = escape_passthrough(c, &p, &osz); | |
503 | if (ret < 0) | |
504 | break; | |
505 | } | |
506 | ||
507 | *dst = p; | |
508 | ||
509 | if (ret < 0) | |
510 | return ret; | |
511 | ||
512 | return p - out; | |
513 | } | |
514 | EXPORT_SYMBOL(string_escape_mem); |