Commit | Line | Data |
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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 MK |
30 | static const char *const units_10[] = { |
31 | "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB", NULL | |
32 | }; | |
33 | static const char *const units_2[] = { | |
34 | "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB", | |
35 | NULL | |
36 | }; | |
37 | static const char *const *const units_str[] = { | |
38 | [STRING_UNITS_10] = units_10, | |
3c9f3681 JB |
39 | [STRING_UNITS_2] = units_2, |
40 | }; | |
68aecfb9 | 41 | static const unsigned int divisor[] = { |
3c9f3681 JB |
42 | [STRING_UNITS_10] = 1000, |
43 | [STRING_UNITS_2] = 1024, | |
44 | }; | |
45 | int i, j; | |
46 | u64 remainder = 0, sf_cap; | |
47 | char tmp[8]; | |
48 | ||
49 | tmp[0] = '\0'; | |
a8659597 PA |
50 | i = 0; |
51 | if (size >= divisor[units]) { | |
52 | while (size >= divisor[units] && units_str[units][i]) { | |
53 | remainder = do_div(size, divisor[units]); | |
54 | i++; | |
55 | } | |
3c9f3681 | 56 | |
a8659597 PA |
57 | sf_cap = size; |
58 | for (j = 0; sf_cap*10 < 1000; j++) | |
59 | sf_cap *= 10; | |
3c9f3681 | 60 | |
a8659597 PA |
61 | if (j) { |
62 | remainder *= 1000; | |
63 | do_div(remainder, divisor[units]); | |
64 | snprintf(tmp, sizeof(tmp), ".%03lld", | |
65 | (unsigned long long)remainder); | |
66 | tmp[j+1] = '\0'; | |
67 | } | |
3c9f3681 JB |
68 | } |
69 | ||
a8659597 | 70 | snprintf(buf, len, "%lld%s %s", (unsigned long long)size, |
3c9f3681 JB |
71 | tmp, units_str[units][i]); |
72 | ||
73 | return 0; | |
74 | } | |
75 | EXPORT_SYMBOL(string_get_size); | |
16c7fa05 AS |
76 | |
77 | static bool unescape_space(char **src, char **dst) | |
78 | { | |
79 | char *p = *dst, *q = *src; | |
80 | ||
81 | switch (*q) { | |
82 | case 'n': | |
83 | *p = '\n'; | |
84 | break; | |
85 | case 'r': | |
86 | *p = '\r'; | |
87 | break; | |
88 | case 't': | |
89 | *p = '\t'; | |
90 | break; | |
91 | case 'v': | |
92 | *p = '\v'; | |
93 | break; | |
94 | case 'f': | |
95 | *p = '\f'; | |
96 | break; | |
97 | default: | |
98 | return false; | |
99 | } | |
100 | *dst += 1; | |
101 | *src += 1; | |
102 | return true; | |
103 | } | |
104 | ||
105 | static bool unescape_octal(char **src, char **dst) | |
106 | { | |
107 | char *p = *dst, *q = *src; | |
108 | u8 num; | |
109 | ||
110 | if (isodigit(*q) == 0) | |
111 | return false; | |
112 | ||
113 | num = (*q++) & 7; | |
114 | while (num < 32 && isodigit(*q) && (q - *src < 3)) { | |
115 | num <<= 3; | |
116 | num += (*q++) & 7; | |
117 | } | |
118 | *p = num; | |
119 | *dst += 1; | |
120 | *src = q; | |
121 | return true; | |
122 | } | |
123 | ||
124 | static bool unescape_hex(char **src, char **dst) | |
125 | { | |
126 | char *p = *dst, *q = *src; | |
127 | int digit; | |
128 | u8 num; | |
129 | ||
130 | if (*q++ != 'x') | |
131 | return false; | |
132 | ||
133 | num = digit = hex_to_bin(*q++); | |
134 | if (digit < 0) | |
135 | return false; | |
136 | ||
137 | digit = hex_to_bin(*q); | |
138 | if (digit >= 0) { | |
139 | q++; | |
140 | num = (num << 4) | digit; | |
141 | } | |
142 | *p = num; | |
143 | *dst += 1; | |
144 | *src = q; | |
145 | return true; | |
146 | } | |
147 | ||
148 | static bool unescape_special(char **src, char **dst) | |
149 | { | |
150 | char *p = *dst, *q = *src; | |
151 | ||
152 | switch (*q) { | |
153 | case '\"': | |
154 | *p = '\"'; | |
155 | break; | |
156 | case '\\': | |
157 | *p = '\\'; | |
158 | break; | |
159 | case 'a': | |
160 | *p = '\a'; | |
161 | break; | |
162 | case 'e': | |
163 | *p = '\e'; | |
164 | break; | |
165 | default: | |
166 | return false; | |
167 | } | |
168 | *dst += 1; | |
169 | *src += 1; | |
170 | return true; | |
171 | } | |
172 | ||
d295634e AS |
173 | /** |
174 | * string_unescape - unquote characters in the given string | |
175 | * @src: source buffer (escaped) | |
176 | * @dst: destination buffer (unescaped) | |
177 | * @size: size of the destination buffer (0 to unlimit) | |
178 | * @flags: combination of the flags (bitwise OR): | |
179 | * %UNESCAPE_SPACE: | |
180 | * '\f' - form feed | |
181 | * '\n' - new line | |
182 | * '\r' - carriage return | |
183 | * '\t' - horizontal tab | |
184 | * '\v' - vertical tab | |
185 | * %UNESCAPE_OCTAL: | |
186 | * '\NNN' - byte with octal value NNN (1 to 3 digits) | |
187 | * %UNESCAPE_HEX: | |
188 | * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) | |
189 | * %UNESCAPE_SPECIAL: | |
190 | * '\"' - double quote | |
191 | * '\\' - backslash | |
192 | * '\a' - alert (BEL) | |
193 | * '\e' - escape | |
194 | * %UNESCAPE_ANY: | |
195 | * all previous together | |
196 | * | |
197 | * Description: | |
198 | * The function unquotes characters in the given string. | |
199 | * | |
200 | * Because the size of the output will be the same as or less than the size of | |
201 | * the input, the transformation may be performed in place. | |
202 | * | |
203 | * Caller must provide valid source and destination pointers. Be aware that | |
204 | * destination buffer will always be NULL-terminated. Source string must be | |
205 | * NULL-terminated as well. | |
206 | * | |
207 | * Return: | |
208 | * The amount of the characters processed to the destination buffer excluding | |
209 | * trailing '\0' is returned. | |
210 | */ | |
16c7fa05 AS |
211 | int string_unescape(char *src, char *dst, size_t size, unsigned int flags) |
212 | { | |
213 | char *out = dst; | |
214 | ||
215 | while (*src && --size) { | |
216 | if (src[0] == '\\' && src[1] != '\0' && size > 1) { | |
217 | src++; | |
218 | size--; | |
219 | ||
220 | if (flags & UNESCAPE_SPACE && | |
221 | unescape_space(&src, &out)) | |
222 | continue; | |
223 | ||
224 | if (flags & UNESCAPE_OCTAL && | |
225 | unescape_octal(&src, &out)) | |
226 | continue; | |
227 | ||
228 | if (flags & UNESCAPE_HEX && | |
229 | unescape_hex(&src, &out)) | |
230 | continue; | |
231 | ||
232 | if (flags & UNESCAPE_SPECIAL && | |
233 | unescape_special(&src, &out)) | |
234 | continue; | |
235 | ||
236 | *out++ = '\\'; | |
237 | } | |
238 | *out++ = *src++; | |
239 | } | |
240 | *out = '\0'; | |
241 | ||
242 | return out - dst; | |
243 | } | |
244 | EXPORT_SYMBOL(string_unescape); | |
c8250381 AS |
245 | |
246 | static int escape_passthrough(unsigned char c, char **dst, size_t *osz) | |
247 | { | |
248 | char *out = *dst; | |
249 | ||
250 | if (*osz < 1) | |
251 | return -ENOMEM; | |
252 | ||
253 | *out++ = c; | |
254 | ||
255 | *dst = out; | |
256 | *osz -= 1; | |
257 | ||
258 | return 1; | |
259 | } | |
260 | ||
261 | static int escape_space(unsigned char c, char **dst, size_t *osz) | |
262 | { | |
263 | char *out = *dst; | |
264 | unsigned char to; | |
265 | ||
266 | if (*osz < 2) | |
267 | return -ENOMEM; | |
268 | ||
269 | switch (c) { | |
270 | case '\n': | |
271 | to = 'n'; | |
272 | break; | |
273 | case '\r': | |
274 | to = 'r'; | |
275 | break; | |
276 | case '\t': | |
277 | to = 't'; | |
278 | break; | |
279 | case '\v': | |
280 | to = 'v'; | |
281 | break; | |
282 | case '\f': | |
283 | to = 'f'; | |
284 | break; | |
285 | default: | |
286 | return 0; | |
287 | } | |
288 | ||
289 | *out++ = '\\'; | |
290 | *out++ = to; | |
291 | ||
292 | *dst = out; | |
293 | *osz -= 2; | |
294 | ||
295 | return 1; | |
296 | } | |
297 | ||
298 | static int escape_special(unsigned char c, char **dst, size_t *osz) | |
299 | { | |
300 | char *out = *dst; | |
301 | unsigned char to; | |
302 | ||
303 | if (*osz < 2) | |
304 | return -ENOMEM; | |
305 | ||
306 | switch (c) { | |
307 | case '\\': | |
308 | to = '\\'; | |
309 | break; | |
310 | case '\a': | |
311 | to = 'a'; | |
312 | break; | |
313 | case '\e': | |
314 | to = 'e'; | |
315 | break; | |
316 | default: | |
317 | return 0; | |
318 | } | |
319 | ||
320 | *out++ = '\\'; | |
321 | *out++ = to; | |
322 | ||
323 | *dst = out; | |
324 | *osz -= 2; | |
325 | ||
326 | return 1; | |
327 | } | |
328 | ||
329 | static int escape_null(unsigned char c, char **dst, size_t *osz) | |
330 | { | |
331 | char *out = *dst; | |
332 | ||
333 | if (*osz < 2) | |
334 | return -ENOMEM; | |
335 | ||
336 | if (c) | |
337 | return 0; | |
338 | ||
339 | *out++ = '\\'; | |
340 | *out++ = '0'; | |
341 | ||
342 | *dst = out; | |
343 | *osz -= 2; | |
344 | ||
345 | return 1; | |
346 | } | |
347 | ||
348 | static int escape_octal(unsigned char c, char **dst, size_t *osz) | |
349 | { | |
350 | char *out = *dst; | |
351 | ||
352 | if (*osz < 4) | |
353 | return -ENOMEM; | |
354 | ||
355 | *out++ = '\\'; | |
356 | *out++ = ((c >> 6) & 0x07) + '0'; | |
357 | *out++ = ((c >> 3) & 0x07) + '0'; | |
358 | *out++ = ((c >> 0) & 0x07) + '0'; | |
359 | ||
360 | *dst = out; | |
361 | *osz -= 4; | |
362 | ||
363 | return 1; | |
364 | } | |
365 | ||
366 | static int escape_hex(unsigned char c, char **dst, size_t *osz) | |
367 | { | |
368 | char *out = *dst; | |
369 | ||
370 | if (*osz < 4) | |
371 | return -ENOMEM; | |
372 | ||
373 | *out++ = '\\'; | |
374 | *out++ = 'x'; | |
375 | *out++ = hex_asc_hi(c); | |
376 | *out++ = hex_asc_lo(c); | |
377 | ||
378 | *dst = out; | |
379 | *osz -= 4; | |
380 | ||
381 | return 1; | |
382 | } | |
383 | ||
384 | /** | |
385 | * string_escape_mem - quote characters in the given memory buffer | |
386 | * @src: source buffer (unescaped) | |
387 | * @isz: source buffer size | |
388 | * @dst: destination buffer (escaped) | |
389 | * @osz: destination buffer size | |
390 | * @flags: combination of the flags (bitwise OR): | |
391 | * %ESCAPE_SPACE: | |
392 | * '\f' - form feed | |
393 | * '\n' - new line | |
394 | * '\r' - carriage return | |
395 | * '\t' - horizontal tab | |
396 | * '\v' - vertical tab | |
397 | * %ESCAPE_SPECIAL: | |
398 | * '\\' - backslash | |
399 | * '\a' - alert (BEL) | |
400 | * '\e' - escape | |
401 | * %ESCAPE_NULL: | |
402 | * '\0' - null | |
403 | * %ESCAPE_OCTAL: | |
404 | * '\NNN' - byte with octal value NNN (3 digits) | |
405 | * %ESCAPE_ANY: | |
406 | * all previous together | |
407 | * %ESCAPE_NP: | |
408 | * escape only non-printable characters (checked by isprint) | |
409 | * %ESCAPE_ANY_NP: | |
410 | * all previous together | |
411 | * %ESCAPE_HEX: | |
412 | * '\xHH' - byte with hexadecimal value HH (2 digits) | |
413 | * @esc: NULL-terminated string of characters any of which, if found in | |
414 | * the source, has to be escaped | |
415 | * | |
416 | * Description: | |
417 | * The process of escaping byte buffer includes several parts. They are applied | |
418 | * in the following sequence. | |
419 | * 1. The character is matched to the printable class, if asked, and in | |
420 | * case of match it passes through to the output. | |
421 | * 2. The character is not matched to the one from @esc string and thus | |
422 | * must go as is to the output. | |
423 | * 3. The character is checked if it falls into the class given by @flags. | |
424 | * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any | |
425 | * character. Note that they actually can't go together, otherwise | |
426 | * %ESCAPE_HEX will be ignored. | |
427 | * | |
428 | * Caller must provide valid source and destination pointers. Be aware that | |
429 | * destination buffer will not be NULL-terminated, thus caller have to append | |
430 | * it if needs. | |
431 | * | |
432 | * Return: | |
433 | * The amount of the characters processed to the destination buffer, or | |
434 | * %-ENOMEM if the size of buffer is not enough to put an escaped character is | |
435 | * returned. | |
436 | * | |
437 | * Even in the case of error @dst pointer will be updated to point to the byte | |
438 | * after the last processed character. | |
439 | */ | |
440 | int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz, | |
441 | unsigned int flags, const char *esc) | |
442 | { | |
443 | char *out = *dst, *p = out; | |
444 | bool is_dict = esc && *esc; | |
445 | int ret = 0; | |
446 | ||
447 | while (isz--) { | |
448 | unsigned char c = *src++; | |
449 | ||
450 | /* | |
451 | * Apply rules in the following sequence: | |
452 | * - the character is printable, when @flags has | |
453 | * %ESCAPE_NP bit set | |
454 | * - the @esc string is supplied and does not contain a | |
455 | * character under question | |
456 | * - the character doesn't fall into a class of symbols | |
457 | * defined by given @flags | |
458 | * In these cases we just pass through a character to the | |
459 | * output buffer. | |
460 | */ | |
461 | if ((flags & ESCAPE_NP && isprint(c)) || | |
462 | (is_dict && !strchr(esc, c))) { | |
463 | /* do nothing */ | |
464 | } else { | |
465 | if (flags & ESCAPE_SPACE) { | |
466 | ret = escape_space(c, &p, &osz); | |
467 | if (ret < 0) | |
468 | break; | |
469 | if (ret > 0) | |
470 | continue; | |
471 | } | |
472 | ||
473 | if (flags & ESCAPE_SPECIAL) { | |
474 | ret = escape_special(c, &p, &osz); | |
475 | if (ret < 0) | |
476 | break; | |
477 | if (ret > 0) | |
478 | continue; | |
479 | } | |
480 | ||
481 | if (flags & ESCAPE_NULL) { | |
482 | ret = escape_null(c, &p, &osz); | |
483 | if (ret < 0) | |
484 | break; | |
485 | if (ret > 0) | |
486 | continue; | |
487 | } | |
488 | ||
489 | /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ | |
490 | if (flags & ESCAPE_OCTAL) { | |
491 | ret = escape_octal(c, &p, &osz); | |
492 | if (ret < 0) | |
493 | break; | |
494 | continue; | |
495 | } | |
496 | if (flags & ESCAPE_HEX) { | |
497 | ret = escape_hex(c, &p, &osz); | |
498 | if (ret < 0) | |
499 | break; | |
500 | continue; | |
501 | } | |
502 | } | |
503 | ||
504 | ret = escape_passthrough(c, &p, &osz); | |
505 | if (ret < 0) | |
506 | break; | |
507 | } | |
508 | ||
509 | *dst = p; | |
510 | ||
511 | if (ret < 0) | |
512 | return ret; | |
513 | ||
514 | return p - out; | |
515 | } | |
516 | EXPORT_SYMBOL(string_escape_mem); |