Commit | Line | Data |
---|---|---|
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 | 6 | */ |
b9f28d86 | 7 | #include <linux/bug.h> |
3c9f3681 JB |
8 | #include <linux/kernel.h> |
9 | #include <linux/math64.h> | |
8bc3bcc9 | 10 | #include <linux/export.h> |
16c7fa05 | 11 | #include <linux/ctype.h> |
c8250381 AS |
12 | #include <linux/errno.h> |
13 | #include <linux/string.h> | |
3c9f3681 JB |
14 | #include <linux/string_helpers.h> |
15 | ||
16 | /** | |
17 | * string_get_size - get the size in the specified units | |
b9f28d86 JB |
18 | * @size: The size to be converted in blocks |
19 | * @blk_size: Size of the block (use 1 for size in bytes) | |
3c9f3681 JB |
20 | * @units: units to use (powers of 1000 or 1024) |
21 | * @buf: buffer to format to | |
22 | * @len: length of buffer | |
23 | * | |
24 | * This function returns a string formatted to 3 significant figures | |
d1214c65 RV |
25 | * giving the size in the required units. @buf should have room for |
26 | * at least 9 bytes and will always be zero terminated. | |
3c9f3681 JB |
27 | * |
28 | */ | |
b9f28d86 | 29 | void string_get_size(u64 size, u64 blk_size, const enum string_size_units units, |
d1214c65 | 30 | char *buf, int len) |
3c9f3681 | 31 | { |
142cda5d | 32 | static const char *const units_10[] = { |
b9f28d86 | 33 | "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB" |
142cda5d MK |
34 | }; |
35 | static const char *const units_2[] = { | |
b9f28d86 | 36 | "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB" |
142cda5d MK |
37 | }; |
38 | static const char *const *const units_str[] = { | |
39 | [STRING_UNITS_10] = units_10, | |
3c9f3681 JB |
40 | [STRING_UNITS_2] = units_2, |
41 | }; | |
68aecfb9 | 42 | static const unsigned int divisor[] = { |
3c9f3681 JB |
43 | [STRING_UNITS_10] = 1000, |
44 | [STRING_UNITS_2] = 1024, | |
45 | }; | |
46 | int i, j; | |
b9f28d86 | 47 | u32 remainder = 0, sf_cap, exp; |
3c9f3681 | 48 | char tmp[8]; |
b9f28d86 | 49 | const char *unit; |
3c9f3681 JB |
50 | |
51 | tmp[0] = '\0'; | |
a8659597 | 52 | i = 0; |
b9f28d86 JB |
53 | if (!size) |
54 | goto out; | |
3c9f3681 | 55 | |
b9f28d86 JB |
56 | while (blk_size >= divisor[units]) { |
57 | remainder = do_div(blk_size, divisor[units]); | |
58 | i++; | |
59 | } | |
60 | ||
61 | exp = divisor[units] / (u32)blk_size; | |
62 | if (size >= exp) { | |
63 | remainder = do_div(size, divisor[units]); | |
64 | remainder *= blk_size; | |
65 | i++; | |
66 | } else { | |
67 | remainder *= size; | |
68 | } | |
69 | ||
70 | size *= blk_size; | |
71 | size += remainder / divisor[units]; | |
72 | remainder %= divisor[units]; | |
3c9f3681 | 73 | |
b9f28d86 JB |
74 | while (size >= divisor[units]) { |
75 | remainder = do_div(size, divisor[units]); | |
76 | i++; | |
3c9f3681 JB |
77 | } |
78 | ||
b9f28d86 JB |
79 | sf_cap = size; |
80 | for (j = 0; sf_cap*10 < 1000; j++) | |
81 | sf_cap *= 10; | |
82 | ||
83 | if (j) { | |
84 | remainder *= 1000; | |
85 | remainder /= divisor[units]; | |
86 | snprintf(tmp, sizeof(tmp), ".%03u", remainder); | |
87 | tmp[j+1] = '\0'; | |
88 | } | |
89 | ||
90 | out: | |
91 | if (i >= ARRAY_SIZE(units_2)) | |
92 | unit = "UNK"; | |
93 | else | |
94 | unit = units_str[units][i]; | |
95 | ||
84b9fbed | 96 | snprintf(buf, len, "%u%s %s", (u32)size, |
b9f28d86 | 97 | tmp, unit); |
3c9f3681 JB |
98 | } |
99 | EXPORT_SYMBOL(string_get_size); | |
16c7fa05 AS |
100 | |
101 | static bool unescape_space(char **src, char **dst) | |
102 | { | |
103 | char *p = *dst, *q = *src; | |
104 | ||
105 | switch (*q) { | |
106 | case 'n': | |
107 | *p = '\n'; | |
108 | break; | |
109 | case 'r': | |
110 | *p = '\r'; | |
111 | break; | |
112 | case 't': | |
113 | *p = '\t'; | |
114 | break; | |
115 | case 'v': | |
116 | *p = '\v'; | |
117 | break; | |
118 | case 'f': | |
119 | *p = '\f'; | |
120 | break; | |
121 | default: | |
122 | return false; | |
123 | } | |
124 | *dst += 1; | |
125 | *src += 1; | |
126 | return true; | |
127 | } | |
128 | ||
129 | static bool unescape_octal(char **src, char **dst) | |
130 | { | |
131 | char *p = *dst, *q = *src; | |
132 | u8 num; | |
133 | ||
134 | if (isodigit(*q) == 0) | |
135 | return false; | |
136 | ||
137 | num = (*q++) & 7; | |
138 | while (num < 32 && isodigit(*q) && (q - *src < 3)) { | |
139 | num <<= 3; | |
140 | num += (*q++) & 7; | |
141 | } | |
142 | *p = num; | |
143 | *dst += 1; | |
144 | *src = q; | |
145 | return true; | |
146 | } | |
147 | ||
148 | static bool unescape_hex(char **src, char **dst) | |
149 | { | |
150 | char *p = *dst, *q = *src; | |
151 | int digit; | |
152 | u8 num; | |
153 | ||
154 | if (*q++ != 'x') | |
155 | return false; | |
156 | ||
157 | num = digit = hex_to_bin(*q++); | |
158 | if (digit < 0) | |
159 | return false; | |
160 | ||
161 | digit = hex_to_bin(*q); | |
162 | if (digit >= 0) { | |
163 | q++; | |
164 | num = (num << 4) | digit; | |
165 | } | |
166 | *p = num; | |
167 | *dst += 1; | |
168 | *src = q; | |
169 | return true; | |
170 | } | |
171 | ||
172 | static bool unescape_special(char **src, char **dst) | |
173 | { | |
174 | char *p = *dst, *q = *src; | |
175 | ||
176 | switch (*q) { | |
177 | case '\"': | |
178 | *p = '\"'; | |
179 | break; | |
180 | case '\\': | |
181 | *p = '\\'; | |
182 | break; | |
183 | case 'a': | |
184 | *p = '\a'; | |
185 | break; | |
186 | case 'e': | |
187 | *p = '\e'; | |
188 | break; | |
189 | default: | |
190 | return false; | |
191 | } | |
192 | *dst += 1; | |
193 | *src += 1; | |
194 | return true; | |
195 | } | |
196 | ||
d295634e AS |
197 | /** |
198 | * string_unescape - unquote characters in the given string | |
199 | * @src: source buffer (escaped) | |
200 | * @dst: destination buffer (unescaped) | |
201 | * @size: size of the destination buffer (0 to unlimit) | |
202 | * @flags: combination of the flags (bitwise OR): | |
203 | * %UNESCAPE_SPACE: | |
204 | * '\f' - form feed | |
205 | * '\n' - new line | |
206 | * '\r' - carriage return | |
207 | * '\t' - horizontal tab | |
208 | * '\v' - vertical tab | |
209 | * %UNESCAPE_OCTAL: | |
210 | * '\NNN' - byte with octal value NNN (1 to 3 digits) | |
211 | * %UNESCAPE_HEX: | |
212 | * '\xHH' - byte with hexadecimal value HH (1 to 2 digits) | |
213 | * %UNESCAPE_SPECIAL: | |
214 | * '\"' - double quote | |
215 | * '\\' - backslash | |
216 | * '\a' - alert (BEL) | |
217 | * '\e' - escape | |
218 | * %UNESCAPE_ANY: | |
219 | * all previous together | |
220 | * | |
221 | * Description: | |
222 | * The function unquotes characters in the given string. | |
223 | * | |
224 | * Because the size of the output will be the same as or less than the size of | |
225 | * the input, the transformation may be performed in place. | |
226 | * | |
227 | * Caller must provide valid source and destination pointers. Be aware that | |
228 | * destination buffer will always be NULL-terminated. Source string must be | |
229 | * NULL-terminated as well. | |
230 | * | |
231 | * Return: | |
232 | * The amount of the characters processed to the destination buffer excluding | |
233 | * trailing '\0' is returned. | |
234 | */ | |
16c7fa05 AS |
235 | int string_unescape(char *src, char *dst, size_t size, unsigned int flags) |
236 | { | |
237 | char *out = dst; | |
238 | ||
239 | while (*src && --size) { | |
240 | if (src[0] == '\\' && src[1] != '\0' && size > 1) { | |
241 | src++; | |
242 | size--; | |
243 | ||
244 | if (flags & UNESCAPE_SPACE && | |
245 | unescape_space(&src, &out)) | |
246 | continue; | |
247 | ||
248 | if (flags & UNESCAPE_OCTAL && | |
249 | unescape_octal(&src, &out)) | |
250 | continue; | |
251 | ||
252 | if (flags & UNESCAPE_HEX && | |
253 | unescape_hex(&src, &out)) | |
254 | continue; | |
255 | ||
256 | if (flags & UNESCAPE_SPECIAL && | |
257 | unescape_special(&src, &out)) | |
258 | continue; | |
259 | ||
260 | *out++ = '\\'; | |
261 | } | |
262 | *out++ = *src++; | |
263 | } | |
264 | *out = '\0'; | |
265 | ||
266 | return out - dst; | |
267 | } | |
268 | EXPORT_SYMBOL(string_unescape); | |
c8250381 | 269 | |
3aeddc7d | 270 | static bool escape_passthrough(unsigned char c, char **dst, char *end) |
c8250381 AS |
271 | { |
272 | char *out = *dst; | |
273 | ||
3aeddc7d RV |
274 | if (out < end) |
275 | *out = c; | |
276 | *dst = out + 1; | |
277 | return true; | |
c8250381 AS |
278 | } |
279 | ||
3aeddc7d | 280 | static bool escape_space(unsigned char c, char **dst, char *end) |
c8250381 AS |
281 | { |
282 | char *out = *dst; | |
283 | unsigned char to; | |
284 | ||
c8250381 AS |
285 | switch (c) { |
286 | case '\n': | |
287 | to = 'n'; | |
288 | break; | |
289 | case '\r': | |
290 | to = 'r'; | |
291 | break; | |
292 | case '\t': | |
293 | to = 't'; | |
294 | break; | |
295 | case '\v': | |
296 | to = 'v'; | |
297 | break; | |
298 | case '\f': | |
299 | to = 'f'; | |
300 | break; | |
301 | default: | |
3aeddc7d | 302 | return false; |
c8250381 AS |
303 | } |
304 | ||
3aeddc7d RV |
305 | if (out < end) |
306 | *out = '\\'; | |
307 | ++out; | |
308 | if (out < end) | |
309 | *out = to; | |
310 | ++out; | |
c8250381 | 311 | |
3aeddc7d RV |
312 | *dst = out; |
313 | return true; | |
c8250381 AS |
314 | } |
315 | ||
3aeddc7d | 316 | static bool escape_special(unsigned char c, char **dst, char *end) |
c8250381 AS |
317 | { |
318 | char *out = *dst; | |
319 | unsigned char to; | |
320 | ||
c8250381 AS |
321 | switch (c) { |
322 | case '\\': | |
323 | to = '\\'; | |
324 | break; | |
325 | case '\a': | |
326 | to = 'a'; | |
327 | break; | |
328 | case '\e': | |
329 | to = 'e'; | |
330 | break; | |
331 | default: | |
3aeddc7d | 332 | return false; |
c8250381 AS |
333 | } |
334 | ||
3aeddc7d RV |
335 | if (out < end) |
336 | *out = '\\'; | |
337 | ++out; | |
338 | if (out < end) | |
339 | *out = to; | |
340 | ++out; | |
c8250381 | 341 | |
3aeddc7d RV |
342 | *dst = out; |
343 | return true; | |
c8250381 AS |
344 | } |
345 | ||
3aeddc7d | 346 | static bool escape_null(unsigned char c, char **dst, char *end) |
c8250381 AS |
347 | { |
348 | char *out = *dst; | |
349 | ||
c8250381 | 350 | if (c) |
3aeddc7d | 351 | return false; |
c8250381 | 352 | |
3aeddc7d RV |
353 | if (out < end) |
354 | *out = '\\'; | |
355 | ++out; | |
356 | if (out < end) | |
357 | *out = '0'; | |
358 | ++out; | |
c8250381 | 359 | |
3aeddc7d RV |
360 | *dst = out; |
361 | return true; | |
c8250381 AS |
362 | } |
363 | ||
3aeddc7d | 364 | static bool escape_octal(unsigned char c, char **dst, char *end) |
c8250381 AS |
365 | { |
366 | char *out = *dst; | |
367 | ||
3aeddc7d RV |
368 | if (out < end) |
369 | *out = '\\'; | |
370 | ++out; | |
371 | if (out < end) | |
372 | *out = ((c >> 6) & 0x07) + '0'; | |
373 | ++out; | |
374 | if (out < end) | |
375 | *out = ((c >> 3) & 0x07) + '0'; | |
376 | ++out; | |
377 | if (out < end) | |
378 | *out = ((c >> 0) & 0x07) + '0'; | |
379 | ++out; | |
c8250381 AS |
380 | |
381 | *dst = out; | |
3aeddc7d | 382 | return true; |
c8250381 AS |
383 | } |
384 | ||
3aeddc7d | 385 | static bool escape_hex(unsigned char c, char **dst, char *end) |
c8250381 AS |
386 | { |
387 | char *out = *dst; | |
388 | ||
3aeddc7d RV |
389 | if (out < end) |
390 | *out = '\\'; | |
391 | ++out; | |
392 | if (out < end) | |
393 | *out = 'x'; | |
394 | ++out; | |
395 | if (out < end) | |
396 | *out = hex_asc_hi(c); | |
397 | ++out; | |
398 | if (out < end) | |
399 | *out = hex_asc_lo(c); | |
400 | ++out; | |
c8250381 AS |
401 | |
402 | *dst = out; | |
3aeddc7d | 403 | return true; |
c8250381 AS |
404 | } |
405 | ||
406 | /** | |
407 | * string_escape_mem - quote characters in the given memory buffer | |
408 | * @src: source buffer (unescaped) | |
409 | * @isz: source buffer size | |
410 | * @dst: destination buffer (escaped) | |
411 | * @osz: destination buffer size | |
412 | * @flags: combination of the flags (bitwise OR): | |
413 | * %ESCAPE_SPACE: | |
414 | * '\f' - form feed | |
415 | * '\n' - new line | |
416 | * '\r' - carriage return | |
417 | * '\t' - horizontal tab | |
418 | * '\v' - vertical tab | |
419 | * %ESCAPE_SPECIAL: | |
420 | * '\\' - backslash | |
421 | * '\a' - alert (BEL) | |
422 | * '\e' - escape | |
423 | * %ESCAPE_NULL: | |
424 | * '\0' - null | |
425 | * %ESCAPE_OCTAL: | |
426 | * '\NNN' - byte with octal value NNN (3 digits) | |
427 | * %ESCAPE_ANY: | |
428 | * all previous together | |
429 | * %ESCAPE_NP: | |
430 | * escape only non-printable characters (checked by isprint) | |
431 | * %ESCAPE_ANY_NP: | |
432 | * all previous together | |
433 | * %ESCAPE_HEX: | |
434 | * '\xHH' - byte with hexadecimal value HH (2 digits) | |
435 | * @esc: NULL-terminated string of characters any of which, if found in | |
436 | * the source, has to be escaped | |
437 | * | |
438 | * Description: | |
439 | * The process of escaping byte buffer includes several parts. They are applied | |
440 | * in the following sequence. | |
441 | * 1. The character is matched to the printable class, if asked, and in | |
442 | * case of match it passes through to the output. | |
443 | * 2. The character is not matched to the one from @esc string and thus | |
444 | * must go as is to the output. | |
445 | * 3. The character is checked if it falls into the class given by @flags. | |
446 | * %ESCAPE_OCTAL and %ESCAPE_HEX are going last since they cover any | |
447 | * character. Note that they actually can't go together, otherwise | |
448 | * %ESCAPE_HEX will be ignored. | |
449 | * | |
450 | * Caller must provide valid source and destination pointers. Be aware that | |
451 | * destination buffer will not be NULL-terminated, thus caller have to append | |
452 | * it if needs. | |
453 | * | |
454 | * Return: | |
41416f23 RV |
455 | * The total size of the escaped output that would be generated for |
456 | * the given input and flags. To check whether the output was | |
457 | * truncated, compare the return value to osz. There is room left in | |
458 | * dst for a '\0' terminator if and only if ret < osz. | |
c8250381 | 459 | */ |
41416f23 | 460 | int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz, |
c8250381 AS |
461 | unsigned int flags, const char *esc) |
462 | { | |
41416f23 | 463 | char *p = dst; |
3aeddc7d | 464 | char *end = p + osz; |
c8250381 | 465 | bool is_dict = esc && *esc; |
c8250381 AS |
466 | |
467 | while (isz--) { | |
468 | unsigned char c = *src++; | |
469 | ||
470 | /* | |
471 | * Apply rules in the following sequence: | |
472 | * - the character is printable, when @flags has | |
473 | * %ESCAPE_NP bit set | |
474 | * - the @esc string is supplied and does not contain a | |
475 | * character under question | |
476 | * - the character doesn't fall into a class of symbols | |
477 | * defined by given @flags | |
478 | * In these cases we just pass through a character to the | |
479 | * output buffer. | |
480 | */ | |
481 | if ((flags & ESCAPE_NP && isprint(c)) || | |
482 | (is_dict && !strchr(esc, c))) { | |
483 | /* do nothing */ | |
484 | } else { | |
3aeddc7d RV |
485 | if (flags & ESCAPE_SPACE && escape_space(c, &p, end)) |
486 | continue; | |
487 | ||
488 | if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end)) | |
489 | continue; | |
490 | ||
491 | if (flags & ESCAPE_NULL && escape_null(c, &p, end)) | |
492 | continue; | |
c8250381 AS |
493 | |
494 | /* ESCAPE_OCTAL and ESCAPE_HEX always go last */ | |
3aeddc7d | 495 | if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end)) |
c8250381 | 496 | continue; |
3aeddc7d RV |
497 | |
498 | if (flags & ESCAPE_HEX && escape_hex(c, &p, end)) | |
c8250381 | 499 | continue; |
c8250381 AS |
500 | } |
501 | ||
3aeddc7d | 502 | escape_passthrough(c, &p, end); |
c8250381 AS |
503 | } |
504 | ||
41416f23 | 505 | return p - dst; |
c8250381 AS |
506 | } |
507 | EXPORT_SYMBOL(string_escape_mem); |