xref: /linux/drivers/acpi/acpica/utstring.c (revision 2ba9268dd603d23e17643437b2246acb6844953b)
1 /*******************************************************************************
2  *
3  * Module Name: utstring - Common functions for strings and characters
4  *
5  ******************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions, and the following disclaimer,
16  *    without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  *    substantially similar to the "NO WARRANTY" disclaimer below
19  *    ("Disclaimer") and any redistribution must be conditioned upon
20  *    including a substantially similar Disclaimer requirement for further
21  *    binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  *    of any contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acnamesp.h"
47 
48 #define _COMPONENT          ACPI_UTILITIES
49 ACPI_MODULE_NAME("utstring")
50 
51 /*
52  * Non-ANSI C library functions - strlwr, strupr, stricmp, and a 64-bit
53  * version of strtoul.
54  */
55 #ifdef ACPI_ASL_COMPILER
56 /*******************************************************************************
57  *
58  * FUNCTION:    acpi_ut_strlwr (strlwr)
59  *
60  * PARAMETERS:  src_string      - The source string to convert
61  *
62  * RETURN:      None
63  *
64  * DESCRIPTION: Convert string to lowercase
65  *
66  * NOTE: This is not a POSIX function, so it appears here, not in utclib.c
67  *
68  ******************************************************************************/
69 void acpi_ut_strlwr(char *src_string)
70 {
71 	char *string;
72 
73 	ACPI_FUNCTION_ENTRY();
74 
75 	if (!src_string) {
76 		return;
77 	}
78 
79 	/* Walk entire string, lowercasing the letters */
80 
81 	for (string = src_string; *string; string++) {
82 		*string = (char)ACPI_TOLOWER(*string);
83 	}
84 
85 	return;
86 }
87 
88 /******************************************************************************
89  *
90  * FUNCTION:    acpi_ut_stricmp (stricmp)
91  *
92  * PARAMETERS:  string1             - first string to compare
93  *              string2             - second string to compare
94  *
95  * RETURN:      int that signifies string relationship. Zero means strings
96  *              are equal.
97  *
98  * DESCRIPTION: Implementation of the non-ANSI stricmp function (compare
99  *              strings with no case sensitivity)
100  *
101  ******************************************************************************/
102 
103 int acpi_ut_stricmp(char *string1, char *string2)
104 {
105 	int c1;
106 	int c2;
107 
108 	do {
109 		c1 = tolower((int)*string1);
110 		c2 = tolower((int)*string2);
111 
112 		string1++;
113 		string2++;
114 	}
115 	while ((c1 == c2) && (c1));
116 
117 	return (c1 - c2);
118 }
119 #endif
120 
121 /*******************************************************************************
122  *
123  * FUNCTION:    acpi_ut_strupr (strupr)
124  *
125  * PARAMETERS:  src_string      - The source string to convert
126  *
127  * RETURN:      None
128  *
129  * DESCRIPTION: Convert string to uppercase
130  *
131  * NOTE: This is not a POSIX function, so it appears here, not in utclib.c
132  *
133  ******************************************************************************/
134 
135 void acpi_ut_strupr(char *src_string)
136 {
137 	char *string;
138 
139 	ACPI_FUNCTION_ENTRY();
140 
141 	if (!src_string) {
142 		return;
143 	}
144 
145 	/* Walk entire string, uppercasing the letters */
146 
147 	for (string = src_string; *string; string++) {
148 		*string = (char)ACPI_TOUPPER(*string);
149 	}
150 
151 	return;
152 }
153 
154 /*******************************************************************************
155  *
156  * FUNCTION:    acpi_ut_strtoul64
157  *
158  * PARAMETERS:  string          - Null terminated string
159  *              base            - Radix of the string: 16 or ACPI_ANY_BASE;
160  *                                ACPI_ANY_BASE means 'in behalf of to_integer'
161  *              ret_integer     - Where the converted integer is returned
162  *
163  * RETURN:      Status and Converted value
164  *
165  * DESCRIPTION: Convert a string into an unsigned value. Performs either a
166  *              32-bit or 64-bit conversion, depending on the current mode
167  *              of the interpreter.
168  *              NOTE: Does not support Octal strings, not needed.
169  *
170  ******************************************************************************/
171 
172 acpi_status acpi_ut_strtoul64(char *string, u32 base, u64 *ret_integer)
173 {
174 	u32 this_digit = 0;
175 	u64 return_value = 0;
176 	u64 quotient;
177 	u64 dividend;
178 	u32 to_integer_op = (base == ACPI_ANY_BASE);
179 	u32 mode32 = (acpi_gbl_integer_byte_width == 4);
180 	u8 valid_digits = 0;
181 	u8 sign_of0x = 0;
182 	u8 term = 0;
183 
184 	ACPI_FUNCTION_TRACE_STR(ut_stroul64, string);
185 
186 	switch (base) {
187 	case ACPI_ANY_BASE:
188 	case 16:
189 
190 		break;
191 
192 	default:
193 
194 		/* Invalid Base */
195 
196 		return_ACPI_STATUS(AE_BAD_PARAMETER);
197 	}
198 
199 	if (!string) {
200 		goto error_exit;
201 	}
202 
203 	/* Skip over any white space in the buffer */
204 
205 	while ((*string) && (ACPI_IS_SPACE(*string) || *string == '\t')) {
206 		string++;
207 	}
208 
209 	if (to_integer_op) {
210 		/*
211 		 * Base equal to ACPI_ANY_BASE means 'ToInteger operation case'.
212 		 * We need to determine if it is decimal or hexadecimal.
213 		 */
214 		if ((*string == '0') && (ACPI_TOLOWER(*(string + 1)) == 'x')) {
215 			sign_of0x = 1;
216 			base = 16;
217 
218 			/* Skip over the leading '0x' */
219 			string += 2;
220 		} else {
221 			base = 10;
222 		}
223 	}
224 
225 	/* Any string left? Check that '0x' is not followed by white space. */
226 
227 	if (!(*string) || ACPI_IS_SPACE(*string) || *string == '\t') {
228 		if (to_integer_op) {
229 			goto error_exit;
230 		} else {
231 			goto all_done;
232 		}
233 	}
234 
235 	/*
236 	 * Perform a 32-bit or 64-bit conversion, depending upon the current
237 	 * execution mode of the interpreter
238 	 */
239 	dividend = (mode32) ? ACPI_UINT32_MAX : ACPI_UINT64_MAX;
240 
241 	/* Main loop: convert the string to a 32- or 64-bit integer */
242 
243 	while (*string) {
244 		if (ACPI_IS_DIGIT(*string)) {
245 
246 			/* Convert ASCII 0-9 to Decimal value */
247 
248 			this_digit = ((u8)*string) - '0';
249 		} else if (base == 10) {
250 
251 			/* Digit is out of range; possible in to_integer case only */
252 
253 			term = 1;
254 		} else {
255 			this_digit = (u8)ACPI_TOUPPER(*string);
256 			if (ACPI_IS_XDIGIT((char)this_digit)) {
257 
258 				/* Convert ASCII Hex char to value */
259 
260 				this_digit = this_digit - 'A' + 10;
261 			} else {
262 				term = 1;
263 			}
264 		}
265 
266 		if (term) {
267 			if (to_integer_op) {
268 				goto error_exit;
269 			} else {
270 				break;
271 			}
272 		} else if ((valid_digits == 0) && (this_digit == 0)
273 			   && !sign_of0x) {
274 
275 			/* Skip zeros */
276 			string++;
277 			continue;
278 		}
279 
280 		valid_digits++;
281 
282 		if (sign_of0x
283 		    && ((valid_digits > 16)
284 			|| ((valid_digits > 8) && mode32))) {
285 			/*
286 			 * This is to_integer operation case.
287 			 * No any restrictions for string-to-integer conversion,
288 			 * see ACPI spec.
289 			 */
290 			goto error_exit;
291 		}
292 
293 		/* Divide the digit into the correct position */
294 
295 		(void)acpi_ut_short_divide((dividend - (u64)this_digit),
296 					   base, &quotient, NULL);
297 
298 		if (return_value > quotient) {
299 			if (to_integer_op) {
300 				goto error_exit;
301 			} else {
302 				break;
303 			}
304 		}
305 
306 		return_value *= base;
307 		return_value += this_digit;
308 		string++;
309 	}
310 
311 	/* All done, normal exit */
312 
313 all_done:
314 
315 	ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Converted value: %8.8X%8.8X\n",
316 			  ACPI_FORMAT_UINT64(return_value)));
317 
318 	*ret_integer = return_value;
319 	return_ACPI_STATUS(AE_OK);
320 
321 error_exit:
322 	/* Base was set/validated above */
323 
324 	if (base == 10) {
325 		return_ACPI_STATUS(AE_BAD_DECIMAL_CONSTANT);
326 	} else {
327 		return_ACPI_STATUS(AE_BAD_HEX_CONSTANT);
328 	}
329 }
330 
331 /*******************************************************************************
332  *
333  * FUNCTION:    acpi_ut_print_string
334  *
335  * PARAMETERS:  string          - Null terminated ASCII string
336  *              max_length      - Maximum output length. Used to constrain the
337  *                                length of strings during debug output only.
338  *
339  * RETURN:      None
340  *
341  * DESCRIPTION: Dump an ASCII string with support for ACPI-defined escape
342  *              sequences.
343  *
344  ******************************************************************************/
345 
346 void acpi_ut_print_string(char *string, u16 max_length)
347 {
348 	u32 i;
349 
350 	if (!string) {
351 		acpi_os_printf("<\"NULL STRING PTR\">");
352 		return;
353 	}
354 
355 	acpi_os_printf("\"");
356 	for (i = 0; (i < max_length) && string[i]; i++) {
357 
358 		/* Escape sequences */
359 
360 		switch (string[i]) {
361 		case 0x07:
362 
363 			acpi_os_printf("\\a");	/* BELL */
364 			break;
365 
366 		case 0x08:
367 
368 			acpi_os_printf("\\b");	/* BACKSPACE */
369 			break;
370 
371 		case 0x0C:
372 
373 			acpi_os_printf("\\f");	/* FORMFEED */
374 			break;
375 
376 		case 0x0A:
377 
378 			acpi_os_printf("\\n");	/* LINEFEED */
379 			break;
380 
381 		case 0x0D:
382 
383 			acpi_os_printf("\\r");	/* CARRIAGE RETURN */
384 			break;
385 
386 		case 0x09:
387 
388 			acpi_os_printf("\\t");	/* HORIZONTAL TAB */
389 			break;
390 
391 		case 0x0B:
392 
393 			acpi_os_printf("\\v");	/* VERTICAL TAB */
394 			break;
395 
396 		case '\'':	/* Single Quote */
397 		case '\"':	/* Double Quote */
398 		case '\\':	/* Backslash */
399 
400 			acpi_os_printf("\\%c", (int)string[i]);
401 			break;
402 
403 		default:
404 
405 			/* Check for printable character or hex escape */
406 
407 			if (ACPI_IS_PRINT(string[i])) {
408 				/* This is a normal character */
409 
410 				acpi_os_printf("%c", (int)string[i]);
411 			} else {
412 				/* All others will be Hex escapes */
413 
414 				acpi_os_printf("\\x%2.2X", (s32) string[i]);
415 			}
416 			break;
417 		}
418 	}
419 	acpi_os_printf("\"");
420 
421 	if (i == max_length && string[i]) {
422 		acpi_os_printf("...");
423 	}
424 }
425 
426 /*******************************************************************************
427  *
428  * FUNCTION:    acpi_ut_valid_acpi_char
429  *
430  * PARAMETERS:  char            - The character to be examined
431  *              position        - Byte position (0-3)
432  *
433  * RETURN:      TRUE if the character is valid, FALSE otherwise
434  *
435  * DESCRIPTION: Check for a valid ACPI character. Must be one of:
436  *              1) Upper case alpha
437  *              2) numeric
438  *              3) underscore
439  *
440  *              We allow a '!' as the last character because of the ASF! table
441  *
442  ******************************************************************************/
443 
444 u8 acpi_ut_valid_acpi_char(char character, u32 position)
445 {
446 
447 	if (!((character >= 'A' && character <= 'Z') ||
448 	      (character >= '0' && character <= '9') || (character == '_'))) {
449 
450 		/* Allow a '!' in the last position */
451 
452 		if (character == '!' && position == 3) {
453 			return (TRUE);
454 		}
455 
456 		return (FALSE);
457 	}
458 
459 	return (TRUE);
460 }
461 
462 /*******************************************************************************
463  *
464  * FUNCTION:    acpi_ut_valid_acpi_name
465  *
466  * PARAMETERS:  name            - The name to be examined. Does not have to
467  *                                be NULL terminated string.
468  *
469  * RETURN:      TRUE if the name is valid, FALSE otherwise
470  *
471  * DESCRIPTION: Check for a valid ACPI name. Each character must be one of:
472  *              1) Upper case alpha
473  *              2) numeric
474  *              3) underscore
475  *
476  ******************************************************************************/
477 
478 u8 acpi_ut_valid_acpi_name(char *name)
479 {
480 	u32 i;
481 
482 	ACPI_FUNCTION_ENTRY();
483 
484 	for (i = 0; i < ACPI_NAME_SIZE; i++) {
485 		if (!acpi_ut_valid_acpi_char(name[i], i)) {
486 			return (FALSE);
487 		}
488 	}
489 
490 	return (TRUE);
491 }
492 
493 /*******************************************************************************
494  *
495  * FUNCTION:    acpi_ut_repair_name
496  *
497  * PARAMETERS:  name            - The ACPI name to be repaired
498  *
499  * RETURN:      Repaired version of the name
500  *
501  * DESCRIPTION: Repair an ACPI name: Change invalid characters to '*' and
502  *              return the new name. NOTE: the Name parameter must reside in
503  *              read/write memory, cannot be a const.
504  *
505  * An ACPI Name must consist of valid ACPI characters. We will repair the name
506  * if necessary because we don't want to abort because of this, but we want
507  * all namespace names to be printable. A warning message is appropriate.
508  *
509  * This issue came up because there are in fact machines that exhibit
510  * this problem, and we want to be able to enable ACPI support for them,
511  * even though there are a few bad names.
512  *
513  ******************************************************************************/
514 
515 void acpi_ut_repair_name(char *name)
516 {
517 	u32 i;
518 	u8 found_bad_char = FALSE;
519 	u32 original_name;
520 
521 	ACPI_FUNCTION_NAME(ut_repair_name);
522 
523 	ACPI_MOVE_NAME(&original_name, name);
524 
525 	/* Check each character in the name */
526 
527 	for (i = 0; i < ACPI_NAME_SIZE; i++) {
528 		if (acpi_ut_valid_acpi_char(name[i], i)) {
529 			continue;
530 		}
531 
532 		/*
533 		 * Replace a bad character with something printable, yet technically
534 		 * still invalid. This prevents any collisions with existing "good"
535 		 * names in the namespace.
536 		 */
537 		name[i] = '*';
538 		found_bad_char = TRUE;
539 	}
540 
541 	if (found_bad_char) {
542 
543 		/* Report warning only if in strict mode or debug mode */
544 
545 		if (!acpi_gbl_enable_interpreter_slack) {
546 			ACPI_WARNING((AE_INFO,
547 				      "Invalid character(s) in name (0x%.8X), repaired: [%4.4s]",
548 				      original_name, name));
549 		} else {
550 			ACPI_DEBUG_PRINT((ACPI_DB_INFO,
551 					  "Invalid character(s) in name (0x%.8X), repaired: [%4.4s]",
552 					  original_name, name));
553 		}
554 	}
555 }
556 
557 #if defined ACPI_ASL_COMPILER || defined ACPI_EXEC_APP
558 /*******************************************************************************
559  *
560  * FUNCTION:    ut_convert_backslashes
561  *
562  * PARAMETERS:  pathname        - File pathname string to be converted
563  *
564  * RETURN:      Modifies the input Pathname
565  *
566  * DESCRIPTION: Convert all backslashes (0x5C) to forward slashes (0x2F) within
567  *              the entire input file pathname string.
568  *
569  ******************************************************************************/
570 
571 void ut_convert_backslashes(char *pathname)
572 {
573 
574 	if (!pathname) {
575 		return;
576 	}
577 
578 	while (*pathname) {
579 		if (*pathname == '\\') {
580 			*pathname = '/';
581 		}
582 
583 		pathname++;
584 	}
585 }
586 #endif
587 
588 #if defined (ACPI_DEBUGGER) || defined (ACPI_APPLICATION)
589 /*******************************************************************************
590  *
591  * FUNCTION:    acpi_ut_safe_strcpy, acpi_ut_safe_strcat, acpi_ut_safe_strncat
592  *
593  * PARAMETERS:  Adds a "DestSize" parameter to each of the standard string
594  *              functions. This is the size of the Destination buffer.
595  *
596  * RETURN:      TRUE if the operation would overflow the destination buffer.
597  *
598  * DESCRIPTION: Safe versions of standard Clib string functions. Ensure that
599  *              the result of the operation will not overflow the output string
600  *              buffer.
601  *
602  * NOTE:        These functions are typically only helpful for processing
603  *              user input and command lines. For most ACPICA code, the
604  *              required buffer length is precisely calculated before buffer
605  *              allocation, so the use of these functions is unnecessary.
606  *
607  ******************************************************************************/
608 
609 u8 acpi_ut_safe_strcpy(char *dest, acpi_size dest_size, char *source)
610 {
611 
612 	if (ACPI_STRLEN(source) >= dest_size) {
613 		return (TRUE);
614 	}
615 
616 	ACPI_STRCPY(dest, source);
617 	return (FALSE);
618 }
619 
620 u8 acpi_ut_safe_strcat(char *dest, acpi_size dest_size, char *source)
621 {
622 
623 	if ((ACPI_STRLEN(dest) + ACPI_STRLEN(source)) >= dest_size) {
624 		return (TRUE);
625 	}
626 
627 	ACPI_STRCAT(dest, source);
628 	return (FALSE);
629 }
630 
631 u8
632 acpi_ut_safe_strncat(char *dest,
633 		     acpi_size dest_size,
634 		     char *source, acpi_size max_transfer_length)
635 {
636 	acpi_size actual_transfer_length;
637 
638 	actual_transfer_length =
639 	    ACPI_MIN(max_transfer_length, ACPI_STRLEN(source));
640 
641 	if ((ACPI_STRLEN(dest) + actual_transfer_length) >= dest_size) {
642 		return (TRUE);
643 	}
644 
645 	ACPI_STRNCAT(dest, source, max_transfer_length);
646 	return (FALSE);
647 }
648 #endif
649