1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2/*******************************************************************************
3 *
4 * Module Name: utstrsuppt - Support functions for string-to-integer conversion
5 *
6 ******************************************************************************/
7
8#include <acpi/acpi.h>
9#include "accommon.h"
10
11#define _COMPONENT ACPI_UTILITIES
12ACPI_MODULE_NAME("utstrsuppt")
13
14/* Local prototypes */
15static acpi_status
16acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit);
17
18static acpi_status
19acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product);
20
21static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum);
22
23/*******************************************************************************
24 *
25 * FUNCTION: acpi_ut_convert_octal_string
26 *
27 * PARAMETERS: string - Null terminated input string
28 * return_value_ptr - Where the converted value is returned
29 *
30 * RETURN: Status and 64-bit converted integer
31 *
32 * DESCRIPTION: Performs a base 8 conversion of the input string to an
33 * integer value, either 32 or 64 bits.
34 *
35 * NOTE: Maximum 64-bit unsigned octal value is 01777777777777777777777
36 * Maximum 32-bit unsigned octal value is 037777777777
37 *
38 ******************************************************************************/
39
40acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value_ptr)
41{
42 u64 accumulated_value = 0;
43 acpi_status status = AE_OK;
44
45 /* Convert each ASCII byte in the input string */
46
47 while (*string) {
48 /*
49 * Character must be ASCII 0-7, otherwise:
50 * 1) Runtime: terminate with no error, per the ACPI spec
51 * 2) Compiler: return an error
52 */
53 if (!(ACPI_IS_OCTAL_DIGIT(*string))) {
54#ifdef ACPI_ASL_COMPILER
55 status = AE_BAD_OCTAL_CONSTANT;
56#endif
57 break;
58 }
59
60 /* Convert and insert this octal digit into the accumulator */
61
62 status = acpi_ut_insert_digit(accumulated_value: &accumulated_value, base: 8, ascii_digit: *string);
63 if (ACPI_FAILURE(status)) {
64 status = AE_OCTAL_OVERFLOW;
65 break;
66 }
67
68 string++;
69 }
70
71 /* Always return the value that has been accumulated */
72
73 *return_value_ptr = accumulated_value;
74 return (status);
75}
76
77/*******************************************************************************
78 *
79 * FUNCTION: acpi_ut_convert_decimal_string
80 *
81 * PARAMETERS: string - Null terminated input string
82 * return_value_ptr - Where the converted value is returned
83 *
84 * RETURN: Status and 64-bit converted integer
85 *
86 * DESCRIPTION: Performs a base 10 conversion of the input string to an
87 * integer value, either 32 or 64 bits.
88 *
89 * NOTE: Maximum 64-bit unsigned decimal value is 18446744073709551615
90 * Maximum 32-bit unsigned decimal value is 4294967295
91 *
92 ******************************************************************************/
93
94acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr)
95{
96 u64 accumulated_value = 0;
97 acpi_status status = AE_OK;
98
99 /* Convert each ASCII byte in the input string */
100
101 while (*string) {
102 /*
103 * Character must be ASCII 0-9, otherwise:
104 * 1) Runtime: terminate with no error, per the ACPI spec
105 * 2) Compiler: return an error
106 */
107 if (!isdigit(c: (int)*string)) {
108#ifdef ACPI_ASL_COMPILER
109 status = AE_BAD_DECIMAL_CONSTANT;
110#endif
111 break;
112 }
113
114 /* Convert and insert this decimal digit into the accumulator */
115
116 status = acpi_ut_insert_digit(accumulated_value: &accumulated_value, base: 10, ascii_digit: *string);
117 if (ACPI_FAILURE(status)) {
118 status = AE_DECIMAL_OVERFLOW;
119 break;
120 }
121
122 string++;
123 }
124
125 /* Always return the value that has been accumulated */
126
127 *return_value_ptr = accumulated_value;
128 return (status);
129}
130
131/*******************************************************************************
132 *
133 * FUNCTION: acpi_ut_convert_hex_string
134 *
135 * PARAMETERS: string - Null terminated input string
136 * return_value_ptr - Where the converted value is returned
137 *
138 * RETURN: Status and 64-bit converted integer
139 *
140 * DESCRIPTION: Performs a base 16 conversion of the input string to an
141 * integer value, either 32 or 64 bits.
142 *
143 * NOTE: Maximum 64-bit unsigned hex value is 0xFFFFFFFFFFFFFFFF
144 * Maximum 32-bit unsigned hex value is 0xFFFFFFFF
145 *
146 ******************************************************************************/
147
148acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr)
149{
150 u64 accumulated_value = 0;
151 acpi_status status = AE_OK;
152
153 /* Convert each ASCII byte in the input string */
154
155 while (*string) {
156 /*
157 * Character must be ASCII A-F, a-f, or 0-9, otherwise:
158 * 1) Runtime: terminate with no error, per the ACPI spec
159 * 2) Compiler: return an error
160 */
161 if (!isxdigit((int)*string)) {
162#ifdef ACPI_ASL_COMPILER
163 status = AE_BAD_HEX_CONSTANT;
164#endif
165 break;
166 }
167
168 /* Convert and insert this hex digit into the accumulator */
169
170 status = acpi_ut_insert_digit(accumulated_value: &accumulated_value, base: 16, ascii_digit: *string);
171 if (ACPI_FAILURE(status)) {
172 status = AE_HEX_OVERFLOW;
173 break;
174 }
175
176 string++;
177 }
178
179 /* Always return the value that has been accumulated */
180
181 *return_value_ptr = accumulated_value;
182 return (status);
183}
184
185/*******************************************************************************
186 *
187 * FUNCTION: acpi_ut_remove_leading_zeros
188 *
189 * PARAMETERS: string - Pointer to input ASCII string
190 *
191 * RETURN: Next character after any leading zeros. This character may be
192 * used by the caller to detect end-of-string.
193 *
194 * DESCRIPTION: Remove any leading zeros in the input string. Return the
195 * next character after the final ASCII zero to enable the caller
196 * to check for the end of the string (NULL terminator).
197 *
198 ******************************************************************************/
199
200char acpi_ut_remove_leading_zeros(char **string)
201{
202
203 while (**string == ACPI_ASCII_ZERO) {
204 *string += 1;
205 }
206
207 return (**string);
208}
209
210/*******************************************************************************
211 *
212 * FUNCTION: acpi_ut_remove_whitespace
213 *
214 * PARAMETERS: string - Pointer to input ASCII string
215 *
216 * RETURN: Next character after any whitespace. This character may be
217 * used by the caller to detect end-of-string.
218 *
219 * DESCRIPTION: Remove any leading whitespace in the input string. Return the
220 * next character after the final ASCII zero to enable the caller
221 * to check for the end of the string (NULL terminator).
222 *
223 ******************************************************************************/
224
225char acpi_ut_remove_whitespace(char **string)
226{
227
228 while (isspace((u8)**string)) {
229 *string += 1;
230 }
231
232 return (**string);
233}
234
235/*******************************************************************************
236 *
237 * FUNCTION: acpi_ut_detect_hex_prefix
238 *
239 * PARAMETERS: string - Pointer to input ASCII string
240 *
241 * RETURN: TRUE if a "0x" prefix was found at the start of the string
242 *
243 * DESCRIPTION: Detect and remove a hex "0x" prefix
244 *
245 ******************************************************************************/
246
247u8 acpi_ut_detect_hex_prefix(char **string)
248{
249 char *initial_position = *string;
250
251 acpi_ut_remove_hex_prefix(string);
252 if (*string != initial_position) {
253 return (TRUE); /* String is past leading 0x */
254 }
255
256 return (FALSE); /* Not a hex string */
257}
258
259/*******************************************************************************
260 *
261 * FUNCTION: acpi_ut_remove_hex_prefix
262 *
263 * PARAMETERS: string - Pointer to input ASCII string
264 *
265 * RETURN: none
266 *
267 * DESCRIPTION: Remove a hex "0x" prefix
268 *
269 ******************************************************************************/
270
271void acpi_ut_remove_hex_prefix(char **string)
272{
273 if ((**string == ACPI_ASCII_ZERO) &&
274 (tolower((int)*(*string + 1)) == 'x')) {
275 *string += 2; /* Go past the leading 0x */
276 }
277}
278
279/*******************************************************************************
280 *
281 * FUNCTION: acpi_ut_detect_octal_prefix
282 *
283 * PARAMETERS: string - Pointer to input ASCII string
284 *
285 * RETURN: True if an octal "0" prefix was found at the start of the
286 * string
287 *
288 * DESCRIPTION: Detect and remove an octal prefix (zero)
289 *
290 ******************************************************************************/
291
292u8 acpi_ut_detect_octal_prefix(char **string)
293{
294
295 if (**string == ACPI_ASCII_ZERO) {
296 *string += 1; /* Go past the leading 0 */
297 return (TRUE);
298 }
299
300 return (FALSE); /* Not an octal string */
301}
302
303/*******************************************************************************
304 *
305 * FUNCTION: acpi_ut_insert_digit
306 *
307 * PARAMETERS: accumulated_value - Current value of the integer value
308 * accumulator. The new value is
309 * returned here.
310 * base - Radix, either 8/10/16
311 * ascii_digit - ASCII single digit to be inserted
312 *
313 * RETURN: Status and result of the convert/insert operation. The only
314 * possible returned exception code is numeric overflow of
315 * either the multiply or add conversion operations.
316 *
317 * DESCRIPTION: Generic conversion and insertion function for all bases:
318 *
319 * 1) Multiply the current accumulated/converted value by the
320 * base in order to make room for the new character.
321 *
322 * 2) Convert the new character to binary and add it to the
323 * current accumulated value.
324 *
325 * Note: The only possible exception indicates an integer
326 * overflow (AE_NUMERIC_OVERFLOW)
327 *
328 ******************************************************************************/
329
330static acpi_status
331acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit)
332{
333 acpi_status status;
334 u64 product;
335
336 /* Make room in the accumulated value for the incoming digit */
337
338 status = acpi_ut_strtoul_multiply64(multiplicand: *accumulated_value, base, out_product: &product);
339 if (ACPI_FAILURE(status)) {
340 return (status);
341 }
342
343 /* Add in the new digit, and store the sum to the accumulated value */
344
345 status =
346 acpi_ut_strtoul_add64(addend1: product,
347 digit: acpi_ut_ascii_char_to_hex(hex_char: ascii_digit),
348 out_sum: accumulated_value);
349
350 return (status);
351}
352
353/*******************************************************************************
354 *
355 * FUNCTION: acpi_ut_strtoul_multiply64
356 *
357 * PARAMETERS: multiplicand - Current accumulated converted integer
358 * base - Base/Radix
359 * out_product - Where the product is returned
360 *
361 * RETURN: Status and 64-bit product
362 *
363 * DESCRIPTION: Multiply two 64-bit values, with checking for 64-bit overflow as
364 * well as 32-bit overflow if necessary (if the current global
365 * integer width is 32).
366 *
367 ******************************************************************************/
368
369static acpi_status
370acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product)
371{
372 u64 product;
373 u64 quotient;
374
375 /* Exit if either operand is zero */
376
377 *out_product = 0;
378 if (!multiplicand || !base) {
379 return (AE_OK);
380 }
381
382 /*
383 * Check for 64-bit overflow before the actual multiplication.
384 *
385 * Notes: 64-bit division is often not supported on 32-bit platforms
386 * (it requires a library function), Therefore ACPICA has a local
387 * 64-bit divide function. Also, Multiplier is currently only used
388 * as the radix (8/10/16), to the 64/32 divide will always work.
389 */
390 acpi_ut_short_divide(ACPI_UINT64_MAX, divisor: base, out_quotient: &quotient, NULL);
391 if (multiplicand > quotient) {
392 return (AE_NUMERIC_OVERFLOW);
393 }
394
395 product = multiplicand * base;
396
397 /* Check for 32-bit overflow if necessary */
398
399 if ((acpi_gbl_integer_bit_width == 32) && (product > ACPI_UINT32_MAX)) {
400 return (AE_NUMERIC_OVERFLOW);
401 }
402
403 *out_product = product;
404 return (AE_OK);
405}
406
407/*******************************************************************************
408 *
409 * FUNCTION: acpi_ut_strtoul_add64
410 *
411 * PARAMETERS: addend1 - Current accumulated converted integer
412 * digit - New hex value/char
413 * out_sum - Where sum is returned (Accumulator)
414 *
415 * RETURN: Status and 64-bit sum
416 *
417 * DESCRIPTION: Add two 64-bit values, with checking for 64-bit overflow as
418 * well as 32-bit overflow if necessary (if the current global
419 * integer width is 32).
420 *
421 ******************************************************************************/
422
423static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum)
424{
425 u64 sum;
426
427 /* Check for 64-bit overflow before the actual addition */
428
429 if ((addend1 > 0) && (digit > (ACPI_UINT64_MAX - addend1))) {
430 return (AE_NUMERIC_OVERFLOW);
431 }
432
433 sum = addend1 + digit;
434
435 /* Check for 32-bit overflow if necessary */
436
437 if ((acpi_gbl_integer_bit_width == 32) && (sum > ACPI_UINT32_MAX)) {
438 return (AE_NUMERIC_OVERFLOW);
439 }
440
441 *out_sum = sum;
442 return (AE_OK);
443}
444