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