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, 8, *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((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, 10, *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, 16, *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(*accumulated_value, base, &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(product,
347				  acpi_ut_ascii_char_to_hex(ascii_digit),
348				  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, base, &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