1 /******************************************************************************* 2 * 3 * Module Name: utstrsuppt - Support functions for string-to-integer conversion 4 * 5 ******************************************************************************/ 6 7 /* 8 * Copyright (C) 2000 - 2018, 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 47 #define _COMPONENT ACPI_UTILITIES 48 ACPI_MODULE_NAME("utstrsuppt") 49 50 /* Local prototypes */ 51 static acpi_status 52 acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit); 53 54 static acpi_status 55 acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product); 56 57 static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum); 58 59 /******************************************************************************* 60 * 61 * FUNCTION: acpi_ut_convert_octal_string 62 * 63 * PARAMETERS: string - Null terminated input string 64 * return_value_ptr - Where the converted value is returned 65 * 66 * RETURN: Status and 64-bit converted integer 67 * 68 * DESCRIPTION: Performs a base 8 conversion of the input string to an 69 * integer value, either 32 or 64 bits. 70 * 71 * NOTE: Maximum 64-bit unsigned octal value is 01777777777777777777777 72 * Maximum 32-bit unsigned octal value is 037777777777 73 * 74 ******************************************************************************/ 75 76 acpi_status acpi_ut_convert_octal_string(char *string, u64 *return_value_ptr) 77 { 78 u64 accumulated_value = 0; 79 acpi_status status = AE_OK; 80 81 /* Convert each ASCII byte in the input string */ 82 83 while (*string) { 84 85 /* Character must be ASCII 0-7, otherwise terminate with no error */ 86 87 if (!(ACPI_IS_OCTAL_DIGIT(*string))) { 88 break; 89 } 90 91 /* Convert and insert this octal digit into the accumulator */ 92 93 status = acpi_ut_insert_digit(&accumulated_value, 8, *string); 94 if (ACPI_FAILURE(status)) { 95 status = AE_OCTAL_OVERFLOW; 96 break; 97 } 98 99 string++; 100 } 101 102 /* Always return the value that has been accumulated */ 103 104 *return_value_ptr = accumulated_value; 105 return (status); 106 } 107 108 /******************************************************************************* 109 * 110 * FUNCTION: acpi_ut_convert_decimal_string 111 * 112 * PARAMETERS: string - Null terminated input string 113 * return_value_ptr - Where the converted value is returned 114 * 115 * RETURN: Status and 64-bit converted integer 116 * 117 * DESCRIPTION: Performs a base 10 conversion of the input string to an 118 * integer value, either 32 or 64 bits. 119 * 120 * NOTE: Maximum 64-bit unsigned decimal value is 18446744073709551615 121 * Maximum 32-bit unsigned decimal value is 4294967295 122 * 123 ******************************************************************************/ 124 125 acpi_status acpi_ut_convert_decimal_string(char *string, u64 *return_value_ptr) 126 { 127 u64 accumulated_value = 0; 128 acpi_status status = AE_OK; 129 130 /* Convert each ASCII byte in the input string */ 131 132 while (*string) { 133 134 /* Character must be ASCII 0-9, otherwise terminate with no error */ 135 136 if (!isdigit(*string)) { 137 break; 138 } 139 140 /* Convert and insert this decimal digit into the accumulator */ 141 142 status = acpi_ut_insert_digit(&accumulated_value, 10, *string); 143 if (ACPI_FAILURE(status)) { 144 status = AE_DECIMAL_OVERFLOW; 145 break; 146 } 147 148 string++; 149 } 150 151 /* Always return the value that has been accumulated */ 152 153 *return_value_ptr = accumulated_value; 154 return (status); 155 } 156 157 /******************************************************************************* 158 * 159 * FUNCTION: acpi_ut_convert_hex_string 160 * 161 * PARAMETERS: string - Null terminated input string 162 * return_value_ptr - Where the converted value is returned 163 * 164 * RETURN: Status and 64-bit converted integer 165 * 166 * DESCRIPTION: Performs a base 16 conversion of the input string to an 167 * integer value, either 32 or 64 bits. 168 * 169 * NOTE: Maximum 64-bit unsigned hex value is 0xFFFFFFFFFFFFFFFF 170 * Maximum 32-bit unsigned hex value is 0xFFFFFFFF 171 * 172 ******************************************************************************/ 173 174 acpi_status acpi_ut_convert_hex_string(char *string, u64 *return_value_ptr) 175 { 176 u64 accumulated_value = 0; 177 acpi_status status = AE_OK; 178 179 /* Convert each ASCII byte in the input string */ 180 181 while (*string) { 182 183 /* Must be ASCII A-F, a-f, or 0-9, otherwise terminate with no error */ 184 185 if (!isxdigit(*string)) { 186 break; 187 } 188 189 /* Convert and insert this hex digit into the accumulator */ 190 191 status = acpi_ut_insert_digit(&accumulated_value, 16, *string); 192 if (ACPI_FAILURE(status)) { 193 status = AE_HEX_OVERFLOW; 194 break; 195 } 196 197 string++; 198 } 199 200 /* Always return the value that has been accumulated */ 201 202 *return_value_ptr = accumulated_value; 203 return (status); 204 } 205 206 /******************************************************************************* 207 * 208 * FUNCTION: acpi_ut_remove_leading_zeros 209 * 210 * PARAMETERS: string - Pointer to input ASCII string 211 * 212 * RETURN: Next character after any leading zeros. This character may be 213 * used by the caller to detect end-of-string. 214 * 215 * DESCRIPTION: Remove any leading zeros in the input string. Return the 216 * next character after the final ASCII zero to enable the caller 217 * to check for the end of the string (NULL terminator). 218 * 219 ******************************************************************************/ 220 221 char acpi_ut_remove_leading_zeros(char **string) 222 { 223 224 while (**string == ACPI_ASCII_ZERO) { 225 *string += 1; 226 } 227 228 return (**string); 229 } 230 231 /******************************************************************************* 232 * 233 * FUNCTION: acpi_ut_remove_whitespace 234 * 235 * PARAMETERS: string - Pointer to input ASCII string 236 * 237 * RETURN: Next character after any whitespace. This character may be 238 * used by the caller to detect end-of-string. 239 * 240 * DESCRIPTION: Remove any leading whitespace in the input string. Return the 241 * next character after the final ASCII zero to enable the caller 242 * to check for the end of the string (NULL terminator). 243 * 244 ******************************************************************************/ 245 246 char acpi_ut_remove_whitespace(char **string) 247 { 248 249 while (isspace((u8)**string)) { 250 *string += 1; 251 } 252 253 return (**string); 254 } 255 256 /******************************************************************************* 257 * 258 * FUNCTION: acpi_ut_detect_hex_prefix 259 * 260 * PARAMETERS: string - Pointer to input ASCII string 261 * 262 * RETURN: TRUE if a "0x" prefix was found at the start of the string 263 * 264 * DESCRIPTION: Detect and remove a hex "0x" prefix 265 * 266 ******************************************************************************/ 267 268 u8 acpi_ut_detect_hex_prefix(char **string) 269 { 270 271 if ((**string == ACPI_ASCII_ZERO) && 272 (tolower((int)*(*string + 1)) == 'x')) { 273 *string += 2; /* Go past the leading 0x */ 274 return (TRUE); 275 } 276 277 return (FALSE); /* Not a hex string */ 278 } 279 280 /******************************************************************************* 281 * 282 * FUNCTION: acpi_ut_detect_octal_prefix 283 * 284 * PARAMETERS: string - Pointer to input ASCII string 285 * 286 * RETURN: True if an octal "0" prefix was found at the start of the 287 * string 288 * 289 * DESCRIPTION: Detect and remove an octal prefix (zero) 290 * 291 ******************************************************************************/ 292 293 u8 acpi_ut_detect_octal_prefix(char **string) 294 { 295 296 if (**string == ACPI_ASCII_ZERO) { 297 *string += 1; /* Go past the leading 0 */ 298 return (TRUE); 299 } 300 301 return (FALSE); /* Not an octal string */ 302 } 303 304 /******************************************************************************* 305 * 306 * FUNCTION: acpi_ut_insert_digit 307 * 308 * PARAMETERS: accumulated_value - Current value of the integer value 309 * accumulator. The new value is 310 * returned here. 311 * base - Radix, either 8/10/16 312 * ascii_digit - ASCII single digit to be inserted 313 * 314 * RETURN: Status and result of the convert/insert operation. The only 315 * possible returned exception code is numeric overflow of 316 * either the multiply or add conversion operations. 317 * 318 * DESCRIPTION: Generic conversion and insertion function for all bases: 319 * 320 * 1) Multiply the current accumulated/converted value by the 321 * base in order to make room for the new character. 322 * 323 * 2) Convert the new character to binary and add it to the 324 * current accumulated value. 325 * 326 * Note: The only possible exception indicates an integer 327 * overflow (AE_NUMERIC_OVERFLOW) 328 * 329 ******************************************************************************/ 330 331 static acpi_status 332 acpi_ut_insert_digit(u64 *accumulated_value, u32 base, int ascii_digit) 333 { 334 acpi_status status; 335 u64 product; 336 337 /* Make room in the accumulated value for the incoming digit */ 338 339 status = acpi_ut_strtoul_multiply64(*accumulated_value, base, &product); 340 if (ACPI_FAILURE(status)) { 341 return (status); 342 } 343 344 /* Add in the new digit, and store the sum to the accumulated value */ 345 346 status = 347 acpi_ut_strtoul_add64(product, 348 acpi_ut_ascii_char_to_hex(ascii_digit), 349 accumulated_value); 350 351 return (status); 352 } 353 354 /******************************************************************************* 355 * 356 * FUNCTION: acpi_ut_strtoul_multiply64 357 * 358 * PARAMETERS: multiplicand - Current accumulated converted integer 359 * base - Base/Radix 360 * out_product - Where the product is returned 361 * 362 * RETURN: Status and 64-bit product 363 * 364 * DESCRIPTION: Multiply two 64-bit values, with checking for 64-bit overflow as 365 * well as 32-bit overflow if necessary (if the current global 366 * integer width is 32). 367 * 368 ******************************************************************************/ 369 370 static acpi_status 371 acpi_ut_strtoul_multiply64(u64 multiplicand, u32 base, u64 *out_product) 372 { 373 u64 product; 374 u64 quotient; 375 376 /* Exit if either operand is zero */ 377 378 *out_product = 0; 379 if (!multiplicand || !base) { 380 return (AE_OK); 381 } 382 383 /* 384 * Check for 64-bit overflow before the actual multiplication. 385 * 386 * Notes: 64-bit division is often not supported on 32-bit platforms 387 * (it requires a library function), Therefore ACPICA has a local 388 * 64-bit divide function. Also, Multiplier is currently only used 389 * as the radix (8/10/16), to the 64/32 divide will always work. 390 */ 391 acpi_ut_short_divide(ACPI_UINT64_MAX, base, "ient, NULL); 392 if (multiplicand > quotient) { 393 return (AE_NUMERIC_OVERFLOW); 394 } 395 396 product = multiplicand * base; 397 398 /* Check for 32-bit overflow if necessary */ 399 400 if ((acpi_gbl_integer_bit_width == 32) && (product > ACPI_UINT32_MAX)) { 401 return (AE_NUMERIC_OVERFLOW); 402 } 403 404 *out_product = product; 405 return (AE_OK); 406 } 407 408 /******************************************************************************* 409 * 410 * FUNCTION: acpi_ut_strtoul_add64 411 * 412 * PARAMETERS: addend1 - Current accumulated converted integer 413 * digit - New hex value/char 414 * out_sum - Where sum is returned (Accumulator) 415 * 416 * RETURN: Status and 64-bit sum 417 * 418 * DESCRIPTION: Add two 64-bit values, with checking for 64-bit overflow as 419 * well as 32-bit overflow if necessary (if the current global 420 * integer width is 32). 421 * 422 ******************************************************************************/ 423 424 static acpi_status acpi_ut_strtoul_add64(u64 addend1, u32 digit, u64 *out_sum) 425 { 426 u64 sum; 427 428 /* Check for 64-bit overflow before the actual addition */ 429 430 if ((addend1 > 0) && (digit > (ACPI_UINT64_MAX - addend1))) { 431 return (AE_NUMERIC_OVERFLOW); 432 } 433 434 sum = addend1 + digit; 435 436 /* Check for 32-bit overflow if necessary */ 437 438 if ((acpi_gbl_integer_bit_width == 32) && (sum > ACPI_UINT32_MAX)) { 439 return (AE_NUMERIC_OVERFLOW); 440 } 441 442 *out_sum = sum; 443 return (AE_OK); 444 } 445