| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | // clang-format off | ||
| 2 | #include "lib_crc.h" | ||
| 3 | |||
| 4 | |||
| 5 | |||
| 6 | /*******************************************************************\ | ||
| 7 | * * | ||
| 8 | * Library : lib_crc * | ||
| 9 | * File : lib_crc.c * | ||
| 10 | * Author : Lammert Bies 1999-2008 * | ||
| 11 | * E-mail : info@lammertbies.nl * | ||
| 12 | * Language : ANSI C * | ||
| 13 | * * | ||
| 14 | * * | ||
| 15 | * Description * | ||
| 16 | * =========== * | ||
| 17 | * * | ||
| 18 | * The file lib_crc.c contains the private and public func- * | ||
| 19 | * tions used for the calculation of CRC-16, CRC-CCITT and * | ||
| 20 | * CRC-32 cyclic redundancy values. * | ||
| 21 | * * | ||
| 22 | * * | ||
| 23 | * Dependencies * | ||
| 24 | * ============ * | ||
| 25 | * * | ||
| 26 | * lib_crc.h CRC definitions and prototypes * | ||
| 27 | * * | ||
| 28 | * * | ||
| 29 | * Modification history * | ||
| 30 | * ==================== * | ||
| 31 | * * | ||
| 32 | * Date Version Comment * | ||
| 33 | * * | ||
| 34 | * 2008-04-20 1.16 Added CRC-CCITT calculation for Kermit * | ||
| 35 | * * | ||
| 36 | * 2007-04-01 1.15 Added CRC16 calculation for Modbus * | ||
| 37 | * * | ||
| 38 | * 2007-03-28 1.14 Added CRC16 routine for Sick devices * | ||
| 39 | * * | ||
| 40 | * 2005-12-17 1.13 Added CRC-CCITT with initial 0x1D0F * | ||
| 41 | * * | ||
| 42 | * 2005-05-14 1.12 Added CRC-CCITT with start value 0 * | ||
| 43 | * * | ||
| 44 | * 2005-02-05 1.11 Fixed bug in CRC-DNP routine * | ||
| 45 | * * | ||
| 46 | * 2005-02-04 1.10 Added CRC-DNP routines * | ||
| 47 | * * | ||
| 48 | * 1999-02-21 1.01 Added FALSE and TRUE mnemonics * | ||
| 49 | * * | ||
| 50 | * 1999-01-22 1.00 Initial source * | ||
| 51 | * * | ||
| 52 | \*******************************************************************/ | ||
| 53 | |||
| 54 | |||
| 55 | |||
| 56 | /*******************************************************************\ | ||
| 57 | * * | ||
| 58 | * #define P_xxxx * | ||
| 59 | * * | ||
| 60 | * The CRC's are computed using polynomials. The coefficients * | ||
| 61 | * for the algorithms are defined by the following constants. * | ||
| 62 | * * | ||
| 63 | \*******************************************************************/ | ||
| 64 | |||
| 65 | #define P_16 (0xA001) | ||
| 66 | #define P_32 (0xEDB88320L) | ||
| 67 | #define P_CCITT (0x1021) | ||
| 68 | #define P_DNP (0xA6BC) | ||
| 69 | #define P_KERMIT (0x8408) | ||
| 70 | #define P_SICK (0x8005) | ||
| 71 | |||
| 72 | |||
| 73 | |||
| 74 | /*******************************************************************\ | ||
| 75 | * * | ||
| 76 | * static int crc_tab...init * | ||
| 77 | * static unsigned ... crc_tab...[] * | ||
| 78 | * * | ||
| 79 | * The algorithms use tables with precalculated values. This * | ||
| 80 | * speeds up the calculation dramatically. The first time the * | ||
| 81 | * CRC function is called, the table for that specific calcu- * | ||
| 82 | * lation is set up. The ...init variables are used to deter- * | ||
| 83 | * mine if the initialization has taken place. The calculated * | ||
| 84 | * values are stored in the crc_tab... arrays. * | ||
| 85 | * * | ||
| 86 | * The variables are declared static. This makes them invisi- * | ||
| 87 | * ble for other modules of the program. * | ||
| 88 | * * | ||
| 89 | \*******************************************************************/ | ||
| 90 | |||
| 91 | static int crc_tab16_init = CRC_FALSE; | ||
| 92 | // F PRIME CHANGE (see header) | ||
| 93 | #if 0 | ||
| 94 | static int crc_tab32_init = CRC_FALSE; | ||
| 95 | #endif | ||
| 96 | static int crc_tabccitt_init = CRC_FALSE; | ||
| 97 | static int crc_tabdnp_init = CRC_FALSE; | ||
| 98 | static int crc_tabkermit_init = CRC_FALSE; | ||
| 99 | |||
| 100 | static unsigned short crc_tab16[256]; | ||
| 101 | // F PRIME CHANGE (see header) | ||
| 102 | #if 0 | ||
| 103 | static unsigned long crc_tab32[256]; | ||
| 104 | #endif | ||
| 105 | static unsigned short crc_tabccitt[256]; | ||
| 106 | static unsigned short crc_tabdnp[256]; | ||
| 107 | static unsigned short crc_tabkermit[256]; | ||
| 108 | |||
| 109 | |||
| 110 | |||
| 111 | /*******************************************************************\ | ||
| 112 | * * | ||
| 113 | * static void init_crc...tab(); * | ||
| 114 | * * | ||
| 115 | * Three local functions are used to initialize the tables * | ||
| 116 | * with values for the algorithm. * | ||
| 117 | * * | ||
| 118 | \*******************************************************************/ | ||
| 119 | |||
| 120 | static void init_crc16_tab( void ); | ||
| 121 | // F PRIME CHANGE (see header) | ||
| 122 | #if 0 | ||
| 123 | static void init_crc32_tab( void ); | ||
| 124 | #endif | ||
| 125 | static void init_crcccitt_tab( void ); | ||
| 126 | static void init_crcdnp_tab( void ); | ||
| 127 | static void init_crckermit_tab( void ); | ||
| 128 | |||
| 129 | |||
| 130 | |||
| 131 | /*******************************************************************\ | ||
| 132 | * * | ||
| 133 | * unsigned short update_crc_ccitt( unsigned long crc, char c ); * | ||
| 134 | * * | ||
| 135 | * The function update_crc_ccitt calculates a new CRC-CCITT * | ||
| 136 | * value based on the previous value of the CRC and the next * | ||
| 137 | * byte of the data to be checked. * | ||
| 138 | * * | ||
| 139 | \*******************************************************************/ | ||
| 140 | |||
| 141 | 95151 | unsigned short update_crc_ccitt( unsigned short crc, char c ) { | |
| 142 | |||
| 143 | unsigned short tmp, short_c; | ||
| 144 | |||
| 145 | 95151 | short_c = 0x00ff & (unsigned short) c; | |
| 146 | |||
| 147 |
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95151 | if ( ! crc_tabccitt_init ) init_crcccitt_tab(); |
| 148 | |||
| 149 | 95151 | tmp = (crc >> 8) ^ short_c; | |
| 150 |
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95151 | crc = (unsigned short)((crc << 8) ^ crc_tabccitt[tmp]); |
| 151 | |||
| 152 | 95151 | return crc; | |
| 153 | |||
| 154 | } /* update_crc_ccitt */ | ||
| 155 | |||
| 156 | |||
| 157 | |||
| 158 | /*******************************************************************\ | ||
| 159 | * * | ||
| 160 | * unsigned short update_crc_sick( * | ||
| 161 | * unsigned long crc, char c, char prev_byte ); * | ||
| 162 | * * | ||
| 163 | * The function update_crc_sick calculates a new CRC-SICK * | ||
| 164 | * value based on the previous value of the CRC and the next * | ||
| 165 | * byte of the data to be checked. * | ||
| 166 | * * | ||
| 167 | \*******************************************************************/ | ||
| 168 | |||
| 169 | ✗ | unsigned short update_crc_sick( unsigned short crc, char c, char prev_byte ) { | |
| 170 | |||
| 171 | unsigned short short_c, short_p; | ||
| 172 | |||
| 173 | ✗ | short_c = 0x00ff & (unsigned short) c; | |
| 174 | ✗ | short_p = (unsigned short)(( 0x00ff & (unsigned short) prev_byte ) << 8); | |
| 175 | |||
| 176 | ✗ | if ( crc & 0x8000 ) crc = (unsigned short)(( crc << 1 ) ^ P_SICK); | |
| 177 | ✗ | else crc = (unsigned short)(crc << 1); | |
| 178 | |||
| 179 | ✗ | crc &= 0xffff; | |
| 180 | ✗ | crc ^= ( short_c | short_p ); | |
| 181 | |||
| 182 | ✗ | return crc; | |
| 183 | |||
| 184 | } /* update_crc_sick */ | ||
| 185 | |||
| 186 | |||
| 187 | |||
| 188 | /*******************************************************************\ | ||
| 189 | * * | ||
| 190 | * unsigned short update_crc_16( unsigned short crc, char c ); * | ||
| 191 | * * | ||
| 192 | * The function update_crc_16 calculates a new CRC-16 value * | ||
| 193 | * based on the previous value of the CRC and the next byte * | ||
| 194 | * of the data to be checked. * | ||
| 195 | * * | ||
| 196 | \*******************************************************************/ | ||
| 197 | |||
| 198 | ✗ | unsigned short update_crc_16( unsigned short crc, char c ) { | |
| 199 | |||
| 200 | unsigned short tmp, short_c; | ||
| 201 | |||
| 202 | ✗ | short_c = 0x00ff & (unsigned short) c; | |
| 203 | |||
| 204 | ✗ | if ( ! crc_tab16_init ) init_crc16_tab(); | |
| 205 | |||
| 206 | ✗ | tmp = crc ^ short_c; | |
| 207 | // Note: when masking by 0xff, range is limited to unsigned char | ||
| 208 | // which fits within unsigned int. | ||
| 209 | ✗ | crc = (crc >> 8) ^ crc_tab16[ (unsigned int)(tmp & 0xff) ]; | |
| 210 | |||
| 211 | ✗ | return crc; | |
| 212 | |||
| 213 | } /* update_crc_16 */ | ||
| 214 | |||
| 215 | |||
| 216 | |||
| 217 | /*******************************************************************\ | ||
| 218 | * * | ||
| 219 | * unsigned short update_crc_kermit( unsigned short crc, char c ); * | ||
| 220 | * * | ||
| 221 | * The function update_crc_kermit calculates a new CRC value * | ||
| 222 | * based on the previous value of the CRC and the next byte * | ||
| 223 | * of the data to be checked. * | ||
| 224 | * * | ||
| 225 | \*******************************************************************/ | ||
| 226 | |||
| 227 | ✗ | unsigned short update_crc_kermit( unsigned short crc, char c ) { | |
| 228 | |||
| 229 | unsigned short tmp, short_c; | ||
| 230 | |||
| 231 | ✗ | short_c = 0x00ff & (unsigned short) c; | |
| 232 | |||
| 233 | ✗ | if ( ! crc_tabkermit_init ) init_crckermit_tab(); | |
| 234 | |||
| 235 | ✗ | tmp = crc ^ short_c; | |
| 236 | ✗ | crc = (crc >> 8) ^ crc_tabkermit[ tmp & 0xff ]; | |
| 237 | |||
| 238 | ✗ | return crc; | |
| 239 | |||
| 240 | } /* update_crc_kermit */ | ||
| 241 | |||
| 242 | |||
| 243 | |||
| 244 | /*******************************************************************\ | ||
| 245 | * * | ||
| 246 | * unsigned short update_crc_dnp( unsigned short crc, char c ); * | ||
| 247 | * * | ||
| 248 | * The function update_crc_dnp calculates a new CRC-DNP value * | ||
| 249 | * based on the previous value of the CRC and the next byte * | ||
| 250 | * of the data to be checked. * | ||
| 251 | * * | ||
| 252 | \*******************************************************************/ | ||
| 253 | |||
| 254 | ✗ | unsigned short update_crc_dnp( unsigned short crc, char c ) { | |
| 255 | |||
| 256 | unsigned short tmp, short_c; | ||
| 257 | |||
| 258 | ✗ | short_c = 0x00ff & (unsigned short) c; | |
| 259 | |||
| 260 | ✗ | if ( ! crc_tabdnp_init ) init_crcdnp_tab(); | |
| 261 | |||
| 262 | ✗ | tmp = crc ^ short_c; | |
| 263 | ✗ | crc = (crc >> 8) ^ crc_tabdnp[ tmp & 0xff ]; | |
| 264 | |||
| 265 | ✗ | return crc; | |
| 266 | |||
| 267 | } /* update_crc_dnp */ | ||
| 268 | |||
| 269 | |||
| 270 | |||
| 271 | /*******************************************************************\ | ||
| 272 | * * | ||
| 273 | * unsigned long update_crc_32( unsigned long crc, char c ); * | ||
| 274 | * * | ||
| 275 | * The function update_crc_32 calculates a new CRC-32 value * | ||
| 276 | * based on the previous value of the CRC and the next byte * | ||
| 277 | * of the data to be checked. * | ||
| 278 | * * | ||
| 279 | \*******************************************************************/ | ||
| 280 | |||
| 281 | // F PRIME CHANGE (see header) | ||
| 282 | #if 0 | ||
| 283 | unsigned long update_crc_32( unsigned long crc, char c ) { | ||
| 284 | |||
| 285 | unsigned long tmp, long_c; | ||
| 286 | |||
| 287 | long_c = 0x000000ffL & (unsigned long) c; | ||
| 288 | |||
| 289 | if ( ! crc_tab32_init ) init_crc32_tab(); | ||
| 290 | |||
| 291 | tmp = crc ^ long_c; | ||
| 292 | crc = (crc >> 8) ^ crc_tab32[ tmp & 0xff ]; | ||
| 293 | |||
| 294 | return crc; | ||
| 295 | |||
| 296 | } /* update_crc_32 */ | ||
| 297 | #endif | ||
| 298 | |||
| 299 | |||
| 300 | |||
| 301 | /*******************************************************************\ | ||
| 302 | * * | ||
| 303 | * static void init_crc16_tab( void ); * | ||
| 304 | * * | ||
| 305 | * The function init_crc16_tab() is used to fill the array * | ||
| 306 | * for calculation of the CRC-16 with values. * | ||
| 307 | * * | ||
| 308 | \*******************************************************************/ | ||
| 309 | |||
| 310 | ✗ | static void init_crc16_tab( void ) { | |
| 311 | |||
| 312 | int i, j; | ||
| 313 | unsigned short crc, c; | ||
| 314 | |||
| 315 | ✗ | for (i=0; i<256; i++) { | |
| 316 | |||
| 317 | ✗ | crc = 0; | |
| 318 | ✗ | c = (unsigned short) i; | |
| 319 | |||
| 320 | ✗ | for (j=0; j<8; j++) { | |
| 321 | |||
| 322 | ✗ | if ( (crc ^ c) & 0x0001 ) crc = ( crc >> 1 ) ^ P_16; | |
| 323 | ✗ | else crc = crc >> 1; | |
| 324 | |||
| 325 | ✗ | c = c >> 1; | |
| 326 | } | ||
| 327 | |||
| 328 | ✗ | crc_tab16[i] = crc; | |
| 329 | } | ||
| 330 | |||
| 331 | ✗ | crc_tab16_init = CRC_TRUE; | |
| 332 | |||
| 333 | ✗ | } /* init_crc16_tab */ | |
| 334 | |||
| 335 | |||
| 336 | |||
| 337 | /*******************************************************************\ | ||
| 338 | * * | ||
| 339 | * static void init_crckermit_tab( void ); * | ||
| 340 | * * | ||
| 341 | * The function init_crckermit_tab() is used to fill the array * | ||
| 342 | * for calculation of the CRC Kermit with values. * | ||
| 343 | * * | ||
| 344 | \*******************************************************************/ | ||
| 345 | |||
| 346 | ✗ | static void init_crckermit_tab( void ) { | |
| 347 | |||
| 348 | int i, j; | ||
| 349 | unsigned short crc, c; | ||
| 350 | |||
| 351 | ✗ | for (i=0; i<256; i++) { | |
| 352 | |||
| 353 | ✗ | crc = 0; | |
| 354 | ✗ | c = (unsigned short) i; | |
| 355 | |||
| 356 | ✗ | for (j=0; j<8; j++) { | |
| 357 | |||
| 358 | ✗ | if ( (crc ^ c) & 0x0001 ) crc = ( crc >> 1 ) ^ P_KERMIT; | |
| 359 | ✗ | else crc = crc >> 1; | |
| 360 | |||
| 361 | ✗ | c = c >> 1; | |
| 362 | } | ||
| 363 | |||
| 364 | ✗ | crc_tabkermit[i] = crc; | |
| 365 | } | ||
| 366 | |||
| 367 | ✗ | crc_tabkermit_init = CRC_TRUE; | |
| 368 | |||
| 369 | ✗ | } /* init_crckermit_tab */ | |
| 370 | |||
| 371 | |||
| 372 | |||
| 373 | /*******************************************************************\ | ||
| 374 | * * | ||
| 375 | * static void init_crcdnp_tab( void ); * | ||
| 376 | * * | ||
| 377 | * The function init_crcdnp_tab() is used to fill the array * | ||
| 378 | * for calculation of the CRC-DNP with values. * | ||
| 379 | * * | ||
| 380 | \*******************************************************************/ | ||
| 381 | |||
| 382 | ✗ | static void init_crcdnp_tab( void ) { | |
| 383 | |||
| 384 | int i, j; | ||
| 385 | unsigned short crc, c; | ||
| 386 | |||
| 387 | ✗ | for (i=0; i<256; i++) { | |
| 388 | |||
| 389 | ✗ | crc = 0; | |
| 390 | ✗ | c = (unsigned short) i; | |
| 391 | |||
| 392 | ✗ | for (j=0; j<8; j++) { | |
| 393 | |||
| 394 | ✗ | if ( (crc ^ c) & 0x0001 ) crc = ( crc >> 1 ) ^ P_DNP; | |
| 395 | ✗ | else crc = crc >> 1; | |
| 396 | |||
| 397 | ✗ | c = c >> 1; | |
| 398 | } | ||
| 399 | |||
| 400 | ✗ | crc_tabdnp[i] = crc; | |
| 401 | } | ||
| 402 | |||
| 403 | ✗ | crc_tabdnp_init = CRC_TRUE; | |
| 404 | |||
| 405 | ✗ | } /* init_crcdnp_tab */ | |
| 406 | |||
| 407 | |||
| 408 | |||
| 409 | /*******************************************************************\ | ||
| 410 | * * | ||
| 411 | * static void init_crc32_tab( void ); * | ||
| 412 | * * | ||
| 413 | * The function init_crc32_tab() is used to fill the array * | ||
| 414 | * for calculation of the CRC-32 with values. * | ||
| 415 | * * | ||
| 416 | \*******************************************************************/ | ||
| 417 | |||
| 418 | // F PRIME CHANGE (see header) | ||
| 419 | #if 0 | ||
| 420 | static void init_crc32_tab( void ) { | ||
| 421 | |||
| 422 | int i, j; | ||
| 423 | unsigned long crc; | ||
| 424 | |||
| 425 | for (i=0; i<256; i++) { | ||
| 426 | |||
| 427 | crc = (unsigned long) i; | ||
| 428 | |||
| 429 | for (j=0; j<8; j++) { | ||
| 430 | |||
| 431 | if ( crc & 0x00000001L ) crc = ( crc >> 1 ) ^ P_32; | ||
| 432 | else crc = crc >> 1; | ||
| 433 | } | ||
| 434 | |||
| 435 | crc_tab32[i] = crc; | ||
| 436 | } | ||
| 437 | |||
| 438 | crc_tab32_init = CRC_TRUE; | ||
| 439 | |||
| 440 | } /* init_crc32_tab */ | ||
| 441 | #endif | ||
| 442 | |||
| 443 | |||
| 444 | |||
| 445 | /*******************************************************************\ | ||
| 446 | * * | ||
| 447 | * static void init_crcccitt_tab( void ); * | ||
| 448 | * * | ||
| 449 | * The function init_crcccitt_tab() is used to fill the array * | ||
| 450 | * for calculation of the CRC-CCITT with values. * | ||
| 451 | * * | ||
| 452 | \*******************************************************************/ | ||
| 453 | |||
| 454 | 5 | static void init_crcccitt_tab( void ) { | |
| 455 | |||
| 456 | int i, j; | ||
| 457 | unsigned short crc, c; | ||
| 458 | |||
| 459 |
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1285 | for (i=0; i<256; i++) { |
| 460 | |||
| 461 | 1280 | crc = 0; | |
| 462 |
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1280 | c = (unsigned short)(((unsigned short) i) << 8); |
| 463 | |||
| 464 |
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11520 | for (j=0; j<8; j++) { |
| 465 | |||
| 466 |
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10240 | if ( (crc ^ c) & 0x8000 ) crc = (unsigned short)(( crc << 1 ) ^ P_CCITT); |
| 467 |
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5120 | else crc = (unsigned short)(crc << 1); |
| 468 | |||
| 469 |
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10240 | c = (unsigned short)(c << 1); |
| 470 | } | ||
| 471 | |||
| 472 | 1280 | crc_tabccitt[i] = crc; | |
| 473 | } | ||
| 474 | |||
| 475 | 5 | crc_tabccitt_init = CRC_TRUE; | |
| 476 | |||
| 477 | 5 | } /* init_crcccitt_tab */ | |
| 478 |