1 /* Copyright (C) 2008 Board of Trustees, Leland Stanford Jr. University.
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to
5 * deal in the Software without restriction, including without limitation the
6 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
25 crc32_init(struct crc32 *crc, unsigned int polynomial)
29 for (i = 0; i < CRC32_TABLE_SIZE; ++i) {
30 unsigned int reg = i << 24;
32 for (j = 0; j < CRC32_TABLE_BITS; j++) {
33 int topBit = (reg & 0x80000000) != 0;
43 crc32_calculate(const struct crc32 *crc, const void *data_, size_t n_bytes)
45 const uint8_t *data = data_;
46 unsigned int result = 0;
49 for (i = 0; i < n_bytes; i++) {
50 unsigned int top = result >> 24;
52 result = (result << 8) ^ crc->table[top];