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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 02:57:58 +0000 |
commit | be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97 (patch) | |
tree | 9754ff1ca740f6346cf8483ec915d4054bc5da2d /web/server/h2o/libh2o/deps/mruby/src/crc.c | |
parent | Initial commit. (diff) | |
download | netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.tar.xz netdata-be1c7e50e1e8809ea56f2c9d472eccd8ffd73a97.zip |
Adding upstream version 1.44.3.upstream/1.44.3upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'web/server/h2o/libh2o/deps/mruby/src/crc.c')
-rw-r--r-- | web/server/h2o/libh2o/deps/mruby/src/crc.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/web/server/h2o/libh2o/deps/mruby/src/crc.c b/web/server/h2o/libh2o/deps/mruby/src/crc.c new file mode 100644 index 00000000..290b2ca0 --- /dev/null +++ b/web/server/h2o/libh2o/deps/mruby/src/crc.c @@ -0,0 +1,39 @@ +/* +** crc.c - calculate CRC +** +** See Copyright Notice in mruby.h +*/ + +#include <limits.h> +#include <stdint.h> +#include <stddef.h> + +/* Calculate CRC (CRC-16-CCITT) +** +** 0000_0000_0000_0000_0000_0000_0000_0000 +** ^|------- CRC -------|- work --| +** carry +*/ +#define CRC_16_CCITT 0x11021ul /* x^16+x^12+x^5+1 */ +#define CRC_XOR_PATTERN (CRC_16_CCITT << 8) +#define CRC_CARRY_BIT (0x01000000) + +uint16_t +calc_crc_16_ccitt(const uint8_t *src, size_t nbytes, uint16_t crc) +{ + size_t ibyte; + uint32_t ibit; + uint32_t crcwk = crc << 8; + + for (ibyte = 0; ibyte < nbytes; ibyte++) { + crcwk |= *src++; + for (ibit = 0; ibit < CHAR_BIT; ibit++) { + crcwk <<= 1; + if (crcwk & CRC_CARRY_BIT) { + crcwk ^= CRC_XOR_PATTERN; + } + } + } + return (uint16_t)(crcwk >> 8); +} + |