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Made crude port of Tofino dynamic hash to C++
Signed-off-by: Anton Korobeynikov <anton@korobeynikov.info>
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backends/tofino/bf-utils/src/dynamic_hash/bfn_hash_algorithm.cpp
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| #include "backends/tofino/bf-utils/include/dynamic_hash/bfn_hash_algorithm.h" | ||
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| #include <errno.h> | ||
| #include <limits.h> | ||
| #include <stdio.h> | ||
| #include <stdlib.h> | ||
| #include <string.h> | ||
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| /** | ||
| * These values are based on the crc calculations provided at this url: | ||
| * http://reveng.sourceforge.net/crc-catalogue/all.htm | ||
| * | ||
| * It is understood that the top bit of the the polynomial is known to be == 1, | ||
| * but any polynomial over 64 bits would not fit. Thus the strings do not have | ||
| * this value | ||
| */ | ||
| static crc_alg_info_t standard_crc_algs[CRC_INVALID] = { | ||
| {"crc_8", 0x07, false, 0, 0}, | ||
| {"crc_8_darc", 0x39, true, 0, 0}, | ||
| {"crc_8_i_code", 0x1d, false, 0xfd, 0}, | ||
| {"crc_8_itu", 0x07, false, 0x55, 0x55}, | ||
| {"crc_8_maxim", 0x31, true, 0, 0}, | ||
| {"crc_8_rohc", 0x07, true, 0xff, 0}, | ||
| {"crc_8_wcdma", 0x9b, true, 0, 0}, | ||
| {"crc_16", 0x8005, true, 0, 0}, | ||
| {"crc_16_bypass", 0x8005, false, 0, 0}, | ||
| {"crc_16_dds_110", 0x8005, false, 0x800d, 0}, | ||
| // This one doesn't appear on the website, but kept to not break | ||
| // regressions | ||
| {"crc_16_dect", 0x0589, false, 1, 1}, | ||
| {"crc_16_dect_r", 0x0589, false, 0, 1}, | ||
| {"crc_16_dect_x", 0x0589, false, 0, 0}, | ||
| {"crc_16_dnp", 0x3d65, true, 0, 0xffff}, | ||
| {"crc_16_en_13757", 0x3d65, false, 0, 0xffff}, | ||
| {"crc_16_genibus", 0x1021, false, 0xffff, 0xffff}, | ||
| {"crc_16_maxim", 0x8005, true, 0, 0xffff}, | ||
| {"crc_16_mcrf4xx", 0x1021, true, 0xffff, 0}, | ||
| {"crc_16_riello", 0x1021, true, 0xb2aa, 0}, | ||
| {"crc_16_t10_dif", 0x8bb7, false, 0, 0}, | ||
| {"crc_16_teledisk", 0xa097, false, 0, 0}, | ||
| {"crc_16_usb", 0x8005, true, 0xffff, 0xffff}, | ||
| {"x_25", 0x1021, true, 0xffff, 0xffff}, | ||
| {"xmodem", 0x1021, false, 0, 0}, | ||
| {"modbus", 0x8005, true, 0xffff, 0}, | ||
| {"kermit", 0x1021, true, 0, 0}, | ||
| {"crc_ccitt_false", 0x1021, false, 0xffff, 0}, | ||
| {"crc_aug_ccitt", 0x1021, false, 0x1d0f, 0}, | ||
| {"crc_32", 0x04c11db7, true, 0xffffffff, 0xffffffff}, | ||
| {"crc_32_bzip2", 0x04c11db7, false, 0xffffffff, 0xffffffff}, | ||
| {"crc_32c", 0x1edc6f41, true, 0xffffffff, 0xffffffff}, | ||
| {"crc_32d", 0xa833982b, true, 0xffffffff, 0xffffffff}, | ||
| {"crc_32_mpeg", 0x04c11db7, false, 0xffffffff, 0}, | ||
| {"posix", 0x04c11db7, false, 0, 0xffffffff}, | ||
| {"crc_32q", 0x814141ab, false, 0, 0}, | ||
| {"jamcrc", 0x04c11db7, true, 0xffffffff, 0}, | ||
| {"xfer", 0x000000af, false, 0, 0}, | ||
| {"crc_64", 0x42f0e1eba9ea3693, false, 0, 0}, | ||
| {"crc_64_go_iso", 0x000000000000001b, true, 0xffffffffffffffff, 0xffffffffffffffff}, | ||
| {"crc_64_we", 0x42f0e1eba9ea3693, false, 0xffffffffffffffff, 0xffffffffffffffff}, | ||
| // This one doesn't appear on the website, but kept to not break | ||
| // regressions | ||
| {"crc_64_jones", 0xad93d23594c935a9, true, 0xffffffffffffffff, 0}}; | ||
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| int determine_msb(uint64_t value) { | ||
| int rv = -1; | ||
| #if defined(__GNUC__) || defined(__clang__) | ||
| if (value) rv = 63 - __builtin_clzl(value); | ||
| #else | ||
| for (int i = 63; i >= 0; i--) { | ||
| if (((1ULL << i) & value) != 0ULL) return i; | ||
| } | ||
| #endif | ||
| return rv; | ||
| } | ||
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| #define BUILD_CRC_ERRORS | ||
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| static const char *bfn_crc_errors[BUILD_CRC_ERRORS] = { | ||
| "Polynomial is not odd", | ||
| "Init value is larger than the polynomial", | ||
| "Final xor value is larger than the polynomial", | ||
| }; | ||
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| bool verify_algorithm(bfn_hash_algorithm_t *alg, const char **error_message) { | ||
| if ((alg->poly & 1) == 0) { | ||
| if (error_message) *error_message = bfn_crc_errors[0]; | ||
| return false; | ||
| } | ||
| if (alg->init && determine_msb(alg->init) + 1 > alg->hash_bit_width) { | ||
| if (error_message) *error_message = bfn_crc_errors[1]; | ||
| return false; | ||
| } | ||
| if (alg->final_xor && determine_msb(alg->final_xor) + 1 > alg->hash_bit_width) { | ||
| if (error_message) *error_message = bfn_crc_errors[2]; | ||
| return false; | ||
| } | ||
| return true; | ||
| } | ||
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| /** | ||
| * Builds the algorithm from the standard crc algorithm position | ||
| */ | ||
| void build_standard_crc_algorithm(bfn_hash_algorithm_t *alg, bfn_crc_alg_t crc_alg) { | ||
| if (crc_alg >= CRC_8 && crc_alg <= CRC_8_WCDMA) | ||
| alg->hash_bit_width = 8; | ||
| else if (crc_alg >= CRC_16 && crc_alg <= CRC_AUG_CCITT) | ||
| alg->hash_bit_width = 16; | ||
| else if (crc_alg >= CRC_32 && crc_alg <= XFER) | ||
| alg->hash_bit_width = 32; | ||
| else if (crc_alg >= CRC_64 && crc_alg <= CRC_64_JONES) | ||
| alg->hash_bit_width = 64; | ||
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| crc_alg_info_t crc_alg_info = standard_crc_algs[(int)crc_alg]; | ||
| alg->poly = crc_alg_info.poly; | ||
| alg->reverse = crc_alg_info.reverse; | ||
| alg->init = crc_alg_info.init; | ||
| alg->final_xor = crc_alg_info.final_xor; | ||
| alg->crc_type = crc_alg_str_to_type(crc_alg_info.crc_name); | ||
| } | ||
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| void initialize_algorithm(bfn_hash_algorithm_t *alg, bfn_hash_alg_type_t hash_alg, bool msb, | ||
| bool extend, bfn_crc_alg_t crc_alg) { | ||
| alg->hash_alg = hash_alg; | ||
| alg->msb = msb; | ||
| alg->extend = extend; | ||
| if (crc_alg != CRC_INVALID) build_standard_crc_algorithm(alg, crc_alg); | ||
| } | ||
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| static uint64_t invert_poly(uint64_t poly, int bit_width) { | ||
| uint64_t ret = 0, i = 0; | ||
| while (poly > 0) { | ||
| ret |= ((poly & 0x1) << (bit_width - i - 1)); | ||
| i++; | ||
| poly >>= 1; | ||
| } | ||
| return ret; | ||
| } | ||
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| static void construct_stream(bfn_hash_algorithm_t *alg, uint64_t val, uint8_t *stream) { | ||
| uint8_t width = (alg->hash_bit_width + 7) / 8; | ||
| for (uint8_t i = 0; i < width; i++) { | ||
| stream[width - i - 1] = (val >> (i * 8)); | ||
| } | ||
| return; | ||
| } | ||
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| static void shift_right(uint8_t *stream, uint8_t bit_width) { | ||
| uint8_t width = (bit_width + 7) / 8; | ||
| for (int i = width - 1; i >= 0; i--) { | ||
| stream[i] >>= 1; | ||
| if (i > 0) { | ||
| stream[i] |= (stream[i - 1] & 0x1) << 7; | ||
| } | ||
| } | ||
| } | ||
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| static void shift_left(uint8_t *stream, uint8_t bit_width) { | ||
| uint8_t width = (bit_width + 7) / 8; | ||
| for (uint8_t i = 0; i < width; i++) { | ||
| stream[i] <<= 1; | ||
| if (i < width - 1) { | ||
| stream[i] |= (stream[i + 1] >> 7) & 0x1; | ||
| } | ||
| } | ||
| } | ||
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| void initialize_crc_matrix(bfn_hash_algorithm_t *alg) { | ||
| if (alg->hash_alg != CRC_DYN) { | ||
| return; | ||
| } | ||
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| uint32_t width = (alg->hash_bit_width + 7) / 8, i = 0; | ||
| std::vector<uint8_t> poly(width, 0), rem(width, 0); | ||
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| uint64_t poly_val = alg->poly; | ||
| if (alg->reverse) { | ||
| poly_val = invert_poly(poly_val, alg->hash_bit_width); | ||
| } | ||
| construct_stream(alg, poly_val, poly.data()); | ||
| uint32_t byte = 0, bit = 0; | ||
| bool need_xor = false; | ||
| if (alg->reverse) { | ||
| for (byte = 0; byte < 256; byte++) { | ||
| memset(rem.data(), 0, width * sizeof(uint8_t)); | ||
| rem[width - 1] = byte; | ||
| for (bit = 0; bit < 8; bit++) { | ||
| need_xor = rem[width - 1] & 0x1; | ||
| shift_right(rem.data(), alg->hash_bit_width); | ||
| if (need_xor) { | ||
| for (i = 0; i < width; i++) { | ||
| rem[i] ^= poly[i]; | ||
| } | ||
| } | ||
| } | ||
| memcpy(alg->crc_matrix[byte], rem.data(), width); | ||
| } | ||
| } else { | ||
| uint8_t offset = alg->hash_bit_width % 8; | ||
| uint8_t top_bit = offset == 0 ? 0x80 : 1 << ((offset - 1) % 8); | ||
| uint8_t top_mask = top_bit == 0x80 ? 0xff : (top_bit << 1) - 1; | ||
| for (byte = 0; byte < 256; byte++) { | ||
| memset(rem.data(), 0, width * sizeof(uint8_t)); | ||
| if (offset == 0) { | ||
| rem[0] = byte; | ||
| } else { | ||
| rem[0] = byte >> (8 - offset); | ||
| rem[1] = byte << offset; | ||
| } | ||
| for (bit = 0; bit < 8; bit++) { | ||
| need_xor = rem[0] & top_bit; | ||
| shift_left(rem.data(), alg->hash_bit_width); | ||
| if (need_xor) { | ||
| for (i = 0; i < width; i++) { | ||
| rem[i] ^= poly[i]; | ||
| } | ||
| } | ||
| rem[0] &= top_mask; | ||
| } | ||
| memcpy(alg->crc_matrix[byte], rem.data(), width); | ||
| } | ||
| } | ||
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| return; | ||
| } | ||
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| static uint8_t get_byte(uint8_t *stream, uint8_t index, uint8_t offset) { | ||
| if (offset == 0) { | ||
| return stream[index]; | ||
| } | ||
| return ((stream[index] << (8 - offset)) | (stream[index + 1] >> offset)); | ||
| } | ||
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| void calculate_crc(bfn_hash_algorithm_t *alg, uint32_t hash_output_bits, uint8_t *stream, | ||
| uint32_t stream_len, uint8_t *crc) { | ||
| uint32_t i = 0; | ||
| uint8_t idx = 0; | ||
| uint8_t width = (alg->hash_bit_width + 7) / 8; | ||
| uint8_t hash_output_bytes = (hash_output_bits + 7) / 8; | ||
| std::vector<uint8_t> final_xor(width, 0); | ||
| memset(crc, 0, hash_output_bytes * sizeof(uint8_t)); | ||
| construct_stream(alg, alg->init, crc); | ||
| construct_stream(alg, alg->final_xor, final_xor.data()); | ||
| uint8_t *crc_str = crc + hash_output_bytes - width; | ||
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| for (i = 0; i < stream_len; i++) { | ||
| if (alg->reverse) { | ||
| idx = crc_str[width - 1] ^ stream[i]; | ||
| for (int j = width - 1; j > 0; j--) { | ||
| crc_str[j] = crc_str[j - 1] ^ alg->crc_matrix[idx][j]; | ||
| } | ||
| crc_str[0] = alg->crc_matrix[idx][0]; | ||
| } else { | ||
| uint8_t offset = alg->hash_bit_width % 8; | ||
| uint8_t mask = offset == 0 ? 0xff : (1 << offset) - 1; | ||
| idx = get_byte(crc_str, 0, offset) ^ stream[i]; | ||
| for (uint8_t j = 0; j < width - 1; j++) { | ||
| crc_str[j] = (crc_str[j + 1] ^ alg->crc_matrix[idx][j]) & mask; | ||
| mask = 0xff; | ||
| } | ||
| crc_str[width - 1] = alg->crc_matrix[idx][width - 1]; | ||
| } | ||
| } | ||
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| for (i = 0; i < width; i++) { | ||
| crc_str[i] ^= final_xor[i]; | ||
| } | ||
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| if (alg->extend) { | ||
| for (i = 0; i < (uint32_t)(hash_output_bytes - width); i++) { | ||
| *(crc_str - i - 1) = crc_str[width - i % width - 1]; | ||
| } | ||
| if (hash_output_bits % 8) { | ||
| crc[0] &= (1 << (hash_output_bits % 8)) - 1; | ||
| } | ||
| } | ||
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| return; | ||
| } |
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