diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/Makefile.am | 7 | ||||
| -rw-r--r-- | src/crcXXgen.c.tpl | 120 |
2 files changed, 126 insertions, 1 deletions
diff --git a/src/Makefile.am b/src/Makefile.am index 739095c8..b0ccaddb 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -14,7 +14,8 @@ libosmocore_la_SOURCES = timer.c select.c signal.c msgb.c bits.c \ write_queue.c utils.c socket.c \ logging.c logging_syslog.c rate_ctr.c \ gsmtap_util.c crc16.c panic.c backtrace.c \ - conv.c application.c + conv.c application.c \ + crc8gen.c crc16gen.c crc32gen.c crc64gen.c if ENABLE_PLUGIN libosmocore_la_SOURCES += plugin.c @@ -34,3 +35,7 @@ endif if ENABLE_SERIAL libosmocore_la_SOURCES += serial.c endif + +crc%gen.c: crcXXgen.c.tpl + @echo " SED $< -> $@" + @sed -e's/XX/$*/g' $< > $@ diff --git a/src/crcXXgen.c.tpl b/src/crcXXgen.c.tpl new file mode 100644 index 00000000..5d70753a --- /dev/null +++ b/src/crcXXgen.c.tpl @@ -0,0 +1,120 @@ +/* + * crcXXgen.c + * + * Generic CRC routines (for max XX bits poly) + * + * Copyright (C) 2011 Sylvain Munaut <tnt@246tNt.com> + * + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +/*! \addtogroup crcgen + * @{ + */ + +/*! \file crcXXgen.c + * \file Osmocom generic CRC routines (for max XX bits poly) + */ + +#include <stdint.h> + +#include <osmocom/core/bits.h> +#include <osmocom/core/crcXXgen.h> + + +/*! \brief Compute the CRC value of a given array of hard-bits + * \param[in] code The CRC code description to apply + * \param[in] in Array of hard bits + * \param[in] len Length of the array of hard bits + * \returns The CRC value + */ +uintXX_t +osmo_crcXXgen_compute_bits(const struct osmo_crcXXgen_code *code, + const ubit_t *in, int len) +{ + const uintXX_t poly = code->poly; + uintXX_t crc = code->init; + int i, n = code->bits-1; + + for (i=0; i<len; i++) { + uintXX_t bit = in[i] & 1; + crc ^= (bit << n); + if (crc & (1 << n)) { + crc <<= 1; + crc ^= poly; + } else { + crc <<= 1; + } + crc &= (1ULL << code->bits) - 1; + } + + crc ^= code->remainder; + + return crc; +} + + +/*! \brief Checks the CRC value of a given array of hard-bits + * \param[in] code The CRC code description to apply + * \param[in] in Array of hard bits + * \param[in] len Length of the array of hard bits + * \param[in] crc_bits Array of hard bits with the alleged CRC + * \returns 0 if CRC matches. 1 in case of error. + * + * The crc_bits array must have a length of code->len + */ +int +osmo_crcXXgen_check_bits(const struct osmo_crcXXgen_code *code, + const ubit_t *in, int len, const ubit_t *crc_bits) +{ + uintXX_t crc; + int i; + + crc = osmo_crcXXgen_compute_bits(code, in, len); + + for (i=0; i<code->bits; i++) + if (crc_bits[i] ^ ((crc >> (code->bits-i-1)) & 1)) + return 1; + + return 0; +} + + +/*! \brief Computes and writes the CRC value of a given array of bits + * \param[in] code The CRC code description to apply + * \param[in] in Array of hard bits + * \param[in] len Length of the array of hard bits + * \param[in] crc_bits Array of hard bits to write the computed CRC to + * + * The crc_bits array must have a length of code->len + */ +void +osmo_crcXXgen_set_bits(const struct osmo_crcXXgen_code *code, + const ubit_t *in, int len, ubit_t *crc_bits) +{ + uintXX_t crc; + int i; + + crc = osmo_crcXXgen_compute_bits(code, in, len); + + for (i=0; i<code->bits; i++) + crc_bits[i] = ((crc >> (code->bits-i-1)) & 1); +} + +/*! }@ */ + +/* vim: set syntax=c: */ |