numam-spdk/lib/iscsi/crc32c.c
Ben Walker d29384bf97 iscsi: Add an iscsi library.
Change-Id: I28f3f4723a66f845eb478a6873d7aedb8f5409b8
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
2016-08-03 14:43:40 -07:00

137 lines
3.6 KiB
C

/*-
* BSD LICENSE
*
* Copyright (C) 2008-2012 Daisuke Aoyama <aoyama@peach.ne.jp>.
* Copyright (c) Intel Corporation.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <inttypes.h>
#include <stdint.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <sys/uio.h>
#include "iscsi/iscsi.h"
#include "iscsi/crc32c.h"
#ifndef USE_ISAL
#define SPDK_USE_CRC32C_TABLE
#endif
#ifdef SPDK_USE_CRC32C_TABLE
static uint32_t spdk_crc32c_table[256];
__attribute__((constructor)) static void
spdk_init_crc32c(void)
{
int i, j;
uint32_t val;
for (i = 0; i < 256; i++) {
val = i;
for (j = 0; j < 8; j++) {
if (val & 1) {
val = (val >> 1) ^ SPDK_CRC32C_POLYNOMIAL_REFLECT;
} else {
val = (val >> 1);
}
}
spdk_crc32c_table[i] = val;
}
}
#endif /* SPDK_USE_CRC32C_TABLE */
#ifndef USE_ISAL
uint32_t
spdk_update_crc32c(const uint8_t *buf, size_t len, uint32_t crc)
{
size_t s;
#ifndef SPDK_USE_CRC32C_TABLE
int i;
uint32_t val;
#endif /* SPDK_USE_CRC32C_TABLE */
for (s = 0; s < len; s++) {
#ifdef SPDK_USE_CRC32C_TABLE
crc = (crc >> 8) ^ spdk_crc32c_table[(crc ^ buf[s]) & 0xff];
#else
val = buf[s];
for (i = 0; i < 8; i++) {
if ((crc ^ val) & 1) {
crc = (crc >> 1) ^ SPDK_CRC32C_POLYNOMIAL_REFLECT;
} else {
crc = (crc >> 1);
}
val = val >> 1;
}
#endif /* SPDK_USE_CRC32C_TABLE */
}
return crc;
}
#endif /* USE_ISAL */
uint32_t
spdk_fixup_crc32c(size_t total, uint32_t crc)
{
uint8_t padding[ISCSI_ALIGNMENT];
size_t pad_length;
size_t rest;
if (total == 0)
return crc;
rest = total % ISCSI_ALIGNMENT;
if (rest != 0) {
pad_length = ISCSI_ALIGNMENT;
pad_length -= rest;
if (pad_length > 0 && pad_length < sizeof padding) {
memset(padding, 0, sizeof padding);
crc = spdk_update_crc32c(padding, pad_length, crc);
}
}
return crc;
}
uint32_t
spdk_crc32c(const uint8_t *buf, size_t len)
{
uint32_t crc32c;
crc32c = SPDK_CRC32C_INITIAL;
crc32c = spdk_update_crc32c(buf, len, crc32c);
if ((len % ISCSI_ALIGNMENT) != 0) {
crc32c = spdk_fixup_crc32c(len, crc32c);
}
crc32c = crc32c ^ SPDK_CRC32C_XOR;
return crc32c;
}