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minix/lib/libc/cdb/cdbr.c
Lionel Sambuc 84d9c625bf Synchronize on NetBSD-CVS (2013/12/1 12:00:00 UTC) 
- Fix for possible unset uid/gid in toproto
 - Fix for default mtree style
 - Update libelf
 - Importing libexecinfo
 - Resynchronize GCC, mpc, gmp, mpfr
 - build.sh: Replace params with show-params.
     This has been done as the make target has been renamed in the same
     way, while a new target named params has been added. This new
     target generates a file containing all the parameters, instead of
     printing it on the console.
 - Update test48 with new etc/services (Fix by Ben Gras <ben@minix3.org)
     get getservbyport() out of the inner loop

Change-Id: Ie6ad5226fa2621ff9f0dee8782ea48f9443d2091
2014-07-28 17:05:06 +02:00

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/* $NetBSD: cdbr.c,v 1.4 2012/09/27 00:37:43 joerg Exp $ */
/*-
* Copyright (c) 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Joerg Sonnenberger.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* 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 HOLDERS 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.
*/
#if HAVE_NBTOOL_CONFIG_H
#include "nbtool_config.h"
#endif
#include <sys/cdefs.h>
__RCSID("$NetBSD: cdbr.c,v 1.4 2012/09/27 00:37:43 joerg Exp $");
#include "namespace.h"
#if !HAVE_NBTOOL_CONFIG_H
#include <sys/bitops.h>
#endif
#if !HAVE_NBTOOL_CONFIG_H || HAVE_SYS_ENDIAN_H
#include <sys/endian.h>
#endif
#include <sys/mman.h>
#include <sys/stat.h>
#include <cdbr.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#if defined(__minix) && !defined(MAP_SHARED)
#define MAP_SHARED MAP_PRIVATE /* LSC: We lose some memory, but it's OK as this is RO. */
#endif /* defined(__minix) && !defined(MAP_SHARED) */
#ifdef __weak_alias
__weak_alias(cdbr_close,_cdbr_close)
__weak_alias(cdbr_find,_cdbr_find)
__weak_alias(cdbr_get,_cdbr_get)
__weak_alias(cdbr_open,_cdbr_open)
#endif
#if HAVE_NBTOOL_CONFIG_H
#define fast_divide32_prepare(d,m,s1,s2) (void)0
#define fast_remainder32(v,d,m,s1,s2) (v%d)
#endif
struct cdbr {
uint8_t *mmap_base;
size_t mmap_size;
uint8_t *hash_base;
uint8_t *offset_base;
uint8_t *data_base;
uint32_t data_size;
uint32_t entries;
uint32_t entries_index;
uint32_t seed;
uint8_t offset_size;
uint8_t index_size;
uint32_t entries_m;
uint32_t entries_index_m;
uint8_t entries_s1, entries_s2;
uint8_t entries_index_s1, entries_index_s2;
};
/* ARGSUSED */
struct cdbr *
cdbr_open(const char *path, int flags)
{
uint8_t buf[40];
int fd;
struct cdbr *cdbr;
struct stat sb;
if ((fd = open(path, O_RDONLY)) == -1)
return NULL;
errno = EINVAL;
if (fstat(fd, &sb) == -1 ||
read(fd, buf, sizeof(buf)) != sizeof(buf) ||
memcmp(buf, "NBCDB\n\0\001", 8) ||
(cdbr = malloc(sizeof(*cdbr))) == NULL) {
close(fd);
return NULL;
}
cdbr->data_size = le32dec(buf + 24);
cdbr->entries = le32dec(buf + 28);
cdbr->entries_index = le32dec(buf + 32);
cdbr->seed = le32dec(buf + 36);
if (cdbr->data_size < 0x100)
cdbr->offset_size = 1;
else if (cdbr->data_size < 0x10000)
cdbr->offset_size = 2;
else
cdbr->offset_size = 4;
if (cdbr->entries_index < 0x100)
cdbr->index_size = 1;
else if (cdbr->entries_index < 0x10000)
cdbr->index_size = 2;
else
cdbr->index_size = 4;
cdbr->mmap_size = (size_t)sb.st_size;
cdbr->mmap_base = mmap(NULL, cdbr->mmap_size, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0);
close(fd);
if (cdbr->mmap_base == MAP_FAILED) {
free(cdbr);
return NULL;
}
cdbr->hash_base = cdbr->mmap_base + 40;
cdbr->offset_base = cdbr->hash_base + cdbr->entries_index * cdbr->index_size;
if (cdbr->entries_index * cdbr->index_size % cdbr->offset_size)
cdbr->offset_base += cdbr->offset_size -
cdbr->entries_index * cdbr->index_size % cdbr->offset_size;
cdbr->data_base = cdbr->offset_base + (cdbr->entries + 1) * cdbr->offset_size;
if (cdbr->hash_base < cdbr->mmap_base ||
cdbr->offset_base < cdbr->mmap_base ||
cdbr->data_base < cdbr->mmap_base ||
cdbr->data_base + cdbr->data_size < cdbr->mmap_base ||
cdbr->data_base + cdbr->data_size >
cdbr->mmap_base + cdbr->mmap_size) {
errno = EINVAL;
cdbr_close(cdbr);
return NULL;
}
if (cdbr->entries) {
fast_divide32_prepare(cdbr->entries, &cdbr->entries_m,
&cdbr->entries_s1, &cdbr->entries_s2);
}
if (cdbr->entries_index) {
fast_divide32_prepare(cdbr->entries_index,
&cdbr->entries_index_m,
&cdbr->entries_index_s1, &cdbr->entries_index_s2);
}
return cdbr;
}
static inline uint32_t
get_uintX(const uint8_t *addr, uint32_t idx, int size)
{
addr += idx * size;
if (size == 4)
return /* LINTED */le32toh(*(const uint32_t *)addr);
else if (size == 2)
return /* LINTED */le16toh(*(const uint16_t *)addr);
else
return *addr;
}
uint32_t
cdbr_entries(struct cdbr *cdbr)
{
return cdbr->entries;
}
int
cdbr_get(struct cdbr *cdbr, uint32_t idx, const void **data, size_t *data_len)
{
uint32_t start, end;
if (idx >= cdbr->entries) {
errno = EINVAL;
return -1;
}
start = get_uintX(cdbr->offset_base, idx, cdbr->offset_size);
end = get_uintX(cdbr->offset_base, idx + 1, cdbr->offset_size);
if (start > end) {
errno = EIO;
return -1;
}
if (end > cdbr->data_size) {
errno = EIO;
return -1;
}
*data = cdbr->data_base + start;
*data_len = end - start;
return 0;
}
int
cdbr_find(struct cdbr *cdbr, const void *key, size_t key_len,
const void **data, size_t *data_len)
{
uint32_t hashes[3], idx;
if (cdbr->entries_index == 0) {
errno = EINVAL;
return -1;
}
mi_vector_hash(key, key_len, cdbr->seed, hashes);
hashes[0] = fast_remainder32(hashes[0], cdbr->entries_index,
cdbr->entries_index_m, cdbr->entries_index_s1,
cdbr->entries_index_s2);
hashes[1] = fast_remainder32(hashes[1], cdbr->entries_index,
cdbr->entries_index_m, cdbr->entries_index_s1,
cdbr->entries_index_s2);
hashes[2] = fast_remainder32(hashes[2], cdbr->entries_index,
cdbr->entries_index_m, cdbr->entries_index_s1,
cdbr->entries_index_s2);
idx = get_uintX(cdbr->hash_base, hashes[0], cdbr->index_size);
idx += get_uintX(cdbr->hash_base, hashes[1], cdbr->index_size);
idx += get_uintX(cdbr->hash_base, hashes[2], cdbr->index_size);
return cdbr_get(cdbr, fast_remainder32(idx, cdbr->entries,
cdbr->entries_m, cdbr->entries_s1, cdbr->entries_s2), data,
data_len);
}
void
cdbr_close(struct cdbr *cdbr)
{
munmap(cdbr->mmap_base, cdbr->mmap_size);
free(cdbr);
}
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