| 1 | /* $NetBSD: cdbr.c,v 1.1 2013/12/11 01:24:08 joerg Exp $ */ |
| 2 | /*- |
| 3 | * Copyright (c) 2010 The NetBSD Foundation, Inc. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * This code is derived from software contributed to The NetBSD Foundation |
| 7 | * by Joerg Sonnenberger. |
| 8 | * |
| 9 | * Redistribution and use in source and binary forms, with or without |
| 10 | * modification, are permitted provided that the following conditions |
| 11 | * are met: |
| 12 | * |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * 2. Redistributions in binary form must reproduce the above copyright |
| 16 | * notice, this list of conditions and the following disclaimer in |
| 17 | * the documentation and/or other materials provided with the |
| 18 | * distribution. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 21 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 22 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| 23 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| 24 | * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 25 | * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, |
| 26 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 27 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
| 28 | * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
| 29 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT |
| 30 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #if HAVE_NBTOOL_CONFIG_H |
| 35 | #include "nbtool_config.h" |
| 36 | #endif |
| 37 | |
| 38 | #include <sys/cdefs.h> |
| 39 | __RCSID("$NetBSD: cdbr.c,v 1.1 2013/12/11 01:24:08 joerg Exp $" ); |
| 40 | |
| 41 | #if !defined(_KERNEL) && !defined(_STANDALONE) |
| 42 | #include "namespace.h" |
| 43 | #endif |
| 44 | |
| 45 | #if !HAVE_NBTOOL_CONFIG_H |
| 46 | #include <sys/bitops.h> |
| 47 | #endif |
| 48 | #if !HAVE_NBTOOL_CONFIG_H || HAVE_SYS_ENDIAN_H |
| 49 | #include <sys/endian.h> |
| 50 | #endif |
| 51 | |
| 52 | #if defined(_KERNEL) || defined(_STANDALONE) |
| 53 | #include <sys/cdbr.h> |
| 54 | #include <sys/kmem.h> |
| 55 | #include <sys/systm.h> |
| 56 | #include <lib/libkern/libkern.h> |
| 57 | #define SET_ERRNO(val) |
| 58 | #define malloc(size) kmem_alloc(size, KM_SLEEP) |
| 59 | #define free(ptr) kmem_free(ptr, sizeof(struct cdbr)) |
| 60 | #else |
| 61 | #include <sys/mman.h> |
| 62 | #include <sys/stat.h> |
| 63 | #include <cdbr.h> |
| 64 | #include <errno.h> |
| 65 | #include <fcntl.h> |
| 66 | #include <inttypes.h> |
| 67 | #include <limits.h> |
| 68 | #include <stdlib.h> |
| 69 | #include <string.h> |
| 70 | #include <unistd.h> |
| 71 | #define SET_ERRNO(val) errno = (val) |
| 72 | #endif |
| 73 | |
| 74 | #if !defined(_KERNEL) && !defined(_STANDALONE) |
| 75 | #ifdef __weak_alias |
| 76 | __weak_alias(cdbr_close,_cdbr_close) |
| 77 | __weak_alias(cdbr_find,_cdbr_find) |
| 78 | __weak_alias(cdbr_get,_cdbr_get) |
| 79 | __weak_alias(cdbr_open,_cdbr_open) |
| 80 | __weak_alias(cdbr_open_mem,_cdbr_open_mem) |
| 81 | #endif |
| 82 | #endif |
| 83 | |
| 84 | #if HAVE_NBTOOL_CONFIG_H |
| 85 | #define fast_divide32_prepare(d,m,s1,s2) (void)0 |
| 86 | #define fast_remainder32(v,d,m,s1,s2) (v%d) |
| 87 | #endif |
| 88 | |
| 89 | struct cdbr { |
| 90 | void (*unmap)(void *, void *, size_t); |
| 91 | void *cookie; |
| 92 | uint8_t *mmap_base; |
| 93 | size_t mmap_size; |
| 94 | |
| 95 | uint8_t *hash_base; |
| 96 | uint8_t *offset_base; |
| 97 | uint8_t *data_base; |
| 98 | |
| 99 | uint32_t data_size; |
| 100 | uint32_t entries; |
| 101 | uint32_t entries_index; |
| 102 | uint32_t seed; |
| 103 | |
| 104 | uint8_t offset_size; |
| 105 | uint8_t index_size; |
| 106 | |
| 107 | uint32_t entries_m; |
| 108 | uint32_t entries_index_m; |
| 109 | uint8_t entries_s1, entries_s2; |
| 110 | uint8_t entries_index_s1, entries_index_s2; |
| 111 | }; |
| 112 | |
| 113 | #if !defined(_KERNEL) && !defined(_STANDALONE) |
| 114 | static void |
| 115 | cdbr_unmap(void *cookie __unused, void *base, size_t size) |
| 116 | { |
| 117 | munmap(base, size); |
| 118 | } |
| 119 | |
| 120 | /* ARGSUSED */ |
| 121 | struct cdbr * |
| 122 | cdbr_open(const char *path, int flags) |
| 123 | { |
| 124 | void *base; |
| 125 | size_t size; |
| 126 | int fd; |
| 127 | struct cdbr *cdbr; |
| 128 | struct stat sb; |
| 129 | |
| 130 | if ((fd = open(path, O_RDONLY)) == -1) |
| 131 | return NULL; |
| 132 | if (fstat(fd, &sb) == -1) { |
| 133 | close(fd); |
| 134 | return NULL; |
| 135 | } |
| 136 | |
| 137 | if (sb.st_size >= SSIZE_MAX) { |
| 138 | close(fd); |
| 139 | SET_ERRNO(EINVAL); |
| 140 | return NULL; |
| 141 | } |
| 142 | |
| 143 | |
| 144 | size = (size_t)sb.st_size; |
| 145 | base = mmap(NULL, size, PROT_READ, MAP_FILE|MAP_SHARED, fd, 0); |
| 146 | close(fd); |
| 147 | |
| 148 | if (base == MAP_FAILED) |
| 149 | return NULL; |
| 150 | |
| 151 | cdbr = cdbr_open_mem(base, size, flags, cdbr_unmap, NULL); |
| 152 | if (cdbr == NULL) |
| 153 | munmap(base, size); |
| 154 | return cdbr; |
| 155 | } |
| 156 | #endif |
| 157 | |
| 158 | struct cdbr * |
| 159 | cdbr_open_mem(void *base, size_t size, int flags, |
| 160 | void (*unmap)(void *, void *, size_t), void *cookie) |
| 161 | { |
| 162 | struct cdbr *cdbr; |
| 163 | uint8_t *buf = base; |
| 164 | if (size < 40 || memcmp(buf, "NBCDB\n\0\001" , 8)) { |
| 165 | SET_ERRNO(EINVAL); |
| 166 | return NULL; |
| 167 | } |
| 168 | |
| 169 | cdbr = malloc(sizeof(*cdbr)); |
| 170 | cdbr->unmap = unmap; |
| 171 | cdbr->cookie = cookie; |
| 172 | |
| 173 | cdbr->data_size = le32dec(buf + 24); |
| 174 | cdbr->entries = le32dec(buf + 28); |
| 175 | cdbr->entries_index = le32dec(buf + 32); |
| 176 | cdbr->seed = le32dec(buf + 36); |
| 177 | |
| 178 | if (cdbr->data_size < 0x100) |
| 179 | cdbr->offset_size = 1; |
| 180 | else if (cdbr->data_size < 0x10000) |
| 181 | cdbr->offset_size = 2; |
| 182 | else |
| 183 | cdbr->offset_size = 4; |
| 184 | |
| 185 | if (cdbr->entries_index < 0x100) |
| 186 | cdbr->index_size = 1; |
| 187 | else if (cdbr->entries_index < 0x10000) |
| 188 | cdbr->index_size = 2; |
| 189 | else |
| 190 | cdbr->index_size = 4; |
| 191 | |
| 192 | cdbr->mmap_base = base; |
| 193 | cdbr->mmap_size = size; |
| 194 | |
| 195 | cdbr->hash_base = cdbr->mmap_base + 40; |
| 196 | cdbr->offset_base = cdbr->hash_base + cdbr->entries_index * cdbr->index_size; |
| 197 | if (cdbr->entries_index * cdbr->index_size % cdbr->offset_size) |
| 198 | cdbr->offset_base += cdbr->offset_size - |
| 199 | cdbr->entries_index * cdbr->index_size % cdbr->offset_size; |
| 200 | cdbr->data_base = cdbr->offset_base + (cdbr->entries + 1) * cdbr->offset_size; |
| 201 | |
| 202 | if (cdbr->hash_base < cdbr->mmap_base || |
| 203 | cdbr->offset_base < cdbr->mmap_base || |
| 204 | cdbr->data_base < cdbr->mmap_base || |
| 205 | cdbr->data_base + cdbr->data_size < cdbr->mmap_base || |
| 206 | cdbr->data_base + cdbr->data_size > |
| 207 | cdbr->mmap_base + cdbr->mmap_size) { |
| 208 | SET_ERRNO(EINVAL); |
| 209 | free(cdbr); |
| 210 | return NULL; |
| 211 | } |
| 212 | |
| 213 | if (cdbr->entries) { |
| 214 | fast_divide32_prepare(cdbr->entries, &cdbr->entries_m, |
| 215 | &cdbr->entries_s1, &cdbr->entries_s2); |
| 216 | } |
| 217 | if (cdbr->entries_index) { |
| 218 | fast_divide32_prepare(cdbr->entries_index, |
| 219 | &cdbr->entries_index_m, |
| 220 | &cdbr->entries_index_s1, &cdbr->entries_index_s2); |
| 221 | } |
| 222 | |
| 223 | return cdbr; |
| 224 | } |
| 225 | |
| 226 | static inline uint32_t |
| 227 | get_uintX(const uint8_t *addr, uint32_t idx, int size) |
| 228 | { |
| 229 | addr += idx * size; |
| 230 | |
| 231 | if (size == 4) |
| 232 | return /* LINTED */le32toh(*(const uint32_t *)addr); |
| 233 | else if (size == 2) |
| 234 | return /* LINTED */le16toh(*(const uint16_t *)addr); |
| 235 | else |
| 236 | return *addr; |
| 237 | } |
| 238 | |
| 239 | uint32_t |
| 240 | cdbr_entries(struct cdbr *cdbr) |
| 241 | { |
| 242 | |
| 243 | return cdbr->entries; |
| 244 | } |
| 245 | |
| 246 | int |
| 247 | cdbr_get(struct cdbr *cdbr, uint32_t idx, const void **data, size_t *data_len) |
| 248 | { |
| 249 | uint32_t start, end; |
| 250 | |
| 251 | if (idx >= cdbr->entries) { |
| 252 | SET_ERRNO(EINVAL); |
| 253 | return -1; |
| 254 | } |
| 255 | |
| 256 | start = get_uintX(cdbr->offset_base, idx, cdbr->offset_size); |
| 257 | end = get_uintX(cdbr->offset_base, idx + 1, cdbr->offset_size); |
| 258 | |
| 259 | if (start > end) { |
| 260 | SET_ERRNO(EIO); |
| 261 | return -1; |
| 262 | } |
| 263 | |
| 264 | if (end > cdbr->data_size) { |
| 265 | SET_ERRNO(EIO); |
| 266 | return -1; |
| 267 | } |
| 268 | |
| 269 | *data = cdbr->data_base + start; |
| 270 | *data_len = end - start; |
| 271 | |
| 272 | return 0; |
| 273 | } |
| 274 | |
| 275 | int |
| 276 | cdbr_find(struct cdbr *cdbr, const void *key, size_t key_len, |
| 277 | const void **data, size_t *data_len) |
| 278 | { |
| 279 | uint32_t hashes[3], idx; |
| 280 | |
| 281 | if (cdbr->entries_index == 0) { |
| 282 | SET_ERRNO(EINVAL); |
| 283 | return -1; |
| 284 | } |
| 285 | |
| 286 | mi_vector_hash(key, key_len, cdbr->seed, hashes); |
| 287 | |
| 288 | hashes[0] = fast_remainder32(hashes[0], cdbr->entries_index, |
| 289 | cdbr->entries_index_m, cdbr->entries_index_s1, |
| 290 | cdbr->entries_index_s2); |
| 291 | hashes[1] = fast_remainder32(hashes[1], cdbr->entries_index, |
| 292 | cdbr->entries_index_m, cdbr->entries_index_s1, |
| 293 | cdbr->entries_index_s2); |
| 294 | hashes[2] = fast_remainder32(hashes[2], cdbr->entries_index, |
| 295 | cdbr->entries_index_m, cdbr->entries_index_s1, |
| 296 | cdbr->entries_index_s2); |
| 297 | |
| 298 | idx = get_uintX(cdbr->hash_base, hashes[0], cdbr->index_size); |
| 299 | idx += get_uintX(cdbr->hash_base, hashes[1], cdbr->index_size); |
| 300 | idx += get_uintX(cdbr->hash_base, hashes[2], cdbr->index_size); |
| 301 | |
| 302 | return cdbr_get(cdbr, fast_remainder32(idx, cdbr->entries, |
| 303 | cdbr->entries_m, cdbr->entries_s1, cdbr->entries_s2), data, |
| 304 | data_len); |
| 305 | } |
| 306 | |
| 307 | void |
| 308 | cdbr_close(struct cdbr *cdbr) |
| 309 | { |
| 310 | if (cdbr->unmap) |
| 311 | (*cdbr->unmap)(cdbr->cookie, cdbr->mmap_base, cdbr->mmap_size); |
| 312 | free(cdbr); |
| 313 | } |
| 314 | |