| File: | src/lib/libc/stdlib/icdb.c |
| Warning: | line 229, column 2 Value stored to 'idxlen' is never read |
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| 1 | /* $OpenBSD: icdb.c,v 1.8 2016/09/04 16:56:02 nicm Exp $ */ |
| 2 | /* |
| 3 | * Copyright (c) 2015 Ted Unangst <tedu@openbsd.org> |
| 4 | * |
| 5 | * Permission to use, copy, modify, and distribute this software for any |
| 6 | * purpose with or without fee is hereby granted, provided that the above |
| 7 | * copyright notice and this permission notice appear in all copies. |
| 8 | * |
| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
| 15 | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 16 | */ |
| 17 | |
| 18 | #include <errno(*__errno()).h> |
| 19 | #include <fcntl.h> |
| 20 | #include <icdb.h> |
| 21 | #include <stddef.h> |
| 22 | #include <stdint.h> |
| 23 | #include <stdio.h> |
| 24 | #include <stdlib.h> |
| 25 | #include <string.h> |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | #include <sys/mman.h> |
| 29 | #include <sys/stat.h> |
| 30 | |
| 31 | #include <siphash.h> |
| 32 | |
| 33 | /* |
| 34 | * Creating a new icdb: icdb_new |
| 35 | * Opening existing icdb: icdb_open |
| 36 | * |
| 37 | * Adding new entries: icdb_add |
| 38 | * Adding entries does not update the disk or indices. |
| 39 | * |
| 40 | * Save to disk: icdb_save |
| 41 | * Update indices: icdb_rehash |
| 42 | * icdb_save will call rehash. |
| 43 | * |
| 44 | * Change an existing entry: icdb_update |
| 45 | * Changing entries does write to disk. |
| 46 | * |
| 47 | * Find an entry: icdb_lookup |
| 48 | * Looking up an entry is only defined when the indices are synced. |
| 49 | * |
| 50 | * Close and free resources: icdb_close |
| 51 | */ |
| 52 | |
| 53 | /* |
| 54 | * There are two major modes of operation. |
| 55 | * |
| 56 | * Existing databases use the mmap codepath. The entire database is mapped |
| 57 | * into the address space for quick access. Individual entries may be updated, |
| 58 | * but no new entries added. |
| 59 | * |
| 60 | * New databases use malloc backed memory instead. The database may be saved |
| 61 | * with icdb_save. It should be saved to a new file to avoid corrupting any |
| 62 | * open databases in other processes. |
| 63 | */ |
| 64 | |
| 65 | /* |
| 66 | * An icdb has the following format: |
| 67 | * struct icbinfo header |
| 68 | * indexes [ uint32_t * indexsize * nkeys ] |
| 69 | * entries [ entrysize * nentries ] |
| 70 | * |
| 71 | * To find an entry in the file, the user specifies which key to use. |
| 72 | * The key is hashed and looked up in the index. The index contains the |
| 73 | * position of the entry in the entries array. -1 identifies not found. |
| 74 | * Chaining is done by rehashing the hash. All keys are fixed size byte arrays. |
| 75 | */ |
| 76 | |
| 77 | /* |
| 78 | * Header info for icdb. This struct is stored on disk. |
| 79 | */ |
| 80 | struct icdbinfo { |
| 81 | uint32_t magic; /* magic */ |
| 82 | uint32_t version; /* user specified version */ |
| 83 | uint32_t nentries; /* number of entries stored */ |
| 84 | uint32_t entrysize; /* size of each entry */ |
| 85 | uint32_t indexsize; /* number of entries in hash index */ |
| 86 | uint32_t nkeys; /* number of keys defined */ |
| 87 | uint32_t keysize[8]; /* size of each key */ |
| 88 | uint32_t keyoffset[8]; /* offset of each key in entry */ |
| 89 | SIPHASH_KEY siphashkey; /* random hash key */ |
| 90 | }; |
| 91 | |
| 92 | /* |
| 93 | * In memory representation with auxiliary data. |
| 94 | * idxdata and entries will be written to disk after info. |
| 95 | */ |
| 96 | struct icdb { |
| 97 | struct icdbinfo *info; |
| 98 | void *idxdata[8]; |
| 99 | void *entries; |
| 100 | size_t maplen; |
| 101 | uint32_t allocated; |
| 102 | int fd; |
| 103 | }; |
| 104 | |
| 105 | static const uint32_t magic = 0x1ca9d0b7; |
| 106 | |
| 107 | static uint32_t |
| 108 | roundup(uint32_t num) |
| 109 | { |
| 110 | uint32_t r = 2; |
| 111 | |
| 112 | while (r < num * 3 / 2) |
| 113 | r *= 2; |
| 114 | return r; |
| 115 | } |
| 116 | |
| 117 | struct icdb * |
| 118 | icdb_new(uint32_t version, uint32_t nentries, uint32_t entrysize, |
| 119 | uint32_t nkeys, const uint32_t *keysizes, const uint32_t *keyoffsets) |
| 120 | { |
| 121 | struct icdb *db; |
| 122 | struct icdbinfo *info; |
| 123 | int i; |
| 124 | |
| 125 | if (entrysize == 0 || entrysize > 1048576 || nkeys > 8) { |
| 126 | errno(*__errno()) = EINVAL22; |
| 127 | return NULL((void*)0); |
| 128 | } |
| 129 | |
| 130 | if (!(db = calloc(1, sizeof(*db)))) |
| 131 | return NULL((void*)0); |
| 132 | if (!(info = calloc(1, sizeof(*info)))) { |
| 133 | free(db); |
| 134 | return NULL((void*)0); |
| 135 | } |
| 136 | db->info = info; |
| 137 | db->fd = -1; |
| 138 | info->magic = magic; |
| 139 | info->version = version; |
| 140 | if (nentries) |
| 141 | if ((db->entries = reallocarray(NULL((void*)0), nentries, entrysize))) |
| 142 | db->allocated = nentries; |
| 143 | info->entrysize = entrysize; |
| 144 | info->nkeys = nkeys; |
| 145 | for (i = 0; i < nkeys; i++) { |
| 146 | info->keysize[i] = keysizes[i]; |
| 147 | info->keyoffset[i] = keyoffsets[i]; |
| 148 | } |
| 149 | return db; |
| 150 | } |
| 151 | DEF_WEAK(icdb_new)__asm__(".weak " "icdb_new" " ; " "icdb_new" " = " "_libc_icdb_new" ); |
| 152 | |
| 153 | struct icdb * |
| 154 | icdb_open(const char *name, int flags, uint32_t version) |
| 155 | { |
| 156 | struct icdb *db = NULL((void*)0); |
| 157 | struct icdbinfo *info; |
| 158 | struct stat sb; |
| 159 | uint8_t *ptr = MAP_FAILED((void *)-1); |
| 160 | uint32_t baseoff, indexsize, idxmask, idxlen; |
| 161 | int fd, i, saved_errno; |
| 162 | |
| 163 | if ((fd = open(name, flags | O_CLOEXEC0x10000)) == -1) |
| 164 | return NULL((void*)0); |
| 165 | if (fstat(fd, &sb) != 0) |
| 166 | goto fail; |
| 167 | if (sb.st_size < sizeof(struct icdbinfo)) |
| 168 | goto fail; |
| 169 | ptr = mmap(NULL((void*)0), sb.st_size, PROT_READ0x01 | |
| 170 | ((flags & O_RDWR0x0002) ? PROT_WRITE0x02 : 0), MAP_SHARED0x0001, fd, 0); |
| 171 | if (ptr == MAP_FAILED((void *)-1)) |
| 172 | goto fail; |
| 173 | info = (struct icdbinfo *)ptr; |
| 174 | if (info->magic != magic || info->version != version) { |
| 175 | errno(*__errno()) = ENOENT2; |
| 176 | goto fail; |
| 177 | } |
| 178 | |
| 179 | if (!(db = calloc(1, sizeof(*db)))) |
| 180 | goto fail; |
| 181 | db->info = info; |
| 182 | |
| 183 | indexsize = info->indexsize; |
| 184 | idxmask = indexsize - 1; |
| 185 | idxlen = indexsize * sizeof(uint32_t); |
| 186 | baseoff = sizeof(*info) + idxlen * info->nkeys; |
| 187 | |
| 188 | for (i = 0; i < info->nkeys; i++) |
| 189 | db->idxdata[i] = ptr + sizeof(*info) + i * idxlen; |
| 190 | db->entries = ptr + baseoff; |
| 191 | db->maplen = sb.st_size; |
| 192 | db->fd = fd; |
| 193 | return db; |
| 194 | |
| 195 | fail: |
| 196 | saved_errno = errno(*__errno()); |
| 197 | if (ptr != MAP_FAILED((void *)-1)) |
| 198 | munmap(ptr, sb.st_size); |
| 199 | if (fd != -1) |
| 200 | close(fd); |
| 201 | free(db); |
| 202 | errno(*__errno()) = saved_errno; |
| 203 | return NULL((void*)0); |
| 204 | } |
| 205 | DEF_WEAK(icdb_open)__asm__(".weak " "icdb_open" " ; " "icdb_open" " = " "_libc_icdb_open" ); |
| 206 | |
| 207 | int |
| 208 | icdb_get(struct icdb *db, void *entry, uint32_t idx) |
| 209 | { |
| 210 | uint32_t entrysize = db->info->entrysize; |
| 211 | |
| 212 | memcpy(entry, (uint8_t *)db->entries + idx * entrysize, entrysize); |
| 213 | return 0; |
| 214 | } |
| 215 | DEF_WEAK(icdb_get)__asm__(".weak " "icdb_get" " ; " "icdb_get" " = " "_libc_icdb_get" ); |
| 216 | |
| 217 | int |
| 218 | icdb_lookup(struct icdb *db, int keynum, const void *key, void *entry, |
| 219 | uint32_t *idxp) |
| 220 | { |
| 221 | struct icdbinfo *info = db->info; |
| 222 | uint32_t offset; |
| 223 | uint64_t hash; |
| 224 | uint32_t indexsize, idxmask, idxlen; |
| 225 | uint32_t *idxdata; |
| 226 | |
| 227 | indexsize = info->indexsize; |
| 228 | idxmask = indexsize - 1; |
| 229 | idxlen = indexsize * sizeof(uint32_t); |
Value stored to 'idxlen' is never read | |
| 230 | |
| 231 | idxdata = db->idxdata[keynum]; |
| 232 | |
| 233 | hash = SipHash24(&info->siphashkey, key, info->keysize[keynum])SipHash((&info->siphashkey), 2, 4, (key), (info->keysize [keynum])); |
| 234 | while ((offset = idxdata[hash & idxmask]) != -1) { |
| 235 | if (icdb_get(db, entry, offset) != 0) { |
| 236 | errno(*__errno()) = ENOENT2; |
| 237 | return -1; |
| 238 | } |
| 239 | if (memcmp((uint8_t *)entry + info->keyoffset[keynum], key, |
| 240 | info->keysize[keynum]) == 0) { |
| 241 | if (idxp) |
| 242 | *idxp = offset; |
| 243 | return 0; |
| 244 | } |
| 245 | hash = SipHash24(&info->siphashkey, &hash, sizeof(hash))SipHash((&info->siphashkey), 2, 4, (&hash), (sizeof (hash))); |
| 246 | } |
| 247 | return 1; |
| 248 | } |
| 249 | DEF_WEAK(icdb_lookup)__asm__(".weak " "icdb_lookup" " ; " "icdb_lookup" " = " "_libc_icdb_lookup" ); |
| 250 | |
| 251 | int |
| 252 | icdb_nentries(struct icdb *db) |
| 253 | { |
| 254 | return db->info->nentries; |
| 255 | } |
| 256 | DEF_WEAK(icdb_nentries)__asm__(".weak " "icdb_nentries" " ; " "icdb_nentries" " = " "_libc_icdb_nentries" ); |
| 257 | |
| 258 | const void * |
| 259 | icdb_entries(struct icdb *db) |
| 260 | { |
| 261 | return db->entries; |
| 262 | } |
| 263 | DEF_WEAK(icdb_entries)__asm__(".weak " "icdb_entries" " ; " "icdb_entries" " = " "_libc_icdb_entries" ); |
| 264 | |
| 265 | int |
| 266 | icdb_update(struct icdb *db, const void *entry, int offset) |
| 267 | { |
| 268 | struct icdbinfo *info = db->info; |
| 269 | uint32_t entrysize = info->entrysize; |
| 270 | uint32_t baseoff; |
| 271 | uint32_t indexsize, idxmask, idxlen; |
| 272 | |
| 273 | indexsize = info->indexsize; |
| 274 | idxmask = indexsize - 1; |
| 275 | idxlen = indexsize * sizeof(uint32_t); |
| 276 | baseoff = sizeof(*info) + idxlen * info->nkeys; |
| 277 | |
| 278 | memcpy((uint8_t *)db->entries + offset * entrysize, entry, entrysize); |
| 279 | if (db->fd != -1) { |
| 280 | msync((uint8_t *)db->entries + offset * entrysize, entrysize, |
| 281 | MS_SYNC0x02); |
| 282 | } |
| 283 | return 0; |
| 284 | } |
| 285 | DEF_WEAK(icdb_update)__asm__(".weak " "icdb_update" " ; " "icdb_update" " = " "_libc_icdb_update" ); |
| 286 | |
| 287 | int |
| 288 | icdb_add(struct icdb *db, const void *entry) |
| 289 | { |
| 290 | struct icdbinfo *info = db->info; |
| 291 | size_t entrysize = info->entrysize; |
| 292 | |
| 293 | if (db->allocated == info->nentries) { |
| 294 | void *p; |
| 295 | size_t amt = db->allocated ? db->allocated * 2 : 63; |
| 296 | if (!(p = reallocarray(db->entries, amt, entrysize))) |
| 297 | return -1; |
| 298 | db->allocated = amt; |
| 299 | db->entries = p; |
| 300 | } |
| 301 | memcpy((uint8_t *)db->entries + info->nentries * entrysize, |
| 302 | entry, entrysize); |
| 303 | info->nentries++; |
| 304 | return 0; |
| 305 | } |
| 306 | DEF_WEAK(icdb_add)__asm__(".weak " "icdb_add" " ; " "icdb_add" " = " "_libc_icdb_add" ); |
| 307 | |
| 308 | int |
| 309 | icdb_rehash(struct icdb *db) |
| 310 | { |
| 311 | struct icdbinfo *info = db->info; |
| 312 | uint32_t entrysize = info->entrysize; |
| 313 | uint32_t indexsize, idxmask, idxlen; |
| 314 | int i, j; |
| 315 | |
| 316 | indexsize = info->indexsize = roundup(info->nentries); |
| 317 | idxmask = indexsize - 1; |
| 318 | idxlen = sizeof(uint32_t) * indexsize; |
| 319 | |
| 320 | arc4random_buf(&info->siphashkey, sizeof(info->siphashkey)); |
| 321 | |
| 322 | for (i = 0; i < info->nkeys; i++) { |
| 323 | uint32_t *idxdata = reallocarray(db->idxdata[i], |
| 324 | indexsize, sizeof(uint32_t)); |
| 325 | if (!idxdata) |
| 326 | return -1; |
| 327 | memset(idxdata, 0xff, idxlen); |
| 328 | db->idxdata[i] = idxdata; |
| 329 | } |
| 330 | for (j = 0; j < info->nentries; j++) { |
| 331 | for (i = 0; i < info->nkeys; i++) { |
| 332 | uint32_t *idxdata = db->idxdata[i]; |
| 333 | uint64_t hash = SipHash24(&info->siphashkey,SipHash((&info->siphashkey), 2, 4, ((uint8_t *)db-> entries + j * entrysize + info->keyoffset[i]), (info->keysize [i])) |
| 334 | (uint8_t *)db->entries + j * entrysize +SipHash((&info->siphashkey), 2, 4, ((uint8_t *)db-> entries + j * entrysize + info->keyoffset[i]), (info->keysize [i])) |
| 335 | info->keyoffset[i], info->keysize[i])SipHash((&info->siphashkey), 2, 4, ((uint8_t *)db-> entries + j * entrysize + info->keyoffset[i]), (info->keysize [i])); |
| 336 | while (idxdata[hash & idxmask] != -1) |
| 337 | hash = SipHash24(&info->siphashkey, &hash, sizeof(hash))SipHash((&info->siphashkey), 2, 4, (&hash), (sizeof (hash))); |
| 338 | idxdata[hash & idxmask] = j; |
| 339 | } |
| 340 | } |
| 341 | return 0; |
| 342 | } |
| 343 | DEF_WEAK(icdb_rehash)__asm__(".weak " "icdb_rehash" " ; " "icdb_rehash" " = " "_libc_icdb_rehash" ); |
| 344 | |
| 345 | int |
| 346 | icdb_save(struct icdb *db, int fd) |
| 347 | { |
| 348 | struct icdbinfo *info = db->info; |
| 349 | uint32_t entrysize = info->entrysize; |
| 350 | uint32_t indexsize, idxlen; |
| 351 | int i; |
| 352 | |
| 353 | if (icdb_rehash(db) != 0) |
| 354 | return -1; |
| 355 | |
| 356 | indexsize = info->indexsize; |
| 357 | idxlen = sizeof(uint32_t) * indexsize; |
| 358 | |
| 359 | if (ftruncate(fd, 0) != 0) |
| 360 | return -1; |
| 361 | if (write(fd, info, sizeof(*info)) != sizeof(*info)) |
| 362 | return -1; |
| 363 | for (i = 0; i < info->nkeys; i++) { |
| 364 | if (write(fd, db->idxdata[i], idxlen) != idxlen) |
| 365 | return -1; |
| 366 | } |
| 367 | if (write(fd, db->entries, info->nentries * entrysize) != |
| 368 | info->nentries * entrysize) |
| 369 | return -1; |
| 370 | return 0; |
| 371 | } |
| 372 | DEF_WEAK(icdb_save)__asm__(".weak " "icdb_save" " ; " "icdb_save" " = " "_libc_icdb_save" ); |
| 373 | |
| 374 | int |
| 375 | icdb_close(struct icdb *db) |
| 376 | { |
| 377 | int i; |
| 378 | |
| 379 | if (db->fd == -1) { |
| 380 | for (i = 0; i < db->info->nkeys; i++) |
| 381 | free(db->idxdata[i]); |
| 382 | free(db->entries); |
| 383 | free(db->info); |
| 384 | } else { |
| 385 | munmap(db->info, db->maplen); |
| 386 | close(db->fd); |
| 387 | } |
| 388 | free(db); |
| 389 | return 0; |
| 390 | } |
| 391 | DEF_WEAK(icdb_close)__asm__(".weak " "icdb_close" " ; " "icdb_close" " = " "_libc_icdb_close" ); |