Travis Geiselbrecht | f86c43c | 2010-05-06 14:17:34 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2009 Travis Geiselbrecht |
| 3 | * |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining |
| 5 | * a copy of this software and associated documentation files |
| 6 | * (the "Software"), to deal in the Software without restriction, |
| 7 | * including without limitation the rights to use, copy, modify, merge, |
| 8 | * publish, distribute, sublicense, and/or sell copies of the Software, |
| 9 | * and to permit persons to whom the Software is furnished to do so, |
| 10 | * subject to the following conditions: |
| 11 | * |
| 12 | * The above copyright notice and this permission notice shall be |
| 13 | * included in all copies or substantial portions of the Software. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| 17 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. |
| 18 | * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY |
| 19 | * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, |
| 20 | * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE |
| 21 | * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. |
| 22 | */ |
| 23 | #include <debug.h> |
| 24 | #include <list.h> |
| 25 | #include <err.h> |
| 26 | #include <string.h> |
| 27 | #include <stdlib.h> |
| 28 | #include <lib/fs.h> |
| 29 | #include <lib/bio.h> |
| 30 | |
| 31 | #if WITH_LIB_FS_EXT2 |
| 32 | #include <lib/fs/ext2.h> |
| 33 | #endif |
| 34 | #if WITH_LIB_FS_FAT32 |
| 35 | #include <lib/fs/fat32.h> |
| 36 | #endif |
| 37 | |
| 38 | #define LOCAL_TRACE 0 |
| 39 | |
| 40 | struct fs_type { |
| 41 | const char *name; |
| 42 | int (*mount)(bdev_t *, fscookie *); |
| 43 | int (*unmount)(fscookie); |
| 44 | int (*open)(fscookie, const char *, filecookie *); |
| 45 | int (*create)(fscookie, const char *, filecookie *); |
| 46 | int (*mkdir)(fscookie, const char *); |
| 47 | int (*stat)(filecookie, struct file_stat *); |
| 48 | int (*read)(filecookie, void *, off_t, size_t); |
| 49 | int (*write)(filecookie, const void *, off_t, size_t); |
| 50 | int (*close)(filecookie); |
| 51 | }; |
| 52 | |
| 53 | struct fs_mount { |
| 54 | struct list_node node; |
| 55 | char *path; |
| 56 | bdev_t *dev; |
| 57 | fscookie cookie; |
| 58 | int refs; |
| 59 | struct fs_type *type; |
| 60 | }; |
| 61 | |
| 62 | struct fs_file { |
| 63 | filecookie cookie; |
| 64 | struct fs_mount *mount; |
| 65 | }; |
| 66 | |
| 67 | static struct list_node mounts; |
| 68 | |
| 69 | static struct fs_type types[] = { |
| 70 | #if WITH_LIB_FS_EXT2 |
| 71 | { |
| 72 | .name = "ext2", |
| 73 | .mount = ext2_mount, |
| 74 | .unmount = ext2_unmount, |
| 75 | .open = ext2_open_file, |
| 76 | .stat = ext2_stat_file, |
| 77 | .read = ext2_read_file, |
| 78 | .close = ext2_close_file, |
| 79 | }, |
| 80 | #endif |
| 81 | #if WITH_LIB_FS_FAT32 |
| 82 | { |
| 83 | .name = "fat32", |
| 84 | .mount = fat32_mount, |
| 85 | .unmount = fat32_unmount, |
| 86 | .open = fat32_open_file, |
| 87 | .create = fat32_create_file, |
| 88 | .mkdir = fat32_make_dir, |
| 89 | .stat = fat32_stat_file, |
| 90 | .read = fat32_read_file, |
| 91 | .write = fat32_write_file, |
| 92 | .close = fat32_close_file, |
| 93 | }, |
| 94 | #endif |
| 95 | }; |
| 96 | |
| 97 | static void test_normalize(const char *in); |
| 98 | static struct fs_mount *find_mount(const char *path, const char **trimmed_path); |
| 99 | |
| 100 | void fs_init(void) |
| 101 | { |
| 102 | list_initialize(&mounts); |
| 103 | #if 0 |
| 104 | test_normalize("/"); |
| 105 | test_normalize("/test"); |
| 106 | test_normalize("/test/"); |
| 107 | test_normalize("test/"); |
| 108 | test_normalize("test"); |
| 109 | test_normalize("/test//"); |
| 110 | test_normalize("/test/foo"); |
| 111 | test_normalize("/test/foo/"); |
| 112 | test_normalize("/test/foo/bar"); |
| 113 | test_normalize("/test/foo/bar//"); |
| 114 | test_normalize("/test//foo/bar//"); |
| 115 | test_normalize("/test//./foo/bar//"); |
| 116 | test_normalize("/test//./.foo/bar//"); |
| 117 | test_normalize("/test//./..foo/bar//"); |
| 118 | test_normalize("/test//./../foo/bar//"); |
| 119 | test_normalize("/test/../foo"); |
| 120 | test_normalize("/test/bar/../foo"); |
| 121 | test_normalize("../foo"); |
| 122 | test_normalize("../foo/"); |
| 123 | test_normalize("/../foo"); |
| 124 | test_normalize("/../foo/"); |
| 125 | test_normalize("/../../foo"); |
| 126 | test_normalize("/bleh/../../foo"); |
| 127 | test_normalize("/bleh/bar/../../foo"); |
| 128 | test_normalize("/bleh/bar/../../foo/.."); |
| 129 | test_normalize("/bleh/bar/../../foo/../meh"); |
| 130 | #endif |
| 131 | } |
| 132 | |
| 133 | static struct fs_mount *find_mount(const char *path, const char **trimmed_path) |
| 134 | { |
| 135 | struct fs_mount *mount; |
| 136 | size_t pathlen = strlen(path); |
| 137 | |
| 138 | list_for_every_entry(&mounts, mount, struct fs_mount, node) { |
| 139 | size_t mountpathlen = strlen(mount->path); |
| 140 | if (pathlen < mountpathlen) |
| 141 | continue; |
| 142 | |
| 143 | LTRACEF("comparing %s with %s\n", path, mount->path); |
| 144 | |
| 145 | if (memcmp(path, mount->path, mountpathlen) == 0) { |
| 146 | if (trimmed_path) |
| 147 | *trimmed_path = &path[mountpathlen]; |
| 148 | |
| 149 | return mount; |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | return NULL; |
| 154 | } |
| 155 | |
| 156 | static int mount(const char *path, const char *device, struct fs_type *type) |
| 157 | { |
| 158 | char temppath[512]; |
| 159 | |
| 160 | strlcpy(temppath, path, sizeof(temppath)); |
| 161 | fs_normalize_path(temppath); |
| 162 | |
| 163 | if(temppath[0] != '/') |
| 164 | return ERR_BAD_PATH; |
| 165 | |
| 166 | if (find_mount(temppath, NULL)) |
| 167 | return ERR_ALREADY_MOUNTED; |
| 168 | |
| 169 | bdev_t *dev = bio_open(device); |
| 170 | if (!dev) |
| 171 | return ERR_NOT_FOUND; |
| 172 | |
| 173 | fscookie cookie; |
| 174 | int err = type->mount(dev, &cookie); |
| 175 | if (err < 0) { |
| 176 | bio_close(dev); |
| 177 | return err; |
| 178 | } |
| 179 | |
| 180 | /* create the mount structure and add it to the list */ |
| 181 | struct fs_mount *mount = malloc(sizeof(struct fs_mount)); |
| 182 | mount->path = strdup(temppath); |
| 183 | mount->dev = dev; |
| 184 | mount->cookie = cookie; |
| 185 | mount->refs = 1; |
| 186 | mount->type = type; |
| 187 | |
| 188 | list_add_head(&mounts, &mount->node); |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | int fs_mount(const char *path, const char *device) |
| 194 | { |
| 195 | return mount(path, device, &types[0]); |
| 196 | } |
| 197 | |
| 198 | int fs_mount_type(const char *path, const char *device, const char *name) |
| 199 | { |
| 200 | size_t i; |
| 201 | |
| 202 | for (i = 0; i < countof(types); i++) { |
| 203 | if (!strcmp(name, types[i].name)) |
| 204 | return mount(path, device, &types[i]); |
| 205 | } |
| 206 | |
| 207 | return ERR_NOT_FOUND; |
| 208 | } |
| 209 | |
| 210 | static void put_mount(struct fs_mount *mount) |
| 211 | { |
| 212 | if (!(--mount->refs)) { |
| 213 | list_delete(&mount->node); |
| 214 | mount->type->unmount(mount->cookie); |
| 215 | free(mount->path); |
| 216 | bio_close(mount->dev); |
| 217 | free(mount); |
| 218 | } |
| 219 | } |
| 220 | |
| 221 | int fs_unmount(const char *path) |
| 222 | { |
| 223 | char temppath[512]; |
| 224 | |
| 225 | strlcpy(temppath, path, sizeof(temppath)); |
| 226 | fs_normalize_path(temppath); |
| 227 | |
| 228 | struct fs_mount *mount = find_mount(temppath, NULL); |
| 229 | if (!mount) |
| 230 | return ERR_NOT_FOUND; |
| 231 | |
| 232 | put_mount(mount); |
| 233 | |
| 234 | return 0; |
| 235 | } |
| 236 | |
| 237 | |
| 238 | int fs_open_file(const char *path, filecookie *fcookie) |
| 239 | { |
| 240 | int err; |
| 241 | char temppath[512]; |
| 242 | filecookie cookie; |
| 243 | |
| 244 | strlcpy(temppath, path, sizeof(temppath)); |
| 245 | fs_normalize_path(temppath); |
| 246 | |
| 247 | LTRACEF("path %s temppath %s\n", path, temppath); |
| 248 | |
| 249 | const char *newpath; |
| 250 | struct fs_mount *mount = find_mount(temppath, &newpath); |
| 251 | if (!mount) |
| 252 | return ERR_NOT_FOUND; |
| 253 | |
| 254 | LTRACEF("path %s temppath %s newpath %s\n", path, temppath, newpath); |
| 255 | |
| 256 | err = mount->type->open(mount->cookie, newpath, &cookie); |
| 257 | if (err < 0) |
| 258 | return err; |
| 259 | |
| 260 | struct fs_file *f = malloc(sizeof(*f)); |
| 261 | f->cookie = cookie; |
| 262 | f->mount = mount; |
| 263 | mount->refs++; |
| 264 | *fcookie = f; |
| 265 | |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | int fs_create_file(const char *path, filecookie *fcookie) |
| 270 | { |
| 271 | int err; |
| 272 | char temppath[512]; |
| 273 | filecookie cookie; |
| 274 | |
| 275 | strlcpy(temppath, path, sizeof(temppath)); |
| 276 | fs_normalize_path(temppath); |
| 277 | |
| 278 | const char *newpath; |
| 279 | struct fs_mount *mount = find_mount(temppath, &newpath); |
| 280 | if (!mount) |
| 281 | return ERR_NOT_FOUND; |
| 282 | |
| 283 | if (!mount->type->create) |
| 284 | return ERR_NOT_SUPPORTED; |
| 285 | |
| 286 | err = mount->type->create(mount->cookie, newpath, &cookie); |
| 287 | if (err < 0) |
| 288 | return err; |
| 289 | |
| 290 | struct fs_file *f = malloc(sizeof(*f)); |
| 291 | f->cookie = cookie; |
| 292 | f->mount = mount; |
| 293 | mount->refs++; |
| 294 | *fcookie = f; |
| 295 | |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | int fs_make_dir(const char *path) |
| 300 | { |
| 301 | char temppath[512]; |
| 302 | |
| 303 | strlcpy(temppath, path, sizeof(temppath)); |
| 304 | fs_normalize_path(temppath); |
| 305 | |
| 306 | const char *newpath; |
| 307 | struct fs_mount *mount = find_mount(temppath, &newpath); |
| 308 | if (!mount) |
| 309 | return ERR_NOT_FOUND; |
| 310 | |
| 311 | if (!mount->type->mkdir) |
| 312 | return ERR_NOT_SUPPORTED; |
| 313 | |
| 314 | return mount->type->mkdir(mount->cookie, newpath); |
| 315 | } |
| 316 | |
| 317 | int fs_read_file(filecookie fcookie, void *buf, off_t offset, size_t len) |
| 318 | { |
| 319 | struct fs_file *f = fcookie; |
| 320 | |
| 321 | return f->mount->type->read(f->cookie, buf, offset, len); |
| 322 | } |
| 323 | |
| 324 | int fs_write_file(filecookie fcookie, const void *buf, off_t offset, size_t len) |
| 325 | { |
| 326 | struct fs_file *f = fcookie; |
| 327 | |
| 328 | if (!f->mount->type->write) |
| 329 | return ERR_NOT_SUPPORTED; |
| 330 | |
| 331 | return f->mount->type->write(f->cookie, buf, offset, len); |
| 332 | } |
| 333 | |
| 334 | int fs_close_file(filecookie fcookie) |
| 335 | { |
| 336 | int err; |
| 337 | struct fs_file *f = fcookie; |
| 338 | |
| 339 | err = f->mount->type->close(f->cookie); |
| 340 | if (err < 0) |
| 341 | return err; |
| 342 | |
| 343 | put_mount(f->mount); |
| 344 | free(f); |
| 345 | return 0; |
| 346 | } |
| 347 | |
| 348 | int fs_stat_file(filecookie fcookie, struct file_stat *stat) |
| 349 | { |
| 350 | struct fs_file *f = fcookie; |
| 351 | |
| 352 | return f->mount->type->stat(f->cookie, stat); |
| 353 | } |
| 354 | |
| 355 | ssize_t fs_load_file(const char *path, void *ptr, size_t maxlen) |
| 356 | { |
| 357 | int err; |
| 358 | filecookie cookie; |
| 359 | |
| 360 | /* open the file */ |
| 361 | err = fs_open_file(path, &cookie); |
| 362 | if (err < 0) |
| 363 | return err; |
| 364 | |
| 365 | /* stat it for size, see how much we need to read */ |
| 366 | struct file_stat stat; |
| 367 | fs_stat_file(cookie, &stat); |
| 368 | |
| 369 | err = fs_read_file(cookie, ptr, 0, MIN(maxlen, stat.size)); |
| 370 | |
| 371 | fs_close_file(cookie); |
| 372 | |
| 373 | return err; |
| 374 | } |
| 375 | |
| 376 | static void test_normalize(const char *in) |
| 377 | { |
| 378 | char path[1024]; |
| 379 | |
| 380 | strlcpy(path, in, sizeof(path)); |
| 381 | fs_normalize_path(path); |
| 382 | printf("'%s' -> '%s'\n", in, path); |
| 383 | } |
| 384 | |
| 385 | void fs_normalize_path(char *path) |
| 386 | { |
| 387 | int outpos; |
| 388 | int pos; |
| 389 | char c; |
| 390 | bool done; |
| 391 | enum { |
| 392 | INITIAL, |
| 393 | FIELD_START, |
| 394 | IN_FIELD, |
| 395 | SEP, |
| 396 | SEEN_SEP, |
| 397 | DOT, |
| 398 | SEEN_DOT, |
| 399 | DOTDOT, |
| 400 | SEEN_DOTDOT, |
| 401 | } state; |
| 402 | |
| 403 | state = INITIAL; |
| 404 | pos = 0; |
| 405 | outpos = 0; |
| 406 | done = false; |
| 407 | |
| 408 | /* remove duplicate path seperators, flatten empty fields (only composed of .), backtrack fields with .., remove trailing slashes */ |
| 409 | while (!done) { |
| 410 | c = path[pos]; |
| 411 | switch (state) { |
| 412 | case INITIAL: |
| 413 | if (c == '/') { |
| 414 | state = SEP; |
| 415 | } else if (c == '.') { |
| 416 | state = DOT; |
| 417 | } else { |
| 418 | state = FIELD_START; |
| 419 | } |
| 420 | break; |
| 421 | case FIELD_START: |
| 422 | if (c == '.') { |
| 423 | state = DOT; |
| 424 | } else if (c == 0) { |
| 425 | done = true; |
| 426 | } else { |
| 427 | state = IN_FIELD; |
| 428 | } |
| 429 | break; |
| 430 | case IN_FIELD: |
| 431 | if (c == '/') { |
| 432 | state = SEP; |
| 433 | } else if (c == 0) { |
| 434 | done = true; |
| 435 | } else { |
| 436 | path[outpos++] = c; |
| 437 | pos++; |
| 438 | } |
| 439 | break; |
| 440 | case SEP: |
| 441 | pos++; |
| 442 | path[outpos++] = '/'; |
| 443 | state = SEEN_SEP; |
| 444 | break; |
| 445 | case SEEN_SEP: |
| 446 | if (c == '/') { |
| 447 | // eat it |
| 448 | pos++; |
| 449 | } else if (c == 0) { |
| 450 | done = true; |
| 451 | } else { |
| 452 | state = FIELD_START; |
| 453 | } |
| 454 | break; |
| 455 | case DOT: |
| 456 | pos++; // consume the dot |
| 457 | state = SEEN_DOT; |
| 458 | break; |
| 459 | case SEEN_DOT: |
| 460 | if (c == '.') { |
| 461 | // dotdot now |
| 462 | state = DOTDOT; |
| 463 | } else if (c == '/') { |
| 464 | // a field composed entirely of a . |
| 465 | // consume the / and move directly to the SEEN_SEP state |
| 466 | pos++; |
| 467 | state = SEEN_SEP; |
| 468 | } else if (c == 0) { |
| 469 | done = true; |
| 470 | } else { |
| 471 | // a field prefixed with a . |
| 472 | // emit a . and move directly into the IN_FIELD state |
| 473 | path[outpos++] = '.'; |
| 474 | state = IN_FIELD; |
| 475 | } |
| 476 | break; |
| 477 | case DOTDOT: |
| 478 | pos++; // consume the dot |
| 479 | state = SEEN_DOTDOT; |
| 480 | break; |
| 481 | case SEEN_DOTDOT: |
| 482 | if (c == '/' || c == 0) { |
| 483 | // a field composed entirely of '..' |
| 484 | // search back and consume a field we've already emitted |
| 485 | if (outpos > 0) { |
| 486 | // we have already consumed at least one field |
| 487 | outpos--; |
| 488 | |
| 489 | // walk backwards until we find the next field boundary |
| 490 | while (outpos > 0) { |
| 491 | if (path[outpos - 1] == '/') { |
| 492 | break; |
| 493 | } |
| 494 | outpos--; |
| 495 | } |
| 496 | } |
| 497 | pos++; |
| 498 | state = SEEN_SEP; |
| 499 | if (c == 0) |
| 500 | done = true; |
| 501 | } else { |
| 502 | // a field prefixed with .. |
| 503 | // emit the .. and move directly to the IN_FIELD state |
| 504 | path[outpos++] = '.'; |
| 505 | path[outpos++] = '.'; |
| 506 | state = IN_FIELD; |
| 507 | } |
| 508 | break; |
| 509 | } |
| 510 | } |
| 511 | |
| 512 | /* dont end with trailing slashes */ |
| 513 | if (outpos > 0 && path[outpos - 1] == '/') |
| 514 | outpos--; |
| 515 | |
| 516 | path[outpos++] = 0; |
| 517 | } |
| 518 | |