1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "make_ext4fs.h" 18 #include "ext4_utils.h" 19 #include "allocate.h" 20 #include "contents.h" 21 #include "uuid.h" 22 #include "wipe.h" 23 24 #include <sparse/sparse.h> 25 26 #include <assert.h> 27 #include <dirent.h> 28 #include <fcntl.h> 29 #include <inttypes.h> 30 #include <libgen.h> 31 #include <stdio.h> 32 #include <stdlib.h> 33 #include <string.h> 34 #include <unistd.h> 35 #include <sys/stat.h> 36 #include <sys/types.h> 37 38 #ifdef USE_MINGW 39 40 #include <winsock2.h> 41 42 /* These match the Linux definitions of these flags. 43 L_xx is defined to avoid conflicting with the win32 versions. 44 */ 45 #define L_S_IRUSR 00400 46 #define L_S_IWUSR 00200 47 #define L_S_IXUSR 00100 48 #define S_IRWXU (L_S_IRUSR | L_S_IWUSR | L_S_IXUSR) 49 #define S_IRGRP 00040 50 #define S_IWGRP 00020 51 #define S_IXGRP 00010 52 #define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP) 53 #define S_IROTH 00004 54 #define S_IWOTH 00002 55 #define S_IXOTH 00001 56 #define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH) 57 #define S_ISUID 0004000 58 #define S_ISGID 0002000 59 #define S_ISVTX 0001000 60 61 #else 62 63 #include <selinux/selinux.h> 64 #include <selinux/label.h> 65 #include <selinux/android.h> 66 67 #define O_BINARY 0 68 69 #endif 70 71 /* TODO: Not implemented: 72 Allocating blocks in the same block group as the file inode 73 Hash or binary tree directories 74 Special files: sockets, devices, fifos 75 */ 76 77 static int filter_dot(const struct dirent *d) 78 { 79 return (strcmp(d->d_name, "..") && strcmp(d->d_name, ".")); 80 } 81 82 static u32 build_default_directory_structure(const char *dir_path, 83 struct selabel_handle *sehnd) 84 { 85 u32 inode; 86 u32 root_inode; 87 struct dentry dentries = { 88 .filename = "lost+found", 89 .file_type = EXT4_FT_DIR, 90 .mode = S_IRWXU, 91 .uid = 0, 92 .gid = 0, 93 .mtime = 0, 94 }; 95 root_inode = make_directory(0, 1, &dentries, 1); 96 inode = make_directory(root_inode, 0, NULL, 0); 97 *dentries.inode = inode; 98 inode_set_permissions(inode, dentries.mode, 99 dentries.uid, dentries.gid, dentries.mtime); 100 101 #ifndef USE_MINGW 102 if (sehnd) { 103 char *path = NULL; 104 char *secontext = NULL; 105 106 asprintf(&path, "%slost+found", dir_path); 107 if (selabel_lookup(sehnd, &secontext, path, S_IFDIR) < 0) { 108 error("cannot lookup security context for %s", path); 109 } else { 110 inode_set_selinux(inode, secontext); 111 freecon(secontext); 112 } 113 free(path); 114 } 115 #endif 116 117 return root_inode; 118 } 119 120 #ifndef USE_MINGW 121 /* Read a local directory and create the same tree in the generated filesystem. 122 Calls itself recursively with each directory in the given directory. 123 full_path is an absolute or relative path, with a trailing slash, to the 124 directory on disk that should be copied, or NULL if this is a directory 125 that does not exist on disk (e.g. lost+found). 126 dir_path is an absolute path, with trailing slash, to the same directory 127 if the image were mounted at the specified mount point */ 128 static u32 build_directory_structure(const char *full_path, const char *dir_path, 129 u32 dir_inode, fs_config_func_t fs_config_func, 130 struct selabel_handle *sehnd, int verbose) 131 { 132 int entries = 0; 133 struct dentry *dentries; 134 struct dirent **namelist = NULL; 135 struct stat stat; 136 int ret; 137 int i; 138 u32 inode; 139 u32 entry_inode; 140 u32 dirs = 0; 141 bool needs_lost_and_found = false; 142 143 if (full_path) { 144 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort); 145 if (entries < 0) { 146 error_errno("scandir"); 147 return EXT4_ALLOCATE_FAILED; 148 } 149 } 150 151 if (dir_inode == 0) { 152 /* root directory, check if lost+found already exists */ 153 for (i = 0; i < entries; i++) 154 if (strcmp(namelist[i]->d_name, "lost+found") == 0) 155 break; 156 if (i == entries) 157 needs_lost_and_found = true; 158 } 159 160 dentries = calloc(entries, sizeof(struct dentry)); 161 if (dentries == NULL) 162 critical_error_errno("malloc"); 163 164 for (i = 0; i < entries; i++) { 165 dentries[i].filename = strdup(namelist[i]->d_name); 166 if (dentries[i].filename == NULL) 167 critical_error_errno("strdup"); 168 169 asprintf(&dentries[i].path, "%s%s", dir_path, namelist[i]->d_name); 170 asprintf(&dentries[i].full_path, "%s%s", full_path, namelist[i]->d_name); 171 172 free(namelist[i]); 173 174 ret = lstat(dentries[i].full_path, &stat); 175 if (ret < 0) { 176 error_errno("lstat"); 177 i--; 178 entries--; 179 continue; 180 } 181 182 dentries[i].size = stat.st_size; 183 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO); 184 dentries[i].mtime = stat.st_mtime; 185 uint64_t capabilities; 186 if (fs_config_func != NULL) { 187 #ifdef ANDROID 188 unsigned int mode = 0; 189 unsigned int uid = 0; 190 unsigned int gid = 0; 191 int dir = S_ISDIR(stat.st_mode); 192 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode, &capabilities); 193 dentries[i].mode = mode; 194 dentries[i].uid = uid; 195 dentries[i].gid = gid; 196 dentries[i].capabilities = capabilities; 197 #else 198 error("can't set android permissions - built without android support"); 199 #endif 200 } 201 #ifndef USE_MINGW 202 if (sehnd) { 203 if (selabel_lookup(sehnd, &dentries[i].secon, dentries[i].path, stat.st_mode) < 0) { 204 error("cannot lookup security context for %s", dentries[i].path); 205 } 206 207 if (dentries[i].secon && verbose) 208 printf("Labeling %s as %s\n", dentries[i].path, dentries[i].secon); 209 } 210 #endif 211 212 if (S_ISREG(stat.st_mode)) { 213 dentries[i].file_type = EXT4_FT_REG_FILE; 214 } else if (S_ISDIR(stat.st_mode)) { 215 dentries[i].file_type = EXT4_FT_DIR; 216 dirs++; 217 } else if (S_ISCHR(stat.st_mode)) { 218 dentries[i].file_type = EXT4_FT_CHRDEV; 219 } else if (S_ISBLK(stat.st_mode)) { 220 dentries[i].file_type = EXT4_FT_BLKDEV; 221 } else if (S_ISFIFO(stat.st_mode)) { 222 dentries[i].file_type = EXT4_FT_FIFO; 223 } else if (S_ISSOCK(stat.st_mode)) { 224 dentries[i].file_type = EXT4_FT_SOCK; 225 } else if (S_ISLNK(stat.st_mode)) { 226 dentries[i].file_type = EXT4_FT_SYMLINK; 227 dentries[i].link = calloc(info.block_size, 1); 228 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1); 229 } else { 230 error("unknown file type on %s", dentries[i].path); 231 i--; 232 entries--; 233 } 234 } 235 free(namelist); 236 237 if (needs_lost_and_found) { 238 /* insert a lost+found directory at the beginning of the dentries */ 239 struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry)); 240 memset(tmp, 0, sizeof(struct dentry)); 241 memcpy(tmp + 1, dentries, entries * sizeof(struct dentry)); 242 dentries = tmp; 243 244 dentries[0].filename = strdup("lost+found"); 245 asprintf(&dentries[0].path, "%slost+found", dir_path); 246 dentries[0].full_path = NULL; 247 dentries[0].size = 0; 248 dentries[0].mode = S_IRWXU; 249 dentries[0].file_type = EXT4_FT_DIR; 250 dentries[0].uid = 0; 251 dentries[0].gid = 0; 252 if (sehnd) { 253 if (selabel_lookup(sehnd, &dentries[0].secon, dentries[0].path, dentries[0].mode) < 0) 254 error("cannot lookup security context for %s", dentries[0].path); 255 } 256 entries++; 257 dirs++; 258 } 259 260 inode = make_directory(dir_inode, entries, dentries, dirs); 261 262 for (i = 0; i < entries; i++) { 263 if (dentries[i].file_type == EXT4_FT_REG_FILE) { 264 entry_inode = make_file(dentries[i].full_path, dentries[i].size); 265 } else if (dentries[i].file_type == EXT4_FT_DIR) { 266 char *subdir_full_path = NULL; 267 char *subdir_dir_path; 268 if (dentries[i].full_path) { 269 ret = asprintf(&subdir_full_path, "%s/", dentries[i].full_path); 270 if (ret < 0) 271 critical_error_errno("asprintf"); 272 } 273 ret = asprintf(&subdir_dir_path, "%s/", dentries[i].path); 274 if (ret < 0) 275 critical_error_errno("asprintf"); 276 entry_inode = build_directory_structure(subdir_full_path, 277 subdir_dir_path, inode, fs_config_func, sehnd, verbose); 278 free(subdir_full_path); 279 free(subdir_dir_path); 280 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) { 281 entry_inode = make_link(dentries[i].link); 282 } else { 283 error("unknown file type on %s", dentries[i].path); 284 entry_inode = 0; 285 } 286 *dentries[i].inode = entry_inode; 287 288 ret = inode_set_permissions(entry_inode, dentries[i].mode, 289 dentries[i].uid, dentries[i].gid, 290 dentries[i].mtime); 291 if (ret) 292 error("failed to set permissions on %s\n", dentries[i].path); 293 294 /* 295 * It's important to call inode_set_selinux() before 296 * inode_set_capabilities(). Extended attributes need to 297 * be stored sorted order, and we guarantee this by making 298 * the calls in the proper order. 299 * Please see xattr_assert_sane() in contents.c 300 */ 301 ret = inode_set_selinux(entry_inode, dentries[i].secon); 302 if (ret) 303 error("failed to set SELinux context on %s\n", dentries[i].path); 304 ret = inode_set_capabilities(entry_inode, dentries[i].capabilities); 305 if (ret) 306 error("failed to set capability on %s\n", dentries[i].path); 307 308 free(dentries[i].path); 309 free(dentries[i].full_path); 310 free(dentries[i].link); 311 free((void *)dentries[i].filename); 312 free(dentries[i].secon); 313 } 314 315 free(dentries); 316 return inode; 317 } 318 #endif 319 320 static u32 compute_block_size() 321 { 322 return 4096; 323 } 324 325 static u32 compute_journal_blocks() 326 { 327 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64; 328 if (journal_blocks < 1024) 329 journal_blocks = 1024; 330 if (journal_blocks > 32768) 331 journal_blocks = 32768; 332 return journal_blocks; 333 } 334 335 static u32 compute_blocks_per_group() 336 { 337 return info.block_size * 8; 338 } 339 340 static u32 compute_inodes() 341 { 342 return DIV_ROUND_UP(info.len, info.block_size) / 4; 343 } 344 345 static u32 compute_inodes_per_group() 346 { 347 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 348 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 349 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups); 350 inodes = ALIGN(inodes, (info.block_size / info.inode_size)); 351 352 /* After properly rounding up the number of inodes/group, 353 * make sure to update the total inodes field in the info struct. 354 */ 355 info.inodes = inodes * block_groups; 356 357 return inodes; 358 } 359 360 static u32 compute_bg_desc_reserve_blocks() 361 { 362 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 363 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 364 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc), 365 info.block_size); 366 367 u32 bg_desc_reserve_blocks = 368 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc), 369 info.block_size) - bg_desc_blocks; 370 371 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32)) 372 bg_desc_reserve_blocks = info.block_size / sizeof(u32); 373 374 return bg_desc_reserve_blocks; 375 } 376 377 void reset_ext4fs_info() { 378 // Reset all the global data structures used by make_ext4fs so it 379 // can be called again. 380 memset(&info, 0, sizeof(info)); 381 memset(&aux_info, 0, sizeof(aux_info)); 382 383 if (ext4_sparse_file) { 384 sparse_file_destroy(ext4_sparse_file); 385 ext4_sparse_file = NULL; 386 } 387 } 388 389 int make_ext4fs_sparse_fd(int fd, long long len, 390 const char *mountpoint, struct selabel_handle *sehnd) 391 { 392 reset_ext4fs_info(); 393 info.len = len; 394 395 return make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 1, 0, 0, sehnd, 0); 396 } 397 398 int make_ext4fs(const char *filename, long long len, 399 const char *mountpoint, struct selabel_handle *sehnd) 400 { 401 int fd; 402 int status; 403 404 reset_ext4fs_info(); 405 info.len = len; 406 407 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); 408 if (fd < 0) { 409 error_errno("open"); 410 return EXIT_FAILURE; 411 } 412 413 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, sehnd, 0); 414 close(fd); 415 416 return status; 417 } 418 419 /* return a newly-malloc'd string that is a copy of str. The new string 420 is guaranteed to have a trailing slash. If absolute is true, the new string 421 is also guaranteed to have a leading slash. 422 */ 423 static char *canonicalize_slashes(const char *str, bool absolute) 424 { 425 char *ret; 426 int len = strlen(str); 427 int newlen = len; 428 char *ptr; 429 430 if (len == 0) { 431 if (absolute) 432 return strdup("/"); 433 else 434 return strdup(""); 435 } 436 437 if (str[0] != '/' && absolute) { 438 newlen++; 439 } 440 if (str[len - 1] != '/') { 441 newlen++; 442 } 443 ret = malloc(newlen + 1); 444 if (!ret) { 445 critical_error("malloc"); 446 } 447 448 ptr = ret; 449 if (str[0] != '/' && absolute) { 450 *ptr++ = '/'; 451 } 452 453 strcpy(ptr, str); 454 ptr += len; 455 456 if (str[len - 1] != '/') { 457 *ptr++ = '/'; 458 } 459 460 if (ptr != ret + newlen) { 461 critical_error("assertion failed\n"); 462 } 463 464 *ptr = '\0'; 465 466 return ret; 467 } 468 469 static char *canonicalize_abs_slashes(const char *str) 470 { 471 return canonicalize_slashes(str, true); 472 } 473 474 static char *canonicalize_rel_slashes(const char *str) 475 { 476 return canonicalize_slashes(str, false); 477 } 478 479 int make_ext4fs_internal(int fd, const char *_directory, 480 const char *_mountpoint, fs_config_func_t fs_config_func, int gzip, 481 int sparse, int crc, int wipe, 482 struct selabel_handle *sehnd, int verbose) 483 { 484 u32 root_inode_num; 485 u16 root_mode; 486 char *mountpoint; 487 char *directory = NULL; 488 489 if (setjmp(setjmp_env)) 490 return EXIT_FAILURE; /* Handle a call to longjmp() */ 491 492 if (_mountpoint == NULL) { 493 mountpoint = strdup(""); 494 } else { 495 mountpoint = canonicalize_abs_slashes(_mountpoint); 496 } 497 498 if (_directory) { 499 directory = canonicalize_rel_slashes(_directory); 500 } 501 502 if (info.len <= 0) 503 info.len = get_file_size(fd); 504 505 if (info.len <= 0) { 506 fprintf(stderr, "Need size of filesystem\n"); 507 return EXIT_FAILURE; 508 } 509 510 if (info.block_size <= 0) 511 info.block_size = compute_block_size(); 512 513 /* Round down the filesystem length to be a multiple of the block size */ 514 info.len &= ~((u64)info.block_size - 1); 515 516 if (info.journal_blocks == 0) 517 info.journal_blocks = compute_journal_blocks(); 518 519 if (info.no_journal == 0) 520 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL; 521 else 522 info.journal_blocks = 0; 523 524 if (info.blocks_per_group <= 0) 525 info.blocks_per_group = compute_blocks_per_group(); 526 527 if (info.inodes <= 0) 528 info.inodes = compute_inodes(); 529 530 if (info.inode_size <= 0) 531 info.inode_size = 256; 532 533 if (info.label == NULL) 534 info.label = ""; 535 536 info.inodes_per_group = compute_inodes_per_group(); 537 538 info.feat_compat |= 539 EXT4_FEATURE_COMPAT_RESIZE_INODE | 540 EXT4_FEATURE_COMPAT_EXT_ATTR; 541 542 info.feat_ro_compat |= 543 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | 544 EXT4_FEATURE_RO_COMPAT_LARGE_FILE | 545 EXT4_FEATURE_RO_COMPAT_GDT_CSUM; 546 547 info.feat_incompat |= 548 EXT4_FEATURE_INCOMPAT_EXTENTS | 549 EXT4_FEATURE_INCOMPAT_FILETYPE; 550 551 552 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks(); 553 554 printf("Creating filesystem with parameters:\n"); 555 printf(" Size: %"PRIu64"\n", info.len); 556 printf(" Block size: %d\n", info.block_size); 557 printf(" Blocks per group: %d\n", info.blocks_per_group); 558 printf(" Inodes per group: %d\n", info.inodes_per_group); 559 printf(" Inode size: %d\n", info.inode_size); 560 printf(" Journal blocks: %d\n", info.journal_blocks); 561 printf(" Label: %s\n", info.label); 562 563 ext4_create_fs_aux_info(); 564 565 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks); 566 printf(" Block groups: %d\n", aux_info.groups); 567 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks); 568 569 ext4_sparse_file = sparse_file_new(info.block_size, info.len); 570 571 block_allocator_init(); 572 573 ext4_fill_in_sb(); 574 575 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED) 576 error("failed to reserve first 10 inodes"); 577 578 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 579 ext4_create_journal_inode(); 580 581 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE) 582 ext4_create_resize_inode(); 583 584 #ifdef USE_MINGW 585 // Windows needs only 'create an empty fs image' functionality 586 assert(!directory); 587 root_inode_num = build_default_directory_structure(mountpoint, sehnd); 588 #else 589 if (directory) 590 root_inode_num = build_directory_structure(directory, mountpoint, 0, 591 fs_config_func, sehnd, verbose); 592 else 593 root_inode_num = build_default_directory_structure(mountpoint, sehnd); 594 #endif 595 596 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; 597 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0); 598 599 #ifndef USE_MINGW 600 if (sehnd) { 601 char *secontext = NULL; 602 603 if (selabel_lookup(sehnd, &secontext, mountpoint, S_IFDIR) < 0) { 604 error("cannot lookup security context for %s", mountpoint); 605 } 606 if (secontext) { 607 if (verbose) { 608 printf("Labeling %s as %s\n", mountpoint, secontext); 609 } 610 inode_set_selinux(root_inode_num, secontext); 611 } 612 freecon(secontext); 613 } 614 #endif 615 616 ext4_update_free(); 617 618 ext4_queue_sb(); 619 620 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n", 621 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count, 622 aux_info.sb->s_inodes_count, 623 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo, 624 aux_info.sb->s_blocks_count_lo); 625 626 if (wipe && WIPE_IS_SUPPORTED) { 627 wipe_block_device(fd, info.len); 628 } 629 630 write_ext4_image(fd, gzip, sparse, crc); 631 632 sparse_file_destroy(ext4_sparse_file); 633 ext4_sparse_file = NULL; 634 635 free(mountpoint); 636 free(directory); 637 638 return 0; 639 } 640
