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