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, time_t fixed_time) 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 if (fixed_time == -1) { 185 dentries[i].mtime = stat.st_mtime; 186 } else { 187 dentries[i].mtime = fixed_time; 188 } 189 uint64_t capabilities; 190 if (fs_config_func != NULL) { 191 #ifdef ANDROID 192 unsigned int mode = 0; 193 unsigned int uid = 0; 194 unsigned int gid = 0; 195 int dir = S_ISDIR(stat.st_mode); 196 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode, &capabilities); 197 dentries[i].mode = mode; 198 dentries[i].uid = uid; 199 dentries[i].gid = gid; 200 dentries[i].capabilities = capabilities; 201 #else 202 error("can't set android permissions - built without android support"); 203 #endif 204 } 205 #ifndef USE_MINGW 206 if (sehnd) { 207 if (selabel_lookup(sehnd, &dentries[i].secon, dentries[i].path, stat.st_mode) < 0) { 208 error("cannot lookup security context for %s", dentries[i].path); 209 } 210 211 if (dentries[i].secon && verbose) 212 printf("Labeling %s as %s\n", dentries[i].path, dentries[i].secon); 213 } 214 #endif 215 216 if (S_ISREG(stat.st_mode)) { 217 dentries[i].file_type = EXT4_FT_REG_FILE; 218 } else if (S_ISDIR(stat.st_mode)) { 219 dentries[i].file_type = EXT4_FT_DIR; 220 dirs++; 221 } else if (S_ISCHR(stat.st_mode)) { 222 dentries[i].file_type = EXT4_FT_CHRDEV; 223 } else if (S_ISBLK(stat.st_mode)) { 224 dentries[i].file_type = EXT4_FT_BLKDEV; 225 } else if (S_ISFIFO(stat.st_mode)) { 226 dentries[i].file_type = EXT4_FT_FIFO; 227 } else if (S_ISSOCK(stat.st_mode)) { 228 dentries[i].file_type = EXT4_FT_SOCK; 229 } else if (S_ISLNK(stat.st_mode)) { 230 dentries[i].file_type = EXT4_FT_SYMLINK; 231 dentries[i].link = calloc(info.block_size, 1); 232 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1); 233 } else { 234 error("unknown file type on %s", dentries[i].path); 235 i--; 236 entries--; 237 } 238 } 239 free(namelist); 240 241 if (needs_lost_and_found) { 242 /* insert a lost+found directory at the beginning of the dentries */ 243 struct dentry *tmp = calloc(entries + 1, sizeof(struct dentry)); 244 memset(tmp, 0, sizeof(struct dentry)); 245 memcpy(tmp + 1, dentries, entries * sizeof(struct dentry)); 246 dentries = tmp; 247 248 dentries[0].filename = strdup("lost+found"); 249 asprintf(&dentries[0].path, "%slost+found", dir_path); 250 dentries[0].full_path = NULL; 251 dentries[0].size = 0; 252 dentries[0].mode = S_IRWXU; 253 dentries[0].file_type = EXT4_FT_DIR; 254 dentries[0].uid = 0; 255 dentries[0].gid = 0; 256 if (sehnd) { 257 if (selabel_lookup(sehnd, &dentries[0].secon, dentries[0].path, dentries[0].mode) < 0) 258 error("cannot lookup security context for %s", dentries[0].path); 259 } 260 entries++; 261 dirs++; 262 } 263 264 inode = make_directory(dir_inode, entries, dentries, dirs); 265 266 for (i = 0; i < entries; i++) { 267 if (dentries[i].file_type == EXT4_FT_REG_FILE) { 268 entry_inode = make_file(dentries[i].full_path, dentries[i].size); 269 } else if (dentries[i].file_type == EXT4_FT_DIR) { 270 char *subdir_full_path = NULL; 271 char *subdir_dir_path; 272 if (dentries[i].full_path) { 273 ret = asprintf(&subdir_full_path, "%s/", dentries[i].full_path); 274 if (ret < 0) 275 critical_error_errno("asprintf"); 276 } 277 ret = asprintf(&subdir_dir_path, "%s/", dentries[i].path); 278 if (ret < 0) 279 critical_error_errno("asprintf"); 280 entry_inode = build_directory_structure(subdir_full_path, 281 subdir_dir_path, inode, fs_config_func, sehnd, verbose, fixed_time); 282 free(subdir_full_path); 283 free(subdir_dir_path); 284 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) { 285 entry_inode = make_link(dentries[i].link); 286 } else { 287 error("unknown file type on %s", dentries[i].path); 288 entry_inode = 0; 289 } 290 *dentries[i].inode = entry_inode; 291 292 ret = inode_set_permissions(entry_inode, dentries[i].mode, 293 dentries[i].uid, dentries[i].gid, 294 dentries[i].mtime); 295 if (ret) 296 error("failed to set permissions on %s\n", dentries[i].path); 297 298 /* 299 * It's important to call inode_set_selinux() before 300 * inode_set_capabilities(). Extended attributes need to 301 * be stored sorted order, and we guarantee this by making 302 * the calls in the proper order. 303 * Please see xattr_assert_sane() in contents.c 304 */ 305 ret = inode_set_selinux(entry_inode, dentries[i].secon); 306 if (ret) 307 error("failed to set SELinux context on %s\n", dentries[i].path); 308 ret = inode_set_capabilities(entry_inode, dentries[i].capabilities); 309 if (ret) 310 error("failed to set capability on %s\n", dentries[i].path); 311 312 free(dentries[i].path); 313 free(dentries[i].full_path); 314 free(dentries[i].link); 315 free((void *)dentries[i].filename); 316 free(dentries[i].secon); 317 } 318 319 free(dentries); 320 return inode; 321 } 322 #endif 323 324 static u32 compute_block_size() 325 { 326 return 4096; 327 } 328 329 static u32 compute_journal_blocks() 330 { 331 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64; 332 if (journal_blocks < 1024) 333 journal_blocks = 1024; 334 if (journal_blocks > 32768) 335 journal_blocks = 32768; 336 return journal_blocks; 337 } 338 339 static u32 compute_blocks_per_group() 340 { 341 return info.block_size * 8; 342 } 343 344 static u32 compute_inodes() 345 { 346 return DIV_ROUND_UP(info.len, info.block_size) / 4; 347 } 348 349 static u32 compute_inodes_per_group() 350 { 351 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 352 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 353 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups); 354 inodes = EXT4_ALIGN(inodes, (info.block_size / info.inode_size)); 355 356 /* After properly rounding up the number of inodes/group, 357 * make sure to update the total inodes field in the info struct. 358 */ 359 info.inodes = inodes * block_groups; 360 361 return inodes; 362 } 363 364 static u32 compute_bg_desc_reserve_blocks() 365 { 366 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 367 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 368 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc), 369 info.block_size); 370 371 u32 bg_desc_reserve_blocks = 372 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc), 373 info.block_size) - bg_desc_blocks; 374 375 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32)) 376 bg_desc_reserve_blocks = info.block_size / sizeof(u32); 377 378 return bg_desc_reserve_blocks; 379 } 380 381 void reset_ext4fs_info() { 382 // Reset all the global data structures used by make_ext4fs so it 383 // can be called again. 384 memset(&info, 0, sizeof(info)); 385 memset(&aux_info, 0, sizeof(aux_info)); 386 387 if (ext4_sparse_file) { 388 sparse_file_destroy(ext4_sparse_file); 389 ext4_sparse_file = NULL; 390 } 391 } 392 393 int make_ext4fs_sparse_fd(int fd, long long len, 394 const char *mountpoint, struct selabel_handle *sehnd) 395 { 396 reset_ext4fs_info(); 397 info.len = len; 398 399 return make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 1, 0, 0, sehnd, 0, -1, NULL); 400 } 401 402 int make_ext4fs(const char *filename, long long len, 403 const char *mountpoint, struct selabel_handle *sehnd) 404 { 405 int fd; 406 int status; 407 408 reset_ext4fs_info(); 409 info.len = len; 410 411 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); 412 if (fd < 0) { 413 error_errno("open"); 414 return EXIT_FAILURE; 415 } 416 417 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, sehnd, 0, -1, NULL); 418 close(fd); 419 420 return status; 421 } 422 423 /* return a newly-malloc'd string that is a copy of str. The new string 424 is guaranteed to have a trailing slash. If absolute is true, the new string 425 is also guaranteed to have a leading slash. 426 */ 427 static char *canonicalize_slashes(const char *str, bool absolute) 428 { 429 char *ret; 430 int len = strlen(str); 431 int newlen = len; 432 char *ptr; 433 434 if (len == 0) { 435 if (absolute) 436 return strdup("/"); 437 else 438 return strdup(""); 439 } 440 441 if (str[0] != '/' && absolute) { 442 newlen++; 443 } 444 if (str[len - 1] != '/') { 445 newlen++; 446 } 447 ret = malloc(newlen + 1); 448 if (!ret) { 449 critical_error("malloc"); 450 } 451 452 ptr = ret; 453 if (str[0] != '/' && absolute) { 454 *ptr++ = '/'; 455 } 456 457 strcpy(ptr, str); 458 ptr += len; 459 460 if (str[len - 1] != '/') { 461 *ptr++ = '/'; 462 } 463 464 if (ptr != ret + newlen) { 465 critical_error("assertion failed\n"); 466 } 467 468 *ptr = '\0'; 469 470 return ret; 471 } 472 473 static char *canonicalize_abs_slashes(const char *str) 474 { 475 return canonicalize_slashes(str, true); 476 } 477 478 static char *canonicalize_rel_slashes(const char *str) 479 { 480 return canonicalize_slashes(str, false); 481 } 482 483 int make_ext4fs_internal(int fd, const char *_directory, 484 const char *_mountpoint, fs_config_func_t fs_config_func, int gzip, 485 int sparse, int crc, int wipe, 486 struct selabel_handle *sehnd, int verbose, time_t fixed_time, 487 FILE* block_list_file) 488 { 489 u32 root_inode_num; 490 u16 root_mode; 491 char *mountpoint; 492 char *directory = NULL; 493 494 if (setjmp(setjmp_env)) 495 return EXIT_FAILURE; /* Handle a call to longjmp() */ 496 497 if (_mountpoint == NULL) { 498 mountpoint = strdup(""); 499 } else { 500 mountpoint = canonicalize_abs_slashes(_mountpoint); 501 } 502 503 if (_directory) { 504 directory = canonicalize_rel_slashes(_directory); 505 } 506 507 if (info.len <= 0) 508 info.len = get_file_size(fd); 509 510 if (info.len <= 0) { 511 fprintf(stderr, "Need size of filesystem\n"); 512 return EXIT_FAILURE; 513 } 514 515 if (info.block_size <= 0) 516 info.block_size = compute_block_size(); 517 518 /* Round down the filesystem length to be a multiple of the block size */ 519 info.len &= ~((u64)info.block_size - 1); 520 521 if (info.journal_blocks == 0) 522 info.journal_blocks = compute_journal_blocks(); 523 524 if (info.no_journal == 0) 525 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL; 526 else 527 info.journal_blocks = 0; 528 529 if (info.blocks_per_group <= 0) 530 info.blocks_per_group = compute_blocks_per_group(); 531 532 if (info.inodes <= 0) 533 info.inodes = compute_inodes(); 534 535 if (info.inode_size <= 0) 536 info.inode_size = 256; 537 538 if (info.label == NULL) 539 info.label = ""; 540 541 info.inodes_per_group = compute_inodes_per_group(); 542 543 info.feat_compat |= 544 EXT4_FEATURE_COMPAT_RESIZE_INODE | 545 EXT4_FEATURE_COMPAT_EXT_ATTR; 546 547 info.feat_ro_compat |= 548 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | 549 EXT4_FEATURE_RO_COMPAT_LARGE_FILE | 550 EXT4_FEATURE_RO_COMPAT_GDT_CSUM; 551 552 info.feat_incompat |= 553 EXT4_FEATURE_INCOMPAT_EXTENTS | 554 EXT4_FEATURE_INCOMPAT_FILETYPE; 555 556 557 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks(); 558 559 printf("Creating filesystem with parameters:\n"); 560 printf(" Size: %"PRIu64"\n", info.len); 561 printf(" Block size: %d\n", info.block_size); 562 printf(" Blocks per group: %d\n", info.blocks_per_group); 563 printf(" Inodes per group: %d\n", info.inodes_per_group); 564 printf(" Inode size: %d\n", info.inode_size); 565 printf(" Journal blocks: %d\n", info.journal_blocks); 566 printf(" Label: %s\n", info.label); 567 568 ext4_create_fs_aux_info(); 569 570 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks); 571 printf(" Block groups: %d\n", aux_info.groups); 572 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks); 573 574 ext4_sparse_file = sparse_file_new(info.block_size, info.len); 575 576 block_allocator_init(); 577 578 ext4_fill_in_sb(); 579 580 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED) 581 error("failed to reserve first 10 inodes"); 582 583 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 584 ext4_create_journal_inode(); 585 586 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE) 587 ext4_create_resize_inode(); 588 589 #ifdef USE_MINGW 590 // Windows needs only 'create an empty fs image' functionality 591 assert(!directory); 592 root_inode_num = build_default_directory_structure(mountpoint, sehnd); 593 #else 594 if (directory) 595 root_inode_num = build_directory_structure(directory, mountpoint, 0, 596 fs_config_func, sehnd, verbose, fixed_time); 597 else 598 root_inode_num = build_default_directory_structure(mountpoint, sehnd); 599 #endif 600 601 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; 602 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0); 603 604 #ifndef USE_MINGW 605 if (sehnd) { 606 char *secontext = NULL; 607 608 if (selabel_lookup(sehnd, &secontext, mountpoint, S_IFDIR) < 0) { 609 error("cannot lookup security context for %s", mountpoint); 610 } 611 if (secontext) { 612 if (verbose) { 613 printf("Labeling %s as %s\n", mountpoint, secontext); 614 } 615 inode_set_selinux(root_inode_num, secontext); 616 } 617 freecon(secontext); 618 } 619 #endif 620 621 ext4_update_free(); 622 623 ext4_queue_sb(); 624 625 if (block_list_file) { 626 size_t dirlen = directory ? strlen(directory) : 0; 627 struct block_allocation* p = get_saved_allocation_chain(); 628 while (p) { 629 if (directory && strncmp(p->filename, directory, dirlen) == 0) { 630 // substitute mountpoint for the leading directory in the filename, in the output file 631 fprintf(block_list_file, "%s%s", mountpoint, p->filename + dirlen); 632 } else { 633 fprintf(block_list_file, "%s", p->filename); 634 } 635 print_blocks(block_list_file, p); 636 struct block_allocation* pn = p->next; 637 free_alloc(p); 638 p = pn; 639 } 640 } 641 642 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n", 643 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count, 644 aux_info.sb->s_inodes_count, 645 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo, 646 aux_info.sb->s_blocks_count_lo); 647 648 if (wipe && WIPE_IS_SUPPORTED) { 649 wipe_block_device(fd, info.len); 650 } 651 652 write_ext4_image(fd, gzip, sparse, crc); 653 654 sparse_file_destroy(ext4_sparse_file); 655 ext4_sparse_file = NULL; 656 657 free(mountpoint); 658 free(directory); 659 660 return 0; 661 } 662
