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#define O_BINARY 0 63 64#endif 65 66/* TODO: Not implemented: 67 Allocating blocks in the same block group as the file inode 68 Hash or binary tree directories 69 Special files: sockets, devices, fifos 70 */ 71 72static int filter_dot(const struct dirent *d) 73{ 74 return (strcmp(d->d_name, "..") && strcmp(d->d_name, ".")); 75} 76 77static u32 build_default_directory_structure() 78{ 79 u32 inode; 80 u32 root_inode; 81 struct dentry dentries = { 82 .filename = "lost+found", 83 .file_type = EXT4_FT_DIR, 84 .mode = S_IRWXU, 85 .uid = 0, 86 .gid = 0, 87 .mtime = 0, 88 }; 89 root_inode = make_directory(0, 1, &dentries, 1); 90 inode = make_directory(root_inode, 0, NULL, 0); 91 *dentries.inode = inode; 92 inode_set_permissions(inode, dentries.mode, 93 dentries.uid, dentries.gid, dentries.mtime); 94 95 return root_inode; 96} 97 98#ifndef USE_MINGW 99/* Read a local directory and create the same tree in the generated filesystem. 100 Calls itself recursively with each directory in the given directory */ 101static u32 build_directory_structure(const char *full_path, const char *dir_path, 102 u32 dir_inode, fs_config_func_t fs_config_func, 103 struct selabel_handle *sehnd) 104{ 105 int entries = 0; 106 struct dentry *dentries; 107 struct dirent **namelist; 108 struct stat stat; 109 int ret; 110 int i; 111 u32 inode; 112 u32 entry_inode; 113 u32 dirs = 0; 114 115 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort); 116 if (entries < 0) { 117 error_errno("scandir"); 118 return EXT4_ALLOCATE_FAILED; 119 } 120 121 dentries = calloc(entries, sizeof(struct dentry)); 122 if (dentries == NULL) 123 critical_error_errno("malloc"); 124 125 for (i = 0; i < entries; i++) { 126 dentries[i].filename = strdup(namelist[i]->d_name); 127 if (dentries[i].filename == NULL) 128 critical_error_errno("strdup"); 129 130 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name); 131 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name); 132 133 free(namelist[i]); 134 135 ret = lstat(dentries[i].full_path, &stat); 136 if (ret < 0) { 137 error_errno("lstat"); 138 i--; 139 entries--; 140 continue; 141 } 142 143 dentries[i].size = stat.st_size; 144 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO); 145 dentries[i].mtime = stat.st_mtime; 146 if (fs_config_func != NULL) { 147#ifdef ANDROID 148 unsigned int mode = 0; 149 unsigned int uid = 0; 150 unsigned int gid = 0; 151 int dir = S_ISDIR(stat.st_mode); 152 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode); 153 dentries[i].mode = mode; 154 dentries[i].uid = uid; 155 dentries[i].gid = gid; 156#else 157 error("can't set android permissions - built without android support"); 158#endif 159 } 160#ifdef HAVE_SELINUX 161 if (sehnd) { 162 char *sepath = NULL; 163 asprintf(&sepath, "/%s", dentries[i].path); 164 if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) { 165 error("cannot lookup security context for %s", sepath); 166 } 167 if (dentries[i].secon) 168 printf("Labeling %s as %s\n", sepath, dentries[i].secon); 169 free(sepath); 170 } 171#endif 172 173 if (S_ISREG(stat.st_mode)) { 174 dentries[i].file_type = EXT4_FT_REG_FILE; 175 } else if (S_ISDIR(stat.st_mode)) { 176 dentries[i].file_type = EXT4_FT_DIR; 177 dirs++; 178 } else if (S_ISCHR(stat.st_mode)) { 179 dentries[i].file_type = EXT4_FT_CHRDEV; 180 } else if (S_ISBLK(stat.st_mode)) { 181 dentries[i].file_type = EXT4_FT_BLKDEV; 182 } else if (S_ISFIFO(stat.st_mode)) { 183 dentries[i].file_type = EXT4_FT_FIFO; 184 } else if (S_ISSOCK(stat.st_mode)) { 185 dentries[i].file_type = EXT4_FT_SOCK; 186 } else if (S_ISLNK(stat.st_mode)) { 187 dentries[i].file_type = EXT4_FT_SYMLINK; 188 dentries[i].link = calloc(info.block_size, 1); 189 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1); 190 } else { 191 error("unknown file type on %s", dentries[i].path); 192 i--; 193 entries--; 194 } 195 } 196 free(namelist); 197 198 inode = make_directory(dir_inode, entries, dentries, dirs); 199 200 for (i = 0; i < entries; i++) { 201 if (dentries[i].file_type == EXT4_FT_REG_FILE) { 202 entry_inode = make_file(dentries[i].full_path, dentries[i].size); 203 } else if (dentries[i].file_type == EXT4_FT_DIR) { 204 entry_inode = build_directory_structure(dentries[i].full_path, 205 dentries[i].path, inode, fs_config_func, sehnd); 206 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) { 207 entry_inode = make_link(dentries[i].full_path, dentries[i].link); 208 } else { 209 error("unknown file type on %s", dentries[i].path); 210 entry_inode = 0; 211 } 212 *dentries[i].inode = entry_inode; 213 214 ret = inode_set_permissions(entry_inode, dentries[i].mode, 215 dentries[i].uid, dentries[i].gid, 216 dentries[i].mtime); 217 if (ret) 218 error("failed to set permissions on %s\n", dentries[i].path); 219 ret = inode_set_selinux(entry_inode, dentries[i].secon); 220 if (ret) 221 error("failed to set SELinux context on %s\n", dentries[i].path); 222 223 free(dentries[i].path); 224 free(dentries[i].full_path); 225 free(dentries[i].link); 226 free((void *)dentries[i].filename); 227 free(dentries[i].secon); 228 } 229 230 free(dentries); 231 return inode; 232} 233#endif 234 235static u32 compute_block_size() 236{ 237 return 4096; 238} 239 240static u32 compute_journal_blocks() 241{ 242 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64; 243 if (journal_blocks < 1024) 244 journal_blocks = 1024; 245 if (journal_blocks > 32768) 246 journal_blocks = 32768; 247 return journal_blocks; 248} 249 250static u32 compute_blocks_per_group() 251{ 252 return info.block_size * 8; 253} 254 255static u32 compute_inodes() 256{ 257 return DIV_ROUND_UP(info.len, info.block_size) / 4; 258} 259 260static u32 compute_inodes_per_group() 261{ 262 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 263 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 264 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups); 265 inodes = ALIGN(inodes, (info.block_size / info.inode_size)); 266 267 /* After properly rounding up the number of inodes/group, 268 * make sure to update the total inodes field in the info struct. 269 */ 270 info.inodes = inodes * block_groups; 271 272 return inodes; 273} 274 275static u32 compute_bg_desc_reserve_blocks() 276{ 277 u32 blocks = DIV_ROUND_UP(info.len, info.block_size); 278 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group); 279 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc), 280 info.block_size); 281 282 u32 bg_desc_reserve_blocks = 283 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc), 284 info.block_size) - bg_desc_blocks; 285 286 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32)) 287 bg_desc_reserve_blocks = info.block_size / sizeof(u32); 288 289 return bg_desc_reserve_blocks; 290} 291 292void reset_ext4fs_info() { 293 // Reset all the global data structures used by make_ext4fs so it 294 // can be called again. 295 memset(&info, 0, sizeof(info)); 296 memset(&aux_info, 0, sizeof(aux_info)); 297 298 if (info.sparse_file) { 299 sparse_file_destroy(info.sparse_file); 300 info.sparse_file = NULL; 301 } 302} 303 304int make_ext4fs(const char *filename, s64 len, 305 const char *mountpoint, struct selabel_handle *sehnd) 306{ 307 int fd; 308 int status; 309 310 reset_ext4fs_info(); 311 info.len = len; 312 313 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); 314 if (fd < 0) { 315 error_errno("open"); 316 return EXIT_FAILURE; 317 } 318 319 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, sehnd); 320 close(fd); 321 322 return status; 323} 324 325int make_ext4fs_internal(int fd, const char *directory, 326 char *mountpoint, fs_config_func_t fs_config_func, int gzip, int sparse, 327 int crc, int wipe, int init_itabs, struct selabel_handle *sehnd) 328{ 329 u32 root_inode_num; 330 u16 root_mode; 331 332 if (setjmp(setjmp_env)) 333 return EXIT_FAILURE; /* Handle a call to longjmp() */ 334 335 if (info.len <= 0) 336 info.len = get_file_size(fd); 337 338 if (info.len <= 0) { 339 fprintf(stderr, "Need size of filesystem\n"); 340 return EXIT_FAILURE; 341 } 342 343 if (info.block_size <= 0) 344 info.block_size = compute_block_size(); 345 346 /* Round down the filesystem length to be a multiple of the block size */ 347 info.len &= ~((u64)info.block_size - 1); 348 349 if (info.journal_blocks == 0) 350 info.journal_blocks = compute_journal_blocks(); 351 352 if (info.no_journal == 0) 353 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL; 354 else 355 info.journal_blocks = 0; 356 357 if (info.blocks_per_group <= 0) 358 info.blocks_per_group = compute_blocks_per_group(); 359 360 if (info.inodes <= 0) 361 info.inodes = compute_inodes(); 362 363 if (info.inode_size <= 0) 364 info.inode_size = 256; 365 366 if (info.label == NULL) 367 info.label = ""; 368 369 info.inodes_per_group = compute_inodes_per_group(); 370 371 info.feat_compat |= 372 EXT4_FEATURE_COMPAT_RESIZE_INODE; 373 374 info.feat_ro_compat |= 375 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER | 376 EXT4_FEATURE_RO_COMPAT_LARGE_FILE; 377 378 info.feat_incompat |= 379 EXT4_FEATURE_INCOMPAT_EXTENTS | 380 EXT4_FEATURE_INCOMPAT_FILETYPE; 381 382 383 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks(); 384 385 printf("Creating filesystem with parameters:\n"); 386 printf(" Size: %llu\n", info.len); 387 printf(" Block size: %d\n", info.block_size); 388 printf(" Blocks per group: %d\n", info.blocks_per_group); 389 printf(" Inodes per group: %d\n", info.inodes_per_group); 390 printf(" Inode size: %d\n", info.inode_size); 391 printf(" Journal blocks: %d\n", info.journal_blocks); 392 printf(" Label: %s\n", info.label); 393 394 ext4_create_fs_aux_info(); 395 396 printf(" Blocks: %llu\n", aux_info.len_blocks); 397 printf(" Block groups: %d\n", aux_info.groups); 398 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks); 399 400 info.sparse_file = sparse_file_new(info.block_size, info.len); 401 402 block_allocator_init(); 403 404 ext4_fill_in_sb(); 405 406 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED) 407 error("failed to reserve first 10 inodes"); 408 409 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL) 410 ext4_create_journal_inode(); 411 412 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE) 413 ext4_create_resize_inode(); 414 415#ifdef USE_MINGW 416 // Windows needs only 'create an empty fs image' functionality 417 assert(!directory); 418 root_inode_num = build_default_directory_structure(); 419#else 420 if (directory) 421 root_inode_num = build_directory_structure(directory, mountpoint, 0, 422 fs_config_func, sehnd); 423 else 424 root_inode_num = build_default_directory_structure(); 425#endif 426 427 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH; 428 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0); 429 430#ifdef HAVE_SELINUX 431 if (sehnd) { 432 char *sepath = NULL; 433 char *secontext = NULL; 434 435 if (mountpoint[0] == '/') 436 sepath = strdup(mountpoint); 437 else 438 asprintf(&sepath, "/%s", mountpoint); 439 if (!sepath) 440 critical_error_errno("malloc"); 441 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) { 442 error("cannot lookup security context for %s", sepath); 443 } 444 if (secontext) { 445 printf("Labeling %s as %s\n", sepath, secontext); 446 inode_set_selinux(root_inode_num, secontext); 447 } 448 free(sepath); 449 freecon(secontext); 450 } 451#endif 452 453 ext4_update_free(); 454 455 if (init_itabs) 456 init_unused_inode_tables(); 457 458 ext4_queue_sb(); 459 460 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n", 461 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count, 462 aux_info.sb->s_inodes_count, 463 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo, 464 aux_info.sb->s_blocks_count_lo); 465 466 if (wipe) 467 wipe_block_device(fd, info.len); 468 469 write_ext4_image(fd, gzip, sparse, crc); 470 471 sparse_file_destroy(info.sparse_file); 472 info.sparse_file = NULL; 473 474 return 0; 475} 476