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
filter_dot(const struct dirent * d)76 static int filter_dot(const struct dirent *d)
77 {
78 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
79 }
80
build_default_directory_structure()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 */
build_directory_structure(const char * full_path,const char * dir_path,u32 dir_inode,fs_config_func_t fs_config_func,struct selabel_handle * sehnd,int verbose)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
compute_block_size()302 static u32 compute_block_size()
303 {
304 return 4096;
305 }
306
compute_journal_blocks()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
compute_blocks_per_group()317 static u32 compute_blocks_per_group()
318 {
319 return info.block_size * 8;
320 }
321
compute_inodes()322 static u32 compute_inodes()
323 {
324 return DIV_ROUND_UP(info.len, info.block_size) / 4;
325 }
326
compute_inodes_per_group()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
compute_bg_desc_reserve_blocks()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
reset_ext4fs_info()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
make_ext4fs_sparse_fd(int fd,long long len,const char * mountpoint,struct selabel_handle * sehnd)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
make_ext4fs(const char * filename,long long len,const char * mountpoint,struct selabel_handle * sehnd)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 */
canonicalize_slashes(const char * str,bool absolute)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
canonicalize_abs_slashes(const char * str)448 static char *canonicalize_abs_slashes(const char *str)
449 {
450 return canonicalize_slashes(str, true);
451 }
452
canonicalize_rel_slashes(const char * str)453 static char *canonicalize_rel_slashes(const char *str)
454 {
455 return canonicalize_slashes(str, false);
456 }
457
make_ext4fs_internal(int fd,const char * _directory,const char * _mountpoint,fs_config_func_t fs_config_func,int gzip,int sparse,int crc,int wipe,struct selabel_handle * sehnd,int verbose)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