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 "output_file.h"
19 #include "ext4_utils.h"
20 #include "allocate.h"
21 #include "contents.h"
22 #include "uuid.h"
23 #include "backed_block.h"
24
25 #include <assert.h>
26 #include <dirent.h>
27 #include <fcntl.h>
28 #include <libgen.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include <sys/stat.h>
34 #include <sys/types.h>
35
36 #ifdef USE_MINGW
37
38 #include <winsock2.h>
39
40 /* These match the Linux definitions of these flags.
41 L_xx is defined to avoid conflicting with the win32 versions.
42 */
43 #define L_S_IRUSR 00400
44 #define L_S_IWUSR 00200
45 #define L_S_IXUSR 00100
46 #define S_IRWXU (L_S_IRUSR | L_S_IWUSR | L_S_IXUSR)
47 #define S_IRGRP 00040
48 #define S_IWGRP 00020
49 #define S_IXGRP 00010
50 #define S_IRWXG (S_IRGRP | S_IWGRP | S_IXGRP)
51 #define S_IROTH 00004
52 #define S_IWOTH 00002
53 #define S_IXOTH 00001
54 #define S_IRWXO (S_IROTH | S_IWOTH | S_IXOTH)
55 #define S_ISUID 0004000
56 #define S_ISGID 0002000
57 #define S_ISVTX 0001000
58
59 #else
60
61 #define O_BINARY 0
62
63 #endif
64
65 /* TODO: Not implemented:
66 Allocating blocks in the same block group as the file inode
67 Hash or binary tree directories
68 Special files: sockets, devices, fifos
69 */
70
filter_dot(const struct dirent * d)71 static int filter_dot(const struct dirent *d)
72 {
73 return (strcmp(d->d_name, "..") && strcmp(d->d_name, "."));
74 }
75
build_default_directory_structure()76 static u32 build_default_directory_structure()
77 {
78 u32 inode;
79 u32 root_inode;
80 struct dentry dentries = {
81 .filename = "lost+found",
82 .file_type = EXT4_FT_DIR,
83 .mode = S_IRWXU,
84 .uid = 0,
85 .gid = 0,
86 .mtime = 0,
87 };
88 root_inode = make_directory(0, 1, &dentries, 1);
89 inode = make_directory(root_inode, 0, NULL, 0);
90 *dentries.inode = inode;
91 inode_set_permissions(inode, dentries.mode,
92 dentries.uid, dentries.gid, dentries.mtime);
93
94 return root_inode;
95 }
96
97 #ifndef USE_MINGW
98 /* Read a local directory and create the same tree in the generated filesystem.
99 Calls itself recursively with each directory in the given directory */
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)100 static u32 build_directory_structure(const char *full_path, const char *dir_path,
101 u32 dir_inode, fs_config_func_t fs_config_func,
102 struct selabel_handle *sehnd)
103 {
104 int entries = 0;
105 struct dentry *dentries;
106 struct dirent **namelist;
107 struct stat stat;
108 int ret;
109 int i;
110 u32 inode;
111 u32 entry_inode;
112 u32 dirs = 0;
113
114 entries = scandir(full_path, &namelist, filter_dot, (void*)alphasort);
115 if (entries < 0) {
116 error_errno("scandir");
117 return EXT4_ALLOCATE_FAILED;
118 }
119
120 dentries = calloc(entries, sizeof(struct dentry));
121 if (dentries == NULL)
122 critical_error_errno("malloc");
123
124 for (i = 0; i < entries; i++) {
125 dentries[i].filename = strdup(namelist[i]->d_name);
126 if (dentries[i].filename == NULL)
127 critical_error_errno("strdup");
128
129 asprintf(&dentries[i].path, "%s/%s", dir_path, namelist[i]->d_name);
130 asprintf(&dentries[i].full_path, "%s/%s", full_path, namelist[i]->d_name);
131
132 free(namelist[i]);
133
134 ret = lstat(dentries[i].full_path, &stat);
135 if (ret < 0) {
136 error_errno("lstat");
137 i--;
138 entries--;
139 continue;
140 }
141
142 dentries[i].size = stat.st_size;
143 dentries[i].mode = stat.st_mode & (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO);
144 dentries[i].mtime = stat.st_mtime;
145 if (fs_config_func != NULL) {
146 #ifdef ANDROID
147 unsigned int mode = 0;
148 unsigned int uid = 0;
149 unsigned int gid = 0;
150 int dir = S_ISDIR(stat.st_mode);
151 fs_config_func(dentries[i].path, dir, &uid, &gid, &mode);
152 dentries[i].mode = mode;
153 dentries[i].uid = uid;
154 dentries[i].gid = gid;
155 #else
156 error("can't set android permissions - built without android support");
157 #endif
158 }
159 #ifdef HAVE_SELINUX
160 if (sehnd) {
161 char *sepath = NULL;
162 asprintf(&sepath, "/%s", dentries[i].path);
163 if (selabel_lookup(sehnd, &dentries[i].secon, sepath, stat.st_mode) < 0) {
164 error("cannot lookup security context for %s", sepath);
165 }
166 if (dentries[i].secon)
167 printf("Labeling %s as %s\n", sepath, dentries[i].secon);
168 free(sepath);
169 }
170 #endif
171
172 if (S_ISREG(stat.st_mode)) {
173 dentries[i].file_type = EXT4_FT_REG_FILE;
174 } else if (S_ISDIR(stat.st_mode)) {
175 dentries[i].file_type = EXT4_FT_DIR;
176 dirs++;
177 } else if (S_ISCHR(stat.st_mode)) {
178 dentries[i].file_type = EXT4_FT_CHRDEV;
179 } else if (S_ISBLK(stat.st_mode)) {
180 dentries[i].file_type = EXT4_FT_BLKDEV;
181 } else if (S_ISFIFO(stat.st_mode)) {
182 dentries[i].file_type = EXT4_FT_FIFO;
183 } else if (S_ISSOCK(stat.st_mode)) {
184 dentries[i].file_type = EXT4_FT_SOCK;
185 } else if (S_ISLNK(stat.st_mode)) {
186 dentries[i].file_type = EXT4_FT_SYMLINK;
187 dentries[i].link = calloc(info.block_size, 1);
188 readlink(dentries[i].full_path, dentries[i].link, info.block_size - 1);
189 } else {
190 error("unknown file type on %s", dentries[i].path);
191 i--;
192 entries--;
193 }
194 }
195 free(namelist);
196
197 inode = make_directory(dir_inode, entries, dentries, dirs);
198
199 for (i = 0; i < entries; i++) {
200 if (dentries[i].file_type == EXT4_FT_REG_FILE) {
201 entry_inode = make_file(dentries[i].full_path, dentries[i].size);
202 } else if (dentries[i].file_type == EXT4_FT_DIR) {
203 entry_inode = build_directory_structure(dentries[i].full_path,
204 dentries[i].path, inode, fs_config_func, sehnd);
205 } else if (dentries[i].file_type == EXT4_FT_SYMLINK) {
206 entry_inode = make_link(dentries[i].full_path, dentries[i].link);
207 } else {
208 error("unknown file type on %s", dentries[i].path);
209 entry_inode = 0;
210 }
211 *dentries[i].inode = entry_inode;
212
213 ret = inode_set_permissions(entry_inode, dentries[i].mode,
214 dentries[i].uid, dentries[i].gid,
215 dentries[i].mtime);
216 if (ret)
217 error("failed to set permissions on %s\n", dentries[i].path);
218 ret = inode_set_selinux(entry_inode, dentries[i].secon);
219 if (ret)
220 error("failed to set SELinux context on %s\n", dentries[i].path);
221
222 free(dentries[i].path);
223 free(dentries[i].full_path);
224 free(dentries[i].link);
225 free((void *)dentries[i].filename);
226 free(dentries[i].secon);
227 }
228
229 free(dentries);
230 return inode;
231 }
232 #endif
233
compute_block_size()234 static u32 compute_block_size()
235 {
236 return 4096;
237 }
238
compute_journal_blocks()239 static u32 compute_journal_blocks()
240 {
241 u32 journal_blocks = DIV_ROUND_UP(info.len, info.block_size) / 64;
242 if (journal_blocks < 1024)
243 journal_blocks = 1024;
244 if (journal_blocks > 32768)
245 journal_blocks = 32768;
246 return journal_blocks;
247 }
248
compute_blocks_per_group()249 static u32 compute_blocks_per_group()
250 {
251 return info.block_size * 8;
252 }
253
compute_inodes()254 static u32 compute_inodes()
255 {
256 return DIV_ROUND_UP(info.len, info.block_size) / 4;
257 }
258
compute_inodes_per_group()259 static u32 compute_inodes_per_group()
260 {
261 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
262 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
263 u32 inodes = DIV_ROUND_UP(info.inodes, block_groups);
264 inodes = ALIGN(inodes, (info.block_size / info.inode_size));
265
266 /* After properly rounding up the number of inodes/group,
267 * make sure to update the total inodes field in the info struct.
268 */
269 info.inodes = inodes * block_groups;
270
271 return inodes;
272 }
273
compute_bg_desc_reserve_blocks()274 static u32 compute_bg_desc_reserve_blocks()
275 {
276 u32 blocks = DIV_ROUND_UP(info.len, info.block_size);
277 u32 block_groups = DIV_ROUND_UP(blocks, info.blocks_per_group);
278 u32 bg_desc_blocks = DIV_ROUND_UP(block_groups * sizeof(struct ext2_group_desc),
279 info.block_size);
280
281 u32 bg_desc_reserve_blocks =
282 DIV_ROUND_UP(block_groups * 1024 * sizeof(struct ext2_group_desc),
283 info.block_size) - bg_desc_blocks;
284
285 if (bg_desc_reserve_blocks > info.block_size / sizeof(u32))
286 bg_desc_reserve_blocks = info.block_size / sizeof(u32);
287
288 return bg_desc_reserve_blocks;
289 }
290
reset_ext4fs_info()291 void reset_ext4fs_info() {
292 // Reset all the global data structures used by make_ext4fs so it
293 // can be called again.
294 memset(&info, 0, sizeof(info));
295 memset(&aux_info, 0, sizeof(aux_info));
296 free_data_blocks();
297 }
298
make_ext4fs(const char * filename,s64 len,const char * mountpoint,struct selabel_handle * sehnd)299 int make_ext4fs(const char *filename, s64 len,
300 const char *mountpoint, struct selabel_handle *sehnd)
301 {
302 int fd;
303 int status;
304
305 reset_ext4fs_info();
306 info.len = len;
307
308 fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644);
309 if (fd < 0) {
310 error_errno("open");
311 return EXIT_FAILURE;
312 }
313
314 status = make_ext4fs_internal(fd, NULL, mountpoint, NULL, 0, 0, 0, 1, 0, sehnd);
315 close(fd);
316
317 return status;
318 }
319
make_ext4fs_internal(int fd,const char * directory,char * mountpoint,fs_config_func_t fs_config_func,int gzip,int sparse,int crc,int wipe,int init_itabs,struct selabel_handle * sehnd)320 int make_ext4fs_internal(int fd, const char *directory,
321 char *mountpoint, fs_config_func_t fs_config_func, int gzip, int sparse,
322 int crc, int wipe, int init_itabs, struct selabel_handle *sehnd)
323 {
324 u32 root_inode_num;
325 u16 root_mode;
326
327 if (setjmp(setjmp_env))
328 return EXIT_FAILURE; /* Handle a call to longjmp() */
329
330 if (info.len <= 0)
331 info.len = get_file_size(fd);
332
333 if (info.len <= 0) {
334 fprintf(stderr, "Need size of filesystem\n");
335 return EXIT_FAILURE;
336 }
337
338 if (info.block_size <= 0)
339 info.block_size = compute_block_size();
340
341 /* Round down the filesystem length to be a multiple of the block size */
342 info.len &= ~((u64)info.block_size - 1);
343
344 if (info.journal_blocks == 0)
345 info.journal_blocks = compute_journal_blocks();
346
347 if (info.no_journal == 0)
348 info.feat_compat = EXT4_FEATURE_COMPAT_HAS_JOURNAL;
349 else
350 info.journal_blocks = 0;
351
352 if (info.blocks_per_group <= 0)
353 info.blocks_per_group = compute_blocks_per_group();
354
355 if (info.inodes <= 0)
356 info.inodes = compute_inodes();
357
358 if (info.inode_size <= 0)
359 info.inode_size = 256;
360
361 if (info.label == NULL)
362 info.label = "";
363
364 info.inodes_per_group = compute_inodes_per_group();
365
366 info.feat_compat |=
367 EXT4_FEATURE_COMPAT_RESIZE_INODE;
368
369 info.feat_ro_compat |=
370 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER |
371 EXT4_FEATURE_RO_COMPAT_LARGE_FILE;
372
373 info.feat_incompat |=
374 EXT4_FEATURE_INCOMPAT_EXTENTS |
375 EXT4_FEATURE_INCOMPAT_FILETYPE;
376
377
378 info.bg_desc_reserve_blocks = compute_bg_desc_reserve_blocks();
379
380 printf("Creating filesystem with parameters:\n");
381 printf(" Size: %llu\n", info.len);
382 printf(" Block size: %d\n", info.block_size);
383 printf(" Blocks per group: %d\n", info.blocks_per_group);
384 printf(" Inodes per group: %d\n", info.inodes_per_group);
385 printf(" Inode size: %d\n", info.inode_size);
386 printf(" Journal blocks: %d\n", info.journal_blocks);
387 printf(" Label: %s\n", info.label);
388
389 ext4_create_fs_aux_info();
390
391 printf(" Blocks: %llu\n", aux_info.len_blocks);
392 printf(" Block groups: %d\n", aux_info.groups);
393 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
394
395 block_allocator_init();
396
397 ext4_fill_in_sb();
398
399 if (reserve_inodes(0, 10) == EXT4_ALLOCATE_FAILED)
400 error("failed to reserve first 10 inodes");
401
402 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
403 ext4_create_journal_inode();
404
405 if (info.feat_compat & EXT4_FEATURE_COMPAT_RESIZE_INODE)
406 ext4_create_resize_inode();
407
408 #ifdef USE_MINGW
409 // Windows needs only 'create an empty fs image' functionality
410 assert(!directory);
411 root_inode_num = build_default_directory_structure();
412 #else
413 if (directory)
414 root_inode_num = build_directory_structure(directory, mountpoint, 0,
415 fs_config_func, sehnd);
416 else
417 root_inode_num = build_default_directory_structure();
418 #endif
419
420 root_mode = S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH;
421 inode_set_permissions(root_inode_num, root_mode, 0, 0, 0);
422
423 #ifdef HAVE_SELINUX
424 if (sehnd) {
425 char *sepath = NULL;
426 char *secontext = NULL;
427
428 if (mountpoint[0] == '/')
429 sepath = strdup(mountpoint);
430 else
431 asprintf(&sepath, "/%s", mountpoint);
432 if (!sepath)
433 critical_error_errno("malloc");
434 if (selabel_lookup(sehnd, &secontext, sepath, S_IFDIR) < 0) {
435 error("cannot lookup security context for %s", sepath);
436 }
437 if (secontext) {
438 printf("Labeling %s as %s\n", sepath, secontext);
439 inode_set_selinux(root_inode_num, secontext);
440 }
441 free(sepath);
442 freecon(secontext);
443 }
444 #endif
445
446 ext4_update_free();
447
448 if (init_itabs)
449 init_unused_inode_tables();
450
451 ext4_queue_sb();
452
453 printf("Created filesystem with %d/%d inodes and %d/%d blocks\n",
454 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
455 aux_info.sb->s_inodes_count,
456 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
457 aux_info.sb->s_blocks_count_lo);
458
459 write_ext4_image(fd, gzip, sparse, crc, wipe);
460
461 return 0;
462 }
463