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 "ext4_utils.h"
18 #include "allocate.h"
19 #include "indirect.h"
20 #include "extent.h"
21 #include "sha1.h"
22
23 #include <sparse/sparse.h>
24 #ifdef REAL_UUID
25 #include <uuid.h>
26 #endif
27
28 #include <fcntl.h>
29 #include <inttypes.h>
30 #include <sys/stat.h>
31 #include <sys/types.h>
32 #include <stddef.h>
33 #include <string.h>
34
35 #ifdef USE_MINGW
36 #include <winsock2.h>
37 #else
38 #include <arpa/inet.h>
39 #include <sys/ioctl.h>
40 #endif
41
42 #if defined(__linux__)
43 #include <linux/fs.h>
44 #elif defined(__APPLE__) && defined(__MACH__)
45 #include <sys/disk.h>
46 #endif
47
48 int force = 0;
49 struct fs_info info;
50 struct fs_aux_info aux_info;
51 struct sparse_file *ext4_sparse_file;
52
53 jmp_buf setjmp_env;
54
55 /* Definition from RFC-4122 */
56 struct uuid {
57 u32 time_low;
58 u16 time_mid;
59 u16 time_hi_and_version;
60 u8 clk_seq_hi_res;
61 u8 clk_seq_low;
62 u16 node0_1;
63 u32 node2_5;
64 };
65
sha1_hash(const char * namespace,const char * name,unsigned char sha1[SHA1_DIGEST_LENGTH])66 static void sha1_hash(const char *namespace, const char *name,
67 unsigned char sha1[SHA1_DIGEST_LENGTH])
68 {
69 SHA1_CTX ctx;
70 SHA1Init(&ctx);
71 SHA1Update(&ctx, (const u8*)namespace, strlen(namespace));
72 SHA1Update(&ctx, (const u8*)name, strlen(name));
73 SHA1Final(sha1, &ctx);
74 }
75
generate_sha1_uuid(const char * namespace,const char * name,u8 result[16])76 static void generate_sha1_uuid(const char *namespace, const char *name, u8 result[16])
77 {
78 unsigned char sha1[SHA1_DIGEST_LENGTH];
79 struct uuid *uuid = (struct uuid *)result;
80
81 sha1_hash(namespace, name, (unsigned char*)sha1);
82 memcpy(uuid, sha1, sizeof(struct uuid));
83
84 uuid->time_low = ntohl(uuid->time_low);
85 uuid->time_mid = ntohs(uuid->time_mid);
86 uuid->time_hi_and_version = ntohs(uuid->time_hi_and_version);
87 uuid->time_hi_and_version &= 0x0FFF;
88 uuid->time_hi_and_version |= (5 << 12);
89 uuid->clk_seq_hi_res &= ~(1 << 6);
90 uuid->clk_seq_hi_res |= 1 << 7;
91 }
92
93 /* returns 1 if a is a power of b */
is_power_of(int a,int b)94 static int is_power_of(int a, int b)
95 {
96 while (a > b) {
97 if (a % b)
98 return 0;
99 a /= b;
100 }
101
102 return (a == b) ? 1 : 0;
103 }
104
bitmap_get_bit(u8 * bitmap,u32 bit)105 int bitmap_get_bit(u8 *bitmap, u32 bit)
106 {
107 if (bitmap[bit / 8] & (1 << (bit % 8)))
108 return 1;
109
110 return 0;
111 }
112
bitmap_clear_bit(u8 * bitmap,u32 bit)113 void bitmap_clear_bit(u8 *bitmap, u32 bit)
114 {
115 bitmap[bit / 8] &= ~(1 << (bit % 8));
116
117 return;
118 }
119
120 /* Returns 1 if the bg contains a backup superblock. On filesystems with
121 the sparse_super feature, only block groups 0, 1, and powers of 3, 5,
122 and 7 have backup superblocks. Otherwise, all block groups have backup
123 superblocks */
ext4_bg_has_super_block(int bg)124 int ext4_bg_has_super_block(int bg)
125 {
126 /* Without sparse_super, every block group has a superblock */
127 if (!(info.feat_ro_compat & EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER))
128 return 1;
129
130 if (bg == 0 || bg == 1)
131 return 1;
132
133 if (is_power_of(bg, 3) || is_power_of(bg, 5) || is_power_of(bg, 7))
134 return 1;
135
136 return 0;
137 }
138
139 /* Function to read the primary superblock */
read_sb(int fd,struct ext4_super_block * sb)140 void read_sb(int fd, struct ext4_super_block *sb)
141 {
142 off64_t ret;
143
144 ret = lseek64(fd, 1024, SEEK_SET);
145 if (ret < 0)
146 critical_error_errno("failed to seek to superblock");
147
148 ret = read(fd, sb, sizeof(*sb));
149 if (ret < 0)
150 critical_error_errno("failed to read superblock");
151 if (ret != sizeof(*sb))
152 critical_error("failed to read all of superblock");
153 }
154
155 /* Function to write a primary or backup superblock at a given offset */
write_sb(int fd,unsigned long long offset,struct ext4_super_block * sb)156 void write_sb(int fd, unsigned long long offset, struct ext4_super_block *sb)
157 {
158 off64_t ret;
159
160 ret = lseek64(fd, offset, SEEK_SET);
161 if (ret < 0)
162 critical_error_errno("failed to seek to superblock");
163
164 ret = write(fd, sb, sizeof(*sb));
165 if (ret < 0)
166 critical_error_errno("failed to write superblock");
167 if (ret != sizeof(*sb))
168 critical_error("failed to write all of superblock");
169 }
170
171 /* Write the filesystem image to a file */
write_ext4_image(int fd,int gz,int sparse,int crc)172 void write_ext4_image(int fd, int gz, int sparse, int crc)
173 {
174 sparse_file_write(ext4_sparse_file, fd, gz, sparse, crc);
175 }
176
177 /* Compute the rest of the parameters of the filesystem from the basic info */
ext4_create_fs_aux_info()178 void ext4_create_fs_aux_info()
179 {
180 aux_info.first_data_block = (info.block_size > 1024) ? 0 : 1;
181 aux_info.len_blocks = info.len / info.block_size;
182 aux_info.inode_table_blocks = DIV_ROUND_UP(info.inodes_per_group * info.inode_size,
183 info.block_size);
184 aux_info.groups = DIV_ROUND_UP(aux_info.len_blocks - aux_info.first_data_block,
185 info.blocks_per_group);
186 aux_info.blocks_per_ind = info.block_size / sizeof(u32);
187 aux_info.blocks_per_dind = aux_info.blocks_per_ind * aux_info.blocks_per_ind;
188 aux_info.blocks_per_tind = aux_info.blocks_per_dind * aux_info.blocks_per_dind;
189
190 aux_info.bg_desc_blocks =
191 DIV_ROUND_UP(aux_info.groups * sizeof(struct ext2_group_desc),
192 info.block_size);
193
194 aux_info.default_i_flags = EXT4_NOATIME_FL;
195
196 u32 last_group_size = aux_info.len_blocks % info.blocks_per_group;
197 u32 last_header_size = 2 + aux_info.inode_table_blocks;
198 if (ext4_bg_has_super_block(aux_info.groups - 1))
199 last_header_size += 1 + aux_info.bg_desc_blocks +
200 info.bg_desc_reserve_blocks;
201 if (last_group_size > 0 && last_group_size < last_header_size) {
202 aux_info.groups--;
203 aux_info.len_blocks -= last_group_size;
204 }
205
206 aux_info.sb = calloc(info.block_size, 1);
207 /* Alloc an array to hold the pointers to the backup superblocks */
208 aux_info.backup_sb = calloc(aux_info.groups, sizeof(char *));
209
210 if (!aux_info.sb)
211 critical_error_errno("calloc");
212
213 aux_info.bg_desc = calloc(info.block_size, aux_info.bg_desc_blocks);
214 if (!aux_info.bg_desc)
215 critical_error_errno("calloc");
216 aux_info.xattrs = NULL;
217 }
218
ext4_free_fs_aux_info()219 void ext4_free_fs_aux_info()
220 {
221 unsigned int i;
222
223 for (i=0; i<aux_info.groups; i++) {
224 if (aux_info.backup_sb[i])
225 free(aux_info.backup_sb[i]);
226 }
227 free(aux_info.sb);
228 free(aux_info.bg_desc);
229 }
230
231 /* Fill in the superblock memory buffer based on the filesystem parameters */
ext4_fill_in_sb(int real_uuid)232 void ext4_fill_in_sb(int real_uuid)
233 {
234 unsigned int i;
235 struct ext4_super_block *sb = aux_info.sb;
236
237 sb->s_inodes_count = info.inodes_per_group * aux_info.groups;
238 sb->s_blocks_count_lo = aux_info.len_blocks;
239 sb->s_r_blocks_count_lo = 0;
240 sb->s_free_blocks_count_lo = 0;
241 sb->s_free_inodes_count = 0;
242 sb->s_first_data_block = aux_info.first_data_block;
243 sb->s_log_block_size = log_2(info.block_size / 1024);
244 sb->s_obso_log_frag_size = log_2(info.block_size / 1024);
245 sb->s_blocks_per_group = info.blocks_per_group;
246 sb->s_obso_frags_per_group = info.blocks_per_group;
247 sb->s_inodes_per_group = info.inodes_per_group;
248 sb->s_mtime = 0;
249 sb->s_wtime = 0;
250 sb->s_mnt_count = 0;
251 sb->s_max_mnt_count = 0xFFFF;
252 sb->s_magic = EXT4_SUPER_MAGIC;
253 sb->s_state = EXT4_VALID_FS;
254 sb->s_errors = EXT4_ERRORS_RO;
255 sb->s_minor_rev_level = 0;
256 sb->s_lastcheck = 0;
257 sb->s_checkinterval = 0;
258 sb->s_creator_os = EXT4_OS_LINUX;
259 sb->s_rev_level = EXT4_DYNAMIC_REV;
260 sb->s_def_resuid = EXT4_DEF_RESUID;
261 sb->s_def_resgid = EXT4_DEF_RESGID;
262
263 sb->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
264 sb->s_inode_size = info.inode_size;
265 sb->s_block_group_nr = 0;
266 sb->s_feature_compat = info.feat_compat;
267 sb->s_feature_incompat = info.feat_incompat;
268 sb->s_feature_ro_compat = info.feat_ro_compat;
269 if (real_uuid == 1) {
270 #ifdef REAL_UUID
271 uuid_generate(sb->s_uuid);
272 #else
273 fprintf(stderr, "Not compiled with real UUID support\n");
274 abort();
275 #endif
276 } else {
277 generate_sha1_uuid("extandroid/make_ext4fs", info.label, sb->s_uuid);
278 }
279 memset(sb->s_volume_name, 0, sizeof(sb->s_volume_name));
280 strncpy(sb->s_volume_name, info.label, sizeof(sb->s_volume_name));
281 memset(sb->s_last_mounted, 0, sizeof(sb->s_last_mounted));
282 sb->s_algorithm_usage_bitmap = 0;
283
284 sb->s_reserved_gdt_blocks = info.bg_desc_reserve_blocks;
285 sb->s_prealloc_blocks = 0;
286 sb->s_prealloc_dir_blocks = 0;
287
288 //memcpy(sb->s_journal_uuid, sb->s_uuid, sizeof(sb->s_journal_uuid));
289 if (info.feat_compat & EXT4_FEATURE_COMPAT_HAS_JOURNAL)
290 sb->s_journal_inum = EXT4_JOURNAL_INO;
291 sb->s_journal_dev = 0;
292 sb->s_last_orphan = 0;
293 sb->s_hash_seed[0] = 0; /* FIXME */
294 sb->s_def_hash_version = DX_HASH_TEA;
295 sb->s_reserved_char_pad = EXT4_JNL_BACKUP_BLOCKS;
296 sb->s_desc_size = sizeof(struct ext2_group_desc);
297 sb->s_default_mount_opts = 0; /* FIXME */
298 sb->s_first_meta_bg = 0;
299 sb->s_mkfs_time = 0;
300 //sb->s_jnl_blocks[17]; /* FIXME */
301
302 sb->s_blocks_count_hi = aux_info.len_blocks >> 32;
303 sb->s_r_blocks_count_hi = 0;
304 sb->s_free_blocks_count_hi = 0;
305 sb->s_min_extra_isize = sizeof(struct ext4_inode) -
306 EXT4_GOOD_OLD_INODE_SIZE;
307 sb->s_want_extra_isize = sizeof(struct ext4_inode) -
308 EXT4_GOOD_OLD_INODE_SIZE;
309 sb->s_flags = 2;
310 sb->s_raid_stride = 0;
311 sb->s_mmp_interval = 0;
312 sb->s_mmp_block = 0;
313 sb->s_raid_stripe_width = 0;
314 sb->s_log_groups_per_flex = 0;
315 sb->s_kbytes_written = 0;
316
317 for (i = 0; i < aux_info.groups; i++) {
318 u64 group_start_block = aux_info.first_data_block + i *
319 info.blocks_per_group;
320 u32 header_size = 0;
321 if (ext4_bg_has_super_block(i)) {
322 if (i != 0) {
323 aux_info.backup_sb[i] = calloc(info.block_size, 1);
324 memcpy(aux_info.backup_sb[i], sb, info.block_size);
325 /* Update the block group nr of this backup superblock */
326 aux_info.backup_sb[i]->s_block_group_nr = i;
327 sparse_file_add_data(ext4_sparse_file, aux_info.backup_sb[i],
328 info.block_size, group_start_block);
329 }
330 sparse_file_add_data(ext4_sparse_file, aux_info.bg_desc,
331 aux_info.bg_desc_blocks * info.block_size,
332 group_start_block + 1);
333 header_size = 1 + aux_info.bg_desc_blocks + info.bg_desc_reserve_blocks;
334 }
335
336 aux_info.bg_desc[i].bg_block_bitmap = group_start_block + header_size;
337 aux_info.bg_desc[i].bg_inode_bitmap = group_start_block + header_size + 1;
338 aux_info.bg_desc[i].bg_inode_table = group_start_block + header_size + 2;
339
340 aux_info.bg_desc[i].bg_free_blocks_count = sb->s_blocks_per_group;
341 aux_info.bg_desc[i].bg_free_inodes_count = sb->s_inodes_per_group;
342 aux_info.bg_desc[i].bg_used_dirs_count = 0;
343 }
344 }
345
ext4_queue_sb(void)346 void ext4_queue_sb(void)
347 {
348 /* The write_data* functions expect only block aligned calls.
349 * This is not an issue, except when we write out the super
350 * block on a system with a block size > 1K. So, we need to
351 * deal with that here.
352 */
353 if (info.block_size > 1024) {
354 u8 *buf = calloc(info.block_size, 1);
355 memcpy(buf + 1024, (u8*)aux_info.sb, 1024);
356 sparse_file_add_data(ext4_sparse_file, buf, info.block_size, 0);
357 } else {
358 sparse_file_add_data(ext4_sparse_file, aux_info.sb, 1024, 1);
359 }
360 }
361
ext4_parse_sb_info(struct ext4_super_block * sb)362 void ext4_parse_sb_info(struct ext4_super_block *sb)
363 {
364 if (sb->s_magic != EXT4_SUPER_MAGIC)
365 error("superblock magic incorrect");
366
367 if ((sb->s_state & EXT4_VALID_FS) != EXT4_VALID_FS)
368 error("filesystem state not valid");
369
370 ext4_parse_sb(sb, &info);
371
372 ext4_create_fs_aux_info();
373
374 memcpy(aux_info.sb, sb, sizeof(*sb));
375
376 if (aux_info.first_data_block != sb->s_first_data_block)
377 critical_error("first data block does not match");
378 }
379
ext4_create_resize_inode()380 void ext4_create_resize_inode()
381 {
382 struct block_allocation *reserve_inode_alloc = create_allocation();
383 u32 reserve_inode_len = 0;
384 unsigned int i;
385
386 struct ext4_inode *inode = get_inode(EXT4_RESIZE_INO);
387 if (inode == NULL) {
388 error("failed to get resize inode");
389 return;
390 }
391
392 for (i = 0; i < aux_info.groups; i++) {
393 if (ext4_bg_has_super_block(i)) {
394 u64 group_start_block = aux_info.first_data_block + i *
395 info.blocks_per_group;
396 u32 reserved_block_start = group_start_block + 1 +
397 aux_info.bg_desc_blocks;
398 u32 reserved_block_len = info.bg_desc_reserve_blocks;
399 append_region(reserve_inode_alloc, reserved_block_start,
400 reserved_block_len, i);
401 reserve_inode_len += reserved_block_len;
402 }
403 }
404
405 inode_attach_resize(inode, reserve_inode_alloc);
406
407 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
408 inode->i_links_count = 1;
409
410 free_alloc(reserve_inode_alloc);
411 }
412
413 /* Allocate the blocks to hold a journal inode and connect them to the
414 reserved journal inode */
ext4_create_journal_inode()415 void ext4_create_journal_inode()
416 {
417 struct ext4_inode *inode = get_inode(EXT4_JOURNAL_INO);
418 if (inode == NULL) {
419 error("failed to get journal inode");
420 return;
421 }
422
423 u8 *journal_data = inode_allocate_data_extents(inode,
424 info.journal_blocks * info.block_size,
425 info.journal_blocks * info.block_size);
426 if (!journal_data) {
427 error("failed to allocate extents for journal data");
428 return;
429 }
430
431 inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
432 inode->i_links_count = 1;
433
434 journal_superblock_t *jsb = (journal_superblock_t *)journal_data;
435 jsb->s_header.h_magic = htonl(JBD2_MAGIC_NUMBER);
436 jsb->s_header.h_blocktype = htonl(JBD2_SUPERBLOCK_V2);
437 jsb->s_blocksize = htonl(info.block_size);
438 jsb->s_maxlen = htonl(info.journal_blocks);
439 jsb->s_nr_users = htonl(1);
440 jsb->s_first = htonl(1);
441 jsb->s_sequence = htonl(1);
442
443 memcpy(aux_info.sb->s_jnl_blocks, &inode->i_block, sizeof(inode->i_block));
444 }
445
446 /* Update the number of free blocks and inodes in the filesystem and in each
447 block group */
ext4_update_free()448 void ext4_update_free()
449 {
450 u32 i;
451
452 for (i = 0; i < aux_info.groups; i++) {
453 u32 bg_free_blocks = get_free_blocks(i);
454 u32 bg_free_inodes = get_free_inodes(i);
455 u16 crc;
456
457 aux_info.bg_desc[i].bg_free_blocks_count = bg_free_blocks;
458 aux_info.sb->s_free_blocks_count_lo += bg_free_blocks;
459
460 aux_info.bg_desc[i].bg_free_inodes_count = bg_free_inodes;
461 aux_info.sb->s_free_inodes_count += bg_free_inodes;
462
463 aux_info.bg_desc[i].bg_used_dirs_count += get_directories(i);
464
465 aux_info.bg_desc[i].bg_flags = get_bg_flags(i);
466
467 crc = ext4_crc16(~0, aux_info.sb->s_uuid, sizeof(aux_info.sb->s_uuid));
468 crc = ext4_crc16(crc, &i, sizeof(i));
469 crc = ext4_crc16(crc, &aux_info.bg_desc[i], offsetof(struct ext2_group_desc, bg_checksum));
470 aux_info.bg_desc[i].bg_checksum = crc;
471 }
472 }
473
get_block_device_size(int fd)474 u64 get_block_device_size(int fd)
475 {
476 u64 size = 0;
477 int ret;
478
479 #if defined(__linux__)
480 ret = ioctl(fd, BLKGETSIZE64, &size);
481 #elif defined(__APPLE__) && defined(__MACH__)
482 ret = ioctl(fd, DKIOCGETBLOCKCOUNT, &size);
483 #else
484 close(fd);
485 return 0;
486 #endif
487
488 if (ret)
489 return 0;
490
491 return size;
492 }
493
is_block_device_fd(int fd)494 int is_block_device_fd(int fd)
495 {
496 #ifdef USE_MINGW
497 return 0;
498 #else
499 struct stat st;
500 int ret = fstat(fd, &st);
501 if (ret < 0)
502 return 0;
503
504 return S_ISBLK(st.st_mode);
505 #endif
506 }
507
get_file_size(int fd)508 u64 get_file_size(int fd)
509 {
510 struct stat buf;
511 int ret;
512 u64 reserve_len = 0;
513 s64 computed_size;
514
515 ret = fstat(fd, &buf);
516 if (ret)
517 return 0;
518
519 if (info.len < 0)
520 reserve_len = -info.len;
521
522 if (S_ISREG(buf.st_mode))
523 computed_size = buf.st_size - reserve_len;
524 else if (S_ISBLK(buf.st_mode))
525 computed_size = get_block_device_size(fd) - reserve_len;
526 else
527 computed_size = 0;
528
529 if (computed_size < 0) {
530 warn("Computed filesystem size less than 0");
531 computed_size = 0;
532 }
533
534 return computed_size;
535 }
536
parse_num(const char * arg)537 u64 parse_num(const char *arg)
538 {
539 char *endptr;
540 u64 num = strtoull(arg, &endptr, 10);
541 if (*endptr == 'k' || *endptr == 'K')
542 num *= 1024LL;
543 else if (*endptr == 'm' || *endptr == 'M')
544 num *= 1024LL * 1024LL;
545 else if (*endptr == 'g' || *endptr == 'G')
546 num *= 1024LL * 1024LL * 1024LL;
547
548 return num;
549 }
550
read_ext(int fd,int verbose)551 int read_ext(int fd, int verbose)
552 {
553 off64_t ret;
554 struct ext4_super_block sb;
555
556 read_sb(fd, &sb);
557
558 ext4_parse_sb_info(&sb);
559
560 ret = lseek64(fd, info.len, SEEK_SET);
561 if (ret < 0)
562 critical_error_errno("failed to seek to end of input image");
563
564 ret = lseek64(fd, info.block_size * (aux_info.first_data_block + 1), SEEK_SET);
565 if (ret < 0)
566 critical_error_errno("failed to seek to block group descriptors");
567
568 ret = read(fd, aux_info.bg_desc, info.block_size * aux_info.bg_desc_blocks);
569 if (ret < 0)
570 critical_error_errno("failed to read block group descriptors");
571 if (ret != (int)info.block_size * (int)aux_info.bg_desc_blocks)
572 critical_error("failed to read all of block group descriptors");
573
574 if (verbose) {
575 printf("Found filesystem with parameters:\n");
576 printf(" Size: %"PRIu64"\n", info.len);
577 printf(" Block size: %d\n", info.block_size);
578 printf(" Blocks per group: %d\n", info.blocks_per_group);
579 printf(" Inodes per group: %d\n", info.inodes_per_group);
580 printf(" Inode size: %d\n", info.inode_size);
581 printf(" Label: %s\n", info.label);
582 printf(" Blocks: %"PRIu64"\n", aux_info.len_blocks);
583 printf(" Block groups: %d\n", aux_info.groups);
584 printf(" Reserved block group size: %d\n", info.bg_desc_reserve_blocks);
585 printf(" Used %d/%d inodes and %d/%d blocks\n",
586 aux_info.sb->s_inodes_count - aux_info.sb->s_free_inodes_count,
587 aux_info.sb->s_inodes_count,
588 aux_info.sb->s_blocks_count_lo - aux_info.sb->s_free_blocks_count_lo,
589 aux_info.sb->s_blocks_count_lo);
590 }
591
592 return 0;
593 }
594
595