xref: /aosp_15_r20/external/exfatprogs/exfat2img/exfat2img.c (revision 508ec739de867a7549a0b8584942a00612dc5f1c)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *   Copyright (C) 2021 LG Electronics.
4  *
5  *   Author(s): Hyunchul Lee <[email protected]>
6  */
7 
8 #include <unistd.h>
9 #include <sys/types.h>
10 #include <sys/stat.h>
11 #include <fcntl.h>
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <getopt.h>
15 #include <inttypes.h>
16 #include <string.h>
17 #include <errno.h>
18 
19 #include "exfat_ondisk.h"
20 #include "libexfat.h"
21 #include "exfat_fs.h"
22 #include "exfat_dir.h"
23 
24 #define EXFAT_MAX_UPCASE_CHARS	0x10000
25 
26 struct exfat2img_hdr {
27 	__le32	magic;
28 	__le32	major_version;
29 	__le32	minor_version;
30 	__le32	data_offset;
31 	__le32	heap_clus_offset;
32 	__le32	cluster_size;
33 	__le32	cluster_count;
34 	__le32	reserved[20];
35 } __packed;
36 
37 #define EI_MAGIC		0xB67598DB
38 #define EI_CC_PAYLOAD_LEN	4
39 
40 enum {
41 	EI_CC_INVALID,
42 	EI_CC_COPY_1,
43 	EI_CC_COPY_2,	/* followed by cluster count(4-byte) */
44 	EI_CC_SKIP_1,
45 	EI_CC_SKIP_2,	/* followed by cluster count(4-byte) */
46 };
47 
48 struct exfat2img {
49 	int			out_fd;
50 	bool			is_stdout;
51 	off_t			stdout_offset;
52 	bool			save_cc;
53 	struct exfat_blk_dev	bdev;
54 	struct exfat		*exfat;
55 	struct buffer_desc	*dump_bdesc;
56 	struct buffer_desc	*scan_bdesc;
57 	struct exfat_de_iter	de_iter;
58 };
59 
60 struct exfat_stat {
61 	long		dir_count;
62 	long		file_count;
63 	long		error_count;
64 	uint64_t	written_bytes;
65 };
66 
67 static struct exfat2img_hdr ei_hdr;
68 static struct exfat2img ei;
69 static struct exfat_stat exfat_stat;
70 static struct path_resolve_ctx path_resolve_ctx;
71 
72 static struct option opts[] = {
73 	{"output",	required_argument,	NULL,	'o' },
74 	{"version",	no_argument,		NULL,	'V' },
75 	{"help",	no_argument,		NULL,	'h' },
76 	{NULL,		0,			NULL,	 0  }
77 };
78 
usage(const char * name)79 static void usage(const char *name)
80 {
81 	fprintf(stderr, "Usage: %s <device> [image-file]\n", name);
82 	fprintf(stderr, "\t-o | --output <image-file> Specify destination file\n");
83 	fprintf(stderr, "\t-V | --version             Show version\n");
84 	fprintf(stderr, "\t-h | --help                Show help\n");
85 	exit(EXIT_FAILURE);
86 }
87 
88 #define ei_err(parent, inode, fmt, ...)			\
89 ({							\
90 		exfat_resolve_path_parent(&path_resolve_ctx,	\
91 			parent, inode);			\
92 		exfat_err("ERROR: %s: " fmt,		\
93 			path_resolve_ctx.local_path,	\
94 			##__VA_ARGS__);			\
95 })
96 
free_exfat2img(struct exfat2img * ei)97 static void free_exfat2img(struct exfat2img *ei)
98 {
99 	if (ei->exfat)
100 		exfat_free_exfat(ei->exfat);
101 	if (ei->dump_bdesc)
102 		exfat_free_buffer(ei->dump_bdesc, 2);
103 	if (ei->scan_bdesc)
104 		exfat_free_buffer(ei->scan_bdesc, 2);
105 	if (ei->out_fd)
106 		close(ei->out_fd);
107 	if (ei->bdev.dev_fd)
108 		close(ei->bdev.dev_fd);
109 }
110 
create_exfat2img(struct exfat2img * ei,struct pbr * bs,const char * out_path)111 static int create_exfat2img(struct exfat2img *ei,
112 			    struct pbr *bs,
113 			    const char *out_path)
114 {
115 	int err;
116 
117 	ei->exfat = exfat_alloc_exfat(&ei->bdev, bs);
118 	if (!ei->exfat)
119 		return -ENOMEM;
120 
121 	ei->dump_bdesc = exfat_alloc_buffer(2,
122 					    ei->exfat->clus_size,
123 					    ei->exfat->sect_size);
124 	if (!ei->dump_bdesc) {
125 		err = -ENOMEM;
126 		goto err;
127 	}
128 
129 	ei->scan_bdesc = exfat_alloc_buffer(2,
130 					    ei->exfat->clus_size,
131 					    ei->exfat->sect_size);
132 	if (!ei->scan_bdesc) {
133 		err = -ENOMEM;
134 		goto err;
135 	}
136 
137 	if (strcmp(out_path, "-")) {
138 		ei->out_fd = open(out_path, O_CREAT | O_TRUNC | O_RDWR, 0664);
139 	} else {
140 		ei->is_stdout = true;
141 		ei->out_fd = fileno(stdout);
142 		ei->save_cc = true;
143 	}
144 	if (ei->out_fd < 0) {
145 		exfat_err("failed to open %s: %s\n", out_path,
146 			  strerror(errno));
147 		err = -errno;
148 		goto err;
149 	}
150 
151 	return 0;
152 err:
153 	free_exfat2img(ei);
154 	return err;
155 }
156 
157 /**
158  * @end: excluded.
159  */
dump_range(struct exfat2img * ei,off_t start,off_t end)160 static ssize_t dump_range(struct exfat2img *ei, off_t start, off_t end)
161 {
162 	struct exfat *exfat = ei->exfat;
163 	size_t len, total_len = 0;
164 	ssize_t ret;
165 
166 	if (ei->is_stdout) {
167 		unsigned int sc, sc_offset;
168 		unsigned int ec, ec_offset;
169 
170 		if (exfat_o2c(ei->exfat, start, &sc, &sc_offset) < 0)
171 			return -ERANGE;
172 		if (exfat_o2c(ei->exfat, end - 1, &ec, &ec_offset) < 0)
173 			return -ERANGE;
174 		exfat_bitmap_set_range(ei->exfat, exfat->alloc_bitmap,
175 				       sc, ec - sc + 1);
176 		return end - start;
177 	}
178 
179 	while (start < end) {
180 		len = (size_t)MIN(end - start, exfat->clus_size);
181 
182 		ret = exfat_read(exfat->blk_dev->dev_fd,
183 				 ei->dump_bdesc[0].buffer,
184 				 len, start);
185 		if (ret != (ssize_t)len) {
186 			exfat_err("failed to read %llu bytes at %llu\n",
187 				  (unsigned long long)len,
188 				  (unsigned long long)start);
189 			return -EIO;
190 		}
191 
192 		ret = pwrite(ei->out_fd, ei->dump_bdesc[0].buffer,
193 			     len, start);
194 		if (ret != (ssize_t)len) {
195 			exfat_err("failed to write %llu bytes at %llu\n",
196 				  (unsigned long long)len,
197 				  (unsigned long long)start);
198 			return -EIO;
199 		}
200 
201 		start += len;
202 		total_len += len;
203 		exfat_stat.written_bytes += len;
204 	}
205 	return total_len;
206 }
207 
dump_sectors(struct exfat2img * ei,off_t start_sect,off_t end_sect_excl)208 static int dump_sectors(struct exfat2img *ei,
209 			off_t start_sect,
210 			off_t end_sect_excl)
211 {
212 	struct exfat *exfat = ei->exfat;
213 	off_t s, e;
214 
215 	s = exfat_s2o(exfat, start_sect);
216 	e = exfat_s2o(exfat, end_sect_excl);
217 	return dump_range(ei, s, e) <= 0 ? -EIO : 0;
218 }
219 
dump_clusters(struct exfat2img * ei,clus_t start_clus,clus_t end_clus_excl)220 static int dump_clusters(struct exfat2img *ei,
221 			 clus_t start_clus,
222 			 clus_t end_clus_excl)
223 {
224 	struct exfat *exfat = ei->exfat;
225 	off_t s, e;
226 
227 	s = exfat_c2o(exfat, start_clus);
228 	e = exfat_c2o(exfat, end_clus_excl);
229 	return dump_range(ei, s, e) <= 0 ? -EIO : 0;
230 }
231 
dump_directory(struct exfat2img * ei,struct exfat_inode * inode,size_t size,clus_t * out_clus_count)232 static int dump_directory(struct exfat2img *ei,
233 			  struct exfat_inode *inode, size_t size,
234 			  clus_t *out_clus_count)
235 {
236 	struct exfat *exfat = ei->exfat;
237 	clus_t clus, possible_count;
238 	uint64_t max_count;
239 	size_t dump_size;
240 	off_t start_off, end_off;
241 
242 	if (size == 0)
243 		return -EINVAL;
244 
245 	if (!(inode->attr & ATTR_SUBDIR))
246 		return -EINVAL;
247 
248 	clus = inode->first_clus;
249 	*out_clus_count = 0;
250 	max_count = DIV_ROUND_UP(inode->size, exfat->clus_size);
251 
252 	possible_count = (256 * MB) >> (exfat->bs->bsx.sect_per_clus_bits +
253 					exfat->bs->bsx.sect_size_bits);
254 	possible_count = MIN(possible_count, exfat->clus_count);
255 
256 	while (exfat_heap_clus(exfat, clus) && *out_clus_count < possible_count) {
257 		dump_size = MIN(size, exfat->clus_size);
258 		start_off = exfat_c2o(exfat, clus);
259 		end_off = start_off + DIV_ROUND_UP(dump_size, 512) * 512;
260 
261 		if (dump_range(ei, start_off, end_off) < 0)
262 			return -EIO;
263 
264 		*out_clus_count += 1;
265 		size -= dump_size;
266 		if (size == 0)
267 			break;
268 
269 		if (inode->is_contiguous) {
270 			if (*out_clus_count >= max_count)
271 				break;
272 		}
273 		if (exfat_get_inode_next_clus(exfat, inode, clus, &clus))
274 			return -EINVAL;
275 	}
276 	return 0;
277 }
278 
dump_root(struct exfat2img * ei)279 static int dump_root(struct exfat2img *ei)
280 {
281 	struct exfat *exfat = ei->exfat;
282 	struct exfat_inode *root;
283 	clus_t clus_count = 0;
284 
285 	root = exfat_alloc_inode(ATTR_SUBDIR);
286 	if (!root)
287 		return -ENOMEM;
288 
289 	root->first_clus = le32_to_cpu(exfat->bs->bsx.root_cluster);
290 	dump_directory(ei, root, (size_t)-1, &clus_count);
291 	root->size = clus_count * exfat->clus_size;
292 
293 	ei->exfat->root = root;
294 	return 0;
295 }
296 
read_file_dentry_set(struct exfat_de_iter * iter,struct exfat_inode ** new_node,int * skip_dentries)297 static int read_file_dentry_set(struct exfat_de_iter *iter,
298 				struct exfat_inode **new_node, int *skip_dentries)
299 {
300 	struct exfat_dentry *file_de, *stream_de, *dentry;
301 	struct exfat_inode *node = NULL;
302 	int i, ret;
303 
304 	ret = exfat_de_iter_get(iter, 0, &file_de);
305 	if (ret || file_de->type != EXFAT_FILE) {
306 		exfat_debug("failed to get file dentry\n");
307 		return -EINVAL;
308 	}
309 
310 	ret = exfat_de_iter_get(iter, 1, &stream_de);
311 	if (ret || stream_de->type != EXFAT_STREAM) {
312 		exfat_debug("failed to get stream dentry\n");
313 		*skip_dentries = 2;
314 		goto skip_dset;
315 	}
316 
317 	*new_node = NULL;
318 	node = exfat_alloc_inode(le16_to_cpu(file_de->file_attr));
319 	if (!node)
320 		return -ENOMEM;
321 
322 	for (i = 2; i <= file_de->file_num_ext; i++) {
323 		ret = exfat_de_iter_get(iter, i, &dentry);
324 		if (ret || dentry->type != EXFAT_NAME)
325 			break;
326 		memcpy(node->name +
327 		       (i - 2) * ENTRY_NAME_MAX, dentry->name_unicode,
328 		       sizeof(dentry->name_unicode));
329 	}
330 
331 	node->first_clus = le32_to_cpu(stream_de->stream_start_clu);
332 	node->is_contiguous =
333 		((stream_de->stream_flags & EXFAT_SF_CONTIGUOUS) != 0);
334 	node->size = le64_to_cpu(stream_de->stream_size);
335 
336 	*skip_dentries = i;
337 	*new_node = node;
338 	return 0;
339 skip_dset:
340 	*new_node = NULL;
341 	exfat_free_inode(node);
342 	return -EINVAL;
343 }
344 
read_file(struct exfat_de_iter * de_iter,struct exfat_inode ** new_node,int * dentry_count)345 static int read_file(struct exfat_de_iter *de_iter,
346 		     struct exfat_inode **new_node, int *dentry_count)
347 {
348 	struct exfat_inode *node;
349 	int ret;
350 
351 	*new_node = NULL;
352 
353 	ret = read_file_dentry_set(de_iter, &node, dentry_count);
354 	if (ret)
355 		return ret;
356 
357 	if (node->attr & ATTR_SUBDIR)
358 		exfat_stat.dir_count++;
359 	else
360 		exfat_stat.file_count++;
361 	*new_node = node;
362 	return ret;
363 }
364 
read_bitmap(struct exfat2img * ei,struct exfat_de_iter * iter)365 static int read_bitmap(struct exfat2img *ei, struct exfat_de_iter *iter)
366 {
367 	struct exfat *exfat = ei->exfat;
368 	struct exfat_dentry *dentry;
369 	int ret;
370 
371 	ret = exfat_de_iter_get(iter, 0, &dentry);
372 	if (ret || dentry->type != EXFAT_BITMAP) {
373 		exfat_debug("failed to get bimtap dentry\n");
374 		return -EINVAL;
375 	}
376 
377 	exfat_debug("start cluster %#x, size %#" PRIx64 "\n",
378 		    le32_to_cpu(dentry->bitmap_start_clu),
379 		    le64_to_cpu(dentry->bitmap_size));
380 
381 	if (!exfat_heap_clus(exfat, le32_to_cpu(dentry->bitmap_start_clu))) {
382 		exfat_err("invalid start cluster of allocate bitmap. 0x%x\n",
383 			  le32_to_cpu(dentry->bitmap_start_clu));
384 		return -EINVAL;
385 	}
386 
387 	exfat->disk_bitmap_clus = le32_to_cpu(dentry->bitmap_start_clu);
388 	exfat->disk_bitmap_size = DIV_ROUND_UP(exfat->clus_count, 8);
389 
390 	return dump_clusters(ei,
391 			     exfat->disk_bitmap_clus,
392 			     exfat->disk_bitmap_clus +
393 			     DIV_ROUND_UP(exfat->disk_bitmap_size,
394 					  exfat->clus_size));
395 }
396 
read_upcase_table(struct exfat2img * ei,struct exfat_de_iter * iter)397 static int read_upcase_table(struct exfat2img *ei,
398 			     struct exfat_de_iter *iter)
399 {
400 	struct exfat *exfat = ei->exfat;
401 	struct exfat_dentry *dentry = NULL;
402 	int retval;
403 	ssize_t size;
404 
405 	retval = exfat_de_iter_get(iter, 0, &dentry);
406 	if (retval || dentry->type != EXFAT_UPCASE) {
407 		exfat_debug("failed to get upcase dentry\n");
408 		return -EINVAL;
409 	}
410 
411 	if (!exfat_heap_clus(exfat, le32_to_cpu(dentry->upcase_start_clu))) {
412 		exfat_err("invalid start cluster of upcase table. 0x%x\n",
413 			  le32_to_cpu(dentry->upcase_start_clu));
414 		return -EINVAL;
415 	}
416 
417 	size = EXFAT_MAX_UPCASE_CHARS * sizeof(__le16);
418 	return dump_clusters(ei, le32_to_cpu(dentry->upcase_start_clu),
419 			     le32_to_cpu(dentry->upcase_start_clu) +
420 			     DIV_ROUND_UP(size, exfat->clus_size));
421 }
422 
read_children(struct exfat2img * ei,struct exfat_inode * dir,off_t * end_file_offset)423 static int read_children(struct exfat2img *ei, struct exfat_inode *dir,
424 			 off_t *end_file_offset)
425 {
426 	struct exfat *exfat = ei->exfat;
427 	struct exfat_inode *node = NULL;
428 	struct exfat_dentry *dentry;
429 	struct exfat_de_iter *de_iter;
430 	int dentry_count;
431 	int ret;
432 
433 	*end_file_offset = 0;
434 	de_iter = &ei->de_iter;
435 	ret = exfat_de_iter_init(de_iter, exfat, dir, ei->scan_bdesc);
436 	if (ret == EOF)
437 		return 0;
438 	else if (ret)
439 		return ret;
440 
441 	while (1) {
442 		ret = exfat_de_iter_get(de_iter, 0, &dentry);
443 		if (ret == EOF) {
444 			break;
445 		} else if (ret) {
446 			ei_err(dir->parent, dir,
447 			       "failed to get a dentry. %d\n", ret);
448 			goto err;
449 		}
450 		dentry_count = 1;
451 
452 		switch (dentry->type) {
453 		case EXFAT_FILE:
454 			ret = read_file(de_iter, &node, &dentry_count);
455 			if (ret < 0) {
456 				exfat_stat.error_count++;
457 				break;
458 			}
459 
460 			if (node) {
461 				if ((node->attr & ATTR_SUBDIR) && node->size) {
462 					node->parent = dir;
463 					list_add_tail(&node->sibling,
464 						      &dir->children);
465 					list_add_tail(&node->list,
466 						      &exfat->dir_list);
467 				} else {
468 					exfat_free_inode(node);
469 				}
470 			}
471 			break;
472 		case EXFAT_LAST:
473 			goto out;
474 		case EXFAT_BITMAP:
475 			if (dir == exfat->root) {
476 				ret = read_bitmap(ei, de_iter);
477 				if (ret)
478 					exfat_debug("failed to read bitmap\n");
479 			}
480 			break;
481 		case EXFAT_UPCASE:
482 			if (dir == exfat->root) {
483 				ret = read_upcase_table(ei, de_iter);
484 				if (ret)
485 					exfat_debug("failed to upcase table\n");
486 			}
487 			break;
488 		case EXFAT_VOLUME:
489 		default:
490 			break;
491 		}
492 
493 		ret = exfat_de_iter_advance(de_iter, dentry_count);
494 	}
495 out:
496 	*end_file_offset = exfat_de_iter_file_offset(de_iter);
497 	exfat_de_iter_flush(de_iter);
498 	return 0;
499 err:
500 	exfat_free_children(dir, false);
501 	INIT_LIST_HEAD(&dir->children);
502 	exfat_de_iter_flush(de_iter);
503 	return ret;
504 }
505 
dump_filesystem(struct exfat2img * ei)506 static int dump_filesystem(struct exfat2img *ei)
507 {
508 	struct exfat *exfat = ei->exfat;
509 	struct exfat_inode *dir;
510 	int ret = 0, dir_errors;
511 	clus_t clus_count;
512 	off_t end_file_offset;
513 
514 	if (!exfat->root) {
515 		exfat_err("root is NULL\n");
516 		return -ENOENT;
517 	}
518 
519 	list_add(&exfat->root->list, &exfat->dir_list);
520 
521 	while (!list_empty(&exfat->dir_list)) {
522 		dir = list_entry(exfat->dir_list.next,
523 				 struct exfat_inode, list);
524 		clus_count = 0;
525 
526 		if (!(dir->attr & ATTR_SUBDIR)) {
527 			ei_err(dir->parent, dir,
528 			       "failed to travel directories. the node is not directory\n");
529 			ret = -EINVAL;
530 			goto out;
531 		}
532 
533 		dir_errors = read_children(ei, dir, &end_file_offset);
534 		if (!dir_errors) {
535 			dump_directory(ei, dir, (size_t)end_file_offset,
536 				       &clus_count);
537 		} else if (dir_errors) {
538 			dump_directory(ei, dir, (size_t)-1,
539 				       &clus_count);
540 			exfat_resolve_path(&path_resolve_ctx, dir);
541 			exfat_debug("failed to check dentries: %s\n",
542 				    path_resolve_ctx.local_path);
543 			ret = dir_errors;
544 		}
545 
546 		list_del(&dir->list);
547 		exfat_free_ancestors(dir);
548 	}
549 out:
550 	exfat_free_dir_list(exfat);
551 	return ret;
552 }
553 
dump_bytes_to_stdout(struct exfat2img * ei,off_t start,off_t end_excl,bool fill_zero)554 static int dump_bytes_to_stdout(struct exfat2img *ei,
555 				off_t start, off_t end_excl, bool fill_zero)
556 {
557 	struct exfat *exfat = ei->exfat;
558 	size_t len;
559 	ssize_t ret;
560 
561 	if (start != ei->stdout_offset) {
562 		exfat_err("try to skip for stdout at %llu, expected: %llu\n",
563 			  (unsigned long long)start,
564 			  (unsigned long long)ei->stdout_offset);
565 		return -EINVAL;
566 	}
567 
568 	while (start < end_excl) {
569 		len = (size_t)MIN(end_excl - start, exfat->clus_size);
570 		if (!fill_zero) {
571 			ret = exfat_read(exfat->blk_dev->dev_fd,
572 					 ei->dump_bdesc[0].buffer,
573 					 len, start);
574 			if (ret != (ssize_t)len) {
575 				exfat_err("failed to read %llu bytes at %llu\n",
576 					  (unsigned long long)len,
577 					  (unsigned long long)start);
578 				return -EIO;
579 			}
580 
581 			ret = write(ei->out_fd, ei->dump_bdesc[0].buffer, len);
582 			if (ret != (ssize_t)len) {
583 				exfat_err("failed to write %llu bytes at %llu\n",
584 					  (unsigned long long)len,
585 					  (unsigned long long)start);
586 				return -EIO;
587 			}
588 		} else {
589 			ret = write(ei->out_fd, exfat->zero_cluster, len);
590 			if (ret != (ssize_t)len) {
591 				exfat_err("failed to write %llu bytes at %llu\n",
592 					  (unsigned long long)len,
593 					  (unsigned long long)start);
594 				return -EIO;
595 			}
596 		}
597 
598 		start += len;
599 		ei->stdout_offset += len;
600 		exfat_stat.written_bytes += len;
601 	}
602 	return 0;
603 }
604 
dump_clusters_to_stdout(struct exfat2img * ei,unsigned int start_clu,unsigned int end_clu,bool fill_zero)605 static int dump_clusters_to_stdout(struct exfat2img *ei,
606 				   unsigned int start_clu, unsigned int end_clu,
607 				   bool fill_zero)
608 {
609 	unsigned int clu, clu_count;
610 	unsigned char cc;
611 	unsigned int cc_clu_count, cc_len;
612 	off_t start_off, end_off_excl;
613 	char buf[1 + EI_CC_PAYLOAD_LEN];
614 
615 	clu = start_clu;
616 	clu_count = end_clu - start_clu + 1;
617 
618 	if (ei->save_cc) {
619 		/* if the count of clusters is less than 5, use SKIP_1 or COPY_2 */
620 		cc_clu_count = clu_count < 5 ? 1 : clu_count;
621 		cc_len = cc_clu_count == 1 ? 1 : 1 + EI_CC_PAYLOAD_LEN;
622 		if (fill_zero)
623 			cc = cc_clu_count == 1 ? EI_CC_SKIP_1 : EI_CC_SKIP_2;
624 		else
625 			cc = cc_clu_count == 1 ? EI_CC_COPY_1 : EI_CC_COPY_2;
626 	} else {
627 		cc = EI_CC_INVALID;
628 		cc_clu_count = clu_count;
629 	}
630 
631 	while (clu <= end_clu) {
632 		if (cc != EI_CC_INVALID) {
633 			buf[0] = cc;
634 			*((__le32 *)&buf[1]) =
635 				cpu_to_le32(cc_clu_count);
636 			if (write(ei->out_fd, buf, cc_len) != (ssize_t)cc_len) {
637 				exfat_err("failed to write cc %d : %u\n for %u ~ %u clusters\n",
638 					  cc, cc_clu_count,
639 					  start_clu, start_clu + cc_clu_count - 1);
640 			}
641 		}
642 
643 		if (cc == EI_CC_COPY_1 || cc == EI_CC_COPY_2) {
644 			start_off = exfat_c2o(ei->exfat, clu);
645 			end_off_excl = exfat_c2o(ei->exfat, clu + cc_clu_count);
646 
647 			if (dump_bytes_to_stdout(ei, start_off, end_off_excl,
648 						 false) < 0)
649 				return -EIO;
650 		} else {
651 			ei->stdout_offset += (off_t)cc_clu_count * ei->exfat->clus_size;
652 		}
653 		clu += cc_clu_count;
654 	}
655 
656 	return 0;
657 }
658 
dump_to_stdout(struct exfat2img * ei)659 static int dump_to_stdout(struct exfat2img *ei)
660 {
661 	struct exfat *exfat = ei->exfat;
662 	off_t start_off, end_off;
663 	unsigned int clu, last_clu, next_clu;
664 	unsigned int start_clu, end_clu;
665 
666 	start_off = 0;
667 	end_off = exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset));
668 	if (dump_bytes_to_stdout(ei, start_off, end_off, false) < 0) {
669 		exfat_err("failed to dump boot sectors and FAT tables\n");
670 		return -EIO;
671 	}
672 
673 	clu = EXFAT_FIRST_CLUSTER;
674 	last_clu = clu + exfat->clus_count;
675 	while (clu < last_clu) {
676 		/* read and write clusters for allocated ones */
677 		start_clu = 0;
678 		while (clu < last_clu &&
679 		       exfat_bitmap_get(exfat->alloc_bitmap, clu)) {
680 			if (!start_clu)
681 				start_clu = clu;
682 			end_clu = clu;
683 			clu++;
684 		}
685 
686 		if (start_clu) {
687 			if (dump_clusters_to_stdout(ei, start_clu, end_clu, false) < 0) {
688 				start_off = exfat_c2o(exfat, start_clu);
689 				end_off = exfat_c2o(exfat, end_clu);
690 				exfat_err("failed to dump range from %llx to %llx\n",
691 					  (unsigned long long)start_off,
692 					  (unsigned long long)end_off);
693 				return -EIO;
694 			}
695 		}
696 
697 		/* exit if all of the remaining clusters are free */
698 		if (clu >= last_clu)
699 			break;
700 		if (exfat_bitmap_find_one(exfat, exfat->alloc_bitmap,
701 					  clu, &next_clu))
702 			next_clu = EXFAT_FIRST_CLUSTER + exfat->clus_count;
703 
704 		/* write zeroes for free clusters */
705 		start_clu = clu;
706 		end_clu = next_clu - 1;
707 		if (dump_clusters_to_stdout(ei, start_clu, end_clu, true) < 0) {
708 			start_off = exfat_c2o(exfat, start_clu);
709 			end_off = exfat_c2o(exfat, end_clu);
710 			exfat_err("failed to dump zero range from %llx to %llx\n",
711 				  (unsigned long long)start_off,
712 				  (unsigned long long)end_off);
713 			return -EIO;
714 		}
715 
716 		clu = next_clu;
717 	}
718 
719 	return 0;
720 }
721 
dump_header(struct exfat2img * ei)722 static int dump_header(struct exfat2img *ei)
723 {
724 	struct exfat *exfat = ei->exfat;
725 
726 	ei_hdr.magic = cpu_to_le32(EI_MAGIC);
727 	ei_hdr.major_version = cpu_to_le32(1);
728 	ei_hdr.minor_version = cpu_to_le32(0);
729 	ei_hdr.data_offset = cpu_to_le32(sizeof(struct exfat2img_hdr));
730 	ei_hdr.heap_clus_offset =
731 		cpu_to_le32(le32_to_cpu(exfat->bs->bsx.clu_offset) *
732 			    exfat->sect_size);
733 	ei_hdr.cluster_size = cpu_to_le32(exfat->clus_size);
734 	ei_hdr.cluster_count = cpu_to_le32(exfat->clus_count);
735 
736 	if (write(ei->out_fd, &ei_hdr, sizeof(ei_hdr)) != (ssize_t)sizeof(ei_hdr)) {
737 		exfat_err("failed to write exfat2img header\n");
738 		return -EIO;
739 	}
740 	return 0;
741 }
742 
read_stream(int fd,void * buf,size_t len)743 static ssize_t read_stream(int fd, void *buf, size_t len)
744 {
745 	size_t read_len = 0;
746 	ssize_t ret;
747 
748 	while (read_len < len) {
749 		ret = read(fd, buf, len - read_len);
750 		if (ret < 0) {
751 			if (errno != -EAGAIN && errno != -EINTR)
752 				return -1;
753 			ret = 0;
754 		} else if (ret == 0) {
755 			return 0;
756 		}
757 		buf = (char *)buf + (size_t)ret;
758 		read_len += (size_t)ret;
759 	}
760 	return read_len;
761 }
762 
restore_from_stdin(struct exfat2img * ei)763 static int restore_from_stdin(struct exfat2img *ei)
764 {
765 	int in_fd, ret = 0;
766 	unsigned char cc;
767 	unsigned int clu, end_clu;
768 	unsigned int cc_clu_count;
769 	unsigned int clus_size;
770 	__le32 t_cc_clu_count;
771 	off_t out_start_off, out_end_off_excl;
772 	off_t in_start_off;
773 	size_t len;
774 
775 	in_fd = fileno(stdin);
776 	if (in_fd < 0) {
777 		exfat_err("failed to get fd from stdin\n");
778 		return in_fd;
779 	}
780 
781 	if (read_stream(in_fd, &ei_hdr, sizeof(ei_hdr)) != (ssize_t)sizeof(ei_hdr)) {
782 		exfat_err("failed to read a header\n");
783 		return -EIO;
784 	}
785 
786 	if (le32_to_cpu(ei_hdr.magic) != EI_MAGIC) {
787 		exfat_err("header has invalid magic %#x, expected %#x\n",
788 			  le32_to_cpu(ei_hdr.magic), EI_MAGIC);
789 		return -EINVAL;
790 	}
791 
792 	clus_size = le32_to_cpu(ei_hdr.cluster_size);
793 
794 	ei->out_fd = ei->bdev.dev_fd;
795 	ei->dump_bdesc = exfat_alloc_buffer(2, clus_size, 512);
796 	if (!ei->dump_bdesc)
797 		return -ENOMEM;
798 
799 	/* restore boot regions, and FAT tables */
800 	in_start_off = le32_to_cpu(ei_hdr.data_offset);
801 	out_start_off = 0;
802 	out_end_off_excl = le32_to_cpu(ei_hdr.heap_clus_offset);
803 	while (out_start_off < out_end_off_excl) {
804 		len = MIN(out_end_off_excl - out_start_off, clus_size);
805 		if (read_stream(in_fd, ei->dump_bdesc[0].buffer, len) != (ssize_t)len) {
806 			exfat_err("failed to read first meta region. %llu ~ %llu\n",
807 				  (unsigned long long)in_start_off,
808 				  (unsigned long long)in_start_off + len);
809 			ret = -EIO;
810 			goto out;
811 		}
812 
813 		if (pwrite(ei->out_fd, ei->dump_bdesc[0].buffer, len, out_start_off)
814 		    != (ssize_t)len) {
815 			exfat_err("failed to write first meta region. %llu ~ %llu\n",
816 				  (unsigned long long)out_start_off,
817 				  (unsigned long long)out_start_off + len);
818 			ret = -EIO;
819 			goto out;
820 		}
821 
822 		out_start_off += len;
823 		in_start_off += len;
824 	}
825 
826 	/* restore heap clusters */
827 	clu = 0;
828 	while (clu < le32_to_cpu(ei_hdr.cluster_count)) {
829 		if (read_stream(in_fd, &cc, sizeof(cc)) != (ssize_t)sizeof(cc)) {
830 			exfat_err("failed to read cc at %llu\n",
831 				  (unsigned long long)in_start_off);
832 			ret = -EIO;
833 			goto out;
834 		}
835 		in_start_off += 1;
836 
837 		if (cc == EI_CC_COPY_2 || cc == EI_CC_SKIP_2) {
838 			if (read_stream(in_fd, &t_cc_clu_count, EI_CC_PAYLOAD_LEN) !=
839 			    (ssize_t)EI_CC_PAYLOAD_LEN) {
840 				exfat_err("failed to read cc cluster count at %llu\n",
841 					  (unsigned long long)in_start_off);
842 				ret = -EIO;
843 				goto out;
844 			}
845 			cc_clu_count = le32_to_cpu(t_cc_clu_count);
846 			in_start_off += EI_CC_PAYLOAD_LEN;
847 		} else if (cc == EI_CC_COPY_1 || cc == EI_CC_SKIP_1) {
848 			cc_clu_count = 1;
849 		} else {
850 			exfat_err("unexpected cc %d at %llu\n",
851 				  cc, (unsigned long long)in_start_off);
852 			ret = -EINVAL;
853 			goto out;
854 		}
855 
856 		if (cc == EI_CC_COPY_1 || cc == EI_CC_COPY_2) {
857 			end_clu = clu + cc_clu_count;
858 			while (clu < end_clu) {
859 				if (read_stream(in_fd, ei->dump_bdesc[0].buffer,
860 						clus_size) != (ssize_t)clus_size) {
861 					exfat_err("failed to read range %llu ~ %llu\n",
862 						  (unsigned long long)in_start_off,
863 						  (unsigned long long)in_start_off + clus_size);
864 					ret = -EIO;
865 					goto out;
866 				}
867 				if (pwrite(ei->out_fd, ei->dump_bdesc[0].buffer,
868 					   clus_size, out_start_off) != (ssize_t)clus_size) {
869 					exfat_err("failed to write range %llu ~ %llu\n",
870 						  (unsigned long long)out_start_off,
871 						  (unsigned long long)out_start_off + clus_size);
872 					ret = -EIO;
873 					goto out;
874 				}
875 
876 				out_start_off += clus_size;
877 				in_start_off += clus_size;
878 				clu++;
879 			}
880 		} else {
881 			out_start_off += (off_t)cc_clu_count * clus_size;
882 			in_start_off +=  (off_t)cc_clu_count * clus_size;
883 			if (lseek(ei->out_fd, out_start_off, SEEK_SET) == (off_t)-1) {
884 				exfat_err("failed to seek to %llu\n",
885 					  (unsigned long long)out_start_off);
886 				ret = -EIO;
887 				goto out;
888 			}
889 			clu += cc_clu_count;
890 		}
891 	}
892 out:
893 	fsync(ei->out_fd);
894 	exfat_free_buffer(ei->dump_bdesc, 2);
895 	return ret;
896 }
897 
main(int argc,char * const argv[])898 int main(int argc, char * const argv[])
899 {
900 	int err = 0, c;
901 	const char *in_path, *out_path = NULL, *blkdev_path;
902 	struct pbr *bs;
903 	struct exfat_user_input ui;
904 	off_t last_sect;
905 	bool restore;
906 
907 	print_level = EXFAT_ERROR;
908 
909 	opterr = 0;
910 	while ((c = getopt_long(argc, argv, "o:Vh", opts, NULL)) != EOF) {
911 		switch (c) {
912 		case 'o':
913 			out_path = optarg;
914 			break;
915 		case 'V':
916 			show_version();
917 			return 0;
918 		case 'h':
919 			/* Fall through */
920 		default:
921 			usage(argv[0]);
922 			break;
923 		}
924 	}
925 
926 	show_version();
927 	if (!(optind == argc - 1 && out_path) &&
928 	    !(optind == argc - 2 && !out_path))
929 		usage(argv[0]);
930 
931 	in_path = argv[optind++];
932 	if (!out_path)
933 		out_path = argv[optind++];
934 
935 	if (!strcmp(in_path, "-")) {
936 		restore = true;
937 		blkdev_path = out_path;
938 	} else {
939 		restore = false;
940 		blkdev_path = in_path;
941 	}
942 
943 	memset(&ui, 0, sizeof(ui));
944 	snprintf(ui.dev_name, sizeof(ui.dev_name), "%s", blkdev_path);
945 	if (restore)
946 		ui.writeable = true;
947 	else
948 		ui.writeable = false;
949 
950 	if (exfat_get_blk_dev_info(&ui, &ei.bdev)) {
951 		exfat_err("failed to open %s\n", ui.dev_name);
952 		return EXIT_FAILURE;
953 	}
954 
955 	if (restore)
956 		return restore_from_stdin(&ei);
957 
958 	err = read_boot_sect(&ei.bdev, &bs);
959 	if (err) {
960 		close(ei.bdev.dev_fd);
961 		return EXIT_FAILURE;
962 	}
963 
964 	err = create_exfat2img(&ei, bs, out_path);
965 	if (err)
966 		return EXIT_FAILURE;
967 
968 	if (!ei.is_stdout) {
969 		err = dump_sectors(&ei, 0, le32_to_cpu(ei.exfat->bs->bsx.clu_offset));
970 		if (err) {
971 			exfat_err("failed to dump boot sectors, fat\n");
972 			goto out;
973 		}
974 
975 		last_sect = (off_t)le32_to_cpu(ei.exfat->bs->bsx.clu_offset) +
976 			(le32_to_cpu(ei.exfat->bs->bsx.clu_count) <<
977 			 ei.exfat->bs->bsx.sect_per_clus_bits) - 1;
978 		err = dump_sectors(&ei, last_sect, last_sect + 1);
979 		if (err) {
980 			exfat_err("failed to dump last sector\n");
981 			goto out;
982 		}
983 	}
984 
985 	err = dump_root(&ei);
986 	if (err) {
987 		exfat_err("failed to dump root\n");
988 		goto out;
989 	}
990 
991 	dump_filesystem(&ei);
992 
993 	if (ei.is_stdout) {
994 		err = dump_header(&ei);
995 		if (err)
996 			goto out;
997 		err = dump_to_stdout(&ei);
998 		if (err)
999 			goto out;
1000 	} else {
1001 		err = fsync(ei.out_fd);
1002 		if (err) {
1003 			exfat_err("failed to fsync %s. %d\n", out_path, errno);
1004 			goto out;
1005 		}
1006 		close(ei.out_fd);
1007 	}
1008 
1009 	printf("%ld files found, %ld directories dumped, %llu kbytes written\n",
1010 	       exfat_stat.file_count,
1011 	       exfat_stat.dir_count,
1012 	       (unsigned long long)DIV_ROUND_UP(exfat_stat.written_bytes, 1024));
1013 
1014 out:
1015 	free_exfat2img(&ei);
1016 	return err == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
1017 }
1018