1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * fat_write.c
4 *
5 * R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
6 */
7
8 #define LOG_CATEGORY LOGC_FS
9
10 #include <command.h>
11 #include <config.h>
12 #include <div64.h>
13 #include <fat.h>
14 #include <log.h>
15 #include <malloc.h>
16 #include <part.h>
17 #include <rand.h>
18 #include <asm/byteorder.h>
19 #include <asm/cache.h>
20 #include <dm/uclass.h>
21 #include <linux/ctype.h>
22 #include <linux/math64.h>
23 #include "fat.c"
24
25 static dir_entry *find_directory_entry(fat_itr *itr, char *filename);
26 static int new_dir_table(fat_itr *itr);
27
28 /* Characters that may only be used in long file names */
29 static const char LONG_ONLY_CHARS[] = "+,;=[]";
30
31 /* Combined size of the name and ext fields in the directory entry */
32 #define SHORT_NAME_SIZE 11
33
34 /**
35 * str2fat() - convert string to valid FAT name characters
36 *
37 * Stop when reaching end of @src or a period.
38 * Ignore spaces.
39 * Replace characters that may only be used in long names by underscores.
40 * Convert lower case characters to upper case.
41 *
42 * To avoid assumptions about the code page we do not use characters
43 * above 0x7f for the short name.
44 *
45 * @dest: destination buffer
46 * @src: source buffer
47 * @length: size of destination buffer
48 * Return: number of bytes in destination buffer
49 */
str2fat(char * dest,char * src,int length)50 static int str2fat(char *dest, char *src, int length)
51 {
52 int i;
53
54 for (i = 0; i < length; ++src) {
55 char c = *src;
56
57 if (!c || c == '.')
58 break;
59 if (c == ' ')
60 continue;
61 if (strchr(LONG_ONLY_CHARS, c) || c > 0x7f)
62 c = '_';
63 else if (c >= 'a' && c <= 'z')
64 c &= 0xdf;
65 dest[i] = c;
66 ++i;
67 }
68 return i;
69 }
70
71 /**
72 * fat_move_to_cluster() - position to first directory entry in cluster
73 *
74 * @itr: directory iterator
75 * @cluster cluster
76 * Return: 0 for success, -EIO on error
77 */
fat_move_to_cluster(fat_itr * itr,unsigned int cluster)78 static int fat_move_to_cluster(fat_itr *itr, unsigned int cluster)
79 {
80 unsigned int nbytes;
81
82 /* position to the start of the directory */
83 itr->next_clust = cluster;
84 itr->last_cluster = 0;
85 if (!fat_next_cluster(itr, &nbytes))
86 return -EIO;
87 itr->dent = (dir_entry *)itr->block;
88 itr->remaining = nbytes / sizeof(dir_entry) - 1;
89 return 0;
90 }
91
92 /**
93 * set_name() - set short name in directory entry
94 *
95 * The function determines if the @filename is a valid short name.
96 * In this case no long name is needed.
97 *
98 * If a long name is needed, a short name is constructed.
99 *
100 * @itr: directory iterator
101 * @filename: long file name
102 * @shortname: buffer of 11 bytes to receive chosen short name and extension
103 * Return: number of directory entries needed, negative on error
104 */
set_name(fat_itr * itr,const char * filename,char * shortname)105 static int set_name(fat_itr *itr, const char *filename, char *shortname)
106 {
107 char *period;
108 char *pos;
109 int period_location;
110 char buf[13];
111 int i;
112 int ret;
113 struct nameext dirent;
114
115 if (!filename)
116 return -EIO;
117
118 /* Initialize buffer */
119 memset(&dirent, ' ', sizeof(dirent));
120
121 /* Convert filename to upper case short name */
122 period = strrchr(filename, '.');
123 pos = (char *)filename;
124 if (*pos == '.') {
125 pos = period + 1;
126 period = 0;
127 }
128 if (period)
129 str2fat(dirent.ext, period + 1, sizeof(dirent.ext));
130 period_location = str2fat(dirent.name, pos, sizeof(dirent.name));
131 if (period_location < 0)
132 return period_location;
133 if (*dirent.name == ' ')
134 *dirent.name = '_';
135 /* Substitute character 0xe5 signaling deletetion by character 0x05 */
136 if (*dirent.name == DELETED_FLAG)
137 *dirent.name = aRING;
138
139 /* If filename and short name are the same, quit. */
140 sprintf(buf, "%.*s.%.3s", period_location, dirent.name, dirent.ext);
141 if (!strcmp(buf, filename)) {
142 ret = 1;
143 goto out;
144 } else if (!strcasecmp(buf, filename)) {
145 goto out_ret;
146 }
147
148 /* Construct an indexed short name */
149 for (i = 1; i < 0x200000; ++i) {
150 int suffix_len;
151 int suffix_start;
152 int j;
153
154 /* To speed up the search use random numbers */
155 if (i < 10) {
156 j = i;
157 } else {
158 j = 30 - fls(i);
159 j = 10 + (rand() >> j);
160 }
161 sprintf(buf, "~%d", j);
162 suffix_len = strlen(buf);
163 suffix_start = 8 - suffix_len;
164 if (suffix_start > period_location)
165 suffix_start = period_location;
166 memcpy(dirent.name + suffix_start, buf, suffix_len);
167 if (*dirent.ext != ' ')
168 sprintf(buf, "%.*s.%.3s", suffix_start + suffix_len,
169 dirent.name, dirent.ext);
170 else
171 sprintf(buf, "%.*s", suffix_start + suffix_len,
172 dirent.name);
173 debug("generated short name: %s\n", buf);
174
175 /* Check that the short name does not exist yet. */
176 ret = fat_move_to_cluster(itr, itr->start_clust);
177 if (ret)
178 return ret;
179 if (find_directory_entry(itr, buf))
180 continue;
181
182 goto out_ret;
183 }
184 return -EIO;
185 out_ret:
186 debug("chosen short name: %s\n", buf);
187 /* Each long name directory entry takes 13 characters. */
188 ret = (strlen(filename) + 25) / 13;
189 out:
190 memcpy(shortname, &dirent, SHORT_NAME_SIZE);
191 return ret;
192 }
193
194 static int total_sector;
disk_write(__u32 block,__u32 nr_blocks,void * buf)195 static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
196 {
197 ulong ret;
198
199 if (!cur_dev)
200 return -1;
201
202 if (cur_part_info.start + block + nr_blocks >
203 cur_part_info.start + total_sector) {
204 printf("error: overflow occurs\n");
205 return -1;
206 }
207
208 ret = blk_dwrite(cur_dev, cur_part_info.start + block, nr_blocks, buf);
209 if (nr_blocks && ret == 0)
210 return -1;
211
212 return ret;
213 }
214
215 /*
216 * Write fat buffer into block device
217 */
flush_dirty_fat_buffer(fsdata * mydata)218 static int flush_dirty_fat_buffer(fsdata *mydata)
219 {
220 int getsize = FATBUFBLOCKS;
221 __u32 fatlength = mydata->fatlength;
222 __u8 *bufptr = mydata->fatbuf;
223 __u32 startblock = mydata->fatbufnum * FATBUFBLOCKS;
224
225 debug("debug: evicting %d, dirty: %d\n", mydata->fatbufnum,
226 (int)mydata->fat_dirty);
227
228 if ((!mydata->fat_dirty) || (mydata->fatbufnum == -1))
229 return 0;
230
231 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
232 if (startblock + getsize > fatlength)
233 getsize = fatlength - startblock;
234
235 startblock += mydata->fat_sect;
236
237 /* Write FAT buf */
238 if (disk_write(startblock, getsize, bufptr) < 0) {
239 debug("error: writing FAT blocks\n");
240 return -1;
241 }
242
243 if (mydata->fats == 2) {
244 /* Update corresponding second FAT blocks */
245 startblock += mydata->fatlength;
246 if (disk_write(startblock, getsize, bufptr) < 0) {
247 debug("error: writing second FAT blocks\n");
248 return -1;
249 }
250 }
251 mydata->fat_dirty = 0;
252
253 return 0;
254 }
255
256 /**
257 * fat_find_empty_dentries() - find a sequence of available directory entries
258 *
259 * @itr: directory iterator
260 * @count: number of directory entries to find
261 * Return: 0 on success or negative error number
262 */
fat_find_empty_dentries(fat_itr * itr,int count)263 static int fat_find_empty_dentries(fat_itr *itr, int count)
264 {
265 unsigned int cluster;
266 dir_entry *dent;
267 int remaining;
268 unsigned int n = 0;
269 int ret;
270
271 ret = fat_move_to_cluster(itr, itr->start_clust);
272 if (ret)
273 return ret;
274
275 for (;;) {
276 if (!itr->dent) {
277 log_debug("Not enough directory entries available\n");
278 return -ENOSPC;
279 }
280 switch (itr->dent->nameext.name[0]) {
281 case 0x00:
282 case DELETED_FLAG:
283 if (!n) {
284 /* Remember first deleted directory entry */
285 cluster = itr->clust;
286 dent = itr->dent;
287 remaining = itr->remaining;
288 }
289 ++n;
290 if (n == count)
291 goto out;
292 break;
293 default:
294 n = 0;
295 break;
296 }
297
298 next_dent(itr);
299 if (!itr->dent &&
300 (!itr->is_root || itr->fsdata->fatsize == 32) &&
301 new_dir_table(itr))
302 return -ENOSPC;
303 }
304 out:
305 /* Position back to first directory entry */
306 if (itr->clust != cluster) {
307 ret = fat_move_to_cluster(itr, cluster);
308 if (ret)
309 return ret;
310 }
311 itr->dent = dent;
312 itr->remaining = remaining;
313 return 0;
314 }
315
316 /*
317 * Set the file name information from 'name' into 'slotptr',
318 */
str2slot(dir_slot * slotptr,const char * name,int * idx)319 static int str2slot(dir_slot *slotptr, const char *name, int *idx)
320 {
321 int j, end_idx = 0;
322
323 for (j = 0; j <= 8; j += 2) {
324 if (name[*idx] == 0x00) {
325 slotptr->name0_4[j] = 0;
326 slotptr->name0_4[j + 1] = 0;
327 end_idx++;
328 goto name0_4;
329 }
330 slotptr->name0_4[j] = name[*idx];
331 (*idx)++;
332 end_idx++;
333 }
334 for (j = 0; j <= 10; j += 2) {
335 if (name[*idx] == 0x00) {
336 slotptr->name5_10[j] = 0;
337 slotptr->name5_10[j + 1] = 0;
338 end_idx++;
339 goto name5_10;
340 }
341 slotptr->name5_10[j] = name[*idx];
342 (*idx)++;
343 end_idx++;
344 }
345 for (j = 0; j <= 2; j += 2) {
346 if (name[*idx] == 0x00) {
347 slotptr->name11_12[j] = 0;
348 slotptr->name11_12[j + 1] = 0;
349 end_idx++;
350 goto name11_12;
351 }
352 slotptr->name11_12[j] = name[*idx];
353 (*idx)++;
354 end_idx++;
355 }
356
357 if (name[*idx] == 0x00)
358 return 1;
359
360 return 0;
361 /* Not used characters are filled with 0xff 0xff */
362 name0_4:
363 for (; end_idx < 5; end_idx++) {
364 slotptr->name0_4[end_idx * 2] = 0xff;
365 slotptr->name0_4[end_idx * 2 + 1] = 0xff;
366 }
367 end_idx = 5;
368 name5_10:
369 end_idx -= 5;
370 for (; end_idx < 6; end_idx++) {
371 slotptr->name5_10[end_idx * 2] = 0xff;
372 slotptr->name5_10[end_idx * 2 + 1] = 0xff;
373 }
374 end_idx = 11;
375 name11_12:
376 end_idx -= 11;
377 for (; end_idx < 2; end_idx++) {
378 slotptr->name11_12[end_idx * 2] = 0xff;
379 slotptr->name11_12[end_idx * 2 + 1] = 0xff;
380 }
381
382 return 1;
383 }
384
385 static int flush_dir(fat_itr *itr);
386
387 /**
388 * fill_dir_slot() - fill directory entries for long name
389 *
390 * @itr: directory iterator
391 * @l_name: long name
392 * @shortname: short name
393 * Return: 0 for success, -errno otherwise
394 */
395 static int
fill_dir_slot(fat_itr * itr,const char * l_name,const char * shortname)396 fill_dir_slot(fat_itr *itr, const char *l_name, const char *shortname)
397 {
398 __u8 temp_dir_slot_buffer[MAX_LFN_SLOT * sizeof(dir_slot)];
399 dir_slot *slotptr = (dir_slot *)temp_dir_slot_buffer;
400 __u8 counter = 0, checksum;
401 int idx = 0, ret;
402
403 /* Get short file name checksum value */
404 checksum = mkcksum((void *)shortname);
405
406 do {
407 memset(slotptr, 0x00, sizeof(dir_slot));
408 ret = str2slot(slotptr, l_name, &idx);
409 slotptr->id = ++counter;
410 slotptr->attr = ATTR_VFAT;
411 slotptr->alias_checksum = checksum;
412 slotptr++;
413 } while (ret == 0);
414
415 slotptr--;
416 slotptr->id |= LAST_LONG_ENTRY_MASK;
417
418 while (counter >= 1) {
419 memcpy(itr->dent, slotptr, sizeof(dir_slot));
420 slotptr--;
421 counter--;
422
423 if (!itr->remaining) {
424 /* Write directory table to device */
425 ret = flush_dir(itr);
426 if (ret)
427 return ret;
428 }
429
430 next_dent(itr);
431 if (!itr->dent)
432 return -EIO;
433 }
434
435 return 0;
436 }
437
438 /*
439 * Set the entry at index 'entry' in a FAT (12/16/32) table.
440 */
set_fatent_value(fsdata * mydata,__u32 entry,__u32 entry_value)441 static int set_fatent_value(fsdata *mydata, __u32 entry, __u32 entry_value)
442 {
443 __u32 bufnum, offset, off16;
444 __u16 val1, val2;
445
446 switch (mydata->fatsize) {
447 case 32:
448 bufnum = entry / FAT32BUFSIZE;
449 offset = entry - bufnum * FAT32BUFSIZE;
450 break;
451 case 16:
452 bufnum = entry / FAT16BUFSIZE;
453 offset = entry - bufnum * FAT16BUFSIZE;
454 break;
455 case 12:
456 bufnum = entry / FAT12BUFSIZE;
457 offset = entry - bufnum * FAT12BUFSIZE;
458 break;
459 default:
460 /* Unsupported FAT size */
461 return -1;
462 }
463
464 /* Read a new block of FAT entries into the cache. */
465 if (bufnum != mydata->fatbufnum) {
466 int getsize = FATBUFBLOCKS;
467 __u8 *bufptr = mydata->fatbuf;
468 __u32 fatlength = mydata->fatlength;
469 __u32 startblock = bufnum * FATBUFBLOCKS;
470
471 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
472 if (startblock + getsize > fatlength)
473 getsize = fatlength - startblock;
474
475 if (flush_dirty_fat_buffer(mydata) < 0)
476 return -1;
477
478 startblock += mydata->fat_sect;
479
480 if (disk_read(startblock, getsize, bufptr) < 0) {
481 debug("Error reading FAT blocks\n");
482 return -1;
483 }
484 mydata->fatbufnum = bufnum;
485 }
486
487 /* Mark as dirty */
488 mydata->fat_dirty = 1;
489
490 /* Set the actual entry */
491 switch (mydata->fatsize) {
492 case 32:
493 ((__u32 *) mydata->fatbuf)[offset] = cpu_to_le32(entry_value);
494 break;
495 case 16:
496 ((__u16 *) mydata->fatbuf)[offset] = cpu_to_le16(entry_value);
497 break;
498 case 12:
499 off16 = (offset * 3) / 4;
500
501 switch (offset & 0x3) {
502 case 0:
503 val1 = cpu_to_le16(entry_value) & 0xfff;
504 ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff;
505 ((__u16 *)mydata->fatbuf)[off16] |= val1;
506 break;
507 case 1:
508 val1 = cpu_to_le16(entry_value) & 0xf;
509 val2 = (cpu_to_le16(entry_value) >> 4) & 0xff;
510
511 ((__u16 *)mydata->fatbuf)[off16] &= ~0xf000;
512 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 12);
513
514 ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xff;
515 ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
516 break;
517 case 2:
518 val1 = cpu_to_le16(entry_value) & 0xff;
519 val2 = (cpu_to_le16(entry_value) >> 8) & 0xf;
520
521 ((__u16 *)mydata->fatbuf)[off16] &= ~0xff00;
522 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 8);
523
524 ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xf;
525 ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
526 break;
527 case 3:
528 val1 = cpu_to_le16(entry_value) & 0xfff;
529 ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff0;
530 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 4);
531 break;
532 default:
533 break;
534 }
535
536 break;
537 default:
538 return -1;
539 }
540
541 return 0;
542 }
543
544 /*
545 * Determine the next free cluster after 'entry' in a FAT (12/16/32) table
546 * and link it to 'entry'. EOC marker is not set on returned entry.
547 */
determine_fatent(fsdata * mydata,__u32 entry)548 static __u32 determine_fatent(fsdata *mydata, __u32 entry)
549 {
550 __u32 next_fat, next_entry = entry + 1;
551
552 while (1) {
553 next_fat = get_fatent(mydata, next_entry);
554 if (next_fat == 0) {
555 /* found free entry, link to entry */
556 set_fatent_value(mydata, entry, next_entry);
557 break;
558 }
559 next_entry++;
560 }
561 debug("FAT%d: entry: %08x, entry_value: %04x\n",
562 mydata->fatsize, entry, next_entry);
563
564 return next_entry;
565 }
566
567 /**
568 * set_sectors() - write data to sectors
569 *
570 * Write 'size' bytes from 'buffer' into the specified sector.
571 *
572 * @mydata: data to be written
573 * @startsect: sector to be written to
574 * @buffer: data to be written
575 * @size: bytes to be written (but not more than the size of a cluster)
576 * Return: 0 on success, -1 otherwise
577 */
578 static int
set_sectors(fsdata * mydata,u32 startsect,u8 * buffer,u32 size)579 set_sectors(fsdata *mydata, u32 startsect, u8 *buffer, u32 size)
580 {
581 int ret;
582
583 debug("startsect: %d\n", startsect);
584
585 if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
586 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
587
588 debug("FAT: Misaligned buffer address (%p)\n", buffer);
589
590 while (size >= mydata->sect_size) {
591 memcpy(tmpbuf, buffer, mydata->sect_size);
592 ret = disk_write(startsect++, 1, tmpbuf);
593 if (ret != 1) {
594 debug("Error writing data (got %d)\n", ret);
595 return -1;
596 }
597
598 buffer += mydata->sect_size;
599 size -= mydata->sect_size;
600 }
601 } else if (size >= mydata->sect_size) {
602 u32 nsects;
603
604 nsects = size / mydata->sect_size;
605 ret = disk_write(startsect, nsects, buffer);
606 if (ret != nsects) {
607 debug("Error writing data (got %d)\n", ret);
608 return -1;
609 }
610
611 startsect += nsects;
612 buffer += nsects * mydata->sect_size;
613 size -= nsects * mydata->sect_size;
614 }
615
616 if (size) {
617 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
618 /* Do not leak content of stack */
619 memset(tmpbuf, 0, mydata->sect_size);
620 memcpy(tmpbuf, buffer, size);
621 ret = disk_write(startsect, 1, tmpbuf);
622 if (ret != 1) {
623 debug("Error writing data (got %d)\n", ret);
624 return -1;
625 }
626 }
627
628 return 0;
629 }
630
631 /**
632 * set_cluster() - write data to cluster
633 *
634 * Write 'size' bytes from 'buffer' into the specified cluster.
635 *
636 * @mydata: data to be written
637 * @clustnum: cluster to be written to
638 * @buffer: data to be written
639 * @size: bytes to be written (but not more than the size of a cluster)
640 * Return: 0 on success, -1 otherwise
641 */
642 static int
set_cluster(fsdata * mydata,u32 clustnum,u8 * buffer,u32 size)643 set_cluster(fsdata *mydata, u32 clustnum, u8 *buffer, u32 size)
644 {
645 return set_sectors(mydata, clust_to_sect(mydata, clustnum),
646 buffer, size);
647 }
648
649 /**
650 * flush_dir() - flush directory
651 *
652 * @itr: directory iterator
653 * Return: 0 for success, -EIO on error
654 */
flush_dir(fat_itr * itr)655 static int flush_dir(fat_itr *itr)
656 {
657 fsdata *mydata = itr->fsdata;
658 u32 startsect, sect_offset, nsects;
659 int ret;
660
661 if (!itr->is_root || mydata->fatsize == 32) {
662 ret = set_cluster(mydata, itr->clust, itr->block,
663 mydata->clust_size * mydata->sect_size);
664 goto out;
665 }
666
667 sect_offset = itr->clust * mydata->clust_size;
668 startsect = mydata->rootdir_sect + sect_offset;
669 /* do not write past the end of rootdir */
670 nsects = min_t(u32, mydata->clust_size,
671 mydata->rootdir_size - sect_offset);
672
673 ret = set_sectors(mydata, startsect, itr->block,
674 nsects * mydata->sect_size);
675 out:
676 if (ret) {
677 log_err("Error: writing directory entry\n");
678 return -EIO;
679 }
680 return 0;
681 }
682
683 /*
684 * Read and modify data on existing and consecutive cluster blocks
685 */
686 static int
get_set_cluster(fsdata * mydata,__u32 clustnum,loff_t pos,__u8 * buffer,loff_t size,loff_t * gotsize)687 get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
688 loff_t size, loff_t *gotsize)
689 {
690 static u8 *tmpbuf_cluster;
691 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
692 __u32 startsect;
693 loff_t clustcount, wsize;
694 int i, ret;
695
696 *gotsize = 0;
697 if (!size)
698 return 0;
699
700 if (!tmpbuf_cluster) {
701 tmpbuf_cluster = memalign(ARCH_DMA_MINALIGN, MAX_CLUSTSIZE);
702 if (!tmpbuf_cluster)
703 return -1;
704 }
705
706 assert(pos < bytesperclust);
707 startsect = clust_to_sect(mydata, clustnum);
708
709 debug("clustnum: %d, startsect: %d, pos: %lld\n",
710 clustnum, startsect, pos);
711
712 /* partial write at beginning */
713 if (pos) {
714 wsize = min(bytesperclust - pos, size);
715 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
716 if (ret != mydata->clust_size) {
717 debug("Error reading data (got %d)\n", ret);
718 return -1;
719 }
720
721 memcpy(tmpbuf_cluster + pos, buffer, wsize);
722 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
723 if (ret != mydata->clust_size) {
724 debug("Error writing data (got %d)\n", ret);
725 return -1;
726 }
727
728 size -= wsize;
729 buffer += wsize;
730 *gotsize += wsize;
731
732 startsect += mydata->clust_size;
733
734 if (!size)
735 return 0;
736 }
737
738 /* full-cluster write */
739 if (size >= bytesperclust) {
740 clustcount = lldiv(size, bytesperclust);
741
742 if (!((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1))) {
743 wsize = clustcount * bytesperclust;
744 ret = disk_write(startsect,
745 clustcount * mydata->clust_size,
746 buffer);
747 if (ret != clustcount * mydata->clust_size) {
748 debug("Error writing data (got %d)\n", ret);
749 return -1;
750 }
751
752 size -= wsize;
753 buffer += wsize;
754 *gotsize += wsize;
755
756 startsect += clustcount * mydata->clust_size;
757 } else {
758 for (i = 0; i < clustcount; i++) {
759 memcpy(tmpbuf_cluster, buffer, bytesperclust);
760 ret = disk_write(startsect,
761 mydata->clust_size,
762 tmpbuf_cluster);
763 if (ret != mydata->clust_size) {
764 debug("Error writing data (got %d)\n",
765 ret);
766 return -1;
767 }
768
769 size -= bytesperclust;
770 buffer += bytesperclust;
771 *gotsize += bytesperclust;
772
773 startsect += mydata->clust_size;
774 }
775 }
776 }
777
778 /* partial write at end */
779 if (size) {
780 wsize = size;
781 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
782 if (ret != mydata->clust_size) {
783 debug("Error reading data (got %d)\n", ret);
784 return -1;
785 }
786 memcpy(tmpbuf_cluster, buffer, wsize);
787 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
788 if (ret != mydata->clust_size) {
789 debug("Error writing data (got %d)\n", ret);
790 return -1;
791 }
792
793 size -= wsize;
794 *gotsize += wsize;
795 }
796
797 assert(!size);
798
799 return 0;
800 }
801
802 /*
803 * Find the first empty cluster
804 */
find_empty_cluster(fsdata * mydata)805 static int find_empty_cluster(fsdata *mydata)
806 {
807 __u32 fat_val, entry = 3;
808
809 while (1) {
810 fat_val = get_fatent(mydata, entry);
811 if (fat_val == 0)
812 break;
813 entry++;
814 }
815
816 return entry;
817 }
818
819 /**
820 * new_dir_table() - allocate a cluster for additional directory entries
821 *
822 * @itr: directory iterator
823 * Return: 0 on success, -EIO otherwise
824 */
new_dir_table(fat_itr * itr)825 static int new_dir_table(fat_itr *itr)
826 {
827 fsdata *mydata = itr->fsdata;
828 int dir_newclust = 0;
829 int dir_oldclust = itr->clust;
830 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
831
832 dir_newclust = find_empty_cluster(mydata);
833
834 /*
835 * Flush before updating FAT to ensure valid directory structure
836 * in case of failure.
837 */
838 itr->clust = dir_newclust;
839 itr->next_clust = dir_newclust;
840 memset(itr->block, 0x00, bytesperclust);
841 if (flush_dir(itr))
842 return -EIO;
843
844 set_fatent_value(mydata, dir_oldclust, dir_newclust);
845 if (mydata->fatsize == 32)
846 set_fatent_value(mydata, dir_newclust, 0xffffff8);
847 else if (mydata->fatsize == 16)
848 set_fatent_value(mydata, dir_newclust, 0xfff8);
849 else if (mydata->fatsize == 12)
850 set_fatent_value(mydata, dir_newclust, 0xff8);
851
852 if (flush_dirty_fat_buffer(mydata) < 0)
853 return -EIO;
854
855 itr->dent = (dir_entry *)itr->block;
856 itr->last_cluster = 1;
857 itr->remaining = bytesperclust / sizeof(dir_entry) - 1;
858
859 return 0;
860 }
861
862 /*
863 * Set empty cluster from 'entry' to the end of a file
864 */
clear_fatent(fsdata * mydata,__u32 entry)865 static int clear_fatent(fsdata *mydata, __u32 entry)
866 {
867 __u32 fat_val;
868
869 while (!CHECK_CLUST(entry, mydata->fatsize)) {
870 fat_val = get_fatent(mydata, entry);
871 if (fat_val != 0)
872 set_fatent_value(mydata, entry, 0);
873 else
874 break;
875
876 entry = fat_val;
877 }
878
879 /* Flush fat buffer */
880 if (flush_dirty_fat_buffer(mydata) < 0)
881 return -1;
882
883 return 0;
884 }
885
886 /*
887 * Set start cluster in directory entry
888 */
set_start_cluster(const fsdata * mydata,dir_entry * dentptr,__u32 start_cluster)889 static void set_start_cluster(const fsdata *mydata, dir_entry *dentptr,
890 __u32 start_cluster)
891 {
892 if (mydata->fatsize == 32)
893 dentptr->starthi =
894 cpu_to_le16((start_cluster & 0xffff0000) >> 16);
895 dentptr->start = cpu_to_le16(start_cluster & 0xffff);
896 }
897
898 /*
899 * Check whether adding a file makes the file system to
900 * exceed the size of the block device
901 * Return -1 when overflow occurs, otherwise return 0
902 */
check_overflow(fsdata * mydata,__u32 clustnum,loff_t size)903 static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
904 {
905 __u32 startsect, sect_num, offset;
906
907 if (clustnum > 0)
908 startsect = clust_to_sect(mydata, clustnum);
909 else
910 startsect = mydata->rootdir_sect;
911
912 sect_num = div_u64_rem(size, mydata->sect_size, &offset);
913
914 if (offset != 0)
915 sect_num++;
916
917 if (startsect + sect_num > total_sector)
918 return -1;
919 return 0;
920 }
921
922 /*
923 * Write at most 'maxsize' bytes from 'buffer' into
924 * the file associated with 'dentptr'
925 * Update the number of bytes written in *gotsize and return 0
926 * or return -1 on fatal errors.
927 */
928 static int
set_contents(fsdata * mydata,dir_entry * dentptr,loff_t pos,__u8 * buffer,loff_t maxsize,loff_t * gotsize)929 set_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, __u8 *buffer,
930 loff_t maxsize, loff_t *gotsize)
931 {
932 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
933 __u32 curclust = START(dentptr);
934 __u32 endclust = 0, newclust = 0;
935 u64 cur_pos, filesize;
936 loff_t offset, actsize, wsize;
937
938 *gotsize = 0;
939 filesize = pos + maxsize;
940
941 debug("%llu bytes\n", filesize);
942
943 if (!filesize) {
944 if (!curclust)
945 return 0;
946 if (!CHECK_CLUST(curclust, mydata->fatsize) ||
947 IS_LAST_CLUST(curclust, mydata->fatsize)) {
948 clear_fatent(mydata, curclust);
949 set_start_cluster(mydata, dentptr, 0);
950 return 0;
951 }
952 debug("curclust: 0x%x\n", curclust);
953 debug("Invalid FAT entry\n");
954 return -1;
955 }
956
957 if (!curclust) {
958 assert(pos == 0);
959 goto set_clusters;
960 }
961
962 /* go to cluster at pos */
963 cur_pos = bytesperclust;
964 while (1) {
965 if (pos <= cur_pos)
966 break;
967 if (IS_LAST_CLUST(curclust, mydata->fatsize))
968 break;
969
970 newclust = get_fatent(mydata, curclust);
971 if (!IS_LAST_CLUST(newclust, mydata->fatsize) &&
972 CHECK_CLUST(newclust, mydata->fatsize)) {
973 debug("curclust: 0x%x\n", curclust);
974 debug("Invalid FAT entry\n");
975 return -1;
976 }
977
978 cur_pos += bytesperclust;
979 curclust = newclust;
980 }
981 if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
982 assert(pos == cur_pos);
983 goto set_clusters;
984 }
985
986 assert(pos < cur_pos);
987 cur_pos -= bytesperclust;
988
989 /* overwrite */
990 assert(IS_LAST_CLUST(curclust, mydata->fatsize) ||
991 !CHECK_CLUST(curclust, mydata->fatsize));
992
993 while (1) {
994 /* search for allocated consecutive clusters */
995 actsize = bytesperclust;
996 endclust = curclust;
997 while (1) {
998 if (filesize <= (cur_pos + actsize))
999 break;
1000
1001 newclust = get_fatent(mydata, endclust);
1002
1003 if (newclust != endclust + 1)
1004 break;
1005 if (IS_LAST_CLUST(newclust, mydata->fatsize))
1006 break;
1007 if (CHECK_CLUST(newclust, mydata->fatsize)) {
1008 debug("curclust: 0x%x\n", curclust);
1009 debug("Invalid FAT entry\n");
1010 return -1;
1011 }
1012
1013 actsize += bytesperclust;
1014 endclust = newclust;
1015 }
1016
1017 /* overwrite to <curclust..endclust> */
1018 if (pos < cur_pos)
1019 offset = 0;
1020 else
1021 offset = pos - cur_pos;
1022 wsize = min_t(unsigned long long, actsize, filesize - cur_pos);
1023 wsize -= offset;
1024
1025 if (get_set_cluster(mydata, curclust, offset,
1026 buffer, wsize, &actsize)) {
1027 printf("Error get-and-setting cluster\n");
1028 return -1;
1029 }
1030 buffer += wsize;
1031 *gotsize += wsize;
1032 cur_pos += offset + wsize;
1033
1034 if (filesize <= cur_pos)
1035 break;
1036
1037 if (IS_LAST_CLUST(newclust, mydata->fatsize))
1038 /* no more clusters */
1039 break;
1040
1041 curclust = newclust;
1042 }
1043
1044 if (filesize <= cur_pos) {
1045 /* no more write */
1046 newclust = get_fatent(mydata, endclust);
1047 if (!IS_LAST_CLUST(newclust, mydata->fatsize)) {
1048 /* truncate the rest */
1049 clear_fatent(mydata, newclust);
1050
1051 /* Mark end of file in FAT */
1052 if (mydata->fatsize == 12)
1053 newclust = 0xfff;
1054 else if (mydata->fatsize == 16)
1055 newclust = 0xffff;
1056 else if (mydata->fatsize == 32)
1057 newclust = 0xfffffff;
1058 set_fatent_value(mydata, endclust, newclust);
1059 }
1060
1061 return 0;
1062 }
1063
1064 curclust = endclust;
1065 filesize -= cur_pos;
1066 assert(!do_div(cur_pos, bytesperclust));
1067
1068 set_clusters:
1069 /* allocate and write */
1070 assert(!pos);
1071
1072 /* Assure that curclust is valid */
1073 if (!curclust) {
1074 curclust = find_empty_cluster(mydata);
1075 set_start_cluster(mydata, dentptr, curclust);
1076 } else {
1077 newclust = get_fatent(mydata, curclust);
1078
1079 if (IS_LAST_CLUST(newclust, mydata->fatsize)) {
1080 newclust = determine_fatent(mydata, curclust);
1081 set_fatent_value(mydata, curclust, newclust);
1082 curclust = newclust;
1083 } else {
1084 debug("error: something wrong\n");
1085 return -1;
1086 }
1087 }
1088
1089 /* TODO: already partially written */
1090 if (check_overflow(mydata, curclust, filesize)) {
1091 printf("Error: no space left: %llu\n", filesize);
1092 return -1;
1093 }
1094
1095 actsize = bytesperclust;
1096 endclust = curclust;
1097 do {
1098 /* search for consecutive clusters */
1099 while (actsize < filesize) {
1100 newclust = determine_fatent(mydata, endclust);
1101
1102 if ((newclust - 1) != endclust)
1103 /* write to <curclust..endclust> */
1104 goto getit;
1105
1106 if (CHECK_CLUST(newclust, mydata->fatsize)) {
1107 debug("newclust: 0x%x\n", newclust);
1108 debug("Invalid FAT entry\n");
1109 return 0;
1110 }
1111 endclust = newclust;
1112 actsize += bytesperclust;
1113 }
1114
1115 /* set remaining bytes */
1116 actsize = filesize;
1117 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
1118 debug("error: writing cluster\n");
1119 return -1;
1120 }
1121 *gotsize += actsize;
1122
1123 /* Mark end of file in FAT */
1124 if (mydata->fatsize == 12)
1125 newclust = 0xfff;
1126 else if (mydata->fatsize == 16)
1127 newclust = 0xffff;
1128 else if (mydata->fatsize == 32)
1129 newclust = 0xfffffff;
1130 set_fatent_value(mydata, endclust, newclust);
1131
1132 return 0;
1133 getit:
1134 if (set_cluster(mydata, curclust, buffer, (u32)actsize) != 0) {
1135 debug("error: writing cluster\n");
1136 return -1;
1137 }
1138 *gotsize += actsize;
1139 filesize -= actsize;
1140 buffer += actsize;
1141
1142 if (CHECK_CLUST(newclust, mydata->fatsize)) {
1143 debug("newclust: 0x%x\n", newclust);
1144 debug("Invalid FAT entry\n");
1145 return 0;
1146 }
1147 actsize = bytesperclust;
1148 curclust = endclust = newclust;
1149 } while (1);
1150
1151 return 0;
1152 }
1153
1154 /**
1155 * dentry_set_time() - set change time
1156 *
1157 * @dentptr: directory entry
1158 */
dentry_set_time(dir_entry * dentptr)1159 static void dentry_set_time(dir_entry *dentptr)
1160 {
1161 if (CONFIG_IS_ENABLED(DM_RTC)) {
1162 struct udevice *dev;
1163 struct rtc_time tm;
1164 u16 date;
1165 u16 time;
1166
1167 uclass_first_device(UCLASS_RTC, &dev);
1168 if (!dev)
1169 goto err;
1170 if (dm_rtc_get(dev, &tm))
1171 goto err;
1172 if (tm.tm_year < 1980 || tm.tm_year > 2107)
1173 goto err;
1174 date = (tm.tm_mday & 0x1f) |
1175 ((tm.tm_mon & 0xf) << 5) |
1176 ((tm.tm_year - 1980) << 9);
1177 time = (tm.tm_sec > 1) |
1178 ((tm.tm_min & 0x3f) << 5) |
1179 (tm.tm_hour << 11);
1180 dentptr->date = date;
1181 dentptr->time = time;
1182 return;
1183 }
1184 err:
1185 dentptr->date = 0x2821; /* 2000-01-01 */
1186 dentptr->time = 0;
1187 }
1188
1189 /**
1190 * fill_dentry() - fill directory entry with shortname
1191 *
1192 * @mydata: private filesystem parameters
1193 * @dentptr: directory entry
1194 * @shortname: chosen short name
1195 * @start_cluster: first cluster of file
1196 * @size: file size
1197 * @attr: file attributes
1198 */
fill_dentry(fsdata * mydata,dir_entry * dentptr,const char * shortname,__u32 start_cluster,__u32 size,__u8 attr)1199 static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
1200 const char *shortname, __u32 start_cluster, __u32 size, __u8 attr)
1201 {
1202 memset(dentptr, 0, sizeof(*dentptr));
1203
1204 set_start_cluster(mydata, dentptr, start_cluster);
1205 dentptr->size = cpu_to_le32(size);
1206
1207 dentptr->attr = attr;
1208
1209 /* Set change date */
1210 dentry_set_time(dentptr);
1211 /* Set creation date */
1212 dentptr->cdate = dentptr->date;
1213 dentptr->ctime = dentptr->time;
1214
1215 memcpy(&dentptr->nameext, shortname, SHORT_NAME_SIZE);
1216 }
1217
1218 /**
1219 * fat_itr_parent() - modifies the iterator to the parent directory of the
1220 * current iterator.
1221 *
1222 * @itr: iterator positioned anywhere in a directory
1223 * @Return: 0 if the iterator is in the parent directory, -errno otherwise
1224 */
fat_itr_parent(fat_itr * itr)1225 static int fat_itr_parent(fat_itr *itr)
1226 {
1227 int ret;
1228
1229 if (itr->is_root)
1230 return -EIO;
1231
1232 /* ensure iterator is at the first directory entry */
1233 ret = fat_move_to_cluster(itr, itr->start_clust);
1234 if (ret)
1235 return ret;
1236
1237 return fat_itr_resolve(itr, "..", TYPE_DIR);
1238 }
1239
1240 /**
1241 * update_parent_dir_props - updates the modified time for the parent directory
1242 *
1243 * @dir_itr: iterator positioned anywhere in a directory whose parent
1244 * should be updated
1245 * @Return: 0 for success, -errno otherwise
1246 */
update_parent_dir_props(fat_itr * dir_itr)1247 static int update_parent_dir_props(fat_itr *dir_itr)
1248 {
1249 int ret = 0;
1250
1251 fat_itr itr;
1252 fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1253 __u32 target_clust = dir_itr->start_clust;
1254
1255 /* Short circuit if no RTC because it only updates timestamps */
1256 if (!CONFIG_IS_ENABLED(DM_RTC))
1257 return ret;
1258
1259 /* duplicate fsdata */
1260 itr = *dir_itr;
1261 fsdata = *itr.fsdata;
1262
1263 /* allocate local fat buffer */
1264 fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1265 if (!fsdata.fatbuf) {
1266 log_debug("Error: allocating memory\n");
1267 ret = -ENOMEM;
1268 return ret;
1269 }
1270
1271 fsdata.fatbufnum = -1;
1272 itr.fsdata = &fsdata;
1273
1274 if (!itr.is_root) {
1275 ret = fat_itr_parent(&itr);
1276 if (ret)
1277 goto exit;
1278
1279 while (fat_itr_next(&itr)) {
1280 if (START(itr.dent) == target_clust)
1281 goto update;
1282 }
1283
1284 /* dent not found */
1285 ret = -EIO;
1286 goto exit;
1287 update:
1288 dentry_set_time(itr.dent);
1289 ret = flush_dir(&itr);
1290 }
1291
1292 exit:
1293 free(fsdata.fatbuf);
1294
1295 return ret;
1296 }
1297
1298 /**
1299 * create_link() - inserts a directory entry for a file or directory
1300 *
1301 * @itr: directory iterator
1302 * @basename: file name
1303 * @clust: cluster number the new directory entry should point to. Use 0
1304 * if no cluster is assigned yet
1305 * @size: file size
1306 * @attr: file attributes
1307 * Return: 0 for success
1308 */
create_link(fat_itr * itr,char * basename,__u32 clust,__u32 size,__u8 attr)1309 static int create_link(fat_itr *itr, char *basename, __u32 clust, __u32 size,
1310 __u8 attr)
1311 {
1312 char shortname[SHORT_NAME_SIZE];
1313 int ndent;
1314 int ret;
1315
1316 /* Check if long name is needed */
1317 ndent = set_name(itr, basename, shortname);
1318 if (ndent < 0)
1319 return ndent;
1320 ret = fat_find_empty_dentries(itr, ndent);
1321 if (ret)
1322 return ret;
1323 if (ndent > 1) {
1324 /* Set long name entries */
1325 ret = fill_dir_slot(itr, basename, shortname);
1326 if (ret)
1327 return ret;
1328 }
1329
1330 fill_dentry(itr->fsdata, itr->dent, shortname, clust, size, attr);
1331 ret = update_parent_dir_props(itr);
1332
1333 return ret;
1334 }
1335
1336 /**
1337 * find_directory_entry() - find a directory entry by filename
1338 *
1339 * @itr: directory iterator
1340 * @filename: name of file to find
1341 * Return: directory entry or NULL
1342 */
find_directory_entry(fat_itr * itr,char * filename)1343 static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
1344 {
1345 int match = 0;
1346
1347 while (fat_itr_next(itr)) {
1348 /* check both long and short name: */
1349 if (!strcasecmp(filename, itr->name))
1350 match = 1;
1351 else if (itr->name != itr->s_name &&
1352 !strcasecmp(filename, itr->s_name))
1353 match = 1;
1354
1355 if (!match)
1356 continue;
1357
1358 if (itr->dent->nameext.name[0] == '\0')
1359 return NULL;
1360 else
1361 return itr->dent;
1362 }
1363
1364 return NULL;
1365 }
1366
split_filename(char * filename,char ** dirname,char ** basename)1367 static int split_filename(char *filename, char **dirname, char **basename)
1368 {
1369 char *p, *last_slash, *last_slash_cont;
1370
1371 again:
1372 p = filename;
1373 last_slash = NULL;
1374 last_slash_cont = NULL;
1375 while (*p) {
1376 if (ISDIRDELIM(*p)) {
1377 last_slash = p;
1378 last_slash_cont = p;
1379 /* continuous slashes */
1380 while (ISDIRDELIM(*p))
1381 last_slash_cont = p++;
1382 if (!*p)
1383 break;
1384 }
1385 p++;
1386 }
1387
1388 if (last_slash) {
1389 if (last_slash_cont == (filename + strlen(filename) - 1)) {
1390 /* remove trailing slashes */
1391 *last_slash = '\0';
1392 goto again;
1393 }
1394
1395 if (last_slash == filename) {
1396 /* avoid ""(null) directory */
1397 *dirname = "/";
1398 } else {
1399 *last_slash = '\0';
1400 *dirname = filename;
1401 }
1402
1403 *last_slash_cont = '\0';
1404 filename = last_slash_cont + 1;
1405 } else {
1406 *dirname = "/"; /* root by default */
1407 }
1408
1409 /*
1410 * The FAT32 File System Specification v1.03 requires leading and
1411 * trailing spaces as well as trailing periods to be ignored.
1412 */
1413 for (; *filename == ' '; ++filename)
1414 ;
1415
1416 /* Keep special entries '.' and '..' */
1417 if (filename[0] == '.' &&
1418 (!filename[1] || (filename[1] == '.' && !filename[2])))
1419 goto done;
1420
1421 /* Remove trailing periods and spaces */
1422 for (p = filename + strlen(filename) - 1; p >= filename; --p) {
1423 switch (*p) {
1424 case ' ':
1425 case '.':
1426 *p = 0;
1427 break;
1428 default:
1429 goto done;
1430 }
1431 }
1432
1433 done:
1434 *basename = filename;
1435
1436 return 0;
1437 }
1438
1439 /**
1440 * normalize_longname() - check long file name and convert to lower case
1441 *
1442 * We assume here that the FAT file system is using an 8bit code page.
1443 * Linux typically uses CP437, EDK2 assumes CP1250.
1444 *
1445 * @l_filename: preallocated buffer receiving the normalized name
1446 * @filename: filename to normalize
1447 * Return: 0 on success, -1 on failure
1448 */
normalize_longname(char * l_filename,const char * filename)1449 static int normalize_longname(char *l_filename, const char *filename)
1450 {
1451 const char *p, illegal[] = "<>:\"/\\|?*";
1452 size_t len;
1453
1454 len = strlen(filename);
1455 if (!len || len >= VFAT_MAXLEN_BYTES || filename[len - 1] == '.')
1456 return -1;
1457
1458 for (p = filename; *p; ++p) {
1459 if ((unsigned char)*p < 0x20)
1460 return -1;
1461 if (strchr(illegal, *p))
1462 return -1;
1463 }
1464
1465 strcpy(l_filename, filename);
1466 downcase(l_filename, VFAT_MAXLEN_BYTES);
1467
1468 return 0;
1469 }
1470
file_fat_write_at(const char * filename,loff_t pos,void * buffer,loff_t size,loff_t * actwrite)1471 int file_fat_write_at(const char *filename, loff_t pos, void *buffer,
1472 loff_t size, loff_t *actwrite)
1473 {
1474 dir_entry *retdent;
1475 fsdata datablock = { .fatbuf = NULL, };
1476 fsdata *mydata = &datablock;
1477 fat_itr *itr = NULL;
1478 int ret = -1;
1479 char *filename_copy, *parent, *basename;
1480 char l_filename[VFAT_MAXLEN_BYTES];
1481
1482 debug("writing %s\n", filename);
1483
1484 filename_copy = strdup(filename);
1485 if (!filename_copy)
1486 return -ENOMEM;
1487
1488 split_filename(filename_copy, &parent, &basename);
1489 if (!strlen(basename)) {
1490 ret = -EINVAL;
1491 goto exit;
1492 }
1493
1494 if (normalize_longname(l_filename, basename)) {
1495 printf("FAT: illegal filename (%s)\n", basename);
1496 ret = -EINVAL;
1497 goto exit;
1498 }
1499
1500 itr = malloc_cache_aligned(sizeof(fat_itr));
1501 if (!itr) {
1502 ret = -ENOMEM;
1503 goto exit;
1504 }
1505
1506 ret = fat_itr_root(itr, &datablock);
1507 if (ret)
1508 goto exit;
1509
1510 total_sector = datablock.total_sect;
1511
1512 ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1513 if (ret) {
1514 printf("%s: doesn't exist (%d)\n", parent, ret);
1515 goto exit;
1516 }
1517
1518 retdent = find_directory_entry(itr, l_filename);
1519
1520 if (retdent) {
1521 if (fat_itr_isdir(itr)) {
1522 ret = -EISDIR;
1523 goto exit;
1524 }
1525
1526 /* A file exists */
1527 if (pos == -1)
1528 /* Append to the end */
1529 pos = FAT2CPU32(retdent->size);
1530 if (pos > retdent->size) {
1531 /* No hole allowed */
1532 ret = -EINVAL;
1533 goto exit;
1534 }
1535
1536 /* Update file size in a directory entry */
1537 retdent->size = cpu_to_le32(pos + size);
1538 /* Update change date */
1539 dentry_set_time(retdent);
1540 } else {
1541 if (pos) {
1542 /* No hole allowed */
1543 ret = -EINVAL;
1544 goto exit;
1545 }
1546
1547 ret = create_link(itr, basename, 0, size, ATTR_ARCH);
1548 if (ret)
1549 goto exit;
1550
1551 retdent = itr->dent;
1552 }
1553
1554 ret = set_contents(mydata, retdent, pos, buffer, size, actwrite);
1555 if (ret < 0) {
1556 printf("Error: writing contents\n");
1557 ret = -EIO;
1558 goto exit;
1559 }
1560 debug("attempt to write 0x%llx bytes\n", *actwrite);
1561
1562 /* Flush fat buffer */
1563 ret = flush_dirty_fat_buffer(mydata);
1564 if (ret) {
1565 printf("Error: flush fat buffer\n");
1566 ret = -EIO;
1567 goto exit;
1568 }
1569
1570 /* Write directory table to device */
1571 ret = flush_dir(itr);
1572
1573 exit:
1574 free(filename_copy);
1575 free(mydata->fatbuf);
1576 free(itr);
1577 return ret;
1578 }
1579
file_fat_write(const char * filename,void * buffer,loff_t offset,loff_t maxsize,loff_t * actwrite)1580 int file_fat_write(const char *filename, void *buffer, loff_t offset,
1581 loff_t maxsize, loff_t *actwrite)
1582 {
1583 return file_fat_write_at(filename, offset, buffer, maxsize, actwrite);
1584 }
1585
fat_dir_entries(fat_itr * itr)1586 static int fat_dir_entries(fat_itr *itr)
1587 {
1588 fat_itr *dirs;
1589 fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1590 /* for FATBUFSIZE */
1591 int count;
1592
1593 dirs = malloc_cache_aligned(sizeof(fat_itr));
1594 if (!dirs) {
1595 debug("Error: allocating memory\n");
1596 count = -ENOMEM;
1597 goto exit;
1598 }
1599
1600 /* duplicate fsdata */
1601 fat_itr_child(dirs, itr);
1602 fsdata = *dirs->fsdata;
1603
1604 /* allocate local fat buffer */
1605 fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1606 if (!fsdata.fatbuf) {
1607 debug("Error: allocating memory\n");
1608 count = -ENOMEM;
1609 goto exit;
1610 }
1611 fsdata.fatbufnum = -1;
1612 dirs->fsdata = &fsdata;
1613
1614 for (count = 0; fat_itr_next(dirs); count++)
1615 ;
1616
1617 exit:
1618 free(fsdata.fatbuf);
1619 free(dirs);
1620 return count;
1621 }
1622
1623 /**
1624 * delete_single_dentry() - delete a single directory entry
1625 *
1626 * @itr: directory iterator
1627 * Return: 0 for success
1628 */
delete_single_dentry(fat_itr * itr)1629 static int delete_single_dentry(fat_itr *itr)
1630 {
1631 struct dir_entry *dent = itr->dent;
1632
1633 memset(dent, 0, sizeof(*dent));
1634 dent->nameext.name[0] = DELETED_FLAG;
1635
1636 if (!itr->remaining)
1637 return flush_dir(itr);
1638 return 0;
1639 }
1640
1641 /**
1642 * delete_long_name() - delete long name directory entries
1643 *
1644 * @itr: directory iterator
1645 * Return: 0 for success
1646 */
delete_long_name(fat_itr * itr)1647 static int delete_long_name(fat_itr *itr)
1648 {
1649 int seqn = itr->dent->nameext.name[0] & ~LAST_LONG_ENTRY_MASK;
1650
1651 while (seqn--) {
1652 struct dir_entry *dent;
1653 int ret;
1654
1655 ret = delete_single_dentry(itr);
1656 if (ret)
1657 return ret;
1658 dent = next_dent(itr);
1659 if (!dent)
1660 return -EIO;
1661 }
1662 return 0;
1663 }
1664
1665 /**
1666 * delete_dentry_link() - deletes a directory entry, but not the cluster chain
1667 * it points to
1668 *
1669 * @itr: the first directory entry (if a longname) to remove
1670 * Return: 0 for success
1671 */
delete_dentry_link(fat_itr * itr)1672 static int delete_dentry_link(fat_itr *itr)
1673 {
1674 int ret;
1675
1676 itr->dent = itr->dent_start;
1677 itr->remaining = itr->dent_rem;
1678 /* Delete long name */
1679 if ((itr->dent->attr & ATTR_VFAT) == ATTR_VFAT &&
1680 (itr->dent->nameext.name[0] & LAST_LONG_ENTRY_MASK)) {
1681 ret = delete_long_name(itr);
1682 if (ret)
1683 return ret;
1684 }
1685 /* Delete short name */
1686 delete_single_dentry(itr);
1687
1688 ret = flush_dir(itr);
1689 if (ret)
1690 return ret;
1691
1692 return update_parent_dir_props(itr);
1693 }
1694
1695 /**
1696 * delete_dentry_long() - remove directory entry
1697 *
1698 * @itr: directory iterator
1699 * Return: 0 for success
1700 */
delete_dentry_long(fat_itr * itr)1701 static int delete_dentry_long(fat_itr *itr)
1702 {
1703 fsdata *mydata = itr->fsdata;
1704 dir_entry *dent = itr->dent;
1705
1706 /* free cluster blocks */
1707 clear_fatent(mydata, START(dent));
1708 if (flush_dirty_fat_buffer(mydata) < 0) {
1709 printf("Error: flush fat buffer\n");
1710 return -EIO;
1711 }
1712 /* Position to first directory entry for long name */
1713 if (itr->clust != itr->dent_clust) {
1714 int ret;
1715
1716 ret = fat_move_to_cluster(itr, itr->dent_clust);
1717 if (ret)
1718 return ret;
1719 }
1720 return delete_dentry_link(itr);
1721 }
1722
fat_unlink(const char * filename)1723 int fat_unlink(const char *filename)
1724 {
1725 fsdata fsdata = { .fatbuf = NULL, };
1726 fat_itr *itr = NULL;
1727 int n_entries, ret;
1728 char *filename_copy, *dirname, *basename;
1729
1730 filename_copy = strdup(filename);
1731 itr = malloc_cache_aligned(sizeof(fat_itr));
1732 if (!itr || !filename_copy) {
1733 printf("Error: out of memory\n");
1734 ret = -ENOMEM;
1735 goto exit;
1736 }
1737 split_filename(filename_copy, &dirname, &basename);
1738
1739 if (!strcmp(dirname, "/") && !strcmp(basename, "")) {
1740 printf("Error: cannot remove root\n");
1741 ret = -EINVAL;
1742 goto exit;
1743 }
1744
1745 ret = fat_itr_root(itr, &fsdata);
1746 if (ret)
1747 goto exit;
1748
1749 total_sector = fsdata.total_sect;
1750
1751 ret = fat_itr_resolve(itr, dirname, TYPE_DIR);
1752 if (ret) {
1753 printf("%s: doesn't exist (%d)\n", dirname, ret);
1754 ret = -ENOENT;
1755 goto exit;
1756 }
1757
1758 if (!find_directory_entry(itr, basename)) {
1759 log_err("%s: doesn't exist (%d)\n", basename, -ENOENT);
1760 ret = -ENOENT;
1761 goto exit;
1762 }
1763
1764 if (fat_itr_isdir(itr)) {
1765 n_entries = fat_dir_entries(itr);
1766 if (n_entries < 0) {
1767 ret = n_entries;
1768 goto exit;
1769 }
1770 if (n_entries > 2) {
1771 printf("Error: directory is not empty: %d\n",
1772 n_entries);
1773 ret = -EINVAL;
1774 goto exit;
1775 }
1776 }
1777
1778 ret = delete_dentry_long(itr);
1779
1780 exit:
1781 free(fsdata.fatbuf);
1782 free(itr);
1783 free(filename_copy);
1784
1785 return ret;
1786 }
1787
fat_mkdir(const char * dirname)1788 int fat_mkdir(const char *dirname)
1789 {
1790 dir_entry *retdent;
1791 fsdata datablock = { .fatbuf = NULL, };
1792 fsdata *mydata = &datablock;
1793 fat_itr *itr = NULL;
1794 char *dirname_copy, *parent, *basename;
1795 char l_dirname[VFAT_MAXLEN_BYTES];
1796 int ret = -1;
1797 loff_t actwrite;
1798 unsigned int bytesperclust;
1799 dir_entry *dotdent = NULL;
1800
1801 dirname_copy = strdup(dirname);
1802 if (!dirname_copy)
1803 goto exit;
1804
1805 split_filename(dirname_copy, &parent, &basename);
1806 if (!strlen(basename)) {
1807 ret = -EINVAL;
1808 goto exit;
1809 }
1810
1811 if (normalize_longname(l_dirname, basename)) {
1812 printf("FAT: illegal filename (%s)\n", basename);
1813 ret = -EINVAL;
1814 goto exit;
1815 }
1816
1817 itr = malloc_cache_aligned(sizeof(fat_itr));
1818 if (!itr) {
1819 ret = -ENOMEM;
1820 goto exit;
1821 }
1822
1823 ret = fat_itr_root(itr, &datablock);
1824 if (ret)
1825 goto exit;
1826
1827 total_sector = datablock.total_sect;
1828
1829 ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1830 if (ret) {
1831 printf("%s: doesn't exist (%d)\n", parent, ret);
1832 goto exit;
1833 }
1834
1835 retdent = find_directory_entry(itr, l_dirname);
1836
1837 if (retdent) {
1838 printf("%s: already exists\n", l_dirname);
1839 ret = -EEXIST;
1840 goto exit;
1841 } else {
1842 if (itr->is_root) {
1843 /* root dir cannot have "." or ".." */
1844 if (!strcmp(l_dirname, ".") ||
1845 !strcmp(l_dirname, "..")) {
1846 ret = -EINVAL;
1847 goto exit;
1848 }
1849 }
1850
1851 ret = create_link(itr, basename, 0, 0, ATTR_DIR | ATTR_ARCH);
1852 if (ret)
1853 goto exit;
1854
1855 retdent = itr->dent;
1856 }
1857
1858 /* Default entries */
1859 bytesperclust = mydata->clust_size * mydata->sect_size;
1860 dotdent = malloc_cache_aligned(bytesperclust);
1861 if (!dotdent) {
1862 ret = -ENOMEM;
1863 goto exit;
1864 }
1865 memset(dotdent, 0, bytesperclust);
1866
1867 memcpy(&dotdent[0].nameext, ". ", 11);
1868 dotdent[0].attr = ATTR_DIR | ATTR_ARCH;
1869
1870 memcpy(&dotdent[1].nameext, ".. ", 11);
1871 dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
1872
1873 if (itr->is_root)
1874 set_start_cluster(mydata, &dotdent[1], 0);
1875 else
1876 set_start_cluster(mydata, &dotdent[1], itr->start_clust);
1877
1878 ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1879 bytesperclust, &actwrite);
1880 if (ret < 0) {
1881 printf("Error: writing contents\n");
1882 goto exit;
1883 }
1884 /* Write twice for "." */
1885 set_start_cluster(mydata, &dotdent[0], START(retdent));
1886 ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1887 bytesperclust, &actwrite);
1888 if (ret < 0) {
1889 printf("Error: writing contents\n");
1890 goto exit;
1891 }
1892
1893 /* Flush fat buffer */
1894 ret = flush_dirty_fat_buffer(mydata);
1895 if (ret) {
1896 printf("Error: flush fat buffer\n");
1897 ret = -EIO;
1898 goto exit;
1899 }
1900
1901 /* Write directory table to device */
1902 ret = flush_dir(itr);
1903
1904 exit:
1905 free(dirname_copy);
1906 free(mydata->fatbuf);
1907 free(itr);
1908 free(dotdent);
1909 return ret;
1910 }
1911
1912 /**
1913 * check_path_prefix() - ensures one path does not contains another path as a
1914 * prefix.
1915 *
1916 * for example: path foo/bar/baz/qux contains the path prefix foo/bar/baz
1917 *
1918 * note: the iterator may be pointing to any directory entry in the directory
1919 *
1920 * @prefix_clust: start cluster of the final directory in the prefix path
1921 * (the start cluster of 'baz' in the above example)
1922 * @path_itr: iterator of the path to check (an iterator pointing to any
1923 * direntry in 'qux' in the above example)
1924 * Return: -errno on error, 0 if path_itr does not have the directory
1925 * at prefix_clust as an ancestor.
1926 */
check_path_prefix(loff_t prefix_clust,fat_itr * path_itr)1927 static int check_path_prefix(loff_t prefix_clust, fat_itr *path_itr)
1928 {
1929 fat_itr itr;
1930 fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1931 int ret;
1932
1933 /* duplicate fsdata */
1934 itr = *path_itr;
1935 fsdata = *itr.fsdata;
1936
1937 /* allocate local fat buffer */
1938 fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1939 if (!fsdata.fatbuf) {
1940 log_debug("Error: allocating memory\n");
1941 ret = -ENOMEM;
1942 goto exit;
1943 }
1944
1945 fsdata.fatbufnum = -1;
1946 itr.fsdata = &fsdata;
1947
1948 /* ensure iterator is at the first directory entry */
1949 ret = fat_move_to_cluster(&itr, itr.start_clust);
1950 if (ret)
1951 goto exit;
1952
1953 while (1) {
1954 if (prefix_clust == itr.start_clust) {
1955 ret = -EINVAL;
1956 goto exit;
1957 }
1958
1959 if (itr.is_root) {
1960 ret = 0;
1961 goto exit;
1962 }
1963
1964 /* Should not occur in a well-formed FAT filesystem besides the root */
1965 if (fat_itr_parent(&itr)) {
1966 log_debug("FAT filesystem corrupt!\n");
1967 log_debug("dir @ clust %u has no parent direntry\n",
1968 itr.start_clust);
1969 ret = -EIO;
1970 goto exit;
1971 }
1972 }
1973
1974 exit:
1975 free(fsdata.fatbuf);
1976 return ret;
1977 }
1978
1979 /**
1980 * fat_rename - rename/move a file or directory
1981 *
1982 * @old_path: path to the existing file/directory
1983 * @new_path: new path/name for the rename/move
1984 * Return: 0 on success, -errno otherwise
1985 */
fat_rename(const char * old_path,const char * new_path)1986 int fat_rename(const char *old_path, const char *new_path)
1987 {
1988 fat_itr *old_itr = NULL, *new_itr = NULL;
1989 fsdata old_datablock = { .fatbuf = NULL, };
1990 fsdata new_datablock = { .fatbuf = NULL, };
1991 /* used for START macro */
1992 fsdata *mydata = &old_datablock;
1993 int ret = -EIO, is_old_dir;
1994 char *old_path_copy, *old_dirname, *old_basename;
1995 char *new_path_copy, *new_dirname, *new_basename;
1996 char l_new_basename[VFAT_MAXLEN_BYTES];
1997 __u32 old_clust;
1998 dir_entry *found_existing;
1999 /* only set if found_existing != NULL */
2000 __u32 new_clust;
2001
2002 old_path_copy = strdup(old_path);
2003 new_path_copy = strdup(new_path);
2004 old_itr = malloc_cache_aligned(sizeof(fat_itr));
2005 new_itr = malloc_cache_aligned(sizeof(fat_itr));
2006 if (!old_path_copy || !new_path_copy || !old_itr || !new_itr) {
2007 log_debug("Error: out of memory\n");
2008 ret = -ENOMEM;
2009 goto exit;
2010 }
2011 split_filename(old_path_copy, &old_dirname, &old_basename);
2012 split_filename(new_path_copy, &new_dirname, &new_basename);
2013
2014 if (normalize_longname(l_new_basename, new_basename)) {
2015 log_debug("FAT: illegal filename (%s)\n", new_basename);
2016 ret = -EINVAL;
2017 goto exit;
2018 }
2019
2020 if (!strcmp(old_basename, ".") || !strcmp(old_basename, "..") ||
2021 !strcmp(old_basename, "") || !strcmp(l_new_basename, ".") ||
2022 !strcmp(l_new_basename, "..") || !strcmp(l_new_basename, "")) {
2023 ret = -EINVAL;
2024 goto exit;
2025 }
2026
2027 /* checking for old_path == new_path is deferred until they're resolved */
2028
2029 /* resolve old_path */
2030 ret = fat_itr_root(old_itr, &old_datablock);
2031 if (ret)
2032 goto exit;
2033
2034 ret = fat_itr_resolve(old_itr, old_dirname, TYPE_DIR);
2035 if (ret) {
2036 log_debug("%s doesn't exist (%d)\n", old_dirname, ret);
2037 ret = -ENOENT;
2038 goto exit;
2039 }
2040
2041 if (!find_directory_entry(old_itr, old_basename)) {
2042 log_debug("%s doesn't exist (%d)\n", old_basename, -ENOENT);
2043 ret = -ENOENT;
2044 goto exit;
2045 }
2046
2047 /* store clust old_path points to, to relink later */
2048 total_sector = old_datablock.total_sect;
2049 old_clust = START(old_itr->dent);
2050 is_old_dir = fat_itr_isdir(old_itr);
2051
2052 /* resolve new_path*/
2053 ret = fat_itr_root(new_itr, &new_datablock);
2054 if (ret)
2055 goto exit;
2056
2057 ret = fat_itr_resolve(new_itr, new_dirname, TYPE_DIR);
2058 if (ret) {
2059 log_debug("%s doesn't exist (%d)\n", new_dirname, ret);
2060 ret = -ENOENT;
2061 goto exit;
2062 }
2063
2064 found_existing = find_directory_entry(new_itr, l_new_basename);
2065
2066 if (found_existing) {
2067 /* store cluster of new_path since it may need to be deleted */
2068 new_clust = START(new_itr->dent);
2069
2070 /* old_path is new_path, noop */
2071 if (old_clust == new_clust) {
2072 ret = 0;
2073 goto exit;
2074 }
2075
2076 if (fat_itr_isdir(new_itr) != is_old_dir) {
2077 if (is_old_dir)
2078 ret = -ENOTDIR;
2079 else
2080 ret = -EISDIR;
2081 goto exit;
2082 }
2083 }
2084
2085 if (is_old_dir) {
2086 ret = check_path_prefix(old_clust, new_itr);
2087 if (ret)
2088 goto exit;
2089 }
2090
2091 /* create/update dentry to point to old_path's data cluster */
2092 if (found_existing) {
2093 struct nameext new_name = new_itr->dent->nameext;
2094 __u8 lcase = new_itr->dent->lcase;
2095
2096 if (is_old_dir) {
2097 int n_entries = fat_dir_entries(new_itr);
2098
2099 if (n_entries < 0) {
2100 ret = n_entries;
2101 goto exit;
2102 }
2103 if (n_entries > 2) {
2104 log_debug("Error: directory is not empty: %d\n",
2105 n_entries);
2106 ret = -ENOTEMPTY;
2107 goto exit;
2108 }
2109 }
2110
2111 *new_itr->dent = *old_itr->dent;
2112 new_itr->dent->nameext = new_name;
2113 new_itr->dent->lcase = lcase;
2114
2115 ret = update_parent_dir_props(new_itr);
2116 if (ret)
2117 goto exit;
2118 } else {
2119 /* reset iterator to the start of the directory */
2120 ret = fat_move_to_cluster(new_itr, new_itr->start_clust);
2121 if (ret)
2122 goto exit;
2123
2124 ret = create_link(new_itr, l_new_basename, old_clust,
2125 old_itr->dent->size,
2126 old_itr->dent->attr | ATTR_ARCH);
2127 if (ret)
2128 goto exit;
2129 }
2130
2131 ret = flush_dir(new_itr);
2132 if (ret)
2133 goto exit;
2134
2135 /* with new_path data cluster unreferenced, clear it */
2136 if (found_existing) {
2137 ret = clear_fatent(&new_datablock, new_clust);
2138 if (ret)
2139 goto exit;
2140 }
2141
2142 /* update moved directory so the parent is new_path */
2143 if (is_old_dir) {
2144 __u32 clust = new_itr->start_clust;
2145 dir_entry *dent;
2146
2147 fat_itr_child(new_itr, new_itr);
2148 dent = find_directory_entry(new_itr, "..");
2149 if (!dent) {
2150 log_debug("FAT filesystem corrupt!\n");
2151 log_debug("dir %s has no parent direntry\n",
2152 l_new_basename);
2153 ret = -EIO;
2154 goto exit;
2155 }
2156 set_start_cluster(&new_datablock, dent, clust);
2157 ret = flush_dir(new_itr);
2158 if (ret)
2159 goto exit;
2160 /* restore directory location to update parent props below */
2161 fat_itr_child(new_itr, new_itr);
2162 }
2163
2164 /* refresh old in case write happened to the same block. */
2165 ret = fat_move_to_cluster(old_itr, old_itr->dent_clust);
2166 if (ret)
2167 goto exit;
2168
2169 ret = delete_dentry_link(old_itr);
2170 exit:
2171 free(new_datablock.fatbuf);
2172 free(old_datablock.fatbuf);
2173 free(new_itr);
2174 free(old_itr);
2175 free(new_path_copy);
2176 free(old_path_copy);
2177
2178 return ret;
2179 }
2180