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