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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 <fat.h>
12 #include <asm/byteorder.h>
13 #include <part.h>
14 #include <linux/ctype.h>
15 #include <div64.h>
16 #include <linux/math64.h>
17 #include "fat.c"
18
19 static void uppercase(char *str, int len)
20 {
21 int i;
22
23 for (i = 0; i < len; i++) {
24 *str = toupper(*str);
25 str++;
26 }
27 }
28
29 static int total_sector;
30 static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
31 {
32 ulong ret;
33
34 if (!cur_dev)
35 return -1;
36
37 if (cur_part_info.start + block + nr_blocks >
38 cur_part_info.start + total_sector) {
39 printf("error: overflow occurs\n");
40 return -1;
41 }
42
43 ret = blk_dwrite(cur_dev, cur_part_info.start + block, nr_blocks, buf);
44 if (nr_blocks && ret == 0)
45 return -1;
46
47 return ret;
48 }
49
50 /*
51 * Set short name in directory entry
52 */
53 static void set_name(dir_entry *dirent, const char *filename)
54 {
55 char s_name[VFAT_MAXLEN_BYTES];
56 char *period;
57 int period_location, len, i, ext_num;
58
59 if (filename == NULL)
60 return;
61
62 len = strlen(filename);
63 if (len == 0)
64 return;
65
66 strcpy(s_name, filename);
67 uppercase(s_name, len);
68
69 period = strchr(s_name, '.');
70 if (period == NULL) {
71 period_location = len;
72 ext_num = 0;
73 } else {
74 period_location = period - s_name;
75 ext_num = len - period_location - 1;
76 }
77
78 /* Pad spaces when the length of file name is shorter than eight */
79 if (period_location < 8) {
80 memcpy(dirent->name, s_name, period_location);
81 for (i = period_location; i < 8; i++)
82 dirent->name[i] = ' ';
83 } else if (period_location == 8) {
84 memcpy(dirent->name, s_name, period_location);
85 } else {
86 memcpy(dirent->name, s_name, 6);
87 dirent->name[6] = '~';
88 dirent->name[7] = '1';
89 }
90
91 if (ext_num < 3) {
92 memcpy(dirent->ext, s_name + period_location + 1, ext_num);
93 for (i = ext_num; i < 3; i++)
94 dirent->ext[i] = ' ';
95 } else
96 memcpy(dirent->ext, s_name + period_location + 1, 3);
97
98 debug("name : %s\n", dirent->name);
99 debug("ext : %s\n", dirent->ext);
100 }
101
102 /*
103 * Write fat buffer into block device
104 */
105 static int flush_dirty_fat_buffer(fsdata *mydata)
106 {
107 int getsize = FATBUFBLOCKS;
108 __u32 fatlength = mydata->fatlength;
109 __u8 *bufptr = mydata->fatbuf;
110 __u32 startblock = mydata->fatbufnum * FATBUFBLOCKS;
111
112 debug("debug: evicting %d, dirty: %d\n", mydata->fatbufnum,
113 (int)mydata->fat_dirty);
114
115 if ((!mydata->fat_dirty) || (mydata->fatbufnum == -1))
116 return 0;
117
118 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
119 if (startblock + getsize > fatlength)
120 getsize = fatlength - startblock;
121
122 startblock += mydata->fat_sect;
123
124 /* Write FAT buf */
125 if (disk_write(startblock, getsize, bufptr) < 0) {
126 debug("error: writing FAT blocks\n");
127 return -1;
128 }
129
130 if (mydata->fats == 2) {
131 /* Update corresponding second FAT blocks */
132 startblock += mydata->fatlength;
133 if (disk_write(startblock, getsize, bufptr) < 0) {
134 debug("error: writing second FAT blocks\n");
135 return -1;
136 }
137 }
138 mydata->fat_dirty = 0;
139
140 return 0;
141 }
142
143 /*
144 * Set the file name information from 'name' into 'slotptr',
145 */
146 static int str2slot(dir_slot *slotptr, const char *name, int *idx)
147 {
148 int j, end_idx = 0;
149
150 for (j = 0; j <= 8; j += 2) {
151 if (name[*idx] == 0x00) {
152 slotptr->name0_4[j] = 0;
153 slotptr->name0_4[j + 1] = 0;
154 end_idx++;
155 goto name0_4;
156 }
157 slotptr->name0_4[j] = name[*idx];
158 (*idx)++;
159 end_idx++;
160 }
161 for (j = 0; j <= 10; j += 2) {
162 if (name[*idx] == 0x00) {
163 slotptr->name5_10[j] = 0;
164 slotptr->name5_10[j + 1] = 0;
165 end_idx++;
166 goto name5_10;
167 }
168 slotptr->name5_10[j] = name[*idx];
169 (*idx)++;
170 end_idx++;
171 }
172 for (j = 0; j <= 2; j += 2) {
173 if (name[*idx] == 0x00) {
174 slotptr->name11_12[j] = 0;
175 slotptr->name11_12[j + 1] = 0;
176 end_idx++;
177 goto name11_12;
178 }
179 slotptr->name11_12[j] = name[*idx];
180 (*idx)++;
181 end_idx++;
182 }
183
184 if (name[*idx] == 0x00)
185 return 1;
186
187 return 0;
188 /* Not used characters are filled with 0xff 0xff */
189 name0_4:
190 for (; end_idx < 5; end_idx++) {
191 slotptr->name0_4[end_idx * 2] = 0xff;
192 slotptr->name0_4[end_idx * 2 + 1] = 0xff;
193 }
194 end_idx = 5;
195 name5_10:
196 end_idx -= 5;
197 for (; end_idx < 6; end_idx++) {
198 slotptr->name5_10[end_idx * 2] = 0xff;
199 slotptr->name5_10[end_idx * 2 + 1] = 0xff;
200 }
201 end_idx = 11;
202 name11_12:
203 end_idx -= 11;
204 for (; end_idx < 2; end_idx++) {
205 slotptr->name11_12[end_idx * 2] = 0xff;
206 slotptr->name11_12[end_idx * 2 + 1] = 0xff;
207 }
208
209 return 1;
210 }
211
212 static int flush_dir_table(fat_itr *itr);
213
214 /*
215 * Fill dir_slot entries with appropriate name, id, and attr
216 * 'itr' will point to a next entry
217 */
218 static int
219 fill_dir_slot(fat_itr *itr, const char *l_name)
220 {
221 __u8 temp_dir_slot_buffer[MAX_LFN_SLOT * sizeof(dir_slot)];
222 dir_slot *slotptr = (dir_slot *)temp_dir_slot_buffer;
223 __u8 counter = 0, checksum;
224 int idx = 0, ret;
225
226 /* Get short file name checksum value */
227 checksum = mkcksum(itr->dent->name, itr->dent->ext);
228
229 do {
230 memset(slotptr, 0x00, sizeof(dir_slot));
231 ret = str2slot(slotptr, l_name, &idx);
232 slotptr->id = ++counter;
233 slotptr->attr = ATTR_VFAT;
234 slotptr->alias_checksum = checksum;
235 slotptr++;
236 } while (ret == 0);
237
238 slotptr--;
239 slotptr->id |= LAST_LONG_ENTRY_MASK;
240
241 while (counter >= 1) {
242 memcpy(itr->dent, slotptr, sizeof(dir_slot));
243 slotptr--;
244 counter--;
245 if (!fat_itr_next(itr))
246 if (!itr->dent && !itr->is_root && flush_dir_table(itr))
247 return -1;
248 }
249
250 if (!itr->dent && !itr->is_root)
251 /*
252 * don't care return value here because we have already
253 * finished completing an entry with name, only ending up
254 * no more entry left
255 */
256 flush_dir_table(itr);
257
258 return 0;
259 }
260
261 /*
262 * Set the entry at index 'entry' in a FAT (12/16/32) table.
263 */
264 static int set_fatent_value(fsdata *mydata, __u32 entry, __u32 entry_value)
265 {
266 __u32 bufnum, offset, off16;
267 __u16 val1, val2;
268
269 switch (mydata->fatsize) {
270 case 32:
271 bufnum = entry / FAT32BUFSIZE;
272 offset = entry - bufnum * FAT32BUFSIZE;
273 break;
274 case 16:
275 bufnum = entry / FAT16BUFSIZE;
276 offset = entry - bufnum * FAT16BUFSIZE;
277 break;
278 case 12:
279 bufnum = entry / FAT12BUFSIZE;
280 offset = entry - bufnum * FAT12BUFSIZE;
281 break;
282 default:
283 /* Unsupported FAT size */
284 return -1;
285 }
286
287 /* Read a new block of FAT entries into the cache. */
288 if (bufnum != mydata->fatbufnum) {
289 int getsize = FATBUFBLOCKS;
290 __u8 *bufptr = mydata->fatbuf;
291 __u32 fatlength = mydata->fatlength;
292 __u32 startblock = bufnum * FATBUFBLOCKS;
293
294 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
295 if (startblock + getsize > fatlength)
296 getsize = fatlength - startblock;
297
298 if (flush_dirty_fat_buffer(mydata) < 0)
299 return -1;
300
301 startblock += mydata->fat_sect;
302
303 if (disk_read(startblock, getsize, bufptr) < 0) {
304 debug("Error reading FAT blocks\n");
305 return -1;
306 }
307 mydata->fatbufnum = bufnum;
308 }
309
310 /* Mark as dirty */
311 mydata->fat_dirty = 1;
312
313 /* Set the actual entry */
314 switch (mydata->fatsize) {
315 case 32:
316 ((__u32 *) mydata->fatbuf)[offset] = cpu_to_le32(entry_value);
317 break;
318 case 16:
319 ((__u16 *) mydata->fatbuf)[offset] = cpu_to_le16(entry_value);
320 break;
321 case 12:
322 off16 = (offset * 3) / 4;
323
324 switch (offset & 0x3) {
325 case 0:
326 val1 = cpu_to_le16(entry_value) & 0xfff;
327 ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff;
328 ((__u16 *)mydata->fatbuf)[off16] |= val1;
329 break;
330 case 1:
331 val1 = cpu_to_le16(entry_value) & 0xf;
332 val2 = (cpu_to_le16(entry_value) >> 4) & 0xff;
333
334 ((__u16 *)mydata->fatbuf)[off16] &= ~0xf000;
335 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 12);
336
337 ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xff;
338 ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
339 break;
340 case 2:
341 val1 = cpu_to_le16(entry_value) & 0xff;
342 val2 = (cpu_to_le16(entry_value) >> 8) & 0xf;
343
344 ((__u16 *)mydata->fatbuf)[off16] &= ~0xff00;
345 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 8);
346
347 ((__u16 *)mydata->fatbuf)[off16 + 1] &= ~0xf;
348 ((__u16 *)mydata->fatbuf)[off16 + 1] |= val2;
349 break;
350 case 3:
351 val1 = cpu_to_le16(entry_value) & 0xfff;
352 ((__u16 *)mydata->fatbuf)[off16] &= ~0xfff0;
353 ((__u16 *)mydata->fatbuf)[off16] |= (val1 << 4);
354 break;
355 default:
356 break;
357 }
358
359 break;
360 default:
361 return -1;
362 }
363
364 return 0;
365 }
366
367 /*
368 * Determine the next free cluster after 'entry' in a FAT (12/16/32) table
369 * and link it to 'entry'. EOC marker is not set on returned entry.
370 */
371 static __u32 determine_fatent(fsdata *mydata, __u32 entry)
372 {
373 __u32 next_fat, next_entry = entry + 1;
374
375 while (1) {
376 next_fat = get_fatent(mydata, next_entry);
377 if (next_fat == 0) {
378 /* found free entry, link to entry */
379 set_fatent_value(mydata, entry, next_entry);
380 break;
381 }
382 next_entry++;
383 }
384 debug("FAT%d: entry: %08x, entry_value: %04x\n",
385 mydata->fatsize, entry, next_entry);
386
387 return next_entry;
388 }
389
390 /*
391 * Write at most 'size' bytes from 'buffer' into the specified cluster.
392 * Return 0 on success, -1 otherwise.
393 */
394 static int
395 set_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer,
396 unsigned long size)
397 {
398 __u32 idx = 0;
399 __u32 startsect;
400 int ret;
401
402 if (clustnum > 0)
403 startsect = clust_to_sect(mydata, clustnum);
404 else
405 startsect = mydata->rootdir_sect;
406
407 debug("clustnum: %d, startsect: %d\n", clustnum, startsect);
408
409 if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
410 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
411
412 printf("FAT: Misaligned buffer address (%p)\n", buffer);
413
414 while (size >= mydata->sect_size) {
415 memcpy(tmpbuf, buffer, mydata->sect_size);
416 ret = disk_write(startsect++, 1, tmpbuf);
417 if (ret != 1) {
418 debug("Error writing data (got %d)\n", ret);
419 return -1;
420 }
421
422 buffer += mydata->sect_size;
423 size -= mydata->sect_size;
424 }
425 } else if (size >= mydata->sect_size) {
426 idx = size / mydata->sect_size;
427 ret = disk_write(startsect, idx, buffer);
428 if (ret != idx) {
429 debug("Error writing data (got %d)\n", ret);
430 return -1;
431 }
432
433 startsect += idx;
434 idx *= mydata->sect_size;
435 buffer += idx;
436 size -= idx;
437 }
438
439 if (size) {
440 ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
441
442 memcpy(tmpbuf, buffer, size);
443 ret = disk_write(startsect, 1, tmpbuf);
444 if (ret != 1) {
445 debug("Error writing data (got %d)\n", ret);
446 return -1;
447 }
448 }
449
450 return 0;
451 }
452
453 static __u8 tmpbuf_cluster[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
454
455 /*
456 * Read and modify data on existing and consecutive cluster blocks
457 */
458 static int
459 get_set_cluster(fsdata *mydata, __u32 clustnum, loff_t pos, __u8 *buffer,
460 loff_t size, loff_t *gotsize)
461 {
462 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
463 __u32 startsect;
464 loff_t wsize;
465 int clustcount, i, ret;
466
467 *gotsize = 0;
468 if (!size)
469 return 0;
470
471 assert(pos < bytesperclust);
472 startsect = clust_to_sect(mydata, clustnum);
473
474 debug("clustnum: %d, startsect: %d, pos: %lld\n",
475 clustnum, startsect, pos);
476
477 /* partial write at beginning */
478 if (pos) {
479 wsize = min(bytesperclust - pos, size);
480 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
481 if (ret != mydata->clust_size) {
482 debug("Error reading data (got %d)\n", ret);
483 return -1;
484 }
485
486 memcpy(tmpbuf_cluster + pos, buffer, wsize);
487 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
488 if (ret != mydata->clust_size) {
489 debug("Error writing data (got %d)\n", ret);
490 return -1;
491 }
492
493 size -= wsize;
494 buffer += wsize;
495 *gotsize += wsize;
496
497 startsect += mydata->clust_size;
498
499 if (!size)
500 return 0;
501 }
502
503 /* full-cluster write */
504 if (size >= bytesperclust) {
505 clustcount = lldiv(size, bytesperclust);
506
507 if (!((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1))) {
508 wsize = clustcount * bytesperclust;
509 ret = disk_write(startsect,
510 clustcount * mydata->clust_size,
511 buffer);
512 if (ret != clustcount * mydata->clust_size) {
513 debug("Error writing data (got %d)\n", ret);
514 return -1;
515 }
516
517 size -= wsize;
518 buffer += wsize;
519 *gotsize += wsize;
520
521 startsect += clustcount * mydata->clust_size;
522 } else {
523 for (i = 0; i < clustcount; i++) {
524 memcpy(tmpbuf_cluster, buffer, bytesperclust);
525 ret = disk_write(startsect,
526 mydata->clust_size,
527 tmpbuf_cluster);
528 if (ret != mydata->clust_size) {
529 debug("Error writing data (got %d)\n",
530 ret);
531 return -1;
532 }
533
534 size -= bytesperclust;
535 buffer += bytesperclust;
536 *gotsize += bytesperclust;
537
538 startsect += mydata->clust_size;
539 }
540 }
541 }
542
543 /* partial write at end */
544 if (size) {
545 wsize = size;
546 ret = disk_read(startsect, mydata->clust_size, tmpbuf_cluster);
547 if (ret != mydata->clust_size) {
548 debug("Error reading data (got %d)\n", ret);
549 return -1;
550 }
551 memcpy(tmpbuf_cluster, buffer, wsize);
552 ret = disk_write(startsect, mydata->clust_size, tmpbuf_cluster);
553 if (ret != mydata->clust_size) {
554 debug("Error writing data (got %d)\n", ret);
555 return -1;
556 }
557
558 size -= wsize;
559 buffer += wsize;
560 *gotsize += wsize;
561 }
562
563 assert(!size);
564
565 return 0;
566 }
567
568 /*
569 * Find the first empty cluster
570 */
571 static int find_empty_cluster(fsdata *mydata)
572 {
573 __u32 fat_val, entry = 3;
574
575 while (1) {
576 fat_val = get_fatent(mydata, entry);
577 if (fat_val == 0)
578 break;
579 entry++;
580 }
581
582 return entry;
583 }
584
585 /*
586 * Write directory entries in itr's buffer to block device
587 */
588 static int flush_dir_table(fat_itr *itr)
589 {
590 fsdata *mydata = itr->fsdata;
591 int dir_newclust = 0;
592 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
593
594 if (set_cluster(mydata, itr->clust, itr->block, bytesperclust) != 0) {
595 printf("error: writing directory entry\n");
596 return -1;
597 }
598 dir_newclust = find_empty_cluster(mydata);
599 set_fatent_value(mydata, itr->clust, dir_newclust);
600 if (mydata->fatsize == 32)
601 set_fatent_value(mydata, dir_newclust, 0xffffff8);
602 else if (mydata->fatsize == 16)
603 set_fatent_value(mydata, dir_newclust, 0xfff8);
604 else if (mydata->fatsize == 12)
605 set_fatent_value(mydata, dir_newclust, 0xff8);
606
607 itr->clust = dir_newclust;
608 itr->next_clust = dir_newclust;
609
610 if (flush_dirty_fat_buffer(mydata) < 0)
611 return -1;
612
613 memset(itr->block, 0x00, bytesperclust);
614
615 itr->dent = (dir_entry *)itr->block;
616 itr->last_cluster = 1;
617 itr->remaining = bytesperclust / sizeof(dir_entry) - 1;
618
619 return 0;
620 }
621
622 /*
623 * Set empty cluster from 'entry' to the end of a file
624 */
625 static int clear_fatent(fsdata *mydata, __u32 entry)
626 {
627 __u32 fat_val;
628
629 while (!CHECK_CLUST(entry, mydata->fatsize)) {
630 fat_val = get_fatent(mydata, entry);
631 if (fat_val != 0)
632 set_fatent_value(mydata, entry, 0);
633 else
634 break;
635
636 entry = fat_val;
637 }
638
639 /* Flush fat buffer */
640 if (flush_dirty_fat_buffer(mydata) < 0)
641 return -1;
642
643 return 0;
644 }
645
646 /*
647 * Set start cluster in directory entry
648 */
649 static void set_start_cluster(const fsdata *mydata, dir_entry *dentptr,
650 __u32 start_cluster)
651 {
652 if (mydata->fatsize == 32)
653 dentptr->starthi =
654 cpu_to_le16((start_cluster & 0xffff0000) >> 16);
655 dentptr->start = cpu_to_le16(start_cluster & 0xffff);
656 }
657
658 /*
659 * Check whether adding a file makes the file system to
660 * exceed the size of the block device
661 * Return -1 when overflow occurs, otherwise return 0
662 */
663 static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
664 {
665 __u32 startsect, sect_num, offset;
666
667 if (clustnum > 0)
668 startsect = clust_to_sect(mydata, clustnum);
669 else
670 startsect = mydata->rootdir_sect;
671
672 sect_num = div_u64_rem(size, mydata->sect_size, &offset);
673
674 if (offset != 0)
675 sect_num++;
676
677 if (startsect + sect_num > total_sector)
678 return -1;
679 return 0;
680 }
681
682 /*
683 * Write at most 'maxsize' bytes from 'buffer' into
684 * the file associated with 'dentptr'
685 * Update the number of bytes written in *gotsize and return 0
686 * or return -1 on fatal errors.
687 */
688 static int
689 set_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos, __u8 *buffer,
690 loff_t maxsize, loff_t *gotsize)
691 {
692 loff_t filesize;
693 unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
694 __u32 curclust = START(dentptr);
695 __u32 endclust = 0, newclust = 0;
696 loff_t cur_pos, offset, actsize, wsize;
697
698 *gotsize = 0;
699 filesize = pos + maxsize;
700
701 debug("%llu bytes\n", filesize);
702
703 if (!filesize) {
704 if (!curclust)
705 return 0;
706 if (!CHECK_CLUST(curclust, mydata->fatsize) ||
707 IS_LAST_CLUST(curclust, mydata->fatsize)) {
708 clear_fatent(mydata, curclust);
709 set_start_cluster(mydata, dentptr, 0);
710 return 0;
711 }
712 debug("curclust: 0x%x\n", curclust);
713 debug("Invalid FAT entry\n");
714 return -1;
715 }
716
717 if (!curclust) {
718 assert(pos == 0);
719 goto set_clusters;
720 }
721
722 /* go to cluster at pos */
723 cur_pos = bytesperclust;
724 while (1) {
725 if (pos <= cur_pos)
726 break;
727 if (IS_LAST_CLUST(curclust, mydata->fatsize))
728 break;
729
730 newclust = get_fatent(mydata, curclust);
731 if (!IS_LAST_CLUST(newclust, mydata->fatsize) &&
732 CHECK_CLUST(newclust, mydata->fatsize)) {
733 debug("curclust: 0x%x\n", curclust);
734 debug("Invalid FAT entry\n");
735 return -1;
736 }
737
738 cur_pos += bytesperclust;
739 curclust = newclust;
740 }
741 if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
742 assert(pos == cur_pos);
743 goto set_clusters;
744 }
745
746 assert(pos < cur_pos);
747 cur_pos -= bytesperclust;
748
749 /* overwrite */
750 assert(IS_LAST_CLUST(curclust, mydata->fatsize) ||
751 !CHECK_CLUST(curclust, mydata->fatsize));
752
753 while (1) {
754 /* search for allocated consecutive clusters */
755 actsize = bytesperclust;
756 endclust = curclust;
757 while (1) {
758 if (filesize <= (cur_pos + actsize))
759 break;
760
761 newclust = get_fatent(mydata, endclust);
762
763 if (IS_LAST_CLUST(newclust, mydata->fatsize))
764 break;
765 if (CHECK_CLUST(newclust, mydata->fatsize)) {
766 debug("curclust: 0x%x\n", curclust);
767 debug("Invalid FAT entry\n");
768 return -1;
769 }
770
771 actsize += bytesperclust;
772 endclust = newclust;
773 }
774
775 /* overwrite to <curclust..endclust> */
776 if (pos < cur_pos)
777 offset = 0;
778 else
779 offset = pos - cur_pos;
780 wsize = min(cur_pos + actsize, filesize) - pos;
781 if (get_set_cluster(mydata, curclust, offset,
782 buffer, wsize, &actsize)) {
783 printf("Error get-and-setting cluster\n");
784 return -1;
785 }
786 buffer += wsize;
787 *gotsize += wsize;
788 cur_pos += offset + wsize;
789
790 if (filesize <= cur_pos)
791 break;
792
793 /* CHECK: newclust = get_fatent(mydata, endclust); */
794
795 if (IS_LAST_CLUST(newclust, mydata->fatsize))
796 /* no more clusters */
797 break;
798
799 curclust = newclust;
800 }
801
802 if (filesize <= cur_pos) {
803 /* no more write */
804 newclust = get_fatent(mydata, endclust);
805 if (!IS_LAST_CLUST(newclust, mydata->fatsize)) {
806 /* truncate the rest */
807 clear_fatent(mydata, newclust);
808
809 /* Mark end of file in FAT */
810 if (mydata->fatsize == 12)
811 newclust = 0xfff;
812 else if (mydata->fatsize == 16)
813 newclust = 0xffff;
814 else if (mydata->fatsize == 32)
815 newclust = 0xfffffff;
816 set_fatent_value(mydata, endclust, newclust);
817 }
818
819 return 0;
820 }
821
822 curclust = endclust;
823 filesize -= cur_pos;
824 assert(!(cur_pos % bytesperclust));
825
826 set_clusters:
827 /* allocate and write */
828 assert(!pos);
829
830 /* Assure that curclust is valid */
831 if (!curclust) {
832 curclust = find_empty_cluster(mydata);
833 set_start_cluster(mydata, dentptr, curclust);
834 } else {
835 newclust = get_fatent(mydata, curclust);
836
837 if (IS_LAST_CLUST(newclust, mydata->fatsize)) {
838 newclust = determine_fatent(mydata, curclust);
839 set_fatent_value(mydata, curclust, newclust);
840 curclust = newclust;
841 } else {
842 debug("error: something wrong\n");
843 return -1;
844 }
845 }
846
847 /* TODO: already partially written */
848 if (check_overflow(mydata, curclust, filesize)) {
849 printf("Error: no space left: %llu\n", filesize);
850 return -1;
851 }
852
853 actsize = bytesperclust;
854 endclust = curclust;
855 do {
856 /* search for consecutive clusters */
857 while (actsize < filesize) {
858 newclust = determine_fatent(mydata, endclust);
859
860 if ((newclust - 1) != endclust)
861 /* write to <curclust..endclust> */
862 goto getit;
863
864 if (CHECK_CLUST(newclust, mydata->fatsize)) {
865 debug("newclust: 0x%x\n", newclust);
866 debug("Invalid FAT entry\n");
867 return 0;
868 }
869 endclust = newclust;
870 actsize += bytesperclust;
871 }
872
873 /* set remaining bytes */
874 actsize = filesize;
875 if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
876 debug("error: writing cluster\n");
877 return -1;
878 }
879 *gotsize += actsize;
880
881 /* Mark end of file in FAT */
882 if (mydata->fatsize == 12)
883 newclust = 0xfff;
884 else if (mydata->fatsize == 16)
885 newclust = 0xffff;
886 else if (mydata->fatsize == 32)
887 newclust = 0xfffffff;
888 set_fatent_value(mydata, endclust, newclust);
889
890 return 0;
891 getit:
892 if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
893 debug("error: writing cluster\n");
894 return -1;
895 }
896 *gotsize += actsize;
897 filesize -= actsize;
898 buffer += actsize;
899
900 if (CHECK_CLUST(newclust, mydata->fatsize)) {
901 debug("newclust: 0x%x\n", newclust);
902 debug("Invalid FAT entry\n");
903 return 0;
904 }
905 actsize = bytesperclust;
906 curclust = endclust = newclust;
907 } while (1);
908
909 return 0;
910 }
911
912 /*
913 * Fill dir_entry
914 */
915 static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
916 const char *filename, __u32 start_cluster, __u32 size, __u8 attr)
917 {
918 set_start_cluster(mydata, dentptr, start_cluster);
919 dentptr->size = cpu_to_le32(size);
920
921 dentptr->attr = attr;
922
923 set_name(dentptr, filename);
924 }
925
926 /*
927 * Find a directory entry based on filename or start cluster number
928 * If the directory entry is not found,
929 * the new position for writing a directory entry will be returned
930 */
931 static dir_entry *find_directory_entry(fat_itr *itr, char *filename)
932 {
933 int match = 0;
934
935 while (fat_itr_next(itr)) {
936 /* check both long and short name: */
937 if (!strcasecmp(filename, itr->name))
938 match = 1;
939 else if (itr->name != itr->s_name &&
940 !strcasecmp(filename, itr->s_name))
941 match = 1;
942
943 if (!match)
944 continue;
945
946 if (itr->dent->name[0] == '\0')
947 return NULL;
948 else
949 return itr->dent;
950 }
951
952 if (!itr->dent && !itr->is_root && flush_dir_table(itr))
953 /* indicate that allocating dent failed */
954 itr->dent = NULL;
955
956 return NULL;
957 }
958
959 static int split_filename(char *filename, char **dirname, char **basename)
960 {
961 char *p, *last_slash, *last_slash_cont;
962
963 again:
964 p = filename;
965 last_slash = NULL;
966 last_slash_cont = NULL;
967 while (*p) {
968 if (ISDIRDELIM(*p)) {
969 last_slash = p;
970 last_slash_cont = p;
971 /* continuous slashes */
972 while (ISDIRDELIM(*p))
973 last_slash_cont = p++;
974 if (!*p)
975 break;
976 }
977 p++;
978 }
979
980 if (last_slash) {
981 if (last_slash_cont == (filename + strlen(filename) - 1)) {
982 /* remove trailing slashes */
983 *last_slash = '\0';
984 goto again;
985 }
986
987 if (last_slash == filename) {
988 /* avoid ""(null) directory */
989 *dirname = "/";
990 } else {
991 *last_slash = '\0';
992 *dirname = filename;
993 }
994
995 *last_slash_cont = '\0';
996 *basename = last_slash_cont + 1;
997 } else {
998 *dirname = "/"; /* root by default */
999 *basename = filename;
1000 }
1001
1002 return 0;
1003 }
1004
1005 static int normalize_longname(char *l_filename, const char *filename)
1006 {
1007 const char *p, legal[] = "!#$%&\'()-.@^`_{}~";
1008 char c;
1009 int name_len;
1010
1011 /* Check that the filename is valid */
1012 for (p = filename; p < filename + strlen(filename); p++) {
1013 c = *p;
1014
1015 if (('0' <= c) && (c <= '9'))
1016 continue;
1017 if (('A' <= c) && (c <= 'Z'))
1018 continue;
1019 if (('a' <= c) && (c <= 'z'))
1020 continue;
1021 if (strchr(legal, c))
1022 continue;
1023 /* extended code */
1024 if ((0x80 <= c) && (c <= 0xff))
1025 continue;
1026
1027 return -1;
1028 }
1029
1030 /* Normalize it */
1031 name_len = strlen(filename);
1032 if (name_len >= VFAT_MAXLEN_BYTES)
1033 /* should return an error? */
1034 name_len = VFAT_MAXLEN_BYTES - 1;
1035
1036 memcpy(l_filename, filename, name_len);
1037 l_filename[name_len] = 0; /* terminate the string */
1038 downcase(l_filename, INT_MAX);
1039
1040 return 0;
1041 }
1042
1043 int file_fat_write_at(const char *filename, loff_t pos, void *buffer,
1044 loff_t size, loff_t *actwrite)
1045 {
1046 dir_entry *retdent;
1047 fsdata datablock = { .fatbuf = NULL, };
1048 fsdata *mydata = &datablock;
1049 fat_itr *itr = NULL;
1050 int ret = -1;
1051 char *filename_copy, *parent, *basename;
1052 char l_filename[VFAT_MAXLEN_BYTES];
1053
1054 debug("writing %s\n", filename);
1055
1056 filename_copy = strdup(filename);
1057 if (!filename_copy)
1058 return -ENOMEM;
1059
1060 split_filename(filename_copy, &parent, &basename);
1061 if (!strlen(basename)) {
1062 ret = -EINVAL;
1063 goto exit;
1064 }
1065
1066 filename = basename;
1067 if (normalize_longname(l_filename, filename)) {
1068 printf("FAT: illegal filename (%s)\n", filename);
1069 ret = -EINVAL;
1070 goto exit;
1071 }
1072
1073 itr = malloc_cache_aligned(sizeof(fat_itr));
1074 if (!itr) {
1075 ret = -ENOMEM;
1076 goto exit;
1077 }
1078
1079 ret = fat_itr_root(itr, &datablock);
1080 if (ret)
1081 goto exit;
1082
1083 total_sector = datablock.total_sect;
1084
1085 ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1086 if (ret) {
1087 printf("%s: doesn't exist (%d)\n", parent, ret);
1088 goto exit;
1089 }
1090
1091 retdent = find_directory_entry(itr, l_filename);
1092
1093 if (retdent) {
1094 if (fat_itr_isdir(itr)) {
1095 ret = -EISDIR;
1096 goto exit;
1097 }
1098
1099 /* A file exists */
1100 if (pos == -1)
1101 /* Append to the end */
1102 pos = FAT2CPU32(retdent->size);
1103 if (pos > retdent->size) {
1104 /* No hole allowed */
1105 ret = -EINVAL;
1106 goto exit;
1107 }
1108
1109 /* Update file size in a directory entry */
1110 retdent->size = cpu_to_le32(pos + size);
1111 } else {
1112 /* Create a new file */
1113
1114 if (itr->is_root) {
1115 /* root dir cannot have "." or ".." */
1116 if (!strcmp(l_filename, ".") ||
1117 !strcmp(l_filename, "..")) {
1118 ret = -EINVAL;
1119 goto exit;
1120 }
1121 }
1122
1123 if (!itr->dent) {
1124 printf("Error: allocating new dir entry\n");
1125 ret = -EIO;
1126 goto exit;
1127 }
1128
1129 if (pos) {
1130 /* No hole allowed */
1131 ret = -EINVAL;
1132 goto exit;
1133 }
1134
1135 memset(itr->dent, 0, sizeof(*itr->dent));
1136
1137 /* Set short name to set alias checksum field in dir_slot */
1138 set_name(itr->dent, filename);
1139 if (fill_dir_slot(itr, filename)) {
1140 ret = -EIO;
1141 goto exit;
1142 }
1143
1144 /* Set attribute as archive for regular file */
1145 fill_dentry(itr->fsdata, itr->dent, filename, 0, size, 0x20);
1146
1147 retdent = itr->dent;
1148 }
1149
1150 ret = set_contents(mydata, retdent, pos, buffer, size, actwrite);
1151 if (ret < 0) {
1152 printf("Error: writing contents\n");
1153 ret = -EIO;
1154 goto exit;
1155 }
1156 debug("attempt to write 0x%llx bytes\n", *actwrite);
1157
1158 /* Flush fat buffer */
1159 ret = flush_dirty_fat_buffer(mydata);
1160 if (ret) {
1161 printf("Error: flush fat buffer\n");
1162 ret = -EIO;
1163 goto exit;
1164 }
1165
1166 /* Write directory table to device */
1167 ret = set_cluster(mydata, itr->clust, itr->block,
1168 mydata->clust_size * mydata->sect_size);
1169 if (ret) {
1170 printf("Error: writing directory entry\n");
1171 ret = -EIO;
1172 }
1173
1174 exit:
1175 free(filename_copy);
1176 free(mydata->fatbuf);
1177 free(itr);
1178 return ret;
1179 }
1180
1181 int file_fat_write(const char *filename, void *buffer, loff_t offset,
1182 loff_t maxsize, loff_t *actwrite)
1183 {
1184 return file_fat_write_at(filename, offset, buffer, maxsize, actwrite);
1185 }
1186
1187 static int fat_dir_entries(fat_itr *itr)
1188 {
1189 fat_itr *dirs;
1190 fsdata fsdata = { .fatbuf = NULL, }, *mydata = &fsdata;
1191 /* for FATBUFSIZE */
1192 int count;
1193
1194 dirs = malloc_cache_aligned(sizeof(fat_itr));
1195 if (!dirs) {
1196 debug("Error: allocating memory\n");
1197 count = -ENOMEM;
1198 goto exit;
1199 }
1200
1201 /* duplicate fsdata */
1202 fat_itr_child(dirs, itr);
1203 fsdata = *dirs->fsdata;
1204
1205 /* allocate local fat buffer */
1206 fsdata.fatbuf = malloc_cache_aligned(FATBUFSIZE);
1207 if (!fsdata.fatbuf) {
1208 debug("Error: allocating memory\n");
1209 count = -ENOMEM;
1210 goto exit;
1211 }
1212 fsdata.fatbufnum = -1;
1213 dirs->fsdata = &fsdata;
1214
1215 for (count = 0; fat_itr_next(dirs); count++)
1216 ;
1217
1218 exit:
1219 free(fsdata.fatbuf);
1220 free(dirs);
1221 return count;
1222 }
1223
1224 static int delete_dentry(fat_itr *itr)
1225 {
1226 fsdata *mydata = itr->fsdata;
1227 dir_entry *dentptr = itr->dent;
1228
1229 /* free cluster blocks */
1230 clear_fatent(mydata, START(dentptr));
1231 if (flush_dirty_fat_buffer(mydata) < 0) {
1232 printf("Error: flush fat buffer\n");
1233 return -EIO;
1234 }
1235
1236 /*
1237 * update a directory entry
1238 * TODO:
1239 * - long file name support
1240 * - find and mark the "new" first invalid entry as name[0]=0x00
1241 */
1242 memset(dentptr, 0, sizeof(*dentptr));
1243 dentptr->name[0] = 0xe5;
1244
1245 if (set_cluster(mydata, itr->clust, itr->block,
1246 mydata->clust_size * mydata->sect_size) != 0) {
1247 printf("error: writing directory entry\n");
1248 return -EIO;
1249 }
1250
1251 return 0;
1252 }
1253
1254 int fat_unlink(const char *filename)
1255 {
1256 fsdata fsdata = { .fatbuf = NULL, };
1257 fat_itr *itr = NULL;
1258 int n_entries, ret;
1259 char *filename_copy, *dirname, *basename;
1260
1261 filename_copy = strdup(filename);
1262 split_filename(filename_copy, &dirname, &basename);
1263
1264 if (!strcmp(dirname, "/") && !strcmp(basename, "")) {
1265 printf("Error: cannot remove root\n");
1266 ret = -EINVAL;
1267 goto exit;
1268 }
1269
1270 itr = malloc_cache_aligned(sizeof(fat_itr));
1271 if (!itr) {
1272 printf("Error: allocating memory\n");
1273 return -ENOMEM;
1274 }
1275
1276 ret = fat_itr_root(itr, &fsdata);
1277 if (ret)
1278 goto exit;
1279
1280 total_sector = fsdata.total_sect;
1281
1282 ret = fat_itr_resolve(itr, dirname, TYPE_DIR);
1283 if (ret) {
1284 printf("%s: doesn't exist (%d)\n", dirname, ret);
1285 ret = -ENOENT;
1286 goto exit;
1287 }
1288
1289 if (!find_directory_entry(itr, basename)) {
1290 printf("%s: doesn't exist\n", basename);
1291 ret = -ENOENT;
1292 goto exit;
1293 }
1294
1295 if (fat_itr_isdir(itr)) {
1296 n_entries = fat_dir_entries(itr);
1297 if (n_entries < 0) {
1298 ret = n_entries;
1299 goto exit;
1300 }
1301 if (n_entries > 2) {
1302 printf("Error: directory is not empty: %d\n",
1303 n_entries);
1304 ret = -EINVAL;
1305 goto exit;
1306 }
1307 }
1308
1309 ret = delete_dentry(itr);
1310
1311 exit:
1312 free(fsdata.fatbuf);
1313 free(itr);
1314 free(filename_copy);
1315
1316 return ret;
1317 }
1318
1319 int fat_mkdir(const char *new_dirname)
1320 {
1321 dir_entry *retdent;
1322 fsdata datablock = { .fatbuf = NULL, };
1323 fsdata *mydata = &datablock;
1324 fat_itr *itr = NULL;
1325 char *dirname_copy, *parent, *dirname;
1326 char l_dirname[VFAT_MAXLEN_BYTES];
1327 int ret = -1;
1328 loff_t actwrite;
1329 unsigned int bytesperclust;
1330 dir_entry *dotdent = NULL;
1331
1332 dirname_copy = strdup(new_dirname);
1333 if (!dirname_copy)
1334 goto exit;
1335
1336 split_filename(dirname_copy, &parent, &dirname);
1337 if (!strlen(dirname)) {
1338 ret = -EINVAL;
1339 goto exit;
1340 }
1341
1342 if (normalize_longname(l_dirname, dirname)) {
1343 printf("FAT: illegal filename (%s)\n", dirname);
1344 ret = -EINVAL;
1345 goto exit;
1346 }
1347
1348 itr = malloc_cache_aligned(sizeof(fat_itr));
1349 if (!itr) {
1350 ret = -ENOMEM;
1351 goto exit;
1352 }
1353
1354 ret = fat_itr_root(itr, &datablock);
1355 if (ret)
1356 goto exit;
1357
1358 total_sector = datablock.total_sect;
1359
1360 ret = fat_itr_resolve(itr, parent, TYPE_DIR);
1361 if (ret) {
1362 printf("%s: doesn't exist (%d)\n", parent, ret);
1363 goto exit;
1364 }
1365
1366 retdent = find_directory_entry(itr, l_dirname);
1367
1368 if (retdent) {
1369 printf("%s: already exists\n", l_dirname);
1370 ret = -EEXIST;
1371 goto exit;
1372 } else {
1373 if (itr->is_root) {
1374 /* root dir cannot have "." or ".." */
1375 if (!strcmp(l_dirname, ".") ||
1376 !strcmp(l_dirname, "..")) {
1377 ret = -EINVAL;
1378 goto exit;
1379 }
1380 }
1381
1382 if (!itr->dent) {
1383 printf("Error: allocating new dir entry\n");
1384 ret = -EIO;
1385 goto exit;
1386 }
1387
1388 memset(itr->dent, 0, sizeof(*itr->dent));
1389
1390 /* Set short name to set alias checksum field in dir_slot */
1391 set_name(itr->dent, dirname);
1392 fill_dir_slot(itr, dirname);
1393
1394 /* Set attribute as archive for regular file */
1395 fill_dentry(itr->fsdata, itr->dent, dirname, 0, 0,
1396 ATTR_DIR | ATTR_ARCH);
1397
1398 retdent = itr->dent;
1399 }
1400
1401 /* Default entries */
1402 bytesperclust = mydata->clust_size * mydata->sect_size;
1403 dotdent = malloc_cache_aligned(bytesperclust);
1404 if (!dotdent) {
1405 ret = -ENOMEM;
1406 goto exit;
1407 }
1408 memset(dotdent, 0, bytesperclust);
1409
1410 memcpy(dotdent[0].name, ". ", 8);
1411 memcpy(dotdent[0].ext, " ", 3);
1412 dotdent[0].attr = ATTR_DIR | ATTR_ARCH;
1413
1414 memcpy(dotdent[1].name, ".. ", 8);
1415 memcpy(dotdent[1].ext, " ", 3);
1416 dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
1417 set_start_cluster(mydata, &dotdent[1], itr->start_clust);
1418
1419 ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1420 bytesperclust, &actwrite);
1421 if (ret < 0) {
1422 printf("Error: writing contents\n");
1423 goto exit;
1424 }
1425 /* Write twice for "." */
1426 set_start_cluster(mydata, &dotdent[0], START(retdent));
1427 ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
1428 bytesperclust, &actwrite);
1429 if (ret < 0) {
1430 printf("Error: writing contents\n");
1431 goto exit;
1432 }
1433
1434 /* Flush fat buffer */
1435 ret = flush_dirty_fat_buffer(mydata);
1436 if (ret) {
1437 printf("Error: flush fat buffer\n");
1438 goto exit;
1439 }
1440
1441 /* Write directory table to device */
1442 ret = set_cluster(mydata, itr->clust, itr->block,
1443 mydata->clust_size * mydata->sect_size);
1444 if (ret)
1445 printf("Error: writing directory entry\n");
1446
1447 exit:
1448 free(dirname_copy);
1449 free(mydata->fatbuf);
1450 free(itr);
1451 free(dotdent);
1452 return ret;
1453 }