// SPDX-License-Identifier: GPL-2.0+
/*
* fat.c
*
* R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
*
* 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
* 2003-03-10 - kharris@nexus-tech.net - ported to uboot
*/
#include <common.h>
#include <blk.h>
#include <config.h>
#include <exports.h>
#include <fat.h>
#include <fs.h>
#include <asm/byteorder.h>
#include <part.h>
#include <malloc.h>
#include <memalign.h>
#include <linux/compiler.h>
#include <linux/ctype.h>
/*
* Convert a string to lowercase. Converts at most 'len' characters,
* 'len' may be larger than the length of 'str' if 'str' is NULL
* terminated.
*/
static void downcase(char *str, size_t len)
{
while (*str != '\0' && len--) {
*str = tolower(*str);
str++;
}
}
static struct blk_desc *cur_dev;
static disk_partition_t cur_part_info;
#define DOS_BOOT_MAGIC_OFFSET 0x1fe
#define DOS_FS_TYPE_OFFSET 0x36
#define DOS_FS32_TYPE_OFFSET 0x52
static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
{
ulong ret;
if (!cur_dev)
return -1;
ret = blk_dread(cur_dev, cur_part_info.start + block, nr_blocks, buf);
if (ret != nr_blocks)
return -1;
return ret;
}
int fat_set_blk_dev(struct blk_desc *dev_desc, disk_partition_t *info)
{
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
cur_dev = dev_desc;
cur_part_info = *info;
/* Make sure it has a valid FAT header */
if (disk_read(0, 1, buffer) != 1) {
cur_dev = NULL;
return -1;
}
/* Check if it's actually a DOS volume */
if (memcmp(buffer + DOS_BOOT_MAGIC_OFFSET, "\x55\xAA", 2)) {
cur_dev = NULL;
return -1;
}
/* Check for FAT12/FAT16/FAT32 filesystem */
if (!memcmp(buffer + DOS_FS_TYPE_OFFSET, "FAT", 3))
return 0;
if (!memcmp(buffer + DOS_FS32_TYPE_OFFSET, "FAT32", 5))
return 0;
cur_dev = NULL;
return -1;
}
int fat_register_device(struct blk_desc *dev_desc, int part_no)
{
disk_partition_t info;
/* First close any currently found FAT filesystem */
cur_dev = NULL;
/* Read the partition table, if present */
if (part_get_info(dev_desc, part_no, &info)) {
if (part_no != 0) {
printf("** Partition %d not valid on device %d **\n",
part_no, dev_desc->devnum);
return -1;
}
info.start = 0;
info.size = dev_desc->lba;
info.blksz = dev_desc->blksz;
info.name[0] = 0;
info.type[0] = 0;
info.bootable = 0;
#if CONFIG_IS_ENABLED(PARTITION_UUIDS)
info.uuid[0] = 0;
#endif
}
return fat_set_blk_dev(dev_desc, &info);
}
/*
* Extract zero terminated short name from a directory entry.
*/
static void get_name(dir_entry *dirent, char *s_name)
{
char *ptr;
memcpy(s_name, dirent->name, 8);
s_name[8] = '\0';
ptr = s_name;
while (*ptr && *ptr != ' ')
ptr++;
if (dirent->lcase & CASE_LOWER_BASE)
downcase(s_name, (unsigned)(ptr - s_name));
if (dirent->ext[0] && dirent->ext[0] != ' ') {
*ptr++ = '.';
memcpy(ptr, dirent->ext, 3);
if (dirent->lcase & CASE_LOWER_EXT)
downcase(ptr, 3);
ptr[3] = '\0';
while (*ptr && *ptr != ' ')
ptr++;
}
*ptr = '\0';
if (*s_name == DELETED_FLAG)
*s_name = '\0';
else if (*s_name == aRING)
*s_name = DELETED_FLAG;
}
static int flush_dirty_fat_buffer(fsdata *mydata);
#if !CONFIG_IS_ENABLED(FAT_WRITE)
/* Stub for read only operation */
int flush_dirty_fat_buffer(fsdata *mydata)
{
(void)(mydata);
return 0;
}
#endif
/*
* Get the entry at index 'entry' in a FAT (12/16/32) table.
* On failure 0x00 is returned.
*/
static __u32 get_fatent(fsdata *mydata, __u32 entry)
{
__u32 bufnum;
__u32 offset, off8;
__u32 ret = 0x00;
if (CHECK_CLUST(entry, mydata->fatsize)) {
printf("Error: Invalid FAT entry: 0x%08x\n", entry);
return ret;
}
switch (mydata->fatsize) {
case 32:
bufnum = entry / FAT32BUFSIZE;
offset = entry - bufnum * FAT32BUFSIZE;
break;
case 16:
bufnum = entry / FAT16BUFSIZE;
offset = entry - bufnum * FAT16BUFSIZE;
break;
case 12:
bufnum = entry / FAT12BUFSIZE;
offset = entry - bufnum * FAT12BUFSIZE;
break;
default:
/* Unsupported FAT size */
return ret;
}
debug("FAT%d: entry: 0x%08x = %d, offset: 0x%04x = %d\n",
mydata->fatsize, entry, entry, offset, offset);
/* Read a new block of FAT entries into the cache. */
if (bufnum != mydata->fatbufnum) {
__u32 getsize = FATBUFBLOCKS;
__u8 *bufptr = mydata->fatbuf;
__u32 fatlength = mydata->fatlength;
__u32 startblock = bufnum * FATBUFBLOCKS;
/* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
if (startblock + getsize > fatlength)
getsize = fatlength - startblock;
startblock += mydata->fat_sect; /* Offset from start of disk */
/* Write back the fatbuf to the disk */
if (flush_dirty_fat_buffer(mydata) < 0)
return -1;
if (disk_read(startblock, getsize, bufptr) < 0) {
debug("Error reading FAT blocks\n");
return ret;
}
mydata->fatbufnum = bufnum;
}
/* Get the actual entry from the table */
switch (mydata->fatsize) {
case 32:
ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
break;
case 16:
ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
break;
case 12:
off8 = (offset * 3) / 2;
/* fatbut + off8 may be unaligned, read in byte granularity */
ret = mydata->fatbuf[off8] + (mydata->fatbuf[off8 + 1] << 8);
if (offset & 0x1)
ret >>= 4;
ret &= 0xfff;
}
debug("FAT%d: ret: 0x%08x, entry: 0x%08x, offset: 0x%04x\n",
mydata->fatsize, ret, entry, offset);
return ret;
}
/*
* Read at most 'size' bytes from the specified cluster into 'buffer'.
* Return 0 on success, -1 otherwise.
*/
static int
get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
{
__u32 idx = 0;
__u32 startsect;
int ret;
if (clustnum > 0) {
startsect = clust_to_sect(mydata, clustnum);
} else {
startsect = mydata->rootdir_sect;
}
debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
debug("FAT: Misaligned buffer address (%p)\n", buffer);
while (size >= mydata->sect_size) {
ret = disk_read(startsect++, 1, tmpbuf);
if (ret != 1) {
debug("Error reading data (got %d)\n", ret);
return -1;
}
memcpy(buffer, tmpbuf, mydata->sect_size);
buffer += mydata->sect_size;
size -= mydata->sect_size;
}
} else {
idx = size / mydata->sect_size;
ret = disk_read(startsect, idx, buffer);
if (ret != idx) {
debug("Error reading data (got %d)\n", ret);
return -1;
}
startsect += idx;
idx *= mydata->sect_size;
buffer += idx;
size -= idx;
}
if (size) {
ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
ret = disk_read(startsect, 1, tmpbuf);
if (ret != 1) {
debug("Error reading data (got %d)\n", ret);
return -1;
}
memcpy(buffer, tmpbuf, size);
}
return 0;
}
/*
* Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
* into 'buffer'.
* Update the number of bytes read in *gotsize or return -1 on fatal errors.
*/
static int get_contents(fsdata *mydata, dir_entry *dentptr, loff_t pos,
__u8 *buffer, loff_t maxsize, loff_t *gotsize)
{
loff_t filesize = FAT2CPU32(dentptr->size);
unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
__u32 curclust = START(dentptr);
__u32 endclust, newclust;
loff_t actsize;
*gotsize = 0;
debug("Filesize: %llu bytes\n", filesize);
if (pos >= filesize) {
debug("Read position past EOF: %llu\n", pos);
return 0;
}
if (maxsize > 0 && filesize > pos + maxsize)
filesize = pos + maxsize;
debug("%llu bytes\n", filesize);
actsize = bytesperclust;
/* go to cluster at pos */
while (actsize <= pos) {
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
debug("Invalid FAT entry\n");
return 0;
}
actsize += bytesperclust;
}
/* actsize > pos */
actsize -= bytesperclust;
filesize -= actsize;
pos -= actsize;
/* align to beginning of next cluster if any */
if (pos) {
__u8 *tmp_buffer;
actsize = min(filesize, (loff_t)bytesperclust);
tmp_buffer = malloc_cache_aligned(actsize);
if (!tmp_buffer) {
debug("Error: allocating buffer\n");
return -ENOMEM;
}
if (get_cluster(mydata, curclust, tmp_buffer, actsize) != 0) {
printf("Error reading cluster\n");
free(tmp_buffer);
return -1;
}
filesize -= actsize;
actsize -= pos;
memcpy(buffer, tmp_buffer + pos, actsize);
free(tmp_buffer);
*gotsize += actsize;
if (!filesize)
return 0;
buffer += actsize;
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
debug("Invalid FAT entry\n");
return 0;
}
}
actsize = bytesperclust;
endclust = curclust;
do {
/* search for consecutive clusters */
while (actsize < filesize) {
newclust = get_fatent(mydata, endclust);
if ((newclust - 1) != endclust)
goto getit;
if (CHECK_CLUST(newclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", newclust);
debug("Invalid FAT entry\n");
return 0;
}
endclust = newclust;
actsize += bytesperclust;
}
/* get remaining bytes */
actsize = filesize;
if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
*gotsize += actsize;
return 0;
getit:
if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
*gotsize += (int)actsize;
filesize -= actsize;
buffer += actsize;
curclust = get_fatent(mydata, endclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
return 0;
}
actsize = bytesperclust;
endclust = curclust;
} while (1);
}
/*
* Extract the file name information from 'slotptr' into 'l_name',
* starting at l_name[*idx].
* Return 1 if terminator (zero byte) is found, 0 otherwise.
*/
static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
{
int j;
for (j = 0; j <= 8; j += 2) {
l_name[*idx] = slotptr->name0_4[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
for (j = 0; j <= 10; j += 2) {
l_name[*idx] = slotptr->name5_10[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
for (j = 0; j <= 2; j += 2) {
l_name[*idx] = slotptr->name11_12[j];
if (l_name[*idx] == 0x00)
return 1;
(*idx)++;
}
return 0;
}
/* Calculate short name checksum */
static __u8 mkcksum(const char name[8], const char ext[3])
{
int i;
__u8 ret = 0;
for (i = 0; i < 8; i++)
ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
for (i = 0; i < 3; i++)
ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
return ret;
}
/*
* Read boot sector and volume info from a FAT filesystem
*/
static int
read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
{
__u8 *block;
volume_info *vistart;
int ret = 0;
if (cur_dev == NULL) {
debug("Error: no device selected\n");
return -1;
}
block = malloc_cache_aligned(cur_dev->blksz);
if (block == NULL) {
debug("Error: allocating block\n");
return -1;
}
if (disk_read(0, 1, block) < 0) {
debug("Error: reading block\n");
goto fail;
}
memcpy(bs, block, sizeof(boot_sector));
bs->reserved = FAT2CPU16(bs->reserved);
bs->fat_length = FAT2CPU16(bs->fat_length);
bs->secs_track = FAT2CPU16(bs->secs_track);
bs->heads = FAT2CPU16(bs->heads);
bs->total_sect = FAT2CPU32(bs->total_sect);
/* FAT32 entries */
if (bs->fat_length == 0) {
/* Assume FAT32 */
bs->fat32_length = FAT2CPU32(bs->fat32_length);
bs->flags = FAT2CPU16(bs->flags);
bs->root_cluster = FAT2CPU32(bs->root_cluster);
bs->info_sector = FAT2CPU16(bs->info_sector);
bs->backup_boot = FAT2CPU16(bs->backup_boot);
vistart = (volume_info *)(block + sizeof(boot_sector));
*fatsize = 32;
} else {
vistart = (volume_info *)&(bs->fat32_length);
*fatsize = 0;
}
memcpy(volinfo, vistart, sizeof(volume_info));
if (*fatsize == 32) {
if (strncmp(FAT32_SIGN, vistart->fs_type, SIGNLEN) == 0)
goto exit;
} else {
if (strncmp(FAT12_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 12;
goto exit;
}
if (strncmp(FAT16_SIGN, vistart->fs_type, SIGNLEN) == 0) {
*fatsize = 16;
goto exit;
}
}
debug("Error: broken fs_type sign\n");
fail:
ret = -1;
exit:
free(block);
return ret;
}
static int get_fs_info(fsdata *mydata)
{
boot_sector bs;
volume_info volinfo;
int ret;
ret = read_bootsectandvi(&bs, &volinfo, &mydata->fatsize);
if (ret) {
debug("Error: reading boot sector\n");
return ret;
}
if (mydata->fatsize == 32) {
mydata->fatlength = bs.fat32_length;
mydata->total_sect = bs.total_sect;
} else {
mydata->fatlength = bs.fat_length;
mydata->total_sect = (bs.sectors[1] << 8) + bs.sectors[0];
if (!mydata->total_sect)
mydata->total_sect = bs.total_sect;
}
if (!mydata->total_sect) /* unlikely */
mydata->total_sect = (u32)cur_part_info.size;
mydata->fats = bs.fats;
mydata->fat_sect = bs.reserved;
mydata->rootdir_sect = mydata->fat_sect + mydata->fatlength * bs.fats;
mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
mydata->clust_size = bs.cluster_size;
if (mydata->sect_size != cur_part_info.blksz) {
printf("Error: FAT sector size mismatch (fs=%hu, dev=%lu)\n",
mydata->sect_size, cur_part_info.blksz);
return -1;
}
if (mydata->clust_size == 0) {
printf("Error: FAT cluster size not set\n");
return -1;
}
if ((unsigned int)mydata->clust_size * mydata->sect_size >
MAX_CLUSTSIZE) {
printf("Error: FAT cluster size too big (cs=%u, max=%u)\n",
(unsigned int)mydata->clust_size * mydata->sect_size,
MAX_CLUSTSIZE);
return -1;
}
if (mydata->fatsize == 32) {
mydata->data_begin = mydata->rootdir_sect -
(mydata->clust_size * 2);
mydata->root_cluster = bs.root_cluster;
} else {
mydata->rootdir_size = ((bs.dir_entries[1] * (int)256 +
bs.dir_entries[0]) *
sizeof(dir_entry)) /
mydata->sect_size;
mydata->data_begin = mydata->rootdir_sect +
mydata->rootdir_size -
(mydata->clust_size * 2);
mydata->root_cluster =
sect_to_clust(mydata, mydata->rootdir_sect);
}
mydata->fatbufnum = -1;
mydata->fat_dirty = 0;
mydata->fatbuf = malloc_cache_aligned(FATBUFSIZE);
if (mydata->fatbuf == NULL) {
debug("Error: allocating memory\n");
return -1;
}
debug("FAT%d, fat_sect: %d, fatlength: %d\n",
mydata->fatsize, mydata->fat_sect, mydata->fatlength);
debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
"Data begins at: %d\n",
mydata->root_cluster,
mydata->rootdir_sect,
mydata->rootdir_sect * mydata->sect_size, mydata->data_begin);
debug("Sector size: %d, cluster size: %d\n", mydata->sect_size,
mydata->clust_size);
return 0;
}
/*
* Directory iterator, to simplify filesystem traversal
*
* Implements an iterator pattern to traverse directory tables,
* transparently handling directory tables split across multiple
* clusters, and the difference between FAT12/FAT16 root directory
* (contiguous) and subdirectories + FAT32 root (chained).
*
* Rough usage:
*
* for (fat_itr_root(&itr, fsdata); fat_itr_next(&itr); ) {
* // to traverse down to a subdirectory pointed to by
* // current iterator position:
* fat_itr_child(&itr, &itr);
* }
*
* For more complete example, see fat_itr_resolve()
*/
typedef struct {
fsdata *fsdata; /* filesystem parameters */
unsigned start_clust; /* first cluster */
unsigned clust; /* current cluster */
unsigned next_clust; /* next cluster if remaining == 0 */
int last_cluster; /* set once we've read last cluster */
int is_root; /* is iterator at root directory */
int remaining; /* remaining dent's in current cluster */
/* current iterator position values: */
dir_entry *dent; /* current directory entry */
char l_name[VFAT_MAXLEN_BYTES]; /* long (vfat) name */
char s_name[14]; /* short 8.3 name */
char *name; /* l_name if there is one, else s_name */
/* storage for current cluster in memory: */
u8 block[MAX_CLUSTSIZE] __aligned(ARCH_DMA_MINALIGN);
} fat_itr;
static int fat_itr_isdir(fat_itr *itr);
/**
* fat_itr_root() - initialize an iterator to start at the root
* directory
*
* @itr: iterator to initialize
* @fsdata: filesystem data for the partition
* @return 0 on success, else -errno
*/
static int fat_itr_root(fat_itr *itr, fsdata *fsdata)
{
if (get_fs_info(fsdata))
return -ENXIO;
itr->fsdata = fsdata;
itr->start_clust = 0;
itr->clust = fsdata->root_cluster;
itr->next_clust = fsdata->root_cluster;
itr->dent = NULL;
itr->remaining = 0;
itr->last_cluster = 0;
itr->is_root = 1;
return 0;
}
/**
* fat_itr_child() - initialize an iterator to descend into a sub-
* directory
*
* Initializes 'itr' to iterate the contents of the directory at
* the current cursor position of 'parent'. It is an error to
* call this if the current cursor of 'parent' is pointing at a
* regular file.
*
* Note that 'itr' and 'parent' can be the same pointer if you do
* not need to preserve 'parent' after this call, which is useful
* for traversing directory structure to resolve a file/directory.
*
* @itr: iterator to initialize
* @parent: the iterator pointing at a directory entry in the
* parent directory of the directory to iterate
*/
static void fat_itr_child(fat_itr *itr, fat_itr *parent)
{
fsdata *mydata = parent->fsdata; /* for silly macros */
unsigned clustnum = START(parent->dent);
assert(fat_itr_isdir(parent));
itr->fsdata = parent->fsdata;
itr->start_clust = clustnum;
if (clustnum > 0) {
itr->clust = clustnum;
itr->next_clust = clustnum;
itr->is_root = 0;
} else {
itr->clust = parent->fsdata->root_cluster;
itr->next_clust = parent->fsdata->root_cluster;
itr->is_root = 1;
}
itr->dent = NULL;
itr->remaining = 0;
itr->last_cluster = 0;
}
static void *next_cluster(fat_itr *itr)
{
fsdata *mydata = itr->fsdata; /* for silly macros */
int ret;
u32 sect;
/* have we reached the end? */
if (itr->last_cluster)
return NULL;
sect = clust_to_sect(itr->fsdata, itr->next_clust);
debug("FAT read(sect=%d), clust_size=%d, DIRENTSPERBLOCK=%zd\n",
sect, itr->fsdata->clust_size, DIRENTSPERBLOCK);
/*
* NOTE: do_fat_read_at() had complicated logic to deal w/
* vfat names that span multiple clusters in the fat16 case,
* which get_dentfromdir() probably also needed (and was
* missing). And not entirely sure what fat32 didn't have
* the same issue.. We solve that by only caring about one
* dent at a time and iteratively constructing the vfat long
* name.
*/
ret = disk_read(sect, itr->fsdata->clust_size,
itr->block);
if (ret < 0) {
debug("Error: reading block\n");
return NULL;
}
itr->clust = itr->next_clust;
if (itr->is_root && itr->fsdata->fatsize != 32) {
itr->next_clust++;
sect = clust_to_sect(itr->fsdata, itr->next_clust);
if (sect - itr->fsdata->rootdir_sect >=
itr->fsdata->rootdir_size) {
debug("nextclust: 0x%x\n", itr->next_clust);
itr->last_cluster = 1;
}
} else {
itr->next_clust = get_fatent(itr->fsdata, itr->next_clust);
if (CHECK_CLUST(itr->next_clust, itr->fsdata->fatsize)) {
debug("nextclust: 0x%x\n", itr->next_clust);
itr->last_cluster = 1;
}
}
return itr->block;
}
static dir_entry *next_dent(fat_itr *itr)
{
if (itr->remaining == 0) {
struct dir_entry *dent = next_cluster(itr);
unsigned nbytes = itr->fsdata->sect_size *
itr->fsdata->clust_size;
/* have we reached the last cluster? */
if (!dent) {
/* a sign for no more entries left */
itr->dent = NULL;
return NULL;
}
itr->remaining = nbytes / sizeof(dir_entry) - 1;
itr->dent = dent;
} else {
itr->remaining--;
itr->dent++;
}
/* have we reached the last valid entry? */
if (itr->dent->name[0] == 0)
return NULL;
return itr->dent;
}
static dir_entry *extract_vfat_name(fat_itr *itr)
{
struct dir_entry *dent = itr->dent;
int seqn = itr->dent->name[0] & ~LAST_LONG_ENTRY_MASK;
u8 chksum, alias_checksum = ((dir_slot *)dent)->alias_checksum;
int n = 0;
while (seqn--) {
char buf[13];
int idx = 0;
slot2str((dir_slot *)dent, buf, &idx);
if (n + idx >= sizeof(itr->l_name))
return NULL;
/* shift accumulated long-name up and copy new part in: */
memmove(itr->l_name + idx, itr->l_name, n);
memcpy(itr->l_name, buf, idx);
n += idx;
dent = next_dent(itr);
if (!dent)
return NULL;
}
itr->l_name[n] = '\0';
chksum = mkcksum(dent->name, dent->ext);
/* checksum mismatch could mean deleted file, etc.. skip it: */
if (chksum != alias_checksum) {
debug("** chksum=%x, alias_checksum=%x, l_name=%s, s_name=%8s.%3s\n",
chksum, alias_checksum, itr->l_name, dent->name, dent->ext);
return NULL;
}
return dent;
}
/**
* fat_itr_next() - step to the next entry in a directory
*
* Must be called once on a new iterator before the cursor is valid.
*
* @itr: the iterator to iterate
* @return boolean, 1 if success or 0 if no more entries in the
* current directory
*/
static int fat_itr_next(fat_itr *itr)
{
dir_entry *dent;
itr->name = NULL;
while (1) {
dent = next_dent(itr);
if (!dent)
return 0;
if (dent->name[0] == DELETED_FLAG ||
dent->name[0] == aRING)
continue;
if (dent->attr & ATTR_VOLUME) {
if ((dent->attr & ATTR_VFAT) == ATTR_VFAT &&
(dent->name[0] & LAST_LONG_ENTRY_MASK)) {
dent = extract_vfat_name(itr);
if (!dent)
continue;
itr->name = itr->l_name;
break;
} else {
/* Volume label or VFAT entry, skip */
continue;
}
}
break;
}
get_name(dent, itr->s_name);
if (!itr->name)
itr->name = itr->s_name;
return 1;
}
/**
* fat_itr_isdir() - is current cursor position pointing to a directory
*
* @itr: the iterator
* @return true if cursor is at a directory
*/
static int fat_itr_isdir(fat_itr *itr)
{
return !!(itr->dent->attr & ATTR_DIR);
}
/*
* Helpers:
*/
#define TYPE_FILE 0x1
#define TYPE_DIR 0x2
#define TYPE_ANY (TYPE_FILE | TYPE_DIR)
/**
* fat_itr_resolve() - traverse directory structure to resolve the
* requested path.
*
* Traverse directory structure to the requested path. If the specified
* path is to a directory, this will descend into the directory and
* leave it iterator at the start of the directory. If the path is to a
* file, it will leave the iterator in the parent directory with current
* cursor at file's entry in the directory.
*
* @itr: iterator initialized to root
* @path: the requested path
* @type: bitmask of allowable file types
* @return 0 on success or -errno
*/
static int fat_itr_resolve(fat_itr *itr, const char *path, unsigned type)
{
const char *next;
/* chomp any extra leading slashes: */
while (path[0] && ISDIRDELIM(path[0]))
path++;
/* are we at the end? */
if (strlen(path) == 0) {
if (!(type & TYPE_DIR))
return -ENOENT;
return 0;
}
/* find length of next path entry: */
next = path;
while (next[0] && !ISDIRDELIM(next[0]))
next++;
if (itr->is_root) {
/* root dir doesn't have "." nor ".." */
if ((((next - path) == 1) && !strncmp(path, ".", 1)) ||
(((next - path) == 2) && !strncmp(path, "..", 2))) {
/* point back to itself */
itr->clust = itr->fsdata->root_cluster;
itr->next_clust = itr->fsdata->root_cluster;
itr->dent = NULL;
itr->remaining = 0;
itr->last_cluster = 0;
if (next[0] == 0) {
if (type & TYPE_DIR)
return 0;
else
return -ENOENT;
}
return fat_itr_resolve(itr, next, type);
}
}
while (fat_itr_next(itr)) {
int match = 0;
unsigned n = max(strlen(itr->name), (size_t)(next - path));
/* check both long and short name: */
if (!strncasecmp(path, itr->name, n))
match = 1;
else if (itr->name != itr->s_name &&
!strncasecmp(path, itr->s_name, n))
match = 1;
if (!match)
continue;
if (fat_itr_isdir(itr)) {
/* recurse into directory: */
fat_itr_child(itr, itr);
return fat_itr_resolve(itr, next, type);
} else if (next[0]) {
/*
* If next is not empty then we have a case
* like: /path/to/realfile/nonsense
*/
debug("bad trailing path: %s\n", next);
return -ENOENT;
} else if (!(type & TYPE_FILE)) {
return -ENOTDIR;
} else {
return 0;
}
}
return -ENOENT;
}
int file_fat_detectfs(void)
{
boot_sector bs;
volume_info volinfo;
int fatsize;
char vol_label[12];
if (cur_dev == NULL) {
printf("No current device\n");
return 1;
}
#if defined(CONFIG_IDE) || \
defined(CONFIG_SATA) || \
defined(CONFIG_SCSI) || \
defined(CONFIG_CMD_USB) || \
defined(CONFIG_MMC)
printf("Interface: ");
switch (cur_dev->if_type) {
case IF_TYPE_IDE:
printf("IDE");
break;
case IF_TYPE_SATA:
printf("SATA");
break;
case IF_TYPE_SCSI:
printf("SCSI");
break;
case IF_TYPE_ATAPI:
printf("ATAPI");
break;
case IF_TYPE_USB:
printf("USB");
break;
case IF_TYPE_DOC:
printf("DOC");
break;
case IF_TYPE_MMC:
printf("MMC");
break;
default:
printf("Unknown");
}
printf("\n Device %d: ", cur_dev->devnum);
dev_print(cur_dev);
#endif
if (read_bootsectandvi(&bs, &volinfo, &fatsize)) {
printf("\nNo valid FAT fs found\n");
return 1;
}
memcpy(vol_label, volinfo.volume_label, 11);
vol_label[11] = '\0';
volinfo.fs_type[5] = '\0';
printf("Filesystem: %s \"%s\"\n", volinfo.fs_type, vol_label);
return 0;
}
int fat_exists(const char *filename)
{
fsdata fsdata;
fat_itr *itr;
int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
if (!itr)
return 0;
ret = fat_itr_root(itr, &fsdata);
if (ret)
goto out;
ret = fat_itr_resolve(itr, filename, TYPE_ANY);
free(fsdata.fatbuf);
out:
free(itr);
return ret == 0;
}
int fat_size(const char *filename, loff_t *size)
{
fsdata fsdata;
fat_itr *itr;
int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
if (!itr)
return -ENOMEM;
ret = fat_itr_root(itr, &fsdata);
if (ret)
goto out_free_itr;
ret = fat_itr_resolve(itr, filename, TYPE_FILE);
if (ret) {
/*
* Directories don't have size, but fs_size() is not
* expected to fail if passed a directory path:
*/
free(fsdata.fatbuf);
fat_itr_root(itr, &fsdata);
if (!fat_itr_resolve(itr, filename, TYPE_DIR)) {
*size = 0;
ret = 0;
}
goto out_free_both;
}
*size = FAT2CPU32(itr->dent->size);
out_free_both:
free(fsdata.fatbuf);
out_free_itr:
free(itr);
return ret;
}
int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
loff_t maxsize, loff_t *actread)
{
fsdata fsdata;
fat_itr *itr;
int ret;
itr = malloc_cache_aligned(sizeof(fat_itr));
if (!itr)
return -ENOMEM;
ret = fat_itr_root(itr, &fsdata);
if (ret)
goto out_free_itr;
ret = fat_itr_resolve(itr, filename, TYPE_FILE);
if (ret)
goto out_free_both;
debug("reading %s at pos %llu\n", filename, pos);
/* For saving default max clustersize memory allocated to malloc pool */
dir_entry *dentptr = itr->dent;
free(itr);
itr = NULL;
ret = get_contents(&fsdata, dentptr, pos, buffer, maxsize, actread);
out_free_both:
free(fsdata.fatbuf);
out_free_itr:
free(itr);
return ret;
}
int file_fat_read(const char *filename, void *buffer, int maxsize)
{
loff_t actread;
int ret;
ret = file_fat_read_at(filename, 0, buffer, maxsize, &actread);
if (ret)
return ret;
else
return actread;
}
int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actread)
{
int ret;
ret = file_fat_read_at(filename, offset, buf, len, actread);
if (ret)
printf("** Unable to read file %s **\n", filename);
return ret;
}
typedef struct {
struct fs_dir_stream parent;
struct fs_dirent dirent;
fsdata fsdata;
fat_itr itr;
} fat_dir;
int fat_opendir(const char *filename, struct fs_dir_stream **dirsp)
{
fat_dir *dir;
int ret;
dir = malloc_cache_aligned(sizeof(*dir));
if (!dir)
return -ENOMEM;
memset(dir, 0, sizeof(*dir));
ret = fat_itr_root(&dir->itr, &dir->fsdata);
if (ret)
goto fail_free_dir;
ret = fat_itr_resolve(&dir->itr, filename, TYPE_DIR);
if (ret)
goto fail_free_both;
*dirsp = (struct fs_dir_stream *)dir;
return 0;
fail_free_both:
free(dir->fsdata.fatbuf);
fail_free_dir:
free(dir);
return ret;
}
int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp)
{
fat_dir *dir = (fat_dir *)dirs;
struct fs_dirent *dent = &dir->dirent;
if (!fat_itr_next(&dir->itr))
return -ENOENT;
memset(dent, 0, sizeof(*dent));
strcpy(dent->name, dir->itr.name);
if (fat_itr_isdir(&dir->itr)) {
dent->type = FS_DT_DIR;
} else {
dent->type = FS_DT_REG;
dent->size = FAT2CPU32(dir->itr.dent->size);
}
*dentp = dent;
return 0;
}
void fat_closedir(struct fs_dir_stream *dirs)
{
fat_dir *dir = (fat_dir *)dirs;
free(dir->fsdata.fatbuf);
free(dir);
}
void fat_close(void)
{
}