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-rw-r--r--fs/fat/fat.c49
-rw-r--r--include/fat.h4
2 files changed, 41 insertions, 12 deletions
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 003666e..744e961 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -439,11 +439,19 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
{
dir_entry *realdent;
dir_slot *slotptr = (dir_slot *)retdent;
- __u8 *nextclust = cluster + mydata->clust_size * SECTOR_SIZE;
+ __u8 *buflimit = cluster + ((curclust == 0) ?
+ LINEAR_PREFETCH_SIZE :
+ (mydata->clust_size * SECTOR_SIZE)
+ );
__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
int idx = 0;
- while ((__u8 *)slotptr < nextclust) {
+ if (counter > VFAT_MAXSEQ) {
+ debug("Error: VFAT name is too long\n");
+ return -1;
+ }
+
+ while ((__u8 *)slotptr < buflimit) {
if (counter == 0)
break;
if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
@@ -452,10 +460,11 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
counter--;
}
- if ((__u8 *)slotptr >= nextclust) {
+ if ((__u8 *)slotptr >= buflimit) {
dir_slot *slotptr2;
- slotptr--;
+ if (curclust == 0)
+ return -1;
curclust = get_fatent(mydata, curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
@@ -470,14 +479,19 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
}
slotptr2 = (dir_slot *)get_vfatname_block;
- while (slotptr2->id > 0x01)
+ while (counter > 0) {
+ if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
+ & 0xff) != counter)
+ return -1;
slotptr2++;
+ counter--;
+ }
/* Save the real directory entry */
- realdent = (dir_entry *)slotptr2 + 1;
- while ((__u8 *)slotptr2 >= get_vfatname_block) {
- slot2str(slotptr2, l_name, &idx);
+ realdent = (dir_entry *)slotptr2;
+ while ((__u8 *)slotptr2 > get_vfatname_block) {
slotptr2--;
+ slot2str(slotptr2, l_name, &idx);
}
} else {
/* Save the real directory entry */
@@ -549,7 +563,7 @@ static dir_entry *get_dentfromdir (fsdata *mydata, int startsect,
dentptr = (dir_entry *)get_dentfromdir_block;
for (i = 0; i < DIRENTSPERCLUST; i++) {
- char s_name[14], l_name[256];
+ char s_name[14], l_name[VFAT_MAXLEN_BYTES];
l_name[0] = '\0';
if (dentptr->name[0] == DELETED_FLAG) {
@@ -841,7 +855,11 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%d\n",
cursect, mydata->clust_size, DIRENTSPERBLOCK);
- if (disk_read(cursect, mydata->clust_size, do_fat_read_block) < 0) {
+ if (disk_read(cursect,
+ (mydata->fatsize == 32) ?
+ (mydata->clust_size) :
+ LINEAR_PREFETCH_SIZE,
+ do_fat_read_block) < 0) {
debug("Error: reading rootdir block\n");
return -1;
}
@@ -849,9 +867,13 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
dentptr = (dir_entry *) do_fat_read_block;
for (i = 0; i < DIRENTSPERBLOCK; i++) {
- char s_name[14], l_name[256];
+ char s_name[14], l_name[VFAT_MAXLEN_BYTES];
l_name[0] = '\0';
+ if (dentptr->name[0] == DELETED_FLAG) {
+ dentptr++;
+ continue;
+ }
if ((dentptr->attr & ATTR_VOLUME)) {
#ifdef CONFIG_SUPPORT_VFAT
if ((dentptr->attr & ATTR_VFAT) &&
@@ -859,7 +881,10 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
prevcksum =
((dir_slot *)dentptr)->alias_checksum;
- get_vfatname(mydata, 0,
+ get_vfatname(mydata,
+ (mydata->fatsize == 32) ?
+ root_cluster :
+ 0,
do_fat_read_block,
dentptr, l_name);
diff --git a/include/fat.h b/include/fat.h
index de48afd..afb2116 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -30,6 +30,10 @@
#include <asm/byteorder.h>
#define CONFIG_SUPPORT_VFAT
+/* Maximum Long File Name length supported here is 128 UTF-16 code units */
+#define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */
+#define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */
+#define LINEAR_PREFETCH_SIZE (SECTOR_SIZE*2) /* Prefetch buffer size */
#define SECTOR_SIZE FS_BLOCK_SIZE