fs: fat: structure for name and extension
The short name and extension of FAT files are stored in adjacent fields of
the directory entry. For some operations like calculating a checksum or
copying both fields it is preferable to treat both as one structure.
Change the definition of the directory entry structure to include a
structure comprising the name and the extension field.
This resolves Coverity CID 316357, CID 316350, CID 316348.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 157dad6..fb6ce09 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -123,16 +123,16 @@
{
char *ptr;
- memcpy(s_name, dirent->name, 8);
+ memcpy(s_name, dirent->nameext.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] != ' ') {
+ if (dirent->nameext.ext[0] && dirent->nameext.ext[0] != ' ') {
*ptr++ = '.';
- memcpy(ptr, dirent->ext, 3);
+ memcpy(ptr, dirent->nameext.ext, 3);
if (dirent->lcase & CASE_LOWER_EXT)
downcase(ptr, 3);
ptr[3] = '\0';
@@ -472,16 +472,15 @@
}
/* Calculate short name checksum */
-static __u8 mkcksum(const char name[8], const char ext[3])
+static __u8 mkcksum(struct nameext *nameext)
{
int i;
+ u8 *pos = (void *)nameext;
__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];
+ for (i = 0; i < 11; i++)
+ ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + pos[i];
return ret;
}
@@ -896,7 +895,7 @@
}
/* have we reached the last valid entry? */
- if (itr->dent->name[0] == 0)
+ if (itr->dent->nameext.name[0] == 0)
return NULL;
return itr->dent;
@@ -905,7 +904,7 @@
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;
+ int seqn = itr->dent->nameext.name[0] & ~LAST_LONG_ENTRY_MASK;
u8 chksum, alias_checksum = ((dir_slot *)dent)->alias_checksum;
int n = 0;
@@ -932,18 +931,19 @@
* We are now at the short file name entry.
* If it is marked as deleted, just skip it.
*/
- if (dent->name[0] == DELETED_FLAG ||
- dent->name[0] == aRING)
+ if (dent->nameext.name[0] == DELETED_FLAG ||
+ dent->nameext.name[0] == aRING)
return NULL;
itr->l_name[n] = '\0';
- chksum = mkcksum(dent->name, dent->ext);
+ chksum = mkcksum(&dent->nameext);
/* 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);
+ chksum, alias_checksum, itr->l_name, dent->nameext.name,
+ dent->nameext.ext);
return NULL;
}
@@ -984,12 +984,12 @@
itr->dent_rem = itr->remaining;
itr->dent_start = itr->dent;
itr->dent_clust = itr->clust;
- if (dent->name[0] == DELETED_FLAG)
+ if (dent->nameext.name[0] == DELETED_FLAG)
continue;
if (dent->attr & ATTR_VOLUME) {
if ((dent->attr & ATTR_VFAT) == ATTR_VFAT &&
- (dent->name[0] & LAST_LONG_ENTRY_MASK)) {
+ (dent->nameext.name[0] & LAST_LONG_ENTRY_MASK)) {
/* long file name */
dent = extract_vfat_name(itr);
/*