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.g...@gmx.de>
---
fs/fat/fat.c | 32 ++++++++++++++++----------------
fs/fat/fat_write.c | 20 +++++++++-----------
include/fat.h | 7 ++++++-
3 files changed, 31 insertions(+), 28 deletions(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 157dad60a4..fb6ce094ac 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -123,16 +123,16 @@ static void get_name(dir_entry *dirent, char *s_name)
{
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 @@ static int slot2str(dir_slot *slotptr, char *l_name, int
*idx)
}
/* 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 @@ static dir_entry *next_dent(fat_itr *itr)
}
/* 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 *next_dent(fat_itr *itr)
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 @@ static dir_entry *extract_vfat_name(fat_itr *itr)
* 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 @@ static int fat_itr_next(fat_itr *itr)
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);
/*
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 2f4391e86f..a17e51750c 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -275,7 +275,7 @@ static int fat_find_empty_dentries(fat_itr *itr, int count)
log_debug("Not enough directory entries available\n");
return -ENOSPC;
}
- switch (itr->dent->name[0]) {
+ switch (itr->dent->nameext.name[0]) {
case 0x00:
case DELETED_FLAG:
if (!n) {
@@ -399,7 +399,7 @@ fill_dir_slot(fat_itr *itr, const char *l_name, const char
*shortname)
int idx = 0, ret;
/* Get short file name checksum value */
- checksum = mkcksum(shortname, shortname + 8);
+ checksum = mkcksum((void *)shortname);
do {
memset(slotptr, 0x00, sizeof(dir_slot));
@@ -1169,7 +1169,7 @@ static void fill_dentry(fsdata *mydata, dir_entry
*dentptr,
dentptr->attr = attr;
- memcpy(dentptr->name, shortname, SHORT_NAME_SIZE);
+ memcpy(&dentptr->nameext, shortname, SHORT_NAME_SIZE);
}
/**
@@ -1194,7 +1194,7 @@ static dir_entry *find_directory_entry(fat_itr *itr, char
*filename)
if (!match)
continue;
- if (itr->dent->name[0] == '\0')
+ if (itr->dent->nameext.name[0] == '\0')
return NULL;
else
return itr->dent;
@@ -1470,7 +1470,7 @@ static int delete_single_dentry(fat_itr *itr)
struct dir_entry *dent = itr->dent;
memset(dent, 0, sizeof(*dent));
- dent->name[0] = DELETED_FLAG;
+ dent->nameext.name[0] = DELETED_FLAG;
if (!itr->remaining)
return flush_dir(itr);
@@ -1486,7 +1486,7 @@ static int delete_single_dentry(fat_itr *itr)
static int delete_long_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;
while (seqn--) {
int ret;
@@ -1531,7 +1531,7 @@ static int delete_dentry_long(fat_itr *itr)
dent = itr->dent_start;
/* Delete long name */
if ((dent->attr & ATTR_VFAT) == ATTR_VFAT &&
- (dent->name[0] & LAST_LONG_ENTRY_MASK)) {
+ (dent->nameext.name[0] & LAST_LONG_ENTRY_MASK)) {
int ret;
ret = delete_long_name(itr);
@@ -1712,12 +1712,10 @@ int fat_mkdir(const char *new_dirname)
}
memset(dotdent, 0, bytesperclust);
- memcpy(dotdent[0].name, ". ", 8);
- memcpy(dotdent[0].ext, " ", 3);
+ memcpy(&dotdent[0].nameext, ". ", 11);
dotdent[0].attr = ATTR_DIR | ATTR_ARCH;
- memcpy(dotdent[1].name, ".. ", 8);
- memcpy(dotdent[1].ext, " ", 3);
+ memcpy(&dotdent[1].nameext, ".. ", 11);
dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
if (itr->is_root)
diff --git a/include/fat.h b/include/fat.h
index b9f273f381..bd8e450b33 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -132,8 +132,13 @@ typedef struct volume_info
#define CASE_LOWER_BASE 8 /* base (name) is lower case */
#define CASE_LOWER_EXT 16 /* extension is lower case */
+struct nameext {
+ char name[8];
+ char ext[3];
+};
+
typedef struct dir_entry {
- char name[8],ext[3]; /* Name and extension */
+ struct nameext nameext; /* Name and extension */
__u8 attr; /* Attribute bits */
__u8 lcase; /* Case for name and ext (CASE_LOWER_x) */
__u8 ctime_ms; /* Creation time, milliseconds */
--
2.29.2
