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Add error checks before calling creat(2)
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Error checks were made after creat(2) was called resulting
in files possibly being created (by e.g. touch) erroneously.
This patch makes sure any internal error checks are performed
before creat(2) or open(2) is called.

This patch also includes some minor cleanup in the raw read
service function(s) and removal of unused bit fields.

Signed-off-by: Hans Beckerus <hans.beckerus at gmail.com>
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Hans Beckerus committed May 9, 2017
1 parent 4467c9d commit d622dc1
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Showing 2 changed files with 59 additions and 52 deletions.
4 changes: 2 additions & 2 deletions filecache.h
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Original file line number Diff line number Diff line change
Expand Up @@ -63,7 +63,7 @@ struct filecache_entry {
unsigned int vsize_resolved:1;
unsigned int :19;
unsigned int unresolved:1;
unsigned int xdir:1;
unsigned int :1;
unsigned int check_atime:1;
unsigned int direct_io:1;
unsigned int avi_tested:1;
Expand All @@ -73,7 +73,7 @@ struct filecache_entry {
unsigned int avi_tested:1;
unsigned int direct_io:1;
unsigned int check_atime:1;
unsigned int xdir:1;
unsigned int :1;
unsigned int unresolved:1;
unsigned int :19;
unsigned int vsize_resolved:1;
Expand Down
107 changes: 57 additions & 50 deletions rar2fs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -820,7 +820,7 @@ static int pclose_(FILE *fp, pid_t pid)
}

/* Size of file in first volume number in which it exists */
#define VOL_FIRST_SZ op->entry_p->vsize_first
#define VOL_FIRST_SZ (op->entry_p->vsize_first)

/*
* Size of file in the following volume numbers (if situated in more than one).
Expand All @@ -835,7 +835,7 @@ static int pclose_(FILE *fp, pid_t pid)
* throw an error if trying to read beyond EOF. The important thing here
* is that the volumes files other than the first and last match this value.
*/
#define VOL_NEXT_SZ op->entry_p->vsize_next
#define VOL_NEXT_SZ (op->entry_p->vsize_next)

/* Size of file data (including headers) in first volume number */
#define VOL_REAL_SZ(x) \
Expand Down Expand Up @@ -1073,6 +1073,39 @@ static void check_atime(const char *path, struct filecache_entry *entry_p)
return;
}

/*!
****************************************************************************
*
****************************************************************************/
static void __get_vol_and_chunk_raw(struct io_context *op, off_t offset,
int *vol, size_t *chunk)
{
/*
* RAR5 (and later?) have a one byte volume number in the
* Main Archive Header for volume 1-127 and two bytes for the rest.
* Check if we need to compensate.
*/
if (op->entry_p->flags.vsize_fixup_needed) {
int vol_contrib = 128 - op->entry_p->vno_base +
op->entry_p->vno_first - 1;
off_t offset_fixup = VOL_FIRST_SZ +
(vol_contrib * VOL_NEXT_SZ);
if (offset >= offset_fixup) {
off_t offset_left = offset - offset_fixup;
*vol = 1 + vol_contrib +
(offset_left / (VOL_NEXT_SZ - 1));
*chunk = (VOL_NEXT_SZ - 1) -
(offset_left % (VOL_NEXT_SZ - 1));
return;
}
}

*vol = offset < VOL_FIRST_SZ ? 0 :
1 + ((offset - VOL_FIRST_SZ) / VOL_NEXT_SZ);
*chunk = offset < VOL_FIRST_SZ ? VOL_FIRST_SZ - offset :
VOL_NEXT_SZ - ((offset - VOL_FIRST_SZ) % VOL_NEXT_SZ);
}

/*!
****************************************************************************
*
Expand All @@ -1082,15 +1115,15 @@ static int lread_raw(char *buf, size_t size, off_t offset,
{
size_t n = 0;
struct io_context *op = FH_TOCONTEXT(fi->fh);
size_t chunk;
int tot = 0;
int force_seek = 0;

op->seq++;

printd(3, "PID %05d calling %s(), seq = %d, offset=%" PRIu64 "\n",
getpid(), __func__, op->seq, offset);

size_t chunk;
int tot = 0;
int force_seek = 0;

/*
* Handle the case when a user tries to read outside file size.
* This is especially important to handle here since last file in a
Expand All @@ -1116,28 +1149,8 @@ static int lread_raw(char *buf, size_t size, off_t offset,
if (op->entry_p->flags.multipart) {
int vol;

/*
* RAR5 (and later?) have a one byte volume number in
* the Main Archive Header for volume 1-127 and two
* bytes for the rest. Check if we need to compensate.
*/
if (op->entry_p->flags.vsize_fixup_needed) {
int vol_contrib = 128 - op->entry_p->vno_base + op->entry_p->vno_first - 1;
if (offset >= (VOL_FIRST_SZ + (vol_contrib * VOL_NEXT_SZ))) {
off_t offset_left =
offset - (VOL_FIRST_SZ + (vol_contrib * VOL_NEXT_SZ));
vol = 1 + vol_contrib + (offset_left / (VOL_NEXT_SZ - 1));
chunk = (VOL_NEXT_SZ - 1) - (offset_left % (VOL_NEXT_SZ - 1));
goto vol_ready;
}
}

vol = offset < VOL_FIRST_SZ ? 0 :
1 + ((offset - VOL_FIRST_SZ) / VOL_NEXT_SZ);
chunk = offset < VOL_FIRST_SZ ? VOL_FIRST_SZ - offset :
VOL_NEXT_SZ - ((offset - VOL_FIRST_SZ) % (VOL_NEXT_SZ));
__get_vol_and_chunk_raw(op, offset, &vol, &chunk);

vol_ready:
/* keep current open file */
if (vol != op->vno) {
/* close/open */
Expand Down Expand Up @@ -1396,7 +1409,7 @@ static int lread_rar(char *buf, size_t size, off_t offset,
printd(3, "seq=%d history access offset=%" PRIu64
" size=%zu op->pos=%" PRIu64
" split=%d\n",
op->seq,offset, size,
op->seq, offset, size,
op->pos,
(offset + (off_t)size) > op->pos);
if ((uint32_t)(op->pos - offset) <= IOB_HIST_SZ) {
Expand Down Expand Up @@ -1619,13 +1632,13 @@ static int lread(char *buffer, size_t size, off_t offset,
static int lopen(const char *path, struct fuse_file_info *fi)
{
ENTER_("%s", path);
struct io_handle *io = malloc(sizeof(struct io_handle));
if (!io)
return -ENOMEM;
int fd = open(path, fi->flags);
if (fd == -1)
if (fd == -1) {
free(io);
return -errno;
struct io_handle *io = malloc(sizeof(struct io_handle));
if (!io) {
close(fd);
return -EIO;
}
FH_SETIO(fi->fh, io);
FH_SETTYPE(fi->fh, IO_TYPE_NRM);
Expand Down Expand Up @@ -4247,29 +4260,23 @@ static int rar2_create(const char *path, mode_t mode, struct fuse_file_info *fi)
if (S_ISREG(mode)) {
if (!access_chk(path, 1)) {
char *root;
struct io_handle *io = NULL;
ABS_ROOT(root, path);
int fd = creat(root, mode);
if (fd == -1)
return -errno;
if (!FH_ISSET(fi->fh)) {
struct io_handle *io =
malloc(sizeof(struct io_handle));
/*
* Does not really matter what is returned in
* case of failure as long as it is not 0.
* Returning anything but 0 will avoid the
* _release() call but will still create the
* file when called from e.g. 'touch'.
*/
if (!io) {
close(fd);
return -EIO;
}
io = malloc(sizeof(struct io_handle));
if (!io)
return -ENOMEM;
FH_SETIO(fi->fh, io);
FH_SETTYPE(fi->fh, IO_TYPE_NRM);
FH_SETENTRY(fi->fh, NULL);
FH_SETFD(fi->fh, fd);
}
int fd = creat(root, mode);
if (fd == -1) {
free(io);
return -errno;
}
if (io)
FH_SETFD(fi->fh, fd);
__dircache_invalidate_for_file(path);
return 0;
}
Expand Down

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