Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

paths: Revisit path parsing, fix trailing slash behavior #1046

Merged
merged 9 commits into from
Dec 6, 2024
+7,338 −227
Merged

paths: Revisit path parsing, fix trailing slash behavior #1046

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
9 commits
Select commit Hold shift + click to select a range
0de0389
paths: Reworked test_paths to cover more corner cases
geky Nov 20, 2024
232e736
paths: Added trailing slashes and dots tests
geky Nov 21, 2024
a603507
paths: Fixed/doc trailing slash/dot POSIX incompatibilities
geky Nov 22, 2024
dc92dec
paths: Reject dotdots above root
geky Nov 23, 2024
815f0d8
paths: Fixed dots followed by dotdots
geky Nov 23, 2024
80ca1ea
paths: Reject empty paths
geky Nov 24, 2024
3094705
paths: Extended tests to cover open with CREAT/EXCL
geky Nov 25, 2024
b735c8f
paths: Added tests over NOENT + trailing slash/dot
geky Nov 25, 2024
999ef66
paths: Changed CREAT with a trailing slash to return NOTDIR
geky Nov 25, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
89 changes: 69 additions & 20 deletions lfs.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -282,6 +282,21 @@ static int lfs_bd_erase(lfs_t *lfs, lfs_block_t block) {


/// Small type-level utilities ///

// some operations on paths
static inline lfs_size_t lfs_path_namelen(const char *path) {
return strcspn(path, "/");
}

static inline bool lfs_path_islast(const char *path) {
lfs_size_t namelen = lfs_path_namelen(path);
return path[namelen + strspn(path + namelen, "/")] == '\0';
}

static inline bool lfs_path_isdir(const char *path) {
return path[lfs_path_namelen(path)] != '\0';
}

// operations on block pairs
static inline void lfs_pair_swap(lfs_block_t pair[2]) {
lfs_block_t t = pair[0];
Expand Down Expand Up @@ -1461,32 +1476,46 @@ static int lfs_dir_find_match(void *data,
return LFS_CMP_EQ;
}

// lfs_dir_find tries to set path and id even if file is not found
//
// returns:
// - 0 if file is found
// - LFS_ERR_NOENT if file or parent is not found
// - LFS_ERR_NOTDIR if parent is not a dir
static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
const char **path, uint16_t *id) {
// we reduce path to a single name if we can find it
const char *name = *path;
if (id) {
*id = 0x3ff;
}

// default to root dir
lfs_stag_t tag = LFS_MKTAG(LFS_TYPE_DIR, 0x3ff, 0);
dir->tail[0] = lfs->root[0];
dir->tail[1] = lfs->root[1];

// empty paths are not allowed
if (*name == '\0') {
return LFS_ERR_INVAL;
}

while (true) {
nextname:
// skip slashes
name += strspn(name, "/");
// skip slashes if we're a directory
if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
name += strspn(name, "/");
}
lfs_size_t namelen = strcspn(name, "/");

// skip '.' and root '..'
if ((namelen == 1 && memcmp(name, ".", 1) == 0) ||
(namelen == 2 && memcmp(name, "..", 2) == 0)) {
// skip '.'
if (namelen == 1 && memcmp(name, ".", 1) == 0) {
name += namelen;
goto nextname;
}

// error on unmatched '..', trying to go above root?
if (namelen == 2 && memcmp(name, "..", 2) == 0) {
return LFS_ERR_INVAL;
}

// skip if matched by '..' in name
const char *suffix = name + namelen;
lfs_size_t sufflen;
Expand All @@ -1498,7 +1527,9 @@ static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
break;
}

if (sufflen == 2 && memcmp(suffix, "..", 2) == 0) {
if (sufflen == 1 && memcmp(suffix, ".", 1) == 0) {
// noop
} else if (sufflen == 2 && memcmp(suffix, "..", 2) == 0) {
depth -= 1;
if (depth == 0) {
name = suffix + sufflen;
Expand All @@ -1512,14 +1543,14 @@ static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
}

// found path
if (name[0] == '\0') {
if (*name == '\0') {
return tag;
}

// update what we've found so far
*path = name;

// only continue if we hit a directory
// only continue if we're a directory
if (lfs_tag_type3(tag) != LFS_TYPE_DIR) {
return LFS_ERR_NOTDIR;
}
Expand All @@ -1539,8 +1570,7 @@ static lfs_stag_t lfs_dir_find(lfs_t *lfs, lfs_mdir_t *dir,
tag = lfs_dir_fetchmatch(lfs, dir, dir->tail,
LFS_MKTAG(0x780, 0, 0),
LFS_MKTAG(LFS_TYPE_NAME, 0, namelen),
// are we last name?
(strchr(name, '/') == NULL) ? id : NULL,
id,
lfs_dir_find_match, &(struct lfs_dir_find_match){
lfs, name, namelen});
if (tag < 0) {
Expand Down Expand Up @@ -2603,12 +2633,12 @@ static int lfs_mkdir_(lfs_t *lfs, const char *path) {
cwd.next = lfs->mlist;
uint16_t id;
err = lfs_dir_find(lfs, &cwd.m, &path, &id);
if (!(err == LFS_ERR_NOENT && id != 0x3ff)) {
if (!(err == LFS_ERR_NOENT && lfs_path_islast(path))) {
return (err < 0) ? err : LFS_ERR_EXIST;
}

// check that name fits
lfs_size_t nlen = strlen(path);
lfs_size_t nlen = lfs_path_namelen(path);
if (nlen > lfs->name_max) {
return LFS_ERR_NAMETOOLONG;
}
Expand Down Expand Up @@ -3057,7 +3087,7 @@ static int lfs_file_opencfg_(lfs_t *lfs, lfs_file_t *file,

// allocate entry for file if it doesn't exist
lfs_stag_t tag = lfs_dir_find(lfs, &file->m, &path, &file->id);
if (tag < 0 && !(tag == LFS_ERR_NOENT && file->id != 0x3ff)) {
if (tag < 0 && !(tag == LFS_ERR_NOENT && lfs_path_islast(path))) {
err = tag;
goto cleanup;
}
Expand All @@ -3077,8 +3107,14 @@ static int lfs_file_opencfg_(lfs_t *lfs, lfs_file_t *file,
goto cleanup;
}

// don't allow trailing slashes
if (lfs_path_isdir(path)) {
err = LFS_ERR_NOTDIR;
goto cleanup;
}

// check that name fits
lfs_size_t nlen = strlen(path);
lfs_size_t nlen = lfs_path_namelen(path);
if (nlen > lfs->name_max) {
err = LFS_ERR_NAMETOOLONG;
goto cleanup;
Expand Down Expand Up @@ -3842,6 +3878,12 @@ static int lfs_stat_(lfs_t *lfs, const char *path, struct lfs_info *info) {
return (int)tag;
}

// only allow trailing slashes on dirs
if (strchr(path, '/') != NULL
&& lfs_tag_type3(tag) != LFS_TYPE_DIR) {
return LFS_ERR_NOTDIR;
}

return lfs_dir_getinfo(lfs, &cwd, lfs_tag_id(tag), info);
}

Expand Down Expand Up @@ -3944,7 +3986,7 @@ static int lfs_rename_(lfs_t *lfs, const char *oldpath, const char *newpath) {
uint16_t newid;
lfs_stag_t prevtag = lfs_dir_find(lfs, &newcwd, &newpath, &newid);
if ((prevtag < 0 || lfs_tag_id(prevtag) == 0x3ff) &&
!(prevtag == LFS_ERR_NOENT && newid != 0x3ff)) {
!(prevtag == LFS_ERR_NOENT && lfs_path_islast(newpath))) {
return (prevtag < 0) ? (int)prevtag : LFS_ERR_INVAL;
}

Expand All @@ -3955,8 +3997,14 @@ static int lfs_rename_(lfs_t *lfs, const char *oldpath, const char *newpath) {
struct lfs_mlist prevdir;
prevdir.next = lfs->mlist;
if (prevtag == LFS_ERR_NOENT) {
// if we're a file, don't allow trailing slashes
if (lfs_path_isdir(newpath)
&& lfs_tag_type3(oldtag) != LFS_TYPE_DIR) {
return LFS_ERR_NOTDIR;
}

// check that name fits
lfs_size_t nlen = strlen(newpath);
lfs_size_t nlen = lfs_path_namelen(newpath);
if (nlen > lfs->name_max) {
return LFS_ERR_NAMETOOLONG;
}
Expand Down Expand Up @@ -4016,7 +4064,8 @@ static int lfs_rename_(lfs_t *lfs, const char *oldpath, const char *newpath) {
{LFS_MKTAG_IF(prevtag != LFS_ERR_NOENT,
LFS_TYPE_DELETE, newid, 0), NULL},
{LFS_MKTAG(LFS_TYPE_CREATE, newid, 0), NULL},
{LFS_MKTAG(lfs_tag_type3(oldtag), newid, strlen(newpath)), newpath},
{LFS_MKTAG(lfs_tag_type3(oldtag),
newid, lfs_path_namelen(newpath)), newpath},
{LFS_MKTAG(LFS_FROM_MOVE, newid, lfs_tag_id(oldtag)), &oldcwd},
{LFS_MKTAG_IF(samepair,
LFS_TYPE_DELETE, newoldid, 0), NULL}));
Expand Down
Loading
Loading