}
char* parent = dirname(dirname_path_copy);
- /* Just kidding, if the path is ".", then dirname will do the wrong
- * thing and give us "." as its parent, too. So, we handle that as a
- * special case.
- *
- * WARNING: it is important that "parent" itself is not used after
- * this point; otherwise we would need to store the correct parent
- * path in there. But since everything uses file descriptors from
- * now on, we only need to ensure that we get the correct parent_fd
- * below. */
- if (strcmp(path, ".") == 0 && strcmp(parent, ".") == 0) {
- parent_fd = safe_open("..", O_DIRECTORY | O_NOFOLLOW);
+ basename_path_copy = strdup(path);
+ if (basename_path_copy == NULL) {
+ perror("apply_default_acl (strdup)");
+ result = ACL_ERROR;
+ goto cleanup;
}
- else {
- parent_fd = safe_open(parent, O_DIRECTORY | O_NOFOLLOW);
+ char* child = basename(basename_path_copy);
+
+ /* Just kidding, if the path is "." or "..", then dirname will do
+ * the wrong thing and give us "." as its parent, too. So, we handle
+ * those as special cases. We use "child" instead of "path" here to
+ * catch things like "./" and "../"
+ */
+ bool path_is_dots = strcmp(child, ".") == 0 || strcmp(child, "..") == 0;
+ char dots_parent[6] = "../";
+ if (path_is_dots) {
+ /* We know that "child" contains no more than two characters here, and
+ using strncat to enforce that belief keeps clang-tidy happy. */
+ parent = strncat(dots_parent, child, 2);
}
+
+ parent_fd = safe_open(parent, O_DIRECTORY | O_NOFOLLOW);
+
if (parent_fd == OPEN_ERROR) {
if (errno == ELOOP || errno == ENOTDIR) {
/* We hit a symlink, either in the last path component (ELOOP)
}
/* We already obtained the parent fd safely, so if we use the
- basename of path here instead of the full thing, then we can get
- away with using openat() and spare ourselves the slowness of
- another safe_open(). */
- basename_path_copy = strdup(path);
- if (basename_path_copy == NULL) {
- perror("apply_default_acl (strdup)");
- result = ACL_ERROR;
- goto cleanup;
- }
-
- /* If the basename is ".", then we don't want to open "." relative
- to the parent_fd, so we need another special case for that
- path. */
- if (strcmp(path, ".") == 0 && strcmp(parent, ".") == 0) {
- fd = open(".", O_NOFOLLOW);
+ * basename of path here instead of the full thing, then we can get
+ * away with using openat() and spare ourselves the slowness of
+ * another safe_open().
+ *
+ * Note that if the basename is "." or "..", then we don't want to
+ * open it relative to the parent_fd, so we need another special
+ * case for those paths here.
+ */
+ if (path_is_dots) {
+ fd = open(child, O_NOFOLLOW);
}
else {
- fd = openat(parent_fd, basename(basename_path_copy), O_NOFOLLOW);
+ fd = openat(parent_fd, child, O_NOFOLLOW);
}
if (fd == OPEN_ERROR) {
if (errno == ELOOP || errno == ENOTDIR) {