+
+bool reapply_default_acl(const char* path) {
+ /* If this is a normal file or directory (i.e. that has just been
+ created), we proceed to find its parent directory which will have
+ a default ACL. */
+ if (path == NULL) {
+ return false;
+ }
+
+ if (!is_regular_file(path) && !is_directory(path)) {
+ return false;
+ }
+
+ /* dirname mangles its argument */
+ char path_copy[PATH_MAX];
+ strncpy(path_copy, path, PATH_MAX-1);
+ path_copy[PATH_MAX] = 0;
+
+ char* parent = dirname(path_copy);
+ if (!is_directory(parent)) {
+ /* Make sure dirname() did what we think it did. */
+ return false;
+ }
+
+ /* This is the original mode of path. We will simply add permissions
+ to it, and then later reapply the result via chmod. */
+ mode_t path_mode = get_mode(path);
+
+
+ /* If parent has a default user ACL, apply it to path via chmod. */
+ if (has_default_user_obj_read(parent)) {
+ path_mode |= S_IRUSR;
+ }
+
+ if (has_default_user_obj_write(parent)) {
+ path_mode |= S_IWUSR;
+ }
+
+ /* However, we don't want to set the execute bit on via the ACL
+ unless it was on originally. Furthermore, if the ACL denies
+ execute, we want to honor that. */
+ if (has_default_user_obj_acl(parent)) {
+ if (!has_default_user_obj_execute(parent)) {
+ /* It has a user ACL, but no user execute is granted. */
+ path_mode &= ~S_IXUSR;
+ }
+ }
+
+
+ /* Do the same thing with the other perms/ACL. */
+ if (has_default_other_read(parent)) {
+ path_mode |= S_IROTH;
+ }
+
+ if (has_default_other_write(parent)) {
+ path_mode |= S_IWOTH;
+ }
+
+ if (has_default_other_acl(parent)) {
+ if (!has_default_other_execute(parent)) {
+ /* It has an other ACL, but no other execute is granted. */
+ path_mode &= ~S_IXOTH;
+ }
+ }
+
+ /* For the group bits, we'll use the ACL's mask instead of the group
+ object bits. If the default ACL had a group entry, it should
+ already have propagated (but might be masked. */
+ if (has_default_mask_read(parent)) {
+ path_mode |= S_IRGRP;
+ }
+
+ if (has_default_mask_write(parent)) {
+ path_mode |= S_IWGRP;
+ }
+
+ /* Honor the mask execute unconditionally. */
+ if (has_default_mask_execute(parent)) {
+ if (mode_has_perm(path_mode, S_IXGRP)) {
+ path_mode |= S_IXGRP;
+ }
+ }
+
+ int result = chmod(path, path_mode);
+ if (result == 0) {
+ return true;
+ }
+ else {
+ return false;
+ }
+}
+
+