user-util: add comments explaining what the user name size limits effectively mean

2024-01-25 13:42:01 +01:00
parent ac0054e686
commit b009782b5d
1 changed files with 3 additions and 3 deletions
@@ -797,11 +797,11 @@ bool valid_user_group_name(const char *u, ValidUserFlags flags) {
                sz = sysconf(_SC_LOGIN_NAME_MAX);
                assert_se(sz > 0);

-                if (l > (size_t) sz)
+                if (l > (size_t) sz) /* glibc: 256 */
                        return false;
-                if (l > NAME_MAX) /* must fit in a filename */
+                if (l > NAME_MAX) /* must fit in a filename: 255 */
                        return false;
-                if (l > UT_NAMESIZE - 1)
+                if (l > UT_NAMESIZE - 1) /* must fit in utmp: 31 */
                        return false;
        }