util-lib: add a comment explaining the user name rules we enforce
This commit is contained in:
parent
27e2e3231f
commit
1429dfe5f8
|
@ -46,6 +46,8 @@
|
|||
|
||||
bool uid_is_valid(uid_t uid) {
|
||||
|
||||
/* Also see POSIX IEEE Std 1003.1-2008, 2016 Edition, 3.436. */
|
||||
|
||||
/* Some libc APIs use UID_INVALID as special placeholder */
|
||||
if (uid == (uid_t) UINT32_C(0xFFFFFFFF))
|
||||
return false;
|
||||
|
@ -519,7 +521,15 @@ bool valid_user_group_name(const char *u) {
|
|||
const char *i;
|
||||
long sz;
|
||||
|
||||
/* Checks if the specified name is a valid user/group name. */
|
||||
/* Checks if the specified name is a valid user/group name. Also see POSIX IEEE Std 1003.1-2008, 2016 Edition,
|
||||
* 3.437. We are a bit stricter here however. Specifically we deviate from POSIX rules:
|
||||
*
|
||||
* - We don't allow any dots (this would break chown syntax which permits dots as user/group name separator)
|
||||
* - We require that names fit into the appropriate utmp field
|
||||
* - We don't allow empty user names
|
||||
*
|
||||
* Note that other systems are even more restrictive, and don't permit underscores or uppercase characters.
|
||||
*/
|
||||
|
||||
if (isempty(u))
|
||||
return false;
|
||||
|
|
Loading…
Reference in a new issue