class method
Process::UID.change_privilege
(::Integer user) -> ::Integer
Process::UID.change_privilege(user) → integer
process.c
View on GitHub ↗
static VALUE
p_uid_change_privilege(VALUE obj, VALUE id)
{
rb_uid_t uid;
check_uid_switch();
uid = OBJ2UID(id);
if (geteuid() == 0) { /* root-user */
#if defined(HAVE_SETRESUID)
if (setresuid(uid, uid, uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
#elif defined(HAVE_SETUID)
if (setuid(uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
if (getuid() == uid) {
if (SAVED_USER_ID == uid) {
if (setreuid(-1, uid) < 0) rb_sys_fail(0);
}
else {
if (uid == 0) { /* (r,e,s) == (root, root, x) */
if (setreuid(-1, SAVED_USER_ID) < 0) rb_sys_fail(0);
if (setreuid(SAVED_USER_ID, 0) < 0) rb_sys_fail(0);
SAVED_USER_ID = 0; /* (r,e,s) == (x, root, root) */
if (setreuid(uid, uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
else {
if (setreuid(0, -1) < 0) rb_sys_fail(0);
SAVED_USER_ID = 0;
if (setreuid(uid, uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
}
}
else {
if (setreuid(uid, uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
#elif defined(HAVE_SETRUID) && defined(HAVE_SETEUID)
if (getuid() == uid) {
if (SAVED_USER_ID == uid) {
if (seteuid(uid) < 0) rb_sys_fail(0);
}
else {
if (uid == 0) {
if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
SAVED_USER_ID = 0;
if (setruid(0) < 0) rb_sys_fail(0);
}
else {
if (setruid(0) < 0) rb_sys_fail(0);
SAVED_USER_ID = 0;
if (seteuid(uid) < 0) rb_sys_fail(0);
if (setruid(uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
}
}
else {
if (seteuid(uid) < 0) rb_sys_fail(0);
if (setruid(uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
#else
(void)uid;
rb_notimplement();
#endif
}
else { /* unprivileged user */
#if defined(HAVE_SETRESUID)
if (setresuid((getuid() == uid)? (rb_uid_t)-1: uid,
(geteuid() == uid)? (rb_uid_t)-1: uid,
(SAVED_USER_ID == uid)? (rb_uid_t)-1: uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
#elif defined(HAVE_SETREUID) && !defined(OBSOLETE_SETREUID)
if (SAVED_USER_ID == uid) {
if (setreuid((getuid() == uid)? (rb_uid_t)-1: uid,
(geteuid() == uid)? (rb_uid_t)-1: uid) < 0)
rb_sys_fail(0);
}
else if (getuid() != uid) {
if (setreuid(uid, (geteuid() == uid)? (rb_uid_t)-1: uid) < 0)
rb_sys_fail(0);
SAVED_USER_ID = uid;
}
else if (/* getuid() == uid && */ geteuid() != uid) {
if (setreuid(geteuid(), uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
if (setreuid(uid, -1) < 0) rb_sys_fail(0);
}
else { /* getuid() == uid && geteuid() == uid */
if (setreuid(-1, SAVED_USER_ID) < 0) rb_sys_fail(0);
if (setreuid(SAVED_USER_ID, uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
if (setreuid(uid, -1) < 0) rb_sys_fail(0);
}
#elif defined(HAVE_SETRUID) && defined(HAVE_SETEUID)
if (SAVED_USER_ID == uid) {
if (geteuid() != uid && seteuid(uid) < 0) rb_sys_fail(0);
if (getuid() != uid && setruid(uid) < 0) rb_sys_fail(0);
}
else if (/* SAVED_USER_ID != uid && */ geteuid() == uid) {
if (getuid() != uid) {
if (setruid(uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
else {
if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
if (setruid(uid) < 0) rb_sys_fail(0);
}
}
else if (/* geteuid() != uid && */ getuid() == uid) {
if (seteuid(uid) < 0) rb_sys_fail(0);
if (setruid(SAVED_USER_ID) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
if (setruid(uid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_44BSD_SETUID
if (getuid() == uid) {
/* (r,e,s)==(uid,?,?) ==> (uid,uid,uid) */
if (setuid(uid) < 0) rb_sys_fail(0);
SAVED_USER_ID = uid;
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_SETEUID
if (getuid() == uid && SAVED_USER_ID == uid) {
if (seteuid(uid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_SETUID
if (getuid() == uid && SAVED_USER_ID == uid) {
if (setuid(uid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#else
rb_notimplement();
#endif
}
return id;
}
Change the current process’s real and effective user ID to that specified by user. Returns the new user ID. Not available on all platforms.
Example
[Process.uid, Process.euid] #=> [0, 0] Process::UID.change_privilege(31) #=> 31 [Process.uid, Process.euid] #=> [31, 31]