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class method
Process::GID.change_privilege
Process::GID.change_privilege(group) → integer
process.c
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static VALUE
p_gid_change_privilege(VALUE obj, VALUE id)
{
rb_gid_t gid;
check_gid_switch();
gid = OBJ2GID(id);
if (geteuid() == 0) { /* root-user */
#if defined(HAVE_SETRESGID)
if (setresgid(gid, gid, gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
#elif defined HAVE_SETGID
if (setgid(gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
#elif defined(HAVE_SETREGID) && !defined(OBSOLETE_SETREGID)
if (getgid() == gid) {
if (SAVED_GROUP_ID == gid) {
if (setregid(-1, gid) < 0) rb_sys_fail(0);
}
else {
if (gid == 0) { /* (r,e,s) == (root, y, x) */
if (setregid(-1, SAVED_GROUP_ID) < 0) rb_sys_fail(0);
if (setregid(SAVED_GROUP_ID, 0) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = 0; /* (r,e,s) == (x, root, root) */
if (setregid(gid, gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
else { /* (r,e,s) == (z, y, x) */
if (setregid(0, 0) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = 0;
if (setregid(gid, gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
}
}
else {
if (setregid(gid, gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
#elif defined(HAVE_SETRGID) && defined (HAVE_SETEGID)
if (getgid() == gid) {
if (SAVED_GROUP_ID == gid) {
if (setegid(gid) < 0) rb_sys_fail(0);
}
else {
if (gid == 0) {
if (setegid(gid) < 0) rb_sys_fail(0);
if (setrgid(SAVED_GROUP_ID) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = 0;
if (setrgid(0) < 0) rb_sys_fail(0);
}
else {
if (setrgid(0) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = 0;
if (setegid(gid) < 0) rb_sys_fail(0);
if (setrgid(gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
}
}
else {
if (setegid(gid) < 0) rb_sys_fail(0);
if (setrgid(gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
#else
rb_notimplement();
#endif
}
else { /* unprivileged user */
#if defined(HAVE_SETRESGID)
if (setresgid((getgid() == gid)? (rb_gid_t)-1: gid,
(getegid() == gid)? (rb_gid_t)-1: gid,
(SAVED_GROUP_ID == gid)? (rb_gid_t)-1: gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
#elif defined(HAVE_SETREGID) && !defined(OBSOLETE_SETREGID)
if (SAVED_GROUP_ID == gid) {
if (setregid((getgid() == gid)? (rb_uid_t)-1: gid,
(getegid() == gid)? (rb_uid_t)-1: gid) < 0)
rb_sys_fail(0);
}
else if (getgid() != gid) {
if (setregid(gid, (getegid() == gid)? (rb_uid_t)-1: gid) < 0)
rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
else if (/* getgid() == gid && */ getegid() != gid) {
if (setregid(getegid(), gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
if (setregid(gid, -1) < 0) rb_sys_fail(0);
}
else { /* getgid() == gid && getegid() == gid */
if (setregid(-1, SAVED_GROUP_ID) < 0) rb_sys_fail(0);
if (setregid(SAVED_GROUP_ID, gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
if (setregid(gid, -1) < 0) rb_sys_fail(0);
}
#elif defined(HAVE_SETRGID) && defined(HAVE_SETEGID)
if (SAVED_GROUP_ID == gid) {
if (getegid() != gid && setegid(gid) < 0) rb_sys_fail(0);
if (getgid() != gid && setrgid(gid) < 0) rb_sys_fail(0);
}
else if (/* SAVED_GROUP_ID != gid && */ getegid() == gid) {
if (getgid() != gid) {
if (setrgid(gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
else {
if (setrgid(SAVED_GROUP_ID) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
if (setrgid(gid) < 0) rb_sys_fail(0);
}
}
else if (/* getegid() != gid && */ getgid() == gid) {
if (setegid(gid) < 0) rb_sys_fail(0);
if (setrgid(SAVED_GROUP_ID) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
if (setrgid(gid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_44BSD_SETGID
if (getgid() == gid) {
/* (r,e,s)==(gid,?,?) ==> (gid,gid,gid) */
if (setgid(gid) < 0) rb_sys_fail(0);
SAVED_GROUP_ID = gid;
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_SETEGID
if (getgid() == gid && SAVED_GROUP_ID == gid) {
if (setegid(gid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#elif defined HAVE_SETGID
if (getgid() == gid && SAVED_GROUP_ID == gid) {
if (setgid(gid) < 0) rb_sys_fail(0);
}
else {
rb_syserr_fail(EPERM, 0);
}
#else
(void)gid;
rb_notimplement();
#endif
}
return id;
}
Change the current process’s real and effective group ID to that specified by group. Returns the new group ID. Not available on all platforms.
Example
[Process.gid, Process.egid] #=> [0, 0] Process::GID.change_privilege(33) #=> 33 [Process.gid, Process.egid] #=> [33, 33]