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/* ISC license. */
#include <skalibs/sysdeps.h>
#include <skalibs/nonposix.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <sys/reboot.h>
#include <skalibs/strerr2.h>
#include <skalibs/sgetopt.h>
#include <skalibs/sig.h>
#include <skalibs/djbunix.h>
#define USAGE PROGNAME " [ -h | -p | -r ] [ -f ]"
#ifdef SKALIBS_HASNSGETPARENT
#include <sys/ioctl.h>
#include <linux/nsfs.h>
static int test_in_namespace (void)
{
int r ;
int fd = open_read("/proc/1/ns/pid") ;
if (fd < 0) return 0 ;
r = ioctl(fd, NS_GET_PARENT) ;
close(fd) ;
return r >= 0 ;
}
#else
/*
When in doubt, always trap signals. This incurs a small race:
if ctrl-alt-del is pressed at the wrong time, the process will
exit and cause a kernel panic. But the alternatives are WAY
more hackish than this.
*/
static int test_in_namespace (void)
{
return 1 ;
}
#endif
static void sigint_handler (int sig)
{
(void)sig ;
_exit(1) ;
}
static void sighup_handler (int sig)
{
(void)sig ;
_exit(0) ;
}
int main (int argc, char const *const *argv)
{
int what = WHATDEFAULT ;
int force = 0 ;
PROG = PROGNAME ;
{
subgetopt_t l = SUBGETOPT_ZERO ;
for (;;)
{
int opt = subgetopt_r(argc, argv, "hprf", &l) ;
if (opt == -1) break ;
switch (opt)
{
case 'h' : what = 1 ; break ;
case 'p' : what = 2 ; break ;
case 'r' : what = 3 ; break ;
case 'f' : force = 1 ; break ;
default : strerr_dieusage(100, USAGE) ;
}
}
argc -= l.ind ; argv += l.ind ;
}
if (geteuid())
{
errno = EPERM ;
strerr_dief1sys(100, "nice try, peon") ;
}
if (force)
{
sync() ;
if (getpid() == 1)
{
if (test_in_namespace())
{
if (sig_catch(SIGINT, &sigint_handler) < 0
|| sig_catch(SIGHUP, &sighup_handler) < 0)
strerr_diefu1sys(111, "catch signals") ;
}
}
reboot(what == 3 ? RB_AUTOBOOT : what == 2 ? RB_POWER_OFF : RB_HALT_SYSTEM) ;
strerr_diefu1sys(111, "reboot()") ;
}
else if (kill(1, what == 3 ? SIGINT : what == 2 ? SIGUSR1 : SIGUSR2) < 0)
strerr_diefu1sys(111, "signal process 1") ;
return 0 ;
}
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