1 files changed, 63 insertions, 0 deletions
diff --git a/src/init/hpr.c b/src/init/hpr.c
index faa0a7c..b587dba 100644
--- a/src/init/hpr.c
+++ b/src/init/hpr.c
@@ -1,13 +1,61 @@
 /* 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(myfd, 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 ;
@@ -32,9 +80,24 @@ int main (int argc, char const *const *argv)
     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()") ;
   }