1 files changed, 19 insertions, 1 deletions

diff --git a/misc.c b/misc.c
index 07d4179e4..65c9222aa 100644
--- a/misc.c
+++ b/misc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: misc.c,v 1.106 2016/10/23 22:04:05 dtucker Exp $ */
+/* $OpenBSD: misc.c,v 1.107 2016/11/30 00:28:31 dtucker Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2005,2006 Damien Miller.  All rights reserved.
@@ -1251,3 +1251,21 @@ bind_permitted(int port, uid_t uid)
                 return 0;
         return 1;
 }
+
+/* returns 1 if process is already daemonized, 0 otherwise */
+int
+daemonized(void)
+{
+        int fd;
+
+        if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) {
+                close(fd);
+                return 0;       /* have controlling terminal */
+        }
+        if (getppid() != 1)
+                return 0;       /* parent is not init */
+        if (getsid(0) != getpid())
+                return 0;       /* not session leader */
+        debug3("already daemonized");
+        return 1;
+}