Revert back previous commit, we have decided that socket files don't cause any

harm if not deleted after the daemon is shutdown and at the same time we also
tackle another attack surface by not allowing the program to create/delete
any more files (by removing "cpath" promise from pledge(2)).
Discussion initiated by a question from deraadt@ OK florian@

src/usr.sbin/ntpd/control.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: control.c,v 1.12 2017/01/09 14:04:31 krw Exp $ */
+/*	$OpenBSD: control.c,v 1.13 2018/08/04 11:07:14 mestre Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -99,13 +99,6 @@ control_shutdown(int fd)
 	close(fd);
 }
 
-void
-control_cleanup(const char *path)
-{
-	if (path)
-		unlink(path);
-}
-
 int
 control_accept(int listenfd)
 {

src/usr.sbin/ntpd/ntpd.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.c,v 1.114 2018/08/02 13:05:34 mestre Exp $ */
+/*	$OpenBSD: ntpd.c,v 1.115 2018/08/04 11:07:14 mestre Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -244,7 +244,7 @@ main(int argc, char *argv[])
 	 * Constraint processes are forked with certificates in memory,
 	 * then privdrop into chroot before speaking to the outside world.
 	 */
-	if (pledge("stdio rpath cpath inet settime proc exec id", NULL) == -1)
+	if (pledge("stdio rpath inet settime proc exec id", NULL) == -1)
 		err(1, "pledge");
 
 	while (quit == 0) {
@@ -327,7 +327,6 @@ main(int argc, char *argv[])
 
 	msgbuf_clear(&ibuf->w);
 	free(ibuf);
-	control_cleanup(CTLSOCKET);
 	log_info("Terminating");
 	return (0);
 }

src/usr.sbin/ntpd/ntpd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntpd.h,v 1.135 2017/05/30 23:30:48 benno Exp $ */
+/*	$OpenBSD: ntpd.h,v 1.136 2018/08/04 11:07:14 mestre Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -397,7 +397,6 @@ void			ntp_dns(struct ntpd_conf *, struct passwd *);
 int			 control_init(char *);
 int			 control_listen(int);
 void			 control_shutdown(int);
-void			 control_cleanup(const char *);
 int			 control_accept(int);
 struct ctl_conn		*control_connbyfd(int);
 int			 control_close(int);