Mirror bluhm's fixes for proc.c daemons to dup /dev/null for child processes

in switchd(8).

OK henning@ bluhm@

3 files changed, 20 insertions, 9 deletions

diff --git a/usr.sbin/switchd/proc.c b/usr.sbin/switchd/proc.c
index 6a69d458fa6..3e1b1752d59 100644
--- a/usr.sbin/switchd/proc.c
+++ b/usr.sbin/switchd/proc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.c,v 1.13 2018/08/05 08:16:24 mestre Exp $	*/
+/*	$OpenBSD: proc.c,v 1.14 2018/09/10 13:21:39 akoshibe Exp $	*/
 
 /*
  * Copyright (c) 2010 - 2016 Reyk Floeter <reyk@openbsd.org>
@@ -29,13 +29,14 @@
 #include <string.h>
 #include <errno.h>
 #include <signal.h>
+#include <paths.h>
 #include <pwd.h>
 #include <event.h>
 #include <imsg.h>
 
 #include "proc.h"
 
-void	 proc_exec(struct privsep *, struct privsep_proc *, unsigned int,
+void	 proc_exec(struct privsep *, struct privsep_proc *, unsigned int, int,
 	    int, char **);
 void	 proc_setup(struct privsep *, struct privsep_proc *, unsigned int);
 void	 proc_open(struct privsep *, int, int);
@@ -80,7 +81,7 @@ proc_getid(struct privsep_proc *procs, unsigned int nproc,
 
 void
 proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
-    int argc, char **argv)
+    int debug, int argc, char **argv)
 {
 	unsigned int		 proc, nargc, i, proc_i;
 	char			**nargv;
@@ -141,6 +142,16 @@ proc_exec(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
 				} else if (fcntl(fd, F_SETFD, 0) == -1)
 					fatal("fcntl");
 
+				/* Daemons detach from terminal. */
+				if (!debug && (fd =
+				    open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
+					(void)dup2(fd, STDIN_FILENO);
+					(void)dup2(fd, STDOUT_FILENO);
+					(void)dup2(fd, STDERR_FILENO);
+					if (fd > 2)
+						(void)close(fd);
+				}
+
 				execvp(argv[0], nargv);
 				fatal("%s: execvp", __func__);
 				break;
@@ -191,7 +202,7 @@ proc_connect(struct privsep *ps)
 
 void
 proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
-    int argc, char **argv, enum privsep_procid proc_id)
+    int debug, int argc, char **argv, enum privsep_procid proc_id)
 {
 	struct privsep_proc	*p = NULL;
 	struct privsep_pipes	*pa, *pb;
@@ -231,7 +242,7 @@ proc_init(struct privsep *ps, struct privsep_proc *procs, unsigned int nproc,
 		}
 
 		/* Engage! */
-		proc_exec(ps, procs, nproc, argc, argv);
+		proc_exec(ps, procs, nproc, debug, argc, argv);
 		return;
 	}
 
diff --git a/usr.sbin/switchd/proc.h b/usr.sbin/switchd/proc.h
index db857b68107..37a1466a929 100644
--- a/usr.sbin/switchd/proc.h
+++ b/usr.sbin/switchd/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.7 2018/08/05 08:16:24 mestre Exp $	*/
+/*	$OpenBSD: proc.h,v 1.8 2018/09/10 13:21:39 akoshibe Exp $	*/
 
 /*
  * Copyright (c) 2010-2015 Reyk Floeter <reyk@openbsd.org>
@@ -126,7 +126,7 @@ TAILQ_HEAD(ctl_connlist, ctl_conn);
 extern  struct ctl_connlist ctl_conns;
 
 /* proc.c */
-void	 proc_init(struct privsep *, struct privsep_proc *, unsigned int,
+void	 proc_init(struct privsep *, struct privsep_proc *, unsigned int, int,
 	    int, char **, enum privsep_procid);
 void	 proc_kill(struct privsep *);
 void	 proc_connect(struct privsep *ps);
diff --git a/usr.sbin/switchd/switchd.c b/usr.sbin/switchd/switchd.c
index 5d4fde3a272..c42ee62fad8 100644
--- a/usr.sbin/switchd/switchd.c
+++ b/usr.sbin/switchd/switchd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: switchd.c,v 1.15 2017/01/09 14:49:22 reyk Exp $	*/
+/*	$OpenBSD: switchd.c,v 1.16 2018/09/10 13:21:39 akoshibe Exp $	*/
 
 /*
  * Copyright (c) 2013-2016 Reyk Floeter <reyk@openbsd.org>
@@ -184,7 +184,7 @@ main(int argc, char *argv[])
 		ps->ps_title[proc_id] = title;
 
 	/* Only the parent returns. */
-	proc_init(ps, procs, nitems(procs), argc0, argv, proc_id);
+	proc_init(ps, procs, nitems(procs), debug, argc0, argv, proc_id);
 
 	if (!debug && daemon(0, 0) == -1)
 		fatal("failed to daemonize");