Use O_CLOEXEC when opening fds local to a function

ok jca@ krw@

src/lib/libutil/logwtmp.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: logwtmp.c,v 1.9 2005/08/02 21:46:23 espie Exp $	*/
+/*	$OpenBSD: logwtmp.c,v 1.10 2016/08/30 14:44:45 guenther Exp $	*/
 /*
  * Copyright (c) 1988, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -46,7 +46,7 @@ logwtmp(const char *line, const char *name, const char *host)
 	struct utmp ut;
 	int fd;
 
-	if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND, 0)) < 0)
+	if ((fd = open(_PATH_WTMP, O_WRONLY|O_APPEND|O_CLOEXEC)) < 0)
 		return;
 	if (fstat(fd, &buf) == 0) {
 		(void) strncpy(ut.ut_line, line, sizeof(ut.ut_line));

src/lib/libutil/pty.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: pty.c,v 1.19 2013/05/21 19:07:02 matthew Exp $	*/
+/*	$OpenBSD: pty.c,v 1.20 2016/08/30 14:44:45 guenther Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -54,7 +54,7 @@ openpty(int *amaster, int *aslave, char *name, struct termios *termp,
 	 * Use /dev/ptm and the PTMGET ioctl to get a properly set up and
 	 * owned pty/tty pair.
 	 */
-	fd = open(PATH_PTMDEV, O_RDWR, 0);
+	fd = open(PATH_PTMDEV, O_RDWR|O_CLOEXEC);
 	if (fd == -1)
 		return (-1);
 	if ((ioctl(fd, PTMGET, &ptm) == -1)) {

src/lib/libutil/readlabel.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: readlabel.c,v 1.13 2015/01/16 16:48:52 deraadt Exp $	*/
+/*	$OpenBSD: readlabel.c,v 1.14 2016/08/30 14:44:45 guenther Exp $	*/
 
 /*
  * Copyright (c) 1996, Jason Downs.  All rights reserved.
@@ -59,7 +59,7 @@ readlabelfs(char *device, int verbose)
 
 	/* Perform disk mapping if device is given as a DUID. */
 	if (isduid(device, 0)) {
-		if ((fd = open("/dev/diskmap", O_RDONLY)) != -1) {
+		if ((fd = open("/dev/diskmap", O_RDONLY|O_CLOEXEC)) != -1) {
 			bzero(&dm, sizeof(struct dk_diskmap));
 			strlcpy(rpath, device, sizeof(rpath));
 			part = rpath[strlen(rpath) - 1];
@@ -105,12 +105,12 @@ readlabelfs(char *device, int verbose)
 	}
 
 	/* If rpath doesn't exist, change that partition back. */
-	fd = open(rpath, O_RDONLY);
+	fd = open(rpath, O_RDONLY|O_CLOEXEC);
 	if (fd < 0) {
 		if (errno == ENOENT) {
 			rpath[strlen(rpath) - 1] = part;
 
-			fd = open(rpath, O_RDONLY);
+			fd = open(rpath, O_RDONLY|O_CLOEXEC);
 			if (fd < 0) {
 				if (verbose)
 					warn("%s", rpath);

src/lib/libutil/uucplock.c

@@ -1,4 +1,4 @@
-/*	$OpenBSD: uucplock.c,v 1.17 2015/11/11 01:12:09 deraadt Exp $	*/
+/*	$OpenBSD: uucplock.c,v 1.18 2016/08/30 14:44:45 guenther Exp $	*/
 /*
  * Copyright (c) 1988, 1993
  *	The Regents of the University of California.  All rights reserved.
@@ -70,7 +70,8 @@ uu_lock(const char *ttyname)
 	    (long)pid);
 	(void)snprintf(lckname, sizeof(lckname), _PATH_UUCPLOCK LOCKFMT,
 	    ttyname);
-	if ((tmpfd = open(lcktmpname, O_CREAT | O_TRUNC | O_WRONLY, 0664)) < 0)
+	tmpfd = open(lcktmpname, O_CREAT|O_TRUNC|O_WRONLY|O_CLOEXEC, 0664);
+	if (tmpfd < 0)
 		GORET(0, UU_LOCK_CREAT_ERR);
 
 	for (i = 0; i < MAXTRIES; i++) {
@@ -82,7 +83,7 @@ uu_lock(const char *ttyname)
 			 * check to see if the process holding the lock
 			 * still exists
 			 */
-			if ((fd = open(lckname, O_RDONLY)) < 0)
+			if ((fd = open(lckname, O_RDONLY | O_CLOEXEC)) < 0)
 				GORET(1, UU_LOCK_OPEN_ERR);
 
 			if ((pid_old = get_pid(fd, &err)) == -1)
@@ -126,7 +127,7 @@ uu_lock_txfr(const char *ttyname, pid_t pid)
 
 	snprintf(lckname, sizeof(lckname), _PATH_UUCPLOCK LOCKFMT, ttyname);
 
-	if ((fd = open(lckname, O_RDWR)) < 0)
+	if ((fd = open(lckname, O_RDWR | O_CLOEXEC)) < 0)
 		return UU_LOCK_OWNER_ERR;
 	if (get_pid(fd, &err) != getpid())
 		ret = UU_LOCK_OWNER_ERR;