From 5b92e02df29f0ef5f18a1ae96205fdf96044b450 Mon Sep 17 00:00:00 2001
From: tedu <tedu@openbsd.org>
Date: Sun, 13 Jul 2014 14:01:04 +0000
Subject: [PATCH] if not seeded explicitly, use arc4random instead. ok deraadt

---
 games/atc/extern.h |  3 ++-
 games/atc/main.c   |  6 ++----
 games/atc/update.c | 27 ++++++++++++++++++++++-----
 3 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/games/atc/extern.h b/games/atc/extern.h
index 0c7351b5892..1e1a293b70b 100644
--- a/games/atc/extern.h
+++ b/games/atc/extern.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: extern.h,v 1.7 2013/10/25 21:57:10 millert Exp $	*/
+/*	$OpenBSD: extern.h,v 1.8 2014/07/13 14:01:04 tedu Exp $	*/
 /*	$NetBSD: extern.h,v 1.4 1995/04/27 21:22:22 mycroft Exp $	*/
 
 /*-
@@ -102,6 +102,7 @@ void		quit(int);
 int		read_file(const char *);
 void		redraw(void);
 void		rezero(void);
+void		setseed(const char *);
 void		setup_screen(const C_SCREEN *);
 int		too_close(const PLANE *p1, const PLANE *p2, int);
 void		update(int);
diff --git a/games/atc/main.c b/games/atc/main.c
index 7262502dd2f..c406822e774 100644
--- a/games/atc/main.c
+++ b/games/atc/main.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: main.c,v 1.22 2014/07/13 13:00:40 tedu Exp $	*/
+/*	$OpenBSD: main.c,v 1.23 2014/07/13 14:01:04 tedu Exp $	*/
 /*	$NetBSD: main.c,v 1.4 1995/04/27 21:22:25 mycroft Exp $	*/
 
 /*-
@@ -112,9 +112,7 @@ main(int ac, char *av[])
 		}
 	}
 	if (seed != NULL)
-		srandom(atol(seed));
-	else
-		srandomdev();
+		setseed(seed);
 
 	if (f_usage)
 		fprintf(stderr, 
diff --git a/games/atc/update.c b/games/atc/update.c
index 7eb9996c54c..f6d09de48e6 100644
--- a/games/atc/update.c
+++ b/games/atc/update.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: update.c,v 1.13 2014/07/13 13:00:40 tedu Exp $	*/
+/*	$OpenBSD: update.c,v 1.14 2014/07/13 14:01:04 tedu Exp $	*/
 
 /*-
  * Copyright (c) 1990, 1993
@@ -43,6 +43,23 @@
 
 #include "include.h"
 
+int seeded;
+void
+setseed(const char *seed)
+{
+	seeded = 1;
+	srandom(atol(seed));
+}
+
+uint32_t
+atcrandom()
+{
+	if (seeded)
+		return random();
+	else
+		return arc4random();
+}
+
 void
 update(int dummy)
 {
@@ -196,7 +213,7 @@ update(int dummy)
 	 * Otherwise, prop jobs show up *on* entrance.  Remember that
 	 * we don't update props on odd updates.
 	 */
-	if ((random() % sp->newplane_time) == 0)
+	if ((atcrandom() % sp->newplane_time) == 0)
 		addplane();
 }
 
@@ -292,10 +309,10 @@ addplane(void)
 	memset(&p, 0, sizeof (p));
 
 	p.status = S_MARKED;
-	p.plane_type = random() % 2;
+	p.plane_type = atcrandom() % 2;
 
 	num_starts = sp->num_exits + sp->num_airports;
-	rnd = random() % num_starts;
+	rnd = atcrandom() % num_starts;
 
 	if (rnd < sp->num_exits) {
 		p.dest_type = T_EXIT;
@@ -308,7 +325,7 @@ addplane(void)
 	/* loop until we get a plane not near another */
 	for (i = 0; i < num_starts; i++) {
 		/* loop till we get a different start point */
-		while ((rnd2 = random() % num_starts) == rnd)
+		while ((rnd2 = atcrandom() % num_starts) == rnd)
 			;
 		if (rnd2 < sp->num_exits) {
 			p.orig_type = T_EXIT;
-- 
2.20.1