From 70f0799f5485b8586c4f098ea517985e8348d16c Mon Sep 17 00:00:00 2001
From: deraadt <>
Date: Tue, 20 Apr 2010 20:49:36 +0000
Subject: [PATCH] Get rid of MAXSENSORDEVICES.  Gaps in sensordev lists are now
 handled by returning ENXIO instead of ENOENT, to essentially indicate hotplug
 sensor that has gone away.  Accessing beyond the end of the sensordev list
 still returns ENOENT, so that you can see there are no further devices. ok
 kettenis oga

---
 src/usr.sbin/ntpd/sensors.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/usr.sbin/ntpd/sensors.c b/src/usr.sbin/ntpd/sensors.c
index eef66a4d..839f90ab 100644
--- a/src/usr.sbin/ntpd/sensors.c
+++ b/src/usr.sbin/ntpd/sensors.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sensors.c,v 1.44 2009/05/13 15:08:10 stevesk Exp $ */
+/*	$OpenBSD: sensors.c,v 1.45 2010/04/20 20:49:36 deraadt Exp $ */
 
 /*
  * Copyright (c) 2006 Henning Brauer <henning@openbsd.org>
@@ -49,13 +49,17 @@ sensor_init(void)
 int
 sensor_scan(void)
 {
-	int		i, n;
+	int		i, n, err;
 	char		d[MAXDEVNAMLEN];
 	struct sensor	s;
 
 	n = 0;
-	for (i = 0; i < MAXSENSORDEVICES; i++)
-		if (sensor_probe(i, d, &s)) {
+	for (i = 0; ; i++)
+		if ((err = sensor_probe(i, d, &s))) {
+			if (err == 0)
+				continue;
+			if (err == -1)	/* no further sensors */
+				break;
 			sensor_add(i, d);
 			n++;
 		}
@@ -63,6 +67,11 @@ sensor_scan(void)
 	return n;
 }
 
+/*
+ * 1 = time sensor!
+ * 0 = sensor exists... but is not a time sensor
+ * -1: no sensor here, and no further sensors after this
+ */
 int
 sensor_probe(int devid, char *dxname, struct sensor *sensor)
 {
@@ -78,9 +87,11 @@ sensor_probe(int devid, char *dxname, struct sensor *sensor)
 
 	sdlen = sizeof(sensordev);
 	if (sysctl(mib, 3, &sensordev, &sdlen, NULL, 0) == -1) {
-		if (errno != ENOENT)
-			log_warn("sensor_probe sysctl");
-		return (0);
+		if (errno == ENXIO)
+			return (0);
+		if (errno == ENOENT)
+			return (-1);
+		log_warn("sensor_probe sysctl");
 	}
 
 	if (sensordev.maxnumt[SENSOR_TIMEDELTA] == 0)