From 1bfbeb3ca8aaf4b8ff045984b6407c918fad093e Mon Sep 17 00:00:00 2001
From: dtucker <>
Date: Mon, 13 Dec 2004 12:22:52 +0000
Subject: [PATCH] Discard replies with alarm flag set or invalid stratum; ok
 henning@

---
 src/usr.sbin/ntpd/client.c | 6 +++++-
 src/usr.sbin/ntpd/ntp.h    | 3 ++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/usr.sbin/ntpd/client.c b/src/usr.sbin/ntpd/client.c
index 94a8613a..e066d310 100644
--- a/src/usr.sbin/ntpd/client.c
+++ b/src/usr.sbin/ntpd/client.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: client.c,v 1.47 2004/12/09 20:24:46 mickey Exp $ */
+/*	$OpenBSD: client.c,v 1.48 2004/12/13 12:22:52 dtucker Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -198,6 +198,10 @@ client_dispatch(struct ntp_peer *p, u_int8_t settime)
 	    msg.orgtime.fractionl != p->query->msg.xmttime.fractionl)
 		return (0);
 
+	if ((msg.status & LI_ALARM) == LI_ALARM || msg.stratum == 0 ||
+	    msg.stratum > NTP_MAXSTRATUM)
+		return (0);
+
 	/*
 	 * From RFC 2030 (with a correction to the delay math):
 	 *
diff --git a/src/usr.sbin/ntpd/ntp.h b/src/usr.sbin/ntpd/ntp.h
index 7da44fca..1c25e249 100644
--- a/src/usr.sbin/ntpd/ntp.h
+++ b/src/usr.sbin/ntpd/ntp.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ntp.h,v 1.10 2004/12/08 15:47:38 mickey Exp $ */
+/*	$OpenBSD: ntp.h,v 1.11 2004/12/13 12:22:52 dtucker Exp $ */
 
 /*
  * Copyright (c) 2004 Henning Brauer <henning@openbsd.org>
@@ -145,5 +145,6 @@ struct ntp_query {
 #define	JAN_1970	2208988800UL	/* 1970 - 1900 in seconds */
 
 #define	NTP_VERSION	4
+#define	NTP_MAXSTRATUM	15
 
 #endif	/* _NTP_H_ */