--- ntpd/ntp_io.c	2010-12-25 10:40:36.000000000 +0100
+++ ntpd/ntp_io.c.oden	2011-01-04 14:48:19.828810123 +0100
@@ -151,6 +151,8 @@ int ninterfaces;			/* Total number of in
 
 int disable_dynamic_updates;		/* scan interfaces once only */
 
+static int pktinfo_status = 0;		/* is IP_PKTINFO on wildipv4 iface enabled? */
+
 #ifdef REFCLOCK
 /*
  * Refclock stuff.	We keep a chain of structures with data concerning
@@ -2254,6 +2256,17 @@ set_reuseaddr(
 #endif /* ! SO_EXCLUSIVEADDRUSE */
 }
 
+static void
+set_pktinfo(int flag)
+{
+	if (wildipv4 == NULL)
+		return;
+	if (setsockopt(wildipv4->fd, SOL_IP, IP_PKTINFO, &flag, sizeof (flag))) {
+		msyslog(LOG_ERR, "set_pktinfo: setsockopt(IP_PKTINFO, %s) failed: %m", flag ? "on" : "off");
+	} else
+		pktinfo_status = flag;
+}
+
 /*
  * This is just a wrapper around an internal function so we can
  * make other changes as necessary later on
@@ -2659,6 +2672,7 @@ io_setbclient(void)
 		}
 	}
 	set_reuseaddr(0);
+	set_pktinfo(1);
 	if (nif > 0)
 		DPRINTF(1, ("io_setbclient: Opened broadcast clients\n"));
 	else if (!nif)
@@ -2685,6 +2699,7 @@ io_unsetbclient(void)
 			continue;
 		socket_broadcast_disable(ep, &ep->sin);
 	}
+	set_pktinfo(0);
 }
 
 /*
@@ -3392,7 +3407,8 @@ read_network_packet(
 #ifdef HAVE_TIMESTAMP
 	struct msghdr msghdr;
 	struct iovec iovec;
-	char control[TIMESTAMP_CTLMSGBUF_SIZE];
+	char control[sizeof (struct cmsghdr) * 2 + sizeof (struct timeval) +
+		sizeof (struct in_pktinfo) + 32];
 #endif
 
 	/*
@@ -3403,7 +3419,7 @@ read_network_packet(
 	 */
 
 	rb = get_free_recv_buffer();
-	if (NULL == rb || itf->ignore_packets) {
+	if (NULL == rb || (itf->ignore_packets && !(pktinfo_status && itf == wildipv4))) {
 		char buf[RX_BUFF_SIZE];
 		sockaddr_u from;
 
@@ -3463,6 +3479,27 @@ read_network_packet(
 		return (buflen);
 	}
 
+	if (pktinfo_status && itf->ignore_packets && itf == wildipv4) {
+		/* check for broadcast on 255.255.255.255, exception allowed on wildipv4 */
+		struct cmsghdr *cmsg;
+		struct in_pktinfo *pktinfo = NULL;
+
+		if ((cmsg = CMSG_FIRSTHDR(&msghdr)))
+			do {
+				if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_PKTINFO)
+					pktinfo = (struct in_pktinfo *) CMSG_DATA(cmsg);
+			} while ((cmsg = CMSG_NXTHDR(&msghdr, cmsg)));
+		if (pktinfo && pktinfo->ipi_addr.s_addr == INADDR_BROADCAST) {
+			DPRINTF(4, ("INADDR_BROADCAST\n"));
+		} else {
+			DPRINTF(4, ("%s on (%lu) fd=%d from %s\n", "ignore",
+				free_recvbuffs(), fd, stoa(&rb->recv_srcadr)));
+			packets_ignored++;
+			freerecvbuf(rb);
+			return (buflen);
+		}
+	}
+
 	DPRINTF(3, ("read_network_packet: fd=%d length %d from %s\n",
 		    fd, buflen, stoa(&rb->recv_srcadr)));