Module Name: src
Committed By: ginsbach
Date: Fri Aug 11 16:47:42 UTC 2017
Modified Files:
src/usr.sbin/timed/timed: readmsg.c
Log Message:
PR bin/42464: Timothy McIntosh: Fix timed interoperability
Fix is a combination of FreeBSD fix and submitted patch.
[From the FreeBSD change]
The timed protocol is not implemented in a compatible way by all
vendors; the size of the tsp_name field is OS-dependent. 4.3BSD
used a 32-byte field, FreeBSD uses MAXHOSTNAMELEN and RedHat
apparently uses a 64-byte field. As a result, sanity checking code
added a few months ago to detect short packets will fail when
interoperating with one of these other vendors.
Change the short packet detection code to expect a minimum packet
size corresponding to the 4.3BSD implementation, which should be
a safe minimum size.
To generate a diff of this commit:
cvs rdiff -u -r1.22 -r1.23 src/usr.sbin/timed/timed/readmsg.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.sbin/timed/timed/readmsg.c
diff -u src/usr.sbin/timed/timed/readmsg.c:1.22 src/usr.sbin/timed/timed/readmsg.c:1.23
--- src/usr.sbin/timed/timed/readmsg.c:1.22 Sat Feb 16 07:30:15 2008
+++ src/usr.sbin/timed/timed/readmsg.c Fri Aug 11 16:47:42 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: readmsg.c,v 1.22 2008/02/16 07:30:15 matt Exp $ */
+/* $NetBSD: readmsg.c,v 1.23 2017/08/11 16:47:42 ginsbach Exp $ */
/*-
* Copyright (c) 1985, 1993 The Regents of the University of California.
@@ -34,7 +34,7 @@
#if 0
static char sccsid[] = "@(#)readmsg.c 8.1 (Berkeley) 6/6/93";
#else
-__RCSID("$NetBSD: readmsg.c,v 1.22 2008/02/16 07:30:15 matt Exp $");
+__RCSID("$NetBSD: readmsg.c,v 1.23 2017/08/11 16:47:42 ginsbach Exp $");
#endif
#endif /* not lint */
@@ -203,15 +203,22 @@ again:
continue;
}
length = sizeof(from);
+ memset(&msgin, 0, sizeof(msgin));
if ((n = recvfrom(sock, &msgin, sizeof(struct tsp), 0,
(struct sockaddr*)(void *)&from, &length)) < 0) {
syslog(LOG_ERR, "recvfrom: %m");
exit(EXIT_FAILURE);
}
- if (n < (ssize_t)sizeof(struct tsp)) {
+ /*
+ * The 4.3BSD protocol spec had a 32-byte tsp_name field, and
+ * this is still OS-dependent. Demand that the packet is at
+ * least long enough to hold a 4.3BSD packet.
+ */
+ if (n < (ssize_t)(sizeof(struct tsp) - MAXHOSTNAMELEN + 32)) {
syslog(LOG_NOTICE,
"short packet (%lu/%lu bytes) from %s",
- (u_long)n, (u_long)sizeof(struct tsp),
+ (u_long)n,
+ (u_long)(sizeof(struct tsp) - MAXHOSTNAMELEN + 32),
inet_ntoa(from.sin_addr));
continue;
}
