Prevent server side overflow for message id in snmp header.

ok sthen@, tb@

diff --git a/usr.sbin/snmpctl/snmpclient.c b/usr.sbin/snmpctl/snmpclient.c
index 902985d..dd0ab23 100644 (file)
--- a/usr.sbin/snmpctl/snmpclient.c
+++ b/usr.sbin/snmpctl/snmpclient.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: snmpclient.c,v 1.16 2018/08/08 18:50:38 rob Exp $     */
+/*     $OpenBSD: snmpclient.c,v 1.17 2018/08/11 04:31:57 rob Exp $     */
 
 /*
  * Copyright (c) 2013 Reyk Floeter <reyk@openbsd.org>
@@ -407,7 +407,7 @@ snmpc_sendreq(struct snmpc *sc, unsigned int type)
                erroridx = SNMPC_MAXREPETITIONS;
 
        /* SNMP header */
-       sc->sc_msgid = arc4random();
+       sc->sc_msgid = arc4random() & 0x7fffffff;
        if ((root = ber_add_sequence(NULL)) == NULL)
                return (-1);
        if ((b = ber_printf_elements(root, "ds{tddd{{O0}}",