[src/trunk]: src/sys/dist/ipf/netinet PR/44070: Avoid zero divide in modulo o...

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3f64fa0e9841
branches:  trunk
changeset: 761977:3f64fa0e9841
user:      christos <christos%NetBSD.org@localhost>
date:      Sat Feb 12 18:14:21 2011 +0000

description:
PR/44070: Avoid zero divide in modulo operations.

diffstat:

 sys/dist/ipf/netinet/ip_nat.c |  14 +++++++++-----
 1 files changed, 9 insertions(+), 5 deletions(-)

diffs (42 lines):

diff -r 5d14c66e9dc1 -r 3f64fa0e9841 sys/dist/ipf/netinet/ip_nat.c
--- a/sys/dist/ipf/netinet/ip_nat.c     Sat Feb 12 18:13:46 2011 +0000
+++ b/sys/dist/ipf/netinet/ip_nat.c     Sat Feb 12 18:14:21 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ip_nat.c,v 1.41 2010/04/17 21:00:44 darrenr Exp $      */
+/*     $NetBSD: ip_nat.c,v 1.42 2011/02/12 18:14:21 christos Exp $     */
 
 /*
  * Copyright (C) 1995-2003 by Darren Reed.
@@ -120,7 +120,7 @@
 #if !defined(lint)
 #if defined(__NetBSD__)
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_nat.c,v 1.41 2010/04/17 21:00:44 darrenr Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_nat.c,v 1.42 2011/02/12 18:14:21 christos Exp $");
 #else
 static const char sccsid[] = "@(#)ip_nat.c     1.11 6/5/96 (C) 1995 Darren Reed";
 static const char rcsid[] = "@(#)Id: ip_nat.c,v 2.195.2.130 2010/03/16 02:24:52 darrenr Exp";
@@ -2037,7 +2037,7 @@
                        /*
                         * "ports auto" (without map-block)
                         */
-                       if ((l > 0) && (l % np->in_ppip == 0)) {
+                       if ((l > 0) && np->in_ppip && (l % np->in_ppip == 0)) {
                                if (l > np->in_space) {
                                        return -1;
                                } else if ((l > np->in_ppip) &&
@@ -2063,8 +2063,12 @@
                        if (np->in_flags & IPN_SEQUENTIAL) {
                                port = np->in_pnext;
                        } else {
-                               port = ipf_random() % (ntohs(np->in_pmax) -
-                                                      ntohs(np->in_pmin));
+                               in_port_t d = ntohs(np->in_pmax) -
+                                   ntohs(np->in_pmin);
+                               if (d)
+                                       port = ipf_random() % d;
+                               else
+                                       port = 0;
                                port += ntohs(np->in_pmin);
                        }
                        port = htons(port);