[src/trunk]: src/sys/net Avoid using a zero family mask.

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

details:   https://anonhg.NetBSD.org/src/rev/d394bea3b089
branches:  trunk
changeset: 827945:d394bea3b089
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Nov 19 18:49:51 2017 +0000

description:
Avoid using a zero family mask.

diffstat:

 sys/net/rtsock.c |  11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diffs (33 lines):

diff -r 136060847210 -r d394bea3b089 sys/net/rtsock.c
--- a/sys/net/rtsock.c  Sun Nov 19 16:59:25 2017 +0000
+++ b/sys/net/rtsock.c  Sun Nov 19 18:49:51 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rtsock.c,v 1.230 2017/11/17 07:37:12 ozaki-r Exp $     */
+/*     $NetBSD: rtsock.c,v 1.231 2017/11/19 18:49:51 christos Exp $    */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -61,7 +61,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1.230 2017/11/17 07:37:12 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rtsock.c,v 1.231 2017/11/19 18:49:51 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -821,8 +821,13 @@
         * (padded with 0's). We keep the original length of the sockaddr.
         */
        if (info.rti_info[RTAX_NETMASK]) {
+               /*
+                * Use the family of RTAX_DST, because RTAX_NETMASK
+                * can have a zero family if it comes from the radix
+                * tree via rt_mask().
+                */
                socklen_t sa_len = sockaddr_getsize_by_family(
-                   info.rti_info[RTAX_NETMASK]->sa_family);
+                   info.rti_info[RTAX_DST]->sa_family);
                socklen_t masklen = sockaddr_getlen(
                    info.rti_info[RTAX_NETMASK]);
                if (sa_len != 0 && sa_len > masklen) {