[src/trunk]: src/sys/netinet Don't pass junk in sin_family and sin_len for SI...

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

details:   https://anonhg.NetBSD.org/src/rev/613495985cf6
branches:  trunk
changeset: 334680:613495985cf6
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Dec 01 17:07:43 2014 +0000

description:
Don't pass junk in sin_family and sin_len for SIOCGIFNETMASK, and explain why.
XXX: pullup 7?

diffstat:

 sys/netinet/in.c |  14 +++++++++++---
 1 files changed, 11 insertions(+), 3 deletions(-)

diffs (42 lines):

diff -r 82d7f4e76776 -r 613495985cf6 sys/netinet/in.c
--- a/sys/netinet/in.c  Mon Dec 01 08:39:43 2014 +0000
+++ b/sys/netinet/in.c  Mon Dec 01 17:07:43 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: in.c,v 1.148 2014/09/09 20:16:12 rmind Exp $   */
+/*     $NetBSD: in.c,v 1.149 2014/12/01 17:07:43 christos Exp $        */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: in.c,v 1.148 2014/09/09 20:16:12 rmind Exp $");
+__KERNEL_RCSID(0, "$NetBSD: in.c,v 1.149 2014/12/01 17:07:43 christos Exp $");
 
 #include "opt_inet.h"
 #include "opt_inet_conf.h"
@@ -427,6 +427,7 @@
                        ia->ia_ifa.ifa_getifa = NULL;
 #endif /* IPSELSRC */
                        ia->ia_sockmask.sin_len = 8;
+                       ia->ia_sockmask.sin_family = AF_INET;
                        if (ifp->if_flags & IFF_BROADCAST) {
                                ia->ia_broadaddr.sin_len = sizeof(ia->ia_addr);
                                ia->ia_broadaddr.sin_family = AF_INET;
@@ -473,7 +474,14 @@
                break;
 
        case SIOCGIFNETMASK:
-               ifreq_setaddr(cmd, ifr, sintocsa(&ia->ia_sockmask));
+               /* 
+                * We keep the number of trailing zero bytes the sin_len field
+                * of ia_sockmask, so we fix this before we pass it back to
+                * userland.
+                */
+               oldaddr = ia->ia_sockmask;
+               oldaddr.sin_len = sizeof(struct sockaddr_in);
+               ifreq_setaddr(cmd, ifr, (const void *)&oldaddr);
                break;
 
        case SIOCSIFDSTADDR: