[src/trunk]: src/sys/net Make sure to not change if_hwdl once set

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/52437e14d490
branches:  trunk
changeset: 323122:52437e14d490
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Fri Jun 01 07:14:13 2018 +0000

description:
Make sure to not change if_hwdl once set

diffstat:

 sys/net/if.c |  23 +++++++++++++----------
 1 files changed, 13 insertions(+), 10 deletions(-)

diffs (83 lines):

diff -r 782cb5d6023c -r 52437e14d490 sys/net/if.c
--- a/sys/net/if.c      Fri Jun 01 07:13:35 2018 +0000
+++ b/sys/net/if.c      Fri Jun 01 07:14:13 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if.c,v 1.425 2018/05/31 02:10:23 ozaki-r Exp $ */
+/*     $NetBSD: if.c,v 1.426 2018/06/01 07:14:13 ozaki-r Exp $ */
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.425 2018/05/31 02:10:23 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.426 2018/06/01 07:14:13 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -202,7 +202,7 @@
 static void sysctl_sndq_setup(struct sysctllog **, const char *,
     struct ifaltq *);
 static void if_slowtimo(void *);
-static void if_free_sadl(struct ifnet *);
+static void if_free_sadl(struct ifnet *, int);
 static void if_attachdomain1(struct ifnet *);
 static int ifconf(u_long, void *);
 static int if_transmit(struct ifnet *, struct mbuf *);
@@ -425,6 +425,7 @@
 
        (void)sockaddr_dl_setaddr(sdl, sdl->sdl_len, lla, ifp->if_addrlen);
        if (factory) {
+               KASSERT(ifp->if_hwdl == NULL);
                ifp->if_hwdl = ifp->if_dl;
                ifaref(ifp->if_hwdl);
        }
@@ -492,7 +493,7 @@
         * link types, and thus switch link names often.
         */
        if (ifp->if_sadl != NULL)
-               if_free_sadl(ifp);
+               if_free_sadl(ifp, 0);
 
        ifa = if_dl_create(ifp, &sdl);
 
@@ -568,11 +569,17 @@
  * a detach helper.  This is called from if_detach().
  */
 static void
-if_free_sadl(struct ifnet *ifp)
+if_free_sadl(struct ifnet *ifp, int factory)
 {
        struct ifaddr *ifa;
        int s;
 
+       if (factory && ifp->if_hwdl != NULL) {
+               ifa = ifp->if_hwdl;
+               ifp->if_hwdl = NULL;
+               ifafree(ifa);
+       }
+
        ifa = ifp->if_dl;
        if (ifa == NULL) {
                KASSERT(ifp->if_sadl == NULL);
@@ -585,10 +592,6 @@
        rtinit(ifa, RTM_DELETE, 0);
        ifa_remove(ifp, ifa);
        if_deactivate_sadl(ifp);
-       if (ifp->if_hwdl == ifa) {
-               ifafree(ifa);
-               ifp->if_hwdl = NULL;
-       }
        splx(s);
 }
 
@@ -1400,7 +1403,7 @@
                goto again;
        }
 
-       if_free_sadl(ifp);
+       if_free_sadl(ifp, 1);
 
        /* Delete stray routes from the routing table. */
        for (i = 0; i <= AF_MAX; i++)