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[src/trunk]: src/sys Avoid double rt_replace_ifa on rtrequest1(RTM_ADD)
details: https://anonhg.NetBSD.org/src/rev/86c2f45c82be
branches: trunk
changeset: 445450:86c2f45c82be
user: ozaki-r <ozaki-r%NetBSD.org@localhost>
date: Tue Oct 30 05:54:41 2018 +0000
description:
Avoid double rt_replace_ifa on rtrequest1(RTM_ADD)
Some callers of rtrequest1(RTM_ADD) adjust rt_ifa of an rtentry created by
rtrequest1 that may change rt_ifa (in ifa_rtrequest) with another ifa that is
different from requested one. It's wasteful and even worse introduces a race
condition. rtrequest1 should just use a passed ifa as is if a caller hopes so.
diffstat:
sys/net/if.c | 10 +++++++---
sys/net/route.c | 48 +++++++-----------------------------------------
sys/net/route.h | 7 ++++++-
sys/netinet/if_arp.c | 9 +++++++--
sys/netinet6/nd6.c | 7 ++++---
5 files changed, 31 insertions(+), 50 deletions(-)
diffs (215 lines):
diff -r 309046a7f6df -r 86c2f45c82be sys/net/if.c
--- a/sys/net/if.c Tue Oct 30 05:30:31 2018 +0000
+++ b/sys/net/if.c Tue Oct 30 05:54:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if.c,v 1.439 2018/10/30 05:29:21 ozaki-r Exp $ */
+/* $NetBSD: if.c,v 1.440 2018/10/30 05:54:42 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 1.439 2018/10/30 05:29:21 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.440 2018/10/30 05:54:42 ozaki-r Exp $");
#if defined(_KERNEL_OPT)
#include "opt_inet.h"
@@ -2183,7 +2183,8 @@
struct psref psref;
if (cmd != RTM_ADD || (ifa = rt->rt_ifa) == NULL ||
- (ifp = ifa->ifa_ifp) == NULL || (dst = rt_getkey(rt)) == NULL)
+ (ifp = ifa->ifa_ifp) == NULL || (dst = rt_getkey(rt)) == NULL ||
+ ISSET(info->rti_flags, RTF_DONTCHANGEIFA))
return;
if ((ifa = ifaof_ifpforaddr_psref(dst, ifp, &psref)) != NULL) {
rt_replace_ifa(rt, ifa);
@@ -2437,6 +2438,9 @@
rt->rt_ifp = lo0ifp;
+ if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA))
+ break;
+
IFADDR_READER_FOREACH(ifa, ifp) {
if (equal(rt_getkey(rt), ifa->ifa_addr))
break;
diff -r 309046a7f6df -r 86c2f45c82be sys/net/route.c
--- a/sys/net/route.c Tue Oct 30 05:30:31 2018 +0000
+++ b/sys/net/route.c Tue Oct 30 05:54:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: route.c,v 1.214 2018/10/30 05:30:31 ozaki-r Exp $ */
+/* $NetBSD: route.c,v 1.215 2018/10/30 05:54:42 ozaki-r Exp $ */
/*-
* Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
@@ -97,7 +97,7 @@
#endif
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.214 2018/10/30 05:30:31 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: route.c,v 1.215 2018/10/30 05:54:42 ozaki-r Exp $");
#include <sys/param.h>
#ifdef RTFLUSH_DEBUG
@@ -1242,7 +1242,7 @@
if (rt == NULL)
senderr(ENOBUFS);
memset(rt, 0, sizeof(*rt));
- rt->rt_flags = RTF_UP | flags;
+ rt->rt_flags = RTF_UP | (flags & ~RTF_DONTCHANGEIFA);
LIST_INIT(&rt->rt_timer);
RT_DPRINTF("rt->_rt_key = %p\n", (void *)rt->_rt_key);
@@ -1605,7 +1605,7 @@
}
memset(&info, 0, sizeof(info));
info.rti_ifa = ifa;
- info.rti_flags = flags | ifa->ifa_flags;
+ info.rti_flags = flags | ifa->ifa_flags | RTF_DONTCHANGEIFA;
info.rti_info[RTAX_DST] = dst;
info.rti_info[RTAX_GATEWAY] = ifa->ifa_addr;
@@ -1636,40 +1636,7 @@
rt_unref(rt);
break;
case RTM_ADD:
- /*
- * XXX it looks just reverting rt_ifa replaced by ifa_rtrequest
- * called via rtrequest1. Can we just prevent the replacement
- * somehow and remove the following code? And also doesn't
- * calling ifa_rtrequest(RTM_ADD) replace rt_ifa again?
- */
- if (rt->rt_ifa != ifa) {
- printf("rtinit: wrong ifa (%p) was (%p)\n", ifa,
- rt->rt_ifa);
-#ifdef NET_MPSAFE
- KASSERT(!cpu_softintr_p());
-
- error = rt_update_prepare(rt);
- if (error == 0) {
-#endif
- if (rt->rt_ifa->ifa_rtrequest != NULL) {
- rt->rt_ifa->ifa_rtrequest(RTM_DELETE,
- rt, &info);
- }
- rt_replace_ifa(rt, ifa);
- rt->rt_ifp = ifa->ifa_ifp;
- if (ifa->ifa_rtrequest != NULL)
- ifa->ifa_rtrequest(RTM_ADD, rt, &info);
-#ifdef NET_MPSAFE
- rt_update_finish(rt);
- } else {
- /*
- * If error != 0, the rtentry is being
- * destroyed, so doing nothing doesn't
- * matter.
- */
- }
-#endif
- }
+ KASSERT(rt->rt_ifa == ifa);
rt_newmsg(cmd, rt);
rt_unref(rt);
RT_REFCNT_TRACE(rt);
@@ -1701,17 +1668,16 @@
struct rtentry *nrt;
memset(&info, 0, sizeof(info));
- info.rti_flags = RTF_HOST | RTF_LOCAL;
+ info.rti_flags = RTF_HOST | RTF_LOCAL | RTF_DONTCHANGEIFA;
info.rti_info[RTAX_DST] = ifa->ifa_addr;
info.rti_info[RTAX_GATEWAY] =
(const struct sockaddr *)ifa->ifa_ifp->if_sadl;
info.rti_ifa = ifa;
nrt = NULL;
e = rtrequest1(RTM_ADD, &info, &nrt);
- if (nrt && ifa != nrt->rt_ifa)
- rt_replace_ifa(nrt, ifa);
rt_newaddrmsg(RTM_ADD, ifa, e, nrt);
if (nrt != NULL) {
+ KASSERT(nrt->rt_ifa == ifa);
#ifdef RT_DEBUG
dump_rt(nrt);
#endif
diff -r 309046a7f6df -r 86c2f45c82be sys/net/route.h
--- a/sys/net/route.h Tue Oct 30 05:30:31 2018 +0000
+++ b/sys/net/route.h Tue Oct 30 05:54:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: route.h,v 1.119 2018/04/19 21:20:43 christos Exp $ */
+/* $NetBSD: route.h,v 1.120 2018/10/30 05:54:42 ozaki-r Exp $ */
/*
* Copyright (c) 1980, 1986, 1993
@@ -172,6 +172,11 @@
#define RTF_LOCAL 0x40000 /* route represents a local address */
#define RTF_BROADCAST 0x80000 /* route represents a bcast address */
#define RTF_UPDATING 0x100000 /* route is updating */
+/*
+ * The flag is nevert set to rt_flags. It just tells rtrequest1 to set a passed
+ * ifa to rt_ifa (via rti_ifa) and not replace rt_ifa in ifa_rtrequest.
+ */
+#define RTF_DONTCHANGEIFA 0x200000 /* suppress rt_ifa replacement */
/*
* 0x400 is exposed to userland just for backward compatibility. For that
diff -r 309046a7f6df -r 86c2f45c82be sys/netinet/if_arp.c
--- a/sys/netinet/if_arp.c Tue Oct 30 05:30:31 2018 +0000
+++ b/sys/netinet/if_arp.c Tue Oct 30 05:54:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_arp.c,v 1.275 2018/05/11 13:56:43 maxv Exp $ */
+/* $NetBSD: if_arp.c,v 1.276 2018/10/30 05:54:41 ozaki-r Exp $ */
/*
* Copyright (c) 1998, 2000, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.275 2018/05/11 13:56:43 maxv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_arp.c,v 1.276 2018/10/30 05:54:41 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
@@ -605,6 +605,11 @@
rt->rt_rmx.rmx_mtu = 0;
}
rt->rt_flags |= RTF_LOCAL;
+
+ if (ISSET(info->rti_flags, RTF_DONTCHANGEIFA)) {
+ pserialize_read_exit(s);
+ goto out;
+ }
/*
* make sure to set rt->rt_ifa to the interface
* address we are using, otherwise we will have trouble
diff -r 309046a7f6df -r 86c2f45c82be sys/netinet6/nd6.c
--- a/sys/netinet6/nd6.c Tue Oct 30 05:30:31 2018 +0000
+++ b/sys/netinet6/nd6.c Tue Oct 30 05:54:41 2018 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: nd6.c,v 1.250 2018/09/03 16:29:36 riastradh Exp $ */
+/* $NetBSD: nd6.c,v 1.251 2018/10/30 05:54:41 ozaki-r Exp $ */
/* $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $ */
/*
@@ -31,7 +31,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.250 2018/09/03 16:29:36 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.251 2018/10/30 05:54:41 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -1566,7 +1566,8 @@
* that the rt_ifa points to the address instead
* of the loopback address.
*/
- if (ifa != rt->rt_ifa)
+ if (!ISSET(info->rti_flags, RTF_DONTCHANGEIFA)
+ && ifa != rt->rt_ifa)
rt_replace_ifa(rt, ifa);
}
} else if (rt->rt_flags & RTF_ANNOUNCE) {
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