Module Name: src
Committed By: ozaki-r
Date: Tue Oct 30 05:54:42 UTC 2018
Modified Files:
src/sys/net: if.c route.c route.h
src/sys/netinet: if_arp.c
src/sys/netinet6: nd6.c
Log Message:
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.
To generate a diff of this commit:
cvs rdiff -u -r1.439 -r1.440 src/sys/net/if.c
cvs rdiff -u -r1.214 -r1.215 src/sys/net/route.c
cvs rdiff -u -r1.119 -r1.120 src/sys/net/route.h
cvs rdiff -u -r1.275 -r1.276 src/sys/netinet/if_arp.c
cvs rdiff -u -r1.250 -r1.251 src/sys/netinet6/nd6.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/if.c
diff -u src/sys/net/if.c:1.439 src/sys/net/if.c:1.440
--- src/sys/net/if.c:1.439 Tue Oct 30 05:29:21 2018
+++ src/sys/net/if.c Tue Oct 30 05:54:42 2018
@@ -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 @@ link_rtrequest(int cmd, struct rtentry *
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 @@ p2p_rtrequest(int req, struct rtentry *r
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;
Index: src/sys/net/route.c
diff -u src/sys/net/route.c:1.214 src/sys/net/route.c:1.215
--- src/sys/net/route.c:1.214 Tue Oct 30 05:30:31 2018
+++ src/sys/net/route.c Tue Oct 30 05:54:42 2018
@@ -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 @@ rtrequest1(int req, struct rt_addrinfo *
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 @@ rtinit(struct ifaddr *ifa, int cmd, int
}
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 @@ rtinit(struct ifaddr *ifa, int cmd, int
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 @@ rt_ifa_addlocal(struct ifaddr *ifa)
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
Index: src/sys/net/route.h
diff -u src/sys/net/route.h:1.119 src/sys/net/route.h:1.120
--- src/sys/net/route.h:1.119 Thu Apr 19 21:20:43 2018
+++ src/sys/net/route.h Tue Oct 30 05:54:42 2018
@@ -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 @@ struct ortentry {
#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
Index: src/sys/netinet/if_arp.c
diff -u src/sys/netinet/if_arp.c:1.275 src/sys/netinet/if_arp.c:1.276
--- src/sys/netinet/if_arp.c:1.275 Fri May 11 13:56:43 2018
+++ src/sys/netinet/if_arp.c Tue Oct 30 05:54:41 2018
@@ -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 @@ arp_rtrequest(int req, struct rtentry *r
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
Index: src/sys/netinet6/nd6.c
diff -u src/sys/netinet6/nd6.c:1.250 src/sys/netinet6/nd6.c:1.251
--- src/sys/netinet6/nd6.c:1.250 Mon Sep 3 16:29:36 2018
+++ src/sys/netinet6/nd6.c Tue Oct 30 05:54:41 2018
@@ -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 @@ nd6_rtrequest(int req, struct rtentry *r
* 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) {
