Module Name: src
Committed By: ozaki-r
Date: Mon Apr 18 01:28:06 UTC 2016
Modified Files:
src/sys/netinet: ip_output.c
Log Message:
Get rid of meaningless RTF_UP check from ip_hresolv_output
The check is meaningless because
- An obtained rtentry is ensured that it's always RTF_UP by rtcache,
rtalloc1 and rtlookup. If the rtentry isn't changed (i.e., RTF_UP gets
dropped) during processing, the check should be unnecessary
- Even if not, i.e., an obtained rtentry can be changed during processing,
checking only at the point doesn't help; the rtentry can be changed after
the check
Instead we have to ensure that RTF_UP isn't dropped if someone is using it
somehow. Note that we already ensure that a rtentry being used isn't freed
by rt_refcnt.
Proposed on tech-kern and tech-net.
To generate a diff of this commit:
cvs rdiff -u -r1.248 -r1.249 src/sys/netinet/ip_output.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/netinet/ip_output.c
diff -u src/sys/netinet/ip_output.c:1.248 src/sys/netinet/ip_output.c:1.249
--- src/sys/netinet/ip_output.c:1.248 Wed Jan 20 22:12:22 2016
+++ src/sys/netinet/ip_output.c Mon Apr 18 01:28:06 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: ip_output.c,v 1.248 2016/01/20 22:12:22 riastradh Exp $ */
+/* $NetBSD: ip_output.c,v 1.249 2016/04/18 01:28:06 ozaki-r Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.248 2016/01/20 22:12:22 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.249 2016/04/18 01:28:06 ozaki-r Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -202,50 +202,20 @@ klock_if_output(struct ifnet * const ifp
* calling ifp's output routine.
*/
int
-ip_hresolv_output(struct ifnet * const ifp0, struct mbuf * const m,
- const struct sockaddr * const dst, struct rtentry *rt00)
+ip_hresolv_output(struct ifnet * const ifp, struct mbuf * const m,
+ const struct sockaddr * const dst, struct rtentry *rt0)
{
int error = 0;
- struct ifnet *ifp = ifp0;
- struct rtentry *rt, *rt0, *gwrt;
+ struct rtentry *rt = rt0, *gwrt;
#define RTFREE_IF_NEEDED(_rt) \
- if ((_rt) != NULL && (_rt) != rt00) \
+ if ((_rt) != NULL && (_rt) != rt0) \
rtfree((_rt));
- rt0 = rt00;
-retry:
- if (!ip_hresolv_needed(ifp)) {
- rt = rt0;
+ if (!ip_hresolv_needed(ifp))
goto out;
- }
-
- if (rt0 == NULL) {
- rt = NULL;
- goto out;
- }
-
- rt = rt0;
-
- /*
- * The following block is highly questionable. How did we get here
- * with a !RTF_UP route? Does rtalloc1() always return an RTF_UP
- * route?
- */
- if ((rt->rt_flags & RTF_UP) == 0) {
- rt = rtalloc1(dst, 1);
- if (rt == NULL) {
- error = EHOSTUNREACH;
- goto bad;
- }
- rt0 = rt;
- if (rt->rt_ifp != ifp) {
- ifp = rt->rt_ifp;
- goto retry;
- }
- }
- if ((rt->rt_flags & RTF_GATEWAY) == 0)
+ if (rt == NULL || (rt->rt_flags & RTF_GATEWAY) == 0)
goto out;
gwrt = rt_get_gwroute(rt);
