[src/trunk]: src/sys/netinet6 Take softnet_lock and kernel lock in frag6_slow...

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

details:   https://anonhg.NetBSD.org/src/rev/94514531da89
branches:  trunk
changeset: 772056:94514531da89
user:      jakllsch <jakllsch%NetBSD.org@localhost>
date:      Fri Dec 16 00:57:59 2011 +0000

description:
Take softnet_lock and kernel lock in frag6_slowtimo and frag6_fasttimo,
similar to how it's done with other protocols.

If we don't do this sending ICMPv6 messages in this path can cause races
in network interface drivers.

diffstat:

 sys/netinet6/frag6.c |  16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diffs (55 lines):

diff -r 5399e13856df -r 94514531da89 sys/netinet6/frag6.c
--- a/sys/netinet6/frag6.c      Thu Dec 15 22:20:26 2011 +0000
+++ b/sys/netinet6/frag6.c      Fri Dec 16 00:57:59 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: frag6.c,v 1.50 2011/11/04 00:22:33 zoltan Exp $        */
+/*     $NetBSD: frag6.c,v 1.51 2011/12/16 00:57:59 jakllsch Exp $      */
 /*     $KAME: frag6.c,v 1.40 2002/05/27 21:40:31 itojun Exp $  */
 
 /*
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: frag6.c,v 1.50 2011/11/04 00:22:33 zoltan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: frag6.c,v 1.51 2011/12/16 00:57:59 jakllsch Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -644,10 +644,16 @@
 void
 frag6_fasttimo(void)
 {
+       mutex_enter(softnet_lock);
+       KERNEL_LOCK(1, NULL);
+
        if (frag6_drainwanted) {
                frag6_drain();
                frag6_drainwanted = 0;
        }
+
+       KERNEL_UNLOCK_ONE(NULL);
+       mutex_exit(softnet_lock);
 }
 
 /*
@@ -660,6 +666,9 @@
 {
        struct ip6q *q6;
 
+       mutex_enter(softnet_lock);
+       KERNEL_LOCK(1, NULL);
+
        mutex_enter(&frag6_lock);
        q6 = ip6q.ip6q_next;
        if (q6)
@@ -685,6 +694,9 @@
        }
        mutex_exit(&frag6_lock);
 
+       KERNEL_UNLOCK_ONE(NULL);
+       mutex_exit(softnet_lock);
+
 #if 0
        /*
         * Routing changes might produce a better route than we last used;