From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932239Ab0JVSsn (ORCPT ); Fri, 22 Oct 2010 14:48:43 -0400 Received: from kroah.org ([198.145.64.141]:45787 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757954Ab0JVSiq (ORCPT ); Fri, 22 Oct 2010 14:38:46 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Oct 22 11:35:59 2010 Message-Id: <20101022183559.679779133@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 22 Oct 2010 11:35:06 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, =?ISO-8859-15?q?Maciej=20=C5=BBenczykowski?= , "David S. Miller" Subject: [39/66] net: Fix IPv6 PMTU disc. w/ asymmetric routes In-Reply-To: <20101022183711.GA23214@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Maciej Żenczykowski [ Upstream commit ae878ae280bea286ff2b1e1cb6e609dd8cb4501d ] Signed-off-by: Maciej Żenczykowski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/route.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1561,14 +1561,13 @@ out: * i.e. Path MTU discovery */ -void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr, - struct net_device *dev, u32 pmtu) +static void rt6_do_pmtu_disc(struct in6_addr *daddr, struct in6_addr *saddr, + struct net *net, u32 pmtu, int ifindex) { struct rt6_info *rt, *nrt; - struct net *net = dev_net(dev); int allfrag = 0; - rt = rt6_lookup(net, daddr, saddr, dev->ifindex, 0); + rt = rt6_lookup(net, daddr, saddr, ifindex, 0); if (rt == NULL) return; @@ -1636,6 +1635,27 @@ out: dst_release(&rt->u.dst); } +void rt6_pmtu_discovery(struct in6_addr *daddr, struct in6_addr *saddr, + struct net_device *dev, u32 pmtu) +{ + struct net *net = dev_net(dev); + + /* + * RFC 1981 states that a node "MUST reduce the size of the packets it + * is sending along the path" that caused the Packet Too Big message. + * Since it's not possible in the general case to determine which + * interface was used to send the original packet, we update the MTU + * on the interface that will be used to send future packets. We also + * update the MTU on the interface that received the Packet Too Big in + * case the original packet was forced out that interface with + * SO_BINDTODEVICE or similar. This is the next best thing to the + * correct behaviour, which would be to update the MTU on all + * interfaces. + */ + rt6_do_pmtu_disc(daddr, saddr, net, pmtu, 0); + rt6_do_pmtu_disc(daddr, saddr, net, pmtu, dev->ifindex); +} + /* * Misc support functions */