From patchwork Fri Mar 19 05:54:43 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Timo Teras X-Patchwork-Id: 48112 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 90F28B7CBB for ; Fri, 19 Mar 2010 16:54:53 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751273Ab0CSFyt (ORCPT ); Fri, 19 Mar 2010 01:54:49 -0400 Received: from mail-ew0-f216.google.com ([209.85.219.216]:61325 "EHLO mail-ew0-f216.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751037Ab0CSFys (ORCPT ); Fri, 19 Mar 2010 01:54:48 -0400 Received: by ewy8 with SMTP id 8so1571211ewy.28 for ; Thu, 18 Mar 2010 22:54:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:from:to:cc:subject :date:message-id:x-mailer; bh=8MMEDdJHRWzyz76Ku8Kvi3LymmQPTKHZKrIJzvM474M=; b=UFcB+Ups/bymKkFJUCSiRT5FKi4Z8PWqHtEzxSK0Xhxk4E3NB9v5G1SpKkKr18b5I9 Tp0/nER9NUcY2wQu6EDLMDW2zifLd/QRUZjvydIR9tFBH+IQrZZ35N68VpWlh6byM1Aq pzODlhQE7pqK0bu3befQXMGPBV2QAjSs8nRmY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer; b=rJNsmYh1plAf2u7sMBToWbR6m9sV2aV925JWBz/yAc7NK+juY4YcWvoHzbvezsyrLg WHcUsKDUBzeQobCO1NfWkcIFvLmMRIz9o6kSshs0dgQ/OCTSw+evb27U/19PWYXO9PqJ SG/edeAxcdHzWfPprzPIEFNGxHAjTh8j5Pq3Q= Received: by 10.213.41.3 with SMTP id m3mr109309ebe.93.1268978087097; Thu, 18 Mar 2010 22:54:47 -0700 (PDT) Received: from localhost.localdomain (letku109.adsl.netsonic.fi [194.29.195.109]) by mx.google.com with ESMTPS id 14sm167433ewy.2.2010.03.18.22.54.46 (version=SSLv3 cipher=RC4-MD5); Thu, 18 Mar 2010 22:54:46 -0700 (PDT) From: Timo Teras To: netdev@vger.kernel.org Cc: Timo Teras Subject: [PATCH] ipv4: check rt_genid in dst_check Date: Fri, 19 Mar 2010 07:54:43 +0200 Message-Id: <1268978083-32070-1-git-send-email-timo.teras@iki.fi> X-Mailer: git-send-email 1.6.3.3 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Xfrm_dst keeps a reference to ipv4 rtable entries on each cached bundle. The only way to renew xfrm_dst when the underlying route has changed, is to implement dst_check for this. This is what ipv6 side does too. The problems started after 87c1e12b5eeb7b30b4b41291bef8e0b41fc3dde9 which fixed a bug causing xfrm_dst to not get reused, until that all lookups always generated new xfrm_dst with new route reference and path mtu worked. But after the fix, the old routes started to get reused even after they were expired causing pmtu to break (well it would occationally work if the rtable gc had run recently and marked the route obsolete causing dst_check to get called). Signed-off-by: Timo Teras Acked-by: Herbert Xu --- net/ipv4/route.c | 14 ++++++++++---- 1 files changed, 10 insertions(+), 4 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index a770df2..8c9d06e 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1441,7 +1441,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, dev_hold(rt->u.dst.dev); if (rt->idev) in_dev_hold(rt->idev); - rt->u.dst.obsolete = 0; + rt->u.dst.obsolete = -1; rt->u.dst.lastuse = jiffies; rt->u.dst.path = &rt->u.dst; rt->u.dst.neighbour = NULL; @@ -1506,7 +1506,7 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst) struct dst_entry *ret = dst; if (rt) { - if (dst->obsolete) { + if (dst->obsolete > 0) { ip_rt_put(rt); ret = NULL; } else if ((rt->rt_flags & RTCF_REDIRECTED) || @@ -1726,7 +1726,9 @@ static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu) static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie) { - return NULL; + if (dst && rt_is_expired((struct rtable *)dst)) + return NULL; + return dst; } static void ipv4_dst_destroy(struct dst_entry *dst) @@ -1888,7 +1890,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr, if (!rth) goto e_nobufs; - rth->u.dst.output= ip_rt_bug; + rth->u.dst.output = ip_rt_bug; + rth->u.dst.obsolete = -1; atomic_set(&rth->u.dst.__refcnt, 1); rth->u.dst.flags= DST_HOST; @@ -2054,6 +2057,7 @@ static int __mkroute_input(struct sk_buff *skb, rth->fl.oif = 0; rth->rt_spec_dst= spec_dst; + rth->u.dst.obsolete = -1; rth->u.dst.input = ip_forward; rth->u.dst.output = ip_output; rth->rt_genid = rt_genid(dev_net(rth->u.dst.dev)); @@ -2218,6 +2222,7 @@ local_input: goto e_nobufs; rth->u.dst.output= ip_rt_bug; + rth->u.dst.obsolete = -1; rth->rt_genid = rt_genid(net); atomic_set(&rth->u.dst.__refcnt, 1); @@ -2444,6 +2449,7 @@ static int __mkroute_output(struct rtable **result, rth->rt_spec_dst= fl->fl4_src; rth->u.dst.output=ip_output; + rth->u.dst.obsolete = -1; rth->rt_genid = rt_genid(dev_net(dev_out)); RT_CACHE_STAT_INC(out_slow_tot);