From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 1/2] ipv6: avoid blackhole and prohibited entries upon prefix purge Date: Sat, 05 Jan 2013 11:59:01 -0800 Message-ID: <1357415941.1678.4163.camel@edumazet-glaptop> References: <0CC79564-4AF2-42F9-8D06-1BCC912A1AF7@ipflavors.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, yoshfuji@linux-ipv6.org, davem@davemloft.net To: Romain KUNTZ Return-path: Received: from mail-pa0-f48.google.com ([209.85.220.48]:54495 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755832Ab3AET7F (ORCPT ); Sat, 5 Jan 2013 14:59:05 -0500 Received: by mail-pa0-f48.google.com with SMTP id fa1so10019135pad.7 for ; Sat, 05 Jan 2013 11:59:04 -0800 (PST) In-Reply-To: <0CC79564-4AF2-42F9-8D06-1BCC912A1AF7@ipflavors.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2013-01-05 at 17:13 +0100, Romain KUNTZ wrote: > Mobile IPv6 provokes a kernel Oops since commit 64c6d08e (ipv6: > del unreachable route when an addr is deleted on lo), because > ip6_route_lookup() may also return blackhole and prohibited > entry. However, these entries have a NULL rt6i_table argument, > which provokes an Oops in __ip6_del_rt() when trying to lock > rt6i_table->tb6_lock. > > Beside, when purging a prefix, blakhole and prohibited entries > should not be selected because they are not what we are looking > for. > > We fix this by adding two new lookup flags (RT6_LOOKUP_F_NO_BLK_HOLE > and RT6_LOOKUP_F_NO_PROHIBIT) in order to ensure that such entries > are skipped during lookup and that the correct entry is returned. > > Signed-off-by: Romain Kuntz > --- > include/net/ip6_route.h | 2 ++ > net/ipv6/addrconf.c | 4 +++- > net/ipv6/fib6_rules.c | 4 ++++ > 3 files changed, 9 insertions(+), 1 deletions(-) > > diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h > index 27d8318..3c93743 100644 > --- a/include/net/ip6_route.h > +++ b/include/net/ip6_route.h > @@ -30,6 +30,8 @@ struct route_info { > #define RT6_LOOKUP_F_SRCPREF_TMP 0x00000008 > #define RT6_LOOKUP_F_SRCPREF_PUBLIC 0x00000010 > #define RT6_LOOKUP_F_SRCPREF_COA 0x00000020 > +#define RT6_LOOKUP_F_NO_BLK_HOLE 0x00000040 > +#define RT6_LOOKUP_F_NO_PROHIBIT 0x00000080 > > /* > * rt6_srcprefs2flags() and rt6_flags2srcprefs() translate > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index 408cac4a..1891e23 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -948,7 +948,9 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp) > fl6.flowi6_oif = ifp->idev->dev->ifindex; > fl6.daddr = prefix; > rt = (struct rt6_info *)ip6_route_lookup(net, &fl6, > - RT6_LOOKUP_F_IFACE); > + RT6_LOOKUP_F_IFACE | > + RT6_LOOKUP_F_NO_BLK_HOLE | > + RT6_LOOKUP_F_NO_PROHIBIT); > > if (rt != net->ipv6.ip6_null_entry && > addrconf_is_prefix_route(rt)) { > diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c > index 2e1a432..d290da5 100644 > --- a/net/ipv6/fib6_rules.c > +++ b/net/ipv6/fib6_rules.c > @@ -64,9 +64,13 @@ static int fib6_rule_action(struct fib_rule *rule, struct flowi *flp, > goto discard_pkt; > default: > case FR_ACT_BLACKHOLE: > + if (flags & RT6_LOOKUP_F_NO_BLK_HOLE) > + goto again; goto out; ??? > rt = net->ipv6.ip6_blk_hole_entry; > goto discard_pkt; > case FR_ACT_PROHIBIT: > + if (flags & RT6_LOOKUP_F_NO_PROHIBIT) > + goto again; goto out; > rt = net->ipv6.ip6_prohibit_entry; > goto discard_pkt; > }