From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 495C0C04AB5 for ; Thu, 6 Jun 2019 20:14:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 267B2206BB for ; Thu, 6 Jun 2019 20:14:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728662AbfFFUON (ORCPT ); Thu, 6 Jun 2019 16:14:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55434 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728641AbfFFUOM (ORCPT ); Thu, 6 Jun 2019 16:14:12 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id BB9F265CE2; Thu, 6 Jun 2019 20:14:09 +0000 (UTC) Received: from epycfail.redhat.com (ovpn-112-18.ams2.redhat.com [10.36.112.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id A0634277CC; Thu, 6 Jun 2019 20:14:05 +0000 (UTC) From: Stefano Brivio To: David Miller Cc: Jianlin Shi , Wei Wang , David Ahern , Martin KaFai Lau , Eric Dumazet , netdev@vger.kernel.org Subject: [PATCH net 1/2] ipv6: Dump route exceptions too in rt6_dump_route() Date: Thu, 6 Jun 2019 22:13:41 +0200 Message-Id: <085ce9fbe0206be0d1d090b36e656aa89cef3d98.1559851514.git.sbrivio@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 06 Jun 2019 20:14:12 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since commit 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache"), route exceptions reside in a separate hash table, and won't be found by walking the FIB, so they won't be dumped to userspace on a RTM_GETROUTE message. This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to have no function anymore: # ip -6 route get fc00:3::1 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium # ip -6 route get fc00:4::1 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium # ip -6 route list cache # ip -6 route flush cache # ip -6 route get fc00:3::1 fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium # ip -6 route get fc00:4::1 fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium because iproute2 lists cached routes using RTM_GETROUTE, and flushes them by listing all the routes, and deleting them with RTM_DELROUTE one by one. Look up exceptions in the hash table associated with the current fib6_info in rt6_dump_route(), and, if present and not expired, add them to the dump. Re-allow userspace to get FIB results by passing the RTM_F_CLONED flag as filter, by reverting commit 08e814c9e8eb ("net/ipv6: Bail early if user only wants cloned entries"). As we do this, we also have to honour this flag while filtering routes in rt6_dump_route() and, if this filter effectively causes some results to be discarded, by passing the NLM_F_DUMP_FILTERED flag back. To flush cached routes, a procfs entry could be introduced instead: that's how it works for IPv4. We already have a rt6_flush_exception() function ready to be wired to it. However, this would not solve the issue for listing, and wouldn't fix the issue with current and previous versions of iproute2. Reported-by: Jianlin Shi Fixes: 2b760fcf5cfb ("ipv6: hook up exception table to store dst cache") Signed-off-by: Stefano Brivio --- This will cause a non-trivial conflict with commit cc5c073a693f ("ipv6: Move exception bucket to fib6_nh") on net-next. I can submit an equivalent patch against net-next, if it helps. net/ipv6/ip6_fib.c | 7 ++----- net/ipv6/route.c | 38 +++++++++++++++++++++++++++++++++++--- 2 files changed, 37 insertions(+), 8 deletions(-) diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 008421b550c6..5be133565819 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -581,13 +581,10 @@ static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) { struct rtmsg *rtm = nlmsg_data(nlh); - arg.filter.flags = rtm->rtm_flags & (RTM_F_PREFIX|RTM_F_CLONED); + if (rtm->rtm_flags & RTM_F_PREFIX) + arg.filter.flags = RTM_F_PREFIX; } - /* fib entries are never clones */ - if (arg.filter.flags & RTM_F_CLONED) - goto out; - w = (void *)cb->args[2]; if (!w) { /* New dump: diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 848e944f07df..51f923b3ad26 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -4862,8 +4862,11 @@ int rt6_dump_route(struct fib6_info *rt, void *p_arg) { struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; struct fib_dump_filter *filter = &arg->filter; + struct rt6_exception_bucket *bucket; unsigned int flags = NLM_F_MULTI; + struct rt6_exception *rt6_ex; struct net *net = arg->net; + int i, err; if (rt == net->ipv6.fib6_null_entry) return 0; @@ -4882,9 +4885,38 @@ int rt6_dump_route(struct fib6_info *rt, void *p_arg) flags |= NLM_F_DUMP_FILTERED; } - return rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 0, - RTM_NEWROUTE, NETLINK_CB(arg->cb->skb).portid, - arg->cb->nlh->nlmsg_seq, flags); + if (!(filter->flags & RTM_F_CLONED)) { + err = rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 0, + RTM_NEWROUTE, + NETLINK_CB(arg->cb->skb).portid, + arg->cb->nlh->nlmsg_seq, flags); + if (err) + return err; + } else { + flags |= NLM_F_DUMP_FILTERED; + } + + bucket = rcu_dereference(rt->rt6i_exception_bucket); + if (!bucket) + return 0; + + for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { + hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { + if (rt6_check_expired(rt6_ex->rt6i)) + continue; + + err = rt6_fill_node(net, arg->skb, rt, + &rt6_ex->rt6i->dst, + NULL, NULL, 0, RTM_NEWROUTE, + NETLINK_CB(arg->cb->skb).portid, + arg->cb->nlh->nlmsg_seq, flags); + if (err) + return err; + } + bucket++; + } + + return 0; } static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, -- 2.20.1