From patchwork Fri Oct 21 16:44:08 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Flavio Leitner X-Patchwork-Id: 121043 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 9F58CB70B1 for ; Sat, 22 Oct 2011 04:55:35 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555Ab1JURzd (ORCPT ); Fri, 21 Oct 2011 13:55:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48170 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754393Ab1JURzc (ORCPT ); Fri, 21 Oct 2011 13:55:32 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p9LHtJtS010528 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 21 Oct 2011 13:55:30 -0400 Received: from localhost (ovpn-113-120.phx2.redhat.com [10.3.113.120]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id p9LGiuIl006601; Fri, 21 Oct 2011 12:44:57 -0400 From: Flavio Leitner To: netdev Cc: David Miller , Flavio Leitner Subject: [PATCH net-next v3] route: fix ICMP redirect validation Date: Fri, 21 Oct 2011 14:44:08 -0200 Message-Id: <1319215448-6777-1-git-send-email-fbl@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The commit f39925dbde7788cfb96419c0f092b086aa325c0f (ipv4: Cache learned redirect information in inetpeer.) removed some ICMP packet validations which are required by RFC 1122, section 3.2.2.2: ... A Redirect message SHOULD be silently discarded if the new gateway address it specifies is not on the same connected (sub-) net through which the Redirect arrived [INTRO:2, Appendix A], or if the source of the Redirect is not the current first-hop gateway for the specified destination (see Section 3.3.1). Signed-off-by: Flavio Leitner --- net/ipv4/route.c | 36 +++++++++++++++++++++++++++++++----- 1 files changed, 31 insertions(+), 5 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 26c77e1..1082460 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1308,7 +1308,12 @@ static void rt_del(unsigned hash, struct rtable *rt) void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, __be32 saddr, struct net_device *dev) { + int s, i; struct in_device *in_dev = __in_dev_get_rcu(dev); + struct rtable *rt; + __be32 skeys[2] = { saddr, 0 }; + int ikeys[2] = { dev->ifindex, 0 }; + struct flowi4 fl4; struct inet_peer *peer; struct net *net; @@ -1331,13 +1336,34 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw, goto reject_redirect; } - peer = inet_getpeer_v4(daddr, 1); - if (peer) { - peer->redirect_learned.a4 = new_gw; + memset(&fl4, 0, sizeof(fl4)); + fl4.daddr = daddr; + for (s = 0; s < 2; s++) { + for (i = 0; i < 2; i++) { + fl4.flowi4_oif = ikeys[i]; + fl4.saddr = skeys[s]; + rt = __ip_route_output_key(net, &fl4); + if (IS_ERR(rt)) + continue; - inet_putpeer(peer); + if (rt->dst.error || rt->dst.dev != dev || + rt->rt_gateway != old_gw) { + ip_rt_put(rt); + continue; + } - atomic_inc(&__rt_peer_genid); + if (!rt->peer) + rt_bind_peer(rt, rt->rt_dst, 1); + + peer = rt->peer; + if (peer) { + peer->redirect_learned.a4 = new_gw; + atomic_inc(&__rt_peer_genid); + } + + ip_rt_put(rt); + return; + } } return;