Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752398AbaDYIFZ (ORCPT ); Fri, 25 Apr 2014 04:05:25 -0400 Received: from ja.ssi.bg ([178.16.129.10]:36328 "EHLO ja.home.ssi.bg" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752310AbaDYIFG (ORCPT ); Fri, 25 Apr 2014 04:05:06 -0400 X-Greylist: delayed 406 seconds by postgrey-1.27 at vger.kernel.org; Fri, 25 Apr 2014 04:05:01 EDT Date: Fri, 25 Apr 2014 10:57:03 +0300 (EEST) From: Julian Anastasov X-X-Sender: ja@ja.home.ssi.bg To: Xufeng Zhang cc: vyasevich@gmail.com, nhorman@tuxdriver.com, davem@davemloft.net, linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] sctp: reset flowi4_oif parameter on route lookup In-Reply-To: <1398410978-15954-1-git-send-email-xufeng.zhang@windriver.com> Message-ID: References: <1398410978-15954-1-git-send-email-xufeng.zhang@windriver.com> User-Agent: Alpine 2.11 (LFD 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, 25 Apr 2014, Xufeng Zhang wrote: > commit 813b3b5db83 (ipv4: Use caller's on-stack flowi as-is > in output route lookups.) introduces another regression which > is very similar to the problem of commit e6b45241c (ipv4: reset > flowi parameters on route connect) wants to fix: > Before we call ip_route_output_key() in sctp_v4_get_dst() to > get a dst that matches a bind address as the source address, > we have already called this function previously and the flowi > parameters have been initialized including flowi4_oif, so when > we call this function again, the process in ip_route_output_slow() > will be different because of the setting of flowi4_oif, and we'll > get a networking device which corresponds to the inputted flowi4_oif > as the output device, this is wrong because we'll never hit this > place if the previously returned source address of dst match one > of the bound addresses. > > To reproduce this problem, a vlan setting is enough: > # ifconfig eth0 up > # route del default > # vconfig add eth0 2 > # vconfig add eth0 3 > # ifconfig eth0.2 10.0.1.14 netmask 255.255.255.0 > # route add default gw 10.0.1.254 dev eth0.2 > # ifconfig eth0.3 10.0.0.14 netmask 255.255.255.0 > # ip rule add from 10.0.0.14 table 4 > # ip route add table 4 default via 10.0.0.254 src 10.0.0.14 dev eth0.3 > # sctp_darn -H 10.0.0.14 -P 36422 -h 10.1.4.134 -p 36422 -s -I > You'll detect that all the flow are routed to eth0.2(10.0.1.254). > > Signed-off-by: Xufeng Zhang > --- > net/sctp/protocol.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c > index c09757f..f8a5968 100644 > --- a/net/sctp/protocol.c > +++ b/net/sctp/protocol.c > @@ -493,6 +493,10 @@ static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr, > (AF_INET == laddr->a.sa.sa_family)) { > fl4->saddr = laddr->a.v4.sin_addr.s_addr; > fl4->fl4_sport = laddr->a.v4.sin_port; > + /* Reset flowi4_oif so that it won't be incorrectly used > + * as input parameter to routing lookups. > + */ > + fl4->flowi4_oif = 0; May be something like this is more correct: flowi4_update_output(fl4, asoc->base.sk->sk_bound_dev_if, RT_CONN_FLAGS(asoc->base.sk), daddr->v4.sin_addr.s_addr, laddr->a.v4.sin_addr.s_addr); > rt = ip_route_output_key(sock_net(sk), fl4); > if (!IS_ERR(rt)) { > dst = &rt->dst; Regards -- Julian Anastasov -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/