From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: [PATCH] net: tcp response should set oif only if it is L3 master Date: Wed, 9 Nov 2016 09:07:26 -0800 Message-ID: <1478711246-17440-1-git-send-email-dsa@cumulusnetworks.com> Cc: lorenzo@google.com, David Ahern To: netdev@vger.kernel.org Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:34105 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753562AbcKIRHe (ORCPT ); Wed, 9 Nov 2016 12:07:34 -0500 Received: by mail-pf0-f176.google.com with SMTP id n85so129721621pfi.1 for ; Wed, 09 Nov 2016 09:07:34 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: Lorenzo noted an Android unit test failed due to e0d56fdd7342: "The expectation in the test was that the RST replying to a SYN sent to a closed port should be generated with oif=0. In other words it should not prefer the interface where the SYN came in on, but instead should follow whatever the routing table says it should do." Revert the change to ip_send_unicast_reply and tcp_v6_send_response such that the oif in the flow is set to the skb_iif only if skb_iif is an L3 master. Fixes: e0d56fdd7342 ("net: l3mdev: remove redundant calls") Reported-by: Lorenzo Colitti Signed-off-by: David Ahern --- net/ipv4/ip_output.c | 3 ++- net/ipv6/tcp_ipv6.c | 8 ++++++-- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 03e7f7310423..7cf627b0b248 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1579,7 +1579,8 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, } oif = arg->bound_dev_if; - oif = oif ? : skb->skb_iif; + if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) + oif = skb->skb_iif; flowi4_init_output(&fl4, oif, IP4_REPLY_MARK(net, skb->mark), diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 5a27ab4eab39..6ca23c2e76f7 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -818,8 +818,12 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 fl6.flowi6_proto = IPPROTO_TCP; if (rt6_need_strict(&fl6.daddr) && !oif) fl6.flowi6_oif = tcp_v6_iif(skb); - else - fl6.flowi6_oif = oif ? : skb->skb_iif; + else { + if (!oif && netif_index_is_l3_master(net, skb->skb_iif)) + oif = skb->skb_iif; + + fl6.flowi6_oif = oif; + } fl6.flowi6_mark = IP6_REPLY_MARK(net, skb->mark); fl6.fl6_dport = t1->dest; -- 2.1.4