From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 02/14] tcp: fix mark propagation with fwmark_reflect enabled Date: Thu, 26 Jan 2017 10:02:40 -0800 Message-ID: <1485453760.5145.144.camel@edumazet-glaptop3.roam.corp.google.com> References: <1485448687-6072-1-git-send-email-pablo@netfilter.org> <1485448687-6072-3-git-send-email-pablo@netfilter.org> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netfilter-devel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org To: Pablo Neira Ayuso Return-path: Received: from mail-pg0-f67.google.com ([74.125.83.67]:36603 "EHLO mail-pg0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752956AbdAZSfr (ORCPT ); Thu, 26 Jan 2017 13:35:47 -0500 In-Reply-To: <1485448687-6072-3-git-send-email-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 2017-01-26 at 17:37 +0100, Pablo Neira Ayuso wrote: > From: Pau Espin Pedrol > > Otherwise, RST packets generated by the TCP stack for non-existing > sockets always have mark 0. > The mark from the original packet is assigned to the netns_ipv4/6 > socket used to send the response so that it can get copied into the > response skb when the socket sends it. > > Fixes: e110861f8609 ("net: add a sysctl to reflect the fwmark on replies") > Cc: Lorenzo Colitti > Signed-off-by: Pau Espin Pedrol > Signed-off-by: Pablo Neira Ayuso > --- > net/ipv4/ip_output.c | 1 + > net/ipv6/tcp_ipv6.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c > index fac275c48108..b67719f45953 100644 > --- a/net/ipv4/ip_output.c > +++ b/net/ipv4/ip_output.c > @@ -1629,6 +1629,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, > sk->sk_protocol = ip_hdr(skb)->protocol; > sk->sk_bound_dev_if = arg->bound_dev_if; > sk->sk_sndbuf = sysctl_wmem_default; > + sk->sk_mark = fl4.flowi4_mark; > err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, > len, 0, &ipc, &rt, MSG_DONTWAIT); > if (unlikely(err)) { > diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c > index 73bc8fc68acd..2b20622a5824 100644 > --- a/net/ipv6/tcp_ipv6.c > +++ b/net/ipv6/tcp_ipv6.c > @@ -840,6 +840,7 @@ static void tcp_v6_send_response(const struct sock *sk, struct sk_buff *skb, u32 > dst = ip6_dst_lookup_flow(ctl_sk, &fl6, NULL); > if (!IS_ERR(dst)) { > skb_dst_set(buff, dst); > + ctl_sk->sk_mark = fl6.flowi6_mark; > ip6_xmit(ctl_sk, buff, &fl6, NULL, tclass); > TCP_INC_STATS(net, TCP_MIB_OUTSEGS); > if (rst) This patch is wrong. ctl_sk is a shared socket, and tcp_v6_send_response() can be called from many different cpus at the same time.