From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: Re: [PATCH 02/14] tcp: fix mark propagation with fwmark_reflect enabled Date: Thu, 26 Jan 2017 20:19:35 +0100 Message-ID: <20170126191935.GA26591@salvia> References: <1485448687-6072-1-git-send-email-pablo@netfilter.org> <1485448687-6072-3-git-send-email-pablo@netfilter.org> <1485453760.5145.144.camel@edumazet-glaptop3.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netfilter-devel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org To: Eric Dumazet Return-path: Content-Disposition: inline In-Reply-To: <1485453760.5145.144.camel@edumazet-glaptop3.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org On Thu, Jan 26, 2017 at 10:02:40AM -0800, Eric Dumazet wrote: > 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. Right. This is not percpu as in IPv4. I can send a follow up patch to get this in sync with the way we do it in IPv4, ie. add percpu socket. Fine with this approach? Thanks!