From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 01/15] netfilter: Fix handling simultaneous open in TCP conntrack
Date: Mon, 14 May 2018 00:36:42 +0200 [thread overview]
Message-ID: <20180513223656.10077-2-pablo@netfilter.org> (raw)
In-Reply-To: <20180513223656.10077-1-pablo@netfilter.org>
From: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Dominique Martinet reported a TCP hang problem when simultaneous open was used.
The problem is that the tcp_conntracks state table is not smart enough
to handle the case. The state table could be fixed by introducing a new state,
but that would require more lines of code compared to this patch, due to the
required backward compatibility with ctnetlink.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Reported-by: Dominique Martinet <asmadeus@codewreck.org>
Tested-by: Dominique Martinet <asmadeus@codewreck.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
include/uapi/linux/netfilter/nf_conntrack_tcp.h | 3 +++
net/netfilter/nf_conntrack_proto_tcp.c | 11 +++++++++++
2 files changed, 14 insertions(+)
diff --git a/include/uapi/linux/netfilter/nf_conntrack_tcp.h b/include/uapi/linux/netfilter/nf_conntrack_tcp.h
index 74b91151d494..bcba72def817 100644
--- a/include/uapi/linux/netfilter/nf_conntrack_tcp.h
+++ b/include/uapi/linux/netfilter/nf_conntrack_tcp.h
@@ -46,6 +46,9 @@ enum tcp_conntrack {
/* Marks possibility for expected RFC5961 challenge ACK */
#define IP_CT_EXP_CHALLENGE_ACK 0x40
+/* Simultaneous open initialized */
+#define IP_CT_TCP_SIMULTANEOUS_OPEN 0x80
+
struct nf_ct_tcp_flags {
__u8 flags;
__u8 mask;
diff --git a/net/netfilter/nf_conntrack_proto_tcp.c b/net/netfilter/nf_conntrack_proto_tcp.c
index e97cdc1cf98c..8e67910185a0 100644
--- a/net/netfilter/nf_conntrack_proto_tcp.c
+++ b/net/netfilter/nf_conntrack_proto_tcp.c
@@ -981,6 +981,17 @@ static int tcp_packet(struct nf_conn *ct,
return NF_ACCEPT; /* Don't change state */
}
break;
+ case TCP_CONNTRACK_SYN_SENT2:
+ /* tcp_conntracks table is not smart enough to handle
+ * simultaneous open.
+ */
+ ct->proto.tcp.last_flags |= IP_CT_TCP_SIMULTANEOUS_OPEN;
+ break;
+ case TCP_CONNTRACK_SYN_RECV:
+ if (dir == IP_CT_DIR_REPLY && index == TCP_ACK_SET &&
+ ct->proto.tcp.last_flags & IP_CT_TCP_SIMULTANEOUS_OPEN)
+ new_state = TCP_CONNTRACK_ESTABLISHED;
+ break;
case TCP_CONNTRACK_CLOSE:
if (index == TCP_RST_SET
&& (ct->proto.tcp.seen[!dir].flags & IP_CT_TCP_FLAG_MAXACK_SET)
--
2.11.0
next prev parent reply other threads:[~2018-05-13 22:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-13 22:36 [PATCH 00/15] Netfilter/IPVS fixes for net Pablo Neira Ayuso
2018-05-13 22:36 ` Pablo Neira Ayuso [this message]
2018-05-13 22:36 ` [PATCH 02/15] netfilter: x_tables: check name length in find_match/target, too Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 03/15] netfilter: nf_tables: skip synchronize_rcu if transaction log is empty Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 04/15] netfilter: bridge: stp fix reference to uninitialized data Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 05/15] netfilter: nf_tables: nft_compat: fix refcount leak on xt module Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 06/15] ipvs: fix refcount usage for conns in ops mode Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 07/15] ipvs: fix stats update from local clients Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 08/15] netfilter: core: add missing __rcu annotation Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 09/15] netfilter: prefer nla_strlcpy for dealing with NLA_STRING attributes Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 10/15] netfilter: x_tables: add module alias for icmp matches Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 11/15] netfilter: nf_tables: don't assume chain stats are set when jumplabel is set Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 12/15] netfilter: nft_compat: prepare for indirect info storage Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 13/15] netfilter: nft_compat: fix handling of large matchinfo size Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 14/15] netfilter: nf_tables: bogus EBUSY in chain deletions Pablo Neira Ayuso
2018-05-13 22:36 ` [PATCH 15/15] netfilter: nf_tables: fix memory leak on error exit return Pablo Neira Ayuso
2018-05-14 1:05 ` [PATCH 00/15] Netfilter/IPVS fixes for net David Miller
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