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authorPaolo Abeni <pabeni@redhat.com>2020-07-23 14:02:31 +0300
committerDavid S. Miller <davem@davemloft.net>2020-07-23 21:47:24 +0300
commit0235d075a592dfde575df81f150feb0d95a5ef5c (patch)
tree4bd2dc5e7e82339d6a60ed8e48a3cced9583b4de /net/mptcp
parent53eb4c383deb97b59f1755fe3035ec7992488375 (diff)
downloadlinux-0235d075a592dfde575df81f150feb0d95a5ef5c.tar.xz
mptcp: mark as fallback even early ones
In the unlikely event of a failure at connect time, we currently clear the request_mptcp flag - so that the MPC handshake is not started at all, but the msk is not explicitly marked as fallback. This would lead to later insertion of wrong DSS options in the xmitted packets, in violation of RFC specs and possibly fooling the peer. Fixes: e1ff9e82e2ea ("net: mptcp: improve fallback to TCP") Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Tested-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/protocol.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 254e6ef2b4e0..2936413171be 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1944,6 +1944,13 @@ unlock:
return err;
}
+static void mptcp_subflow_early_fallback(struct mptcp_sock *msk,
+ struct mptcp_subflow_context *subflow)
+{
+ subflow->request_mptcp = 0;
+ __mptcp_do_fallback(msk);
+}
+
static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
int addr_len, int flags)
{
@@ -1975,10 +1982,10 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
* TCP option space.
*/
if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
- subflow->request_mptcp = 0;
+ mptcp_subflow_early_fallback(msk, subflow);
#endif
if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk))
- subflow->request_mptcp = 0;
+ mptcp_subflow_early_fallback(msk, subflow);
do_connect:
err = ssock->ops->connect(ssock, uaddr, addr_len, flags);