mptcp: Check connection state before attempting send

MPTCP should wait for an active connection or skip sending depending on
the connection state, as TCP does. This happens before the possible
passthrough to a regular TCP sendmsg because the subflow's socket type
(MPTCP or TCP fallback) is not known until the connection is
complete. This is also relevent at disconnect time, where data should
not be sent in certain MPTCP-level connection states.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mat Martineau 2020-02-28 15:47:39 -08:00 committed by David S. Miller
parent 0a303214f8
commit 1954b86016

View File

@ -419,6 +419,15 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
return -EOPNOTSUPP;
lock_sock(sk);
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
ret = sk_stream_wait_connect(sk, &timeo);
if (ret)
goto out;
}
ssock = __mptcp_tcp_fallback(msk);
if (unlikely(ssock)) {
fallback:
@ -427,8 +436,6 @@ fallback:
return ret >= 0 ? ret + copied : (copied ? copied : ret);
}
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
ssk = mptcp_subflow_get(msk);
if (!ssk) {
release_sock(sk);
@ -460,6 +467,7 @@ fallback:
ssk_check_wmem(msk, ssk);
release_sock(ssk);
out:
release_sock(sk);
return ret;
}