mptcp: Check connection state before attempting send (1954b860) · Commits · 戴 / test

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>

net/mptcp/protocol.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -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;
		}

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