net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback (c3c123d1) · Commits · 戴 / test

it's still possible for packetdrill to hang in mptcp_sendmsg(), when the MPTCP socket falls back to regular TCP (e.g. after receiving unsupported flags/version during the three-way handshake). Adjust MPTCP socket state earlier, to ensure correct functionality of mptcp_sendmsg() even in case of TCP fallback. Fixes: ("net: mptcp: don't hang before sending 'MP capable with data'") Fixes: ("mptcp: Check connection state before attempting send") Signed-off-by:

Davide Caratti <dcaratti@redhat.com> Acked-by:

Paolo Abeni <pabeni@redhat.com> Reviewed-by:

Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/mptcp/protocol.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -1055,10 +1055,6 @@ void mptcp_finish_connect(struct sock *ssk)
		WRITE_ONCE(msk->write_seq, subflow->idsn + 1);
		WRITE_ONCE(msk->ack_seq, ack_seq);
		WRITE_ONCE(msk->can_ack, 1);
		if (inet_sk_state_load(sk) != TCP_ESTABLISHED) {
		inet_sk_state_store(sk, TCP_ESTABLISHED);
		sk->sk_state_change(sk);
		}
		}

		static void mptcp_sock_graft(struct sock sk, struct socket parent)

net/mptcp/subflow.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -109,9 +109,15 @@ static void subflow_v6_init_req(struct request_sock *req,
		static void subflow_finish_connect(struct sock sk, const struct sk_buff skb)
		{
		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
		struct sock *parent = subflow->conn;

		subflow->icsk_af_ops->sk_rx_dst_set(sk, skb);

		if (inet_sk_state_load(parent) != TCP_ESTABLISHED) {
		inet_sk_state_store(parent, TCP_ESTABLISHED);
		parent->sk_state_change(parent);
		}

		if (!subflow->conn_finished) {
		pr_debug("subflow=%p, remote_key=%llu", mptcp_subflow_ctx(sk),
		subflow->remote_key);

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