From c3c123d16c0ed4a81b9b18d3759a31c58b2fe504 Mon Sep 17 00:00:00 2001 From: Davide Caratti Date: Thu, 19 Mar 2020 22:45:37 +0100 Subject: [PATCH] net: mptcp: don't hang in mptcp_sendmsg() after TCP fallback 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: 767d3ded5fb8 ("net: mptcp: don't hang before sending 'MP capable with data'") Fixes: 1954b86016cf ("mptcp: Check connection state before attempting send") Signed-off-by: Davide Caratti Acked-by: Paolo Abeni Reviewed-by: Matthieu Baerts Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 4 ---- net/mptcp/subflow.c | 6 ++++++ 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e959104832ef..92d5382e71f4 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -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) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index e1faa88855bf..5bae12da2769 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -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);