From 1954b86016cf8522970e1b7aba801233d777ec47 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Fri, 28 Feb 2020 15:47:39 -0800 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index a844540..07559b4 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -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; } -- 2.7.4