From 6920b851584cc69a61ebf2cff3948bb153bcef20 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Tue, 28 Jul 2020 15:12:04 -0700 Subject: mptcp: Add mptcp_close_state() helper This will be used to transition to the appropriate state on close and determine if a DATA_FIN needs to be sent for that state transition. Signed-off-by: Mat Martineau Signed-off-by: David S. Miller --- net/mptcp/protocol.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'net') diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e1c71bfd61a3..51370b69e30b 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1498,6 +1498,33 @@ static void mptcp_subflow_shutdown(struct sock *ssk, int how) release_sock(ssk); } +static const unsigned char new_state[16] = { + /* current state: new state: action: */ + [0 /* (Invalid) */] = TCP_CLOSE, + [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_SYN_SENT] = TCP_CLOSE, + [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, + [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, + [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, + [TCP_TIME_WAIT] = TCP_CLOSE, /* should not happen ! */ + [TCP_CLOSE] = TCP_CLOSE, + [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, + [TCP_LAST_ACK] = TCP_LAST_ACK, + [TCP_LISTEN] = TCP_CLOSE, + [TCP_CLOSING] = TCP_CLOSING, + [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ +}; + +static int mptcp_close_state(struct sock *sk) +{ + int next = (int)new_state[sk->sk_state]; + int ns = next & TCP_STATE_MASK; + + inet_sk_state_store(sk, ns); + + return next & TCP_ACTION_FIN; +} + static void mptcp_close(struct sock *sk, long timeout) { struct mptcp_subflow_context *subflow, *tmp; -- cgit v1.2.3