diff options
| author | Mat Martineau <mathew.j.martineau@linux.intel.com> | 2020-07-28 15:12:06 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-07-28 17:02:42 -0700 |
| commit | 43b54c6ee382f026fc93babf5301ec79e1c9614a (patch) | |
| tree | f7000ee2af1d5f86cbf2c30df0e814991d0cfc5c /net/mptcp/options.c | |
| parent | 16a9a9da17234797b01ca05024d33269872a0ae0 (diff) | |
mptcp: Use full MPTCP-level disconnect state machine
RFC 8684 appendix D describes the connection state machine for
MPTCP. This patch implements the DATA_FIN / DATA_ACK exchanges and
MPTCP-level socket state changes described in that appendix, rather than
simply sending DATA_FIN along with TCP FIN when disconnecting subflows.
DATA_FIN is now sent and acknowledged before shutting down the
subflows. Received DATA_FIN information (if not part of a data packet)
is written to the MPTCP socket when the incoming DSS option is parsed by
the subflow, and the MPTCP worker is scheduled to process the
flag. DATA_FIN received as part of a full DSS mapping will be handled
when the mapping is processed.
The DATA_FIN is acknowledged by the worker if the reader is caught
up. If there is still data to be moved to the MPTCP-level queue, ack_seq
will be incremented to account for the DATA_FIN when it reaches the end
of the stream and a DATA_ACK will be sent to the peer.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp/options.c')
| -rw-r--r-- | net/mptcp/options.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 38583d1b9b5f..b4458ecd01f8 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -868,6 +868,17 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb, if (mp_opt.use_ack) update_una(msk, &mp_opt); + /* Zero-length packets, like bare ACKs carrying a DATA_FIN, are + * dropped by the caller and not propagated to the MPTCP layer. + * Copy the DATA_FIN information now. + */ + if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { + if (mp_opt.data_fin && mp_opt.data_len == 1 && + mptcp_update_rcv_data_fin(msk, mp_opt.data_seq) && + schedule_work(&msk->work)) + sock_hold(subflow->conn); + } + mpext = skb_ext_add(skb, SKB_EXT_MPTCP); if (!mpext) return; |