From: Mat Martineau mathew.j.martineau@linux.intel.com
[ Upstream commit 6477dd39e62c3a67cfa368ddc127410b4ae424c6 ]
With this change, the MPTCP-level retransmission timer is used to resend DATA_FIN. The retranmit timer is not stopped while waiting for a MPTCP-level ACK of DATA_FIN, and retransmitted DATA_FINs are sent on all subflows. The retry interval starts at TCP_RTO_MIN and then doubles on each attempt, up to TCP_RTO_MAX.
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/146 Fixes: 43b54c6ee382 ("mptcp: Use full MPTCP-level disconnect state machine") Acked-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Mat Martineau mathew.j.martineau@linux.intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/protocol.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 5043c7cb0782..65e5d3eb1078 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -399,6 +399,14 @@ static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq) return false; }
+static void mptcp_set_datafin_timeout(const struct sock *sk) +{ + struct inet_connection_sock *icsk = inet_csk(sk); + + mptcp_sk(sk)->timer_ival = min(TCP_RTO_MAX, + TCP_RTO_MIN << icsk->icsk_retransmits); +} + static void mptcp_set_timeout(const struct sock *sk, const struct sock *ssk) { long tout = ssk && inet_csk(ssk)->icsk_pending ? @@ -1052,7 +1060,7 @@ out: }
if (snd_una == READ_ONCE(msk->snd_nxt)) { - if (msk->timer_ival) + if (msk->timer_ival && !mptcp_data_fin_enabled(msk)) mptcp_stop_timer(sk); } else { mptcp_reset_timer(sk); @@ -2276,8 +2284,19 @@ static void __mptcp_retrans(struct sock *sk)
__mptcp_clean_una_wakeup(sk); dfrag = mptcp_rtx_head(sk); - if (!dfrag) + if (!dfrag) { + if (mptcp_data_fin_enabled(msk)) { + struct inet_connection_sock *icsk = inet_csk(sk); + + icsk->icsk_retransmits++; + mptcp_set_datafin_timeout(sk); + mptcp_send_ack(msk); + + goto reset_timer; + } + return; + }
ssk = mptcp_subflow_get_retrans(msk); if (!ssk) @@ -2460,6 +2479,8 @@ void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how) pr_debug("Sending DATA_FIN on subflow %p", ssk); mptcp_set_timeout(sk, ssk); tcp_send_ack(ssk); + if (!mptcp_timer_pending(sk)) + mptcp_reset_timer(sk); } break; }