mptcp: Add helper to process acks of DATA_FIN

After DATA_FIN has been sent, the peer will acknowledge it. An ack of
the relevant MPTCP-level sequence number will update the MPTCP
connection state appropriately.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Mat Martineau 2020-07-28 15:12:05 -07:00 committed by David S. Miller
parent 6920b85158
commit 16a9a9da17

View file

@ -143,6 +143,14 @@ static void __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk,
MPTCP_SKB_CB(skb)->offset = offset;
}
static void mptcp_stop_timer(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
mptcp_sk(sk)->timer_ival = 0;
}
/* both sockets must be locked */
static bool mptcp_subflow_dsn_valid(const struct mptcp_sock *msk,
struct sock *ssk)
@ -164,6 +172,42 @@ static bool mptcp_subflow_dsn_valid(const struct mptcp_sock *msk,
return mptcp_subflow_data_available(ssk);
}
static void mptcp_check_data_fin_ack(struct sock *sk)
{
struct mptcp_sock *msk = mptcp_sk(sk);
if (__mptcp_check_fallback(msk))
return;
/* Look for an acknowledged DATA_FIN */
if (((1 << sk->sk_state) &
(TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) &&
msk->write_seq == atomic64_read(&msk->snd_una)) {
mptcp_stop_timer(sk);
WRITE_ONCE(msk->snd_data_fin_enable, 0);
switch (sk->sk_state) {
case TCP_FIN_WAIT1:
inet_sk_state_store(sk, TCP_FIN_WAIT2);
sk->sk_state_change(sk);
break;
case TCP_CLOSING:
fallthrough;
case TCP_LAST_ACK:
inet_sk_state_store(sk, TCP_CLOSE);
sk->sk_state_change(sk);
break;
}
if (sk->sk_shutdown == SHUTDOWN_MASK ||
sk->sk_state == TCP_CLOSE)
sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
else
sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
}
}
static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq)
{
struct mptcp_sock *msk = mptcp_sk(sk);
@ -222,6 +266,8 @@ static void mptcp_check_data_fin(struct sock *sk)
WRITE_ONCE(msk->rcv_data_fin, 0);
sk->sk_shutdown |= RCV_SHUTDOWN;
smp_mb__before_atomic(); /* SHUTDOWN must be visible first */
set_bit(MPTCP_DATA_READY, &msk->flags);
switch (sk->sk_state) {
case TCP_ESTABLISHED:
@ -455,14 +501,6 @@ static void mptcp_check_for_eof(struct mptcp_sock *msk)
}
}
static void mptcp_stop_timer(struct sock *sk)
{
struct inet_connection_sock *icsk = inet_csk(sk);
sk_stop_timer(sk, &icsk->icsk_retransmit_timer);
mptcp_sk(sk)->timer_ival = 0;
}
static bool mptcp_ext_cache_refill(struct mptcp_sock *msk)
{
const struct sock *sk = (const struct sock *)msk;