@@ -2276,8 +2276,14 @@ static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk,
lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
- if (flags & MPTCP_CF_FASTCLOSE)
+ if (flags & MPTCP_CF_FASTCLOSE) {
+ /* be sure to force the tcp_disconnect() path,
+ * to generate the egress reset
+ */
+ ssk->sk_lingertime = 0;
+ sock_set_flag(ssk, SOCK_LINGER);
subflow->send_fastclose = 1;
+ }
need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk);
if (!dispose_it) {
@@ -2540,6 +2546,16 @@ static void mptcp_mp_fail_no_response(struct mptcp_sock *msk)
mptcp_reset_timeout(msk, 0);
}
+static void mptcp_do_fastclose(struct sock *sk)
+{
+ struct mptcp_subflow_context *subflow, *tmp;
+ struct mptcp_sock *msk = mptcp_sk(sk);
+
+ mptcp_for_each_subflow_safe(msk, subflow, tmp)
+ __mptcp_close_ssk(sk, mptcp_subflow_tcp_sock(subflow),
+ subflow, MPTCP_CF_FASTCLOSE);
+}
+
static void mptcp_worker(struct work_struct *work)
{
struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
@@ -2571,6 +2587,7 @@ static void mptcp_worker(struct work_struct *work)
if (sock_flag(sk, SOCK_DEAD) &&
(mptcp_check_close_timeout(sk) || sk->sk_state == TCP_CLOSE)) {
inet_sk_state_store(sk, TCP_CLOSE);
+ mptcp_do_fastclose(sk);
__mptcp_destroy_sock(sk);
goto unlock;
}
@@ -2823,6 +2840,18 @@ static void __mptcp_destroy_sock(struct sock *sk)
sock_put(sk);
}
+static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
+{
+ /* Concurrent splices from sk_receive_queue into receive_queue will
+ * always show at least one non-empty queue when checked in this order.
+ */
+ if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) &&
+ skb_queue_empty_lockless(&msk->receive_queue))
+ return 0;
+
+ return EPOLLIN | EPOLLRDNORM;
+}
+
static void mptcp_close(struct sock *sk, long timeout)
{
struct mptcp_subflow_context *subflow;
@@ -2837,8 +2866,13 @@ static void mptcp_close(struct sock *sk, long timeout)
goto cleanup;
}
- if (mptcp_close_state(sk))
+ if (mptcp_check_readable(msk)) {
+ /* the msk has read data, do the MPTCP equivalent of TCP reset */
+ inet_sk_state_store(sk, TCP_CLOSE);
+ mptcp_do_fastclose(sk);
+ } else if (mptcp_close_state(sk)) {
__mptcp_wr_shutdown(sk);
+ }
sk_stream_wait_close(sk, timeout);
@@ -3646,18 +3680,6 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
return err;
}
-static __poll_t mptcp_check_readable(struct mptcp_sock *msk)
-{
- /* Concurrent splices from sk_receive_queue into receive_queue will
- * always show at least one non-empty queue when checked in this order.
- */
- if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) &&
- skb_queue_empty_lockless(&msk->receive_queue))
- return 0;
-
- return EPOLLIN | EPOLLRDNORM;
-}
-
static __poll_t mptcp_check_writeable(struct mptcp_sock *msk)
{
struct sock *sk = (struct sock *)msk;
Daire reported a user-space application hang-up when the peer is forcibly closed before the data transfer completion. The relevant application expects the peer to either do an application-level clean shutdown or a transport-level connection reset. We can accommodate a such user by extending the fastclose usage: at fd close time, if the msk socket has some unread data, and at FIN_WAIT timeout. Note that at MPTCP close time we must ensure that the TCP subflows will reset: set the linger socket option to a suitable value. Signed-off-by: Paolo Abeni <pabeni@redhat.com> -- v2 -> v3: - move self-tests update to a different patch v1 -> v2: - ensure mptcp_do_fastclose will reset all the subflows, - update fastclose self-tests --- net/mptcp/protocol.c | 50 +++++++++++++++++++++++++++++++------------- 1 file changed, 36 insertions(+), 14 deletions(-)