Bluetooth: Handle L2CAP case when the remote receiver is busy

Implement all issues related to RemoteBusy in the RECV state table.

Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 23 insertions, 2 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 0a36c61c011f..40fbf5cb1f7e 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1350,7 +1350,8 @@ static int l2cap_ertm_send(struct sock *sk)
         if (pi->conn_state & L2CAP_CONN_WAIT_F)
                 return 0;
 
-        while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))) {
+        while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))
+                        && !(pi->conn_state & L2CAP_CONN_REMOTE_BUSY)) {
                 tx_skb = skb_clone(skb, GFP_ATOMIC);
 
                 if (pi->remote_max_tx &&
@@ -3351,7 +3352,10 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
                         control |= L2CAP_SUPER_RCV_READY |
                                 (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT);
                         l2cap_send_sframe(l2cap_pi(sk), control);
+                        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
+
                 } else if (rx_control & L2CAP_CTRL_FINAL) {
+                        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
                         pi->expected_ack_seq = tx_seq;
                         l2cap_drop_acked_frames(sk);
 
@@ -3366,13 +3370,19 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
                 } else {
                         pi->expected_ack_seq = tx_seq;
                         l2cap_drop_acked_frames(sk);
-                        if (pi->unacked_frames > 0)
+
+                        if ((pi->conn_state & L2CAP_CONN_REMOTE_BUSY)
+                                        && (pi->unacked_frames > 0))
                                 __mod_retrans_timer();
+
                         l2cap_ertm_send(sk);
+                        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
                 }
                 break;
 
         case L2CAP_SUPER_REJECT:
+                pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
+
                 pi->expected_ack_seq = __get_reqseq(rx_control);
                 l2cap_drop_acked_frames(sk);
 
@@ -3384,6 +3394,8 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
                 break;
 
         case L2CAP_SUPER_SELECT_REJECT:
+                pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
+
                 if (rx_control & L2CAP_CTRL_POLL) {
                         l2cap_retransmit_frame(sk, tx_seq);
                         pi->expected_ack_seq = tx_seq;
@@ -3410,6 +3422,15 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
                 break;
 
         case L2CAP_SUPER_RCV_NOT_READY:
+                pi->conn_state |= L2CAP_CONN_REMOTE_BUSY;
+                pi->expected_ack_seq = tx_seq;
+                l2cap_drop_acked_frames(sk);
+
+                del_timer(&l2cap_pi(sk)->retrans_timer);
+                if (rx_control & L2CAP_CTRL_POLL) {
+                        u16 control = L2CAP_CTRL_FINAL | L2CAP_SUPER_RCV_READY;
+                        l2cap_send_sframe(l2cap_pi(sk), control);
+                }
                 break;
         }