Bluetooth: Implement SendAck() Action on ERTM.

Shall be used to ack received frames, It must decide type of
acknowledgment between a RR frame, a RNR frame or transmission of
pending I-frames.
It also modifies l2cap_ertm_send() to report the number of frames sent.

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
Reviewed-by: João Paulo Rechi Vita <jprvita@profusion.mobi>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 2e354d2..0a739ef 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -352,6 +352,11 @@ static inline int l2cap_send_sframe(struct l2cap_pinfo *pi, u16 control)
        count = min_t(unsigned int, conn->mtu, hlen);
        control |= L2CAP_CTRL_FRAME_TYPE;
 
+       if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
+               control |= L2CAP_CTRL_FINAL;
+               pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
+       }
+
        skb = bt_skb_alloc(count, GFP_ATOMIC);
        if (!skb)
                return -ENOMEM;
@@ -1364,7 +1369,7 @@ static int l2cap_ertm_send(struct sock *sk)
        struct sk_buff *skb, *tx_skb;
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u16 control, fcs;
-       int err;
+       int err, nsent = 0;
 
        if (pi->conn_state & L2CAP_CONN_WAIT_F)
                return 0;
@@ -1414,8 +1419,27 @@ static int l2cap_ertm_send(struct sock *sk)
                        sk->sk_send_head = NULL;
                else
                        sk->sk_send_head = skb_queue_next(TX_QUEUE(sk), skb);
+
+               nsent++;
        }
 
+       return nsent;
+}
+
+static int l2cap_send_ack(struct l2cap_pinfo *pi)
+{
+       struct sock *sk = (struct sock *)pi;
+       u16 control = 0;
+
+       control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
+
+       if (pi->conn_state & L2CAP_CONN_LOCAL_BUSY) {
+               control |= L2CAP_SUPER_RCV_NOT_READY;
+               return l2cap_send_sframe(pi, control);
+       } else if (l2cap_ertm_send(sk) == 0) {
+               control |= L2CAP_SUPER_RCV_READY;
+               return l2cap_send_sframe(pi, control);
+       }
        return 0;
 }
 
@@ -1678,7 +1702,7 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
                else
                        err = l2cap_ertm_send(sk);
 
-               if (!err)
+               if (err >= 0)
                        err = len;
                break;
 
@@ -3178,10 +3202,6 @@ static inline void l2cap_send_i_or_rr_or_rnr(struct sock *sk)
        if (!(pi->conn_state & L2CAP_CONN_LOCAL_BUSY) &&
                        pi->frames_sent == 0) {
                control |= L2CAP_SUPER_RCV_READY;
-               if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
-                       control |= L2CAP_CTRL_FINAL;
-                       pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
-               }
                l2cap_send_sframe(pi, control);
        }
 }
@@ -3362,7 +3382,6 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_txseq(rx_control);
        u8 req_seq = __get_reqseq(rx_control);
-       u16 tx_control = 0;
        u8 sar = rx_control >> L2CAP_CTRL_SAR_SHIFT;
        int err = 0;
 
@@ -3449,11 +3468,9 @@ expected:
                return err;
 
        pi->num_to_ack = (pi->num_to_ack + 1) % L2CAP_DEFAULT_NUM_TO_ACK;
-       if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1) {
-               tx_control |= L2CAP_SUPER_RCV_READY;
-               tx_control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
-               l2cap_send_sframe(pi, tx_control);
-       }
+       if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1)
+               l2cap_send_ack(pi);
+
        return 0;
 }