Bluetooth: Implement 'Send IorRRorRNR' event

After receive a RR with P bit set ERTM shall use this funcion to choose
what type of frame to reply with F bit = 1.

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>

1 files changed, 39 insertions, 4 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index a9c152a09f0b..06687e264703 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1383,6 +1383,10 @@ static int l2cap_ertm_send(struct sock *sk)
                 bt_cb(skb)->retries++;
 
                 control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+                if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
+                        control |= L2CAP_CTRL_FINAL;
+                        pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
+                }
                 control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT)
                                 | (pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
                 put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
@@ -1404,6 +1408,7 @@ static int l2cap_ertm_send(struct sock *sk)
                 pi->next_tx_seq = (pi->next_tx_seq + 1) % 64;
 
                 pi->unacked_frames++;
+                pi->frames_sent++;
 
                 if (skb_queue_is_last(TX_QUEUE(sk), skb))
                         sk->sk_send_head = NULL;
@@ -2191,6 +2196,7 @@ static inline void l2cap_ertm_init(struct sock *sk)
         l2cap_pi(sk)->unacked_frames = 0;
         l2cap_pi(sk)->buffer_seq = 0;
         l2cap_pi(sk)->num_to_ack = 0;
+        l2cap_pi(sk)->frames_sent = 0;
 
         setup_timer(&l2cap_pi(sk)->retrans_timer,
                         l2cap_retrans_timeout, (unsigned long) sk);
@@ -3148,6 +3154,38 @@ static int l2cap_check_fcs(struct l2cap_pinfo *pi,  struct sk_buff *skb)
         return 0;
 }
 
+static inline void l2cap_send_i_or_rr_or_rnr(struct sock *sk)
+{
+        struct l2cap_pinfo *pi = l2cap_pi(sk);
+        u16 control = 0;
+
+        pi->frames_sent = 0;
+        pi->conn_state |= L2CAP_CONN_SEND_FBIT;
+
+        control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
+
+        if (pi->conn_state & L2CAP_CONN_LOCAL_BUSY) {
+                control |= L2CAP_SUPER_RCV_NOT_READY | L2CAP_CTRL_FINAL;
+                l2cap_send_sframe(pi, control);
+                pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
+        }
+
+        if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY && pi->unacked_frames > 0)
+                __mod_retrans_timer();
+
+        l2cap_ertm_send(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);
+        }
+}
+
 static void l2cap_add_to_srej_queue(struct sock *sk, struct sk_buff *skb, u8 tx_seq, u8 sar)
 {
         struct sk_buff *next_skb;
@@ -3418,10 +3456,7 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
         switch (rx_control & L2CAP_CTRL_SUPERVISE) {
         case L2CAP_SUPER_RCV_READY:
                 if (rx_control & L2CAP_CTRL_POLL) {
-                        u16 control = L2CAP_CTRL_FINAL;
-                        control |= L2CAP_SUPER_RCV_READY |
-                                (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT);
-                        l2cap_send_sframe(l2cap_pi(sk), control);
+                        l2cap_send_i_or_rr_or_rnr(sk);
                         pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
 
                 } else if (rx_control & L2CAP_CTRL_FINAL) {