Bluetooth: Handle all cases of receipt of RNR-frames into L2CAP

We weren't handling the receipt under SREJ_SENT state table.
It also introduce l2cap_send_srejtail(). It will be used in the nexts
commits too.

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, 28 insertions, 4 deletions

diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index 068edf7704bf..8937a842347a 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1448,6 +1448,22 @@ static int l2cap_send_ack(struct l2cap_pinfo *pi)
         return 0;
 }
 
+static int l2cap_send_srejtail(struct sock *sk)
+{
+        struct srej_list *tail;
+        u16 control;
+
+        control = L2CAP_SUPER_SELECT_REJECT;
+        control |= L2CAP_CTRL_FINAL;
+
+        tail = list_entry(SREJ_LIST(sk)->prev, struct srej_list, list);
+        control |= tail->tx_seq << L2CAP_CTRL_REQSEQ_SHIFT;
+
+        l2cap_send_sframe(l2cap_pi(sk), control);
+
+        return 0;
+}
+
 static inline int l2cap_skbuff_fromiovec(struct sock *sk, struct msghdr *msg, int len, int count, struct sk_buff *skb)
 {
         struct l2cap_conn *conn = l2cap_pi(sk)->conn;
@@ -3582,11 +3598,19 @@ static inline void l2cap_data_channel_rnrframe(struct sock *sk, u16 rx_control)
         pi->expected_ack_seq = tx_seq;
         l2cap_drop_acked_frames(sk);
 
-        del_timer(&pi->retrans_timer);
-        if (rx_control & L2CAP_CTRL_POLL) {
-                u16 control = L2CAP_CTRL_FINAL;
-                l2cap_send_rr_or_rnr(pi, control);
+        if (!(pi->conn_state & L2CAP_CONN_SREJ_SENT)) {
+                del_timer(&pi->retrans_timer);
+                if (rx_control & L2CAP_CTRL_POLL) {
+                        u16 control = L2CAP_CTRL_FINAL;
+                        l2cap_send_rr_or_rnr(pi, control);
+                }
+                return;
         }
+
+        if (rx_control & L2CAP_CTRL_POLL)
+                l2cap_send_srejtail(sk);
+        else
+                l2cap_send_sframe(pi, L2CAP_SUPER_RCV_READY);
 }
 
 static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, struct sk_buff *skb)