Bluetooth: Refactor l2cap_retransmit_frame()

Make the code flow cleaner and changes the function to void.
It also fixes a potential NULL dereference with skb.

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 7e74d5b..1c35c32 100644 (file)
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -1331,43 +1331,44 @@ static int l2cap_streaming_send(struct sock *sk)
        return 0;
 }
 
-static int l2cap_retransmit_frame(struct sock *sk, u8 tx_seq)
+static void l2cap_retransmit_frame(struct sock *sk, u8 tx_seq)
 {
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        struct sk_buff *skb, *tx_skb;
        u16 control, fcs;
 
        skb = skb_peek(TX_QUEUE(sk));
-       do {
-               if (bt_cb(skb)->tx_seq != tx_seq) {
-                       if (skb_queue_is_last(TX_QUEUE(sk), skb))
-                               break;
-                       skb = skb_queue_next(TX_QUEUE(sk), skb);
-                       continue;
-               }
+       if (!skb)
+               return;
 
-               if (pi->remote_max_tx &&
-                               bt_cb(skb)->retries == pi->remote_max_tx) {
-                       l2cap_send_disconn_req(pi->conn, sk);
+       do {
+               if (bt_cb(skb)->tx_seq == tx_seq)
                        break;
-               }
 
-               tx_skb = skb_clone(skb, GFP_ATOMIC);
-               bt_cb(skb)->retries++;
-               control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
-               control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT)
-                               | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
-               put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
+               if (skb_queue_is_last(TX_QUEUE(sk), skb))
+                       return;
 
-               if (pi->fcs == L2CAP_FCS_CRC16) {
-                       fcs = crc16(0, (u8 *)tx_skb->data, tx_skb->len - 2);
-                       put_unaligned_le16(fcs, tx_skb->data + tx_skb->len - 2);
-               }
+       } while ((skb = skb_queue_next(TX_QUEUE(sk), skb)));
 
-               l2cap_do_send(sk, tx_skb);
-               break;
-       } while(1);
-       return 0;
+       if (pi->remote_max_tx &&
+                       bt_cb(skb)->retries == pi->remote_max_tx) {
+               l2cap_send_disconn_req(pi->conn, sk);
+               return;
+       }
+
+       tx_skb = skb_clone(skb, GFP_ATOMIC);
+       bt_cb(skb)->retries++;
+       control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+       control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT)
+                       | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
+       put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
+
+       if (pi->fcs == L2CAP_FCS_CRC16) {
+               fcs = crc16(0, (u8 *)tx_skb->data, tx_skb->len - 2);
+               put_unaligned_le16(fcs, tx_skb->data + tx_skb->len - 2);
+       }
+
+       l2cap_do_send(sk, tx_skb);
 }
 
 static int l2cap_ertm_send(struct sock *sk)