Bluetooth: Refactor l2cap_ertm_send
The new implementation is aware of the new transmit state machine, and
uses struct l2cap_ctrl to compose ERTM headers. It also has improved
error handling for allocation failures, and does not send the packet
until after all skb and channel data structures are updated.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 25edccf..429a67e 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -1741,9 +1741,10 @@
static int l2cap_ertm_send(struct l2cap_chan *chan)
{
struct sk_buff *skb, *tx_skb;
- u16 fcs;
- u32 control;
- int nsent = 0;
+ struct l2cap_ctrl *control;
+ int sent = 0;
+
+ BT_DBG("chan %p", chan);
if (chan->state != BT_CONNECTED)
return -ENOTCONN;
@@ -1751,61 +1752,57 @@
if (test_bit(CONN_REMOTE_BUSY, &chan->conn_state))
return 0;
- while ((skb = chan->tx_send_head) && (!l2cap_tx_window_full(chan))) {
+ while (chan->tx_send_head &&
+ chan->unacked_frames < chan->remote_tx_win &&
+ chan->tx_state == L2CAP_TX_STATE_XMIT) {
- if (bt_cb(skb)->control.retries == chan->remote_max_tx &&
- chan->remote_max_tx) {
- l2cap_send_disconn_req(chan->conn, chan, ECONNABORTED);
- break;
- }
+ skb = chan->tx_send_head;
- tx_skb = skb_clone(skb, GFP_ATOMIC);
-
- bt_cb(skb)->control.retries++;
-
- control = __get_control(chan, tx_skb->data + L2CAP_HDR_SIZE);
- control &= __get_sar_mask(chan);
+ bt_cb(skb)->control.retries = 1;
+ control = &bt_cb(skb)->control;
if (test_and_clear_bit(CONN_SEND_FBIT, &chan->conn_state))
- control |= __set_ctrl_final(chan);
+ control->final = 1;
- control |= __set_reqseq(chan, chan->buffer_seq);
- control |= __set_txseq(chan, chan->next_tx_seq);
- control |= __set_ctrl_sar(chan, bt_cb(skb)->control.sar);
+ control->reqseq = chan->buffer_seq;
+ chan->last_acked_seq = chan->buffer_seq;
+ control->txseq = chan->next_tx_seq;
- __put_control(chan, control, tx_skb->data + L2CAP_HDR_SIZE);
+ __pack_control(chan, control, skb);
if (chan->fcs == L2CAP_FCS_CRC16) {
- fcs = crc16(0, (u8 *)skb->data,
- tx_skb->len - L2CAP_FCS_SIZE);
- put_unaligned_le16(fcs, skb->data +
- tx_skb->len - L2CAP_FCS_SIZE);
+ u16 fcs = crc16(0, (u8 *) skb->data, skb->len);
+ put_unaligned_le16(fcs, skb_put(skb, L2CAP_FCS_SIZE));
}
- l2cap_do_send(chan, tx_skb);
+ /* Clone after data has been modified. Data is assumed to be
+ read-only (for locking purposes) on cloned sk_buffs.
+ */
+ tx_skb = skb_clone(skb, GFP_KERNEL);
+
+ if (!tx_skb)
+ break;
__set_retrans_timer(chan);
- bt_cb(skb)->control.txseq = chan->next_tx_seq;
-
chan->next_tx_seq = __next_seq(chan, chan->next_tx_seq);
-
- if (bt_cb(skb)->control.retries == 1) {
- chan->unacked_frames++;
-
- if (!nsent++)
- __clear_ack_timer(chan);
- }
-
+ chan->unacked_frames++;
chan->frames_sent++;
+ sent++;
if (skb_queue_is_last(&chan->tx_q, skb))
chan->tx_send_head = NULL;
else
chan->tx_send_head = skb_queue_next(&chan->tx_q, skb);
+
+ l2cap_do_send(chan, tx_skb);
+ BT_DBG("Sent txseq %d", (int)control->txseq);
}
- return nsent;
+ BT_DBG("Sent %d, %d unacked, %d in ERTM queue", sent,
+ (int) chan->unacked_frames, skb_queue_len(&chan->tx_q));
+
+ return sent;
}
static int l2cap_retransmit_frames(struct l2cap_chan *chan)
@@ -2009,7 +2006,11 @@
lh->cid = cpu_to_le16(chan->dcid);
lh->len = cpu_to_le16(len + (hlen - L2CAP_HDR_SIZE));
- __put_control(chan, 0, skb_put(skb, __ctrl_size(chan)));
+ /* Control header is populated later */
+ if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+ put_unaligned_le32(0, skb_put(skb, L2CAP_EXT_CTRL_SIZE));
+ else
+ put_unaligned_le16(0, skb_put(skb, L2CAP_ENH_CTRL_SIZE));
if (sdulen)
put_unaligned_le16(sdulen, skb_put(skb, L2CAP_SDULEN_SIZE));
@@ -2020,9 +2021,7 @@
return ERR_PTR(err);
}
- if (chan->fcs == L2CAP_FCS_CRC16)
- put_unaligned_le16(0, skb_put(skb, L2CAP_FCS_SIZE));
-
+ bt_cb(skb)->control.fcs = chan->fcs;
bt_cb(skb)->control.retries = 0;
return skb;
}
