Two new states are required to implement channel moves with the ERTM
receive state machine.
The "WAIT_P" state is used by a move responder to wait for a "poll"
flag after a move is completed (success or failure). "WAIT_F" is
similarly used by a move initiator to wait for a "final" flag when the
move is completing. In either state, the reqseq value in the
poll/final frame tells the state machine exactly which frame should be
expected next.
Signed-off-by: Mat Martineau <mathewm@xxxxxxxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 106 insertions(+)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 649c06b..aab7f79 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -5207,6 +5207,106 @@ static int l2cap_rx_state_srej_sent(struct l2cap_chan *chan,
return err;
}
+static int l2cap_finish_move(struct l2cap_chan *chan)
+{
+ int err = 0;
+
+ BT_DBG("chan %p", chan);
+
+ chan->move_role = L2CAP_MOVE_ROLE_NONE;
+ chan->rx_state = L2CAP_RX_STATE_RECV;
+
+ if (chan->hs_hcon)
+ chan->conn->mtu = chan->hs_hcon->hdev->acl_mtu;
+ else
+ chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
+
+ /* Placeholder - resegment based on new conn->mtu */
+ /*err = l2cap_resegment(chan);*/
+
+ return err;
+}
+
+static int l2cap_rx_state_wait_p(struct l2cap_chan *chan,
+ struct l2cap_ctrl *control,
+ struct sk_buff *skb, u8 event)
+{
+ int err = -EPROTO;
+
+ BT_DBG("chan %p, control %p, skb %p, event %d", chan, control, skb,
+ event);
+
+ if (!control->poll)
+ return err;
+
+ l2cap_process_reqseq(chan, control->reqseq);
+
+ if (!skb_queue_empty(&chan->tx_q))
+ chan->tx_send_head = skb_peek(&chan->tx_q);
+ else
+ chan->tx_send_head = NULL;
+
+ /* Rewind next_tx_seq to the point expected
+ * by the receiver.
+ */
+ chan->next_tx_seq = control->reqseq;
+ chan->unacked_frames = 0;
+
+ err = l2cap_finish_move(chan);
+
+ if (err)
+ return err;
+
+ set_bit(CONN_SEND_FBIT, &chan->conn_state);
+ l2cap_send_i_or_rr_or_rnr(chan);
+
+ if (event == L2CAP_EV_RECV_IFRAME)
+ err = -EPROTO;
+ else
+ err = l2cap_rx_state_recv(chan, control, NULL, event);
+
+ return err;
+}
+
+static int l2cap_rx_state_wait_f(struct l2cap_chan *chan,
+ struct l2cap_ctrl *control,
+ struct sk_buff *skb, u8 event)
+{
+ int err = -EPROTO;
+
+ if (control->final) {
+ clear_bit(CONN_REMOTE_BUSY, &chan->conn_state);
+ chan->move_role = L2CAP_MOVE_ROLE_NONE;
+
+ chan->rx_state = L2CAP_RX_STATE_RECV;
+ l2cap_process_reqseq(chan, control->reqseq);
+
+ if (!skb_queue_empty(&chan->tx_q))
+ chan->tx_send_head = skb_peek(&chan->tx_q);
+ else
+ chan->tx_send_head = NULL;
+
+ /* Rewind next_tx_seq to the point expected
+ * by the receiver.
+ */
+ chan->next_tx_seq = control->reqseq;
+ chan->unacked_frames = 0;
+
+ if (chan->hs_hcon)
+ chan->conn->mtu = chan->hs_hcon->hdev->acl_mtu;
+ else
+ chan->conn->mtu = chan->conn->hcon->hdev->acl_mtu;
+
+ /* Placeholder - resegment based on new conn->mtu */
+ /*err = l2cap_resegment(chan);*/
+
+ if (!err)
+ err = l2cap_rx_state_recv(chan, control, skb, event);
+ }
+
+ return err;
+}
+
static bool __valid_reqseq(struct l2cap_chan *chan, u16 reqseq)
{
/* Make sure reqseq is for a packet that has been sent but not acked */
@@ -5233,6 +5333,12 @@ static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
err = l2cap_rx_state_srej_sent(chan, control, skb,
event);
break;
+ case L2CAP_RX_STATE_WAIT_P:
+ err = l2cap_rx_state_wait_p(chan, control, skb, event);
+ break;
+ case L2CAP_RX_STATE_WAIT_F:
+ err = l2cap_rx_state_wait_f(chan, control, skb, event);
+ break;
default:
/* shut it down */
break;
--
1.7.12.3
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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