Bluetooth: Send SREJ frames when packets go missing

The ERTM specification lays out three scenarios for sending SREJ
frames to request retransmission of specific frames.  l2cap_send_srej
requests all frames up to a given txseq that are not already queued
for reassembly.  l2cap_send_srej_tail only requests the most recent
missing frame.  l2cap_send_srej_list resends SREJ frames for data that
was requested for resend but never received.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This commit is contained in:
Mat Martineau 2012-05-17 20:53:44 -07:00 committed by Johan Hedberg
parent e1fbd4c19a
commit bed68bde7e

View file

@ -2239,17 +2239,67 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
static void l2cap_send_srej(struct l2cap_chan *chan, u16 txseq)
{
/* Placeholder */
struct l2cap_ctrl control;
u16 seq;
BT_DBG("chan %p, txseq %d", chan, txseq);
memset(&control, 0, sizeof(control));
control.sframe = 1;
control.super = L2CAP_SUPER_SREJ;
for (seq = chan->expected_tx_seq; seq != txseq;
seq = __next_seq(chan, seq)) {
if (!l2cap_ertm_seq_in_queue(&chan->srej_q, seq)) {
control.reqseq = seq;
l2cap_send_sframe(chan, &control);
l2cap_seq_list_append(&chan->srej_list, seq);
}
}
chan->expected_tx_seq = __next_seq(chan, txseq);
}
static void l2cap_send_srej_tail(struct l2cap_chan *chan)
{
/* Placeholder */
struct l2cap_ctrl control;
BT_DBG("chan %p", chan);
if (chan->srej_list.tail == L2CAP_SEQ_LIST_CLEAR)
return;
memset(&control, 0, sizeof(control));
control.sframe = 1;
control.super = L2CAP_SUPER_SREJ;
control.reqseq = chan->srej_list.tail;
l2cap_send_sframe(chan, &control);
}
static void l2cap_send_srej_list(struct l2cap_chan *chan, u16 txseq)
{
/* Placeholder */
struct l2cap_ctrl control;
u16 initial_head;
u16 seq;
BT_DBG("chan %p, txseq %d", chan, txseq);
memset(&control, 0, sizeof(control));
control.sframe = 1;
control.super = L2CAP_SUPER_SREJ;
/* Capture initial list head to allow only one pass through the list. */
initial_head = chan->srej_list.head;
do {
seq = l2cap_seq_list_pop(&chan->srej_list);
if (seq == txseq || seq == L2CAP_SEQ_LIST_CLEAR)
break;
control.reqseq = seq;
l2cap_send_sframe(chan, &control);
l2cap_seq_list_append(&chan->srej_list, seq);
} while (chan->srej_list.head != initial_head);
}
static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)