From: Mat Martineau <mathewm@codeaurora.org>
To: linux-bluetooth@vger.kernel.org, gustavo@padovan.org,
marcel@holtmann.org, ulisses@profusion.mobi
Cc: pkrystad@codeaurora.org
Subject: [PATCH 02/25] Bluetooth: Add a new L2CAP ERTM transmit state machine.
Date: Thu, 17 May 2012 20:53:32 -0700 [thread overview]
Message-ID: <1337313235-26535-3-git-send-email-mathewm@codeaurora.org> (raw)
In-Reply-To: <1337313235-26535-1-git-send-email-mathewm@codeaurora.org>
This implements a top-level transmit state machine with handlers for
the two ERTM states defined in the specification: XMIT and WAIT_F.
The state machine accepts an event and, optionally, a list of skbs to
transmit. In addition to data transmission, the local busy state can
be modified, acks are processed, and monitor and retransmit timeouts
are handled. This mirrors the structure of the state tables in the
spec.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
---
net/bluetooth/l2cap_core.c | 254 ++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 246 insertions(+), 8 deletions(-)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 6557367..a131403 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -73,6 +73,9 @@ static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data);
static void l2cap_send_disconn_req(struct l2cap_conn *conn,
struct l2cap_chan *chan, int err);
+static int l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+ struct sk_buff_head *skbs, u8 event);
+
/* ---- L2CAP channels ---- */
static struct l2cap_chan *__l2cap_get_chan_by_dcid(struct l2cap_conn *conn, u16 cid)
@@ -224,6 +227,19 @@ static inline void l2cap_chan_set_err(struct l2cap_chan *chan, int err)
release_sock(sk);
}
+static struct sk_buff *l2cap_ertm_seq_in_queue(struct sk_buff_head *head,
+ u16 seq)
+{
+ struct sk_buff *skb;
+
+ skb_queue_walk(head, skb) {
+ if (bt_cb(skb)->control.txseq == seq)
+ return skb;
+ }
+
+ return NULL;
+}
+
/* ---- L2CAP sequence number lists ---- */
/* For ERTM, ordered lists of sequence numbers must be tracked for
@@ -2117,16 +2133,15 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
if (err)
break;
- if (chan->mode == L2CAP_MODE_ERTM && chan->tx_send_head == NULL)
- chan->tx_send_head = seg_queue.next;
- skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
-
- if (chan->mode == L2CAP_MODE_ERTM)
- err = l2cap_ertm_send(chan);
- else
+ if (chan->mode == L2CAP_MODE_ERTM) {
+ err = l2cap_tx(chan, 0, &seg_queue,
+ L2CAP_EV_DATA_REQUEST);
+ } else {
+ skb_queue_splice_tail_init(&seg_queue, &chan->tx_q);
l2cap_streaming_send(chan);
+ }
- if (err >= 0)
+ if (!err)
err = len;
/* If the skbs were not queued for sending, they'll still be in
@@ -2143,6 +2158,229 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
return err;
}
+static void l2cap_process_reqseq(struct l2cap_chan *chan, u16 reqseq)
+{
+ struct sk_buff *acked_skb;
+ u16 ackseq;
+
+ BT_DBG("chan %p, reqseq %d", chan, reqseq);
+
+ if (chan->unacked_frames == 0 || reqseq == chan->expected_ack_seq)
+ return;
+
+ BT_DBG("expected_ack_seq %d, unacked_frames %d",
+ chan->expected_ack_seq, chan->unacked_frames);
+
+ for (ackseq = chan->expected_ack_seq; ackseq != reqseq;
+ ackseq = __next_seq(chan, ackseq)) {
+
+ acked_skb = l2cap_ertm_seq_in_queue(&chan->tx_q, ackseq);
+ if (acked_skb) {
+ skb_unlink(acked_skb, &chan->tx_q);
+ kfree_skb(acked_skb);
+ chan->unacked_frames--;
+ }
+ }
+
+ chan->expected_ack_seq = reqseq;
+
+ if (chan->unacked_frames == 0)
+ __clear_retrans_timer(chan);
+
+ BT_DBG("unacked_frames %d", (int) chan->unacked_frames);
+}
+
+static void l2cap_abort_rx_srej_sent(struct l2cap_chan *chan)
+{
+ BT_DBG("chan %p", chan);
+
+ chan->expected_tx_seq = chan->buffer_seq;
+ l2cap_seq_list_clear(&chan->srej_list);
+ skb_queue_purge(&chan->srej_q);
+ chan->rx_state = L2CAP_RX_STATE_RECV;
+}
+
+static int l2cap_tx_state_xmit(struct l2cap_chan *chan,
+ struct l2cap_ctrl *control,
+ struct sk_buff_head *skbs, u8 event)
+{
+ int err = 0;
+
+ BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
+ event);
+
+ switch (event) {
+ case L2CAP_EV_DATA_REQUEST:
+ if (chan->tx_send_head == NULL)
+ chan->tx_send_head = skb_peek(skbs);
+
+ skb_queue_splice_tail_init(skbs, &chan->tx_q);
+ l2cap_ertm_send(chan);
+ break;
+ case L2CAP_EV_LOCAL_BUSY_DETECTED:
+ BT_DBG("Enter LOCAL_BUSY");
+ set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+ if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
+ /* The SREJ_SENT state must be aborted if we are to
+ * enter the LOCAL_BUSY state.
+ */
+ l2cap_abort_rx_srej_sent(chan);
+ }
+
+ l2cap_send_ack(chan);
+
+ break;
+ case L2CAP_EV_LOCAL_BUSY_CLEAR:
+ BT_DBG("Exit LOCAL_BUSY");
+ clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+ if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
+ struct l2cap_ctrl local_control;
+
+ memset(&local_control, 0, sizeof(local_control));
+ local_control.sframe = 1;
+ local_control.super = L2CAP_SUPER_RR;
+ local_control.poll = 1;
+ local_control.reqseq = chan->buffer_seq;
+ l2cap_send_sframe(chan, 0);
+
+ chan->retry_count = 1;
+ __set_monitor_timer(chan);
+ chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+ }
+ break;
+ case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
+ l2cap_process_reqseq(chan, control->reqseq);
+ break;
+ case L2CAP_EV_EXPLICIT_POLL:
+ l2cap_send_rr_or_rnr(chan, 1);
+ chan->retry_count = 1;
+ __set_monitor_timer(chan);
+ __clear_ack_timer(chan);
+ chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+ break;
+ case L2CAP_EV_RETRANS_TO:
+ l2cap_send_rr_or_rnr(chan, 1);
+ chan->retry_count = 1;
+ __set_monitor_timer(chan);
+ chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+ break;
+ case L2CAP_EV_RECV_FBIT:
+ /* Nothing to process */
+ break;
+ default:
+ break;
+ }
+
+ return err;
+}
+
+static int l2cap_tx_state_wait_f(struct l2cap_chan *chan,
+ struct l2cap_ctrl *control,
+ struct sk_buff_head *skbs, u8 event)
+{
+ int err = 0;
+
+ BT_DBG("chan %p, control %p, skbs %p, event %d", chan, control, skbs,
+ event);
+
+ switch (event) {
+ case L2CAP_EV_DATA_REQUEST:
+ if (chan->tx_send_head == NULL)
+ chan->tx_send_head = skb_peek(skbs);
+ /* Queue data, but don't send. */
+ skb_queue_splice_tail_init(skbs, &chan->tx_q);
+ break;
+ case L2CAP_EV_LOCAL_BUSY_DETECTED:
+ BT_DBG("Enter LOCAL_BUSY");
+ set_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+ if (chan->rx_state == L2CAP_RX_STATE_SREJ_SENT) {
+ /* The SREJ_SENT state must be aborted if we are to
+ * enter the LOCAL_BUSY state.
+ */
+ l2cap_abort_rx_srej_sent(chan);
+ }
+
+ l2cap_send_ack(chan);
+
+ break;
+ case L2CAP_EV_LOCAL_BUSY_CLEAR:
+ BT_DBG("Exit LOCAL_BUSY");
+ clear_bit(CONN_LOCAL_BUSY, &chan->conn_state);
+
+ if (test_bit(CONN_RNR_SENT, &chan->conn_state)) {
+ struct l2cap_ctrl local_control;
+ memset(&local_control, 0, sizeof(local_control));
+ local_control.sframe = 1;
+ local_control.super = L2CAP_SUPER_RR;
+ local_control.poll = 1;
+ local_control.reqseq = chan->buffer_seq;
+ l2cap_send_sframe(chan, 0);
+
+ chan->retry_count = 1;
+ __set_monitor_timer(chan);
+ chan->tx_state = L2CAP_TX_STATE_WAIT_F;
+ }
+ break;
+ case L2CAP_EV_RECV_REQSEQ_AND_FBIT:
+ l2cap_process_reqseq(chan, control->reqseq);
+
+ /* Fall through */
+
+ case L2CAP_EV_RECV_FBIT:
+ if (control && control->final) {
+ __clear_monitor_timer(chan);
+ if (chan->unacked_frames > 0)
+ __set_retrans_timer(chan);
+ chan->retry_count = 0;
+ chan->tx_state = L2CAP_TX_STATE_XMIT;
+ BT_DBG("recv fbit tx_state 0x2.2%x", chan->tx_state);
+ }
+ break;
+ case L2CAP_EV_EXPLICIT_POLL:
+ /* Ignore */
+ break;
+ case L2CAP_EV_MONITOR_TO:
+ if (chan->max_tx == 0 || chan->retry_count < chan->max_tx) {
+ l2cap_send_rr_or_rnr(chan, 1);
+ __set_monitor_timer(chan);
+ chan->retry_count++;
+ } else {
+ l2cap_send_disconn_req(chan->conn, chan, ECONNABORTED);
+ }
+ break;
+ default:
+ break;
+ }
+
+ return err;
+}
+
+static int l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+ struct sk_buff_head *skbs, u8 event)
+{
+ int err = 0;
+
+ BT_DBG("chan %p, control %p, skbs %p, event %d, state %d",
+ chan, control, skbs, event, chan->tx_state);
+
+ switch (chan->tx_state) {
+ case L2CAP_TX_STATE_XMIT:
+ err = l2cap_tx_state_xmit(chan, control, skbs, event);
+ break;
+ case L2CAP_TX_STATE_WAIT_F:
+ err = l2cap_tx_state_wait_f(chan, control, skbs, event);
+ break;
+ default:
+ /* Ignore event */
+ break;
+ }
+
+ return err;
+}
+
/* Copy frame to all raw sockets on that connection */
static void l2cap_raw_recv(struct l2cap_conn *conn, struct sk_buff *skb)
{
--
1.7.10
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
next prev parent reply other threads:[~2012-05-18 3:53 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-18 3:53 [PATCH 00/25] ERTM state machine changes, part 3 Mat Martineau
2012-05-18 3:53 ` [PATCH 01/25] Bluetooth: Change default state of ERTM disable flag Mat Martineau
2012-05-18 3:53 ` Mat Martineau [this message]
2012-05-18 19:54 ` [PATCH 02/25] Bluetooth: Add a new L2CAP ERTM transmit state machine Gustavo Padovan
2012-05-18 20:19 ` Mat Martineau
2012-05-18 3:53 ` [PATCH 03/25] Bluetooth: Refactor l2cap_streaming_send Mat Martineau
2012-05-18 3:53 ` [PATCH 04/25] Bluetooth: Refactor l2cap_ertm_send Mat Martineau
2012-05-18 3:53 ` [PATCH 05/25] Bluetooth: Refactor l2cap_send_sframe Mat Martineau
2012-05-18 3:53 ` [PATCH 06/25] Bluetooth: Consolidate common receive code for ERTM and streaming mode Mat Martineau
2012-05-18 3:53 ` [PATCH 07/25] Bluetooth: Add streaming mode receive and incoming packet classifier Mat Martineau
2012-05-18 3:53 ` [PATCH 08/25] Bluetooth: Remove receive code that has been superceded Mat Martineau
2012-05-18 3:53 ` [PATCH 09/25] Bluetooth: Refactor l2cap_send_ack Mat Martineau
2012-05-18 3:53 ` [PATCH 10/25] Bluetooth: Use the transmit state machine for busy state changes Mat Martineau
2012-05-18 3:53 ` [PATCH 11/25] Bluetooth: Update l2cap_send_i_or_rr_or_rnr to fit the spec better Mat Martineau
2012-05-18 3:53 ` [PATCH 12/25] Bluetooth: Add the ERTM receive state machine Mat Martineau
2012-05-18 3:53 ` [PATCH 13/25] Bluetooth: Add implementation for retransmitting all unacked frames Mat Martineau
2012-05-18 3:53 ` [PATCH 14/25] Bluetooth: Send SREJ frames when packets go missing Mat Martineau
2012-05-18 3:53 ` [PATCH 15/25] Bluetooth: Reassemble all available data when retransmissions succeed Mat Martineau
2012-05-18 3:53 ` [PATCH 16/25] Bluetooth: Handle SREJ requests to resend unacked frames Mat Martineau
2012-05-18 3:53 ` [PATCH 17/25] Bluetooth: Handle incoming REJ frames Mat Martineau
2012-05-18 3:53 ` [PATCH 18/25] Bluetooth: Use new header structures in l2cap_send_rr_or_rnr Mat Martineau
2012-05-18 3:53 ` [PATCH 19/25] Bluetooth: Check rules when setting retransmit or monitor timers Mat Martineau
2012-05-18 3:53 ` [PATCH 20/25] Bluetooth: Use the ERTM transmit state machine from timeout handlers Mat Martineau
2012-05-18 3:53 ` [PATCH 21/25] Bluetooth: Simplify the ERTM ack timeout Mat Martineau
2012-05-18 3:53 ` [PATCH 22/25] Bluetooth: Remove unneccesary inline Mat Martineau
2012-05-18 3:53 ` [PATCH 23/25] Bluetooth: Set txwin values for streaming mode Mat Martineau
2012-05-18 3:53 ` [PATCH 24/25] Bluetooth: Remove unused ERTM control field macros Mat Martineau
2012-05-18 3:53 ` [PATCH 25/25] Bluetooth: Enable ERTM by default Mat Martineau
2012-05-18 20:56 ` Gustavo Padovan
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