Creates a new l2cap_data_rcv function that combines previous code from
l2cap_ertm_data_rcv and l2cap_data_channel. This reduces duplicate
code for streaming mode, and sets up a framework for the ERTM receive
state machine.
Signed-off-by: Mat Martineau <mathewm@xxxxxxxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 126 ++++++++++++++++++++++----------------------
1 file changed, 62 insertions(+), 64 deletions(-)
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index fd645ff..3f6bec9 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -789,9 +789,11 @@ static inline void __unpack_control(struct l2cap_chan *chan,
if (test_bit(FLAG_EXT_CTRL, &chan->flags)) {
__unpack_extended_control(get_unaligned_le32(skb->data),
&bt_cb(skb)->control);
+ skb_pull(skb, L2CAP_EXT_CTRL_SIZE);
} else {
__unpack_enhanced_control(get_unaligned_le16(skb->data),
&bt_cb(skb)->control);
+ skb_pull(skb, L2CAP_ENH_CTRL_SIZE);
}
}
@@ -4817,27 +4819,39 @@ static inline int l2cap_data_channel_sframe(struct l2cap_chan *chan, u32 rx_cont
return 0;
}
-static int l2cap_ertm_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
+static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+ struct sk_buff *skb, u8 event)
{
- u32 control;
- u16 req_seq;
- int len, next_tx_seq_offset, req_seq_offset;
+ /* Placeholder */
+ return -ENOTSUPP;
+}
+
+static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
+ struct sk_buff *skb)
+{
+ /* Placeholder */
+ return -ENOTSUPP;
+}
+
+static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
+{
+ struct l2cap_ctrl *control = &bt_cb(skb)->control;
+ u16 len;
+ u8 event;
__unpack_control(chan, skb);
- control = __get_control(chan, skb->data);
- skb_pull(skb, __ctrl_size(chan));
len = skb->len;
/*
* We can just drop the corrupted I-frame here.
* Receiver will miss it and start proper recovery
- * procedures and ask retransmission.
+ * procedures and ask for retransmission.
*/
if (l2cap_check_fcs(chan, skb))
goto drop;
- if (__is_sar_start(chan, control) && !__is_sframe(chan, control))
+ if (!control->sframe && control->sar == L2CAP_SAR_START)
len -= L2CAP_SDULEN_SIZE;
if (chan->fcs == L2CAP_FCS_CRC16)
@@ -4848,34 +4862,57 @@ static int l2cap_ertm_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
goto drop;
}
- req_seq = __get_reqseq(chan, control);
+ if (!control->sframe) {
+ int err;
- req_seq_offset = __seq_offset(chan, req_seq, chan->expected_ack_seq);
+ BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d",
+ control->sar, control->reqseq, control->final,
+ control->txseq);
- next_tx_seq_offset = __seq_offset(chan, chan->next_tx_seq,
- chan->expected_ack_seq);
-
- /* check for invalid req-seq */
- if (req_seq_offset > next_tx_seq_offset) {
- l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
- goto drop;
- }
-
- if (!__is_sframe(chan, control)) {
- if (len < 0) {
- l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
+ /* Validate F-bit - F=0 always valid, F=1 only
+ * valid in TX WAIT_F
+ */
+ if (control->final && chan->tx_state != L2CAP_TX_STATE_WAIT_F)
goto drop;
+
+ if (chan->mode != L2CAP_MODE_STREAMING) {
+ event = L2CAP_EV_RECV_IFRAME;
+ err = l2cap_rx(chan, control, skb, event);
+ } else {
+ err = l2cap_stream_rx(chan, control, skb);
}
- l2cap_data_channel_iframe(chan, control, skb);
+ if (err)
+ l2cap_send_disconn_req(chan->conn, chan,
+ ECONNRESET);
} else {
+ const u8 rx_func_to_event[4] = {
+ L2CAP_EV_RECV_RR, L2CAP_EV_RECV_REJ,
+ L2CAP_EV_RECV_RNR, L2CAP_EV_RECV_SREJ
+ };
+
+ /* Only I-frames are expected in streaming mode */
+ if (chan->mode == L2CAP_MODE_STREAMING)
+ goto drop;
+
+ BT_DBG("sframe reqseq %d, final %d, poll %d, super %d",
+ control->reqseq, control->final, control->poll,
+ control->super);
+
if (len != 0) {
BT_ERR("%d", len);
l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
goto drop;
}
- l2cap_data_channel_sframe(chan, control, skb);
+ /* Validate F and P bits */
+ if (control->final && (control->poll ||
+ chan->tx_state != L2CAP_TX_STATE_WAIT_F))
+ goto drop;
+
+ event = rx_func_to_event[control->super];
+ if (l2cap_rx(chan, control, skb, event))
+ l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
}
return 0;
@@ -4888,9 +4925,6 @@ drop:
static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
{
struct l2cap_chan *chan;
- u32 control;
- u16 tx_seq;
- int len;
chan = l2cap_get_chan_by_scid(conn, cid);
if (!chan) {
@@ -4920,44 +4954,8 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
break;
case L2CAP_MODE_ERTM:
- l2cap_ertm_data_rcv(chan, skb);
-
- goto done;
-
case L2CAP_MODE_STREAMING:
- control = __get_control(chan, skb->data);
- skb_pull(skb, __ctrl_size(chan));
- len = skb->len;
-
- if (l2cap_check_fcs(chan, skb))
- goto drop;
-
- if (__is_sar_start(chan, control))
- len -= L2CAP_SDULEN_SIZE;
-
- if (chan->fcs == L2CAP_FCS_CRC16)
- len -= L2CAP_FCS_SIZE;
-
- if (len > chan->mps || len < 0 || __is_sframe(chan, control))
- goto drop;
-
- tx_seq = __get_txseq(chan, control);
-
- if (chan->expected_tx_seq != tx_seq) {
- /* Frame(s) missing - must discard partial SDU */
- kfree_skb(chan->sdu);
- chan->sdu = NULL;
- chan->sdu_last_frag = NULL;
- chan->sdu_len = 0;
-
- /* TODO: Notify userland of missing data */
- }
-
- chan->expected_tx_seq = __next_seq(chan, tx_seq);
-
- if (l2cap_reassemble_sdu(chan, skb, control) == -EMSGSIZE)
- l2cap_send_disconn_req(chan->conn, chan, ECONNRESET);
-
+ l2cap_data_rcv(chan, skb);
goto done;
default:
--
1.7.10
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum
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