diff options
| author | Gustavo F. Padovan <gustavo@las.ic.unicamp.br> | 2009-08-21 03:25:59 +0200 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2009-08-22 23:55:20 +0200 |
| commit | 30afb5b2aa83adf4f69e5090d48e1bb04b64c58a (patch) | |
| tree | f47506c5f02b8e1d23123cadee49f518c928afa5 /net/bluetooth | |
| parent | Bluetooth: Add support for Segmentation and Reassembly of SDUs (diff) | |
| download | linux-30afb5b2aa83adf4f69e5090d48e1bb04b64c58a.tar.xz linux-30afb5b2aa83adf4f69e5090d48e1bb04b64c58a.zip | |
Bluetooth: Initial support for retransmission of packets with REJ frames
When receiving an I-frame with unexpected txSeq, receiver side start the
recovery procedure by sending a REJ S-frame to the transmitter side. So
the transmitter can re-send the lost I-frame.
This patch just adds a basic support for retransmission, it doesn't
mean that ERTM now has full support for packet retransmission.
Signed-off-by: Gustavo F. Padovan <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth')
| -rw-r--r-- | net/bluetooth/l2cap.c | 57 |
1 files changed, 43 insertions, 14 deletions
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 167e02532697..35e9f5b80545 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -2951,22 +2951,36 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len); - if (tx_seq != pi->expected_tx_seq) - return -EINVAL; + if (tx_seq == pi->expected_tx_seq) { + if (pi->conn_state & L2CAP_CONN_UNDER_REJ) + pi->conn_state &= ~L2CAP_CONN_UNDER_REJ; - err = l2cap_sar_reassembly_sdu(sk, skb, rx_control); - if (err < 0) - return err; + err = l2cap_sar_reassembly_sdu(sk, skb, rx_control); + if (err < 0) + return err; + + pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64; + pi->num_to_ack = (pi->num_to_ack + 1) % L2CAP_DEFAULT_NUM_TO_ACK; + if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1) { + tx_control |= L2CAP_SUPER_RCV_READY; + tx_control |= pi->expected_tx_seq << L2CAP_CTRL_REQSEQ_SHIFT; + goto send; + } + } else { + /* Unexpected txSeq. Send a REJ S-frame */ + kfree_skb(skb); + if (!(pi->conn_state & L2CAP_CONN_UNDER_REJ)) { + tx_control |= L2CAP_SUPER_REJECT; + tx_control |= pi->expected_tx_seq << L2CAP_CTRL_REQSEQ_SHIFT; + pi->conn_state |= L2CAP_CONN_UNDER_REJ; - pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64; - pi->num_to_ack = (pi->num_to_ack + 1) % L2CAP_DEFAULT_NUM_TO_ACK; - if (pi->num_to_ack == L2CAP_DEFAULT_NUM_TO_ACK - 1) { - tx_control |= L2CAP_CTRL_FRAME_TYPE; - tx_control |= L2CAP_SUPER_RCV_READY; - tx_control |= pi->expected_tx_seq << L2CAP_CTRL_REQSEQ_SHIFT; - err = l2cap_send_sframe(pi, tx_control); + goto send; + } } - return err; + return 0; + +send: + return l2cap_send_sframe(pi, tx_control); } static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, struct sk_buff *skb) @@ -2982,8 +2996,18 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str l2cap_ertm_send(sk); break; - case L2CAP_SUPER_RCV_NOT_READY: case L2CAP_SUPER_REJECT: + pi->expected_ack_seq = __get_reqseq(rx_control); + l2cap_drop_acked_frames(sk); + + sk->sk_send_head = TX_QUEUE(sk)->next; + pi->next_tx_seq = pi->expected_ack_seq; + + l2cap_ertm_send(sk); + + break; + + case L2CAP_SUPER_RCV_NOT_READY: case L2CAP_SUPER_SELECT_REJECT: break; } @@ -3030,6 +3054,11 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk if (__is_sar_start(control)) len -= 2; + /* + * We can just drop the corrupted I-frame here. + * Receiver will miss it and start proper recovery + * procedures and ask retransmission. + */ if (len > L2CAP_DEFAULT_MAX_PDU_SIZE) goto drop; |