From 9f121a5a80b4417c6db5a35e26d2e79c29c3fc0d Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:38 -0300 Subject: [PATCH] Bluetooth: Fix sending ReqSeq on I-frames As specified by ERTM spec an ERTM channel can acknowledge received I-frames(the data frames) by sending an I-frame with the proper ReqSeq value (i.e. ReqSeq is set to BufferSeq). Until now we aren't setting the ReqSeq value on I-frame control bits. That way we can save sending S-frames(Supervise frames) only to acknowledge receipt of I-frames. It is very helpful to the full-duplex channel. ReqSeq is the packet sequence number sent in an acknowledgement frame to acknowledge receipt of frames up to (ReqSeq - 1). BufferSeq controls the receiver buffer, it is used to delay acknowledgement of new frames to not cause buffer overflow. BufferSeq value is not increased until frames are pulled by reassembly function. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- include/net/bluetooth/l2cap.h | 1 - net/bluetooth/l2cap.c | 8 ++++++-- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h index 9516f4b..327eb57 100644 --- a/include/net/bluetooth/l2cap.h +++ b/include/net/bluetooth/l2cap.h @@ -324,7 +324,6 @@ struct l2cap_pinfo { __u8 next_tx_seq; __u8 expected_ack_seq; - __u8 req_seq; __u8 expected_tx_seq; __u8 buffer_seq; __u8 buffer_seq_srej; diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 2d5d375..78ab881 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -1333,7 +1333,7 @@ static int l2cap_retransmit_frame(struct sock *sk, u8 tx_seq) tx_skb = skb_clone(skb, GFP_ATOMIC); bt_cb(skb)->retries++; control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE); - control |= (pi->req_seq << L2CAP_CTRL_REQSEQ_SHIFT) + control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT) | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT); put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE); @@ -1375,7 +1375,7 @@ static int l2cap_ertm_send(struct sock *sk) bt_cb(skb)->retries++; control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE); - control |= (pi->req_seq << L2CAP_CTRL_REQSEQ_SHIFT) + control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT) | (pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT); put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE); @@ -3298,12 +3298,16 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str { struct l2cap_pinfo *pi = l2cap_pi(sk); u8 tx_seq = __get_txseq(rx_control); + u8 req_seq = __get_reqseq(rx_control); u16 tx_control = 0; u8 sar = rx_control >> L2CAP_CTRL_SAR_SHIFT; int err = 0; BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len); + pi->expected_ack_seq = req_seq; + l2cap_drop_acked_frames(sk); + if (tx_seq == pi->expected_tx_seq) goto expected; -- 2.7.4