From 8f17154f1f70fcc6faa31ac82164fcf7f0599f38 Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Thu, 20 Aug 2009 22:26:03 -0300 Subject: Bluetooth: Add support for L2CAP SREJ exception When L2CAP loses an I-frame we send a SREJ frame to the transmitter side requesting the lost packet. This patch implement all Recv I-frame events on SREJ_SENT state table except the ones that deal with SendRej (the REJ exception at receiver side is yet not implemented). Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 220 ++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 196 insertions(+), 24 deletions(-) (limited to 'net') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 4c31900..70aff92 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -1292,6 +1292,50 @@ static int l2cap_streaming_send(struct sock *sk) return 0; } +static int l2cap_retransmit_frame(struct sock *sk, u8 tx_seq) +{ + struct l2cap_pinfo *pi = l2cap_pi(sk); + struct sk_buff *skb, *tx_skb; + u16 control, fcs; + int err; + + skb = skb_peek(TX_QUEUE(sk)); + do { + if (bt_cb(skb)->tx_seq != tx_seq) { + if (skb_queue_is_last(TX_QUEUE(sk), skb)) + break; + skb = skb_queue_next(TX_QUEUE(sk), skb); + continue; + } + + if (pi->remote_max_tx && + bt_cb(skb)->retries == pi->remote_max_tx) { + l2cap_send_disconn_req(pi->conn, sk); + break; + } + + 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) + | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT); + put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE); + + if (l2cap_pi(sk)->fcs == L2CAP_FCS_CRC16) { + fcs = crc16(0, (u8 *)tx_skb->data, tx_skb->len - 2); + put_unaligned_le16(fcs, tx_skb->data + tx_skb->len - 2); + } + + err = l2cap_do_send(sk, tx_skb); + if (err < 0) { + l2cap_send_disconn_req(pi->conn, sk); + return err; + } + break; + } while(1); + return 0; +} + static int l2cap_ertm_send(struct sock *sk) { struct sk_buff *skb, *tx_skb; @@ -2705,6 +2749,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr l2cap_monitor_timeout, (unsigned long) sk); __skb_queue_head_init(TX_QUEUE(sk)); + __skb_queue_head_init(SREJ_QUEUE(sk)); l2cap_chan_ready(sk); goto unlock; } @@ -2784,8 +2829,10 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr sk->sk_state = BT_CONNECTED; l2cap_pi(sk)->expected_tx_seq = 0; + l2cap_pi(sk)->buffer_seq = 0; l2cap_pi(sk)->num_to_ack = 0; __skb_queue_head_init(TX_QUEUE(sk)); + __skb_queue_head_init(SREJ_QUEUE(sk)); l2cap_chan_ready(sk); } @@ -2817,6 +2864,7 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd sk->sk_shutdown = SHUTDOWN_MASK; skb_queue_purge(TX_QUEUE(sk)); + skb_queue_purge(SREJ_QUEUE(sk)); del_timer(&l2cap_pi(sk)->retrans_timer); del_timer(&l2cap_pi(sk)->monitor_timer); @@ -2843,6 +2891,7 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd return 0; skb_queue_purge(TX_QUEUE(sk)); + skb_queue_purge(SREJ_QUEUE(sk)); del_timer(&l2cap_pi(sk)->retrans_timer); del_timer(&l2cap_pi(sk)->monitor_timer); @@ -3038,6 +3087,33 @@ static int l2cap_check_fcs(struct l2cap_pinfo *pi, struct sk_buff *skb) return 0; } +static void l2cap_add_to_srej_queue(struct sock *sk, struct sk_buff *skb, u8 tx_seq, u8 sar) +{ + struct sk_buff *next_skb; + + bt_cb(skb)->tx_seq = tx_seq; + bt_cb(skb)->sar = sar; + + next_skb = skb_peek(SREJ_QUEUE(sk)); + if (!next_skb) { + __skb_queue_tail(SREJ_QUEUE(sk), skb); + return; + } + + do { + if (bt_cb(next_skb)->tx_seq > tx_seq) { + __skb_queue_before(SREJ_QUEUE(sk), next_skb, skb); + return; + } + + if (skb_queue_is_last(SREJ_QUEUE(sk), next_skb)) + break; + + } while((next_skb = skb_queue_next(SREJ_QUEUE(sk), next_skb))); + + __skb_queue_tail(SREJ_QUEUE(sk), skb); +} + static int l2cap_sar_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 control) { struct l2cap_pinfo *pi = l2cap_pi(sk); @@ -3118,50 +3194,143 @@ static int l2cap_sar_reassembly_sdu(struct sock *sk, struct sk_buff *skb, u16 co return err; } +static void l2cap_check_srej_gap(struct sock *sk, u8 tx_seq) +{ + struct sk_buff *skb; + u16 control = 0; + + while((skb = skb_peek(SREJ_QUEUE(sk)))) { + if (bt_cb(skb)->tx_seq != tx_seq) + break; + + skb = skb_dequeue(SREJ_QUEUE(sk)); + control |= bt_cb(skb)->sar << L2CAP_CTRL_SAR_SHIFT; + l2cap_sar_reassembly_sdu(sk, skb, control); + l2cap_pi(sk)->buffer_seq_srej = + (l2cap_pi(sk)->buffer_seq_srej + 1) % 64; + tx_seq++; + } +} + +static void l2cap_resend_srejframe(struct sock *sk, u8 tx_seq) +{ + struct l2cap_pinfo *pi = l2cap_pi(sk); + struct srej_list *l, *tmp; + u16 control; + + list_for_each_entry_safe(l,tmp, SREJ_LIST(sk), list) { + if (l->tx_seq == tx_seq) { + list_del(&l->list); + kfree(l); + return; + } + control = L2CAP_SUPER_SELECT_REJECT; + control |= l->tx_seq << L2CAP_CTRL_REQSEQ_SHIFT; + l2cap_send_sframe(pi, control); + list_del(&l->list); + list_add_tail(&l->list, SREJ_LIST(sk)); + } +} + +static void l2cap_send_srejframe(struct sock *sk, u8 tx_seq) +{ + struct l2cap_pinfo *pi = l2cap_pi(sk); + struct srej_list *new; + u16 control; + + while (tx_seq != pi->expected_tx_seq) { + control = L2CAP_SUPER_SELECT_REJECT; + control |= pi->expected_tx_seq << L2CAP_CTRL_REQSEQ_SHIFT; + l2cap_send_sframe(pi, control); + + new = kzalloc(sizeof(struct srej_list), GFP_ATOMIC); + new->tx_seq = pi->expected_tx_seq++; + list_add_tail(&new->list, SREJ_LIST(sk)); + } + pi->expected_tx_seq++; +} + static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, struct sk_buff *skb) { struct l2cap_pinfo *pi = l2cap_pi(sk); u8 tx_seq = __get_txseq(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); - if (tx_seq == pi->expected_tx_seq) { - if (pi->conn_state & L2CAP_CONN_UNDER_REJ) - pi->conn_state &= ~L2CAP_CONN_UNDER_REJ; + if (tx_seq == pi->expected_tx_seq) + goto expected; - err = l2cap_sar_reassembly_sdu(sk, skb, rx_control); - if (err < 0) - return err; + if (pi->conn_state & L2CAP_CONN_SREJ_SENT) { + struct srej_list *first; - 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; + first = list_first_entry(SREJ_LIST(sk), + struct srej_list, list); + if (tx_seq == first->tx_seq) { + l2cap_add_to_srej_queue(sk, skb, tx_seq, sar); + l2cap_check_srej_gap(sk, tx_seq); + + list_del(&first->list); + kfree(first); + + if (list_empty(SREJ_LIST(sk))) { + pi->buffer_seq = pi->buffer_seq_srej; + pi->conn_state &= ~L2CAP_CONN_SREJ_SENT; + } + } else { + struct srej_list *l; + l2cap_add_to_srej_queue(sk, skb, tx_seq, sar); + + list_for_each_entry(l, SREJ_LIST(sk), list) { + if (l->tx_seq == tx_seq) { + l2cap_resend_srejframe(sk, tx_seq); + return 0; + } + } + l2cap_send_srejframe(sk, tx_seq); } } 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->conn_state |= L2CAP_CONN_SREJ_SENT; - goto send; - } + INIT_LIST_HEAD(SREJ_LIST(sk)); + pi->buffer_seq_srej = pi->buffer_seq; + + __skb_queue_head_init(SREJ_QUEUE(sk)); + l2cap_add_to_srej_queue(sk, skb, tx_seq, sar); + + l2cap_send_srejframe(sk, tx_seq); } return 0; -send: - return l2cap_send_sframe(pi, tx_control); +expected: + pi->expected_tx_seq = (pi->expected_tx_seq + 1) % 64; + + if (pi->conn_state & L2CAP_CONN_SREJ_SENT) { + l2cap_add_to_srej_queue(sk, skb, tx_seq, sar); + return 0; + } + + pi->buffer_seq = (pi->buffer_seq + 1) % 64; + + err = l2cap_sar_reassembly_sdu(sk, skb, rx_control); + if (err < 0) + return err; + + 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->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT; + l2cap_send_sframe(pi, tx_control); + } + return 0; } static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, struct sk_buff *skb) { struct l2cap_pinfo *pi = l2cap_pi(sk); + u8 tx_seq = __get_reqseq(rx_control); BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len); @@ -3181,7 +3350,7 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str if (pi->unacked_frames > 0) __mod_retrans_timer(); } else { - pi->expected_ack_seq = __get_reqseq(rx_control); + pi->expected_ack_seq = tx_seq; l2cap_drop_acked_frames(sk); if (pi->unacked_frames > 0) __mod_retrans_timer(); @@ -3200,8 +3369,11 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str break; - case L2CAP_SUPER_RCV_NOT_READY: case L2CAP_SUPER_SELECT_REJECT: + l2cap_retransmit_frame(sk, tx_seq); + break; + + case L2CAP_SUPER_RCV_NOT_READY: break; } -- cgit v1.1