From cec8ab6e20a7fbdc056894ff7b3fbdbc2a82a563 Mon Sep 17 00:00:00 2001 From: Mat Martineau Date: Thu, 17 May 2012 20:53:36 -0700 Subject: [PATCH] Bluetooth: Consolidate common receive code for ERTM and streaming mode 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 Signed-off-by: Gustavo Padovan --- 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 c7bf613294c..a84d3376919 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -791,9 +791,11 @@ 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); } } @@ -4820,27 +4822,39 @@ 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) @@ -4851,34 +4865,57 @@ static int l2cap_ertm_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb) goto drop; } - req_seq = __get_reqseq(chan, control); - - req_seq_offset = __seq_offset(chan, req_seq, chan->expected_ack_seq); - - next_tx_seq_offset = __seq_offset(chan, chan->next_tx_seq, - chan->expected_ack_seq); + if (!control->sframe) { + int err; - /* check for invalid req-seq */ - if (req_seq_offset > next_tx_seq_offset) { - l2cap_send_disconn_req(chan->conn, chan, ECONNRESET); - goto drop; - } + BT_DBG("iframe sar %d, reqseq %d, final %d, txseq %d", + control->sar, control->reqseq, control->final, + control->txseq); - 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; @@ -4891,9 +4928,6 @@ 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) { @@ -4923,44 +4957,8 @@ 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: -- 2.20.1