From 0565c1c24af94130b891f989fa608faddfadc52c Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:36 -0300 Subject: Bluetooth: Initialize variables and timers for both channel's sides Fix ERTM's full-duplex channel to work as specified by ERTM spec. ERTM needs to handle state vars, timers and counters to send and receive I-frames(the data frames), i.e., for both sides of data communication. We initialize all of them to the default values here. Full-duplex channel is a mandatory feature of ERTM spec. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 54 ++++++++++++++++++++++++++++++++++----------------- 1 file changed, 36 insertions(+), 18 deletions(-) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 54992f782301..dfd0327cf8da 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -2173,6 +2173,21 @@ static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val) *ptr += L2CAP_CONF_OPT_SIZE + len; } +static inline void l2cap_ertm_init(struct sock *sk) +{ + l2cap_pi(sk)->expected_ack_seq = 0; + l2cap_pi(sk)->unacked_frames = 0; + l2cap_pi(sk)->buffer_seq = 0; + l2cap_pi(sk)->num_to_ack = 0; + + setup_timer(&l2cap_pi(sk)->retrans_timer, + l2cap_retrans_timeout, (unsigned long) sk); + setup_timer(&l2cap_pi(sk)->monitor_timer, + l2cap_monitor_timeout, (unsigned long) sk); + + __skb_queue_head_init(SREJ_QUEUE(sk)); +} + static int l2cap_mode_supported(__u8 mode, __u32 feat_mask) { u32 local_feat_mask = l2cap_feat_mask; @@ -2761,17 +2776,13 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16; sk->sk_state = BT_CONNECTED; - l2cap_pi(sk)->next_tx_seq = 0; - l2cap_pi(sk)->expected_ack_seq = 0; - l2cap_pi(sk)->unacked_frames = 0; - - setup_timer(&l2cap_pi(sk)->retrans_timer, - l2cap_retrans_timeout, (unsigned long) sk); - setup_timer(&l2cap_pi(sk)->monitor_timer, - l2cap_monitor_timeout, (unsigned long) sk); + l2cap_pi(sk)->next_tx_seq = 0; + l2cap_pi(sk)->expected_tx_seq = 0; __skb_queue_head_init(TX_QUEUE(sk)); - __skb_queue_head_init(SREJ_QUEUE(sk)); + if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) + l2cap_ertm_init(sk); + l2cap_chan_ready(sk); goto unlock; } @@ -2850,11 +2861,12 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16; sk->sk_state = BT_CONNECTED; + l2cap_pi(sk)->next_tx_seq = 0; 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)); + if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) + l2cap_ertm_init(sk); + l2cap_chan_ready(sk); } @@ -2886,9 +2898,12 @@ 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); + + if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) { + skb_queue_purge(SREJ_QUEUE(sk)); + del_timer(&l2cap_pi(sk)->retrans_timer); + del_timer(&l2cap_pi(sk)->monitor_timer); + } l2cap_chan_del(sk, ECONNRESET); bh_unlock_sock(sk); @@ -2913,9 +2928,12 @@ 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); + + if (l2cap_pi(sk)->mode == L2CAP_MODE_ERTM) { + skb_queue_purge(SREJ_QUEUE(sk)); + del_timer(&l2cap_pi(sk)->retrans_timer); + del_timer(&l2cap_pi(sk)->monitor_timer); + } l2cap_chan_del(sk, 0); bh_unlock_sock(sk); -- cgit v1.2.2 From 889a3ca466018ab68363c3168993793bc2d984f1 Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:37 -0300 Subject: Bluetooth: Fix unset of SrejActioned flag SrejActioned is a flag that when set prevents local side to retransmit a I-frame(the data frame) already retransmitted. The local entity can retransmit again only when it receives a SREJ frame with the F-bit set. SREJ frame - Selective Reject frame - is sent when an entity wants the retransmission of a specific I-frame that was lost or corrupted. This bug can put ERTM in an unknown state once the entity can't retransmit. A frame with the Final bit set is expected when the local side sends a frame with the Poll bit set due to a local busy condition or a retransmission timer expired. (Receipt of P-bit shall always be replied by a frame with the F-bit set). pi->conn_state keeps informations about many ERTM flags including SrejActioned. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index dfd0327cf8da..2d5d37545b10 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -3443,7 +3443,7 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str } else if (rx_control & L2CAP_CTRL_FINAL) { if ((pi->conn_state & L2CAP_CONN_SREJ_ACT) && pi->srej_save_reqseq == tx_seq) - pi->srej_save_reqseq &= ~L2CAP_CONN_SREJ_ACT; + pi->conn_state &= ~L2CAP_CONN_SREJ_ACT; else l2cap_retransmit_frame(sk, tx_seq); } -- cgit v1.2.2 From 9f121a5a80b4417c6db5a35e26d2e79c29c3fc0d Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:38 -0300 Subject: 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 --- net/bluetooth/l2cap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 2d5d37545b10..78ab8811e5ef 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; -- cgit v1.2.2 From 4ec10d9720ef78cd81d8bcc30a3238665744569f Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:39 -0300 Subject: Bluetooth: Implement RejActioned flag RejActioned is used to prevent retransmission when a entity is on the WAIT_F state, i.e., waiting for a frame with F-bit set due local busy condition or a expired retransmission timer. (When these two events raise they send a frame with the Poll bit set and enters in the WAIT_F state to wait for a frame with the Final bit set.) The local entity doesn't send I-frames(the data frames) until the receipt of a frame with F-bit set. When that happens it also set RejActioned to false. RejActioned is a mandatory feature of ERTM spec. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 38 +++++++++++++++++++++++++++++++++++--- 1 file changed, 35 insertions(+), 3 deletions(-) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 78ab8811e5ef..73bda0ae41d6 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -3362,6 +3362,16 @@ expected: return 0; } + if (rx_control & L2CAP_CTRL_FINAL) { + if (pi->conn_state & L2CAP_CONN_REJ_ACT) + pi->conn_state &= ~L2CAP_CONN_REJ_ACT; + else { + sk->sk_send_head = TX_QUEUE(sk)->next; + pi->next_tx_seq = pi->expected_ack_seq; + l2cap_ertm_send(sk); + } + } + pi->buffer_seq = (pi->buffer_seq + 1) % 64; err = l2cap_sar_reassembly_sdu(sk, skb, rx_control); @@ -3398,6 +3408,14 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str pi->expected_ack_seq = tx_seq; l2cap_drop_acked_frames(sk); + if (pi->conn_state & L2CAP_CONN_REJ_ACT) + pi->conn_state &= ~L2CAP_CONN_REJ_ACT; + else { + sk->sk_send_head = TX_QUEUE(sk)->next; + pi->next_tx_seq = pi->expected_ack_seq; + l2cap_ertm_send(sk); + } + if (!(pi->conn_state & L2CAP_CONN_WAIT_F)) break; @@ -3425,10 +3443,24 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str 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; + if (rx_control & L2CAP_CTRL_FINAL) { + if (pi->conn_state & L2CAP_CONN_REJ_ACT) + pi->conn_state &= ~L2CAP_CONN_REJ_ACT; + else { + sk->sk_send_head = TX_QUEUE(sk)->next; + pi->next_tx_seq = pi->expected_ack_seq; + l2cap_ertm_send(sk); + } + } else { + sk->sk_send_head = TX_QUEUE(sk)->next; + pi->next_tx_seq = pi->expected_ack_seq; + l2cap_ertm_send(sk); - l2cap_ertm_send(sk); + if (pi->conn_state & L2CAP_CONN_WAIT_F) { + pi->srej_save_reqseq = tx_seq; + pi->conn_state |= L2CAP_CONN_REJ_ACT; + } + } break; -- cgit v1.2.2 From 2ab25cdd7b54473dd42dcffc9872737de2517466 Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Sat, 3 Oct 2009 02:34:40 -0300 Subject: Bluetooth: Fix 'SendRRorRNR' to send the ReqSeq value SendRRorRNR needs to acknowledge received I-frames (actually every packet needs to acknowledge received I-frames by sending the proper packet sequence number), so ReqSeq is set to the next I-frame number sequence to be pulled by the reassembly function. SendRRorRNR tells the remote side about local busy conditions, it sends a Receiver Ready frame if local busy is false or a Receiver Not Ready if local busy is true. ReqSeq is the packet's field to send the number of the acknowledged packets. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 73bda0ae41d6..c898f3439d1c 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -373,6 +373,8 @@ static inline int l2cap_send_rr_or_rnr(struct l2cap_pinfo *pi, u16 control) else control |= L2CAP_SUPER_RCV_READY; + control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT; + return l2cap_send_sframe(pi, control); } -- cgit v1.2.2 From 5fbcd3d1a07e234583e17830e8aef47282c22141 Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Mon, 5 Oct 2009 11:35:43 +0200 Subject: Bluetooth: Add L2CAP option for max transmit value For testing purposes it is important to modify the max transmit value. Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net/bluetooth/l2cap.c') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index c898f3439d1c..5129b88c8e5b 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -54,6 +54,7 @@ #define VERSION "2.14" static int enable_ertm = 0; +static int max_transmit = L2CAP_DEFAULT_MAX_TX; static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN; static u8 l2cap_fixed_chan[8] = { 0x02, }; @@ -2253,7 +2254,7 @@ done: case L2CAP_MODE_ERTM: rfc.mode = L2CAP_MODE_ERTM; rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW; - rfc.max_transmit = L2CAP_DEFAULT_MAX_TX; + rfc.max_transmit = max_transmit; rfc.retrans_timeout = 0; rfc.monitor_timeout = 0; rfc.max_pdu_size = cpu_to_le16(L2CAP_DEFAULT_MAX_PDU_SIZE); @@ -4060,6 +4061,9 @@ module_exit(l2cap_exit); module_param(enable_ertm, bool, 0644); MODULE_PARM_DESC(enable_ertm, "Enable enhanced retransmission mode"); +module_param(max_transmit, uint, 0644); +MODULE_PARM_DESC(max_transmit, "Max transmit value (default = 3)"); + MODULE_AUTHOR("Marcel Holtmann "); MODULE_DESCRIPTION("Bluetooth L2CAP ver " VERSION); MODULE_VERSION(VERSION); -- cgit v1.2.2