From e90bac061b17cd81bd0df30606c64f4543bf5ca0 Mon Sep 17 00:00:00 2001 From: "Gustavo F. Padovan" Date: Thu, 20 Aug 2009 22:26:00 -0300 Subject: Bluetooth: Add support for Retransmission and Monitor Timers L2CAP uses retransmission and monitor timers to inquiry the other side about unacked I-frames. After sending each I-frame we (re)start the retransmission timer. If it expires, we start a monitor timer that send a S-frame with P bit set and wait for S-frame with F bit set. If monitor timer expires, try again, at a maximum of L2CAP_DEFAULT_MAX_TX. Signed-off-by: Gustavo F. Padovan Signed-off-by: Marcel Holtmann --- net/bluetooth/l2cap.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 82 insertions(+), 4 deletions(-) (limited to 'net/bluetooth') diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c index 35e9f5b8054..97172f7c0a6 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -1178,6 +1178,39 @@ static int l2cap_sock_getname(struct socket *sock, struct sockaddr *addr, int *l return 0; } +static void l2cap_monitor_timeout(unsigned long arg) +{ + struct sock *sk = (void *) arg; + u16 control; + + if (l2cap_pi(sk)->retry_count >= l2cap_pi(sk)->remote_max_tx) { + l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk); + return; + } + + l2cap_pi(sk)->retry_count++; + __mod_monitor_timer(); + + control = L2CAP_CTRL_POLL; + control |= L2CAP_SUPER_RCV_READY; + l2cap_send_sframe(l2cap_pi(sk), control); +} + +static void l2cap_retrans_timeout(unsigned long arg) +{ + struct sock *sk = (void *) arg; + u16 control; + + l2cap_pi(sk)->retry_count = 1; + __mod_monitor_timer(); + + l2cap_pi(sk)->conn_state |= L2CAP_CONN_WAIT_F; + + control = L2CAP_CTRL_POLL; + control |= L2CAP_SUPER_RCV_READY; + l2cap_send_sframe(l2cap_pi(sk), control); +} + static void l2cap_drop_acked_frames(struct sock *sk) { struct sk_buff *skb; @@ -1192,6 +1225,9 @@ static void l2cap_drop_acked_frames(struct sock *sk) l2cap_pi(sk)->unacked_frames--; } + if (!l2cap_pi(sk)->unacked_frames) + del_timer(&l2cap_pi(sk)->retrans_timer); + return; } @@ -1216,19 +1252,32 @@ static int l2cap_ertm_send(struct sock *sk) u16 control; int err; + if (pi->conn_state & L2CAP_CONN_WAIT_F) + return 0; + while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))) { tx_skb = skb_clone(skb, GFP_ATOMIC); + if (pi->remote_max_tx && + bt_cb(skb)->retries == pi->remote_max_tx) { + l2cap_send_disconn_req(pi->conn, sk); + break; + } + + bt_cb(skb)->retries++; + control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE); control |= (pi->req_seq << L2CAP_CTRL_REQSEQ_SHIFT) | (pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT); put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE); + err = l2cap_do_send(sk, tx_skb); if (err < 0) { l2cap_send_disconn_req(pi->conn, sk); return err; } + __mod_retrans_timer(); bt_cb(skb)->tx_seq = pi->next_tx_seq; pi->next_tx_seq = (pi->next_tx_seq + 1) % 64; @@ -1365,6 +1414,8 @@ static struct sk_buff *l2cap_create_ertm_pdu(struct sock *sk, struct msghdr *msg kfree_skb(skb); return ERR_PTR(err); } + + bt_cb(skb)->retries = 0; return skb; } @@ -2058,7 +2109,7 @@ done: case L2CAP_MODE_ERTM: rfc.mode = L2CAP_MODE_ERTM; rfc.txwin_size = L2CAP_DEFAULT_TX_WINDOW; - rfc.max_transmit = L2CAP_DEFAULT_MAX_RECEIVE; + rfc.max_transmit = L2CAP_DEFAULT_MAX_TX; rfc.retrans_timeout = 0; rfc.monitor_timeout = 0; rfc.max_pdu_size = cpu_to_le16(L2CAP_DEFAULT_MAX_PDU_SIZE); @@ -2553,6 +2604,12 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr 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); + __skb_queue_head_init(TX_QUEUE(sk)); l2cap_chan_ready(sk); goto unlock; @@ -2662,6 +2719,8 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd sk->sk_shutdown = SHUTDOWN_MASK; skb_queue_purge(TX_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); @@ -2686,6 +2745,8 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd return 0; skb_queue_purge(TX_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); @@ -2991,9 +3052,26 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str switch (rx_control & L2CAP_CTRL_SUPERVISE) { case L2CAP_SUPER_RCV_READY: - pi->expected_ack_seq = __get_reqseq(rx_control); - l2cap_drop_acked_frames(sk); - l2cap_ertm_send(sk); + if (rx_control & L2CAP_CTRL_POLL) { + u16 control = L2CAP_CTRL_FINAL; + control |= L2CAP_SUPER_RCV_READY; + l2cap_send_sframe(l2cap_pi(sk), control); + } else if (rx_control & L2CAP_CTRL_FINAL) { + if (!(pi->conn_state & L2CAP_CONN_WAIT_F)) + break; + + pi->conn_state &= ~L2CAP_CONN_WAIT_F; + del_timer(&pi->monitor_timer); + + if (pi->unacked_frames > 0) + __mod_retrans_timer(); + } else { + pi->expected_ack_seq = __get_reqseq(rx_control); + l2cap_drop_acked_frames(sk); + if (pi->unacked_frames > 0) + __mod_retrans_timer(); + l2cap_ertm_send(sk); + } break; case L2CAP_SUPER_REJECT: -- cgit v1.2.3