Return-Path: Subject: Re: [PATCH 4/4] Bluetooth: Add support for Retransmission and Monitor Timers From: Marcel Holtmann To: "Gustavo F. Padovan" Cc: linux-bluetooth@vger.kernel.org, gustavo@padovan.org In-Reply-To: <1248675424-20977-5-git-send-email-gustavo@las.ic.unicamp.br> References: <1248675424-20977-1-git-send-email-gustavo@las.ic.unicamp.br> <1248675424-20977-2-git-send-email-gustavo@las.ic.unicamp.br> <1248675424-20977-3-git-send-email-gustavo@las.ic.unicamp.br> <1248675424-20977-4-git-send-email-gustavo@las.ic.unicamp.br> <1248675424-20977-5-git-send-email-gustavo@las.ic.unicamp.br> Content-Type: text/plain Date: Mon, 27 Jul 2009 12:08:44 +0200 Message-Id: <1248689324.28545.194.camel@violet> Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Gustavo, > L2CAP uses rentransmission and monitor timers to inquiry the other side > about unacked I-frames. After send 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, it try again, at a maximum of > L2CAP_DEFAULT_MAX_TX. > > Signed-off-by: Gustavo F. Padovan > --- > include/net/bluetooth/bluetooth.h | 1 + > include/net/bluetooth/l2cap.h | 15 +++++- > net/bluetooth/l2cap.c | 83 +++++++++++++++++++++++++++++++++++-- > 3 files changed, 92 insertions(+), 7 deletions(-) > > diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h > index 65a5cf8..b8b9a84 100644 > --- a/include/net/bluetooth/bluetooth.h > +++ b/include/net/bluetooth/bluetooth.h > @@ -139,6 +139,7 @@ struct bt_skb_cb { > __u8 pkt_type; > __u8 incoming; > __u8 tx_seq; > + __u8 retries; > }; > #define bt_cb(skb) ((struct bt_skb_cb *)((skb)->cb)) > > diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h > index 653c313..02871df 100644 > --- a/include/net/bluetooth/l2cap.h > +++ b/include/net/bluetooth/l2cap.h > @@ -31,9 +31,9 @@ > #define L2CAP_DEFAULT_FLUSH_TO 0xffff > #define L2CAP_DEFAULT_TX_WINDOW 63 > #define L2CAP_DEFAULT_NUM_TO_ACK (L2CAP_DEFAULT_TX_WINDOW/5) > -#define L2CAP_DEFAULT_MAX_RECEIVE 1 > -#define L2CAP_DEFAULT_RETRANS_TO 300 /* 300 milliseconds */ > -#define L2CAP_DEFAULT_MONITOR_TO 1000 /* 1 second */ > +#define L2CAP_DEFAULT_MAX_TX 3 > +#define L2CAP_DEFAULT_RETRANS_TO 1000 /* 1 second */ > +#define L2CAP_DEFAULT_MONITOR_TO 12000 /* 12 seconds */ > #define L2CAP_DEFAULT_MAX_PDU_SIZE 672 > > #define L2CAP_CONN_TIMEOUT (40000) /* 40 seconds */ > @@ -320,6 +320,7 @@ struct l2cap_pinfo { > __u8 req_seq; > __u8 expected_tx_seq; > __u8 unacked_frames; > + __u8 retry_count; > __u8 num_to_ack; > __u16 sdu_len; > __u16 partial_sdu_len; > @@ -336,6 +337,8 @@ struct l2cap_pinfo { > > __le16 sport; > > + struct timer_list retrans_timer; > + struct timer_list monitor_timer; > struct sk_buff_head tx_queue; > struct l2cap_conn *conn; > struct sock *next_c; > @@ -355,6 +358,12 @@ struct l2cap_pinfo { > > #define L2CAP_CONN_SAR_SDU 0x01 > #define L2CAP_CONN_UNDER_REJ 0x02 > +#define L2CAP_CONN_WAIT_ACK 0x04 > + > +#define __mod_retrans_timer() mod_timer(&l2cap_pi(sk)->retrans_timer, \ > + jiffies + msecs_to_jiffies(L2CAP_DEFAULT_RETRANS_TO)); > +#define __mod_monitor_timer() mod_timer(&l2cap_pi(sk)->monitor_timer, \ > + jiffies + msecs_to_jiffies(L2CAP_DEFAULT_MONITOR_TO)); > > static inline int l2cap_tx_window_full(struct sock *sk) > { > diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c > index 938d6db..bcfa9b9 100644 > --- a/net/bluetooth/l2cap.c > +++ b/net/bluetooth/l2cap.c > @@ -1179,6 +1179,37 @@ 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; > + 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_ACK; > + > + control = L2CAP_CTRL_POLL; > + l2cap_send_sframe(l2cap_pi(sk), control); > +} > + > static void l2cap_drop_acked_frames(struct sock *sk) > { > struct sk_buff *skb; > @@ -1193,6 +1224,9 @@ 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; > } > > @@ -1219,10 +1253,21 @@ static int l2cap_ertm_send(struct sock *sk) > u16 *control; > int err; > > + if (pi->conn_state & L2CAP_CONN_WAIT_ACK) > + return 0; > + > while ((skb = sk->sk_send_head) && (!l2cap_tx_window_full(sk))) { > tx_seq = pi->next_tx_seq; > 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 = (u16 *)(skb->data + L2CAP_HDR_SIZE); > *control |= cpu_to_le16( > (pi->req_seq << L2CAP_CTRL_REQSEQ_SHIFT) > @@ -1234,6 +1279,8 @@ static int l2cap_ertm_send(struct sock *sk) > return err; > } > > + __mod_retrans_timer(); > + > L2CAP_SEQ_NUM_INC(pi->next_tx_seq); > bt_cb(skb)->tx_seq = tx_seq; > > @@ -1323,6 +1370,8 @@ static struct sk_buff *l2cap_create_pdu(struct sock *sk, struct msghdr *msg, siz > kfree_skb(skb); > return ERR_PTR(err); > } > + > + bt_cb(skb)->retries = 0; > return skb; > } > > @@ -2011,7 +2060,7 @@ 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); > @@ -2506,6 +2555,12 @@ 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; > @@ -2615,6 +2670,8 @@ 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); > @@ -2639,6 +2696,8 @@ 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); > @@ -2944,9 +3003,25 @@ 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; > + l2cap_send_sframe(l2cap_pi(sk), control); > + } > + else if (rx_control & L2CAP_CTRL_FINAL) { Coding style is } else if. > + if (pi->conn_state & L2CAP_CONN_WAIT_ACK) > + break; > + > + pi->conn_state &= !L2CAP_CONN_WAIT_ACK; > + del_timer(&pi->monitor_timer); > + > + if (pi->unacked_frames > 0) > + __mod_retrans_timer(); > + } > + else { Same here. > + pi->expected_ack_seq = __get_reqseq(rx_control); > + l2cap_drop_acked_frames(sk); > + l2cap_ertm_send(sk); > + } > break; > > case L2CAP_SUPER_REJECT: Regards Marcel