Return-Path: From: "Gustavo F. Padovan" To: linux-bluetooth@vger.kernel.org Cc: marcel@holtmann.org, gustavo@padovan.org Subject: [PATCH 4/5] Bluetooth: Add support for Retransmission and Monitor Timers Date: Sat, 8 Aug 2009 17:03:11 -0300 Message-Id: <1249761792-21148-4-git-send-email-gustavo@las.ic.unicamp.br> In-Reply-To: <1249761792-21148-3-git-send-email-gustavo@las.ic.unicamp.br> References: <1249761792-21148-1-git-send-email-gustavo@las.ic.unicamp.br> <1249761792-21148-2-git-send-email-gustavo@las.ic.unicamp.br> <1249761792-21148-3-git-send-email-gustavo@las.ic.unicamp.br> List-ID: 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 | 80 +++++++++++++++++++++++++++++++++++-- 3 files changed, 89 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 a1d8ec4..33aea42 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 */ @@ -318,6 +318,7 @@ 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; @@ -333,6 +334,8 @@ 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; @@ -352,6 +355,12 @@ 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 c7dec70..f04beba 100644 --- a/net/bluetooth/l2cap.c +++ b/net/bluetooth/l2cap.c @@ -1178,6 +1178,37 @@ 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; @@ -1192,6 +1223,9 @@ 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; } @@ -1217,9 +1251,20 @@ 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_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) @@ -1230,6 +1275,7 @@ static int l2cap_ertm_send(struct sock *sk) 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; @@ -1366,6 +1412,8 @@ 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; } @@ -2059,7 +2107,7 @@ 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); @@ -2554,6 +2602,12 @@ 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; @@ -2663,6 +2717,8 @@ 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); @@ -2687,6 +2743,8 @@ 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); @@ -2992,9 +3050,23 @@ 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) { + 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 { + pi->expected_ack_seq = __get_reqseq(rx_control); + l2cap_drop_acked_frames(sk); + l2cap_ertm_send(sk); + } break; case L2CAP_SUPER_REJECT: -- 1.6.3.3