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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 <gustavo@las.ic.unicamp.br>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Gustavo F. Padovan 2009-08-20 22:26:00 -03:00 committed by Marcel Holtmann
parent 30afb5b2aa
commit e90bac061b
3 changed files with 95 additions and 7 deletions
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1
include/net/bluetooth/bluetooth.h
View File

@ -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))

15
include/net/bluetooth/l2cap.h
View File

@ -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_F 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)
{

86
net/bluetooth/l2cap.c
View File

@ -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: