Re: [PATCHv1 01/17] Bluetooth: A2MP: Create A2MP channel

[Mat Martineau <mathewm@codeaurora.org>]

Andrei -

On Fri, 18 May 2012, Andrei Emeltchenko wrote:

> From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
>
> Create and initialize fixed A2MP channel
>
> Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> ---
> include/net/bluetooth/l2cap.h |    5 ++++
> net/bluetooth/Makefile        |    3 ++-
> net/bluetooth/a2mp.c          |   59 +++++++++++++++++++++++++++++++++++++++++
> net/bluetooth/l2cap_core.c    |    4 +--
> 4 files changed, 68 insertions(+), 3 deletions(-)
> create mode 100644 net/bluetooth/a2mp.c
>
> diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> index 8fdfaca..8cc739f 100644
> --- a/include/net/bluetooth/l2cap.h
> +++ b/include/net/bluetooth/l2cap.h
> @@ -52,6 +52,8 @@
> #define L2CAP_CONN_TIMEOUT		msecs_to_jiffies(40000)
> #define L2CAP_INFO_TIMEOUT		msecs_to_jiffies(4000)
>
> +#define L2CAP_A2MP_DEFAULT_MTU		670
> +
> /* L2CAP socket address */
> struct sockaddr_l2 {
> 	sa_family_t	l2_family;
> @@ -232,6 +234,7 @@ struct l2cap_conn_rsp {
> /* channel indentifier */
> #define L2CAP_CID_SIGNALING	0x0001
> #define L2CAP_CID_CONN_LESS	0x0002
> +#define L2CAP_CID_A2MP		0x0003
> #define L2CAP_CID_LE_DATA	0x0004
> #define L2CAP_CID_LE_SIGNALING	0x0005
> #define L2CAP_CID_SMP		0x0006
> @@ -931,5 +934,7 @@ int l2cap_chan_send(struct l2cap_chan *chan, struct msghdr *msg, size_t len,
> void l2cap_chan_busy(struct l2cap_chan *chan, int busy);
> int l2cap_chan_check_security(struct l2cap_chan *chan);
> void l2cap_chan_set_defaults(struct l2cap_chan *chan);
> +int l2cap_ertm_init(struct l2cap_chan *chan);
> +void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
>
> #endif /* __L2CAP_H */
> diff --git a/net/bluetooth/Makefile b/net/bluetooth/Makefile
> index 2dc5a57..fa6d94a 100644
> --- a/net/bluetooth/Makefile
> +++ b/net/bluetooth/Makefile
> @@ -9,4 +9,5 @@ obj-$(CONFIG_BT_CMTP)	+= cmtp/
> obj-$(CONFIG_BT_HIDP)	+= hidp/
>
> bluetooth-y := af_bluetooth.o hci_core.o hci_conn.o hci_event.o mgmt.o \
> -	hci_sock.o hci_sysfs.o l2cap_core.o l2cap_sock.o smp.o sco.o lib.o
> +	hci_sock.o hci_sysfs.o l2cap_core.o l2cap_sock.o smp.o sco.o lib.o \
> +	a2mp.o
> diff --git a/net/bluetooth/a2mp.c b/net/bluetooth/a2mp.c
> new file mode 100644
> index 0000000..1f733b5
> --- /dev/null
> +++ b/net/bluetooth/a2mp.c
> @@ -0,0 +1,59 @@
> +/*
> +   Copyright (c) 2010,2011 Code Aurora Forum.  All rights reserved.
> +   Copyright (c) 2011,2012 Intel Corp.
> +
> +   This program is free software; you can redistribute it and/or modify
> +   it under the terms of the GNU General Public License version 2 and
> +   only version 2 as published by the Free Software Foundation.
> +
> +   This program is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +   GNU General Public License for more details.
> +*/
> +
> +#include <net/bluetooth/bluetooth.h>
> +#include <net/bluetooth/hci_core.h>
> +#include <net/bluetooth/l2cap.h>
> +
> +static struct l2cap_ops a2mp_chan_ops = {
> +	.name = "L2CAP A2MP channel",
> +};
> +
> +static struct l2cap_chan *a2mp_chan_open(struct l2cap_conn *conn)
> +{
> +	struct l2cap_chan *chan;
> +
> +	chan = l2cap_chan_create();
> +	if (!chan)
> +		return NULL;
> +
> +	BT_DBG("chan %p", chan);
> +
> +	hci_conn_hold(conn->hcon);

Holding the hcon will keep the ACL open after all of the other L2CAP 
channels have closed (unless I missed some code later in the patch 
series).  The A2MP fixed channel should not keep the ACL open.  If the 
connection is not held here, then there shouldn't be a put in 
l2cap_chan_del for the A2MP channel either.

> +
> +	chan->omtu = L2CAP_A2MP_DEFAULT_MTU;
> +	chan->imtu = L2CAP_A2MP_DEFAULT_MTU;
> +	chan->flush_to = L2CAP_DEFAULT_FLUSH_TO;
> +
> +	chan->ops = &a2mp_chan_ops;
> +
> +	l2cap_chan_set_defaults(chan);
> +	chan->remote_max_tx = chan->max_tx;
> +	chan->remote_tx_win = chan->tx_win;
> +
> +	chan->retrans_timeout = L2CAP_DEFAULT_RETRANS_TO;
> +	chan->monitor_timeout = L2CAP_DEFAULT_MONITOR_TO;
> +
> +	skb_queue_head_init(&chan->tx_q);
> +
> +	chan->mode = L2CAP_MODE_ERTM;
> +	l2cap_ertm_init(chan);
> +
> +	l2cap_chan_add(conn, chan);
> +
> +	chan->remote_mps = chan->omtu;
> +	chan->mps = chan->omtu;
> +
> +	return chan;
> +}
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index 65e56d5..ee333f0 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -469,7 +469,7 @@ static void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
> 	list_add(&chan->list, &conn->chan_l);
> }
>
> -static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
> +void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
> {
> 	mutex_lock(&conn->chan_lock);
> 	__l2cap_chan_add(conn, chan);
> @@ -2349,7 +2349,7 @@ static void l2cap_ack_timeout(struct work_struct *work)
> 	l2cap_chan_put(chan);
> }
>
> -static inline int l2cap_ertm_init(struct l2cap_chan *chan)
> +int l2cap_ertm_init(struct l2cap_chan *chan)
> {
> 	int err;
>
> -- 
> 1.7.9.5


Regards,
--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum