Re: [PATCH -v3 07/10] Bluetooth: Add chan->ops->defer()

[Marcel Holtmann <marcel@holtmann.org>]

Hi Gustavo,

> When DEFER_SETUP is set defer() will trigger an authorization request
> to the userspace.
> 
> Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
> ---
>  include/net/bluetooth/l2cap.h |    1 +
>  net/bluetooth/l2cap_core.c    |   14 ++++++--------
>  net/bluetooth/l2cap_sock.c    |   12 ++++++++++++
>  3 files changed, 19 insertions(+), 8 deletions(-)
> 
> diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> index 0ea4cf1..6d0864e 100644
> --- a/include/net/bluetooth/l2cap.h
> +++ b/include/net/bluetooth/l2cap.h
> @@ -535,6 +535,7 @@ struct l2cap_ops {
>  	void			(*state_change) (struct l2cap_chan *chan,
>  						 int state);
>  	void			(*ready) (struct l2cap_chan *chan);
> +	void			(*defer) (struct l2cap_chan *chan);
>  	struct sk_buff		*(*alloc_skb) (struct l2cap_chan *chan,
>  					       unsigned long len, int nb);
>  };
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index d0c1ebe..35c2c52 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -1058,12 +1058,10 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
>  				lock_sock(sk);
>  				if (test_bit(CONF_DEFER_SETUP,
>  					     &chan->conf_state)) {
> -					struct sock *parent = bt_sk(sk)->parent;
>  					rsp.result = __constant_cpu_to_le16(L2CAP_CR_PEND);
>  					rsp.status = __constant_cpu_to_le16(L2CAP_CS_AUTHOR_PEND);
> -					if (parent)
> -						parent->sk_data_ready(parent, 0);
> -
> +					if(chan->ops->defer)

Coding style issue here.

> +						chan->ops->defer(chan->data);
>  				} else {
>  					__l2cap_state_change(chan, BT_CONFIG);
>  					rsp.result = __constant_cpu_to_le16(L2CAP_CR_SUCCESS);
> @@ -3381,7 +3379,8 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
>  				__l2cap_state_change(chan, BT_CONNECT2);
>  				result = L2CAP_CR_PEND;
>  				status = L2CAP_CS_AUTHOR_PEND;
> -				parent->sk_data_ready(parent, 0);
> +				if(chan->ops->defer)

And here.

> +					chan->ops->defer(chan->data);
>  			} else {
>  				__l2cap_state_change(chan, BT_CONFIG);
>  				result = L2CAP_CR_SUCCESS;
> @@ -5409,11 +5408,10 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
>  			if (!status) {
>  				if (test_bit(CONF_DEFER_SETUP,
>  					     &chan->conf_state)) {
> -					struct sock *parent = bt_sk(sk)->parent;
>  					res = L2CAP_CR_PEND;
>  					stat = L2CAP_CS_AUTHOR_PEND;
> -					if (parent)
> -						parent->sk_data_ready(parent, 0);
> +					if(chan->ops->defer)

And here.

> +						chan->ops->defer(chan->data);
>  				} else {
>  					__l2cap_state_change(chan, BT_CONFIG);
>  					res = L2CAP_CR_SUCCESS;
> diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> index a421a4e..e81e910 100644
> --- a/net/bluetooth/l2cap_sock.c
> +++ b/net/bluetooth/l2cap_sock.c
> @@ -1044,6 +1044,17 @@ static void l2cap_sock_ready_cb(struct l2cap_chan *chan)
>  	release_sock(sk);
>  }
>  
> +static void l2cap_sock_defer_cb(struct l2cap_chan *chan)
> +{
> +	struct sock *sk = chan->data;
> +	struct sock *parent;
> +
> +	parent = bt_sk(sk)->parent;
> +
> +	if (parent)
> +		parent->sk_data_ready(parent, 0);
> +}
> +
>  static struct l2cap_ops l2cap_chan_ops = {
>  	.name		= "L2CAP Socket Interface",
>  	.new_connection	= l2cap_sock_new_connection_cb,
> @@ -1052,6 +1063,7 @@ static struct l2cap_ops l2cap_chan_ops = {
>  	.teardown	= l2cap_sock_teardown_cb,
>  	.state_change	= l2cap_sock_state_change_cb,
>  	.ready		= l2cap_sock_ready_cb,
> +	.defer		= l2cap_sock_defer_cb,
>  	.alloc_skb	= l2cap_sock_alloc_skb_cb,
>  };
>  

In addition can you explain to me how this is suppose to work if defer
is not set. Then we never call ready.

Also this is a pretty bad idea inside the code. We better do something
like l2cap_sock_no_defer like the network subsystem does for general
socket. Since otherwise you keep spreading if (defer) all over the
places.

Regards

Marcel