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

[Gustavo Padovan <gustavo@padovan.org>]

Hi Marcel,

* Marcel Holtmann <marcel@holtmann.org> [2012-05-28 05:54:20 +0200]:

> 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.

If you don't set defer_setup, you probably don't need to call ready. That was the
idea here.

> 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.

Sure, I agree, I'll remove all if (defer) from the code for now. And as
l2cap_sock is still the sole user of this we don't need to add
l2cap_sock_no_defer yet.

	Gustavo