Re: [RFCv2 6/7] Bluetooth: add EFS option in l2cap conf req

[Emeltchenko Andrei <Andrei.Emeltchenko.news@gmail.com>]

Hi Szymon,

On Thu, Sep 01, 2011 at 02:45:03PM +0200, Szymon Janc wrote:
> Hi Andrei,
> 
> > From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> > 
> > Adds extended flowspec option when building l2cap config request
> > EFS is added if both the local and remote L2CAP entities have
> > indicated support for the Extended Flow Specification for BR/EDR
> > 
> > Based upon haijun.liu <haijun.liu@atheros.com> series of patches
> > (sent Sun, 22 Aug 2010)
> > 
> > Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> > ---
> >  include/net/bluetooth/l2cap.h |    2 +
> >  net/bluetooth/l2cap_core.c    |   70 ++++++++++++++++++++++++++++++++++++++++-
> >  2 files changed, 71 insertions(+), 1 deletions(-)
> > 
> > diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> > index 1f26a39..fc81771 100644
> > --- a/include/net/bluetooth/l2cap.h
> > +++ b/include/net/bluetooth/l2cap.h
> > @@ -445,6 +445,8 @@ struct l2cap_conn {
> >  	__u32		rx_len;
> >  	__u8		tx_ident;
> >  
> > +	__u8		flowspec_ident;
> > +
> >  	__u8		disc_reason;
> >  
> >  	__u8		preq[7]; /* SMP Pairing Request */
> > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> > index 02908f0..c2c5eb7 100644
> > --- a/net/bluetooth/l2cap_core.c
> > +++ b/net/bluetooth/l2cap_core.c
> > @@ -549,6 +549,26 @@ static u8 l2cap_get_ident(struct l2cap_conn *conn)
> >  	return id;
> >  }
> >  
> > +static inline u8 l2cap_flowspec_ident(struct l2cap_conn *conn)
> > +{
> > +	u8 id;
> > +
> > +	/* Get next available ident for the flow spec of guaranteed channel.
> > +	 *    2 - 255 are used.
> > +	 */
> > +
> > +	spin_lock_bh(&conn->lock);
> > +
> > +	if (++conn->flowspec_ident > 256)
> > +		conn->flowspec_ident = 2;
> 
> flowspec_ident is u8, shouldn't this be 'if (++conn->flowspec_ident < 2)' ?
> Also shouldn't you check if there is no channel with specified id before using that id?

Yes you are right here. But I am thinking to drop this function as we
might to support only Best Effort with fixed ident.

Best regards 
Andrei Emeltchenko 


> 
> > +
> > +	id = conn->flowspec_ident;
> > +
> > +	spin_unlock_bh(&conn->lock);
> > +
> > +	return id;
> > +}
> > +
> >  static void l2cap_send_cmd(struct l2cap_conn *conn, u8 ident, u8 code, u16 len, void *data)
> >  {
> >  	struct sk_buff *skb = l2cap_build_cmd(conn, code, ident, len, data);
> > @@ -1908,6 +1928,7 @@ static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data)
> >  {
> >  	struct l2cap_conf_req *req = data;
> >  	struct l2cap_conf_rfc rfc = { .mode = chan->mode };
> > +	struct l2cap_conf_efs efs = { .service_type = L2CAP_SERV_BESTEFFORT };
> >  	void *ptr = req->data;
> >  
> >  	BT_DBG("chan %p", chan);
> > @@ -1921,7 +1942,11 @@ static int l2cap_build_conf_req(struct l2cap_chan *chan, void *data)
> >  		if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state))
> >  			break;
> >  
> > -		/* fall through */
> > +		if (__l2cap_efs_supported(chan))
> > +			set_bit(FLAG_EFS_ENABLE, &chan->flags);
> > +
> > +		break;
> > +
> >  	default:
> >  		chan->mode = l2cap_select_mode(rfc.mode, chan->conn->feat_mask);
> >  		break;
> > @@ -1961,6 +1986,33 @@ done:
> >  		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
> >  							(unsigned long) &rfc);
> >  
> > +		if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
> > +			efs.service_type = chan->local_stype;
> > +			efs.max_sdu_size = cpu_to_le16(chan->local_msdu);
> > +			efs.sdu_inter_time = cpu_to_le32(chan->local_sdu_itime);
> > +
> > +			if (chan->local_stype == L2CAP_SERV_BESTEFFORT) {
> > +				chan->local_id = 1;
> > +				efs.id = chan->local_id;
> > +				efs.access_latency =
> > +					cpu_to_le32(L2CAP_DEFAULT_ACCESS_LATENCY);
> > +				efs.flush_timeout =
> > +					cpu_to_le32(L2CAP_DEFAULT_FLUSH_TO);
> > +			} else {
> > +				/* As spec, the ident shall be unique within
> > +				   the scope of a physical link.
> > +				 */
> > +				chan->local_id = l2cap_flowspec_ident(chan->conn);
> > +				efs.id = chan->local_id;
> > +				efs.access_latency =
> > +					cpu_to_le32(chan->local_acc_lat);
> > +				efs.flush_timeout =
> > +					cpu_to_le32(chan->local_flush_to);
> > +			}
> > +			l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
> > +					sizeof(efs), (unsigned long) &efs);
> > +		}
> > +
> >  		if (!(chan->conn->feat_mask & L2CAP_FEAT_FCS))
> >  			break;
> >  
> > @@ -1969,6 +2021,7 @@ done:
> >  			chan->fcs = L2CAP_FCS_NONE;
> >  			l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, chan->fcs);
> >  		}
> > +
> >  		break;
> >  
> >  	case L2CAP_MODE_STREAMING:
> > @@ -1984,6 +2037,20 @@ done:
> >  		l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
> >  							(unsigned long) &rfc);
> >  
> > +		if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
> > +			efs.id = 1;
> > +			efs.service_type = L2CAP_SERV_BESTEFFORT;
> > +			efs.max_sdu_size =
> > +				cpu_to_le16(chan->local_msdu);
> > +			efs.sdu_inter_time =
> > +				cpu_to_le32(chan->local_sdu_itime);
> > +			efs.access_latency = 0;
> > +			efs.flush_timeout = 0;
> > +
> > +			l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS,
> > +					sizeof(efs), (unsigned long) &efs);
> > +		}
> > +
> >  		if (!(chan->conn->feat_mask & L2CAP_FEAT_FCS))
> >  			break;
> >  
> > @@ -1992,6 +2059,7 @@ done:
> >  			chan->fcs = L2CAP_FCS_NONE;
> >  			l2cap_add_conf_opt(&ptr, L2CAP_CONF_FCS, 1, chan->fcs);
> >  		}
> > +
> >  		break;
> >  	}
> >  
> > 
> 
> -- 
> BR
> Szymon Janc