Re: [PATCH 04/19] Bluetooth: Lookup channel structure based on DCID

[Marcel Holtmann <marcel@holtmann.org>]

Hi Mat,

> Processing a move channel request involves getting the channel
> structure using the destination channel ID.  Previous code could only
> look up using the source channel ID.
> 
> Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
> ---
>  net/bluetooth/l2cap_core.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index ec2b4d9..a55644f 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -100,6 +100,22 @@ static struct l2cap_chan *l2cap_get_chan_by_scid(struct l2cap_conn *conn,
>  	return c;
>  }
>  
> +/* Find channel with given DCID.
> + * Returns locked channel. */
> +static struct l2cap_chan *l2cap_get_chan_by_dcid(struct l2cap_conn *conn,
> +						 u16 cid)
> +{
> +	struct l2cap_chan *c;
> +
> +	mutex_lock(&conn->chan_lock);
> +	c = __l2cap_get_chan_by_dcid(conn, cid);
> +	if (c)
> +		l2cap_chan_lock(c);
> +	mutex_unlock(&conn->chan_lock);
> +
> +	return c;
> +}
> +
>  static struct l2cap_chan *__l2cap_get_chan_by_ident(struct l2cap_conn *conn,
>  						    u8 ident)
>  {
> @@ -4139,6 +4155,7 @@ static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
>  					 u16 cmd_len, void *data)
>  {
>  	struct l2cap_move_chan_req *req = data;
> +	struct l2cap_chan *chan;
>  	u16 icid = 0;
>  	u16 result = L2CAP_MR_NOT_ALLOWED;
>  
> @@ -4152,9 +4169,14 @@ static inline int l2cap_move_channel_req(struct l2cap_conn *conn,
>  	if (!enable_hs)
>  		return -EINVAL;
>  
> +	chan = l2cap_get_chan_by_dcid(conn, icid);
> +

	if (!chan)
		goto refuse;

	/* Placeholder ... */

refuse:

>  	/* Placeholder: Always refuse */
>  	l2cap_send_move_chan_rsp(conn, cmd->ident, icid, result);
>  
	l2cap_chan_unlock(chan);

>  	return 0;
>  }
>  

You might have some intention here that I do not see yet, but I think
this is a bit too complicated.

Regards

Marcel