Re: [PATCH 3/7] Bluetooth: LE disconnection and connect cancel support

[Marcel Holtmann <marcel@holtmann.org>]

Hi Ville,

> Add supprt to cancel and disconnet connections.
> 
> Signed-off-by: Ville Tervo <ville.tervo@nokia.com>
> ---
>  include/net/bluetooth/hci.h      |    5 ++---
>  include/net/bluetooth/hci_core.h |    3 +++
>  net/bluetooth/hci_conn.c         |   30 ++++++++++++++++++++++++++++++
>  3 files changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index b326240..d04ecea 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -191,6 +191,8 @@ enum {
>  
>  #define LMP_EV4		0x01
>  #define LMP_EV5		0x02
> +#define LMP_NO_BR	0x20
> +#define LMP_LE		0x40

Keep these in sync with the constants we use in userspace.
 
>  #define LMP_SNIFF_SUBR	0x02
>  #define LMP_EDR_ESCO_2M	0x20
> @@ -627,9 +629,6 @@ struct hci_cp_le_create_conn {
>  } __packed;
>  
>  #define HCI_OP_LE_CREATE_CONN_CANCEL	0x200e
> -struct hci_cp_le_create_conn_cancel {
> -	__u8     status;
> -} __packed;
>  
>  #define HCI_OP_LE_SET_ADVERTISE_ENABLE	0x200a
>  	#define LE_ADVERTISE_ENABLED	0x01
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 89f4b10..a430a57 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -455,10 +455,13 @@ void hci_conn_del_sysfs(struct hci_conn *conn);
>  #define lmp_rswitch_capable(dev)   ((dev)->features[0] & LMP_RSWITCH)
>  #define lmp_encrypt_capable(dev)   ((dev)->features[0] & LMP_ENCRYPT)
>  #define lmp_sniff_capable(dev)     ((dev)->features[0] & LMP_SNIFF)
> +#define lmp_br_capable(dev)        (!((dev)->features[4] & LMP_NO_BR))

This makes no sense to me. And leave this out for now. This is more
complicated when running on LE only.

> +#define lmp_le_capable(dev)        ((dev)->features[4] & LMP_LE)

I would just add this at the end of the list and not intermix it with
sniff and sniffsubr defines.

>  #define lmp_sniffsubr_capable(dev) ((dev)->features[5] & LMP_SNIFF_SUBR)
>  #define lmp_esco_capable(dev)      ((dev)->features[3] & LMP_ESCO)
>  #define lmp_ssp_capable(dev)       ((dev)->features[6] & LMP_SIMPLE_PAIR)
>  
> +
>  /* ----- HCI protocols ----- */
>  struct hci_proto {
>  	char		*name;
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index cb41d64..50f8973 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -66,6 +66,31 @@ void hci_le_connect(struct hci_conn *conn)
>  	hci_send_cmd(hdev, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
>  }
>  
> +static void hci_le_connect_cancel(struct hci_conn *conn)
> +{
> +	struct hci_dev *hdev = conn->hdev;
> +
> +	BT_DBG("%p", conn);
> +
> +	if (!lmp_le_capable(hdev))
> +		return;

This should not be needed. We should not have tried to establish a LE
link if we don't support LE in the first place.

> +
> +	hci_send_cmd(conn->hdev, HCI_OP_LE_CREATE_CONN_CANCEL, 0, NULL);
> +}
> +
> +void hci_le_disconn(struct hci_conn *conn, __u8 reason)
> +{
> +	struct hci_cp_disconnect cp;
> +
> +	BT_DBG("%p", conn);
> +
> +	conn->le_state = BT_DISCONN;
> +
> +	cp.handle = cpu_to_le16(conn->handle);
> +	cp.reason = reason;
> +	hci_send_cmd(conn->hdev, HCI_OP_DISCONNECT, sizeof(cp), &cp);
> +}

When just using conn->state, then this becomes obsolete and we can use
the generic one.

> +
>  void hci_acl_connect(struct hci_conn *conn)
>  {
>  	struct hci_dev *hdev = conn->hdev;
> @@ -221,6 +246,8 @@ static void hci_conn_timeout(unsigned long arg)
>  	case BT_CONNECT2:
>  		if (conn->type == ACL_LINK && conn->out)
>  			hci_acl_connect_cancel(conn);
> +		if (conn->type == LE_LINK && conn->out)
> +			hci_le_connect_cancel(conn);

This should be redone with as this:

	if (conn->out) {
		if (ACL_LINK)
			...
		else if (LE_LINK)
			...
	}

>  		break;
>  	case BT_CONFIG:
>  	case BT_CONNECTED:
> @@ -397,6 +424,9 @@ struct hci_conn *hci_connect(struct hci_dev *hdev, int type, bdaddr_t *dst, __u8
>  	BT_DBG("%s dst %s", hdev->name, batostr(dst));
>  
>  	if (type == LE_LINK) {
> +		if (!lmp_le_capable(hdev))
> +			return NULL;
> +
>  		le = hci_conn_hash_lookup_ba(hdev, LE_LINK, dst);
>  
>  		if (!le)

We might need to move that lmp_le_capable check into L2CAP. Since
otherwise we can not give a proper return value if someone tries to use
LE on a BR/EDR only controller.

Regards

Marcel