Hi Alfonso,
> Systematically removing the LE connection parameters and autoconnect
> action is inconvenient for rebonding without disconnecting from
> userland (i.e. unpairing followed by repairing without
> disconnecting). The parameters will be lost after unparing and
> userland needs to take care of book-keeping them and re-adding them.
>
> This patch allows userland to forget about parameter management when
> rebonding without disconnecting. It defers clearing the connection
> parameters when unparing without disconnecting, giving a chance of
> keeping the parameters if a repairing happens before the connection is
> closed.
>
> Signed-off-by: Alfonso Acosta <fons@xxxxxxxxxxx>
>
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index 07ddeed62..b8685a7 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -555,6 +555,7 @@ enum {
> HCI_CONN_STK_ENCRYPT,
> HCI_CONN_AUTH_INITIATOR,
> HCI_CONN_DROP,
> + HCI_CONN_PARAM_REMOVAL_PEND,
> };
>
> static inline bool hci_conn_ssp_enabled(struct hci_conn *conn)
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index b9517bd..11aac06 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -544,6 +544,9 @@ int hci_conn_del(struct hci_conn *conn)
>
> hci_conn_del_sysfs(conn);
>
> + if (test_bit(HCI_CONN_PARAM_REMOVAL_PEND, &conn->flags))
> + hci_conn_params_del(conn->hdev, &conn->dst, conn->dst_type);
> +
> hci_dev_put(hdev);
>
> hci_conn_put(conn);
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 3fd88b0..2911a5e 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -2725,10 +2725,29 @@ static int unpair_device(struct sock *sk, struct hci_dev *hdev, void *data,
> }
>
> if (cp->addr.type == BDADDR_BREDR) {
> + if (cp->disconnect)
> + conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK,
> + &cp->addr.bdaddr);
> + else
> + conn = NULL; /* Avoid disconnecting later on*/
> +
I do not think this is a comment style that is valid in the network subsystem coding style and even if it is valid, it would be pretty unusual.
Generally I would do comment on the whole code. So something like this:
/* When disconnect of the the connection is requested,
* then look up the connection. If the remote device is
* connected, it will be later used to terminate the
* link.
*
* Setting it to NULL explicitly will cause no
* termination of the link.
*/
if (cp->disconnect)
conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK,
&cp->addr.bdaddr);
else
conn = NULL;
> err = hci_remove_link_key(hdev, &cp->addr.bdaddr);
> } else {
> u8 addr_type;
>
> + conn = hci_conn_hash_lookup_ba(hdev, LE_LINK,
> + &cp->addr.bdaddr);
> + if (conn) {
> + /* Defer clearing up the connection parameters
> + * until closing to give a chance of keeping
> + * them if a repairing happens.
> + */
> + set_bit(HCI_CONN_PARAM_REMOVAL_PEND, &conn->flags);
> +
> + if (!cp->disconnect)
> + conn = NULL; /* Avoid disconnecting later on*/
And here I would do this:
/* If disconnection is not requested, then clear the
* connection variable so that that the link is not
* terminated.
*/
if (!cp->disconnect)
conn = NULL;
> + }
> +
> if (cp->addr.type == BDADDR_LE_PUBLIC)
> addr_type = ADDR_LE_DEV_PUBLIC;
> else
> @@ -2736,8 +2755,6 @@ static int unpair_device(struct sock *sk, struct hci_dev *hdev, void *data,
>
> hci_remove_irk(hdev, &cp->addr.bdaddr, addr_type);
>
> - hci_conn_params_del(hdev, &cp->addr.bdaddr, addr_type);
> -
> err = hci_remove_ltk(hdev, &cp->addr.bdaddr, addr_type);
> }
>
> @@ -2747,17 +2764,6 @@ static int unpair_device(struct sock *sk, struct hci_dev *hdev, void *data,
> goto unlock;
> }
>
> - if (cp->disconnect) {
> - if (cp->addr.type == BDADDR_BREDR)
> - conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK,
> - &cp->addr.bdaddr);
> - else
> - conn = hci_conn_hash_lookup_ba(hdev, LE_LINK,
> - &cp->addr.bdaddr);
> - } else {
> - conn = NULL;
> - }
> -
And here I would just add a minor comment to remind us why this is correct:
/* If the connection variable is set, then termination of the
* link is requested.
*/
> if (!conn) {
> err = cmd_complete(sk, hdev->id, MGMT_OP_UNPAIR_DEVICE, 0,
> &rp, sizeof(rp));
> @@ -3062,6 +3068,11 @@ static void pairing_complete(struct pending_cmd *cmd, u8 status)
> hci_conn_put(conn);
>
> mgmt_pending_remove(cmd);
> +
> + /* The device is paired so there is no need to remove
> + * its connection parameters anymore.
> + */
> + clear_bit(HCI_CONN_PARAM_REMOVAL_PEND, &conn->flags);
> }
>
> void mgmt_smp_complete(struct hci_conn *conn, bool complete)
>From a logic point of view the patch looks good to me. This is just style changes to make it easier to remember why things are done. Johan might should have a second look at it before applying.
Regards
Marcel
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