[RFC v11 00/15] LE auto connection

[RFC v11 00/15] LE auto connection

[Andre Guedes]

Hi all,

This patch set takes in consideration Marcel's comments from previous revirew as
well as introduces privacy feature support to LE auto connection mechanism.

Below follows a summary to help the review process:

    * Patches from 1-10 are pretty much the same from previous version
      (exception to Patch 8). They introduce the LE auto connection
      infrastructure and auto connnection options.

    * Patch 8 modifies hci_conn_params_add() and hci_conn_params_del() so they
      also add/delete pending LE connections according to the auto_connect
      option. This way, background scan is automatically triggered/untriggered
      when connection parameters are added/removed. This feature was requested
      in "[RFC v10 10/10] Bluetooth: Add le_auto_conn file on debugfs" review.

    * Patches 11-12 add resolvable addresses support for LE auto connection
      mechanism.

    * Patches 14-15 change set_scan_params() so it restart background scan when
      new scanning parameters are set. This allows us to update scanning
      parameters on the fly.

This patch set don't filter duplicates on background scanning. The "time to
time re-enable scan" approach suggested in previous review might not be good
enough. Depending on how many time we wait to restart background scan, some
low latency reconnection profiles, such as HID over GATT, can become
impractical.

Moreover, just fine-tuning the scan parameters might be good enough. With
patches 14-15, we can easily change background scan parameters and do lots
experiments.

Finally, if enabling filter duplicates is really the way to go, I can write a
small patch set improving the background scan routine.

BR,

Andre


Andre Guedes (15):
  Bluetooth: Create hci_req_add_le_scan_disable helper
  Bluetooth: Declare le_conn_failed in hci_core.h
  Bluetooth: Stop scanning on LE connection
  Bluetooth: Remove unused function
  Bluetooth: Introduce hdev->pend_le_conn list
  Bluetooth: Introduce LE auto connection infrastructure
  Bluetooth: Introduce LE auto connect options
  Bluetooth: Connection parameters and auto connection
  Bluetooth: Temporarily stop background scanning on discovery
  Bluetooth: Auto connection and power on
  Bluetooth: Connection parameters and resolvable address
  Bluetooth: Support resolvable private addresses
  Bluetooth: Add le_auto_conn file on debugfs
  Bluetooth: Create hci_req_add_le_passive_scan helper
  Bluetooth: Update background scan parameters

 include/net/bluetooth/hci.h      |   1 +
 include/net/bluetooth/hci_core.h |  36 +++-
 net/bluetooth/hci_conn.c         |  85 +++++++--
 net/bluetooth/hci_core.c         | 365 +++++++++++++++++++++++++++++++++++++--
 net/bluetooth/hci_event.c        |  78 ++++++++-
 net/bluetooth/mgmt.c             |  40 +++--
 6 files changed, 552 insertions(+), 53 deletions(-)

-- 
1.8.5.4

[RFC v11 01/15] Bluetooth: Create hci_req_add_le_scan_disable helper

[Andre Guedes]

This patch moves stop LE scanning duplicate code to one single
place and reuses it. This will avoid more duplicate code in
upcoming patches.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_core.c         | 14 ++++++++++----
 net/bluetooth/mgmt.c             |  6 +-----
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 269c820..e394577 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1128,6 +1128,7 @@ void hci_req_add(struct hci_request *req, u16 opcode, u32 plen,
 void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen,
 		    const void *param, u8 event);
 void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
+void hci_req_add_le_scan_disable(struct hci_request *req);
 
 struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
 			       const void *param, u32 timeout);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 669c76e..9a078cf 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3318,7 +3318,6 @@ static void le_scan_disable_work(struct work_struct *work)
 {
 	struct hci_dev *hdev = container_of(work, struct hci_dev,
 					    le_scan_disable.work);
-	struct hci_cp_le_set_scan_enable cp;
 	struct hci_request req;
 	int err;
 
@@ -3326,9 +3325,7 @@ static void le_scan_disable_work(struct work_struct *work)
 
 	hci_req_init(&req, hdev);
 
-	memset(&cp, 0, sizeof(cp));
-	cp.enable = LE_SCAN_DISABLE;
-	hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
+	hci_req_add_le_scan_disable(&req);
 
 	err = hci_req_run(&req, le_scan_disable_work_complete);
 	if (err)
@@ -4872,3 +4869,12 @@ static void hci_cmd_work(struct work_struct *work)
 		}
 	}
 }
+
+void hci_req_add_le_scan_disable(struct hci_request *req)
+{
+	struct hci_cp_le_set_scan_enable cp;
+
+	memset(&cp, 0, sizeof(cp));
+	cp.enable = LE_SCAN_DISABLE;
+	hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
+}
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 25b8b27..c722914 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -3526,7 +3526,6 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
 	struct hci_cp_remote_name_req_cancel cp;
 	struct inquiry_entry *e;
 	struct hci_request req;
-	struct hci_cp_le_set_scan_enable enable_cp;
 	int err;
 
 	BT_DBG("%s", hdev->name);
@@ -3562,10 +3561,7 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
 		} else {
 			cancel_delayed_work(&hdev->le_scan_disable);
 
-			memset(&enable_cp, 0, sizeof(enable_cp));
-			enable_cp.enable = LE_SCAN_DISABLE;
-			hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE,
-				    sizeof(enable_cp), &enable_cp);
+			hci_req_add_le_scan_disable(&req);
 		}
 
 		break;
-- 
1.8.5.4

Re: [RFC v11 01/15] Bluetooth: Create hci_req_add_le_scan_disable helper

[Johan Hedberg]

Hi Andre,

On Mon, Feb 24, 2014, Andre Guedes wrote:
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1128,6 +1128,7 @@ void hci_req_add(struct hci_request *req, u16 opcode, u32 plen,
>  void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen,
>  		    const void *param, u8 event);
>  void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
> +void hci_req_add_le_scan_disable(struct hci_request *req);

It doesn't feel right to put this straight next to the generic async
request API. I'd at least have an empty line between the generic API and
this new function.

> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -3318,7 +3318,6 @@ static void le_scan_disable_work(struct work_struct *work)
>  {
>  	struct hci_dev *hdev = container_of(work, struct hci_dev,
>  					    le_scan_disable.work);
> -	struct hci_cp_le_set_scan_enable cp;
>  	struct hci_request req;
>  	int err;
>  
> @@ -3326,9 +3325,7 @@ static void le_scan_disable_work(struct work_struct *work)
>  
>  	hci_req_init(&req, hdev);
>  
> -	memset(&cp, 0, sizeof(cp));
> -	cp.enable = LE_SCAN_DISABLE;
> -	hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
> +	hci_req_add_le_scan_disable(&req);
>  
>  	err = hci_req_run(&req, le_scan_disable_work_complete);
>  	if (err)
> @@ -4872,3 +4869,12 @@ static void hci_cmd_work(struct work_struct *work)
>  		}
>  	}
>  }
> +
> +void hci_req_add_le_scan_disable(struct hci_request *req)
> +{
> +	struct hci_cp_le_set_scan_enable cp;
> +
> +	memset(&cp, 0, sizeof(cp));
> +	cp.enable = LE_SCAN_DISABLE;
> +	hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
> +}
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index 25b8b27..c722914 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -3526,7 +3526,6 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
>  	struct hci_cp_remote_name_req_cancel cp;
>  	struct inquiry_entry *e;
>  	struct hci_request req;
> -	struct hci_cp_le_set_scan_enable enable_cp;
>  	int err;
>  
>  	BT_DBG("%s", hdev->name);
> @@ -3562,10 +3561,7 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
>  		} else {
>  			cancel_delayed_work(&hdev->le_scan_disable);
>  
> -			memset(&enable_cp, 0, sizeof(enable_cp));
> -			enable_cp.enable = LE_SCAN_DISABLE;
> -			hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE,
> -				    sizeof(enable_cp), &enable_cp);
> +			hci_req_add_le_scan_disable(&req);
>  		}
>  
>  		break;

You've missed one place in clean_up_hci_state() in mgmt.c (which was
added by the recent "graceful power down" patch set.

Johan

Re: [RFC v11 01/15] Bluetooth: Create hci_req_add_le_scan_disable helper

[Andre Guedes]

Hi Johan,

On Tue, Feb 25, 2014 at 2:57 AM, Johan Hedberg <johan.hedberg@gmail.com> wrote:
> Hi Andre,
>
> On Mon, Feb 24, 2014, Andre Guedes wrote:
>> --- a/include/net/bluetooth/hci_core.h
>> +++ b/include/net/bluetooth/hci_core.h
>> @@ -1128,6 +1128,7 @@ void hci_req_add(struct hci_request *req, u16 opcode, u32 plen,
>>  void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen,
>>                   const void *param, u8 event);
>>  void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
>> +void hci_req_add_le_scan_disable(struct hci_request *req);
>
> It doesn't feel right to put this straight next to the generic async
> request API. I'd at least have an empty line between the generic API and
> this new function.

I'll add an empty line then.

>> --- a/net/bluetooth/hci_core.c
>> +++ b/net/bluetooth/hci_core.c
>> @@ -3318,7 +3318,6 @@ static void le_scan_disable_work(struct work_struct *work)
>>  {
>>       struct hci_dev *hdev = container_of(work, struct hci_dev,
>>                                           le_scan_disable.work);
>> -     struct hci_cp_le_set_scan_enable cp;
>>       struct hci_request req;
>>       int err;
>>
>> @@ -3326,9 +3325,7 @@ static void le_scan_disable_work(struct work_struct *work)
>>
>>       hci_req_init(&req, hdev);
>>
>> -     memset(&cp, 0, sizeof(cp));
>> -     cp.enable = LE_SCAN_DISABLE;
>> -     hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
>> +     hci_req_add_le_scan_disable(&req);
>>
>>       err = hci_req_run(&req, le_scan_disable_work_complete);
>>       if (err)
>> @@ -4872,3 +4869,12 @@ static void hci_cmd_work(struct work_struct *work)
>>               }
>>       }
>>  }
>> +
>> +void hci_req_add_le_scan_disable(struct hci_request *req)
>> +{
>> +     struct hci_cp_le_set_scan_enable cp;
>> +
>> +     memset(&cp, 0, sizeof(cp));
>> +     cp.enable = LE_SCAN_DISABLE;
>> +     hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
>> +}
>> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
>> index 25b8b27..c722914 100644
>> --- a/net/bluetooth/mgmt.c
>> +++ b/net/bluetooth/mgmt.c
>> @@ -3526,7 +3526,6 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
>>       struct hci_cp_remote_name_req_cancel cp;
>>       struct inquiry_entry *e;
>>       struct hci_request req;
>> -     struct hci_cp_le_set_scan_enable enable_cp;
>>       int err;
>>
>>       BT_DBG("%s", hdev->name);
>> @@ -3562,10 +3561,7 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
>>               } else {
>>                       cancel_delayed_work(&hdev->le_scan_disable);
>>
>> -                     memset(&enable_cp, 0, sizeof(enable_cp));
>> -                     enable_cp.enable = LE_SCAN_DISABLE;
>> -                     hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE,
>> -                                 sizeof(enable_cp), &enable_cp);
>> +                     hci_req_add_le_scan_disable(&req);
>>               }
>>
>>               break;
>
> You've missed one place in clean_up_hci_state() in mgmt.c (which was
> added by the recent "graceful power down" patch set.

I'll fix it.

Thanks,

Andre

[RFC v11 02/15] Bluetooth: Declare le_conn_failed in hci_core.h

[Andre Guedes]

This patch adds the "hci_" prefix to le_conn_failed() helper and
declares it in hci_core.h so it can be reused in hci_event.c.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h | 2 ++
 net/bluetooth/hci_conn.c         | 4 ++--
 net/bluetooth/hci_event.c        | 6 +-----
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index e394577..ebc9c4f 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -653,6 +653,8 @@ int hci_conn_switch_role(struct hci_conn *conn, __u8 role);
 
 void hci_conn_enter_active_mode(struct hci_conn *conn, __u8 force_active);
 
+void hci_le_conn_failed(struct hci_conn *conn, u8 status);
+
 /*
  * hci_conn_get() and hci_conn_put() are used to control the life-time of an
  * "hci_conn" object. They do not guarantee that the hci_conn object is running,
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 3d6b1cf..dc8aad9 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -515,7 +515,7 @@ struct hci_dev *hci_get_route(bdaddr_t *dst, bdaddr_t *src)
 EXPORT_SYMBOL(hci_get_route);
 
 /* This function requires the caller holds hdev->lock */
-static void le_conn_failed(struct hci_conn *conn, u8 status)
+void hci_le_conn_failed(struct hci_conn *conn, u8 status)
 {
 	struct hci_dev *hdev = conn->hdev;
 
@@ -545,7 +545,7 @@ static void create_le_conn_complete(struct hci_dev *hdev, u8 status)
 	if (!conn)
 		goto done;
 
-	le_conn_failed(conn, status);
+	hci_le_conn_failed(conn, status);
 
 done:
 	hci_dev_unlock(hdev);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 877cee8..eaa6965 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3658,11 +3658,7 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	}
 
 	if (ev->status) {
-		mgmt_connect_failed(hdev, &conn->dst, conn->type,
-				    conn->dst_type, ev->status);
-		hci_proto_connect_cfm(conn, ev->status);
-		conn->state = BT_CLOSED;
-		hci_conn_del(conn);
+		hci_le_conn_failed(conn, ev->status);
 		goto unlock;
 	}
 
-- 
1.8.5.4

[RFC v11 03/15] Bluetooth: Stop scanning on LE connection

[Andre Guedes]

Some LE controllers don't support scanning and creating a connection
at the same time. So we should always stop scanning in order to
establish the connection.

Since we may prematurely stop the discovery procedure in favor of
the connection establishment, we should also cancel hdev->le_scan_
disable delayed work and set the discovery state to DISCOVERY_STOPPED.

This change does a small improvement since it is not mandatory the
user stops scanning before connecting anymore. Moreover, this change
is required by upcoming LE auto connection mechanism in order to work
properly with controllers that don't support background scanning and
connection establishment at the same time.

In future, we might want to do a small optimization by checking if
controller is able to scan and connect at the same time. For now,
we want the simplest approach so we always stop scanning (even if
the controller is able to carry out both operations).

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci.h |  1 +
 net/bluetooth/hci_conn.c    | 89 ++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 88 insertions(+), 2 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 1bb45a4..c3834d3 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -356,6 +356,7 @@ enum {
 
 /* ---- HCI Error Codes ---- */
 #define HCI_ERROR_AUTH_FAILURE		0x05
+#define HCI_ERROR_MEMORY_EXCEEDED	0x07
 #define HCI_ERROR_CONNECTION_TIMEOUT	0x08
 #define HCI_ERROR_REJ_BAD_ADDR		0x0f
 #define HCI_ERROR_REMOTE_USER_TERM	0x13
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index dc8aad9..ae2c3e1 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -594,12 +594,83 @@ static int hci_create_le_conn(struct hci_conn *conn)
 	return 0;
 }
 
+static void hci_req_add_le_create_conn(struct hci_request *req,
+				       struct hci_conn *conn)
+{
+	struct hci_cp_le_create_conn cp;
+	struct hci_dev *hdev = conn->hdev;
+	u8 own_addr_type;
+
+	memset(&cp, 0, sizeof(cp));
+
+	/* Update random address, but set require_privacy to false so
+	 * that we never connect with an unresolvable address.
+	 */
+	if (hci_update_random_address(req, false, &own_addr_type))
+		return;
+
+	conn->src_type = own_addr_type;
+
+	cp.scan_interval = cpu_to_le16(hdev->le_scan_interval);
+	cp.scan_window = cpu_to_le16(hdev->le_scan_window);
+	bacpy(&cp.peer_addr, &conn->dst);
+	cp.peer_addr_type = conn->dst_type;
+	cp.own_address_type = conn->src_type;
+	cp.conn_interval_min = cpu_to_le16(conn->le_conn_min_interval);
+	cp.conn_interval_max = cpu_to_le16(conn->le_conn_max_interval);
+	cp.supervision_timeout = __constant_cpu_to_le16(0x002a);
+	cp.min_ce_len = __constant_cpu_to_le16(0x0000);
+	cp.max_ce_len = __constant_cpu_to_le16(0x0000);
+
+	hci_req_add(req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
+}
+
+static void stop_scan_complete(struct hci_dev *hdev, u8 status)
+{
+	struct hci_request req;
+	struct hci_conn *conn;
+	int err;
+
+	conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
+	if (!conn)
+		return;
+
+	if (status) {
+		BT_DBG("HCI request failed to stop scanning: status 0x%2.2x",
+		       status);
+
+		hci_dev_lock(hdev);
+		hci_le_conn_failed(conn, status);
+		hci_dev_unlock(hdev);
+		return;
+	}
+
+	/* Since we may have prematurely stopped discovery procedure, we should
+	 * update discovery state.
+	 */
+	cancel_delayed_work(&hdev->le_scan_disable);
+	hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
+
+	hci_req_init(&req, hdev);
+
+	hci_req_add_le_create_conn(&req, conn);
+
+	err = hci_req_run(&req, create_le_conn_complete);
+	if (err) {
+		hci_dev_lock(hdev);
+		hci_le_conn_failed(conn, HCI_ERROR_MEMORY_EXCEEDED);
+		hci_dev_unlock(hdev);
+		return;
+	}
+}
+
 static struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 				    u8 dst_type, u8 sec_level, u8 auth_type)
 {
 	struct hci_conn_params *params;
 	struct hci_conn *conn;
 	struct smp_irk *irk;
+	struct hci_request req;
 	int err;
 
 	if (test_bit(HCI_ADVERTISING, &hdev->flags))
@@ -675,9 +746,23 @@ static struct hci_conn *hci_connect_le(struct hci_dev *hdev, bdaddr_t *dst,
 		conn->le_conn_max_interval = hdev->le_conn_max_interval;
 	}
 
-	err = hci_create_le_conn(conn);
-	if (err)
+	hci_req_init(&req, hdev);
+
+	/* If controller is scanning, we stop it since some controllers are
+	 * not able to scan and connect at the same time.
+	 */
+	if (test_bit(HCI_LE_SCAN, &hdev->dev_flags)) {
+		hci_req_add_le_scan_disable(&req);
+		err = hci_req_run(&req, stop_scan_complete);
+	} else {
+		hci_req_add_le_create_conn(&req, conn);
+		err = hci_req_run(&req, create_le_conn_complete);
+	}
+
+	if (err) {
+		hci_conn_del(conn);
 		return ERR_PTR(err);
+	}
 
 done:
 	hci_conn_hold(conn);
-- 
1.8.5.4

[RFC v11 04/15] Bluetooth: Remove unused function

[Andre Guedes]

This patch removes hci_create_le_conn() since it is not used anymore.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_conn.c | 43 -------------------------------------------
 1 file changed, 43 deletions(-)

diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index ae2c3e1..a823d30 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -551,49 +551,6 @@ done:
 	hci_dev_unlock(hdev);
 }
 
-static int hci_create_le_conn(struct hci_conn *conn)
-{
-	struct hci_dev *hdev = conn->hdev;
-	struct hci_cp_le_create_conn cp;
-	struct hci_request req;
-	u8 own_addr_type;
-	int err;
-
-	hci_req_init(&req, hdev);
-
-	memset(&cp, 0, sizeof(cp));
-
-	/* Update random address, but set require_privacy to false so
-	 * that we never connect with an unresolvable address.
-	 */
-	err = hci_update_random_address(&req, false, &own_addr_type);
-	if (err < 0)
-		return err;
-
-	conn->src_type = own_addr_type;
-
-	cp.scan_interval = cpu_to_le16(hdev->le_scan_interval);
-	cp.scan_window = cpu_to_le16(hdev->le_scan_window);
-	bacpy(&cp.peer_addr, &conn->dst);
-	cp.peer_addr_type = conn->dst_type;
-	cp.own_address_type = own_addr_type;
-	cp.conn_interval_min = cpu_to_le16(conn->le_conn_min_interval);
-	cp.conn_interval_max = cpu_to_le16(conn->le_conn_max_interval);
-	cp.supervision_timeout = __constant_cpu_to_le16(0x002a);
-	cp.min_ce_len = __constant_cpu_to_le16(0x0000);
-	cp.max_ce_len = __constant_cpu_to_le16(0x0000);
-
-	hci_req_add(&req, HCI_OP_LE_CREATE_CONN, sizeof(cp), &cp);
-
-	err = hci_req_run(&req, create_le_conn_complete);
-	if (err) {
-		hci_conn_del(conn);
-		return err;
-	}
-
-	return 0;
-}
-
 static void hci_req_add_le_create_conn(struct hci_request *req,
 				       struct hci_conn *conn)
 {
-- 
1.8.5.4

[RFC v11 05/15] Bluetooth: Introduce hdev->pend_le_conn list

[Andre Guedes]

This patch introduces the hdev->pend_le_conn list which holds the
device addresses the kernel should autonomously connect. It also
introduces some helper functions to manipulate the list.

The list and helper functions will be used by the next patch which
implements the LE auto connection infrastructure.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |  7 +++++
 net/bluetooth/hci_core.c         | 68 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index ebc9c4f..b1ceaad 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -284,6 +284,7 @@ struct hci_dev {
 	struct list_head	identity_resolving_keys;
 	struct list_head	remote_oob_data;
 	struct list_head	le_conn_params;
+	struct list_head	pend_le_conns;
 
 	struct hci_dev_stats	stat;
 
@@ -797,6 +798,12 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_conn_params_clear(struct hci_dev *hdev);
 
+struct bdaddr_list *hci_pend_le_conn_lookup(struct hci_dev *hdev,
+					    bdaddr_t *addr, u8 addr_type);
+void hci_pend_le_conn_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
+void hci_pend_le_conn_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
+void hci_pend_le_conns_clear(struct hci_dev *hdev);
+
 void hci_uuids_clear(struct hci_dev *hdev);
 
 void hci_link_keys_clear(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 9a078cf..142ecd8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3259,6 +3259,72 @@ void hci_conn_params_clear(struct hci_dev *hdev)
 	BT_DBG("All LE connection parameters were removed");
 }
 
+/* This function requires the caller holds hdev->lock */
+struct bdaddr_list *hci_pend_le_conn_lookup(struct hci_dev *hdev,
+					    bdaddr_t *addr, u8 addr_type)
+{
+	struct bdaddr_list *entry;
+
+	list_for_each_entry(entry, &hdev->pend_le_conns, list) {
+		if (bacmp(&entry->bdaddr, addr) == 0 &&
+		    entry->bdaddr_type == addr_type)
+			return entry;
+	}
+
+	return NULL;
+}
+
+/* This function requires the caller holds hdev->lock */
+void hci_pend_le_conn_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
+{
+	struct bdaddr_list *entry;
+
+	entry = hci_pend_le_conn_lookup(hdev, addr, addr_type);
+	if (entry)
+		return;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry) {
+		BT_ERR("Out of memory");
+		return;
+	}
+
+	bacpy(&entry->bdaddr, addr);
+	entry->bdaddr_type = addr_type;
+
+	list_add(&entry->list, &hdev->pend_le_conns);
+
+	BT_DBG("addr %pMR (type %u)", addr, addr_type);
+}
+
+/* This function requires the caller holds hdev->lock */
+void hci_pend_le_conn_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
+{
+	struct bdaddr_list *entry;
+
+	entry = hci_pend_le_conn_lookup(hdev, addr, addr_type);
+	if (!entry)
+		return;
+
+	list_del(&entry->list);
+	kfree(entry);
+
+	BT_DBG("addr %pMR (type %u)", addr, addr_type);
+}
+
+/* This function requires the caller holds hdev->lock */
+void hci_pend_le_conns_clear(struct hci_dev *hdev)
+{
+	struct bdaddr_list *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &hdev->pend_le_conns, list) {
+		list_del(&entry->list);
+		kfree(entry);
+	}
+
+	BT_DBG("All LE pending connections cleared");
+}
+
 static void inquiry_complete(struct hci_dev *hdev, u8 status)
 {
 	if (status) {
@@ -3441,6 +3507,7 @@ struct hci_dev *hci_alloc_dev(void)
 	INIT_LIST_HEAD(&hdev->identity_resolving_keys);
 	INIT_LIST_HEAD(&hdev->remote_oob_data);
 	INIT_LIST_HEAD(&hdev->le_conn_params);
+	INIT_LIST_HEAD(&hdev->pend_le_conns);
 	INIT_LIST_HEAD(&hdev->conn_hash.list);
 
 	INIT_WORK(&hdev->rx_work, hci_rx_work);
@@ -3642,6 +3709,7 @@ void hci_unregister_dev(struct hci_dev *hdev)
 	hci_smp_irks_clear(hdev);
 	hci_remote_oob_data_clear(hdev);
 	hci_conn_params_clear(hdev);
+	hci_pend_le_conns_clear(hdev);
 	hci_dev_unlock(hdev);
 
 	hci_dev_put(hdev);
-- 
1.8.5.4

[RFC v11 06/15] Bluetooth: Introduce LE auto connection infrastructure

[Andre Guedes]

This patch introduces the LE auto connection infrastructure which
will be used to implement the LE auto connection options.

In summary, the auto connection mechanism works as follows: Once the
first pending LE connection is created, the background scanning is
started. When the target device is found in range, the kernel
autonomously starts the connection attempt. If connection is
established successfully, that pending LE connection is deleted and
the background is stopped.

To achieve that, this patch introduces the hci_update_background_scan()
which controls the background scanning state. This function starts or
stops the background scanning based on the hdev->pend_le_conns list. If
there is no pending LE connection, the background scanning is stopped.
Otherwise, we start the background scanning.

Then, every time a pending LE connection is added we call hci_update_
background_scan() so the background scanning is started (in case it is
not already running). Likewise, every time a pending LE connection is
deleted we call hci_update_background_scan() so the background scanning
is stopped (in case this was the last pending LE connection) or it is
started again (in case we have more pending LE connections). Finally,
we also call hci_update_background_scan() in hci_le_conn_failed() so
the background scan is restarted in case the connection establishment
fails. This way the background scanning keeps running until all pending
LE connection are established.

At this point, resolvable addresses are not support by this
infrastructure. The proper support is added in upcoming patches.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |  2 +
 net/bluetooth/hci_conn.c         |  5 +++
 net/bluetooth/hci_core.c         | 89 +++++++++++++++++++++++++++++++++++++++-
 net/bluetooth/hci_event.c        | 44 ++++++++++++++++++++
 4 files changed, 138 insertions(+), 2 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index b1ceaad..950a7d8 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -804,6 +804,8 @@ void hci_pend_le_conn_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_pend_le_conn_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_pend_le_conns_clear(struct hci_dev *hdev);
 
+void hci_update_background_scan(struct hci_dev *hdev);
+
 void hci_uuids_clear(struct hci_dev *hdev);
 
 void hci_link_keys_clear(struct hci_dev *hdev);
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index a823d30..d654a90 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -527,6 +527,11 @@ void hci_le_conn_failed(struct hci_conn *conn, u8 status)
 	hci_proto_connect_cfm(conn, status);
 
 	hci_conn_del(conn);
+
+	/* Since we may have temporarily stopped the background scanning in
+	 * favor of connection establishment, we should restart it.
+	 */
+	hci_update_background_scan(hdev);
 }
 
 static void create_le_conn_complete(struct hci_dev *hdev, u8 status)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 142ecd8..b1c247f 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3281,7 +3281,7 @@ void hci_pend_le_conn_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
 
 	entry = hci_pend_le_conn_lookup(hdev, addr, addr_type);
 	if (entry)
-		return;
+		goto done;
 
 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 	if (!entry) {
@@ -3295,6 +3295,9 @@ void hci_pend_le_conn_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
 	list_add(&entry->list, &hdev->pend_le_conns);
 
 	BT_DBG("addr %pMR (type %u)", addr, addr_type);
+
+done:
+	hci_update_background_scan(hdev);
 }
 
 /* This function requires the caller holds hdev->lock */
@@ -3304,12 +3307,15 @@ void hci_pend_le_conn_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
 
 	entry = hci_pend_le_conn_lookup(hdev, addr, addr_type);
 	if (!entry)
-		return;
+		goto done;
 
 	list_del(&entry->list);
 	kfree(entry);
 
 	BT_DBG("addr %pMR (type %u)", addr, addr_type);
+
+done:
+	hci_update_background_scan(hdev);
 }
 
 /* This function requires the caller holds hdev->lock */
@@ -4946,3 +4952,82 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 	cp.enable = LE_SCAN_DISABLE;
 	hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
 }
+
+static void update_background_scan_complete(struct hci_dev *hdev, u8 status)
+{
+	if (status)
+		BT_DBG("HCI request failed to update background scanning: "
+		       "status 0x%2.2x", status);
+}
+
+/* This function controls the background scanning based on hdev->pend_le_conns
+ * list. If there are pending LE connection we start the background scanning,
+ * otherwise we stop it.
+ *
+ * This function requires the caller holds hdev->lock.
+ */
+void hci_update_background_scan(struct hci_dev *hdev)
+{
+	struct hci_cp_le_set_scan_param param_cp;
+	struct hci_cp_le_set_scan_enable enable_cp;
+	struct hci_request req;
+	struct hci_conn *conn;
+	int err;
+
+	hci_req_init(&req, hdev);
+
+	if (list_empty(&hdev->pend_le_conns)) {
+		/* If there is no pending LE connections, we should stop
+		 * the background scanning.
+		 */
+
+		/* If controller is not scanning we are done. */
+		if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+			return;
+
+		hci_req_add_le_scan_disable(&req);
+
+		BT_DBG("%s stopping background scanning", hdev->name);
+	} else {
+		u8 own_addr_type;
+
+		/* If there is at least one pending LE connection, we should
+		 * keep the background scan running.
+		 */
+
+		/* If controller is already scanning we are done. */
+		if (test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+			return;
+
+		/* If controller is connecting, we should not start scanning
+		 * since some controllers are not able to scan and connect at
+		 * the same time.
+		 */
+		conn = hci_conn_hash_lookup_state(hdev, LE_LINK, BT_CONNECT);
+		if (conn)
+			return;
+
+		if (hci_update_random_address(&req, false, &own_addr_type))
+			return;
+
+		memset(&param_cp, 0, sizeof(param_cp));
+		param_cp.type = LE_SCAN_PASSIVE;
+		param_cp.interval = cpu_to_le16(hdev->le_scan_interval);
+		param_cp.window = cpu_to_le16(hdev->le_scan_window);
+		param_cp.own_address_type = own_addr_type;
+		hci_req_add(&req, HCI_OP_LE_SET_SCAN_PARAM, sizeof(param_cp),
+			    &param_cp);
+
+		memset(&enable_cp, 0, sizeof(enable_cp));
+		enable_cp.enable = LE_SCAN_ENABLE;
+		enable_cp.filter_dup = LE_SCAN_FILTER_DUP_DISABLE;
+		hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp),
+			    &enable_cp);
+
+		BT_DBG("%s starting background scanning", hdev->name);
+	}
+
+	err = hci_req_run(&req, update_background_scan_complete);
+	if (err)
+		BT_ERR("Failed to run HCI request: err %d", err);
+}
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index eaa6965..d5bf23d 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3677,25 +3677,69 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 	hci_proto_connect_cfm(conn, ev->status);
 
+	hci_pend_le_conn_del(hdev, &conn->dst, conn->dst_type);
+
 unlock:
 	hci_dev_unlock(hdev);
 }
 
+/* This function requires the caller holds hdev->lock */
+static void check_pending_le_conn(struct hci_dev *hdev, bdaddr_t *addr,
+				  u8 addr_type)
+{
+	struct hci_conn *conn;
+	u8 bdaddr_type;
+
+	if (!hci_pend_le_conn_lookup(hdev, addr, addr_type))
+		return;
+
+	if (addr_type == ADDR_LE_DEV_PUBLIC)
+		bdaddr_type = BDADDR_LE_PUBLIC;
+	else
+		bdaddr_type = BDADDR_LE_RANDOM;
+
+	conn = hci_connect(hdev, LE_LINK, addr, bdaddr_type, BT_SECURITY_LOW,
+			   HCI_AT_NO_BONDING);
+	if (!IS_ERR(conn))
+		return;
+
+	switch (PTR_ERR(conn)) {
+	case -EBUSY:
+		/* If hci_connect() returns -EBUSY it means there is already
+		 * an LE connection attempt going on. Since controllers don't
+		 * support more than one connection attempt at the time, we
+		 * don't consider this an error case.
+		 */
+		break;
+	default:
+		BT_DBG("Failed to connect: err %ld", PTR_ERR(conn));
+	}
+}
+
 static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	u8 num_reports = skb->data[0];
 	void *ptr = &skb->data[1];
 	s8 rssi;
 
+	hci_dev_lock(hdev);
+
 	while (num_reports--) {
 		struct hci_ev_le_advertising_info *ev = ptr;
 
+		if (ev->evt_type == LE_ADV_IND ||
+		    ev->evt_type == LE_ADV_DIRECT_IND)
+			check_pending_le_conn(hdev, &ev->bdaddr,
+					      ev->bdaddr_type);
+
 		rssi = ev->data[ev->length];
 		mgmt_device_found(hdev, &ev->bdaddr, LE_LINK, ev->bdaddr_type,
 				  NULL, rssi, 0, 1, ev->data, ev->length);
 
 		ptr += sizeof(*ev) + ev->length + 1;
 	}
+
+	hci_dev_unlock(hdev);
 }
 
 static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
-- 
1.8.5.4

Re: [RFC v11 06/15] Bluetooth: Introduce LE auto connection infrastructure

[Johan Hedberg]

Hi Andre,

On Mon, Feb 24, 2014, Andre Guedes wrote:
> +		if (hci_update_random_address(&req, false, &own_addr_type))
> +			return;

Don't we want require_privacy = true here?

> +	if (addr_type == ADDR_LE_DEV_PUBLIC)
> +		bdaddr_type = BDADDR_LE_PUBLIC;
> +	else
> +		bdaddr_type = BDADDR_LE_RANDOM;
> +
> +	conn = hci_connect(hdev, LE_LINK, addr, bdaddr_type, BT_SECURITY_LOW,
> +			   HCI_AT_NO_BONDING);

All hci_connect is is a very short wrapper to hci_connect_acl/le. The
hci_connect_le function in turn does the following:

        /* Convert from L2CAP channel address type to HCI address type */
        if (dst_type == BDADDR_LE_PUBLIC)
                dst_type = ADDR_LE_DEV_PUBLIC;
        else
                dst_type = ADDR_LE_DEV_RANDOM;

So it seems a bit silly to do this kind of back and forth conversions.
Instead, I think the hci_connect API should take the address type that's
used for struct hci_conn, i.e. the HCI one (not the L2CAP/mgmt one).

Also, since pretty much all places that are calling hci_connect pass an
explicit value as the link type I think the most sensible thing to do
would be to completely remove this function and export hci_connect_le &
hci_connect_acl from hci_conn.c.

Johan

Re: [RFC v11 06/15] Bluetooth: Introduce LE auto connection infrastructure

[Andre Guedes]

Hi Johan,

On Tue, Feb 25, 2014 at 1:23 AM, Johan Hedberg <johan.hedberg@gmail.com> wrote:
> Hi Andre,
>
> On Mon, Feb 24, 2014, Andre Guedes wrote:
>> +             if (hci_update_random_address(&req, false, &own_addr_type))
>> +                     return;
>
> Don't we want require_privacy = true here?

require_privacy = true enables non-resolvable address. Since this is a
passive scanning (no SCAN_REQ is sent), I don't think this is
required.

>> +     if (addr_type == ADDR_LE_DEV_PUBLIC)
>> +             bdaddr_type = BDADDR_LE_PUBLIC;
>> +     else
>> +             bdaddr_type = BDADDR_LE_RANDOM;
>> +
>> +     conn = hci_connect(hdev, LE_LINK, addr, bdaddr_type, BT_SECURITY_LOW,
>> +                        HCI_AT_NO_BONDING);
>
> All hci_connect is is a very short wrapper to hci_connect_acl/le. The
> hci_connect_le function in turn does the following:
>
>         /* Convert from L2CAP channel address type to HCI address type */
>         if (dst_type == BDADDR_LE_PUBLIC)
>                 dst_type = ADDR_LE_DEV_PUBLIC;
>         else
>                 dst_type = ADDR_LE_DEV_RANDOM;
>
> So it seems a bit silly to do this kind of back and forth conversions.
> Instead, I think the hci_connect API should take the address type that's
> used for struct hci_conn, i.e. the HCI one (not the L2CAP/mgmt one).
>
> Also, since pretty much all places that are calling hci_connect pass an
> explicit value as the link type I think the most sensible thing to do
> would be to completely remove this function and export hci_connect_le &
> hci_connect_acl from hci_conn.c.

I agree. I can do this refactoring in the next version.

BR,

Andre

Re: [RFC v11 06/15] Bluetooth: Introduce LE auto connection infrastructure

[Marcel Holtmann]

Hi Andre,

>>> +             if (hci_update_random_address(&req, false, &own_addr_type))
>>> +                     return;
>> 
>> Don't we want require_privacy = true here?
> 
> require_privacy = true enables non-resolvable address. Since this is a
> passive scanning (no SCAN_REQ is sent), I don't think this is
> required.

that is correct, it is not strictly speaking needed. However I would prefer we set this to true anyway and add a proper comment for it like we do with the other places.

Regards

Marcel

[RFC v11 07/15] Bluetooth: Introduce LE auto connect options

[Andre Guedes]

This patch introduces the LE auto connection options: HCI_AUTO_CONN_
ALWAYS and HCI_AUTO_CONN_LINK_LOSS. Their working mechanism are
described as follows:

The HCI_AUTO_CONN_ALWAYS option configures the kernel to always re-
establish the connection, no matter the reason the connection was
terminated. This feature is required by some LE profiles such as
HID over GATT, Health Thermometer and Blood Pressure. These profiles
require the host autonomously connect to the device as soon as it
enters in connectable mode (start advertising) so the device is able
to delivery notifications or indications.

The BT_AUTO_CONN_LINK_LOSS option configures the kernel to re-
establish the connection in case the connection was terminated due
to a link loss. This feature is required by the majority of LE
profiles such as Proximity, Find Me, Cycling Speed and Cadence and
Time.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |  9 ++++++++-
 net/bluetooth/hci_core.c         | 11 +++++++----
 net/bluetooth/hci_event.c        | 18 ++++++++++++++++++
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 950a7d8..5539dea 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -402,6 +402,12 @@ struct hci_conn_params {
 
 	u16 conn_min_interval;
 	u16 conn_max_interval;
+
+	enum {
+		HCI_AUTO_CONN_DISABLED,
+		HCI_AUTO_CONN_ALWAYS,
+		HCI_AUTO_CONN_LINK_LOSS,
+	} auto_connect;
 };
 
 extern struct list_head hci_dev_list;
@@ -794,7 +800,8 @@ int hci_blacklist_del(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
 					       bdaddr_t *addr, u8 addr_type);
 void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
-			 u16 conn_min_interval, u16 conn_max_interval);
+			 u8 auto_connect, u16 conn_min_interval,
+			 u16 conn_max_interval);
 void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_conn_params_clear(struct hci_dev *hdev);
 
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index b1c247f..dbd4e8a 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3202,7 +3202,8 @@ struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
 
 /* This function requires the caller holds hdev->lock */
 void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
-			 u16 conn_min_interval, u16 conn_max_interval)
+			 u8 auto_connect, u16 conn_min_interval,
+			 u16 conn_max_interval)
 {
 	struct hci_conn_params *params;
 
@@ -3210,6 +3211,7 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 	if (params) {
 		params->conn_min_interval = conn_min_interval;
 		params->conn_max_interval = conn_max_interval;
+		params->auto_connect = auto_connect;
 		return;
 	}
 
@@ -3223,12 +3225,13 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 	params->addr_type = addr_type;
 	params->conn_min_interval = conn_min_interval;
 	params->conn_max_interval = conn_max_interval;
+	params->auto_connect = auto_connect;
 
 	list_add(&params->list, &hdev->le_conn_params);
 
-	BT_DBG("addr %pMR (type %u) conn_min_interval 0x%.4x "
-	       "conn_max_interval 0x%.4x", addr, addr_type, conn_min_interval,
-	       conn_max_interval);
+	BT_DBG("addr %pMR (type %u) auto_connect %u conn_min_interval 0x%.4x "
+	       "conn_max_interval 0x%.4x", addr, addr_type, auto_connect,
+	       conn_min_interval, conn_max_interval);
 }
 
 /* This function requires the caller holds hdev->lock */
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d5bf23d..7acf066 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1841,6 +1841,7 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
 	struct hci_ev_disconn_complete *ev = (void *) skb->data;
 	u8 reason = hci_to_mgmt_reason(ev->reason);
+	struct hci_conn_params *params;
 	struct hci_conn *conn;
 	bool mgmt_connected;
 	u8 type;
@@ -1868,6 +1869,23 @@ static void hci_disconn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	if (conn->type == ACL_LINK && conn->flush_key)
 		hci_remove_link_key(hdev, &conn->dst);
 
+	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
+	if (params) {
+		switch (params->auto_connect) {
+		case HCI_AUTO_CONN_LINK_LOSS:
+			if (ev->reason != HCI_ERROR_CONNECTION_TIMEOUT)
+				break;
+			/* Fall through */
+
+		case HCI_AUTO_CONN_ALWAYS:
+			hci_pend_le_conn_add(hdev, &conn->dst, conn->dst_type);
+			break;
+
+		default:
+			break;
+		}
+	}
+
 	type = conn->type;
 
 	hci_proto_disconn_cfm(conn, ev->reason);
-- 
1.8.5.4

[RFC v11 08/15] Bluetooth: Connection parameters and auto connection

[Andre Guedes]

This patch modifies hci_conn_params_add() and hci_conn_params_del() so
they also add/delete pending LE connections according to the auto_
connect option. This way, background scan is automatically triggered/
untriggered when connection parameters are added/removed.

For instance, when a new connection parameters with HCI_AUTO_CONN_ALWAYS
option is added and we are not connected to the device, we add a pending
LE connection for that device.

Likewise, when the connection parameters are updated we add or delete
a pending LE connection according to its new auto_connect option.

Finally, when the connection parameter is deleted we also delete the
pending LE connection (if any).

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_core.c | 42 +++++++++++++++++++++++++++++++++++-------
 1 file changed, 35 insertions(+), 7 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index dbd4e8a..0c1d2e3 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3200,6 +3200,23 @@ struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
 	return NULL;
 }
 
+static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
+{
+	struct hci_conn *conn;
+
+	conn = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
+	if (!conn)
+		return false;
+
+	if (conn->dst_type != type)
+		return false;
+
+	if (conn->state != BT_CONNECTED)
+		return false;
+
+	return true;
+}
+
 /* This function requires the caller holds hdev->lock */
 void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 			 u8 auto_connect, u16 conn_min_interval,
@@ -3208,12 +3225,8 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 	struct hci_conn_params *params;
 
 	params = hci_conn_params_lookup(hdev, addr, addr_type);
-	if (params) {
-		params->conn_min_interval = conn_min_interval;
-		params->conn_max_interval = conn_max_interval;
-		params->auto_connect = auto_connect;
-		return;
-	}
+	if (params)
+		goto update;
 
 	params = kzalloc(sizeof(*params), GFP_KERNEL);
 	if (!params) {
@@ -3223,11 +3236,24 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 
 	bacpy(&params->addr, addr);
 	params->addr_type = addr_type;
+
+	list_add(&params->list, &hdev->le_conn_params);
+
+update:
 	params->conn_min_interval = conn_min_interval;
 	params->conn_max_interval = conn_max_interval;
 	params->auto_connect = auto_connect;
 
-	list_add(&params->list, &hdev->le_conn_params);
+	switch (auto_connect) {
+	case HCI_AUTO_CONN_DISABLED:
+	case HCI_AUTO_CONN_LINK_LOSS:
+		hci_pend_le_conn_del(hdev, addr, addr_type);
+		break;
+	case HCI_AUTO_CONN_ALWAYS:
+		if (!is_connected(hdev, addr, addr_type))
+			hci_pend_le_conn_add(hdev, addr, addr_type);
+		break;
+	}
 
 	BT_DBG("addr %pMR (type %u) auto_connect %u conn_min_interval 0x%.4x "
 	       "conn_max_interval 0x%.4x", addr, addr_type, auto_connect,
@@ -3243,6 +3269,8 @@ void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type)
 	if (!params)
 		return;
 
+	hci_pend_le_conn_del(hdev, addr, addr_type);
+
 	list_del(&params->list);
 	kfree(params);
 
-- 
1.8.5.4

[RFC v11 09/15] Bluetooth: Temporarily stop background scanning on discovery

[Andre Guedes]

If the user sends a mgmt start discovery command while the background
scanning is running, we should temporarily stop it. Once the discovery
finishes, we start the background scanning again.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_core.c |  2 ++
 net/bluetooth/mgmt.c     | 12 ++++++------
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 0c1d2e3..831cca8 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1786,6 +1786,8 @@ void hci_discovery_set_state(struct hci_dev *hdev, int state)
 
 	switch (state) {
 	case DISCOVERY_STOPPED:
+		hci_update_background_scan(hdev);
+
 		if (hdev->discovery.state != DISCOVERY_STARTING)
 			mgmt_discovering(hdev, 0);
 		break;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index c722914..7c8a611 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -3432,12 +3432,12 @@ static int start_discovery(struct sock *sk, struct hci_dev *hdev,
 			goto failed;
 		}
 
-		if (test_bit(HCI_LE_SCAN, &hdev->dev_flags)) {
-			err = cmd_status(sk, hdev->id, MGMT_OP_START_DISCOVERY,
-					 MGMT_STATUS_BUSY);
-			mgmt_pending_remove(cmd);
-			goto failed;
-		}
+		/* If controller is scanning, it means the background scanning
+		 * is running. Thus, we should temporarily stop it in order to
+		 * set the discovery scanning parameters.
+		 */
+		if (test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+			hci_req_add_le_scan_disable(&req);
 
 		memset(&param_cp, 0, sizeof(param_cp));
 
-- 
1.8.5.4

[RFC v11 10/15] Bluetooth: Auto connection and power on

[Andre Guedes]

When hdev is closed (e.g. Mgmt power off command, RFKILL or controller
is reset), the ongoing active connections are silently dropped by the
controller (no Disconnection Complete Event is sent to host). For that
reason, the devices that require HCI_AUTO_CONN_ALWAYS are not added to
hdev->pend_le_conns list and they won't auto connect.

So to fix this issue, during hdev closing, we remove all pending LE
connections. After adapter is powered on, we add a pending LE connection
for each HCI_AUTO_CONN_ALWAYS address.

This way, the auto connection mechanism works propely after a power
off and power on sequence as well as RFKILL block/unblock.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_core.c |  1 +
 net/bluetooth/mgmt.c     | 13 +++++++++++++
 2 files changed, 14 insertions(+)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 831cca8..e78e48e 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2266,6 +2266,7 @@ static int hci_dev_do_close(struct hci_dev *hdev)
 	hci_dev_lock(hdev);
 	hci_inquiry_cache_flush(hdev);
 	hci_conn_hash_flush(hdev);
+	hci_pend_le_conns_clear(hdev);
 	hci_dev_unlock(hdev);
 
 	hci_notify(hdev, HCI_DEV_DOWN);
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 7c8a611..a08c2bf 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -4662,6 +4662,17 @@ void mgmt_index_removed(struct hci_dev *hdev)
 	mgmt_event(MGMT_EV_INDEX_REMOVED, hdev, NULL, 0, NULL);
 }
 
+/* This function requires the caller holds hdev->lock */
+static void restart_le_auto_conns(struct hci_dev *hdev)
+{
+	struct hci_conn_params *p;
+
+	list_for_each_entry(p, &hdev->le_conn_params, list) {
+		if (p->auto_connect == HCI_AUTO_CONN_ALWAYS)
+			hci_pend_le_conn_add(hdev, &p->addr, p->addr_type);
+	}
+}
+
 static void powered_complete(struct hci_dev *hdev, u8 status)
 {
 	struct cmd_lookup match = { NULL, hdev };
@@ -4670,6 +4681,8 @@ static void powered_complete(struct hci_dev *hdev, u8 status)
 
 	hci_dev_lock(hdev);
 
+	restart_le_auto_conns(hdev);
+
 	mgmt_pending_foreach(MGMT_OP_SET_POWERED, hdev, settings_rsp, &match);
 
 	new_settings(hdev, match.sk);
-- 
1.8.5.4

[RFC v11 11/15] Bluetooth: Connection parameters and resolvable address

[Andre Guedes]

We should only add connection parameters for public, random static and
random private resolvable with IRK. If we allow non-resolvable or
resolvable without IRK, the background scan may run indefinitely. So, to
avoid this undesired behavior, we should check the address type in
hci_conn_params_add().

Additionally, since the IRK is removed during unpair, we should also
remove the connection parameters from that device.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h | 18 +++++++++++++++---
 net/bluetooth/hci_core.c         | 24 ++++++++++++++++++++----
 net/bluetooth/mgmt.c             |  2 ++
 3 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5539dea..c81847e 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -799,9 +799,9 @@ int hci_blacklist_del(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 
 struct hci_conn_params *hci_conn_params_lookup(struct hci_dev *hdev,
 					       bdaddr_t *addr, u8 addr_type);
-void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
-			 u8 auto_connect, u16 conn_min_interval,
-			 u16 conn_max_interval);
+int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
+			u8 auto_connect, u16 conn_min_interval,
+			u16 conn_max_interval);
 void hci_conn_params_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_conn_params_clear(struct hci_dev *hdev);
 
@@ -1117,6 +1117,18 @@ static inline bool hci_bdaddr_is_rpa(bdaddr_t *bdaddr, u8 addr_type)
 	return false;
 }
 
+/* Check if address is "random private non-resolvable" type */
+static inline bool hci_bdaddr_is_non_rpa(bdaddr_t *bdaddr, u8 addr_type)
+{
+	if (addr_type != 0x01)
+		return false;
+
+	if ((bdaddr->b[5] & 0xc0) == 0x00)
+		return true;
+
+	return false;
+}
+
 static inline struct smp_irk *hci_get_irk(struct hci_dev *hdev,
 					  bdaddr_t *bdaddr, u8 addr_type)
 {
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e78e48e..a8baf9a 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -3221,12 +3221,26 @@ static bool is_connected(struct hci_dev *hdev, bdaddr_t *addr, u8 type)
 }
 
 /* This function requires the caller holds hdev->lock */
-void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
-			 u8 auto_connect, u16 conn_min_interval,
-			 u16 conn_max_interval)
+int hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
+			u8 auto_connect, u16 conn_min_interval,
+			u16 conn_max_interval)
 {
 	struct hci_conn_params *params;
 
+	if (hci_bdaddr_is_non_rpa(addr, addr_type))
+		return -EINVAL;
+
+	if (hci_bdaddr_is_rpa(addr, addr_type)) {
+		struct smp_irk *irk;
+
+		irk = hci_get_irk(hdev, addr, addr_type);
+		if (!irk)
+			return -EINVAL;
+
+		addr = &irk->bdaddr;
+		addr_type = irk->addr_type;
+	}
+
 	params = hci_conn_params_lookup(hdev, addr, addr_type);
 	if (params)
 		goto update;
@@ -3234,7 +3248,7 @@ void hci_conn_params_add(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type,
 	params = kzalloc(sizeof(*params), GFP_KERNEL);
 	if (!params) {
 		BT_ERR("Out of memory");
-		return;
+		return -ENOMEM;
 	}
 
 	bacpy(&params->addr, addr);
@@ -3261,6 +3275,8 @@ update:
 	BT_DBG("addr %pMR (type %u) auto_connect %u conn_min_interval 0x%.4x "
 	       "conn_max_interval 0x%.4x", addr, addr_type, auto_connect,
 	       conn_min_interval, conn_max_interval);
+
+	return 0;
 }
 
 /* This function requires the caller holds hdev->lock */
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index a08c2bf..4745fb5 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -2419,6 +2419,8 @@ 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);
 	}
 
-- 
1.8.5.4

[RFC v11 12/15] Bluetooth: Support resolvable private addresses

[Andre Guedes]

Only identity addresses are inserted into hdev->pend_le_conns. So,
in order to support resolvable private addresses in auto connection
mechanism, we should resolve the address before checking for pending
connections.

Thus, this patch adds an extra check in check_pending_le_conn() and
updates 'addr' and 'addr_type' variables before hci_pend_le_conn_
lookup().

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_event.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 7acf066..d44cb23 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3706,8 +3706,18 @@ static void check_pending_le_conn(struct hci_dev *hdev, bdaddr_t *addr,
 				  u8 addr_type)
 {
 	struct hci_conn *conn;
+	struct smp_irk *irk;
 	u8 bdaddr_type;
 
+	/* If this is a resolvable address, we should resolve it and then
+	 * update address and address type variables.
+	 */
+	irk = hci_get_irk(hdev, addr, addr_type);
+	if (irk) {
+		addr = &irk->bdaddr;
+		addr_type = irk->addr_type;
+	}
+
 	if (!hci_pend_le_conn_lookup(hdev, addr, addr_type))
 		return;
 
-- 
1.8.5.4

[RFC v11 13/15] Bluetooth: Add le_auto_conn file on debugfs

[Andre Guedes]

This patch adds to debugfs the le_auto_conn file. This file will be
used to test LE auto connection infrastructure.

To add a new auto connection address we write on le_auto_conn file
following the format <address> <address type> <auto_connect>.

The <address type> values are:
  * 0 for public address
  * 1 for random address

The <auto_connect> values are (for more details see struct hci_
conn_params):
  * 0 for disabled
  * 1 for always
  * 2 for link loss

So for instance, if you want the kernel autonomously establishes
connections with device AA:BB:CC:DD:EE:FF (public address) every
time the device enters in connectable mode (starts advertising),
you should run the command:
$ echo "AA:BB:CC:DD:EE:FF 0 1" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

To get the list of connection parameters configured in kernel, read
the le_auto_conn file:
$ cat /sys/kernel/debug/bluetooth/hci0/le_auto_conn

Finally, to clear the connection parameters list, write an empty
string:
$ echo "" > /sys/kernel/debug/bluetooth/hci0/le_auto_conn

This file is created only if LE is enabled.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_core.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index a8baf9a..5d51086 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -896,6 +896,96 @@ static const struct file_operations lowpan_debugfs_fops = {
 	.llseek		= default_llseek,
 };
 
+static int le_auto_conn_show(struct seq_file *sf, void *ptr)
+{
+	struct hci_dev *hdev = sf->private;
+	struct hci_conn_params *p;
+
+	hci_dev_lock(hdev);
+
+	list_for_each_entry(p, &hdev->le_conn_params, list) {
+		seq_printf(sf, "%pMR %u %u\n", &p->addr, p->addr_type,
+			   p->auto_connect);
+	}
+
+	hci_dev_unlock(hdev);
+
+	return 0;
+}
+
+static int le_auto_conn_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, le_auto_conn_show, inode->i_private);
+}
+
+static ssize_t le_auto_conn_write(struct file *file, const char __user *data,
+				  size_t count, loff_t *offset)
+{
+	struct seq_file *sf = file->private_data;
+	struct hci_dev *hdev = sf->private;
+	u8 auto_connect;
+	bdaddr_t addr;
+	u8 addr_type;
+	char *buf;
+	int err;
+	int n;
+
+	/* Don't allow partial write */
+	if (*offset != 0)
+		return -EINVAL;
+
+	/* If empty string, clear the connection parameters and pending LE
+	 * connection list.
+	 */
+	if (count == 1) {
+		hci_dev_lock(hdev);
+		hci_conn_params_clear(hdev);
+		hci_pend_le_conns_clear(hdev);
+		hci_update_background_scan(hdev);
+		hci_dev_unlock(hdev);
+		return count;
+	}
+
+	buf = kzalloc(count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	if (copy_from_user(buf, data, count)) {
+		kfree(buf);
+		return -EFAULT;
+	}
+
+	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu %hhu", &addr.b[5],
+		   &addr.b[4], &addr.b[3], &addr.b[2], &addr.b[1], &addr.b[0],
+		   &addr_type, &auto_connect);
+	if (n != 8) {
+		kfree(buf);
+		return -EINVAL;
+	}
+
+	hci_dev_lock(hdev);
+	err = hci_conn_params_add(hdev, &addr, addr_type, auto_connect,
+				  hdev->le_conn_min_interval,
+				  hdev->le_conn_max_interval);
+	hci_dev_unlock(hdev);
+
+	if (err) {
+		kfree(buf);
+		return err;
+	}
+
+	kfree(buf);
+	return count;
+}
+
+static const struct file_operations le_auto_conn_fops = {
+	.open		= le_auto_conn_open,
+	.read		= seq_read,
+	.write		= le_auto_conn_write,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
 /* ---- HCI requests ---- */
 
 static void hci_req_sync_complete(struct hci_dev *hdev, u8 result)
@@ -1694,6 +1784,8 @@ static int __hci_init(struct hci_dev *hdev)
 				    hdev, &adv_channel_map_fops);
 		debugfs_create_file("6lowpan", 0644, hdev->debugfs, hdev,
 				    &lowpan_debugfs_fops);
+		debugfs_create_file("le_auto_conn", 0644, hdev->debugfs, hdev,
+				    &le_auto_conn_fops);
 	}
 
 	return 0;
-- 
1.8.5.4

[RFC v11 14/15] Bluetooth: Create hci_req_add_le_passive_scan helper

[Andre Guedes]

This patches creates the hci_req_add_le_passive_scan helper so it can
be re-used in the next patch.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_core.c | 46 ++++++++++++++++++++++++++--------------------
 1 file changed, 26 insertions(+), 20 deletions(-)

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 5d51086..e0ebbd9 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -5095,6 +5095,31 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
 	hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
 }
 
+static void hci_req_add_le_passive_scan(struct hci_request *req,
+					struct hci_dev *hdev)
+{
+	struct hci_cp_le_set_scan_param param_cp;
+	struct hci_cp_le_set_scan_enable enable_cp;
+	u8 own_addr_type;
+
+	if (hci_update_random_address(req, true, &own_addr_type))
+		return;
+
+	memset(&param_cp, 0, sizeof(param_cp));
+	param_cp.type = LE_SCAN_PASSIVE;
+	param_cp.interval = cpu_to_le16(hdev->le_scan_interval);
+	param_cp.window = cpu_to_le16(hdev->le_scan_window);
+	param_cp.own_address_type = own_addr_type;
+	hci_req_add(req, HCI_OP_LE_SET_SCAN_PARAM, sizeof(param_cp),
+		    &param_cp);
+
+	memset(&enable_cp, 0, sizeof(enable_cp));
+	enable_cp.enable = LE_SCAN_ENABLE;
+	enable_cp.filter_dup = LE_SCAN_FILTER_DUP_DISABLE;
+	hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp),
+		    &enable_cp);
+}
+
 static void update_background_scan_complete(struct hci_dev *hdev, u8 status)
 {
 	if (status)
@@ -5110,8 +5135,6 @@ static void update_background_scan_complete(struct hci_dev *hdev, u8 status)
  */
 void hci_update_background_scan(struct hci_dev *hdev)
 {
-	struct hci_cp_le_set_scan_param param_cp;
-	struct hci_cp_le_set_scan_enable enable_cp;
 	struct hci_request req;
 	struct hci_conn *conn;
 	int err;
@@ -5131,8 +5154,6 @@ void hci_update_background_scan(struct hci_dev *hdev)
 
 		BT_DBG("%s stopping background scanning", hdev->name);
 	} else {
-		u8 own_addr_type;
-
 		/* If there is at least one pending LE connection, we should
 		 * keep the background scan running.
 		 */
@@ -5149,22 +5170,7 @@ void hci_update_background_scan(struct hci_dev *hdev)
 		if (conn)
 			return;
 
-		if (hci_update_random_address(&req, false, &own_addr_type))
-			return;
-
-		memset(&param_cp, 0, sizeof(param_cp));
-		param_cp.type = LE_SCAN_PASSIVE;
-		param_cp.interval = cpu_to_le16(hdev->le_scan_interval);
-		param_cp.window = cpu_to_le16(hdev->le_scan_window);
-		param_cp.own_address_type = own_addr_type;
-		hci_req_add(&req, HCI_OP_LE_SET_SCAN_PARAM, sizeof(param_cp),
-			    &param_cp);
-
-		memset(&enable_cp, 0, sizeof(enable_cp));
-		enable_cp.enable = LE_SCAN_ENABLE;
-		enable_cp.filter_dup = LE_SCAN_FILTER_DUP_DISABLE;
-		hci_req_add(&req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(enable_cp),
-			    &enable_cp);
+		hci_req_add_le_passive_scan(&req, hdev);
 
 		BT_DBG("%s starting background scanning", hdev->name);
 	}
-- 
1.8.5.4

[RFC v11 15/15] Bluetooth: Update background scan parameters

[Andre Guedes]

If new scanning parameters are set while background scan is running,
we should restart background scanning so these parameters are updated.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_core.c         | 26 ++++++++++++++++++++++++++
 net/bluetooth/mgmt.c             |  7 +++++++
 3 files changed, 34 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index c81847e..2c5289d 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -812,6 +812,7 @@ void hci_pend_le_conn_del(struct hci_dev *hdev, bdaddr_t *addr, u8 addr_type);
 void hci_pend_le_conns_clear(struct hci_dev *hdev);
 
 void hci_update_background_scan(struct hci_dev *hdev);
+void hci_restart_background_scan(struct hci_dev *hdev);
 
 void hci_uuids_clear(struct hci_dev *hdev);
 
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index e0ebbd9..55c01e9 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -5179,3 +5179,29 @@ void hci_update_background_scan(struct hci_dev *hdev)
 	if (err)
 		BT_ERR("Failed to run HCI request: err %d", err);
 }
+
+static void restart_background_scan_complete(struct hci_dev *hdev, u8 status)
+{
+	if (status)
+		BT_DBG("HCI request failed to restart background scan: "
+		       "status 0x%2.2x", status);
+}
+
+void hci_restart_background_scan(struct hci_dev *hdev)
+{
+	struct hci_request req;
+	int err;
+
+	hci_req_init(&req, hdev);
+
+	hci_req_add_le_scan_disable(&req);
+	hci_req_add_le_passive_scan(&req, hdev);
+
+	err = hci_req_run(&req, restart_background_scan_complete);
+	if (err) {
+		BT_ERR("Failed to run HCI request: err %d", err);
+		return;
+	}
+
+	BT_DBG("%s re-starting background scanning", hdev->name);
+}
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 4745fb5..679670d 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -3917,6 +3917,13 @@ static int set_scan_params(struct sock *sk, struct hci_dev *hdev,
 
 	err = cmd_complete(sk, hdev->id, MGMT_OP_SET_SCAN_PARAMS, 0, NULL, 0);
 
+	/* If background scan is running, restart it so new parameters are
+	 * loaded.
+	 */
+	if (test_bit(HCI_LE_SCAN, &hdev->dev_flags) &&
+	    hdev->discovery.state == DISCOVERY_STOPPED)
+		hci_restart_background_scan(hdev);
+
 	hci_dev_unlock(hdev);
 
 	return err;
-- 
1.8.5.4