diff mbox series

[2/2] Bluetooth: Send AdvMonitor Dev Found for all matched devices

Message ID 20220312020707.2.Ie20f132ad5cb6bcd435d6c6e0fca8a9d858e83d4@changeid
State Accepted
Commit 1b144a7a05120ad60fe5a3f285a4f3d760fa27f5
Headers show
Series [1/2] Bluetooth: msft: Clear tracked devices on resume | expand

Commit Message

Manish Mandlik March 12, 2022, 10:08 a.m. UTC 
When an Advertisement Monitor is configured with SamplingPeriod 0xFF,
the controller reports only one adv report along with the MSFT Monitor
Device event.

When an advertiser matches multiple monitors, some controllers send one
adv report for each matched monitor; whereas, some controllers send just
one adv report for all matched monitors.

In such a case, report Adv Monitor Device Found event for each matched
monitor.

Signed-off-by: Manish Mandlik <mmandlik@google.com>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
---

 net/bluetooth/mgmt.c | 70 +++++++++++++++++++++++---------------------
 1 file changed, 37 insertions(+), 33 deletions(-)

Comments

Marcel Holtmann March 16, 2022, 2:42 p.m. UTC | #1 
Hi Manish,

> When an Advertisement Monitor is configured with SamplingPeriod 0xFF,
> the controller reports only one adv report along with the MSFT Monitor
> Device event.
> 
> When an advertiser matches multiple monitors, some controllers send one
> adv report for each matched monitor; whereas, some controllers send just
> one adv report for all matched monitors.
> 
> In such a case, report Adv Monitor Device Found event for each matched
> monitor.
> 
> Signed-off-by: Manish Mandlik <mmandlik@google.com>
> Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
> ---
> 
> net/bluetooth/mgmt.c | 70 +++++++++++++++++++++++---------------------
> 1 file changed, 37 insertions(+), 33 deletions(-)

patch has been applied to bluetooth-next tree.

> 
> diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> index d59c70e9166f..e4da2318a2f6 100644
> --- a/net/bluetooth/mgmt.c
> +++ b/net/bluetooth/mgmt.c
> @@ -9628,17 +9628,44 @@ void mgmt_adv_monitor_device_lost(struct hci_dev *hdev, u16 handle,
> 		   NULL);
> }
> 
> +static void mgmt_send_adv_monitor_device_found(struct hci_dev *hdev,
> +					       struct sk_buff *skb,
> +					       struct sock *skip_sk,
> +					       u16 handle)
> +{
> +	struct sk_buff *advmon_skb;
> +	size_t advmon_skb_len;
> +	__le16 *monitor_handle;
> +
> +	if (!skb)
> +		return;
> +
> +	advmon_skb_len = (sizeof(struct mgmt_ev_adv_monitor_device_found) -
> +			  sizeof(struct mgmt_ev_device_found)) + skb->len;
> +	advmon_skb = mgmt_alloc_skb(hdev, MGMT_EV_ADV_MONITOR_DEVICE_FOUND,
> +				    advmon_skb_len);
> +	if (!advmon_skb)
> +		return;
> +
> +	/* ADV_MONITOR_DEVICE_FOUND is similar to DEVICE_FOUND event except
> +	 * that it also has 'monitor_handle'. Make a copy of DEVICE_FOUND and
> +	 * store monitor_handle of the matched monitor.
> +	 */
> +	monitor_handle = skb_put(advmon_skb, sizeof(*monitor_handle));
> +	*monitor_handle = cpu_to_le16(handle);
> +	skb_put_data(advmon_skb, skb->data, skb->len);
> +
> +	mgmt_event_skb(advmon_skb, skip_sk);
> +}
> +

However, this is rather hackish code. It will blow up in our faces at some point and we will spent weeks to find the bug.

I realized that you already got this pattern merged by Luiz and that is why I merged your patch. I would have not accepted this in the first place. Maybe you need to spent some development cycles and check how all DEVICE_FOUND events can be properly generalized.

Regards

Marcel
diff mbox series

Patch

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index d59c70e9166f..e4da2318a2f6 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9628,17 +9628,44 @@  void mgmt_adv_monitor_device_lost(struct hci_dev *hdev, u16 handle,
 		   NULL);
 }
 
+static void mgmt_send_adv_monitor_device_found(struct hci_dev *hdev,
+					       struct sk_buff *skb,
+					       struct sock *skip_sk,
+					       u16 handle)
+{
+	struct sk_buff *advmon_skb;
+	size_t advmon_skb_len;
+	__le16 *monitor_handle;
+
+	if (!skb)
+		return;
+
+	advmon_skb_len = (sizeof(struct mgmt_ev_adv_monitor_device_found) -
+			  sizeof(struct mgmt_ev_device_found)) + skb->len;
+	advmon_skb = mgmt_alloc_skb(hdev, MGMT_EV_ADV_MONITOR_DEVICE_FOUND,
+				    advmon_skb_len);
+	if (!advmon_skb)
+		return;
+
+	/* ADV_MONITOR_DEVICE_FOUND is similar to DEVICE_FOUND event except
+	 * that it also has 'monitor_handle'. Make a copy of DEVICE_FOUND and
+	 * store monitor_handle of the matched monitor.
+	 */
+	monitor_handle = skb_put(advmon_skb, sizeof(*monitor_handle));
+	*monitor_handle = cpu_to_le16(handle);
+	skb_put_data(advmon_skb, skb->data, skb->len);
+
+	mgmt_event_skb(advmon_skb, skip_sk);
+}
+
 static void mgmt_adv_monitor_device_found(struct hci_dev *hdev,
 					  bdaddr_t *bdaddr, bool report_device,
 					  struct sk_buff *skb,
 					  struct sock *skip_sk)
 {
-	struct sk_buff *advmon_skb;
-	size_t advmon_skb_len;
-	__le16 *monitor_handle;
 	struct monitored_device *dev, *tmp;
 	bool matched = false;
-	bool notify = false;
+	bool notified = false;
 
 	/* We have received the Advertisement Report because:
 	 * 1. the kernel has initiated active discovery
@@ -9660,25 +9687,6 @@  static void mgmt_adv_monitor_device_found(struct hci_dev *hdev,
 		return;
 	}
 
-	advmon_skb_len = (sizeof(struct mgmt_ev_adv_monitor_device_found) -
-			  sizeof(struct mgmt_ev_device_found)) + skb->len;
-	advmon_skb = mgmt_alloc_skb(hdev, MGMT_EV_ADV_MONITOR_DEVICE_FOUND,
-				    advmon_skb_len);
-	if (!advmon_skb) {
-		if (report_device)
-			mgmt_event_skb(skb, skip_sk);
-		else
-			kfree_skb(skb);
-		return;
-	}
-
-	/* ADV_MONITOR_DEVICE_FOUND is similar to DEVICE_FOUND event except
-	 * that it also has 'monitor_handle'. Make a copy of DEVICE_FOUND and
-	 * store monitor_handle of the matched monitor.
-	 */
-	monitor_handle = skb_put(advmon_skb, sizeof(*monitor_handle));
-	skb_put_data(advmon_skb, skb->data, skb->len);
-
 	hdev->advmon_pend_notify = false;
 
 	list_for_each_entry_safe(dev, tmp, &hdev->monitored_devices, list) {
@@ -9686,8 +9694,10 @@  static void mgmt_adv_monitor_device_found(struct hci_dev *hdev,
 			matched = true;
 
 			if (!dev->notified) {
-				*monitor_handle = cpu_to_le16(dev->handle);
-				notify = true;
+				mgmt_send_adv_monitor_device_found(hdev, skb,
+								   skip_sk,
+								   dev->handle);
+				notified = true;
 				dev->notified = true;
 			}
 		}
@@ -9697,25 +9707,19 @@  static void mgmt_adv_monitor_device_found(struct hci_dev *hdev,
 	}
 
 	if (!report_device &&
-	    ((matched && !notify) || !msft_monitor_supported(hdev))) {
+	    ((matched && !notified) || !msft_monitor_supported(hdev))) {
 		/* Handle 0 indicates that we are not active scanning and this
 		 * is a subsequent advertisement report for an already matched
 		 * Advertisement Monitor or the controller offloading support
 		 * is not available.
 		 */
-		*monitor_handle = 0;
-		notify = true;
+		mgmt_send_adv_monitor_device_found(hdev, skb, skip_sk, 0);
 	}
 
 	if (report_device)
 		mgmt_event_skb(skb, skip_sk);
 	else
 		kfree_skb(skb);
-
-	if (notify)
-		mgmt_event_skb(advmon_skb, skip_sk);
-	else
-		kfree_skb(advmon_skb);
 }
 
 void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,