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Date:   Sat, 12 Mar 2022 02:08:59 -0800
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Subject: [PATCH 2/2] Bluetooth: Send AdvMonitor Dev Found for all matched devices
From:   Manish Mandlik <mmandlik@google.com>
To:     marcel@holtmann.org, luiz.dentz@gmail.com
Cc:     chromeos-bluetooth-upstreaming@chromium.org,
        linux-bluetooth@vger.kernel.org,
        Manish Mandlik <mmandlik@google.com>,
        Miao-chen Chou <mcchou@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

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(-)

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,
-- 
2.35.1.723.g4982287a31-goog