[RFC] Bluetooth: hci_core: Introduce hci_recv_event_data

[Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx>]

From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>

This introduces hci_recv_event_data to make it simpler to access the
contents of last received event rather than having to pass its contents
to the likes of *_ind/*_cfm callbacks.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
---
 include/net/bluetooth/hci_core.h |  2 ++
 net/bluetooth/hci_core.c         | 32 ++++++++++++++++++++++++++++++++
 net/bluetooth/hci_event.c        |  3 +++
 3 files changed, 37 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index f5caff1ddb29..c454913794bf 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -516,6 +516,7 @@ struct hci_dev {
 	struct sk_buff_head	cmd_q;
 
 	struct sk_buff		*sent_cmd;
+	struct sk_buff		*recv_event;
 
 	struct mutex		req_lock;
 	wait_queue_head_t	req_wait_q;
@@ -1727,6 +1728,7 @@ void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags);
 void hci_send_sco(struct hci_conn *conn, struct sk_buff *skb);
 
 void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode);
+void *hci_recv_event_data(struct hci_dev *hdev, __u8 event);
 
 u32 hci_conn_get_phy(struct hci_conn *conn);
 
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index b4782a6c1025..5d1167b67a47 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2740,6 +2740,7 @@ void hci_release_dev(struct hci_dev *hdev)
 
 	ida_simple_remove(&hci_index_ida, hdev->id);
 	kfree_skb(hdev->sent_cmd);
+	kfree_skb(hdev->recv_event);
 	kfree(hdev);
 }
 EXPORT_SYMBOL(hci_release_dev);
@@ -3024,6 +3025,37 @@ void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode)
 	return hdev->sent_cmd->data + HCI_COMMAND_HDR_SIZE;
 }
 
+/* Get data from last received event */
+void *hci_recv_event_data(struct hci_dev *hdev, __u8 event)
+{
+	struct hci_event_hdr *hdr;
+	int offset;
+
+	if (!hdev->recv_event)
+		return NULL;
+
+	hdr = (void *) hdev->recv_event->data;
+	offset = sizeof(hdr);
+
+	if (hdr->evt != event) {
+		/* In case of LE metaevent check the subevent match */
+		if (hdr->evt == HCI_EV_LE_META) {
+			struct hci_ev_le_meta *ev;
+
+			ev = (void *) hdev->recv_event->data + offset;
+			offset += sizeof(*ev);
+			if (ev->subevent == event)
+				goto found;
+		}
+		return NULL;
+	}
+
+found:
+	bt_dev_dbg(hdev, "event 0x%2.2x", event);
+
+	return hdev->recv_event->data + offset;
+}
+
 /* Send ACL data */
 static void hci_add_acl_hdr(struct sk_buff *skb, __u16 handle, __u16 flags)
 {
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 63b925921c87..613050bd80cc 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -6898,6 +6898,9 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 		goto done;
 	}
 
+	kfree_skb(hdev->recv_event);
+	hdev->recv_event = skb_clone(skb, GFP_KERNEL);
+
 	event = hdr->evt;
 	if (!event) {
 		bt_dev_warn(hdev, "Received unexpected HCI Event 0x%2.2x",
-- 
2.34.1