If MGMT_OP_STOP_DISCOVERY command is issued before the kernel
receives the HCI Inquiry Command Status Event from the controller
then that command will fail and the discovery procedure won't be
stopped. This situation may occur if a MGMT_OP_STOP_DISCOVERY
command is issued just after a MGMT_OP_START_DISCOVERY.
This race condition can be handled by checking for pending
MGMT_OP_STOP_DISCOVERY command in inquiry command status event
handler. If we have a pending MGMT_OP_STOP_DISCOVERY command we
cancel the ongoing discovery.
Signed-off-by: Andre Guedes <andre.guedes@xxxxxxxxxxxxx>
---
include/net/bluetooth/hci_core.h | 1 +
net/bluetooth/hci_event.c | 3 +++
net/bluetooth/mgmt.c | 14 +++++++++++++-
3 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 8992f24..6c2b8b5 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -878,6 +878,7 @@ int mgmt_discovering(u16 index, u8 discovering);
int mgmt_device_blocked(u16 index, bdaddr_t *bdaddr);
int mgmt_device_unblocked(u16 index, bdaddr_t *bdaddr);
int mgmt_discovery_complete(u16 index, u8 status);
+int mgmt_has_pending_stop_discov(u16 index);
/* HCI info for socket */
#define hci_pi(sk) ((struct hci_pinfo *) sk)
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 2dba110..95b8a6c 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -963,6 +963,9 @@ static inline void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
set_bit(HCI_INQUIRY, &hdev->flags);
mgmt_discovering(hdev->id, 1);
+
+ if (mgmt_has_pending_stop_discov(hdev->id))
+ hci_cancel_inquiry(hdev);
}
static inline void hci_cs_create_conn(struct hci_dev *hdev, __u8 status)
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 8a2f243..31c3d2a 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1695,7 +1695,11 @@ static int stop_discovery(struct sock *sk, u16 index)
goto failed;
}
- err = hci_cancel_inquiry(hdev);
+ if (test_bit(HCI_INQUIRY, &hdev->flags))
+ err = hci_cancel_inquiry(hdev);
+ else
+ err = 0;
+
if (err < 0)
mgmt_pending_remove(cmd);
@@ -2389,3 +2393,11 @@ int mgmt_discovery_complete(u16 index, u8 status)
return 0;
}
+
+int mgmt_has_pending_stop_discov(u16 index)
+{
+ if (mgmt_pending_find(MGMT_OP_STOP_DISCOVERY, index))
+ return 1;
+
+ return 0;
+}
--
1.7.5.2
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