Bluetooth: Add discovery state tracking

This patch adds proper state tracking to the device discovery process.
This makes it possible to return appropriate errors when trying to stop
a non-active discovery or start discovery when it is already ongoing.
Once name resolving is implemented this also makes it possible to know
what the right action to do is when a remote name lookup is cancelled.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 5a566fd5e2a613ec373063ad7f89c0a43baa28d4..2f19de4770b6870eb6d79d59bb5dc02f6ae8d585 100644 (file)
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -57,6 +57,12 @@ struct inquiry_entry {
 };
 
 struct discovery_state {
+       enum {
+               DISCOVERY_STOPPED,
+               DISCOVERY_STARTING,
+               DISCOVERY_ACTIVE,
+               DISCOVERY_STOPPING,
+       } state;
        struct list_head all;           /* All devices found during inquiry */
        struct list_head unknown;       /* Name state not known */
        struct list_head resolve;       /* Name needs to be resolved */
@@ -359,11 +365,14 @@ extern int sco_recv_scodata(struct hci_conn *hcon, struct sk_buff *skb);
 
 static inline void discovery_init(struct hci_dev *hdev)
 {
+       hdev->discovery.state = DISCOVERY_STOPPED;
        INIT_LIST_HEAD(&hdev->discovery.all);
        INIT_LIST_HEAD(&hdev->discovery.unknown);
        INIT_LIST_HEAD(&hdev->discovery.resolve);
 }
 
+void hci_discovery_set_state(struct hci_dev *hdev, int state);
+
 static inline int inquiry_cache_empty(struct hci_dev *hdev)
 {
        return list_empty(&hdev->discovery.all);

diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 55509b0a810ae0c32f34bbe3f09b94ed805b9b4c..b687192306015a138b60ebb8c56a3adf026616c3 100644 (file)
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -355,6 +355,30 @@ struct hci_dev *hci_dev_get(int index)
 }
 
 /* ---- Inquiry support ---- */
+
+void hci_discovery_set_state(struct hci_dev *hdev, int state)
+{
+       BT_DBG("%s state %u -> %u", hdev->name, hdev->discovery.state, state);
+
+       if (hdev->discovery.state == state)
+               return;
+
+       switch (state) {
+       case DISCOVERY_STOPPED:
+               mgmt_discovering(hdev, 0);
+               break;
+       case DISCOVERY_STARTING:
+               break;
+       case DISCOVERY_ACTIVE:
+               mgmt_discovering(hdev, 1);
+               break;
+       case DISCOVERY_STOPPING:
+               break;
+       }
+
+       hdev->discovery.state = state;
+}
+
 static void inquiry_cache_flush(struct hci_dev *hdev)
 {
        struct discovery_state *cache = &hdev->discovery;
@@ -367,6 +391,7 @@ static void inquiry_cache_flush(struct hci_dev *hdev)
 
        INIT_LIST_HEAD(&cache->unknown);
        INIT_LIST_HEAD(&cache->resolve);
+       cache->state = DISCOVERY_STOPPED;
 }
 
 struct inquiry_entry *hci_inquiry_cache_lookup(struct hci_dev *hdev, bdaddr_t *bdaddr)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index d4d20df9fbbf7f8289476d79e6d148d5bd2d68aa..43d69569a0d553f7aa887a3927c95d57bf6d6e2a 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -65,7 +65,7 @@ static void hci_cc_inquiry_cancel(struct hci_dev *hdev, struct sk_buff *skb)
        clear_bit(HCI_INQUIRY, &hdev->flags);
 
        hci_dev_lock(hdev);
-       mgmt_discovering(hdev, 0);
+       hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
        hci_dev_unlock(hdev);
 
        hci_req_complete(hdev, HCI_OP_INQUIRY_CANCEL, status);
@@ -1119,7 +1119,7 @@ static inline void hci_cs_inquiry(struct hci_dev *hdev, __u8 status)
        set_bit(HCI_INQUIRY, &hdev->flags);
 
        hci_dev_lock(hdev);
-       mgmt_discovering(hdev, 1);
+       hci_discovery_set_state(hdev, DISCOVERY_ACTIVE);
        hci_dev_unlock(hdev);
 }
 
@@ -1507,7 +1507,7 @@ static inline void hci_inquiry_complete_evt(struct hci_dev *hdev, struct sk_buff
                return;
 
        hci_dev_lock(hdev);
-       mgmt_discovering(hdev, 0);
+       hci_discovery_set_state(hdev, DISCOVERY_STOPPED);
        hci_dev_unlock(hdev);
 }
 

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 894f11bc571dc6632a4e73fe8f698d99ad1e9537..590966ddfa639f9517230a7a97aaf806d951524f 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -1918,6 +1918,12 @@ static int start_discovery(struct sock *sk, u16 index,
                goto failed;
        }
 
+       if (hdev->discovery.state != DISCOVERY_STOPPED) {
+               err = cmd_status(sk, index, MGMT_OP_START_DISCOVERY,
+                                               MGMT_STATUS_BUSY);
+               goto failed;
+       }
+
        cmd = mgmt_pending_add(sk, MGMT_OP_START_DISCOVERY, hdev, NULL, 0);
        if (!cmd) {
                err = -ENOMEM;
@@ -1927,6 +1933,8 @@ static int start_discovery(struct sock *sk, u16 index,
        err = hci_do_inquiry(hdev, INQUIRY_LEN_BREDR);
        if (err < 0)
                mgmt_pending_remove(cmd);
+       else
+               hci_discovery_set_state(hdev, DISCOVERY_STARTING);
 
 failed:
        hci_dev_unlock(hdev);
@@ -1950,6 +1958,12 @@ static int stop_discovery(struct sock *sk, u16 index)
 
        hci_dev_lock(hdev);
 
+       if (hdev->discovery.state != DISCOVERY_ACTIVE) {
+               err = cmd_status(sk, index, MGMT_OP_STOP_DISCOVERY,
+                                               MGMT_STATUS_REJECTED);
+               goto failed;
+       }
+
        cmd = mgmt_pending_add(sk, MGMT_OP_STOP_DISCOVERY, hdev, NULL, 0);
        if (!cmd) {
                err = -ENOMEM;
@@ -1959,6 +1973,8 @@ static int stop_discovery(struct sock *sk, u16 index)
        err = hci_cancel_inquiry(hdev);
        if (err < 0)
                mgmt_pending_remove(cmd);
+       else
+               hci_discovery_set_state(hdev, DISCOVERY_STOPPING);
 
 failed:
        hci_dev_unlock(hdev);