[PATCH v3 0/4] Bluetooth: Add synchronous HCI command helpers

[PATCH v3 0/4] Bluetooth: Add synchronous HCI command helpers

[Johan Hedberg]

Hi,

Same as v2 except that the necessary EXPORT_SYMBOL declarations have
been added to __hci_cmd_sync and __hci_cmd_sync_ev.

Johan

----------------------------------------------------------------
Johan Hedberg (4):
      Bluetooth: Track received events in hdev
      Bluetooth: Add __hci_cmd_sync() helper function
      Bluetooth: Add support for custom event terminated commands
      Bluetooth: Add __hci_cmd_sync_ev function

 include/net/bluetooth/bluetooth.h |    1 +
 include/net/bluetooth/hci_core.h  |    8 +++
 net/bluetooth/hci_core.c          |  123 ++++++++++++++++++++++++++++++++++++-
 net/bluetooth/hci_event.c         |   23 ++++++-
 4 files changed, 153 insertions(+), 2 deletions(-)

[PATCH v3 1/4] Bluetooth: Track received events in hdev

[Johan Hedberg]

From: Johan Hedberg <johan.hedberg@intel.com>

This patch adds tracking of received HCI events to the hci_dev struct.
This is necessary so that a subsequent patch can implement a function
for sending a single command synchronously and returning the resulting
command complete parameters in the function return value.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
---
 include/net/bluetooth/hci_core.h |    1 +
 net/bluetooth/hci_core.c         |    3 +++
 net/bluetooth/hci_event.c        |   12 ++++++++++++
 3 files changed, 16 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 88dd46e..beae2e8 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -244,6 +244,7 @@ struct hci_dev {
 	struct sk_buff_head	raw_q;
 	struct sk_buff_head	cmd_q;
 
+	struct sk_buff		*recv_evt;
 	struct sk_buff		*sent_cmd;
 	struct sk_buff		*reassembly[NUM_REASSEMBLY];
 
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 9e07f2f..40249f6 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1123,6 +1123,9 @@ static int hci_dev_do_close(struct hci_dev *hdev)
 		hdev->sent_cmd = NULL;
 	}
 
+	kfree_skb(hdev->recv_evt);
+	hdev->recv_evt = NULL;
+
 	/* After this point our queues are empty
 	 * and no tasks are scheduled. */
 	hdev->close(hdev);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 7e7fbca..ed0efb7 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3699,6 +3699,18 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 	struct hci_event_hdr *hdr = (void *) skb->data;
 	__u8 event = hdr->evt;
 
+	hci_dev_lock(hdev);
+
+	/* Received events are (currently) only needed when a request is
+	 * ongoing so avoid unnecessary memory allocation.
+	 */
+	if (hdev->req_status == HCI_REQ_PEND) {
+		kfree_skb(hdev->recv_evt);
+		hdev->recv_evt = skb_clone(skb, GFP_KERNEL);
+	}
+
+	hci_dev_unlock(hdev);
+
 	skb_pull(skb, HCI_EVENT_HDR_SIZE);
 
 	switch (event) {
-- 
1.7.10.4

[PATCH v3 2/4] Bluetooth: Add __hci_cmd_sync() helper function

[Johan Hedberg]

From: Johan Hedberg <johan.hedberg@intel.com>

This patch adds a helper function for sending a single HCI command
waiting for its completion and then returning back the parameters in the
resulting command complete event (if there was one).

The implementation is very similar to that of hci_req_sync() except that
instead of invocing a callback for sending HCI commands the function
constructs and sends one itself and after being woken up picks the last
received event from hdev->recv_evt (if it matches the right criteria)
and returns it.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
---
 include/net/bluetooth/hci_core.h |    3 ++
 net/bluetooth/hci_core.c         |   97 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index beae2e8..38b653d 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1056,6 +1056,9 @@ int hci_req_run(struct hci_request *req, hci_req_complete_t complete);
 void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, void *param);
 void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
 
+struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
+			       void *param, u32 timeout);
+
 int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen, void *param);
 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);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 40249f6..f3e9768 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -79,6 +79,103 @@ static void hci_req_cancel(struct hci_dev *hdev, int err)
 	}
 }
 
+struct sk_buff *hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode)
+{
+	struct hci_ev_cmd_complete *ev;
+	struct hci_event_hdr *hdr;
+	struct sk_buff *skb;
+
+	hci_dev_lock(hdev);
+
+	skb = hdev->recv_evt;
+	hdev->recv_evt = NULL;
+
+	hci_dev_unlock(hdev);
+
+	if (!skb)
+		return ERR_PTR(-ENODATA);
+
+	hdr = (void *) skb->data;
+	skb_pull(skb, HCI_EVENT_HDR_SIZE);
+
+	if (hdr->evt != HCI_EV_CMD_COMPLETE) {
+		BT_DBG("Last event is not cmd complete (0x%2.2x)", hdr->evt);
+		goto failed;
+	}
+
+	if (skb->len < sizeof(*ev)) {
+		BT_ERR("Too short cmd_complete event");
+		goto failed;
+	}
+
+	ev = (void *) skb->data;
+	skb_pull(skb, sizeof(*ev));
+
+	if (opcode == __le16_to_cpu(ev->opcode))
+		return skb;
+
+	BT_DBG("opcode doesn't match (0x%2.2x != 0x%2.2x)", opcode,
+	       __le16_to_cpu(ev->opcode));
+
+failed:
+	kfree_skb(skb);
+	return ERR_PTR(-ENODATA);
+}
+
+struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
+			       void *param, u32 timeout)
+{
+	DECLARE_WAITQUEUE(wait, current);
+	struct hci_request req;
+	int err = 0;
+
+	BT_DBG("%s", hdev->name);
+
+	hci_req_init(&req, hdev);
+
+	hci_req_add(&req, opcode, plen, param);
+
+	hdev->req_status = HCI_REQ_PEND;
+
+	err = hci_req_run(&req, hci_req_sync_complete);
+	if (err < 0)
+		return ERR_PTR(err);
+
+	add_wait_queue(&hdev->req_wait_q, &wait);
+	set_current_state(TASK_INTERRUPTIBLE);
+
+	schedule_timeout(timeout);
+
+	remove_wait_queue(&hdev->req_wait_q, &wait);
+
+	if (signal_pending(current))
+		return ERR_PTR(-EINTR);
+
+	switch (hdev->req_status) {
+	case HCI_REQ_DONE:
+		err = -bt_to_errno(hdev->req_result);
+		break;
+
+	case HCI_REQ_CANCELED:
+		err = -hdev->req_result;
+		break;
+
+	default:
+		err = -ETIMEDOUT;
+		break;
+	}
+
+	hdev->req_status = hdev->req_result = 0;
+
+	BT_DBG("%s end: err %d", hdev->name, err);
+
+	if (err < 0)
+		return ERR_PTR(err);
+
+	return hci_get_cmd_complete(hdev, opcode);
+}
+EXPORT_SYMBOL(__hci_cmd_sync);
+
 /* Execute request and wait for completion. */
 static int __hci_req_sync(struct hci_dev *hdev,
 			  void (*func)(struct hci_request *req,
-- 
1.7.10.4

[PATCH v3 3/4] Bluetooth: Add support for custom event terminated commands

[Johan Hedberg]

From: Johan Hedberg <johan.hedberg@intel.com>

This patch adds support for having commands within HCI requests that do
not result in a command complete but some other event. This is at least
needed for some vendor specific commands to be issued in the
hdev->setup() procecure, but might also be useful for other commands.

The way that the support is implemented is by extending the skb control
buffer to have a field to indicate that the command is expected to
terminate with a special event. After sending the command each received
event can then be compared against this field through hdev->sent_cmd.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
---
 include/net/bluetooth/bluetooth.h |    1 +
 include/net/bluetooth/hci_core.h  |    2 ++
 net/bluetooth/hci_core.c          |   10 +++++++++-
 net/bluetooth/hci_event.c         |   11 ++++++++++-
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/include/net/bluetooth/bluetooth.h b/include/net/bluetooth/bluetooth.h
index ed6e955..591fee7 100644
--- a/include/net/bluetooth/bluetooth.h
+++ b/include/net/bluetooth/bluetooth.h
@@ -266,6 +266,7 @@ typedef void (*hci_req_complete_t)(struct hci_dev *hdev, u8 status);
 
 struct hci_req_ctrl {
 	bool			start;
+	u8			event;
 	hci_req_complete_t	complete;
 };
 
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 38b653d..b2be51c 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1054,6 +1054,8 @@ struct hci_request {
 void hci_req_init(struct hci_request *req, struct hci_dev *hdev);
 int hci_req_run(struct hci_request *req, hci_req_complete_t complete);
 void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, void *param);
+void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen, void *param,
+		    u8 event);
 void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
 
 struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index f3e9768..a02c4b2 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -2625,7 +2625,8 @@ int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen, void *param)
 EXPORT_SYMBOL(hci_send_cmd);
 
 /* Queue a command to an asynchronous HCI request */
-void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, void *param)
+void hci_req_add_ev(struct hci_request *req, u16 opcode, u32 plen, void *param,
+		    u8 event)
 {
 	struct hci_dev *hdev = req->hdev;
 	struct sk_buff *skb;
@@ -2649,9 +2650,16 @@ void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, void *param)
 	if (skb_queue_empty(&req->cmd_q))
 		bt_cb(skb)->req.start = true;
 
+	bt_cb(skb)->req.event = event;
+
 	skb_queue_tail(&req->cmd_q, skb);
 }
 
+void hci_req_add(struct hci_request *req, u16 opcode, u32 plen, void *param)
+{
+	hci_req_add_ev(req, opcode, plen, param, 0);
+}
+
 /* Get data from the previously sent command */
 void *hci_sent_cmd_data(struct hci_dev *hdev, __u16 opcode)
 {
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index ed0efb7..0a2b128 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2463,7 +2463,9 @@ static void hci_cmd_status_evt(struct hci_dev *hdev, struct sk_buff *skb)
 	if (opcode != HCI_OP_NOP)
 		del_timer(&hdev->cmd_timer);
 
-	hci_req_cmd_complete(hdev, opcode, ev->status);
+	if (ev->status ||
+	    (hdev->sent_cmd && !bt_cb(hdev->sent_cmd)->req.event))
+		hci_req_cmd_complete(hdev, opcode, ev->status);
 
 	if (ev->ncmd && !test_bit(HCI_RESET, &hdev->flags)) {
 		atomic_set(&hdev->cmd_cnt, 1);
@@ -3713,6 +3715,13 @@ void hci_event_packet(struct hci_dev *hdev, struct sk_buff *skb)
 
 	skb_pull(skb, HCI_EVENT_HDR_SIZE);
 
+	if (hdev->sent_cmd && bt_cb(hdev->sent_cmd)->req.event == event) {
+		struct hci_command_hdr *hdr = (void *) hdev->sent_cmd->data;
+		u16 opcode = __le16_to_cpu(hdr->opcode);
+
+		hci_req_cmd_complete(hdev, opcode, 0);
+	}
+
 	switch (event) {
 	case HCI_EV_INQUIRY_COMPLETE:
 		hci_inquiry_complete_evt(hdev, skb);
-- 
1.7.10.4

[PATCH v3 4/4] Bluetooth: Add __hci_cmd_sync_ev function

[Johan Hedberg]

From: Johan Hedberg <johan.hedberg@intel.com>

This patch adds a __hci_cmd_sync_ev function, analogous to
__hci_cmd_sync except that it also takes an event parameter to indicate
that the command completes with a special event instead of command
complete. Internally this new function takes advantage of the
hci_req_add_ev function introduced in the previous patch.

The primary expected user of this new function are the setup routines of
HCI drivers which may want to send custom commands and return only when
they have completed.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
---
 include/net/bluetooth/hci_core.h |    2 ++
 net/bluetooth/hci_core.c         |   23 ++++++++++++++++++-----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index b2be51c..d4e13bf 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1060,6 +1060,8 @@ void hci_req_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 status);
 
 struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
 			       void *param, u32 timeout);
+struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
+				  void *param, u8 event, u32 timeout);
 
 int hci_send_cmd(struct hci_dev *hdev, __u16 opcode, __u32 plen, void *param);
 void hci_send_acl(struct hci_chan *chan, struct sk_buff *skb, __u16 flags);
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index a02c4b2..719510a 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -79,7 +79,7 @@ static void hci_req_cancel(struct hci_dev *hdev, int err)
 	}
 }
 
-struct sk_buff *hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode)
+struct sk_buff *hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode, u8 event)
 {
 	struct hci_ev_cmd_complete *ev;
 	struct hci_event_hdr *hdr;
@@ -98,6 +98,12 @@ struct sk_buff *hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode)
 	hdr = (void *) skb->data;
 	skb_pull(skb, HCI_EVENT_HDR_SIZE);
 
+	if (event) {
+		if (hdr->evt != event)
+			goto failed;
+		return skb;
+	}
+
 	if (hdr->evt != HCI_EV_CMD_COMPLETE) {
 		BT_DBG("Last event is not cmd complete (0x%2.2x)", hdr->evt);
 		goto failed;
@@ -122,8 +128,8 @@ failed:
 	return ERR_PTR(-ENODATA);
 }
 
-struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
-			       void *param, u32 timeout)
+struct sk_buff *__hci_cmd_sync_ev(struct hci_dev *hdev, u16 opcode, u32 plen,
+				  void *param, u8 event, u32 timeout)
 {
 	DECLARE_WAITQUEUE(wait, current);
 	struct hci_request req;
@@ -133,7 +139,7 @@ struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
 
 	hci_req_init(&req, hdev);
 
-	hci_req_add(&req, opcode, plen, param);
+	hci_req_add_ev(&req, opcode, plen, param, event);
 
 	hdev->req_status = HCI_REQ_PEND;
 
@@ -172,7 +178,14 @@ struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
 	if (err < 0)
 		return ERR_PTR(err);
 
-	return hci_get_cmd_complete(hdev, opcode);
+	return hci_get_cmd_complete(hdev, opcode, event);
+}
+EXPORT_SYMBOL(__hci_cmd_sync_ev);
+
+struct sk_buff *__hci_cmd_sync(struct hci_dev *hdev, u16 opcode, u32 plen,
+			       void *param, u32 timeout)
+{
+	return __hci_cmd_sync_ev(hdev, opcode, plen, param, 0, timeout);
 }
 EXPORT_SYMBOL(__hci_cmd_sync);
 
-- 
1.7.10.4