[PATCH 13/15] Bluetooth: hci_event: Use of a function table to handle LE subevents

Luiz Augusto von Dentz
2021-12-01T00:04:26Z

This change the use of switch statement to a function table which is
easier to extend and can include min/max length of each subevent.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
net/bluetooth/hci_event.c | 247 +++++++++++++++++++-------------------
1 file changed, 122 insertions(+), 125 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 6fbb16997849..c39f5ea1736a 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -5969,16 +5969,12 @@ static void le_conn_complete_evt(struct hci_dev *hdev, u8 status,
hci_dev_unlock(hdev);
}

-static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_conn_complete_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_ev_le_conn_complete *ev;
-
- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_CONN_COMPLETE,
- sizeof(*ev));
- if (!ev)
- return;
+ struct hci_ev_le_conn_complete *ev = data;

- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

le_conn_complete_evt(hdev, ev->status, &ev->bdaddr, ev->bdaddr_type,
NULL, ev->role, le16_to_cpu(ev->handle),
@@ -5987,17 +5983,12 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
le16_to_cpu(ev->supervision_timeout));
}

-static void hci_le_enh_conn_complete_evt(struct hci_dev *hdev,
+static void hci_le_enh_conn_complete_evt(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
- struct hci_ev_le_enh_conn_complete *ev;
+ struct hci_ev_le_enh_conn_complete *ev = data;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_ENHANCED_CONN_COMPLETE,
- sizeof(*ev));
- if (!ev)
- return;
-
- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

le_conn_complete_evt(hdev, ev->status, &ev->bdaddr, ev->bdaddr_type,
&ev->local_rpa, ev->role, le16_to_cpu(ev->handle),
@@ -6006,18 +5997,14 @@ static void hci_le_enh_conn_complete_evt(struct hci_dev *hdev,
le16_to_cpu(ev->supervision_timeout));
}

-static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_evt_le_ext_adv_set_term *ev;
+ struct hci_evt_le_ext_adv_set_term *ev = data;
struct hci_conn *conn;
struct adv_info *adv, *n;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_EXT_ADV_SET_TERM,
- sizeof(*ev));
- if (!ev)
- return;
-
- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

adv = hci_find_adv_instance(hdev, ev->handle);

@@ -6075,18 +6062,13 @@ static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, struct sk_buff *skb)
}
}

-static void hci_le_conn_update_complete_evt(struct hci_dev *hdev,
+static void hci_le_conn_update_complete_evt(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
- struct hci_ev_le_conn_update_complete *ev;
+ struct hci_ev_le_conn_update_complete *ev = data;
struct hci_conn *conn;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_CONN_UPDATE_COMPLETE,
- sizeof(*ev));
- if (!ev)
- return;
-
- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

if (ev->status)
return;
@@ -6402,14 +6384,10 @@ static void process_adv_report(struct hci_dev *hdev, u8 type, bdaddr_t *bdaddr,
clear_pending_adv_report(hdev);
}

-static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_adv_report_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_ev_le_advertising_report *ev;
-
- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_ADVERTISING_REPORT,
- sizeof(*ev));
- if (!ev)
- return;
+ struct hci_ev_le_advertising_report *ev = data;

if (!ev->num)
return;
@@ -6487,14 +6465,10 @@ static u8 ext_evt_type_to_legacy(struct hci_dev *hdev, u16 evt_type)
return LE_ADV_INVALID;
}

-static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_ev_le_ext_adv_report *ev;
-
- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_EXT_ADV_REPORT,
- sizeof(*ev));
- if (!ev)
- return;
+ struct hci_ev_le_ext_adv_report *ev = data;

if (!ev->num)
return;
@@ -6528,18 +6502,13 @@ static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb)
hci_dev_unlock(hdev);
}

-static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev,
+static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
- struct hci_ev_le_remote_feat_complete *ev;
+ struct hci_ev_le_remote_feat_complete *ev = data;
struct hci_conn *conn;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_EXT_ADV_REPORT,
- sizeof(*ev));
- if (!ev)
- return;
-
- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

hci_dev_lock(hdev);

@@ -6575,19 +6544,16 @@ static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev,
hci_dev_unlock(hdev);
}

-static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_ltk_request_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_ev_le_ltk_req *ev;
+ struct hci_ev_le_ltk_req *ev = data;
struct hci_cp_le_ltk_reply cp;
struct hci_cp_le_ltk_neg_reply neg;
struct hci_conn *conn;
struct smp_ltk *ltk;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_LTK_REQ, sizeof(*ev));
- if (!ev)
- return;
-
- BT_DBG("%s handle 0x%4.4x", hdev->name, __le16_to_cpu(ev->handle));
+ bt_dev_dbg(hdev, "handle 0x%4.4x", __le16_to_cpu(ev->handle));

hci_dev_lock(hdev);

@@ -6655,18 +6621,15 @@ static void send_conn_param_neg_reply(struct hci_dev *hdev, u16 handle,
&cp);
}

-static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
+static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
- struct hci_ev_le_remote_conn_param_req *ev;
+ struct hci_ev_le_remote_conn_param_req *ev = data;
struct hci_cp_le_conn_param_req_reply cp;
struct hci_conn *hcon;
u16 handle, min, max, latency, timeout;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_REMOTE_CONN_PARAM_REQ,
- sizeof(*ev));
- if (!ev)
- return;
+ bt_dev_dbg(hdev, "handle 0x%4.4x", __le16_to_cpu(ev->handle));

handle = le16_to_cpu(ev->handle);
min = le16_to_cpu(ev->interval_min);
@@ -6718,17 +6681,12 @@ static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
hci_send_cmd(hdev, HCI_OP_LE_CONN_PARAM_REQ_REPLY, sizeof(cp), &cp);
}

-static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
+static void hci_le_direct_adv_report_evt(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
- struct hci_ev_le_direct_adv_report *ev;
+ struct hci_ev_le_direct_adv_report *ev = data;
int i;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_DIRECT_ADV_REPORT,
- sizeof(*ev));
- if (!ev)
- return;
-
if (!hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_DIRECT_ADV_REPORT,
flex_array_size(ev, info, ev->num)))
return;
@@ -6750,17 +6708,13 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,
hci_dev_unlock(hdev);
}

-static void hci_le_phy_update_evt(struct hci_dev *hdev, struct sk_buff *skb)
+static void hci_le_phy_update_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
{
- struct hci_ev_le_phy_update_complete *ev;
+ struct hci_ev_le_phy_update_complete *ev = data;
struct hci_conn *conn;

- ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_PHY_UPDATE_COMPLETE,
- sizeof(*ev));
- if (ev)
- return;
-
- BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);
+ bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

if (ev->status)
return;
@@ -6778,59 +6732,102 @@ static void hci_le_phy_update_evt(struct hci_dev *hdev, struct sk_buff *skb)
hci_dev_unlock(hdev);
}

-static void hci_le_meta_evt(struct hci_dev *hdev, void *data,
- struct sk_buff *skb)
-{
- struct hci_ev_le_meta *ev = data;
-
- switch (ev->subevent) {
- case HCI_EV_LE_CONN_COMPLETE:
- hci_le_conn_complete_evt(hdev, skb);
- break;
-
- case HCI_EV_LE_CONN_UPDATE_COMPLETE:
- hci_le_conn_update_complete_evt(hdev, skb);
- break;
+#define HCI_LE_EV_VL(_op, _func, _min_len, _max_len) \
+[_op] = { \
+ .func = _func, \
+ .min_len = _min_len, \
+ .max_len = _max_len, \
+}

- case HCI_EV_LE_ADVERTISING_REPORT:
- hci_le_adv_report_evt(hdev, skb);
- break;
+#define HCI_LE_EV(_op, _func, _len) \
+ HCI_LE_EV_VL(_op, _func, _len, _len)

- case HCI_EV_LE_REMOTE_FEAT_COMPLETE:
- hci_le_remote_feat_complete_evt(hdev, skb);
- break;
+#define HCI_LE_EV_STATUS(_op, _func) \
+ HCI_LE_EV(_op, _func, sizeof(struct hci_ev_status))

- case HCI_EV_LE_LTK_REQ:
- hci_le_ltk_request_evt(hdev, skb);
- break;
+/* Entries in this table shall have their position according to the subevent
+ * opcode they handle so the use of the macros above is recommend since it does
+ * attempt to initialize at its proper index using Designated Initializers that
+ * way events without a callback function can be ommited.
+ */
+static const struct hci_le_ev {
+ void (*func)(struct hci_dev *hdev, void *data, struct sk_buff *skb);
+ u16 min_len;
+ u16 max_len;
+} hci_le_ev_table[U8_MAX + 1] = {
+ /* [0x01 = HCI_EV_LE_CONN_COMPLETE] */
+ HCI_LE_EV(HCI_EV_LE_CONN_COMPLETE, hci_le_conn_complete_evt,
+ sizeof(struct hci_ev_le_conn_complete)),
+ /* [0x02 = HCI_EV_LE_ADVERTISING_REPORT] */
+ HCI_LE_EV_VL(HCI_EV_LE_ADVERTISING_REPORT, hci_le_adv_report_evt,
+ sizeof(struct hci_ev_le_advertising_report),
+ HCI_MAX_EVENT_SIZE),
+ /* [0x03 = HCI_EV_LE_CONN_UPDATE_COMPLETE] */
+ HCI_LE_EV(HCI_EV_LE_CONN_UPDATE_COMPLETE,
+ hci_le_conn_update_complete_evt,
+ sizeof(struct hci_ev_le_conn_update_complete)),
+ /* [0x04 = HCI_EV_LE_REMOTE_FEAT_COMPLETE] */
+ HCI_LE_EV(HCI_EV_LE_REMOTE_FEAT_COMPLETE,
+ hci_le_remote_feat_complete_evt,
+ sizeof(struct hci_ev_le_remote_feat_complete)),
+ /* [0x05 = HCI_EV_LE_LTK_REQ] */
+ HCI_LE_EV(HCI_EV_LE_LTK_REQ, hci_le_ltk_request_evt,
+ sizeof(struct hci_ev_le_ltk_req)),
+ /* [0x06 = HCI_EV_LE_REMOTE_CONN_PARAM_REQ] */
+ HCI_LE_EV(HCI_EV_LE_REMOTE_CONN_PARAM_REQ,
+ hci_le_remote_conn_param_req_evt,
+ sizeof(struct hci_ev_le_remote_conn_param_req)),
+ /* [0x0a = HCI_EV_LE_ENHANCED_CONN_COMPLETE] */
+ HCI_LE_EV(HCI_EV_LE_ENHANCED_CONN_COMPLETE,
+ hci_le_enh_conn_complete_evt,
+ sizeof(struct hci_ev_le_enh_conn_complete)),
+ /* [0x0b = HCI_EV_LE_DIRECT_ADV_REPORT] */
+ HCI_LE_EV_VL(HCI_EV_LE_DIRECT_ADV_REPORT, hci_le_direct_adv_report_evt,
+ sizeof(struct hci_ev_le_direct_adv_report),
+ HCI_MAX_EVENT_SIZE),
+ /* [0x0c = HCI_EV_LE_PHY_UPDATE_COMPLETE] */
+ HCI_LE_EV(HCI_EV_LE_PHY_UPDATE_COMPLETE, hci_le_phy_update_evt,
+ sizeof(struct hci_ev_le_phy_update_complete)),
+ /* [0x0d = HCI_EV_LE_EXT_ADV_REPORT] */
+ HCI_LE_EV_VL(HCI_EV_LE_EXT_ADV_REPORT, hci_le_ext_adv_report_evt,
+ sizeof(struct hci_ev_le_ext_adv_report),
+ HCI_MAX_EVENT_SIZE),
+ /* [0x12 = HCI_EV_LE_EXT_ADV_SET_TERM] */
+ HCI_LE_EV(HCI_EV_LE_EXT_ADV_SET_TERM, hci_le_ext_adv_term_evt,
+ sizeof(struct hci_evt_le_ext_adv_set_term)),
+};

- case HCI_EV_LE_REMOTE_CONN_PARAM_REQ:
- hci_le_remote_conn_param_req_evt(hdev, skb);
- break;
+static void hci_le_meta_evt(struct hci_dev *hdev, void *data,
+ struct sk_buff *skb)
+{
+ struct hci_ev_le_meta *ev = data;
+ const struct hci_le_ev *subev;

- case HCI_EV_LE_DIRECT_ADV_REPORT:
- hci_le_direct_adv_report_evt(hdev, skb);
- break;
+ bt_dev_dbg(hdev, "subevent 0x%2.2x", ev->subevent);

- case HCI_EV_LE_PHY_UPDATE_COMPLETE:
- hci_le_phy_update_evt(hdev, skb);
- break;
+ subev = &hci_le_ev_table[ev->subevent];
+ if (!subev->func)
+ return;

- case HCI_EV_LE_EXT_ADV_REPORT:
- hci_le_ext_adv_report_evt(hdev, skb);
- break;
+ if (skb->len < subev->min_len) {
+ bt_dev_err(hdev, "unexpected subevent 0x%2.2x length: %u < %u",
+ ev->subevent, skb->len, subev->min_len);
+ return;
+ }

- case HCI_EV_LE_ENHANCED_CONN_COMPLETE:
- hci_le_enh_conn_complete_evt(hdev, skb);
- break;
+ /* Just warn if the length is over max_len size it still be
+ * possible to partially parse the event so leave to callback to
+ * decide if that is acceptable.
+ */
+ if (skb->len > subev->max_len)
+ bt_dev_warn(hdev, "unexpected subevent 0x%2.2x length: %u > %u",
+ ev->subevent, skb->len, subev->max_len);

- case HCI_EV_LE_EXT_ADV_SET_TERM:
- hci_le_ext_adv_term_evt(hdev, skb);
- break;
+ data = hci_le_ev_skb_pull(hdev, skb, ev->subevent, subev->min_len);
+ if (!data)
+ return;

- default:
- break;
- }
+ subev->func(hdev, data, skb);
}

static bool hci_get_cmd_complete(struct hci_dev *hdev, u16 opcode,
--
2.33.1