gistfile1.txt

commit 6d6868e4c03153eda1bb137e920ef0477bf9187d (HEAD -> bluetooth-next)
Author: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date:   Fri Dec 3 11:50:50 2021 -0800

    Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_FOUND
    
    This makes use of mgmt_alloc_skb to build MGMT_EV_DEVICE_FOUND so the
    data is copied directly to skb that is then sent using
    mgmt_send_event_skb eliminating the necessity of intermediary buffers.
    
    Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 7d3c69c3cf62..bc2a24e7de90 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -335,6 +335,13 @@ static int mgmt_event(u16 event, struct hci_dev *hdev, void *data, u16 len,
                               HCI_SOCK_TRUSTED, skip_sk);
 }
 
+static int mgmt_event_skb(u16 event, struct hci_dev *hdev, struct sk_buff *skb,
+                         struct sock *skip_sk)
+{
+       return mgmt_send_event_skb(event, hdev, HCI_CHANNEL_CONTROL, skb,
+                                  HCI_SOCK_TRUSTED, skip_sk);
+}
+
 static u8 le_addr_type(u8 mgmt_addr_type)
 {
        if (mgmt_addr_type == BDADDR_LE_PUBLIC)
@@ -9538,9 +9545,8 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
                       u8 addr_type, u8 *dev_class, s8 rssi, u32 flags,
                       u8 *eir, u16 eir_len, u8 *scan_rsp, u8 scan_rsp_len)
 {
-       char buf[512];
-       struct mgmt_ev_device_found *ev = (void *)buf;
-       size_t ev_size;
+       struct sk_buff *skb;
+       struct mgmt_ev_device_found *ev;
 
        /* Don't send events for a non-kernel initiated discovery. With
         * LE one exception is if we have pend_le_reports > 0 in which
@@ -9575,13 +9581,12 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
                }
        }
 
-       /* Make sure that the buffer is big enough. The 5 extra bytes
-        * are for the potential CoD field.
-        */
-       if (sizeof(*ev) + eir_len + scan_rsp_len + 5 > sizeof(buf))
+       /* Allocate skb. The 5 extra bytes are for the potential CoD field */
+       skb = mgmt_alloc_skb(sizeof(ev) + eir_len + scan_rsp_len + 5);
+       if (!skb)
                return;
 
-       memset(buf, 0, sizeof(buf));
+       ev = skb_put(skb, sizeof(*ev));
 
        /* In case of device discovery with BR/EDR devices (pre 1.2), the
         * RSSI value was reported as 0 when not available. This behavior
@@ -9602,21 +9607,23 @@ void mgmt_device_found(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 
        if (eir_len > 0)
                /* Copy EIR or advertising data into event */
-               memcpy(ev->eir, eir, eir_len);
+               skb_put_data(skb, eir, eir_len);
 
-       if (dev_class && !eir_get_data(ev->eir, eir_len, EIR_CLASS_OF_DEV,
-                                      NULL))
-               eir_len = eir_append_data(ev->eir, eir_len, EIR_CLASS_OF_DEV,
-                                         dev_class, 3);
+       if (dev_class && !eir_get_data(eir, eir_len, EIR_CLASS_OF_DEV, NULL)) {
+               u8 eir_cod[5];
+
+               eir_len += eir_append_data(eir_cod, 0, EIR_CLASS_OF_DEV,
+                                          dev_class, 3);
+               skb_put_data(skb, eir_cod, eir_len);
+       }
 
        if (scan_rsp_len > 0)
                /* Append scan response data to event */
-               memcpy(ev->eir + eir_len, scan_rsp, scan_rsp_len);
+               skb_put_data(skb, scan_rsp, scan_rsp_len);
 
        ev->eir_len = cpu_to_le16(eir_len + scan_rsp_len);
-       ev_size = sizeof(*ev) + eir_len + scan_rsp_len;
 
-       mgmt_event(MGMT_EV_DEVICE_FOUND, hdev, ev, ev_size, NULL);
+       mgmt_event_skb(MGMT_EV_DEVICE_FOUND, hdev, skb, NULL);
 }