linux_dsm_epyc7002/net/bluetooth/msft.c
Gustavo A. R. Silva b08eadd272 Bluetooth: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-10-29 17:22:59 -05:00

150 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Google Corporation
*/
#include <net/bluetooth/bluetooth.h>
#include <net/bluetooth/hci_core.h>
#include "msft.h"
#define MSFT_OP_READ_SUPPORTED_FEATURES 0x00
struct msft_cp_read_supported_features {
__u8 sub_opcode;
} __packed;
struct msft_rp_read_supported_features {
__u8 status;
__u8 sub_opcode;
__le64 features;
__u8 evt_prefix_len;
__u8 evt_prefix[];
} __packed;
struct msft_data {
__u64 features;
__u8 evt_prefix_len;
__u8 *evt_prefix;
};
static bool read_supported_features(struct hci_dev *hdev,
struct msft_data *msft)
{
struct msft_cp_read_supported_features cp;
struct msft_rp_read_supported_features *rp;
struct sk_buff *skb;
cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
HCI_CMD_TIMEOUT);
if (IS_ERR(skb)) {
bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
PTR_ERR(skb));
return false;
}
if (skb->len < sizeof(*rp)) {
bt_dev_err(hdev, "MSFT supported features length mismatch");
goto failed;
}
rp = (struct msft_rp_read_supported_features *)skb->data;
if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
goto failed;
if (rp->evt_prefix_len > 0) {
msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
GFP_KERNEL);
if (!msft->evt_prefix)
goto failed;
}
msft->evt_prefix_len = rp->evt_prefix_len;
msft->features = __le64_to_cpu(rp->features);
kfree_skb(skb);
return true;
failed:
kfree_skb(skb);
return false;
}
void msft_do_open(struct hci_dev *hdev)
{
struct msft_data *msft;
if (hdev->msft_opcode == HCI_OP_NOP)
return;
bt_dev_dbg(hdev, "Initialize MSFT extension");
msft = kzalloc(sizeof(*msft), GFP_KERNEL);
if (!msft)
return;
if (!read_supported_features(hdev, msft)) {
kfree(msft);
return;
}
hdev->msft_data = msft;
}
void msft_do_close(struct hci_dev *hdev)
{
struct msft_data *msft = hdev->msft_data;
if (!msft)
return;
bt_dev_dbg(hdev, "Cleanup of MSFT extension");
hdev->msft_data = NULL;
kfree(msft->evt_prefix);
kfree(msft);
}
void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
struct msft_data *msft = hdev->msft_data;
u8 event;
if (!msft)
return;
/* When the extension has defined an event prefix, check that it
* matches, and otherwise just return.
*/
if (msft->evt_prefix_len > 0) {
if (skb->len < msft->evt_prefix_len)
return;
if (memcmp(skb->data, msft->evt_prefix, msft->evt_prefix_len))
return;
skb_pull(skb, msft->evt_prefix_len);
}
/* Every event starts at least with an event code and the rest of
* the data is variable and depends on the event code.
*/
if (skb->len < 1)
return;
event = *skb->data;
skb_pull(skb, 1);
bt_dev_dbg(hdev, "MSFT vendor event %u", event);
}
__u64 msft_get_features(struct hci_dev *hdev)
{
struct msft_data *msft = hdev->msft_data;
return msft ? msft->features : 0;
}