mirror of
https://github.com/torvalds/linux
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b08eadd272
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>
149 lines
2.9 KiB
C
149 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2020 Google Corporation
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*/
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#include <net/bluetooth/bluetooth.h>
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#include <net/bluetooth/hci_core.h>
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#include "msft.h"
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#define MSFT_OP_READ_SUPPORTED_FEATURES 0x00
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struct msft_cp_read_supported_features {
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__u8 sub_opcode;
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} __packed;
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struct msft_rp_read_supported_features {
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__u8 status;
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__u8 sub_opcode;
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__le64 features;
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__u8 evt_prefix_len;
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__u8 evt_prefix[];
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} __packed;
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struct msft_data {
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__u64 features;
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__u8 evt_prefix_len;
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__u8 *evt_prefix;
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};
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static bool read_supported_features(struct hci_dev *hdev,
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struct msft_data *msft)
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{
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struct msft_cp_read_supported_features cp;
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struct msft_rp_read_supported_features *rp;
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struct sk_buff *skb;
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cp.sub_opcode = MSFT_OP_READ_SUPPORTED_FEATURES;
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skb = __hci_cmd_sync(hdev, hdev->msft_opcode, sizeof(cp), &cp,
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HCI_CMD_TIMEOUT);
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if (IS_ERR(skb)) {
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bt_dev_err(hdev, "Failed to read MSFT supported features (%ld)",
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PTR_ERR(skb));
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return false;
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}
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if (skb->len < sizeof(*rp)) {
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bt_dev_err(hdev, "MSFT supported features length mismatch");
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goto failed;
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}
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rp = (struct msft_rp_read_supported_features *)skb->data;
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if (rp->sub_opcode != MSFT_OP_READ_SUPPORTED_FEATURES)
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goto failed;
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if (rp->evt_prefix_len > 0) {
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msft->evt_prefix = kmemdup(rp->evt_prefix, rp->evt_prefix_len,
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GFP_KERNEL);
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if (!msft->evt_prefix)
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goto failed;
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}
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msft->evt_prefix_len = rp->evt_prefix_len;
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msft->features = __le64_to_cpu(rp->features);
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kfree_skb(skb);
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return true;
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failed:
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kfree_skb(skb);
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return false;
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}
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void msft_do_open(struct hci_dev *hdev)
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{
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struct msft_data *msft;
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if (hdev->msft_opcode == HCI_OP_NOP)
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return;
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bt_dev_dbg(hdev, "Initialize MSFT extension");
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msft = kzalloc(sizeof(*msft), GFP_KERNEL);
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if (!msft)
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return;
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if (!read_supported_features(hdev, msft)) {
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kfree(msft);
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return;
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}
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hdev->msft_data = msft;
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}
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void msft_do_close(struct hci_dev *hdev)
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{
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struct msft_data *msft = hdev->msft_data;
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if (!msft)
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return;
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bt_dev_dbg(hdev, "Cleanup of MSFT extension");
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hdev->msft_data = NULL;
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kfree(msft->evt_prefix);
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kfree(msft);
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}
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void msft_vendor_evt(struct hci_dev *hdev, struct sk_buff *skb)
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{
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struct msft_data *msft = hdev->msft_data;
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u8 event;
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if (!msft)
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return;
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/* When the extension has defined an event prefix, check that it
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* matches, and otherwise just return.
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*/
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if (msft->evt_prefix_len > 0) {
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if (skb->len < msft->evt_prefix_len)
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return;
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if (memcmp(skb->data, msft->evt_prefix, msft->evt_prefix_len))
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return;
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skb_pull(skb, msft->evt_prefix_len);
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}
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/* Every event starts at least with an event code and the rest of
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* the data is variable and depends on the event code.
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*/
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if (skb->len < 1)
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return;
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event = *skb->data;
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skb_pull(skb, 1);
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bt_dev_dbg(hdev, "MSFT vendor event %u", event);
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}
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__u64 msft_get_features(struct hci_dev *hdev)
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{
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struct msft_data *msft = hdev->msft_data;
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return msft ? msft->features : 0;
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}
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