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// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (c) 2025 TUXEDO Computers GmbH
*/
#include "vmlinux.h"
#include "hid_bpf.h"
#include "hid_bpf_helpers.h"
#include <bpf/bpf_tracing.h>
HID_BPF_CONFIG(
HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, 0x048D, 0x8910)
);
SEC(HID_BPF_DEVICE_EVENT)
int BPF_PROG(ignore_key_fix_event, struct hid_bpf_ctx *hid_ctx)
{
const int expected_length = 37;
const int expected_report_id = 1;
__u8 *data;
int i;
if (hid_ctx->size < expected_length)
return 0;
data = hid_bpf_get_data(hid_ctx, 0, expected_length);
if (!data || data[0] != expected_report_id)
return 0;
// Zero out F13 (HID usage ID: 0x68) key press.
// The first 6 parallel key presses (excluding modifier keys) are
// encoded in an array containing usage IDs.
for (i = 3; i < 9; ++i)
if (data[i] == 0x68)
data[i] = 0x00;
// Additional parallel key presses starting with the 7th (excluding
// modifier keys) are encoded as a bit flag with the offset being
// the usage ID.
data[22] &= 0xfe;
return 0;
}
HID_BPF_OPS(ignore_button) = {
.hid_device_event = (void *)ignore_key_fix_event,
};
char _license[] SEC("license") = "GPL";
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