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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright (c) 2023 Benjamin Tissoires3 */4 5#include "vmlinux.h"6#include "hid_bpf.h"7#include "hid_bpf_helpers.h"8#include <bpf/bpf_tracing.h>9 10#define VID_HP 0x03F011#define PID_ELITE_PRESENTER 0x464A12 13HID_BPF_CONFIG(14 HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_GENERIC, VID_HP, PID_ELITE_PRESENTER)15);16 17/*18 * Already fixed as of commit 0db117359e47 ("HID: add quirk for 03f0:464a19 * HP Elite Presenter Mouse") in the kernel, but this is a slightly better20 * fix.21 *22 * The HP Elite Presenter Mouse HID Record Descriptor shows23 * two mice (Report ID 0x1 and 0x2), one keypad (Report ID 0x5),24 * two Consumer Controls (Report IDs 0x6 and 0x3).25 * Prior to these fixes it registers one mouse, one keypad26 * and one Consumer Control, and it was usable only as a27 * digital laser pointer (one of the two mouses).28 * We replace the second mouse collection with a pointer collection,29 * allowing to use the device both as a mouse and a digital laser30 * pointer.31 */32 33SEC(HID_BPF_RDESC_FIXUP)34int BPF_PROG(hid_fix_rdesc, struct hid_bpf_ctx *hctx)35{36 __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */);37 38 if (!data)39 return 0; /* EPERM check */40 41 /* replace application mouse by application pointer on the second collection */42 if (data[79] == 0x02)43 data[79] = 0x01;44 45 return 0;46}47 48HID_BPF_OPS(hp_elite_presenter) = {49 .hid_rdesc_fixup = (void *)hid_fix_rdesc,50};51 52SEC("syscall")53int probe(struct hid_bpf_probe_args *ctx)54{55 ctx->retval = ctx->rdesc_size != 264;56 if (ctx->retval)57 ctx->retval = -EINVAL;58 59 return 0;60}61 62char _license[] SEC("license") = "GPL";63