[linux-2.6-block.git] / drivers / hid / bpf / progs / HP__Elite-Presenter.bpf.c

// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2023 Benjamin Tissoires
 */

#include "vmlinux.h"
#include "hid_bpf.h"
#include "hid_bpf_helpers.h"
#include <bpf/bpf_tracing.h>

#define VID_HP 0x03F0
#define PID_ELITE_PRESENTER 0x464A

HID_BPF_CONFIG(
	HID_DEVICE(BUS_BLUETOOTH, HID_GROUP_GENERIC, VID_HP, PID_ELITE_PRESENTER)
);

/*
 * Already fixed as of commit 0db117359e47 ("HID: add quirk for 03f0:464a
 * HP Elite Presenter Mouse") in the kernel, but this is a slightly better
 * fix.
 *
 * The HP Elite Presenter Mouse HID Record Descriptor shows
 * two mice (Report ID 0x1 and 0x2), one keypad (Report ID 0x5),
 * two Consumer Controls (Report IDs 0x6 and 0x3).
 * Prior to these fixes it registers one mouse, one keypad
 * and one Consumer Control, and it was usable only as a
 * digital laser pointer (one of the two mouses).
 * We replace the second mouse collection with a pointer collection,
 * allowing to use the device both as a mouse and a digital laser
 * pointer.
 */

SEC("fmod_ret/hid_bpf_rdesc_fixup")
int BPF_PROG(hid_fix_rdesc, struct hid_bpf_ctx *hctx)
{
	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */);

	if (!data)
		return 0; /* EPERM check */

	/* replace application mouse by application pointer on the second collection */
	if (data[79] == 0x02)
		data[79] = 0x01;

	return 0;
}

SEC("syscall")
int probe(struct hid_bpf_probe_args *ctx)
{
	ctx->retval = ctx->rdesc_size != 264;
	if (ctx->retval)
		ctx->retval = -EINVAL;

	return 0;
}

char _license[] SEC("license") = "GPL";
Commit	Line	Data
4e6d2a29 BT	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/* Copyright (c) 2023 Benjamin Tissoires
	3	*/
	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 0x03F0
	11	#define PID_ELITE_PRESENTER 0x464A
	12
	13	HID_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 03f0:464a
	19	* HP Elite Presenter Mouse") in the kernel, but this is a slightly better
	20	* fix.
	21	*
	22	* The HP Elite Presenter Mouse HID Record Descriptor shows
	23	* 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 keypad
	26	* and one Consumer Control, and it was usable only as a
	27	* 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 laser
	30	* pointer.
	31	*/
	32
	33	SEC("fmod_ret/hid_bpf_rdesc_fixup")
	34	int 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
	48	SEC("syscall")
	49	int probe(struct hid_bpf_probe_args *ctx)
	50	{
	51	ctx->retval = ctx->rdesc_size != 264;
	52	if (ctx->retval)
	53	ctx->retval = -EINVAL;
	54
	55	return 0;
	56	}
	57
	58	char _license[] SEC("license") = "GPL";