// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2024 José Expósito
*/
#include "vmlinux.h"
#include "hid_bpf.h"
#include "hid_bpf_helpers.h"
#include <bpf/bpf_tracing.h>
#define VID_RAPOO 0x24AE
#define PID_M50 0x2015
#define RDESC_SIZE 186
HID_BPF_CONFIG(
HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_RAPOO, PID_M50)
);
/*
* The Rapoo M50 Plus Silent mouse has 2 side buttons in addition to the left,
* right and middle buttons. However, its original HID descriptor has a Usage
* Maximum of 3, preventing the side buttons to work. This HID-BPF driver
* changes that usage to 5.
*
* For reference, this is the original report descriptor:
*
* 0x05, 0x01, // Usage Page (Generic Desktop) 0
* 0x09, 0x02, // Usage (Mouse) 2
* 0xa1, 0x01, // Collection (Application) 4
* 0x85, 0x01, // Report ID (1) 6
* 0x09, 0x01, // Usage (Pointer) 8
* 0xa1, 0x00, // Collection (Physical) 10
* 0x05, 0x09, // Usage Page (Button) 12
* 0x19, 0x01, // Usage Minimum (1) 14
* 0x29, 0x03, // Usage Maximum (3) 16 <- change to 0x05
* 0x15, 0x00, // Logical Minimum (0) 18
* 0x25, 0x01, // Logical Maximum (1) 20
* 0x75, 0x01, // Report Size (1) 22
* 0x95, 0x05, // Report Count (5) 24
* 0x81, 0x02, // Input (Data,Var,Abs) 26
* 0x75, 0x03, // Report Size (3) 28
* 0x95, 0x01, // Report Count (1) 30
* 0x81, 0x01, // Input (Cnst,Arr,Abs) 32
* 0x05, 0x01, // Usage Page (Generic Desktop) 34
* 0x09, 0x30, // Usage (X) 36
* 0x09, 0x31, // Usage (Y) 38
* 0x16, 0x01, 0x80, // Logical Minimum (-32767) 40
* 0x26, 0xff, 0x7f, // Logical Maximum (32767) 43
* 0x75, 0x10, // Report Size (16) 46
* 0x95, 0x02, // Report Count (2) 48
* 0x81, 0x06, // Input (Data,Var,Rel) 50
* 0x09, 0x38, // Usage (Wheel) 52
* 0x15, 0x81, // Logical Minimum (-127) 54
* 0x25, 0x7f, // Logical Maximum (127) 56
* 0x75, 0x08, // Report Size (8) 58
* 0x95, 0x01, // Report Count (1) 60
* 0x81, 0x06, // Input (Data,Var,Rel) 62
* 0xc0, // End Collection 64
* 0xc0, // End Collection 65
* 0x05, 0x0c, // Usage Page (Consumer Devices) 66
* 0x09, 0x01, // Usage (Consumer Control) 68
* 0xa1, 0x01, // Collection (Application) 70
* 0x85, 0x02, // Report ID (2) 72
* 0x75, 0x10, // Report Size (16) 74
* 0x95, 0x01, // Report Count (1) 76
* 0x15, 0x01, // Logical Minimum (1) 78
* 0x26, 0x8c, 0x02, // Logical Maximum (652) 80
* 0x19, 0x01, // Usage Minimum (1) 83
* 0x2a, 0x8c, 0x02, // Usage Maximum (652) 85
* 0x81, 0x00, // Input (Data,Arr,Abs) 88
* 0xc0, // End Collection 90
* 0x05, 0x01, // Usage Page (Generic Desktop) 91
* 0x09, 0x80, // Usage (System Control) 93
* 0xa1, 0x01, // Collection (Application) 95
* 0x85, 0x03, // Report ID (3) 97
* 0x09, 0x82, // Usage (System Sleep) 99
* 0x09, 0x81, // Usage (System Power Down) 101
* 0x09, 0x83, // Usage (System Wake Up) 103
* 0x15, 0x00, // Logical Minimum (0) 105
* 0x25, 0x01, // Logical Maximum (1) 107
* 0x19, 0x01, // Usage Minimum (1) 109
* 0x29, 0x03, // Usage Maximum (3) 111
* 0x75, 0x01, // Report Size (1) 113
* 0x95, 0x03, // Report Count (3) 115
* 0x81, 0x02, // Input (Data,Var,Abs) 117
* 0x95, 0x05, // Report Count (5) 119
* 0x81, 0x01, // Input (Cnst,Arr,Abs) 121
* 0xc0, // End Collection 123
* 0x05, 0x01, // Usage Page (Generic Desktop) 124
* 0x09, 0x00, // Usage (Undefined) 126
* 0xa1, 0x01, // Collection (Application) 128
* 0x85, 0x05, // Report ID (5) 130
* 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page 1) 132
* 0x09, 0x01, // Usage (Vendor Usage 1) 135
* 0x15, 0x81, // Logical Minimum (-127) 137
* 0x25, 0x7f, // Logical Maximum (127) 139
* 0x75, 0x08, // Report Size (8) 141
* 0x95, 0x07, // Report Count (7) 143
* 0xb1, 0x02, // Feature (Data,Var,Abs) 145
* 0xc0, // End Collection 147
* 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page 1) 148
* 0x09, 0x0e, // Usage (Vendor Usage 0x0e) 151
* 0xa1, 0x01, // Collection (Application) 153
* 0x85, 0xba, // Report ID (186) 155
* 0x95, 0x1f, // Report Count (31) 157
* 0x75, 0x08, // Report Size (8) 159
* 0x26, 0xff, 0x00, // Logical Maximum (255) 161
* 0x15, 0x00, // Logical Minimum (0) 164
* 0x09, 0x01, // Usage (Vendor Usage 1) 166
* 0x91, 0x02, // Output (Data,Var,Abs) 168
* 0x85, 0xba, // Report ID (186) 170
* 0x95, 0x1f, // Report Count (31) 172
* 0x75, 0x08, // Report Size (8) 174
* 0x26, 0xff, 0x00, // Logical Maximum (255) 176
* 0x15, 0x00, // Logical Minimum (0) 179
* 0x09, 0x01, // Usage (Vendor Usage 1) 181
* 0x81, 0x02, // Input (Data,Var,Abs) 183
* 0xc0, // End Collection 185
*/
SEC(HID_BPF_RDESC_FIXUP)
int BPF_PROG(hid_rdesc_fixup_rapoo_m50, struct hid_bpf_ctx *hctx)
{
__u8 *data = hid_bpf_get_data(hctx, 0, HID_MAX_DESCRIPTOR_SIZE);
if (!data)
return 0; /* EPERM check */
if (data[17] == 0x03)
data[17] = 0x05;
return 0;
}
HID_BPF_OPS(rapoo_m50) = {
.hid_rdesc_fixup = (void *)hid_rdesc_fixup_rapoo_m50,
};
SEC("syscall")
int probe(struct hid_bpf_probe_args *ctx)
{
ctx->retval = ctx->rdesc_size != RDESC_SIZE;
if (ctx->retval)
ctx->retval = -EINVAL;
return 0;
}
char _license[] SEC("license") = "GPL";
