Rapoo__M50-Plus-Silent.bpf.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/* Copyright (c) 2024 José Expósito
  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_RAPOO	0x24AE
 11#define PID_M50		0x2015
 12#define RDESC_SIZE	186
 13
 14HID_BPF_CONFIG(
 15	HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_RAPOO, PID_M50)
 16);
 17
 18/*
 19 * The Rapoo M50 Plus Silent mouse has 2 side buttons in addition to the left,
 20 * right and middle buttons. However, its original HID descriptor has a Usage
 21 * Maximum of 3, preventing the side buttons to work. This HID-BPF driver
 22 * changes that usage to 5.
 23 *
 24 * For reference, this is the original report descriptor:
 25 *
 26 * 0x05, 0x01,       // Usage Page (Generic Desktop)        0
 27 * 0x09, 0x02,       // Usage (Mouse)                       2
 28 * 0xa1, 0x01,       // Collection (Application)            4
 29 * 0x85, 0x01,       //  Report ID (1)                      6
 30 * 0x09, 0x01,       //  Usage (Pointer)                    8
 31 * 0xa1, 0x00,       //  Collection (Physical)              10
 32 * 0x05, 0x09,       //   Usage Page (Button)               12
 33 * 0x19, 0x01,       //   Usage Minimum (1)                 14
 34 * 0x29, 0x03,       //   Usage Maximum (3)                 16 <- change to 0x05
 35 * 0x15, 0x00,       //   Logical Minimum (0)               18
 36 * 0x25, 0x01,       //   Logical Maximum (1)               20
 37 * 0x75, 0x01,       //   Report Size (1)                   22
 38 * 0x95, 0x05,       //   Report Count (5)                  24
 39 * 0x81, 0x02,       //   Input (Data,Var,Abs)              26
 40 * 0x75, 0x03,       //   Report Size (3)                   28
 41 * 0x95, 0x01,       //   Report Count (1)                  30
 42 * 0x81, 0x01,       //   Input (Cnst,Arr,Abs)              32
 43 * 0x05, 0x01,       //   Usage Page (Generic Desktop)      34
 44 * 0x09, 0x30,       //   Usage (X)                         36
 45 * 0x09, 0x31,       //   Usage (Y)                         38
 46 * 0x16, 0x01, 0x80, //   Logical Minimum (-32767)          40
 47 * 0x26, 0xff, 0x7f, //   Logical Maximum (32767)           43
 48 * 0x75, 0x10,       //   Report Size (16)                  46
 49 * 0x95, 0x02,       //   Report Count (2)                  48
 50 * 0x81, 0x06,       //   Input (Data,Var,Rel)              50
 51 * 0x09, 0x38,       //   Usage (Wheel)                     52
 52 * 0x15, 0x81,       //   Logical Minimum (-127)            54
 53 * 0x25, 0x7f,       //   Logical Maximum (127)             56
 54 * 0x75, 0x08,       //   Report Size (8)                   58
 55 * 0x95, 0x01,       //   Report Count (1)                  60
 56 * 0x81, 0x06,       //   Input (Data,Var,Rel)              62
 57 * 0xc0,             //  End Collection                     64
 58 * 0xc0,             // End Collection                      65
 59 * 0x05, 0x0c,       // Usage Page (Consumer Devices)       66
 60 * 0x09, 0x01,       // Usage (Consumer Control)            68
 61 * 0xa1, 0x01,       // Collection (Application)            70
 62 * 0x85, 0x02,       //  Report ID (2)                      72
 63 * 0x75, 0x10,       //  Report Size (16)                   74
 64 * 0x95, 0x01,       //  Report Count (1)                   76
 65 * 0x15, 0x01,       //  Logical Minimum (1)                78
 66 * 0x26, 0x8c, 0x02, //  Logical Maximum (652)              80
 67 * 0x19, 0x01,       //  Usage Minimum (1)                  83
 68 * 0x2a, 0x8c, 0x02, //  Usage Maximum (652)                85
 69 * 0x81, 0x00,       //  Input (Data,Arr,Abs)               88
 70 * 0xc0,             // End Collection                      90
 71 * 0x05, 0x01,       // Usage Page (Generic Desktop)        91
 72 * 0x09, 0x80,       // Usage (System Control)              93
 73 * 0xa1, 0x01,       // Collection (Application)            95
 74 * 0x85, 0x03,       //  Report ID (3)                      97
 75 * 0x09, 0x82,       //  Usage (System Sleep)               99
 76 * 0x09, 0x81,       //  Usage (System Power Down)          101
 77 * 0x09, 0x83,       //  Usage (System Wake Up)             103
 78 * 0x15, 0x00,       //  Logical Minimum (0)                105
 79 * 0x25, 0x01,       //  Logical Maximum (1)                107
 80 * 0x19, 0x01,       //  Usage Minimum (1)                  109
 81 * 0x29, 0x03,       //  Usage Maximum (3)                  111
 82 * 0x75, 0x01,       //  Report Size (1)                    113
 83 * 0x95, 0x03,       //  Report Count (3)                   115
 84 * 0x81, 0x02,       //  Input (Data,Var,Abs)               117
 85 * 0x95, 0x05,       //  Report Count (5)                   119
 86 * 0x81, 0x01,       //  Input (Cnst,Arr,Abs)               121
 87 * 0xc0,             // End Collection                      123
 88 * 0x05, 0x01,       // Usage Page (Generic Desktop)        124
 89 * 0x09, 0x00,       // Usage (Undefined)                   126
 90 * 0xa1, 0x01,       // Collection (Application)            128
 91 * 0x85, 0x05,       //  Report ID (5)                      130
 92 * 0x06, 0x00, 0xff, //  Usage Page (Vendor Defined Page 1) 132
 93 * 0x09, 0x01,       //  Usage (Vendor Usage 1)             135
 94 * 0x15, 0x81,       //  Logical Minimum (-127)             137
 95 * 0x25, 0x7f,       //  Logical Maximum (127)              139
 96 * 0x75, 0x08,       //  Report Size (8)                    141
 97 * 0x95, 0x07,       //  Report Count (7)                   143
 98 * 0xb1, 0x02,       //  Feature (Data,Var,Abs)             145
 99 * 0xc0,             // End Collection                      147
100 * 0x06, 0x00, 0xff, // Usage Page (Vendor Defined Page 1)  148
101 * 0x09, 0x0e,       // Usage (Vendor Usage 0x0e)           151
102 * 0xa1, 0x01,       // Collection (Application)            153
103 * 0x85, 0xba,       //  Report ID (186)                    155
104 * 0x95, 0x1f,       //  Report Count (31)                  157
105 * 0x75, 0x08,       //  Report Size (8)                    159
106 * 0x26, 0xff, 0x00, //  Logical Maximum (255)              161
107 * 0x15, 0x00,       //  Logical Minimum (0)                164
108 * 0x09, 0x01,       //  Usage (Vendor Usage 1)             166
109 * 0x91, 0x02,       //  Output (Data,Var,Abs)              168
110 * 0x85, 0xba,       //  Report ID (186)                    170
111 * 0x95, 0x1f,       //  Report Count (31)                  172
112 * 0x75, 0x08,       //  Report Size (8)                    174
113 * 0x26, 0xff, 0x00, //  Logical Maximum (255)              176
114 * 0x15, 0x00,       //  Logical Minimum (0)                179
115 * 0x09, 0x01,       //  Usage (Vendor Usage 1)             181
116 * 0x81, 0x02,       //  Input (Data,Var,Abs)               183
117 * 0xc0,             // End Collection                      185
118 */
119
120SEC(HID_BPF_RDESC_FIXUP)
121int BPF_PROG(hid_rdesc_fixup_rapoo_m50, struct hid_bpf_ctx *hctx)
122{
123	__u8 *data = hid_bpf_get_data(hctx, 0, HID_MAX_DESCRIPTOR_SIZE);
124
125	if (!data)
126		return 0; /* EPERM check */
127
128	if (data[17] == 0x03)
129		data[17] = 0x05;
130
131	return 0;
132}
133
134HID_BPF_OPS(rapoo_m50) = {
135	.hid_rdesc_fixup = (void *)hid_rdesc_fixup_rapoo_m50,
136};
137
138SEC("syscall")
139int probe(struct hid_bpf_probe_args *ctx)
140{
141	ctx->retval = ctx->rdesc_size != RDESC_SIZE;
142	if (ctx->retval)
143		ctx->retval = -EINVAL;
144
145	return 0;
146}
147
148char _license[] SEC("license") = "GPL";