new file mode 100644
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+// 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";