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 14 HID_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 */ 119 120 SEC(HID_BPF_RDESC_FIXUP) 121 int 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 } 133 134 HID_BPF_OPS(rapoo_m50) = { 135 .hid_rdesc_fixup = (void *)hid_rdesc_fixup_rapoo_m50, 136 }; 137 138 SEC("syscall") 139 int 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 } 147 148 char _license[] SEC("license") = "GPL"; 149