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_IOGEAR 0x258A /* VID is shared with SinoWealth and Glorious and prob others */ 11 #define PID_MOMENTUM 0x0027 12 13 HID_BPF_CONFIG( 14 HID_DEVICE(BUS_USB, HID_GROUP_GENERIC, VID_IOGEAR, PID_MOMENTUM) 15 ); 16 17 /* 18 * The IOGear Kaliber Gaming MMOmentum Pro mouse has multiple buttons (12) 19 * but only 5 are accessible out of the box because the report descriptor 20 * marks the other buttons as constants. 21 * We just fix the report descriptor to enable those missing 7 buttons. 22 */ 23 24 SEC(HID_BPF_RDESC_FIXUP) 25 int BPF_PROG(hid_fix_rdesc, struct hid_bpf_ctx *hctx) 26 { 27 const u8 offsets[] = {84, 112, 140}; 28 __u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */); 29 30 if (!data) 31 return 0; /* EPERM check */ 32 33 /* if not Keyboard */ 34 if (data[3] != 0x06) 35 return 0; 36 37 for (int idx = 0; idx < ARRAY_SIZE(offsets); idx++) { 38 u8 offset = offsets[idx]; 39 40 /* if Input (Cnst,Var,Abs) , make it Input (Data,Var,Abs) */ 41 if (data[offset] == 0x81 && data[offset + 1] == 0x03) 42 data[offset + 1] = 0x02; 43 } 44 45 return 0; 46 } 47 48 HID_BPF_OPS(iogear_kaliber_momentum) = { 49 .hid_rdesc_fixup = (void *)hid_fix_rdesc, 50 }; 51 52 SEC("syscall") 53 int probe(struct hid_bpf_probe_args *ctx) 54 { 55 /* only bind to the keyboard interface */ 56 ctx->retval = ctx->rdesc_size != 213; 57 if (ctx->retval) 58 ctx->retval = -EINVAL; 59 60 return 0; 61 } 62 63 char _license[] SEC("license") = "GPL"; 64