1/* SPDX-License-Identifier: GPL-2.0-only */
2/* Copyright (c) 2022 Benjamin Tissoires
3 */
4
5#ifndef __HID_BPF_HELPERS_H
6#define __HID_BPF_HELPERS_H
7
8/* "undefine" structs and enums in vmlinux.h, because we "override" them below */
9#define hid_bpf_ctx hid_bpf_ctx___not_used
10#define hid_report_type hid_report_type___not_used
11#define hid_class_request hid_class_request___not_used
12#define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
13#define HID_INPUT_REPORT         HID_INPUT_REPORT___not_used
14#define HID_OUTPUT_REPORT        HID_OUTPUT_REPORT___not_used
15#define HID_FEATURE_REPORT       HID_FEATURE_REPORT___not_used
16#define HID_REPORT_TYPES         HID_REPORT_TYPES___not_used
17#define HID_REQ_GET_REPORT       HID_REQ_GET_REPORT___not_used
18#define HID_REQ_GET_IDLE         HID_REQ_GET_IDLE___not_used
19#define HID_REQ_GET_PROTOCOL     HID_REQ_GET_PROTOCOL___not_used
20#define HID_REQ_SET_REPORT       HID_REQ_SET_REPORT___not_used
21#define HID_REQ_SET_IDLE         HID_REQ_SET_IDLE___not_used
22#define HID_REQ_SET_PROTOCOL     HID_REQ_SET_PROTOCOL___not_used
23#define HID_BPF_FLAG_NONE        HID_BPF_FLAG_NONE___not_used
24#define HID_BPF_FLAG_INSERT_HEAD HID_BPF_FLAG_INSERT_HEAD___not_used
25#define HID_BPF_FLAG_MAX         HID_BPF_FLAG_MAX___not_used
26
27#include "vmlinux.h"
28
29#undef hid_bpf_ctx
30#undef hid_report_type
31#undef hid_class_request
32#undef hid_bpf_attach_flags
33#undef HID_INPUT_REPORT
34#undef HID_OUTPUT_REPORT
35#undef HID_FEATURE_REPORT
36#undef HID_REPORT_TYPES
37#undef HID_REQ_GET_REPORT
38#undef HID_REQ_GET_IDLE
39#undef HID_REQ_GET_PROTOCOL
40#undef HID_REQ_SET_REPORT
41#undef HID_REQ_SET_IDLE
42#undef HID_REQ_SET_PROTOCOL
43#undef HID_BPF_FLAG_NONE
44#undef HID_BPF_FLAG_INSERT_HEAD
45#undef HID_BPF_FLAG_MAX
46
47#include <bpf/bpf_helpers.h>
48#include <bpf/bpf_tracing.h>
49#include <linux/const.h>
50
51enum hid_report_type {
52	HID_INPUT_REPORT		= 0,
53	HID_OUTPUT_REPORT		= 1,
54	HID_FEATURE_REPORT		= 2,
55
56	HID_REPORT_TYPES,
57};
58
59struct hid_bpf_ctx {
60	__u32 index;
61	const struct hid_device *hid;
62	__u32 allocated_size;
63	enum hid_report_type report_type;
64	union {
65		__s32 retval;
66		__s32 size;
67	};
68} __attribute__((preserve_access_index));
69
70enum hid_class_request {
71	HID_REQ_GET_REPORT		= 0x01,
72	HID_REQ_GET_IDLE		= 0x02,
73	HID_REQ_GET_PROTOCOL		= 0x03,
74	HID_REQ_SET_REPORT		= 0x09,
75	HID_REQ_SET_IDLE		= 0x0A,
76	HID_REQ_SET_PROTOCOL		= 0x0B,
77};
78
79enum hid_bpf_attach_flags {
80	HID_BPF_FLAG_NONE = 0,
81	HID_BPF_FLAG_INSERT_HEAD = _BITUL(0),
82	HID_BPF_FLAG_MAX,
83};
84
85/* following are kfuncs exported by HID for HID-BPF */
86extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
87			      unsigned int offset,
88			      const size_t __sz) __ksym;
89extern int hid_bpf_attach_prog(unsigned int hid_id, int prog_fd, u32 flags) __ksym;
90extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __ksym;
91extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __ksym;
92extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
93			      __u8 *data,
94			      size_t buf__sz,
95			      enum hid_report_type type,
96			      enum hid_class_request reqtype) __ksym;
97
98#endif /* __HID_BPF_HELPERS_H */
99