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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_bpf_ops hid_bpf_ops___not_used
11#define hid_report_type hid_report_type___not_used
12#define hid_class_request hid_class_request___not_used
13#define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
14#define HID_INPUT_REPORT HID_INPUT_REPORT___not_used
15#define HID_OUTPUT_REPORT HID_OUTPUT_REPORT___not_used
16#define HID_FEATURE_REPORT HID_FEATURE_REPORT___not_used
17#define HID_REPORT_TYPES HID_REPORT_TYPES___not_used
18#define HID_REQ_GET_REPORT HID_REQ_GET_REPORT___not_used
19#define HID_REQ_GET_IDLE HID_REQ_GET_IDLE___not_used
20#define HID_REQ_GET_PROTOCOL HID_REQ_GET_PROTOCOL___not_used
21#define HID_REQ_SET_REPORT HID_REQ_SET_REPORT___not_used
22#define HID_REQ_SET_IDLE HID_REQ_SET_IDLE___not_used
23#define HID_REQ_SET_PROTOCOL HID_REQ_SET_PROTOCOL___not_used
24
25/* do not define kfunc through vmlinux.h as this messes up our custom hack */
26#define BPF_NO_KFUNC_PROTOTYPES
27
28#include "vmlinux.h"
29
30#undef hid_bpf_ctx
31#undef hid_bpf_ops
32#undef hid_report_type
33#undef hid_class_request
34#undef hid_bpf_attach_flags
35#undef HID_INPUT_REPORT
36#undef HID_OUTPUT_REPORT
37#undef HID_FEATURE_REPORT
38#undef HID_REPORT_TYPES
39#undef HID_REQ_GET_REPORT
40#undef HID_REQ_GET_IDLE
41#undef HID_REQ_GET_PROTOCOL
42#undef HID_REQ_SET_REPORT
43#undef HID_REQ_SET_IDLE
44#undef HID_REQ_SET_PROTOCOL
45
46#include <bpf/bpf_helpers.h>
47#include <bpf/bpf_tracing.h>
48#include <linux/const.h>
49
50enum hid_report_type {
51 HID_INPUT_REPORT = 0,
52 HID_OUTPUT_REPORT = 1,
53 HID_FEATURE_REPORT = 2,
54
55 HID_REPORT_TYPES,
56};
57
58struct hid_bpf_ctx {
59 struct hid_device *hid;
60 __u32 allocated_size;
61 union {
62 __s32 retval;
63 __s32 size;
64 };
65} __attribute__((preserve_access_index));
66
67enum hid_class_request {
68 HID_REQ_GET_REPORT = 0x01,
69 HID_REQ_GET_IDLE = 0x02,
70 HID_REQ_GET_PROTOCOL = 0x03,
71 HID_REQ_SET_REPORT = 0x09,
72 HID_REQ_SET_IDLE = 0x0A,
73 HID_REQ_SET_PROTOCOL = 0x0B,
74};
75
76struct hid_bpf_ops {
77 int hid_id;
78 u32 flags;
79 struct list_head list;
80 int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type,
81 u64 source);
82 int (*hid_rdesc_fixup)(struct hid_bpf_ctx *ctx);
83 int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum,
84 enum hid_report_type rtype, enum hid_class_request reqtype,
85 u64 source);
86 int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source);
87 struct hid_device *hdev;
88};
89
90#ifndef BPF_F_BEFORE
91#define BPF_F_BEFORE (1U << 3)
92#endif
93
94/* following are kfuncs exported by HID for HID-BPF */
95extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
96 unsigned int offset,
97 const size_t __sz) __weak __ksym;
98extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __weak __ksym;
99extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __weak __ksym;
100extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
101 __u8 *data,
102 size_t buf__sz,
103 enum hid_report_type type,
104 enum hid_class_request reqtype) __weak __ksym;
105extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
106 __u8 *buf, size_t buf__sz) __weak __ksym;
107extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
108 enum hid_report_type type,
109 __u8 *data,
110 size_t buf__sz) __weak __ksym;
111extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,
112 enum hid_report_type type,
113 __u8 *data,
114 size_t buf__sz) __weak __ksym;
115
116/* bpf_wq implementation */
117extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;
118extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym;
119extern int bpf_wq_set_callback_impl(struct bpf_wq *wq,
120 int (callback_fn)(void *map, int *key, void *wq),
121 unsigned int flags__k, void *aux__ign) __weak __ksym;
122#define bpf_wq_set_callback(timer, cb, flags) \
123 bpf_wq_set_callback_impl(timer, cb, flags, NULL)
124
125#endif /* __HID_BPF_HELPERS_H */