Quelle  hid_bpf_helpers.h   Sprache: C

/* SPDX-License-Identifier: GPL-2.0-only */
/* Copyright (c) 2022 Benjamin Tissoires
 */

#ifndef __HID_BPF_HELPERS_H
#define __HID_BPF_HELPERS_H

/* "undefine" structs and enums in vmlinux.h, because we "override" them below */
#define hid_bpf_ctx hid_bpf_ctx___not_used
#define hid_bpf_ops hid_bpf_ops___not_used
#define hid_report_type hid_report_type___not_used
#define hid_class_request hid_class_request___not_used
#define hid_bpf_attach_flags hid_bpf_attach_flags___not_used
#define HID_INPUT_REPORT         HID_INPUT_REPORT___not_used
#define HID_OUTPUT_REPORT        HID_OUTPUT_REPORT___not_used
#define HID_FEATURE_REPORT       HID_FEATURE_REPORT___not_used
#define HID_REPORT_TYPES         HID_REPORT_TYPES___not_used
#define HID_REQ_GET_REPORT       HID_REQ_GET_REPORT___not_used
#define HID_REQ_GET_IDLE         HID_REQ_GET_IDLE___not_used
#define HID_REQ_GET_PROTOCOL     HID_REQ_GET_PROTOCOL___not_used
#define HID_REQ_SET_REPORT       HID_REQ_SET_REPORT___not_used
#define HID_REQ_SET_IDLE         HID_REQ_SET_IDLE___not_used
#define HID_REQ_SET_PROTOCOL     HID_REQ_SET_PROTOCOL___not_used

/* do not define kfunc through vmlinux.h as this messes up our custom hack */
#define BPF_NO_KFUNC_PROTOTYPES

#include "vmlinux.h"

#undef hid_bpf_ctx
#undef hid_bpf_ops
#undef hid_report_type
#undef hid_class_request
#undef hid_bpf_attach_flags
#undef HID_INPUT_REPORT
#undef HID_OUTPUT_REPORT
#undef HID_FEATURE_REPORT
#undef HID_REPORT_TYPES
#undef HID_REQ_GET_REPORT
#undef HID_REQ_GET_IDLE
#undef HID_REQ_GET_PROTOCOL
#undef HID_REQ_SET_REPORT
#undef HID_REQ_SET_IDLE
#undef HID_REQ_SET_PROTOCOL

#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <linux/const.h>

enum hid_report_type {
 HID_INPUT_REPORT  = 0,
 HID_OUTPUT_REPORT  = 1,
 HID_FEATURE_REPORT  = 2,

 HID_REPORT_TYPES,
};

struct hid_bpf_ctx {
 struct hid_device *hid;
 __u32 allocated_size;
 union {
  __s32 retval;
  __s32 size;
 };
} __attribute__((preserve_access_index));

enum hid_class_request {
 HID_REQ_GET_REPORT  = 0x01,
 HID_REQ_GET_IDLE  = 0x02,
 HID_REQ_GET_PROTOCOL  = 0x03,
 HID_REQ_SET_REPORT  = 0x09,
 HID_REQ_SET_IDLE  = 0x0A,
 HID_REQ_SET_PROTOCOL  = 0x0B,
};

struct hid_bpf_ops {
 int   hid_id;
 u32   flags;
 struct list_head list;
 int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type,
    u64 source);
 int (*hid_rdesc_fixup)(struct hid_bpf_ctx *ctx);
 int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum,
          enum hid_report_type rtype, enum hid_class_request reqtype,
          u64 source);
 int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source);
 struct hid_device *hdev;
};

#ifndef BPF_F_BEFORE
#define BPF_F_BEFORE (1U << 3)
#endif

/* following are kfuncs exported by HID for HID-BPF */
extern __u8 *hid_bpf_get_data(struct hid_bpf_ctx *ctx,
         unsigned int offset,
         const size_t __sz) __weak __ksym;
extern struct hid_bpf_ctx *hid_bpf_allocate_context(unsigned int hid_id) __weak __ksym;
extern void hid_bpf_release_context(struct hid_bpf_ctx *ctx) __weak __ksym;
extern int hid_bpf_hw_request(struct hid_bpf_ctx *ctx,
         __u8 *data,
         size_t buf__sz,
         enum hid_report_type type,
         enum hid_class_request reqtype) __weak __ksym;
extern int hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx,
        __u8 *buf, size_t buf__sz) __weak __ksym;
extern int hid_bpf_input_report(struct hid_bpf_ctx *ctx,
    enum hid_report_type type,
    __u8 *data,
    size_t buf__sz) __weak __ksym;
extern int hid_bpf_try_input_report(struct hid_bpf_ctx *ctx,
        enum hid_report_type type,
        __u8 *data,
        size_t buf__sz) __weak __ksym;

/* bpf_wq implementation */
extern int bpf_wq_init(struct bpf_wq *wq, void *p__map, unsigned int flags) __weak __ksym;
extern int bpf_wq_start(struct bpf_wq *wq, unsigned int flags) __weak __ksym;
extern int bpf_wq_set_callback_impl(struct bpf_wq *wq,
  int (callback_fn)(void *map, int *key, void *wq),
  unsigned int flags__k, void *aux__ign) __weak __ksym;
#define bpf_wq_set_callback(timer, cb, flags) \
 bpf_wq_set_callback_impl(timer, cb, flags, NULL)

#endif /* __HID_BPF_HELPERS_H */