// SPDX-License-Identifier: GPL-3.0-or-later

#ifndef NETDATA_EBPF_H
#define NETDATA_EBPF_H 1

#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include <stdlib.h> // Necessary for stdtoul

#define NETDATA_DEBUGFS "/sys/kernel/debug/tracing/"
#define NETDATA_KALLSYMS "/proc/kallsyms"

// Config files
#define EBPF_GLOBAL_SECTION "global"
#define EBPF_CFG_LOAD_MODE "ebpf load mode"
#define EBPF_CFG_LOAD_MODE_DEFAULT "entry"
#define EBPF_CFG_LOAD_MODE_RETURN "return"
#define EBPF_MAX_MODE_LENGTH 6

#define EBPF_CFG_UPDATE_EVERY "update every"
#define EBPF_CFG_PID_SIZE "pid table size"
#define EBPF_CFG_APPLICATION "apps"
#define EBPF_CFG_CGROUP "cgroups"

/**
 * The next magic number is got doing the following math:
 *  294960 = 4*65536 + 11*256 + 0
 *
 *  For more details, please, read /usr/include/linux/version.h
 */
#define NETDATA_MINIMUM_EBPF_KERNEL 264960

/**
 * The RedHat magic number was got doing:
 *
 * 1797 = 7*256 + 5
 *
 *  For more details, please, read /usr/include/linux/version.h
 *  in any Red Hat installation.
 */
#define NETDATA_MINIMUM_RH_VERSION 1797

/**
 * 2048 = 8*256 + 0
 */
#define NETDATA_RH_8 2048

/**
 *  Kernel 5.11
 *
 *  330240 = 5*65536 + 11*256
 */
#define NETDATA_EBPF_KERNEL_5_11 330496

/**
 *  Kernel 5.10
 *
 *  330240 = 5*65536 + 10*256
 */
#define NETDATA_EBPF_KERNEL_5_10 330240

/**
 *  Kernel 5.0
 *
 *  327680 = 5*65536 +256*0
 */
#define NETDATA_EBPF_KERNEL_5_0 327680

/**
 *  Kernel 4.17
 *
 *  266496 = 4*65536 + 17*256
 */
#define NETDATA_EBPF_KERNEL_4_17 266496

/**
 *  Kernel 4.15
 *
 *  265984 = 4*65536 + 15*256
 */
#define NETDATA_EBPF_KERNEL_4_15 265984

/**
 *  Kernel 4.11
 *
 *  264960 = 4*65536 + 15*256
 */
#define NETDATA_EBPF_KERNEL_4_11 264960

#define VERSION_STRING_LEN 256
#define EBPF_KERNEL_REJECT_LIST_FILE "ebpf_kernel_reject_list.txt"

#define ND_EBPF_DEFAULT_MIN_PID 1U
#define ND_EBPF_MAP_FD_NOT_INITIALIZED (int)-1

typedef struct ebpf_addresses {
    char *function;
    uint32_t hash;
    // We use long as address, because it matches system length
    unsigned long addr;
} ebpf_addresses_t;

extern char *ebpf_user_config_dir;
extern char *ebpf_stock_config_dir;

typedef struct ebpf_data {
    int *map_fd;

    char *kernel_string;
    uint32_t running_on_kernel;
    int isrh;
} ebpf_data_t;

typedef enum {
    MODE_RETURN = 0, // This attaches kprobe when the function returns
    MODE_DEVMODE,    // This stores log given description about the errors raised
    MODE_ENTRY       // This attaches kprobe when the function is called
} netdata_run_mode_t;

#define ND_EBPF_DEFAULT_PID_SIZE 32768U

enum netdata_ebpf_map_type {
    NETDATA_EBPF_MAP_STATIC = 0,
    NETDATA_EBPF_MAP_RESIZABLE = 1,
    NETDATA_EBPF_MAP_CONTROLLER = 2,
    NETDATA_EBPF_MAP_CONTROLLER_UPDATED = 4,
    NETDATA_EBPF_MAP_PID = 8
};

enum netdata_controller {
    NETDATA_CONTROLLER_APPS_ENABLED,

    NETDATA_CONTROLLER_END
};

typedef struct ebpf_local_maps {
    char *name;
    uint32_t internal_input;
    uint32_t user_input;
    uint32_t type;
    int map_fd;
} ebpf_local_maps_t;

typedef struct ebpf_specify_name {
    char *program_name;
    char *function_to_attach;
    char *optional;
    bool retprobe;
} ebpf_specify_name_t;

typedef struct ebpf_module {
    const char *thread_name;
    const char *config_name;
    int enabled;
    void *(*start_routine)(void *);
    int update_every;
    int global_charts;
    int apps_charts;
    int cgroup_charts;
    netdata_run_mode_t mode;
    uint32_t thread_id;
    int optional;
    void (*apps_routine)(struct ebpf_module *em, void *ptr);
    ebpf_local_maps_t *maps;
    ebpf_specify_name_t *names;
    uint32_t pid_map_size;
    struct config *cfg;
    const char *config_file;
} ebpf_module_t;

extern int ebpf_get_kernel_version();
extern int get_redhat_release();
extern int has_condition_to_run(int version);
extern char *ebpf_kernel_suffix(int version, int isrh);
extern void ebpf_update_kernel(char *ks, size_t length, int isrh, int version);
extern struct bpf_link **ebpf_load_program(char *plugins_dir,
                             ebpf_module_t *em,
                             char *kernel_string,
                             struct bpf_object **obj);

extern void ebpf_mount_config_name(char *filename, size_t length, char *path, const char *config);
extern int ebpf_load_config(struct config *config, char *filename);
extern void ebpf_update_module(ebpf_module_t *em);
extern void ebpf_update_names(ebpf_specify_name_t *opt, ebpf_module_t *em);
extern void ebpf_load_addresses(ebpf_addresses_t *fa, int fd);
extern void ebpf_fill_algorithms(int *algorithms, size_t length, int algorithm);
extern char **ebpf_fill_histogram_dimension(size_t maximum);

// Histogram
#define NETDATA_EBPF_HIST_MAX_BINS 24UL
#define NETDATA_DISK_MAX 256U
#define NETDATA_DISK_HISTOGRAM_LENGTH (NETDATA_DISK_MAX * NETDATA_EBPF_HIST_MAX_BINS)

typedef struct netdata_ebpf_histogram {
    char *name;
    char *title;
    int order;
    uint64_t histogram[NETDATA_EBPF_HIST_MAX_BINS];
} netdata_ebpf_histogram_t;

extern void ebpf_histogram_dimension_cleanup(char **ptr, size_t length);

// Tracepoint helpers
// For more information related to tracepoints read https://www.kernel.org/doc/html/latest/trace/tracepoints.html
extern int ebpf_is_tracepoint_enabled(char *subsys, char *eventname);
extern int ebpf_enable_tracing_values(char *subsys, char *eventname);
extern int ebpf_disable_tracing_values(char *subsys, char *eventname);

#endif /* NETDATA_EBPF_H */