blob: 96c55fac54c314167bb81f248c67107e77becf5f [file] [log] [blame]
/* SPDX-License-Identifier: LGPL-2.1 */
* Common eBPF ELF object loading operations.
* Copyright (C) 2013-2015 Alexei Starovoitov <>
* Copyright (C) 2015 Wang Nan <>
* Copyright (C) 2015 Huawei Inc.
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License (not later!)
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, see <>
#ifndef __BPF_LIBBPF_H
#define __BPF_LIBBPF_H
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h> // for size_t
#include <linux/bpf.h>
enum libbpf_errno {
/* Something wrong in libelf */
LIBBPF_ERRNO__FORMAT, /* BPF object format invalid */
LIBBPF_ERRNO__KVERSION, /* Incorrect or no 'version' section */
LIBBPF_ERRNO__ENDIAN, /* Endian mismatch */
LIBBPF_ERRNO__INTERNAL, /* Internal error in libbpf */
LIBBPF_ERRNO__RELOC, /* Relocation failed */
LIBBPF_ERRNO__LOAD, /* Load program failure for unknown reason */
LIBBPF_ERRNO__VERIFY, /* Kernel verifier blocks program loading */
LIBBPF_ERRNO__PROG2BIG, /* Program too big */
LIBBPF_ERRNO__KVER, /* Incorrect kernel version */
LIBBPF_ERRNO__PROGTYPE, /* Kernel doesn't support this program type */
LIBBPF_ERRNO__WRNGPID, /* Wrong pid in netlink message */
LIBBPF_ERRNO__INVSEQ, /* Invalid netlink sequence */
int libbpf_strerror(int err, char *buf, size_t size);
* __printf is defined in include/linux/compiler-gcc.h. However,
* it would be better if libbpf.h didn't depend on Linux header files.
* So instead of __printf, here we use gcc attribute directly.
typedef int (*libbpf_print_fn_t)(const char *, ...)
__attribute__((format(printf, 1, 2)));
void libbpf_set_print(libbpf_print_fn_t warn,
libbpf_print_fn_t info,
libbpf_print_fn_t debug);
/* Hide internal to user */
struct bpf_object;
struct bpf_object_open_attr {
const char *file;
enum bpf_prog_type prog_type;
struct bpf_object *bpf_object__open(const char *path);
struct bpf_object *bpf_object__open_xattr(struct bpf_object_open_attr *attr);
struct bpf_object *bpf_object__open_buffer(void *obj_buf,
size_t obj_buf_sz,
const char *name);
int bpf_object__pin(struct bpf_object *object, const char *path);
void bpf_object__close(struct bpf_object *object);
/* Load/unload object into/from kernel */
int bpf_object__load(struct bpf_object *obj);
int bpf_object__unload(struct bpf_object *obj);
const char *bpf_object__name(struct bpf_object *obj);
unsigned int bpf_object__kversion(struct bpf_object *obj);
int bpf_object__btf_fd(const struct bpf_object *obj);
struct bpf_program *
bpf_object__find_program_by_title(struct bpf_object *obj, const char *title);
struct bpf_object *bpf_object__next(struct bpf_object *prev);
#define bpf_object__for_each_safe(pos, tmp) \
for ((pos) = bpf_object__next(NULL), \
(tmp) = bpf_object__next(pos); \
(pos) != NULL; \
(pos) = (tmp), (tmp) = bpf_object__next(tmp))
typedef void (*bpf_object_clear_priv_t)(struct bpf_object *, void *);
int bpf_object__set_priv(struct bpf_object *obj, void *priv,
bpf_object_clear_priv_t clear_priv);
void *bpf_object__priv(struct bpf_object *prog);
int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
enum bpf_attach_type *expected_attach_type);
/* Accessors of bpf_program */
struct bpf_program;
struct bpf_program *bpf_program__next(struct bpf_program *prog,
struct bpf_object *obj);
#define bpf_object__for_each_program(pos, obj) \
for ((pos) = bpf_program__next(NULL, (obj)); \
(pos) != NULL; \
(pos) = bpf_program__next((pos), (obj)))
typedef void (*bpf_program_clear_priv_t)(struct bpf_program *,
void *);
int bpf_program__set_priv(struct bpf_program *prog, void *priv,
bpf_program_clear_priv_t clear_priv);
void *bpf_program__priv(struct bpf_program *prog);
void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex);
const char *bpf_program__title(struct bpf_program *prog, bool needs_copy);
int bpf_program__fd(struct bpf_program *prog);
int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
int instance);
int bpf_program__pin(struct bpf_program *prog, const char *path);
struct bpf_insn;
* Libbpf allows callers to adjust BPF programs before being loaded
* into kernel. One program in an object file can be transformed into
* multiple variants to be attached to different hooks.
* bpf_program_prep_t, bpf_program__set_prep and bpf_program__nth_fd
* form an API for this purpose.
* - bpf_program_prep_t:
* Defines a 'preprocessor', which is a caller defined function
* passed to libbpf through bpf_program__set_prep(), and will be
* called before program is loaded. The processor should adjust
* the program one time for each instance according to the instance id
* passed to it.
* - bpf_program__set_prep:
* Attaches a preprocessor to a BPF program. The number of instances
* that should be created is also passed through this function.
* - bpf_program__nth_fd:
* After the program is loaded, get resulting FD of a given instance
* of the BPF program.
* If bpf_program__set_prep() is not used, the program would be loaded
* without adjustment during bpf_object__load(). The program has only
* one instance. In this case bpf_program__fd(prog) is equal to
* bpf_program__nth_fd(prog, 0).
struct bpf_prog_prep_result {
* If not NULL, load new instruction array.
* If set to NULL, don't load this instance.
struct bpf_insn *new_insn_ptr;
int new_insn_cnt;
/* If not NULL, result FD is written to it. */
int *pfd;
* Parameters of bpf_program_prep_t:
* - prog: The bpf_program being loaded.
* - n: Index of instance being generated.
* - insns: BPF instructions array.
* - insns_cnt:Number of instructions in insns.
* - res: Output parameter, result of transformation.
* Return value:
* - Zero: pre-processing success.
* - Non-zero: pre-processing error, stop loading.
typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
struct bpf_insn *insns, int insns_cnt,
struct bpf_prog_prep_result *res);
int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
bpf_program_prep_t prep);
int bpf_program__nth_fd(struct bpf_program *prog, int n);
* Adjust type of BPF program. Default is kprobe.
int bpf_program__set_socket_filter(struct bpf_program *prog);
int bpf_program__set_tracepoint(struct bpf_program *prog);
int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
int bpf_program__set_kprobe(struct bpf_program *prog);
int bpf_program__set_sched_cls(struct bpf_program *prog);
int bpf_program__set_sched_act(struct bpf_program *prog);
int bpf_program__set_xdp(struct bpf_program *prog);
int bpf_program__set_perf_event(struct bpf_program *prog);
void bpf_program__set_type(struct bpf_program *prog, enum bpf_prog_type type);
void bpf_program__set_expected_attach_type(struct bpf_program *prog,
enum bpf_attach_type type);
bool bpf_program__is_socket_filter(struct bpf_program *prog);
bool bpf_program__is_tracepoint(struct bpf_program *prog);
bool bpf_program__is_raw_tracepoint(struct bpf_program *prog);
bool bpf_program__is_kprobe(struct bpf_program *prog);
bool bpf_program__is_sched_cls(struct bpf_program *prog);
bool bpf_program__is_sched_act(struct bpf_program *prog);
bool bpf_program__is_xdp(struct bpf_program *prog);
bool bpf_program__is_perf_event(struct bpf_program *prog);
* No need for __attribute__((packed)), all members of 'bpf_map_def'
* are all aligned. In addition, using __attribute__((packed))
* would trigger a -Wpacked warning message, and lead to an error
* if -Werror is set.
struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
* The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
* so no need to worry about a name clash.
struct bpf_map;
struct bpf_map *
bpf_object__find_map_by_name(struct bpf_object *obj, const char *name);
* Get bpf_map through the offset of corresponding struct bpf_map_def
* in the BPF object file.
struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
struct bpf_map *
bpf_map__next(struct bpf_map *map, struct bpf_object *obj);
#define bpf_map__for_each(pos, obj) \
for ((pos) = bpf_map__next(NULL, (obj)); \
(pos) != NULL; \
(pos) = bpf_map__next((pos), (obj)))
int bpf_map__fd(struct bpf_map *map);
const struct bpf_map_def *bpf_map__def(struct bpf_map *map);
const char *bpf_map__name(struct bpf_map *map);
__u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
__u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
int bpf_map__set_priv(struct bpf_map *map, void *priv,
bpf_map_clear_priv_t clear_priv);
void *bpf_map__priv(struct bpf_map *map);
int bpf_map__reuse_fd(struct bpf_map *map, int fd);
bool bpf_map__is_offload_neutral(struct bpf_map *map);
void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
int bpf_map__pin(struct bpf_map *map, const char *path);
long libbpf_get_error(const void *ptr);
struct bpf_prog_load_attr {
const char *file;
enum bpf_prog_type prog_type;
enum bpf_attach_type expected_attach_type;
int ifindex;
int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
struct bpf_object **pobj, int *prog_fd);
int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd);
int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
enum bpf_perf_event_ret {
typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(void *event,
void *priv);
int bpf_perf_event_read_simple(void *mem, unsigned long size,
unsigned long page_size,
void **buf, size_t *buf_len,
bpf_perf_event_print_t fn, void *priv);