path: root/tools/lib/bpf/libbpf.h

/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */

/*
 * Common eBPF ELF object loading operations.
 *
 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
 * Copyright (C) 2015 Huawei Inc.
 */
#ifndef __LIBBPF_LIBBPF_H
#define __LIBBPF_LIBBPF_H

#include <stdarg.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <sys/types.h>  // for size_t
#include <linux/bpf.h>

#include "libbpf_common.h"

#ifdef __cplusplus
extern "C" {
#endif

enum libbpf_errno {
	__LIBBPF_ERRNO__START = 4000,

	/* Something wrong in libelf */
	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
	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 */
	LIBBPF_ERRNO__NLPARSE,	/* netlink parsing error */
	__LIBBPF_ERRNO__END,
};

LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);

enum libbpf_print_level {
        LIBBPF_WARN,
        LIBBPF_INFO,
        LIBBPF_DEBUG,
};

typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
				 const char *, va_list ap);

LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);

/* Hide internal to user */
struct bpf_object;

struct bpf_object_open_attr {
	const char *file;
	enum bpf_prog_type prog_type;
};

struct bpf_object_open_opts {
	/* size of this struct, for forward/backward compatiblity */
	size_t sz;
	/* object name override, if provided:
	 * - for object open from file, this will override setting object
	 *   name from file path's base name;
	 * - for object open from memory buffer, this will specify an object
	 *   name and will override default "<addr>-<buf-size>" name;
	 */
	const char *object_name;
	/* parse map definitions non-strictly, allowing extra attributes/data */
	bool relaxed_maps;
	/* DEPRECATED: handle CO-RE relocations non-strictly, allowing failures.
	 * Value is ignored. Relocations always are processed non-strictly.
	 * Non-relocatable instructions are replaced with invalid ones to
	 * prevent accidental errors.
	 * */
	bool relaxed_core_relocs;
	/* maps that set the 'pinning' attribute in their definition will have
	 * their pin_path attribute set to a file in this directory, and be
	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
	 */
	const char *pin_root_path;
	__u32 attach_prog_fd;
	/* Additional kernel config content that augments and overrides
	 * system Kconfig for CONFIG_xxx externs.
	 */
	const char *kconfig;
};
#define bpf_object_open_opts__last_field kconfig

LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
LIBBPF_API struct bpf_object *
bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
LIBBPF_API struct bpf_object *
bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
		     const struct bpf_object_open_opts *opts);

/* deprecated bpf_object__open variants */
LIBBPF_API struct bpf_object *
bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
			const char *name);
LIBBPF_API struct bpf_object *
bpf_object__open_xattr(struct bpf_object_open_attr *attr);

enum libbpf_pin_type {
	LIBBPF_PIN_NONE,
	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
	LIBBPF_PIN_BY_NAME,
};

/* pin_maps and unpin_maps can both be called with a NULL path, in which case
 * they will use the pin_path attribute of each map (and ignore all maps that
 * don't have a pin_path set).
 */
LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
				      const char *path);
LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
					const char *path);
LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
					  const char *path);
LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
LIBBPF_API void bpf_object__close(struct bpf_object *object);

struct bpf_object_load_attr {
	struct bpf_object *obj;
	int log_level;
	const char *target_btf_path;
};

/* Load/unload object into/from kernel */
LIBBPF_API int bpf_object__load(struct bpf_object *obj);
LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
LIBBPF_API int bpf_object__unload(struct bpf_object *obj);

LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);

struct btf;
LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);

LIBBPF_API struct bpf_program *
bpf_object__find_program_by_title(const struct bpf_object *obj,
				  const char *title);
LIBBPF_API struct bpf_program *
bpf_object__find_program_by_name(const struct bpf_object *obj,
				 const char *name);

LIBBPF_API 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 *);
LIBBPF_API int bpf_object__set_priv(struct bpf_object *obj, void *priv,
				    bpf_object_clear_priv_t clear_priv);
LIBBPF_API void *bpf_object__priv(const struct bpf_object *prog);

LIBBPF_API int
libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
			 enum bpf_attach_type *expected_attach_type);
LIBBPF_API int libbpf_attach_type_by_name(const char *name,
					  enum bpf_attach_type *attach_type);
LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
					  enum bpf_attach_type attach_type);

/* Accessors of bpf_program */
struct bpf_program;
LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
						 const 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)))

LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
						 const struct bpf_object *obj);

typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);

LIBBPF_API int bpf_program__set_priv(struct bpf_program *prog, void *priv,
				     bpf_program_clear_priv_t clear_priv);

LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
					 __u32 ifindex);

LIBBPF_API const char *bpf_program__name(const