blob: 9de0f299706b1450c8fa158b95e5537ef04ae0fe [file] [log] [blame]
/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
* Common eBPF ELF object loading operations.
* Copyright (C) 2013-2015 Alexei Starovoitov <>
* Copyright (C) 2015 Wang Nan <>
* Copyright (C) 2015 Huawei Inc.
#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"
#include "libbpf_legacy.h"
#ifdef __cplusplus
extern "C" {
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 */
LIBBPF_ERRNO__NLPARSE, /* netlink parsing error */
LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
enum libbpf_print_level {
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.
* */
LIBBPF_DEPRECATED_SINCE(0, 6, "field has no effect")
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;
LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__set_attach_target() on each individual bpf_program")
__u32 attach_prog_fd;
/* Additional kernel config content that augments and overrides
* system Kconfig for CONFIG_xxx externs.
const char *kconfig;
/* Path to the custom BTF to be used for BPF CO-RE relocations.
* This custom BTF completely replaces the use of vmlinux BTF
* for the purpose of CO-RE relocations.
* NOTE: any other BPF feature (e.g., fentry/fexit programs,
* struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
const char *btf_custom_path;
#define bpf_object_open_opts__last_field btf_custom_path
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 {
/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
/* 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_DEPRECATED_SINCE(0, 6, "bpf_object__unload() is deprecated, use bpf_object__close() instead")
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);
LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
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 LIBBPF_DEPRECATED_SINCE(0, 7, "track bpf_objects in application code instead")
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_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 LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__next_program() instead")
struct bpf_program *bpf_program__next(struct bpf_program *prog,
const struct bpf_object *obj);
LIBBPF_API struct bpf_program *
bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
#define bpf_object__for_each_program(pos, obj) \
for ((pos) = bpf_object__next_program((obj), NULL); \
(pos) != NULL; \
(pos) = bpf_object__next_program((obj), (pos)))
LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__prev_program() instead")
struct bpf_program *bpf_program__prev(struct bpf_program *prog,
const struct bpf_object *obj);
LIBBPF_API struct bpf_program *
bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
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 struct bpf_program *prog);
LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
LIBBPF_API LIBBPF_DEPRECATED("BPF program title is confusing term; please use bpf_program__section_name() instead")
const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy);
LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
/* returns program size in bytes */
LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insn_cnt() instead")
LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
struct bpf_insn;
* @brief **bpf_program__insns()** gives read-only access to BPF program's
* underlying BPF instructions.
* @param prog BPF program for which to return instructions
* @return a pointer to an array of BPF instructions that belong to the
* specified BPF program
* Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
* pointed to can be fetched using **bpf_program__insn_cnt()** API.
* Keep in mind, libbpf can modify and append/delete BPF program's
* instructions as it processes BPF object file and prepares everything for
* uploading into the kernel. So depending on the point in BPF object
* lifetime, **bpf_program__insns()** can return different sets of
* instructions. As an example, during BPF object load phase BPF program
* instructions will be CO-RE-relocated, BPF subprograms instructions will be
* appended, ldimm64 instructions will have FDs embedded, etc. So instructions
* returned before **bpf_object__load()** and after it might be quite
* different.
LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
* @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
* that form specified BPF program.
* @param prog BPF program for which to return number of BPF instructions
* See **bpf_program__insns()** documentation for notes on how libbpf can
* change instructions and their count during different phases of
* **bpf_object** lifetime.
LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
__u32 kern_version);
LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
const char *path,
int instance);
LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
const char *path,
int instance);
LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
struct bpf_link;
LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
struct bpf_program *prog);
LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
LIBBPF_API int bpf_link__detach(struct bpf_link *link);
LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
LIBBPF_API struct bpf_link *
bpf_program__attach(const struct bpf_program *prog);
struct bpf_perf_event_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
#define bpf_perf_event_opts__last_field bpf_cookie
LIBBPF_API struct bpf_link *
bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
LIBBPF_API struct bpf_link *
bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
const struct bpf_perf_event_opts *opts);
struct bpf_kprobe_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
/* function's offset to install kprobe to */
size_t offset;
/* kprobe is return probe */
bool retprobe;
size_t :0;
#define bpf_kprobe_opts__last_field retprobe
LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
const char *func_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
const char *func_name,
const struct bpf_kprobe_opts *opts);
struct bpf_uprobe_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
/* offset of kernel reference counted USDT semaphore, added in
* a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
size_t ref_ctr_offset;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
/* uprobe is return probe, invoked at function return time */
bool retprobe;
size_t :0;
#define bpf_uprobe_opts__last_field retprobe
LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
pid_t pid, const char *binary_path,
size_t func_offset);
LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
const char *binary_path, size_t func_offset,
const struct bpf_uprobe_opts *opts);
struct bpf_tracepoint_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
#define bpf_tracepoint_opts__last_field bpf_cookie
LIBBPF_API struct bpf_link *
bpf_program__attach_tracepoint(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
const char *tp_category,
const char *tp_name,
const struct bpf_tracepoint_opts *opts);
LIBBPF_API struct bpf_link *
bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
const char *tp_name);
LIBBPF_API struct bpf_link *
bpf_program__attach_trace(const struct bpf_program *prog);
LIBBPF_API struct bpf_link *
bpf_program__attach_lsm(const struct bpf_program *prog);
LIBBPF_API struct bpf_link *
bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
LIBBPF_API struct bpf_link *
bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
LIBBPF_API struct bpf_link *
bpf_program__attach_freplace(const struct bpf_program *prog,
int target_fd, const char *attach_func_name);
struct bpf_map;
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
struct bpf_iter_attach_opts {
size_t sz; /* size of this struct for forward/backward compatibility */
union bpf_iter_link_info *link_info;
__u32 link_info_len;
#define bpf_iter_attach_opts__last_field link_info_len
LIBBPF_API struct bpf_link *
bpf_program__attach_iter(const struct bpf_program *prog,
const struct bpf_iter_attach_opts *opts);
* 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).
LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insns() for getting bpf_program instructions")
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);
LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insns() for getting bpf_program instructions")
LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
bpf_program_prep_t prep);
LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
* Adjust type of BPF program. Default is kprobe.
LIBBPF_API int bpf_program__set_socket_filter(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_tracepoint(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_raw_tracepoint(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_kprobe(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_lsm(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_sched_cls(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_sched_act(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_xdp(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_perf_event(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_tracing(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_struct_ops(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_extension(struct bpf_program *prog);
LIBBPF_API int bpf_program__set_sk_lookup(struct bpf_program *prog);
LIBBPF_API enum bpf_prog_type bpf_program__get_type(const struct bpf_program *prog);
LIBBPF_API void bpf_program__set_type(struct bpf_program *prog,
enum bpf_prog_type type);
LIBBPF_API enum bpf_attach_type
bpf_program__get_expected_attach_type(const struct bpf_program *prog);
bpf_program__set_expected_attach_type(struct bpf_program *prog,
enum bpf_attach_type type);
bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
const char *attach_func_name);
LIBBPF_API bool bpf_program__is_socket_filter(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_tracepoint(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_raw_tracepoint(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_kprobe(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_lsm(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_sched_cls(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_sched_act(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_xdp(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_perf_event(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_tracing(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_struct_ops(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_extension(const struct bpf_program *prog);
LIBBPF_API bool bpf_program__is_sk_lookup(const 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;
* @brief **bpf_object__find_map_by_name()** returns BPF map of
* the given name, if it exists within the passed BPF object
* @param obj BPF object
* @param name name of the BPF map
* @return BPF map instance, if such map exists within the BPF object;
* or NULL otherwise.
LIBBPF_API struct bpf_map *
bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
* Get bpf_map through the offset of corresponding struct bpf_map_def
* in the BPF object file.
LIBBPF_API struct bpf_map *
bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__next_map() instead")
struct bpf_map *bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
LIBBPF_API struct bpf_map *
bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
#define bpf_object__for_each_map(pos, obj) \
for ((pos) = bpf_object__next_map((obj), NULL); \
(pos) != NULL; \
(pos) = bpf_object__next_map((obj), (pos)))
#define bpf_map__for_each bpf_object__for_each_map
LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__prev_map() instead")
struct bpf_map *bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
LIBBPF_API struct bpf_map *
bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
* @brief **bpf_map__fd()** gets the file descriptor of the passed
* BPF map
* @param map the BPF map instance
* @return the file descriptor; or -EINVAL in case of an error
LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
/* get map definition */
LIBBPF_API const struct bpf_map_def *bpf_map__def(const struct bpf_map *map);
/* get map name */
LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
/* get/set map type */
LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
/* get/set map size (max_entries) */
LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
/* get/set map flags */
LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
/* get/set map NUMA node */
LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
/* get/set map key size */
LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
/* get/set map value size */
LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
/* get map key/value BTF type IDs */
LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
/* get/set map if_index */
LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
/* get/set map map_extra flags */
LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
bpf_map_clear_priv_t clear_priv);
LIBBPF_API void *bpf_map__priv(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
const void *data, size_t size);
LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
* @brief **bpf_map__is_internal()** tells the caller whether or not the
* passed map is a special map created by libbpf automatically for things like
* global variables, __ksym externs, Kconfig values, etc
* @param map the bpf_map
* @return true, if the map is an internal map; false, otherwise
LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
* @brief **libbpf_get_error()** extracts the error code from the passed
* pointer
* @param ptr pointer returned from libbpf API function
* @return error code; or 0 if no error occured
* Many libbpf API functions which return pointers have logic to encode error
* codes as pointers, and do not return NULL. Meaning **libbpf_get_error()**
* should be used on the return value from these functions immediately after
* calling the API function, with no intervening calls that could clobber the
* `errno` variable. Consult the individual functions documentation to verify
* if this logic applies should be used.
* For these API functions, if `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)`
* is enabled, NULL is returned on error instead.
* If ptr is NULL, then errno should be already set by the failing
* API, because libbpf never returns NULL on success and it now always
* sets errno on error.
* Example usage:
* struct perf_buffer *pb;
* pb = perf_buffer__new(bpf_map__fd(obj->, PERF_BUFFER_PAGES, &opts);
* err = libbpf_get_error(pb);
* if (err) {
* pb = NULL;
* fprintf(stderr, "failed to open perf buffer: %d\n", err);
* goto cleanup;
* }
LIBBPF_API 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 log_level;
int prog_flags;
LIBBPF_API int bpf_prog_load_xattr(const struct bpf_prog_load_attr *attr,
struct bpf_object **pobj, int *prog_fd);
LIBBPF_API int bpf_prog_load(const char *file, enum bpf_prog_type type,
struct bpf_object **pobj, int *prog_fd);
/* XDP related API */
struct xdp_link_info {
__u32 prog_id;
__u32 drv_prog_id;
__u32 hw_prog_id;
__u32 skb_prog_id;
__u8 attach_mode;
struct bpf_xdp_set_link_opts {
size_t sz;
int old_fd;
size_t :0;
#define bpf_xdp_set_link_opts__last_field old_fd
LIBBPF_API int bpf_set_link_xdp_fd(int ifindex, int fd, __u32 flags);
LIBBPF_API int bpf_set_link_xdp_fd_opts(int ifindex, int fd, __u32 flags,
const struct bpf_xdp_set_link_opts *opts);
LIBBPF_API int bpf_get_link_xdp_id(int ifindex, __u32 *prog_id, __u32 flags);
LIBBPF_API int bpf_get_link_xdp_info(int ifindex, struct xdp_link_info *info,
size_t info_size, __u32 flags);
/* TC related API */
enum bpf_tc_attach_point {
BPF_TC_INGRESS = 1 << 0,
BPF_TC_EGRESS = 1 << 1,
BPF_TC_CUSTOM = 1 << 2,
#define BPF_TC_PARENT(a, b) \
((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
enum bpf_tc_flags {
BPF_TC_F_REPLACE = 1 << 0,
struct bpf_tc_hook {
size_t sz;
int ifindex;
enum bpf_tc_attach_point attach_point;
__u32 parent;
size_t :0;
#define bpf_tc_hook__last_field parent
struct bpf_tc_opts {
size_t sz;
int prog_fd;
__u32 flags;
__u32 prog_id;
__u32 handle;
__u32 priority;
size_t :0;
#define bpf_tc_opts__last_field priority
LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
struct bpf_tc_opts *opts);
LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
const struct bpf_tc_opts *opts);
LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
struct bpf_tc_opts *opts);
/* Ring buffer APIs */
struct ring_buffer;
typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
struct ring_buffer_opts {
size_t sz; /* size of this struct, for forward/backward compatiblity */
#define ring_buffer_opts__last_field sz
LIBBPF_API struct ring_buffer *
ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
const struct ring_buffer_opts *opts);
LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
ring_buffer_sample_fn sample_cb, void *ctx);
LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
/* Perf buffer APIs */
struct perf_buffer;
typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
void *data, __u32 size);
typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
/* common use perf buffer options */
struct perf_buffer_opts {
/* if specified, sample_cb is called for each sample */
perf_buffer_sample_fn sample_cb;
/* if specified, lost_cb is called for each batch of lost samples */
perf_buffer_lost_fn lost_cb;
/* ctx is provided to sample_cb and lost_cb */
void *ctx;
LIBBPF_API struct perf_buffer *
perf_buffer__new(int map_fd, size_t page_cnt,
const struct perf_buffer_opts *opts);
enum bpf_perf_event_ret {
struct perf_event_header;
typedef enum bpf_perf_event_ret
(*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
/* raw perf buffer options, giving most power and control */
struct perf_buffer_raw_opts {
/* perf event attrs passed directly into perf_event_open() */
struct perf_event_attr *attr;
/* raw event callback */
perf_buffer_event_fn event_cb;
/* ctx is provided to event_cb */
void *ctx;
/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
* max_entries of given PERF_EVENT_ARRAY map)
int cpu_cnt;
/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
int *cpus;
/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
int *map_keys;
LIBBPF_API struct perf_buffer *
perf_buffer__new_raw(int map_fd, size_t page_cnt,
const struct perf_buffer_raw_opts *opts);
LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
typedef enum bpf_perf_event_ret
(*bpf_perf_event_print_t)(struct perf_event_header *hdr,
void *private_data);
LIBBPF_API enum bpf_perf_event_ret
bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
void **copy_mem, size_t *copy_size,
bpf_perf_event_print_t fn, void *private_data);
struct bpf_prog_linfo;
struct bpf_prog_info;
LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
LIBBPF_API struct bpf_prog_linfo *
bpf_prog_linfo__new(const struct bpf_prog_info *info);
LIBBPF_API const struct bpf_line_info *
bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
__u64 addr, __u32 func_idx, __u32 nr_skip);
LIBBPF_API const struct bpf_line_info *
bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
__u32 insn_off, __u32 nr_skip);
* Probe for supported system features
* Note that running many of these probes in a short amount of time can cause
* the kernel to reach the maximal size of lockable memory allowed for the
* user, causing subsequent probes to fail. In this case, the caller may want
* to adjust that limit with setrlimit().
LIBBPF_API bool bpf_probe_prog_type(enum bpf_prog_type prog_type,
__u32 ifindex);
LIBBPF_API bool bpf_probe_map_type(enum bpf_map_type map_type, __u32 ifindex);
LIBBPF_API bool bpf_probe_helper(enum bpf_func_id id,
enum bpf_prog_type prog_type, __u32 ifindex);
LIBBPF_API bool bpf_probe_large_insn_limit(__u32 ifindex);
* Get bpf_prog_info in continuous memory
* struct bpf_prog_info has multiple arrays. The user has option to choose
* arrays to fetch from kernel. The following APIs provide an uniform way to
* fetch these data. All arrays in bpf_prog_info are stored in a single
* continuous memory region. This makes it easy to store the info in a
* file.
* Before writing bpf_prog_info_linear to files, it is necessary to
* translate pointers in bpf_prog_info to offsets. Helper functions
* bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
* are introduced to switch between pointers and offsets.
* Examples:
* # To fetch map_ids and prog_tags:
* __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
* struct bpf_prog_info_linear *info_linear =
* bpf_program__get_prog_info_linear(fd, arrays);
* # To save data in file
* bpf_program__bpil_addr_to_offs(info_linear);
* write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
* # To read data from file
* read(f, info_linear, <proper_size>);
* bpf_program__bpil_offs_to_addr(info_linear);
enum bpf_prog_info_array {
struct bpf_prog_info_linear {
/* size of struct bpf_prog_info, when the tool is compiled */
__u32 info_len;
/* total bytes allocated for data, round up to 8 bytes */
__u32 data_len;
/* which arrays are included in data */
__u64 arrays;
struct bpf_prog_info info;
__u8 data[];
LIBBPF_API struct bpf_prog_info_linear *
bpf_program__get_prog_info_linear(int fd, __u64 arrays);
bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
* @brief **libbpf_num_possible_cpus()** is a helper function to get the
* number of possible CPUs that the host kernel supports and expects.
* @return number of possible CPUs; or error code on failure
* Example usage:
* int ncpus = libbpf_num_possible_cpus();
* if (ncpus < 0) {
* // error handling
* }
* long values[ncpus];
* bpf_map_lookup_elem(per_cpu_map_fd, key, values);
LIBBPF_API int libbpf_num_possible_cpus(void);
struct bpf_map_skeleton {
const char *name;
struct bpf_map **map;
void **mmaped;
struct bpf_prog_skeleton {
const char *name;
struct bpf_program **prog;
struct bpf_link **link;
struct bpf_object_skeleton {
size_t sz; /* size of this struct, for forward/backward compatibility */
const char *name;
const void *data;
size_t data_sz;
struct bpf_object **obj;
int map_cnt;
int map_skel_sz; /* sizeof(struct bpf_skeleton_map) */
struct bpf_map_skeleton *maps;
int prog_cnt;
int prog_skel_sz; /* sizeof(struct bpf_skeleton_prog) */
struct bpf_prog_skeleton *progs;
bpf_object__open_skeleton(struct bpf_object_skeleton *s,
const struct bpf_object_open_opts *opts);
LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
struct gen_loader_opts {
size_t sz; /* size of this struct, for forward/backward compatiblity */
const char *data;
const char *insns;
__u32 data_sz;
__u32 insns_sz;
#define gen_loader_opts__last_field insns_sz
LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
struct gen_loader_opts *opts);
enum libbpf_tristate {
TRI_NO = 0,
TRI_YES = 1,
struct bpf_linker_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
#define bpf_linker_opts__last_field sz
struct bpf_linker_file_opts {
/* size of this struct, for forward/backward compatiblity */
size_t sz;
#define bpf_linker_file_opts__last_field sz
struct bpf_linker;
LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
const char *filename,
const struct bpf_linker_file_opts *opts);
LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
#ifdef __cplusplus
} /* extern "C" */
#endif /* __LIBBPF_LIBBPF_H */