linux/tools/lib/bpf/libbpf.h
Mykyta Yatsenko 08ac454e25 libbpf: Auto-attach struct_ops BPF maps in BPF skeleton
Similarly to `bpf_program`, support `bpf_map` automatic attachment in
`bpf_object__attach_skeleton`. Currently only struct_ops maps could be
attached.

On bpftool side, code-generate links in skeleton struct for struct_ops maps.
Similarly to `bpf_program_skeleton`, set links in `bpf_map_skeleton`.

On libbpf side, extend `bpf_map` with new `autoattach` field to support
enabling or disabling autoattach functionality, introducing
getter/setter for this field.

`bpf_object__(attach|detach)_skeleton` is extended with
attaching/detaching struct_ops maps logic.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240605175135.117127-1-yatsenko@meta.com
2024-06-06 10:06:05 -07:00

1909 lines
73 KiB
C

/* 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"
#include "libbpf_legacy.h"
#ifdef __cplusplus
extern "C" {
#endif
LIBBPF_API __u32 libbpf_major_version(void);
LIBBPF_API __u32 libbpf_minor_version(void);
LIBBPF_API const char *libbpf_version_string(void);
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);
/**
* @brief **libbpf_bpf_attach_type_str()** converts the provided attach type
* value into a textual representation.
* @param t The attach type.
* @return Pointer to a static string identifying the attach type. NULL is
* returned for unknown **bpf_attach_type** values.
*/
LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t);
/**
* @brief **libbpf_bpf_link_type_str()** converts the provided link type value
* into a textual representation.
* @param t The link type.
* @return Pointer to a static string identifying the link type. NULL is
* returned for unknown **bpf_link_type** values.
*/
LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t);
/**
* @brief **libbpf_bpf_map_type_str()** converts the provided map type value
* into a textual representation.
* @param t The map type.
* @return Pointer to a static string identifying the map type. NULL is
* returned for unknown **bpf_map_type** values.
*/
LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t);
/**
* @brief **libbpf_bpf_prog_type_str()** converts the provided program type
* value into a textual representation.
* @param t The program type.
* @return Pointer to a static string identifying the program type. NULL is
* returned for unknown **bpf_prog_type** values.
*/
LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
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);
/**
* @brief **libbpf_set_print()** sets user-provided log callback function to
* be used for libbpf warnings and informational messages. If the user callback
* is not set, messages are logged to stderr by default. The verbosity of these
* messages can be controlled by setting the environment variable
* LIBBPF_LOG_LEVEL to either warn, info, or debug.
* @param fn The log print function. If NULL, libbpf won't print anything.
* @return Pointer to old print function.
*
* This function is thread-safe.
*/
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_opts {
/* size of this struct, for forward/backward compatibility */
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;
/* 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 :32; /* stub out now removed 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;
/* Pointer to a buffer for storing kernel logs for applicable BPF
* commands. Valid kernel_log_size has to be specified as well and are
* passed-through to bpf() syscall. Keep in mind that kernel might
* fail operation with -ENOSPC error if provided buffer is too small
* to contain entire log output.
* See the comment below for kernel_log_level for interaction between
* log_buf and log_level settings.
*
* If specified, this log buffer will be passed for:
* - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden
* with bpf_program__set_log() on per-program level, to get
* BPF verifier log output.
* - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get
* BTF sanity checking log.
*
* Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite
* previous contents, so if you need more fine-grained control, set
* per-program buffer with bpf_program__set_log_buf() to preserve each
* individual program's verification log. Keep using kernel_log_buf
* for BTF verification log, if necessary.
*/
char *kernel_log_buf;
size_t kernel_log_size;
/*
* Log level can be set independently from log buffer. Log_level=0
* means that libbpf will attempt loading BTF or program without any
* logging requested, but will retry with either its own or custom log
* buffer, if provided, and log_level=1 on any error.
* And vice versa, setting log_level>0 will request BTF or prog
* loading with verbose log from the first attempt (and as such also
* for successfully loaded BTF or program), and the actual log buffer
* could be either libbpf's own auto-allocated log buffer, if
* kernel_log_buffer is NULL, or user-provided custom kernel_log_buf.
* If user didn't provide custom log buffer, libbpf will emit captured
* logs through its print callback.
*/
__u32 kernel_log_level;
/* Path to BPF FS mount point to derive BPF token from.
*
* Created BPF token will be used for all bpf() syscall operations
* that accept BPF token (e.g., map creation, BTF and program loads,
* etc) automatically within instantiated BPF object.
*
* If bpf_token_path is not specified, libbpf will consult
* LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be
* taken as a value of bpf_token_path option and will force libbpf to
* either create BPF token from provided custom BPF FS path, or will
* disable implicit BPF token creation, if envvar value is an empty
* string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are
* set at the same time.
*
* Setting bpf_token_path option to empty string disables libbpf's
* automatic attempt to create BPF token from default BPF FS mount
* point (/sys/fs/bpf), in case this default behavior is undesirable.
*/
const char *bpf_token_path;
size_t :0;
};
#define bpf_object_open_opts__last_field bpf_token_path
/**
* @brief **bpf_object__open()** creates a bpf_object by opening
* the BPF ELF object file pointed to by the passed path and loading it
* into memory.
* @param path BPF object file path.
* @return pointer to the new bpf_object; or NULL is returned on error,
* error code is stored in errno
*/
LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
/**
* @brief **bpf_object__open_file()** creates a bpf_object by opening
* the BPF ELF object file pointed to by the passed path and loading it
* into memory.
* @param path BPF object file path
* @param opts options for how to load the bpf object, this parameter is
* optional and can be set to NULL
* @return pointer to the new bpf_object; or NULL is returned on error,
* error code is stored in errno
*/
LIBBPF_API struct bpf_object *
bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
/**
* @brief **bpf_object__open_mem()** creates a bpf_object by reading
* the BPF objects raw bytes from a memory buffer containing a valid
* BPF ELF object file.
* @param obj_buf pointer to the buffer containing ELF file bytes
* @param obj_buf_sz number of bytes in the buffer
* @param opts options for how to load the bpf object
* @return pointer to the new bpf_object; or NULL is returned on error,
* error code is stored in errno
*/
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);
/**
* @brief **bpf_object__load()** loads BPF object into kernel.
* @param obj Pointer to a valid BPF object instance returned by
* **bpf_object__open*()** APIs
* @return 0, on success; negative error code, otherwise, error code is
* stored in errno
*/
LIBBPF_API int bpf_object__load(struct bpf_object *obj);
/**
* @brief **bpf_object__close()** closes a BPF object and releases all
* resources.
* @param obj Pointer to a valid BPF object
*/
LIBBPF_API void bpf_object__close(struct bpf_object *obj);
/**
* @brief **bpf_object__pin_maps()** pins each map contained within
* the BPF object at the passed directory.
* @param obj Pointer to a valid BPF object
* @param path A directory where maps should be pinned.
* @return 0, on success; negative error code, otherwise
*
* If `path` is NULL `bpf_map__pin` (which is being used on each map)
* will use the pin_path attribute of each map. In this case, maps that
* don't have a pin_path set will be ignored.
*/
LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
/**
* @brief **bpf_object__unpin_maps()** unpins each map contained within
* the BPF object found in the passed directory.
* @param obj Pointer to a valid BPF object
* @param path A directory where pinned maps should be searched for.
* @return 0, on success; negative error code, otherwise
*
* If `path` is NULL `bpf_map__unpin` (which is being used on each map)
* will use the pin_path attribute of each map. In this case, maps that
* don't have a pin_path set will be ignored.
*/
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 int bpf_object__unpin(struct bpf_object *object, const char *path);
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_name(const struct bpf_object *obj,
const char *name);
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_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 struct bpf_program *
bpf_object__prev_program(const struct bpf_object *obj, 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 bool bpf_program__autoload(const struct bpf_program *prog);
LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
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__set_insns()** can set BPF program's underlying
* BPF instructions.
*
* WARNING: This is a very advanced libbpf API and users need to know
* what they are doing. This should be used from prog_prepare_load_fn
* callback only.
*
* @param prog BPF program for which to return instructions
* @param new_insns a pointer to an array of BPF instructions
* @param new_insn_cnt number of `struct bpf_insn`'s that form
* specified BPF program
* @return 0, on success; negative error code, otherwise
*/
LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
struct bpf_insn *new_insns, size_t new_insn_cnt);
/**
* @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__fd(const struct bpf_program *prog);
/**
* @brief **bpf_program__pin()** pins the BPF program to a file
* in the BPF FS specified by a path. This increments the programs
* reference count, allowing it to stay loaded after the process
* which loaded it has exited.
*
* @param prog BPF program to pin, must already be loaded
* @param path file path in a BPF file system
* @return 0, on success; negative error code, otherwise
*/
LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
/**
* @brief **bpf_program__unpin()** unpins the BPF program from a file
* in the BPFFS specified by a path. This decrements the programs
* reference count.
*
* The file pinning the BPF program can also be unlinked by a different
* process in which case this function will return an error.
*
* @param prog BPF program to unpin
* @param path file path to the pin in a BPF file system
* @return 0, on success; negative error code, otherwise
*/
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);
/**
* @brief **bpf_link__pin()** pins the BPF link to a file
* in the BPF FS specified by a path. This increments the links
* reference count, allowing it to stay loaded after the process
* which loaded it has exited.
*
* @param link BPF link to pin, must already be loaded
* @param path file path in a BPF file system
* @return 0, on success; negative error code, otherwise
*/
LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
/**
* @brief **bpf_link__unpin()** unpins the BPF link from a file
* in the BPFFS specified by a path. This decrements the links
* reference count.
*
* The file pinning the BPF link can also be unlinked by a different
* process in which case this function will return an error.
*
* @param prog BPF program to unpin
* @param path file path to the pin in a BPF file system
* @return 0, on success; negative error code, otherwise
*/
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);
/**
* @brief **bpf_program__attach()** is a generic function for attaching
* a BPF program based on auto-detection of program type, attach type,
* and extra paremeters, where applicable.
*
* @param prog BPF program to attach
* @return Reference to the newly created BPF link; or NULL is returned on error,
* error code is stored in errno
*
* This is supported for:
* - kprobe/kretprobe (depends on SEC() definition)
* - uprobe/uretprobe (depends on SEC() definition)
* - tracepoint
* - raw tracepoint
* - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
*/
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 compatibility */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
/* don't use BPF link when attach BPF program */
bool force_ioctl_attach;
size_t :0;
};
#define bpf_perf_event_opts__last_field force_ioctl_attach
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);
/**
* enum probe_attach_mode - the mode to attach kprobe/uprobe
*
* force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will
* be returned if it is not supported by the kernel.
*/
enum probe_attach_mode {
/* attach probe in latest supported mode by kernel */
PROBE_ATTACH_MODE_DEFAULT = 0,
/* attach probe in legacy mode, using debugfs/tracefs */
PROBE_ATTACH_MODE_LEGACY,
/* create perf event with perf_event_open() syscall */
PROBE_ATTACH_MODE_PERF,
/* attach probe with BPF link */
PROBE_ATTACH_MODE_LINK,
};
struct bpf_kprobe_opts {
/* size of this struct, for forward/backward compatibility */
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;
/* kprobe attach mode */
enum probe_attach_mode attach_mode;
size_t :0;
};
#define bpf_kprobe_opts__last_field attach_mode
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_kprobe_multi_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* array of function symbols to attach */
const char **syms;
/* array of function addresses to attach */
const unsigned long *addrs;
/* array of user-provided values fetchable through bpf_get_attach_cookie */
const __u64 *cookies;
/* number of elements in syms/addrs/cookies arrays */
size_t cnt;
/* create return kprobes */
bool retprobe;
/* create session kprobes */
bool session;
size_t :0;
};
#define bpf_kprobe_multi_opts__last_field session
LIBBPF_API struct bpf_link *
bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
const char *pattern,
const struct bpf_kprobe_multi_opts *opts);
struct bpf_uprobe_multi_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* array of function symbols to attach to */
const char **syms;
/* array of function addresses to attach to */
const unsigned long *offsets;
/* optional, array of associated ref counter offsets */
const unsigned long *ref_ctr_offsets;
/* optional, array of associated BPF cookies */
const __u64 *cookies;
/* number of elements in syms/addrs/cookies arrays */
size_t cnt;
/* create return uprobes */
bool retprobe;
size_t :0;
};
#define bpf_uprobe_multi_opts__last_field retprobe
/**
* @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
* to multiple uprobes with uprobe_multi link.
*
* User can specify 2 mutually exclusive set of inputs:
*
* 1) use only path/func_pattern/pid arguments
*
* 2) use path/pid with allowed combinations of
* syms/offsets/ref_ctr_offsets/cookies/cnt
*
* - syms and offsets are mutually exclusive
* - ref_ctr_offsets and cookies are optional
*
*
* @param prog BPF program to attach
* @param pid Process ID to attach the uprobe to, 0 for self (own process),
* -1 for all processes
* @param binary_path Path to binary
* @param func_pattern Regular expression to specify functions to attach
* BPF program to
* @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
* @return 0, on success; negative error code, otherwise
*/
LIBBPF_API struct bpf_link *
bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
pid_t pid,
const char *binary_path,
const char *func_pattern,
const struct bpf_uprobe_multi_opts *opts);
struct bpf_ksyscall_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 bpf_cookie;
/* attach as return probe? */
bool retprobe;
size_t :0;
};
#define bpf_ksyscall_opts__last_field retprobe
/**
* @brief **bpf_program__attach_ksyscall()** attaches a BPF program
* to kernel syscall handler of a specified syscall. Optionally it's possible
* to request to install retprobe that will be triggered at syscall exit. It's
* also possible to associate BPF cookie (though options).
*
* Libbpf automatically will determine correct full kernel function name,
* which depending on system architecture and kernel version/configuration
* could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
* attach specified program using kprobe/kretprobe mechanism.
*
* **bpf_program__attach_ksyscall()** is an API counterpart of declarative
* **SEC("ksyscall/<syscall>")** annotation of BPF programs.
*
* At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
* not handle all the calling convention quirks for mmap(), clone() and compat
* syscalls. It also only attaches to "native" syscall interfaces. If host
* system supports compat syscalls or defines 32-bit syscalls in 64-bit
* kernel, such syscall interfaces won't be attached to by libbpf.
*
* These limitations may or may not change in the future. Therefore it is
* recommended to use SEC("kprobe") for these syscalls or if working with
* compat and 32-bit interfaces is required.
*
* @param prog BPF program to attach
* @param syscall_name Symbolic name of the syscall (e.g., "bpf")
* @param opts Additional options (see **struct bpf_ksyscall_opts**)
* @return Reference to the newly created BPF link; or NULL is returned on
* error, error code is stored in errno
*/
LIBBPF_API struct bpf_link *
bpf_program__attach_ksyscall(const struct bpf_program *prog,
const char *syscall_name,
const struct bpf_ksyscall_opts *opts);
struct bpf_uprobe_opts {
/* size of this struct, for forward/backward compatibility */
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;
/* Function name to attach to. Could be an unqualified ("abc") or library-qualified
* "abc@LIBXYZ" name. To specify function entry, func_name should be set while
* func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an
* offset within a function, specify func_name and use func_offset argument to specify
* offset within the function. Shared library functions must specify the shared library
* binary_path.
*/
const char *func_name;
/* uprobe attach mode */
enum probe_attach_mode attach_mode;
size_t :0;
};
#define bpf_uprobe_opts__last_field attach_mode
/**
* @brief **bpf_program__attach_uprobe()** attaches a BPF program
* to the userspace function which is found by binary path and
* offset. You can optionally specify a particular proccess to attach
* to. You can also optionally attach the program to the function
* exit instead of entry.
*
* @param prog BPF program to attach
* @param retprobe Attach to function exit
* @param pid Process ID to attach the uprobe to, 0 for self (own process),
* -1 for all processes
* @param binary_path Path to binary that contains the function symbol
* @param func_offset Offset within the binary of the function symbol
* @return Reference to the newly created BPF link; or NULL is returned on error,
* error code is stored in errno
*/
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);
/**
* @brief **bpf_program__attach_uprobe_opts()** is just like
* bpf_program__attach_uprobe() except with a options struct
* for various configurations.
*
* @param prog BPF program to attach
* @param pid Process ID to attach the uprobe to, 0 for self (own process),
* -1 for all processes
* @param binary_path Path to binary that contains the function symbol
* @param func_offset Offset within the binary of the function symbol
* @param opts Options for altering program attachment
* @return Reference to the newly created BPF link; or NULL is returned on error,
* error code is stored in errno
*/
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_usdt_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* custom user-provided value accessible through usdt_cookie() */
__u64 usdt_cookie;
size_t :0;
};
#define bpf_usdt_opts__last_field usdt_cookie
/**
* @brief **bpf_program__attach_usdt()** is just like
* bpf_program__attach_uprobe_opts() except it covers USDT (User-space
* Statically Defined Tracepoint) attachment, instead of attaching to
* user-space function entry or exit.
*
* @param prog BPF program to attach
* @param pid Process ID to attach the uprobe to, 0 for self (own process),
* -1 for all processes
* @param binary_path Path to binary that contains provided USDT probe
* @param usdt_provider USDT provider name
* @param usdt_name USDT probe name
* @param opts Options for altering program attachment
* @return Reference to the newly created BPF link; or NULL is returned on error,
* error code is stored in errno
*/
LIBBPF_API struct bpf_link *
bpf_program__attach_usdt(const struct bpf_program *prog,
pid_t pid, const char *binary_path,
const char *usdt_provider, const char *usdt_name,
const struct bpf_usdt_opts *opts);
struct bpf_tracepoint_opts {
/* size of this struct, for forward/backward compatibility */
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);
struct bpf_raw_tracepoint_opts {
size_t sz; /* size of this struct for forward/backward compatibility */
__u64 cookie;
size_t :0;
};
#define bpf_raw_tracepoint_opts__last_field cookie
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_raw_tracepoint_opts(const struct bpf_program *prog,
const char *tp_name,
struct bpf_raw_tracepoint_opts *opts);
struct bpf_trace_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* custom user-provided value fetchable through bpf_get_attach_cookie() */
__u64 cookie;
};
#define bpf_trace_opts__last_field cookie
LIBBPF_API struct bpf_link *
bpf_program__attach_trace(const struct bpf_program *prog);
LIBBPF_API struct bpf_link *
bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
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_sockmap(const struct bpf_program *prog, int map_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_netfilter_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
__u32 pf;
__u32 hooknum;
__s32 priority;
__u32 flags;
};
#define bpf_netfilter_opts__last_field flags
LIBBPF_API struct bpf_link *
bpf_program__attach_netfilter(const struct bpf_program *prog,
const struct bpf_netfilter_opts *opts);
struct bpf_tcx_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
__u32 flags;
__u32 relative_fd;
__u32 relative_id;
__u64 expected_revision;
size_t :0;
};
#define bpf_tcx_opts__last_field expected_revision
LIBBPF_API struct bpf_link *
bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
const struct bpf_tcx_opts *opts);
struct bpf_netkit_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
__u32 flags;
__u32 relative_fd;
__u32 relative_id;
__u64 expected_revision;
size_t :0;
};
#define bpf_netkit_opts__last_field expected_revision
LIBBPF_API struct bpf_link *
bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
const struct bpf_netkit_opts *opts);
struct bpf_map;
LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
LIBBPF_API int bpf_link__update_map(struct bpf_link *link, 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_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
/**
* @brief **bpf_program__set_type()** sets the program
* type of the passed BPF program.
* @param prog BPF program to set the program type for
* @param type program type to set the BPF map to have
* @return error code; or 0 if no error. An error occurs
* if the object is already loaded.
*
* This must be called before the BPF object is loaded,
* otherwise it has no effect and an error is returned.
*/
LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
enum bpf_prog_type type);
LIBBPF_API enum bpf_attach_type
bpf_program__expected_attach_type(const struct bpf_program *prog);
/**
* @brief **bpf_program__set_expected_attach_type()** sets the
* attach type of the passed BPF program. This is used for
* auto-detection of attachment when programs are loaded.
* @param prog BPF program to set the attach type for
* @param type attach type to set the BPF map to have
* @return error code; or 0 if no error. An error occurs
* if the object is already loaded.
*
* This must be called before the BPF object is loaded,
* otherwise it has no effect and an error is returned.
*/
LIBBPF_API int
bpf_program__set_expected_attach_type(struct bpf_program *prog,
enum bpf_attach_type type);
LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
/* Per-program log level and log buffer getters/setters.
* See bpf_object_open_opts comments regarding log_level and log_buf
* interactions.
*/
LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
/**
* @brief **bpf_program__set_attach_target()** sets BTF-based attach target
* for supported BPF program types:
* - BTF-aware raw tracepoints (tp_btf);
* - fentry/fexit/fmod_ret;
* - lsm;
* - freplace.
* @param prog BPF program to set the attach type for
* @param type attach type to set the BPF map to have
* @return error code; or 0 if no error occurred.
*/
LIBBPF_API int
bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
const char *attach_func_name);
/**
* @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);
LIBBPF_API int
bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
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 struct bpf_map *
bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
/**
* @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
* BPF map during BPF object load phase.
* @param map the BPF map instance
* @param autocreate whether to create BPF map during BPF object load
* @return 0 on success; -EBUSY if BPF object was already loaded
*
* **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
* BPF map. By default, libbpf will attempt to create every single BPF map
* defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
* and fill in map FD in BPF instructions.
*
* This API allows to opt-out of this process for specific map instance. This
* can be useful if host kernel doesn't support such BPF map type or used
* combination of flags and user application wants to avoid creating such
* a map in the first place. User is still responsible to make sure that their
* BPF-side code that expects to use such missing BPF map is recognized by BPF
* verifier as dead code, otherwise BPF verifier will reject such BPF program.
*/
LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
/**
* @brief **bpf_map__set_autoattach()** sets whether libbpf has to auto-attach
* map during BPF skeleton attach phase.
* @param map the BPF map instance
* @param autoattach whether to attach map during BPF skeleton attach phase
* @return 0 on success; negative error code, otherwise
*/
LIBBPF_API int bpf_map__set_autoattach(struct bpf_map *map, bool autoattach);
/**
* @brief **bpf_map__autoattach()** returns whether BPF map is configured to
* auto-attach during BPF skeleton attach phase.
* @param map the BPF map instance
* @return true if map is set to auto-attach during skeleton attach phase; false, otherwise
*/
LIBBPF_API bool bpf_map__autoattach(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 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);
/* 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 map value size */
LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
/**
* @brief **bpf_map__set_value_size()** sets map value size.
* @param map the BPF map instance
* @return 0, on success; negative error, otherwise
*
* There is a special case for maps with associated memory-mapped regions, like
* the global data section maps (bss, data, rodata). When this function is used
* on such a map, the mapped region is resized. Afterward, an attempt is made to
* adjust the corresponding BTF info. This attempt is best-effort and can only
* succeed if the last variable of the data section map is an array. The array
* BTF type is replaced by a new BTF array type with a different length.
* Any previously existing pointers returned from bpf_map__initial_value() or
* corresponding data section skeleton pointer must be reinitialized.
*/
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);
LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
const void *data, size_t size);
LIBBPF_API void *bpf_map__initial_value(const struct bpf_map *map, size_t *psize);
/**
* @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);
/**
* @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
* BPF map should be pinned. This does not actually create the 'pin'.
* @param map The bpf_map
* @param path The path
* @return 0, on success; negative error, otherwise
*/
LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
/**
* @brief **bpf_map__pin_path()** gets the path attribute that tells where the
* BPF map should be pinned.
* @param map The bpf_map
* @return The path string; which can be NULL
*/
LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
/**
* @brief **bpf_map__is_pinned()** tells the caller whether or not the
* passed map has been pinned via a 'pin' file.
* @param map The bpf_map
* @return true, if the map is pinned; false, otherwise
*/
LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
/**
* @brief **bpf_map__pin()** creates a file that serves as a 'pin'
* for the BPF map. This increments the reference count on the
* BPF map which will keep the BPF map loaded even after the
* userspace process which loaded it has exited.
* @param map The bpf_map to pin
* @param path A file path for the 'pin'
* @return 0, on success; negative error, otherwise
*
* If `path` is NULL the maps `pin_path` attribute will be used. If this is
* also NULL, an error will be returned and the map will not be pinned.
*/
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
/**
* @brief **bpf_map__unpin()** removes the file that serves as a
* 'pin' for the BPF map.
* @param map The bpf_map to unpin
* @param path A file path for the 'pin'
* @return 0, on success; negative error, otherwise
*
* The `path` parameter can be NULL, in which case the `pin_path`
* map attribute is unpinned. If both the `path` parameter and
* `pin_path` map attribute are set, they must be equal.
*/
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 **bpf_map__lookup_elem()** allows to lookup BPF map value
* corresponding to provided key.
* @param map BPF map to lookup element in
* @param key pointer to memory containing bytes of the key used for lookup
* @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
* @param value pointer to memory in which looked up value will be stored
* @param value_sz size in byte of value data memory; it has to match BPF map
* definition's **value_size**. For per-CPU BPF maps value size has to be
* a product of BPF map value size and number of possible CPUs in the system
* (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
* per-CPU values value size has to be aligned up to closest 8 bytes for
* alignment reasons, so expected size is: `round_up(value_size, 8)
* * libbpf_num_possible_cpus()`.
* @flags extra flags passed to kernel for this operation
* @return 0, on success; negative error, otherwise
*
* **bpf_map__lookup_elem()** is high-level equivalent of
* **bpf_map_lookup_elem()** API with added check for key and value size.
*/
LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
const void *key, size_t key_sz,
void *value, size_t value_sz, __u64 flags);
/**
* @brief **bpf_map__update_elem()** allows to insert or update value in BPF
* map that corresponds to provided key.
* @param map BPF map to insert to or update element in
* @param key pointer to memory containing bytes of the key
* @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
* @param value pointer to memory containing bytes of the value
* @param value_sz size in byte of value data memory; it has to match BPF map
* definition's **value_size**. For per-CPU BPF maps value size has to be
* a product of BPF map value size and number of possible CPUs in the system
* (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
* per-CPU values value size has to be aligned up to closest 8 bytes for
* alignment reasons, so expected size is: `round_up(value_size, 8)
* * libbpf_num_possible_cpus()`.
* @flags extra flags passed to kernel for this operation
* @return 0, on success; negative error, otherwise
*
* **bpf_map__update_elem()** is high-level equivalent of
* **bpf_map_update_elem()** API with added check for key and value size.
*/
LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
const void *key, size_t key_sz,
const void *value, size_t value_sz, __u64 flags);
/**
* @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
* corresponds to provided key.
* @param map BPF map to delete element from
* @param key pointer to memory containing bytes of the key
* @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
* @flags extra flags passed to kernel for this operation
* @return 0, on success; negative error, otherwise
*
* **bpf_map__delete_elem()** is high-level equivalent of
* **bpf_map_delete_elem()** API with added check for key size.
*/
LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
const void *key, size_t key_sz, __u64 flags);
/**
* @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
* corresponding to provided key and atomically delete it afterwards.
* @param map BPF map to lookup element in
* @param key pointer to memory containing bytes of the key used for lookup
* @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
* @param value pointer to memory in which looked up value will be stored
* @param value_sz size in byte of value data memory; it has to match BPF map
* definition's **value_size**. For per-CPU BPF maps value size has to be
* a product of BPF map value size and number of possible CPUs in the system
* (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
* per-CPU values value size has to be aligned up to closest 8 bytes for
* alignment reasons, so expected size is: `round_up(value_size, 8)
* * libbpf_num_possible_cpus()`.
* @flags extra flags passed to kernel for this operation
* @return 0, on success; negative error, otherwise
*
* **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
* **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
*/
LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
const void *key, size_t key_sz,
void *value, size_t value_sz, __u64 flags);
/**
* @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
* fetching next key that follows current key.
* @param map BPF map to fetch next key from
* @param cur_key pointer to memory containing bytes of current key or NULL to
* fetch the first key
* @param next_key pointer to memory to write next key into
* @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
* @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
* negative error, otherwise
*
* **bpf_map__get_next_key()** is high-level equivalent of
* **bpf_map_get_next_key()** API with added check for key size.
*/
LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
const void *cur_key, void *next_key, size_t key_sz);
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
struct bpf_xdp_attach_opts {
size_t sz;
int old_prog_fd;
size_t :0;
};
#define bpf_xdp_attach_opts__last_field old_prog_fd
struct bpf_xdp_query_opts {
size_t sz;
__u32 prog_id; /* output */
__u32 drv_prog_id; /* output */
__u32 hw_prog_id; /* output */
__u32 skb_prog_id; /* output */
__u8 attach_mode; /* output */
__u64 feature_flags; /* output */
__u32 xdp_zc_max_segs; /* output */
size_t :0;
};
#define bpf_xdp_query_opts__last_field xdp_zc_max_segs
LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
const struct bpf_xdp_attach_opts *opts);
LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
const struct bpf_xdp_attach_opts *opts);
LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
/* 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;
struct ring;
struct user_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 compatibility */
};
#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__consume_n(struct ring_buffer *rb, size_t n);
LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
/**
* @brief **ring_buffer__ring()** returns the ringbuffer object inside a given
* ringbuffer manager representing a single BPF_MAP_TYPE_RINGBUF map instance.
*
* @param rb A ringbuffer manager object.
* @param idx An index into the ringbuffers contained within the ringbuffer
* manager object. The index is 0-based and corresponds to the order in which
* ring_buffer__add was called.
* @return A ringbuffer object on success; NULL and errno set if the index is
* invalid.
*/
LIBBPF_API struct ring *ring_buffer__ring(struct ring_buffer *rb,
unsigned int idx);
/**
* @brief **ring__consumer_pos()** returns the current consumer position in the
* given ringbuffer.
*
* @param r A ringbuffer object.
* @return The current consumer position.
*/
LIBBPF_API unsigned long ring__consumer_pos(const struct ring *r);
/**
* @brief **ring__producer_pos()** returns the current producer position in the
* given ringbuffer.
*
* @param r A ringbuffer object.
* @return The current producer position.
*/
LIBBPF_API unsigned long ring__producer_pos(const struct ring *r);
/**
* @brief **ring__avail_data_size()** returns the number of bytes in the
* ringbuffer not yet consumed. This has no locking associated with it, so it
* can be inaccurate if operations are ongoing while this is called. However, it
* should still show the correct trend over the long-term.
*
* @param r A ringbuffer object.
* @return The number of bytes not yet consumed.
*/
LIBBPF_API size_t ring__avail_data_size(const struct ring *r);
/**
* @brief **ring__size()** returns the total size of the ringbuffer's map data
* area (excluding special producer/consumer pages). Effectively this gives the
* amount of usable bytes of data inside the ringbuffer.
*
* @param r A ringbuffer object.
* @return The total size of the ringbuffer map data area.
*/
LIBBPF_API size_t ring__size(const struct ring *r);
/**
* @brief **ring__map_fd()** returns the file descriptor underlying the given
* ringbuffer.
*
* @param r A ringbuffer object.
* @return The underlying ringbuffer file descriptor
*/
LIBBPF_API int ring__map_fd(const struct ring *r);
/**
* @brief **ring__consume()** consumes available ringbuffer data without event
* polling.
*
* @param r A ringbuffer object.
* @return The number of records consumed (or INT_MAX, whichever is less), or
* a negative number if any of the callbacks return an error.
*/
LIBBPF_API int ring__consume(struct ring *r);
/**
* @brief **ring__consume_n()** consumes up to a requested amount of items from
* a ringbuffer without event polling.
*
* @param r A ringbuffer object.
* @param n Maximum amount of items to consume.
* @return The number of items consumed, or a negative number if any of the
* callbacks return an error.
*/
LIBBPF_API int ring__consume_n(struct ring *r, size_t n);
struct user_ring_buffer_opts {
size_t sz; /* size of this struct, for forward/backward compatibility */
};
#define user_ring_buffer_opts__last_field sz
/**
* @brief **user_ring_buffer__new()** creates a new instance of a user ring
* buffer.
*
* @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
* @param opts Options for how the ring buffer should be created.
* @return A user ring buffer on success; NULL and errno being set on a
* failure.
*/
LIBBPF_API struct user_ring_buffer *
user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
/**
* @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
* user ring buffer.
* @param rb A pointer to a user ring buffer.
* @param size The size of the sample, in bytes.
* @return A pointer to an 8-byte aligned reserved region of the user ring
* buffer; NULL, and errno being set if a sample could not be reserved.
*
* This function is *not* thread safe, and callers must synchronize accessing
* this function if there are multiple producers. If a size is requested that
* is larger than the size of the entire ring buffer, errno will be set to
* E2BIG and NULL is returned. If the ring buffer could accommodate the size,
* but currently does not have enough space, errno is set to ENOSPC and NULL is
* returned.
*
* After initializing the sample, callers must invoke
* **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
* the sample must be freed with **user_ring_buffer__discard()**.
*/
LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
/**
* @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
* ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
* available.
* @param rb The user ring buffer.
* @param size The size of the sample, in bytes.
* @param timeout_ms The amount of time, in milliseconds, for which the caller
* should block when waiting for a sample. -1 causes the caller to block
* indefinitely.
* @return A pointer to an 8-byte aligned reserved region of the user ring
* buffer; NULL, and errno being set if a sample could not be reserved.
*
* This function is *not* thread safe, and callers must synchronize
* accessing this function if there are multiple producers
*
* If **timeout_ms** is -1, the function will block indefinitely until a sample
* becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
* is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
* will occur and the function will return immediately after attempting to
* reserve a sample.
*
* If **size** is larger than the size of the entire ring buffer, errno is set
* to E2BIG and NULL is returned. If the ring buffer could accommodate
* **size**, but currently does not have enough space, the caller will block
* until at most **timeout_ms** has elapsed. If insufficient space is available
* at that time, errno is set to ENOSPC, and NULL is returned.
*
* The kernel guarantees that it will wake up this thread to check if
* sufficient space is available in the ring buffer at least once per
* invocation of the **bpf_ringbuf_drain()** helper function, provided that at
* least one sample is consumed, and the BPF program did not invoke the
* function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
* kernel does not guarantee this. If the helper function is invoked with
* BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
* consumed.
*
* When a sample of size **size** is found within **timeout_ms**, a pointer to
* the sample is returned. After initializing the sample, callers must invoke
* **user_ring_buffer__submit()** to post the sample to the ring buffer.
* Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
*/
LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
__u32 size,
int timeout_ms);
/**
* @brief **user_ring_buffer__submit()** submits a previously reserved sample
* into the ring buffer.
* @param rb The user ring buffer.
* @param sample A reserved sample.
*
* It is not necessary to synchronize amongst multiple producers when invoking
* this function.
*/
LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
/**
* @brief **user_ring_buffer__discard()** discards a previously reserved sample.
* @param rb The user ring buffer.
* @param sample A reserved sample.
*
* It is not necessary to synchronize amongst multiple producers when invoking
* this function.
*/
LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
/**
* @brief **user_ring_buffer__free()** frees a ring buffer that was previously
* created with **user_ring_buffer__new()**.
* @param rb The user ring buffer being freed.
*/
LIBBPF_API void user_ring_buffer__free(struct user_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 {
size_t sz;
__u32 sample_period;
size_t :0;
};
#define perf_buffer_opts__last_field sample_period
/**
* @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
* BPF_PERF_EVENT_ARRAY map
* @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
* code to send data over to user-space
* @param page_cnt number of memory pages allocated for each per-CPU buffer
* @param sample_cb function called on each received data record
* @param lost_cb function called when record loss has occurred
* @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
* @return a new instance of struct perf_buffer on success, NULL on error with
* *errno* containing an error code
*/
LIBBPF_API struct perf_buffer *
perf_buffer__new(int map_fd, size_t page_cnt,
perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
const struct perf_buffer_opts *opts);
enum bpf_perf_event_ret {
LIBBPF_PERF_EVENT_DONE = 0,
LIBBPF_PERF_EVENT_ERROR = -1,
LIBBPF_PERF_EVENT_CONT = -2,
};
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 {
size_t sz;
long :0;
long :0;
/* 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;
};
#define perf_buffer_raw_opts__last_field map_keys
struct perf_event_attr;
LIBBPF_API struct perf_buffer *
perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
perf_buffer_event_fn event_cb, void *ctx,
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);
/**
* @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
* memory region of the ring buffer.
* This ring buffer can be used to implement a custom events consumer.
* The ring buffer starts with the *struct perf_event_mmap_page*, which
* holds the ring buffer managment fields, when accessing the header
* structure it's important to be SMP aware.
* You can refer to *perf_event_read_simple* for a simple example.
* @param pb the perf buffer structure
* @param buf_idx the buffer index to retreive
* @param buf (out) gets the base pointer of the mmap()'ed memory
* @param buf_size (out) gets the size of the mmap()'ed region
* @return 0 on success, negative error code for failure
*/
LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
size_t *buf_size);
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().
*/
/**
* @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
* BPF programs of a given type.
* @param prog_type BPF program type to detect kernel support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given program type is supported; 0, if given program type is
* not supported; negative error code if feature detection failed or can't be
* performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
/**
* @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
* BPF maps of a given type.
* @param map_type BPF map type to detect kernel support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given map type is supported; 0, if given map type is
* not supported; negative error code if feature detection failed or can't be
* performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
/**
* @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
* use of a given BPF helper from specified BPF program type.
* @param prog_type BPF program type used to check the support of BPF helper
* @param helper_id BPF helper ID (enum bpf_func_id) to check support for
* @param opts reserved for future extensibility, should be NULL
* @return 1, if given combination of program type and helper is supported; 0,
* if the combination is not supported; negative error code if feature
* detection for provided input arguments failed or can't be performed
*
* Make sure the process has required set of CAP_* permissions (or runs as
* root) when performing feature checking.
*/
LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
enum bpf_func_id helper_id, const void *opts);
/**
* @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_link **link;
};
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_map_skeleton) */
struct bpf_map_skeleton *maps;
int prog_cnt;
int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
struct bpf_prog_skeleton *progs;
};
LIBBPF_API int
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 bpf_var_skeleton {
const char *name;
struct bpf_map **map;
void **addr;
};
struct bpf_object_subskeleton {
size_t sz; /* size of this struct, for forward/backward compatibility */
const struct bpf_object *obj;
int map_cnt;
int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
struct bpf_map_skeleton *maps;
int prog_cnt;
int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
struct bpf_prog_skeleton *progs;
int var_cnt;
int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
struct bpf_var_skeleton *vars;
};
LIBBPF_API int
bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
LIBBPF_API void
bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
struct gen_loader_opts {
size_t sz; /* size of this struct, for forward/backward compatibility */
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,
TRI_MODULE = 2,
};
struct bpf_linker_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
};
#define bpf_linker_opts__last_field sz
struct bpf_linker_file_opts {
/* size of this struct, for forward/backward compatibility */
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);
/*
* Custom handling of BPF program's SEC() definitions
*/
struct bpf_prog_load_opts; /* defined in bpf.h */
/* Called during bpf_object__open() for each recognized BPF program. Callback
* can use various bpf_program__set_*() setters to adjust whatever properties
* are necessary.
*/
typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
/* Called right before libbpf performs bpf_prog_load() to load BPF program
* into the kernel. Callback can adjust opts as necessary.
*/
typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
struct bpf_prog_load_opts *opts, long cookie);
/* Called during skeleton attach or through bpf_program__attach(). If
* auto-attach is not supported, callback should return 0 and set link to
* NULL (it's not considered an error during skeleton attach, but it will be
* an error for bpf_program__attach() calls). On error, error should be
* returned directly and link set to NULL. On success, return 0 and set link
* to a valid struct bpf_link.
*/
typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
struct bpf_link **link);
struct libbpf_prog_handler_opts {
/* size of this struct, for forward/backward compatibility */
size_t sz;
/* User-provided value that is passed to prog_setup_fn,
* prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
* register one set of callbacks for multiple SEC() definitions and
* still be able to distinguish them, if necessary. For example,
* libbpf itself is using this to pass necessary flags (e.g.,
* sleepable flag) to a common internal SEC() handler.
*/
long cookie;
/* BPF program initialization callback (see libbpf_prog_setup_fn_t).
* Callback is optional, pass NULL if it's not necessary.
*/
libbpf_prog_setup_fn_t prog_setup_fn;
/* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
* Callback is optional, pass NULL if it's not necessary.
*/
libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
/* BPF program attach callback (see libbpf_prog_attach_fn_t).
* Callback is optional, pass NULL if it's not necessary.
*/
libbpf_prog_attach_fn_t prog_attach_fn;
};
#define libbpf_prog_handler_opts__last_field prog_attach_fn
/**
* @brief **libbpf_register_prog_handler()** registers a custom BPF program
* SEC() handler.
* @param sec section prefix for which custom handler is registered
* @param prog_type BPF program type associated with specified section
* @param exp_attach_type Expected BPF attach type associated with specified section
* @param opts optional cookie, callbacks, and other extra options
* @return Non-negative handler ID is returned on success. This handler ID has
* to be passed to *libbpf_unregister_prog_handler()* to unregister such
* custom handler. Negative error code is returned on error.
*
* *sec* defines which SEC() definitions are handled by this custom handler
* registration. *sec* can have few different forms:
* - if *sec* is just a plain string (e.g., "abc"), it will match only
* SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
* in an error;
* - if *sec* is of the form "abc/", proper SEC() form is
* SEC("abc/something"), where acceptable "something" should be checked by
* *prog_init_fn* callback, if there are additional restrictions;
* - if *sec* is of the form "abc+", it will successfully match both
* SEC("abc") and SEC("abc/whatever") forms;
* - if *sec* is NULL, custom handler is registered for any BPF program that
* doesn't match any of the registered (custom or libbpf's own) SEC()
* handlers. There could be only one such generic custom handler registered
* at any given time.
*
* All custom handlers (except the one with *sec* == NULL) are processed
* before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
* SEC() handlers by registering custom ones for the same section prefix
* (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
* handler).
*
* Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
* libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
* to ensure synchronization if there is a risk of running this API from
* multiple threads simultaneously.
*/
LIBBPF_API int libbpf_register_prog_handler(const char *sec,
enum bpf_prog_type prog_type,
enum bpf_attach_type exp_attach_type,
const struct libbpf_prog_handler_opts *opts);
/**
* @brief *libbpf_unregister_prog_handler()* unregisters previously registered
* custom BPF program SEC() handler.
* @param handler_id handler ID returned by *libbpf_register_prog_handler()*
* after successful registration
* @return 0 on success, negative error code if handler isn't found
*
* Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
* libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
* to ensure synchronization if there is a risk of running this API from
* multiple threads simultaneously.
*/
LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* __LIBBPF_LIBBPF_H */