1/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
   2
   3/*
   4 * Common eBPF ELF object loading operations.
   5 *
   6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org>
   7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com>
   8 * Copyright (C) 2015 Huawei Inc.
   9 */
  10#ifndef __LIBBPF_LIBBPF_H
  11#define __LIBBPF_LIBBPF_H
  12
  13#include <stdarg.h>
  14#include <stdio.h>
  15#include <stdint.h>
  16#include <stdbool.h>
  17#include <sys/types.h>  // for size_t
  18#include <linux/bpf.h>
  19
  20#include "libbpf_common.h"
  21#include "libbpf_legacy.h"
  22
  23#ifdef __cplusplus
  24extern "C" {
  25#endif
  26
  27LIBBPF_API __u32 libbpf_major_version(void);
  28LIBBPF_API __u32 libbpf_minor_version(void);
  29LIBBPF_API const char *libbpf_version_string(void);
  30
  31enum libbpf_errno {
  32	__LIBBPF_ERRNO__START = 4000,
  33
  34	/* Something wrong in libelf */
  35	LIBBPF_ERRNO__LIBELF = __LIBBPF_ERRNO__START,
  36	LIBBPF_ERRNO__FORMAT,	/* BPF object format invalid */
  37	LIBBPF_ERRNO__KVERSION,	/* Incorrect or no 'version' section */
  38	LIBBPF_ERRNO__ENDIAN,	/* Endian mismatch */
  39	LIBBPF_ERRNO__INTERNAL,	/* Internal error in libbpf */
  40	LIBBPF_ERRNO__RELOC,	/* Relocation failed */
  41	LIBBPF_ERRNO__LOAD,	/* Load program failure for unknown reason */
  42	LIBBPF_ERRNO__VERIFY,	/* Kernel verifier blocks program loading */
  43	LIBBPF_ERRNO__PROG2BIG,	/* Program too big */
  44	LIBBPF_ERRNO__KVER,	/* Incorrect kernel version */
  45	LIBBPF_ERRNO__PROGTYPE,	/* Kernel doesn't support this program type */
  46	LIBBPF_ERRNO__WRNGPID,	/* Wrong pid in netlink message */
  47	LIBBPF_ERRNO__INVSEQ,	/* Invalid netlink sequence */
  48	LIBBPF_ERRNO__NLPARSE,	/* netlink parsing error */
  49	__LIBBPF_ERRNO__END,
  50};
  51
  52LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
  53
  54/**
  55 * @brief **libbpf_bpf_attach_type_str()** converts the provided attach type
  56 * value into a textual representation.
  57 * @param t The attach type.
  58 * @return Pointer to a static string identifying the attach type. NULL is
  59 * returned for unknown **bpf_attach_type** values.
  60 */
  61LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t);
  62
  63/**
  64 * @brief **libbpf_bpf_link_type_str()** converts the provided link type value
  65 * into a textual representation.
  66 * @param t The link type.
  67 * @return Pointer to a static string identifying the link type. NULL is
  68 * returned for unknown **bpf_link_type** values.
  69 */
  70LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t);
  71
  72/**
  73 * @brief **libbpf_bpf_map_type_str()** converts the provided map type value
  74 * into a textual representation.
  75 * @param t The map type.
  76 * @return Pointer to a static string identifying the map type. NULL is
  77 * returned for unknown **bpf_map_type** values.
  78 */
  79LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t);
  80
  81/**
  82 * @brief **libbpf_bpf_prog_type_str()** converts the provided program type
  83 * value into a textual representation.
  84 * @param t The program type.
  85 * @return Pointer to a static string identifying the program type. NULL is
  86 * returned for unknown **bpf_prog_type** values.
  87 */
  88LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
  89
  90enum libbpf_print_level {
  91        LIBBPF_WARN,
  92        LIBBPF_INFO,
  93        LIBBPF_DEBUG,
  94};
  95
  96typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
  97				 const char *, va_list ap);
  98
  99LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
 
 
 
 
 
 
 
 
 
 
 100
 101/* Hide internal to user */
 102struct bpf_object;
 103
 104struct bpf_object_open_opts {
 105	/* size of this struct, for forward/backward compatibility */
 106	size_t sz;
 107	/* object name override, if provided:
 108	 * - for object open from file, this will override setting object
 109	 *   name from file path's base name;
 110	 * - for object open from memory buffer, this will specify an object
 111	 *   name and will override default "<addr>-<buf-size>" name;
 112	 */
 113	const char *object_name;
 114	/* parse map definitions non-strictly, allowing extra attributes/data */
 115	bool relaxed_maps;
 116	/* maps that set the 'pinning' attribute in their definition will have
 117	 * their pin_path attribute set to a file in this directory, and be
 118	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
 119	 */
 120	const char *pin_root_path;
 121
 122	__u32 :32; /* stub out now removed attach_prog_fd */
 123
 124	/* Additional kernel config content that augments and overrides
 125	 * system Kconfig for CONFIG_xxx externs.
 126	 */
 127	const char *kconfig;
 128	/* Path to the custom BTF to be used for BPF CO-RE relocations.
 129	 * This custom BTF completely replaces the use of vmlinux BTF
 130	 * for the purpose of CO-RE relocations.
 131	 * NOTE: any other BPF feature (e.g., fentry/fexit programs,
 132	 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
 133	 */
 134	const char *btf_custom_path;
 135	/* Pointer to a buffer for storing kernel logs for applicable BPF
 136	 * commands. Valid kernel_log_size has to be specified as well and are
 137	 * passed-through to bpf() syscall. Keep in mind that kernel might
 138	 * fail operation with -ENOSPC error if provided buffer is too small
 139	 * to contain entire log output.
 140	 * See the comment below for kernel_log_level for interaction between
 141	 * log_buf and log_level settings.
 142	 *
 143	 * If specified, this log buffer will be passed for:
 144	 *   - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden
 145	 *     with bpf_program__set_log() on per-program level, to get
 146	 *     BPF verifier log output.
 147	 *   - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get
 148	 *     BTF sanity checking log.
 149	 *
 150	 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite
 151	 * previous contents, so if you need more fine-grained control, set
 152	 * per-program buffer with bpf_program__set_log_buf() to preserve each
 153	 * individual program's verification log. Keep using kernel_log_buf
 154	 * for BTF verification log, if necessary.
 155	 */
 156	char *kernel_log_buf;
 157	size_t kernel_log_size;
 158	/*
 159	 * Log level can be set independently from log buffer. Log_level=0
 160	 * means that libbpf will attempt loading BTF or program without any
 161	 * logging requested, but will retry with either its own or custom log
 162	 * buffer, if provided, and log_level=1 on any error.
 163	 * And vice versa, setting log_level>0 will request BTF or prog
 164	 * loading with verbose log from the first attempt (and as such also
 165	 * for successfully loaded BTF or program), and the actual log buffer
 166	 * could be either libbpf's own auto-allocated log buffer, if
 167	 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf.
 168	 * If user didn't provide custom log buffer, libbpf will emit captured
 169	 * logs through its print callback.
 170	 */
 171	__u32 kernel_log_level;
 172
 173	size_t :0;
 174};
 175#define bpf_object_open_opts__last_field kernel_log_level
 176
 177LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
 178
 179/**
 180 * @brief **bpf_object__open_file()** creates a bpf_object by opening
 181 * the BPF ELF object file pointed to by the passed path and loading it
 182 * into memory.
 183 * @param path BPF object file path
 184 * @param opts options for how to load the bpf object, this parameter is
 185 * optional and can be set to NULL
 186 * @return pointer to the new bpf_object; or NULL is returned on error,
 187 * error code is stored in errno
 188 */
 189LIBBPF_API struct bpf_object *
 190bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
 191
 192/**
 193 * @brief **bpf_object__open_mem()** creates a bpf_object by reading
 194 * the BPF objects raw bytes from a memory buffer containing a valid
 195 * BPF ELF object file.
 196 * @param obj_buf pointer to the buffer containing ELF file bytes
 197 * @param obj_buf_sz number of bytes in the buffer
 198 * @param opts options for how to load the bpf object
 199 * @return pointer to the new bpf_object; or NULL is returned on error,
 200 * error code is stored in errno
 201 */
 202LIBBPF_API struct bpf_object *
 203bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
 204		     const struct bpf_object_open_opts *opts);
 205
 206/* Load/unload object into/from kernel */
 207LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 208
 209LIBBPF_API void bpf_object__close(struct bpf_object *object);
 210
 211/* pin_maps and unpin_maps can both be called with a NULL path, in which case
 212 * they will use the pin_path attribute of each map (and ignore all maps that
 213 * don't have a pin_path set).
 214 */
 215LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
 216LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
 217				      const char *path);
 218LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
 219					const char *path);
 220LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
 221					  const char *path);
 222LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
 223
 224LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
 225LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
 226LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
 227
 228struct btf;
 229LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
 230LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
 231
 232LIBBPF_API struct bpf_program *
 233bpf_object__find_program_by_name(const struct bpf_object *obj,
 234				 const char *name);
 235
 236LIBBPF_API int
 237libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 238			 enum bpf_attach_type *expected_attach_type);
 239LIBBPF_API int libbpf_attach_type_by_name(const char *name,
 240					  enum bpf_attach_type *attach_type);
 241LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
 242					  enum bpf_attach_type attach_type);
 243
 244/* Accessors of bpf_program */
 245struct bpf_program;
 
 
 246
 247LIBBPF_API struct bpf_program *
 248bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
 249
 250#define bpf_object__for_each_program(pos, obj)			\
 251	for ((pos) = bpf_object__next_program((obj), NULL);	\
 252	     (pos) != NULL;					\
 253	     (pos) = bpf_object__next_program((obj), (pos)))
 254
 255LIBBPF_API struct bpf_program *
 256bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
 257
 258LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
 259					 __u32 ifindex);
 260
 261LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
 262LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
 263LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
 264LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
 265LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
 266LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
 267
 268struct bpf_insn;
 269
 270/**
 271 * @brief **bpf_program__insns()** gives read-only access to BPF program's
 272 * underlying BPF instructions.
 273 * @param prog BPF program for which to return instructions
 274 * @return a pointer to an array of BPF instructions that belong to the
 275 * specified BPF program
 276 *
 277 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
 278 * pointed to can be fetched using **bpf_program__insn_cnt()** API.
 279 *
 280 * Keep in mind, libbpf can modify and append/delete BPF program's
 281 * instructions as it processes BPF object file and prepares everything for
 282 * uploading into the kernel. So depending on the point in BPF object
 283 * lifetime, **bpf_program__insns()** can return different sets of
 284 * instructions. As an example, during BPF object load phase BPF program
 285 * instructions will be CO-RE-relocated, BPF subprograms instructions will be
 286 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
 287 * returned before **bpf_object__load()** and after it might be quite
 288 * different.
 289 */
 290LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
 291
 292/**
 293 * @brief **bpf_program__set_insns()** can set BPF program's underlying
 294 * BPF instructions.
 295 *
 296 * WARNING: This is a very advanced libbpf API and users need to know
 297 * what they are doing. This should be used from prog_prepare_load_fn
 298 * callback only.
 299 *
 300 * @param prog BPF program for which to return instructions
 301 * @param new_insns a pointer to an array of BPF instructions
 302 * @param new_insn_cnt number of `struct bpf_insn`'s that form
 303 * specified BPF program
 304 * @return 0, on success; negative error code, otherwise
 305 */
 306LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
 307				      struct bpf_insn *new_insns, size_t new_insn_cnt);
 308
 309/**
 310 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
 311 * that form specified BPF program.
 312 * @param prog BPF program for which to return number of BPF instructions
 313 *
 314 * See **bpf_program__insns()** documentation for notes on how libbpf can
 315 * change instructions and their count during different phases of
 316 * **bpf_object** lifetime.
 317 */
 318LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
 319
 320LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
 321
 322/**
 323 * @brief **bpf_program__pin()** pins the BPF program to a file
 324 * in the BPF FS specified by a path. This increments the programs
 325 * reference count, allowing it to stay loaded after the process
 326 * which loaded it has exited.
 327 *
 328 * @param prog BPF program to pin, must already be loaded
 329 * @param path file path in a BPF file system
 330 * @return 0, on success; negative error code, otherwise
 331 */
 332LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
 333
 334/**
 335 * @brief **bpf_program__unpin()** unpins the BPF program from a file
 336 * in the BPFFS specified by a path. This decrements the programs
 337 * reference count.
 338 *
 339 * The file pinning the BPF program can also be unlinked by a different
 340 * process in which case this function will return an error.
 341 *
 342 * @param prog BPF program to unpin
 343 * @param path file path to the pin in a BPF file system
 344 * @return 0, on success; negative error code, otherwise
 345 */
 346LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
 347LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
 348
 349struct bpf_link;
 350
 351LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
 352LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
 353LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
 354/**
 355 * @brief **bpf_link__pin()** pins the BPF link to a file
 356 * in the BPF FS specified by a path. This increments the links
 357 * reference count, allowing it to stay loaded after the process
 358 * which loaded it has exited.
 359 *
 360 * @param link BPF link to pin, must already be loaded
 361 * @param path file path in a BPF file system
 362 * @return 0, on success; negative error code, otherwise
 363 */
 364
 365LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
 366
 367/**
 368 * @brief **bpf_link__unpin()** unpins the BPF link from a file
 369 * in the BPFFS specified by a path. This decrements the links
 370 * reference count.
 371 *
 372 * The file pinning the BPF link can also be unlinked by a different
 373 * process in which case this function will return an error.
 374 *
 375 * @param prog BPF program to unpin
 376 * @param path file path to the pin in a BPF file system
 377 * @return 0, on success; negative error code, otherwise
 378 */
 379LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
 380LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
 381					struct bpf_program *prog);
 382LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
 383LIBBPF_API int bpf_link__detach(struct bpf_link *link);
 384LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 385
 386/**
 387 * @brief **bpf_program__attach()** is a generic function for attaching
 388 * a BPF program based on auto-detection of program type, attach type,
 389 * and extra paremeters, where applicable.
 390 *
 391 * @param prog BPF program to attach
 392 * @return Reference to the newly created BPF link; or NULL is returned on error,
 393 * error code is stored in errno
 394 *
 395 * This is supported for:
 396 *   - kprobe/kretprobe (depends on SEC() definition)
 397 *   - uprobe/uretprobe (depends on SEC() definition)
 398 *   - tracepoint
 399 *   - raw tracepoint
 400 *   - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
 401 */
 402LIBBPF_API struct bpf_link *
 403bpf_program__attach(const struct bpf_program *prog);
 404
 405struct bpf_perf_event_opts {
 406	/* size of this struct, for forward/backward compatiblity */
 407	size_t sz;
 408	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 409	__u64 bpf_cookie;
 410};
 411#define bpf_perf_event_opts__last_field bpf_cookie
 412
 413LIBBPF_API struct bpf_link *
 414bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
 415
 416LIBBPF_API struct bpf_link *
 417bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
 418				    const struct bpf_perf_event_opts *opts);
 419
 420struct bpf_kprobe_opts {
 421	/* size of this struct, for forward/backward compatiblity */
 422	size_t sz;
 423	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 424	__u64 bpf_cookie;
 425	/* function's offset to install kprobe to */
 426	size_t offset;
 427	/* kprobe is return probe */
 428	bool retprobe;
 429	size_t :0;
 430};
 431#define bpf_kprobe_opts__last_field retprobe
 432
 433LIBBPF_API struct bpf_link *
 434bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
 435			   const char *func_name);
 436LIBBPF_API struct bpf_link *
 437bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 438                                const char *func_name,
 439                                const struct bpf_kprobe_opts *opts);
 440
 441struct bpf_kprobe_multi_opts {
 442	/* size of this struct, for forward/backward compatibility */
 443	size_t sz;
 444	/* array of function symbols to attach */
 445	const char **syms;
 446	/* array of function addresses to attach */
 447	const unsigned long *addrs;
 448	/* array of user-provided values fetchable through bpf_get_attach_cookie */
 449	const __u64 *cookies;
 450	/* number of elements in syms/addrs/cookies arrays */
 451	size_t cnt;
 452	/* create return kprobes */
 453	bool retprobe;
 454	size_t :0;
 455};
 456
 457#define bpf_kprobe_multi_opts__last_field retprobe
 458
 459LIBBPF_API struct bpf_link *
 460bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
 461				      const char *pattern,
 462				      const struct bpf_kprobe_multi_opts *opts);
 463
 464struct bpf_ksyscall_opts {
 465	/* size of this struct, for forward/backward compatiblity */
 466	size_t sz;
 467	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 468	__u64 bpf_cookie;
 469	/* attach as return probe? */
 470	bool retprobe;
 471	size_t :0;
 472};
 473#define bpf_ksyscall_opts__last_field retprobe
 474
 475/**
 476 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
 477 * to kernel syscall handler of a specified syscall. Optionally it's possible
 478 * to request to install retprobe that will be triggered at syscall exit. It's
 479 * also possible to associate BPF cookie (though options).
 480 *
 481 * Libbpf automatically will determine correct full kernel function name,
 482 * which depending on system architecture and kernel version/configuration
 483 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
 484 * attach specified program using kprobe/kretprobe mechanism.
 485 *
 486 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
 487 * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
 488 *
 489 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
 490 * not handle all the calling convention quirks for mmap(), clone() and compat
 491 * syscalls. It also only attaches to "native" syscall interfaces. If host
 492 * system supports compat syscalls or defines 32-bit syscalls in 64-bit
 493 * kernel, such syscall interfaces won't be attached to by libbpf.
 494 *
 495 * These limitations may or may not change in the future. Therefore it is
 496 * recommended to use SEC("kprobe") for these syscalls or if working with
 497 * compat and 32-bit interfaces is required.
 498 *
 499 * @param prog BPF program to attach
 500 * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
 501 * @param opts Additional options (see **struct bpf_ksyscall_opts**)
 502 * @return Reference to the newly created BPF link; or NULL is returned on
 503 * error, error code is stored in errno
 504 */
 505LIBBPF_API struct bpf_link *
 506bpf_program__attach_ksyscall(const struct bpf_program *prog,
 507			     const char *syscall_name,
 508			     const struct bpf_ksyscall_opts *opts);
 509
 510struct bpf_uprobe_opts {
 511	/* size of this struct, for forward/backward compatiblity */
 512	size_t sz;
 513	/* offset of kernel reference counted USDT semaphore, added in
 514	 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
 515	 */
 516	size_t ref_ctr_offset;
 517	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 518	__u64 bpf_cookie;
 519	/* uprobe is return probe, invoked at function return time */
 520	bool retprobe;
 521	/* Function name to attach to.  Could be an unqualified ("abc") or library-qualified
 522	 * "abc@LIBXYZ" name.  To specify function entry, func_name should be set while
 523	 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0.  To trace an
 524	 * offset within a function, specify func_name and use func_offset argument to specify
 525	 * offset within the function.  Shared library functions must specify the shared library
 526	 * binary_path.
 527	 */
 528	const char *func_name;
 529	size_t :0;
 530};
 531#define bpf_uprobe_opts__last_field func_name
 532
 533/**
 534 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
 535 * to the userspace function which is found by binary path and
 536 * offset. You can optionally specify a particular proccess to attach
 537 * to. You can also optionally attach the program to the function
 538 * exit instead of entry.
 539 *
 540 * @param prog BPF program to attach
 541 * @param retprobe Attach to function exit
 542 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
 543 * -1 for all processes
 544 * @param binary_path Path to binary that contains the function symbol
 545 * @param func_offset Offset within the binary of the function symbol
 546 * @return Reference to the newly created BPF link; or NULL is returned on error,
 547 * error code is stored in errno
 548 */
 549LIBBPF_API struct bpf_link *
 550bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
 551			   pid_t pid, const char *binary_path,
 552			   size_t func_offset);
 553
 554/**
 555 * @brief **bpf_program__attach_uprobe_opts()** is just like
 556 * bpf_program__attach_uprobe() except with a options struct
 557 * for various configurations.
 558 *
 559 * @param prog BPF program to attach
 560 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
 561 * -1 for all processes
 562 * @param binary_path Path to binary that contains the function symbol
 563 * @param func_offset Offset within the binary of the function symbol
 564 * @param opts Options for altering program attachment
 565 * @return Reference to the newly created BPF link; or NULL is returned on error,
 566 * error code is stored in errno
 567 */
 568LIBBPF_API struct bpf_link *
 569bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 570				const char *binary_path, size_t func_offset,
 571				const struct bpf_uprobe_opts *opts);
 572
 573struct bpf_usdt_opts {
 574	/* size of this struct, for forward/backward compatibility */
 575	size_t sz;
 576	/* custom user-provided value accessible through usdt_cookie() */
 577	__u64 usdt_cookie;
 578	size_t :0;
 579};
 580#define bpf_usdt_opts__last_field usdt_cookie
 581
 582/**
 583 * @brief **bpf_program__attach_usdt()** is just like
 584 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
 585 * Statically Defined Tracepoint) attachment, instead of attaching to
 586 * user-space function entry or exit.
 587 *
 588 * @param prog BPF program to attach
 589 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
 590 * -1 for all processes
 591 * @param binary_path Path to binary that contains provided USDT probe
 592 * @param usdt_provider USDT provider name
 593 * @param usdt_name USDT probe name
 594 * @param opts Options for altering program attachment
 595 * @return Reference to the newly created BPF link; or NULL is returned on error,
 596 * error code is stored in errno
 597 */
 598LIBBPF_API struct bpf_link *
 599bpf_program__attach_usdt(const struct bpf_program *prog,
 600			 pid_t pid, const char *binary_path,
 601			 const char *usdt_provider, const char *usdt_name,
 602			 const struct bpf_usdt_opts *opts);
 603
 604struct bpf_tracepoint_opts {
 605	/* size of this struct, for forward/backward compatiblity */
 606	size_t sz;
 607	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 608	__u64 bpf_cookie;
 609};
 610#define bpf_tracepoint_opts__last_field bpf_cookie
 611
 612LIBBPF_API struct bpf_link *
 613bpf_program__attach_tracepoint(const struct bpf_program *prog,
 614			       const char *tp_category,
 615			       const char *tp_name);
 616LIBBPF_API struct bpf_link *
 617bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
 618				    const char *tp_category,
 619				    const char *tp_name,
 620				    const struct bpf_tracepoint_opts *opts);
 621
 622LIBBPF_API struct bpf_link *
 623bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
 624				   const char *tp_name);
 625
 626struct bpf_trace_opts {
 627	/* size of this struct, for forward/backward compatibility */
 628	size_t sz;
 629	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 630	__u64 cookie;
 631};
 632#define bpf_trace_opts__last_field cookie
 633
 634LIBBPF_API struct bpf_link *
 635bpf_program__attach_trace(const struct bpf_program *prog);
 636LIBBPF_API struct bpf_link *
 637bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
 638
 639LIBBPF_API struct bpf_link *
 640bpf_program__attach_lsm(const struct bpf_program *prog);
 641LIBBPF_API struct bpf_link *
 642bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
 643LIBBPF_API struct bpf_link *
 644bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
 645LIBBPF_API struct bpf_link *
 646bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
 647LIBBPF_API struct bpf_link *
 648bpf_program__attach_freplace(const struct bpf_program *prog,
 649			     int target_fd, const char *attach_func_name);
 650
 651struct bpf_map;
 652
 653LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
 654
 655struct bpf_iter_attach_opts {
 656	size_t sz; /* size of this struct for forward/backward compatibility */
 657	union bpf_iter_link_info *link_info;
 658	__u32 link_info_len;
 659};
 660#define bpf_iter_attach_opts__last_field link_info_len
 661
 662LIBBPF_API struct bpf_link *
 663bpf_program__attach_iter(const struct bpf_program *prog,
 664			 const struct bpf_iter_attach_opts *opts);
 665
 666LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
 667
 668/**
 669 * @brief **bpf_program__set_type()** sets the program
 670 * type of the passed BPF program.
 671 * @param prog BPF program to set the program type for
 672 * @param type program type to set the BPF map to have
 673 * @return error code; or 0 if no error. An error occurs
 674 * if the object is already loaded.
 675 *
 676 * This must be called before the BPF object is loaded,
 677 * otherwise it has no effect and an error is returned.
 678 */
 679LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
 680				     enum bpf_prog_type type);
 681
 682LIBBPF_API enum bpf_attach_type
 683bpf_program__expected_attach_type(const struct bpf_program *prog);
 684
 685/**
 686 * @brief **bpf_program__set_expected_attach_type()** sets the
 687 * attach type of the passed BPF program. This is used for
 688 * auto-detection of attachment when programs are loaded.
 689 * @param prog BPF program to set the attach type for
 690 * @param type attach type to set the BPF map to have
 691 * @return error code; or 0 if no error. An error occurs
 692 * if the object is already loaded.
 693 *
 694 * This must be called before the BPF object is loaded,
 695 * otherwise it has no effect and an error is returned.
 696 */
 697LIBBPF_API int
 698bpf_program__set_expected_attach_type(struct bpf_program *prog,
 699				      enum bpf_attach_type type);
 700
 701LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
 702LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
 703
 704/* Per-program log level and log buffer getters/setters.
 705 * See bpf_object_open_opts comments regarding log_level and log_buf
 706 * interactions.
 707 */
 708LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
 709LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
 710LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
 711LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
 712
 713/**
 714 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
 715 * for supported BPF program types:
 716 *   - BTF-aware raw tracepoints (tp_btf);
 717 *   - fentry/fexit/fmod_ret;
 718 *   - lsm;
 719 *   - freplace.
 720 * @param prog BPF program to set the attach type for
 721 * @param type attach type to set the BPF map to have
 722 * @return error code; or 0 if no error occurred.
 723 */
 724LIBBPF_API int
 725bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
 726			       const char *attach_func_name);
 727
 728/**
 729 * @brief **bpf_object__find_map_by_name()** returns BPF map of
 730 * the given name, if it exists within the passed BPF object
 731 * @param obj BPF object
 732 * @param name name of the BPF map
 733 * @return BPF map instance, if such map exists within the BPF object;
 734 * or NULL otherwise.
 735 */
 736LIBBPF_API struct bpf_map *
 737bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
 738
 739LIBBPF_API int
 740bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
 741
 742LIBBPF_API struct bpf_map *
 743bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
 744
 745#define bpf_object__for_each_map(pos, obj)		\
 746	for ((pos) = bpf_object__next_map((obj), NULL);	\
 747	     (pos) != NULL;				\
 748	     (pos) = bpf_object__next_map((obj), (pos)))
 749#define bpf_map__for_each bpf_object__for_each_map
 750
 751LIBBPF_API struct bpf_map *
 752bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
 753
 754/**
 755 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
 756 * BPF map during BPF object load phase.
 757 * @param map the BPF map instance
 758 * @param autocreate whether to create BPF map during BPF object load
 759 * @return 0 on success; -EBUSY if BPF object was already loaded
 760 *
 761 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
 762 * BPF map. By default, libbpf will attempt to create every single BPF map
 763 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
 764 * and fill in map FD in BPF instructions.
 765 *
 766 * This API allows to opt-out of this process for specific map instance. This
 767 * can be useful if host kernel doesn't support such BPF map type or used
 768 * combination of flags and user application wants to avoid creating such
 769 * a map in the first place. User is still responsible to make sure that their
 770 * BPF-side code that expects to use such missing BPF map is recognized by BPF
 771 * verifier as dead code, otherwise BPF verifier will reject such BPF program.
 772 */
 773LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
 774LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
 775
 776/**
 777 * @brief **bpf_map__fd()** gets the file descriptor of the passed
 778 * BPF map
 779 * @param map the BPF map instance
 780 * @return the file descriptor; or -EINVAL in case of an error
 781 */
 782LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
 783LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 784/* get map name */
 785LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
 786/* get/set map type */
 787LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
 788LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
 789/* get/set map size (max_entries) */
 790LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
 791LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
 792/* get/set map flags */
 793LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
 794LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
 795/* get/set map NUMA node */
 796LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
 797LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
 798/* get/set map key size */
 799LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
 800LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
 801/* get/set map value size */
 802LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
 803LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
 804/* get map key/value BTF type IDs */
 805LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
 806LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
 807/* get/set map if_index */
 808LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
 809LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
 810/* get/set map map_extra flags */
 811LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
 812LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
 813
 814LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
 815					  const void *data, size_t size);
 816LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
 817
 818/**
 819 * @brief **bpf_map__is_internal()** tells the caller whether or not the
 820 * passed map is a special map created by libbpf automatically for things like
 821 * global variables, __ksym externs, Kconfig values, etc
 822 * @param map the bpf_map
 823 * @return true, if the map is an internal map; false, otherwise
 824 */
 825LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 826LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
 827LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
 828LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
 829LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
 830LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 831
 832LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 833LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
 834
 835/**
 836 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
 837 * corresponding to provided key.
 838 * @param map BPF map to lookup element in
 839 * @param key pointer to memory containing bytes of the key used for lookup
 840 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
 841 * @param value pointer to memory in which looked up value will be stored
 842 * @param value_sz size in byte of value data memory; it has to match BPF map
 843 * definition's **value_size**. For per-CPU BPF maps value size has to be
 844 * a product of BPF map value size and number of possible CPUs in the system
 845 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
 846 * per-CPU values value size has to be aligned up to closest 8 bytes for
 847 * alignment reasons, so expected size is: `round_up(value_size, 8)
 848 * * libbpf_num_possible_cpus()`.
 849 * @flags extra flags passed to kernel for this operation
 850 * @return 0, on success; negative error, otherwise
 851 *
 852 * **bpf_map__lookup_elem()** is high-level equivalent of
 853 * **bpf_map_lookup_elem()** API with added check for key and value size.
 854 */
 855LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
 856				    const void *key, size_t key_sz,
 857				    void *value, size_t value_sz, __u64 flags);
 858
 859/**
 860 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
 861 * map that corresponds to provided key.
 862 * @param map BPF map to insert to or update element in
 863 * @param key pointer to memory containing bytes of the key
 864 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
 865 * @param value pointer to memory containing bytes of the value
 866 * @param value_sz size in byte of value data memory; it has to match BPF map
 867 * definition's **value_size**. For per-CPU BPF maps value size has to be
 868 * a product of BPF map value size and number of possible CPUs in the system
 869 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
 870 * per-CPU values value size has to be aligned up to closest 8 bytes for
 871 * alignment reasons, so expected size is: `round_up(value_size, 8)
 872 * * libbpf_num_possible_cpus()`.
 873 * @flags extra flags passed to kernel for this operation
 874 * @return 0, on success; negative error, otherwise
 875 *
 876 * **bpf_map__update_elem()** is high-level equivalent of
 877 * **bpf_map_update_elem()** API with added check for key and value size.
 878 */
 879LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
 880				    const void *key, size_t key_sz,
 881				    const void *value, size_t value_sz, __u64 flags);
 882
 883/**
 884 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
 885 * corresponds to provided key.
 886 * @param map BPF map to delete element from
 887 * @param key pointer to memory containing bytes of the key
 888 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
 889 * @flags extra flags passed to kernel for this operation
 890 * @return 0, on success; negative error, otherwise
 891 *
 892 * **bpf_map__delete_elem()** is high-level equivalent of
 893 * **bpf_map_delete_elem()** API with added check for key size.
 894 */
 895LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
 896				    const void *key, size_t key_sz, __u64 flags);
 897
 898/**
 899 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
 900 * corresponding to provided key and atomically delete it afterwards.
 901 * @param map BPF map to lookup element in
 902 * @param key pointer to memory containing bytes of the key used for lookup
 903 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
 904 * @param value pointer to memory in which looked up value will be stored
 905 * @param value_sz size in byte of value data memory; it has to match BPF map
 906 * definition's **value_size**. For per-CPU BPF maps value size has to be
 907 * a product of BPF map value size and number of possible CPUs in the system
 908 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
 909 * per-CPU values value size has to be aligned up to closest 8 bytes for
 910 * alignment reasons, so expected size is: `round_up(value_size, 8)
 911 * * libbpf_num_possible_cpus()`.
 912 * @flags extra flags passed to kernel for this operation
 913 * @return 0, on success; negative error, otherwise
 914 *
 915 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
 916 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
 917 */
 918LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
 919					       const void *key, size_t key_sz,
 920					       void *value, size_t value_sz, __u64 flags);
 921
 922/**
 923 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
 924 * fetching next key that follows current key.
 925 * @param map BPF map to fetch next key from
 926 * @param cur_key pointer to memory containing bytes of current key or NULL to
 927 * fetch the first key
 928 * @param next_key pointer to memory to write next key into
 929 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
 930 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
 931 * negative error, otherwise
 932 *
 933 * **bpf_map__get_next_key()** is high-level equivalent of
 934 * **bpf_map_get_next_key()** API with added check for key size.
 935 */
 936LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
 937				     const void *cur_key, void *next_key, size_t key_sz);
 938
 939struct bpf_xdp_set_link_opts {
 940	size_t sz;
 941	int old_fd;
 942	size_t :0;
 943};
 944#define bpf_xdp_set_link_opts__last_field old_fd
 945
 946struct bpf_xdp_attach_opts {
 947	size_t sz;
 948	int old_prog_fd;
 949	size_t :0;
 950};
 951#define bpf_xdp_attach_opts__last_field old_prog_fd
 952
 953struct bpf_xdp_query_opts {
 954	size_t sz;
 955	__u32 prog_id;		/* output */
 956	__u32 drv_prog_id;	/* output */
 957	__u32 hw_prog_id;	/* output */
 958	__u32 skb_prog_id;	/* output */
 959	__u8 attach_mode;	/* output */
 960	size_t :0;
 961};
 962#define bpf_xdp_query_opts__last_field attach_mode
 963
 964LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
 965			      const struct bpf_xdp_attach_opts *opts);
 966LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
 967			      const struct bpf_xdp_attach_opts *opts);
 968LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
 969LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
 970
 971/* TC related API */
 972enum bpf_tc_attach_point {
 973	BPF_TC_INGRESS = 1 << 0,
 974	BPF_TC_EGRESS  = 1 << 1,
 975	BPF_TC_CUSTOM  = 1 << 2,
 976};
 977
 978#define BPF_TC_PARENT(a, b) 	\
 979	((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
 980
 981enum bpf_tc_flags {
 982	BPF_TC_F_REPLACE = 1 << 0,
 983};
 984
 985struct bpf_tc_hook {
 986	size_t sz;
 987	int ifindex;
 988	enum bpf_tc_attach_point attach_point;
 989	__u32 parent;
 990	size_t :0;
 991};
 992#define bpf_tc_hook__last_field parent
 993
 994struct bpf_tc_opts {
 995	size_t sz;
 996	int prog_fd;
 997	__u32 flags;
 998	__u32 prog_id;
 999	__u32 handle;
1000	__u32 priority;
1001	size_t :0;
1002};
1003#define bpf_tc_opts__last_field priority
1004
1005LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1006LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1007LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1008			     struct bpf_tc_opts *opts);
1009LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1010			     const struct bpf_tc_opts *opts);
1011LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1012			    struct bpf_tc_opts *opts);
1013
1014/* Ring buffer APIs */
1015struct ring_buffer;
1016struct user_ring_buffer;
1017
1018typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1019
1020struct ring_buffer_opts {
1021	size_t sz; /* size of this struct, for forward/backward compatiblity */
1022};
1023
1024#define ring_buffer_opts__last_field sz
1025
1026LIBBPF_API struct ring_buffer *
1027ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1028		 const struct ring_buffer_opts *opts);
1029LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1030LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1031				ring_buffer_sample_fn sample_cb, void *ctx);
1032LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1033LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1034LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1035
1036struct user_ring_buffer_opts {
1037	size_t sz; /* size of this struct, for forward/backward compatibility */
1038};
1039
1040#define user_ring_buffer_opts__last_field sz
1041
1042/* @brief **user_ring_buffer__new()** creates a new instance of a user ring
1043 * buffer.
1044 *
1045 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1046 * @param opts Options for how the ring buffer should be created.
1047 * @return A user ring buffer on success; NULL and errno being set on a
1048 * failure.
1049 */
1050LIBBPF_API struct user_ring_buffer *
1051user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1052
1053/* @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1054 * user ring buffer.
1055 * @param rb A pointer to a user ring buffer.
1056 * @param size The size of the sample, in bytes.
1057 * @return A pointer to an 8-byte aligned reserved region of the user ring
1058 * buffer; NULL, and errno being set if a sample could not be reserved.
1059 *
1060 * This function is *not* thread safe, and callers must synchronize accessing
1061 * this function if there are multiple producers.  If a size is requested that
1062 * is larger than the size of the entire ring buffer, errno will be set to
1063 * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1064 * but currently does not have enough space, errno is set to ENOSPC and NULL is
1065 * returned.
1066 *
1067 * After initializing the sample, callers must invoke
1068 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1069 * the sample must be freed with **user_ring_buffer__discard()**.
1070 */
1071LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1072
1073/* @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1074 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1075 * available.
1076 * @param rb The user ring buffer.
1077 * @param size The size of the sample, in bytes.
1078 * @param timeout_ms The amount of time, in milliseconds, for which the caller
1079 * should block when waiting for a sample. -1 causes the caller to block
1080 * indefinitely.
1081 * @return A pointer to an 8-byte aligned reserved region of the user ring
1082 * buffer; NULL, and errno being set if a sample could not be reserved.
1083 *
1084 * This function is *not* thread safe, and callers must synchronize
1085 * accessing this function if there are multiple producers
1086 *
1087 * If **timeout_ms** is -1, the function will block indefinitely until a sample
1088 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1089 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1090 * will occur and the function will return immediately after attempting to
1091 * reserve a sample.
1092 *
1093 * If **size** is larger than the size of the entire ring buffer, errno is set
1094 * to E2BIG and NULL is returned. If the ring buffer could accommodate
1095 * **size**, but currently does not have enough space, the caller will block
1096 * until at most **timeout_ms** has elapsed. If insufficient space is available
1097 * at that time, errno is set to ENOSPC, and NULL is returned.
1098 *
1099 * The kernel guarantees that it will wake up this thread to check if
1100 * sufficient space is available in the ring buffer at least once per
1101 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1102 * least one sample is consumed, and the BPF program did not invoke the
1103 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1104 * kernel does not guarantee this. If the helper function is invoked with
1105 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1106 * consumed.
1107 *
1108 * When a sample of size **size** is found within **timeout_ms**, a pointer to
1109 * the sample is returned. After initializing the sample, callers must invoke
1110 * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1111 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1112 */
1113LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1114						    __u32 size,
1115						    int timeout_ms);
1116
1117/* @brief **user_ring_buffer__submit()** submits a previously reserved sample
1118 * into the ring buffer.
1119 * @param rb The user ring buffer.
1120 * @param sample A reserved sample.
1121 *
1122 * It is not necessary to synchronize amongst multiple producers when invoking
1123 * this function.
1124 */
1125LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1126
1127/* @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1128 * @param rb The user ring buffer.
1129 * @param sample A reserved sample.
1130 *
1131 * It is not necessary to synchronize amongst multiple producers when invoking
1132 * this function.
1133 */
1134LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1135
1136/* @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1137 * created with **user_ring_buffer__new()**.
1138 * @param rb The user ring buffer being freed.
1139 */
1140LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1141
1142/* Perf buffer APIs */
1143struct perf_buffer;
1144
1145typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1146				      void *data, __u32 size);
1147typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1148
1149/* common use perf buffer options */
1150struct perf_buffer_opts {
1151	size_t sz;
1152};
1153#define perf_buffer_opts__last_field sz
1154
1155/**
1156 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1157 * BPF_PERF_EVENT_ARRAY map
1158 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1159 * code to send data over to user-space
1160 * @param page_cnt number of memory pages allocated for each per-CPU buffer
1161 * @param sample_cb function called on each received data record
1162 * @param lost_cb function called when record loss has occurred
1163 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1164 * @return a new instance of struct perf_buffer on success, NULL on error with
1165 * *errno* containing an error code
1166 */
1167LIBBPF_API struct perf_buffer *
1168perf_buffer__new(int map_fd, size_t page_cnt,
1169		 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1170		 const struct perf_buffer_opts *opts);
1171
1172enum bpf_perf_event_ret {
1173	LIBBPF_PERF_EVENT_DONE	= 0,
1174	LIBBPF_PERF_EVENT_ERROR	= -1,
1175	LIBBPF_PERF_EVENT_CONT	= -2,
1176};
1177
1178struct perf_event_header;
1179
1180typedef enum bpf_perf_event_ret
1181(*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1182
1183/* raw perf buffer options, giving most power and control */
1184struct perf_buffer_raw_opts {
1185	size_t sz;
1186	long :0;
1187	long :0;
1188	/* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1189	 * max_entries of given PERF_EVENT_ARRAY map)
1190	 */
1191	int cpu_cnt;
1192	/* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1193	int *cpus;
1194	/* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1195	int *map_keys;
1196};
1197#define perf_buffer_raw_opts__last_field map_keys
1198
1199struct perf_event_attr;
1200
1201LIBBPF_API struct perf_buffer *
1202perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1203		     perf_buffer_event_fn event_cb, void *ctx,
1204		     const struct perf_buffer_raw_opts *opts);
1205
1206LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1207LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1208LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1209LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1210LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1211LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1212LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1213/**
1214 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1215 * memory region of the ring buffer.
1216 * This ring buffer can be used to implement a custom events consumer.
1217 * The ring buffer starts with the *struct perf_event_mmap_page*, which
1218 * holds the ring buffer managment fields, when accessing the header
1219 * structure it's important to be SMP aware.
1220 * You can refer to *perf_event_read_simple* for a simple example.
1221 * @param pb the perf buffer structure
1222 * @param buf_idx the buffer index to retreive
1223 * @param buf (out) gets the base pointer of the mmap()'ed memory
1224 * @param buf_size (out) gets the size of the mmap()'ed region
1225 * @return 0 on success, negative error code for failure
1226 */
1227LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1228				   size_t *buf_size);
1229
1230struct bpf_prog_linfo;
1231struct bpf_prog_info;
1232
1233LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1234LIBBPF_API struct bpf_prog_linfo *
1235bpf_prog_linfo__new(const struct bpf_prog_info *info);
1236LIBBPF_API const struct bpf_line_info *
1237bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1238				__u64 addr, __u32 func_idx, __u32 nr_skip);
1239LIBBPF_API const struct bpf_line_info *
1240bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1241		      __u32 insn_off, __u32 nr_skip);
1242
1243/*
1244 * Probe for supported system features
1245 *
1246 * Note that running many of these probes in a short amount of time can cause
1247 * the kernel to reach the maximal size of lockable memory allowed for the
1248 * user, causing subsequent probes to fail. In this case, the caller may want
1249 * to adjust that limit with setrlimit().
1250 */
1251
1252/**
1253 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1254 * BPF programs of a given type.
1255 * @param prog_type BPF program type to detect kernel support for
1256 * @param opts reserved for future extensibility, should be NULL
1257 * @return 1, if given program type is supported; 0, if given program type is
1258 * not supported; negative error code if feature detection failed or can't be
1259 * performed
1260 *
1261 * Make sure the process has required set of CAP_* permissions (or runs as
1262 * root) when performing feature checking.
1263 */
1264LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1265/**
1266 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1267 * BPF maps of a given type.
1268 * @param map_type BPF map type to detect kernel support for
1269 * @param opts reserved for future extensibility, should be NULL
1270 * @return 1, if given map type is supported; 0, if given map type is
1271 * not supported; negative error code if feature detection failed or can't be
1272 * performed
1273 *
1274 * Make sure the process has required set of CAP_* permissions (or runs as
1275 * root) when performing feature checking.
1276 */
1277LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1278/**
1279 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1280 * use of a given BPF helper from specified BPF program type.
1281 * @param prog_type BPF program type used to check the support of BPF helper
1282 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1283 * @param opts reserved for future extensibility, should be NULL
1284 * @return 1, if given combination of program type and helper is supported; 0,
1285 * if the combination is not supported; negative error code if feature
1286 * detection for provided input arguments failed or can't be performed
1287 *
1288 * Make sure the process has required set of CAP_* permissions (or runs as
1289 * root) when performing feature checking.
1290 */
1291LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1292				       enum bpf_func_id helper_id, const void *opts);
1293
1294/**
1295 * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1296 * number of possible CPUs that the host kernel supports and expects.
1297 * @return number of possible CPUs; or error code on failure
1298 *
1299 * Example usage:
1300 *
1301 *     int ncpus = libbpf_num_possible_cpus();
1302 *     if (ncpus < 0) {
1303 *          // error handling
1304 *     }
1305 *     long values[ncpus];
1306 *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1307 */
1308LIBBPF_API int libbpf_num_possible_cpus(void);
1309
1310struct bpf_map_skeleton {
1311	const char *name;
1312	struct bpf_map **map;
1313	void **mmaped;
1314};
1315
1316struct bpf_prog_skeleton {
1317	const char *name;
1318	struct bpf_program **prog;
1319	struct bpf_link **link;
1320};
1321
1322struct bpf_object_skeleton {
1323	size_t sz; /* size of this struct, for forward/backward compatibility */
1324
1325	const char *name;
1326	const void *data;
1327	size_t data_sz;
1328
1329	struct bpf_object **obj;
1330
1331	int map_cnt;
1332	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1333	struct bpf_map_skeleton *maps;
1334
1335	int prog_cnt;
1336	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1337	struct bpf_prog_skeleton *progs;
1338};
1339
1340LIBBPF_API int
1341bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1342			  const struct bpf_object_open_opts *opts);
1343LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1344LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1345LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1346LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1347
1348struct bpf_var_skeleton {
1349	const char *name;
1350	struct bpf_map **map;
1351	void **addr;
1352};
1353
1354struct bpf_object_subskeleton {
1355	size_t sz; /* size of this struct, for forward/backward compatibility */
1356
1357	const struct bpf_object *obj;
 
 
 
1358
1359	int map_cnt;
1360	int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1361	struct bpf_map_skeleton *maps;
1362
1363	int prog_cnt;
1364	int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1365	struct bpf_prog_skeleton *progs;
1366
1367	int var_cnt;
1368	int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1369	struct bpf_var_skeleton *vars;
1370};
1371
1372LIBBPF_API int
1373bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1374LIBBPF_API void
1375bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1376
1377struct gen_loader_opts {
1378	size_t sz; /* size of this struct, for forward/backward compatiblity */
1379	const char *data;
1380	const char *insns;
1381	__u32 data_sz;
1382	__u32 insns_sz;
1383};
 
 
 
1384
1385#define gen_loader_opts__last_field insns_sz
1386LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1387				      struct gen_loader_opts *opts);
1388
1389enum libbpf_tristate {
1390	TRI_NO = 0,
1391	TRI_YES = 1,
1392	TRI_MODULE = 2,
1393};
1394
1395struct bpf_linker_opts {
1396	/* size of this struct, for forward/backward compatiblity */
1397	size_t sz;
1398};
1399#define bpf_linker_opts__last_field sz
1400
1401struct bpf_linker_file_opts {
1402	/* size of this struct, for forward/backward compatiblity */
1403	size_t sz;
 
 
 
 
 
 
 
 
1404};
1405#define bpf_linker_file_opts__last_field sz
1406
1407struct bpf_linker;
1408
1409LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1410LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1411				    const char *filename,
1412				    const struct bpf_linker_file_opts *opts);
1413LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1414LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1415
1416/*
1417 * Custom handling of BPF program's SEC() definitions
1418 */
1419
1420struct bpf_prog_load_opts; /* defined in bpf.h */
1421
1422/* Called during bpf_object__open() for each recognized BPF program. Callback
1423 * can use various bpf_program__set_*() setters to adjust whatever properties
1424 * are necessary.
1425 */
1426typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1427
1428/* Called right before libbpf performs bpf_prog_load() to load BPF program
1429 * into the kernel. Callback can adjust opts as necessary.
1430 */
1431typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1432					     struct bpf_prog_load_opts *opts, long cookie);
1433
1434/* Called during skeleton attach or through bpf_program__attach(). If
1435 * auto-attach is not supported, callback should return 0 and set link to
1436 * NULL (it's not considered an error during skeleton attach, but it will be
1437 * an error for bpf_program__attach() calls). On error, error should be
1438 * returned directly and link set to NULL. On success, return 0 and set link
1439 * to a valid struct bpf_link.
1440 */
1441typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1442				       struct bpf_link **link);
1443
1444struct libbpf_prog_handler_opts {
1445	/* size of this struct, for forward/backward compatiblity */
1446	size_t sz;
1447	/* User-provided value that is passed to prog_setup_fn,
1448	 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1449	 * register one set of callbacks for multiple SEC() definitions and
1450	 * still be able to distinguish them, if necessary. For example,
1451	 * libbpf itself is using this to pass necessary flags (e.g.,
1452	 * sleepable flag) to a common internal SEC() handler.
1453	 */
1454	long cookie;
1455	/* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1456	 * Callback is optional, pass NULL if it's not necessary.
1457	 */
1458	libbpf_prog_setup_fn_t prog_setup_fn;
1459	/* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1460	 * Callback is optional, pass NULL if it's not necessary.
1461	 */
1462	libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1463	/* BPF program attach callback (see libbpf_prog_attach_fn_t).
1464	 * Callback is optional, pass NULL if it's not necessary.
1465	 */
1466	libbpf_prog_attach_fn_t prog_attach_fn;
1467};
1468#define libbpf_prog_handler_opts__last_field prog_attach_fn
1469
1470/**
1471 * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1472 * SEC() handler.
1473 * @param sec section prefix for which custom handler is registered
1474 * @param prog_type BPF program type associated with specified section
1475 * @param exp_attach_type Expected BPF attach type associated with specified section
1476 * @param opts optional cookie, callbacks, and other extra options
1477 * @return Non-negative handler ID is returned on success. This handler ID has
1478 * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1479 * custom handler. Negative error code is returned on error.
1480 *
1481 * *sec* defines which SEC() definitions are handled by this custom handler
1482 * registration. *sec* can have few different forms:
1483 *   - if *sec* is just a plain string (e.g., "abc"), it will match only
1484 *   SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1485 *   in an error;
1486 *   - if *sec* is of the form "abc/", proper SEC() form is
1487 *   SEC("abc/something"), where acceptable "something" should be checked by
1488 *   *prog_init_fn* callback, if there are additional restrictions;
1489 *   - if *sec* is of the form "abc+", it will successfully match both
1490 *   SEC("abc") and SEC("abc/whatever") forms;
1491 *   - if *sec* is NULL, custom handler is registered for any BPF program that
1492 *   doesn't match any of the registered (custom or libbpf's own) SEC()
1493 *   handlers. There could be only one such generic custom handler registered
1494 *   at any given time.
1495 *
1496 * All custom handlers (except the one with *sec* == NULL) are processed
1497 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1498 * SEC() handlers by registering custom ones for the same section prefix
1499 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1500 * handler).
1501 *
1502 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1503 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1504 * to ensure synchronization if there is a risk of running this API from
1505 * multiple threads simultaneously.
1506 */
1507LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1508					    enum bpf_prog_type prog_type,
1509					    enum bpf_attach_type exp_attach_type,
1510					    const struct libbpf_prog_handler_opts *opts);
1511/**
1512 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1513 * custom BPF program SEC() handler.
1514 * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1515 * after successful registration
1516 * @return 0 on success, negative error code if handler isn't found
1517 *
1518 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1519 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1520 * to ensure synchronization if there is a risk of running this API from
1521 * multiple threads simultaneously.
1522 */
1523LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1524
1525#ifdef __cplusplus
1526} /* extern "C" */
1527#endif
1528
1529#endif /* __LIBBPF_LIBBPF_H */