1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
4 * Common eBPF ELF object loading operations.
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.
10 #ifndef __LIBBPF_LIBBPF_H
11 #define __LIBBPF_LIBBPF_H
17 #include <sys/types.h> // for size_t
18 #include <linux/bpf.h>
20 #include "libbpf_common.h"
21 #include "libbpf_legacy.h"
27 LIBBPF_API __u32 libbpf_major_version(void);
28 LIBBPF_API __u32 libbpf_minor_version(void);
29 LIBBPF_API const char *libbpf_version_string(void);
32 __LIBBPF_ERRNO__START = 4000,
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 */
52 LIBBPF_API int libbpf_strerror(int err, char *buf, size_t size);
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.
61 LIBBPF_API const char *libbpf_bpf_attach_type_str(enum bpf_attach_type t);
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.
70 LIBBPF_API const char *libbpf_bpf_link_type_str(enum bpf_link_type t);
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.
79 LIBBPF_API const char *libbpf_bpf_map_type_str(enum bpf_map_type t);
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.
88 LIBBPF_API const char *libbpf_bpf_prog_type_str(enum bpf_prog_type t);
90 enum libbpf_print_level {
96 typedef int (*libbpf_print_fn_t)(enum libbpf_print_level level,
97 const char *, va_list ap);
100 * @brief **libbpf_set_print()** sets user-provided log callback function to
101 * be used for libbpf warnings and informational messages.
102 * @param fn The log print function. If NULL, libbpf won't print anything.
103 * @return Pointer to old print function.
105 * This function is thread-safe.
107 LIBBPF_API libbpf_print_fn_t libbpf_set_print(libbpf_print_fn_t fn);
109 /* Hide internal to user */
112 struct bpf_object_open_opts {
113 /* size of this struct, for forward/backward compatibility */
115 /* object name override, if provided:
116 * - for object open from file, this will override setting object
117 * name from file path's base name;
118 * - for object open from memory buffer, this will specify an object
119 * name and will override default "<addr>-<buf-size>" name;
121 const char *object_name;
122 /* parse map definitions non-strictly, allowing extra attributes/data */
124 /* maps that set the 'pinning' attribute in their definition will have
125 * their pin_path attribute set to a file in this directory, and be
126 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
128 const char *pin_root_path;
130 __u32 :32; /* stub out now removed attach_prog_fd */
132 /* Additional kernel config content that augments and overrides
133 * system Kconfig for CONFIG_xxx externs.
136 /* Path to the custom BTF to be used for BPF CO-RE relocations.
137 * This custom BTF completely replaces the use of vmlinux BTF
138 * for the purpose of CO-RE relocations.
139 * NOTE: any other BPF feature (e.g., fentry/fexit programs,
140 * struct_ops, etc) will need actual kernel BTF at /sys/kernel/btf/vmlinux.
142 const char *btf_custom_path;
143 /* Pointer to a buffer for storing kernel logs for applicable BPF
144 * commands. Valid kernel_log_size has to be specified as well and are
145 * passed-through to bpf() syscall. Keep in mind that kernel might
146 * fail operation with -ENOSPC error if provided buffer is too small
147 * to contain entire log output.
148 * See the comment below for kernel_log_level for interaction between
149 * log_buf and log_level settings.
151 * If specified, this log buffer will be passed for:
152 * - each BPF progral load (BPF_PROG_LOAD) attempt, unless overriden
153 * with bpf_program__set_log() on per-program level, to get
154 * BPF verifier log output.
155 * - during BPF object's BTF load into kernel (BPF_BTF_LOAD) to get
156 * BTF sanity checking log.
158 * Each BPF command (BPF_BTF_LOAD or BPF_PROG_LOAD) will overwrite
159 * previous contents, so if you need more fine-grained control, set
160 * per-program buffer with bpf_program__set_log_buf() to preserve each
161 * individual program's verification log. Keep using kernel_log_buf
162 * for BTF verification log, if necessary.
164 char *kernel_log_buf;
165 size_t kernel_log_size;
167 * Log level can be set independently from log buffer. Log_level=0
168 * means that libbpf will attempt loading BTF or program without any
169 * logging requested, but will retry with either its own or custom log
170 * buffer, if provided, and log_level=1 on any error.
171 * And vice versa, setting log_level>0 will request BTF or prog
172 * loading with verbose log from the first attempt (and as such also
173 * for successfully loaded BTF or program), and the actual log buffer
174 * could be either libbpf's own auto-allocated log buffer, if
175 * kernel_log_buffer is NULL, or user-provided custom kernel_log_buf.
176 * If user didn't provide custom log buffer, libbpf will emit captured
177 * logs through its print callback.
179 __u32 kernel_log_level;
183 #define bpf_object_open_opts__last_field kernel_log_level
186 * @brief **bpf_object__open()** creates a bpf_object by opening
187 * the BPF ELF object file pointed to by the passed path and loading it
189 * @param path BPF object file path.
190 * @return pointer to the new bpf_object; or NULL is returned on error,
191 * error code is stored in errno
193 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
196 * @brief **bpf_object__open_file()** creates a bpf_object by opening
197 * the BPF ELF object file pointed to by the passed path and loading it
199 * @param path BPF object file path
200 * @param opts options for how to load the bpf object, this parameter is
201 * optional and can be set to NULL
202 * @return pointer to the new bpf_object; or NULL is returned on error,
203 * error code is stored in errno
205 LIBBPF_API struct bpf_object *
206 bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
209 * @brief **bpf_object__open_mem()** creates a bpf_object by reading
210 * the BPF objects raw bytes from a memory buffer containing a valid
211 * BPF ELF object file.
212 * @param obj_buf pointer to the buffer containing ELF file bytes
213 * @param obj_buf_sz number of bytes in the buffer
214 * @param opts options for how to load the bpf object
215 * @return pointer to the new bpf_object; or NULL is returned on error,
216 * error code is stored in errno
218 LIBBPF_API struct bpf_object *
219 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
220 const struct bpf_object_open_opts *opts);
223 * @brief **bpf_object__load()** loads BPF object into kernel.
224 * @param obj Pointer to a valid BPF object instance returned by
225 * **bpf_object__open*()** APIs
226 * @return 0, on success; negative error code, otherwise, error code is
229 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
232 * @brief **bpf_object__close()** closes a BPF object and releases all
234 * @param obj Pointer to a valid BPF object
236 LIBBPF_API void bpf_object__close(struct bpf_object *obj);
239 * @brief **bpf_object__pin_maps()** pins each map contained within
240 * the BPF object at the passed directory.
241 * @param obj Pointer to a valid BPF object
242 * @param path A directory where maps should be pinned.
243 * @return 0, on success; negative error code, otherwise
245 * If `path` is NULL `bpf_map__pin` (which is being used on each map)
246 * will use the pin_path attribute of each map. In this case, maps that
247 * don't have a pin_path set will be ignored.
249 LIBBPF_API int bpf_object__pin_maps(struct bpf_object *obj, const char *path);
252 * @brief **bpf_object__unpin_maps()** unpins each map contained within
253 * the BPF object found in the passed directory.
254 * @param obj Pointer to a valid BPF object
255 * @param path A directory where pinned maps should be searched for.
256 * @return 0, on success; negative error code, otherwise
258 * If `path` is NULL `bpf_map__unpin` (which is being used on each map)
259 * will use the pin_path attribute of each map. In this case, maps that
260 * don't have a pin_path set will be ignored.
262 LIBBPF_API int bpf_object__unpin_maps(struct bpf_object *obj,
264 LIBBPF_API int bpf_object__pin_programs(struct bpf_object *obj,
266 LIBBPF_API int bpf_object__unpin_programs(struct bpf_object *obj,
268 LIBBPF_API int bpf_object__pin(struct bpf_object *object, const char *path);
270 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
271 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
272 LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
275 LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj);
276 LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
278 LIBBPF_API struct bpf_program *
279 bpf_object__find_program_by_name(const struct bpf_object *obj,
283 libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
284 enum bpf_attach_type *expected_attach_type);
285 LIBBPF_API int libbpf_attach_type_by_name(const char *name,
286 enum bpf_attach_type *attach_type);
287 LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
288 enum bpf_attach_type attach_type);
290 /* Accessors of bpf_program */
293 LIBBPF_API struct bpf_program *
294 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
296 #define bpf_object__for_each_program(pos, obj) \
297 for ((pos) = bpf_object__next_program((obj), NULL); \
299 (pos) = bpf_object__next_program((obj), (pos)))
301 LIBBPF_API struct bpf_program *
302 bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
304 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
307 LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
308 LIBBPF_API const char *bpf_program__section_name(const struct bpf_program *prog);
309 LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
310 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
311 LIBBPF_API bool bpf_program__autoattach(const struct bpf_program *prog);
312 LIBBPF_API void bpf_program__set_autoattach(struct bpf_program *prog, bool autoattach);
317 * @brief **bpf_program__insns()** gives read-only access to BPF program's
318 * underlying BPF instructions.
319 * @param prog BPF program for which to return instructions
320 * @return a pointer to an array of BPF instructions that belong to the
321 * specified BPF program
323 * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
324 * pointed to can be fetched using **bpf_program__insn_cnt()** API.
326 * Keep in mind, libbpf can modify and append/delete BPF program's
327 * instructions as it processes BPF object file and prepares everything for
328 * uploading into the kernel. So depending on the point in BPF object
329 * lifetime, **bpf_program__insns()** can return different sets of
330 * instructions. As an example, during BPF object load phase BPF program
331 * instructions will be CO-RE-relocated, BPF subprograms instructions will be
332 * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
333 * returned before **bpf_object__load()** and after it might be quite
336 LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
339 * @brief **bpf_program__set_insns()** can set BPF program's underlying
342 * WARNING: This is a very advanced libbpf API and users need to know
343 * what they are doing. This should be used from prog_prepare_load_fn
346 * @param prog BPF program for which to return instructions
347 * @param new_insns a pointer to an array of BPF instructions
348 * @param new_insn_cnt number of `struct bpf_insn`'s that form
349 * specified BPF program
350 * @return 0, on success; negative error code, otherwise
352 LIBBPF_API int bpf_program__set_insns(struct bpf_program *prog,
353 struct bpf_insn *new_insns, size_t new_insn_cnt);
356 * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
357 * that form specified BPF program.
358 * @param prog BPF program for which to return number of BPF instructions
360 * See **bpf_program__insns()** documentation for notes on how libbpf can
361 * change instructions and their count during different phases of
362 * **bpf_object** lifetime.
364 LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
366 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
369 * @brief **bpf_program__pin()** pins the BPF program to a file
370 * in the BPF FS specified by a path. This increments the programs
371 * reference count, allowing it to stay loaded after the process
372 * which loaded it has exited.
374 * @param prog BPF program to pin, must already be loaded
375 * @param path file path in a BPF file system
376 * @return 0, on success; negative error code, otherwise
378 LIBBPF_API int bpf_program__pin(struct bpf_program *prog, const char *path);
381 * @brief **bpf_program__unpin()** unpins the BPF program from a file
382 * in the BPFFS specified by a path. This decrements the programs
385 * The file pinning the BPF program can also be unlinked by a different
386 * process in which case this function will return an error.
388 * @param prog BPF program to unpin
389 * @param path file path to the pin in a BPF file system
390 * @return 0, on success; negative error code, otherwise
392 LIBBPF_API int bpf_program__unpin(struct bpf_program *prog, const char *path);
393 LIBBPF_API void bpf_program__unload(struct bpf_program *prog);
397 LIBBPF_API struct bpf_link *bpf_link__open(const char *path);
398 LIBBPF_API int bpf_link__fd(const struct bpf_link *link);
399 LIBBPF_API const char *bpf_link__pin_path(const struct bpf_link *link);
401 * @brief **bpf_link__pin()** pins the BPF link to a file
402 * in the BPF FS specified by a path. This increments the links
403 * reference count, allowing it to stay loaded after the process
404 * which loaded it has exited.
406 * @param link BPF link to pin, must already be loaded
407 * @param path file path in a BPF file system
408 * @return 0, on success; negative error code, otherwise
411 LIBBPF_API int bpf_link__pin(struct bpf_link *link, const char *path);
414 * @brief **bpf_link__unpin()** unpins the BPF link from a file
415 * in the BPFFS specified by a path. This decrements the links
418 * The file pinning the BPF link can also be unlinked by a different
419 * process in which case this function will return an error.
421 * @param prog BPF program to unpin
422 * @param path file path to the pin in a BPF file system
423 * @return 0, on success; negative error code, otherwise
425 LIBBPF_API int bpf_link__unpin(struct bpf_link *link);
426 LIBBPF_API int bpf_link__update_program(struct bpf_link *link,
427 struct bpf_program *prog);
428 LIBBPF_API void bpf_link__disconnect(struct bpf_link *link);
429 LIBBPF_API int bpf_link__detach(struct bpf_link *link);
430 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
433 * @brief **bpf_program__attach()** is a generic function for attaching
434 * a BPF program based on auto-detection of program type, attach type,
435 * and extra paremeters, where applicable.
437 * @param prog BPF program to attach
438 * @return Reference to the newly created BPF link; or NULL is returned on error,
439 * error code is stored in errno
441 * This is supported for:
442 * - kprobe/kretprobe (depends on SEC() definition)
443 * - uprobe/uretprobe (depends on SEC() definition)
446 * - tracing programs (typed raw TP/fentry/fexit/fmod_ret)
448 LIBBPF_API struct bpf_link *
449 bpf_program__attach(const struct bpf_program *prog);
451 struct bpf_perf_event_opts {
452 /* size of this struct, for forward/backward compatibility */
454 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
456 /* don't use BPF link when attach BPF program */
457 bool force_ioctl_attach;
460 #define bpf_perf_event_opts__last_field force_ioctl_attach
462 LIBBPF_API struct bpf_link *
463 bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
465 LIBBPF_API struct bpf_link *
466 bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
467 const struct bpf_perf_event_opts *opts);
470 * enum probe_attach_mode - the mode to attach kprobe/uprobe
472 * force libbpf to attach kprobe/uprobe in specific mode, -ENOTSUP will
473 * be returned if it is not supported by the kernel.
475 enum probe_attach_mode {
476 /* attach probe in latest supported mode by kernel */
477 PROBE_ATTACH_MODE_DEFAULT = 0,
478 /* attach probe in legacy mode, using debugfs/tracefs */
479 PROBE_ATTACH_MODE_LEGACY,
480 /* create perf event with perf_event_open() syscall */
481 PROBE_ATTACH_MODE_PERF,
482 /* attach probe with BPF link */
483 PROBE_ATTACH_MODE_LINK,
486 struct bpf_kprobe_opts {
487 /* size of this struct, for forward/backward compatibility */
489 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
491 /* function's offset to install kprobe to */
493 /* kprobe is return probe */
495 /* kprobe attach mode */
496 enum probe_attach_mode attach_mode;
499 #define bpf_kprobe_opts__last_field attach_mode
501 LIBBPF_API struct bpf_link *
502 bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
503 const char *func_name);
504 LIBBPF_API struct bpf_link *
505 bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
506 const char *func_name,
507 const struct bpf_kprobe_opts *opts);
509 struct bpf_kprobe_multi_opts {
510 /* size of this struct, for forward/backward compatibility */
512 /* array of function symbols to attach */
514 /* array of function addresses to attach */
515 const unsigned long *addrs;
516 /* array of user-provided values fetchable through bpf_get_attach_cookie */
517 const __u64 *cookies;
518 /* number of elements in syms/addrs/cookies arrays */
520 /* create return kprobes */
525 #define bpf_kprobe_multi_opts__last_field retprobe
527 LIBBPF_API struct bpf_link *
528 bpf_program__attach_kprobe_multi_opts(const struct bpf_program *prog,
530 const struct bpf_kprobe_multi_opts *opts);
532 struct bpf_uprobe_multi_opts {
533 /* size of this struct, for forward/backward compatibility */
535 /* array of function symbols to attach to */
537 /* array of function addresses to attach to */
538 const unsigned long *offsets;
539 /* optional, array of associated ref counter offsets */
540 const unsigned long *ref_ctr_offsets;
541 /* optional, array of associated BPF cookies */
542 const __u64 *cookies;
543 /* number of elements in syms/addrs/cookies arrays */
545 /* create return uprobes */
550 #define bpf_uprobe_multi_opts__last_field retprobe
553 * @brief **bpf_program__attach_uprobe_multi()** attaches a BPF program
554 * to multiple uprobes with uprobe_multi link.
556 * User can specify 2 mutually exclusive set of inputs:
558 * 1) use only path/func_pattern/pid arguments
560 * 2) use path/pid with allowed combinations of
561 * syms/offsets/ref_ctr_offsets/cookies/cnt
563 * - syms and offsets are mutually exclusive
564 * - ref_ctr_offsets and cookies are optional
567 * @param prog BPF program to attach
568 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
569 * -1 for all processes
570 * @param binary_path Path to binary
571 * @param func_pattern Regular expression to specify functions to attach
573 * @param opts Additional options (see **struct bpf_uprobe_multi_opts**)
574 * @return 0, on success; negative error code, otherwise
576 LIBBPF_API struct bpf_link *
577 bpf_program__attach_uprobe_multi(const struct bpf_program *prog,
579 const char *binary_path,
580 const char *func_pattern,
581 const struct bpf_uprobe_multi_opts *opts);
583 struct bpf_ksyscall_opts {
584 /* size of this struct, for forward/backward compatibility */
586 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
588 /* attach as return probe? */
592 #define bpf_ksyscall_opts__last_field retprobe
595 * @brief **bpf_program__attach_ksyscall()** attaches a BPF program
596 * to kernel syscall handler of a specified syscall. Optionally it's possible
597 * to request to install retprobe that will be triggered at syscall exit. It's
598 * also possible to associate BPF cookie (though options).
600 * Libbpf automatically will determine correct full kernel function name,
601 * which depending on system architecture and kernel version/configuration
602 * could be of the form __<arch>_sys_<syscall> or __se_sys_<syscall>, and will
603 * attach specified program using kprobe/kretprobe mechanism.
605 * **bpf_program__attach_ksyscall()** is an API counterpart of declarative
606 * **SEC("ksyscall/<syscall>")** annotation of BPF programs.
608 * At the moment **SEC("ksyscall")** and **bpf_program__attach_ksyscall()** do
609 * not handle all the calling convention quirks for mmap(), clone() and compat
610 * syscalls. It also only attaches to "native" syscall interfaces. If host
611 * system supports compat syscalls or defines 32-bit syscalls in 64-bit
612 * kernel, such syscall interfaces won't be attached to by libbpf.
614 * These limitations may or may not change in the future. Therefore it is
615 * recommended to use SEC("kprobe") for these syscalls or if working with
616 * compat and 32-bit interfaces is required.
618 * @param prog BPF program to attach
619 * @param syscall_name Symbolic name of the syscall (e.g., "bpf")
620 * @param opts Additional options (see **struct bpf_ksyscall_opts**)
621 * @return Reference to the newly created BPF link; or NULL is returned on
622 * error, error code is stored in errno
624 LIBBPF_API struct bpf_link *
625 bpf_program__attach_ksyscall(const struct bpf_program *prog,
626 const char *syscall_name,
627 const struct bpf_ksyscall_opts *opts);
629 struct bpf_uprobe_opts {
630 /* size of this struct, for forward/backward compatibility */
632 /* offset of kernel reference counted USDT semaphore, added in
633 * a6ca88b241d5 ("trace_uprobe: support reference counter in fd-based uprobe")
635 size_t ref_ctr_offset;
636 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
638 /* uprobe is return probe, invoked at function return time */
640 /* Function name to attach to. Could be an unqualified ("abc") or library-qualified
641 * "abc@LIBXYZ" name. To specify function entry, func_name should be set while
642 * func_offset argument to bpf_prog__attach_uprobe_opts() should be 0. To trace an
643 * offset within a function, specify func_name and use func_offset argument to specify
644 * offset within the function. Shared library functions must specify the shared library
647 const char *func_name;
648 /* uprobe attach mode */
649 enum probe_attach_mode attach_mode;
652 #define bpf_uprobe_opts__last_field attach_mode
655 * @brief **bpf_program__attach_uprobe()** attaches a BPF program
656 * to the userspace function which is found by binary path and
657 * offset. You can optionally specify a particular proccess to attach
658 * to. You can also optionally attach the program to the function
659 * exit instead of entry.
661 * @param prog BPF program to attach
662 * @param retprobe Attach to function exit
663 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
664 * -1 for all processes
665 * @param binary_path Path to binary that contains the function symbol
666 * @param func_offset Offset within the binary of the function symbol
667 * @return Reference to the newly created BPF link; or NULL is returned on error,
668 * error code is stored in errno
670 LIBBPF_API struct bpf_link *
671 bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
672 pid_t pid, const char *binary_path,
676 * @brief **bpf_program__attach_uprobe_opts()** is just like
677 * bpf_program__attach_uprobe() except with a options struct
678 * for various configurations.
680 * @param prog BPF program to attach
681 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
682 * -1 for all processes
683 * @param binary_path Path to binary that contains the function symbol
684 * @param func_offset Offset within the binary of the function symbol
685 * @param opts Options for altering program attachment
686 * @return Reference to the newly created BPF link; or NULL is returned on error,
687 * error code is stored in errno
689 LIBBPF_API struct bpf_link *
690 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
691 const char *binary_path, size_t func_offset,
692 const struct bpf_uprobe_opts *opts);
694 struct bpf_usdt_opts {
695 /* size of this struct, for forward/backward compatibility */
697 /* custom user-provided value accessible through usdt_cookie() */
701 #define bpf_usdt_opts__last_field usdt_cookie
704 * @brief **bpf_program__attach_usdt()** is just like
705 * bpf_program__attach_uprobe_opts() except it covers USDT (User-space
706 * Statically Defined Tracepoint) attachment, instead of attaching to
707 * user-space function entry or exit.
709 * @param prog BPF program to attach
710 * @param pid Process ID to attach the uprobe to, 0 for self (own process),
711 * -1 for all processes
712 * @param binary_path Path to binary that contains provided USDT probe
713 * @param usdt_provider USDT provider name
714 * @param usdt_name USDT probe name
715 * @param opts Options for altering program attachment
716 * @return Reference to the newly created BPF link; or NULL is returned on error,
717 * error code is stored in errno
719 LIBBPF_API struct bpf_link *
720 bpf_program__attach_usdt(const struct bpf_program *prog,
721 pid_t pid, const char *binary_path,
722 const char *usdt_provider, const char *usdt_name,
723 const struct bpf_usdt_opts *opts);
725 struct bpf_tracepoint_opts {
726 /* size of this struct, for forward/backward compatibility */
728 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
731 #define bpf_tracepoint_opts__last_field bpf_cookie
733 LIBBPF_API struct bpf_link *
734 bpf_program__attach_tracepoint(const struct bpf_program *prog,
735 const char *tp_category,
736 const char *tp_name);
737 LIBBPF_API struct bpf_link *
738 bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
739 const char *tp_category,
741 const struct bpf_tracepoint_opts *opts);
743 LIBBPF_API struct bpf_link *
744 bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
745 const char *tp_name);
747 struct bpf_trace_opts {
748 /* size of this struct, for forward/backward compatibility */
750 /* custom user-provided value fetchable through bpf_get_attach_cookie() */
753 #define bpf_trace_opts__last_field cookie
755 LIBBPF_API struct bpf_link *
756 bpf_program__attach_trace(const struct bpf_program *prog);
757 LIBBPF_API struct bpf_link *
758 bpf_program__attach_trace_opts(const struct bpf_program *prog, const struct bpf_trace_opts *opts);
760 LIBBPF_API struct bpf_link *
761 bpf_program__attach_lsm(const struct bpf_program *prog);
762 LIBBPF_API struct bpf_link *
763 bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
764 LIBBPF_API struct bpf_link *
765 bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
766 LIBBPF_API struct bpf_link *
767 bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
768 LIBBPF_API struct bpf_link *
769 bpf_program__attach_freplace(const struct bpf_program *prog,
770 int target_fd, const char *attach_func_name);
772 struct bpf_netfilter_opts {
773 /* size of this struct, for forward/backward compatibility */
781 #define bpf_netfilter_opts__last_field flags
783 LIBBPF_API struct bpf_link *
784 bpf_program__attach_netfilter(const struct bpf_program *prog,
785 const struct bpf_netfilter_opts *opts);
787 struct bpf_tcx_opts {
788 /* size of this struct, for forward/backward compatibility */
793 __u64 expected_revision;
796 #define bpf_tcx_opts__last_field expected_revision
798 LIBBPF_API struct bpf_link *
799 bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
800 const struct bpf_tcx_opts *opts);
804 LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
805 LIBBPF_API int bpf_link__update_map(struct bpf_link *link, const struct bpf_map *map);
807 struct bpf_iter_attach_opts {
808 size_t sz; /* size of this struct for forward/backward compatibility */
809 union bpf_iter_link_info *link_info;
812 #define bpf_iter_attach_opts__last_field link_info_len
814 LIBBPF_API struct bpf_link *
815 bpf_program__attach_iter(const struct bpf_program *prog,
816 const struct bpf_iter_attach_opts *opts);
818 LIBBPF_API enum bpf_prog_type bpf_program__type(const struct bpf_program *prog);
821 * @brief **bpf_program__set_type()** sets the program
822 * type of the passed BPF program.
823 * @param prog BPF program to set the program type for
824 * @param type program type to set the BPF map to have
825 * @return error code; or 0 if no error. An error occurs
826 * if the object is already loaded.
828 * This must be called before the BPF object is loaded,
829 * otherwise it has no effect and an error is returned.
831 LIBBPF_API int bpf_program__set_type(struct bpf_program *prog,
832 enum bpf_prog_type type);
834 LIBBPF_API enum bpf_attach_type
835 bpf_program__expected_attach_type(const struct bpf_program *prog);
838 * @brief **bpf_program__set_expected_attach_type()** sets the
839 * attach type of the passed BPF program. This is used for
840 * auto-detection of attachment when programs are loaded.
841 * @param prog BPF program to set the attach type for
842 * @param type attach type to set the BPF map to have
843 * @return error code; or 0 if no error. An error occurs
844 * if the object is already loaded.
846 * This must be called before the BPF object is loaded,
847 * otherwise it has no effect and an error is returned.
850 bpf_program__set_expected_attach_type(struct bpf_program *prog,
851 enum bpf_attach_type type);
853 LIBBPF_API __u32 bpf_program__flags(const struct bpf_program *prog);
854 LIBBPF_API int bpf_program__set_flags(struct bpf_program *prog, __u32 flags);
856 /* Per-program log level and log buffer getters/setters.
857 * See bpf_object_open_opts comments regarding log_level and log_buf
860 LIBBPF_API __u32 bpf_program__log_level(const struct bpf_program *prog);
861 LIBBPF_API int bpf_program__set_log_level(struct bpf_program *prog, __u32 log_level);
862 LIBBPF_API const char *bpf_program__log_buf(const struct bpf_program *prog, size_t *log_size);
863 LIBBPF_API int bpf_program__set_log_buf(struct bpf_program *prog, char *log_buf, size_t log_size);
866 * @brief **bpf_program__set_attach_target()** sets BTF-based attach target
867 * for supported BPF program types:
868 * - BTF-aware raw tracepoints (tp_btf);
869 * - fentry/fexit/fmod_ret;
872 * @param prog BPF program to set the attach type for
873 * @param type attach type to set the BPF map to have
874 * @return error code; or 0 if no error occurred.
877 bpf_program__set_attach_target(struct bpf_program *prog, int attach_prog_fd,
878 const char *attach_func_name);
881 * @brief **bpf_object__find_map_by_name()** returns BPF map of
882 * the given name, if it exists within the passed BPF object
883 * @param obj BPF object
884 * @param name name of the BPF map
885 * @return BPF map instance, if such map exists within the BPF object;
888 LIBBPF_API struct bpf_map *
889 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
892 bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
894 LIBBPF_API struct bpf_map *
895 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
897 #define bpf_object__for_each_map(pos, obj) \
898 for ((pos) = bpf_object__next_map((obj), NULL); \
900 (pos) = bpf_object__next_map((obj), (pos)))
901 #define bpf_map__for_each bpf_object__for_each_map
903 LIBBPF_API struct bpf_map *
904 bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
907 * @brief **bpf_map__set_autocreate()** sets whether libbpf has to auto-create
908 * BPF map during BPF object load phase.
909 * @param map the BPF map instance
910 * @param autocreate whether to create BPF map during BPF object load
911 * @return 0 on success; -EBUSY if BPF object was already loaded
913 * **bpf_map__set_autocreate()** allows to opt-out from libbpf auto-creating
914 * BPF map. By default, libbpf will attempt to create every single BPF map
915 * defined in BPF object file using BPF_MAP_CREATE command of bpf() syscall
916 * and fill in map FD in BPF instructions.
918 * This API allows to opt-out of this process for specific map instance. This
919 * can be useful if host kernel doesn't support such BPF map type or used
920 * combination of flags and user application wants to avoid creating such
921 * a map in the first place. User is still responsible to make sure that their
922 * BPF-side code that expects to use such missing BPF map is recognized by BPF
923 * verifier as dead code, otherwise BPF verifier will reject such BPF program.
925 LIBBPF_API int bpf_map__set_autocreate(struct bpf_map *map, bool autocreate);
926 LIBBPF_API bool bpf_map__autocreate(const struct bpf_map *map);
929 * @brief **bpf_map__fd()** gets the file descriptor of the passed
931 * @param map the BPF map instance
932 * @return the file descriptor; or -EINVAL in case of an error
934 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
935 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
937 LIBBPF_API const char *bpf_map__name(const struct bpf_map *map);
938 /* get/set map type */
939 LIBBPF_API enum bpf_map_type bpf_map__type(const struct bpf_map *map);
940 LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
941 /* get/set map size (max_entries) */
942 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
943 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
944 /* get/set map flags */
945 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);
946 LIBBPF_API int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags);
947 /* get/set map NUMA node */
948 LIBBPF_API __u32 bpf_map__numa_node(const struct bpf_map *map);
949 LIBBPF_API int bpf_map__set_numa_node(struct bpf_map *map, __u32 numa_node);
950 /* get/set map key size */
951 LIBBPF_API __u32 bpf_map__key_size(const struct bpf_map *map);
952 LIBBPF_API int bpf_map__set_key_size(struct bpf_map *map, __u32 size);
953 /* get map value size */
954 LIBBPF_API __u32 bpf_map__value_size(const struct bpf_map *map);
956 * @brief **bpf_map__set_value_size()** sets map value size.
957 * @param map the BPF map instance
958 * @return 0, on success; negative error, otherwise
960 * There is a special case for maps with associated memory-mapped regions, like
961 * the global data section maps (bss, data, rodata). When this function is used
962 * on such a map, the mapped region is resized. Afterward, an attempt is made to
963 * adjust the corresponding BTF info. This attempt is best-effort and can only
964 * succeed if the last variable of the data section map is an array. The array
965 * BTF type is replaced by a new BTF array type with a different length.
966 * Any previously existing pointers returned from bpf_map__initial_value() or
967 * corresponding data section skeleton pointer must be reinitialized.
969 LIBBPF_API int bpf_map__set_value_size(struct bpf_map *map, __u32 size);
970 /* get map key/value BTF type IDs */
971 LIBBPF_API __u32 bpf_map__btf_key_type_id(const struct bpf_map *map);
972 LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
973 /* get/set map if_index */
974 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
975 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
976 /* get/set map map_extra flags */
977 LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
978 LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
980 LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
981 const void *data, size_t size);
982 LIBBPF_API void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
985 * @brief **bpf_map__is_internal()** tells the caller whether or not the
986 * passed map is a special map created by libbpf automatically for things like
987 * global variables, __ksym externs, Kconfig values, etc
988 * @param map the bpf_map
989 * @return true, if the map is an internal map; false, otherwise
991 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
994 * @brief **bpf_map__set_pin_path()** sets the path attribute that tells where the
995 * BPF map should be pinned. This does not actually create the 'pin'.
996 * @param map The bpf_map
997 * @param path The path
998 * @return 0, on success; negative error, otherwise
1000 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
1003 * @brief **bpf_map__pin_path()** gets the path attribute that tells where the
1004 * BPF map should be pinned.
1005 * @param map The bpf_map
1006 * @return The path string; which can be NULL
1008 LIBBPF_API const char *bpf_map__pin_path(const struct bpf_map *map);
1011 * @brief **bpf_map__is_pinned()** tells the caller whether or not the
1012 * passed map has been pinned via a 'pin' file.
1013 * @param map The bpf_map
1014 * @return true, if the map is pinned; false, otherwise
1016 LIBBPF_API bool bpf_map__is_pinned(const struct bpf_map *map);
1019 * @brief **bpf_map__pin()** creates a file that serves as a 'pin'
1020 * for the BPF map. This increments the reference count on the
1021 * BPF map which will keep the BPF map loaded even after the
1022 * userspace process which loaded it has exited.
1023 * @param map The bpf_map to pin
1024 * @param path A file path for the 'pin'
1025 * @return 0, on success; negative error, otherwise
1027 * If `path` is NULL the maps `pin_path` attribute will be used. If this is
1028 * also NULL, an error will be returned and the map will not be pinned.
1030 LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);
1033 * @brief **bpf_map__unpin()** removes the file that serves as a
1034 * 'pin' for the BPF map.
1035 * @param map The bpf_map to unpin
1036 * @param path A file path for the 'pin'
1037 * @return 0, on success; negative error, otherwise
1039 * The `path` parameter can be NULL, in which case the `pin_path`
1040 * map attribute is unpinned. If both the `path` parameter and
1041 * `pin_path` map attribute are set, they must be equal.
1043 LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
1045 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
1046 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
1049 * @brief **bpf_map__lookup_elem()** allows to lookup BPF map value
1050 * corresponding to provided key.
1051 * @param map BPF map to lookup element in
1052 * @param key pointer to memory containing bytes of the key used for lookup
1053 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1054 * @param value pointer to memory in which looked up value will be stored
1055 * @param value_sz size in byte of value data memory; it has to match BPF map
1056 * definition's **value_size**. For per-CPU BPF maps value size has to be
1057 * a product of BPF map value size and number of possible CPUs in the system
1058 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1059 * per-CPU values value size has to be aligned up to closest 8 bytes for
1060 * alignment reasons, so expected size is: `round_up(value_size, 8)
1061 * * libbpf_num_possible_cpus()`.
1062 * @flags extra flags passed to kernel for this operation
1063 * @return 0, on success; negative error, otherwise
1065 * **bpf_map__lookup_elem()** is high-level equivalent of
1066 * **bpf_map_lookup_elem()** API with added check for key and value size.
1068 LIBBPF_API int bpf_map__lookup_elem(const struct bpf_map *map,
1069 const void *key, size_t key_sz,
1070 void *value, size_t value_sz, __u64 flags);
1073 * @brief **bpf_map__update_elem()** allows to insert or update value in BPF
1074 * map that corresponds to provided key.
1075 * @param map BPF map to insert to or update element in
1076 * @param key pointer to memory containing bytes of the key
1077 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1078 * @param value pointer to memory containing bytes of the value
1079 * @param value_sz size in byte of value data memory; it has to match BPF map
1080 * definition's **value_size**. For per-CPU BPF maps value size has to be
1081 * a product of BPF map value size and number of possible CPUs in the system
1082 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1083 * per-CPU values value size has to be aligned up to closest 8 bytes for
1084 * alignment reasons, so expected size is: `round_up(value_size, 8)
1085 * * libbpf_num_possible_cpus()`.
1086 * @flags extra flags passed to kernel for this operation
1087 * @return 0, on success; negative error, otherwise
1089 * **bpf_map__update_elem()** is high-level equivalent of
1090 * **bpf_map_update_elem()** API with added check for key and value size.
1092 LIBBPF_API int bpf_map__update_elem(const struct bpf_map *map,
1093 const void *key, size_t key_sz,
1094 const void *value, size_t value_sz, __u64 flags);
1097 * @brief **bpf_map__delete_elem()** allows to delete element in BPF map that
1098 * corresponds to provided key.
1099 * @param map BPF map to delete element from
1100 * @param key pointer to memory containing bytes of the key
1101 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1102 * @flags extra flags passed to kernel for this operation
1103 * @return 0, on success; negative error, otherwise
1105 * **bpf_map__delete_elem()** is high-level equivalent of
1106 * **bpf_map_delete_elem()** API with added check for key size.
1108 LIBBPF_API int bpf_map__delete_elem(const struct bpf_map *map,
1109 const void *key, size_t key_sz, __u64 flags);
1112 * @brief **bpf_map__lookup_and_delete_elem()** allows to lookup BPF map value
1113 * corresponding to provided key and atomically delete it afterwards.
1114 * @param map BPF map to lookup element in
1115 * @param key pointer to memory containing bytes of the key used for lookup
1116 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1117 * @param value pointer to memory in which looked up value will be stored
1118 * @param value_sz size in byte of value data memory; it has to match BPF map
1119 * definition's **value_size**. For per-CPU BPF maps value size has to be
1120 * a product of BPF map value size and number of possible CPUs in the system
1121 * (could be fetched with **libbpf_num_possible_cpus()**). Note also that for
1122 * per-CPU values value size has to be aligned up to closest 8 bytes for
1123 * alignment reasons, so expected size is: `round_up(value_size, 8)
1124 * * libbpf_num_possible_cpus()`.
1125 * @flags extra flags passed to kernel for this operation
1126 * @return 0, on success; negative error, otherwise
1128 * **bpf_map__lookup_and_delete_elem()** is high-level equivalent of
1129 * **bpf_map_lookup_and_delete_elem()** API with added check for key and value size.
1131 LIBBPF_API int bpf_map__lookup_and_delete_elem(const struct bpf_map *map,
1132 const void *key, size_t key_sz,
1133 void *value, size_t value_sz, __u64 flags);
1136 * @brief **bpf_map__get_next_key()** allows to iterate BPF map keys by
1137 * fetching next key that follows current key.
1138 * @param map BPF map to fetch next key from
1139 * @param cur_key pointer to memory containing bytes of current key or NULL to
1140 * fetch the first key
1141 * @param next_key pointer to memory to write next key into
1142 * @param key_sz size in bytes of key data, needs to match BPF map definition's **key_size**
1143 * @return 0, on success; -ENOENT if **cur_key** is the last key in BPF map;
1144 * negative error, otherwise
1146 * **bpf_map__get_next_key()** is high-level equivalent of
1147 * **bpf_map_get_next_key()** API with added check for key size.
1149 LIBBPF_API int bpf_map__get_next_key(const struct bpf_map *map,
1150 const void *cur_key, void *next_key, size_t key_sz);
1152 struct bpf_xdp_set_link_opts {
1157 #define bpf_xdp_set_link_opts__last_field old_fd
1159 struct bpf_xdp_attach_opts {
1164 #define bpf_xdp_attach_opts__last_field old_prog_fd
1166 struct bpf_xdp_query_opts {
1168 __u32 prog_id; /* output */
1169 __u32 drv_prog_id; /* output */
1170 __u32 hw_prog_id; /* output */
1171 __u32 skb_prog_id; /* output */
1172 __u8 attach_mode; /* output */
1173 __u64 feature_flags; /* output */
1174 __u32 xdp_zc_max_segs; /* output */
1177 #define bpf_xdp_query_opts__last_field xdp_zc_max_segs
1179 LIBBPF_API int bpf_xdp_attach(int ifindex, int prog_fd, __u32 flags,
1180 const struct bpf_xdp_attach_opts *opts);
1181 LIBBPF_API int bpf_xdp_detach(int ifindex, __u32 flags,
1182 const struct bpf_xdp_attach_opts *opts);
1183 LIBBPF_API int bpf_xdp_query(int ifindex, int flags, struct bpf_xdp_query_opts *opts);
1184 LIBBPF_API int bpf_xdp_query_id(int ifindex, int flags, __u32 *prog_id);
1186 /* TC related API */
1187 enum bpf_tc_attach_point {
1188 BPF_TC_INGRESS = 1 << 0,
1189 BPF_TC_EGRESS = 1 << 1,
1190 BPF_TC_CUSTOM = 1 << 2,
1193 #define BPF_TC_PARENT(a, b) \
1194 ((((a) << 16) & 0xFFFF0000U) | ((b) & 0x0000FFFFU))
1197 BPF_TC_F_REPLACE = 1 << 0,
1200 struct bpf_tc_hook {
1203 enum bpf_tc_attach_point attach_point;
1207 #define bpf_tc_hook__last_field parent
1209 struct bpf_tc_opts {
1218 #define bpf_tc_opts__last_field priority
1220 LIBBPF_API int bpf_tc_hook_create(struct bpf_tc_hook *hook);
1221 LIBBPF_API int bpf_tc_hook_destroy(struct bpf_tc_hook *hook);
1222 LIBBPF_API int bpf_tc_attach(const struct bpf_tc_hook *hook,
1223 struct bpf_tc_opts *opts);
1224 LIBBPF_API int bpf_tc_detach(const struct bpf_tc_hook *hook,
1225 const struct bpf_tc_opts *opts);
1226 LIBBPF_API int bpf_tc_query(const struct bpf_tc_hook *hook,
1227 struct bpf_tc_opts *opts);
1229 /* Ring buffer APIs */
1231 struct user_ring_buffer;
1233 typedef int (*ring_buffer_sample_fn)(void *ctx, void *data, size_t size);
1235 struct ring_buffer_opts {
1236 size_t sz; /* size of this struct, for forward/backward compatibility */
1239 #define ring_buffer_opts__last_field sz
1241 LIBBPF_API struct ring_buffer *
1242 ring_buffer__new(int map_fd, ring_buffer_sample_fn sample_cb, void *ctx,
1243 const struct ring_buffer_opts *opts);
1244 LIBBPF_API void ring_buffer__free(struct ring_buffer *rb);
1245 LIBBPF_API int ring_buffer__add(struct ring_buffer *rb, int map_fd,
1246 ring_buffer_sample_fn sample_cb, void *ctx);
1247 LIBBPF_API int ring_buffer__poll(struct ring_buffer *rb, int timeout_ms);
1248 LIBBPF_API int ring_buffer__consume(struct ring_buffer *rb);
1249 LIBBPF_API int ring_buffer__epoll_fd(const struct ring_buffer *rb);
1251 struct user_ring_buffer_opts {
1252 size_t sz; /* size of this struct, for forward/backward compatibility */
1255 #define user_ring_buffer_opts__last_field sz
1258 * @brief **user_ring_buffer__new()** creates a new instance of a user ring
1261 * @param map_fd A file descriptor to a BPF_MAP_TYPE_USER_RINGBUF map.
1262 * @param opts Options for how the ring buffer should be created.
1263 * @return A user ring buffer on success; NULL and errno being set on a
1266 LIBBPF_API struct user_ring_buffer *
1267 user_ring_buffer__new(int map_fd, const struct user_ring_buffer_opts *opts);
1270 * @brief **user_ring_buffer__reserve()** reserves a pointer to a sample in the
1272 * @param rb A pointer to a user ring buffer.
1273 * @param size The size of the sample, in bytes.
1274 * @return A pointer to an 8-byte aligned reserved region of the user ring
1275 * buffer; NULL, and errno being set if a sample could not be reserved.
1277 * This function is *not* thread safe, and callers must synchronize accessing
1278 * this function if there are multiple producers. If a size is requested that
1279 * is larger than the size of the entire ring buffer, errno will be set to
1280 * E2BIG and NULL is returned. If the ring buffer could accommodate the size,
1281 * but currently does not have enough space, errno is set to ENOSPC and NULL is
1284 * After initializing the sample, callers must invoke
1285 * **user_ring_buffer__submit()** to post the sample to the kernel. Otherwise,
1286 * the sample must be freed with **user_ring_buffer__discard()**.
1288 LIBBPF_API void *user_ring_buffer__reserve(struct user_ring_buffer *rb, __u32 size);
1291 * @brief **user_ring_buffer__reserve_blocking()** reserves a record in the
1292 * ring buffer, possibly blocking for up to @timeout_ms until a sample becomes
1294 * @param rb The user ring buffer.
1295 * @param size The size of the sample, in bytes.
1296 * @param timeout_ms The amount of time, in milliseconds, for which the caller
1297 * should block when waiting for a sample. -1 causes the caller to block
1299 * @return A pointer to an 8-byte aligned reserved region of the user ring
1300 * buffer; NULL, and errno being set if a sample could not be reserved.
1302 * This function is *not* thread safe, and callers must synchronize
1303 * accessing this function if there are multiple producers
1305 * If **timeout_ms** is -1, the function will block indefinitely until a sample
1306 * becomes available. Otherwise, **timeout_ms** must be non-negative, or errno
1307 * is set to EINVAL, and NULL is returned. If **timeout_ms** is 0, no blocking
1308 * will occur and the function will return immediately after attempting to
1311 * If **size** is larger than the size of the entire ring buffer, errno is set
1312 * to E2BIG and NULL is returned. If the ring buffer could accommodate
1313 * **size**, but currently does not have enough space, the caller will block
1314 * until at most **timeout_ms** has elapsed. If insufficient space is available
1315 * at that time, errno is set to ENOSPC, and NULL is returned.
1317 * The kernel guarantees that it will wake up this thread to check if
1318 * sufficient space is available in the ring buffer at least once per
1319 * invocation of the **bpf_ringbuf_drain()** helper function, provided that at
1320 * least one sample is consumed, and the BPF program did not invoke the
1321 * function with BPF_RB_NO_WAKEUP. A wakeup may occur sooner than that, but the
1322 * kernel does not guarantee this. If the helper function is invoked with
1323 * BPF_RB_FORCE_WAKEUP, a wakeup event will be sent even if no sample is
1326 * When a sample of size **size** is found within **timeout_ms**, a pointer to
1327 * the sample is returned. After initializing the sample, callers must invoke
1328 * **user_ring_buffer__submit()** to post the sample to the ring buffer.
1329 * Otherwise, the sample must be freed with **user_ring_buffer__discard()**.
1331 LIBBPF_API void *user_ring_buffer__reserve_blocking(struct user_ring_buffer *rb,
1336 * @brief **user_ring_buffer__submit()** submits a previously reserved sample
1337 * into the ring buffer.
1338 * @param rb The user ring buffer.
1339 * @param sample A reserved sample.
1341 * It is not necessary to synchronize amongst multiple producers when invoking
1344 LIBBPF_API void user_ring_buffer__submit(struct user_ring_buffer *rb, void *sample);
1347 * @brief **user_ring_buffer__discard()** discards a previously reserved sample.
1348 * @param rb The user ring buffer.
1349 * @param sample A reserved sample.
1351 * It is not necessary to synchronize amongst multiple producers when invoking
1354 LIBBPF_API void user_ring_buffer__discard(struct user_ring_buffer *rb, void *sample);
1357 * @brief **user_ring_buffer__free()** frees a ring buffer that was previously
1358 * created with **user_ring_buffer__new()**.
1359 * @param rb The user ring buffer being freed.
1361 LIBBPF_API void user_ring_buffer__free(struct user_ring_buffer *rb);
1363 /* Perf buffer APIs */
1366 typedef void (*perf_buffer_sample_fn)(void *ctx, int cpu,
1367 void *data, __u32 size);
1368 typedef void (*perf_buffer_lost_fn)(void *ctx, int cpu, __u64 cnt);
1370 /* common use perf buffer options */
1371 struct perf_buffer_opts {
1373 __u32 sample_period;
1376 #define perf_buffer_opts__last_field sample_period
1379 * @brief **perf_buffer__new()** creates BPF perfbuf manager for a specified
1380 * BPF_PERF_EVENT_ARRAY map
1381 * @param map_fd FD of BPF_PERF_EVENT_ARRAY BPF map that will be used by BPF
1382 * code to send data over to user-space
1383 * @param page_cnt number of memory pages allocated for each per-CPU buffer
1384 * @param sample_cb function called on each received data record
1385 * @param lost_cb function called when record loss has occurred
1386 * @param ctx user-provided extra context passed into *sample_cb* and *lost_cb*
1387 * @return a new instance of struct perf_buffer on success, NULL on error with
1388 * *errno* containing an error code
1390 LIBBPF_API struct perf_buffer *
1391 perf_buffer__new(int map_fd, size_t page_cnt,
1392 perf_buffer_sample_fn sample_cb, perf_buffer_lost_fn lost_cb, void *ctx,
1393 const struct perf_buffer_opts *opts);
1395 enum bpf_perf_event_ret {
1396 LIBBPF_PERF_EVENT_DONE = 0,
1397 LIBBPF_PERF_EVENT_ERROR = -1,
1398 LIBBPF_PERF_EVENT_CONT = -2,
1401 struct perf_event_header;
1403 typedef enum bpf_perf_event_ret
1404 (*perf_buffer_event_fn)(void *ctx, int cpu, struct perf_event_header *event);
1406 /* raw perf buffer options, giving most power and control */
1407 struct perf_buffer_raw_opts {
1411 /* if cpu_cnt == 0, open all on all possible CPUs (up to the number of
1412 * max_entries of given PERF_EVENT_ARRAY map)
1415 /* if cpu_cnt > 0, cpus is an array of CPUs to open ring buffers on */
1417 /* if cpu_cnt > 0, map_keys specify map keys to set per-CPU FDs for */
1420 #define perf_buffer_raw_opts__last_field map_keys
1422 struct perf_event_attr;
1424 LIBBPF_API struct perf_buffer *
1425 perf_buffer__new_raw(int map_fd, size_t page_cnt, struct perf_event_attr *attr,
1426 perf_buffer_event_fn event_cb, void *ctx,
1427 const struct perf_buffer_raw_opts *opts);
1429 LIBBPF_API void perf_buffer__free(struct perf_buffer *pb);
1430 LIBBPF_API int perf_buffer__epoll_fd(const struct perf_buffer *pb);
1431 LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms);
1432 LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb);
1433 LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx);
1434 LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb);
1435 LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx);
1437 * @brief **perf_buffer__buffer()** returns the per-cpu raw mmap()'ed underlying
1438 * memory region of the ring buffer.
1439 * This ring buffer can be used to implement a custom events consumer.
1440 * The ring buffer starts with the *struct perf_event_mmap_page*, which
1441 * holds the ring buffer managment fields, when accessing the header
1442 * structure it's important to be SMP aware.
1443 * You can refer to *perf_event_read_simple* for a simple example.
1444 * @param pb the perf buffer structure
1445 * @param buf_idx the buffer index to retreive
1446 * @param buf (out) gets the base pointer of the mmap()'ed memory
1447 * @param buf_size (out) gets the size of the mmap()'ed region
1448 * @return 0 on success, negative error code for failure
1450 LIBBPF_API int perf_buffer__buffer(struct perf_buffer *pb, int buf_idx, void **buf,
1453 struct bpf_prog_linfo;
1454 struct bpf_prog_info;
1456 LIBBPF_API void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo);
1457 LIBBPF_API struct bpf_prog_linfo *
1458 bpf_prog_linfo__new(const struct bpf_prog_info *info);
1459 LIBBPF_API const struct bpf_line_info *
1460 bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
1461 __u64 addr, __u32 func_idx, __u32 nr_skip);
1462 LIBBPF_API const struct bpf_line_info *
1463 bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
1464 __u32 insn_off, __u32 nr_skip);
1467 * Probe for supported system features
1469 * Note that running many of these probes in a short amount of time can cause
1470 * the kernel to reach the maximal size of lockable memory allowed for the
1471 * user, causing subsequent probes to fail. In this case, the caller may want
1472 * to adjust that limit with setrlimit().
1476 * @brief **libbpf_probe_bpf_prog_type()** detects if host kernel supports
1477 * BPF programs of a given type.
1478 * @param prog_type BPF program type to detect kernel support for
1479 * @param opts reserved for future extensibility, should be NULL
1480 * @return 1, if given program type is supported; 0, if given program type is
1481 * not supported; negative error code if feature detection failed or can't be
1484 * Make sure the process has required set of CAP_* permissions (or runs as
1485 * root) when performing feature checking.
1487 LIBBPF_API int libbpf_probe_bpf_prog_type(enum bpf_prog_type prog_type, const void *opts);
1489 * @brief **libbpf_probe_bpf_map_type()** detects if host kernel supports
1490 * BPF maps of a given type.
1491 * @param map_type BPF map type to detect kernel support for
1492 * @param opts reserved for future extensibility, should be NULL
1493 * @return 1, if given map type is supported; 0, if given map type is
1494 * not supported; negative error code if feature detection failed or can't be
1497 * Make sure the process has required set of CAP_* permissions (or runs as
1498 * root) when performing feature checking.
1500 LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void *opts);
1502 * @brief **libbpf_probe_bpf_helper()** detects if host kernel supports the
1503 * use of a given BPF helper from specified BPF program type.
1504 * @param prog_type BPF program type used to check the support of BPF helper
1505 * @param helper_id BPF helper ID (enum bpf_func_id) to check support for
1506 * @param opts reserved for future extensibility, should be NULL
1507 * @return 1, if given combination of program type and helper is supported; 0,
1508 * if the combination is not supported; negative error code if feature
1509 * detection for provided input arguments failed or can't be performed
1511 * Make sure the process has required set of CAP_* permissions (or runs as
1512 * root) when performing feature checking.
1514 LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
1515 enum bpf_func_id helper_id, const void *opts);
1518 * @brief **libbpf_num_possible_cpus()** is a helper function to get the
1519 * number of possible CPUs that the host kernel supports and expects.
1520 * @return number of possible CPUs; or error code on failure
1524 * int ncpus = libbpf_num_possible_cpus();
1528 * long values[ncpus];
1529 * bpf_map_lookup_elem(per_cpu_map_fd, key, values);
1531 LIBBPF_API int libbpf_num_possible_cpus(void);
1533 struct bpf_map_skeleton {
1535 struct bpf_map **map;
1539 struct bpf_prog_skeleton {
1541 struct bpf_program **prog;
1542 struct bpf_link **link;
1545 struct bpf_object_skeleton {
1546 size_t sz; /* size of this struct, for forward/backward compatibility */
1552 struct bpf_object **obj;
1555 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1556 struct bpf_map_skeleton *maps;
1559 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1560 struct bpf_prog_skeleton *progs;
1564 bpf_object__open_skeleton(struct bpf_object_skeleton *s,
1565 const struct bpf_object_open_opts *opts);
1566 LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
1567 LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
1568 LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
1569 LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
1571 struct bpf_var_skeleton {
1573 struct bpf_map **map;
1577 struct bpf_object_subskeleton {
1578 size_t sz; /* size of this struct, for forward/backward compatibility */
1580 const struct bpf_object *obj;
1583 int map_skel_sz; /* sizeof(struct bpf_map_skeleton) */
1584 struct bpf_map_skeleton *maps;
1587 int prog_skel_sz; /* sizeof(struct bpf_prog_skeleton) */
1588 struct bpf_prog_skeleton *progs;
1591 int var_skel_sz; /* sizeof(struct bpf_var_skeleton) */
1592 struct bpf_var_skeleton *vars;
1596 bpf_object__open_subskeleton(struct bpf_object_subskeleton *s);
1598 bpf_object__destroy_subskeleton(struct bpf_object_subskeleton *s);
1600 struct gen_loader_opts {
1601 size_t sz; /* size of this struct, for forward/backward compatibility */
1608 #define gen_loader_opts__last_field insns_sz
1609 LIBBPF_API int bpf_object__gen_loader(struct bpf_object *obj,
1610 struct gen_loader_opts *opts);
1612 enum libbpf_tristate {
1618 struct bpf_linker_opts {
1619 /* size of this struct, for forward/backward compatibility */
1622 #define bpf_linker_opts__last_field sz
1624 struct bpf_linker_file_opts {
1625 /* size of this struct, for forward/backward compatibility */
1628 #define bpf_linker_file_opts__last_field sz
1632 LIBBPF_API struct bpf_linker *bpf_linker__new(const char *filename, struct bpf_linker_opts *opts);
1633 LIBBPF_API int bpf_linker__add_file(struct bpf_linker *linker,
1634 const char *filename,
1635 const struct bpf_linker_file_opts *opts);
1636 LIBBPF_API int bpf_linker__finalize(struct bpf_linker *linker);
1637 LIBBPF_API void bpf_linker__free(struct bpf_linker *linker);
1640 * Custom handling of BPF program's SEC() definitions
1643 struct bpf_prog_load_opts; /* defined in bpf.h */
1645 /* Called during bpf_object__open() for each recognized BPF program. Callback
1646 * can use various bpf_program__set_*() setters to adjust whatever properties
1649 typedef int (*libbpf_prog_setup_fn_t)(struct bpf_program *prog, long cookie);
1651 /* Called right before libbpf performs bpf_prog_load() to load BPF program
1652 * into the kernel. Callback can adjust opts as necessary.
1654 typedef int (*libbpf_prog_prepare_load_fn_t)(struct bpf_program *prog,
1655 struct bpf_prog_load_opts *opts, long cookie);
1657 /* Called during skeleton attach or through bpf_program__attach(). If
1658 * auto-attach is not supported, callback should return 0 and set link to
1659 * NULL (it's not considered an error during skeleton attach, but it will be
1660 * an error for bpf_program__attach() calls). On error, error should be
1661 * returned directly and link set to NULL. On success, return 0 and set link
1662 * to a valid struct bpf_link.
1664 typedef int (*libbpf_prog_attach_fn_t)(const struct bpf_program *prog, long cookie,
1665 struct bpf_link **link);
1667 struct libbpf_prog_handler_opts {
1668 /* size of this struct, for forward/backward compatibility */
1670 /* User-provided value that is passed to prog_setup_fn,
1671 * prog_prepare_load_fn, and prog_attach_fn callbacks. Allows user to
1672 * register one set of callbacks for multiple SEC() definitions and
1673 * still be able to distinguish them, if necessary. For example,
1674 * libbpf itself is using this to pass necessary flags (e.g.,
1675 * sleepable flag) to a common internal SEC() handler.
1678 /* BPF program initialization callback (see libbpf_prog_setup_fn_t).
1679 * Callback is optional, pass NULL if it's not necessary.
1681 libbpf_prog_setup_fn_t prog_setup_fn;
1682 /* BPF program loading callback (see libbpf_prog_prepare_load_fn_t).
1683 * Callback is optional, pass NULL if it's not necessary.
1685 libbpf_prog_prepare_load_fn_t prog_prepare_load_fn;
1686 /* BPF program attach callback (see libbpf_prog_attach_fn_t).
1687 * Callback is optional, pass NULL if it's not necessary.
1689 libbpf_prog_attach_fn_t prog_attach_fn;
1691 #define libbpf_prog_handler_opts__last_field prog_attach_fn
1694 * @brief **libbpf_register_prog_handler()** registers a custom BPF program
1696 * @param sec section prefix for which custom handler is registered
1697 * @param prog_type BPF program type associated with specified section
1698 * @param exp_attach_type Expected BPF attach type associated with specified section
1699 * @param opts optional cookie, callbacks, and other extra options
1700 * @return Non-negative handler ID is returned on success. This handler ID has
1701 * to be passed to *libbpf_unregister_prog_handler()* to unregister such
1702 * custom handler. Negative error code is returned on error.
1704 * *sec* defines which SEC() definitions are handled by this custom handler
1705 * registration. *sec* can have few different forms:
1706 * - if *sec* is just a plain string (e.g., "abc"), it will match only
1707 * SEC("abc"). If BPF program specifies SEC("abc/whatever") it will result
1709 * - if *sec* is of the form "abc/", proper SEC() form is
1710 * SEC("abc/something"), where acceptable "something" should be checked by
1711 * *prog_init_fn* callback, if there are additional restrictions;
1712 * - if *sec* is of the form "abc+", it will successfully match both
1713 * SEC("abc") and SEC("abc/whatever") forms;
1714 * - if *sec* is NULL, custom handler is registered for any BPF program that
1715 * doesn't match any of the registered (custom or libbpf's own) SEC()
1716 * handlers. There could be only one such generic custom handler registered
1717 * at any given time.
1719 * All custom handlers (except the one with *sec* == NULL) are processed
1720 * before libbpf's own SEC() handlers. It is allowed to "override" libbpf's
1721 * SEC() handlers by registering custom ones for the same section prefix
1722 * (i.e., it's possible to have custom SEC("perf_event/LLC-load-misses")
1725 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1726 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1727 * to ensure synchronization if there is a risk of running this API from
1728 * multiple threads simultaneously.
1730 LIBBPF_API int libbpf_register_prog_handler(const char *sec,
1731 enum bpf_prog_type prog_type,
1732 enum bpf_attach_type exp_attach_type,
1733 const struct libbpf_prog_handler_opts *opts);
1735 * @brief *libbpf_unregister_prog_handler()* unregisters previously registered
1736 * custom BPF program SEC() handler.
1737 * @param handler_id handler ID returned by *libbpf_register_prog_handler()*
1738 * after successful registration
1739 * @return 0 on success, negative error code if handler isn't found
1741 * Note, like much of global libbpf APIs (e.g., libbpf_set_print(),
1742 * libbpf_set_strict_mode(), etc)) these APIs are not thread-safe. User needs
1743 * to ensure synchronization if there is a risk of running this API from
1744 * multiple threads simultaneously.
1746 LIBBPF_API int libbpf_unregister_prog_handler(int handler_id);
1752 #endif /* __LIBBPF_LIBBPF_H */